Physical modelling and numerical finite element method (FEM) simulation of forging in open die of alloy AIMgSi0,5

This paper researches the process of forging in open die of gradual axial-symmetric workpiece made of alloy AIMg-Si0,5. The physical modelling was carried out, for which an original method for physical discretisation and numerical FEM analysis was developed. The components of tensor were determined: strain, strain rate, stress and the corresponding effective parameters. The results obtained experimentally and through a numerical FEM simulation were compared and analysed

Supplementary data for the article: Antonijević, I. S.; Janjić, G. V.; Milčić, M. K.; Zarić, S. D. Preferred Geometries and Energies of Sulfur-Sulfur Interactions in Crystal Structures. Crystal Growth and Design 2016, 16 (2), 632–639. https://doi.org/10.1021/acs.cgd.5b01058

Supplementary material for: [https://doi.org/10.1021/acs.cgd.5b01058]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2042]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3596

Supramolecular insight into the substitution of sulfur by selenium, based on crystal structures, quantum-chemical calculations and biosystem recognition

Statistical analysis of data from crystal structures extracted from the Cambridge Structural Database (CSD) has shown that S and Se atoms display a similar tendency towards specific types of interaction if they are part of a fragment that corresponds to the side chains of cysteine (Cys), methionine (Met) selenocysteine (Sec) and selenomethionine (Mse). The most numerous are structures with C-H..Se and C-H..S interactions (∼80%), notably less numerous are structures with Se..Se and S..S interactions (∼5%), and Se..π and S..π interactions are the least numerous. The results of quantum-chemical calculations have indicated that C-H..Se (∼-0.8 kcal mol-1) and C-H..S interactions are weaker than the most stable parallel interaction (∼-3.3 kcal mol-1) and electrostatic interactions of σ/π type (∼-2.6 kcal mol-1). Their significant presence can be explained by the abundance of CH groups compared with the numbers of Se and S atoms in the crystal structures, and also by the influence of substituents bonded to the Se or S atom that further reduce their possibilities for interacting with species from the environment. This can also offer an explanation as to why O-H..Se (∼-4.4 kcal mol-1) and N-H..Se interactions (∼-2.2 kcal mol-1) are less numerous. Docking studies revealed that S and Se rarely participate in interactions with the amino acid residues of target enzymes, mostly because those residues preferentially interact with the substituents bonded to Se and S. The differences between Se and S ligands in the number and positions of their binding sites are more pronounced if the substituents are polar and if there are more Se/S atoms in the ligand. © 2020 International Union of Crystallography

Influece of the austempering temperature on the tensile strength of the austempered ductile iron (ADI) samples

Austempered Ductile Iron (ADI) is a class of ductile iron subjected to a two-step heat treatment process – austenitization and austempering. The heat treatment gives to ADI a high value of tensile strength and an especially good strength-to-weight ratio. However, designers in most cases are unfamiliar with this material that can compete favorably with steel and aluminum castings, weldments and forgings. The high tensile strength of ADI is the result of its unique ausferrite microstructure. In this paper, an investigation of the influence of the austempering temperature on the tensile strength of the ADI samples is presented

Cavernous silicotuberculosis associated with diabetes

Od svih profesionalnih bolesti pneumokonioze su na prvom mjestu u Jugoslaviji. Poznato je da se silikoza i druge pneumokonioze razvijaju obično nakon dužeg radnog staža, pa, kako su to hronične bolesti, smrt nastaje najčešće u starijim godinama života. Bolesnik čiji ćemo slučaj prikazati oboleo je u mladim godinama od silikoze i umro u 31. godini života.A case of silicotuberculosis associated with diabetes mellitus is reported. The patient\u27s working conditions, the history of the disease and autopsy findings are discussed

Element concentration and fatty acid composition of Serbian bee bread

The element concentration (Cu, Fe, Zn, Mn, Cr, Co, Ni, Se, K, Na, Ca and Mg), heavy metal concentration (Cd, Hg, Pb and As) and fatty acid composition of 12 Serbian bee bread samples from different geographical origins were examined. The element concentration was examined using ICP-MS, and total lipids for fatty acid determination were extracted from homogenized bee bread samples with hexane/isopropanol mixture by accelerated solvent extraction. Potassium was the major element, ranging between 5515 +/- 361.20 mg/kg and 7487 +/- 381.50 mg/kg. The highest As and Pb concentrations were found in bee breads from Lazarevac. This bee bread also contained the highest level of PUFA and SFA. Also, the n-6/n-3 ratio ranged between 0.86 +/- 0.28 and 1.40 +/- 0.05, indicating bee bread can be a good source of unsaturated fatty acids. Bee bread could be useful in monitoring environmental contamination by heavy metals (Cd, Hg, Pb and As), although complex studies of all bee products give sufficient information on this topic

Household food waste in Belgrade - sin and unconcern

The aim of this study was to examine the actual procedures with food in households and consumer attitudes about food waste. The survey was conducted in 83 households in Belgrade, Serbia. All participants were interviewed using a standardized questionnaire. The results obtained show that awareness of food waste is at a satisfactory level, but the actual situation is that food is discarded in large quantities, even though people are aware of what a global problem this is. Large contradictions were observed among the respondents answers in this study. Respondents who stated that they never discard food, in further responses, declared they throw away significant amounts of food for various reasons (too long storage, overconsumption, improper preparation, etc.). We conclude that people are either unaware of how much food they discard, or they do not want to admit it to themselves. However, participants largely have a sense of guilt about discarding food. This indicates consumer awareness of food waste, and is an encouraging sign that further education could be effective in consumers taking into account their food waste habits, starting from procurement planning, through storage and preparation

CHROMATOGRAPHIC BEHAVIOR AND LIPOPHILICITY OF N-(4-PHENYLSUBSTITUTED)-2,3-DIPHENYLPROPANAMIDES

Retention behavior of some N-(4-phenylsubstituted)-2,3-diphenylpropanamides was investigated on reversed phase thin layer chromatography (RP-C18). Retention constants of investigated compounds were determined in the following solvent systems: water-ethanol, watern-propanol and water-i-propanol. Linear relationships were obtained between retention, RM and volume fraction of organic solvent, ϕ. As a measure of lipophilicity of tested propanamides, Hansch`s lipophilicity parameter, π, were calculated. Chromatography retention constants RM0 were correlated with Hansch`s lipophilicity parameter, and good linear relationships were obtained. These results confirm, that retention constants, (RM0 ), determined in reversed phase thin-layer chromatography (RP-TCL) can be used, as criteria of lipophilicity

Distinct Expression Patterns of Osteopontin and Dentin Matrix Protein 1 Genes in Pituitary Gonadotrophs

Cell-matrix interactions play important roles in pituitary development, physiology, and pathogenesis. In other tissues, a family of non-collagenous proteins, termed SIBLINGs, are known to contribute to cell-matrix interactions. Anterior pituitary gland expresses two SIBLING genes, Dmp1 (dentin matrix protein-1) and Spp1 (secreted phosphoprotein-1) encoding DMP1 and osteopontin proteins, respectively, but their expression pattern and roles in pituitary functions have not been clarified. Here we provide novel evidence supporting the conclusion that Spp1/osteopontin, like Dmp1/DMP1, are expressed in gonadotrophs in a sex- and age-specific manner. Other anterior pituitary cell types do not express these genes. In contrast to Dmp1, Spp1 expression is higher in males; in females, the expression reaches the peak during the diestrus phase of estrous cycle. In further contrast to Dmp1 and marker genes for gonadotrophs, the expression of Spp1 is not regulated by gonadotropin-releasing hormone in vivo and in vitro. However, Spp1 expression increases progressively after pituitary cell dispersion in both female and male cultures. We may speculate that gonadotrophs signal to other pituitary cell types about changes in the structure of pituitary cell-matrix network by osteopontin, a function consistent with the role of this secretory protein in postnatal tissue remodeling, extracellular matrix reorganization after injury, and tumorigenesis

Physical modelling and numerical finite element method (FEM) simulation of forging in open die of alloy AIMgSi0,5

This paper researches the process of forging in open die of gradual axial-symmetric workpiece made of alloy AIMg-Si0,5. The physical modelling was carried out, for which an original method for physical discretisation and numerical FEM analysis was developed. The components of tensor were determined: strain, strain rate, stress and the corresponding effective parameters. The results obtained experimentally and through a numerical FEM simulation were compared and analysed