148 research outputs found

    Experimental and Theoretical Study Of UV-Vis Spectra of Schiff Bases

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    The UV-Vis properties of ten Schiff bases were systematically investigated. The time-dependent density functional theory (TDDFT) approach in combination with the B3LYP functional was used for simulation of UV-Vis spectra of examined compounds. The shapes of the Kohn-Sham molecular orbitals involved in electronic transitions were misleading. To provide better understanding of distribution of electron density natural bond orbital (NBO) analysis was used. NLMO clusters were constructed and they represent a part of a molecule characterized with eminent electron density. The TDDFT and NBO theories are complementary, and the results from these two approaches are combined to interpret the UV-Vis spectra

    Geological influence on the formation of Samar natural bridge and collapse valley of Ravna River from the NE Kučaj Mountains (Carpatho-Balkanides, eastern Serbia)

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    The paper deals with the description of Samar natural bridge and collapse valley of Ravna River in eastern Serbia aiming to suggest an interpretation of their origin and development, in relationship with lithological and tectonic conditions, karst processes, and petrological analyses. In this study we present the geological setting, detailed morphology and hypothesis on the genesis of these karst landforms. The relationship between surface karst development and the geology is considerably acknowledged. The major contribution of the paper is to propose a framework for considering how recrystallization of limestone can affect the weathering potential of karst landforms and to introduce a term collapse valley. Finally, this study shows that the weathering potencial of the Samar natural bridge is decreased concerning the diagenetic changes these limestones underwent.

    Uticaj završne mase mladih bikova simentalske rase na randman

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    Domestic Simmental is the most common breed of catlle in our country. The quality of the carcassеs have been the subject of interest, both primary production and the meat industry. The classification of carcasses is conducted immediately after veterinary examination and weight of carcasses and determinate of carcasses mass. In this paper was investigated the influence finished mass of young bulls of Simmental race on randman and depedence randman from finished mass of young bulls. The investigation was carried out on the 54 carcasses young bulls devided in two groups. The first group of young bulls was from 450 to 500 kg mass, and secund group between 550 to 600 kg. The results of investigation are showed that randman in first group was between 42% to 56%, and in secund group from 49% to 57%.Domaće šareno goveče u tipu simentalca je rasa goveda koja se najviše gaji na našim prostorima. Kvаlitet trupovа zаklаnih životinjа je predmet interesovаnjа, kаko primаrne proizvodnje, tаko i industrije mesа. Postupаk klаsirаnjа trupovа odnosno polutki sprovodi se u klаnicаmа neposredno nаkon veterinаrskog pregledа i utvrđivаnjа mаse trupа. U rаdu je ispitаn uticaj završne mase mladih bikova simentalske rase iz otkupa na randman i zavisnost randmana od završne mase mladih bikova. Ispitivаnje je sprovedeno nа 54 trupа junаdi (mlаdih bikovа) podeljenih u dve grupe. Prvu grupu su činili bikovi završne telesne mаse 450-500 kg, a drugu 550-600 kg. Rezultati su pokazali da se randman kod prve grupe kretao od 42% do 56%, a kod druge grupe od 49% do 57%

    Molecular docking study on the interaction of Rhodopsin-like receptor with tetra-coordinated gold(III) complex

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    The pharmacologic properties of gold compounds have been known since the end of the 19th century. In the last decade, gold complexes have received increased attention due to the variety of their applications. Rhodopsin-like receptors are a family of proteins that belong to the largest group of G protein-coupled receptors (GPCRs). In this paper, the molecular interactions between active binding sites of the Rhodopsin-like receptor (RLR) and synthesized gold(III) complex ([Au(DPP)Cl2]+ where DPP=4,7-diphenyl-1,10-phenanthroline) were investigated by molecular docking simulations. The crystal structure of investigated receptor RLR (PDB ID: 4A4M) was extracted from RCSB Protein Data Bank in PDB format. The native bound ligand (11-cis-retinal) was extracted from receptor and binding pocket analysis was performed. Re-docking was performed with the gold(III) complex to generate the same docking pose as found in co-crystallized form of receptor. The binding energy of gold(III) complex to RLR was found to be -35.35 kJ/mol, as opposed to 11-cis-retinal which of about - 40.5 kJ/mol. The obtained results of revealed that gold(III) complex binds at the same binding pockets to RLR, as well as native bound ligand, by weak non-covalent interactions. The most prominent interactions are hydrogen bonds, alkyl-π, and π-π interactions. The preliminary results suggest that gold(III) complex showed good binding affinity against RLR, as well as native bound ligand, 11-cisretinal, as evident from the free binding energy (ΔGbind in kJ/mol).The authors are grateful to the Ministry of Education, Science and Technological Development of the Republic of Serbia (Agreement No. 451-03-9/2021-14/200378 and Agreement No. 451-03-68/2021-14/200122) for financial supportPublishe

    Influence of initial operating conditions on technological function parameters of servicing systems - machines and devices

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    U skladišnim i proizvodnim sustavima, svaki novi početak rada uređaja ili stroja poslije otkaza ili na početku nove smjene, dovodi do njihovog nestacionarnog režima rada izazvanog određenim brojem zaostalih neopsluženih jedinica. U skladišnim sustavima nestacionarni režim rada je uobičajena situacija kada je skladištenje paletizirane robe moguće u jednoj ili dvije smjene dok se proizvodnja odvija u dvije ili tri smjene. Opisane situacije utječu na parametre tehnološke funkcije (TFP) skladišnih ili proizvodnih sustava. Nestacionarni režim rada pojedinačnih uređaja ili strojeva može se modelirati kao jednokanalni sustav opsluživanja s ograničenim redom – M/M/1/K. Stoga je opći analitički izraz za integracijske konstante izveden na osnovu proizvoljnih početnih vrijednosti vjerojatnoća stanja sustava. Utjecaj početnog nestacionarnog režima, kao i njegovo trajanje, na TFP skladišnog sustava je kvantificiran uzimajući u obzir radne uvjete u postojećem paletnom visokoregalnom skladištu.In warehousing and production systems, every device or machine re-commissioning after malfunction or at the start of a new shift, leads to their non-stationary operating regime caused by a certain number of residual unprocessed units. In warehouse systems, non-stationary operating regime is common when palletized goods are stored in one (two) shifts while their production runs in two (three) shifts. Such situations influence technological function parameters (TFPs) of production or warehousing systems. On the other hand, non-stationary operating regime of a single device or machine may be modelled as a single server servicing system with a finite waiting room – M/M/1/K. As a result, general analytical integration constants expression was derived based on initial arbitrary system state probability values. Influence of initial non-stationary operating regime and its duration on warehousing system TFPs is evaluated in view of the operating conditions of an existing high bay pallet warehouse

    A GENERALIZATION OF NIL-CLEAN RINGS

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    The conditions that allow an element of an associative, unital, not necessarily commutative ring R, to be represented as a sum of (commuting) idempotents and one nilpotent element are analyzed. Some applications to group rings are also presented
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