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1999

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The Wigner Problem In Electrodynamics, Andrzej Horzela Jan 1999

The Wigner Problem In Electrodynamics, Andrzej Horzela

Turkish Journal of Physics

The relation between canonical commutation rules and a shape of acting force is analysed. It is shown that canonical commutation relations and Newtonian equations of motion for a single particle dynamics do imply the force to be of the Lorentz type but the inverse is not true. The example of a single particle motion in a constant magnetic field shows that equations of motion allow an alternative to canonical commutation relations to exist and it is a Lie algebra. The algebra found is of the type of algebras found in studies leading towards noncommutative geometry approaches to physical problems.

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On The Concept Of Spin In Electrodynamics, Ivangoe Pestov Jan 1999

On The Concept Of Spin In Electrodynamics, Ivangoe Pestov

Turkish Journal of Physics

It is substantiated that spin is a notion associated with the group of internal symmetry that is tightly connected with the geometrical structure of spacetime. The wave equation for the description of a particle with spin one half is proposed. On this ground it is shown that the spin of electron is exhibited through the quantum number and accordingly the Dirac equation describes properties of particles with the projection of spin \pm \hbar/2. On the contrary, we put forward the conjecture that the spin of the quark cannot be considered as a quantum number, but only as an origin of …

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New Aspects Of Vavilov-Cherenkov Radiation, Georgy Afanasiev, Vladimir Kartavenko Jan 1999

New Aspects Of Vavilov-Cherenkov Radiation, Georgy Afanasiev, Vladimir Kartavenko

Turkish Journal of Physics

The effects arising from accelerated and decelerated motion of charged point particles inside a medium are studied. It is shown explicitly that, in addition to the bremsstrahlung and Cherenkov shock wave, the electromagnetic shock wave arising from the charge velocity exceeding the medium light velocity should be observed. This shock wave has the same singularity as the Cherenkov one and therefore, it is more singular than the bremsstrahlung shock wave. The space-time regions where these shock waves exist and conditionsunder which they appear are determined.

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The Gauge Freedoms Of Enlarged Helmholtz Theorem And Debye Potentials; Their Use In The Multipole Expansion Of Conserved Current, Elena N. Bukina, Vladimir M. Dubovik Jan 1999

The Gauge Freedoms Of Enlarged Helmholtz Theorem And Debye Potentials; Their Use In The Multipole Expansion Of Conserved Current, Elena N. Bukina, Vladimir M. Dubovik

Turkish Journal of Physics

We discuss gauge freedom within the scope of the enlarged Helmholtz theorem and Neumann-Debye decomposition and then demonstrate its realization for the multipole expansion of a conserved electromagnetic current. The exact solution to the latter problem was obtained in 1974, but answers to some purely mathematical questions raised by I.B. French and Y. Shimamoto [1] about 40 years ago are given in this paper for the first time.

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On The Experimental Search For Photon Mixing, Vsevolod Popov Jan 1999

On The Experimental Search For Photon Mixing, Vsevolod Popov

Turkish Journal of Physics

The experimental searches for photon mixing in the Okun model [1] are discussed.

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Cover And Contents Jan 1999

Cover And Contents

Turkish Journal of Physics

No abstract provided.

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Influence Of Electrical Field On Pulsed Laser Beam Welding Of Stainless Steel (304), Salah A. H. Fawzi̇, Raz N. Ari̇f Jan 1999

Influence Of Electrical Field On Pulsed Laser Beam Welding Of Stainless Steel (304), Salah A. H. Fawzi̇, Raz N. Ari̇f

Turkish Journal of Physics

Pulsed laser beam welding experiment were carried out on stainless steel (SUS 304), using vertical and horizontal electric fields of different intensities to study its effectiveness on the welding process, regarding depth and weld quality. Pulsed Nd: YAG laser emitting 10 ms pulses in the TEM_{00} mode at 1.06 \mu m wave length was employed, microstructure of welded zone and defect were investigated using optical and scanning electron microscopes. Tensile test and microhardness measurements were carried out to evaluate the weld quality. Welding by this method increased the efficiency tremendously and a depth increase of 85% was achieved.

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Electrical Switching In Potassium-Boro-Vanadate-Iron Glasses, H. R. Panchal, D. K. Kanchan Jan 1999

Electrical Switching In Potassium-Boro-Vanadate-Iron Glasses, H. R. Panchal, D. K. Kanchan

Turkish Journal of Physics

Electrical switching has been observed in 20K_2O : (75-y)V_2O_5 : yB_2O_3 : 5Fe_2O_3 glasses which were prepared by a splat quenching method. To investigate switching phenomenon, glass samples of the same dimension from as quenched material were examined for their I-V characteristics at various ambient temperatures. The exponential decrease of switching voltage is observed with increasing ambient temperature indicating the cause of switching due to Joule's heating. It is also observed that the switching voltage can be controlled by varying the ambient temperature and switching temperature by changing the voltage. The dependence of switching temperature on the amount of V_2O_5 …

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Effect Of Ionizing Radiation On The Silicon Impatt Diode Characteristics, M. B. Tagaev Jan 1999

Effect Of Ionizing Radiation On The Silicon Impatt Diode Characteristics, M. B. Tagaev

Turkish Journal of Physics

We investigated the effect of ^{60}Co \gamma-irradiation (doses from 10^2 to 2 \times 10^6 Gy), both without and with heat annealing, on silicon IMPATT diode parameters. It is shown that such treatments improve the diode characteristics (particularly decrease the reverse current and increase both the output and the diffusion length of the minority charge carriers) due to radiation-enhanced processes.

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The Peculiarities Of The Electrical And Thermoelectrical Properties Of P-Type Ag_2te, Ali̇ İhsan Demi̇rel, S. A. Aliev, F. F. Aliev, F. Z. Guseynov, Sali̇m Orak Jan 1999

The Peculiarities Of The Electrical And Thermoelectrical Properties Of P-Type Ag_2te, Ali̇ İhsan Demi̇rel, S. A. Aliev, F. F. Aliev, F. Z. Guseynov, Sali̇m Orak

Turkish Journal of Physics

The electrical and thermoelectrical properties of p-type Ag_2Te have been investigated. Various peculiarities were observed: the minimum (at T \approx 65 K) and maximum (at T \approx 200 K) on the temperature dependence of conductivity \sigma (T); the weak dependence of Hall coefficient R(T) (in 200-300 K range) and the maximum (at T \approx 100 K and 250 K) on the temperature dependence of thermal power \alpha_0 (T). The investigation results were interpreted by two-bands model. It is shown that mentioned peculiarities have been stimulated by the narrow gap of Ag_2Te and its temperature dependence.

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Relative L X-Ray Fluorescene Cross-Sections In Heavy Elements In The Energy Region Of 16-122 Kev, Oğuz Doğan, Mehmet Ertuğrul, Önder Şi̇mşek, Ümi̇t Turgut, Hasan Erdoğan Jan 1999

Relative L X-Ray Fluorescene Cross-Sections In Heavy Elements In The Energy Region Of 16-122 Kev, Oğuz Doğan, Mehmet Ertuğrul, Önder Şi̇mşek, Ümi̇t Turgut, Hasan Erdoğan

Turkish Journal of Physics

Relative L1, L\alpha, L\beta and L\gamma x-ray fluorescence cross-sections were observed in Ta, W, Re, Au, Hg, T1, Pb, Bi, Th and U of 16.03, 17.78, 22.58, 25.77, 32.89, 38.18, 43.94, 50.21, 59,5 and 122 keV energies. In this study, L X-ray fluorescence cross-sections were measured at 59.5 and 122 keV and measured values of the other energies were taken from tables by Mann et. al. (1). The experimental relative fluorescene cross-sections were computed for the excitation energies 16.03, 17.78, 22.58, 25.77, 32.89, 38.18, 43.94, 50.21, 59.5 and 122 keV, compared with the theoretically calculated values by Scofield(11). The experimental …

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Supersymmetric Electroweak Radiative Corrections To E^+ E^- -> W^+W^-, S. Alam Jan 1999

Supersymmetric Electroweak Radiative Corrections To E^+ E^- -> W^+W^-, S. Alam

Turkish Journal of Physics

In this short note we summarize some of the work of our thesis, which is also reported elsewhere in detail. We have examined the one loop quantum corrections to the W pair production in the electron positron annihilation in the context of supersymmetric electroweak theory. We have adopted the On Mass Shell Renormalization scheme of Sakakibara and previously demonstrated the consistency of this scheme. The relevant analytic results are written out. A complete computer program for these corrections has been developed. This program has been checked in several ways to ensure against errors over the life of the calculation where …

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Effect Of Illumination Temperature On Thermally Stimulated Current Spectrum Of Tlins_2, Selahatti̇n Özdemi̇r, Rauf Süleymanov, Mahmut Bucurgat, Enver Bulur Jan 1999

Effect Of Illumination Temperature On Thermally Stimulated Current Spectrum Of Tlins_2, Selahatti̇n Özdemi̇r, Rauf Süleymanov, Mahmut Bucurgat, Enver Bulur

Turkish Journal of Physics

The effect of pre-illumination on both thermally stimulated current and photocurrent spectra of TlInS_2 crystal is investigated. The increase in the photosensitivity of the crystal by several orders of magnitude together with the appearance of a new peak in the thermally stimulated current spectrum are observed as a result of the pre-illumination process. The filling of the traps, especially the sensitizing centers, during the pre-illumination is found to be the most favourable physical mechanism to explain the results.

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Confined Bipolarons In The Strong Coupling Limit, R. Tuğrul Senger, Ati̇lla Erçelebi̇ Jan 1999

Confined Bipolarons In The Strong Coupling Limit, R. Tuğrul Senger, Ati̇lla Erçelebi̇

Turkish Journal of Physics

Within the framework of the strong-coupling polaron theory and the bulk phonon approximation we report the possibility and criteria in achieving stable bipolaron states in confined media. We use a simple model of two electrons constrained within an anisotropic three dimensional parabolic potential box of tunable barrier slopes. Conforming the confining potential from one geometry to the other, we obtain an explicit tracking of the stability criteria as a function of the degree of confinement uncovering all low dimensional major geometric configurations of common interest.

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Cover And Contents Jan 1999

Cover And Contents

Turkish Journal of Physics

No abstract provided.

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Implications Of \Delta\Rho And Charm Ii Data For Z' Physics, Durmuş Ali̇ Demi̇r Jan 1999

Implications Of \Delta\Rho And Charm Ii Data For Z' Physics, Durmuş Ali̇ Demi̇r

Turkish Journal of Physics

We discuss the constraints on the Z^{\prime} model parameters coming from Z-pole and low-energy \nu_{\mu}-e scattering data in the frame work of GUT-motivated models. We find that when the coupling constant of the extra U(1) is small (large) the parameter space is mainly determined by the Z-pole (the low-energy \nu_{\mu}-e scattering) data.

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Electroweak Symmetry Breaking In Low-Scale Quantum Gravity, M. Boz, A. Demi̇r, Namik Kemal Pak Jan 1999

Electroweak Symmetry Breaking In Low-Scale Quantum Gravity, M. Boz, A. Demi̇r, Namik Kemal Pak

Turkish Journal of Physics

We discuss the implications of low-scale quantum gravity on electroweak symmetry breaking by computing one-loop gravitational corrections to the Higgs potential. We conclude that these radiative corrections are quite large after summing over the graviton and dilaton Kaluza-Klein towers, and there is no possibility of electroweak symmetry breaking unless one allows for the complex vacuum expectation value for the Higgs field.

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Projectile Fragmentation In Emulsion At (4.1-4.5) A Gev/C, A. El-Naghy, S. A. H. Abou-Steit, M. Mohery Jan 1999

Projectile Fragmentation In Emulsion At (4.1-4.5) A Gev/C, A. El-Naghy, S. A. H. Abou-Steit, M. Mohery

Turkish Journal of Physics

The fragmentation process has been investigated for 4.5A GeV/c^{28}Si nuclei in emulsion and compared with the results of 4.5A GeV/c^{24}Mg and 4.1A GeV/c^{22}Ne in order to test the validity of the different theoretical models. It has been found that a single parameter distribution is insufficient to explain exactly the fragmentation process. Correlation studies have shown to be necessary for distinguishing between the different theoretical models for the fragmentation. The impact parameter, which defines the nature of the collision, has been found to influence considerably the shape of the charge yield distribution. The angular distributions of the projectile fragments can be …

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Electrodynamics With Toroid Polarization, V. M. Dubovik, B. H. Saha Jan 1999

Electrodynamics With Toroid Polarization, V. M. Dubovik, B. H. Saha

Turkish Journal of Physics

A modified system of equations of electrodynamics of continuous media has been obtained. Beside the Lagrangian system an alternative gauge-like formalism has been developed to introduce the toroid moment contributions in the obtained equations. The two potential formalism that was worked out by us earlier has been developed further where along with the two vector potentials we introduce two scalar potentials thus taking into account all four basic equations of electromagnetism.

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Stellar Observations Made At The Malatya Danjon Astrolabe Station, Orhan Gölbaşi, Hüseyi̇n Kiliç, Fernand Chollet Jan 1999

Stellar Observations Made At The Malatya Danjon Astrolabe Station, Orhan Gölbaşi, Hüseyi̇n Kiliç, Fernand Chollet

Turkish Journal of Physics

We give here the first results of astrometric stellar observations made at the Malatya Station with the modified astrolabe of Paris observatory. This campaign is conducted as part of a cooperation between Inönü University and the Paris Observatory. The astrolabe, which is strictly similar to that of Santiago de Chile, can use two reflecting prisms instead of the trnsparent prism of the Danjon Astrolabe. Consequently, it is possible to observe at the two zenith distances of 30° and 60°. The time is supplied by a GPS receiver which gives UTC with the necessary precision. As the station is a new …

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Canonical Treatment Of Regular Lagrangians With Holonomic Constraints As Singular Systems, Eqab M. Rabei Jan 1999

Canonical Treatment Of Regular Lagrangians With Holonomic Constraints As Singular Systems, Eqab M. Rabei

Turkish Journal of Physics

Regular Lagrangians with holomonic constraints are treated as singular systems using the canonical method. The Lagrange multipliers are introduced as generalized coordinates. The regular Lagrangians are extended to be singular and the Hamiltonian formulation is obtained. The equations of motion are written as total differential equations in terms of the time t and the Lagrange multipliers. It is also shown that Lagrange multipliers can be determined from the integrability conditions.

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Magnetisation In Two-Dimensions, Bengü Kaplan Jan 1999

Magnetisation In Two-Dimensions, Bengü Kaplan

Turkish Journal of Physics

We discuss the magnetisation deviation in two-dimensions (2d) for an iron film for which the anisotropy is much smaller and hence the magnetisation is a stronger function of temperature. The magnetisation deviation can be adequately described by an RPA (random phase approximation) approach. Our results fit the experimental data at high fields and hence can be used to estimate the value of the effective exchange interaction (J_{2d}) for monolayer (ML) films.

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A Magnetization And Gmr Study On Multilayered Fe/Ag/Co Thin Film, Cengi̇z Bi̇rli̇kseven, Alpan Bek, Hüseyi̇n Zafer Durusoy Jan 1999

A Magnetization And Gmr Study On Multilayered Fe/Ag/Co Thin Film, Cengi̇z Bi̇rli̇kseven, Alpan Bek, Hüseyi̇n Zafer Durusoy

Turkish Journal of Physics

Single layer Fe(20Å) and Co(20Å) and multilayered Ag(20Å)/[Fe(20Å)/Ag(40Å)/Co(20Å)/Ag (40Å)] x 3/Ag(20Å) films were prepared in UHV by magnetron sputtering technique onto the silicon substates. Films were determined to have polycrystalline nature through SEM examination. Magnetization measurements were made on single and multilayer films. Due to the polycrystalline structure of the films, rounded magnetization curves were obtained. The GMR effect showed a rounded behaviour which also is an indication of the polycrystallinity of the films. The GMR effect, measured in Fe/Ag/Co multilayer structure, was analyzed with the help of magnetization behaviour of the multilayer structure and magnetization behaviour of the single …

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Low-Magnetic Field Microwave Absorption In Superconductors And Conducting Polymers, I. L. Khairullin, P. K. Khabibullaev, V. Yu. Sokolov, A. A. Zakhidov Jan 1999

Low-Magnetic Field Microwave Absorption In Superconductors And Conducting Polymers, I. L. Khairullin, P. K. Khabibullaev, V. Yu. Sokolov, A. A. Zakhidov

Turkish Journal of Physics

Low-magnetic field microwave absorption (MA) in superconductors and conducting polymers is analysed in a low-field signal (LFS) version of the MA detecting method. The temperature dependences, hysteretic benavior and other properties of a LFS are compared in superconducting versus non-superonducting systems. Spin selective hopping processes between polarons and bipolarons is proposed to be one of the possible mechanisms of a LFS in non-degenarate conducting polymers.

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Cover And Contents Jan 1999

Cover And Contents

Turkish Journal of Physics

No abstract provided.

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On Generalizations I: A Preliminary Exploration, Terence J. Anderson Jan 1999

On Generalizations I: A Preliminary Exploration, Terence J. Anderson

Articles

No abstract provided.

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The Constitution And Encryption Regulation: Do We Need A "New Privacy"?, A. Michael Froomkin Jan 1999

The Constitution And Encryption Regulation: Do We Need A "New Privacy"?, A. Michael Froomkin

Articles

No abstract provided.

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Sraffa's Critique Of Atomism, John B. Davis Jan 1999

Sraffa's Critique Of Atomism, John B. Davis

Economics Faculty Research and Publications

No abstract provided.

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Disestablishing Local School Districts As A Remedy For Educational Inadequacy Note, Aaron J. Saiger Jan 1999

Disestablishing Local School Districts As A Remedy For Educational Inadequacy Note, Aaron J. Saiger

Faculty Scholarship

Most state constitutions recognize a right to education, but courts have been hard pressed to respond to violations of that right. Some state courts have imposed financial and substantive reforms, only to see their implementation miscarry as educational deficiencies stubbornly persist. Other state courts, fearing such outcomes, instead treat education claims as nonjusticiable political questions; in these states, public education is a right with no remedy. This Note argues that courts should instead base remedies on state statutes that permit states to disestablish-i.e., to withdraw authority from-deficient school districts. Disestablishment, like other structural remedies, is largely self-implementing and avoids judicial …

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When Is Property Intellectual: The Leveraging Problem Essays, Mark R. Patterson Jan 1999

When Is Property Intellectual: The Leveraging Problem Essays, Mark R. Patterson

Faculty Scholarship

Patents and copyrights protect inventions and expression; they do not protect products. This distinction, I argue in this essay, is a key to the antitrust problem of the "leveraging" of intellectual property. In a typical leveraging case, the manufacturer of a durable good, like a copier or computer, refuses to sell replacement parts for its equipment unless the purchaser also hires the manufacturer to service the equipment. Such a practice can be illegal under antitrust law, but when the leveraging products-in this example, replacement parts-are protected by patent or copyright, the manufacturer will often claim that the leveraging is a …

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