Papers

This study was carried out to develop a product from fonio, Digitaria iburua, and to evaluate the physical, chemical and sensory attributes of the developed product. Fonio grain was cleaned, steam cooked and drum dried to give a flaking roll. The thickness and the colour of the developed fonio meal was comparable to that of the commercial oat. Proximate composition of the meal indicated a moisture content of 9.02%; protein, 8.44%; fat, 1.49%; ash, 0.56%; carbohydrate, 80.66% and crude fibre, 0.71%. It was also high in calcium (8.14mg/100g), phosphorus (28.40mg/100g) and iron (10.74mg/100g). The amino acid profile was attractive having six of the essential amino acids: lysine (32.26mg/100g), threonine (11.95mg/100g), methionine (6.7mg/100g), leucine (38.89mg/100g), iso-leucine (17.21mg/100g) and tryptophan (4.53mg/100g). In sensory evaluation, the panellists rated the product better than commercial oat meal, but statistical analysis indicated that the difference between the meal and a commercial oat product was not significant (P>0.05).

Ultrasonic velocity measurements have been made in an anionic surfactant sodium laureyl sulphate (SLS) with Dextrin (Dx), Hydroxy ethyl cellulose (HEC) and Hydroxy Propyl cellulose (HPC) in ethanol solution as a function of concentration, at a fixed frequency (2MHz). SLS with different polymers are prepared and dissolved in different concentration ratio (1:9 to 9:1). Limiting parameters have been used to explain the salvation of surfactant-polymer molecules.

Due to layered structure, the electronic conduction in high-T_c cuprate superconductors is highly anisotropic. Therefore, in the present work, we have made an attempt to study the anisotropy in supercurrent density in layered cuprate superconductors likeYBa₂Cu₃O_6+x. We have considered tight binding bilayered Hubbard Hamiltonian. The situation considered here for the bilayered cuprates is similar to a SIS junction. Using Green function technique, we have got the expressions for superconducting order parameters, carrier density and supercurrent densities.The numerical analysis shows that the anisotropy in supercurrent density depends on the temperature and various other microscopic parameters of the model Hamiltonian. The anisotropy in supercurrent density increases with temperature and diverges as system reaches towards the superconducting transition temperature. On increasing the carrier density within the plane, the anisotropy in supercurrent density decreases because around optimal doping region, bilayer system(YBaCuO) behaves like almost isotropic three dimensional superconductors. On increasing the interlayer attractive interaction, the anisotropy in supercurrent density decreases. It is also shown that when interlayer attractive interaction (W) is just equal to the intralayer pairing interaction (U), the anisotropy in supercurrent density vanishes i.e. the bilayer Quasi-2D system becomes almost isotropic(three dimensional) in supercurrent flow in the superconducting state. We have shown, using tight binding bilayer Hubbard model within BCS meanfield formalism, that the anisotropy in supercurrent density depend on various microscopic intra and interlayer interactions as well as on the thermodynamics of superconducting order parameter in an essential way. Finally we have compared our theoretical results of anisotropy in supercurrent density with the existing experimental findings in bilayered cuprate superconductors.

PACS: 74.50.+r, 74.72.Bk, 74.81.Fa.

Qualitative analysis of two-stage Darlington pair amplifier is carried out. Enhancement in voltage and current gain is observed with distinct behaviour of bandwidth. This two-stage amplifier may be quite useful for amplification of small signals of mili-volts range and suitable for various analog electronics and communication applications.

Geologically, Iran is the land of faults. Except in northern part, the Iran is an arid region and for the centuries the Iranians selected the place of springs for living and village or city establishing. But most of these places are fault-related and faults supply the groundwaters. There are different geohazards in Iran that are in relation with faults: 1- Earthquake, 2- Ophiolites and asbestos minerals, 3- Radioactive, toxic, and heavy metal elements mineralization, 4- Radon and CO₂ releasing.

We show that the optical binding between dielectric particles through millimeter wave propagation at 30-50 GHz having bulk mixture of two dielectric bodies at different sizes. We suppose the dielectric particles having dimensionless than the wavelength of the interacting light under millimeter wave propagation. An optimum increase in binding energy was noted for all cases. This study further indicates the suitability of this technique for construction of two or three-dimensional arrangement of objects. The observed dependence of the separation of optically bond particles on millimeter wave propagation is in good agreement with earliest theoretical predictions.

Kinetics of oxidation of mixture of glycine + anthranilic acid by chromic acid in presence of sulphuric acid have been studied. The probable products are benzoic acid, formaldehyde, ammonia and carbon dioxide. The rate of oxidation increase with increase in the concentration of sulphuric acid. Ostwald isolation method is used for study the rate of the reaction. The rate of reaction with respect to hydrogen ion is one. Kinetics of oxidation of mixture of glycine + anthranilic acid by chromic acid shows first order reaction. The kinetic parameters such as energy of activation, catalytic constant, temperature coefficient are calculated.

Using the theoretical model developed by Ya. M. Blanter et. al. (Nuovo Cemento 12, 1900 (1900). We have studied the giant oscillations of thermoelectric power of the normal metal in the presence of magnetic field. This is achieved because of electronic topological transition (EET). Our theoretically evaluated result indicates the anharmonical behaviour of the thermoelectric power in the region .

The effects of chemical reaction on transient MHD free convection and mass transfer flow of dissipative fluid past an infinite vertical porous isothermal plate in the presence of heat generation, thermal diffusion and viscous dissipation is studied numerically. The Problem is governed by a coupled nonlinear system of partial differential equations. This system is solved numerically by applying explicit finite difference method. The effect of chemical reaction parameter (K) in the presence of Heat generation parameter (H) and Soret number (S₀) is examined on Velocity, Temperature and Concentration. The numerical values of the skin friction, the rate of heat transfer and the rate of mass transfer are entered in tables. It is found that chemical reaction parameter K decreases velocity and concentration in the presence or no presence of Heat source parameter H and Soret number S₀. Further, it has no effect on temperature.

Kinetic phenomena in the vicinity of electronic topological transition predicted by Lifshitz have been widely studied both theoretically and experimentally. Using one electron Green's function in the framework of temperature diagrammatic technique developed by Ya. M. Blantr et. al. Nuovo Cimento vol. 12, 1900 (1990), we have studied the relaxation time for EET transition. Our result shows that there is an influence of magnetic field of EET relaxation time .