ARTICLE | doi:10.20944/preprints201704.0131.v1
Subject: Materials Science, Polymers & Plastics Keywords: polyurethane foams; castor oil; crude glycerol; biopolyols
Online: 20 April 2017 (04:27:10 CEST)
Rigid polyurethane foams were synthesized using a renewable polyol from the simple physical mixture of castor oil and crude glycerol. The effect of the catalyst and blowing agent in the foams properties was evaluated. The use of physical blowing agent (cyclopentane and n-pentane) allowed obtaining foams with smaller cells in comparison with the foams produced with a chemical blowing agent (water). The increase of water content caused a decrease of density, thermal conductivity, compressive strength and Young's modulus, which indicates that the increment of CO2 production contributes to the formation of larger cells. Higher amount of catalyst in the foam formulations caused a slight density decrease and an increase small significance of thermal conductivity, compressive strength and Young's modulus values. These green foams presented properties that indicate a great potential to be used as thermal insulation, as density (23 - 41 kg m-3), thermal conductivity (0.0128 – 0.0207 W m-1 K-1), compressive strength (45 - 188 kPa) and Young's modulus (3 - 28 kPa). These biofoams are also environmental friendly alternatives and can aggregate revenue to biodiesel industry, contributing for reduction of this fuel prices.
Subject: Medicine & Pharmacology, Allergology Keywords: Cordyceps militaris; crude polysaccharides; selenium-rich crude polysaccharides; high-fat diet (HFD); obesity; dyslipidemia; hypertriglyceridemia; gut microbiota
Online: 3 December 2020 (10:26:45 CET)
Administration of crude polysaccharides extract from natural product is a promising gut microbiota-targeted approach to preventing obesity and associated metabolic disorders. Dietary restrictions can change the type and number of gut bacteria, which is an important factor in delaying the onset and burden of diseases. This study aimed to investigate the effects of high-yield crude polysaccharides from Cordyceps militaris (CMP) on high-fat diet (HFD) mice model and the gut microbiota community assembly, and to identify whether selenium (Se) addition would improve CMP action mode during cultivation. We found that the CMP treatment ameliorated adipose and liver pathologic morphology and fat accumulation in obese mice, while, SeCMP intervention was not superior than CMP in body mass gain, but notably decreasing serum triglyceride level increased by HFD. The upregulated expression of gene Cyp7a1 in liver and protein UCP1 in brown adipose tissue (BAT) preliminary indicated that the effect might relate to bile acids (BAs) metabolism pathway and thermogenesis. In addition, CMP showed a drastic decrease in the gut microbes which positively correlated with dyslipidemia parameters. Our result reveals the potential of CMP to be used as functional food in the prevention of diet-induced adipose and liver steatosis, so does SeCMP has outstanding capacity of improving dyslipidemia.
ARTICLE | doi:10.20944/preprints202011.0271.v1
Online: 9 November 2020 (10:13:21 CET)
The experiment was conducted in three locations Jari, Chefa and Sirinka of Eastern Amhara to select the best performing varieties, in terms of biomass yield, chemical composition, haulm yield, seed yield and other agronomic characteristics of Glycine max (L.) Merrill grown under the rain- fed condition of lowland areas of Eastern Amhara in a randomized complete block design with tree replications. Twelve released soybean varieties were Afgat ,Belesa-95, Boshe , Cheri , Dhidhessa, Gishama , Gizo, Korme, Pawe-03, katta, Wegayen and Wollo were used as a treatments. The seeds were planted in 40 cm between rows and 10 cm between plants on a plot size of 3.2m*4m. Spacing between blocks and plots were 1 and 0.5m, respectively. The seed rate was 60 kg/ha and a fertilizer rate 100 kg/ha NPS was applied during seed planting. The combined analysis of variance over two years at location Jari for dry matter yield of varieties Afgat, Gizo, Pawe-03, Wogayen and Wollo were significantly higher as compared to other soybean varieties. The combined analysis across locations at Jari and Sirinka (2019-second year) showed that varieties Afgat, Gishama, Gizo, Pawe-03, Wogayen and Wollo had higher dry matter yield and varieties Gishama (3.97 t/ha), Gizo (3.60 t/ha), Pawe-03 (4.04 t/ha) and Wogayen (3.36 t/ha) had higher haulm yield as compared with other varieties. The combined analysis across locations at Jari and Sirinka (2019) showed that varieties Pawe-03(2951 kg/ha), Gizo (2862 kg/ha), Afgat (2859 kg/ha), Gishama (2654 kg/ha),Wollo (2461 kg/ha) and Wogayen (2404 kg/ha) had higher seed yield as compared with other varieties. The variety Wollo gave higher crud protein content in two locations (Jari and Sirinka) .Therefore, varieties Afgat, Pawe-03 and Wollo were recommends for the given areas of Jari , Chefa, Sirinka and could be produced in similar environments for the best of produced optimal amount of dry matter, haulm and seed yield and good protein supplement for production of ruminants.Thus, further researches will be needed to investigate on the utilization of livestock.
ARTICLE | doi:10.20944/preprints202209.0055.v1
Subject: Biology, Other Keywords: Adenocarcinoma HeLa; Anticancer; Apoptosis; Crude extract; Stomopneustes variolaris
Online: 5 September 2022 (09:31:44 CEST)
Cancer is one of the world's most serious health problems and the top cause of mortality today. S. variolaris is a valuable sea creature that has long been used as a folk medicine to cure and prevent ailments. A subcritical water extraction was used method to obtain crude extract from spikes of S. variolaris. The extract had shown antiproliferative effect in HeLa cells with an IC50 of 723.1 ± 9.73 µg/ml, but no toxicity in HEK293. Westernblot was used to detect protein expression; Bax, caspase-8, and IκBα were increased, whereas IKKα and p-NFκB-65(Ser 536) were downregulated. RNA/mRNA expression was revealed by RT-qPCR, and fold changes of caspase-3, cytochrome-c, Bax, Apaf-1, caspase-9, and Bak genes’ expression were raised. Using gel electrophoresis, the treatment groups showed more DNA fragmentation than the control group. GC-MS was used to identify the components in the crude extract; anticancer activity could be attributed to dodecanoic acid, hexadecanoic acid, and tetradecanoic acid content. In conclusion, these results showed the potential use of the crude extract of a spike from S. variolaris with anticancer activity against cervical cancer.
ARTICLE | doi:10.20944/preprints201809.0505.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: renewable energy, microwave, free fatty acid, crude oil
Online: 26 September 2018 (10:31:20 CEST)
A novel method proposed in the production of Calophyllum inophyllum biodiesel has been investigated experimentally. In this study, we report the results of biodiesel processing with electromagnetic induction technology. The method used is to compare the results of Calophyllum inophyllum biodiesel processing between conventional, microwave and electromagnetic induction. The degumming, transesterification, and esterification process of the 3 methods are measured by stopwatch to obtain time comparison data. Characteristics of viscosity, density, and Fatty Acid Metil Ester (FAME) were obtained from testing of a Gas Chromatography-mass Spectrometry (GCMS) at the Polytechnic Chemistry Laboratory of the State of Malang. The results show that the biodiesel produced by this method satisfies the biodiesel standards and their characteristics are better than the biodiesel produced by conventional and microwave methods. The electromagnetic induction method also offers a fast and easy route to produce biodiesel with the advantage of increasing the reaction rate and improving the separation process compared to other methods. This advanced technology has the potential to significantly increase biodiesel production with considerable potential to reduce production time and costs.
ARTICLE | doi:10.20944/preprints202005.0501.v1
Subject: Mathematics & Computer Science, Probability And Statistics Keywords: Crude oil; Global financial crisis; COVID-19; Stock; Returns; Persistence
Online: 31 May 2020 (20:15:29 CEST)
This study investigates the impact of global financial crisis and the present COVID-19 pandemic on daily and weekly Crude oil futures using four variants of ARMA-GARCH models: ARMA-sGARCH, ARMA-eGARCH, ARMA-TGARCH and ARMA- aPARCH with dummy variables We also investigated the persistence, half-life and backtesting of the models. This study therefore seeks to contribute to the body of literature on the impact of global financial crisis and the present COVID-19 pandemic on crude oil futures market. This investigation of the impact of global financial crisis and the COVID-19 on crude oil futures has not been much studied at present. We obtained and analyzed the daily and weekly crude oil futures from secondary sources. Daily crude oil futures used in this study covers the period from the 4th January 2000 to 27th April 2020 while the weekly crude oil futures covered from 2ndJanuary 2000 to 26th April 2020 . The global financial crisis period covered from 2nd July 2007 to 31st March 2009 and the current COVID-19 pandemic covered from 1st January 2020 to 27th April, 2020. The study used both student t and skewed student t innovations with AIC, goodness-of-test fit and backtesting to select the best model. Most of the estimated ARMA-GARCH models are supported by skewed student t distribution while most of the ARMA-GARCH models exhibited high persistence values in the presence of global financial crisis and the COVID-19 pandemic. In the overall, the estimated ARMA(1,0)-eGARCH(2,1) and ARMA(1,0)-eGARCH(2,2) model for daily crude oil futures and weekly crude oil futures respectively have been significantly impacted by the global financial crisis and the Present COVID-19 pandemic while the preferred estimated models also passed the goodness-of-test fit and backtesting.This study recommends shareholders and investors should think outside the box as crude oil futures tend to be affected by global financial crisis and COVID-19 pandemic while countries also that depend mostly on crude oil are encouraged to diversify their economy in other to survive and be sustained during financial and health crisis.
Subject: Social Sciences, Finance Keywords: crude oil; East Asian stock markets; wavelet; copula; dynamic hedging
Online: 7 December 2019 (01:28:25 CET)
This paper examines the dynamic dependence structure of crude oil and East Asian stock markets at multiple frequencies using wavelet and copulas. We also investigate risk management implications and diversification benefits of oil-stock portfolios by calculating and comparing risk and tail risk hedging performance. Our results provide strong evidence of time-varying dependence and asymmetric tail dependence between crude oil and East Asian stock markets at different frequencies. The level and fluctuation of their dependencies increase as time scale increases. Furthermore, we find the time-varying hedging benefits differ at investment horizons and reduced over the long run.
ARTICLE | doi:10.20944/preprints201801.0296.v1
Subject: Social Sciences, Finance Keywords: crude oil price; dollar index; time-varying; key mediating factor
Online: 31 January 2018 (15:52:35 CET)
Using DCC-GARCH and EGARCH model, this paper finds that since 1990, the relationship between crude oil prices and the US dollar index is time-varying, demonstrating a process of “very weak correlation—negative correlation—enhanced negative correlation—weakening negative correlation”, but the existing research does not provide enough reasonable explanation. Therefore, this paper proposed a “key mediating factors” hypothesis which points out that whether there is a common “key mediating factor” is important source of the time-varying relationship between two assets. We argue that market trend and financial market sentiment undertook the role of “key mediating factor” during the period of “2002 to the financial crisis” and “financial crisis to 2013”, while other periods lack the “key mediating factors”.
ARTICLE | doi:10.20944/preprints202108.0312.v1
Subject: Life Sciences, Microbiology Keywords: Komagataeibacter rhaeticus; Bacterial cellulose; Crude glycerol; Minimal medium; Whole-genome analysis; Acetate
Online: 16 August 2021 (08:32:19 CEST)
Komagataeibacter spp. have been used for the bioconversion of industrial wastes and lignocellulosic hydrolysates to bacterial cellulose (BC). Recently studies have demonstrated the capacity of Komagataeibacter spp. in the biotransformation of inhibitors found in lignocellulosic hydrolysates, aromatic lignin-derived monomers (LDMs) and acetate. In general, detoxification and BC synthesis from lignocellulosic inhibitors requires a carbon flow from acetyl-coA towards tricarboxylic acid and gluconeogenesis, respectively. However, the related molecular aspects have not yet been identified in Komagataeibacter spp. In this study, we isolated a cellulose producing bacteria capable of synthesizing BC in a minimal medium containing crude glycerol, a by-product from biodiesel production process. The isolate, affiliated to Komagataeibacter genus, synthesized cellulose in minimal medium containing glucose (3.3±0.3 g/L), pure glycerol (2.2±0.1 g/L) and crude glycerol (2.1±0.1 g/L). Genome assembly and annotation identified four copies of bacterial cellulose synthase operon and genes for redirecting the carbon from central metabolic pathway to gluconeogenesis. According to the genome annotations, a BC production route from acetyl-CoA, a central metabolic intermediate, was hypothesized and was validated using acetate. We identified that when K. rhaeticus ENS9b was grown in minimal medium supplemented with acetate, BC production was not observed. However, in presence of readily utilizable substrate, such as spent yeast hydrolysate, acetate supplementation improved BC synthesis.
ARTICLE | doi:10.20944/preprints202009.0697.v1
Subject: Earth Sciences, Atmospheric Science Keywords: UAV; Structure from Motion; photogrammetry; crude protein; acid detergent fibre; hyperspectral sensing
Online: 29 September 2020 (09:07:02 CEST)
The aim of this research was to test recent developments in the use of Remotely Piloted Aircraft Systems or Unmanned Aerial Vehicles (UAV) to map pasture biomass yield and nutrient status, across a selected range of field sites throughout the rangelands of Queensland. Improved pasture management begins with an understanding of the state of the resource base, UAV based methods can potentially achieve this at improved spatial and temporal scales. This study developed predictive models of both pasture yield and pasture nutrient status. An automated pasture height surface modelling technique was developed, tested and used along with field site measurements of pasture yields, to predict further estimates across each field site. Both prior knowledge and automated predictive modelling techniques were employed to predict pasture yield and nutrition. Pasture height surface modelling was assessed against field measurements using a rising plate meter, results reported correlation coefficients (R2) ranging from 0.2 to 0.4 for both woodland and grassland field sites. Accuracy of the predictive modelling was determined from further field measurements of pasture yield and on average indicated an error of 0.8 t ha-1 in grasslands and 1.3 t ha-1 in mixed woodlands across both modelling approaches. Correlation analyses between measures of pasture quality, acid detergent fibre and crude protein (ADF, CP), and spectral reflectance data indicated the visible red (651 nm) and red-edge (759 nm) regions were highly correlated (ADF R2 = 0.9 and CP R2 = 0.5 mean values). These findings agreed with previous studies linking specific absorption features with grass chemical composition. These results conclude that the practical application of such techniques, to efficiently and accurately map pasture yield and quality, is possible at the field site scale, however further research is needed, in particular further field sampling of both yield and nutrient elements across such a diverse landscape, with the potential to scale up to a satellite platform for broader scale monitoring.
ARTICLE | doi:10.20944/preprints202009.0615.v1
Subject: Engineering, Energy & Fuel Technology Keywords: Polymer-coated nanoparticles; Crude oil recovery; Interfacial tension; Wettability alteration; flow diversion
Online: 25 September 2020 (14:22:21 CEST)
Nanoparticles have been proposed for enhanced oil recovery (EOR). The research has demonstrated marvelous effort to understand the mechanisms of nanoparticles-EOR. Nevertheless, gaps still exist in terms of understanding the improved fluids and fluid-rock interactions by nanoparticles, which are the key driving forces for oil mobilization. This paper investigates four types of polymer-coated silica nanoparticles as additives for water flooding oil recovery in water-wet reservoirs. A series of flooding experiments were performed with nanoparticles at 0.1 wt.% in seawater at ambient conditions. The dynamics of fluids, fluid-rock interface interactions and fluid flow behavior were characterized in order to understand oil recovery mechanisms of nanoparticles. Experimental results showed an increase in oil recovery up to 14.8%-point with nanofluid injection compared to an average of 40% of the original oil in place (OOIP) obtained from control water flood test. Moreover, the nanoparticles mobilized residual oil and incremented oil recovery up to 9.2% of the OOIP. Displacement studies show that no single mechanism could account for the EOR effect with the application of nanoparticles. Instead, the mobilization of oil seemed to occur through a combination of reduced oil/water IFT, change in the rock surface roughness and wettability to more water-wet, and microscopic flow diversion due to clogging of the pores.
BRIEF REPORT | doi:10.20944/preprints201810.0292.v1
Subject: Materials Science, Other Keywords: computational fluid dynamics; glass fiber reinforced composites; heavy crude oil; pressure waves
Online: 15 October 2018 (08:58:29 CEST)
Filament wound composite pipes are frequently used in the field were transmission of high pressured chemical fluids, disposal of industrial wastes, oil and natural gas transmission takes place. In oil and gas industry, the pipelines transporting heavy crude oil are subjected to variable pressure waves causing fluctuating stress levels in the pipes. Computational Fluid Dynamics Analysis was performed using Ansys 15.0 Fluent software to study the effects of these pressure waves on some specified joints in the pipes. Depending on the type of heavy crude oil being used, the flow behavior indicated a considerable degree of stress levels in certain connecting joints, causing the joints to become weak over a prolonged period of use. In this research comparison of various pipe joints was done by using different material and the output result of the stress levels of the pipe joints were checked so that the life of the pipe joints can be optimized by the change of material.
ARTICLE | doi:10.20944/preprints202106.0596.v1
Subject: Earth Sciences, Atmospheric Science Keywords: North Eurasia; crude oil; geochemistry; ICP-MS method; microelement composition; rare-earth elements
Online: 24 June 2021 (09:02:00 CEST)
Emerging of mass-spectroscopy with inductively-coupled plasma (ICP-MS) made possible to study the microelement composition of crude oil and its derivatives (with the limit of detection at the ppt level). We have studied the crude oil composition of some West Siberian and Tatarstan oilfields with the ICP-MS method to detect 50 rare, rare-earth, and other microelements. The elemental composition is reasonably comparable to their concentrations in ultrabasites whereas the contents of most of the elements are low to the limit. On the diagrams of rare-earth elements, one can see the prevalence of light lanthanides and positive europium anomaly. The study shows that crude oils have a specific microelement composition that stands out from other geological systems.
ARTICLE | doi:10.20944/preprints201807.0202.v1
Subject: Engineering, Other Keywords: bioremediation; Ex-situ; Aspergillus niger; Pseudomonas aeruginosa; Total Petroleum Hydrocarbon; crude oil; biostimulant efficiency; Kinetics
Online: 11 July 2018 (13:13:04 CEST)
The study was done to investigate the kinetics of first order bioremediation. The effectiveness of remediating soils polluted with raw crude oil and treated crude oil using Aspergillus niger (fungi) and Pseudomonas aeruginosa (bacteria) were investigated. Eight systems of 500g soil sample were polluted with both raw and treated crude oil. Four systems were polluted with 40g treated crude oil while the other remaining four systems were polluted with 40g raw crude oil. Two systems with raw crude and treated crude were left as control (RCC and TCC). Raw crude samples were treated with Aspergillus niger only (RCA) and Pseudomonas aeruginosa (RCP) while treated crude samples were also treated with same (TCA) and (TCP) only. The last two systems were treated with both Pseudomonas aeruginosa and Aspergillus niger (RCAP and TCAP). The first order bioremediation kinetics and biostimulant efficiency for these systems were studied by monitoring Total Petroleum Hydrocarbon (TPH). At the end of the bioremediation period, the results obtained showed that treated crude oil polluted soil generally remediated faster and better than raw crude oil polluted soil. The highest level of bioremediation occurred in systems amended with both Pseudomonas aeruginosa and Aspergillus niger which had about 98% TPH decrease.
ARTICLE | doi:10.20944/preprints201912.0112.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: apoptosis; necrosis; brown algae,; mitochondria; mg63 cells; fucoidan; molecular weight fraction; crude extract; cell cycle; transmission electron microscopy
Online: 9 December 2019 (03:45:59 CET)
Fucoidan is a brown algae-derived polysaccharide having several biomedical applications. This study simultaneously compares the anticancer activities of crude fucoidans from Fucus vesiculosus and Sargassum filipendula, and effects of low (LMW, 10-50kDa), medium (MMW, 50-100kDa) and high (HMW, >100kDa) molecular weight fractions of S. filipendula fucoidan against osteosarcoma cells. Glucose, fucose and acid levels were lower and sulphation was higher in F. vesiculosus crude fucoidan compared to S. filipendula crude fucoidan. MMW had highest the levels of sugars, acids and sulphation among molecular weight fractions. There was a dose dependent drop in focal adhesion formation and proliferation of cells for all fucoidan-types, but F. vesiculosus fucoidan and HMW had the strongest effects. G1-phase arrest was induced by F. vesiculosus fucoidan, MMW and HMW, however F. vesiculosus fucoidan treatment also caused accumulation in sub G1-phase. Mitochondrial damage occurred for all fucoidan-types, however F. vesiculosus fucoidan led to mitochondrial fragmentation. Annexin V/PI, TUNEL and cytochrome c staining confirmed stress induced apoptosis-like cell death for F. vesiculosus fucoidan but features of stress-induced necrosis-like cell death for S. filipendula fucoidans. There was also variation in penetrability of different fucoidans inside the cell. These differences in anti-cancer activity of fucoidans are applicable for osteosarcoma treatment.
ARTICLE | doi:10.20944/preprints201804.0087.v1
Subject: Biology, Animal Sciences & Zoology Keywords: Mongolian oak cups; ethanol crude extract (ECE); ellagic acid- and kaempferol-derivatives; alloxan-induced rats; type 1 diabetes; hypoglycemic effect
Online: 8 April 2018 (08:45:39 CEST)
Our previous in vitro reports showed that crude extract prepared with 50% ethanol (ethanol crude extract, ECE) from Mongolian oak cups possessed excellent antioxidant capacities as well as inhibitory activities against α-glucosidase, α-amylase and protein glycation caused by its enrichment in phenolics, including mainly ellagic acid, kaempferol and their derivatives. Nevertheless, few in vivo studies on antidiabetic activities of these phenolics were conducted. The present study investigated hypoglycemic effects with normal and diabetic rats being administrated orally without or with ECE at 200 and 800 mg/kg for 15 days. In normal rats, no significant differences were exhibited after ECE administration in body weight, fasting blood glucose level, levels of chelesterol, triglyceride, LDL and AST in serum, organ indexes, and levels of GSH and MDA in organs. In diabetic rats, the fasting blood glucose level, indexes of heart and liver, and levels of chelesterol and triglyceride in serum and MDA in heart tissue were significantly decreased. Moreover, HDL levels in serum and SOD activities in the four organs of diabetic rats were significantly improved after ECE administration at 800 mg/kg. Thus, in addition to inhibiting α-glucosidase, α-amylase and protein glycation reported previously, oak cups might contain novel dietary phytonutrients in preventing abnormal changes in blood glucose and lipid profile and attenuating oxidant stress in vivo. The results also implied that it is ellagic acid, kaempferol and their derivatives enriched in ECE that might play vital roles in managing type 1 as well as type 2 diabetes.
ARTICLE | doi:10.20944/preprints202110.0364.v1
Subject: Engineering, Energy & Fuel Technology Keywords: Artificial Intelligence; Machine Learning; Explainable Artificial Intelligence; Soft Sensors; Industry 4.0; Smart Manufacturing; Cyber-Physical System; Crude Oil Distillation; Debutanization; LPG Purification
Online: 25 October 2021 (15:43:08 CEST)
Refineries execute a series of interlinked processes, where the product of one unit serves as the input to another process. Potential failures within these processes affect the quality of the end products, operational efficiency, and revenue of the entire refinery. In this context, implementation of a real-time cognitive module, referring to predictive machine learning models, enables to provide equipment state monitoring services and to generate decision-making for equipment operations. In this paper, we propose two machine learning models: 1) to forecast the amount of pentane (C5) content in the final product mixture; 2) to identify if C5 content exceeds the specification thresholds for the final product quality. We validate our approach by using a use case from a real-world refinery. In addition, we develop a visualization to assess which features are considered most important during feature selection, and later by the machine learning models. Finally, we provide insights on the sensor values in the dataset, which help to identify the operational conditions for using such machine learning models.