for Journals by Title or ISSN
for Articles by Keywords
help
Followed Journals
Journal you Follow: 0
 
Sign Up to follow journals, search in your chosen journals and, optionally, receive Email Alerts when new issues of your Followed Jurnals are published.
Already have an account? Sign In to see the journals you follow.
Journal Cover   Research & Reviews : Journal of Physics
  Follow
    
   Full-text available via subscription Subscription journal
   ISSN (Print) 2278-2265 - ISSN (Online) 2278-2265
   Published by STM Journals Homepage  [61 journals]
  • Fabrication and parametric analysis of Thermal Sensing Dielectric PZT
           thick film nano ceramic Device developed by SOL GEL technique
    • Authors: Kushal Roy
      Abstract: Abstract Extensive investigation carried out during earlier half of twentieth century, prominently established that the ionic radius of an atom gets reduced to significant levels with decrease in coordination number. The findings of Goldsmith and Pauling [1] showed that ionic radii contracts by 4%,6% and 12% when coordination number is reduced from 12 to 8, 6 and 4 respectively[2]. It is obvious that coordination number reduction takes place at the surface partly owing to surface tension phenomena [3]. Recent past has seen extensive study in this field as it is realized that it plays a vital role in oxygen chemisorption [4], hence affecting various material properties when nano scaled particle size is considered. Pb[Zrx,Ti(1-x)]O3, popularly known as PZT has remained a point of attraction for the scientists and researchers in the field of synthetically developed Engineering Material since its discovery by Jaffe et. al. Last few decades have seen various devices like miniature relays[4], smart structures[5], memories[5]etc all utilizing, to a major extent the well known piezoelectric and pyroelectric properties found in PZT. After being reported about various parametric changes in piezoelectric coefficient, polarization and dielectric constant K by addition of some foreign ions lead to the further classification of PZTs as hard and soft PZTs. As reported by various authors, soft PZTs have highly enhanced piezoelectric properties which makes them highly suitable for fabrication of various electrical and electronic devices owing to high gain and better response, but on the other hand hard PZTs are reported to have highly decreased dielectric constants and piezoelectric coefficients leading their incapability to serve as a affective material for fabrication of actuators [6]. However a considerable linearity in the variation of K is reported in these hard doped materials [7], which can indirectly be utilized for other low gain and low response systems. It is also been reported that when miniaturizing a device, the grain size plays a important role in governing various parameters like dielectric constant, curie temperature, polarization etc of the composite material. Due to the complexity and various independent constraints involved, the origin of grain size effect is yet to be understood well [8]. In the presented work, the author investigates the nature of variation in curie temperature, dielectric constant, and polarization of the composite material Pb[Zrx,Ti(1-x)]O3, for x = 0.6, 0.7 and 0.8 and the effect of hard dopant Mg+2, with a objective to develop a composite solid solution of hard doped PZT which can be used as a temperature sensing element, when incorporated in a capacitive arrangement using simple electronic circuitry. Some interesting results are hereby obtained when the variation of polarization, dielectric constant and curie temperature is studied in detail with the variation in grain size.   Key Words: PZT thermal sensors, XRD, hard doping, SOL-GEL fabrication technique.
      PubDate: 2015-04-10
      Issue No: Vol. 4 (2015)
       
  • Photo-degradation in Nanocrystalline Porous Silicon
    • Authors: S.C. Agarwal
      Abstract: We study the metastabilities created by light soaking (LS) in nanocrystalline porous silicon (nc-PSi), prepared by the electrochemical anodization technique. At first sight, these appear similar to the effects of LS observed in hydrogenated amorphous silicon (a-Si:H) prepared by PECVD (Plasma-enhanced chemical vapor deposition) method. In nc-PSi, the ESR (Electron Spin Resonance) and Raman results indicate the presence of a-Si:H. This suggests a-Si:H as a possible cause of photo-degradation in nc-PSi. A careful look, however, reveals the differences. Amongst these is the finding that a polymer coating on nc-PSi is found to stabilize it against LS, but does so only partially for a-Si:H. This and several other experiments seem to indicate that the LS in nc-PSi affects the surface, whereas it is generally regarded to be a bulk effect in a-Si:H. We discuss these and related puzzles and suggest their possible explanations.Keywords: Light induced degradation, amorphous silicon, nanocrystalline silicon, porous silicon, Staebler Wronski effect, photodegradationCite this Article: Agarwal SC. Photo-degradation in Nanocrystalline Porous Silicon. Research & Reviews: Journal of Physics. 2015; 4(1): 22–30p.
      PubDate: 2015-04-07
      Issue No: Vol. 4 (2015)
       
  • Studies on Effect of Varying Geometric Parameters of Solar Receiver Tube
           on Thermal Loss Suffered By It
    • Authors: Arun Madival, Jai Kumar S., Sudeshkumar C.A., Vishalreddy ., M.R. Srinivas, M.S. Krupashankara
      Abstract: The radiative and convective heat losses from a solar receiver tube at a given operating temperature are a function of temperature of the outer glass envelope and outer surface area of the glass envelope. But the temperature of the outer glass envelope and its outer surface area are themselves a function of outer diameter of the heat pipe enclosed within the glass envelope and the annular gap between the outer surface of the heat pipe and the inner surface of the glass envelope. Hence the thermal losses associated with the receiver tube are a function of the size (outer diameter) of the heat pipe, annular gap between the glass envelope and the heat pipe, the operating temperature of the receiver tube. Theoretical thermal model is developed that describes various heat transfer phenomenon taking place in the solar receiver tube, under valid physical assumptions. Theoretical heat loss investigation is conducted by varying the values of outer diameter of the heat pipe (25–75 mm) and annular gap (25–75 mm) at three different operating temperatures of the receiver tube: 150, 300 and 450°C respectively, employing the thermal model developed. The radiative, convective and hence total losses associated with a solar receiver tube are quantified. The effect of varying the geometric parameters of the receiver tube on the heat loss suffered by it is studied.Keywords: Solar receiver tube, operating temperature, thermal losses, annular gapCite this Article: Arun Madival, Jai Kumar S, Sudeshkumar CA, Vishalreddy, Srinivas MR, Krupashankara MS. Studies on Effect of Varying Geometric Parameters of Solar Receiver Tube on Thermal Loss Suffered By It. Research & Reviews: Journal of Physics. 2015; 4(1): 10–21p.
      PubDate: 2015-03-30
      Issue No: Vol. 4 (2015)
       
  • Design and Control of Conveyors with Buffer System and Integrated Drilling
           using PLC
    • Authors: Raziuddin Annsari K., Prithvi Mahabaleshwara, Kundan Kumar, Jha Dadhichi, Subhadra Binod
      Abstract: Conveyors are one of the most widely used means of moving the product almost everywhere. The result of design and control of conveyor with buffer system and integrated drilling system using PLC helps to solve the problem of overload of conveyor system and packaging unit, never effects the production and avoids the complete shutdown of the entire system. Conveyor system is designed such that the production rate has the maximum efficiency by keeping time constraints in mind. The shutdown problem being hindered due to malfunction of the conveyors is tackled using the buffer system and dual-speed conveyors. If one of the belt suffers from a malfunction the speed of the other belts increases so as to accommodate the extra incoming work pieces. The buffer conveyor belt gets activated when more than one output conveyor belts goes off. The intelligent distributer only distributes to running conveyors. It also provides enough time for the malfunctioned conveyors to get back to working condition without hindering the on-going process. Drilling process indicates one of the various processes that take place in the industry.Keywords: Buffer, production unit, packaging unit, shutdown, distributer, drillingCite this Article: Raziuddin Annsari K, Prithvi Mahabaleshwara, Kundan Kumar, et al. Design and Control of Conveyors with Buffer System and Integrated Drilling Using PLC. Research & Reviews: Journal of Physics. 2015; 4(1): 7–9p.
      PubDate: 2015-03-27
      Issue No: Vol. 4 (2015)
       
  • Anti-synchronization of Bhalekar–Gejji Chaotic System via Nonlinear
           Active Control
    • Authors: Singh Jay Prakash, Singh Piyush Pratap, Roy B.K.
      Abstract: In this paper, a scheme of global anti-synchronization between two identical newly developed Bhalekar–Gejji chaotic system is proposed. This anti-synchronization scheme is achieved by using nonlinear active control since the parameters of both the systems are known and states are measurable. Lyapunov stability theory is used to ensure stability of error dynamics. Controller is designed by using the sum of relevant variables in master and slave chaotic systems. Simulation results reveal that proposed scheme is working satisfactorily.Keywords: Bhalekar–Gejji chaotic system, synchronization, anti-synchronization, nonlinear active control, lyapunov stabilityCite this Article: Prakash SJ, Pratap SP, Roy B. Anti-synchronization of Bhalekar–Gejji Chaotic System via Nonlinear Active Control. Research & Reviews: Journal of Physics. 2015; 4(1): 1–6p.
      PubDate: 2015-02-28
      Issue No: Vol. 4 (2015)
       
  • Simulation and Analysis of Static Synchronous Series Compensator
    • Authors: G. D Kamalapur, V. R. Sheelavant, Shobha M.N., Snehal Kanakal, Surekha Dhotre, Swetha B.
      Abstract: With the increasing size and complexity of the transmission networks, the performance of the power systems decreases due to problems related with the load flow, power oscillations and voltage quality. Flexible ac transmission (FACTS) offers effective schemes to meet these demands. FACTS technology increases power grid delivery capability and removes identified network bottlenecks. An attempt is made in this paper to study a FACT scheme static synchronous series compensator (SSSC), modelling with SIMULINK, voltage regulation and reactive power aspects.Keywords: FACTS, SSSC, transmission
      PubDate: 2015-01-09
      Issue No: Vol. 3 (2015)
       
  • Adaptive Control Scheme for Anti-synchronization of Identical
           Bhalekar-Gejji Chaotic Systems
    • Authors: Singh Piyush Pratap, Singh Jay Prakash, Roy. B K
      Abstract: This paper addresses the anti-synchronization problem of two Bhalekar-Gejji Chaotic systems in the presence of unknown system parameters. Based on Lyapunov stability theory an adaptive control law is devised to make the states of two identical Bhalekar-Gejji chaotic systems with unknown system parameters asymptotically synchronized. Finally, numerical simulations are presented to show the effectiveness of the proposed chaos anti-synchronization scheme and the objective. 
      PubDate: 2015-01-06
      Issue No: Vol. 3 (2015)
       
  • The Non-Local Aspects of Two Different Quantum Correlations Quantum
           Discord and Measurement Induced Non-locality
    • Authors: Amit Bhar
      Abstract: Quantum discord and measurement induced non-locality (MIN) have a deep impact on the context of quantification of quantumness of correlations in composed quantum systems as well as the non-local aspects of the quantum states. In this paper, we have tried to investigate and visualize the evolution of non-local aspects of these quantumness measurers. The underline motivation is to reestablish quantum discord and MIN as non-local measures.Keywords: LOCC, entanglement, discord, measurement induced non-locality(MIN), quantum channels
      PubDate: 2014-11-14
      Issue No: Vol. 3 (2014)
       
  • CARBON NANO SPHERES: SYNTHESIS AND EXPLORATION OF STRUCTURE
    • Authors: B Manoj
      Abstract: Large scale production of pure carbon spheres, with diameter from 27 to 108 nm, has been achieved via direct thermal decomposition of kerosene and diesel in the absence of catalyst. Microstructure of carbon black is also investigated for comparison purpose. The resulting material has been characterized using UV-Vis-NIR spectroscopy, FTIR, XRD and SEM-EDS. The UV-Vis-NIR spectrum reveals absorption peaks in the region 900–1500 nm are due to the lowest E11 sub-band absorption; whereas those in the 550–900 nm regions correspond to second E22 sub-band transitions. In the spectra, absorption peaks at 233, 232 and 229 nm are attributed to π-π* transition of the C=C bonding. The samples show two distinct, highly intense peaks at ~24º and a slightly broadened peak around 42º due to (002) and (010) reflections of graphite, respectively. The peaks at 3431 and 1047 cm-1 were assigned to O–H and C–O stretching vibrations, respectively. The band observed at 1619 cm-1 manifest the skeletal vibrations from graphitic domains and hence indicates the presence of crystalline graphitic carbon. The absorption bands at 2920 and 2850 cm-1 are because of the existence of aliphatic groups in the soot sample. The SEM analysis shows that the carbon spheres formed consist of agglomerated spheres.
      Keywords: Carbon spheres, Hydrocarbon soot, Graphene, Carbon, Aromaticity
      PubDate: 2014-11-06
      Issue No: Vol. 3 (2014)
       
  • Compositional and Optical Properties of Sb Doped ZnO Thin Films
    • Authors: Bhuiyan M. R. A., Begum J., Hoq E.
      Abstract: Sb doped ZnO thin films were deposited onto cleaned glass substrates at different substrate temperature by using thermal evaporation method in vacuum. The atomic compositions of the grown films have been determined by Energy Dispersive Analysis of X-ray (EDAX) method by using an attachment to the Scanning Electron Microscope. The optical properties were measured in the photon wavelength ranging in between 300 and 2500 nm by using a UV-VIS-NIR spectrophotometer. An EDAX spectrum reveals that Sb is doped into the ZnO thin films. The film shows higher transmittance in infrared regions and reflectance in UV regions. The films have high absorption co-efficient (~105 cm1) above the fundamental absorption region that direct allowed transitions band gap. The band gap energy of the films found from 2.409 to 2.929 eV for substrate temperature variation.
      Keywords: Sb doped ZnO, Compositional properties, Optical properties, Band gap energy
      PubDate: 2014-09-11
      Issue No: Vol. 3 (2014)
       
  • First Principles Band-gap Calculations of 3d Transition Metals-added
           Rock-salt ZnO
    • Authors: M. Ashraf, A. Afaq
      Abstract: The band-gaps of rock-salt Zinc Oxide added with 3d transition metals (TM = Mn, Fe, Co, Ni) are estimated by Density Functional Theory (DFT) as implemented in the WIEN2k code. We employed Full Potential Linearized Augmented Plane Wave (FP-LAPW) method, within the Local Density Approximation (LDA) and the Generalized Gradient Approximation (GGA), in order to find band-structures of Zn1-x(TM)xO alloys at x = 25, 50, and 75%. The results showed metallic nature for all TM-doped ZnO alloys, contrary to the semiconducting nature as predicted by the experimentalists. This reveals an inadequacy of simple LDA and GGA schemes for band-gap calculations of highly correlated systems as in our case.
      Keywords: Band-gaps, Density Functional Theory, Transition Metals, LDA, GGA
      PubDate: 2014-08-19
      Issue No: Vol. 3 (2014)
       
  • High-Spin Structure in 192-196pt Isotopes
    • Authors: Huda H. Kassim, Fadhil I. Sharrad
      Abstract: The 129 -196Pt isotopes with proton number Z=78 and neutron numbers (n) are 114,116, and 118 in O(6) region were investigated. The energy level, E2 transition probabilities, and the potential energy surface have been calculated within the framework using Interacting Boson Model (IBM-1). The calculated results are compared with the most recent experimental data. Good agreements are obtained between the theoretical and experimental results for 192-196Pt isotopes. The contour plot of the potential energy surfaces shows that the interested nuclei are deformed and have γ-unstable-like characters.
      Keywords: IBM-1, Neutron-rich, B(E2) values, Energy levels, Potential energy surface
      PubDate: 2014-08-19
      Issue No: Vol. 3 (2014)
       
  • Fragility of Ge40S60 Glass Forming Liquid
    • Authors: G M SAFFARINI, A. Saiter, J. M. Saiter
      Abstract: From differential scanning calorimetry (DSC) measurements performed on Ge40S60 chalcogenide glass forming liquid, the values of the apparent activation energy Δh*, and the fragility index, m, as defined in the strong-fragile glass forming liquid concept, have been determined. The calculated value of m for this glass forming liquid is equal to 82. From this m value, it is suffice to conclude that this glass forming liquid belongs to an intermediate category that exhibits a kinetic behaviour between strong and fragile.
      PACS: 61.43.Fs; 64.70.Pf; 65.60. +a
      Keywords: Strong-fragile concept, Ge-S glasses, Differential scanning calorimetry
      PubDate: 2014-08-19
      Issue No: Vol. 3 (2014)
       
  • Field Dependence of Third Order Perturbed Energy of Cobalt Ferrite Thick
           Films
    • Authors: P. Samarasekara
      Abstract: Third order perturbed classical Heisenberg Hamiltonian was modified to describe the variation of magnetic properties and easy axis orientation of cobalt ferrite films with applied magnetic field and number of layers of the film. According to our theoretical studies explained in this manuscript, the magnetically easy and hard directions of cobalt ferrite films solely depend on in plane and out of plane magnetic fields. According to 3-D and 2-D plots, there are many easy and hard directions at one particular value of in plane or out of plane magnetic field. The magnetic properties were investigated for cobalt ferrite films with thickness up to 10,000 unit cells. The total magnetic energy was calculated for a unit spin of cobalt.

      Keywords: Heisenberg hamiltonian, Cobalt ferrite, Perturbation
      PubDate: 2014-05-08
      Issue No: Vol. 3 (2014)
       
  • Optical Properties of SiO2 Nanoparticles Doped PEO-LiClO4 Nanocomposite
           Polymer Electrolyte Films
    • Authors: Shishir U. Patil, S. S. Yawale, S. P. Yawale
      Abstract: The optical transmission and absorption spectra were recorded in the wavelength range 200-800 nm for optimized high conducting concentrations of SiO2 nanoparticles in PEO-LiClO4 -m wt% SiO2 polymer matrix. Values of absorption coefficient, direct band gap energy, measure of extent of band trailing or Urbach energy, absorption edge and constant, B, have been investigated by optical characterization method. Effect of concentration of SiO2 nanoparticles in the polymer matrix on these parameters has been discussed. It has been observed that addition of SiO2 nanoparticles increases structural disorder and fluctuations of the internal fields associated with it. Small change in the concentration of SiO2 nanoparticles changes optical properties of nanocomposite polymer matrix. It was also found that direct band gap fits in the lower energy region of fundamental absorption edge.

      Keywords: Absorption coefficient, Optical energy gap, Optical properties, Absorption edge, Urbach energy, Bang trailing, Nanocomposite polymer matrix
      PubDate: 2014-05-08
      Issue No: Vol. 3 (2014)
       
  • Spectral Analysis and Estimation of Depths to Magnetic Rocks below the
           Katsina Area, Northern Nigerian Basement Complex
    • Authors: Sabiu Bala Muhammad, E. E. Udensi, M. Momoh, Y. A. Sanusi, T. Suleiman, O. Ajana
      Abstract: Airborne magnetic data over the Katsina area of the Northern Nigerian Basement Complex were analyzed and interpreted in this study. The study area covers parts of the Northern Nigerian Basement Complex, bounded by longitudes 7000’ and 80 30’; and latitudes 12030’ and 13030’. Regional-Residual Separation was carried out using Least Square Method. The resulting regional map revealed a regional trend in the NE-SW direction. The magnetic residual values ranged from -329.74 nT to 202.91 nT. Method of spectral analysis was applied to the residual data. The result revealed two distinct layers. The first layer which occupies the high frequency tail is due to the effects of shallower ensembles of magnetic sources and noise in the data. The first layer depth ranges from 0.04 km to 0.74 km. The second layer is associated with the intermediate frequencies and lies between the depths of 0.1 km and 0.80 km. The lowest depth of 0.1 km occurred.Keywords: Spectral analysis, Katsina area, Basement complex
      PubDate: 2014-05-08
      Issue No: Vol. 3 (2014)
       
  • Structural Properties and DC Conductivity Study of Barium Hexaferrite
           Powder
    • Authors: Rajshree B. Jotania, Atashi Ajmera, Rajshree Jotania
      Abstract: M-type barium hexaferrite powder with chemical composition BaFe12O19 has been synthesized using Co-precipitation method. High purity Nitrates, Oxides and Carbonates of Iron (III), Barium (II) and Ammonium Hydroxide were used as starting materials. The prepared precursors calcined at temperature 950 °C for 4 h in a furnace and characterized by FTIR, SEM, XRD, TGA and DC conductivity measurements. Microstructure of prepared samples was observed via SEM. X-ray diffraction studies confirm the presence of a single phase with the theoretical space group P63/mmc barium hexaferrite (BaM), which crystallizes in the hexagonal system and has a uniaxial magnetoplumbite structure, displays good chemical stability and structural properties.Keywords: Barium hexaferrite, XRD, SEM, TGA
      PubDate: 2014-05-08
      Issue No: Vol. 3 (2014)
       
  • Structural and Dielectric Properties Hexaferrite/Poly (Vinyl Alcohol)
           Composites
    • Authors: Amrin Kagdi, Rajshree B. Jotania
      Abstract: Magnetic barium cobalt hexaferrite particles-PVA composites with of different mass ratio:  9:1, 8:2, 7:3, 6:4 and 5:5 were prepared. Structural properties of the composites were characterized by Infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM). The effect of the concentration of Ba2Co2Fe28O46 hexaferrites on structural and dielectric properties of magnetic-PVA  composites were investigated. FTIR result revealed  that composite samples show absorption peaks of both ferrites and PVA. The X-ray diffraction investigations confirm the formation of mono phase of hexaferrite particles. Scanning electron microscopy images reveal that the shape and size of barium cobalt hexaferrite powder particles is irregular. The addition of PVA not much changed the shape and  size of particles  (ranging from 200-300 nm) but porosity found to decrease.  

      PubDate: 2014-01-16
      Issue No: Vol. 2 (2014)
       
  • Orientation of Easy Axis of Ferromagnetic Films as Explained by Third
           Order Perturbed Heisenberg Hamiltonian
    • Authors: P. Samarasekara, Prabhani Rajakaruna
      Abstract: The third order perturbed Heisenberg Hamiltonian has been applied to explain the magnetic easy axis orientation. Ferromagnetic CoPt/AlN multilayer thin films with number of layers N=11, 16 and 21synthesized on fused quartz substrates using dc magnetron sputtering technique have been employed as experimental data. According to experimental research performed by some other researchers, easy axis of these fcc structured ferromagnetic films is oriented in the plane of the film above one particular temperature. Average value of out of plane spin component was plotted against temperature in order to determine the spin reorientation temperature. The spin reorientation temperature was highly sensitive to 2nd order magnetic anisotropy constant.
      PubDate: 2014-01-16
      Issue No: Vol. 2 (2014)
       
  • Deconvolution of X-ray Diffraction Spectrum of Polypropylene
    • Authors: B. Sanjeeva Rao, N. Maramu, Venkateswar Rao, N. Srinivasa Rao, K. Rajendra Prasad
      Abstract: Deconvolution methods have been used to evaluate degree of crystallinity and particle size from diffractogram of polypropylene(PP). The deconvolution method is used to separate the various peaks from the total XRD spectrum and it is successful in separating the crystalline, amorphous and background regions of a diffractogram. The degree of crystallinity of PP is calculated to be 49%. The particle size of crystallites in different crystalline phase is calculated using Scherrer equation. 
      PubDate: 2014-01-16
      Issue No: Vol. 2 (2014)
       
  • Studies on Electrical and Thermal Transport of InN based on Two Layer
           Model
    • Authors: A. Chakraboerty, B. Sharma, C. K. Sarkar
      Abstract: InN, a material of huge potential in device applications, is grown on sapphire substrate. But due to the high lattice mismatch between the sapphire and InN, the large number of dislocations develops near the interface between the two materials. However, the density of threading dislocation falls sharply in the bulk layer. The charge density has also similar variation. Therefore, the bulk InN crystal may be treated to be consisting of two layers, one the interfacial layer where the density of dislocations is very high and the layer on the interfacial layer, called bulk layer which has much lower density of dislocation and is considered to be negligible. We have calculated the mobility of InN and Seebeck Coefficient of InN based on the two layer model. We find that the theoretical values of mobility based on two layer model matches quite well with the experimental data.  In our model, in the interfacial layer, the dislocation scattering and ionized impurity scattering mechanisms are considered to be the dominating scattering mechanisms while for the bulk layer, the acoustic phonon scattering via deformation potential and piezo electric coupling, ionized impurity scattering and optical phonon scattering mechanisms are considered. The theoretical values of the thermoelectric power of InN, calculated on the basis of two layer model are found to be in good agreement with experimental data. 
      PubDate: 2013-09-09
      Issue No: Vol. 2 (2013)
       
  • In Plane Oriented Strontium Ferrite Thin Films Described by Spin
           Reorientation
    • Authors: Pubudu Samarasekara, Udara Saparamadu
      Abstract: For the first time, in plane orientation of magnetic easy axis of sputtered strontium hexaferrite thin films has been explained using modified Heisenberg Hamiltonian model with stress induced anisotropy term. The variation of average value of in plane spin component with temperature was plotted in order to determine the temperature at which easy axis is oriented in the plane of the strontium ferrite film. The average value of in plane spin component in this 2-D model reaches zero at one particular temperature. This particular temperature obtained using our theoretical model agrees with the experimental value of the temperature of rf sputtered polycrystalline strontium ferrite thin films deposited on polycrystalline Al2O3 substrates (500°C). This spin reorientation temperature solely depends on the values of energy parameters used in our modified Heisenberg Hamiltonian equation.   
      PubDate: 2013-09-09
      Issue No: Vol. 2 (2013)
       
  • Fast Asymmetric MHD Modes in Structured Media with Steady Flows
    • Authors: A. Satya Narayanan, V. S. Pandey
      Abstract: The effect of steady-flows on fast kink waves amplitude as well as on its heating rate profile are examined in inhomogeneous layers. We assume the equilibrium magnetic and plasma configuration  as a slab-geometry: z-axis of the slab is along the uniform background magnetic field. We allow density stratification perpendicular to the direction of background magnetic field. In this study we evaluate the extent to which fast kink waves can be collisionally dissipated and their dissipation by viscosity and heat conduction invoking the presence of a steady flow and compare the results with the minimum required optically thin radiative cooling rate. Only body waves exist for the field-aligned propagation. However, surface wave is present along with body waves for oblique propagation. We find that steady-flows have negligible effect on surface waves. However, it modulates the wave amplitude and thereby heating rate profile of body waves. The steady flow shows opposite behaviour on the field-aligned propagating fast body waves than obliquely propagating body waves. In the case of field-aligned propagation the anti-parallel flows increases both the wave amplitude and heating rate as compared to parallel flows. However, for the oblique propagation we get the opposite pattern. The obliquely propagating kink body waves are more effective in heating as compared to field-aligned propagating kink body waves. We have also studied the wave and heating profile of shear kink waves propagating principally almost normal to the interface. We find that the transverse components (i.e., ) of shear surface waves are equal and it is larger than the longitudinal component (i.e., ) by three orders of magnitude. 
      PubDate: 2013-09-09
      Issue No: Vol. 2 (2013)
       
  • Binding Energy and Energy Level with B(E2; 0ـــ2) of
           Neutron-Rich 60-66Fe Isotopes using NuShellX
    • Authors: F. I. Sharrad
      Abstract: Binding energy of the ground state, energy levels and B(E2; ) values for even-even Fe isotopes with proton number Z=26 and neutron numbers (n) between 34 and 40  have been calculated through shell model calculations using the shell model code NuShellX for Windows by employing harmonic oscillator (HO) model space and the GXPF1A, KB3G and FPD6 interactions. The binding energies calculations are reasonably consistent with the available experimental data. The predicted low-lying levels (energies, spins and parities) are in good agreement with newly experimental data, and by employed FPD6 for 60Fe nucleus, GXPF1A for 62Fe nucleus and KB3G for 64,66Fe nuclei. Furthermore, B(E2; ) values are in good agreements with available experimental data. 
      PubDate: 2013-09-09
      Issue No: Vol. 2 (2013)
       
  • Measurement of Radon Exhalation Rate from Building Materials
    • Authors: F. Shoqwara, N. Dwaikat, G Saffarini
      Abstract: Indoor radon has been recognized as one of the health hazards for mankind because long-term exposure to radon increases the risk of developing lung cancer. This study aims at assessing the contribution of building materials towards the total indoor radon exposure to the inhabitants of Nablus district, Palestine. The radon exhalation rate has been carried out for different building materials of international origin used in construction in Nablus district. The “closed-can technique” has been employed in this study using solid state nuclear track detectors (CR-39). After 100 days of exposure, CR-39 detectors were etched chemically and then counted under an optical microscope. Results show that Radon exhalation rates from granite and marble have relatively high values as compared to other building materials followed- in order- by cement, ceramic, concrete, building stones, and porcelain, while gypsum, sand, gravel and bricks contribute less to radon exhalation rate which was found to range from (55.37 ± 15.01) mBq/m2h for gypsum samples to (589.54 ± 73.24) mBq/m2h for granite samples, with a total average value of (268.56 ± 166.21) mBq/m2h. The corresponding radon concentration, effective radium content, and annual effective dose average values were (148.49 ± 91.13) Bq/m3, (1.93 ± 1.20) Bq/Kg and (3.74 ± 2.30) mSv/y, respectively. In general, the radon exhalation rate from the investigated building materials is low and under the global value except for granite, marble and some cement samples and thus except for the excluded, the studied materials are safe as construction materials.  
      PubDate: 2013-04-16
      Issue No: Vol. 2 (2013)
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2015