ARTICLE | doi:10.20944/preprints202301.0023.v9
Subject: Physical Sciences, Quantum Science And Technology Keywords: Bell’s theorem; local realism; Bell-CHSH inequalities; quantum correlations; Bell-test experimentsexperiments
Online: 28 March 2023 (05:39:30 CEST)
I demonstrate that Bell's theorem is based on circular reasoning and thus a fundamentally flawed argument. It unjustifiably assumes the additivity of expectation values for dispersion-free states of contextual hidden variable theories for non-commuting observables involved in Bell-test experiments, which is tautologous to assuming the bounds of ±2 on the Bell-CHSH sum of expectation values. Its premises thus assume in a different guise the bounds of ±2 it sets out to prove. Once this oversight is ameliorated from Bell's argument, the bounds on the Bell-CHSH sum of expectation values work out to be ±2√2 instead of ±2, thereby mitigating the conclusion of Bell's theorem. Consequently, what is ruled out by the Bell-test experiments is not local realism but the additivity of expectation values, which does not hold for non-commuting observables in any hidden variable theories to begin with.
ARTICLE | doi:10.20944/preprints202205.0274.v3
Subject: Arts And Humanities, Philosophy Keywords: Bell inequality; locality; nonlocality; realism; counterfactual definiteness
Online: 17 August 2022 (11:43:24 CEST)
We present a pragmatic analysis of the different meanings assigned to the term "local realism'' in the context of the empirical violations of Bell-type inequalities since its inception in the late 1970s. We point out that most of them are inconsistent and arise from a deeply ingrained prejudice that originated in the celebrated 1935 paper by Einstein-Podolski-Rosen. We highlight the correct connotation that arises once we discard unnecessary metaphysics.
ARTICLE | doi:10.20944/preprints202205.0015.v4
Subject: Physical Sciences, Quantum Science And Technology Keywords: Bell inequality; locality; nonlocality; local causality
Online: 6 April 2023 (09:19:32 CEST)
Through a historical analysis of John Stewart Bell's works, we confront a stance that distorts his views on the nature of quantum theory, more concretely, on quantum nonlocality. We briefly analyze Bell's arguments for quantum nonlocality as he developed them from 1964 until his sudden and unexpected death in 1990. As is well known, the alleged nonlocal character of quantum mechanics is inextricably related to the formulation of the Bell theorem. However, the departure from the clear line of reasoning that John Bell tried to convey has led to a polarization of part of the scientific community into radical irreconcilable positions. We show how the correct appreciation of Bell's work calls for reinterpreting the usual significance given to the Bell theorem yielding a more rational perspective of the problem. We formalize the correct argument sustaining the nonlocal character of quantum mechanics and comment on alternatives that may justify considering quantum mechanics as a local theory.
ARTICLE | doi:10.20944/preprints201809.0205.v1
Subject: Physical Sciences, Quantum Science And Technology Keywords: Bell-inequalities; quantum nonlocality; computer simulations of Bell tests; local causality; contextuality loophole; photon identification loophole
Online: 12 September 2018 (01:06:46 CEST)
Bell type inequalities are proven using oversimplified probabilistic models and/or counterfactual definiteness (CFD). If setting-dependent variables describing measuring instruments are correctly introduced none of these inequalities may be proven. In spite of this a belief in a mysterious quantum nonlocality is not fading. Computer simulations of Bell tests allow studying different scenarios how the experimental data might have been created. They allow also to generate outcomes of various counterfactual experiments such as repeated or simultaneous measurements performed in different settings on the same ‘’ photon-pair” etc. They allow reinforcing or relaxing CFD- compliance and /or to study the impact of various “photon identification procedures” mimicking those used in real experiments. Using a specific setting- dependent identification procedure data samples consistent with quantum predictions may be generated. It reflects an active role of instruments during the measurement process. Each setting dependent data samples are consistent with specific setting –dependent probabilistic models which may not be deduced using non-contextual local realistic or stochastic hidden variables. In this paper we discuss the results of these simulations. Since the data samples are generated in a locally causal way, these simulations provide additional strong arguments for closing the door on quantum nonlocality
ARTICLE | doi:10.20944/preprints201708.0090.v1
Subject: Computer Science And Mathematics, Algebra And Number Theory Keywords: Bell number; Bell polynomial; generalization; explicit formula; inversion formula; inversion theorem; Stirling number; Bell polynomial of the second kind; determinantal inequality; product inequality; completely monotonic function; logarithmic convexity
Online: 26 August 2017 (09:12:05 CEST)
In the paper, the authors present unified generalizations for the Bell numbers and polynomials, establish explicit formulas and inversion formulas for these generalizations in terms of the Stirling numbers of the first and second kinds with the help of the Faà di Bruno formula, properties of the Bell polynomials of the second kind, and the inversion theorem connected with the Stirling numbers of the first and second kinds, construct determinantal and product inequalities for these generalizations with aid of properties of the completely monotonic functions, and derive the logarithmic convexity for the sequence of these generalizations.
HYPOTHESIS | doi:10.20944/preprints201809.0456.v1
Subject: Chemistry And Materials Science, Physical Chemistry Keywords: glass transitions, universality, Bell-Evans-Polanyi principle
Online: 24 September 2018 (12:44:06 CEST)
The Vogel-Fulcher-Tammann equation is exposed as a particular example of the mean field theory. It is generalized by taking into account an arbitrary critical exponent of susceptibility, discriminating between different classes of universality. The Bell-Evans-Polanyi principle is employed to estimate the difference between the activation energies of flows in crystals and glasses, which appears to coincide with the excess Gibbs energy of the glass compared to the crystal.
ARTICLE | doi:10.20944/preprints202106.0703.v1
Subject: Physical Sciences, Acoustics Keywords: Feynman, Bell, Ballentine, Koopman, two slit experiment, Bell type experiments, classical probability theory, Kolmogorov, conditional versus unconditional probability
Online: 29 June 2021 (12:50:11 CEST)
We start with the discussion on misapplication of classical probability theory by Feynman in his analysis of the two slit experiment (by following the critical argumentation of Koopman, Ballentine, and the author of this paper). The seed of Feynman's conclusion on the impossibility to apply the classical probabilistic description for the two slit experiment is treatment of conditional probabilities corresponding to different experimental contexts as unconditional ones. Then we move to the Bell type inequalities. Bell applied classical probability theory in the same manner as Feynman and, as can be expected, he also obtained the impossibility statement. In contrast to Feynman, he formulated his no-go statement not in the probabilistic terms, but by appealing to nonlocality. This note can be considered as a part of the author's attempts for getting rid off nonlocality from quantum physics.
ARTICLE | doi:10.20944/preprints202203.0382.v1
Subject: Engineering, Mechanical Engineering Keywords: CFRP; vacuum infusion; water absorption; tensile test; bending test; compressive test
Online: 29 March 2022 (12:22:53 CEST)
This research aims to investigate the carbon fiber reinforced polymer (CFRP) when subjected to tensile, bending, and compression. Half of the specimens are also subjected to water to find out how water influences. The CFRP is created using a combination of carbon fiber layers and epoxy resin Bisphenol A Epichlorohydrin with hardener and is formed using the vacuum infusion method. From the water absorption test, it was found that the average weight gain of the specimens was 2.9% and the lowest value was at 0.6%, it was concluded that the increase in wet specimen weight was not too significant and water absorption tended to be slow. Mechanical testing ob-tained the highest average tensile stress, bending stress, compressive stress, and modulus of elasticity of 195 MPa, 295 MPa, 96 MPa, and 8914 MPa were from dry specimens while the lowest average values were 146 MPa, 286 MPa, 81 MPa, and 6160 MPa from wet specimens. The results of micro-photo observations on the tensile test fracture show that the specimen has a XGM fracture character with delamination and splitting fractures happening in multiple areas. In the bending test, the specimens experienced buckling fracture due to the fiber breaking and the inability of the matrix to withstand the additional stress. Shear fracture happened during the compressive test. In conclusion, water absorption has a bad impact towards the composite strength.
ARTICLE | doi:10.20944/preprints202004.0036.v1
Subject: Physical Sciences, Mathematical Physics Keywords: Bell theorem; Local function computer program; Violation CHSH
Online: 3 April 2020 (15:29:01 CEST)
If a clear and valid no-go for Einsteinian hidden parameters is real, it must in no way be possible to violate the CHSH with a local hidden variables based computer simulation. In the paper we show that with the use of a modied Glauber-Sudarshan method it is possible to violate the CHSH.The criterion value comes close to the quantum value and is approximately 2.4. The proof (POC) is presented with the use of an R computer program. The important snippets of the code are discussed and the complete code is presented in an appendix.
ARTICLE | doi:10.20944/preprints201705.0103.v1
Subject: Physical Sciences, Quantum Science And Technology Keywords: negativity; quantum discord; violation of bell inequalities; decoherence
Online: 12 May 2017 (05:30:28 CEST)
Quantum Correlations are studied extensively in quantum information domain. Entanglement Measures and Quantum Discord are good examples of these actively studied correlations. Detection of violation in Bell inequalities is also a widely active area in quantum information theory world. In this work, we revisit the problem of analyzing the behavior of quantum correlations and violation of Bell inequalities in noisy channels. We extend the problem defined in  by observing the changes in negativity measure, quantum discord and a modified version of Horodecki measure for violation of Bell inequalities under amplitude damping, phase damping and depolarizing channels. We report different interesting results for each of these correlations and measures. All these correlations and measures decrease under decoherence channels, but some changes are very dramatical comparing to others. We investigate also separability conditions of example studied states.
ARTICLE | doi:10.20944/preprints201908.0213.v1
Subject: Computer Science And Mathematics, Algebra And Number Theory Keywords: Central Bell polynomials; central factorial numbers; degenerate central Bell polynomials; Stirling numbers of the first kind; special numbers; special polynomials.
Online: 20 August 2019 (11:13:05 CEST)
In this paper, we firstly consider extended degenerate central factorial numbers of the second kind and provide some properties of them. We then introduce unified degenerate central Bell polynomials and numbers and investigate many relations and formulas including summation formula, explicit formula and derivative property. Moreover, we derive several correlations for the fully degenerate central Bell polynomials associated with the degenerate Bernstein polynomials and the degenerate Bernoulli, Euler and Genocchi numbers.
ARTICLE | doi:10.20944/preprints202304.0444.v1
Subject: Engineering, Civil Engineering Keywords: Dowels and cramps; Diagonal compression test; Multi-leaf stone wall; shear test; Compression test
Online: 17 April 2023 (10:26:23 CEST)
This study discusses the experimental assessment of the in-plane mechanical behavior of a multi-leaf stone masonry wall built from cut stone and reinforced with metal connectors (cramps and dowels). The wall, inspired by conventional multi-leaf stone walls, is meant for use in modern stone masonry buildings. The wall is constructed from two parallel load-bearing walls with a cavity between them, which aims to conceal the installation and insulation needed in modern buildings. The load-bearing walls are connected with cramps and dowels at certain intervals so that the wall works as a single section against horizontal and vertical loads. To characterize the in-plane behavior of the proposed wall, compressive, triplet, and diagonal compression tests were conducted to investigate the compressive strength, shear strength, modulus of elasticity, stiffness, ductility, and energy absorption of the wall. Compared with dry and mortar joint walls, the use of dowels increased the initial shear capacity of the wall by 11 and 19 times, respectively. The application of cramps without curving channels inside the individual stone elements decreased the compressive strength by 18%. The energy absorption of the designed walls with metal connectors was substantially increased to that of the specimens representing conventional stone walls. The results obtained show the applicability of the wall due to its higher shear strength and minimal drop in compressive strength, which is within acceptable limits.
ARTICLE | doi:10.20944/preprints202108.0373.v1
Subject: Engineering, Civil Engineering Keywords: Random filling; slate rock; core; wheel impression test; topographic settlement test; plate bearing test
Online: 18 August 2021 (08:23:11 CEST)
The construction of random fillings from the excavation of medium hardness rocks, with high particle sizes, presents limitations in compaction control. This research applies new control techniques with revised test procedures in the construction of the random fillings core, which constitutes the main part of the embankment, with the bigger volume and provides the geotechnical stability to the infrastructure. The maximum layer thickness researched was 800mm. As there are many types of rocks, this research is applied to metamorphic slates. Quality control has been carried out by applying new research associated with the revision of wheel impression test, topographic settlements and plate bearing test (PBT). A statistical analysis of the core of 16 slate random fillings has been carried out, with a total of 2250 in situ determination of density and moisture content, 75 wheel impression tests, 75 topographic settlement control and 75 PBT. The strong associations found between different tests have allowed to simplify the quality control.
ARTICLE | doi:10.20944/preprints201801.0118.v1
Subject: Physical Sciences, Mathematical Physics Keywords: Maximally multiqubit entangled state; Bell-pair state; CNOT gates
Online: 12 January 2018 (17:19:05 CET)
We propose a novel protocol to build a maximally entangled state based on controlled-not (CNOT) gates. In particular, we give detailed steps to construct maximally entangled state for 4-, 5-, and 6-qubit systems. The advantage of our method is the simple algebraic structure which can be realized via current experimental technology.
ARTICLE | doi:10.20944/preprints201705.0099.v1
Subject: Computer Science And Mathematics, Computer Science Keywords: quantum discord; entanglement; negativity; violation of Bell inequalities; decoherence
Online: 11 May 2017 (16:05:33 CEST)
Quantum Correlations are studied extensively in quantum information domain. Entanglement Measures and Quantum Discord are good examples of these actively studied correlations. Detection of violation in Bell inequalities is also a widely active area in quantum information theory world. In this work, we revisit the problem of analyzing the behavior of quantum correlations and violation of Bell inequalities in noisy channels. We extend the problem defined in a recent study by observing the changes in negativity measure, quantum discord and a modified version of Horodecki measure for violation of Bell inequalities under amplitude damping, phase damping and depolarizing channels. We report different interesting results for each of these correlations and measures. All these correlations and measures decrease under decoherence channels, but some changes are very dramatical comparing to others. We investigate also separability conditions of example studied states.
COMMUNICATION | doi:10.20944/preprints202107.0500.v1
Subject: Engineering, Automotive Engineering Keywords: Clinching; binding mechanism; process chain; torsion test; electrical test
Online: 21 July 2021 (15:33:17 CEST)
The multi-material design and the adaptability of a modern process chain require joining connections with specifically adjustable mechanical, thermal, chemical or electrical properties, whereby previous considerations have focused primarily on the mechanical properties. With clinching, the multitude of possible combinations of requirements, materials and component or joint geometry makes it impossible to determine these joint properties empirically. As a result of the established and empirically based procedure, no model exists to date that considers all questions of joinability, i.e. the materials (suitability for joining), the design (joining safety) and the production (joining possibility) and allows a calculation of the achievable properties. It is therefore necessary to describe the physical properties of the joint as a function of the three bonding mechanisms force closure, form closure and material closure in relation to the application. This approach enables the illustration of the relationships along the causal chain "joint requirement - binding mechanism - joining parameters". In this way the adaptability of the mechanical joining technology can be improved. A geometric comparison is made using metallographic cross sections, of clinched joints of the combination of aluminum and steel. The torsional testing of the rotationally symmetric clinching points for detection of the mechanical stress state are qualified as examination method and technological test. By measuring the electrical resistance in the base material, in the clinch joint and during the production cycle (after clinching, before precipitation hardening and after precipitation hardening), this change in the stress state can also be detected.
REVIEW | doi:10.20944/preprints201811.0405.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: immunoassay; rapid test; point-of-care testing; immunochromatographic test
Online: 16 November 2018 (11:12:43 CET)
Simultaneous measurement of different substances from a single sample is an emerging issue to achieve efficient and high-throughput detection in several fields of application. Although immunoanalytical techniques have well-established and prevailing advantages over alternative screening analytical platforms, one of the incoming challenges for immunoassay is exactly multiplexing. The Lateral Flow Immunoassay (LFIA) is a leading immunoanalytical technique for onsite analysis thanks to its simplicity, rapidity and cost-effectiveness. Moreover, LFIA architecture is adaptable to multiplexing and therefore candidates as a possible answer to the pressing demand of multiplexing point-of-need analysis. The review present an overview of diverse approaches for multiplex LFIA, with a special focus on strategies based on new types of magnetic, fluorescent and colored labels
Subject: Medicine And Pharmacology, Epidemiology And Infectious Diseases Keywords: COVID-19; RT-PCR test; pre-test probability; positive rate
Online: 5 May 2020 (06:04:41 CEST)
Several articles have reported that the low number of COVID-19 cases in Japan is attributed to the small number of diagnostic RT-PCR tests performed. The criticism is based on the low number of the tests performed, and they suspected there would be more potential cases in Japan. The use of pre-test probability among tested subjects is proposed in order to evaluate of the sufficiency of test availability instead of the number of the tests. The pre-test probability means the average probability, i.e., ‘suspicion level’, of having coronavirus among the tested subject in a country. The higher pre-test probability is regarded as less sufficient opportunity of the tests, and the test availability could be evaluated by the pre-test probability. Thus, potential problems of underestimation of COVID-19 cases by insufficient amount of the test would be clear by using pre-test probability. The comparison of the pre-test probability could be replaced with that of the positive rate of the test because of the linear relationship between them under the assumption of common sensitivity and specificity. Japan shows the third lowest rate (8.6%), and is considered that the considerably sufficient number of the tests have been performed. In conclusion, the positive rate of the test as a surrogate index of the pre-test probability is useful to evaluate the sufficiency of test amount instead of the number of the tests performed. In present, the potential problem of underestimation by insufficient test availability would be less serious in Japan.
ARTICLE | doi:10.20944/preprints201805.0061.v1
Subject: Medicine And Pharmacology, Orthopedics And Sports Medicine Keywords: combined elevation test; musculoskeletal screening test; normative data; swimming; adolescent
Online: 3 May 2018 (09:05:21 CEST)
The Combined Elevation Test (CET) is a musculoskeletal screening technique (MST) replicates the streamline position in swimming and is commonly used in various sports. Although the CET is widely used, no normative data exist within an adolescent population. Therefore, the purpose of this study was to develop a normative data set for the CET within an adolescent population and to evaluate the influence various demographic and anthropometric variables. Data was collected for 416 participants aged between 8 and 18 years old. Age and arm span showed a significant correlation with CET scores (arm span rs (105) = .478, p = .000, age rs (416) = .238 p = .000). Regression analysis further quantified the influence of arm span and age on CET scores accounting for 23.1% and 5.3% of variability respectively. These results can be used as a reference point for clinicians and coaches who are using the CET within their assessment.
ARTICLE | doi:10.20944/preprints202006.0214.v1
Subject: Computer Science And Mathematics, Information Systems Keywords: COVID-19; Prediction model; Pandemic bell curve; India; Different scenarios
Online: 17 June 2020 (09:40:23 CEST)
This paper is an attempt to present a COVID-19 prediction model for India. Lockdown plays an important role in the arrest of community spread of the disease. This was evident from the study of other countries such as Russia, Belgium and Germany, where peak cases were recorded within a month of the imposition of lockdown, that it showed an immediate positive effect. However, in India, even after 65 days of lockdown, there is no decrease in the number of daily new cases reported. There were many models prepared for India and almost all of them were proven wrong by the increase in the number of cases. The model in this paper is prepared using the COVID-19 trend in other countries, population density and the pandemic bell curve. Based on the available data until 24th May 2020, two scenarios have been presented. In one, the peak shall be obtained when the number of daily new cases per million reaches 190 and in the second when the daily new cases per million reach 724. One model predicts the number of cases to reach 1 million by mid-July 2020. The other model predicts the number of cases to peak by mid-July with the total cases reaching 20 million. The predicted cases were compared with the actual cases recorded for the period 25th May to 11th June 2020. It was observed that the actual values matched quite reasonably with the predicted values.
Subject: Physical Sciences, Quantum Science And Technology Keywords: Tsirelson bound; Bell-CHSH inequality; superquantum correlations; quantum information theory
Online: 2 July 2019 (04:24:45 CEST)
To answer Wheeler's question "Why the quantum?" via quantum information theory according to Bub, one must explain both why the world is quantum rather than classical and why the world is quantum rather than superquantum, i.e., "Why the Tsirelson bound?" We show that the quantum correlations and quantum states corresponding to the Bell basis states, which uniquely produce the Tsirelson bound for the Clauser-Horne-Shimony-Holt quantity, can be derived from conservation per no preferred reference frame (NPRF). A reference frame in this context is defined by a measurement configuration, just as with the light postulate of special relativity. We therefore argue that the Tsirelson bound is ultimately based on NPRF just as the postulates of special relativity. This constraint-based/principle answer to Bub's question addresses Fuchs' desideratum that we "take the structure of quantum theory and change it from this very overt mathematical speak ... into something like [special relativity]." Thus, the answer to Bub's question per Fuchs' desideratum is, "the Tsirelson bound obtains due to conservation per NPRF."
REVIEW | doi:10.20944/preprints202305.0369.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: SARS-CoV-2; clinical diagnostics; molecular assays; direct test; indirect test
Online: 5 May 2023 (14:07:20 CEST)
Due to species barriers and poor adaptability to new host environments, few pathogens cause global pandemics. But, SARS-CoV-2 is one exception with its high transmissivity and delayed onset of symptoms. Fortunately, the world was able to tap on the technologies especially the maturing RT-qPCR designed to combat SARS to launch an initial offensive on SARS-CoV-2. These initial efforts may have bought time for scientists to develop more refined diagnostic tests that specifically target SARS-CoV-2. This article describes the effort put forth by the biotech industry and academia in Singapore to develop diagnostic tests that aid the early detection of positive cases, and thereby help contain the virus. Direct tests such as RT-qPCR and antigen rapid test profile the virus nucleic acid and surface proteins, respectively. But, of equal importance in case detection and treatment is serological tests that measure the relative abundance of IgM and IgG which is indicative of infection phase and quality of immune response in positive cases. Other tests such as isothermal amplification, CRISPR-based diagnostics and breath tests are also in development or at initial field deployment, and would undoubtedly provide valuable use experience useful for the development of molecular assays to detect and combat the next pathogen of global concern.
ARTICLE | doi:10.20944/preprints202102.0153.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: Surgical mask; exercise; treadmill test; stress test; Oxygen saturation; Covid19; ECG
Online: 5 February 2021 (10:03:09 CET)
In the context of the COVID-19 Pandemic, the use of surgical masks has become the new normal. The use of these devices in exercise and medical situations has been advocated with the purpose of reducing contagions, but some concerns exist regarding its safety. We performed maximal treadmill stress tests in 12 healthy young subjects, with and without surgical mask use, and measured exercise capacity, oxygen saturation (rest, peak exercise and post-exercise) and electrocardiographic changes. Exercise capacity and Oxygen saturation levels decreased in peak exercise vs rest in a statistically significant manner when mask was used. ECG changes, although not significant, were present in 3 subjects when mask was used and disappeared when the test was made unmasked. We conclude that masked exercise has the potential to cause decreased exercise load and oxygen saturation and potentially cause diagnostic errors in medical exams.
ARTICLE | doi:10.20944/preprints202009.0463.v1
Subject: Physical Sciences, Quantum Science And Technology Keywords: quantum mechanics; probability; quantum logic; uncertainty relation; Bell-Kochen-Specker theorem
Online: 20 September 2020 (14:01:11 CEST)
Max Born's statistical interpretation made probabilities play a major role in quantum theory. Here we show that these quantum probabilities and the classical probabilities have very different origins. While the lat- ter always result from an assumed probability measure, the first include transition probabilities with a purely algebraic origin. Moreover, the gen- eral definition of transition probability introduced here comprises not only the well-known quantum mechanical transition probabilities between pure states or wave functions, but further novel cases. A transition probability that differs from 0 and 1 manifests the typical quantum indeterminacy in a similar way as Heisenberg's and others' un- certainty relations and, furthermore, rules out deterministic states in the same way as the Bell-Kochen-Specker theorem. However, the transition probability defined here achieves a lot more beyond that: it demonstrates that the algebraic structure of the Hilbert space quantum logic dictates the precise values of certain probabilities and it provides an unexpected access to these quantum probabilities that does not rely on states or wave functions.
REVIEW | doi:10.20944/preprints202306.0165.v1
Subject: Public Health And Healthcare, Public Health And Health Services Keywords: Egocentric neglect; Allocentric neglect; Digital therapeutics; Apple cancellation test; Broken hearts test
Online: 2 June 2023 (09:01:01 CEST)
Various therapeutic approaches have been developed for neglect. Many studies have demonstrated the effect of Digital therapeutics(DTx) on neglect. By contrast, only a few studies have reported on the effects of DTx on egocentric and allocentric neglect. In this article, seven studies on DTx of egocentric and allocentric neglect were reviewed. DTx, which was employed in these studies, could be classified as follows: 1) software adaptation in traditional treatment, 2) VR game using the head-mount display as treatment, and 3) development of new digital program like ReMoVES. In addition, more studies and effective results were reported on egocentric neglect than allocentric neglect. In future studies, each effect on egocentric and allocentric neglect should be identified in detail through the appropriate use of differential evaluation and long-term application of independent digital therapeutics.
REVIEW | doi:10.20944/preprints202207.0082.v1
Subject: Computer Science And Mathematics, Applied Mathematics Keywords: ANOVA; homogeneity of variance; Levene’s test; multiple comparison analysis; post hoc test
Online: 6 July 2022 (03:41:23 CEST)
The importance of statistics in biological research is inevitable. The appliance of statistics is the most powerful tool to support the scientific hypothesis and to give credibility to biological research methodology, to interpret convoluted explanations and conclusions based on the research findings. The evidences from literatures point the persistent statistical errors, selection of non-proper statistical test with the consequence of misinterpretation of the scientific results which are published in international journals. One of the most extensively used statistical tests in the field of biology (preclinical and clinical) is analysis of variance (ANOVA). ANOVA test is in place of multiple T-tests to compare the means of more than two groups at a time; and there are some important points which biologists should be aware of them to avoid possible misinterpretation of results with the consequence of wrong conclusion. Accordingly, the aim of the current review is to help biologists to understand the basic concepts of ANOVA test and reach to a more valid interpretation of achieved results.
REVIEW | doi:10.20944/preprints202203.0338.v1
Subject: Computer Science And Mathematics, Probability And Statistics Keywords: COVID-19; rapid testing; test sensitivity; test frequency; testing programs; compartmental models
Online: 25 March 2022 (03:50:14 CET)
Objectives: This paper presents a statistical review of modelling simulations for frequency and sensitivity of COVID-19 testing paradigms. Methods: We performed a review of preprints and published articles on PubMed from January 1, 2020 – March 1, 2021 using the search terms “COVID screening testing”, “COVID testing frequency”, “COVID testing frequency screening” and “SARS-CoV-2 testing frequency”.Results: Several authors’ conclusions support the claim that test frequency and test sensitivity both play a role in reducing SARS-CoV-2 transmission. We highlight the interplay between frequency of testing, test sensitivity and the speed at which test results are available in our review. Conclusions: Evidence suggests that sensitivity and frequency of testing both play a part in decreasing transmission of disease. We conclude that, overall, test sensitivity plays less of a role in reducing disease transmission in a population compared to the frequency of testing and how quickly test results are available.
ARTICLE | doi:10.20944/preprints202011.0328.v1
Subject: Engineering, Automotive Engineering Keywords: Charpy test; PA6; PP; EPDM; simulation; FE analysis; constitutive model; tensile test
Online: 12 November 2020 (08:30:48 CET)
This paper presents results from numerical and experimental investigation on Charpy tests in order to point out failure mechanisms and to evaluate new polymeric blends PP+PA6+EPDM. Charpy tests were done for initial velocity of the impactor of 0.96 m/s and its mass of 3.219 kg and these data were also introduced in the finite element model. The proposed model take into account the system of four balls, including support and the ring of fixing the three balls and it has a finer discretization of the impact area to highlight the mechanisms of failure and their development in time. The constitutive models for four materials (polypropylene with 1% Kritilen, two blends PP+PA6+EPDM and a blend PA6+EPDM) were derived from tensile tests. Running simulations for each constitutive model of material makes possible to differentiate the destruction mechanisms according to the material introduced in the simulation, including the initiation and the development of the crack(s), based on equivalent plastic strain at break (EPS) for each material. The validation of the model and the simulation results was done qualitatively, analysing the shape of broken surfaces and comparing them to SEM images and quantitatively by comparing the impact duration, energy absorbed by the sample, the value of maximum force during impact. The duration of the destruction of the specimen is longer than the actual one, explainable by the fact that the material model does not take into account the influence of the material deformation speed in Charpy test, the model being designed with the help of tests done at 0.016 m/s (1000 mm/min) (maximum strain rate for the tensile tests). Experimental results are encouraging for recommending the blends 20% PP+42% PA6+28% EPDM and 60% PA6+ 40%EPDM as materials for impact protection at low velocity (1m/s). Simulation results are closer to the experimental ones for the more brittle tested materials (with less content of PA6 and EPDM) and more distanced for the more ductile materials (with higher content of PA6 and EPDM).
ARTICLE | doi:10.20944/preprints202008.0534.v1
Subject: Engineering, Civil Engineering Keywords: jute fibre; reinforcement; modified compaction test; California bearing ratio test; stabilization; shear strength
Online: 25 August 2020 (03:30:40 CEST)
Abstract: This paper is focusing on the stabilisation of soil using jute fibre as soil stabilizer. Stabilisation is the process of modifying the properties of a soil to improve its engineering performance and used it for a variety of engineering works. This study examines the potential of soil stabilization with jute fibre when it is cut into roughly 30mm lengths as stabilizer. The varying percentages like 0.5%, 1%, 1.5 and 2% of pieces of jute fibre were used and mixed it with soil. The laboratory tests such as California Bearing Ratio (CBR) test, modified compaction tests and direct shear strength tests have been conducted to observe the change in engineering properties of soil. On the basis of the experiments performed, it can be concluded that the stabilization of soil using 30mm pieces of jute as stabilizer improves the strength characteristics of the soil so that it becomes usable as one of the reinforcing material for the construction of roadways, parking areas, site development projects, airports and many other situations where sub-soils are not suitable for construction.
ARTICLE | doi:10.20944/preprints202306.0445.v1
Subject: Physical Sciences, Applied Physics Keywords: Bell-and-Bloom; atomic magnetometer; Dynamic response; Time-dependent field; Larmor precession
Online: 6 June 2023 (11:26:16 CEST)
The dynamic response of a Bell-and-Bloom magnetometer to a parallel (to the bias field) time-dependent field is modelled beyond the commonly assumed quasi-static regime. The results unveil features that are related to the parametric nature of the considered system. It is shown that a for low-amplitude time-dependent field different operating conditions are possible and that, beside the commonly reported low-pass-filter behaviour, a band-pass response emerges. Moreover, we numerically show that for larger field amplitude the system, due to its parametric nature, has a kind of ``non-linear'' response.
ARTICLE | doi:10.20944/preprints202211.0120.v1
Subject: Physical Sciences, Quantum Science And Technology Keywords: Bell inequalities; Hidden variables; Contextuality; Entanglement; Local realism; Quantum nonlocality; Synchronization; Electrodynamics
Online: 7 November 2022 (11:25:03 CET)
We show that loophole-free Bell-type no-go theorems cannot be derived in theories involving local hidden fields. At the time of measurement, a contextuality loophole appears because each particle’s electromagnetic field interacts with the field of its respective apparatus, preventing the expression of the probability density as a function independent of the orientation of the measuring devices. Then, we use the dynamical evolution of the probability distribution to show that the spin-correlation integral can neither be expressed in terms of initial Cauchy data restricted to the particles. A correlation loophole ensues, which prevents the usage of the non-contextual correlation integrals required to demonstrate the CHSH-Bell inequality. We obtain a new inequality not violated by quantum correlation functions of entangled spin pairs, and propose that Maxwell’s electrodynamic field is the missing hidden variable triggering the coupled nonlinear oscillations of the particles, which bring about the synchronicities observed in the Einstein-Podolsky-Rosen-Bohm (EPRB) experiment.
ARTICLE | doi:10.20944/preprints202304.0725.v1
Subject: Medicine And Pharmacology, Ophthalmology Keywords: visual function; Howell test; alternate Cover test; Thorington test; dissociated phoria state; break value of near point of convergence; degree of stereopsis
Online: 21 April 2023 (11:09:41 CEST)
Purpose: This research, compared the dissociated phoria state at near and distance fixation in free space, using three different techniques; the Howell test, alternate Cover test and Thorington test. Methods: A total of 220 healthy Mexican children from Querétaro, 5.06 to 17.11 years of age, participated in this study. The magnitude of phorias at both distances was quantified using each of the tests, starting from the least to the most disruptive one. The degree of stereopsis, break, and recovery value of the near point of convergence were also analyzed to understand the interaction among them and their impact on the sensorimotor balance of the visual system. Results: Despite their different ways of dissociation, for patients with exophoria or esophoria at near, the alternate Cover test and Thorington provide similar values. If examining the exophoria state at distance, the alternate Cover and Howell test are similar, whereas for the esophoria, the alternate Cover and Thorington give similar results. The break value and the magnitude of exophoria at near can predict the stereopsis degree. The break value and the magnitude of exophoria are related to each other. Gender doesn´t relate to any variable, whereas age, is associated with the degree of stereopsis and the break of NPC. Conclusions: The statistical analysis showed that the alternate Cover and Thorington test, despite their different ways of dissociation, can substitute one another, whereas the Howell test, cannot be interchangeable with the other two. The different way of dissociation this test uses, can be related to the obtained results. By analyzing the crucial elements of the binocular visual system, can help professionals determine the interaction among them and their impact on its sensorimotor balance.
ARTICLE | doi:10.20944/preprints201809.0548.v1
Subject: Engineering, Civil Engineering Keywords: asphalt mixture; low-temperature cracking; tensile strength; strength reserve; flexural strength; Uniaxial Tension Stress Test (UTST); Thermal Stress Restrained Specimen Test (TSRST); Bending Beam Test (BBT); Semi-Circular Bending Test (SCB);
Online: 27 September 2018 (14:43:05 CEST)
In regions with low-temperature action transverse cracks can appear in asphalt pavements as a result of thermal stresses that exceed the fracture strength of materials used in asphalt layers. To better understand thermal cracking phenomenon, strength properties of different asphalt mixtures were investigated. Four test methods were used to assess the influence of bitumen type and mixture composition on tensile strength properties of asphalt mixtures: tensile strength using the Thermal Stress Restrained Specimen Test (TSRST) and the Uniaxial Tension Stress Test (UTST), flexural strength using the Bending Beam Test (BBT) and fracture toughness using the Semi-Circular Bending Test (SCB). The strength reserve behavior of tested asphalt mixtures was assessed as well. The influence of cooling rate on strength reserve was investigated and correlations between results from different test methods were also analyzed and discussed. It was observed that the type of bitumen is a factor of crucial importance to low-temperature properties of the tested asphalt concretes. This conclusion was proved by all test methods that were used. It was also observed that the level of cooling rate influences the strength reserve and, in consequence, resistance to low-temperature cracking. It was concluded that reasonably good correlations were observed between strength results for the UTST, BBT and SCB test methods.
ARTICLE | doi:10.20944/preprints202107.0403.v1
Subject: Engineering, Automotive Engineering Keywords: Processors testing; FPGA; test optimization
Online: 19 July 2021 (10:51:37 CEST)
This paper describes a new optimization methodology of testing vector sets reduction for testing of soft-processor cores and their individual blocks. The deterministic test vectors both for whole core and its individual blocks are investigated that significantly reduce the testing time and amount of test data that needs to be stored on the tester memory. The processor executes an assembler program which together with determined testing vectors ex-ercise its functionality. The new BIST methodology applicable at industrial testing of processor cores, diagnostics and dynamic reconfiguration of FPGA is proposed. This novel methodology combined with dynamic reconfiguration of FPGAs can be profitable applied for missions-critical i.e. FPGAs operate in space, or other difficult condition where are explore on radiation. Experimental results demonstrate that the proposed approach reduces many times testing time.
ARTICLE | doi:10.20944/preprints202211.0342.v1
Subject: Social Sciences, Behavior Sciences Keywords: neuroethology; methodology; sexual differences; aging; Alzheimer’s disease; marble burying test; burrowing test; repetitive behavior
Online: 18 November 2022 (01:08:33 CET)
Burying and burrowing are promising rodent-typical behaviors to model neuropsychiatric symptoms (NPS). However, the original tests could be insufficient to conclude which NPS are modeled. Here, we propose methodological modifications such as the two-zone configuration and dual analysis in the Marble Burying Test (MB). Also, a new Brief Burrowing Test (BB), a 20 min brief version of the Deacon’s Burrowing Test (DB). We comprehensively studied these behaviors in 12-month-old male and female mice with normal and Alzheimer’s disease (AD)-pathological aging. The results: 1) confirm our precedent report of sexual dimorphism, with enhanced burying in male 3xTg-AD mice; 2) describe for the first time burrowing behavior in 3xTg-AD mice and its sex dependence; 3) regardless of the pattern, MB and BB reflected a goal-directed rather than an indiscriminate digging; 4) using the MB and BB to model anxiety-like behavior it’s not recommended; 5) burying and burrowing represent a repetitive rather than a stereotyped-like or perseverative behavior. In addition: 1) burying and burrowing behavioral patterns are alike, connected by several correlations; 2) the two-zones configuration is a useful tool to assess the intentionality of the burying and burrowing behaviors and to perform a more accurate screening of the NPS modeled by them.
ARTICLE | doi:10.20944/preprints202111.0521.v1
Subject: Physical Sciences, Radiation And Radiography Keywords: Multi-beam profile fast test method; Phased array antenna; Source reconstruction; Antenna test method
Online: 29 November 2021 (11:34:30 CET)
The testing requirements of the active phased array antennas are very different from those of traditional passive antennas, due to its beam steering capability. Usually, each beam profile of the active phased array needs a separate radiation pattern test, which makes the overall testing time extremely long. Thus the traditional antenna test method can no longer meet the efficiency and cost requirements of new active phased array antennas test. In this paper, a fast test method tailored for phased array antennas is proposed that offers significantly reduced testing time at the expense of slight sacrifice of the accuracy. Using the simulated element pattern in array and ideal port excitation, the beam profile in any direction can be predicted by testing only a certain beam profile. Through theoretical derivation and experiments, the effectiveness of the method is verified, and the testing efficiency of the phased array antenna is demonstrated to be improved by ten times or even more.
ARTICLE | doi:10.20944/preprints202006.0234.v1
Subject: Engineering, Civil Engineering Keywords: fiber reinforced concrete; direct tensile test; push-off test; polyolefin fiber; digital image correlation
Online: 19 June 2020 (04:24:48 CEST)
This work proposes a novel methodology for the complete characterization of fiber reinforced concrete (FRC). The method includes bending tests of prismatic notched specimens, based on the Standards for FRC, tensile and pure shear tests. The values adopted by the standards for designing FRC are the obtained from bending tests, typically fR3, even for shear and pure tension loading. This paper shows that the remaining strength of FRC, supplied by the fibers, depends on the type of loading. In the case of shear and tensile loading the prescriptions of the standards may be unsafe. In this work, the remaining halves of specimens subjected to bending test are prepared and used for shear and tension tests. This means significant savings in specimen preparation and a greater amount of information for structural use of FRC. The results provide relevant information for the design of structural elements of FRC compared with the only use of data supplied by bending tests. In addition, a video-extensometry system was used to analyze the crack generation and cracking patterns. The video-extensometry applied to shear tests allowed the assessment of the sliding values and crack opening values at the crack discontinuity. These values may be quite relevant for the study of the FRC behavior when subjected to shear according to the shear-friction model theories.
ARTICLE | doi:10.20944/preprints201807.0617.v1
Subject: Engineering, Civil Engineering Keywords: Hexagon joint, Helical pile, Bearing capacity, Static pile load test, Dynamic pile load test
Online: 31 July 2018 (10:07:54 CEST)
This study aims to improve the shaft with hexagon joints to be a type not requiring welding or bolts in the static load test . In order to evaluate the bearing capacity of helical piles, two sites were selected to conduct pile installation for the field test and the pile load test. For the pile load test, the static pile load test and the dynamic pile load test were carried out, and torque was measured during pile installation for the field test to compare and analyze expected bearing capacity and thus assess the feasibility of the method for estimating the bearing capacity. The field pile load test revealed the bearing capacity of the gravity grout pile was the same or greater than 600kN in the static pile load test in accordance with AC 358 Code. The non-grout pile showed the bearing capacity the same or smaller than 600kN, suggesting gravity grouting is required. Moreover, the field pile load test was used to establish the bearing capacity equation considering the torque in pile installation, and a small number of samples were used to establish the equation which can be used as a basic data.
ARTICLE | doi:10.20944/preprints201708.0079.v2
Subject: Computer Science And Mathematics, Algebra And Number Theory Keywords: Bell polynomial; Bell number; Bell polynomial of the second kind; higher order derivative; generating function; Faa di Bruno formula; inversion theorem; Stirling number of the first kind; Stirling number of the second kind; explicit formula; inversion formula; logarithmically absolute monotonicity; logarithmically complete monotonicity; determinantal inequality; product inequality
Online: 25 August 2017 (08:41:30 CEST)
In the paper, the author (1) presents an explicit formula and its inversion formula for higher order derivatives of generating functions of the Bell polynomials, with the help of the Faà di Bruno formula, properties of the Bell polynomials of the second kind, and the inversion theorem for the Stirling numbers of the first and second kinds; (2) recovers an explicit formula and its inversion formula for the Bell polynomials in terms of the Stirling numbers of the first and second kinds, with the aid of the above explicit formula and its inversion formula for higher order derivatives of generating functions of the Bell polynomials; (3) constructs some determinantal and product inequalities and deduces the logarithmic convexity of the Bell polynomials, with the assistance of the complete monotonicity of generating functions of the Bell polynomials. These inequalities are main results of the paper.
ARTICLE | doi:10.20944/preprints201708.0044.v1
Subject: Computer Science And Mathematics, Analysis Keywords: identity; Bell polynomial; unnamed polynomial; explicit formula; inversion theorem; Stirling number; binomial coeﬃcient
Online: 11 August 2017 (13:51:05 CEST)
In the paper, using two inversion theorems for the Stirling numbers and binomial coecients, employing properties of the Bell polynomials of the second kind, and utilizing a higher order derivative formula for the ratio of two dierentiable functions, the authors present two explicit formulas, a determinantal expression, and a recursive relation for a sequence of unnamed polynomials, derive two identities connecting the sequence of unnamed polynomials with the Bell polynomials, and recover a known identity connecting the sequence of unnamed polynomials with the Bell polynomials.
ARTICLE | doi:10.20944/preprints201703.0223.v1
Subject: Computer Science And Mathematics, Computer Science Keywords: entanglement; relative entropy of entanglement; negativity; bell inequalities violation; quantum fisher information; optimization
Online: 31 March 2017 (08:14:32 CEST)
The violation of Bell's theorem is a very simple way to see that there is no underlying classical interpretation of quantum mechanics. The measurements made on the photons shows that light signal (information) could travel between them, hence completely eliminating any chance that the result was due to anything other than entanglement. Entanglement has been studied extensively for understanding the mysteries of non-classical correlations between quantum systems. It was found that violation of Bell's inequalities could be trivially calculated and for sets of nonmaximally entangled states of two qubits, comparing these entanglement measures may lead to different entanglement orderings of the states. On the other hand, although it is not an entanglement measure and not monotonic under local operations, due to its ability of detecting multipartite entanglement, quantum Fisher information (QFI) has recently received an intense attraction generally with entanglement in the focus. In this work, we visit violation of Bell's inequalities problem with a different approach. Generating a thousand random quantum states and performing an optimization based on local general rotations of each qubit, we calculate the maximal QFI for each state. We analyze the maximized QFI in comparison with violation in Bell's inequalities and we make similar comparison of this violation with commonly studied entanglement measures, negativity and relative entropy of entanglement. We show that there are interesting orderings for system states.
ARTICLE | doi:10.20944/preprints202203.0040.v1
Subject: Biology And Life Sciences, Virology Keywords: SARS-CoV-2; rapid antigen test; RT-PCR test; COVID-19; image processing; Raspberry Pi
Online: 2 March 2022 (08:06:49 CET)
At-home rapid antigen test (RAT) kits for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are valuable public health tools during the present coronavirus disease (COVID-19) pandemic. They provide fast identification of coronavirus infection, which can help to reduce the transmission rates and burden on the healthcare system. However, they have lower sensitivity when compared with the reverse transcription polymerase chain reaction (RT-PCR) tests. One of the reasons for the lower sensitivity is due to the RAT color indicators being indistinct or invisible to the naked eye after the measurements. For this reason, we propose a systematic approach, through which we investigated anonymously provided at-home RAT kit results by using our in-house open source image processing scripts developed for affordable Raspberry Pi computer and Raspberry Pi HQ camera systems (available at https://github.com/kmiikki/ratcv). Therefore, we aimed at minimizing the human-related analysis errors for such kits. We believe that our framework can contribute to reduced the delayed quarantines of infected individuals and spreading of the current infectious disease.
ARTICLE | doi:10.20944/preprints202009.0570.v1
Subject: Engineering, Civil Engineering Keywords: Asphalt concrete; Glass wool fibers; indirect tensile strength; tensile strength ratio; Kim test; Marshall test
Online: 24 September 2020 (08:01:47 CEST)
Nowadays, in order to improve asphalt pavement performance, durability and reduce environmental pollution caused by asphalt binder, many researchers are studying to modify asphalt concrete (AC) and find alternative paving materials to extend service life of asphalt pavement. One of the successful materials used in a modification of AC are fibers. Different types of fibers have been reinforced in AC mixture and improvements have been observed. This research studies the performance of glass wool fiber reinforced in a dense-graded asphalt mixture. Generally, glass fibers are known to have excellent mechanical properties such as high tensile modulus, 100% elastic recovery and a very high tolerance to heat. The glass wool fibers are commonly used as a thermal insulation material. In this research to evaluate the performance of glass wool fiber in AC, laboratory tests Marshall mix design test, Indirect tensile strength (IDT), Tensile strength ratio (TSR) and Kim test were conducted to determine a proper mix design, tensile properties, moisture susceptibility, rutting and fatigue behaviors. Results show that addition of glass wool fibers does affect the properties of AC mixture. The use of glass wool fibers showed a positive consistence results, in which it improved the moisture susceptibility and rutting resistance of the AC. Also result showed addition of fiber increased tensile strength and toughness which indicates that fibers have a potential to resist distresses that occur on a surface of the road as a result of heavy traffic loading. The overall results showed that addition of glass wool fiber in AC mixture is beneficial in improving properties of AC pavements.
ARTICLE | doi:10.20944/preprints201704.0163.v1
Subject: Engineering, Civil Engineering Keywords: tunnel lining; health assessment; fractal dimension; tunnel-lining crack index; digital inspection test; field test
Online: 26 April 2017 (05:59:58 CEST)
The stability assessment of aged tunnel linings were mainly evaluated based on the visual inspection, and the Tunnel-lining Crack Index (TCI) is one of the most widely used tunnel lining health assessment indexes in Japan. However, the intersection and distribution of cracks, which can influence the stability of tunnel lining greatly, were not considered in the TCI. A new method was proposed for the health assessment of tunnel lining, which evaluate the lining states according to the fractal dimension of cracks. Based on the machine vision-based method, the crack image can be extracted efficiently. The fractal dimension of lining cracks in one span can be obtained in a few minutes. A series of comparative tests and field tests were conducted to evaluate the validity of this new method. The comparative tests confirmed that fractal dimension can characterize the density, width, and distribution of cracks. The results also certificated that the influence of crack width is larger than the crack density. The intersection of cracks, which will increase the risk of lining collapse, can also increase the fractal dimension, whereas the TCI keep constant. The fractal dimensions of tunnel lining cracks were obtained according to the digital inspection test of Hidake Tunnel in Japan for all the 65 spans. Moreover, the TCI was obtained through statistical methods. The correlation between fractal dimension and TCI of tunnel lining was studied. The significance of the new evaluation index is that it can identify some unusual spans of tunnel lining and provide a basis for further internal testing. As a complement to the conventional visual inspection method, the fractal dimension of the cracks is a promising health assessment index.
ARTICLE | doi:10.20944/preprints202211.0030.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: PCR; Salmonella Typhi; Widal Test; BHI
Online: 1 November 2022 (12:43:58 CET)
Salmonella is a foodborne pathogen associated with localized outbreaks that potentially pose a huge risk to the public health in some countries such as Africa and India, especially in the regions lacking health care measures. The focus of the present study is the molecular detection method of salmonella. The study was conducted to identify Salmonella strains by PCR targeting flagellin specific gene from suspected patient’s clinical blood samples. Serologically, Widal test results showed that all serum samples except one patient (ID 7) were positive for O antigen. The serum of three patients (ID 4, 5 and 10) were found to be positive for H and O antigens while one patient (ID 9) showed agglutination for antigen H. The PCR approach used in this study was successful for fast and precise detection of clinically related Salmonella Typhi. Seven samples out of 10 were positive for Salmonella Typhi as fragments of 458-497bp were observed on the gel-agarose 0.8% corresponds to flagellin gene of S. Typhi. Relatively, smaller amplicons of 366-343bp were observed utilizing nested PCR as well, which seems more sensitive than the conventional PCR. Therefore, we recommend the PCR approach performed in this study to be used as a fast, cost-effective, and time-consuming tool for diagnostic purposes of Salmonella.
ARTICLE | doi:10.20944/preprints202210.0384.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: Cognitive Test; Education; Cognitive Impairment; Dementia
Online: 25 October 2022 (09:37:41 CEST)
Introduction:Few robust studies have analyzed association between cognitive tests and the marital status of Mild Cognitive Impairment (MCI) group with ADNI dataset. To test the hypothesis that Rey Auditory Verbal Learning test (RAVLT) cognition performance with marital status is associated with greater odds of MCI group than either RAVLT independently, we used TADPOLE data to evaluate cross-sectional associations between RAVLT performance in immediate response, learning, forgetting, and perception of forgetting with marital status and MCI. Methods: Subjects with MCI and Normal Cognition were included. Logistic regression models indicate associations between four RAVLT subgroups (low and high performance of immediate response, immediate response with learning, performance of immediate response with learning and forgetting, performance of immediate response with learning, forgetting and perception of forgetting) and MCI group. Models adjust for age, sex, race, marital status, ethnicity, education, APOE4 genotype, hippocampus, whole-brain, ventricles and ICV. Results: The sample (n=6560) had a mean age of 77 / 67 years, 44% were female, 58% in MCI group. Only all RAVLT subgroups test with age 61 to 70(OR 0.26, 95% CI 0.15-0.45), age 71 or older(OR 0.07, 95% CI,0.04-0.12), race:black/african american(OR 0.13, 95% CI 0.03-0.52)race:more than one(OR 0.05, 95% CI 0.01-0.24), marital status:never married(OR 0.2, 95% CI 0.12-0.34). Conclusion: Studies are needed to evaluate other cognitive test with missing data within TADPOLE dataset as modifiable risk factor for MCI.
ARTICLE | doi:10.20944/preprints202108.0179.v1
Subject: Engineering, Mechanical Engineering Keywords: aramid fibber; ballistic test; failure mechanism
Online: 9 August 2021 (08:04:46 CEST)
The main objective of this study focuses on designing and testing body protection systems using advanced materials based on aramid fibers, for high impact speeds of up to 410...430 m/s. The investigation of the failure mechanisms identifies issues of protective materials, major challenges and technological problems for efficient development of these systems. The authors presents an investigation on the failure processes and destructive stages of a ballistic package made of succesive layers of LFT SB1plus, taking into account the particular test conditions from NIJ Standard-0101.06 Ballistic Resistance of Body Armor. The main parameter of interest was the backface signature (BFS), but also details of projectile arrest and SEM investigaton could offer arguments in using this material for individual protection.
ARTICLE | doi:10.20944/preprints202008.0343.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: forest environments; forest experience; psychometric test
Online: 15 August 2020 (08:34:05 CEST)
In this study a method for predicting the preferred pleasantness induced by different forest environments, represented by virtual photographs, was proposed and evaluated using a novel Anti-Environmental Forest Experience Scale psychometric test. The evaluation questionnaire contained twenty-one items divided into four different subscales. The factor structure was assessed in two separate samples collected online (sample 1: N = 254, sample 2: N = 280). The internal validity of the four subscales was confirmed using an exploratory factor analysis. Discriminant validity was tested and confirmed using the Amoebic Self Scale (Spatial-Symbolic domain). Concurrent validity was confirmed using the Connectedness to Nature Scale. Predictive validity was based on assessment of pleasantness induced by nine different photographs (control – urban landscapes, forest landscapes, dense forest landscapes), with subscales differently correlated with the level of pleasantness assessed for each photograph. This evaluation instrument is appropriate for predicting preferred pleasantness induced by different forest environments.
ARTICLE | doi:10.20944/preprints202006.0252.v1
Subject: Medicine And Pharmacology, Epidemiology And Infectious Diseases Keywords: Salmonella typhi; control; Widal test; incidence
Online: 21 June 2020 (10:23:15 CEST)
Typhoid fever is a communicable disease transmitted by the bacteria Salmonella typhi, related to serotype paratyphi A, B and C. The disease is of a significant health concern in most developing countries especially Cameroon. Objectives: The study aimed at determining the prevalence and associated risk factors of typhoid fever in children ( 0-18 years) attending the “Deo Gratias” hospital in Douala. Method: A hospital base cross sectional study from August to September 2018 was carried out in patients’ age 0-18 years suffering from typhoid fever at the Deo gratias Catholic hospital. Widal slide agglutination test was the diagnostic test used. Positive tested patients were administered questionnaires to evaluate the level of knowledge, attitude and practice toward the disease, as well as their self-management abilities. Data obtained from respondents was analysed by descriptive statistics. One-way ANOVA and means comparison using Tukey’s test (α = 0.05) was performed to check whether the population of respondents differed significantly across risk factor practices. Results were finally presented on bar charts, tables and pie chart. Results: Typhoid fever was more prevalent in females (52.3%) than in males (47.7%), with a high proportion in the ages 5-9 years (38.6%). A significant difference was observed in population of respondents across risk factor practices. Conclusion: Water quality have a great impact on the burden of typhoid fever among children. The identification of risk factors associated to the disease is of great importance in the development of rational control strategies of the disease.
ARTICLE | doi:10.20944/preprints202110.0347.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: Cannabidiol; S-Ketamine; Sex; Mice strain; Flinders Sensitive Line rats; Tail suspension test; Forced Swim Test.
Online: 25 October 2021 (12:32:45 CEST)
Cannabidiol (CBD) is a non-intoxicating compound extracted from Cannabis sativa, showing antidepressant-like effects in different rodent models. However, inconsistent results have been described depending on the species and the strain used to assess depressive-like behaviour. Moreover, only a few studies have investigated the effect of CBD in female rodents. Therefore, we aimed to i) investigate the effects of CBD in two different strains of mice (Swiss and C57BL/6) and in a rat model of depression based on selective breeding (Flinders Sensitive and Resistant Lines, FSL and FRL) subjected to tests predictive of antidepressant-like effects; and ii) investigate the influence of sex in the effects of CBD in both mice and rats. CBD induced an antidepressant-like effect in male Swiss but not in female Swiss or C57BL/6 mice in the tail suspension test (TST). In male FSL rats, CBD produced an antidepressant-like effect one-hour post-injection. However, in female FSL, CBD induced a bimodal effect, increasing the immobility time at one hour and decreasing it at two hours. Ketamine produced an antidepressant-like effect in male and female FSL rats at different doses. In conclusion, strain, sex, and administration time affect CBD's behavioural response to rodents exposed to tests predictive of antidepressant effects.
TECHNICAL NOTE | doi:10.20944/preprints202001.0045.v3
Subject: Computer Science And Mathematics, Probability And Statistics Keywords: detection-loophole; coincidence-loophole; Bell experiments; quantum entanglement; event-based simulation; EPR-B experiments
Online: 15 April 2021 (13:37:27 CEST)
In this note, I analyze the data generated by M. Fodje's (2013) simulation programs "epr-simple" and "epr-clocked". They were written in Python and published on Github. Inspection of the program descriptions shows that they make use of the detection-loophole and the coincidence-loophole respectively. I evaluate them with appropriate modified Bell-CHSH type inequalities: the Larsson detection-loophole adjusted CHSH, and the Larsson-Gill coincidence-loophole adjusted CHSH (NB: its correctness is conjecture, we do not have proof). The experimental efficiencies turn out to be approximately eta = 81% (close to optimal) and gamma = 55% (far from optimal). The observed values of CHSH are, as they should be, within the appropriately adjusted bounds. Fodjes' detection-loophole model turns out to be very, very close to Pearle's famous 1970 model, so the efficiency is close to optimal. The model has the same defect as Pearle's: the joint detection rates exhibit signaling. Fodje's coincidence-loophole model is actually a clever modification of his detection-loophole model. Because of this, however, it cannot lead to optimal efficiency.
SHORT NOTE | doi:10.20944/preprints201703.0055.v1
Subject: Computer Science And Mathematics, Analysis Keywords: closed form; Stirling polynomial; Stirling number; Bernoulli number; Faá di Bruno's formula; Bell polynomial
Online: 10 March 2017 (10:28:19 CET)
In the paper, by virtue of the Faá di Bruno formula and two identities for the Bell polynomial of the second kind, the authors find a closed form for the Stirling polynomials in terms of the Stirling numbers of the first and second kinds.
ARTICLE | doi:10.20944/preprints202305.0343.v1
Subject: Computer Science And Mathematics, Software Keywords: Modified Condition/Decision Coverage; Decision Coverage; Test Coverage; Test Data; Object Constraint Language; Structured Misuse Case Description.
Online: 5 May 2023 (10:03:55 CEST)
As time continues to advance, the need for robust security threat mitigation has become increasingly vital in software. However, ensuring early effective security threat mitigation requires optimal test data and consistent test case design. It is a constant struggle to maximize test coverage through test data optimization. We conducted explanatory research to maximize test coverage of security requirements as modeled in Structured Misuse Case Description (SMCD) i.e., structured specification of misuse case, so as to improve consistency in optimal test data generation. We specified constraints upon Mal activity in Object Constraint Language (OCL) in order to minimize human dependency and improve consistency in optimal test data generation. It was evident through results that MC/DC generated optimal test data of security threats through SMCD in comparison to the Decision Coverage method thus resulting in designing a significantly lower number of test cases and yet maximizing test coverage of security threats. MC/DC generated test data with n+1, while Decision Coverage generated test data with〖 2〗^n, we, therefore, conclude that MC/DC maximizes test coverage through optimal test data from SMCD in comparison to Decision Coverage.
ARTICLE | doi:10.20944/preprints202206.0196.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: biofilm formation; S. aureus; CRA plating test; CVMP test; ica genes; bap gene; foods; public health; Bangladesh
Online: 14 June 2022 (06:10:13 CEST)
Staphylococcus aureus is a major food-borne pathogen. The ability of S. aureus to produce biofilm is a significant virulence factor triggering its persistence in hostile environments. In this study, we screened a total of 420 different food samples and human hand swabs to detect S. aureus and to determine their biofilm formation ability. Samples analyzed were meat, milk, egg, fish, fast foods, and hand swabs. S. aureus were detected by culturing, staining, biochemical, and PCR. Biofilm formation ability was determined by Congo Red Agar (CRA) plate and Crystal Violet Microtiter Plate (CVMP) tests. The icaA, icaB, icaC, icaD, and bap genes involved in the synthesis of bio-film-forming intracellular adhesion compounds were detected by PCR. About 23.81% (100/420; 95% CI: 14.17-29.98%) samples harbored S. aureus as revealed by detection of the nuc gene. CRA plate revealed 20% of S. aureus isolates as strong biofilm producers, while 69% and 11% as in-termediate and non-biofilm producers, respectively. By the CVMP staining method, 20%, 77%, and 3% of the isolates were found strong, intermediate, and non-biofilm producers. Furthermore, 21% of S. aureus isolates carried at least one biofilm-forming gene, where icaA, icaB, icaC, icaD, and bap genes were detected in 15%, 20%, 7%, 20%, and 10% of the S. aureus isolates, respectively. Bivariate analysis showed high significant correlations (p<0.001) between any of the two adhesion genes of S. aureus isolates. To the best of our knowledge, this is the first study in Bangladesh describing the detection of biofilm-forming S. aureus from foods and hand swabs with molecular-based evidence. Our findings suggest that food samples should be deemed a potential reservoir of biofilm-forming S. aureus that indicates a potential public health significance.
ARTICLE | doi:10.20944/preprints201809.0286.v1
Subject: Chemistry And Materials Science, Surfaces, Coatings And Films Keywords: water jet peening; multifunction cavitation; Hot corrosion; Thermal stress cycle; Cr-Mo steel; embedding test; coating test
Online: 17 September 2018 (08:02:10 CEST)
This research investigated high-temperature corrosion (500 °C) of Cr-Mo steel processed using water jet peening or multifunction cavitation (MFC), and the suitability of such steel for high-temperature boilers and reaction vessels. High-temperature corrosion was induced using an embedment test and a coating test using sulfide-type K2SO4-Na2SO4 powder. To measure the relaxation of the residual stress due to the decrease in work hardening caused by an increase in specimen temperature and the difference in thermal shrinkage between the surface and interior of the specimen, a thermal cycling test was conducted. For the MFC-processed specimen, the oxide film that formed on the surface suppressed mass loss, prevented crack formation, and reduced the compressive residual stress caused by high-temperature corrosion. MFC-processed Cr-Mo steel is thus suitable for a high-temperature corrosion environment.
ARTICLE | doi:10.20944/preprints201807.0193.v2
Subject: Physical Sciences, Applied Physics Keywords: bell states; BSM; EPR pairs; LOCC; no-cloning theorem; quantum communications; quantum entanglement; quantum teleportation
Online: 26 July 2018 (04:59:03 CEST)
A simplified version of the quantum teleportation protocol is presented in here. Its experimental confirmation will have deep implications for a better understanding of Quantum Entanglement with a particular projection on Quantum Communications.
ARTICLE | doi:10.20944/preprints201611.0092.v2
Subject: Computer Science And Mathematics, Artificial Intelligence And Machine Learning Keywords: semantic spatial trajectory; role based access control; Bell-Lapadula model; multi-policy; Web Ontology Language
Online: 17 November 2016 (15:19:51 CET)
With the proliferation of locating devices, more and more raw spatial trajectories are formed, and many works enrich these raw trajectories with semantics, and mine patterns from both raw and semantic trajectories, but access control of spatial trajectories is not considered yet. We present a multi-policy secure model for semantic spatial trajectories. In our model, Mandatory Access Control, Role Based Access Control and Discretionary Access control are all enforced, separately and combined, and we represent the model semi-formally in Ontology Web Language.
ARTICLE | doi:10.20944/preprints202209.0059.v1
Subject: Chemistry And Materials Science, Polymers And Plastics Keywords: PLA-Mg; FTIR; DSC; crystallinity; tensile test
Online: 5 September 2022 (12:53:24 CEST)
The effect of Mg particles on PLA's thermal, chemical, physical, and mechanical properties has been studied. The thermal and physical properties have been studied by differential scanning calorimetry, analysing the stability of the α and α’-crystals of the PLA. A colloidal route was used to introduce Mg particles inside the PLA matrix, ensuring a good dispersion of the particles. Materials with Mg contents from 0 to 10 wt.% have been prepared, with additions of polyethyleneimine (PEI) and polyethylene glycol (PEG). Fourier Transform Infrared Spectroscopy has been used to confirm the influence of Mg, PEI, and PEG on PLA properties. The mechanical properties have been measured with a universal tensile test machine on printed filaments via Fused Filament Fabrication (FFF), which were naturally aged to stable conditions. Filaments with and without a notch were studied to obtain the materials' tensile strength, elastic modulus, and fracture toughness. Different analytical models to explain the results of the PLA-Mg were studied, in which the interface strength of the PLA-Mg composites was calculated.
ARTICLE | doi:10.20944/preprints202203.0066.v1
Subject: Engineering, Electrical And Electronic Engineering Keywords: indoor localization; test and evaluation; methodology; benchmarking
Online: 3 March 2022 (14:00:15 CET)
Despite their enormous potential the use of Indoor Localization Systems (ILS) remains seldom. One reason is the lack of market transparency and stakeholders’ trust in the systems’ performance as a consequence of insufficient use of Test and Evaluation (T&E) methodologies. The heterogeneous nature of ILS, their influences, and their applications pose various challenges for the design of a methodology that provides meaningful results. Methodologies for building-wide testing exist, but their use is mostly limited to associated indoor localization competitions. In this work, the T&E 4iLoc Framework is proposed - a methodology for T&E of indoor localization systems in semi-controlled environments based on a system-level and black-box approach. In contrast to building-wide testing, T&E in semi-controlled environments, such as test halls is characterized by lower costs, higher reproducibility, and better comparability of the results. The limitation of low transferability to real world applications is addressed by an application-driven design approach. The empirical validation of the T&E 4iLoc Framework, based on the examination of a contour-based Light Detection and Ranging ILS, an Ultra Wideband ILS, and a camera-based ILS for the application of Automated Guided Vehicles in warehouse operation, demonstrates the benefits of T&E with the T&E 4iLoc Framework.
ARTICLE | doi:10.20944/preprints202111.0403.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: anticancer agent; cytotoxicity; cell viability test; QSAR
Online: 22 November 2021 (14:18:14 CET)
2-(Morpholin-4-yl)-4,5-bis(2’’,2’’,2’’-trinitroethoxy)-1,3,5-triazine having QSAR-predicted anti-tumor activity was tested for the cytotoxicity using MTT and LDH cell viability tests. The experiments were conducted using human fibroblasts, peripheral blood mononuclear cells and breast cancer cells and allowed to identify effective cytotoxic concentration ant therapeutic range of this compound. The data obtained suggest the feasibility of the further studies of the test compound as a potential anti-cancer agent.
ARTICLE | doi:10.20944/preprints202102.0254.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: Chemical composition; Dry matter digestibility; Gas test
Online: 10 February 2021 (12:32:21 CET)
This investigation was conducted to determine the chemical composition and nutritional value of five plant species commonly used as ruminant feeds namely: Artemisia herba-alba, Acer monspessulanum, Amygdalus lycoides, Amygdalus scoparia, and Atriplex leucoclada. After the collecting samples, the chemical compositions of plants included dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), ash (CA), cell wall (NDF), and non-lignin cell wall (ADF) were determined according to standard methods. For degradation testing, the nylon bag technique was applied using three native Sistani fistula calves. Organic matter digestibility (OMD) and metabolisable energy (ME) were determined through the gas production technique. The CP value ranged from 5.30 (Amygdalus scoparia) to 11.72% (Atriplex leucoclada) while NDF value ranged from 52.62 (Amygdalus lycoides) to 69.05% (Amygdalus scoparia). The range of OMD, DOMD, and ME was from 36.67 to 53.27%, 34.67 to 49.11%, and 5.57 to 8.08 (MJ/kg), respectively. The results showed a positive correlation between cell wall composition and dry matter digestibility in plant species. The nutritional value of Amygdalus lycoides, Atriplex leucoclada, Acer monspessulanum, and Artemisia herba-alba was acceptable composition and digestibility.
ARTICLE | doi:10.20944/preprints202011.0185.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: heart failure; 6-minute walk test; prognosis
Online: 4 November 2020 (10:08:38 CET)
Background: The 6-minute walk test (6MWT) is a simple and low-cost method that allows assessment of functional capacity in patients with heart failure (HF). However, the prognostic role of 6MWT in HF remains uncertain. Objectives: We aimed to evaluate the 6MWT as a predictor of mid-term adverse outcomes in patients with HF with mid-range and reduced ejection fraction. Methods: Prospective single-center cohort study that included patients with HF with an ejection fraction under 50% at a specialized outpatient HF service. Patients underwent the 6MWT on admission and were compared according to the distance walked: Group I walked ≥350 meters and group II <350 meters. The primary outcome was a composite of death from any cause or hospitalization for HF decompensation in one-year follow-up. Secondary outcomes were the components of the primary outcome in an isolated analysis. Results: Sixty patients were included, 43.3% male, with a mean age of 61.1 ± 12.9 years and ejection fraction 34.3 ± 10.1%. 52 patients (86.7%) were on guideline-directed triple therapy for HF. The average distance walked in the 6MWT was 395.1 ± 98.8 meters, with 40 patients (66.7%) in group I and 20 (33.3%) in group II. The primary outcome in groups I and II were, respectively, 15,0% and 35,0% (p=0.05). One-year mortality was 5.0% vs 15.0% (p=0.18) and the hospitalization rate was 10.0% vs 20.0% (p=0.28). Conclusions: There was no association of distance <350 meters in the 6MWT with the primary outcome in patients with HF. Despite the higher occurrence of outcomes in group II, the difference was not statistically significant in this analysis. On a selective basis, the 6MWT may be a useful tool for prognostic stratification in HF, if combined with other methods.
REVIEW | doi:10.20944/preprints202006.0278.v1
Subject: Medicine And Pharmacology, Pulmonary And Respiratory Medicine Keywords: COVID-19; serological diagnostic test; performance evaluation
Online: 21 June 2020 (14:58:20 CEST)
In only a few months after initial discovery in Wuhan, China, SARS-CoV-2 and the associated COVID-19 disease has become a global pandemic causing significant mortality and morbidity. In the absence of vaccines and effective therapeutics, reliable serological testing can be a key element of public health policy to control further spread of the disease and gradually ease quarantine measures. However, prior to launch of large-scale seroprevalence studies to assess herd immunity, it is critical to understand the limits and potential of current SARS-CoV-2 serological tests on the market. In this study, we provide an overview of serological testing and conduct a systematic review of independent evaluations of SARS-CoV-2 serological tests performance. Our findings show significant variability in the accuracy of marketed tests and highlight several lab-based and point-of-care rapid diagnostic tests with high performance level in detecting SRAS-CoV-2 specific antibodies. The findings of this review highlight the need for ongoing independent evaluations of commercialized COVID-19 diagnostic tests.
REVIEW | doi:10.20944/preprints202005.0452.v1
Subject: Social Sciences, Sociology Keywords: Judgement Bias; Personality; Social Status; Test Design
Online: 27 May 2020 (12:10:45 CEST)
The assessment of positive emotional states in animals has been advanced considerably through the use of judgement bias testing. JBT methods have now been reported in a range of species. Generally, these tests show good validity as ascertained through use of corroborating methods of affective state determination. However, published reports of judgement bias task findings can be counter-intuitive and show high inter-individual variability. It is proposed that these outcomes may arise as a result of inherent inter- and intra-individual differences as a result of biology. This review discusses the potential impact of sex and reproductive cycles, social status, genetics, early life experience and personality on judgement bias test outcomes. We also discuss some aspects of test design that may interact with these factors to further confound test interpretation. There is some evidence that a range of biological factors affect judgement bias test outcomes, but in many cases this evidence is limited and needs further characterisation to reproduce the findings and confirm directions of effect. It is our proposition that researchers should consider dedicated study on these factors and their impact on judgement biasing. This is needed to confirm effect and investigate mechanisms. Alternately, consideration and reporting of these factors in JBT studies through incorporation in statistical analyses will provide much needed additional data on their impact. These actions will enhance the validity and practical applicability of the JBT for welfare assessment.
ARTICLE | doi:10.20944/preprints201905.0286.v1
Subject: Physical Sciences, Applied Physics Keywords: shear band, pyrometry, punch test, streak camera
Online: 23 May 2019 (16:26:52 CEST)
This paper presents the development of a new system designed to measure the local temperature field in adiabatic shear band. Transient temperature field are simultaneously recorded by an array of 32 InSb infrared (IR) detectors and a streak camera working in visible-near infrared (VIS-NIR). Observations in IR offer a low temperature detection limit (350°C) but they are highly sensitive to uncertainty in the emissivity. Observations in VIS-NIR allow for measurement only at high temperatures (750°C) but they are less affected by uncertainty on emissivity and present a higher temperature sensitivity. By performing simultaneous measurements, it is possible to obtain data on a large temperature range with an improved accuracy at high temperature. The different sources of errors caused by uncertainty in the emissivity, spatial and temporal resolution of the detectors has been analyzed and an estimation of the total measurement uncertainty of the system is given.
ARTICLE | doi:10.20944/preprints201901.0127.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: metal nanoparticles; laser ablation; antibacterial test; LSPR
Online: 14 January 2019 (07:21:21 CET)
We report the production of metal oxide (TiFe2O4, ZnFe2O4) nanoparticles by pulsed laser ablation technique in liquid environment. We used nano second Nd: YAG laser systems working at 532 nm and 1064 nm of wavelength, the energy of the laser beam was kept constant at 80 mJ. Absorbance spectra, surface plasmon resonance, optical band-gap and nanoparticle morphology were investigated using ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Changing the wavelength of the laser for growth, nanoparticles shown shift between the absorbance and surface plasmon resonance peaks in their UV-Vis spectra, this implies that the optical properties of the colloid nanoparticles depends on laser parameters, this was confirmed with the variation of the band gap energy. Furthermore, red shift for the absorbance peak was observed for samples as-growth at 532 nm around the 150 nm as function of time preparation. Whereas, for the samples as-growth at 1064 nm there is no shift in the absorbance spectra, this can be due to agglomeration and formation of larger particles. The characterization results shown appropriate plasmonic photo-catalysts properties of the particles, hence the photo activation of the nanoparticles was examined on antibacterial effect using colonies of Staphylococcus Aureus and Escherichia coli.
ARTICLE | doi:10.20944/preprints201812.0191.v1
Subject: Engineering, Architecture, Building And Construction Keywords: polymer waste; polyurethane foam; leaching test; microstructure
Online: 17 December 2018 (10:47:59 CET)
In the European Union, the demand for polyurethane is continually growing. In 2017, the estimated production value of polyurethane was 700,400T, of which 27.3% is taken to landfill, which causes an environmental problem. In this paper the behaviour of various polyurethane foams from the waste of different types of industries will be analysed with the aim of assessing their potential use in construction materials. In order to this, the wastes were chemically tested by means of CHNS, TGA, and leaching tests. They were tested microstructurally by means of SEM. The processing parameters of the waste was calculated after finding out its granulometry and its physical properties i.e. density and water absorption capacity. In addition, the possibility of incorporating these wastes in plaster matrices was studied by determining its rendering in an operational context, finding out its mechanical resistance to flexion and compression at 7 days, its reaction to fire as well as its weight per unit of area and its thermal behaviour. The results show that in all cases, the waste is inert and does not undergo leaching. The generation process of the waste determines the foam’s microstructure in addition to its physical-chemical properties that directly affect building materials in which they are included, thus offering different ways in which they can be applied.
ARTICLE | doi:10.20944/preprints201807.0344.v1
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: brazing; alumina dispersion-strengthened copper; mechanical test
Online: 19 July 2018 (05:18:58 CEST)
Alumina dispersion-strengthened copper, Glidcop, is used widely in high-heat-load ultra-high-vacuum components for synchrotron light sources (absorbers), accelerator components (beam intercepting devices) and in nuclear power plants. Glidcop has similar thermal and electrical properties to OFE (oxygen free electrical) copper, but has superior mechanical properties, thus making it a feasible structural material; its yield and ultimate strength are equivalent to those of mild-carbon steel. The purpose of this work has been to develop a brazing technique to join Glidcop to Mo, using a commercial Cu-based alloy. The effects of the excessive diffusion of the braze along the grain boundaries on the interfacial chemistry and joint microstructure, as well as on the mechanical performance of the brazed joints, has been investigated. In order to prevent the diffusion of the braze into the Glidcop alloy, a copper barrier layer has been deposited on Glidcop by means of RF-sputtering.
ARTICLE | doi:10.20944/preprints201803.0225.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: chemosensors; CN− selective sensor; test strip sensor
Online: 27 March 2018 (12:13:34 CEST)
4-(thiazol-2-yldiazenyl)phenol (L1) and 2-((4-hydroxyphenyl) diazenyl)-5-nitrophenol (L2) based on azo phenol were synthesised and used as selective colorimetric sensor for CN- and AcO− ion in DMSO/H2O-HEPES (v/v; 1:1, pH–7.3 ± 0.2) and showed good sensitivity with large red shifts and nanomolar detection limit for CN- and AcO- ion. The stoichiometry of L1 with CN−/AcO− ion was found to be 1:1 and L2 with CN−/AcO− ion was found to be 1:2. Binding constant for L1+ CN−, L1 + AcO−, L2 + CN− and L2 + AcO− were calculated by B-H plot as 1.6 × 103, 8.0 × 102, 8.4 × 103 and 1.7 × 102 respectively. L2 showed high selectivity towards CN− ion with low detection limit of 81 nM and large binding constant. In addition, 1H NMR titration and DFT studies also supported the deprotonation mechanism of receptors in the presence of selective anions.
ARTICLE | doi:10.20944/preprints201902.0009.v1
Subject: Engineering, Civil Engineering Keywords: asphalt mixture; low-temperature cracking; Tensile Creep Test (TCT); Bending Beam Creep Test (BBCT); tensile strength; thermal stress;
Online: 1 February 2019 (09:45:08 CET)
Thermal stresses belong to the leading factors that influence low-temperature cracking behavior of asphalt pavements. During winter, when temperature drops to significantly low values, tensile thermal stresses develop as a result of pavement contraction. Creep test methods can be suitable for the assessment of low-temperature properties of asphalt mixtures. To evaluate the influence of creep test methods on the obtained low-temperature properties of asphalt mixtures, three point bending and uniaxial tensile creep tests were applied and the master curves of stiffness modulus were analyzed. On the basis of creep test results, rheological parameters describing elastic and viscous properties of the asphalt mixtures were determined. Thermal stresses were calculated and compared to tensile strength of the material to obtain the failure temperature of the analyzed asphalt mixtures. It was noted that lower strain values of creep curves were obtained for the Tensile Creep Test (TCT) than for the Bending Beam Creep Test (BBCT), especially at lower temperatures. Results of thermal stress calculations indicated that higher reliability was obtained for the viscoelastic Monismith method based on the TCT results than for the simple quasi-elastic solution of Hills and Brien. The highest agreement with the TSRST results was also obtained for the Monismith method based on the TCT results. No clear relationships were noted between the predicted failure temperature and different methods of thermal stress calculations.
ARTICLE | doi:10.20944/preprints202304.0380.v1
Subject: Social Sciences, Other Keywords: polarization of climatic phenomena; GPCC data; NOAA data; monthly precipitation; average temperature; climate trends; Mann Kendall test; Pettitt test
Online: 17 April 2023 (03:16:45 CEST)
The article presents an analysis of monthly precipitation totals based on the GPCC database, and monthly mean temperatures (NOAA data) for 377 catchments distributed across the globe. The analysis included 110-year data sequences from 1901 to 2010 calculated from grid data with a spatial resolution of 0.5°x 0.5° longitude and latitude. Long-term sequences of precipitation and temperature were used to assess the polarization of climatic phenomena. The noticeable impact of polarization in the area of extreme changes in temperature and precipitation is related to anthropogenic factors such as greenhouse gas emissions, deforestation and pollution, which affect ecosystem functioning, biodiversity, water resources and economies. The paper demonstrates the existence of trends related to the polarization of temperature and precipitation phenomena. The measures of polarization used in science are discussed. A simple measure of polarization was proposed and applied to both long-term sequences of monthly precipitation totals and monthly mean temperature. Due to the nature of the proposed polarization measure, other characteristics of the precipitation and temperature sequences are also presented as background for the discussion of the polarization index. The paper presents, for a selection of several hundred catchments from around the world, analyses of the assessment of precipitation and temperature trends using non-parametric tests. The trend analyses use Mann -Kendall tests at the 5% significance level. A Pettitt test was used to determine the trend change point for precipitation and temperature data. The whole is supported by rich graphical analyses and the results are presented tabularly.
ARTICLE | doi:10.20944/preprints201711.0039.v1
Subject: Computer Science And Mathematics, Probability And Statistics Keywords: composite likelihood; maximum composite likelihood estimator; Wald test statistic; composite minimum density power divergence estimator; Wald-type test statistics.
Online: 6 November 2017 (12:59:45 CET)
In this paper a robust version of the Wald test statistic for composite likelihood is considered by using the composite minimum density power divergence estimator instead of the composite maximum likelihood estimator. This new family of test statistics will be called Wald-type test statistics. The problem of testing a simple and a composite null hypothesis is considered and the robustness is studied on the basis of a simulation study. Previously, the composite minimum density power divergence estimator is introduced and its asymptotic properties are studied.
ARTICLE | doi:10.20944/preprints201908.0214.v1
Subject: Computer Science And Mathematics, Probability And Statistics Keywords: Poisson distribution; raw moments; Bell polynomials; degenerate exponential function; unsigned Stirling number of the first kind.
Online: 20 August 2019 (11:14:22 CEST)
The main purpose of this paper is to introduce and investigate degenerate Poisson distrib- ution which is a new extension of the Poisson distribution including the degenerate expo- nential function. We then provide several properties of the degenerate Poisson distribution such as the first and the second raw moments and di¤erence operator property. Moreover, we acquired the skewness and the kurtosis for the degenerate Poisson distribution. We also derive its moment generating function by which we define the degenerate Bell polynomials and give a connection for these polynomials related to the unsigned Stirling numbers of the rst kind.
ARTICLE | doi:10.20944/preprints202304.0905.v1
Subject: Physical Sciences, Quantum Science And Technology Keywords: superconducting cavity; accelerator physics; magnetic defects; vertical test
Online: 25 April 2023 (09:19:33 CEST)
The magnetic heating effect for the superconducting quarter-wave resonator (QWR) cavities is investigated, and the Q slopes of the superconducting cavities are measured with an increasing accelerating field. Physical phenomena for zero-temperature limit are introduced. Bardeen–Cooper–Schrieffer (BCS) resistance and Casimir force are calculated for the zero-temperature limit. The vertical test is shown for the performance test of the quarter-wave resonator (QWR) cavities. The parameters for the quarter-wave resonator (QWR) cavity are presented. The Q slopes are measured as a function of an accelerating electric field at 4.2 K. The surface resistance of the superconducting cavity increases with an increasing peak magnetic field. The magnetic defects cause the degradation for the quality factor. From the magnetic degradation, we can find the magnetic moments of the superconducting cavities. All the quarter-wave resonator (QWR) cryomodules are installed in the tunnel, and beam commissioning is performed successfully.
ARTICLE | doi:10.20944/preprints202204.0272.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: immunochromatography; test strips; RBD protein; COVID-19; coronavirus
Online: 28 April 2022 (05:09:49 CEST)
Nowadays, the presence of pathogen-specific antibodies in the blood is widely controlled by a serodiagnostic technique based on the lateral flow immunoassay (LFIA). However, its common one-stage format with an antigen immobilized in the binding zone of a test strip and a nanodis-persed label conjugated with immunoglobulin-binding proteins is associated with risks of very low analytical signals. It is caused by the presence of non-specific immunoglobulins in very large excess to the target antibodies in the tested samples thus decreasing their binding with the detected labels. In this study, the first stage of the immunochromatographic serodiagnosis was carried out in its traditional format using a conjugate of gold nanoparticles with staphylococcal immunoglobulin-binding protein A and an antigen immobilized on a working membrane. At the second stage, a labeled immunoglobulin-binding protein was added, which enhanced the coloration of the bound immune complexes. The use of two separated steps, binding of specific antibodies, and further coloration of the formed complexes allowed a significant reducing the influence of non-specific immunoglobulins on the assay results. The proposed approach was ap-plied for the serodiagnosis using a recombinant RBD protein of SARS-CoV-2. As a result, an in-crease in the intensity of test zone coloration by more than two orders of magnitude was demonstrated, which enabled to significantly reduce false-negative results. When testing a panel of 16 positive and 8 negative serum samples, the diagnostic sensitivity of the LFIA was 62.5% for the common format and 100% for the enhanced format; the diagnostic specificity of both variants was 100%.
ARTICLE | doi:10.20944/preprints202105.0770.v1
Subject: Engineering, Automotive Engineering Keywords: shear test; scale effect; roughness; photogrammetry; friction angle
Online: 31 May 2021 (12:35:04 CEST)
An accurate understanding of jointed rock mass behavior is important in many applications ranging from deep geological disposal of nuclear waste to deep mining to urban geoengineering projects. The roughness of rock fractures and the matching of the fracture surfaces are the key contributors to the shear strength of rock fractures. In this research, push shear tests with three normal stress levels of 3.6, 6.0, and 8.5 kPa were conducted with two granite samples with artificially induced well-matching tensile fractures with sizes of 500 mm × 250 mm and 1000 mm × 500 mm. The large sample reached on average a -60 % weaker peak shear stress than the medium-sized sample, and a strong negative scale effect was observed in the peak shear strength. The roughness of the surfaces was measured using a profilometer and photogrammetry. The scale-corrected profilometer-based method (JRC) underestimates the peak friction angle for the medium-sized slabs by -27 % for the medium sample and -9 % for the large sample. The photogrammetry-based (Z’2) method produces an estimate with -7% (medium) and +12 % (large) errors. The photogrammetry-based Z’2 is an objective method that consistently produces usable estimates for the JRC and peak friction angle.
ARTICLE | doi:10.20944/preprints202105.0570.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Polymethyl methacrylate, Cycloolefin copolymer, Mechanical test, Electron Beam
Online: 24 May 2021 (13:26:07 CEST)
Polymethyl methacrylate (PMMA) is a transparent thermoplastic with excellent optical properties, transparent surface, low moisture absorption, tensile and electrical resistance. In this study, the alloy was prepared through PMMA and cycloolefin copolymer (COC) due to some similar properties. The mechanical test showed that properties such as impact resistance, elongation, tensile, and flexural strength decreased by adding COC by up to 20% due to less incompatibility and miscibility, but mentioned properties improved by adding COC 40% due to sub-phase generation. The DSC and DMTA tests showed improvement in the thermal properties of alloys by adding 40% COC. SEM micrographs exhibited a softer surface and more phase elongation of the alloy. Finally, the sample was selected as the optimal sample in terms of mechanical properties irradiated by electron beam, and amplification results showed that a dose of 50 KGY increased the mechanical and thermal properties relatively.
REVIEW | doi:10.20944/preprints201912.0002.v1
Subject: Medicine And Pharmacology, Pulmonary And Respiratory Medicine Keywords: tuberculosis (TB); diagnostics; lipoarabinomannan (LAM); urinary test; diagnosis
Online: 2 December 2019 (04:18:41 CET)
Most diagnostic tests for tuberculosis (TB) rely on sputum samples, which are difficult to obtain and have low sensitivity in immunocompromised patients, patients with disseminated TB, and children, delaying treatment initiation. The World Health Organization (WHO) calls for the development of a rapid, biomarker-based, non-sputum test capable of detecting all forms of TB at the point-of-care to enable immediate treatment initiation. Lipoarabinomannan (LAM) is the only WHO-endorsed TB biomarker which can be detected in urine, an easily collected sample. This review discusses the characteristics of LAM as a biomarker, describes the performance of first-generation urine LAM tests and reasons for slow uptake, and presents considerations for developing the next-generation of more sensitive and impactful tests. Next-generation urine LAM tests have the potential to reach adult and pediatric patients regardless of HIV status or site of infection and facilitate global TB control. Implementation and scale-up of existing LAM tests and development of next-generation assays should be prioritized.
ARTICLE | doi:10.20944/preprints201907.0296.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: point-of-care; cholesterol; clinical diagnostics; laboratory test
Online: 26 July 2019 (01:13:11 CEST)
Managing blood cholesterol levels is important for the treatment and prevention of diabetes, cardiovascular disease, and obesity. An easy-to-use, portable cholesterol blood test will accelerate more frequent testing by patients and at-risk populations. We aim to evaluate the performance of smartphone-based point-of-care cholesterol blood tests as compared to that of hospital-grade laboratory tests. We used smartphone systems that are already familiar to many people. Because smartphone systems can be carried around everywhere, blood can be measured easily and frequently. We compared the results of cholesterol tests with those of existing clinical diagnostic laboratory methods. We found that smartphone-based point-of-care lipid blood tests are as accurate as hospital-grade laboratory tests (N=116, R>0.97, P<0.001 for all 3 cholesterol blood tests: total cholesterol, high density lipoprotein, and triglyceride). Our system will be useful for those who need to manage blood cholesterol levels to motivate them to track and control their behavior.
ARTICLE | doi:10.20944/preprints201812.0234.v1
Subject: Engineering, Civil Engineering Keywords: Steel; Tensile Test; XRCT; Damage Evolution; Gurson Model
Online: 19 December 2018 (12:14:27 CET)
This paper analyses the evolution of the internal damage in two types of steel that show different fracture behaviours, with one of them being the initial material used for manufacturing prestressing steel wires, which shows a flat fracture surface perpendicular to the loading direction, and the other one being a standard steel used in reinforced concrete structures, which shows the typical cup-cone surface. 3mm-diameter cylindrical specimens are tested with a tensile test carried out in several loading stages and, after each of them, unloaded and analysed with X-ray tomography, which allows detection of internal damage throughout the tensile test. In the steel used for reinforcement, damage is developed progressively in the whole specimen, as predicted by Gurson-type models, while in the steel used for manufacturing prestressing steel-wire damage is developed only in the very last part of the test. In addition to the experimental study, a numerical analysis is carried out by means of the finite element method by using a Gurson model to reproduce the material behaviour.
ARTICLE | doi:10.20944/preprints201811.0464.v1
Subject: Medicine And Pharmacology, Orthopedics And Sports Medicine Keywords: resistance training; strength test; muscle strength; older women
Online: 19 November 2018 (11:58:41 CET)
Background: The maximal one-repetition test (1-RM) is widely used in scientific research; however, there are conflict results regarding its reproducibility in elderly population. The present study aimed to analyze the reproducibility the test both before and after a 12 week training period by using the bench press and leg press 45° 1-RM tests in the elderly taking into consideration the training experience and strength level of the women. Methods: Elderly women (n = 376; age, 68.5 ± 14.1 years; height, 162.7 ± 5.5 cm; body mass, 71.2 ± 16.0 kg) who underwent ≥3 months of resistance training performed an initial week of familiarization and a second week of testing and retest, with a 48–72 hour interval. Results: The results showed maximal and relative load strength of 39.3 kg and 0.59 kg/body mass for lower limbs and 20.9 kg and 0.31 kg/body mass for upper limbs. The Kappa indices were 0.93 and 0.95, and the intraclass correlation coefficients were 0.99 and 0.99 for the lower and upper limbs, respectively. Conclusion: Therefore, the present study confirms that the 1-RM test has high reliability and reproducibility in the elderly, for both upper and lower limbs.
COMMUNICATION | doi:10.20944/preprints201808.0469.v1
Subject: Medicine And Pharmacology, Orthopedics And Sports Medicine Keywords: aerobic capacity, graded‑exercise test, total work-load
Online: 27 August 2018 (16:31:45 CEST)
The aim of this study was to clarify effects of 3-week work-matched high-intensity intermittent cycling training (HIICT) with different cadences on VO2max in university athletes. Eighteen university athletes performed HIICT with either 60 rpm (n = 9) or 120 rpm (n = 9). HIICT consisted of eight sets of 20-s exercise with a 10-s passive rest between each sets. The initial training intensity was set at 135% of VO2 max and was decreased by 5% every two sets. Athletes in both groups performed 9 sessions of HIICT during 3-week. The total work-load and achievement rate of the work load calculated before experiments in each group were used for analysis. VO2max was measured pre and post-training. After 3-week of training, no significant differences in the total work-load and achievement rate of the work load were found between the two groups. VO2max similarly increased in both groups from pre to post training (p = 0.016), with no significant differences between the groups (p = 0.680). These results suggest that cadence during HIICT is not training variable affecting effect of VO2max.
ARTICLE | doi:10.20944/preprints201803.0242.v1
Subject: Chemistry And Materials Science, Surfaces, Coatings And Films Keywords: accelerated weathering test; color change; poplar OSB; wettability
Online: 29 March 2018 (04:38:44 CEST)
Oriented strand board (OSB) panels are widely marketed for several applications, from building to packaging. The manufacturing of poplar OSB started recently in Northern Italy representing a relevant innovation in the sector since this product is usually made of coniferous wood. The thermal treatment is widely used for reducing the hygroscopicity of wood-based products, nonetheless it influences the mechanical behavior and degrades the main components of wood, which can affect their finishing. Therefore, it is important to know the properties of the treated surfaces. To this purpose, in this study a lot of OSB panels, made of poplar wood, 15 mm thick and with a density of 590 kg/m3, were thermally treated under vacuum conditions at 190 °C for 2 h and then subjected to accelerated weathering. The changes in color and in wettability due to treatment and accelerated weathering were studied. The thermal treatment determined a significant darkening of the color; the accelerated weathering darkened the untreated surfaces and, on the opposite, lightened the thermo-treated surfaces. The wettability decreased after thermal treatment and increased after weathering, more evidently in treated panels. Overall, this study improves the knowledge about the behavior of the surface of thermo-treated poplar OSB, which is relevant for the industrial coating of this product.
ARTICLE | doi:10.20944/preprints201703.0194.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: aromatic plants; HPLC; antioxidant capacity; DPPH; Rancimat test
Online: 27 March 2017 (09:57:43 CEST)
The antioxidant properties and polyphenol content of some selected aromatic plants grown in Greece were studied. Plants were refluxed with 60% methanol after acid hydrolysis. The phenolic substances were quantified by HPLC-DAD. The antioxidant capacity of the extracts was determined with the Rancimat test using sunflower oil as substrate. Free radical scavenging activity was measured using the stable free radical 1, 1-diphenyl-2-picrylhydrazyl (DPPH). Results were compared with standard BHT and ascorbic acid. Total phenol concentration of the extracts was estimated with Folin-Ciocalteu reagent using gallic acid as standard.
ARTICLE | doi:10.20944/preprints201612.0147.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: piezoresistive sensor; electron microscope; in situ mechanical test
Online: 30 December 2016 (04:16:25 CET)
In this work, we designed a MEMS device which allows simultaneous direct measurement of mechanical properties during deformation under external stress and characterization of the evolution of microstructure of nanomaterials within a transmission electron microscope. This MEMS device makes it easy to establish the correlation between microstructure and mechanical properties of nanomaterials. The device uses piezoresistive sensors to qualitatively measure the force and displacement of nanomaterials, e.g., in wire and thin plate forms. The device has a theoretical displacement resolution of 0.19 nm and a force resolution of 2.1 μN. The device has a theoretical displacement range limit of 2.74 μm and a load range limit of 27.75 mN.
ARTICLE | doi:10.20944/preprints201612.0047.v1
Subject: Engineering, Mechanical Engineering Keywords: tool surface texture; lubricant entrapment; strip drawing test
Online: 8 December 2016 (10:09:36 CET)
While texturing of workpiece surfaces to promote lubrication in metal forming has been applied for several decades tool surface texturing is rather new. In the present paper tool texturing is studied as a method to prevent galling. Adopting a strip reduction test longitudinal pocket geometries oriented perpendicular to the sliding direction, with shallow pocket depth, small pocket angle to the workpiece surface and varying distance between pockets are investigated. The experiments reveal that the distance between pockets should be larger than the pocket width thereby creating a topography similar to flat table mountains to avoid mechanical interlocking in the valleys; otherwise an increase in drawing load and pick-up on the tools is observed. The textured tool surface lowers friction and improves lubrication performance provided that the distance between pockets is 2-4 times larger than the pocket width. Larger drawing speed facilitates escape of the entrapped lubricant in the pockets. Testing with low to medium viscosity oils leads to a low sheet roughness on the plateaus but also local workpiece material pick-up on the tool plateaus. Large lubricant viscosity results in higher sheet plateau roughness but also prevents pick-up and galling.
Subject: Computer Science And Mathematics, Discrete Mathematics And Combinatorics Keywords: discrete degenerate random variables; degenerate binomial random variable; degenerate Poisson random variable; new type degenerate Bell polynomials
Online: 15 November 2019 (16:43:03 CET)
In this paper, we introduce two discrete degenerate random variables, namely the degenerate binomial and degenerate Poisson random variables. We deduce the expectations of the degenerate binomial random variables. We compute the generating function of the moments of the degenerate Poisson random variables, which leads us to define the new type degenerate Bell polynomials, and hence obtain explicit expressions for the moments of those random variables in terms of such polynomials. We also get the variances of the degenerate Poisson random variables. Finally, we illustrate two examples of the degenerate Poisson random variables.
ARTICLE | doi:10.20944/preprints202305.2188.v1
Subject: Engineering, Aerospace Engineering Keywords: WAAM; surface waviness; fatigue; bending test; durability; fracture mechanics
Online: 31 May 2023 (07:47:02 CEST)
This paper reports the effect of as-deposited surface condition on the fatigue strength in an additive manufactured titanium alloy Ti-6Al-4V (WAAM Ti64). First, local stress concentration caused by the surface waviness was quantified by a metrology technique followed by numerical modelling. Fatigue tests were conducted under bending load with the as-deposited surface being under tensile cyclic stress. The applicability of two predictive methods was studied and compared with the fatigue test results. The traditional notch stress method overestimated the fatigue strength by a factor of 1.5 at a given life; the poor agreement with the test is attributed to the crack propagation from the waviness being dominant in the bending test, i.e., the crack initiation stage was short, hence the local stress method is unsuitable. The fracture mechanics approach has delivered good predictions at every applied stress levels. The method treats a waviness trough as an initial crack. This approach is suitable for predicting the fatigue life in materials built by wire based directed energy deposition processes.
ARTICLE | doi:10.20944/preprints202305.1208.v1
Subject: Engineering, Aerospace Engineering Keywords: landing gear; variable stroke; test; displacement control; follow-up
Online: 17 May 2023 (08:21:52 CEST)
The fixed stroke fatigue test can not simulate the real load condition of the landing gear, and the variable stroke fatigue test has increasingly become the mainstream. A modular test device for fatigue test for aircraft landing gears was designed, the automatic control of the buffer stroke was realized with ectopic displacement control technology effectively, the horizontal loading cylinder could follow the wheel axis actively with the displacement active control technology, follow-up loading along the vertical direction was realized through constructing a polar coordinate system and making the load line automatic alignment, a split-type dummy wheel was designed to improve the loading accuracy, a booster cylinder was designed to realize the control loading of high pressure combined with the hydraulic control system. The test shows that the technical scheme meets the design requirements, and the fatigue test was completed successfully. The device for landing gear variable stroke fatigue testing can be applied to other landing gear static / fatigue tests.
ARTICLE | doi:10.20944/preprints202302.0340.v1
Subject: Engineering, Civil Engineering Keywords: ASR; Aggregates; Moisture; Mortar bas test; Supplementary cementitious materials
Online: 20 February 2023 (10:23:21 CET)
Alkali-silica reactivity (ASR) is one of multiple reactions responsible for premature loss in concrete infrastructure service life. ASR is a deleterious reaction initiated when highly reactive silicious content of aggregates reacts with alkali hydroxides content within portland cement in the presence of moisture. ASR results in the formation of expansive, white-colored gel-like material which results in internal stresses within hardened concrete. ASR induced stresses result in concrete cracking, spalling, and increased reinforcement steel corrosion rates. The main objective of this research is to improve the conditions of concrete infrastructure projects conditions by mitigating ASR damaging effect. The expansion of accelerated mortar bars poured using fine aggregates collected from different sources is measured versus time to evaluate aggregate’s reactivity. Different percentages of supplementary cementitious materials (SCMs) including class c fly ash, micro-silica, were used in remixing mortar bars to evaluate the efficiency of different types of SCMs in mitigating mortar bar expansion. Research findings showed that SCMs can mitigate ASR, thus, decrease the mortar bar expansion. The efficiency of SCMs in ASR mitigation is highly dependent on the incorporated SCM percentage and particle fineness. Silica fume, having the least particle size, displayed higher rates of ASR mitigation followed by fly ash, respectively. The outcomes of this research will assist design engineers in avoiding future losses due to ASR cracking in concrete infrastructure projects, and reduce the excessive need to maintenance, repair, and replacement activities.
ARTICLE | doi:10.20944/preprints202112.0211.v1
Subject: Engineering, Automotive Engineering Keywords: advanced vehicle safety; standard airbag; nanobag; frontal sled test
Online: 13 December 2021 (15:57:43 CET)
Objective: The future mobility challenges leads to considering new safety systems to protect vehicle passengers in non-standard and complex seating configurations. The objective of this study is to assess the performance of a brand new safety system called nanobag and to compare it to the traditional airbag performance in the frontal sled test scenario. Methods: The nanobag technology is assessed in the frontal crash test scenario and compared with the standard airbag by numerical simulation. The previously identified material model is used to assemble the nanobag numerical model. The paper exploits an existing validated human body model to assess the performance of the nanobag safety system. Using both the new nanobag and the standard airbag, the sled test numerical simulations with the variation of human bodies are performed in 30 km/h and 50 km/h frontal impacts. Results: The sled test results for both the nanobag and the standard airbag based on injury criteria shows a good and acceptable performance of the nanobag safety system compared to the traditional airbag. Conclusion: The results show that the nanobag system has its performance compared to the standard airbag, which means that thanks to the design, the nanobag safety system has a high potential and extended application for multi-directional protection against impact.
ARTICLE | doi:10.20944/preprints202109.0346.v1
Subject: Medicine And Pharmacology, Ophthalmology Keywords: goniopuncture; ab interno trabeculectomy; porcine eyes; glaucoma; predictive test
Online: 20 September 2021 (16:34:00 CEST)
Purpose: To investigate trabeculopuncture (TP) for predicting the outcome of ab interno trabeculectomy (AIT). AIT is an effective, low-risk procedure for open angle glaucoma. Despite widespread utilization, it fails in patients with an unidentified distal outflow resistance. Methods: We bisected 81 enucleated porcine eyes and perfused them for 72 hours. They were assigned to two groups: trial (n=42) and control (n=39). Intraocular pressure (IOP) was measured continuously. At 24 hours, four YAG-laser trabeculopunctures on the nasal trabecular meshwork were performed, followed by a 180° AIT at the same site at 48 hours. Eyes were divided into TP and AIT responders and non-responders; the proportion of TP responders between both AIT groups was compared. Results: Both post-TP and post-AIT IOPs were lower than baseline IOP (p=0.015 and p<0.01, respectively). The success rates of TP and AIT were 69% and 85.7%, respectively. The proportion of TP responders among AIT responders was greater than that of AIT non-responders (p<0.01). Sensitivity and specificity values of TP as predictive test for AIT success were 77.7% and 83.3%, respectively. The positive and negative predictive values were 96.6% and 38.5%, respectively. Conclusion: A 10% reduction in IOP after TP can be used as predictor for the success (>20% IOP decrease) of 180° AIT in porcine eyes.
ARTICLE | doi:10.20944/preprints202107.0386.v1
Subject: Computer Science And Mathematics, Software Keywords: Automated Test Oracle; Game Testing; GUI Testing; Deep Learning
Online: 16 July 2021 (16:17:02 CEST)
Graphically-rich applications such as games are ubiquitous with attractive visual effects of Graphical User Interface (GUI) that offers a bridge between software applications and end-users. However, various types of graphical glitches may arise from such GUI complexity and have become one of the main component of software compatibility issues. Our study on bug reports from game development teams in NetEase Inc. indicates that graphical glitches frequently occur during the GUI rendering and severely degrade the quality of graphically-rich applications such as video games. Existing automated testing techniques for such applications focus mainly on generating various GUI test sequences and check whether the test sequences can cause crashes. These techniques require constant human attention to captures non-crashing bugs such as bugs causing graphical glitches. In this paper, we present the first step in automating the test oracle for detecting non-crashing bugs in graphically-rich applications. Specifically, we propose GLIB based on a code-based data augmentation technique to detect game GUI glitches. We perform an evaluation of GLIB on 20 real-world game apps (with bug reports available) and the result shows that GLIB can achieve 100\% precision and 99.5\% recall in detecting non-crashing bugs such as game GUI glitches. Practical application of GLIB on another 14 real-world games (without bug reports) further demonstrates that GLIB can effectively uncover GUI glitches, with 48 of 53 bugs reported by GLIB having been confirmed and fixed so far.
REVIEW | doi:10.20944/preprints202103.0448.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: colorectal cancer screening; test; alternative; non-invasive; CRC; review
Online: 17 March 2021 (16:01:58 CET)
Colorectal cancer (CRC) is one of the leading cancer-related causes of death in the world. Since the 70s, many countries have adopted different CRC screening programs which has resulted in a decrease in mortality. However, current screening test options still present downsides. The commercialized stool-based tests present high false-positive rates and low sensitivity, which negatively affects the detection of early stage carcinogenesis. The gold standard colonoscopy has low uptake due to its invasiveness and the perception of discomfort and embarrassment that the procedure may bring.In this review, we collected and described the latest data about alternative CRC screening techniques that can overcome these disadvantages. Web of Science and PubMed were employed as search engines for studies reporting on CRC screening tests and future perspectives. The searches generated 555 articles, of which 93 titles were selected. Finally, a total of 50 studies, describing 14 different CRC alternative tests, were included. Among the investigated techniques the main feature that could have an impact on CRC screening perception and uptake was the ease of sample collection. Urine, exhaled breath and blood-based tests promise to achieve good diagnostic performance (sensitivity of 63-100%, 90-95%, 47-97%, respectively) while minimizing stress and discomfort for the patient.
ARTICLE | doi:10.20944/preprints202101.0257.v1
Subject: Chemistry And Materials Science, Ceramics And Composites Keywords: Test bricks; Fired bricks; handmade bricks; ceramics; mechanical strengths
Online: 13 January 2021 (16:04:43 CET)
Fired bricks have shown tremendous potential as a construction material due to their properties. However, their use required some specifications in terms of quality, resistance, and durability. In developing countries, the lack of tools to make test specimens leads to many defects in these brick specimens responsible for low durability and weak precision during mechanical tests and shrinkage. In this study, a simple and traditional method of making test bricks is presented. This simple method allows the production of bricks with the required properties. This method is especially efficient for a firm or semi-soft pastes consistency. The handmade pastes do not stick into the walls of the mold like the case of steel molds and it gives specimens with standard shape, smooth surface, and sharp edges. The resulting fired bricks exhibit high mechanical strength comparable and even better than those of conventional methods.
ARTICLE | doi:10.20944/preprints202007.0679.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: Sub Clinical Mastitis; prevalence; Surf Field Mastitis Test; Jhenaidah
Online: 28 July 2020 (10:40:34 CEST)
A cross-sectional study was carried out to determine the prevalence of subclinical mastitis (SCM) among medium to large scale household dairy farms in southwestern district, Jhenaidah, Bangladesh during July to December 2019. A total of 78 (n=100) lactating cows from household dairy farms (N=32) having three or more dairy cows were selected randomly as sampled populations. Milk samples were screened for SCM by using Surf Field Mastitis Test (SFMT). The prevalence of SCM varied among farm level [71.9% (95% CI: 53.3-86.3)], individual animal level [67.9% (95% CI: 56.4-86.3)] and quarter level [29.5% (95% CI: 24.5-34.9)]. Descriptive statistics represented the farmers and farm demography, characteristics of the sampled population, and overall management feature. Random Effect Logistic Regression identified, Body Condition Score (BCS) [OR=3.8 and 2.9, at cows level and quarter level respectively (BCS-2 vs. BCS-≥3)], and breed [OR=5.1 and 2.9, at cows level and quarter level respectively (HF× Sahiwal vs. HF × Local)] as potential risk factors. This study shows that SCM is highly prevalent in the study area, which is a major threat to the dairy industry's production performance. Regular screening by SFMT, proper hygiene, improve the management system, and farmer’s awareness is required to control the disease.
ARTICLE | doi:10.20944/preprints202005.0368.v2
Subject: Medicine And Pharmacology, Epidemiology And Infectious Diseases Keywords: SARS-CoV2; personal protection devices; snorkel masks; safety test
Online: 30 June 2020 (07:43:58 CEST)
Introduction: The SARS-CoV2 pandemic has led to an worldwide shortage of Personal Protection Devices (PPD) for medical and paramedical personnel. Adaptation of commercially available snorkel masks to serve as full face masks has been proposed. Even not formally approved as PPD, they are publicized on social media as suitable for this use. Concerns about actual protection levels and risk of carbon dioxide (CO2) accumulation while wearing them for extended periods made us perform a systematic testing of various brands, in order to verify whether they are as safe and effective as claimed. Methods: A ‘fit’ test was performed, analogous to gas mask testing. Respiratory safety was evaluated by measuring end-tidal CO2 and oxygen saturation while wearing the masks in rest and during physical exercise. Masks were tested with 3D adaptors to mount regular bacterial-viral ventilator filters when available, or with snorkel openings covered with N95/FFP2 cloth. Results: Modified masks performed reasonably well on the fit test, comparable to regular N95/FFP2 masks. Not all ventilator filters are equally protective. For all masks, a small initial increase in end-tidal CO2 was noted, remaining within physiological limits. Masks with specific adaptors (3D printed or provided by the manufacturer) are safer, have more flexibility and reliability than makeshift adaptations. Conclusions: These masks can offer benefit as a substitute for complete protective gear as they are easier to don and remove and offer full-face protection. They may be more comfortable to wear for extended periods. Proper selection of mask size, fit testing, quality of 3D printed parts and choice of filter are important.
BRIEF REPORT | doi:10.20944/preprints201910.0166.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Chagas Disease; Trypanosoma cruzi; benznidazole; nifurtimox; antimicrobial susceptibility test
Online: 15 October 2019 (08:26:29 CEST)
We ascertain the in vitro Benznidazole (BZN) and Nifurtimox (NFX) susceptibility pattern of epimastigotes, trypomastigotes, and amastigotes of 21 T. cruzi strains, from patients, reservoir and triatomine bugs of various geographic origin. Using this panel of isolates, we compute the Epidemiological cut off value (COwt). Then, the frequency of the susceptible phenotype (Wild type) towards BZN and nifurtimox (NFX) within this set of strains belonging to 3 discrete typing units (DTUs), TcI, TcII, and TcV was deduced. We have observed that the susceptibility status of individual T. cruzi isolates toward BZN and NFX is related to the genetic background and to underlying factors probably related to the individual life trait history of each strain. Analyzing drug susceptibility in this conceptual framework would offers the possibility to evidence a link between isolates expressing a low susceptibility level (not wild-type) as define by the COwt value and none-curative treatment. It will also permit to tract drug-resistant parasites in T. cruzi population.
ARTICLE | doi:10.20944/preprints201904.0299.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: X-ray diffraction; bioactivities; cytotoxicity test; Anti-cancer activities
Online: 26 April 2019 (11:00:21 CEST)
Owing to fascinating applications of ZnO in modern devices, it is interesting to explore its more features for future devices. Hence, herein, we have synthesized the high quality ZnO spherical nanoparticles (SNPs) through a facile green synthesis route and robust structural and biomedical studies are carried out. Hexagonal phase with 93.2% crystallinity was confirmed through XRD analysis. ZnO nanoparticles were tested for their bioactivities both in vivo (acute cytotoxicity test) and in vitro (Anti-cancer activities on liver (HepG2) and cervical (Hela) cancer cell lines, stimulatory/inhibitory effects on normal rat splenic cells and hemolytic effects on red blood cells). Results showed that ZnO SNPs has no cytotoxic effects on vital organ like liver and has no hemolytic action on red blood cells. ZnO SNPs showed inhibitory consequence on normal rat splenic cells growth at all tested concentrations. ZnO nanoparticles showed an inhibitory effect on HepG2 cell line. While showed stimulatory effect on Hela cell line. Current study presents the synthesized ZnO SNPs as highly applicable in bio-optoelectronics.
Subject: Engineering, Civil Engineering Keywords: stepped revetment; wave overtopping; surface roughness; physical model test
Online: 19 April 2019 (12:38:01 CEST)
Wave overtopping, i.e., excess of water over the crest of a coastal protection infrastructure due to wave run-up, of a smooth slope can be reduced by introducing slope roughness. A stepped revetment ideally constitutes a slope with uniform roughness. Apart from reducing overtopping, a stepped revetment provides safer access to a beach compared to conventional rubble. In recent years, research studies on stepped revetments have provided valuable findings regarding the performance and design optimization of stepped revetments as a typical mean of coastal protection. A stepped revetment can reduce overtopping volumes of breaking waves up to compared to a smooth slope. The effectiveness of the overtopping reduction decreases with increasing Iribarren number. However, up to date a unique approach applicable for a wide range of boundary conditions is still missing. The present paper critically reviews previous findings, gathers and analyzes data from previous studies and proposes a new formula for robust prediction of overtopping of stepped revetments. By means of this approach a critical assessment based on beforehand disclosed parameter ranges between a smooth slope on the one hand and a plain vertical wall on the other are contrasted. By analysis of a new data set compounded from different original studies a novel empirical formulation is derived to predict the roughness reduction coefficient of a stepped revetment for breaking and non-breaking waves. This coefficient is developed and adjusted for a direct incorporation into the present design guidelines. Underlying uncertainties are clearly addressed and quantified. Scale effects are highlighted.