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Full-Text Articles in Physical Sciences and Mathematics

Determination Of Patent Blue V And Carmoisine In Gelatine Desserts By Derivative Spectrophotometry, Yüksel Özdemi̇r, Ayşe Arzu Akkan Jan 1999

Determination Of Patent Blue V And Carmoisine In Gelatine Desserts By Derivative Spectrophotometry, Yüksel Özdemi̇r, Ayşe Arzu Akkan

Turkish Journal of Chemistry

A first-derivative spectrophotometric method was developed for quantitative determination of two synthetic organic dyes, Carmoisine and Patent Blue V, which are under governmental regulations all over the world because of their toxicity and carcinogenity. In this study, Carmoisine and Patent Blue V were simultaneously determined in their binary mixtures by first-derivative spectrophotometry. The method was applied to different gelatine desserts. The first-derivative derivative method did not eliminate turbid background in the samples. A simple background correction procedure involving a C_{18}-cartridge sample preparation step was developed for determination of dyes in gelatine dessert by first-derivative spectrophotometry. The C_{18}-cartridge sample preparation step …


Chlorination Of Two Turkish Lignites In Water And Water-Carbon Tetrachloride Media, Semra Karaca, Yücel Yaşar Kadioğlu, Sami̇h Bayrakçeken, M. Şahi̇n Gülaboğlu Jan 1999

Chlorination Of Two Turkish Lignites In Water And Water-Carbon Tetrachloride Media, Semra Karaca, Yücel Yaşar Kadioğlu, Sami̇h Bayrakçeken, M. Şahi̇n Gülaboğlu

Turkish Journal of Chemistry

The chlorine uptake of two Turkish lignites during chlorinolysis with chlorine gas in water and water-carbon tetrachloride media at ambient pressure (\cong 610 mmHg) was examined. The effects of speed of stirring (5-20s^{-1}), particle size (74-88, 150-180 and 250-425 \mu m), temperature (13-70°C) and chlorination time (0-18000 s) were studied. It is shown that the amount of chlorine uptake of both coals increased with decreasing particle size and increasing temperature.


Stabilities Of Complexes Of Scandium(Iii) And Yttrium(Iii) With Salicylic Acid, Naci̇ye Türkel, Rahmi̇ye Aydin, Ulvi̇ye Özer Jan 1999

Stabilities Of Complexes Of Scandium(Iii) And Yttrium(Iii) With Salicylic Acid, Naci̇ye Türkel, Rahmi̇ye Aydin, Ulvi̇ye Özer

Turkish Journal of Chemistry

The interactions of Sc(III) and Y(III) ions with salicyclic acid, SA (H_2L), were studied in aqueous solution by means of potentiometric and spectroscopic methods. The binding of SA occurs in Y(III):SA system, either in (1:1) or (1:2) mole ratios. The stability constants of the mono protonated complex, YHL^{2+}, and Y(HL)_2^+ type complex were calculated. The coordination of Sc(III) to SA was defined by means of Job's plot and its formation curve. The stability constants of ScL^+ and Sc(HL)L type complexes were determined by analysis of the potentiometric data; the coordination of SA to Sc(III) occurred through carboxylate and phenolic oxygens. …


Conformational Analysis Of Linear Peptide (Glu^1-Leu^2-Leu^3-Gly^4-Gly^5-Arg^6-Phe^7nh_2 ), Lütfü Demi̇r, Abdulhali̇k Karabulut, Gökhan Budak, Yusuf Şahi̇n, Nagif Sefteroğlu Jan 1999

Conformational Analysis Of Linear Peptide (Glu^1-Leu^2-Leu^3-Gly^4-Gly^5-Arg^6-Phe^7nh_2 ), Lütfü Demi̇r, Abdulhali̇k Karabulut, Gökhan Budak, Yusuf Şahi̇n, Nagif Sefteroğlu

Turkish Journal of Chemistry

Conformational energy-minimization of the Sea Anemone and Sea Pansy neuropeptide Pol-RFamide (Glu^1-Leu^2-Leu^3-Gly^4-Gly^5-Arg^6-Phe^7-NH_2) was carried out by molecular mechanics (MM). The linkage bonds were characterized by the torsion angles \theta, \psi and \omega and the side groups were characterized by the torsion angles \chi_1, \chi_2, \chi_3\ldots The energy-map for each monopeptide of the Pol-RFamide I was drawn in the range of -180° to 180° with increments of 20°. Conformation facilities for monopeptides were determined from these maps. These results were used in the analysis of the dipeptide (Glu^1-Leu^2). Then, the (Glu^1-Leu^2-Leu^3) tripeptide was examined using the calculated results for the dipeptide. …


^1h Nmr Spectra Of Some Amidrazone Derivatives, Şule Bahçeci̇, Haydar Yüksek, A. Aykut İki̇zler Jan 1999

^1h Nmr Spectra Of Some Amidrazone Derivatives, Şule Bahçeci̇, Haydar Yüksek, A. Aykut İki̇zler

Turkish Journal of Chemistry

Fifteen amidrazone derivatives (six being new compounds) were synthesized and their proton magnetic resonance spectra were recorded in trifluoroacetic acid (TFA). The protonation shifts, related to alkyl groups and observed on comparison of the spectra run in a neutral solvent and TFA, were attributed to an amidinium-type resonance of the resulting cations in the acidic medium.


Thin Layer Chromatographic Separation And Quantitation Of L-Dopa And L-Tyrosine In Mixtures, Gülendem Günendi̇, Farünni̇sa Pamuk Jan 1999

Thin Layer Chromatographic Separation And Quantitation Of L-Dopa And L-Tyrosine In Mixtures, Gülendem Günendi̇, Farünni̇sa Pamuk

Turkish Journal of Chemistry

A new TLC separation and quantitation method for L-tyrosine and L-Dopa mixtures was developed. The minimum tyrosine and Dopa quantities which can be measured by this technique are 0.7 and 1.5 \mu g respectively. The method may be used to measure the kinetic parameters of polyphenoloxidase as well as to trace the enzyme catalyzed conversion of L-tyrosine into L-Dopa. For a set of 20 measurements the maximum difference between any two measurements of spot areas was found to be 3 mm^2 (4.5\%) for L-Dopa (4 \mu g) and 2mm^2 (5.6\%) for L-tyrosine (1\mu g).


Spectrophotometric Determination Of Uranium In Waste Water Of Phosphoric Acid And Fertilizer Manufacturing Process, Ahmet Uyanik, Ni̇hat Tinkiliç, M. Odabaşoğlu, Hüseyi̇n Karaca Jan 1999

Spectrophotometric Determination Of Uranium In Waste Water Of Phosphoric Acid And Fertilizer Manufacturing Process, Ahmet Uyanik, Ni̇hat Tinkiliç, M. Odabaşoğlu, Hüseyi̇n Karaca

Turkish Journal of Chemistry

In this study, waste water drains and produced phosphate fertilizers of conventional wet-process (hemihydrate) phosphoric acid and phosphate fertilizer plants were investigated to determine the average uranium contents in the active manufacturing period. The method chosen for the determination of uranium was an extension of an existing spectroanalytical method and was adopted for waste water analysis as described. The results show that average uranium contents (mg m^{-3}) in a three-month period are appreciable in the waste water channel of the H_3PO_4 unit, produce acid containing 28% P_2O_5 (20.75), H_3PO_4 unit, produce acid containing 54% P_2O_5 (35.69), NPK (Nitrogen, Phosphorus, Potassium …


Hydrogen Evolution At Platinum (Pt) And At Platinized Platinum (Ptz) Cathodes, Bi̇rgül Yazici Jan 1999

Hydrogen Evolution At Platinum (Pt) And At Platinized Platinum (Ptz) Cathodes, Bi̇rgül Yazici

Turkish Journal of Chemistry

In this study, the cathodic behaviours of bright platinum (Pt) and at platinized platinum (Ptz) on the platinum anode were investigated in a 1M Na_2SO_4 electrolyte (pH, from 2 to 8) by means of electrolysis. The theoretical (\Delta Erev) and experimental (\Delta E_{exp}) discharge potentials and the cathodic overpotentials (\etac) of the systems were determined. The amounts of hydrogen gas produced at different times on the cathodes at a constant potential (5V) were measured and the hydrogen yield was calculated. The resulting scheme has been very helpful to obtain wodified electrocatalytic coating and electrode structures at Ptz cathode, able to …


Reaction Mechanism And Kinetics Of Aqueous Solutions Of Primary And Secondary Alkanolamines And Carbon Dioxide, Olgac Bavbek, Erdoğan Alper Jan 1999

Reaction Mechanism And Kinetics Of Aqueous Solutions Of Primary And Secondary Alkanolamines And Carbon Dioxide, Olgac Bavbek, Erdoğan Alper

Turkish Journal of Chemistry

The mechanism and kinetics of the reaction between aqueous solutions of CO_2 and the alkanolamines 1-amino-2-propanol, 3-amino-1-propanol,2-methyl aminoethanol and 2-ethyl aminoethanol were investigated using a stopped flow technique. It was found that the reaction orders according to power law kinetics were between 1.1 and 2.0, depending on the alkanolamine and the concentration ranges investigated. This fractional order was therefore considered to be further evidence that carbamate formation takes place according to a zwitterion mechanism rather than a one-step reaction. The kinetic rate parameters for these alkanolamines were evaluated from experimental data at 303 K according to this mechanism.


Acidity Of Silica-Alumina Catalysts By Amine Titration Using Hammett Indicators And Ft-Ir Study Of Pyridine Adsorption, Mürüvvet Yurdakoç, Mehmet Akçay, Yalçin Tonbul, Kadi̇r Yurdakoç Jan 1999

Acidity Of Silica-Alumina Catalysts By Amine Titration Using Hammett Indicators And Ft-Ir Study Of Pyridine Adsorption, Mürüvvet Yurdakoç, Mehmet Akçay, Yalçin Tonbul, Kadi̇r Yurdakoç

Turkish Journal of Chemistry

In this study, characterization and surface acidity of Siral (SiO_2-Al_2O_3) compounds were investigated with Hammett acidity functions, the n-butylamine titration method and FTIR analysis of the spectra of pyridine adsorption. All the samples had an acid strength of H_0\leq+2.8. The calculated total amount of acid of the samples increased with the increase in SiO_2 content up to Siral 40 and then decreased sharply in the case of Siral 80. Maximum amount of acidity was observed in the case of Siral 40 as 1.37mmole/g. No evidence was found for a band at 1540 cm^{-1} on Pural indicating that there were no …


Chemical Investigation Of The Sponge Verongia Aerophoba, Zeynep Aydoğmuş, Nebi̇ye Ersoy, Sedat İmre Jan 1999

Chemical Investigation Of The Sponge Verongia Aerophoba, Zeynep Aydoğmuş, Nebi̇ye Ersoy, Sedat İmre

Turkish Journal of Chemistry

The solvent effect on Verongia aerophoba metabolites during the extraction and isolation processes were examined in this study. A major compound (6), a stereoisomer of fistularin-3, and a new compound (2) were isolated from the acetone extract of dried and ethanol extract of fresh V. aerophoba samples respectively. The structures of these metabolites were elucidated using spectroscopic methods.


Development Of Black Cobalt Selective Absorber On Copper For Solar Collectors, Fi̇gen Kadirgan, Mete Söhmen Jan 1999

Development Of Black Cobalt Selective Absorber On Copper For Solar Collectors, Fi̇gen Kadirgan, Mete Söhmen

Turkish Journal of Chemistry

An eletrolyte is proposed for the deposition of black cobalt selective absorber coating on copper plate. The influence of the electrolyte composition and operating parameters on the properties of black cobalt coatings including optical properties were studied. The optimum conditions to obtain a high absorptance/emittance ratio are described.


Comparative Mechanistic Studies On The Oxidation Of Aromatic And Aliphatic Hydroxyl Derivatives In An Alkaline Medium At Preanodized Pt, Au And Pt/Au Electrodes In Presence Of Redox Mediators, Sasha Kalcheva, Philip Iotov Jan 1999

Comparative Mechanistic Studies On The Oxidation Of Aromatic And Aliphatic Hydroxyl Derivatives In An Alkaline Medium At Preanodized Pt, Au And Pt/Au Electrodes In Presence Of Redox Mediators, Sasha Kalcheva, Philip Iotov

Turkish Journal of Chemistry

The role of redox mediators obtained from Pt, Au, and Pt/Au electrodes in the process of electrocatalytic oxidation of aromatic/aliphatic hydroxyl derivatives in an alkaline medium has been studied by applying cyclic voltammetry. Phenol and glycerol were used as aromatic and aliphatic hydroxyl derivatives in the electrochemical oxidation experiments. The results revealed that the presence of redox mediators formed by preliminary electrode anodization is crucial for the process of oxidation of aromatic compounds and imposes a different oxidation route for the aliphatic hydroxyl derivatives. The effect of preanodization has been related to the formation and dissolution of the corresponding higher …


Electrochemical Characterization Of Al_2 O_3 -Ni Thin Film Selective Surface On Aluminium, Fi̇gen Kadirgan, Ewa Wackelgard, Mete Söhmen Jan 1999

Electrochemical Characterization Of Al_2 O_3 -Ni Thin Film Selective Surface On Aluminium, Fi̇gen Kadirgan, Ewa Wackelgard, Mete Söhmen

Turkish Journal of Chemistry

Solar thermal collectors represent a widely used type of system for the conversion of solar energy. In order to produce selective coatings on aluminium substrates to be used as absorber plates in high efficiency solar collectors, nickel pigmentation was applied to anodically oxidised surfaces. Electrochemical dc methods are used to study the oxidation of aluminium as functions of the following electrolysis conditions: applied current, pH, temperature and concentration of electrolyte. The properties of the oxidised aluminium surfaces are investigated by cyclic voltammetry. Nickel pigmentation of porous aluminium surfaces was also performed as a function of electrochemical pigmentation conditions by ac …


The Effects Of Detergent Pollution On The Corrosion Of Iron And Aluminium, Si̇bel Zor, B. Yazici, M. Erbi̇l Jan 1999

The Effects Of Detergent Pollution On The Corrosion Of Iron And Aluminium, Si̇bel Zor, B. Yazici, M. Erbi̇l

Turkish Journal of Chemistry

The current-potential values were measured with iron or aluminium electrodes in solutions of 3.5% NaCl containing 30, 150, 300 ppm linear alkylbenzene (LAB) and detergents (LAS) at pH8. Polarization resistances (Rp) were determined using the values of current and potentials. The corrosion rates of iron and aluminium were determined in 2 and 4 hour intervals using the Mansfeld-Oldham equation based on the Stern-Geary and Butler-Volmer equations.


Reactions Of N-Aminopyrimidine Derivatives With 1,3-Dicarbonyl Compounds, Zülbi̇ye Önal, Behzat Altural Jan 1999

Reactions Of N-Aminopyrimidine Derivatives With 1,3-Dicarbonyl Compounds, Zülbi̇ye Önal, Behzat Altural

Turkish Journal of Chemistry

The reactions of 1-Amino-pyrimidine derivatives (1) and some 1,3-dicarbonyl compounds (2) were realized in the presence of p-toluensulfonic acid catalyst to give convenient enamine (3) and/or imine derivatives (4). In the same way, the enamine (5) and/or imine derivatives (6) were synthesized using (1) and 1,3-indanedione which is one of the different 1,3-dicarbonyl compounds. The molecular structures of all the prepared compounds were determined by ^1H-nmr, ^{13}C-nmr, i.r. spectra and elemental analyses, and were drawn by taking imine-enamine tautomerism into account.


A Modified Potentiometric Method For The Estimation Of Phenol In Aqueous Systems, Farhat Huma, Muhammad Jaffar, Khalid Masud Jan 1999

A Modified Potentiometric Method For The Estimation Of Phenol In Aqueous Systems, Farhat Huma, Muhammad Jaffar, Khalid Masud

Turkish Journal of Chemistry

A modified potentiometric titration is proposed for the estimation of phenol in aqueous systems. The method is evolved on the basis of a critical dependence of pH on log V rather than simple V, as used in conventional potentiometric titrations. The method incorporates titrants in a concentration range several orders of magnitude greater than that of phenol in the aqueous phase. Derivative potentiometric curves so obtained provide a clear exposition of the equivalence point and the overall error is found to be between \pm 1.0 and 1.5%. The range of phenol concentration investigated was from 10^{-2} to 10^{-3} M. and …


Electrochemical Behaviour Of Hexa[4-(Phenylazo) Phenoxy]Cyclotriphasphazene, Necati̇ Menek, Günseli̇ Turgut, Mustafa Odabaşioğlu Jan 1999

Electrochemical Behaviour Of Hexa[4-(Phenylazo) Phenoxy]Cyclotriphasphazene, Necati̇ Menek, Günseli̇ Turgut, Mustafa Odabaşioğlu

Turkish Journal of Chemistry

The polarographic and voltammetric behaviour of hexa[4-(phenylazo)phenoxy]cyclotriphasphazene in tetrahydrofuran-water 50% (v/v) was studied at room temperature using various electrochemical techniques. In this study, the reduction of the azo group to the amino group of the organophosphazenes compound was observed as the electrode reaction. An electrode reaction mechanism was suggested for the compound.


Synthesis, Structural And Thermal Studies Of Titanium(Iv) Complexes Of N-Alkyl Phenothiazines, Jaldappa Seetharamappa, Boregowda Keshavan Jan 1999

Synthesis, Structural And Thermal Studies Of Titanium(Iv) Complexes Of N-Alkyl Phenothiazines, Jaldappa Seetharamappa, Boregowda Keshavan

Turkish Journal of Chemistry

New coordination compounds of the type [Ti(C_2O_4)_2L]2H_2O where L=N-alkyl phenothiazines (NAPs) were synthesised and characterised by elemental analyses, molar conductance, magnetic, thermal and spectral data. The spectral data suggest the bidentate nature of NAPs in the complexes. An octahedral structure is proposed for all the complexes. Thermal studies were used to evaluate the kinetic and thermodynamic parameters.


Photometric Imaging Of Starspots, Techniques And Reliability, Zeki̇ Eker Jan 1999

Photometric Imaging Of Starspots, Techniques And Reliability, Zeki̇ Eker

Turkish Journal of Physics

Historical development of the starspot hypothesis and the unsolved problems associated with it are presented. The "non{uniqueness" attributed to the spot solutions is a major problem which could still discredit current efforts of starspot modeling by photometric or spectroscopic data. The basics of the starspot photometry(direct and inverse photometric problem, and the error analysis of the inverse problem) are presented. Since an analytical formulation exists to compute synthetic light curves from the physical parameters of spots, and recomputing original parameters analytically from the synthetic curves are also possible, the starspot hypothesis is a consistent physical problem. According to the error …


Ionizing Radiations And Annealing Influence On Mosfet Charge States, Zainabidinov Ciragiddin, Atamuratov Atabek, Ysupov Akhmed, Adinaev Kuvondik Jan 1999

Ionizing Radiations And Annealing Influence On Mosfet Charge States, Zainabidinov Ciragiddin, Atamuratov Atabek, Ysupov Akhmed, Adinaev Kuvondik

Turkish Journal of Physics

The threshold voltage shift \Delta V_T and its components due to trapped-oxide charges \Delta V_{Not} and Si-SiO_2 interface traps \Delta V_N in MOSFET exposed to Bremsstrahlung, Co_{60} irradiation and annealing were studied. Several effects caused by differences in the photon energies from two types of sources are discussed as well as a mechanism of changing the trapped-oxide and Si-SiO_2 interface traps by annealing. The mechanism is based on previously available models.


Electrons In Large-Bandgap Bulk Semiconductors And Quantum Wells, N. A. Zakhleniuk, M. Babiker, C. R. Bennett, B. K. Ridley Jan 1999

Electrons In Large-Bandgap Bulk Semiconductors And Quantum Wells, N. A. Zakhleniuk, M. Babiker, C. R. Bennett, B. K. Ridley

Turkish Journal of Physics

The analytical theory of hot electrons interacting with lattice vibrations, impurities, and interface roughness in quantum wells is developed. We have obtained new distribution functions which describe all the kinetic properties of the non-equilibrium electron gas. As a specific example we present the electric field dependence of the electron mobility in GaN-based quantum wells and in bulk GaN. The relative importance of the different scattering mechanisms is analysed in detail.


Giant Efficiency Of Fröhlich Interaction In Self-Assembled Quantum Dots, A. W. E. Minnaert, A. Yu. Silov, J. E. M. Haverkort, J. H. Wolter, A. Garcia, V. N. Gladilin, V. M. Fomn, J. T. Devreese Jan 1999

Giant Efficiency Of Fröhlich Interaction In Self-Assembled Quantum Dots, A. W. E. Minnaert, A. Yu. Silov, J. E. M. Haverkort, J. H. Wolter, A. Garcia, V. N. Gladilin, V. M. Fomn, J. T. Devreese

Turkish Journal of Physics

A transition is being observed from an inhomogeneously broadened photoluminescence band under non-resonant excitation of InAs/GaAs Self-Assembled quantum Dots (SAD's) into up to five phonon-assisted emission bands under selective excitation. A similar effect is obtained from photoluminescence excitation experiments (PLE). We interpret the phonon-assisted PL as being due to a giant efficiency of the Fröhlich interaction between an exciton polarized by strain in the SAD and LO-phonons. The model is consistent with the pronounced p-type polarization of the emission observed in our cleaved-side PL-measurements. Further support is obtained from our calculations in which a different localization of the electrons and …


Electron Liquid Beyond The Random Phase Approximation, Mehmet Tomak, Ceyhun Bulutay Jan 1999

Electron Liquid Beyond The Random Phase Approximation, Mehmet Tomak, Ceyhun Bulutay

Turkish Journal of Physics

A deeper understanding of low-dimensional and small-scale electronic systems requires an accurate characterization of the many-electron effects. Based on the electron liquid (EL) model, these many-body effects in the three-dimensional (3D) and two-dimensional (2D) electronic systems are dealt going beyond the random phase approximation within the zero-temperature framework. The dielectric formulation of the many-body problem is recapitulated and the longitudinal dielectric function of the EL is obtained using the self-consistent local-field correction scheme, known as STLS, under a general spin-valley degeneracy. Extensive explicit expressions are provided for the use of other researchers. The performance of this formalism is compared in …


Energy Relaxation Rate Of Hot Electrons In N-Type Gan Epilayers Using Heat Pulse Techniques, P. Hawker, A. J. Kent, T. S. Cheng, C. T. Foxon Jan 1999

Energy Relaxation Rate Of Hot Electrons In N-Type Gan Epilayers Using Heat Pulse Techniques, P. Hawker, A. J. Kent, T. S. Cheng, C. T. Foxon

Turkish Journal of Physics

We have measured the energy relaxation rate of hot electrons in MBE grown bulk GaN epilayers on GaAs and sapphire substrates over the electron temperature range 1 - 130 K. The measurements were made using heat pulse techniques. For layers grown on GaAs substrates the results show that the carriers reside in the substrate, probably as in a GaAs/AlGaAs heterojunction. For layers grown on sapphire substrates we obtain a P \propto T^4_e dependence for the relaxation rate in the low temperature limit, consistent with piezoelectric coupling in the so-called `dirty' regime, changing to a linear dependence in the high temperature, …


Feasibility Of The Gainp/Ingaas/Gaas System For Modulation Doped Field-Effect Transistors, C. Besi̇kci̇, Y. Ci̇van Jan 1999

Feasibility Of The Gainp/Ingaas/Gaas System For Modulation Doped Field-Effect Transistors, C. Besi̇kci̇, Y. Ci̇van

Turkish Journal of Physics

Si-doped single Ga_{0.51}In_{0.49}P layers and GaInP/InGaAs/GaAs modulation doped field-effect transistor structures grown by gas source molecular beam epitaxy were characterized in detail through Hall-Effect and Deep Level Transient Spectroscopy techniques. Electrical characterization of the undoped and moderately Si-doped (N_D = 3 x 10^{17} cm^{-3}) GaInP layers yielded an electron trap with an activation energy of 0.75 eV and a temperature dependent capture cross section with a capture barrier of 0.593 eV showing DX center properties. The trap was not detected in highly Si doped (N_D = 4 x 10^{18} cm^{-3}) as grown layers suggesting that it is a defect complex …


The Concept Of Free Electromagnetic Field In Quantum Domain, Alexander Shumovsky, Özgür Müstecaplioğlu Jan 1999

The Concept Of Free Electromagnetic Field In Quantum Domain, Alexander Shumovsky, Özgür Müstecaplioğlu

Turkish Journal of Physics

By virtue of the consideration of polarization and phase properties of dipole radiation in the quantum domain, it is shown that the concept of free electromagnetic field should be considered as a quite risky approximation in the description of quantum fluctuations of some physical observables.


Bands Of Localized Electromagnetic Waves In Random Collections Of Dielectric Particles, Marian Rusek, Arkadiusz Orlowski Jan 1999

Bands Of Localized Electromagnetic Waves In Random Collections Of Dielectric Particles, Marian Rusek, Arkadiusz Orlowski

Turkish Journal of Physics

Anderson localization of electromagnetic waves in random arrays of dielectric cylinders is studied. An effective theoretical approach based on the finite size scaling analysis of transmission is developed. The disordered dielectric medium is modeled by a system of randomly distributed 2D electric dipoles. The appearance of the band of localized waves emerging in the limit of an infinite medium is discovered. It suggests deeper insight into existing experimental and theoretical results.


Gauge Theory Of Phase And Scale, Marek Pawlowski Jan 1999

Gauge Theory Of Phase And Scale, Marek Pawlowski

Turkish Journal of Physics

Old Weyl's the idea of scale recalibration freedom and Infeld's and van der Waerden's (IW) ideas concerning geometrical interpretation of natural spinor phase gauge symmetry are discussed in the context of modern models of fundamental particle interactions. It is argued that (IW) gauge symmetry can be naturaly identified with the U(1) symmetry of the Weinberg-Salam model. It is also argued that there are no serious reasons to reject Weyl's gauge theory from consideration. Its inclusion enriches the original Weinberg-Salam theory and leads to prediction of new phenomena that do not contradict experiments.


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.