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An explicit integration algorithm using a texture-based plastic potential and isotropic hardening has been developed and implemented into a commercial explicit finite-element software program through a user material subroutine (VUMAT in ABAQUS/Explicit). Simulations of cup drawing of an IF-steel are presented and compared to both experimental data and calculation results obtained with a previously developed fully implicit approach (UMAT in ABAQUS/Standard). The explicit formulation has the advantage of being more stable, but local sheet thickness variations cannot be reproduced with the same accuracy.

Diamond coatings were deposited onto different cylindrical substrates (Cu, SiC, W and Mo) by the hot filament chemical vapor deposition (CVD) method. Continuous, adhered and well-faceted crystalline coatings of diamond were obtained on Cu-wire using a special pretreatment with a mixture of diamond and metal powders as well as carefully controlled deposition at lower power. Diamond deposition on SiC-fiber gave continuous and uniform coatings when only the filament power was properly selected. Uniform, homogeneous, euchedral diamond coatings on W-and Mo-wires, attained at a higher filament power, confirmed once more the convenience of refractory metals as substrates for diamond deposition by the CVD technique. Characterization of the obtained coatings was realized using scanning electron microscopy (SEM). The obtained results are compared with the literature data. Differences are discussed with regard to the chemical nature of the substrates as well as their thermophysical characteristics.

Sažetak: U vazduhu Kosovske Mitrovice i Zvečana prisutni su polutanti svih agregatnih stanja koji u vazduh dospevaju iz različitih izvora. Analizom dobijenih eksperimentalnih podataka utvrđeno je da su zagađujuće materije (kao što su olovo, azot-dioksid, taložne materije) pretežno industrijskog porekla čiji su glavni izvori postrojenja RMHK "Trepča", kao i da postoje zagađujuće materije drugog porekla. Određene su koncentracije primarnih i specifičnih zagađujućih materija tokom godine: azotdioksida, čađi, ukupne taložne materije i prašine, i teških metala u taložnim materijama (Pb, Zn, Cd, Ni i Cr). Koncentracija olova na pojedinim mestima u radnoj i urbanoj sredini je manja od zakonom propisanih vrednosti za GVI. Međutim, u toku povremenih metalurških procesa ovaj sadržaj, može biti znatno povećan. Dobijeni rezultati pokazuju da je u jesenjem periodu u toku godine, koncentracija azot -dioksida i taložnih materija ispod graničnih vrednosti, tako da nije došlo do bitnijeg zagađenja. Koncentracija čađi je neznatno povećana u odnosu na MDK i pored industrijskog, može biti i drugog porekla. Najveće izmerene koncentracije čađi, izmerene su u zimskom periodu i imaju sezonski karakter porasta. Zbog prisustva olovne prašine u vazduhu, neophodno je preduzeti sve potrebne mere u cilju stvaranja zdravijeg životnog prostora.

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