Deen Dayal Upadhyay Gorakhpur University

About: Deen Dayal Upadhyay Gorakhpur University is a education organization based out in Gorakhpur, Uttar Pradesh, India. It is known for research contribution in the topics: Thermal decomposition & Lymnaea acuminata. The organization has 1032 authors who have published 1591 publications receiving 21734 citations. The organization is also known as: Gorakhpur University.

Production, purification and biochemical characterization of an exo-polygalacturonase from Aspergillus niger MTCC 478 suitable for clarification of orange juice

Abstract: Polygalacturonases (PG) represent an important member of pectinases group of enzymes with immense industrial applications A fungal strain Aspergillus niger MTCC478 was used for the production of polygalacturonase both under submerged and solid-state fermentation condition Further its production was optimized under solid-state fermentation condition with media comprising of wheat bran and tea extract Purification of an exo-PG was achieved by acetone precipitation (60–90%) and CM-cellulose column chromatography revealing 1528-fold purification with a specific activity of 3347 U/mg protein and 12% yield A relative molecular mass of purified PG was approximately 1240 kDa The pH and temperature optimum was found to be 4 and 50 °C, respectively The k cat and K m value for degradation of PGA by the purified enzyme was found to be 194 s−1 and 23 mg/mL, respectively Cu2+ was found to enhance the PG activity while Ag+ completely inhibited the enzyme activity The application of the purified PG in orange juice clarification was elucidated

Self-similar analytical solutions for blast waves in inhomogeneous atmospheres with frozen-in-magnetic field

Abstract: In the present paper, we have made an attempt to study the effects of the presence of a magnetic field on the cavity formation inside a blast wave propagating into a perfectly conducting gas with density varying as some power of distance from the plane or line of explosion. In order to obtain the closed form solutions for the flow variables inside the blast wave and to solve the problem of cavity formation analytically, a relation is taken between the ordinary pressure and the total pressure. It i s found that if the value of the inhomogeneity index $\alpha$ is greater than a critical value $\alpha_c$ (a function of MA - Alfven Mach Number, $\gamma$ - adiabatic index and i - wave geometry index), a contact discontinuity appears at some point inside the blast wave and the cavity formation occurs. The effect of the presence of magnetic field is found to increase the tendency of cavity formation.

Propagation of shock waves in a dusty gas with heat conduction, radiation heat flux and exponentially varying density

Abstract: The propagation of shock waves in a dusty gas with heat conduction and radiation heat flux, in which density varies exponentially, is investigated. The dusty gas is assumed to be a mixture of small solid particles and a perfect gas. The equilibrium flow conditions are assumed to be maintained, and the heat conduction is expressed in terms of Fourier's law and the radiation is considered to be of the diffusion type for an optically thick grey gas model. The thermal conductivity K and the absorption coefficient ?R are assumed to vary with temperature and density. The shock wave moves with variable velocity and the total energy of the wave is non-constant. Non-similar solutions are obtained and the effects of variation of the heat transfer parameters and time are investigated. The effects of an increase in (i) the mass concentration of solid particles in the mixture and (ii) the ratio of the density of solid particles to the initial density of the gas on the flow variables in the region behind the shock are also investigated at given times.

Preparation, X-ray crystallography, and thermal decomposition of some transition metal perchlorate complexes of hexamethylenetetramine.

Abstract: The perchlorate complexes of manganese, nickel, and zinc with hexamethylenetetramine (HMTA) of the general formula [M(H2O−HMTA−H2O)2(H2O−ClO4)2(H2O)2] (where M = Mn, Ni, and Zn) have been prepared and characterized by X-ray crystallography. Thermal studies were undertaken using thermogravimetry (TG), differential thermal analysis (DTA), and explosion delay (DE) measurements. The kinetics of thermal decomposition of these complexes was investigated using isothermal TG data by applying isoconversional method. The decomposition pathways of the complexes have also been proposed. These were found to explode when subjected to higher temperatures.