ARTICLE | doi:10.20944/preprints201806.0379.v1
Subject: Business, Economics And Management, Economics Keywords: exchange rate misalignment; real effective exchange rate; undervaluation; overvaluation; growth; autoregressive distributed lag bounds testing approach; Trinidad and Tobago
Online: 25 June 2018 (10:46:41 CEST)
Conventional economic theory outlines that developing countries experience economic growth through an undervalued exchange rate and that exchange rate overvaluations has negative long term effects on economic growth. This paper examined the impact of exchange rate movements as well as exchange rate misalignments on economic growth for the Trinidad and Tobago economy over the period 1960 to 2016. We find statistically significant evidence that both exchange rate appreciation and misalignments impact negatively on economic growth in the T&T economy. Drilling deeper we find interestingly that there exist no non-linear effects of exchange rate misalignments on growth. Specifically we find statistically significant evidence that both overvaluations and undervaluations hamper economic growth in the Trinidad and Tobago economy. We attribute this to T&T’s small and underdeveloped manufacturing sector that tends to be overlooked on account of its energy resources, in addition to the fact that its manufacturing sector is highly import oriented. A major policy recommendation would be for the critical reassessment of the rules governing the HSF, as government expenditure was allowed to follow energy revenues due to its current limitations.
ARTICLE | doi:10.20944/preprints202003.0465.v1
Subject: Computer Science And Mathematics, Probability And Statistics Keywords: inflation; exchange rates; heteroskedasticity; Granger causality; copula, bivariate; volatility clustering
Online: 31 March 2020 (22:45:00 CEST)
Inflation and exchange rates have great influence on consumer prices especially on imports and exports. Exchange rate fluctuations create inefficiency and distort world prices whereas changes in inflation rates have a direct impact on consumer goods prices which incidentally include exchange rates. There is a direct interdependence between inflation and exchange rates and this paper is aimed at investigating this relationship in dynamic context. It tries to find out how changes in inflation and exchange rates impact on another by adopting the econometric and copula approaches. Both inflation and exchange rates data are susceptible to volatility clustering, possess fat tails and are skewed coupled with conditional heteroskedasticity. Hence we model the univariate distributions by using ARMA$(p,q)$-GARCH$(x,y)$ so as to capture the most important stylized features of inflation and exchange rates. A bivariate model is then constructed by coupling the marginal distributions of inflation and exchange rates using the survival Clayton copula. Empirical results from monthly inflation and exchange rates data show positive correlation between the two based on Kendall $\tau$ test which confirms that a change in inflation results in change of exchange rates an vice versa hence there is co-movement. Furthermore, by the Granger causality test, exchange rates spikes cause changes in inflation rates. The results of the study have implications on economic policy design and hedging strategies for traders on imports and exports.
ARTICLE | doi:10.20944/preprints201610.0053.v1
Subject: Business, Economics And Management, Economics Keywords: terrorism; exchange rate; ARDL; error correction
Online: 14 October 2016 (10:30:30 CEST)
In this study the impact of terrorist attacks on exchange rate is estimated. Particularly, the study focuses on Turkish terrorist attacks and its implication on Turkish lira versus pound sterling exchange rate. In order, to find the causal effect the study employed Autoregressive distributive lag (ARDL) bound testing approach as an estimation technique. Accordingly, the analysis reveals that terrorist attack has a negative impact on the exchange rate in both short and long-run. However, the negative effect of terrorism tends to be small in both the short-run and long-run. More precisely, terrorist attack depreciates the exchange rate between Turkish lira and pound sterling by approximately 0.00072 in the next trading day. The long-term effect also shows that terrorist attack depreciates the exchange rate on average by 0.00212.
ARTICLE | doi:10.20944/preprints202311.1435.v1
Subject: Business, Economics And Management, Finance Keywords: Exchange Rate Volatility; Exports; NARDL; Smooth Threshold Regression
Online: 22 November 2023 (13:48:53 CET)
This research paper aimed to examine the impact of exchange rate volatility on South Africa's exports from 1994 Q1 to 2023 Q2. The study used the Augmented Dickey-Fuller (ADF) and Phillips-Perron (PP) tests to test for stationarity. The nonlinear autoregressive distributed lag (NARDL) model and smooth threshold regression (STR) are employed to analyse the relationship between exchange rate volatility and exports. The GARCH (1.1) technique is used to construct the exchange rate volatility data. The results of the stationarity tests reveal that variables are either integrated in order I(0) or I(1). This implies that the variables used in this study are stationary, which is crucial for conducting accurate analyses. Moreover, the NARDL test approach provided insights into the long-run effects of exchange rate volatility on South Africa's exports. Based on the NARDL test, positive shocks have a greater but statistically insignificant effect on exports than negative shocks. Therefore, a greater level of exchange rate volatility may lead to increased exports from South Africa. Furthermore, the STR also reveals that the impact of exchange rate volatility is insignificant. These findings provide valuable insights for policymakers and firms to make informed decisions regarding exchange rate management and export strategies in South Africa.
ARTICLE | doi:10.20944/preprints201904.0199.v1
Subject: Business, Economics And Management, Finance Keywords: monetary liquidity; exchange rates; Granger causality; Kalman filter; adequacy error
Online: 17 April 2019 (11:20:13 CEST)
The influence of both the absolute values of the dollar/ruble exchange rate (rate) and its changes per day on the balance of the Bank of Russia operations for ruble liquidity provision and absorption (saldo) was investigated. Daily data were used from January 2015 to April 2018. It was found that the change in the rate 6 days ago is the cause (according to Granger) of the saldo value. For the saldo dynamics, an oscillatory model with an external force - a change in the rate - is proposed. Using the Kalman filter, the model parameters were estimated and saldo forecasted. Found period of self-oscillation is 4.218 days and attenuation of the amplitude for a day in 2.179 times. The rate growth of 1 RUB, after 6 days, causes saldo increase of approximately 20 billion rubles. In fact, the changes in rate cause the variability of the saldo not more than for found coefficient of determination (26.7%), but the "change in the rate-liquidity saldo" system during the crisis-free period has a high "Q-factor," and changes in the rate, repeated with a period close to self-one, can cause large-amplitude fluctuations in saldo.
ARTICLE | doi:10.20944/preprints201810.0442.v1
Subject: Business, Economics And Management, Finance Keywords: asymmetry; exchange rate pass-through; NARDL; inflation; sub-Saharan Africa
Online: 19 October 2018 (08:03:04 CEST)
This paper examines the asymmetrical relationship between exchange rate and consumer prices in 40 Sub-Saharan African (SSA) countries from 1990q1 to 2017q4. The exchange rate pass-through (ERPT) to consumer prices is estimated for each country by using the nonlinear autoregressive distributed lags (NARDL) framework and dynamic panel estimators robust to cross-sectionally correlated errors. Firstly, our findings suggest an asymmetrical ERPT in the SSA region during the short-term, whereas there are mixed results across sub-regions in the long-term. Next, we find incomplete and significant ERPT to consumer prices in the entire SSA region which is higher during the depreciation of the local currency than after appreciations. Third, we find nonlinear ERPT with respect to the size of the exchange rate. The pass-through is higher during large exchange rate changes than after small changes. Finally, we find that the pass-through is greater in the countries with fixed exchange rate regime (CFA franc zone) having low inflationary environment than in the other SSA countries with flexible exchange rate regime and high inflation levels. As a result, policymakers should take into account these asymmetries and non-linearities to improve the credibility of monetary policy, strengthen trade liberalization and establish competitive market structures in the Sub-Saharan region.
ARTICLE | doi:10.20944/preprints201608.0212.v1
Subject: Business, Economics And Management, Economics Keywords: FDI; GARCH; real exchange rate and price volatility; Latin America and the Caribbean
Online: 26 August 2016 (09:59:32 CEST)
This paper investigates the impact of price and real exchange rate volatility on Foreign Direct Investment (FDI) inflows in a panel of 10 Latin American and Caribbean countries, observed between 1990 and 2012. Both price and exchange rate volatility series are estimated through the Generalized Autoregressive Conditional Heteroscedasticity model (GARCH). Our results, obtained employing the Fixed Effects estimator, confirm the theory of hysteresis and option value, in so far it is found a statistically significant negative effect of exchange rate volatility on FDI. Price volatility, instead, turns out to be positive but insignificant. Moreover, we show that human capital and trade openness are key for attracting foreign capital. From the policy perspective, our analysis suggests the importance of stabilization policies as well as the one of government credibility in promoting trade openness and human capital formation.
ARTICLE | doi:10.20944/preprints201901.0289.v1
Subject: Computer Science And Mathematics, Probability And Statistics Keywords: Exchange rate, Inflation rate; Gross Domestic Product, Broad Money, Monetary Policy, ARDL Cointegration
Online: 29 January 2019 (09:28:19 CET)
The present reality of the Nigerian economy is the fact that inflation has remained unabated in spite of all exchange rate measures that have been adopted by the monetary authority. This calls for investigation into the extent to which exchange rate impact on inflation in Nigeria. The research paper examined the impact of exchange rate depreciation on inflation in Nigeria for the period 1981–2017, using Auto Regressive Distributed Lag (ARDL) Bounds Test Cointegration Procedure. The research shows that inflation rate in Nigeria is highly susceptible to lagged inflation rate, exchange rate, lagged exchange rate, lagged broad money, and lagged gross domestic product at 5% level of significance. A long run relationship was also found to exist between inflation rate, gross domestic product and general government expenditure, indicating that the model has a self-adjusting mechanism for correcting any deviation of the variables from equilibrium. Therefore, this study concludes that exchange rate is an important tool to manage inflation in the country; thus, this paper recommends that policies that have direct influence on inflation as well as exchange rate policies that would checkmate inflation movement in the country, should be used by the Central Bank of Nigeria. Also, monetary growth and import management policies should be put in place to encourage domestic production of export commodities, which are currently short-supplied. In addition, policy makers should not rely on this instrument totally to control inflation, but should use it as a complement to other macro-economic policies.
ARTICLE | doi:10.20944/preprints202204.0214.v1
Subject: Business, Economics And Management, Accounting And Taxation Keywords: Bank Central Asia (BCA) interest rate; Dollar exchange rate (USD); Stock Price
Online: 24 April 2022 (04:55:14 CEST)
This study aims to determine how the effect of interest rates and changes in the dollar exchange rate (USD) on the stock price. The type of research carried out in this research is quantitative research with the object of research, namely Bank Central Asia (BCA). The data used in this study comes from secondary data, namely from books, the internet, documents, and banking sites. This study indicates that the independent variable, namely the interest rate, has a significant negative effect on the joint-stock price index and the other independent variable, namely the dollar exchange rate (USD), has a significant positive effect on the joint-stock price index. The coefficient test results show that interest rates and exchange rates (USD) simultaneously affect stock prices, namely 67.2% while the remaining 32.8% is influenced by other factors.
ARTICLE | doi:10.20944/preprints201902.0098.v1
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: exchange bias effect; perpendicular exchange bias
Online: 12 February 2019 (10:18:19 CET)
The perpendicular exchange bias effect is observed in the ferromagnetic Co/Ni multilayers adjacent to the antiferromagnetic FeRh layer. It is found that as the antiferromagnetic FeRh thickness increases from 10 Å to 50 Å, the hysteresis loop is gradually changed from the symmetric shape to the asymmetric shape shifted by some amount corresponding to the exchange-biased field at the thickness of 25 Å. Also, the magnetic domain observation experiment confirms that the domain reversals in the increasing and the decreasing field regions of the sample with the thickness of 50 Å exhibit the same single domain wall motion even though they have the different coercivities.
ARTICLE | doi:10.20944/preprints202111.0449.v2
Subject: Business, Economics And Management, Economics Keywords: exchange; exchange theory; money; money theory; power
Online: 26 November 2021 (12:47:48 CET)
Modern exchange theories model a large market, but do not explain single exchange. The paper considers the phenomenon of single exchange and formulates the general exchange problem in the form of a system of two equations, subjective and objective. Subjective equilibrium is given by the Walras-Jevons marginal utility equation. Objective equilibrium equations by Walras and Jevons are averaged over all transactions in the market and can only give a rough general picture without explaining the specific price of an individual exchange. An exchange micro-condition must be found that, when averaged, will give the Walras market equilibrium macro-condition. The study of the internal structure of exchange leads to the need to consider power. The concept of generalized power is introduced. It is generalized power that serves as the primary comparable and measurable objective basis of exchange. The power theory of exchange provides the objective price-equation. It is demonstrated that money is a measure of generalized power in exchange and a certification of generalized power in subsequent exchanges. The proposed theory is able to uniformly explain any exchange, including a single one, which is impossible with the existing theories of exchange.
ARTICLE | doi:10.20944/preprints202106.0240.v1
Subject: Business, Economics And Management, Economics Keywords: Foreign exchange rate, economy, inflation
Online: 8 June 2021 (15:59:19 CEST)
The Foreign Exchange rate is very much crucial for determining the economic health level of the country. The foreign exchange rate provides financial stability, enhances purchasing power and allows global trades. This rate usually fluctuates due to the market forces which control the supply and demand of the currency. Nominal and relative inflation and income level have a substantial effect on determining the exchange rates. Government measures, international situations, natural disasters or any unexpected situation like Covid-19, Rohingya crisis etc. can affect the exchange rates. Besides this, the interaction between the factors can create different reasoning to affect the market. This study tries to identify some factors with relevant examples.
ARTICLE | doi:10.20944/preprints201812.0233.v1
Subject: Chemistry And Materials Science, Theoretical Chemistry Keywords: First principles, Exchange energy, magnetocrystalline anisotropy
Online: 19 December 2018 (07:58:19 CET)
We have performed first-principles calculations to study the interfacial exchange coupling and magnetocrystalline anisotropy (MCA) energy in a SmCo5/Sm2Co17 multilayer model systems. The phase of SmCo5 and Sm2Co17 stacking along (0001) direction are structurally well matched. The atomic structure, including the alignment and the separation between layers, were firstly optimized. Then the non-collinear magnetic structures were calculated to explore the exchange coupling across the interface and the variation of MCA energy. We found that the inter-phase exchange coupling strength, rotating behavior and MCA energy are strongly dependent on the atomic thickness of the SmCo5 and Sm2Co17 phase.
COMMUNICATION | doi:10.20944/preprints201811.0539.v1
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: nickel; HER; anion exchange membrane; electrolysis
Online: 22 November 2018 (05:30:57 CET)
Anion exchange membrane (AEM) electrolysis is hampered by two main issues: stability and performance. Focusing on the latter, this work demonstrates a highly active NiMo cathode for hydrogen evolution in AEM electrolysis. We demonstrate an electrolyzer performance of 1 A cm−2 at 1.9 V (total cell voltage) with a NiMo loading of 5 mg cm−2 and an iridium black anode in 1 M KOH at 50 °C, that may be compared to 1.8 V for a similar cell with Pt at the cathode. The catalysts developed here will be significant in supporting the pursuit of cheap and environmentally friendly hydrogen fuel.
ARTICLE | doi:10.20944/preprints201610.0012.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: data exchange; resource donations; text mining
Online: 5 October 2016 (15:08:32 CEST)
Bio-molecular reagents like antibodies required in experimental biology are expensive and their effectiveness, among other things, is critical to the success of the experiment. Although such resources are sometimes donated by one investigator to another through personal communication between the two, there is no previous study to our knowledge on the extent of such donations, nor a central platform that directs resource seekers to donors. In this paper, we describe, to our knowledge, a first attempt at building a web-portal titled Bio-Resource Exchange that attempts to bridge this gap between resource seekers and donors in the domain of experimental biology. Users on this portal can request for or donate antibodies, cell-lines and DNA Constructs. This resource could also serve as a crowd-sourced database of resources for experimental biology. Further, in order to index donations outside of our portal, we mined scientific articles to find instances of donations of antibodies and attempted to extract information about these donations at the finest granularity. Specifically, we extracted the name of the donor, his/her affiliation and the name of the antibody for every donation by parsing the acknowledgements sections of articles. To extract annotations at this level, we propose two approaches – a rule based algorithm and a bootstrapped relation learning algorithm. The algorithms extracted donor names, affiliations and antibody names with average accuracies of 57% and 62% respectively. We also created a dataset of 50 expert-annotated acknowledgements sections that will serve as a gold standard dataset to evaluate extraction algorithms in the future. Contact: firstname.lastname@example.org, email@example.com Database URL: http://tonks.dbmi.pitt.edu/brx Supplementary information: Supplementary data are available at Database online.
ARTICLE | doi:10.20944/preprints202306.1989.v1
Subject: Engineering, Mechanical Engineering Keywords: embedded cooling; microchannel; heat dissipation; heat exchange
Online: 28 June 2023 (10:26:07 CEST)
High in reliability, multi in function, strong in tracking and detecting, active phased array antennas have been widely applied in radar system. Heat dissipation is a major technological barrier preventing the realization of next-generation high-performance phased array antennas. As a result of the advancement of miniaturization and the in-tegration of microelectronics technology, the study and development of embedded di-rect cooling or heat dissipation has significantly enhanced the heat dissipation effect. In this paper, a novel swept-back fishnet embedded microchannel topology (SBFEMCT) is designed, and various microchannel models with different fishnet runner mesh den-sity ratios and different fishnet runner layers are established to characterize the chip Tmax, runner Pmax, and Tmax and analyze the thermal effect of SBFEMCT under these two operating conditions. The Pmax is reduced to 72.37% and 57.12% of the original at mesh density ratios of 0.5, 0.25, and 0.125, respectively. The maximum temperature reduction figures are average with little change in maximum velocity and a small increase in maximum pressure drop for the number of fishing mesh runner layers of 0-4. This paper provides a study of the latest embedded thermal dissipation from the dimension of a single chip to provide a certain degree of new ideas and ref-erences for solving the thermal technology bottleneck of next-generation high-performance phased array antennas.
ARTICLE | doi:10.20944/preprints202202.0145.v1
Subject: Computer Science And Mathematics, Analysis Keywords: Smart grids; Optimization; Prediction methods; Energy exchange
Online: 10 February 2022 (07:55:02 CET)
The concept of distributed generation has made photovoltaic an integral source of energy in smart grid systems, especially in peer-to-peer energy trading frameworks that exploit excess power to fulfill the energy requirements of consumers in cost-efficient and eco-friendly manner. It is believed that P2P energy trading will dominate a significant portion of research in forthcoming power generation systems due to the excessive rise of energy demands across the globe. Despite a plethora of studies on energy optimization solutions in P2P trading, minimizing nanogrid energy trading cost and efficient energy sharing between consumers and prosumers are deemed among the challenging problems. This study overcomes essential issues overlooked by the contemporary P2P energy trading models by introducing a predictive optimization-oriented nanogrid energy trading model. The proposed study encompasses two stages: (1) predictive optimization model which harnesses BD-LSTM-based forecasted energy parameters (energy load, energy consumption, and PV generation) that are later incorporated in PSO-enabled objective function to reduce nanogrid trading cost, (2) optimal energy sharing plan is devised to decide the role of nanogrids as prosumers or consumers by emphasizing the use of PV-produced energy. The proposed model is validated on the case study containing nanogrid houses data. The simulation provides detailed experiments by comparing the energy demand and response using the proposed energy sharing model. The outcomes yield that the energy sharing plan holds a significant potential to fulfill maximum energy requirements of nanogrid house in P2P cluster and significantly reduces the energy cost compared to grid.
ARTICLE | doi:10.20944/preprints202012.0563.v2
Subject: Computer Science And Mathematics, Data Structures, Algorithms And Complexity Keywords: kidney exchange; Particle Swarm; Meta-heuristics; Optimization
Online: 14 May 2021 (11:03:30 CEST)
In this paper, we implement a new method binary Particle Swarm Optimization (PSO) for solving the kidney exchange problem, which will improve the future decisions of kidney exchange programs. Because using a kidney exchange, we can help incompatible patient-donor couples to swap donors to receive a compatible kidney. Kidney paired donation programs provide an innovative approach for increasing the number of available kidneys. Further, we implementing binary particle swarm optimization in parallel with MATLAB with one, two, three and four threads and from the computations point of view, the authors compare the performance to reduce the running time for kidney exchange to match patients as fast as possible to help clinicians. Moreover, implementing binary particle swarm optimization in solving the kidney exchange problem is an effective method. The obtained results indicate that binary PSO outperforms other stochastic-based methods such as genetic algorithm, ant lion optimization, and efficient the number of resulting exchanges.
ARTICLE | doi:10.20944/preprints201702.0086.v1
Subject: Chemistry And Materials Science, Metals, Alloys And Metallurgy Keywords: Diatomite; ionic exchange; metals removal; heavy metals
Online: 23 February 2017 (10:37:50 CET)
This work shows the physicochemical and mineralogical characterization of diatomites form the Hidalgo and Jalisco States, Mexico. In the case of the mineral from Hidalgo State, this has the following chemical composition; 70.0 % wt. SiO2, 11.63 wt. % Al2O3, 1.95 wt. % FeO, 1.79 wt. % MgO, 2.41 wt. % K2O, 0.85 wt. % CaO and 6.10 wt. % Na2O. On the other hand, the mineral from Jalisco has the following chemical composition; 93.58 wt. % SiO2, 3.03 wt. % Al2O3, 1.81 wt. % FeO, 0.40 wt. % MgO, 0.92 wt. % K2O, 0.11 wt. % CaO and 0.24 wt. % Na2O. For recovery of metals, both minerals got arsenic, silver, lead and nickel recoveries upper to 95 % and lower to 10 % for chromium. According to efficiency of interchange, the mineral from Hidalgo is slightly higher in the case of arsenic, lead and silver; while for nickel and particularly chromium (VI) the efficiency is higher for the mineral from Jalisco.
ARTICLE | doi:10.20944/preprints202311.1845.v1
Subject: Biology And Life Sciences, Insect Science Keywords: aphids; shrubs; gas exchange; photosynthetic pigments; CHN partition
Online: 29 November 2023 (11:05:44 CET)
Shrubs are a significant component of urban vegetation residing in parks, but they experience various influences of biotic and abiotic agents, among which aphids play an important role. In this work, the effect of aphid colonization on three shrub species in urban environment was examined. Fourteen parameters have been analyzed, describing photosynthetic pigment content and gas exchange to carbon, nitrogen, and hydrogen partition. While no significant effect of colonization was found on photosynthetic pigment parameters, the effect was significant on gas exchange parameters. The strongest effect aphid colonization achieved on nitrogen partition and C/N ratio, parameters that could be suggested in further similar studies. All parameters were classified in two groups according to principal component analysis, suggesting correlation between nitrogen and carbon content, C/N ratio, measured gas exchange parameters and chlorophyll a content. The ratio between net photosynthesis and dark respiration (A/K) was in the second group, suggesting that this parameter provide additional information on the effect of aphid colonization, and deserve special attention in further studies. There were differences in reaction of examined shrub species, where the strongest reaction by gross primary productivity (GPP) achieved Hybiscus syriacus, and by nitrogen partition and C/N ratio Spirea trilobata and Cydonia japonica.
ARTICLE | doi:10.20944/preprints202310.1625.v2
Subject: Social Sciences, Other Keywords: graded exercise test; gas exchange analysis; metabolic cart
Online: 31 October 2023 (08:21:46 CET)
Several factors, such as internal algorithm, sensor technology, and obsolescence might skew outcomes when comparing different gas analysers measurements during CPET. Besides aerosol borne infectious disease are a source of contamination during cardiopulmonary exercise tests (CPET). Thus, the main aim of this study was to determine the agreement degree between the Quark RMR and the Jaeger Oxycon Pro, using an antibacterial filter with the latter. Forty-two participants (19-54 years old) performed two non-consecutive maximal graded exercise tests on a cycle-ergometer on two counterbalance and different days using the Oxycon Pro and the Quark RMR in a randomized order. Differences between devices were tested using a generalized linear model adjusted by Bonferroni, and correlation and agreement was assessed using Pearson’s correlation coefficient (R), intraclass coefficient correlation (ICC), Lin’s concordance correlation coefficient (CCC) and Bland-Altman plots. No significant differences were found between devices in any of metabolic or ventilatory parameters for cardiorespiratory fitness assessment (VO2max: 3131.3±882.1 vs. 3189.8±894.8, p=0.071, VCO2max: 3436.3±936.0 vs. 3550.3±1043.2, p=0.071, for Quark RMR and Oxycon Pro, respectively). However, Bland-Altman plots showed a trivial tendency towards Oxycon Pro overestimation relative to Quark RMR as air flow volume increases. Both devices showed strong correlation and high level of agreement during maximal and submaximal exercise intensities (Pearson’s R: 0.974 & 0.977; ICC: 0.985 & 0.987; Lin’s CCC: 0.971 & 0.974, for VO2 and VCO2, respectively). Therefore, providing consistency to CPET data comparison between both devices, and insight into whether the use of these metabolic carts could be interchangeable or combined when a single device cannot be used for CPET assessment.
ARTICLE | doi:10.20944/preprints202310.1593.v2
Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: Anthropogenic Emissions; Revelle Factor; Exchange Flux; Bomb Pulse
Online: 26 October 2023 (09:52:37 CEST)
Based upon a radically new approach, this paper describes a 2-box absolute flow model that calculates the CO2 transfer between the atmosphere and a terrestrial / ocean mixing reservoir. Given the inputs of anthropogenic fossil fuel emissions (CO2ff), atmospheric CO2 mixing-ratio and nuclear weapons bomb yields, the model calculates atmospheric d13C and Δ14C time-series, with the level of agreement for d13C being to within ± 0.05 ‰, for Δ14C to within ± 3‰, spanning 200 years. The model contains only seven internal parameters which are varied to optimize the fit. Yet according to conventional wisdom, this model should not work. It is commonly held that the 13C and 14C isotopic forms of carbon bypass seawater carbonate chemistry, resulting in very different absorption properties (Revelle factor) as compared to 12C. This study rejects this assumption, and uses the same residence time and reservoir mixing properties for all isotopes. The paper includes an analysis justifying why the isotopic bypass of the Revelle factor is not significant. The study describes the use of the model to track CO2ff takeup using two separate measures, a) the amount of molecular CO2ff remaining in the atmosphere and b) the amount of atmospheric growth attributable to CO2ff, thereby resolving discrepancies in published values.
ARTICLE | doi:10.20944/preprints202304.0634.v1
Subject: Engineering, Energy And Fuel Technology Keywords: Advanced manufacture; Energy security; Heat exchange; Cleaan energy
Online: 20 April 2023 (08:40:32 CEST)
The spiral tube heat exchange is widely used in large-scale liquefaction process. However, the research on the friction pressure drop of the two-phase flow in the spiral tube is limited, especially for the offshore sloshing condition. In this paper, an experimental system is designed and built, and the effects of sloshing form (roll, pitch, heave), sloshing period (5-15s), mass flux (200-800 kg/(m2·s)), vapor quality (0.3-0.9) and operating pressure (2-4 MPa) on friction pressure drop of methane/ethane (C1/C2) mixture in spiral tube are studied. The result shows that the growth rate of time-averaged friction pressure drop during condensation under sloshing condition is less than 0, which indicates that sloshing will lead to drag reduction. And under the three sloshing parameters, the growth rate of time-averaged friction pressure drop of C1/C2 is reduced by-5.99%%, 5.97% and -6.70% respectively.
ARTICLE | doi:10.20944/preprints202103.0224.v1
Subject: Computer Science And Mathematics, Algebra And Number Theory Keywords: Fractional moment; stock exchange; multiple factor; semi variance
Online: 8 March 2021 (13:44:31 CET)
Complex models have received significant interest in recent years and are being increasingly used to explain the stochastic phenomenon with upward and downward fluctuation such as the stock market. Different from existing semi-variance methods in traditional integer dimension construction for two variables, this paper proposes a simplified multi-factorized fractional dimension derivation with the exact Excel tool algorithm involving the fractional center moment extension to covariance, which is a complex parameter average that is a multi-factorized extension to Pearson covariance. By examining the peaks and troughs of gold price averages, the proposed algorithm provides more insight into revealing underlying stock market trends to see who is the financial market leader during good economic times. The calculation results demonstrate that the complex covariance is able to distinguish subtle differences among stock market performances and gold prices for the same field that the two variable covariance may overlook. We take the London, Tokyo, Shanghai, Toronto and Nasdaq as the representative examples.
ARTICLE | doi:10.20944/preprints201909.0134.v1
Subject: Business, Economics And Management, Finance Keywords: Algiers Stock Exchange; Box-Jenkins methodology; SARIMA model
Online: 13 September 2019 (12:33:41 CEST)
The Algiers Stock Exchange (ASE) is the only stock exchange in Algeria. It’s one of the newest and smallest emerging stock exchanges in the world. The focus of this paper is to model and forecast monthly returns of the ASE index (DZAIRINDEX) using The Box- Jenkins methodology. The period of this study is from Jun 2010 to July 2019. According to Akaike’s Information Criterion (AIC) estimator, the Seasonal Autoregressive Integrated Moving Average SARIMA(2,0,0)(0,0,1) is chosen as the best model for forecasting the monthly DZAIRINDEX returns. Diagnostic tests confirm that the fitted model is adequate, where the residuals of this model are normally distributed with no autocorrelation and no heteroskedasticity. The forecast of the monthly DZAIRINDEX returns for one year ahead using this model shows a decreasing fluctuations trend. Based on different measures of forecast accuracy such as ME, MAE, RMSE, MASE, we show that the forecast accuracy of SARIMA(2,0,0)(0,0,1) is acceptable and this model performs much better than a naïve model. These results could be used by the financial communities in Algeria to deal with stock exchange risks and to improve their decisions.
Subject: Business, Economics And Management, Human Resources And Organizations Keywords: Leader-Member Exchange; Characteristics of Task; Employee Performance
Online: 15 May 2019 (12:16:12 CEST)
This study aims to examines three elements shape leadership in Leader-Member Exchange (LMX) theory as a relationship and process. LMX quality is important for the company, because it relates to employee behavior and attitudes, including improving employee performance. The research method applied literature review using description logic and systematics. In this article the theory will be observed specially the effect of LMX on employee performance and antecedents of LMX. The results of the study found that the effect of LMX quality on performance is determined by the characteristics of the task as antecedent LMX in the company.
ARTICLE | doi:10.20944/preprints201901.0242.v2
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: skyrmion; Dzyaloshinskii–Moriya interaction; exchange energy; magnetic anisotropy
Online: 13 February 2019 (10:33:34 CET)
In atomic GdFe$_2$ films capped by 4$d$ and 5$d$ transition metals, we show that skyrmions with diameters smaller than 12 nm can emerge. The Dzyaloshinskii--Moriya interaction (DMI), exchange energy, and the magnetocrystalline anisotropy (MCA) energy were investigated based on density functional theory. Since DMI and MCA are caused by spin--orbit coupling (SOC), they are increased with 5$d$ capping layers which exhibit strong SOC strength. We discover a skyrmion phase by using atomistic spin dynamic simulations at small magnetic fields of $\sim$1 T. In addition, a ground state that a spin spiral phase is remained even at zero magnetic field for both films with 4$d$ and 5$d$ capping layers.
ARTICLE | doi:10.20944/preprints201809.0190.v1
Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: zeolite; ion-exchange; adsorption; ammonium; Si/Al; temperature
Online: 11 September 2018 (08:50:29 CEST)
We investigate the ammonium removal abilities of natural and synthetic zeolites, which have distinct Si/Al ratios and various surface areas, to study how adsorption and ion-exchange processes in zeolites perform under different ammonium concentrations and different temperatures. Five zeolites including natural mordenite, chabazite, erionite, clinoptilolite and synthetic merlinoite were immersed in 20 mg/kg, 50 mg/kg and 100 mg/kg ammonium solutions. The results demonstrate that zeolites under high ammonium concentrations (100 mg/kg) possess higher physical adsorption capacity (0.398–0.468 meq/g), whereas those under lower ammonium concentrations (20 mg/kg) possess greater ion-exchange property (64–99%). The ion-exchange ability of zeolites are extremely dependent on the cation content of the zeolites, and the cation content is affected by the Si/Al ratio. The surface area of zeolites also has a partial influence on its physical adsorption ability. When the surface area is less than 100 m2/g, the adsorption ability of zeolite increases obviously with surface area; however, adsorption ability is saturated as the surface area becomes larger than this critical value of 100 m2/g. When we carried out the zeolites in 50 mg/kg ammonium concentration at different temperatures (5~50 ℃), we found that zeolites exhibit the highest ammonium removal ability at 30°C and the potassium release was enhanced at 30~40 ℃.
ARTICLE | doi:10.20944/preprints201803.0056.v1
Subject: Physical Sciences, Atomic And Molecular Physics Keywords: atomic structure; hartree fock; exchange; line broadening; scattering
Online: 8 March 2018 (02:10:55 CET)
Atomic structure of N-electron atoms is often determined using the Hartree-Fock method, which is an integro-differential equation. The exchange term of the Hartree-Fock equations is usually treated as an inhomogeneous term of a differential equation, or with a local density approximation. This work uses matrix methods to solve for the Hartree-Fock equations, rather than the more commonly-used shooting method to integrate an inhomogeneous differential equation. It is well known that a derivative operator can be expressed as a matrix made of finite-difference coefficients; energy eigenvalues and eigenvectors can be obtained by using computer linear-algebra packages. We extend the same technique to integro-differential equations, where a discretized integral can be written as a sum in matrix form. This method is compared against experiment and standard atomic structure calculations. We also can use this method for free-electron wavefunctions. This technique is important for spectral line broadening in two ways: improving the atomic structure calculations, and improving the motion of the plasma electrons that collide with the atom.
ARTICLE | doi:10.20944/preprints201707.0071.v1
Subject: Social Sciences, Tourism, Leisure, Sport And Hospitality Keywords: social exchange theory; structural equation modeling; tourism development
Online: 26 July 2017 (06:32:58 CEST)
Background: Tourism is one of the prominent industry that has a capability to generate handsome income for developed as well as developing countries. However, the study to investigate specifically the perception of local residents towards tourism is still lacking. The perception of the locals is important since it could determine the extent of their support for tourism development. Plus, previous research found that male residents are more support better towards the tourism development. Thus, this factor is adapted as well in this study to examine whether this gender may influence to the tourism industry. 2) Methods: This study used Structural Equation Modeling (SEM) technique for determining the structural estimates between constructs. 3) Results: The respondents agree that positive perception, negative perception and tourism impact has a significant impact on support for tourism development in which has been recognized as Social Exchange Theory model. Moreover, the finding also revealed that gender has a potential to moderates the causal effect of tourism impact on tourism development. 4) Conclusion: The resident understand the tourism sector could strengthen economic nation but they also want the natural resources should be protected.
ARTICLE | doi:10.20944/preprints201609.0061.v1
Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: dry intrusion; Stratosphere-troposphere exchange; mid-latitude; satellite
Online: 18 September 2016 (10:27:56 CEST)
Dry intrusion is an important mid-latitude atmosphere phenomenon within the upper troposphere and lower stratosphere. It is always found to be related to the cyclogenesis, rainstorm, as well as convection generation and precipitation enhancement. Since the atmosphere environment for any of these above-mentioned weather is terribly complicated, those preexisting popular schemes which takes no account of water vapor may not suitable for detecting the dry intrusion related to these weathers. With regard to the merits and demerits of the current preexisting schemes, a new scheme based on Fengyun-2E geo-stationary satellite data is presented in this study to detect the atmospheric dry intrusion. The scheme is set up based on the statistical relationship between water vapor at high level troposphere, the general moist potential vorticity, ozone concentration and upper-level jet. After using the total amount of ozone and ozone profile operational products retrieved by Fengyun-3 Polar Orbiting Meteorological Satellites and the potential vorticity calculated by ECMWF Interim data for validation, this scheme is applied to analyze two typical middle-latitude weather processes. One is the famous Beijing extreme rainfall of 21 July 2012 and the other is a hailstorm occurred on the eastern China during March 19, 2014. A good application effect in both cases suggests that our new method of detecting dry intrusion is feasible and can be helpful in middle-latitude disastrous weather monitoring and forecasting.
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: Net ecosystem exchange; Gross ecosystem production; Mesocosm; Rotation; Tillage
Online: 25 March 2021 (14:42:07 CET)
Atmospheric CO2 concentration, temperature and precipitation escalate and it is critical to investigate the agricultural practices best suited to face such new conditions. An important aspect is soil management, which alters soil organic matter content, nutrients and structure, and thus soil/atmosphere interactions and ultimately production. This in vitro study addresses greenhouse gas (GHG) emissions from two long-term soil management experiments in France. One set of soil columns were managed with either grain legume + cover crops or no grain legumes + bare fallow. The other with either plowed or reduced tillage soils. GHG exchange (CO2, N2O) measurements was conducted under different environmental conditions, before and during growth of barley and eventually with three levels of barley biomass cuts (everything removed, cut halfway, intact). The gas exchange was influenced by time and environmental settings, and to a smaller degree management history, with highly variable emissions of N2O. The environmental treatments induced different patterns of effect depending on the management history of the soils. The gas exchange from soil with grain legume was more responsive to the environmental treatments than the rotation without grain legumes. Depending on the history of tillage, the gas exchange responded likewise differently to the induced environment.
ARTICLE | doi:10.20944/preprints202007.0552.v1
Subject: Medicine And Pharmacology, Endocrinology And Metabolism Keywords: Insulin lispro; BPro28-BLys29 Exchange; Interfacial biophysics; Structural analysis;
Online: 23 July 2020 (11:45:01 CEST)
Insulin lispro was the first fast acting insulin analogue to obtain regulatory approval for therapeutic use. This article puts forward a novel biophysical mechanism where the net impact of the simple B28Pro-B29Lys exchange from regular insulin to insulin lispro is the establishment of a novel set of interfacial electrostatic interactions between Lys28 of insulin lispro and Asp12 of insulin receptor (IR). In addition, a set of structural analysis was presented in this article to further strengthen the binding of insulin lispro to IR, where two polar amino acid residues (Gln51 and Asn74 of insulin lispro) were put forward as two potential targets for site-directed mutagenesis of insulin lispro at its binding interface with IR.
ARTICLE | doi:10.20944/preprints202002.0251.v1
Subject: Social Sciences, Education Keywords: higher education; exchange programs; Taiwan; ASEAN countries; globalization; localization
Online: 17 February 2020 (16:04:41 CET)
Teachers of English as a foreign language in Taiwan are challenged to organize multi-dimensional language activities for foreign students coming from ASEAN countries, including Japan, the Philippines, South Korea, and Vietnam. With different cultural backgrounds, these students have different prior knowledge of Taiwanese culture, and, because of the similarities and differences between Taiwan and these countries, it is meaningful to explore the development of globalization with the students, who are learning both English and Chinese. The different historical backgrounds, various cultural and religious differences, and social conditions, such as gender relationships in working places, are significant topics for class discussions. When teachers serve as discussion facilitators, they encourage students to express their own multi-identities and expectations for the exchange program. Most interesting of all is to find out about their own short-term and long-term career goals. 32 foreign students from the Philippines and Vietnam were recruited for research. Questionnaires were used to assess their foreign language learning motivation and strategies, as well as to discover the learning environment they prefer and their globalization prospects. It was found that multi-lingual language policies for promoting globalization in higher education are very likely to influence the success of foreign student study in Taiwan.
ARTICLE | doi:10.20944/preprints201703.0141.v3
Subject: Environmental And Earth Sciences, Environmental Science Keywords: Forest ecosystem; Fluxnet; Soil respiration; Net ecosystem Exchange; Phenology
Online: 15 June 2017 (15:45:04 CEST)
Understanding the dynamics of Organic Carbon mineralization is fundamental in forecasting biosphere to atmosphere Net Carbon Ecosystem Exchange (NEE). With this perspective, we developed 3D-CMCC-PSM, a new version of the hybrid Process Based Model 3D‐CMCC FEM where also heterotrophic respiration (Rh) is explicitly simulated. The aim was to quantify NEE as a forward problem, by subtracting Ecosystem Respiration (Reco) to Gross Primary Productivity (GPP). To do so, we developed a simplification of the Soil Carbon dynamics routine proposed in DNDC . The method calculates decomposition as a function of soil moisture, temperature, state of the organic compartments, and relative abundance of microbial pools. Given the pulse dynamics of soil respiration, we introduced modifications in some of the principal constitutive relations involved in phenology and littering sub-routines. We quantified the model structure related uncertainty in NEE, by running our training simulations over 1000 random parameter-sets extracted from parameters distributions expected from literature. 3D-CMCC-PSM predictability was tested on independent time series for 6 Fluxnet sites. The model resulted in daily and monthly estimations highly consistent with the observed time series. It showed lower predictability in Mediterranean ecosystems, suggesting that it may need further improvements in addressing evapotranspiration and water dynamics.
ARTICLE | doi:10.20944/preprints201608.0238.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: anisotropic exchange; single molecule magnets; Spin Hamiltonian; CASSCF; NEVPT2
Online: 31 August 2016 (10:56:43 CEST)
The rationalization of single molecule magnets’ (SMMs) magnetic properties by quantum mechanical approaches represents a major task in the field of the Molecular Magnetism. The fundamental interpretative key of molecular magnetism is the phenomenological Spin Hamiltonian and the understanding of the role of its different terms by electronic structure calculations is expected to steer the rational design of new and more performing SMMs. This paper deals with the ab initio calculation of isotropic and anisotropic exchange contributions in the Fe(III) dimer [Fe2(OCH3)2(dbm)4]. This system represents the building block of one of the most studied Single Molecule Magnets ([Fe4RC(CH2O)3)2(dpm)6] where R can be an aliphatic chain or a phenyl group just to name the most common functionalization groups) and its relatively reduced size allows the use of a high computational level of theory. Calculations were performed using CASSCF and NEVPT2 approaches on the X-ray geometry as assessment of the computational protocol, which has then be used to evinced the importance of the outer coordination shell nature through organic ligand modelization. Magneto-structural correlations as function of internal degrees of freedom for isotropic and anisotropic exchange contributions are also presented, outlining for the first time the extremely rapidly changing nature of the anisotropic exchange coupling.
ARTICLE | doi:10.20944/preprints202309.1197.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Automation; Triticum aestivum; gas exchange; drought tolerance; high-throughput; Cerrado
Online: 19 September 2023 (05:47:28 CEST)
Selecting drought-tolerant and more water-efficient wheat genotypes is a research priority, spe-cifically in regions with irregular rainfall or areas where climate change is expected to result in reduced water availability. The objective of this work was to use high-throughput measurements with morphophysiological traits to characterize wheat genotypes in relation to water stress. Field experiments were conducted from May to September 2018 and 2019, using a sprinkler bar irriga-tion system to control water availability to eighteen wheat genotypes: BRS 254; BRS 264; CPAC 01019; CPAC 01047; CPAC 07258; CPAC 08318; CPAC 9110; BRS 394 (irrigated biotypes) and Aliança; BR 18_Terena; BRS 404; MGS Brilhante; PF 020037; PF 020062; PF 120337; PF 100368; PF 080492; TBIO Sintonia (rainfed biotypes). The water regimes varied from 22 to 100% of the crop evapotranspiration replacement. Water stress negatively affected gas exchange, vegetation indices and grain yield. High throughput variables TCARI, NDVI, OSAVI, SAVI, PRI, NDRE and GNDVI had higher correlation with yield and morphophysiological measurements. The drought re-sistance index indicated that genotypes Aliança BRS 254, BRS 404, CPAC 01019, PF 020062, and PF 080492 were more drought tolerant.
ARTICLE | doi:10.20944/preprints202308.0066.v1
Subject: Physical Sciences, Nuclear And High Energy Physics Keywords: superscaling; quasielastic electron scattering; meson-exchange currents, relativistic mean field
Online: 1 August 2023 (10:55:29 CEST)
We present a model that incorporates the effect of two-body currents in quasielastic electron-nucleus scattering within the framework of a consistent superscaling formalism. This is achieved by defining an averaged single-nucleon hadronic tensor based on the 1p1h matrix element of the one-body current plus meson-exchange currents (MEC). The consistent treatment of one- and two-body currents in our model enables the calculation of exchange current effects in the kinematical region where the Fermi gas response is zero, but not the scaling function. The effect of MEC is consistently taken into account when extracting the phenomenological scaling function from electron scattering data. With this model, we investigate the effect of MEC on the response functions taking into account the effective mass of the nucleon, and examine the consequences it has on the inclusive (e,e′) cross section. We find that 1p1h MEC deplete the quasielastic transverse response, while they not alter significantly the scaling behavior of (e,e′) data.
ARTICLE | doi:10.20944/preprints202302.0459.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: copper ferrite; magnetic properties; anion-exchange resin precipitation; magnetic nanoparticles
Online: 27 February 2023 (08:38:56 CET)
Copper ferrite attracts a lot of interest from researchers as a material with unique magnetic, optical, catalytic and structural properties. In particular, the magnetic properties of this material are structurally sensitive and can be tuned by changing the distribution of Cu and Fe cations in octahedral and tetrahedral positions by controlling synthesis parameters. In this study, we propose a new simple and convenient method for the synthesis of copper ferrite nanoparticles using a strongly basic anion exchange resin in OH form. The effect and possible mechanism of polysaccharides addition on the elemental composition, yield and particle size of CuFe2O4 is investigated and discussed. It is shown that anion exchange resin precipitation leads to a mixture of unstable at standard temperature cubic (c-CuFe2O4) and stable tetragonal (t-CuFe2O4) phases. The effect of the reaction conditions on the c-CuFe2O4 stability is studied by temperature-dependent XRD measurements and discussed in terms of the cations distribution, Jahn−Teller distortion and Cu2+ and oxygen vacancies in the copper ferrite lattice. The obtained differences in the values of saturation magnetization and the coercive force of prepared samples are explained with a reference to variations in the particle sizes and the structural characteristics of copper ferrite.
ARTICLE | doi:10.20944/preprints202212.0100.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: olive solid waste; cow manure; phosphorus; potassium; cation exchange capacity
Online: 6 December 2022 (10:06:43 CET)
A field experiment was conducted on the farm of Abi Jarash in Agricultural Collage, different rates of olive solid waste and cow manure were used, as follows: (control, fresh olive solid waste 100%, fresh olive solid waste 75%+ cow manure 25%, fresh olive solid waste 50%+ cow manure 50%, fresh olive solid waste 25+ cow manure 75%, Fermented Olive Solid Waste 100%, Fermented olive solid waste 75%+ cow manure 25%, Fermented olive solid waste 50%+ cow manure 50%, Fermented olive solid waste 25+ cow manure 75%), wheat was seeded. The impact of fresh and fermented olive solid waste and cow manure on some chemical and fertility soil properties was studied. the olive solid waste treatment 100% which added had more effect on the organic matter, exchange capacity, nitrogen, phosphorus and potassium in soil, plant and productivity, after that the fermented olive solid waste 75% + cow manure, fresh olive solid waste 100% comparing with the control, the values of organic matter were (25% 2.73, 2.39) and the cation exchange capacity (21.76, 20.44, 19.38) and for phosphorus (303.3, 277.8, 171.8) mg / kg, while the values of potassium were (303.3, 277.8, 171.8) mg / kg. In terms of plant content, the plant content of nitrogen, phosphorus and potassium were the same as for grains (2.784, 2.606, 2.126), (0.4535, 0.4226, 0.2753), (1.876, 1.762, 1.234) respectively, (0.2875, 0.2016) respectively for the same previous treatments and elements. olive solid waste 100% was the highest productivity comparing with the other treatments, where the productivity of wheat was (9.513) ton. ha-1.
ARTICLE | doi:10.20944/preprints202205.0055.v1
Subject: Chemistry And Materials Science, Physical Chemistry Keywords: ion exchange membrane; diffusion permeability; weak electrolyte; ammonium chloride; simulation
Online: 5 May 2022 (16:49:08 CEST)
It is known that ammonium has a higher permeability through anion-exchange and bipolar membranes compared to K+ cation that has the same mobility in water. However, the mechanism of this high permeability is not clear enough. We develop a mathematical model based of the Nernst-Planck and Poisson equations for diffusion of ammonium chloride through an anion-exchange membrane; proton exchange reactions between ammonium, water and ammonia are taken into account. It is assumed that ammonium, chloride and OH− ions can only pass through membrane hydrophilic pores, while ammonia can also dissolve in membrane matrix fragments not containing water and diffuse through these fragments. It is found that due to the Donnan exclusion of H+ ions as coions, the pH in the membrane internal solution increases when approaching the membrane side facing distilled water. Consequently, there is a change in the principal nitrogen-atom carrier in the membrane: in the part close to the side facing the feed NH4Cl solution (pH<8.8), it is the NH4+ cation, and in the part close to distilled water, NH3 molecules. The concentration of NH4+ reaches almost zero at a point close to the middle of the membrane cross-section, which approximately halves the effective thickness of the diffusion layer for the transport of this ion. When NH3 takes over the nitrogen transport, it only needs to pass through the other half of the membrane. Leaving the membrane, it captures an H+ ion from water, and the released OH− goes towards the membrane side facing the feed solution to meet the NH4+ ions. The comparison of the simulation with experiment shows a satisfactory agreement.
ARTICLE | doi:10.20944/preprints202102.0347.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: Ulmus pumila; salt stress; salt-tolerance; antioxidants; osmolytes; gas-exchange
Online: 17 February 2021 (09:22:23 CET)
Elevated salinity is one of the major environmental limitation factors of plant growth and development and salinity stress compromises the production and survival of plantation and urban forests and agricultural crops in the arid, semi-arid, and intertidal zones. Ulmus pumila, a salt- indigenous tree species in Asia and is widely deployed in salt-affected areas in China, and U.pumila is promising for multi-varietal forestry in plantation and urban forests. The comprehensive mechanism of the intraspecific salt tolerance is still not clear yet. Here, we investigated the physiological responses of the salinity stress based on the antioxidant enzyme activities, osmotic adjustments, and gas exchange among salt-tolerant U. pumila genotypes for 100 days under five different NaCl levels (0%, 0.3%, 0.5%, 0.7%, and 0.9% w/v) with natural surroundings and rain shade at age-2. Salt stress decreased height (HR), ground diameter (DR), and dry weight (biomass) were significantly different among genotypes. HR and performance indices were positively correlated with photosynthesis rate (Pn), apparent mesophyll conductance (AMC), and chlorophyll (CHLL) with (r= 0.7 - 0.8 ***), but were negatively related to the free proline, sugar, and protein accumulation (r=-0.5 ~ -0.7***). We found that high accumulation of sugars and more activities of SOD enzyme in leaf tissue contribute to the osmotic adjustment and ROS scavenging system under salinity treatment; the sugar content and SOD activity play key roles in U. pumila’s tolerance to salt stress, and are promising indicators for U. pumila species ex vitro selections. The ex vitro selection results align with the previous in vitro studies  and is promising for the MVF development.
ARTICLE | doi:10.20944/preprints202010.0581.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: ionic exchange; self-assembly; modified ammonium polyphosphate; polypropylene; combustion behavior
Online: 28 October 2020 (10:06:57 CET)
Modified ammonium polyphosphate (MAPP) as a novel mono-component intumescent flame retardant (IFR) was prepared via the ionic exchange between ammonium polyphosphate (APP) and piperazine sulfonate, which is synthesized by self-assembly using 1-(2-Amioethyl) piperazine (AEP) and p-amino benzene sulfonic acid (ASC) as raw materials. This all-in-one IFR integrating three functional elements (carbon, acid, and gas source) showed more efficient flame retardancy and excellent smoke suppression as well as better mechanical properties than the conventional APP. The incorporation of 22.5 wt.% MAPP into polypropylene (PP) eliminated the melt dripping phenomenon and passed the UL-94 V-0 rating. The results of the cone calorimetry test (CCT) revealed that the release of heat, smoke, and CO is significantly decreased, demonstrating that this novel IFR endows PP with excellent fire safety more effectively. For PP/MAPP composites, a possible IFR mechanism was proposed based on the analysis of the pyrolysis gas and char residues.
ARTICLE | doi:10.20944/preprints201909.0328.v1
Subject: Chemistry And Materials Science, Polymers And Plastics Keywords: proton exchange membranes; semi-crystalline polymers; small-angle neutron scattering
Online: 29 September 2019 (06:25:39 CEST)
Membranes based on sulfonated synditoactic polystyrene were thoroughly characterized by contrast variation SANS over a wide Q-range in dry and hydrated states. The film samples were prepared by solid-state sulfonation that allowed a uniform sulfonation of only the amorphous phase while preserving the crystallinity of the membrane. The samples were loaded with different guest molecules in either the amorphous (fullerenes) or the crystalline (toluene) regions, in order to vary the neutron contrast or to reproduce the conditions enabling an increased resistance of the membranes to chemical decomposition. The use of uni-axially deformed film samples and contrast variation with different H2O/D2O mixtures allowed for the identification and characterization of different structural levels with sizes between nm and μm, which form and evolve in the membrane morphology in dry and hydrated states and produce scattering features on different detection sectors and at different detection distances after the sample, depending on their size and orientation.
ARTICLE | doi:10.20944/preprints201810.0410.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: Anion exchange, DOC, Dissolved phosphorus, Forest soil, Lysimeters, P transport
Online: 18 October 2018 (10:10:20 CEST)
Incidental P losses from non-point sources may contribute to eutrophication and to decreased soil fertility. These incidents have been related to heavy rainfall on freshly fertilized agricultural soils and little is known about such incidents on more natural soils or in forests. The aim of this work is to determine if incidents of high P leaching also occur in spruce forests, and if such incidents are of significance in P cycling. We found a peak in the mineral soil solution showing that single events of high P leaching occur. The orthophosphate concentration in the Bf-horizon of the 80-year old spruce forest peaked in the autumn of the second year of a continuous monitoring. The concentration increased by more than 85 times compared to the highest concentration obtained earlier during the sampling. The amount leached during this 6 months peak is 10 times higher than the average annual leaching. This P leaching might be due to a combination of high P deposition/through-fall and a high anion exchange with dissolved-organic-carbon and Cl-. We suggest that single events of high sub-surface P leaching may contribute to the overall P leaching, and might increase with the global warming as more DOC is expected to be released to the soil solution.
ARTICLE | doi:10.20944/preprints201804.0266.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: gas exchange; leaf canopy temperature; life forms; thermography; woody vines
Online: 20 April 2018 (11:55:08 CEST)
Leaf temperature (Tleaf) influences photosynthesis and respiration. Currently, there is a growing interest on including lianas in productivity models due to their increasing abundance, and their detrimental effects on net primary productivity in tropical environments. Therefore, understanding the differences of Tleaf between lianas and trees is important for future of forest on whole ecosystem productivity. Here we determined the displayed leaf temperature (Td= Tleaf – ambient temperature) of several species of lianas and their host trees during ENSO and non-ENSO years to evaluate if the presence of lianas affects the Td of their host trees, and if leaves of lianas and their host trees exhibit differences in Td. Our results suggest that close to midday, the presence of lianas does not affect the Td of their host trees; however, lianas tend to have higher values of Td than their hosts across seasons, in both ENSO and non-ENSO years. Although lianas and trees tend to have similar physiological-temperature responses, differences in Td could lead to significant differences in rates of photosynthesis and respiration based temperature response curves. Future models should thus consider differences in leaf temperature between these life forms to achieve robust predictions of productivity.
ARTICLE | doi:10.20944/preprints201803.0175.v1
Subject: Environmental And Earth Sciences, Oceanography Keywords: Hypersaline Bay; circulation; turbulent mixing; exchange flow; Australia; Shark Bay
Online: 20 March 2018 (08:44:49 CET)
In Shark Bay, a large hypersaline bay in Western Australia, longitudinal density gradients force gravitational circulation that is important for Bay-ocean exchange. Observations of vertical stratification and velocity are presented, confirming a steady near-bed dense water outflow from Shark Bay’s northern Geographe Channel that persisted through all stages of the tide. Outflow velocities were 2–3 times stronger than the outflows recorded previously in Naturaliste Channel (in the west) and were more resistant to breakdown by tidal mixing. Estimates of turbulent kinetic energy production derived from ADCP data using the variance method showed a more complex structure in Geographe Channel, due to shear associated with the stratified conditions, with peak levels of turbulence occurring during reversal of tidal flows. For both channels the main source of turbulence was tidal flow along the seabed, with the bottom current speed cubed, |Ub3|, providing a reasonable proxy for tidal mixing and prediction of dense water outflows from Shark Bay the majority of the time. Orientation and deeper water of Geographe Channel along the main axis of the longitudinal density gradient provided an explanation for the predominant outflow from the Bay’s northern entrance. These density-driven currents could potentially influence recruitment of commercially fished scallops and prawns through dispersal and flushing of larvae.
ARTICLE | doi:10.20944/preprints202310.0306.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: Whitefly; photosynthetic parameters; gas exchange; insect pest; plants resistance; Glycine max.
Online: 6 October 2023 (05:06:57 CEST)
The whitefly leads extensive damage to plants through direct feeding, honeydew secretion, plant physiological disorders, and vectoring plant viruses. This study aimed to evaluate the physiological characteristics of susceptible and resistant soybean cultivars to B. tabaci. The experiments were conducted in a greenhouse. Eleven soybean cultivars were selected and infested with 100 adults of B. tabaci at the V3 stage. The evaluation of photosynthetic parameters, such as photosynthetic rate, leaf transpiration, stomatal conductance, and internal CO2 concentration, revealed that B. tabaci infestation influenced gas exchange in soybean plants. The photosynthetic rate was higher in cultivars AS3810 and M8349 during the V6 stage. Infestations led to alterations in photosynthetic parameters, suggesting increased energy demand to maintain photosynthetic activity. However, the response to infestation varied among different cultivars, indicating varying levels of resistance and tolerance to the whitefly's damage. Additionally, the impact of infestation was more significant during the vegetative phenological. In conclusion, B. tabaci infestation affects soybean plants' physiology, leading to changes in gas exchange parameters and water use efficiency. The response to infestation varied among soybean cultivars, suggesting potential differences in resistance to the pest. The study highlights the importance of evaluating the physiological impact of whitefly infestations on soybean.
ARTICLE | doi:10.20944/preprints202309.1586.v1
Subject: Environmental And Earth Sciences, Ecology Keywords: carbon dioxide fluxes; net ecosystem exchange; photosynthetically active radiation; salt marshes
Online: 26 September 2023 (08:19:12 CEST)
Abstract: This study observes the characteristics and influencing factors of carbon fluxes of the Momoge salt marsh ecosystem over four years, which behaves as a CO2 sink. The daily, seasonal, and interannual variations of CO2 fluxes in the Momoge salt marshes were observed using the eddy covariance method and compared with various environmental factors. An overall daily “U” shaped distribution was observed, with uptake during the day (negative values) and release at night (positive values). Annually, the carbon fluxes in the study area roughly exhibit a “V” shape. Carbon fluxes during the non-growing season predominantly showed positive values, indicating the release of CO2 into the atmosphere. Photosynthetically active radiation was the primary influencing factor affecting hourly and daytime variations in net ecosystem exchange (NEE) during the growing season, while temperature was the main factor influencing nighttime NEE dynamics. Air temperature, soil temperature, photosynthetically active radiation, precipitation, and water level all had significant impacts on daily net CO2 exchange. At the monthly scale, larger values of soil temperature, air temperature, photosynthetically active radiation, and aboveground biomass correspond to a stronger carbon absorption capacity of the ecosystem. Overall, temperature remains the primary factor for carbon fluxes in the Momoge wetlands.
ARTICLE | doi:10.20944/preprints202309.1147.v1
Subject: Business, Economics And Management, Finance Keywords: financial performance; sustainability reporting; sustainable performance; content analysis; Istanbul Stock Exchange
Online: 19 September 2023 (03:51:51 CEST)
This study investigated the impact of sustainability reporting on financial performance, with a focus on companies in the Turkish food, beverage and tobacco and textile, wearing apparel and leather sectors. The sustainability reports of 48 companies listed on the Istanbul Stock Exchange for 2022 were studied, and the quality of sustainability practices was determined by using a general index (Sustainability Reporting Disclosure Quality Index (SRDQI)) and three partial indices (Environmental Disclosure Quality Index, Social Disclosure Quality Index, and Corporate Governance Disclosure Quality Index (CGDQI)). To analyze the relationships between financial performance and sustainability practices two types of regression models were developed, based on which eight models were directly examined. The results indicate the complete absence of a statistically significant impact of SRDQI on all financial performance measures used. Among the partial indices, only CGDQI has a significant positive effect on the Assets Turnover Ratio. An analysis of the influence of control variables shows a multidirectional dependence of individual financial performance measures on the size of companies, their age, industry affiliation, as well as on the structure of capital used. Finally, this study provides directions for improving the institutional environment of sustainability reporting for Turkish companies.
REVIEW | doi:10.20944/preprints202304.0426.v2
Subject: Computer Science And Mathematics, Computer Science Keywords: Internet of Medical Things (IoMT); data exchange: healthcare; medical data; interoperability
Online: 5 June 2023 (08:12:36 CEST)
A medical entity (hospital, nursing home, rest home, revalidation center, etc.) usually includes a multitude of information systems that allow for quick decision-making close to the medical sensors. The Internet of Medical Things (IoMT) is an area of IoT that generates a lot of data of different natures (radio, CT scan, medical reports, medical sensor data). However, these systems need to share and exchange medical information in a seamless, timely, and efficient manner with systems that are either located within the same entity or located in other healthcare entities. The lack of inter and intra entity interoperability causes major problems in the analysis of patient records and leads to additional financial costs (e.g., redone examinations). In order to develop a medical data interoperability architecture model that will allow providers and different actors in the medical community to exchange patient summary information with other caregivers and partners in order to improve the quality of care, the level of data security, and the efficiency of care, we take stock of the state of knowledge.
ARTICLE | doi:10.20944/preprints202305.0915.v1
Subject: Environmental And Earth Sciences, Water Science And Technology Keywords: water accumulation in permafrost; thermal surface boundary; water temperature; heat exchange
Online: 12 May 2023 (09:43:19 CEST)
With permafrost degenerating caused by climate change, water accumulation increases in permafrost regions during last decades. Water accumulation will deteriorate existing status of engineering in cold regions. Water accumulation can make a thermal effect on permafrost under construction, even result in failure of the subgrade. Moreover, the thermal effect is related to water temperature. However, temperature variation of water accumulation is complex, and its influence factors include air temperature, environment, scope of water accumulation and so on. In order to make analysis of the damage mechanism of water accumulation on permafrost, it is necessary to explore the internal temperature change of water accumulation. This paper proposes a review about temperature calculation method of water accumulation in cold environment. The thermal calculation method between air and water boundary of water accumulation is summarized. Water temperature change of water accumulation with various type is analyzed. The thermal calculation considering phase transformation in water accumulation is discussed, and heat transfer from the bottom of water accumulation to the underlying soil is further studied. Finally, the key factors which are advantageous to make research about the thermal effect of water accumulation in permafrost is proposed to optimize calculation method.
ARTICLE | doi:10.20944/preprints202304.1179.v1
Subject: Chemistry And Materials Science, Physical Chemistry Keywords: ion-exchange membrane; neutralization dialysis; modelling; phenylalanine losses; amino acid; demineralization
Online: 28 April 2023 (11:37:33 CEST)
A non-steady state mathematical model of amino acid (phenylalanine (Phe)) and mineral salt (NaCl) solution separation by neutralization dialysis (ND) carried out in a batch mode is proposed. The model takes into account the characteristics of membranes (thickness, ion-exchange capacity and conductivity) and solutions (concentration, composition), as well as the flow rate of the solution in the dialyzer compartments. As compared to previously developed models, the new one considers the local equilibrium of Phe protolysis reactions in solutions and membranes and, also, the transport of all the phenylalanine forms (zwitterionic, positively and negatively charged) through membranes. A series of experiments on ND demineralization of NaCl and Phe mixed solution was carried out. In order to minimize Phe losses, the solution pH in the desalination compartment was controlled by changing the concentrations of the solutions in the acid and alkali compartments of the ND cell. The validity of the model was verified by comparison of simulated and experimental time dependencies of solution electric conductivity and pH, as well as the concentration of Na+, Cl– ions and Phe species in the desalination compartment. Based on the simulation results, the role of Phe transport mechanisms in the losses of this amino acid during ND was discussed.
ARTICLE | doi:10.20944/preprints202212.0580.v1
Subject: Business, Economics And Management, Finance Keywords: credence goods; price and performance; incomplete contracts; gift exchange and reciprocity
Online: 30 December 2022 (09:55:50 CET)
When sellers set the price for ex-ante unobservable and ex-post unenforceable quality, price signals credence quality. Hedge funds resemble incomplete long-term contracts for credence goods under buyer-determined auctions. I show that hedge funds' ability to solicit investments at higher management fees signals their capacity to generate higher net returns. This result is more pronounced during bust cycles and closer to financial hubs, i.e., when signaling quality is more valuable. The findings are relevant to understanding price and effort in the provision of credence goods like medical procedures and legal advice.
ARTICLE | doi:10.20944/preprints202211.0394.v2
Subject: Chemistry And Materials Science, Nanotechnology Keywords: permanent magnets; hexaferrites; magnetic nanocomposites; nanomagnets; epitaxy; exchange coupling; shape anisotropy
Online: 15 December 2022 (07:03:38 CET)
Herein, we demonstrate the synthesis of sandwiched composite nanomagnets, which consist of hard magnetic Cr-substituted hexaferrite cores and magnetite outer layers. The hexaferrite plate-like nanoparticles with average dimensions of 36.3 nm × 5.2 nm were prepared by glass crystallization method and were covered by spinel-type iron oxide via thermal decomposition of iron acetylacetonate in hexadecane solution. The hexaferrite nanoplates act as seeds for the epitaxial growth of the magnetite, which results in uniform continuous outer layers on both sides. The thickness of the layers can be adjusted by controlling the concentration of metal ions. In this way, layers with average thickness of 3.7 and 4.9 nm were obtained. Due to an atomically smooth interface the magnetic composites demonstrate the exchange coupling effect, acting as single phases during remagnetization. The developed approach can be applied to any spinel-type material with matching lattice parameters and opens the way to expand the performance of hexaferrite nanomagnets due to a combination of various functional properties.
ARTICLE | doi:10.20944/preprints202209.0273.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: net ecosystem exchange; eddy-covariance; regression; upscaling; data augmentation; feature selection
Online: 19 September 2022 (10:17:33 CEST)
Despite a rapid rise in NBS development in recent years, the methods for evaluating NBS still have certain gaps. We propose an approach based on a combination of remote sensing data and meteorological variables to reconstruct the spatio-temporal variation of net ecosystem exchange from eddy-covariance stations. Lagrangian particle dispersion model was used for upscaling of satellite images and flux towers. We trained data-driven models based on kernel methods separately for each selected land cover class. The results suggest that the proposed approach to quantifying carbon exchange on a medium-to-large scale by blending eddy covariance flux data with moderate resolution satellite and weather data provides a set of key advantages over previously deployed methods: (1) scalability, achieved via the validation design based on a separate set of eddy covariance stations; (2) high spatial and temporal resolution due to use of the Landsat imagery; (3) robust and accurate predictions due to improved data quality control, advanced machine learning techniques, and rigorous validation. The machine learning models yielded high cross-validation results. Overall we present here globally scaled technology for the land sector based on high resolution remote sensing imagery, meteorological variables, and direct carbon flux measurements of eddy covariance flux stations.
ARTICLE | doi:10.20944/preprints202110.0035.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: hydrogen-deuterium exchange; mass spectrometry; isobaric ions; ambient ionization; metabolic profiling
Online: 4 October 2021 (09:21:39 CEST)
Isobaric ions having the same mass-to-charge ratio cannot be separately identified by mass spectrometry (MS) alone, but this limitation can be overcome using hydrogen-deuterium exchange (HDX) in microdroplets. Because isobaric ions may contain a varied number of exchangeable sites and different types of functional groups, each one produces a unique MS spectral pattern after droplet spray HDX without the need for MS/MS experiments or introduction of ion mobility measurements. As an example of the power of this approach, isobaric ions in urinary metabolic profiles are identified and used to distinguish between healthy individuals and those having bladder cancer.
ARTICLE | doi:10.20944/preprints202003.0086.v2
Subject: Business, Economics And Management, Economics Keywords: broad money supply; currency outflow; money creation; exchange rate; Kalman filter
Online: 20 September 2021 (10:36:27 CEST)
The paper explains the dynamics of monetary aggregates in Russia with the help of country's trade balance, the creation of deposits by commercial banks and cross-border flows of rubles and (foreign) currency. The volumes of deposits and flows, in turn, depend on changes in the currency/ruble exchange rate and favorable external economic conditions. The model was estimated by the Kalman filter, the adequacy was confirmed by stimulation. Monthly money supply forecasts have an accuracy of ~ 1%. It was found that the volume of additional deposits created per month is ~ 300 billion RUB (this leads to real inflation of 9.5% per annum), money flows that are not related to payments for goods: rubles inflow from abroad ~ 100 billion RUB, currency goes abroad ~ 15 billion USD. With the growth / fall of the dollar exchange rate by 1 RUB per month, during the same month, the creation of additional ruble deposits and the arrival of rubles from outside decreases / increases by 0.114 billion USD. The increase of the Currency Reserve Assets of Russia is accompanied by going abroad ~ 5% of the increase.
ARTICLE | doi:10.20944/preprints202012.0400.v1
Subject: Engineering, Automotive Engineering Keywords: wireless monitoring; electrical resistance sensors; humidity; crystalline admixtures; water exchange; concrete
Online: 16 December 2020 (09:43:35 CET)
The development of a remote sensing system is proposed in the present study for monitoring of the electrical resistance of concrete in real time. The sensor is embedded in the concrete bulk, and the data are sent via a gateway to a computer for the data analysis. The sensibility of the sensors to the effect of the presence of a crystalline admixture has been also assessed in the study. Different cycles of drying and water penetration have been considered to assess the sensor performance in different water content conditions. Sensors have shown to capable of detecting changes in electrical resistance when humidity changes. The sensitive of the sensors to the action of waterproofing admixtures in the mortar has been also confirmed. The contribution of the temperature plays a critical role on the sensor response, and its simultaneous monitoring is recommended.
ARTICLE | doi:10.20944/preprints202006.0291.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: food exchange list; sports foods; dietary supplements; dietetic practice; menu planning
Online: 24 June 2020 (09:41:43 CEST)
Food exchange lists have been widely used in dietary practice in health and disease situations, but there are still no exchange lists for sports foods. The aim of this study was to develop a sports foods exchange list based on previously published statistical criteria. A cross-sectional study of the nutritional composition of sports foods, regarding macronutrients and energy, was carried out. A total of 323 sports foods from 18 companies were selected and divided into seven groups: sports drinks; sports gels; sports bars; sports confectionery; protein powders; protein bars; and liquid meals. A sports foods composition database based on portion size was created. Food exchange groups, with the definition of the amounts - in grams - of each sports foods within each group, were designed using the same methodology and statistical criteria as previously published. The nutritional composition of the portions usually consumed by athletes and/or recommended in commercial packaging was used to calculate the mean energy and macronutrient values for each group. Within each sports foods group, different subgroups were defined due to differences in the main and/or secondary macronutrient. The mean nutrient values of each exchange group and the subgroups were determined according to previously established rounding criteria. This sports foods exchange list, made up of commercial sports products, is a novel tool for dietetic practice. Its management will allow dietitians to adapt dietary plans more precisely to the training and/or competition of the athlete.
ARTICLE | doi:10.20944/preprints201911.0370.v1
Subject: Engineering, Control And Systems Engineering Keywords: aluminium; nafion; ion exchange dialysis; response surface methodology (rsm); desirability; enrichment
Online: 29 November 2019 (04:36:11 CET)
An ion exchange dialysis (IED) is used in the recovery of aluminium from residue. In this papers, the face-centered central composite design (FC-CCD) of the response surface methodology (RSM) and desirability approach is used for experimental design, modelling and process optimization of a counter flow IED system. The feed concentration, feed flowrate, sweep flowrate and sweep concentration are selected as the process variables, with the Al-transport across a Nafion 117 membrane as the target response. A total of 30 experimental runs were conducted with 6 center points. The response obtained was analysed by analysis of variance (ANOVA) and fitted to a second-order polynomial model using multiple regression analysis. The actual R2 and standard deviation of the model are 0.9548 and 0.2932 respectively. The influences of significant variables are plotted on 3D surface and contour plots. The designed variables were numerically optimized by applying the desirability function to achieve the maximum Al-transport. The optimised condition values were found to be feed concentration (1600 ppm), feed flowrate (61.76%), sweep flowrate (37.50%) and sweep concentration (0.75 N) for the 80% target response at 32hrs. Overall, the model can be used to effectively predict Al-recovery using the designed system
ARTICLE | doi:10.20944/preprints201903.0167.v1
Subject: Engineering, Energy And Fuel Technology Keywords: Bioelectrochemical system; Cation exchange membranes; Ageing of membranes; Microbial electrolysis cell.
Online: 18 March 2019 (09:07:18 CET)
Bioelectrochemical systems (BES) encompass a group of biobased technologies capable of directly converting organic matter into electricity. In these systems, which are derived from conventional electrochemical systems, the ion exchange membrane represents a key element because of its influence on the economic feasibility and on the performance of BES. This study examines the impact of long-term operation of a BES on the mechanical, chemical and electrochemical properties of five different kind of cation exchange membranes (Nafion-117, CMI-7001, Zirfon UTP 500, FKE and FKB) through several techniques: (i) scanning electron microscopy (SEM) and atomic force microscopy (AFM) to assess the changes on the membranes surface, (ii) thermogravimetric analysis (TGA) to evaluate the structural stability of the membranes, and (iii) ion exchange capacity (IEC) to monitor any change in their electrochemical properties. Results confirmed that there is not an ideal membrane for BES. While Nafion and CMI-7000 exhibited the strongest chemical structure, they also underwent the highest fouling as revealed by a fast increase in surface roughness.
ARTICLE | doi:10.20944/preprints201807.0385.v2
Subject: Engineering, Transportation Science And Technology Keywords: low carbon island; electric motorcycles; green transport; battery exchange; carbon emissions
Online: 5 September 2018 (16:23:53 CEST)
Global warming and climate change have led to extreme changes in climatic conditions in recent years. The Taiwan government designates the construction of the Kinmen County as low carbon islands, to promote the operation of 100 electric motorcycles and battery demonstration. This study combined with island tourism, after boarding the island, visitors can rent electric motorcycles from the passenger service center and coordinate with the island tour map to show the location of the battery exchange points, so as to facilitate the search. During the operation, the amount of electric motorcycle lease is 15,551 times, the total mileage of motor vehicle is 284,404 km, the number of battery exchange is 622 times, the lease income is about NT$900,000. To reduce carbon and economic benefits of the assessment, compared to the motorcycles (50 c.c), electric motorcycles (EM 100) can reduce the carbon emissions by 8,726 kg, reducing energy costs of NT$422,594.
ARTICLE | doi:10.20944/preprints202307.0535.v1
Subject: Chemistry And Materials Science, Metals, Alloys And Metallurgy Keywords: magnetization; band structure; paramagnetic behavior; cobalt magnetism; short range order; exchange interactions
Online: 10 July 2023 (11:09:59 CEST)
The magnetic properties of RCo3B2 compounds, with heavy rare earths, are investigated by using magnetic measurements and electronic structure calculations. The cobalt sublattice magnetizations are very small and antiparallel oriented to rare earths moments. Contributions of cobalt moments to the Curie constants were also shown. The cobalt magnetic behavior has been analyzed in spin fluctuations model. The presence of short-range order above the Curie temperatures in RCo3B2 compounds with R=Tb, Dy, and Ho has been attributed to reminiscent R5d-Co3d interactions.
TECHNICAL NOTE | doi:10.20944/preprints202305.0518.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: farm anaimals,; farm animals; gas exchange; energy expenditure; metabolic rate; respirometric chambers
Online: 8 May 2023 (10:32:02 CEST)
Indirect calorimetry (IC) is a widely used method to study animal energy metabolism by measuring gas exchange. The accuracy of IC depends on detecting variations in signals reflecting the metabolic response, which can be challenging due to measurement noise and external factors. In this study, we propose a methodology to validate IC systems, including an easy-to-use spreadsheet for data computing, to verify accuracy and detect whole-system leaks. We conducted a re-covery test using a simulation of CO2 dynamics in MS Excel and injecting a known CO2 concentration into four respirometry chambers. The clearance rate of CO2 was observed and compared to the expected clearance rate from the simulation. The results from the recovery test in our system show that the proposed methodology is accurate and precise. The proposed methodology and recovery test can be used to standardize the validation of IC systems, providing accurate measurements of animal energy metabolism in different environmental conditions and energy utilization from feeds.
ARTICLE | doi:10.20944/preprints201905.0306.v1
Subject: Business, Economics And Management, Finance Keywords: return reversals; exchange-traded funds (ETFs); attention hypothesis; disagreement hypothesis; short selling
Online: 27 May 2019 (09:53:03 CEST)
We find that the overnight returns of Korean exchange-traded index funds (ETFs) are significantly positive, whereas the subsequent intraday returns are negative. These intraday return reversals are caused by relatively higher opening prices than the closing prices. In the Korean ETF market, where institutional investors are dominant participants, the return reversals are not explained by the attention hypothesis as in Berkman et al. . Hence, we investigate whether the disagreement hypothesis can explain return reversals. Under the disagreement situations between positive and negative traders at the open, positive traders can have a positive influence on the ETF prices by increasing their investments. However, negative traders, who give up investments due to limited short selling opportunities in the ETF market, have no effects on the prices. Comparing ETF markets with KOSPI 200 Futures where there are no restrictions on short selling, we find that short selling constraints are significant factors for the return reversals. This implies that disagreement among the investors can cause return reversals even in the markets without noise traders. Using unique Korean market data, we conclude that return reversals cannot be completely explained by the attention hypothesis, and that disagreement among investors is also a significant factor for the return reversals. This study contributes to the existing literature by showing that the attention hypothesis does not explain return reversals in the ETF market completely, and suggesting the disagreement hypothesis as an alternative.
ARTICLE | doi:10.20944/preprints201607.0094.v1
Subject: Business, Economics And Management, Finance Keywords: Exchange traded funds, ETFs, tracking error, panel regression model, fixed effects estimation
Online: 29 July 2016 (12:39:32 CEST)
This paper uses panel data to find the determinants of tracking errors in exchange traded funds (ETFs) in the Hong Kong stock market. A comparison of tracking errors between physical and synthetic ETFs also indicates that the synthetic ETFs have higher tracking errors. The magnitude of tracking errors is found to be negatively related to size but positively related to dividend yield, trading volumes of funds, and market risk. However, this study also finds that expense ratio has a negative impact on tracking error, which is not consistent with previous studies, and which this paper addresses.
ARTICLE | doi:10.20944/preprints202311.1867.v1
Subject: Business, Economics And Management, Other Keywords: economic sociology; power theory of exchange and money; power; generalized power
Online: 29 November 2023 (09:14:21 CET)
The Power Theory of Exchange and Money (PTEM) refines the economic neoclassical two-equation model of exchange. PTEM replaces the statistical average condition of exchange, which represents the equality of supply and demand for all transactions in the market, with a more specific equation of the equality of the generalized power of the parties in relation to their objects of exchange. The purpose of the article is to show the application of PTEM for the study of various social phenomena. Along with a brief summary of the main statements of this theory, its integration into the existing corpus of theories and ideas in economics and sociology is considered. The conclusions of power theory are then applied to consider the following topics: the objective motivation of exchange by the desire to increase power, the power nature of market equilibrium, the power nature of money, the accumulation of power through profit, the creation of money as a power act, the role of the state in the creation of money, the measure of power as a possible tool for social and political research.
ARTICLE | doi:10.20944/preprints202310.1606.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: cobalt-platinum alloy; L10 phase; CoPt; Co3Pt; exchange coupling; bimetallic nanoparticles; polyol method
Online: 25 October 2023 (11:19:05 CEST)
Bimetallic colloidal CoPt nanoalloys, with a very low platinum content, were successfully synthesized following a modified polyol approach. Powder X-ray diffraction, IR spectroscopy, thermogravimetric analysis, and Transmission Electron Microscopy studies were performed to estimate the crystal structure, morphology and surface functionalization of the colloids respectively, while the room temperature magnetic properties were measured using Vibrating Sample Magnetometer. The particles exhibit excellent uniformity, with a narrow size distribution, and display strong room temperature hysteretic ferromagnetic behavior even in the as-made form. Upon annealing at elevated temperatures, progressive formation and co-existence of exchange coupled both chemically ordered and disordered phases, significantly enhance the room temperature coercivity.
ARTICLE | doi:10.20944/preprints202309.1707.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: common wheat; Triticum aestivum L., water deficit; drought; gas exchange; fluorescence; water regime
Online: 26 September 2023 (05:00:41 CEST)
Water deficit (drought) is still one of the most important stress factors affecting not only yields, but also production quality. Breeders are focusing on breeding cultivars and crop lines that are more resistant to water shortages. In addition to breeding, for example, for the size of the roots and changes in the color of the leaves, focus on changing the morphotype i.e. long chaff, multirowed ear. It is predicted that wheat genotypes with a morphotype change should be more drought tolerant. Therefore, our research focused on the study of changes in the physiological parameters of wheat (cv. ´Bohemia´) with a changed morphotype (genotypes ´284-17´ [long chaff] and genotype ´29-17´ [multirowed ear]) in relation to exposure to drought. Pigment content, photosynthesis and transpiration rate, water potential were measured in plants irrigated and affected by water deficit. Water deficit was shown to have a statistically significant effect on transpiration rate, photosynthetic rate, water potential and total chlorophyll content. Furthermore, the influence of the genotype on the observed parameters and on the effect of water deficit was demonstrated. Due to the fact that cv. ´Bohemia´, increases during such periods of transpiration, so for this reason it is not suitable for dry areas. Genotype ́29-17 ́ appears promising with respect to drought resistance.
ARTICLE | doi:10.20944/preprints202307.0575.v1
Subject: Physical Sciences, Nuclear And High Energy Physics Keywords: LaBr3 scintillator; gamma ray detection; high counting rate; double charge exchange reactions; NUMEN
Online: 10 July 2023 (10:37:20 CEST)
The G-NUMEN array is the future gamma spectrometer of the NUMEN experiment (Nuclear Matrix Element for the Neutrinoless double beta decay), to be installed around the object point of the MAGNEX magnetic spectrometer at the INFN-LNS laboratory.. This project aims at exploring Double Charge Exchange (DCE) reactions in order to obtain crucial information about the neutrinoless double beta decay (0νββ). The primary objective of the G-NUMEN array is to detect the gamma rays emitted from the de-excitation of the excited states populated via DCE reactions with good energy resolution and detection efficiency, amidst a background composed of transitions from competingreaction channels with far higher cross-sections. To achieve this, the G-NUMEN signalswill be processed in coincidence with those generated by the detection of the reaction ejectiles in the MAGNEX Focal Plane Detector(FPD). Under the expected experimental conditions, G-NUMEN detectors will operate at high counting rates, of the order of hundreds of kHz per detector, while maintaining excellent energy and timing resolutions. The complete array will consist of over 100 LaBr3(Ce) scintillators. Initial tests have been conducted on the first detectors of the array, allowing for the determination of their performance at high rates.
ARTICLE | doi:10.20944/preprints202305.1511.v1
Subject: Engineering, Energy And Fuel Technology Keywords: Keywords: Hydrogen production; PEM electrolyzer; Proton Exchange Membrane; Water electrolysis, Electrolytic hydrogen production
Online: 22 May 2023 (10:56:51 CEST)
Energy demand has exponentially increased with the increase in the world population and ur-banization. Renewable energy is clean, renewable, and environmentally friendly. Hydrogen production through Proton Exchange Membrane (PEM) electrolyzer is an efficient way to produce renewable energy. The efficiency and energy consumption of the PEM electrolyzer depends on the feed water quality. In this report, we study the effect of pH, TDS, and conductivity on hydrogen production as well as energy consumption during the process. pH values (3, 7, 9), TDS values (300ppm, 600ppm, 900ppm), and conductivity values (30mS/cm, 70mS/cm, 100mS/cm) were studied to understand and optimize the hydrogen production using PEM electrolyzer. The in-vestigations showed that hydrogen production is significantly affected by pH, total dissolved solids, and conductivity, and the best levels of each variable were identified by extensive testing. The findings show both the scientific significance of proton exchange electrolysis in meeting the growing energy demands of society as well as the importance of knowing the influence that di-verse conditions have on the creation of hydrogen. Our research, in general, contributes to the expanding body of scientific knowledge on the topic of the effective production of hydrogen and offers useful insights for the continuation of investigation in this field.
ARTICLE | doi:10.20944/preprints202108.0452.v1
Subject: Business, Economics And Management, Finance Keywords: Financial Liberalization, Agriculture Output, Lending Rate, Inflation Rate, Exchange Rate, Commercial bank credit
Online: 23 August 2021 (14:31:05 CEST)
This study examined the relationship between financial sector liberalization and agricultural sector output in Nigeria using annual data spanning the period 1986-2020. Specifically, the objectives of the study are to examine the relationship between lending rate, exchange rate, commercial bank credit to agriculture, inflation rate and agricultural sector output in Nigeria. Ex-post facto research design was employed and the annual time series data were collated from Central Bank of Nigeria (CBN) Statistical Bulletin. The econometrics methods of unit root, co-integration and error correction mechanism were used for the analyses. The outcome of the ADF unit root test show that the variables were stationary. Also the co-integration result showed that there exist co-integration amongst the variables in the model. The results from Error Correction Model indicates that lending rate and inflation rate have a negative relationship on agricultural sector output while exchange rate and commercial bank credit to agriculture have positive relationship on agricultural sector output. Based on these results, this study recommends that government and policy makers in Nigerian should initial policies that will boost investments in the agricultural sector through direct provision of credits to agriculturist and banks should also lend at a very low and subsidized interest rate to enable farmers’ access agricultural loans that will boost agricultural productivity in the economy.
ARTICLE | doi:10.20944/preprints202007.0627.v1
Subject: Medicine And Pharmacology, Pediatrics, Perinatology And Child Health Keywords: Erythrocytapheresis; red blood cell exchange; sickle cell disease; target HbS level; heparin locking
Online: 26 July 2020 (02:22:35 CEST)
The aim of our study was to describe our experience using a Spectra Optia® automated apheresis system in children with sickle cell disease (SCD). We used automated red blood cell exchange (RCE) to treat acute and chronic complications in 75 children with SCD who had a median age of 10 years [7-13]. We analysed 649 exchange sessions. Peripheral venous access was limited in a number of the children, thus requiring a femoral central double‐lumen venous catheter (CVC). We recommend the use of heparin locking, with 500 units in each lumen of a CVC. This method was well tolerated, with few complications during the procedures. For preoperative prevention, all of the patients had achieved a post-RCE HbS level of <30% since this is a mandatory condition imposed by the anaesthesiologist. With a post-RCE Hb level of approximately 10-11 g/dL, a blood exchange volume of ≥32 mL/kg, and an interval between each RCE procedure of ≤30 days, it was able to maintain the residual HbS level below 30%. Despite a target pre‐exchange HbS level of 47%, we did not encounter a single stroke recurrence. Erythrocytapheresis is useful and safe for children with SCD.
ARTICLE | doi:10.20944/preprints201811.0285.v1
Subject: Chemistry And Materials Science, Electrochemistry Keywords: proton exchange membrane water electrolysis; anode catalyst; oxygen evolution reaction; iridium; tin oxide
Online: 12 November 2018 (11:03:24 CET)
We have developed IrOx/M-SnO2 (M = Nb, Ta, and Sb) anode catalysts, IrOx nanoparticles uniformly dispersed on M-SnO2 supports with fused-aggregate structures, which make it possible to evolve oxygen efficiently, even with a reduced amount of noble metal (Ir) in proton exchange membrane water electrolysis. Polarization properties of IrOx/M-SnO2 catalysts for the oxygen evolution reaction (OER) were examined at 80 °C in both 0.1 M HClO4 solution (half cell) and a single cell with a Nafion® membrane (thickness = 50 μm). While all catalysts exhibited similar OER activities in the half cell, the cell potential (Ecell) of the single cell was found to decrease with the increasing apparent conductivities (σapp, catalyst) of these catalysts: an Ecell of 1.61 V (voltage efficiency of 92%) at 1 A cm-2 was achieved in a single cell by the use of an IrOx/Sb-SnO2 anode (highest σapp, catalyst) with a low Ir-metal loading of 0.11 mgIr cm-2 and Pt supported on graphitized carbon black (Pt/GCB) as the cathode, with 0.35 mgPt cm−2. In addition to the reduction of the ohmic loss in the anode catalyst layer, the increased electronic conductivity contributed to decreasing the OER overpotential due to the effective utilization of the IrOx nanocatalysts on the M-SnO2 supports, which is an essential factor in improving the performance with low noble metal loadings.
ARTICLE | doi:10.20944/preprints201809.0432.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: infrared spectroscopy; diffuse reflectance infrared Fourier transform spectroscopy; ion-exchange resin; drinking water
Online: 21 September 2018 (08:29:11 CEST)
Infrared spectroscopy is an effective method for the determination of compositions and concentrations of liquids, with advantages of fast response, no-sampling, flexible in use and is able for on-line monitoring. However, for trace substances in drinking water, such as nitrates and heavy metals, infrared spectroscopy is not sensitive enough for the quantitative and qualitative measurement. In this study, we improved the sensitivity of infrared spectroscopy for nitrite determination by developing an ion-exchange-enhanced diffuse reflectance spectroscopy, which consist of an accessory based on ion-exchange resin for enrichment and a FTIR spectrometer for measurement. Using this method, the limit of detection for nitrate is 1.7 mg/L, which is enough for drinking water sensing. We also verified the quantitative measurement ability of the method. Furthermore, the limit of detection and quantitative measuring range could be adjusted by changing the mass of resin and adsorption time. This study demonstrated the method can be used to detect trace nitrites in drinking water, can be applied in the field, and is sensitive, rapid, and inexpensive with a wide dynamic range.
ARTICLE | doi:10.20944/preprints202311.1841.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: 2D semiconductors; chirality; CdSe nanoplatelets; circular dichroism; amino acids, excitons; ligand exchange, colloidal synthesis
Online: 29 November 2023 (06:11:04 CET)
Chiral semiconductor nanostructures and nanoparticles are promising materials for applications in biological sensing, enantioselective separation, photonics, and spin-polarized devices. Here, we have studied the induction of chirality in atomically thin only 2 monolayers thick CdSe nanoplatelets (NPLs) grown by a colloidal method and exchanged with L-alanine and L-phenylalanine as model thiol-free chiral ligands. We have developed a novel two-step approach to completely exchange the native oleic acid ligands for chiral amino acids at the basal planes of NPLs. We performed an analysis of the optical and chiroptical properties of the chiral CdSe nanoplatelets with amino acids, which was supplemented by an analysis of the composition and coordination of ligands. After the exchange, the nanoplatelets retain HH, LH and SO exciton absorbance and bright HH exciton luminescence. Capping with thiol-free enantiomer amino acid ligands induce pronounced chirality of excitons in the nanoplatelets, as proven by circular dichroism spectroscopy, with high dissymmetry g-factor up to 3.4 × 10−3 achieved for HH excitons in the case of L-phenylalanine.
ARTICLE | doi:10.20944/preprints202311.0252.v1
Subject: Business, Economics And Management, Economics Keywords: resilience; grain supply chain; external supply shock; external cost shock; exchange rate volatility shock
Online: 3 November 2023 (12:56:18 CET)
Grain supply is the lifeblood of a country, and the stability of the supply chain is a crucial prerequisite for ensuring national grain security. This paper draws on the definition of resilience in physics and economics. It takes supply chain fracture resilience, impact resilience, and synergy resilience as the secondary indicators. It constructs a comprehensive evaluation indicator system of the grain supply chain resilience, measures the resilience indicator of China's grain supply chain from 1996 to 2021, and analyzes the role of supply, cost, exchange rate, and other external shocks in influencing the resilience of China's grain supply chain on this basis. The study found that the overall level of China's total grain supply chain resilience has been growing year by year and can be divided into three stages: low-level stabilization stage, continuous growth stage, and high-level stabilization stage. Grain supply chain fracture resilience has been growing steadily, grain supply chain impact resilience fluctuation is more obvious, and grain supply chain synergy resilience has been changing more gently. In the inquiry of the impact of external shocks on the resilience of China's grain supply chain, it was found that world grain exports and the RMB exchange rate have a significant positive impact on China's grain supply chain resilience level, while the international oil price has a significant negative impact. Based on this, the paper puts forward suggestions for ensuring stable production and supply in the grain market, improving the structure of foreign trade in grain, and actively coping with international commodity price shocks.
ARTICLE | doi:10.20944/preprints202310.0711.v1
Subject: Physical Sciences, Quantum Science And Technology Keywords: interference in quantum mechanics; identical particle; equal wavelength interference mechanism; exchange effect interference mechanism
Online: 11 October 2023 (09:37:39 CEST)
The phenomenon of interference is a characteristic of all waves. This paper reviews the interference of classical waves and of matter waves in quantum mechanics. In quantum mechanics, there are two interference mechanisms between identical particles. One is that the de Broglie wavelengths of two interference waves are the same, which is called the equal wavelength interference mechanism. The other is that the wavelengths of interference waves can also be different, in which case there should be an exchange term in additional to the direction term in the wave function. There is a fixed phase difference between the two terms, which causes interference. This is called exchange effect interference mechanism. We propose an experiment, which is simpler to what has been done, to show the exchange effect interference. There is a special case where two interference waves can satisfy both the two mechanisms. We propose an experiment to discriminate that in this case which mechanism plays a role on earth.
ARTICLE | doi:10.20944/preprints202211.0108.v1
Subject: Chemistry And Materials Science, Electrochemistry Keywords: diffusion dialysis; concentration; electrodialysis; ion-exchange membrane; separation of acids and salts; acid recovery
Online: 7 November 2022 (06:10:02 CET)
In the present study, the problem of the sulfuric acid recycling from spent copper plating solution was solved using a hybrid membrane technology, including diffusion dialysis and electrodialysis. A real solution from the production of copper-coated steel wire, containing 1.45 mol/L of sulfuric acid, 0.67 mol/L of ferrous sulfate and 0.176 mol/L of copper sulfate was processed. Diffusion dialysis with anion-exchange membranes was used to separate sulfuric acid and salts of heavy metals. Then purified dilute sulfuric acid was concentrated by electrodialysis. Energy consumption for sulfuric acid electrodialysis concentration at a current density of 400 A/m2 was 162 W·h/mol with current efficiency 16 %. After processing according to the hybrid membrane scheme, the solution contained 1.13 mol/L sulfuric acid, 0.077 mol/L ferrous sulfate and 0.022 mol/L copper sulfate. The resulting acid solution with a small amount of ferrous sulfate and copper sulfate met the established requirements for a copper plating bath solution and can be reused in production.
ARTICLE | doi:10.20944/preprints202201.0180.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: ion-exchange membrane; electric conductivity; diffusion permeability; permselectivity; structure–properties relationship; modification; microheterogeneous model
Online: 12 January 2022 (17:53:23 CET)
Ion-exchange membranes (IEMs) are widely used in desalination, waste water treatment, food, energy production and other applications. There is a strong demand for cost-effective IEMs characterized by high selective transport of ions of a certain sign of charge. In this paper, we simulate the experimental results of V. Sarapulova et al. (IJMS 2021) on the modification of an inexpensive anion-exchange membrane (CJMA-7, Hefei Chemjoy Polymer Materials Co. Ltd., China) with a perfluorosulfonated ionomer (PFSI). The modification was made in several stages including keeping the membrane at a low temperature, applying a PFSI solution on its surface, and subsequent drying it at an elevated temperature. We apply the known microheterogeneous model with some new amendments to simulate each stage of the membrane modification. It has been shown that the PFSI film formed on the membrane-substrate does not affect significantly its properties due to the small thickness of the film (4 m) and similar properties of the film and substrate. The main effect is caused by the fact that PFSI material “clogs” the macropores of the CJMA-7 membrane, thereby blocking the transport of coions through the membrane. In this case, the membrane microporous gel phase, which has a high selectivity to counterions, remains the primary pathway for both counterions and coions. Due to the above modification of the CJMA-7 membrane, the coion (Na+) transport number in the membrane equilibrated with 1 M NaCl solution decreased from 0.11 to 0.03. Thus, the modified membrane becomes comparable in its transport characteristics with more expensive IEMs available on the market.
ARTICLE | doi:10.20944/preprints202005.0117.v1
Subject: Medicine And Pharmacology, Epidemiology And Infectious Diseases Keywords: Coronaviruses; Blockchain Technology; COVID-19; Smart Contracts; Data Exchange; Secure; Distributed Ledger Technology; Healthcare
Online: 7 May 2020 (10:10:00 CEST)
WHO was informed on 31 December 2019 of cases of unknown cause pneumonia in Wuhan City, China. On 7 January 2020 Chinese authorities reported a novel coronavirus as the cause and was temporarily labeled "2019-nCoV." Coronaviruses (CoV) are a wide family of viruses which cause diseases ranging from common cold to more serious illnesses. A novel coronavirus (nCoV) is a new strain not previously found in humans. Countries around the globe have stepped up their surveillance to quickly detect any new 2019-nCoV cases. Blockchain is developing into a safe and efficient network for secure data sharing in applications such as the financial industry, operations management, food industry, energy market, the Internet of Things and healthcare. In this paper, we are using blockchain technology as a mean to share authentic data, tracking of relevant information and help speed up the treatment process. At the same time it will preserve person’s identity. Timely deployment and suitable implementation of the proposed model have the opportunity to curb COVID-19 transmissions and associated mortality, especially in environments with inadequate access to testing facilities. This work will also facilitate in the treatment of other infectious diseases. Smart contract have been designed and implemented using the ethereum blockchain platform which has been presented in this paper. This work would facilitate multiple stakeholders who are involved within the medical system to curb the transmission of this disease.
ARTICLE | doi:10.20944/preprints201809.0393.v1
Subject: Engineering, Energy And Fuel Technology Keywords: exchange current; energy efficiency; heat generation; attached biomass; suspended biomass; single chamber air-cathode
Online: 20 September 2018 (04:10:40 CEST)
The model proposed in this study was based on the assumption that the biomass attached to the anode served as biocatalysts for MFC exoelectrogenesis, and this catalytic effect was quantified by the exchange current density of anode. By modifying the Freter model and combining it with the Butler-Volmer equation, this model could adequately describe the processes of electricity generation, substrate utilization, and the suspended and attached biomass concentrations, at both batch and continuous operating modes. MFC performance is affected by the operating variables such as initial substrate concentration, external resistor, influent substrate concentration, and dilution rate, and these variables were revealed to have complex interactions by data simulation. The external power generation and energy efficiency were considered as indices for MFC performance. The simulated results explained that an intermediate initial substrate concentration (about 100 mg/L under this reactor configuration) needed to be chosen to achieve maximum overall energy efficiency from substrate in the batch mode. An external resistor with the value about that of the internal resistance boosted the power generation, and a resistor with several times of that of the internal resistance achieved better overall energy efficiency. At continuous mode, dilution rate significantly impacted the steady-state substrate concentration level (thus substrate removal efficiency and rate), and attached biomass could be fully developed when the influent substrate concentration was equal to or higher than 100 mg/L at any dilution rate of the tested range. Overall, this relatively simple model provided a convenient way for evaluating and optimizing the performance of MFC reactors by regulating operating parameters.
ARTICLE | doi:10.20944/preprints201809.0062.v1
Subject: Chemistry And Materials Science, Electrochemistry Keywords: Nernst voltage; activation overvoltage; concentration loss; equilibrium potential; exchange current density; net current density
Online: 4 September 2018 (11:56:23 CEST)
Normally, the Nernst voltage calculated from the concentration of the reaction gas in the flow channel is considered to be the ideal voltage (reversible voltage) of the oxyhydrogen fuel cell, but actually it will cause a concentration gradient when the reaction gas flows from the flow channel through the gas diffusion layer to the catalyst layer. The Nernst voltage loss in fuel cells in most of the current literature is thought to be due to the difference in concentration of reaction gas in the flow channel and concentration of reaction gas on the catalyst layer at the time when the high net current density is generated. Based on the Butler-Volmer equation in oxyhydrogen fuel cell, this paper demonstrates that the Nernst voltage loss is caused by the concentration difference of reaction gas in flow channel and on the catalytic layer at the time when equilibrium potential (Galvanic potential) of each electrode is generated.
ARTICLE | doi:10.20944/preprints202309.0719.v1
Subject: Physical Sciences, Optics And Photonics Keywords: atomic co-magnetometer; spin exchange optical pumping; optical pumped magnetometer; magnetoencephalography (MEG); atomic spin gyroscope
Online: 12 September 2023 (05:02:07 CEST)
K-Rb-83Kr based atomic co-magnetometer for measuring moving MEGs is theoretically studied in this paper. Parameters such as the spin exchange rates, the spin dephasing rates and the polarization of the nuclear spins are studied to configure the co-magnetometer. Results show that the nuclear spin could generate around 700 nT magnetic field under which the nuclear spin could compensate wide range of magnetic fields. We also showed the hybrid optical pumping vapor cell fabrication process in this paper. Alkali metals were mixed in a glove box and then was connected to the alkali vapor cell fabrication system. The vapor cell fabrication process is illustrated in this paper.
ARTICLE | doi:10.20944/preprints202307.1190.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: Arabica coffee; drought; genotype; seed; germination; moisture content; seedling vigor; gas exchange; cell membrane stability
Online: 18 July 2023 (08:51:01 CEST)
The coffee plant is highly susceptible to drought, and different genotypes exhibit varying degrees of tolerance to low soil moisture. The current study aims to investigate the connection between drought tolerance and sensitivity in terms of seed traits, germination, and post-germination events, and their influence on the growth and physiology of young coffee plants. Two consecutive experiments were conducted to examine the impact of these factors. In the first experiment, germination performance was examined for three groups of coffee genotypes: relatively tolerant (Ca74140, Ca74112, and Ca74110), moderately sensitive (Ca74158, Ca74165, and CaJ-21), and sensitive (Ca754, CaJ-19, and CaGeisha). The subsequent experiment focused on the growth and physiological responses of two relatively tolerant (Ca74110 and Ca74112) and two sensitive (CaJ-19 and Ca754) genotypes under drought stress condition. The relatively tolerant genotypes showed quicker and more complete germination compared to other groups. This was associated with higher moisture content, higher seed surface area to volume ratio, and higher coefficient of velocity of germination, coefficient of variation of germination time, and germination index. Additionally, the relatively tolerant genotypes showed higher seedling vigor. The results of the second experiment demonstrated superior growth performance in relative tolerant genotypes compared to the sensitive groups. Young plants of coffee belonging to relatively tolerant genotypes exhibited higher growth performance than the sensitive genotypes, with a net assimilation rate strongly correlated to relative water content, leaf number, stomatal conductance, and chlorophyll-a. In addition, a strong correlation was exhibited between the growth of young coffee plants and the surface area to volume ratio of the seeds, as well as the germination percentage. The seedling vigor index showed a strong correlation with net assimilation rate, chlorophyll content, seedling growth, and cell membrane stability. Furthermore, principal component analysis illustrated distinct clustering of genotypes based on their germination and growth-physiological performance. Overall, the findings of this study suggest the importance of seed traits, germination, and post-germination events are integral factors in determining drought tolerance and sensitivity, as well as the growth and physiological responses of adult coffee plants.
ARTICLE | doi:10.20944/preprints202307.0047.v1
Subject: Business, Economics And Management, Finance Keywords: bank asset quality; real GDP; inflation; average lending rate; real exchange rate; changing market conditions
Online: 3 July 2023 (12:54:53 CEST)
This study assesses the dynamic relationship between macroeconomic factors and bank asset quality based on changes in the condition of stock market returns. A Generalized Method of Moments (GMM) model is employed, using panel data from 18 universal banks spanning the period 2007 to 2021. The analysis revealed that the real GDP growth rate, the average lending rate, and the real exchange rate represent a set of macroeconomic factors with a marked influence on banks' asset quality. In addition, a high inflation rate was found to exert an adverse effect on asset quality, as it affects borrowers' financial ability to meet loan repayment obligations. Furthermore, the study verified the existence of a positive relationship between market condition and asset quality, which implies that bank performance adapts to changes in market conditions as posited under the Adaptive Market Hypothesis (AMH). Bank managers should consolidate banks' asset bases during conditions of market stability to withstand periodic market fluctuations to boost trading momentum. Policy recommendations are suggested to foster a conducive business environment for bank stability.
ARTICLE | doi:10.20944/preprints202304.1166.v2
Subject: Computer Science And Mathematics, Probability And Statistics Keywords: Pairwise-order model; D-optimal; A-optimal; M.S.-optimal; particle swarm optimization; Fedorov exchange algorithm
Online: 31 May 2023 (08:45:18 CEST)
For order-of-addition experiments, the response is affected by the addition order of the experimental materials. Consequently, the main interest focuses on creating a predictive model and an optimal design for optimizing the response. Van Nostrand (1995) proposed the pairwise-order (PWO) model for detecting PWO effects. Under the PWO model, the full PWO design is optimal under various criteria but is often unaffordable because of the large run size. In this paper, we consider the D-, A- and M.S.-optimal fractional PWO designs. We first present some results on information matrices. Then, a flexible and efficient algorithm is given for generating these optimal PWO designs. Numerical simulation shows that the generated design has an appealing efficiency in comparison with the full PWO design, though with only a small fraction of runs. Several comparisons with existing designs illustrate that the generated designs achieve better efficiencies, and the best PWO designs and some selected 100% efficient PWO designs generated by the new algorithm are reported.
ARTICLE | doi:10.20944/preprints202305.1726.v1
Subject: Chemistry And Materials Science, Electronic, Optical And Magnetic Materials Keywords: Cu3-3OH complex; pyrazolato ligands; trinuclear complex; Spin Frustration; magnetic susceptibility; antisymmetric exchange; DFT calculations.
Online: 25 May 2023 (03:37:25 CEST)
The synthesis and structural characterization of a new triangular Cu3-3OH pyrazolato complex of formula, [Cu3(μ3-OH)(pz)3(Hpz)3][BF4]2 (1-Cu3), Hpz = pyrazole, is presented. The triangular unit forms a quasi-isosceles triangle with Cu-Cu distances of 3.3739(9), 3.3571(9), and 3.370(1) Å. This complex is isostructural to the hexanuclear complex [Cu3(μ3-OH)(pz)3(Hpz)3](ClO4)2]2 (QOPJIP). A comparative structural analysis with other reported triangular Cu3-3OH pyrazolato complexes has been done, showing that, depending on the pyrazolato derivative, auxiliary ligand or counter-anion can affect the nuclearity and/or the dimensionality of the system. The magnetic properties of 1-Cu3 are analyzed by experimental data and DFT calculation. A detailed analysis is done on the magnetic properties comparing experimental and theoretical data of other molecular triangular Cu3-3OH complexes, showing that the displacement of the μ3-OH- from the Cu3 plane, together with the type of organic ligands, influences the nature of the magnetic exchange interaction between the spin-carrier centers, since it affects the overlap of the magnetic orbitals involved in the exchange pathways. Finally, a detailed comparison of the magnetic properties of 1-Cu3 and QOPJIP was done, which allowed us to understand the differences in their magnetic properties.
ARTICLE | doi:10.20944/preprints202302.0259.v1
Subject: Chemistry And Materials Science, Theoretical Chemistry Keywords: External electric field; reaction selectivity; explosive sensitivity; intermolecular hydrogen exchange concerted reaction; surface electrostatic potential
Online: 16 February 2023 (02:07:32 CET)
Controlling the selectivity of detonation initiation reaction of explosive is a Holy Grail, and it seems to be an “idiot's daydream”, by strengthening external electric field, to reduce the explosive sensitivity. The effects of external electric fields on the initiation reactions in NH2NO2∙∙∙NH3, a model system of the nitroamine explosive with alkaline additive, were investigated at the MP2/6-311++G(2d,p) and CCSD/6-311++G(2d,p) level. The concerted effect in the intermolecular hydrogen exchange is characterized by an index of the imaginary vibrations. Due to the weakened concerted effects by the electric field along the −x-direction opposite to the “reaction axis”, the dominant reaction changes from the hydrogen exchange to 1,3-intramolecular hydrogen transference with the increase of the field strengths. Furthermore, the stronger the field strengths, the higher the barrier heights become, indicating the lower sensitivities. Therefore, by strengthening the field strength and adjusting the orientation between the field and “reaction axis”, not only can the reaction selectivity be controlled, but also the sensitivity can be reduced, in particular under a super-strong field. Thus, a traditional concept, which the explosive is dangerous under the super-strong external electric field, is broken theoretically. Compared to the neutral medium, the low sensitivity of the explosive with alkaline can be achieved under the stronger field. Employing atoms in molecules, reduced density gradient and surface electrostatic potentials, the origin of the reaction selectivity and sensitivity change is revealed. This work provides a new idea to the technical improvement for adding the external electric field into the explosive system.
ARTICLE | doi:10.20944/preprints202206.0170.v1
Subject: Medicine And Pharmacology, Ophthalmology Keywords: Fluid gas exchange; flap closure; idiopathic macular hole; vitrectomy; inverted internal limiting membrane flap technique
Online: 13 June 2022 (05:35:46 CEST)
Purpose: We evaluated the outcomes of fluid-gas exchange (FGE) for long-term flap closure of idiopathic macular hole (MH) after the inverted internal limiting (ILM) flap technique. Methods: We included eyes showed flap closure without complete MH closure, connection of the apart macular tissue, 1 month postoperatively after the inverted ILM flap technique. The eyes stayed at flap closure at 2 months postoperatively further underwent in-office FGE with 16% C3F8. Results: Among 10 eyes, 5 eyes (50%) showed flap closure at 2 months postoperatively further underwent FGE for complete MH closure while the remaining 5 eyes (50%) progressed directly at 2 months postoperatively. The improvement in vision of all flap closure from baseline was significant (p=0.015), with the mean baseline vision was 1.19 [Snellen equivalent (SE), 20/307] ± 0.52 logMAR and the mean final vision being 0.63 (SE, 20/85) ± 0.38 logMAR. The group that underwent FGE showed a better final vision of 0.45 (SE, 20/75) ± 0.23 logMAR than the group that didn’t undergo FGE (0.81 [SE, 20/128] ±0.44 logMAR). All eyes achieved complete MH closure, including the eyes that underwent FGE in a mean period of 5.60 months (range 3-10 months) after the inverted ILM flap technique. The eyes that underwent FGE achieved higher rate of foveal restoration [complete external limiting membrane (ELM): 80%; complete ellipsoid zone (EZ): 60%] than those that didn’t receive FGE (complete ELM: 40%; complete EZ: 10%). Conclusions: Eyes that underwent FGE accelerated complete MH closure and showed better final vision and fovea l restoration.
ARTICLE | doi:10.20944/preprints202108.0526.v1
Subject: Business, Economics And Management, Economics Keywords: exchange rates; arbitrage; trade; LOP; PPP; transaction costs; retail; wholesale; forward; auction; CIP; semantic rules.
Online: 27 August 2021 (14:32:34 CEST)
Semantic rules link purely theoretical terms like “price” and “electron” to things we can measure. Without them, theories cannot be tested empirically. When inappropriate, they produce false rejections. Economists routinely ignore semantic rules. Empirical journal articles essentially never mention them. More to the point, the conventional tests that reject the Law of One Price and Purchasing Power Parity never consider them. As a result, those rejections are unwarranted because such tests use inappropriate semantic rules. Both theories should be restored to not rejected and then retested using the more appropriate semantic rules described here. By using appropriate semantic rules, this paper is able to combine Covered Interest Parity and Purchasing Power Parity into a single theory that links auction markets for financial assets and commodities to auction markets for exchange rates. Using appropriate semantic rules for both theories also explains several puzzles in open economy macroeconomics and opens up broad new vistas for research.
Subject: Business, Economics And Management, Accounting And Taxation Keywords: Foreign Exchange Market, Volatility Spillover, Return Spillover, VAR Framework, Variance Decomposition, Financial Crisis, Financial Interdependence
Online: 8 June 2021 (13:03:39 CEST)
In this paper, we investigate the “statics and dynamics” return and volatility spillovers transmission across developed and developing countries. Quoted against the U.S. dollar, we study twenty-three global currencies over 2005 – 2016. Focusing on the spillover index methodology, the generalised VAR framework is employed. Our findings indicate no evidence of bi-directional return and volatility spillovers between developed and developing countries. However, a unidirectional volatility spillover from developed to developing countries is highlighted. Furthermore, our findings document significant bi-directional volatility spillovers within the European region (Eurozone and non-Eurozone currencies) with the British Pound (GBP) and the Euro (EUR) as the most significant transmitters of volatility. The findings reiterate the prominence of volatility spillovers to financial regulators.
ARTICLE | doi:10.20944/preprints201909.0249.v1
Subject: Physical Sciences, Optics And Photonics Keywords: channel waveguide; proton exchange; fundamental mode; pyroelectric effect; mobile charge; fiber optic gyroscope; phase modulator
Online: 21 September 2019 (09:27:27 CEST)
It is shown that the termination of the channeling of the fundamental radiation mode in the waveguide can be observed upon heating of an optical integrated circuit based on proton exchange channel waveguides formed in a lithium niobate single crystal. This process is reversible, but restoration of waveguide performance takes tens of minutes. The effect of the waveguide disappearance is observed upon rapid heating (5 °C/min) from a low temperature (minus 40 °C). This effect can lead to a temporary failure of navigation systems using fiber optic gyroscopes with modulators based on a lithium niobate crystal
ARTICLE | doi:10.20944/preprints201902.0108.v1
Subject: Chemistry And Materials Science, Surfaces, Coatings And Films Keywords: semiconductor thin films; CSS; ion-exchange; XRD; SEM; p-type carriers; band gap; solar cell
Online: 13 February 2019 (10:24:01 CET)
Stabilized un-doped Zinc Telluride (ZnTe) thin films were grown on glass substrates under vacuum using closed space sublimation (CSS) technique. A dilute copper nitrate solution (0.1/100 ml) was prepared for copper doping known as ion exchange process in the matrix of ZnTe thin film. The reproducible polycrystalline cubic structure of undoped and Cu doped ZnTe thin films with preferred orientation (111) was confirmed by X-rays diffraction (XRD) technique. Lattice parameter analyses verified the expansion of unit cell volume after incorporation of Cu species into ZnTe thin films samples. The micrographs of scanning electron microscopy (SEM) were used to measure the variation in crystal sizes of samples. The energy dispersive X-rays was used to validate the elemental composition of undoped and Cu-doped ZnTe thin films. The bandgap energy 2.24 eV of ZnTe thin film decreased after doping Cu to 2.20 eV may be due to the introduction of acceptors states near to valance band. Optical studies showed that refractive index was measured from 2.18 to 3.24 whereas thicknesses varied between 220 nm to 320 nm for un-doped and Cu doped ZnTe thin film respectively using Swanepoel model. The oxidation states of Zn+2, Te+2 and Cu+1 through high resolution X-ray photoelectron spectroscopy (XPS) analyses was observed. The resistivity of thin films changed from ~107 Ω-cm for undoped ZnTe to ~1 Ω-cm for Cu-doped ZnTe thin film, whereas p-type carrier concentration increased from to respectively. These results predicted that Cu-doped ZnTe thin film can be used as an ideal, efficient and stable intermediate layer between metallic and absorber back contact for the heterojunction thin film solar cell technology.
ARTICLE | doi:10.20944/preprints201901.0097.v1
Subject: Chemistry And Materials Science, Theoretical Chemistry Keywords: 2-Hydroxypropyl-β-cyclodextrin (HPβCD); Replica exchange molecular dynamics (REMD); Conformational change; Cavity self-closure
Online: 10 January 2019 (11:43:44 CET)
2-Hydroxypropyl-β-cyclodextrin (HPβCD) has unique properties to enhance the stability and the solubility of low water-soluble compounds by inclusion complexation. Understanding of the structural properties of HPβCD and its derivatives based on the number of 2-hydroxypropyl (HP) substituents at the a-D-glucopyranose subunits is rather important. In this work, replica exchange molecular dynamics simulations were performed to investigate the conformational changes of single- and double-sided HP-substitution called as 6-HPβCDs and 2,6-HPβCDs, respectively. The results show that glucose subunits in both 6-HPβCDs and 2,6-HPβCDs have lower chance to flip than in βCD. Also, HP groups are occasionally blocking the hydrophobic cavity of HPβCDs, thus hindering the drug inclusion. We found that HPβCDs with high number of HP-substitutions are more likely to be blocked, while HPβCDs with double-sided HP-substitution are even more probable to be blocked. Overall, 6-HPβCDs with three and four HP-substitutions are highlighted as the most suitable structures for guest encapsulation based on our conformational analyses such as structural distortion, radius of gyration, circularity and cavity self-closure of the HPβCDs.
ARTICLE | doi:10.20944/preprints201806.0477.v1
Subject: Chemistry And Materials Science, Organic Chemistry Keywords: radicals; exchange coupling; cross-coupling; broken symmetry DFT; EPR spectroscopy; X-ray crystallography; redox chemistry
Online: 28 June 2018 (15:32:47 CEST)
This work explores the use of Kuhn verdazyl radicals as building blocks in multifunctional molecular materials in an exemplary study, focusing on the magnetic and the electron transfer (ET) characteristics, but also addressing the question whether chemical modification by cross-coupling is possible. The ET in solution is studied spectroscopically whereas solid state measurements afford information about the magnetic susceptibility or the conductivity of the given samples. The observed results are rationalized based on the chemical structures of the molecules, which have been obtained by X-ray crystallography. The crystallographically observed molecular structures as well as the interpretation based on the spectroscopic and physical measurements are backed up by DFT calculations. The measurements indicate that only weak, antiferromagnetic coupling is observed in Kuhn verdazyls owed to the low tendency to form face-to-face stacks, but also that steric reasons alone are not sufficient to explain this behavior. Furthermore, it is also demonstrated that ET reactions proceed rapidly in verdazyls/verdazylium redox couples and that Kuhn verdazyls are suited as donor molecules in ET reactions.
ARTICLE | doi:10.20944/preprints201701.0059.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: cation exchange chromatography; minor milk protein; response surface modeling; simulation; steric mass action (SMA); optimization
Online: 12 January 2017 (09:59:40 CET)
Lactoperoxidase (LP), which is a high-value minor whey protein, has recently drawn extensive attention from research scientists and industry due to its multi-function and potential therapeutic applications. In this study, the separation and optimization of two similar-sized proteins, LP and lactoferrin (LF) were investigated using strong cation exchange column chromatography. Optimization was started with central composite design based experiments to characterize the importance of different decision variables. The three variables used in the optimization were flow rate, length of gradient and final salt concentration in the linear elution gradient step. The obtained empiric functional model represented the effect of the significant factors on the yield as the objective function. Afterwards, the calibrated mechanistic model was employed to predict accurate optimal set of variables. The optimal operating points were found and the results were compared with validation experiments. Predictions respecting yield confirmed a very good agreement with experimental results while keeping purity, a product quality characteristic, equal or above to a predefined value.
ARTICLE | doi:10.20944/preprints201605.0003.v1
Subject: Chemistry And Materials Science, Polymers And Plastics Keywords: poly(lactide-co-glycolide); hydroxyapatite; porous scaffold; microchannel; cell ingrowth; mass exchange; bone tissue engineering
Online: 27 May 2016 (11:25:30 CEST)
Mass transfer restrictions of scaffolds are currently hindering the development of three-dimensional (3D), clinically viable, and tissue engineered constructs. For this situation, a 3D poly(lactide-co-glycolide)/hydroxyapatite porous scaffold, which was much favorable for transfer of nutrients to and waste products from the cells in the pores, was developed in this study. The 3D scaffold had an innovative structure, including macropores with diameters of 300−450 μm for cell ingrowth and microchannels with diameters of 2−4 μm for nutrition and waste exchange. The mechanical strength in wet state was strong enough to offer the structural support. The typical structure was more beneficial for the attachment, proliferation, and differentiation of rabbit bone marrow mesenchymal stem cells (rBMSCs). The alkaline phosphatase (ALP) activity and calcium (Ca) deposition were evaluated on the differentiation of rBMSCs, and the results indicated that the microchannel structure was very favorable for differentiating rBMSCs into maturing osteoblasts. For repairing rabbit radius defects in vivo, there was rapid healing in the defects treated with the 3D porous scaffold with microchannels, where the bridging by a large bony callus was observed at 12 weeks post-surgery. Based on the results, the 3D porous scaffold with microchannels was a promising candidate for bone defect repair.
ARTICLE | doi:10.20944/preprints202301.0354.v1
Subject: Chemistry And Materials Science, Physical Chemistry Keywords: diffusion dialysis; ion-exchange membrane; diffusion permeability; sulfuric acid; nickel sulfate; water flux; osmosis; water permeability
Online: 19 January 2023 (09:22:44 CET)
The application of diffusion dialysis using various types of ion-exchange membranes for the separation of sulfuric acid and nickel sulfate has been evaluated. The process of dialysis separation of a real waste solution from an electroplating facility containing 252.3 g/L of sulfuric acid, 20.9 g/L of nickel ions and small amounts of zinc, iron, copper ions, etc. has been studied. Heterogeneous cation-exchange membrane containing sulfo groups and heterogeneous anion-exchange membranes with different thicknesses (from 145 μm to 550 μm) and types of fixed groups (4 samples with quaternary amino groups and 1 sample with secondary and tertiary amino groups) are used. The diffusion fluxes of sulfuric acid, nickel sulfate, and the total and osmotic fluxes of the solvent are determined. The use of a cation-exchange membrane does not allow separation of the components, since the fluxes of both components are low and comparable in magnitude. The use of anion-exchange membranes makes it possible to efficiently separate sulfuric acid and nickel sulfate. At the same time, the thin dialysis membrane turns out to be the most effective, as well as the membranes with quaternary amino groups, and the membrane with secondary and tertiary amino groups proved to be the least effective.