Vol. 6 & Issue 4 ; Section C : Physical Sciences

Date : Aug. to Oct.2016

 

Effect of pyridoxine hydrochloride on copper corrosion in 1M HNO3

M A Tigori, P M Niamien, A J Yapo, A Trokourey

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    The inhibitive action of pyridoxine hydrochloride (PHC) on copper corrosion in 1M HNO3 medium has been studied using mass loss technique and quantum chemical methods based on Density Functional Theory (DFT). The gravimetric study has been achieved in the interval temperature of 308-328K and in the concentration range of 0.13 mM to 0.53 mM. Mass loss and inhibition efficiency were found to be concentration and temperature dependent. Adsorption isotherms including Langmuir, Freundlich and Flory Huggins models were used to fit the adsorption behavior of pyridoxine but the results showed that it adsorbs on copper according to the Langmuir modified adsorption isotherm. The thermodynamic functions(Δads,Hºads, ΔSºads) related to the adsorption phenomenon of pyridoxine and the activation ones (EαHαSα) were determined and discussed. They revealed a spontaneous adsorption and an endothermic activation process. DFT at B3LYP level with 6-31G (d) and LanL2DZ basis sets was used to determine molecular parameters correlated to the inhibition efficiency such as EHOMO(highest occupied molecular orbital energy), ELUMO (lowest unoccupied molecular orbital energy), the energy gap (ΔE), hardness (n), softness (S), dipole moment (μ), electron affinity (A), ionization potential (I), the absolute electronegativity (χ), the fraction of electrons transferred (ΔN) and the electrophilicity index (ω).The local selectivity has been analyzed through the condensed Fukui function and condensed softness indices in order to determine the possible sites for nucleophilic and electrophilic attacks.

Assessment of Beam Quality in Some Radio Diagnostic Centers.

Sehad Kadiri, Gezim Hodolli, Gazmend Nafezi, and Konstandin Dollani.

  • Abstract

    In general, ionizing radiation and in particular X-rays plays a very important role in medical examinations for diagnostic purposes. The rapid growth of the number of procedures for diagnostic reason in medicine as a result led to increase the number of equipment for X ray generation, which consequently has increased the patients dose and in the same time is increased the risk of malignant diseases. Measurement parameters of quality assessment for X radiation generators are done at nine different diagnostic centers of public sector in Kosovo during the period 2014-2015. Measurements consist on accuracy of tube voltage, reproducibility of output voltage, total filtration of the x-ray tube and delivered radiation dose. Measurements were performed using Multimeter PTW NOMEX and DAP (Dose Area Product) Meter PTW Diamentor CM.

Energy Content of Cinnamic Acid Derivatives Found in Coffee Bean by Combustion Calorimetry

E. Adriana Camarillo, Henoc Flores, Omar Santiago

  • Abstract

    The determination of the energy content of pure compounds found in foods is an important part of many investigations on nutrition. The present work describes the determination of the energy  content of some derivatives of cinnamic acid, i.e., 3,4- dihydroxycinnamic acid, 3,4-dihydroxyhy -drocinnamic acid, and 2,4-dihydroxycinnamic acid, found in coffee bean, carried out by means of a static bomb combustion calorimeter and under an oxygen atmosphere. The values of the energy content per mass found for these compounds were Δo μ°= (-21.8692±0.0051) kJ·g-1, (-22. 7047  ± 0.0025) kJ·g-1, and (-21.7782 ± 0.0025) kJ·g-1, respectively. According to the values obtained, the compounds release energy in order as follows: 2,4-dihydroxycinnamic acid < 3,4-dihydroxycinnamic acid < 3,4-dihydroxyhydrocinnamic acid.

Hydromagnetic Axisymmetric Stagnation Point Flow of a Reiner-Rivlin Fluid towards a Moving Plate

B. Alanbel Ersin and S. Barış

  • Abstract

    This study is concerned with the axisymmetric stagnation point flow of a Reiner-Rivlin fluid towards an infinite plate moving parallel to itself with constant velocity in the presence of a transverse uniform magnetic field. The governing partial differential equations were converted into ordinary nonlinear differential equations using similarity transformations available in the literature. It was found that the crossviscous and magnetic effects depend on two non-dimensional numbers S and M respectively. We employed the Matlab routine bvp4c to obtain numerical solutions of the problem under consideration. The effects of controlling parameters on the dimensionless velocity temperature, wall shear stress and heat transfer rate were analyzed and discussed through graphs and tables. 

Effect of Magnetic Field and Suspended Particles on Micropolar Fluid Heated and Soluted from
Below Saturating Porous Medium

Sumit Gupta and Veena Sharma

  • Abstract

    This paper deals with the convection of micropolar fluids heated and soluted from below in the presence of suspended particles (fine dust) and uniform vertical magnetic field Η(0,0,H)in a porous medium and using the Boussinesq approximation, the linearized stability theory and normal mode analysis, the exact solutions are obtained for the case of two free boundaries. It is found that the presence of the suspended particles number density, the magnetic field intensity, stable solute  parameter and medium permeability bring oscillatory modes which were non–existent in their absence. It is found that the presence of coupling between thermal and micropolar effects, magnetic field intensity, solute parameter and suspended particles may introduce overstability in the system. Graphs have been plotted by giving numerical values to the parameters accounting for magnetic field intensity Η(0,0,H) solute parameter, the dynamic microrotation viscosity Κ and coefficient of angular viscosity γ' to depict the stability characteristics, for both the cases of stationary convection and overstability. It is found that Rayleigh number for the case of overstability and stationary convection increases with increase in magnetic field intensity, solute parameter and decreases with increase in micropolar coefficients and medium permeability, for a fixed wave number, implying thereby the stabilizing effect of magnetic field intensity, solute parameter and destabilizing effect of micropolar coefficients and medium permeability on the thermosolutal convection of micropolar fluids.

Viscometric Study of Substituted 2-oxo-2-H-chromene-3-carbohydrazide Derivatives in 70% DMF- Water at Different Temperature

P. P. Choudhari, D. S. Hedaoo, M. P. Wadekar

  • Abstract

    Density and viscometric measurements of substituted 2-oxo-2-H-chromene-3-carbohydrazide derivatives in binary mixture of 70% DMF-water are performed. The data obtained is analyzed by Jones-Dole empirical equation. Determination of thermodynamic parameters Gibbs free energy change (ΔG), enthalpy change (ΔH) and entropy change (ΔS) is done. The solute-solute, solute-solvent and solvent-solvent interactions are studied.

Electrochemical Reduction of Hexavalent Chromium from Chemical Oxygen Demand Hazardous Waste Chemicals using Graphite Electrode

Jemborn D. Igcalinos and Ronnie L. Besagas

  • Abstract

    The removal of hexavalent chromium, Cr (VI), from highly acidic, essentially nonaqueous laboratory waste by electrochemical reduction was studied using graphite electrode. This study evaluated the effectiveness of graphite electrode to electrochemically reduce the unreduced Cr (VI) in the hazardous spent chemical oxygen demand (COD) reagent to trivalent chromium. The effect of four factors were investigated in the experiment which are the initial Cr (VI) concentration ([Cr6+]0, 1/2[Cr6+]0, and 1/4[Cr6+]0), the initial acidity of the COD spent chemicals ([Acidity]0, 1/2[Acidity]0 and 1/4[Acidity]0), applied electric current (0A, 1A, and 6A), and reaction time. The voltage, type and size of graphite of electrodes were held constant. The result shows that the varied factors significantly affect the effectiveness of graphite electrode in reducing Cr (VI) to Cr (III). Optimum reduction of 100% is attained at the following conditions: maximum Cr (VI) concentration in spent reagent (i.e. at [Cr6+]0), 1/4[Acidity]0, and with 6 ampere of electric current for reaction time of 2.5 hours. However, total removal of Cr (VI) can still be achieved even if the acidity is not lowered that is maintaining it at [Acidity]0.

Preparation and Study of Some Optical Properties of (PVA-FeCl3) Composites Films

Sabah A. Salman, Asaad A. Kamil, Maysam A. R. Iesa

  • Abstract

    The pure films of polymer (polyvinyl alcohol (PVA)) and doped then with have )wt. %) (1, 3, 5, 7 and 9(ations salt with different concentr FeCl3 chloride ironbeen prepared by using casting technique. The optical properties of pure and doped films were studied. The transmission and absorption spectra have been recorded in )(PVA-FeCl3 The experimental results of 1100) nm.-(250the wavelength range composite film show that the transmittance decreases with increasing the filler content while the absorbance increases with increasing the filler content. The absorption coefficient, refractive index, extinction coefficient and real and imaginary parts of dielectric constant were found to increase with increasing the filler content. Moreover, the results show that the electronic transitions are allowed indirect transitions, the energy gap (Eg) and Urbach energy (Eu) decreases with increasing the filler content

Synthesis of α-Fe2O3, γ-Fe2O3 and Fe3O4 Nanoparticles by Electrochemical Method

Hussain I. Abdulah, Dhia H. Hussain, Ahmed M. Rheima

  • Abstract

    Different phases of iron oxides nanoparticles have been synthesized by electrochemical method using iron plate as anode with various materials as cathode and aqueous solutions electrolyte. The synthesized nanoparticles characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV visible spectroscopy. Results shows that α-Fe2O3 nanoparticles have uniform rhombohedra shape with an average size of 25 to 42 nm and γ-Fe2O3 nanoparticles have tetragonal shape with an average size of 19 to 36 nm and Fe3O4 nanoparticles have cubic shape with an average size of 26 to 40 nm by different techniques.

Determination of Mass Attenuation Coefficient and Water Content of Fruit leaves Using Beta Attenuation

Chetna Sood, Parveen Bala and Amandeep Sharma

  • Abstract

    The objective of present work is to determination mass attenuation coefficient and water content of fruit leaves of Guava and Papaya using beta transmission technique. The radioisotopes 204Tl and 60Co with end point energies 0.777 MeV and 0.319 MeV respectively are used as beta emitters. The Geiger Muller Counter is used as detector for the beta attenuation measurement of leaf samples. The measured value of mass attenuation coefficient agrees well with that calculated from statistical regression method. Also, the percentage water content values are determined using beta attenuation and found to be in close agreement with direct weighing. For all the fitted curves, the adjusted R2 lies in the range of 0.96 to 0.98 thereby justifying the linear dependence of transmitted intensity on water content, which is significant (p < 0.001). The beta attenuation method is non-destructive, easy to handle and can be done on intact planted leaves.

Ultrasonic Study of Substituted 2-oxo-2H-chromene-3 carbohydrazide Derivatives in 70% DMF-Water

P. P. Choudhari, A. V. Ingale, M. P. Wadekar

  • Abstract

    Ultrasonic study of substituted 2-oxo-2H-chromene-3-carbohydrazide derivatives in 70% DMF- ater at 305K is done. The experimental data is used to calculate intermolecular free length (Lf), specific acoustic impedance (Z) and relative association (RA). These acoustic parameters are used to xplain the interaction between the solute and solvent.

Variations of Entropy and Enthalpy with acoustic parameters of L-Serine in aqueous NaI solutions

V. A. Giratkar, R. B. Lanjewar and S. M. Gadegone

  • Abstract

    The ultrasonic velocity (u), density (ρ) and viscosity (η) of L-Serine of various concentration in 2% of NaI solutions have been investigated at different temperatures. From these experimentally determined parameters acoustic parameters such as acoustic impedance, Rao constant, Wada constant, enthalpy and entropy have been calculated.

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