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2015

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Articles 9241 - 9270 of 9578

Full-Text Articles in Physical Sciences and Mathematics

A Popular And Potentially Sustainable Fishery Resource Under Pressure-Extinction Risk And Conservation Of Brazilian Sciaenidae (Teleostei: Perciformes), Ning L. Chao, Flávia L. Frédou, Manuel Haimovici, Monica B. Peres, Beth Polidoro, Marcelo Raseira, Rosana Subira, Kent E. Carpenter Jan 2015

A Popular And Potentially Sustainable Fishery Resource Under Pressure-Extinction Risk And Conservation Of Brazilian Sciaenidae (Teleostei: Perciformes), Ning L. Chao, Flávia L. Frédou, Manuel Haimovici, Monica B. Peres, Beth Polidoro, Marcelo Raseira, Rosana Subira, Kent E. Carpenter

Biological Sciences Faculty Publications

Croakers (Sciaenidae) are major fishery resource in Brazil; constituting 22% of marine and 9% of freshwater fishery landings. Croakers are subject to heavy fishing pressure throughout Brazil, but habitat alteration is also an important threat to regional populations. In this regional Sciaenidae assessment, each species was analyzed for relative risk of extinction, including the identification and quantification of the impact of major threats and existing conservation measures, based on application of the Categories and Criteria of the IUCN Red List of Threatened Species. Of the 52 species of Sciaenid fishes (34 marine and 18 freshwater) present in Brazilian waters, the …

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Tropical North Atlantic Subsurface Warming Events As A Fingerprint For Amoc Variability During Marine Isotope Stage 3, Andrew O. Parker, Matthew W. Schmidt, Ping Chang Jan 2015

Tropical North Atlantic Subsurface Warming Events As A Fingerprint For Amoc Variability During Marine Isotope Stage 3, Andrew O. Parker, Matthew W. Schmidt, Ping Chang

OES Faculty Publications

The role of Atlantic Meridional Overturning Circulation (AMOC) as the driver of Dansgaard-Oeschger (DO) variability that characterized Marine Isotope Stage 3 (MIS 3) has long been hypothesized. Although there is ample proxy evidence suggesting that DO events were robust features of glacial climate, there is little data supporting a link with AMOC. Recently, modeling studies and subsurface temperature reconstructions have suggested that subsurface warming across the tropical North Atlantic can be used to fingerprint a weakened AMOC during the deglacial because a reduction in the strength of the western boundary current allows warm salinity maximum water of the subtropical gyre …

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Genetic Indicators Of Iron Limitation In Wild Populations Of Thalassiosira Oceanica From The Northeast Pacific Ocean, P. Dreux Chappell, Leann P. Whitney, Joselynn R. Wallace, Adam I. Darer, Samua Jean-Charles, Bethany D. Jenkins Jan 2015

Genetic Indicators Of Iron Limitation In Wild Populations Of Thalassiosira Oceanica From The Northeast Pacific Ocean, P. Dreux Chappell, Leann P. Whitney, Joselynn R. Wallace, Adam I. Darer, Samua Jean-Charles, Bethany D. Jenkins

OES Faculty Publications

Assessing the iron (Fe) nutritional status of natural diatom populations has proven challenging as physiological and molecular responses can differ in diatoms of the same genus. We evaluated expression of genes encoding flavodoxin (FLDA1) and an Fe-starvation induced protein (ISIP3) as indicators of Fe limitation in the marine diatom Thalassiosira oceanica. The specificity of the response to Fe limitation was tested in cultures grown under Fe-and macronutrient-deficient conditions, as well as throughout the diurnal light cycle. Both genes showed a robust and specific response to Fe limitation in laboratory cultures and were detected in small volume samples collected from …

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Iron Deficiency Increases Growth And Nitrogen-Fixation Rates Of Phosphorus-Deficient Marine Cyanobacteria, Nathan S. Garcia, Feixue Fu, Peter N. Sedwick, David A. Hutchins Jan 2015

Iron Deficiency Increases Growth And Nitrogen-Fixation Rates Of Phosphorus-Deficient Marine Cyanobacteria, Nathan S. Garcia, Feixue Fu, Peter N. Sedwick, David A. Hutchins

OES Faculty Publications

Marine dinitrogen (N2)-fixing cyanobacteria have large impacts on global biogeochemistry as they fix carbon dioxide (CO2) and fertilize oligotrophic ocean waters with new nitrogen. Iron (Fe) and phosphorus (P) are the two most important limiting nutrients for marine biological N2 fixation, and their availabilities vary between major ocean basins and regions. A long-standing question concerns the ability of two globally dominant N2-fixing cyanobacteria, unicellular Crocosphaera and filamentous Trichodesmium, to maintain relatively high N2-fixation rates in these regimes where both Fe and P are typically scarce. We show that under P-deficient …

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Divergent Responses Of Atlantic Coastal And Oceanic Synechococcus To Iron Limitation, Katherine R. M. Mackey, Anton F. Post, Matthew R. Mcilvin, Gregory A. Cutter, Seth G. John, Mak A. Saito Jan 2015

Divergent Responses Of Atlantic Coastal And Oceanic Synechococcus To Iron Limitation, Katherine R. M. Mackey, Anton F. Post, Matthew R. Mcilvin, Gregory A. Cutter, Seth G. John, Mak A. Saito

OES Faculty Publications

Marine Synechococcus are some of the most diverse and ubiquitous phytoplankton, and iron (Fe) is an essential micronutrient that limits productivity in many parts of the ocean. To investigate how coastal and oceanic Atlantic Synechococcus strains acclimate to Fe availability, we compared the growth, photophysiology, and quantitative proteomics of two Synechococcus strains from different Fe regimes. Synechococcus strain WH8102, from a region in the southern Sargasso Sea that receives substantial dust deposition, showed impaired growth and photophysiology as Fe declined, yet used few acclimation responses. Coastal WH8020, from the dynamic, seasonally variable New England shelf, displayed a multitiered, hierarchical cascade …

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First Principles Predictions Of Van Der Waals Bonded Inorganic Crystal Structures: Test Case, Hgcl2, Valentino R. Cooper, Kelling J. Donald Jan 2015

First Principles Predictions Of Van Der Waals Bonded Inorganic Crystal Structures: Test Case, Hgcl2, Valentino R. Cooper, Kelling J. Donald

Chemistry Faculty Publications

We study the crystals structure and stability of four possible polymorphs of HgCl2 using first principles density functional theory. Mercury (II) halides are a unique class of materials which, depending on the halide species, form in a wide range of crystal structures, ranging from densely packed solids to layered materials and molecular solids. Predicting the groundstate structure of any member of this group from first principles, therefore, requires a general purpose functional that treats van der Waals bonding and covalent/ionic bonding adequately. Here, we demonstrate that the non-local van der Waals density functional paired with the C09 exchange functional …

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Friedel–Crafts Hydroxyalkylation Of Indoles Mediated By Trimethylsilyl Trifluoromethanesulfonate, C. Wade Downey, Christopher D. Poff, Alissa N. Nizinski Jan 2015

Friedel–Crafts Hydroxyalkylation Of Indoles Mediated By Trimethylsilyl Trifluoromethanesulfonate, C. Wade Downey, Christopher D. Poff, Alissa N. Nizinski

Chemistry Faculty Publications

Indoles and N-alkylindoles undergo Friedel–Crafts addition to aldehydes in the presence of trimethylsilyl trifluoromethanesulfonate and a trialkylamine to produce 3-(1- silyloxyalkyl)indoles. Neutralization of the reaction mixture with pyridine followed by deprotection under basic conditions with tetrabutylammonium fluoride provides the 1:1 adduct as the free alcohol. This method prevents spontaneous conversion of the desired products to the thermodynamically favored bisindolyl(aryl)methanes, a process typically observed when indoles are reacted with aldehydes under acidic conditions.

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One-Pot Silyl Ketene Acetal-Formation-Mukaiyama–Mannich Additions To Imines Mediated By Trimethylsilyl Trifluoromethanesulfonate, C. Wade Downey, Jared A. Ingersoll, Hadleigh M. Glist, Carolyn M. Dombrowski, Adam T. Barnett Jan 2015

One-Pot Silyl Ketene Acetal-Formation-Mukaiyama–Mannich Additions To Imines Mediated By Trimethylsilyl Trifluoromethanesulfonate, C. Wade Downey, Jared A. Ingersoll, Hadleigh M. Glist, Carolyn M. Dombrowski, Adam T. Barnett

Chemistry Faculty Publications

In the presence of trimethylsilyl trifluoromethanesulfonate and trialkylamine base, thioesters are readily converted to silyl ketene acetals in situ and undergo Mukaiyama–Mannich addition to N-phenylimines in one pot. The silyl triflates appears to play two roles, activating both the thioester and the imine. This process also works well when thioesters are replaced with amides, esters, or ketones. Products are isolated as desilylated anilines without the necessity of a deprotection step. Yields range from 65-99%.

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Reply To Comment On Origin Of Surface Canting Within Fe3o4 Nanoparticles, Kathryn L. Krycka, Julie A. Borchers, R.A. Booth, Yumi Ijiri, K. Hasz, James J. Rhyne, Sara A. Majetich Jan 2015

Reply To Comment On Origin Of Surface Canting Within Fe3o4 Nanoparticles, Kathryn L. Krycka, Julie A. Borchers, R.A. Booth, Yumi Ijiri, K. Hasz, James J. Rhyne, Sara A. Majetich

Faculty & Staff Scholarship

No abstract provided.

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An Approach To Extract The Parameters Of Solar Cells From Their Illuminated I-V Curves Using The Lambert W Function, Ahmed A. El Tayyan Jan 2015

An Approach To Extract The Parameters Of Solar Cells From Their Illuminated I-V Curves Using The Lambert W Function, Ahmed A. El Tayyan

Turkish Journal of Physics

In this article an approach based on the Lambert W function is applied to analysis of various types solar cells and solar modules at a given insolation level and temperature; it can be used to extract accurate values of the parameters of a solar cell/module using experimental data or information available from the datasheet. These parameters are the photocurrent I_{ph}, the reverse saturation current I_o, the diode ideality factor a, the series resistance R_s, and the shunt resistance R_{sh}. The parameters I_o, a, R_s, and R_{sh} are calculated with the aid of 4 equations that can be solved simultaneously while …

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Electric And Magnetic Field Induced Geometric Phases For The 2d Harmonic Oscillator In Noncommutative Phase Space, Mai-Lin Liang, Li-Fang Xu Jan 2015

Electric And Magnetic Field Induced Geometric Phases For The 2d Harmonic Oscillator In Noncommutative Phase Space, Mai-Lin Liang, Li-Fang Xu

Turkish Journal of Physics

In this work, we point out the phenomenon whereby the noncommutative corrections to the geometric phases induced by an electric field and a magnetic field have different orders in terms of the noncommutative parameters. The first order correction is zero for the electric field induced geometric phase and it is nonzero for the magnetic field induced geometric phase. In our calculation, the system is in coherent states when the electric field is applied, so the corresponding geometric phase calculated is that of the coherent states. Considering that the noncommutative parameters are very small, it is better to use the magnetic …

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Dye-Sensitized Solar Cells Based On Dyes Extracted From Dried Plant Leaves, Sofyan A. Taya, Taher M. El-Agez, Kamal S. Elrefi, Monzir S. Abdel-Latif Jan 2015

Dye-Sensitized Solar Cells Based On Dyes Extracted From Dried Plant Leaves, Sofyan A. Taya, Taher M. El-Agez, Kamal S. Elrefi, Monzir S. Abdel-Latif

Turkish Journal of Physics

In this work, natural dyes were extracted from dried plant leaves of plant cream, apricot, figs, apples, sage, thyme, mint, Ziziphus jujuba, orange, shade tree, basil, berry, Mirabelle plum, Victoria plum, peach, mango, pomegranate, banana, guava, and fluoridation-treated plant. The extracts were used as photosensitizers for dye-sensitized solar cells (DSSCs). The cells were assembled using nanostructured TiO_2 films. The best performance was observed for the DSSC sensitized with Ziziphus jujuba with an efficiency of 1.077%. The impedance spectroscopy of 3 cells was carried out and the equivalent circuits were found.

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The Effects Of Plaster On Radiation Doses Given To Patients, Onur Karaman, Ayşe Güneş Tanir, Mustafa Hi̇cabi̇ Bölükdemi̇r Jan 2015

The Effects Of Plaster On Radiation Doses Given To Patients, Onur Karaman, Ayşe Güneş Tanir, Mustafa Hi̇cabi̇ Bölükdemi̇r

Turkish Journal of Physics

The purpose of this investigation is to measure the total attenuation coefficients (TACs) of plaster materials using different geometries of the plaster, field sizes, and photon beam energies. The percent depth dose measurements were made using X-rays at 6 MV and 18 MV from the linear accelerator in order to plan the probable radiation dose to be given to the patient wearing a plaster cast. The TAC was experimentally determined in solid phantoms of various thicknesses both with and without plaster over areas of 5 x 5 cm^2, 10 x 10 cm^2, and 15 x 15 cm^2. The experimentally measured …

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Schrödinger Equation With Modified Smorodinsky-Winternitz Potential, Akpan Ndem Ikot, Hassan Hassanabadi, Elham Maghsoodi, Saber Zarrinkamar Jan 2015

Schrödinger Equation With Modified Smorodinsky-Winternitz Potential, Akpan Ndem Ikot, Hassan Hassanabadi, Elham Maghsoodi, Saber Zarrinkamar

Turkish Journal of Physics

We present solutions of the Schrödinger equation for the modified Smorodinsky-Winternitz potential in an exact analytical manner. The considered potential is of noncentral nature and includes the Pöschl-Teller potential in the radial as the radial term and includes both azimuthal and polar angle-dependent terms. The problem, after separation of variables, is solved via the Nikiforov-Uvarov method and the solutions are reported.

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Higher-Dimensional Bianchi Type-Iii Universe With Strange Quark Matter Attached To String Cloud In General Relativity, Pradyumn Kumar Sahoo, Bivudutta Mishra Jan 2015

Higher-Dimensional Bianchi Type-Iii Universe With Strange Quark Matter Attached To String Cloud In General Relativity, Pradyumn Kumar Sahoo, Bivudutta Mishra

Turkish Journal of Physics

In this paper, our intention is to construct 5-dimensional Bianchi type-III cosmological models for quark matter attached to a string cloud in general relativity. Different cases for the metric potentials are considered and studied. The physical and kinematical behaviors of all the models are discussed. It is observed that most of the models admit initial singularity.

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Cosmological Models Filled With A Perfect Fluid Source In The F(R,T) Theory Of Gravity, Dnyaneshwar Dadaji Pawar, Yadao Solanke Jan 2015

Cosmological Models Filled With A Perfect Fluid Source In The F(R,T) Theory Of Gravity, Dnyaneshwar Dadaji Pawar, Yadao Solanke

Turkish Journal of Physics

We investigated the physical behavior of an LRS Bianchi type I cosmological model in the framework of the f(R,T) theory of gravity in the presence of a perfect fluid, where R is the Ricci scalar and T is the trace of the stress energy tensor of the matter. In order to obtain a deterministic solution of the field equations we assumed the special law of variation of the Hubble parameter proposed by Berman that yields the constant deceleration parameter. Some physical properties of the models are discussed.

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Usage Of Attenuation Coefficients Of Some Tissue-Equivalent Materials, Ayşe Güneş Tanir, Fatma Serap Ketenci̇, Mustafa Hi̇cabi̇ Bölükdemi̇r Jan 2015

Usage Of Attenuation Coefficients Of Some Tissue-Equivalent Materials, Ayşe Güneş Tanir, Fatma Serap Ketenci̇, Mustafa Hi̇cabi̇ Bölükdemi̇r

Turkish Journal of Physics

The total attenuation coefficients of 11 biological targets against photon energies were plotted within the energy range 1-10 MeV. From these plots a possible equation describing the relationship between photon energy and the total attenuation coefficient was derived. The suggested equation is mu/ rho = 0.0696/ surd E. To test the validity of the equation and to compare the results of the total attenuation coefficients of 3 tissue-equivalent materials (bolus, rice grains, and boiled rice) that could not be determined before, they were determined experimentally by using X-rays produced at 6 MV and 18 MV. The results of the experiment …

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Extension Of The Class Of Exactly Solvable Nonstationary Quantum Mechanics Problems, Rana Gazanfar Aghayeva Jan 2015

Extension Of The Class Of Exactly Solvable Nonstationary Quantum Mechanics Problems, Rana Gazanfar Aghayeva

Turkish Journal of Physics

A modified factorization method for a charged particle in a time-dependent magnetic field has been developed by virtue of motion quantum integrals. Application of this method to the considered system helps to find exact solutions for a range of nonstationary potentials.

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Studies On Mass Attenuation Coefficient, Mass Energy Absorption Coefficient, And Kerma For Fe Alloys At Photon Energies Of 17.44 To 51.70 Kev, Demet Yilmaz, Yusuf Şahi̇n, Lütfü Demi̇r Jan 2015

Studies On Mass Attenuation Coefficient, Mass Energy Absorption Coefficient, And Kerma For Fe Alloys At Photon Energies Of 17.44 To 51.70 Kev, Demet Yilmaz, Yusuf Şahi̇n, Lütfü Demi̇r

Turkish Journal of Physics

The mass attenuation coefficient (mu_m), the mass energy absorption coefficient (mu_{en}/ rho), and kerma relative to air were determined for some alloys, namely Fe_{0.5}Cr_{0.5}, Fe_{0.7}Cr_{0.3}, Fe_{0.8}Cr_{0.2}, Fe_{0.9}Cr_{0.1}, Fe_{0.2}Ni_{0.8}, Fe_{0.3}Ni_{0.7}, Fe_{0.5}Ni_{0.5}, Fe_{0.6}Ni_{0.4}, Fe_{0.7}Ni_{0.3}, and Fe_{0.8}Ni_{0.2}, at 17.44, 19.63, 22.10, 24.90, 32.06, 36.39, 37.26, 43.74, 44.48, 50.38, and 51.70 photon energies by using an HPGe detector with a resolution of 182 eV at 5.9 keV. The experimental results of mu_m were compared with the theoretical results. The theoretical values of mu_{en}/ rho were compared with the semiempirical values. It was observed that kerma values relative to air values were different in Fe-Ce …

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A Theoretical Way To Determine Gamma-Ray Mass Attenuation Coefficients Of Materials, Eli̇f Ebru Ermi̇ş, Ercan Pi̇li̇çer, Cüneyt Çeli̇ktaş Jan 2015

A Theoretical Way To Determine Gamma-Ray Mass Attenuation Coefficients Of Materials, Eli̇f Ebru Ermi̇ş, Ercan Pi̇li̇çer, Cüneyt Çeli̇ktaş

Turkish Journal of Physics

The gamma-ray mass attenuation coefficients of various absorber materials such as Ag, Al, Au, Bakelite, Cu, Fe, Pb, Plexiglas, Si, Sn, water, and Zn were determined theoretically at different gamma-ray energies and different absorber thicknesses in order to investigate how the number of gamma photons and their energies affect the calculation of mass attenuation coefficients of the absorbers since no study such a comprehensive work here was encountered. For this purpose, the FLUKA Monte Carlo (MC) and XCOM programs were used. Calculated coefficients were compared to the literature values and found to agree well with them. The FLUKA MC program …

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Polaron Effects On The Second-Harmonic Generation In Asymmetrical Semiexponential Quantum Wells, Bo Xiao, Kangxian Guo, Sen Mou, Zhongmin Zhang Jan 2015

Polaron Effects On The Second-Harmonic Generation In Asymmetrical Semiexponential Quantum Wells, Bo Xiao, Kangxian Guo, Sen Mou, Zhongmin Zhang

Turkish Journal of Physics

Polaron effects on the second-harmonic generation (SHG) in asymmetrical semiexponential quantum wells (ASEQWs) are investigated theoretically. By using the framework of the compact-density-matrix approach and iterative method, the analytical expression of the SHG coefficients in ASEQWs is presented. Numerical results are illustrated for a typical GaAs/AlGaAs. By considering the electron--LO--phonon interaction (ELOPI), the energy levels and the wave functions of an electron confined in ASEQWs are obtained. It is found that whether we consider the ELOPI or not, the incident photon frequency $\omega$ and parameters $U_0$ and $\sigma$ also affect the SHG coefficient obviously.

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On The Capacitance Of Crystalline Silicon Solar Cells In Steady State, Fabe Idrissa Barro, Moustapha Sane, Bernard Zouma Jan 2015

On The Capacitance Of Crystalline Silicon Solar Cells In Steady State, Fabe Idrissa Barro, Moustapha Sane, Bernard Zouma

Turkish Journal of Physics

In this work, an analytical approach is presented for modeling the capacitance of crystalline silicon solar cells. Based on a one-dimensional modeling of the cell, the excess minority carrier density, the photovoltage, and the capacitance are calculated. The motivation of this work are two-fold: to show base doping density and illumination effects on the capacitance of silicon solar cells, and to propose a determination technique for both dark capacitance and base doping density from C-V characteristics.

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A Computational Study On The Interaction Between O$_{2}$ And Pristine And Ge-Doped Aluminum Phosphide Nanotubes, Mahdi Rezaei Sameti, Alireza Kazemi Jan 2015

A Computational Study On The Interaction Between O$_{2}$ And Pristine And Ge-Doped Aluminum Phosphide Nanotubes, Mahdi Rezaei Sameti, Alireza Kazemi

Turkish Journal of Physics

In this research the interaction between oxygen molecules and the outside and inside surfaces of pristine and Ge-doped (4,4) armchair and (6,0) zigzag models of aluminum phosphide nanotubes (AlPNTs) was systematically investigated using density function theory. Structural parameters, adsorption energy, quantum parameters, HOMO/LUMO orbitals, and nuclear quadrupole resonance (NQR) parameters were calculated for all models of AlPNTs. The aim of this work was to investigate the effects of Ge doping and O$_{2}$ adsorption on the electrical and structural parameters of (4,4) armchair and (8,0) zigzag models of AlPNTs. The results revealed that adsorption energies for all models were negative with …

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Search For Mixed-Symmetry State In Even-Even $^{130-138}$Ce Isotopes Within The Interacting Boson Model-2, Ali Mahdi Abdul Hussain, Falih Hussain Al-Khudair, Abdul Ridha Hussain Subber Jan 2015

Search For Mixed-Symmetry State In Even-Even $^{130-138}$Ce Isotopes Within The Interacting Boson Model-2, Ali Mahdi Abdul Hussain, Falih Hussain Al-Khudair, Abdul Ridha Hussain Subber

Turkish Journal of Physics

The energy levels and reduced transition probabilities B(M1) and B(E2) of the even-even $^{130-138}$Ce isotopes were calculated by using the interacting boson model-2. We have analyzed the F-spin values and produced the symmetry labeling of the states. The calculated results were compared with the available experimental data. It was proved that the proton--neutron interacting boson model is a reasonable model for calculating low-lying spectra in the set of Ce isotopes and the quality of fit presented in this work is acceptable.

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Survey Of Muon Stripping In The Muon-Catalyzed $D-D$ Fusion Cycle In Pure Deuterium, Seyed Mohammad Motevalli, Maedeh Mohammdapourfard Jan 2015

Survey Of Muon Stripping In The Muon-Catalyzed $D-D$ Fusion Cycle In Pure Deuterium, Seyed Mohammad Motevalli, Maedeh Mohammdapourfard

Turkish Journal of Physics

Muon-catalyzed fusion is a very efficient nuclear fusion method to which a wide variety of experimental and theoretical studies have been devoted in recent years. The mixtures of hydrogen isotopes are the most appropriate particles to do this kind of fusion. The efficiency of muon-catalyzed fusion in mixtures of pure deuterium is due to the abundance of this isotope as compared to other hydrogen isotopes. The most important issue of reducing the efficiency of the muon-catalyzed fusion chain in pure deuterium mixtures is the probability of muons sticking to the helium-3 particle produced after the $d-d$ nuclear fusion reaction. In …

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Description Of The Yrast Superdeformed Bands In Even-Even Nuclei In A $\Sim$ 190 Region Using The Nuclear Softness Model, Ali Khalaf, Karima Abdelmageed, Manal Sirag Jan 2015

Description Of The Yrast Superdeformed Bands In Even-Even Nuclei In A $\Sim$ 190 Region Using The Nuclear Softness Model, Ali Khalaf, Karima Abdelmageed, Manal Sirag

Turkish Journal of Physics

A two-parameter nuclear softness (NS2) model for the transition energies is proposed by treating the variation of the moment of inertia with spin. The model has been applied to the yrast superdeformed (SD) bands in even-even nuclei in the mass region A $\sim $ 190. The model parameters have been determined from the fitting procedure in order to minimize the relative root mean square deviation between the experimental E2 transition $\gamma $-ray energies and the calculated ones. The basic experimental data on SD bands are given in the form of a series of $\gamma $-ray transitional energies and the spins …

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Synthesis And Properties Of A Spinel Cathode Material For Lithium Ion Battery With Flat Potential Plateau, Ahmed Abdulrahman Ahmed Al-Tabbakh, Norlida Kamarulzaman, Aseel Al-Zubaidi Jan 2015

Synthesis And Properties Of A Spinel Cathode Material For Lithium Ion Battery With Flat Potential Plateau, Ahmed Abdulrahman Ahmed Al-Tabbakh, Norlida Kamarulzaman, Aseel Al-Zubaidi

Turkish Journal of Physics

A potential cathode material for lithium ion battery was synthesised by combustion reaction. The thermal behaviour of the as-synthesised precursor was measured using a thermogravimetric analyser and the range of calcination temperature from 500 $^{\circ}$C to 800 $^{\circ}$C was determined. X-ray diffraction analysis showed that all calcined powders crystallised in the cubic spinel structure of the $Fd\bar{3}m$ space group. The particle size distributions and morphologies of the powders were obtained using a particle size analyser and scanning electron microscope. The effect of calcination temperature on the electrochemical performance was investigated using galvanostatic charge/discharge measurements. The potential profiles of charge and …

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A Full Relativistic Treatment In Analyzing $\Alpha $-$^{12}$C And $\Alpha $-$^{40,42,44,48}$Ca Elastic Scattering Data At 1.37 Gev, Zuhair Fayyad Mahmoud Shehadeh Jan 2015

A Full Relativistic Treatment In Analyzing $\Alpha $-$^{12}$C And $\Alpha $-$^{40,42,44,48}$Ca Elastic Scattering Data At 1.37 Gev, Zuhair Fayyad Mahmoud Shehadeh

Turkish Journal of Physics

A simple optical potential of Woods-Saxon form is used within the framework of the Klein-Gordon equation, for the first time, to analyze the elastic differential cross sections for 1.37 GeV (lab) incident $\alpha $-particles on $^{12}$C and calcium isotopes $^{40,42,44,48}$Ca. The relativistic energy-momentum relation assures the need for relativistic calculations. As such, the previously determined parameters of all optical potential forms, used in the nonrelativistic Schrödinger equation and successfully analyzing the $\alpha $-$^{12}$C and $\alpha $-$^{40,42,44,48}$Ca data at 1.37 GeV, are to be revised. In the presence of Coulomb potential, as in the cases under consideration, the asymptotic solution of …

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Symmetry And The Order Of Events In Time: The Thermodynamics Of Blackbodies Composed Of Positive Or Negative Masssymmetry And The Order Of Events In Time: The Thermodynamics Of Blackbodies Composed Of Positive Or Negative Mass, Randy Wayne Jan 2015

Symmetry And The Order Of Events In Time: The Thermodynamics Of Blackbodies Composed Of Positive Or Negative Masssymmetry And The Order Of Events In Time: The Thermodynamics Of Blackbodies Composed Of Positive Or Negative Mass, Randy Wayne

Turkish Journal of Physics

I have previously proposed a discrete symmetry called CPM (charge-parity-mass) symmetry that defines matter as having positive mass and antimatter as having negative mass-both being involved in processes that proceed forward in time. I have generalized the second law of thermodynamics to describe and predict the order of events in time that take place in reversible thermodynamic systems composed of positive or negative mass. Here I extend the CPM symmetry to irreversible thermo-optical radiation systems characterized by the Stefan-Boltzmann law, Planck's blackbody radiation law, and Einstein's law of specific heat. The laws of radiation analyzed in terms of CPM symmetry …

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Crystal Dynamics Of Zinc Chalcogenides I: An Application To Znscrystal Dynamics Of Zinc Chalcogenides I: An Application To Zns, Jay Prakash Dubey, Raj Kishor Tiwari, Kripa Shankar Upadhyaya, Pramod Kumar Pandey Jan 2015

Crystal Dynamics Of Zinc Chalcogenides I: An Application To Znscrystal Dynamics Of Zinc Chalcogenides I: An Application To Zns, Jay Prakash Dubey, Raj Kishor Tiwari, Kripa Shankar Upadhyaya, Pramod Kumar Pandey

Turkish Journal of Physics

A van der Waals three body force rigid shell model (VTRSM) developed earlier for NaCl and CsCl structure was expanded by us for zinc blende structure (ZBS). This model includes the effect of three body interactions and van der Waals interactions in the rigid shell model where short-range interactions were considered up to the second neighbor. Our model thus developed was applied to study the phonon dispersion curves, Debye temperature variation, two phonon Raman/IR spectra, and anharmonic elastic properties of ZnS. Our results are in good agreement with the measured data wherever available.

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