Najnoviji radovi

• 01 Apr 2024

Synthesis of Zinc Doped Phosphate Tungsten Bronzes and its Redox Activity in Aqueous Solution of LiNO3

Ацковић, Јована

Phosphate tungsten bronzes (WPB) have been intensively investigated for many applications due to their interesting chemical, optical, electrical, and mechanical properties. Their most known usages are as a pigment in traditional ceramics, a chemical sensor in different electric and electrochromic devices, and an electrocatalyst in fuel cells. Phosphate tungsten bronzes have a specific layered structure formed by the collapse of the Keggin anion at a temperature around 602 °C. Its three-dimension ...

• 01 Apr 2024

PHYSICAL-CHEMICAL CHARACTERIZATION OF PHOSPHATETUNGSTEN BRONZE DOPED WITH IRON FROM HETEROPOLY SALTS AS PRECURSORS

Ацковић, Јована

Heteropolyacids, with a general formula ofH3+xAM12O40∙nH2O (x=0-1; A=P, Si, B, As, Ge;M=Mo, W; n=30-6) are of special interest as newmaterials because of their high conductivities. Among them special attention deserves the 12-tungstophosphoric (29- WPA) acid. Heteropolies of acids and salts heteropolises of acids can also be used as starting materials for the production of tungsten bronzes. These bronzes have a specific structure that results from the collapse of the Kegin anion at a tempe ...

• 01 Apr 2024

PHYSICOCHEMICAL INVESTIGATION Zn DOPED PWB

Ацковић, Јована

Polyoxometalates (POMs), although having more than a hundred years of history, continue to attract the attention of researchers as catalysts, solid superionic proton conductors at room temperatures, applicable in different electrochemical devices, and also as photochromic, biochemical and biomedical active materials. [1] The best-known group of polyoxometalates (POMs) are the heteropoly compounds (HPCs) with the Keggin anion structure. Heteropolyacids, with a general formula of H3+xAM12O40 ∙ n ...

• 01 Apr 2024

TOXIC METALS IN SOIL SAMPLES NEAR SOURCE OF POLLUTION WITH ECOLOGICAL RISK IN NORTHERN KOSOVO AND METOHIJA

Мицић, Ружица

The term toxic metals means heavy and light metals. Higher toxicity of heavy metals compared to light ones was stated, while many light metals belong to physiological and oligo-elements. The term heavy metals means metals that have specific gravity > 5 g/cm3. In this work the concentrations of Pb, As, Cd, Cr, Th, U in soil samples were determined by the ICP-MS and ICP-OES method. Pb/Zn production and industrial waste disposal significantly increased the pseudo-total concentrations of heavy metal ...

• 01 Apr 2024

The Role Of Analytical Chemistry Of Metal Ions In Monitoring The Quality Of The Environment

Мицић, Ружица

There is no doubt analytical laboratories have an essential role to play in environmental protection through monitoring of pollutants in air, water or soil. Research on trace elements and the effects of their ingestion on human health is also often seen in scientific literature. The term heavy metal is often used to refer to the group of metals and semimetals (metalloids) that have been associated with contamination and potential toxicity or ecotoxicity. Environmental medium is exposed to ...

• 01 Apr 2024

Preparation and characterization of phosphatetungsten bronze doped with iron from heteropoly salts as precursors

Ацковић, Јована

Heteropolies of acids and salts heteropolises of acids can also be used as starting materials for the production of tungsten bronzes. These bronzes have a specific structure that results from the collapse of the Kegin anion at a temperatures up to 602 0C. This structure is layered and consists of interconnected PO4tetrahedra and WO6octahedra. In such a structure, pentagonal and hexagonal openings (cavities, channels) are formed in which there is a complete or partial exchange of H ions in WPA. I ...

• 01 Apr 2024

Sadržaj i distribucija teških metala u reci Ibar tokom poplava i izlivanja jalovišta

Мицић, Ружица

This paper examines the impact of high flood magnitude on heavy metal pollution in the Ibar River, northern Kosovo and Metohija. The area of analysis is one of the most important industrial regions of Pb / Zn in Europe. River water samples were taken during and after the flood in January, 2021. Almost all heavy metals cause various cancers and diseases, cumulative effect after prolonged intake through drinking water. The paper provides information on the content of heavy metals in river water us ...

TURKISH JOURNAL OF MATHEMATICS (Scientific and Technical Research Council of Turkey - TUBITAK^(Turkiye Bilimsel ve Teknik Arastirma Kurumu)) • 21 Jan 2021

Infinitesimal bending of DNA helices

Maksimović, Miroslav • Velimirović, Ljubica • Najdanović, Marija

The mathematics of DNA molecules is often studied as a double helix model. This paper focuses on the modelling of infinitesimal bending of DNA helices. The paper checks the flexibility of DNA molecule, i.e. the flexibility of double helix in infinitesimal bending theory. Actually, first, we find infinitesimal bending field of an arbitrary curve on the helicoid, that leaves bent curves on the helicoid, and show that helix bending on the helicoid is not possible. Finally, we deal with the infinite ...

Turkish Journal of Mathematics • 01 Apr 2024

Notes on product semi-symmetric connection in a locally decomposable Riemannian space

Maksimović, Miroslav • Stanković, Mića

The purpose of this paper is to investigate the product semisymmetric connection in a locally decomposable Riemannian space. The curvature tensors of this connection were considered. Some properties of almost product structure, some properties of torsion tensor of product semisymmetric connection and some relations between curvature tensors and almost product structure are given. Also, the paper checks a special case of such connection when its generator is a gradient vector.

• 01 Apr 2024

Савремене методе масене спектрометрије у аналитици психоактивних супстанци у судској токсикологији

Лукић, Вера

Mass spectrometry as an analytical technique has advanced extremely rapidly. New instruments with extraordinary characteristics have appeared on the market. Atmospheric ion sources have been developed, existing mass analyzers have been improved, and new hybrid instruments have been combined, the characteristics of which have raised mass spectrometry to an exceptional position by the analytical method. At the same time, newly designed psychoactive molecules are appearing on the drug market, which ...

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