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The latest articles from Hindawi Publishing Corporation
© 2014 , Hindawi Publishing Corporation . All rights reserved.

Retracted: Influence of Magnesium Substitution on Thermal and Electrical Properties of NiCuZn Ferrites for Microinductor Core Applications
Thu, 30 Oct 2014 08:30:58 +0000
http://www.hindawi.com/journals/physri/2014/657271/
Physics Research International
Copyright © 2014 Physics Research International. All rights reserved.

Resolution of the AgeOld Dilemma about a Magnitude of the Momentum of Light in Matter
Tue, 28 Oct 2014 06:29:28 +0000
http://www.hindawi.com/journals/physri/2014/126436/
There are two competitive opinions about a magnitude of the momentum of light in matter. The Balazs thought experiment gives unambiguous theoretical evidence based only on laws of mechanics that the momentum of light in matter is smaller by n times than that of the same light in free space where n is the refractive index of the matter. On the other hand, there is other theoretical evidence confirmed by experimental investigation that the momentum of light in matter is greater by n times than that in free space. This ancient dilemma cannot be resolved till now. We show that the momentum density flux of light in matter is greater by n times than that in free space. In the same time we present an alternative interpretation of the Balazs thought experiment where two optical pressures arising in the regions of the matter where leading and trailing edges of the pulse are propagating are taken into account. This enables us to match contradictory results of mentioned experiments. Since the contradiction is overcome, the dilemma disappears.
V. P. Torchigin and A. V. Torchigin
Copyright © 2014 V. P. Torchigin and A. V. Torchigin. All rights reserved.

Structural and Electrical Properties of Li–Ni Nanoferrites Synthesised by Citrate Gel Autocombustion Method
Mon, 20 Oct 2014 09:12:50 +0000
http://www.hindawi.com/journals/physri/2014/672739/
An attempt has been made to synthesize nanocrystalline lithiumnickel ferrites with a compositional formula Li0.5−0.5xNixFe2.5−0.5xO4 (where to 1.0 with step of 0.2) by a low temperature citrate gel autocombustion method. Single phase cubic structure is confirmed by Xray diffraction analysis. This result demonstrates that the prepared samples are homogeneous and the sharp peaks reveal that the samples are in good crystalline form. As the Ni concentration is increased, various interesting changes in the values of the structural parameters like lattice parameter, Xray density, bulk density, and porosity have been observed. The surface morphology of the prepared samples was studied using scanning electron microscopy (SEM). The DC resistivity measurements were carried out using twoprobe method from 200°C to 600°C. The variation of with reciprocal of temperature shows a discontinuity at Curie temperature. versus plot of the pure lithium ferrites is almost linear which indicates the Curie temperature of the pure lithium ferrites was beyond our measured temperature. The dielectric properties of these ferrites have been studied using a LCR meter from the room temperature to 700 K at various frequencies up to 5 MHz, which reveals that all the prepared samples have dielectric transition temperature around 600 K.
G. Aravind, D. Ravinder, and V. Nathanial
Copyright © 2014 G. Aravind et al. All rights reserved.

Multigap Superconductivity in the Ferromagnetic Superconductor UCoGe Revealed by Thermal Conductivity Measurements
Thu, 09 Oct 2014 08:02:03 +0000
http://www.hindawi.com/journals/physri/2014/454939/
We performed thermal conductivity measurements on a single crystal of the ferromagnetic superconductor UCoGe under magnetic field. Two different temperature dependencies of the thermal conductivity are observed, for : linear at low magnetic field and quadratic for magnetic field larger than 1 Tesla. At the same field value, a plateau appears in the field dependency of the residual term of thermal conductivity. Such observations suggest a multigap superconductivity with a line of nodes in the superconducting gap.
Ludovic Howald, Mathieu Taupin, and Dai Aoki
Copyright © 2014 Ludovic Howald et al. All rights reserved.

Reconstruction of Dielectric Constants of Core and Cladding of Optical Fibers Using Propagation Constants Measurements
Thu, 18 Sep 2014 12:51:08 +0000
http://www.hindawi.com/journals/physri/2014/253435/
We present new numerical methods for the solution of inverse spectral problem to determine the dielectric constants of core and cladding in optical fibers. These methods use measurements of propagation constants. Our algorithms are based on approximate solution of a nonlinear nonselfadjoint eigenvalue problem for a system of weakly singular integral equations. We study three inverse problems and prove that they are well posed. Our numerical results indicate good accuracy of new algorithms.
E. M. Karchevskii, A. O. Spiridonov, A. I. Repina, and L. Beilina
Copyright © 2014 E. M. Karchevskii et al. All rights reserved.

Full Symmetry Groups and Exact Solutions to BKP and GKP Equations
Thu, 18 Sep 2014 05:34:57 +0000
http://www.hindawi.com/journals/physri/2014/786965/
We investigate the (2+1)dimensional nonlinear BKP and GKP equations with the modified direct CK’s method. Then, we get its Lie point groups and the full symmetry group, and a relationship is constructed between the new solutions and the old one. Based on the relationship, the new solutions can be obtained by using a given solution of the equations.
Bo Ren and JianYong Wang
Copyright © 2014 Bo Ren and JianYong Wang. All rights reserved.

Retracted: Structural and Optical Properties of Germanium Thin Films Prepared by the Vacuum Evaporation Technique
Tue, 16 Sep 2014 00:00:00 +0000
http://www.hindawi.com/journals/physri/2014/128505/
Physics Research International
Copyright © 2014 Physics Research International. All rights reserved.

Drift Modified Longitudinal Electrokinetic Mode in Colloids Laden Semiconductor Quantum Plasmas
Mon, 15 Sep 2014 09:10:17 +0000
http://www.hindawi.com/journals/physri/2014/634763/
Dispersion and absorption characteristics of electrokinetic wave in unmagnetised extrinsic semiconductor with streaming carriers are analytically investigated. By using quantum hydrodynamic model, a linear dispersion relation is derived for longitudinal electrokinetic wave in colloids laden semiconductor plasma under slow electrokinetic mode regime. Results indicate that quantum effect through Bohm potential significantly modifies the dispersion and absorption characteristics of electrokinetic wave spectrum. The outcome is hoped to add substantially to the present knowledge of wave spectrum of longitudinal electrokinetic wave in colloids laden quantum semiconductor plasma subjected to a dc electric field along the direction of wave propagation.
Sandhya Chaudhary, Nilesh Nimje, Nishchhal Yadav, and S. Ghosh
Copyright © 2014 Sandhya Chaudhary et al. All rights reserved.

Cusp Catastrophe Model for Description of Bistability in Ferroelectric Liquid Crystals
Mon, 01 Sep 2014 00:00:00 +0000
http://www.hindawi.com/journals/physri/2014/294723/
We propose a new theoretical approach for description of the equilibrium and bistable states of ferroelectric liquid crystal. A sample of ferroelectric liquid crystal is considered in the “bookshelf” geometry under the influence of electric field. Continuum and perturbation theories are used in order to establish the relation between the scale coefficients in the expansion for the azimuthal angle. The equilibrium states of ferroelectric SmC* are determined in the framework of the catastrophe theory.
Nail Migranov, Aleksey Kudreyko, and Denis Kondratyev
Copyright © 2014 Nail Migranov et al. All rights reserved.

Monte Carlo Simulations of a Scanning System Based on a Panoramic XRay Tube with a Conical Anode
Thu, 21 Aug 2014 07:11:42 +0000
http://www.hindawi.com/journals/physri/2014/847651/
Monte Carlo simulations were used to study photon production in a panoramic Xray tube with a conical tungsten target to determine the optimal characteristics of the target shape and electron beam configuration. Several simulations were performed for accelerating potentials equal to 250 kV, 300 kV, and 500 kV with electron beams of various radii and anode sizes. The angular distribution of the photon intensity was analysed by numerical calculations for an assembly composed of an Xray tube and an external collimator with a cylindrical hole to simulate a panoramic scanning system with an Xray pencil beam.
Andrii Sofiienko, Chad Jarvis, and Ådne Voll
Copyright © 2014 Andrii Sofiienko et al. All rights reserved.

Can SGRs/AXPs Originate from Neutron Star Binaries?
Thu, 21 Aug 2014 06:04:07 +0000
http://www.hindawi.com/journals/physri/2014/375624/
Soft gamma repeaters (SGRs) and anomalous Xray pulsars (AXPs) are two groups of enigmatic objects, which have been extensively investigated in past few decades. Based on the ample information about their timing behaviors, spectra, and variability properties, it was proposed that SGRs/AXPs are isolated neutron stars (NSs) with extremely strong magnetic fields, the socalled magnetars. Nonetheless, some alternative models are probably equally convincing such as those proposing that they are accreting NSs with a fallback disk or rotationpowered magnetized and massive white dwarfs. The nature and nurture of SGRs/AXPs remain controversial. In this paper, we propose that SGRs/AXPs can, alternatively, originate from normal NSs in binary systems, which resorts to the reexplosion of normal NS induced by instant contraction of the massive star envelope in a ThorneŻytkow object (TZO). The spinperiod clustering is due to either the brake of a slowly rotating envelope or the frictional drag during the commonenvelope phase.
Joan Jing Wang and HsiangKuang Chang
Copyright © 2014 Joan Jing Wang and HsiangKuang Chang. All rights reserved.

How Much Asymmetry of Colliding Pair Affects Nuclear Dynamics at Balance Point?
Wed, 20 Aug 2014 07:28:13 +0000
http://www.hindawi.com/journals/physri/2014/619360/
Using the quantum molecular dynamics model, we study the nuclear dynamics at the balance energy of mass asymmetric colliding nuclei by keeping the total mass of the system fixed and by varying the mass asymmetry (, where and are the masses of the target and projectile, resp.) of the reaction. In particular, we study the various quantities like average and maximum density and temperature, collision rate, participantspectator matter, anisotropic ratio, relative momentum, and their mass asymmetry and mass dependence. Our results indicate sizeable effect of mass asymmetry on these quantities.
Supriya Goyal
Copyright © 2014 Supriya Goyal. All rights reserved.

Multiparty Quantum Communication Using Multiqubit Entanglement and Teleportation
Mon, 11 Aug 2014 11:34:53 +0000
http://www.hindawi.com/journals/physri/2014/948750/
We propose a qubit entangled channel that can be used to teleport qubits in a network to a single receiver. We describe the structure of this channel and explicitly demonstrate how the protocol works. The channel can be used to implement a scheme in which all parties have to participate in order for the teleportation to be successful. This can be advantageous in various scenarios and we discuss the potential application of this protocol to voting.
S. Ghose, A. Kumar, and A. M. Hamel
Copyright © 2014 S. Ghose et al. All rights reserved.

Measurement in the de BroglieBohm Interpretation: DoubleSlit, SternGerlach, and EPRB
Sun, 10 Aug 2014 08:55:34 +0000
http://www.hindawi.com/journals/physri/2014/605908/
We propose a pedagogical presentation of measurement in the de BroglieBohm interpretation. In this heterodox interpretation, the position of a quantum particle exists and is piloted by the phase of the wave function. We show how this position explains determinism and realism in the three most important experiments of quantum measurement: doubleslit, SternGerlach, and EPRB. First, we demonstrate the conditions in which the de BroglieBohm interpretation can be assumed to be valid through continuity with classical mechanics. Second, we present a numerical simulation of the doubleslit experiment performed by Jönsson in 1961 with electrons. It demonstrates the continuity between classical mechanics and quantum mechanics. Third, we present an analytic expression of the wave function in the SternGerlach experiment. This explicit solution requires the calculation of a Pauli spinor with a spatial extension. This solution enables us to demonstrate the decoherence of the wave function and the three postulates of quantum measurement. Finally, we study the Bohm version of the EinsteinPodolskyRosen experiment. Its theoretical resolution in space and time shows that a causal interpretation exists where each atom has a position and a spin.
Michel Gondran and Alexandre Gondran
Copyright © 2014 Michel Gondran and Alexandre Gondran. All rights reserved.

Work Criteria Function of Irreversible Heat Engines
Tue, 05 Aug 2014 11:57:19 +0000
http://www.hindawi.com/journals/physri/2014/890713/
The irreversible heat engine is reconsidered with a general heat transfer law. Three criteria known in the literature—power, power density, and efficient power—are redefined in terms of the work criteria function (WCF), a concept introduced in this study. The formulation enabled the suggestion and analysis of a unique criterion—the efficient power density (which accounts for the efficiency and power density). Practically speaking, the efficient power and the efficient power density could be defined on any order based on the WCF. The applicability of the WCF is illustrated for the Newtonian heat transfer law (n=1) and for the radiative law (n=4). The importance of WCF is twofold: it gives an explicit design and educational tool to analyze and to display graphically the different criteria side by side and thus helps in design process. Finally, the criteria were compared and some conclusions were drawn.
Mahmoud Huleihil
Copyright © 2014 Mahmoud Huleihil. All rights reserved.

Various Constructions of Qudit SWAP Gate
Tue, 05 Aug 2014 07:51:25 +0000
http://www.hindawi.com/journals/physri/2014/479320/
It is known that SWAP operation for quantum systems of arbitrary dimension can be implemented using various qudit gates. In this paper, equivalence of some important qudit operations is demonstrated. Equivalence of the qudit operations is exploited to minimize the circuit complexity in the previously proposed qudit SWAP gate constructions. Further, constructions of qudit SWAP operation with minimum number of qudit gates are also proposed. Importantly, these circuit constructions of SWAP retain its properties like symmetry and simplicity.
S. Balakrishnan
Copyright © 2014 S. Balakrishnan. All rights reserved.

Structural and Optical Investigations of Heterostructures Based on :Si Solid Solutions Obtained by MOCVD
Wed, 23 Jul 2014 06:40:34 +0000
http://www.hindawi.com/journals/physri/2014/782357/
We investigated MOCVD epitaxial heterostructures based on AlxGa1−xAs ternary solid solutions, obtained in the range of compositions and doped with high concentrations of phosphorus and silicon atoms. Using the methods of highresolution Xray diffraction, scanning electron microscopy, Xray microanalysis, Raman spectroscopy, and photoluminescence spectroscopy we have shown that grown epitaxial films represent fivecomponent (AlxGa1−xAs1−yPy)1−zSiz solid solutions. The implementation of silicon in solid solution with a concentration of ~ 0.01 at.% leads to the formation of the structure with deep levels, DX centers, the occurrence of which fundamentally affects the energy characteristics of received materials.
P. V. Seredin
Copyright © 2014 P. V. Seredin. All rights reserved.

Synthesis, Structural and Optical Investigations of (Pb, Bi)TiO3 Borosilicate Glasses
Sun, 13 Jul 2014 09:55:22 +0000
http://www.hindawi.com/journals/physri/2014/606709/
A new series of lead bismuth titanate borosilicate glasses with addition of one percent lanthanum oxide have been synthesized using meltquench technique. Xray diffraction patterns have been recorded to confirm the amorphous nature of the prepared glass samples. The synthesized glasses have been characterized by using various spectroscopic techniques such as UVvisible, infrared, and Raman spectroscopy. UVvisible measurements were recorded in the wavelength range from 200 to 1100 nm whereas IR and Raman spectroscopic measurements were recorded over a continuous wavenumber range from 400 to 5000 cm−1 and 1000 to 2000 cm−1 respectively. The different absorption peaks/bands were formed in IR spectral patterns. The spectral bands appear towards the lower wavenumber sides due to the Bi and Pb, content while the bands appear towards the higher wavenumber sides due to the formation of diborate and triborate network units.
Chandkiram Gautam
Copyright © 2014 Chandkiram Gautam. All rights reserved.

Renormalization of QED Near Decoupling Temperature
Tue, 24 Jun 2014 09:01:06 +0000
http://www.hindawi.com/journals/physri/2014/489163/
We study the effective parameters of QED near decoupling temperatures and show that the QED perturbative series is convergent, at temperatures below the decoupling temperature. The renormalization constant of QED acquires different values if a system cools down from a hotter system to the electron mass temperature or heats up from a cooler system to the same temperature. At , the first order contribution to the electron selfmass, is 0.0076 for a heating system and 0.0115 for a cooling system and the difference between two values is equal to 1/3 of the low temperature value and 1/2 of the high temperature value around . This difference is a measure of hot fermion background at high temperatures. With the increase in release of more fermions at hotter temperatures, the fermion background contribution dominates and weak interactions have to be incorporated to understand the background effects.
Samina S. Masood
Copyright © 2014 Samina S. Masood. All rights reserved.

Vector Potential Quantization and the Quantum Vacuum
Thu, 19 Jun 2014 10:46:32 +0000
http://www.hindawi.com/journals/physri/2014/187432/
We investigate the quantization of the vector potential amplitude of the electromagnetic field to a single photon state starting from the fundamental link equations between the classical electromagnetic theory and the quantum mechanical expressions. The resulting waveparticle formalism ensures a coherent transition between the classical electromagnetic wave theory and the quantum representation. A quantization constant of the photon vector potential is defined. A new quantum vacuum description results directly in having very low energy density. The calculated spontaneous emission rate and Lambs shift for the states of the hydrogen atom are in agreement with quantum electrodynamics. This low energy quantum vacuum state might be compatible with recent astrophysical observations.
Constantin Meis
Copyright © 2014 Constantin Meis. All rights reserved.

Coherent and Incoherent Scattering Cross Sections of Some Lead and Sodium Compounds at Angles below 10° for 241Am Gamma Rays
Mon, 02 Jun 2014 06:50:07 +0000
http://www.hindawi.com/journals/physri/2014/594767/
We report the total (coherent + incoherent) scattering cross sections of some lead and sodium compounds measured at angles less than 10° for 241Am (59.54 keV) gamma rays. The experimental cross sections so obtained are compared with the data interpolated from theoretical compilations based on nonrelativistic HartreeFock (NRHF) model for the samples of interest. In the low momentum transfer region studied, it is observed that the nonrelativistic theoretical total scattering cross sections computed using HF form factor and scattering function tabulated by NRHF are quite adequate in explaining the measured total scattering cross sections.
L. Vinaykumar and T. K. Umesh
Copyright © 2014 L. Vinaykumar and T. K. Umesh. All rights reserved.

Free Convective Fluctuating MHD Flow through Porous Media Past a Vertical Porous Plate with Variable Temperature and Heat Source
Tue, 06 May 2014 07:54:23 +0000
http://www.hindawi.com/journals/physri/2014/587367/
Free convective magnetohydrodynamics (MHD) flow of a viscous incompressible and electrically conducting fluid past a hot vertical porous plate embedded in a porous medium in the presence of heat source has been studied in this paper. The temperature of the plate varies both in space and time. The main objective of this paper is to study the effect of porosity of the medium coupled with the variation of plate temperature with regard to space and in time. The effect of pertinent parameters characterizing the flow has been presented through the graphs. It is important to record that the presence of porous media has no significant contribution to the flow characteristics and viscous dissipation compensates for the heating and cooling of the plate due to convective current.
A. K. Acharya, G. C. Dash, and S. R. Mishra
Copyright © 2014 A. K. Acharya et al. All rights reserved.

Investigation of Gamma and Neutron Shielding Parameters for Borate Glasses Containing NiO and PbO
Wed, 23 Apr 2014 07:19:01 +0000
http://www.hindawi.com/journals/physri/2014/954958/
The mass attenuation coefficients, , halfvalue layer, HVL, tenthvalue layer, TVL, effective atomic numbers, , and effective electron densities, , of borate glass sample systems of (100) Na2B4O7 : PbO : NiO (where and , and 10 weight percentage) containing PbO and NiO, with potential gamma ray and neutron shielding applications, have been investigated. The gamma ray interaction parameters, , HVL, TVL, , and , were computed for photon energy range 1 keV–100 GeV. The macroscopic fast neutron removal crosssections () have also been calculated. Appreciable variations were noted for all the interaction parameters by varying the photon energy and the chemical composition of the glass samples. The better shielding properties of borate glass samples containing PbO were found. These results indicated that borate glass samples are a good radiation shielding material.
Vishwanath P. Singh and N. M. Badiger
Copyright © 2014 Vishwanath P. Singh and N. M. Badiger. All rights reserved.

Linear Sigma Model at Finite Temperature and Baryonic Chemical Potential Using the Midpoint Technique
Thu, 06 Mar 2014 00:00:00 +0000
http://www.hindawi.com/journals/physri/2014/435023/
A baryonic chemical potential () is included in the linear sigma model at finite temperature. The effective mesonic potential is numerically calculated using the midpoint rule. The meson masses are investigated as functions of the temperature () at fi…xed value of baryonic chemical potential. The pressure and energy density are investigated as functions of temperature at fixed value of . The obtained results are in good agreement in comparison with other techniques. We conclude that the calculated effective potential successfully predicts the meson properties and thermodynamic properties at finite baryonic chemical potential.
M. AbuShady
Copyright © 2014 M. AbuShady. All rights reserved.

Estimating the Cation Distributions in Ferrites Using XRay, FTIR, and Magnetization Measurements
Tue, 04 Mar 2014 13:04:56 +0000
http://www.hindawi.com/journals/physri/2014/579745/
The fundamental requirements for the shift of critical frequency to microwave frequencies are smaller grains with single domain, high resistivity, high saturation magnetization, moderate permeability, moderate magnetic anisotropy, and low spin relaxation time. With these guidelines an attempt to produce high performance ferrite for high frequency applications the present work aimed to synthesize cobalt substituted NiZn ferrites using solgel method. Investigation of effects of cobalt on crystallite size, saturation magnetization, initial permeability, magnetic anisotropy, and spin relaxation time reveals the suitability of these materials for high frequency applications. Further in this paper cat ion distribution was proposed from the basis of variations in these properties. The results of this paper are thus useful to tailor the properties apt for high frequency applications.
M. Chaitanya Varma, GSVRK Choudary, A. Mahesh Kumar, and K. H. Rao
Copyright © 2014 M. Chaitanya Varma et al. All rights reserved.

Structural and Optical Properties of Germanium Thin Films Prepared by the Vacuum Evaporation Technique
Mon, 17 Feb 2014 08:55:44 +0000
http://www.hindawi.com/journals/physri/2014/594968/
Germanium (Ge) thin films have been deposited onto the glass substrates by the vacuum evaporation technique. The effect of annealing temperature on the structural and optical properties of the germanium thin films was investigated. The structural and optical properties of thin films were characterized by XRD, SEM, and UVVis techniques. XRD results showed that the structure of the deposited thin films changed from amorphous phase for the films, which deposited at room temperature, to crystalline phase for the films, which deposited at high temperature. Optimum temperature to obtain a good crystalline structure was 525°C. The SEM image also showed that the crystallization of the thin films is increased with increasing of annealing temperature. Transmittance and reflectance spectral were used to calculate the absorption coefficient. Two absorption edges in two spectral regions were distinguished according to direct and indirect electron transitions. Energy band gap was calculated by using the Tauc relationship for both direct and indirect electron transitions. The average value of was equal to 0.79 eV and 0.61 eV for direct and indirect transitions, respectively.
Z. AlSharafi, S. Mohyeddine, Samir Osman Mohammed, and R. M. Kershi
Copyright © 2014 Z. AlSharafi et al. All rights reserved.

Magnetohydrodynamic Boundary Layer Flow of Nanofluid over an Exponentially Stretching Permeable Sheet
Wed, 08 Jan 2014 07:51:52 +0000
http://www.hindawi.com/journals/physri/2014/592536/
A mathematical model of the steady boundary layer flow of nanofluid due to an exponentially permeable stretching sheet with external magnetic field is presented. In the model, the effects of Brownian motion and thermophoresis on heat transfer and nanoparticle volume friction are considered. Using shooting technique with fourthorder RungeKutta method the transformed equations are solved. The study reveals that the governing parameters, namely, the magnetic parameter, the wall mass transfer parameter, the Prandtl number, the Lewis number, Brownian motion parameter, and thermophoresis parameter, have major effects on the flow field, the heat transfer, and the nanoparticle volume fraction. The magnetic field makes enhancement in temperature and nanoparticle volume fraction, whereas the wall mass transfer through the porous sheet causes reduction of both. For the Brownian motion, the temperature increases and the nanoparticle volume fraction decreases. Heat transfer rate becomes low with increase of Lewis number. For thermophoresis effect, the thermal boundary layer thickness becomes larger.
Krishnendu Bhattacharyya and G. C. Layek
Copyright © 2014 Krishnendu Bhattacharyya and G. C. Layek. All rights reserved.

Preparation, Characterization, and Luminescence Properties of Orthorhombic Sodium Sulphate
Tue, 24 Dec 2013 11:15:39 +0000
http://www.hindawi.com/journals/physri/2013/641631/
A highly efficient thermoluminescence Na2SO4 phosphor with thenardite polymorphic structure was prepared by simple slow evaporation technique followed by subsequent calcination at 200°C, 400°C, and 600°C for 4 h and the resultant crystals were characterized by various analytical techniques. All the samples exhibited thermodynamically stable thenardite phase and the grain growth was increased for the calcined samples. SEM analysis indicated the fine distribution of twinned orthogonal prism and pyramidal structure without any agglomeration. The electron spin resonance spectroscopy showed the existence of radicals as trap centre. The thermoluminescence behavior suggested the charge carrier recombination dynamics in the thenardite sample followed secondorder kinetics. The trapping parameters such as activation energy (), order of kinetics (), and frequency factor () have been determined using Chen’s peak shape method. Further fading of the TL intensity of Na2SO4 showed that thenardite is quite suitable for radiation dosimetry even up to 15 days. The photoluminescence band of Na2SO4 reduced in its intensity after γirradiation, suggesting that defects are unstable and decay rapidly.
Y. S. Vidya and B. N. Lakshminarasappa
Copyright © 2013 Y. S. Vidya and B. N. Lakshminarasappa. All rights reserved.

Molecular Tomography of the Quantum State by TimeResolved Electron Diffraction
Mon, 23 Dec 2013 09:40:53 +0000
http://www.hindawi.com/journals/physri/2013/236743/
A procedure is described that can be used to reconstruct the quantum state of a molecular ensemble from timedependent internuclear probability density functions determined by timeresolved electron diffraction. The procedure makes use of established techniques for evaluating the density matrix and the phasespace joint probability density, that is, the Wigner function. A novel expression for describing electron diffraction intensities in terms of the Wigner function is presented. An approximate variant of the method, neglecting the offdiagonal elements of the density matrix, was tested by analyzing gas electron diffraction data for N2 in a Boltzmann distribution and TRED data obtained from the 193 nm photodissociation of CS2 to carbon monosulfide, CS, at 20, 40, and 120 ns after irradiation. The coherent changes in the nuclear subsystem by timeresolved electron diffraction method determine the fundamental transition from the standard kinetics to the dynamics of the phase trajectory of the molecule and the tomography of molecular quantum state.
A. A. Ischenko
Copyright © 2013 A. A. Ischenko. All rights reserved.

Reconciliating the Vertical and Horizontal Gradients of the Sunspot Magnetic Field
Mon, 23 Dec 2013 08:26:43 +0000
http://www.hindawi.com/journals/physri/2013/195403/
In the literature, we found 15 references showing that the sunspot photospheric magnetic field vertical gradient is on the order of 34 G/km, with field strength decreasing with height, whereas the horizontal gradient is nine times weaker on the order of 0.40.5 G/km. This is confirmed by our recent THEMIS observations. As a consequence, the vanishing of is not realized. In other words, a loss of magnetic flux is observed with increasing height, which is not compensated for by an increase of the horizontal flux. We show that the lack of spatial resolution, vertical as well as horizontal, cannot be held responsible for the nonvanishing observed . The present paper is devoted to the investigation of this problem. We investigate how the magnetic field is influenced by the plasma anisotropy due to the stratification, which is responsible for an “aspect ratio” between horizontal and vertical typical lengths. On the example of our THEMIS observations, made of two spectral lines formed at two different depths, which enables the retrieval of the three components entering , it is shown that once this aspect ratio is applied, the rescaled vanishes, which suggests a new methodology for MHD modeling in the photosphere.
Véronique Bommier
Copyright © 2013 Véronique Bommier. All rights reserved.