No description available.

The objectives of the present study were to: (a) replicate the results of Arthur et al. (2002) by comparing race-based subgroup differences on a multiple-choice and constructed response test in a laboratory setting using a larger sample, (b) extend their work by investigating the role of reading ability, test-taking skills, and test perceptions that could explain why subgroup differences are reduced when the test format is changed from multiple-choice to a constructed response format, and (c) assess the criterion-related validity of the constructed response test. Two hundred sixty White and 204 African Americans completed a demographic questionnaire, Test Attitudes and Perceptions Survey, a multiple-choice or constructed response test, the Raven's Advanced Progressive Matrices Short Form, the Nelson-Denny Reading Test, Experimental Test of Testwiseness, and a post-test questionnaire. In general, the pattern of results supported the hypotheses in the predicted direction. For example, although there was a reduction in subgroup differences in performance on the constructed response compared to the multiple-choice test, the difference was not statistically significant. However, analyses by specific test content yielded a significant reduction in subgroup differences on the science reasoning section. In addition, all of the hypothesized study variables, with the exception of face validity, were significantly related to test performance. Significant subgroup differences were also obtained for all study variables except for belief in tests and stereotype threat. The results also indicate that reading ability, test-taking skills, and perceived fairness partially mediated the relationship between race and test performance. Finally, the criterion-related validity for the constructed response test was stronger than that for the multiple-choice test. The results suggested that the constructed response test format investigated in the present study may be a viable alternative to the traditional multiple-choice format in high-stakes testing to solve the organizational dilemma of using the most valid predictors of job performance and simultaneously reducing subgroup differences and subsequent adverse impact on tests of knowledge, skill, ability, and achievement. However, additional research is needed to further demonstrate the appropriateness of the constructed response format as an alternative to traditional testing methods.

The objectives of the present study were to: (a) replicate the results of Arthur et al. (2002) by comparing race-based subgroup differences on a multiple-choice and constructed response test in a laboratory setting using a larger sample, (b) extend their work by investigating the role of reading ability, test-taking skills, and test perceptions that could explain why subgroup differences are reduced when the test format is changed from multiple-choice to a constructed response format, and (c) assess the criterion-related validity of the constructed response test. Two hundred sixty White and 204 African Americans completed a demographic questionnaire, Test Attitudes and Perceptions Survey, a multiple-choice or constructed response test, the Raven's Advanced Progressive Matrices Short Form, the Nelson-Denny Reading Test, Experimental Test of Testwiseness, and a post-test questionnaire. In general, the pattern of results supported the hypotheses in the predicted direction. For example, although there was a reduction in subgroup differences in performance on the constructed response compared to the multiple-choice test, the difference was not statistically significant. However, analyses by specific test content yielded a significant reduction in subgroup differences on the science reasoning section. In addition, all of the hypothesized study variables, with the exception of face validity, were significantly related to test performance. Significant subgroup differences were also obtained for all study variables except for belief in tests and stereotype threat. The results also indicate that reading ability, test-taking skills, and perceived fairness partially mediated the relationship between race and test performance. Finally, the criterion-related validity for the constructed response test was stronger than that for the multiple-choice test. The results suggested that the constructed response test format investigated in the present study may be a viable alternative to the traditional multiple-choice format in high-stakes testing to solve the organizational dilemma of using the most valid predictors of job performance and simultaneously reducing subgroup differences and subsequent adverse impact on tests of knowledge, skill, ability, and achievement. However, additional research is needed to further demonstrate the appropriateness of the constructed response format as an alternative to traditional testing methods.

The NIST miniature paste prism test was developed to assess sulphate resistance of cements faster than the commonly used ASTM C 1012 test. The goal of this research is to address the current limitations regarding the NIST procedure to determine the optimum testing parameters and to establish appropriate expansion limits. A range of variables including details of specimen design, curing regime, water-to-cementitious materials ratio, and prism length were tested on the materials with a wide range of sulphate performance. The findings of the study demonstrate that even though it can yield results in only three months, the NIST test can provide an erroneous differentiation between certain cementitious materials. Reliability and repeatability of the test results can be improved by using longer specimens and longer curing times. The NIST test can be used as a preliminary screening test, but users need to be aware of its limitations.

The NIST miniature paste prism test was developed to assess sulphate resistance of cements faster than the commonly used ASTM C 1012 test. The goal of this research is to address the current limitations regarding the NIST procedure to determine the optimum testing parameters and to establish appropriate expansion limits. A range of variables including details of specimen design, curing regime, water-to-cementitious materials ratio, and prism length were tested on the materials with a wide range of sulphate performance. The findings of the study demonstrate that even though it can yield results in only three months, the NIST test can provide an erroneous differentiation between certain cementitious materials. Reliability and repeatability of the test results can be improved by using longer specimens and longer curing times. The NIST test can be used as a preliminary screening test, but users need to be aware of its limitations.

Gimdos kaklelio vėžys pasaulyje yra antroji, o Lietuvoje ketvirtoji pagal dažnumą moterų onkologinė liga. Pagrindinė gimdos kaklelio vėžio priežastis yra žmogaus papilomos viruso (ŽPV) infekcija gimdos kaklelyje. Vakarų šalyse ikivėžiniams pokyčiams ar vėžinėms ląstelės nustatyti yra naudojamas citologija paremtas Papanicolaou testas (Pap) ir ŽPV DNR testas. Šiuo metu naudojami ŽPV diagnostiniai testai remiasi molekulinės biologijos tyrimo metodais. Tyrimui buvo pasirinktas polimerazės grandininės reakcijos (PGR) metodas, o ne plačiai naudojamas JAV bei Europos kokybės sertifikatus turintis Hybrid Capture 2 (HC2) metodas. PGR yra ypač jautrus, greitas, komerciškai prieinamas metodas, kuriam reikalingas nedidelis tiriamosios medžiagos kiekis, ir kuriuo galima tiksliai identifikuoti ŽPV tipus. HC2 metodas nenustato ŽPV genotipų, galimi klaidingai neigiami rezultatai, nes nėra vidinės kontrolės, o dėl kryžminių reakcijų galimi klaidingai teigiami rezultatai. Naujausi literatūros šaltiniai teigia, kad PGR turi daug perspektyvų ateityje ir manoma, kad ŽPV nustatymo standartas bus 14 DR-ŽPV tyrimas sujungtas su ŽPV-16 ir ŽPV-18 tipų nustatymu. Todėl siekiant ŽPV tyrimams pasirinkti optimaliausią iš Lietuvoje siūlomų komercinių rinkinių Valstybiniame patologijos centre buvo atliekamas šis tyrimas. Įvertinus tyrimų rezultatus, tolesniems tyrimams pasirinktas „Seeplex® HPV4A ACE Screening“ ŽPV nustatymo rinkinys. / Cervical cancer is the second oncological disease in women in the world, and the fourth one in Lithuania. The main cause of the cervical cancer is Human papillomavirus (HPV) infection in the cervix uteri. In order to detect precancerous changes or cancer cells, a Papanicolaou (Pap) test based on cytology and HPV DNA test are used in the Western world. Currently used HPV diagnostic tests are based on molecular biology testing methods. The polymerase chain reaction (PCR) method, not the extensively used Hybrid Capture 2 (HC2) method awarded the certificate of quality by both the USA and Europe, was chosen. PCR is a particularly sensitive, fast, and commercially available method that needs a small quantity of research material and can identify the types of HPV. HC2 method does not detect HPV genotypes, false-negative results are possible because there is no internal control, and due to cross reactions, false-positive results are possible. The newest written sources state that PCR will have much potential in the future and it is thought that HPV detection standard will become 14 HR-HPV test combined with the detection of the types of HPV-16 and HPV-18. Therefore, in order to chose the optimum one for HPV tests from the commercial kits offered in Lithuania, this investigation was carried out in the National Centre of Pathology. Four different HPV diagnostic kits were used for the research. Having evaluated the research results, „Seeplex® HPV4A ACE Screening“ HPV diagnostic kit was... [to full text]

The introduction of the diploma thesis contains basic concepts of testing of plastic moulded products and their general characteristics essential for use in the medical device industry. In the following theoretical part there is described the methodology of practical testing techniques used by Phillips Medisize CZ company. At the closing part of the diploma thesis there is made a summary of the testing methods, their evaluation and potential proposals for improvement of the applied methodology.

This thesis is focused on detecting air leakage in serial production of pneumatic linear actuators. Testing for air leakage is an important part of the production process in which the manufacturer ensures that the product satisfies quality requirements and works correctly. The thesis was created in collaboration with the Czech manufacturing plant of SMC Industrial Automation CZ s.r.o., which produces pneumatic actuators. Goal of the design part of the thesis is to select the most effective method for testing and finding universal principle for testing in specified conditions. The principle is then applied to design a testing device for the CQ2 cylinders. The testing device consists of three parts - pneumatic circuit, control circuit and electric circuit. Thesis conclusion contains comparison of the newly designed testing device with the device currently in use.

No description available.

When processing materials, there are a number of factors which influence the final quality of products. The possibility of defects occurrence, both sub-surface and surface ones, is one of the factors. In the precision engineering production, the automotive, bearing or aerospace industry in particular, no level of defects is tolerable. The thesis deals with the causes and consequences of the occurrence of such defects, and the methods for their identification. For this purpose, a new contactless optical method for the fully automatic inspection of the surface defects has been developed by Mesing, spol. s r.o. In order to verify the performance of the aforementioned method, four specific products have been tested by the author using the method. Finally, there are examples of the successful implementation of the automatic machines, for a design of which the results of the model testing were utilized.