Beleška o arheološkom nadzoru na autoputu E-75 tokom 2015. i 2016. godine

Nakon obimnih iskopavanja u režiji, pre svega, Arheološkog insituta (Перић, Булатовић 2016), stručni arheološki nadzor na trasi autoputa E-75 Koridora 10, tokom 2015. i 2016. godine, obavljan je na deonici Grabovnica–Donji Neradovac.2 Tokom dvogodišnjeg aktivnog nadzora zemljanih radova registrovani su arheološki ostaci na lokalitetima Kamenitica u Maloj Kopašnici, Sveta Trojica u selu Kržince, Kalčine šume u Vladičinom Hanu, Čivlak u Polomu, Pudarnica u Bresnici, kao nalazištima i Donje Vranje 1 i 2 u naselju Palestina. Uz to, u mahali Oslarci u Polomu zabeleženi su ostaci recentnog objekta. Tokom te dve godine obim radova na ovoj teškoj deonici, koja najvećim delom obuhvata Grdeličku klisuru, bio je povećan, ali treba napomenuti da su zemljani radovi na pojedinim mestima (lokalitetima) trajali i po nekoliko godina. Drugim rečima, broj potencijalnih ugroženih lokaliteta je bio manji, ali je zbog intenziteta i dugotrajnosti radova nadzor morao češće da obilazi pojedine potese

Struktura i stereohemija poli-(1-naftilamina) elektrohemijski sintetisanog u neutralnom acetonitrilnom rastvoru

Poly-(1-naphthylamine) films were synthesized potentiodinamically and potentiostatically from 1-naphthylamine in neutral acetonitrile medium using a platinum electrode. These polymer films were investigated by infrared spectroscopy. Contrary to earlier published results neglecting the stereochemistry of the poly-(1-naphthylamine), we predict on the basis of quantum stereochemical analysis of the possible structural subunits of the polymer, that the ordinary N–C(4) coupled product is not predominant in the polymer because it is far removed from the expected planarity. Based on the results of IR investigations and semiempirical quantum chemical calculations, it is proposed that the polymer products are formed via mixed N–C(4), N–C(5) and N–C(7) coupling routes. The heats of formation of the oxidized 1-naphthylamine dimers and hexamers were calculated.Poli-(1-naftilaminski) filmovi sintetisani su potenciostatski i potenciodinamički iz neutralnog acetonitrilnog rastvora 1-naftilamina na platinskoj elektrodi. Ovi polimerni filmovi ispitivani su IR spektroskopijom. Za razliku od ranije publikovanih rezultata koji su zanemarivali stereohemiju poli-1(-naftilamina), u ovom radu se predviđa na osnovu kvantne stereohemijske analize mogućih strukturnih jedinica polimera da uobičajeni N–C(4) kuplovani produkt nije predominantan u polimeru, jer njegova struktura nije planarna. Na osnovu rezultata IR ispitivanja i semiempirijskih kvantno-hemijskih proračuna mi pretpostavljeno je da se polimerni produkti formiraju kombinovanim N–C(4), N–C(5) i N–C(7) načinima vezivanja 1-naftilamina. U ovom radu su takođe izračunate toplote nastajanja oksidovanih dimera i heksamera 1-naftilamina

IR i ramanska ispitivanja strukturnih modifikacija bakarne soli 12-volframfosforne kiseline

In this paper local processes and structural phase transformations of the copper salt of 12-tungstophosphoric acid are investigated. The structural phase transformations were followed through bands, characteristic for the host lattice, in the IR and Raman spectra. The results of these investigations, as well as those of XRPD analysis and impedance measurements as a function of temperature show that some local processes provoke the change in the secondary structure of the Keggin anions.U ovom radu ispitivani su lokalni procesi i strukturne fazne transformacije soli bakra 12-volframfosforne kiseline. Strukturne fazne transformacije praćene su preko traka karakterističnih za kristalnu rešetku u infracrvenim i ramanskim spektrima. Rezultati ovih ispitivanja, kao i oni dobiveni rendgeno-strukturnom analizom i iz impedansnih merenja, odnosno provodljivost u funkciji temperature, pokazuju da je fazna transformacija vezana za promene lokalne strukture, tj. sekundarne strukture Keginovih anjona. PR Projekat Ministarstva nauke Republike Srbije

Electrocatalysis of fuel cells reaction on Pt and Pt-bimetallic anode catalysts: A selective review

In this review we selectively summarize recent progress, primarily from our laboratory, in the development of interrelationships between the kinetics of the fuel cells reactions and the structure/composition of anode catalysts. The focus is placed on two types of metallic surfaces: platinum single crystals and bimetallic surfaces based on Pt. In the first part it was illustrated that the hydcogen reaction is structure sensitive process, with Pt(110) being an order of magnitude more active than either of the atomically "flatter" (100) and (111) surfaces. The hydrogen reaction on Pt(hkl) modified by pseudomorphic Pd (sub)monolayers shows the "volcano-like" behavior, having the maximum rate on Pt(111) modified by 1 ML of Pd. The Pt(111)-Pd system is used to demonstrate how the energetics of intermediates formed in the hydrogen reaction is affected by interfacial bonding and energetic constraints produced between pseudomorphic Pd films and the Pt(111) substrate. In the second part it was shown that the oxidation of Ha in the presence of CO occurs concurrently with CO oxidation on Pt and Pt bimetallic surfaces. The Pt-Ru system is used to demonstrate that both the bifunctional effect and the ligand effect contribute to the influence of Ru on the CO oxidation rate and for Hz oxidation process in the presence of CO. The knowledge is then used to create the real-life catalyst with the catalytic activities which are, to the greatest extend possible similar to the tailor-made surface

A CONTRIBUTION TO THE KNOWLEDGE OF THE APEARANCE AND OF THE EXPANSION OF APGIS ( Aphididae, hompotera) ON SUNFLOWER FIELDS IN VOJVODINA

Among the specieses from the family Aphididae attacking the, crops ot sunflower in Vojvodina (North-east part of Yugoslavia), Aphis fabae Scop and Brachycaudus helichrysi Kalt dominate. In the last years the sunflower crops were mostly attacked by Aphis fabae Scop (in 1972 and 1973) whereas in 1974 the sunflower crops were especially attacked by Brachycaudus helycristi Kalt, which seems to cause more damages on the earlier seeded crops. Aphis appear on the sunflower in the second of May, in June and partly in July, the attacks in June being the most vehement. All arial parts of sunflower plants are the subject of the attacks, the leaves and the heads before flowering are prevalently attacked. The upper parts of the plants are mostly infected, even though the whole plant is sometimes attacked. All plants on one field can be infected. The attacks cause the curling and the deformation of leaves and the plants retard in grow. The aphis belongs to the most damaging pestson sunflower crops in Vojvodina, and late in spring the aphis is the most important enemy to sunflower. Aphididae appear every year on sunfloweer fields. From time to time there appear considerably important attacks on a ratheer extendeed area like in the years: 1957,1959, 1965, 1972 to 1974.In the first decade of June in 1972 the aphis were found on all 84 inspected sunflower fields, the infection: variying from 7 to 100% of plants or in average 53%. In the first half of June in 1973, 93,50 % of fields were attacked and in the last decade of June 100% of plants were attacked, the attaks being slightly loweer to the attacks in the previous year. Aphis was found on all sunflower plots, ,the average number of the infected plants being 97%, mass curling of leaves followed. ln 1974 there appeared the most vehement attack in the last 30 years ever noticed in Vojvodina. The spacies Aphis fabae Scop. attacks the marginal rows on sunflower fields more than the central rows (early in June 1973 the relation of the attacked plants being 42 to 9% consequently). On the marginal part of a big sunflower field, in the midle of May in 1974 there were 40 - 94% attacked plants by B. helichrysti Kalt, and 7 - 16% in the central rows only. The aphididae attacks the sunflower fields neighboring ,to treelined paths and forests more than the fields distant from them, they also attack more frequently the fields which are overgrown by the spontaneous weeds. The losses are bigger if less agrotechical measures are appilied

Undecylprodigiosin conjugated monodisperse gold nanoparticles efficiently cause apoptosis in colon cancer cells in vitro

Bacterial pigment undecylprodigiosin (UP) was produced using Streptomyces sp. JS520 and conjugated to monodisperse gold nanoparticles (UP-Au). Both UP and UP-Au showed cytocidal activity towards melanoma (A375), lung carcinoma (A549), breast cancer (MCF-7) and colon cancer (HCT-116) cells, inducing apoptosis with IC50 values ranging from 0.4 to 4 mu g ml(-1). Unconjugated UP had a tendency to lose its activity over time and to change biophysical characteristics over pH. The loss of the pigment potency was overcome by conjugation with gold nanoparticles. UP-Au exhibited high stability over pH 3.8 to 7.4 and its activity remained unaffected in time. Nano-packing changed the mechanism of UP toxicity by converting the intracellular signals from a mitochondrial dependent to a mitochondrial independent apoptotic process. The availability of nonpyrogenic UP in high amounts, together with specific anticancer activity and improved stability in the complex with gold nanoparticles, presents a novel platform for further development of UP-Au complexes as an anticancer drug suitable for clinical applications

Prediction of heat generation in rubber or rubber-metal springs

The temperature of rubber or rubber-metal springs increases under cyclic loading, due to hysteresis losses and low rubber thermal conductivity. Hysteresis losses correspond to energy dissipation from the rubber, which is primarily converted into heat. This well-known phenomenon, called heat build-up, is the primary reason for rubber aging. Increase in temperature within the rubber compound leads to degradation of its physical and chemical properties, increase in stiffness and loss of damping capability. This paper presents a novel procedure of heat generation prediction in rubber or rubber-metal springs. The procedure encompasses the prediction of hysteresis loss, i. e. dissipated energy within the rubber, by finite element analysis and application of a modern visco-plastic rubber constitutive model. The obtained dissipated energy was used as an input for transient thermal analysis. Verification of the proposed procedure was performed by comparison of simulation results with experimentally obtained data during the dynamic loading of the rubber specimen. The proposed procedure is highly computationally efficient and it enables time integration, which can be problematic in coupled mechanical thermal analysis. [Projekat Ministarstva nauke Republike Srbije, br. TR35005: Research and Development of New Generation of Wind Turbines of High Energy Efficiency

Design of Advanced Thin-Film Catalysts for Electrooxidation of Formic Acid

Successful development of catalysts for electrochemical formic acid oxidation (FAO) requires fnding an optimal balance between catalytic performance (activity, stability, and selectivity) and catalyst cost. While platinum is one of the most active catalyst materials for FAO, it suffers from performance loss at low overpotentials due to poisoning with CO, which is one of the intermediates formed in the so-called indirect path of FAO. In this work, we explored the synergistic effects of the supporting material and annealing temperature on the performance of Pt thin flms for FAO in acidic media. Compared to the as-prepared Pt flms, the annealed flms show up to 5-fold and 15-fold improvement for FAO on Pt@Ni and Pt@Cr, respectively. While the most active Pt@Ni thin flm shows the lowest stability, the most active Pt@Cr thin flm is also the most stable, challenging conventional tradeoffs in electrocatalysis and providing a promising candidate for FAO nanocatalyst synthesis