Objectives: Medical students are more susceptible to depression than other students. Moreover, students with the symptoms of depression statistically more often abuse drugs and have suicidal thoughts and anxiety. The level of stress and the factors that lead to in among medical students at Polish universities have not yet been measured. The aim of this study was to translate to Polish and validate the Perceived Medical School Stress Instrument (PMSS-PL) and to measure the resulting version’s psychometric abilities.
Materials and Methods: We validated the Polish translation of PMSS in accordance with the recommendations published by the Translation and Cultural Adaptation group of the Quality of Life Special Interest group of the International Society for Pharmacoeconomics and Outcomes Research. The Perceived Stress Scale (PSS-10) was used as an external test to validate the PMSS-PL questionnaire. A total of 430 undergraduate medical students at the Medical College of Jagiellonian University took part.
Results: The mean PMSS-PL score was 36.43 and it varied from 13 to 65. The mean PSS-10 was 21.35. The internal reliability, as indicated by Cronbach’s alpha, was 0.803, which means there was internal reliability between PSS-10 and PMSS-PL. Moreover, all questions from PMSS-PL had a positive discri-mination power, so each question correlated positively with the other questions in PMSS-PL.
Conclusions: PMSS-PL may be used to psychometrically analyze the stress load on undergraduate medical students at Polish universities. The PMSS-PL may also be used as an external test for validating and calculating the reliability and accuracy of other psychometric instruments.
Validation results of a theoretical model that describes the formation of bromate during ozonation of bromide-containing natural waters are presented. An axial dispersion model integrating the nonideal mixing, mass-transfer and a kinetic model that links ozone decomposition reactions from the Tomiyasu, Fukutomi and Gordon ozone decay model with direct and indirect bromide oxidation reactions, oxidation of natural organicmatter and reactions of dissolved organics and aqueous bromine was verified. Themodel was successfully validated with results obtained both at a laboratory and a full scale. Its applicability to different water supply systems was approved.
In the paper, problem of proper tuning of second-order Reduced Active Disturbance Rejection Controller (RADRC2) is considered in application for industrial processes with significant (but not dominant) delay time. For First-Order plus Delay Time (FOPDT) and Second-Order plus Delay Time (SOPDT) processes, tuning rules are derived to provide minimal Integral Absolute Error (IAE) assuming robustness defined by gain and phase margins. Derivation was made using optimization procedure based on D-partition method. The paper also shows results of comprehensive simulation validation based on examplary benchmark processes of more complex dynamics as well as final practical validation. Comparison with PID controller shows that RADRC2 tuned by the proposed rules can be practical alternative for industrial control applications.
An HPLC-DAD method was developed for the determination of formaldehyde in animal feed and silage. The method is based on the determination of the product of chemical reaction between formaldehyde and 2,4-dinitrophenylhydrazine. A 3 g of feed or silage were extracted with Milli-Q water with phosphoric acid and next formaldehyde was derivative with the use 2,4-dinitrophenyl- hydrazine in acetronitrile solution. The extract was purified with 0.45 µm syringe filters and separeted on Zorbax Eclipse XDB C18 column and detection was carried out at 360 nm. Formal- dehyde was eluted with a mobile phase consisting of acetonitrile/water in isocratic elution. This method provided average recoveries of 90.6% to 102.2%, with CVs of 2.6% to 6.4% for feed and from 91.3% to 108.7% with CVs of 1.1% to 4.1% for silage in the ranged of 50 to 1000 mg/kg feeds and silage. The LOD and LOQ for formaldehyde in feed and silage ranged from 1.6 to 2.6 and 2.7 to 5.7 mg/kg, respectively. The methodology was applied for the analysis of feed and silage samples collected from poultry, pigs and cows farms.
Simplifications used in simulation program codes require the use of substitute parameters in the material databases (also called apparent or substitutive). On the one hand, they formally fit into the records used in the heat flow model, porosity, properties etc. and on the other hand they should be determined in conditions most similar to the real casting-mould system.
The article presents results of a research on thermophysical parameters of gypsum mould used for precision casting moulds. Experiments were carried out on a cylindrical mould made of Plasticast gypsum, in which the heat source was a cylinder filled with liquid aluminium alloy of the temperature of 655°C. Energetic validation was carried out by using the NovaFlow&Solid ver. 6.3 simulation code. As a result of validation tests, substitute thermophysical parameters of gypsum were determined. For determined parameters, best-fit of solidification time from the experiment and simulation was obtained and the curves of gypsum mass heating were satisfactorily recreate.
Buildings consume half of all energy use and are also responsible for a similar proportion of carbon dioxide emission. The heat transfer across the building envelope - the shell of a house that separates the inside and outside - should generally be minimized. In the paper validation and verification based on Building Energy Simulation Test (BESTEST) of Energy3D computer code is presented. Next, computations performed by means of Energy 3D and Energy Plus for BESTEST building are compared. In the last part of the paper results for computations for real building are presented. Program Energy 3D proved to be an excellent tool for qualitative and quantitative analysis of buildings with respect to energy consumption.
In the article, a validation module, being a component of an integrated system supporting routing in software defined networks (SDNRoute), is proposed and thoroughly examined. The module allows for the verification of the results provided by the optimization module before these results are deployed in the production network. Routing policies are validated for their impact on the network quality parameters and against the threat of overloading (congestion).
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