The Influence of Microstructure on Hydrogen Diffusion and Embrittlement of Multiphase Fine-Grained Steels with Increased Plasticity and Strength

The influence of microstructure on hydrogen diffusion and embrittlement of multiphase fine-grained structural steels with increased plasticity and strength was studied with electrochemical experiments which provide the hydrogenation of specimens in conditions simulating practice requirements. By means of all experimental data obtained from permeation experiments, mechanical investigations, SEM and EDS analyses, TRIP steel has shown greater resistance to hydrogen embrittlement than DP steel, testified by lower index of hydrogen embrittlement, lower diffusion coefficient, less inclusions and favourable microstructure with residual austenite. Namely, the residual austenite in the aspect of hydrogen embrittlement is a favourable phase in relation to martensite, because of its higher solubility of carbon and hydrogen and lower hardness. Therefore, TRIP steel could be considered the more suitable structural material than DP steel for application in conditions where contact with hydrogen is inevitable

Adsorption of Organic Acids on Blast Furnace Sludge

This paper describes the adsorption of two organic (acetic and citric) acids on the blast furnace sludge, a representative by-product of the steelmaking industry. By PIXE, XRD, BETand SEM methods, it was shown that blast furnace sludge is a complex heterogeneous material with a specific surface area of s = 31.46 m2 g–1, composed mainly of amorphous phase (w = 76.2 %), calcite (w = 9.9 %), magnetite (w = 6.3 %) and kaolinite (w = 2.2 %). Chemically, blast furnace sludge is dominated by O (w = 42.23 %) and C (w = 31.74 %). The adsorption process is analyzed using the theories of Freundlich and Langmuir. The experimental data were better fitted to the Langmuir isotherm. The negative Gibbs energy values indicate the spontaneous nature of adsorption. After adsorption the surface image changes in the BFS were observed, and BET surface area increased when acetic acid was adsorbed. Contrarily, blast furnace sludge became almost non-porous in the case of citric acid adsorption and BETsurface area decreased significantly

A prospective analysis of the injury incidence of young male professional football players on artificial turf

Background: The effects of synthetic surfaces on the risk of injuries is still debated in literature and the majority of published data seems to be contradictory. For such reasons the understanding of injury incidence on such surfaces, especially in youth sport, is fundamental for injury prevention. Objectives: The aim of this study was to prospectively report the epidemiology of injuries in young football players, playing on artificial turfs, during a one sports season. Patients and Methods: 80 young male football players (age 16.1 ± 3.7 years; height 174 ± 6.6 cm; weight 64.2 ± 6.3 kg) were enrolled in a prospective cohort study. The participants were then divided in two groups; the first included players age ranging from 17 to 19 (OP) whereas the second included players age ranging from 13 to 16 (YP). Injury incidence was recorded prospectively, according to the consensus statement for soccer. Results: A total of 107 injuries (35 from the OP and 72 from the YP) were recorded during an exposure time of 83.760 hours (incidence 1.28/1000 per player hours); 22 during matches (incidence 2.84/1000 per player hours, 20.5%) and 85 during training (incidence 1.15/1000 per player hours, 79.5%). Thigh and groin were the most common injury locations (33.6% and 21.5%, respectively) while muscle injuries such as contractures and strains were the most common injury typologies (68.23%). No statistical differences between groups were displayed, except for the rate of severe injuries during matches, with the OP displaying slightly higher rates compared to the YP. Severe injuries accounted for 10.28% of the total injuries reported. The average time lost due to injuries was 14 days. Re-injuries accounted for 4.67% of all injuries sustained during the season. Conclusions: In professional youth soccer injury rates are reasonably low. Muscle injuries are the most common type of injuries while groin and thigh the most common locations. Artificial turf pitches don’t seem to contribute to injury incidence in young football players

Kinetic Aspects of Methylene Blue Adsorption on Blast Furnace Sludge

In this paper the potential of blast furnace sludge (BFS) in methylene blue (MeB) removal from aqueous solutions was studied by following the adsorption of dye. The BFS was used without any modification/activation. The kinetics of adsorption on the sludge was studied in laboratory batch experiments by monitoring the effect of contact time and dye concentration (20–160 mg L−1) on the adsorption capacity at room temperature (293 K) and at natural pH (7±0.5). It was found that the adsorption capacity at equilibrium increased from 10.3 to 70.6 mg g−1, as the initial MeB concentration increased from 20 to 160 mg L−1. For analysis of experimental data, three kinetic models were applied: pseudo first-order, pseudo second-order and Weber-Morris intra-particle diffusion model. Results demonstrate that kinetics of dye adsorption on BFS is best described by the pseudo second-order equation (R2 ≥ 0.99, F-value=0.86) while fitting to Weber-Morris model has shown that the pore diffusion is not the only rate limiting process in MeB-uptake. Such kinetics can be related to surface characteristics of BFS used: particle diameter dp ≤ 56 mm, specific area 31.46 m2 g–1, pore volume 157·10–3 cm3 g–1, and average pore diameter 17.88 nm, mark this industrial by-product as a mesoporous material. Its surface morphology change after MeB adsorption was confirmed by SEM/EDS analyses. The results obtained allow concluding that untreated BFS has the capacity for MeB uptake within the range of concentrations employed and could be considered as potential low cost adsorbent for treating of dye-polluted waste waters

Lens epithelial cell apoptosis and intracellular Ca(2+) increase in the presence of xanthurenic acid

BACKGROUND: Xanthurenic acid is an endogenous product of tryptophan degradation by indoleamine 2,3-dioxygenase (IDO). We have previously reported that IDO is present in mammalian lenses, and xanthurenic acid is accumulated in the lenses with aging. Here, we studied the involvement of xanthurenic acid in the human lens epithelial cell physiology. METHODS: Human lens epithelial cells primary cultures were used. Control cells, and cells in the presence of xanthurenic acid grow in the dark. Western blot analysis and immunofluorescence studies were performed. RESULTS: In the presence of xanthurenic acid human lens epithelial cells undergo apoptosis-like cell death. In the control cells gelsolin stained the perinuclear region, whereas in the presence of 10 μM xanthurenic acid gelsolin is translocated to the cytoskeleton, but does not lead to cytoskeleton breakdown. In the same condition caspase-3 activation, and DNA fragmentation was observed. At low (5 to 10 μM) of xanthurenic acid concentration, the elongation of the cytoskeleton was associated with migration of mitochondria and cytochrome c release. At higher concentrations xanthurenic acid (20 μM and 40 μM) damaged mitochondria were observed in the perinuclear region, and nuclear DNA cleavage was observed. We observed an induction of calpain Lp 82 and an increase of free Ca(2+) in the cells in a xanthurenic acid concentration-dependent manner. CONCLUSIONS: The results show that xanthurenic acid accumulation in human lens epithelial cells disturbs the normal cell physiology and leads to a cascade of pathological events. Xanthurenic acid induces calpain Lp82 and caspases in the cells growing in the dark and can be involved in senile cataract development

The Change in Surface Area Properties of Blast Furnace Sludge Treated by Acetic Acid

Različitim postupcima kemijske i toplinske obrade mogu se dobiti materijali poboljšanih površinskih svojstava. Visokopećni mulj - VPM je nusproizvod i otpadni materijal industrije željeza i čelika, čije su adsorpcijske sposobnosti u posljednje vrijeme sve zanimljivije. Cilj ovog rada je ispitivanje utjecaja kemijske i toplinske obrade na površinska svojstva VPM. Kemijska obrada je provedena octenom kiselinom, a toplinska zagrijavanjem visokopećnog mulja na 700 °C. Mikroskopska ispitivanja provedena su pretražnom elektronskom mikroskopijom (SEM). Promjene ispitanih površinskih svojstava analizirane su metodama Brunauer-Emmett-Teller (BET) i Barrett-Joyner-Halenda (BJH). Povećanje specifične površine, smanjenje veličine pora i bolja raspodjela pora VPM-a registrirani su nakon provedenih ispitivanja. Dobiveni rezultati pokazali su da provedena kemijska i toplinska obrada predstavljaju aktivaciju visokopećnog mulja.Blast furnace sludge-BFS is a by-product and waste material of the iron and steel industry. Recently, the adsorption capabilities of blast furnace sludge have been attracting great interest. It is known that materials with modified surface properties can be obtained by different chemical and thermal treatments. The aim of this work was to investigate the influence of chemical treatment by acetic acid and thermal treatment by heating at 700 °C, on the surface properties of blast furnace sludge. Chemical treatment was performed by acetic acid adsorption on BFS. Microscopic observation was conducted using scanning electron microscopy (SEM method). Changes in examined surface area properties were analyzed by Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods. Increasing of specific surface area, decreasing of pore size and better pore size distribution in BFS samples were registered after the applied experimental procedure. The obtained results revealed that the performed chemical and heat treatment presented the activation of blast furnace sludge

Usporedba korozijskih svojstava nekih zubnih slitina

In this paper corrosion resistance of experimental dental Co-Cr-X (X = Mo, Ni) alloys, high purity titanium and Ag-amalgam was studied in Ringer’s solution. On the basis of electrochemical measurements, the relevant indicator of general corrosion jcorr, which is used for ranking of materials, was determined. It was found that commercial alloy Wironit® is the most stable material followed by pure titanium, Co-Cr-Mo and Co-Cr-Ni alloys, while amalgam showed the lowest resistance in the experimental conditions of model oral cavity medium.U ovom radu ispitana je korozijska otpornost eksperimentalnih zubnih Co-Cr-X (X = Mo, Ni) slitina, titana i Ag-amalgama u Ringerovoj otopini. Na osnovi elektrokemijskih mjerenja određen je relevantni pokazatelj opće korozije jkor, koji se koristi za rangiranje materijala. Pokazalo se, da je korozijski najstabilnija komercijalna slitina Wironit®, koju slijede čisti titan, te Co-Cr-Mo i Co-Cr-Ni slitine, dok se amalgam pokazao najmanje otpornim u ispitnim uvjetima koji simuliraju medij usne šupljine

non-linear relationships in children 6-10 years

Background: Given the concern for health?related consequences of an elevated body mass index (BMI; obesity), the potential consequences of a low BMI in children are often overlooked. The purpose was to evaluate the relationship between the BMI across its entire spectrum and motor coordination (MC) in children 6?10 years. Methods: Height, weight, and MC (K?rperkoordinationstest f?r Kinder, KTK test battery) were measured in 1,912 boys and 1,826 girls of 6?10 years of age. BMI (kg/m2) was calculated. KTK scores for each of the four tests were also converted to a motor quotient (MQ). One?way ANOVA was used to test differences in the BMI, individual test items, and MQ among boys and girls within age groups. Sex?specific quadratic regressions of individual KTK items and the MQ on the BMI were calculated. Girls and boys were also classified into four weight status groups using International Obesity Task Force criteria: thin, normal, overweight, and obese. Differences in specific test items and MQ between weight status groups were evaluated by age group in each sex. Results: Thirty?one percent of the sample was overweight or obese, whereas 5% was thin. On average, normal weight children had the highest MQ in both sexes across the age range with few exceptions. Overweight/obese children had a lower MQ than normal weight and thin children. The quadratic regression lines generally presented an inverted parabolic relationship between the BMI and MC and suggested a decrease in MC with an increase in the BMI. Conclusion: In general, BMI shows a curvilinear, inverted parabolic relationship with MC in children 6?10 years.4811-99FE-2ECD | Luis Paulo Rodriguesinfo:eu-repo/semantics/publishedVersio

Limits on the early afterglow phase of gamma-ray burst sources from TAROT-1

The T\'elescope \`a Action Rapide pour les Objets Transitoires (TAROT-1) has as prime objective the observation of the prompt and delayed emission of cosmic gamma-ray bursts (GRBs). We have performed a search for optical emission from 6 GRBs detected by BATSE. The positioning error circle was fully covered within typically thirty minutes after the trigger. No detection of the early afterglow phase was made, and magnitude limits in the range of $\mathrm{m}_{\mathrm{R}} = 13-15$ were estimated using 20s exposures. These limits are compared to optical afterglow data obtained in later phases and the results are interpreted in terms of source distances. They correspond to a median redshift of z = 0.5. With HETE-2 and the planned instrument upgrade, TAROT-1 will be able to detect the early optical emission of GRBs up to a redshift of the order of 5.Comment: 7 pages, accepted in Astronomy and Astrophysic

About the psychological peculiarities of parents oriented on early development of children

The early development of the child for the modern parent becomes the norm of life, the rejection of which can cost the adult condemnation and censure from the immediate environment. There is a natural growth of expectations, fears and anxiety about the correctness of the educational strategy, self-assessment as a parent. In this regard, the study of factors contributing to the desire of parents to facilitate the development of children becomes particularly relevant. The aim of the study is a comparative study of the psychological characteristics of parents focused on the early development of children and parents who do not share the ideas of early development of children.Целью исследования является сравнительное изучение психологических особенностей родителей, ориентированных на раннее развитие детей, и родителей, не разделяющих идей раннего развития детей