Przedstawiono wyniki ilościowej analizy dyfuzji nieizobarycznej przez materiały makroporowate. Na podstawie uogólnionego modelu gazu zapylonego dokonano oceny udziału przepływu lepkiego. Zaobserwowano zjawisko odwrócenia strumieni molowych, pojawiające się dla pewnej średnicy porów, nawet wówczas gdy dyfuzja następuje przy ustalonej różnicy ciśnień pomiędzy obydwiema stronami membrany. Podano sposób określenia tej średnicy. Zaproponowano uproszczoną metodę obliczania średniej lepkości gazów i dokonano jej oceny. Przedstawione równania modelu są słuszne dla dyfuzji K-składnikowej. Metodę zilustrowano na przykładzie roztworu dwuskładnikowego: argon, metan.
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Numerical studies of mass diffusion through porous materials were carried out for a two-component mixt. of Ar and CH4 gases. Using the generalized dusty gas model, an assessment of viscous flow contribution was performed. Reversing of molar fluxes were obsd. for certain pore diam. even at fixed transmembrane pressure difference. A method for detg. the diam. was given. A simplified method for detg. av. viscosity of gaseous mixts. was proposed and assessed. Presented model equations are valid for multicomponent diffusion.
Indicators, different in terms of nature and grading scales, are used to recognise hazardous and harmful factors that affect human health. However, no single methodology is available for their assessment, and the variety of qualimetric assessment methods requires in-depth research, in part on optimality and efficiency. Therefore, this work aimed to conduct several scientific studies to obtain the results of the assessment in unified units of measurement, which would provide a generalised indicator of harmful factors at the workplace. The article proposes to use dependencies to assess indicators of harmful factors, considering the maximum, minimum, and optimal values as well as the shape parameter, the change of which produces various assessments in a dimensionless scale. A hierarchy analysis method was used to obtain reliable values with a small number of experts and determine the form parameter. These efforts resulted in the value of the overall index for harmful factors, which serves as grounds for decisions regarding further improvements in working conditions. The developed methodology was used to assess the safety of working conditions at a machine-building enterprise, and the results are presented in the article.
Ship’s bridge simulators are very popular in the worldwide training and assessment of merchant navy deck officers. The examiners of simulator courses presently do not have a method to quantitatively assess the performance of a group or an individual. Some examiners use checklists and others use their gut feeling to grade competence. In this paper a novel methodology is established that uses the Evidential Reasoning algorithm to quantitatively assess the Non-Technical Skills (NTS) of merchant navy officers. To begin with, interviews were conducted with experienced deck officers to develop the taxonomy and behavioural markers that would be used in the assessment process. A random selection of students studying towards their Chief Officer’s Certificate of Competency were recruited to have their NTS to be observed in a ship’s bridge simulator. The participant’s behaviour was rated against five criteria and the subsequent data was entered into the Evidential Reasoning algorithm to produce a crisp number. The results that were generated demonstrate that this approach provides a reliable method to quantitatively assess the NTS performance of merchant navy officers in a simulated bridge environment.
Celem artykułu jest analiza zasad i wyników oceny okresowej nauczycieli akademickich na przykładzie Politechniki Śląskiej. Artykuł został podzielony na 4 rozdziały. W pierwszym z nich opisano zasady oceny nauczycieli akademickich przed 2012 roku. Drugi rozdział koncentruje się na przedstawieniu sparametryzowanych kryteriów oceny pracowników po 2012 roku. W rozdziale 3 posłużono się zebranymi w 2015 roku danymi, które wykorzystano w procesie opracowania wyników za pomocą podstawowych statystyk, podsumowujących przeprowadzoną ocenę okresową. W ostatnim rozdziale przeprowadzono porównanie oceny jakościowej i ilościowej pracowników naukowych w Politechnice Śląskiej.
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The objective of the article is to analyze the principles and the results of the interim evaluation of academic teachers for example of the Silesian University of Technology. Article has been divided into 4 chapters. The first of these describes the principles for the evaluation of university teachers before 2012. The second chapter focuses on the presentation of parameterized evaluation criteria after 2012. In Chapter 3 the authors used data collected in 2015 to present the results of evaluation. They present main descriptive statistics, summarizing taken consideration and research. In the last chapter the comparative analysis between internal units of examined faculty is establish.
This paper presents the process of quantitative assessment of selected factors influencing the probability of grounding. All grounding accidents that occurred during one year (2013) in the Baltic Sea area were analysed. The research area was chosen because of very high traffic intensity and a large number of narrow passages that make it difficult for navigation. The research period was limited by the latest data reported by HELCOM up to the year 2013. The Method of Grounding Probability Coefficient (GPC) calculation is proposed to reach the assumed goal. Either internal factors such as the ships size and ship type or external factors such as time of day, wind force and season were taken into account. As a result the values of coefficients describing the impact of various factors on the probability are evaluated. This coefficients, taking into consideration coupling effect, can be used in future in the navigational safety simulation models based on the assumed value of accident probability.
Wyjątkowe wartości obciążeń, które należy brać pod uwagę w projektowaniu konstrukcji, nie mają w eurokodach definicji probabilistycznej. W artykule rozpatrzono możliwość zdefiniowania wyjątkowego obciążenia śniegiem jako znacznie odbiegającego od pozostałych wartości zmierzonych. Przedstawiono propozycję wyznaczenia wartości wyjątkowych jako stosunku maksymalnych wartości obciążenia śniegiem gruntu, zmierzonych w rozpatrywanym okresie obserwacji, do wartości prognozowanych o takim samym okresie powrotu jak czas obserwacji.
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Exceptional loads that are to be taken into account in structural calculations are not defined in Eurocodes in the term of probabilistic analysis yet. The paper deals with the possibility to define the exceptional snow loads on the ground as outliers on the empirical distribution plot of measured values. The ratio of the maximum measured values to the foreseen ones of the same return period has been proposed as the exceptional snow loads.
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W artykule opisano jakościowe i ilościowe metody oceny napowietrzenia betonu, tak zawarte w normach jak i nieznormalizowane. Z tych ostatnich opisano badania "wskaźnika piany", "trwałości piany", "wyporu hydrostatycznego", a także podano ich zalety i wady. Poruszono także wpływ na uzyskiwane wyniki dodatku popiołów lotnych. Dużo miejsca poświęcono mikroskopowym metodom badania mikrostruktury porów. Podkreślono niedogodność związaną z brakiem normy na ten temat. Wymieniono także normy duńskie i niemieckie, a kanadyjskie pod kątem wymagań związanych z infrastrukturą drogową.
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In the paper the qualitative and quantitative methods of concrete air entrainment were presented, not only these which are in standard, but also behind them. From the last ones the foam index, foam stability and the method applying buoyancy rule of particles migration were described and their drawbacks as well as the good points are given. Detailed discussion is devoted to microscopic method of pores structure determination and the drawback of standard lack is underlined. Also the Danish, German and Canadian Standard are discussed, the last one especially in the case of roads construction.
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W artykule przedstawiono zastosowanie termografii aktywnej do ilościowej oceny zawartości proszku węgla (grafitu i węgla antracytowego) w kompozytach o osnowie epoksydowej. Uzyskane podczas badań termograficznych charakterystyki czasowo-temperaturowe użyto do wyznaczenia dyfuzyjności cieplnej kompozytów. Na podstawie uzyskanych wyników badań stwierdzono, że zaproponowana metoda badawcza może być z powodzeniem zastosowana do ilościowej oceny zawartości proszku węgla w kompozytach polimerowych o osnowie epoksydowej.
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The application of active thermography for the quantitative assessment of carbon powder (graphite and anthracite coal) content in epoxy matrix has been presented in this article. Temperature-time dependences obtained during thermographic measurements were used to determine the thermal diffusivity of composites. On the basis of obtained results of the measurements, it was summarized that the proposed testing method can be applied in quantitative assessment of carbon powder content in epoxy matrix composites.
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The paper describes the influence of age-hardening by solution treatment at 515 C with holding time 4 hours, water quenching at 40 C and artificial aging at different temperature 130 C, 150 C and 170 C with different holding time 2, 4, 8, 16 and 32 hours on mechanical properties (strength tensile and Brinell hardness) and changes in the morphology of eutectic Si, Fe-rich and Cu-rich intermetallic phases in secondary (recycled) AlSi9Cu3 cast alloy. The structure with of black-white etching was observed (Dix-Keller, H2SO4). A quantitative study of changes in the morphology of eutectic Si, Cu-rich and Fe-rich phases was carried out using Image Analyzer software NIS-Elements. The analysis of intermetallic phases was performed on SEM using EDX. Mechanical properties were measured in line with STN EN ISO. Age-hardening led to changes in the microstructure including spheroidization and coarsening of eutectic silicon, gradual disintegration, shortening and thinning of Fe-rich intermetallic phases, the dissolution of precipitates and the precipitation of finer hardening phase (Al2Cu), further increase in the hardness and tensile strength in the alloy.
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