Effect of Nb and Ti micro-additives and thermo-mechanical treatment of high-manganese steels with aluminium and silicon on their microstructure and mechanical properties

The r esults are based on two experimental high-manganese X98MnAlSiNbTi24-11 and X105MnAlSi24-11 steels subjected to thermo-mechanical treatment by hot-rolling on a semi-industrial processing line. The paper presents the results of diffraction and structural studies using scanning and transmission electron microscopy showing the role of Nb and Ti micro-additives in shaping high strength properties of high-manganese austenitic-ferritic steels with complex carbides. The performed investigations of two experimental steels allow to explain how the change cooling conditions after thermo-mechanical treatment of the analysed steels affects the change of their microstructure and mechanical properties. The obtained results allow assessing the impact of both the chemical composition and the applied thermo-mechanical treatment technology on the structural effects of strengthening of the newly developed steels

Changes in the prevalence of cigarette smoking and quitting smoking determinants in adult inhabitants of rural areas in Poland between 2003 and 2012.

OBJECTIVES: We investigate trends in the prevalence of cigarette smoking among adults at all ages in two time points 9 years apart in two neighbouring rural populations and examine social and respiratory health determinants of quitting smoking. STUDY DESIGN: Repeated cross-sectional study. METHODS: Two cross-sectional surveys were conducted in the same rural area of lower Silesia in Poland in 2003 and 2012. A total of 1328 (91% of adult eligible individuals) in 2003 and 1449 (92% of eligible) in 2012 adult inhabitants were surveyed, 908 people (560 villagers and 348 town inhabitants) participated in both surveys. Participants completed a questionnaire on smoking behaviour, education level and respiratory diseases. RESULTS: Current smoking was higher in the villages than the town, among men than women and those with a middle level of education. The prevalence of current smokers decreased over time, although this decline was much more pronounced in the town than in the villages (30.2% vs 23% and 35.5% vs 33.7%, respectively). Men were more likely to stop smoking than women both in villages and in town. The prevalence of current smokers among village women even increased between the two surveys from 27.6% to 29.3%. Respiratory diseases did not influence quitting smoking. CONCLUSIONS: The degree of decreasing trend in smoking prevalence varied considerably within neighbouring populations. It was mainly seen in the town and among younger people. Men and those better educated were more willing to quit smoking. The discrepancies between two close rural populations indicates the need for an individual approach when designing programs of tobacco control

Identyfikacja i ocena wady frekle w kierunkowo krystalizowanym odlewie z nadstopu niklu PWA 1426

Manufacturing of modern aero engine turbine blades made of nickel-based superalloys is very complex and expensive. The thrust and performance of new engines must address constantly more demanding requirements. Therefore, turbine blades must be characterised by very good mechanical properties, which is possible only if the blades are free of casting defects. An important innovation has been the launching of directionally solidified (DS) and single crystal (SX) turbine blades. But, manufacturing procedures and the chemical composition of many superalloys promote the formation of casting defects that are characteristic only for directional solidification. One of these defects is freckles. Freckles are small equiaxed grains in the form of long chains parallel to the solidification direction and are located on the surface of the casting. Freckles decrease the mechanical properties of DS and SX blades; therefore, they should be always unambiguously identified to improve the manufacturing process. This work presents the possibilities of identifying and evaluating freckles in DS casting made of PWA 1426 superalloy by combining the scanning electron microscopy (SEM), electron probe microanalysis (EPMA) and electron backscatter diffraction (EBSD) techniques.Wytwarzanie łopatek turbin nowoczesnych silników lotniczych jest bardzo złożone i kosztowne. Stale rosną też wymagania dotyczące ciągu i sprawności nowych silników. Dlatego łopatki turbin musza charakteryzować się bardzo dobrymi właściwościami mechanicznymi. Jest to możliwe tylko wtedy, gdy łopatki nie wykazują wad odlewniczych. Ważną innowacją w wytwarzaniu łopatek było wprowadzenie łopatek kierunkowo krystalizowanych (DS) i monokrystalicznych (SX). Skład chemiczny wielu nadstopów i proces wytwarzania łopatek stanowią czasem czynniki sprzyjające powstawaniu wad odlewniczych, charakterystycznych tylko dla procesu kierunkowej krystalizacji. Przykładem takiej wady są frekle. Wada ta ma postać małych, równoosiowych ziaren tworzących łańcuchy, przeważnie równoległe do kierunku krystalizacji. Wada ta znacznie obniża właściwości mechaniczne łopatek DS i SX, dlatego powinna być zawsze jednoznacznie identyfikowana w celu usprawnienia procesu ich wytwarzania. W pracy przedstawiono możliwości identyfikacji i oceny wady frekle w kierunkowo krystalizowanym odlewie z nadstopu niklu PWA 1426 przy użyciu elektronowej mikroskopii skaningowej (SEM), mikroanalizy rentgenowskiej (EPMA) i dyfrakcji elektronów wstecznie rozproszonych (EBSD)

Investigation of Stress Corrosion Cracking in Magnesium Alloys by Quantitative Fractography Methods

The article shows that the use of quantitative fracture description may lead to significant progress in research on the phenomenon of stress corrosion cracking of the WE43 magnesium alloy. Tests were carried out on samples in air, and after hydrogenation in 0.1 M Na2SO4 with cathodic polarization. Fracture surfaces were analyzed after different variants of the Slow Strain Rate Test. It was demonstrated that the parameters for quantitative evaluation of fracture surface microcracks can be closely linked with the susceptibility of the WE43 magnesium alloy operating under complex state of the mechanical load in corrosive environments. The final result of the study was the determination of the quantitative relationship between Slow Strain Rate Test parameters, the mechanical properties, and the parameters of the quantitative evaluation of fracture surface (microcracks)

Characterization of Corrosion and Stress Corrosion Cracking of AE44 Magnesium Alloy

The paper presents the susceptibility of AE44 magnesium alloy to electrochemical corrosion and stress corrosion cracking (SCC). The evaluation of the intensity of the interaction of the corrosive environment was carried out using the corrosion tests and the Slow Strain Rate Test (SSRT). Corrosion tests performed in 0.1 M Na2 SO4 solution (immersion in solution and under cathodic polarization conditions) revealed that the layer of corrosion products was much thicker after immersion test. The results of SSRT showed that the AE44 alloy deformed in the solution was characterized by higher plasticity compared to the alloy deformed in the air after immersion in solution. Moreover, the fractures were characterized by different morphology. In the case of an alloy deformed in the solution under cathodic polarization many microcracks on the fracture were observed, which were not observed in the case of the alloy deformed in the air

Consumption of unpasteurized milk and its effects on atopy and asthma in children and adult inhabitants in rural Poland.

BACKGROUND: Consumption of unpasteurized cow's milk has been identified as a possible protective factor for atopy and asthma. Most studies have been conducted among children and in farming populations. We investigated the effects of consumption of unpasteurized milk in early life on atopy, asthma, and rhinitis in village and town inhabitants in a region of Poland and assessed whether any protective effects of milk consumption differed according to place of residence and farming status. METHODS: We surveyed the inhabitants (aged >5 years) of a small town and seven nearby villages in southwest Poland (n = 1700, response rate 88%). Participants (or their parents for those <16 years of age) completed a questionnaire on farm exposures and symptoms of asthma and rhinitis. In particular, information was collected on unpasteurized milk consumption in early life. Atopy was assessed using skin prick tests. RESULTS: Consumption of unpasteurized milk in the first year of life was inversely associated with atopy and asthma both among town and village inhabitants - town: adjusted odds ratio (aOR) for atopy 0.46 [95% confidence interval (CI) 0.37-0.52] asthma 0.51 (0.32-0.74); villages: atopy 0.59 (0.44-0.70) and asthma 0.59 (0.42-0.74). For atopy, the protective effect was more clearly seen among nonfarmers (0.42; 0.34-0.46) than in farmers (0.82; 0.54-1.11). For doctor-diagnosed hay fever and current rhinitis symptoms, the protective effect was only observed among town inhabitants and/or nonfarmers. CONCLUSIONS: Early-life exposure to unpasteurized milk may protect against atopy, asthma, and related conditions, independently of place of residence and farming status, and in both children and adults

Changes in atopy prevalence and sibship effect in rural population at all ages.

BACKGROUND: We examined the associations of family size and birth order with atopy prevalence in rural Poland at two time periods. METHODS: Two cross-sectional surveys were conducted in the same villages and a small town of lower Silesia at an interval of 9 years. In 2003, 1700 (88% of eligible individuals), and in 2012, 1730 (86%) inhabitants aged 5 years or more completed a questionnaire and had a skin prick test for atopy. RESULTS: There was an inverse association between family size and atopy in the village population in 2003; the prevalence of atopy was the highest for those with no siblings (15.2%) and decreased to 5.4% for those with three and more siblings (OR = 0.22; 0.07-0.66). In contrast, there was little or no such protective effect in the town population where the prevalence of atopy was much higher (7.3% in the villages, 20.0% in the town). Nine years later, the prevalence of atopy had increased in the village to be similar to that in the town (19.6% and 19.9% respectively), and the protective effects of family size and birth order in the villages were much weaker (OR = 0.64; 95% CI 0.33-1.27 for three or more siblings). Both protective effects were strongest among children. CONCLUSIONS: The protective effects of family size and birth order on atopy were much stronger in children than in adults and among those living in a village. They largely disappeared with the steep increase in atopy prevalence at all ages; this followed environmental changes on the village farms

Effect of body weight on disability and chronic disease rates in the elderly in south-eastern Poland

Introduction and objective. The rapid aging of the human population is an increasing challenge to public health. Effective strategies are required to prevent disability and dependency of the elderly. This study aimed to evaluate the effect of body weight on the prevalence of disability and chronic diseases among 60–80-year-old people living in south-eastern Poland. Materials and method. The study included 1,800 randomly selected people aged 60–80 years living in the Podkarpackie region of south-eastern Poland. Respondents, holders of a – personal identification number (PESEL), were randomly drawn by the Ministry of Interior and Administration (MSWiA) in Poland. The study was conducted in the form of a face-to-face interview at the respondent’s residence. The WHODAS 2.0 questionnaire was used to assess disability and functioning. Socio-demographic data were also collected, and the body weight measured in 5% of the respondents after completion of the study. Statistical analysis was performed using Statistica 10. Results. Respondents with Body Mass Index (BMI)<18.5 and BMI ≥35.0 had significantly higher disability levels than those in the normal weight and overweight categories. The greatest limitations were found in participating in everyday life, household activities, getting along and mobility. There was also a statistically significant relationship between BMI and the number of chronic diseases (p<0.001). Conclusions. When planning a healthcare strategy for people aged 60–80 living in Poland, additional support should be provided to those at risk in the categories of underweight and obesity. The obtained findings indicate that the health behaviour of seniors should be assessed – especially regarding their diet and eating habits, physical activity, and participation in social life – in order to tailor prevention programmes specifically to their needs