Browsing Природно-математички факултет by Issue Date
Now showing items 41-60 of 269
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Total Normalcy of Knots
(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 curvature of knots under second-order infinitesimal bending
(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 ... -
Suzuki type fixed point results and applications in partially ordered Sb -metric spaces
(University of Novi Sad, Faculty of Sciences, Department for Mathematics and Informatics, 2019-01-12)In this paper we give some applications to integral equations as well as homotopy theory via Suzuki type fixed point theorems in partially ordered complete Sb - metric space by using generalized contractive conditions. We ... -
Elastomers based on NR/BR/SBR ternary rubber blend: morphological, mechanical and thermal properties
(Association of Chemical Engeneers of Serbia, 2019-01-24)The elastomeric materials based on NR/BR/SBR ternary rubber blend were investigated. The polyisoprene (NR), butadiene (BR) and styrene butadiene (SBR) rubbers were used as network precursors and carbon black (CB) as an ... -
Figurative numbers contribution in perceiving the legality in numerous strings tasks and log-term memory of numerous data
(Modestum, 2019-01-27)Contemporary mathematics teaching is mostly reduced to the application of algebraic formulas and algebraic procedures. The visual-logical approach in solving mathematical tasks is very little represented in teaching ... -
Strukturiranje elastomernih materijala za primenu u poljoprivredi
(UNIVERZITET U KRAGUJEVCU, AGRONOMSKI FAKULTET U ČAČKU, 2019-03-15)Poljoprivreda i poljoprivredna industrija zahtevaju elastomeme proizvode koji mogu izdržati dugotrajnu izloženost ekstremnim naponima i hemikalijama. Elastomeri dobijeni od etilen-propilen-dienskog kaučuka (EPDM) nalaze ... -
Existence and Unique Coupled Solution in Sb-Metric Spaces by Rational Contraction with Application
(MDPI (Basel, Switzerland), 2019-03-28)In this paper, we prove a unique common coupled fixed point theorem for two pairs of w-compatible mappings in Sb -metric spaces. We also furnish an example to support our main result. -
Some Remarks and New Results in Ordered Partial b-Metric Spaces
(MDPI (Basel, Switzerland), 2019-04-06)We improve and generalize some new results in fixed point theory in the context of partial b-metric spaces -
Caristi, Nadler and H + -Type Contractive Mappings and Their Fixed Points in θ-Metric Spaces
(MDPI (Basel, Switzerland), 2019-04-07)A new proper generalization of metric called as θ -metric is introduced by Khojasteh et al. (Mathematical Problems in Engineering (2013) Article ID 504609). In this paper, first we prove the Caristi type fixed point theorem ... -
Properties Of Elastomeric Composites Based On Three Network Precursors
(Wiley, 2019-04-10)The powder recycled rubber (PRR) can be used as a filler and a modifier for elastomeric materials and asphalt. Composites based on elastomers and recycled rubber powders are a serious challenge for the environment. The ... -
Biocomposites Based On Cellulose And Starch Modified Urea-Formaldehyde Resin: Hydrolytic, Thermal And Radiation Stability
(Wiley, 2019-04-10)Two biocomposites based on cellulose (UFC) and starch modified urea formaldehyde (UFS) resin (F/U ratio of 0.8) were synthesized using the same procedure. The hydrolitical, thermal, and radiation stability of biocomposites ... -
Diethyl-ether flower washings of Dianthus cruentus Griseb. (Caryophyllaceae): Derivatization reactions leading to the identification of new wax constituents
(Wiley-VHCA AG, Zurich, Switzerland, 2019-05-07)Some carnation species (Dianthus spp., Caryophyllaceae) exhibit a strong resistance to drought stress that is connected with the increased surface wax formation. Wax composition is unknown for the majority of Dianthus spp. ... -
The crystal structure of aqua-bis(3-acetyl-2-oxo-2H-chromen-4-olato-κ2O,O′)zinc(II)monohydrate, C22H18O10Zn
(2019-05-08)C22H18O10Zn, triclinic, P1̄ (no. 2), a = 7.9616(3) Å, b = 9.5386(3) Å, c = 14.2569(4) Å, α = 81.713(3)°, β = 82.724(3)°, γ = 73.103(3)°, V = 1021.03(6) Å3, Z = 2, Rgt(F) = 0.0223, wRref(F2) = 0.0603, T = 295(2) K. CCDC ... -
Optimization and validation of the kinetic spectrophotometric method for quantitative determination of the pesticide atrazine and its application in infant formulae and cereal-based baby food
(Wiley-VHCA AG, Zurich, Switzerland, 2019-05-11)BACKGROUND: Pesticides are potentially toxic to humans and can produce both acute and chronic health effects, depending on the quantity and the ways in which a person is exposed. Exposure to pesticides can cause serious ... -
(C , Ψ * , G ) Class of Contractions and Fixed Points in a Metric Space Endowed with a Graph
(MDPI (Basel, Switzerland), 2019-05-27)In this paper, we introduce the (C,Ψ∗,G) class of contraction mappings using C-class functions and some improved control functions for a pair of set valued mappings as well as a pair of single-valued mappings, and prove ... -
The effect of UV irradiation on hydrolytic stability of urea-formaldehyde resins filled with thermally modified montmorillonite
(RAD Centre, Niš, Serbia, 2019-06-10)The hydrolytic stability of organic-inorganic nano-composites prepared by a two-stage polymerization of urea-formaldehyde resin (UF) filled with thermally activated montmorillonite (MMT) has been assessed before and after ... -
Radiation stability and thermal behaviour of modified UF resin using biorenewable raw material-furfuryl alcohol
(Elsevier, 2019-06-15)The thermal stability of organic-inorganic nano-composites prepared by a two-stage polymerization of urea-formaldehyde resin (UF) with furfuryl alcohol (FA) and TiO2 before and after irradiation has been researched. The ... -
The vulcanization properties of hybrid elastomeric materials based on waste rubber powder
(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 ... -
System performances of sc reception in asymmetric multipath fading environments
(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 ... -
Controlling the bandwidth of W-type plastic-clad silica optical fibers
(IOP Publishing, 2019-06-27)A new design of a multimode plastic-clad silica optical fiber that takes the characteristic W-shaped index profile is proposed. The bandwidth and steady-state loss are determined for such a W-type plastic-clad silica ...