Vol. 7 & Issue 4 ; Section C : Physical Sciences

Date : Aug. to Oct.2017


Investigation and Mitigation of Power Quality Events in Distribution System

Chetan E. Morkhade and Chetan M. Bobade

JCBPS; Section C; August 2017 – October 2017, Vol. 7, No. 4; 801-808

[DOI: 10.24214/jcbps.C.7.4.80108.]

  • Abstract

    The investigation and mitigation of power quality events in power systems are important work in monitoring and protection of power system network. Most of the power system disturbances are non-stationary and transitory in nature and new tools are being used nowadays for the analysis of power quality disturbances. This paper presents a wavelet based feature extraction method for the detection of power quality problem. The disturbance waveforms obtained from simulation are decomposed by discrete wavelet transform. The custom power device DSTATCOM is used for the mitigation of power quality events. Voltage sag, Transient and under voltage have been tested and mitigated in PSCAD.

Radiation and Hall Effects on Unsteady Free MHD Convection Flow past a Vertical Porous Plate with Heat Absorption, Thermo Diffusion and Chemical Reaction in Slip Flow Regime

K.Balamurugan and V.Amuthavalli

JCBPS; Section C; August 2017 – October, 2017, Vol. 7, No. 4; 809-822,

[DOI: 10.24214/jcbps.C.7.4.80922]

  • Abstract

    The present paper deals with the analysis of unsteady free MHD convection heat and mass transfer flow of a viscous fluid through a vertical moving porous plate in slip flow regime with radiation, Hall Effect and heat absorption in presence of chemical reaction and thermo diffusion effect. Approximate solutions for velocity, temperature and concentration fields are obtained by solving the governing equations of the flow field using perturbation technique. The expressions for skin-friction, rate of heat transfer and rate of mass transfer are also derived. The effect of various parameters like Schmidt number(Sc), Prandtl number(Pr), Grashof number(Gr), Modified Grashof number(Gm), Magnetic parameter(M), Radiation parameter(F), Porosity parameter(K), Hall parameter(m), Heat absorption parameter(S), Chemical reaction parameter(R) and Soret effect(So) on velocity, temperature and concentration profiles are discussed with the help of numerical values and the graphs.

A theoretical study of super fluidity of an atomic Fermi gas near the unitary limit and evaluation of gap function as a function of K/KF in the unitary limit

Shivram nath Upadhay, Vijay Kumar Verma and L. K. Mishra

JCBPS; Section C; August 2017 – October, 2017, Vol. 7, No. 4; 823-841.

[DOI: 10.24214/jcbps.C.7.4.82341.]

  • Abstract

    Using the theoretical formalism of S.De Palo etal (Laser Phys. 15, 376 (2005)), we have theoretically studied super fluidity of an atomic Fermi gas near the unitarily limit. Our theoretically evaluated values of gap function Δ(k) as a function of k/kfor different values of  g /¯n/EF  show that the gap function has a damped oscillatory behaviour. Our theoretically valuated results of the ratio Δο/EF and μ/Eas a function of g/¯n/Eshow that Δο/Edecreases and μ/Eincreases as a function of g /¯n/EF  For large value of g /¯n/EF  Δο/Ebecomes constant while μ/EF  increases and becomes positive from negative values. These results also indicate that the resonance is along BEC side. Our theoretically evaluated results of Δο/KβTas a function T/ Tfor different values of g /¯n/Eindicate that the values decrease as T/ Tfor all values of g /¯n/E We observed that the narrow resonance favours occurrence of super fluidity. It is also observed that the smooth temperature behaviour is the manifestation of short ranged, bosonic character of the result. Using the theoretical formalism of Q. Chen [Phys. Rev. A86, 023610 (2012)], we have theoretically evaluated the super fluid transition temperature in a unitary atomic Fermi gas on a lattice. Our theoretically evaluated result of TC /6t  as a function of –U/6t  for different densities show that maximum TC occurs on the BEC side of unitary limit. We theoretically evaluated results of TC / Eas a function of  –U/6t for different densities which indicate that TC has a functional form Tα /– t2/ U Our theoretically evaluated result of TC / EF  as a function of n1/3 show that TC / EF  exhibits higher order nonlinear dependence of n1/3 The minimum value of TC is on BCS region. Our theoretically evaluated results are in good agreement with the other theoretical workers.These theoretical studies may be relevant for constructing a complete theoretical description of the crossover from BEC of composite bosons to BCS of Cooper pairs. Till today, we do not have very successful reliable theory for high TC-superconductors. It is our firm belief that BCS-BEC crossover physics can give some valuable insight into this direction.

Approximate solution of Schrödinger equation for X1Σ+g state of CS2 molecule through proper quantization rule method

Bo An,

JCBPS; Section C; August 2017 – October, 2017, Vol. 7, No. 4; 842-849.

[DOI: 10.24214/jcbps.A.7.4.84249.]

  • Abstract

    Proper quantization rule ( xaxb k (x)dx  - x0ax0b k0 (x) dx=ηπ is a new method for thesolution of Schrödinger equation with eflection symmetry. By this rule the energy spectra of a solvable system with shape-invariant potential can be obtained just from its ground-state energy. We calculated the Schrödinger equation including Morse potential with arbitrary rotational quantum number in multi-dimensional space. The proper quantization rule gives exact answers for energy levels of X1Σ+g state of Cs2 molecule. By discussing the relations of energy spectra with multi-dimensional space and vibrational quantum number, we found that: (1) the rotation-vibrational energies for X1Σ+g state of Cs2 molecule become more convergent as the number of multi-dimensional space in the presence of a constant vibrational quantum number and arbitrary rotational quantum number; (2) the vibrational energies in higher dimensions and in three-dimensional system have the similar form.

An evaluation of exciton diamagnetic shift as a function of magnetic field for InAs/InP and self-assembled quantum wires and evaluation of electron energy levels of quantum wire in a  ransverse magnetic field

Priyanka Kumari, Sangeeta Sinha and L. K. Mishra

JCBPS; Section C; August 2017 – October, 2017, Vol. 7, No. 4; 850-865,

[DOI: 10.24214/jcbps.C.7.4.85065.]

  • Abstract

    Using the theoretical formalism of Y. Sidor et al.[Phys. Rev. B76, 195320(2007)], we have theoretically studied the exciton confinement in InAs/InP quantum wells(QW) and quantum wires(QWR) in the presence of magnetic field. We have evaluated the exciton diamagnetic shift ΔE (meV) for QW along z-direction and QWR along 110 in the presence of magnetic field both with wire height and well width. Our theoretically evaluated results show that ΔE increase with magnetic field B(T) for decreasing well width and wire height. Our results also show that ΔE evaluated taking parabolic mass is larger than without parabolic mass. In other calculation, our evaluated results for the radii of electron ρgre (Aº) heavy hole ρgrhh (Aº) and exciton radii ρgrex (Aº) along the growth direction of QW and along 110 for QWR with different h show that ρgre decreases with h whiledecreases with h while ρgrhh and ρgrex increases with h. Our other results indicate that exciton reduced mass [including band nonparabolicity effect]μnonp (mo) is large  than  μpar (mo)[without including band nonparabolicity effect]where m0 is vacuum electron mass. Our evaluated results are in good agreement with other theoretical workers.Using the theoretical formalism of Xin-Zhi Duan et al. [Physical science InternationalJournal 4(10), 1400 (2014)], we have theoretically studied the electron energy levels of an elliptically quantum wire (QWR) in a transverse magnetic field. Our evaluated results of ground state energy E0 (meV) end first excited state energy E1 (meV) as a function of ξo (a dimensionless parameter which describe the shape of the ellipse) for two different transverse magnetic field B⊥ =0.55T and 1.5T for two different length of the wire h=
    0.15a* o........................................................................see the text paper

Unsteady MHD slip flow past a vertical porous plate with radiation and soret effect in a rotating system with fluctuating temperature and concentration in presence of hall current and temperature gradient dependent heat source

K.Balamurugan and V.Gopikrishnan,

JCBPS; Section C; August 2017 – October, 2017, Vol. 7, No. 4; 866-880,

[DOI: 10.24214/jcbps.C.7.4.86680.]

  • Abstract

    This paper analyze unsteady free convection heat and mass transfer flow through a non-homogeneous porous medium bounded by an infinite porous vertical plate with slip flow taking into account the radiation, chemical reaction, hall current, soret effect and temperature gradient dependent heat source. The approximate profiles for velocity, temperature, concentration are obtained by using perturbation techniques. The expressions for skin friction, heat and mass flux are derived.

Structural, Optical and Electrical Properties of Thermally Deposited CdS Thin Films

Nabeel A. Bakr, Falah I. Mustafa and Roaa J. Mohammed,

JCBPS; Section C; August 2017 – October, 2017, Vol. 7, No. 4; 881-889,

[DOI: 10.24214/jcbps.C.7.488189.]

  • Abstract

    Thermal evaporation technique is used to deposit CdS thin films on glass substrates using CdS powder. Various characterization techniques have been used to investigate the structural, optical and electrical properties of the prepared thin films. The results of XRD analysis showed that the as-deposited and annealed (at 200 ̊C for 1 hour) CdS films were single crystalline having a cubic structure with (111) plane orientation according to International Center for Diffraction Data (ICDD) card number 10-0454. The crystallite size is found to be 37.32 nm and 39.78 nm for the as-deposited and annealed films respectively. The "AFM" outcomes show uniform, homogeneous and tightly adherent films over the entire glass substrate surface without any voids, pinholes or cracks and having a large number of grains. The UV-Visible-NIR absorbance spectra were recorded in the range of (400- 1100) nm to investigate the optical characteristics. The results have shown that the CdS films have a low absorbance in the visible-near infrared region from ~ 500 nm to 1100 nm. The energy gap was calculated using Tauc’s plot and it was around 2.4 eV for the as-deposited and annealed films. The electrical characterization included D.C. conductivity and Hall Effect measurements were carried out. From D.C. measurements, it was found that the deposited films have two transport mechanisms of free carriers and two activation energies were estimated. Hall measurement results showed that the deposited films are n-type, and the carrier concentration and mobility have been estimated.

Influence of Post Annealing on SnO2 Nanoparticles and its Photocatalytic Activity in Methylene Blue Dye Degradation

P D Sahare and Surender Kumar,

JCBPS; Section C; August 2017 – October, 2017, Vol. 7, No. 4; 890-.899,

[DOI: 10.24214/jcbps.C.7.4.89099.]

  • Abstract

    SnO2 nanoparticles were synthesized using flux method. Synthesized SnO2 nanoparticles were characterized for their structure and morphology using X-ray diffraction and scanning electron microscopy respectively. The average particle size of as synthesized SnO2 nanoparticles was about 60 nm and the diameter of nanoparticles increases with increasing annealing temperature by keeping its spherical shape. Photocatalytic properties of as synthesized and annealed nanoparticles were studied for methyl blue organic dye under UV light. Pristine SnO2 nanoparticles were found to be highly photocatalytic active and with increasing annealing temperature the photocatalytic activity decreases.

The effects of the dispersant on the Powder Morphology of Nb-Ti-Cr-Si Based Ultrahigh Temperature Alloy

Li Hailong and Guo Baohui,

JCBPS; Section C; August 2017 – October, 2017, Vol. 7, No. 4; 900-905,

[DOI: 10.24214/jcbps.C.7.4.90005.]

  • Abstract

    The effects of the process control agent on the powder morphology of Nb-Ti-Cr-Si based ultrahigh temperature alloy were investigated. The results showed that the alcohol as a dispersantt reduced the powder agglomeration, and the stearic acid as a dispersant reduced the agglomeration of the powder greatly

Hall current effect on MHD free Convective flow past a moving Inclined Porous Plate in presence of Chemical Reaction with Ohmic heating, Radiation, Viscous dissipation, Heat Source and Soret effect

K.Balamurugan and V.Amuthavalli,

JCBPS; Section C; August 2017 – October, 2017, Vol. 7, No. 4; 906-920,

[DOI: 10.24214/jcbps.C.7.4.90620.]

  • Abstract

    The present article discusses with the analysis of hall current effect on heat and mass transfer in MHD free convection flow of an incompressible and electrically conducting viscous fluid through a moving inclined heated porous plate with ohmic heating, radiation, viscous dissipation, heat source and Soret effect in presence of chemical reaction. The governing non-linear partial differential equations of the problem are reduced to a set of ordinary differential equations which are then solved analytically by using perturbation technique. The effect of different parameters like Magnetic parameter(M), Porosity parameter(K), Hall parameter(m), Soret effect(So), Grashof number(Gr), Modified Grashof number(Gm), Heat source parameter(H), Prandtl number(Pr), Radiation parameter(F), Schmidt number(Sc) and Chemical reaction parameter(R) on velocity, temperature, concentration profiles and skin friction are
    displayed with the help of numerical values and the graphs.

Experimental Research on Optimization of Array Beamforming Based on Proximal Support Vector Machine

Guancheng Lin,

JCBPS; Section C; August 2017 – October, 2017, Vol. 7, No. 4; 921-933.

[DOI: 10.24214/jcbps.C.7.4.92133.]

  • Abstract

    In order to investigate the performances of main lobe width, sidelobe level,array gain and running time for beam former based on Proximal Support Vector Machine (PSVM) algorithm in real acoustic environment, it sets the constraints of support vector regression equations and proposes the beam optimization method based on proximal support vector machine. Then the optimization model of beamformer based on proximal support vector machine is established, the beam optimization model and the concrete implementation process of beamformer based on the proximal support vector machine is discussed, and the experiments in anechoic water tank are carried out. The experimental results show that the method reduces the computational complexity and decreases the memory occupancy and improves the training speed with the performance of the beamformer substantially unchanged. Compared with the traditional support vector regression beamforming, it has characteristics of fast response for real time requirement and provides a new and effective ways for the optimization design of beamformer

Advanced band structure and optical properties of disordered ZnCdTe2 within mBJLDA approach

Arvind K. Sharma, Ankur Taya, Priti Rani, and L. P. Purohit, Manish K. Kashyap,

JCBPS; Section C; August 2017 – October, 2017, Vol. 7, No. 4; 943-951.

[DOI: 10.24214/jcbps.C.7.4.94351.]

  • Abstract

    An ab-initio report on the electronic, structural and optical properties of pristine and disordered ZnCdTe2 compound is presented. For the exchange-correlation potential, modified Becke Johnson potential (mBJ) have been used to estimate the improved band gap of ZnCdTe2-xSex (x = 0, 0.125) over generalized gradient approximation (GGA). The optical response has been explained in terms of various electronic transition. A clear anisotropy for dielectric function response is observed along basal plane and z-axis in pristine and disordered ZnCdTe2. Further Se-disorder onsets the increased optical transitions after fundamental absorption as evident from imaginary part of dielectric function (ξ2 (ω )  ) spectra.

A theoretical evaluation of momentum distribution, BCS pair function and BCS distribution function of atomic Fermi gas near the unitarity limit

Shivram Nath Upadhaya, Vijay Kumar Verma and L. K. Mishra,

JCBPS; Section C; August 2017 – October, 2017, Vol. 7, No. 4; 952-965.

[DOI: 10.24214/jcbps.C.7.4.95265.]

  • Abstract

    Using the theoretical formulism of S. De Palo etal [Laser Physics, 15, 376 (2005)], we have evaluated momentum distribution n(k) of atomic Fermi gas near the unitarity limit as a function of k/kF for different values of g√n/Eand also different values of T/TF Our Theoretically evaluated results show that n(k) decrease as k/kF for both fixed value of g√n/E and also for fixed value of T/TF This type of behaviour is an indication of normal Fermi gas character with large value of jump at k=kF. This results also demonstrate that there is a BCS-like solutions for narrower well and momentum distribution n(k) is more pronounced with bosonic character. Our theoretically evaluated results for BCS-pair function φ(r) as a function of  (r / ao ) for different values of g√n/EF  show that node of wave function is shifted towards larger value of g (r). Our obtained results indicate that the size of the Cooper pair is related to the spatial extension of the pair function. Our theoretically evaluated results of BCS pair distribution function g(r) as a function of [r/(rsao)] for different values of T/TF . show that g(r) increase with [r/(rsao)] for each value of T/TF  The results also indicate that g(r) has a higher peak as T →0. But the peak is washed out as T approaches TF. Using the theoretical formalism of G. Watanabe etal [arXiv:1301:3363v4 (cond.mat:quant.gas) Oct 2013], we have evaluated ratio[k-1/ k-1 (S=0)],(m* /m) and [ Cs/Cs(0)] all as a function of(EF/ER ) for different values of s, where EF is Fermi energy, ER is recoil energy and ‘s’ is the lattice intensity in the dimensionless unit. Our theoretically evaluated results indicate that [k-1/ k-1 (S=0)],(m* /m) and [ Cs/Cs(0)] all increase first, attain maximum value and then decrease as a function of (EF/ER ) for all different values of s. These results were obtained for unitary Fermi gas on the optical lattice. These parameters play an important role in the formation of molecules induced by the lattice. Our theoretically obtained results are in good agreement with those of other theoretical workers.The obtained results have great significance in the crossover physics of BCS and BEC states. As the scattering length diverges at the unitarity limit the present study of BCS and BEC Fermi super fluid have been performed in a unified point of view

Research on characteristics and modeling of photovoltaic array under partial shading

Peng Zhang,

JCBPS; Section C; August 2017 – October, 2017, Vol. 7, No. 4; 966-975,

[DOI: 10.24214/jcbps.C.7.4.96675.]

  • Abstract

    PV array output characteristics become more complex under partial shading condition, traditional PV model is not suitable for this situation, establish an accurate and efficient PV array model under partial shading condition has important significance for maximum power point tracking algorithm, PV array optimize layout and other aspects research. Based on double diode cell model which can meet engineering precision, analysis the influence of bypass diodes under partial shading condition. Deduce PV array engineering mathematical model for uniform illumination and partial shading condition. The proposed model simulation results show that the model can accurately reflect the output characteristics of PV array under partial shading conditions accordingly draw useful conclusions about PV array output characteristics and shading distribution provided strong support for the optimal engineering design of PV systems under completed shading condition.

An Evaluation Of Interlayer Optical Conductivity σ1 (ω)Of Single Layer And Double Layer At TC And T<TC For High-Temperature Superconductors And Reflectance R (ω) As A Function Of Frequency ω In The Study Of Its Electrodynamics

Santosh Kumar and Lalit Kumar Mishra,

JCBPS; Section C; August 2017 – October, 2017, Vol. 7, No. 4; 976-989,

[DOI: 10.24214/jcbps.C.7.4.97689]

  • Abstract

    Using the theoretical formalism of D N Basov and T Timusk [Rev Mod Phys 71, 721 (2005)], we have evaluated interlayer optical conductivity σ1 (ω) of single layer of two superconductors HgBa2CuO4+x (Hg-1201) (TC=97K) and Tl2Ba2CuO6+x (Tl-2201) (TC= 88K) at T=TC and double layer of two superconductors YBa2Cu3O6.95 (YBCO) (TC=90K) and Bi2Sr2CaCu2O8 (Bi- 2212) (TC=110K) at T<Tas a function of frequencyω. Our theoretically evaluated results show that σ1 (ω) increase and decrease with  for all these four superconductors at T=TC and also at T<TC. Our theoretically evaluated results are in reasonable agreement with the experimental data. Our theoretically obtained results of the reflectance R(ω) for superconductor YBa2Cu3O6.95 (TC=90K) as a function of frequency ω for three different temperature also reveal the similar behaviour. R(ω) also increase and decrease with ω for all temperature taken. Our theoretically evaluated results of doping dependence of super fluid density ωs, frequency position of c-axis response ω0 and dc conductivity σdc for superconductor YBa2Cu3Ox indicate that all these parameters decrease with decreasing doping concentration x. Our evaluated results are in good agreement with the experimental data and also with other theoretical workers. These evaluated results play a very important role in the electromagnetic response of high TC superconductors. These parameters represent intrinsic properties of CuO2 plane along with the genuine feature of the interlayer conductivity.