Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 9451 - 9480 of 10317

Full-Text Articles in Physical Sciences and Mathematics

Temperature Dependence Of Vickers Microhardness And Creep Study Of In_X Bi_{2-X} Te_3 Crystals, G. R. Pandya, S. R. Bhavsar, C. F. Desai Jan 2000

Temperature Dependence Of Vickers Microhardness And Creep Study Of In_X Bi_{2-X} Te_3 Crystals, G. R. Pandya, S. R. Bhavsar, C. F. Desai

Turkish Journal of Physics

Temperature dependence of Vickers microhardness of ln$_x$ Bi$_{2-x}$ Te$_3$ single crystals with x ranging from 0.1 to 0.5 has been studied. Loading time dependence of microhardness at different temperatures has been used for creep study in the temperature range 300 K to 400 K. The activation energy for indentation creep of the crystals has been evaluated.


Geochemistry And Significance Of Mafic Dyke Swarms In The Pozantı-Karsantı Ophiolite (Southern Turkey), Osman Parlak Jan 2000

Geochemistry And Significance Of Mafic Dyke Swarms In The Pozantı-Karsantı Ophiolite (Southern Turkey), Osman Parlak

Turkish Journal of Earth Sciences

The Pozantı-Karsantı ophiolite, which is one of a number of the Late Cretaceous oceanic lithospheric remnants in southern Turkey, is situated in the eastern Tauride belt and consists of three distinct thrust sheets: an ophiolitic melange, a metamorphic sole, and an ophiolitic stratigraphic sequence. These units (except the ophiolitic melange) are intruded by isolated microgabbro-diabase dykes at all structural levels. The dykes from the lower crustal rocks (cumulates) are subalkaline in character and chemically similar to island arc tholeiitic basalts and basaltic andesites. They are enriched in some LIL elements (Rb, Ba, K and Sr) and depleted in HFS elements …


Intrinsic Equations For A Relaxed Elastic Line On An Oriented Hypersurface In The Minkowski Space R^N_1, Nevi̇n Gürbüz, Ali̇ Görgülü Jan 2000

Intrinsic Equations For A Relaxed Elastic Line On An Oriented Hypersurface In The Minkowski Space R^N_1, Nevi̇n Gürbüz, Ali̇ Görgülü

Turkish Journal of Mathematics

We gived the intrinsic equations for a relaxed elastic line on an oriented surface in ${\Bbb {R}}_1^3$ ([1],[2]). In this paper, we derived the intrinsic equations for a relaxed elastic line on an oriented time-like hypersurface and space-like hypersurface in the Minkowski space ${\Bbb {R}}_1^n$ and gived additional results about relaxed elastic lines on various timelike and spacelike hypersurface in the Minkowski space ${\Bbb {R}}_1^n$.


High-Performance Liquid Chromatographic Determination Of Oxytetracycline Residue In Cured Meat Products, Hami̇de Z. Şenyuva, Tuncel Özden, Deni̇z Yurtsever Sarica Jan 2000

High-Performance Liquid Chromatographic Determination Of Oxytetracycline Residue In Cured Meat Products, Hami̇de Z. Şenyuva, Tuncel Özden, Deni̇z Yurtsever Sarica

Turkish Journal of Chemistry

The development of a sensitive automated method for residue control of oxytetracycline (OTC) in cured meat (soudjouk) is described. The principle steps involve the extraction of OTC from cured meat in the presence of citric acid with nitric acid, methanol and de-ionized water, and then the determination by HPLC. In HPLC, Hypersil BDC C18 column was used and OTC was separated at 24 ^{o}C using a mobile phase of H_2O (pH=2.10 with H_2SO_4): ACN (85:15, v/v) at a flow rate of 1.5 ml/min. A variable wavelength detector was set at 360 nm. The detection limit of the method was calculated …


Adsorption Of Some Heavy Metal Ions From Aqueous Solution By Activated Carbon And Comparison Of Percent Adsorption Results Of Activated Carbon With Those Of Some Other Adsorbents, İlhan Uzun, Fuat Güzel Jan 2000

Adsorption Of Some Heavy Metal Ions From Aqueous Solution By Activated Carbon And Comparison Of Percent Adsorption Results Of Activated Carbon With Those Of Some Other Adsorbents, İlhan Uzun, Fuat Güzel

Turkish Journal of Chemistry

In this study, removal of some heavy metals ions (Mn^{2+}, Fe^{2+}, Ni^{2+} and Cu^{2+}) from aqueous solution by adsorption was investigated. For this purpose, high-grade MnSO_4.H_2O, FeSO_4.7H_2O, NiSO_4.7H_2O and CuSO_4.5H_2O were used as heavy metal samples. The commercial activated carbon (Merck 2514), chitosan and agar were used as adsorbents. The pH of each solution was not controlled. This is because the net interaction between the adsorbent and the heavy metal could be disturbed by the buffer solution. Therefore, all experiments were carried out in a pH range from 5.3 to 5.5. The equilibrium adsorption contact times were determined for M …


Asymptotic Behavior Of The Zero Solutions To Generalized Pipe And Rotating Shaft Equations, Ayfer Kurt Jan 2000

Asymptotic Behavior Of The Zero Solutions To Generalized Pipe And Rotating Shaft Equations, Ayfer Kurt

Turkish Journal of Mathematics

A non-autonomous partial differential equation describing the dynamics of a uniform pipe and a system describing the dynamics of a rotating shaft are considered.Sufficient conditions for the global asymptotic stability of the zero solution of the boundary value problem for the differential equation and the system under consideration are established by using the Lyapunov function technique.


Efficient Presentations For Some Direct Products Of Groups, Bi̇lal Vatansever, David M. Gill Jan 2000

Efficient Presentations For Some Direct Products Of Groups, Bi̇lal Vatansever, David M. Gill

Turkish Journal of Mathematics

In this paper we give efficient presentations for $A_4\times D_n$, where n is odd number, or n is even number and (n,3)=1. We also give efficient presentations for $A_5\times D_n$ where n is an even or odd number.


Zeros Of \Zeta^{''}(S) & \Zeta^{'''}(S) In \Sigma< 1/2, Cem Yalçin Yildirim Jan 2000

Zeros Of \Zeta^{''}(S) & \Zeta^{'''}(S) In \Sigma< 1/2, Cem Yalçin Yildirim

Turkish Journal of Mathematics

There is only one pair of non-real zeros of $\zeta^{''}(s)$, and of $\zeta^{'''}(s)$, in the left half-plane. The Riemann Hypothesis implies that $\zeta''(s)$ and $\zeta'''(s)$ have no zeros in the strip $0 \leq \Re\,s < {1\over 2} $.


Some Results On Derivation Groups, Murat Alp Jan 2000

Some Results On Derivation Groups, Murat Alp

Turkish Journal of Mathematics

In this paper we describe a share package XMOD of functions for computing with finite, permutation crossed modules, their morphisms and derivations; cat$^1$-groups, their morphisms and their sections, written using the GAP \cite{GAP} group theory programming language. We also give some mathematical results for derivations. These results are suggested by the output produced by the XMOD package.


A Generalized Trapezoid Inequality For Functions Of Bounded Variation, P. Cerone, S. S. Dragomir, C. E. M. Pearce Jan 2000

A Generalized Trapezoid Inequality For Functions Of Bounded Variation, P. Cerone, S. S. Dragomir, C. E. M. Pearce

Turkish Journal of Mathematics

We establish a generalization of a recent trapezoid inequality for functions of bounded variation. A number of special cases are considered. Applications are made to quadrature formulae, probability theory, special means and the estimation of the beta function.


Some Commutativity Results For S -Unital Rings, Moharram A. Khan Jan 2000

Some Commutativity Results For S -Unital Rings, Moharram A. Khan

Turkish Journal of Mathematics

In the present paper, it is shown that if $R$ is a left ( resp. right) $s$-unital ring satisfying $[f(y^mx^ry^s) \pm x^ty, x] = 0$ (resp. $[f(y^mx^ry^s) \pm yx^t, x] = 0),$ where $m, r, s, t$ are fixed non-negative integers and $f(\lambda)$ is a polynomial in ${\lambda}^2{\bf Z}[\lambda],$ then $R$ is commutative. Commutativity of $R$ has also been investigated under different sets of constraints on integral exponents.


Some Graph Type Hypersurfaces In A Semi-Euclidean Space, Ikawa Toshihiko, Honda Kyoko Jan 2000

Some Graph Type Hypersurfaces In A Semi-Euclidean Space, Ikawa Toshihiko, Honda Kyoko

Turkish Journal of Mathematics

We consider some graph type hypersurfaces in a semi-Euclidean space $\Bbb R^{n+1}_{q}$ and give conditions of the dimension $n+1$ and the index $q$ when a hypersurface is lightlike, totally geodesic and minimal.


Conjugacy Classes Of Elliptic Elements In The Picard Group, Ni̇hal Yilmaz, İsmai̇l Naci̇ Cangül Jan 2000

Conjugacy Classes Of Elliptic Elements In The Picard Group, Ni̇hal Yilmaz, İsmai̇l Naci̇ Cangül

Turkish Journal of Mathematics

The Picard group $\mathbf{P}$ is a discrete subgroup of $PSL(2,\Bbb{C})$ with Gaussian integer coefficients. Here it is shown that the total number of conjugacy classes of elliptic elements of order 2 and 3 in $\mathbf{P}$, which is given as seven by B. Fine $\left[ 3\right] $, can actually be reduced to four and using this, the conditions for the maximal Fuchsian subgroups of $\mathbf{P}$ to have elliptic elements of orders 2 and 3 are found.


Lifts Of Derivations To The Semitangent Bundle, Ari̇f A. Salimov, Ekrem Kadioğlu Jan 2000

Lifts Of Derivations To The Semitangent Bundle, Ari̇f A. Salimov, Ekrem Kadioğlu

Turkish Journal of Mathematics

The main purpose of this paper is to investigate the complete lifts of derivations for semitangent bundle and to discuss relations between these and lifts already known.


On Characterization Of Metric Completeness, Guo-Jing Jiang Jan 2000

On Characterization Of Metric Completeness, Guo-Jing Jiang

Turkish Journal of Mathematics

We give seven necessary and sufficient conditions for a metric space to be complete.


On Generalized Higher Derivations, Atsushi Nakajima Jan 2000

On Generalized Higher Derivations, Atsushi Nakajima

Turkish Journal of Mathematics

We define the notion of generalized higher derivations and give some elementary relations between generalized higher derivations and higher derivations in the usual sense. We extend the result of an exact sequence of the set of all derivations $\text{Der}(A, M)$ and the set of all generalized derivations $g\text{Der}(A, M)$ given in [N1, Theorem 2.4]. Moreover, we discuss generalized higher Jordan derivations and Lie derivations.


Conjugacy Structure Type And Degree Structure Type In Finite P-Groups, Yadalah Marefat Jan 2000

Conjugacy Structure Type And Degree Structure Type In Finite P-Groups, Yadalah Marefat

Turkish Journal of Mathematics

Let $G$ be a finite $p-$group, and denote by $k(G)$ number of conjugacy classes in $G$. The aim of this paper is to introduce the conjugacy structure type and degree structure type for $p-$groups, and determine these parameters for $p-$groups of order $p^5$, and calculate $k(G)$ for them.


New And Old Types Of Homogeneity, Ali̇ Ahmad Fora Jan 2000

New And Old Types Of Homogeneity, Ali̇ Ahmad Fora

Turkish Journal of Mathematics

We introduce new types of homogeneity ; namely : locally homogeneity and closed homogeneity .Several results are included discussing some relations between these types and the old ones. Some characterization and decomposition theorems are obtained. Relevant examples and counterexamples are discussed throughout this paper.


A Borsuk-Ulak Theorem For Heisenberg Group Actions, Necdet Güner Jan 2000

A Borsuk-Ulak Theorem For Heisenberg Group Actions, Necdet Güner

Turkish Journal of Mathematics

Let $G=H_{2n+1}$ be a $(2n+1)$-dimensional Heisenberg Lie group acts on $M=C^m-\{0\}$ and $M^{'}=C^{m'}-\{0\}$ exponentially. By using Cohomological Index we proved the following theorem. If $f:M{\to}M^{'}$ is a $G$-equivariant map, then $m{\le}m'$.


On Conjugation In The Mod-P Steenrod Algebra, İsmet Karaca, İlkay Yaslan Karaca Jan 2000

On Conjugation In The Mod-P Steenrod Algebra, İsmet Karaca, İlkay Yaslan Karaca

Turkish Journal of Mathematics

In this paper we prove a formula involving the canonical anti-automorphism $\chi$ of the mod-$p$ Steenrod algebra.


The P-Stirling Numbers, Russel Merris Jan 2000

The P-Stirling Numbers, Russel Merris

Turkish Journal of Mathematics

The purpose of this article is to introduce \( p \)-Stirling numbers of the first and second kinds.


Some Radius Problem For Certain Families Of Analytic Functions, Yaşar Polatoğlu, Meti̇n Bolcal Jan 2000

Some Radius Problem For Certain Families Of Analytic Functions, Yaşar Polatoğlu, Meti̇n Bolcal

Turkish Journal of Mathematics

The aim of this paper is to give bounds of the radius of $\alpha $-convexity for certain families of analytic functions in the unit disc. The radius of $\alpha $-convexity is generalization of the radius of convexity and the radius of starlikeness, and introduced by S.S.Miller; P.T.Mocanu and M.O.Reade [3,4]


An Efficient Algorithm To Determine The Periodic Steady-State Solutions Of Nonlinear Systems Using Extended Spectral Analysis, Gülay Tohumoğlu Jan 2000

An Efficient Algorithm To Determine The Periodic Steady-State Solutions Of Nonlinear Systems Using Extended Spectral Analysis, Gülay Tohumoğlu

Turkish Journal of Electrical Engineering and Computer Sciences

A new method for the solution of nonlinear periodic systems was developed. It avoids the time domain calculations of the whole network equations. In the proposed method, by forming the augmented network as linear and nonlinear subnetworks these subnetworks are formulated in complex frequency and time domain respectively. Using spectral analysis the steady-state periodic solution of the whole nonlinear network is reached by an iterative approach. The method can be applied efficiently to weak and strong nonlinear circuits equally well. When we divide the network into a large linear subnetwork and a small nonlinear subnetwork, this method can be applied …


A Pseudo Spot Price Algorithm Applied To The Pumped-Storage Hydraulic Unit Scheduling Problem, Sali̇h Fadil, Celal Yaşar Jan 2000

A Pseudo Spot Price Algorithm Applied To The Pumped-Storage Hydraulic Unit Scheduling Problem, Sali̇h Fadil, Celal Yaşar

Turkish Journal of Electrical Engineering and Computer Sciences

A lossy electric power system that contains thermal units and a pumped-storage hydraulic unit is considered in this paper. The total cost of thermal units in an operation cycle is minimized under some possible electric and hydraulic constraints of the units. The operation cycle is divided into time intervals where the system loads are assumed to remain constant. The proposed solution technique has two main parts. In the first part, the active thermal generations and active generation or pumping power of the pumped-storage unit in all time intervals are determined by using units' active generation incremental costs and pseudo spot …


Distance Spectra For Trellis Coded Modulation Schemes On Channels With Intersymbol Interference, Sabi̇re Haciömeroğlu, Melek D. Yücel Jan 2000

Distance Spectra For Trellis Coded Modulation Schemes On Channels With Intersymbol Interference, Sabi̇re Haciömeroğlu, Melek D. Yücel

Turkish Journal of Electrical Engineering and Computer Sciences

The effect of intersymbol interference on distance spectra for trellis coded 8-PSK, 16-QAM and 32-AMPM modulation schemes is evaluated using the methods proposed by Schlegel. Distance spectra of 16-state 8-PSK scheme are computed for different intersymbol interference channels. It is seen that on channels with intersymbol interference the spectral lines are spread into a nearly continuous spectrum and the minimum Euclidean distance between codewords decreases severely. Hence, although the main contribution at large signal to noise ratios comes from the minimum Euclidean distance ( d_{free} ) , higher spectral components also become very important at moderate values of the signal …


A Study On N-Hydroxyamide Ethoxycarbonylhydrazones, A. Aykut İki̇zler, Ahmet Demi̇rbaş, Rza Abbasoğlu Jan 2000

A Study On N-Hydroxyamide Ethoxycarbonylhydrazones, A. Aykut İki̇zler, Ahmet Demi̇rbaş, Rza Abbasoğlu

Turkish Journal of Chemistry

The structures and electronic properties of N-hydroxyamide ethoxycarbonylhydrazones were investigated by a quantum-chemical method AMl. The total energies, heats of formation, dipol moments, ionization potentials, proton affinities and energies of frontier molecular orbitals (E_{HOMO} and E_{LUMO}) were calculated and discussed. The stabilities of the tautomeric forms and of E and Z isomers for these compounds were determined. The complex forming ability of these compounds with metal cations was also studied. The geometry and electronic properties of the complexes formed by N-hydroxyacetamide ethoxycarbonylhydrazone with Ni^{2+} and Cu^{2+} were investigated using ZINDO/1 semiempirical method. Moreover, these complexes were synthesized and identified.


The Measurement Of Surface Areas Of Some Silicates By Solution Adsorption, Oğuz İnel, Fatma Tümsek Jan 2000

The Measurement Of Surface Areas Of Some Silicates By Solution Adsorption, Oğuz İnel, Fatma Tümsek

Turkish Journal of Chemistry

In this study, the adsorption from solution technique was used for the determination of surface areas of some silicate samples (bentonite, sepiolite, zeolitic tuff and kaolin). Methylene blue (MB), orthophenanthroline (OP) and p-nitrophenol (PNP) were selected as solutes. The adsorption data was found to conform with the Langmuir equation within the concentration range studied, and Langmuir constants were determined for each of the samples. The surface area values obtained were compared with those determined by nitrogen adsorption. Also the results were discussed with respect to the cation exchange capacities of the samples. The specific surface area values of the samples …


Properties Of Electrodeposited Cadmium Sulfide Films For Photovoltaic Devices With Comparison To Cds Films Prepared By Other Methods, Fi̇gen Kadirgan, Duli Mao, Wenjie Song, Tim Ohno, Brian Mccandless Jan 2000

Properties Of Electrodeposited Cadmium Sulfide Films For Photovoltaic Devices With Comparison To Cds Films Prepared By Other Methods, Fi̇gen Kadirgan, Duli Mao, Wenjie Song, Tim Ohno, Brian Mccandless

Turkish Journal of Chemistry

Films of CdS for photovoltaic devices were electrochemically deposited on tin oxide coated glass substrates at different conditions. The films were found to be smooth and uniform with a small grain size. X-ray diffraction measurement and analysis indicated a hexagonal phase rather than the cubic phase. The surface composition of the films was investigated by Auger Spectroscopy. Electrochemical deposition parameters were studied to obtain the optimum conditions for the best CdS films. Our films are compared from the pinhole number and particulate point of view with the films prepared by other methods.


Fundamental Noise Studies In Flame Atomic Magneto-Optic Rotation And Atomic Absorption Spectrometry, Ahmet T. İnce, Richard D. Snook, Jhon B. Dawson Jan 2000

Fundamental Noise Studies In Flame Atomic Magneto-Optic Rotation And Atomic Absorption Spectrometry, Ahmet T. İnce, Richard D. Snook, Jhon B. Dawson

Turkish Journal of Chemistry

A study of inherent noise sources present in a purpose built flame atomic magneto-optic rotation (AMOR) spectrometer system was carried out with a view to identifying their sources. Two different optical configurations were employed, a crossed polariser and a 45° offset polariser configuration. The offset polariser configuration was operated in both an AMOR and atomic absorption (AA) mode for the noise measurements. Two main interference frequencies were found to occur in all the optical measurement modes. An interference flame feature frequency (15.5 Hz -39.0 Hz) which arose from an ``organ-pipe'' effect in the gas flow through the flame cooling sheets. …


Synthesis And Reactivity Of Some Mannich Bases. Vi. New Arylamine Mannich Bases Derived From 2-Hydroxy-5-Methylacetophenone, Gheorghe Roman, Diana Nanu, Eugenia Comanita, Bogdan Comanita Jan 2000

Synthesis And Reactivity Of Some Mannich Bases. Vi. New Arylamine Mannich Bases Derived From 2-Hydroxy-5-Methylacetophenone, Gheorghe Roman, Diana Nanu, Eugenia Comanita, Bogdan Comanita

Turkish Journal of Chemistry

The amine exchange reaction has been applied for obtaining a new series of arylamine Mannich bases from variously substituted aromatic amines and 3-(dimethylamino)-1-(2'-hydroxy-5'-methylphenyl) propan-1-one. The structures of the newly synthesised Mannich bases have been investigated by IR, ^1H- and ^{13}C-NMR and shown to be in good agreement with the proposed ones.