Vol. 8 & Issue 2 ; Section C : Physical Sciences

Date : Feb.2018 to April 2018

 

DSC and TGA Properties of PVA Films Filled with  Na2S2O3.5H2O Salt

Sabah A. Salman, Nabeel A. Bakr, Hudaa T. Homad,

JCBPS; Section C; February 2018 – April 2018, Vol. 8, No. 2; 001-011,

[DOI: 10.24214/jcbps.C.8.2.00111]

  • Abstract

    Pure and sodium thiosulphate pentahydrate (Na2S2O3.5H2O) salt filled polyvinyl alcohol (PVA) films with different concentrations of (2, 4, 6, 8, 10, 12, 14, and16 ) wt % were prepared by solution asting method to study the effect of this salt on thermal properties of (PVA) films by using Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). The DSC test showed that most of the samples filled with (Na2S2O3.5H2O) salt exhibit an increase in the glass transition temperature compared with pure PVA film, while melting point had unsystematic dependence on the (Na2S2O3.5H2O salt concentration compared with pure PVA film. Moreover, TGA curves indicated that the pure PVA film underwent two stages of thermal decomposition of the weight loss while (Na2S2O3.5H2O) salt filled PVA films had two and three stages of thermal decomposition of the weight loss process where the values of total weight loss of the films are lower compared with pure PVA film.

A theoretical study of Quantum well intermixing in GaInNAs/GaAs structure and evaluation of transition energies as a function of diffusion length and evaluation of dipole moments of TE and TM polarization as a function of wave vector A0-1.

Supriya Kumari, P. K. Verma and L. K. Mishra,

JCBPS; Section C; February 2018 – April - 2018, Vol. 8, No. 2; 012-025.

[DOI: 10.24214/jcbps.C.8.2.01225.]

  • Abstract

    Using the theoretical formalism of H D Sun etal [J. of Appl. Phys. 94, 7581 (2003)], A. Mika etal. [Optica Applicata Vol XLIII, No1 (2013)] and Y. N. Qiu etal. [Semicond. Sci. Technol. 23, 095010 (2008)], we have theoretically studied the effect of quantum well intermixing on the material gain of GaInNAs/GaAs quantum well. We have evaluated optical transition oscillator strength and square of the overlap integral as a function of photon energy. Our theoretically obtained results show that oscillator strength increases with photon energy whereas square of the overlap integral for two values of Qc (chemical band offset) increases and decreases with photon energy. Our theoretically evaluated results for optical transition energy for two transition E1-HH1 (electron and heavy-Hole transition) and E1-LH1 (electron and light Hole) increase with diffusion length and the results are in good agreement with the experimental data. Our obtained results of dipole moment indicate that with different diffusion lengths the wave function overlapping between electron and heavy/light Holes in terms of TE and TM modes are different. The calculation shows that with the increase of diffusion length the contribution from E1-LH1 transition to dipole moments of TE or TM modes are suppressed very quickly. For contribution to E1-HH1, TE mode decreases slowly but the dipole moment of TM mode increases slightly.The entire evaluation gives the effect of quantum well intermixing on the material gain of GaInNAs/GaAs quantum well. The evaluation confirms that the variation of material band gap and the degeneracy between heavy and light Holes are the main factors which determine the quantized energy levels of intermixed quantum well. These studies will be quite helpful in the design of integrated photonic devices based on this material.

Anharmonicity of Lattice Waves in Electronic Specific Heat of Materials at Very Low Temperature

P. Poddar, A.K. Sah, D.P. Singh & Murari Pd. Sinha,

JCBPS; Section C; February 2018 – April - 2018, Vol. 8, No. 2; 026-035.

[DOI: 10.24214/jcbps.C.8.2.02635.]

  • Abstract

    In this paper we discuss the role of anharmonicity of lattice waves in electronic specific heat of metals and insulators at very low temperatures. Previous researchers have revealed the anharmonicity of the lattice waves to cause deviation in specific heat from Debye T3 law. Different researchers have given different concepts of anharmonicity in electronic specific heat of metals at very low temperatures. The energy spectrum of phonons cannot be fully described by the Debye law. On the whole all reports dilute the contention of the electronic contribution to be responsible for linear temperature dependent component of specific heat of metals at very low temperatures. For anharmonicity of lattice waves this contribution must be expected for metals and insulators also.

Investigation of the interaction between vitamin C and vitamin B12 with human serum albumin using spectroscopic techniques

Husain Alsamamra, Ibrahim Hawwarin, Sawsan Abusharkh, Musa Abutier,

JCBPS; Section C; February 2018 – April - 2018, Vol. 8, No. 2; 036-53,

[DOI: 10.24214/jcbps.C.8.2.03653]

  • Abstract

    Vitamin C is an important regulatory for iron uptake and vitamin B12 is essential for proper functioning of folic acid. Human serum albumin is an abundant plasma protein, the major soluble protein constituent of the circulatory system and has many physiological functions including transport of a variety of compounds. In this work, the molecular interaction between vitamin C and B12 with human serum albumin was investigated using constant protein concentration and various drug concentrations at pH 7.4. Three different spectroscopic methods were used; fluorescence spectroscopy, UV absorption and FT-IR spectroscopy. From spectral analysis, both vitamins showed a strong ability to quench the intrinsic fluorescence of human serum albumin through a static quenching procedure.The binding constant (k) is estimated from UV-absorption as k=1.28×104 M-1 for HSA-Vitamin C and k=2.21×104 M-1 for HSA-vitamin B12. Both results showed a good agreement with the binding constants obtained from the modified Stern-Volmer equation using florescence technique. The appearance or disappearance of the bands is a good sign to understand the mechanisms at the molecular level. The FT-IR spectral changes indicates an increase of intensity for HSA-vitamin C interaction and a reduction of intensity for HSA-vitamin B12 interaction. For HSA-vitamin C complexes, positive features are related to increase in intensity of the amide I and II bands upon drug-complexation due to drug binding to protein C=O, C-N and N-H groups. While in the difference spectra of vitamin B12-HSA complexes, intensity decreases as the concentration of vitamin B12 increases for amide I band at 1656cm-1, and amid II band at 1544 cm-1, this results in stabilization by hydrogen bonding by having the C-N bond assuming partial double character due to a flow of electrons from the C=O to the C-N.

Synthesis of CoZnFe2O4 nanoparticles by microwave assisted combustion method and antibacterial properties

Falah M.Abdelhasan, Mukhlis M. Ismail, Nada S. Ahmade,

JCBPS; Section C; February 2018 – April - 2018, Vol. 8, No. 2; 054-067,

[DOI: 10.24214/jcbps.C.8.2.05467.]

  • Abstract

    In this research work, we have used a microwave combustion method to synthesize cobalt-zinc ferrite (Zn1_xCoxFe2O4) nanoparticles with four nanocrystalline ferrites including: Co1Fe2O4, Co0.9Zn0.1Fe2O4 , Co1.1Zn0.1Fe2O4 and Co 0.3Zn 0.7Fe2O4. Using urea and glycine as a fuel. The obtained ferrites were characterized studied by X-ray powder Diffraction (XRD), results showed that the material had cubic spinal structure. The experimental values of the lattice constant (aexp) were increased from 8.064 to 8.329 nm with the addition of zinc ions but it was decreased with increased cobalt ions. The theoretical values of the calculated lattice constant (ath) were found in a good agreement with the experimental results. It was found that the increased of the crystallite size with addition of zinc but after crystallite size (D) were decreased with increased zinc ion and decreased with decreased cobalt ion. Fourier transform infrared spectroscopy (FT-IR) measurement exhibit two absorption bands (ʋ1 and ʋ2) around 400-600 cm-1 which confirms the existence of tetrahedral and octahedral sites of ferrite. The antibacterial activities of the co-zn-ferrites were tested on Gram-negative bacterium: E. coli. The antibacterial results of the co-zn ferrites nanoparticle on microorganisms showed that the nanoparticles shows effect on the inhibitory growth of E. coli with high antibacterial effect on E. coli of 3.5 mm diameter of inhibition.

Absorption studies in dilute solutions of few amino acids at 662 keV gamma energy

T. Rajeshwari

JCBPS; Section C; February 2018 – April - 2018, Vol. 8, No. 2; 068-074

[DOI: 10.24214/jcbps.C.8.2.06874.]

  • Abstract

    The gamma absorption studies in dilute solutions of amino acids has been carried out using NaI(Tl) scintillation detector coupled with single channel analyzer at 662 keV gamma energy. The mass absorption coefficients of gamma radiation by dilute amino acid solutions are studied for 10 % concentration. The present study explored the validated exponential absorption law for gamma radiation in solutions. A comparison of experimental results with theoretical values revealed the validity of mixture rule. This study proved to be a base study for extension of applications towards investigating the purity of liquid samples and quality control of the liquid materials.

A theoretical evaluation of superfluid density of states (DOS) and pseudogap parameters in BCS-BEC crossover regime of a superfluid Fermi gas

Shipra Kumari, Pradhan Durga Shankar Prasad and L. K. Mishra

JCBPS; Section C; February 2018 – April - 2018, Vol. 8, No. 2; 075-91,

[DOI: 10.24214/jcbps.C.8.2.07591]

  • Abstract

    Using the theoretical formalism of Shunji Tsuchiya etal[Phys. Rev A80, 033613 (2009)], Ryota Watanabe etal [Phys. Rev. A82, 043630 (2010)] and Shunji Tsuchiya etal [Phys. Rev. A82, 033629 (2010)], we have theoretically studied the single-particle excitations and strong-coupling effect in the BCS-BEC crossover regime of a super fluid Fermi gas. We have evaluated super fluid order parameter Δ/ T and Fermi Chemical potential μ / Tas a function of (KFas )-1 the BCS-BEC crossover region. Our theoretically evaluated results show that super fluid order parameter decrease, attain minimum value and then increase as a function of in BCS-BEC region. But Fermi chemical potential crosses positive to negative value for the function -2<KFas )-1 >3 Our theoretically obtained results of pseudogap DOS [p(ω)/ mkF/2π2] ] as a function of ....................(kindly see the textin the article)