Variation Of Test Parameters Research Articles

Validation of the Microlab Salmonella for Detection of Salmonella O Group A-E in Selected Foods: AOAC Performance Tested MethodSM 052401.

Microlab Salmonella is an all-in-one solution for detection of Salmonella O Groups A-E that integrates, in a single disposable device, all elements to perform the analysis: a ready-to-use enrichment broth, a lateral flow immunochromatography test, and a chemical agent for bacterial inactivation. Microlab Salmonella can be easily used on-site and does not require specific laboratory equipment or technical skills. The device is sealed during the analysis, avoiding risks of contamination, and is therefore safe to use in food production environments. This report details the method validation study for raw ground beef, raw turkey (thermal processed, marinated), fresh cheese, deli ham, and pasteurized liquid egg. Matrix studies and inclusivity/exclusivity, product consistency/stability, and robustness testing were conducted to assess the method's performance. Inclusivity/exclusivity testing showed that the Microlab Salmonella method was able to detect Salmonella O Group A-E isolates while excluding the non-Salmonella strains. In the matrix studies, the differences between the candidate and reference methods were not statistically significant. Minor variations in test parameters (enrichment time, time to read results, and enrichment temperature) did not affect the performance of the Microlab assay. There were no statistically significant differences between recently manufactured lots and those that were halfway through their expiration period or between those that were close to expiring. The reported data confirm that Microlab Salmonella is reliable for detecting Salmonella in raw ground beef, raw turkey (thermal processed, marinated), fresh cheese, pasteurized liquid egg, and deli ham. Microlab Salmonella is validated to detect Salmonella in select food matrixes. Microlab Salmonella integrates the steps of enrichment, detection, and inactivation in a single device.

Test conditions of texture profile analysis for frozen dough

Wheat flour is very important for making frozen dough. This paper firstly conducted an analysis of the basic properties of six varieties of wheat flour from different places and found that the variety BDHhgwf is most suitable to make frozen dough. Texture profile analysis (TPA) has been implemented in the dough-based food industry, and the properties of frozen dough were firstly investigated in this study. The results showed during TPA determination process of frozen dough, the variation of test parameters have an influence on the final result to some extent. The use of TPA in assessing the properties of frozen dough is presented. The recommended test conditions are: pre-test speed 3.0 mm/s, test speed (TS) 1.0 mm/s, posttest speed 1.0 mm/s, and compression ratio (CR) 50%. In a word, in this test method, the variation coefficient of dough was smaller and the dough was destroyed less by the texture analyzer and can truly reflect the texture of frozen dough.

INFLUENCE OF ASSESSMENT METHODS ON INTERMEDIATE RESULTS OF MEDICAL STUDENTS

The conducted research revealed that first-year students of the medical faculty prefer distance learning and the use of multiple-choice testing on an electronic educational platform when studying the course "Bioorganic Chemistry." Meanwhile, traditional classroom sessions without visual aids and open-ended questions showed the lowest performance indicators. However, students mentioned that they most effectively assimilate the educational material during such sessions, while also acknowledging the positive impact of quality visual aids on comprehension. Based on the obtained results, it is recommended to continue developing a question bank and utilizing the electronic educational platform with multiple-choice testing, but with modifications to the tasks and variations in test parameters. The research indicates that students perceive the use of technology and interactive teaching methods positively, which provide a more flexible learning environment and the opportunity for independent study. The research findings can be valuable in curriculum development and improving the quality of the educational process. Furthermore, it is worth considering the possibility of implementing a wider range of interactive teaching methods and utilizing modern technologies that foster active student engagement in the learning process.
 Keywords: quality of education; academic success; testing; form of education.

Quality assessment of analog to digital converter chip using test data set

Analog to Digital Converter (ADC) chip test generates a test data set including several dynamic parameters at various frequency. It is a challenge to obtained its quality quantitatively from test data set due to its high dimension and various units. This paper develops a method named quality-spectrum to analyzing ADC quality characteristics using its data set. It displays all variation of test parameters on one picture. Meanwhile, the relationship among these parameters could be quantatitived through three viewpoints which is chip, parameter and frequency. First, define classifier rule according with the characteristics of ADC chip. Second, form the quality-spectrum which is a digital color image by mapping the test data set to a classification matrix Q and color it. Last, obtain the chip's quality distribution quantitatively by calculating the fault score of classification matrix Q from different dimensions. The quality characteristics distribution of ADC chips could be observed directly and calculated quantitatively through quality-spectrum. A test data set of ADC chip is used to verify the validation of this method.

Structural and wear assessment of H11 die steel as a function of tempering temperature

H11 steel is widely used in helicopter landing gears and dies for extrusion and forging. The property of H11 steel can be enhanced by several types of heat treatments for a long life span and improved design accuracy. In the present work, an attempt is made to study the effect of the tempering cycle on the two-body abrasive wear behavior. The structural characterization of hardened and tempered specimens was carried out using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Two body abrasive wear tests were carried out using silicon carbide abrasive with a systematic and simultaneous variation of test parameters. The different tempering temperatures used in the present investigation are 200 °C, 400 °C and 600 °C. The result showed that the wear mechanism like (ploughing and micro-cutting) in each condition was dominated by the types of phases present in the material and their morphology. The wear debris was flaky and ductile. There was the presence of a small amount of SiC particles from the abrasive wear paper in wear debris for high load (40 N) wear tests. The wear debris particles were relatively finer in as-quenched condition and low tempering temperature (200 °C), while those were large for samples tempered at 400, 600 °C and fully annealed condition. The wear debris analysis through micrographs and iron oxide particles were not detected in XRD patterns.

Analysis of bitumen material test methods and bitumen surface phase characteristics via atomic force microscopy-based infrared spectroscopy

• Suitable sample preparation methods, probe types, and imaging modes are recommended for AFM-IR tests. • Some imaging parameters have the significant effect on imaging quality. • The difference of nanoscale property of various phases on bitumen surface may not be entirely caused by chemical composition. Atomic force microscopy-based infrared spectroscopy (AFM-IR) combines the chemical analysis capability of IR with the nanoscale resolution of AFM. Considering the importance of test methods to imaging quality, it is necessary to explore the suitable AFM-IR test methods for bitumen materials including bitumen and bituminous mixtures. As for bitumen sample preparation, solution-cast methods, heat-cast methods, and hot-bitumen-pouring methods have proved to be feasible. Additionally, this study develops frozen-storage and low-temperature-cutting methods to prepare bituminous mixture samples for AFM-IR tests. Afterwards, samples of base bitumen aged by PAV for 25 h are subjected to explore the influence of different probe types, imaging modes, and test parameters. It is found that the PR-EX-TnIR-A probe can be used to capture chemical information in the tapping mode and the contact mode. Accordingly, only the tapping mode is suitable for obtaining rapid narrow-band chemical maps, while the contact mode can be used to collect broad-band point infrared spectra besides the tapping mode. On this basis, the variation of test parameters has shown that IR power and start power strongly influence the obtained chemical information. Finally, based on the proposed AFM-IR test methods for bitumen materials, we capture infrared spectra of each phase on the virgin base bitumen surface and then conduct the analysis of surface phase characteristics, combining with nanomechanical properties obtained by the AFM peak force quantitative nanomechanical mode (PF-QNM). The results indicate that chemical composition of various phases is similar, and the obvious difference of microstructure and nanomechanical properties is not completely related to chemical composition.

Perbandingan Kinerja Web Server Terhadap Performa Integrasi Multi Basis Data

The research is focused for the purpose of analyzing the performance of which web server is able to receive more requests with a short connection time to support the performance of the integration application and can simulate the user with the jmeter application to test the web server. The performance test process is carried out using the benchmark test method using the Jmeter application by adjusting the input scenario and then analyzing the results based on the TIPHON standard. The results obtained from several variations of test parameters are known that the server's ability to send responses with the largest bytes is the apache web server, while the lowest error rate is nginx, while in terms of server network infrastructure, the apache web server is better because it can send a faster response. good and stable compared to nginx.Based on the test results above, it can be concluded that the apache web server has more effective results in web service performance against multi-database

The use of a two-frequency eddy current method for measuring the electrically conductive wall thickness under significant variations in the test parameter and the lift-off

The paper addresses the problem of eddy current testing of the wall thickness of light-alloy drill pipes under significant variations in both the test and the influence parameter of the test object – the lift-off between the eddy current probe and the test object surface. The performance of the two-frequency eddy current method is shown through the use of the signal of the surface eddy current probe of the added high-frequency voltage amplitude as an informative parameter to measure the lift-off and the phase of the added low-frequency voltage. Experimentally obtained dependences of the informative parameters on test and influence parameters are presented. The phase and amplitude-phase multi-parameter methods used to suppress the effect of stray parameters in eddy current testing are analyzed; the effectiveness of their application under significant variations in test and other influence parameters of the test object is shown to be limited. The effectiveness of nonlinear functions for the inverse transformation of the informative parameter into the test parameter to suppress the lift-off effect on test results is estimated. Criteria of choice for informative parameters of the eddy current probe signal are considered. The measurement error caused by the approximation error of the nonlinear functions of the inverse transformation of the informative parameters into the test parameter within the variation ranges of the test and influence parameters is estimated.

Influence of variability in testing parameters on cookstove performance metrics based on the water boiling test

Biomass cookstoves have been studied extensively for several decades. The Water Boiling Test (WBT) has been a widely adopted protocol for obtaining measurements needed to quantify biomass cookstove performance metrics. WBT metrics have been commonly used to evaluate cookstove effectiveness and serve as a basis for comparing biomass cookstoves. This paper demonstrates the influence of variations in testing parameters on measured or calculated metrics, especially since changes in multiple testing parameters may have competing effects on a given metric. In controlled experiments, this study assessed the effects of variations in the presence or absence of a pot lid, firepower, pot size, the initial mass of water, and presence or absence of boiling on the performance metrics of overall thermal efficiency (η), thermal efficiency associated with heating water (ηheat), specific consumption (SC), and the time to reach 90 °C. η was not greatly affected by variations in any of the testing parameters (i.e. no effect was greater than 6% of the base case). SC and ηheat, which are interrelated metrics, can provide additional insights on cookstove efficiency. Although these latter metrics showed a wide range of values due to variations in testing parameters, the use of a lid greatly reduced variations in both ηheat and SC metrics even when there were significant variations in the other testing parameters. Thus, the use of a lid would provide better consistency for cookstove comparisons when using these metrics. The time to reach 90 °C varied widely among changes in testing parameters. Therefore, this metric is difficult to use for cookstove comparison without strict control of testing protocols.

Comparison of Stimuli for Nonlinear System Response Classification

As part of the development of an automated virtual design classification approach for nonlinear structural dynamics, alternative excitation functions are evaluated with respect to their overall performance and efficiency in feature-based response analysis. Robust design of nonlinear structures requires analysis of extensive parameter variations. Both the character of the stimulus and feature metrics used are central to the performance of a response classification approach. The main purpose of this study is to compare stimulus candidates with respect to their efficiency in response classification. A deterministic multilevel, multifrequency stepped-sine periodic test function is used as a baseline. Order-wise differences between generalized and linearized system frequency response functions are evaluated by a selected feature metric to allow categorization into primary, sub and super harmonic responses, as well as odd and even order response distortions. An alternative excitation function type is the pseudorandom phase multi-sine. Its robust variant estimates the best linear approximation of the generalized frequency response function and related nonlinear and noise variances, which can be used for response classification. The fast variant of this method further detects and classifies occurring even and odd order nonlinear responses using a hypothesis test. This article describes the application of these three methods to a virtually running two-piece rotor shaft model. Time response signals from simulated test parameter variations are used to calculate selected nonlinear feature metric values. The total simulation and measurement time, as well as the predictive performance in a few typical nonlinear response cases are evaluated.

Improvement Approaches for the Combustion Process of Recent Diesel Natural Gas Dual Fuel Engines – A Technical Review

Ship main engine exhaust gas emissions are a worldwide concern. Dual fuel diesel engines are a type of ship main engine that complies with MARPOL Annex VI. Low exhaust emissions and operational cost are the main advantages of using natural gas as fuel. Moreover, the use of natural gas improves lean combustion process; it results in fewer exhaust emissions and improves performance. Some technical adjustments are required to achieve maximum efficiency. This paper has reviewed various technical approaches to understand the combustion phenomenon of natural gas dual fuel engine diesel with experimental and numerical studies. Gaseous fuel/air mixture phenomena, pilot-fuel injection, and flame propagation processes that occur in the cylinder chamber are reviewed. Some improvements to the variation of test parameters of dual fuel diesel engines are highlighted to determine the characteristics. Additionally, the impact of natural gas-diesel dual fuel engines for performance and emissions is accurately described.

A new preparation method and imaging parameters of asphalt binder samples for atomic force microscopy

The sample preparation and the image acquisition method of asphalt binders are of importance to atomic force microscopy (AFM) imaging quality, especially for the peak force quantitative nanomechanical (PF-QNM) mode. Based on the heat-cast method, a new hot asphalt pouring method for asphalt binder AFM sample preparation was developed in this study. For different probe types and test parameters, samples of the commercial SK-70# asphalt binder prepared by the proposed technique were subjected to PF-QNM tests. The experimental results obtained proved the feasibility and stability of the proposed sample preparation method. Aluminum-coated probes with a nominal spring constant range from 0.4 to 6 N/m were found to furnish the optimal solution to the construction of topography and nanomechanical property maps of SK-70#. The variation of test parameters has shown that the peak force setpoint and peak force tapping (PFT) gain strongly influenced the microstructure topography and nanomechanical property maps. Using reasonable probes and imaging parameters, good AFM maps could be obtained. In this research, only one asphalt binder was tested and the effect of other probe types and test parameters on other asphalt binders need to be further studied in the future.

The suture retention test, revisited and revised.

A systematic investigation of the factors affecting the suture retention test is performed. The specimen width w and the distance a of the suture bite from the specimen free edge emerge as the most influential geometrical parameters. A conservative approach for the quantification of suture retention strength is identified, based on the use of a camera to monitor the incipient failure and detect the instant of earliest crack propagation. The corresponding critical force, called break starting strength, is extremely robust against test parameter variations and its dependence on the specimen geometry becomes negligible when a≥ 2mm and w≥ 10mm. Comparison of suture retention and mode I crack opening tests reveals a linear correlation between break starting strength and tearing energy. This suggests that the defect created by the needle and the load applied by the suture thread lead to a fracture mechanics problem, which dominates the initiation of failure.

Hydrogen explosions in 20′ ISO container

This paper describes a series of explosion experiments in inhomogeneous hydrogen air clouds in a standard 20′ ISO container. Test parameter variations included nozzle configuration, jet direction, reservoir back pressure, time of ignition after release and degree of obstacles. The paper presents the experimental setup, resulting pressure records and high speed videos. The explosion pressures from the experiments without obstacles were in the range of 0.4–7 kPa. In the experiments with obstacles the gas exploded more violently producing pressures in order of 100 kPa.

Effect of In Vitro Testing Parameters on Ceftazidime-Avibactam Minimum Inhibitory Concentrations.

Effects of varying in vitro susceptibility testing parameters of the broth microdilution assay on ceftazidime-avibactam MICs were determined and compared to meropenem and piperacillin-tazobactam for 9 Enterobacteriaceae and 4 Pseudomonas aeruginosa isolates. The effect of varying incubation conditions (ambient air or 5% CO2), pH of medium, medium composition (cation-adjusted Mueller Hinton Broth with and without laked horse blood and Haemophilus Test Medium), cation content of the medium, and inoculum density were tested. Most variations had no effect on ceftazidime-avibactam MIC values (no more than a 2-fold change). However, acidic pH or high inoculum resulted in 4- to 16-fold changes in MIC, which was similar to those observed for meropenem and piperacillin-tazobactam under these conditions. Overall, this study shows that slight variations in testing parameters during routine MIC testing will likely have no significant effect on ceftazidime-avibactam MIC values.

Microstructure evolution and abrasive wear behavior of D2 steel

The effect of heat treatment on microstructure and abrasive wear resistance of AISI D2 steel has been investigated in the present work. The structural characterization of hardened and multiple tempered specimens was carried out using scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). Two body abrasive wear tests were carried out using silicon carbide abrasive with systematic and simultaneous variation of test parameters. The abrasive wear volume loss increased with increasing tempering temperature and increasing severity of test conditions, although the increase was not proportionate. The worn out surface, wear debris and subsurface damage were examined using SEM, EDS and XRD. The results of present work were rationalized with respect to microstructure and operating wear mechanisms as influenced by severity of wear test conditions.

Variation in the seed progeny of smooth brome grass, Bromus inermis Leyss., under conditions of chronic irradiation in the zone of the Eastern Ural Radioactive Trace

Long-term studies have been performed on the seed progeny of B. inermis from test plots established along the radioactive contamination gradient in the zone of the Eastern Ural Radioactive Trace (EURT), where dose loads on maternal plants and embryos of seeds from chronically irradiated cenopopulations (with natural background radiation taken into account) exceed control values by factors of 2 to 107. Interannual and individual variation in the viability, mutability, and radiosensitivity of the seed progeny has been revealed. Against the background of high interpopulation variation in test parameters in the EURT zone, weather conditions appear to have no significant effect on seed quality, while such effects are appreciable in background cenopopulations. It has been shown that a positive correlation exist between the initial viability of the seed progeny and their radioresistance. Chronic irradiation in a wide dose range induces an increased frequency of different mutations and morphological modifications. The contents of low-molecular antioxidants in seedlings from impact cenopopulations proved to be higher than in the background sample. The results obtained characterize the potential of protective and restorative mechanisms acquired in the course of evolution that allow plants to survive in the changing environment under exposure to technogenic stress.

Effect of test parameters on large particle high speed slurry erosion testing

A high speed slurry-pot wear tester was developed for close-to-reality heavy-duty wear testing of materials used in mineral applications. The samples are attached on four levels in a pin mill configuration. The tester and the developed sample rotation test method deliver reproducible results. This study focuses on the effects of testing parameters in large particle slurry testing. Parameters such as the speed, particle size and slurry concentration were varied. The effect of test duration was also examined. Round steel samples and slurry of water and granite gravel were used for testing. The test parameter variations were 4 to 10 mm for particle size, up to 23 wt-% for concentration and up to 20 m s−1 for the sample tip speed. The relationships between the parameters are discussed. The kinetic energy of the large abrasive particles is also considered. Wear surfaces studied with optical and electron microscopy are also presented and discussed.

Diagnostic performance of the canine Influenza A Virus subtype H3N8 hemagglutination inhibition assay

Canine Influenza A virus subtype H3N8 (H3N8 CIV) was recognized in 2004 as a novel respiratory pathogen for dogs. To date, infections have been diagnosed in thousands of dogs in 38 U.S. states. Diagnostic techniques such as reverse transcription polymerase chain reaction (RT-PCR) and virus isolation may yield false-negative results if samples are collected after virus shedding has ceased. Therefore, serology is often necessary to confirm diagnosis. The hemagglutination inhibition (HI) assay is the test of choice for serological diagnosis of influenza infections in animals. However, discrepancies exist between diagnostic laboratories and research groups in some of the test parameters for the H3N8 CIV HI assay and the cutoff antibody titer for seropositivity. The objectives of the current study were 1) to assess the diagnostic performance of a H3N8 CIV HI assay using field sera from canine infectious respiratory disease outbreaks and 2) to evaluate the effect of test parameter variations on test performance, including the use of different red blood cell (RBC) species, serum treatment methods, and virus isolates. Based on a receiver operating characteristic analysis using serum microneutralization assay titers as the gold standard, the H3N8 CIV HI assay described in the present study is highly sensitive (99.6%) and specific (94.6%) when the cutoff antibody titer for seropositivity is 32. Evaluation of parameter variations determined that the sensitivity and specificity of the H3N8 CIV HI assay depend on serum pretreatment with a receptor-destroying enzyme or periodate, use of 0.5% turkey or chicken RBCs, and use of antigenically well-matched H3N8 virus strains.

Electrochemical investigation of erosion–corrosion using a slurry pot erosion tester

The aim of this paper is to use a modified slurry pot erosion tester to perform in-situ electrochemical measurements during solid particle impingement to investigate the effects of velocity, sand size and sand concentration on a passive metal (UNS S31603). Samples are subjected to a set of erosion–corrosion experiments. The electrochemical response of UNS S31603 to the test parameters is plotted and compared to develop an understanding of the erosion–corrosion process. The current trend with variation of test parameters has been explained by an erosion enhanced corrosion synergistic effect. The current transients associated with depassivation and repassivation during solid particle impingement are observed through electrochemical noise measurements. It was observed that the increase in velocity and sand concentration increased the current levels during erosion–corrosion. However, the increase in sand size had a more complex response. Single particle impact experiments conducted revealed that the peak corrosion current and the repassivation time increased with increase in velocity. A linear trend was seen between the peak current and the kinetic energy. A second-order exponential decay was fitted to the repassivation kinetics of the single particle impact. SEM has been used to develop a mechanistic understanding of erosion–corrosion. The surface scars reveal that the depth of the craters and the length of the lips increase with increase in velocity. Micro-cracks also appear on these lips, believed to be due to corrosive action attacking the roots of these lips.