Prikazano Природно-математички факултет za naslov

Prikaz rezultata 244-263 od 269

    • System performances of sc reception in asymmetric multipath fading environments 

      Djosić, Danijel; Stefanović, Caslav; Milić, Dejan; Stefanović, Mihajlo (2019-06-23)
      The paper takes into consideration dual-branch selection combining (SC) diversity reception technique in the presence of dissimilar fading at their branches. We efficiently obtained first and second order closed form ...

    • Ternary NR/BR/SBR rubber blend nanocomposites 

      Jovanović, Slaviša; Samaržija-Jovanović, Suzana; Marković, Gordana; Jovanović, Vojislav; Adamović, Tijana; Marinović-Cincović, Milena (SAGE, 2018-02-24)
      The goal of this work was to synthesize and characterize ternary rubber blends based on polyisoprene (natural rubber (NR)), polybutadiene rubber (BR), and styrene–butadiene rubber (SBR) (NR/BR/SBR = 25/25/50) reinforced ...

    • Theoretical investigation of bandwidth of multimode step-index silica photonic crystal fibers 

      Drljača, Branko; Savović, Svetislav; Kovačević, Milan; Simović, Ana; Kuzmanović, Ljubica; Djordjevich, Alexandar; Min, Rui (MDPI, 2022-03-23)
      Solving the time-dependent power flow equation (PFE) provides a useful method to study the transmission bandwidth of step-index silica photonic crystal fibers (SI SPCFs). The transmission bandwidth of these kinds of ...

    • Theoretical investigation of the capacity of space division multiplexing with step-index air-clad silica optical fibers 

      Savović, Svetislav; Djordjevich, Alexandar; Savović, Isidora; Drljača, Branko; Simović, Ana; Min, Rui (MDPI, 2022-02-23)
      We studied the effect of mode coupling on the space division multiplexing (SDM) capabilities of multimode step-index (SI) air-clad silica optical fibers by numerically solving the power flow equation. Mode coupling ...

    • Theoretical Investigation of the Influence of Wavelength on the Bandwidth in Multimode W-Type Plastic Optical Fibers with Graded-Index Core Distribution 

      Simović, Ana; Savović, Svetislav; Drljača, Branko; Alexandar, Djordjevich; Min, Rui (MDPI, 2021-11-17)
      The bandwidth of multimode W-type plastic optical fibers (POFs) with graded-index (GI) core distribution is investigated by solving the time-dependent power flow equation. The multimode W-type GI POF is designed from a ...

    • Thermal behavior of gamma-irradiated urea-formaldehyde composites based on the differently activated montmorillonite K10 

      Samaržija-Jovanović, Suzana; Jovanović, Vojislav; Jovanović, Tijana; Petković, Branka; Marković, Gordana; Porobić, Slavica; Marinović-Cincović, Milena (Springer, 2022-07-09)
      This work investigated the thermal characteristics of irradiated composite materials formulated on the urea–formaldehyde resin (UF) and differently activated montmorillonite (K10). UF resin with molar ratio F:U  =  0.8 was ...

    • Thermolysis prepared Co3O4 carbon paste electrode decorated with single wall nanotubes as voltammetric sensor for determination of antioxidant α-lipoic acid 

      Petković, Branka; Stanković, Dalibor; Ognjanović, Miloš; Viktorovich Avdin, Vyacheslav; Radović, Magdalena; Manojlović, Dragan; Vranješ Đurić, Sanja
      The novel carbon material modified with Co3O4 particles, prepared by calcination and mixed with single wall carbon nanotubes, was characterized and used for sensing of prominent antioxidant α- lipoic acid (LA). The new ...

    • The total curvature of knots under second-order infinitesimal bending 

      Najdanović, Marija; Rančić, Svetozar; Kauffman, Louis; Velimirović, Ljubica (World Scientific Publishing Co. Pte. Ltd., 2019-01-03)
      In this paper, we consider infinitesimal bending of the second-order of curves and knots. The total curvature of the knot during the second-order infinitesimal bending is discussed and expressions for the first and the ...

    • Total Normalcy of Knots 

      Rančić, Svetozar; Najdanović, Marija; Velimirović, Ljubica (Faculty of Sciences and Mathematics, University of Niš, 2019-01-01)
      In this paper we consider first order infinitesimal bending of curves and knots. The total normalcy of the knot during the first order infinitesimal bending is discussed and expressions for the first variation of the total ...

    • THE TOTAL TORSION OF KNOTS UNDER SECOND ORDER INFINITESIMAL BENDING 

      Najdanović, Marija; Velimirović, Ljubica; Rančić, Svetozar (University of Belgrade - School of Electrical Engineering, 2021-10-26)
      In this paper we consider infinitesimal bending of the second order of curves and knots. The total torsion of the knot during the second order infinitesimal bending is discussed and expressions for the first and the ...

    • Tourism and sustainable development of rural settlements in protected areas - Example NP Кopaonik (Serbia) 

      Ristić, Dušan; Vukoičić, Danijela; Milinčić, Miroljub (Elsevier Ltd., 2019-09-21)
      With the formulation of tourism development strategies for the social and economic development of an area, rural tourism moved to a more complex phase of development. Numerous empirical studies have shown that different ...

    • 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 ...

    • A transmission length limit for space division multiplexing in step-index silica optical fibers 

      Savović, Svetislav; Djordjevich, Alexandar; Simović, Ana; Drljača, Branko (Taylor & Francis, 2019-08-28)
      By solving the power flow equation, we investigate the influence of mode coupling on space division multiplexing capability of three multimode step-index silica optical fibres with a different strengths of mode coupling. ...

    • Transmission performance of multimode W- type microstructured polymer optical fibers 

      Drljača, Branko; Savović, Svetislav; Kovačević, Milan; Simović, Ana; Kuzmanović, Ljubica; Djordjevich, Alexandar; Min, Rui (Optica Publishing Group (Formerly OSA), 2022-06-23)
      By solving the time-independent power flow equation (TI PFE), we study mode coupling in a multimode W-type microstructured polymer optical fiber (mPOF) with a solid-core. The multimode W-type mPOF is created by modifying ...

    • Two Interval Upper-Bound Q-Function Approximations with Applications 

      Perić, Zoran; Marković, Aleksandar; Kontrec, Nataša; Nikolić, Jelena; Petković, Marko; Jovanović, Aleksandra (Mathematics and computer sciences, 2022-10-10)
      The Gaussian Q-function has considerable applications in numerous areas of science and engineering. However, the fact that a closed-form expression for this function does not exist encourages finding approximations or ...

    • USE OF GEOGEBRA IN THE STUDY OF ROTATIONS 

      Maksimović, Miroslav; Kontrec, Nataša; Panić, Stefan (Western Serbia Academy of Applied Studies, Užice (Serbia), 2021-10-08)
      With the development of information technologies and educational software, there was a need for research and examination of how and in what way to use them in teaching, without losing the quality of existing traditional ...

    • Uticaj razlicitih doza y-zračenja na hidrolitičku stabilnost modifikovanih urea-formaldehidnih (UF) smola 

      Jovanović, Vojislav; Samaržija-Jovanović, Suzana; Jevtić, Sonja; Petković, Branka; Marković, Gordana; Marinović-Cincović, Milena (Srpsko hemijsko drustvo, 2018-05-30)
      Zbog emisije formaldehida (CH2O) iz drvenih proizvoda, gde se urea- formaldehidne (UF) smole, izmedu ostalog, koriste za impregnaciju drvenih panela koje se koriste u unutrašnjosti stambenih i drugih objekata pozeljno ...

    • Visoke koncentracije radona u porodičnoj kući u okolini Kosovske Mitrovice 

      Spasić, Dušica; Gulan, Ljiljana
      U ovom radu su prikazani rezultati merenja koncentracije radona u jednoj porodičnoj kući u blizini Kosovske Mitrovice u periodu od 24.03.2020 – 31.05.2020. Interval merenja je obuhvatio period proglašenja vanredne situacije ...

    • VISUALIZATION OF GEOMETRIC OBJECTS USING PROGRAM PACKAGE MATHEMATICA 

      Ljajko, Eugen; Najdanović, Marija; Maksimović, Miroslav; Kontrec, Nataša
      In geometry teaching, visualization is an indispensable method of work. Its importance is emphasized in the study of abstract theories when the human mind is not capable enough to perceive the regularities determined by ...

    • The vulcanization properties of hybrid elastomeric materials based on waste rubber powder 

      Budinski-Simendić, Jaroslava; Kojić, Dejan; Marković, Gordana; Jovanović, Slaviša; Erceg, Tamara; Vukić, Nevena; Tanasić, Ljiljana; Samaržija-Jovanović, Suzana (University of Belgrade, Technical Faculty in Bor, 2019-06-18)
      Elastomeric materials have viscoelastic properties and can be designed for numerous applications, tires production, vibration isolation and damping. These properties can be tailored for a wide temperature range and in ...