Showing papers by "Narula Institute of Technology published in 2007"

Biooxidation of Fatty Acid Distillates to Dibasic Acids by a Mutant of Candida tropicalis

Abstract: Fatty acid distillates (FADs) produced during physical refining of vegetable oil contains large amount of free fatty acid. A mutant of Candida tropicalis (M20) obtained after several stages of UV mutation are utilized to produce dicarboxylic acids (DCAs) from the fatty acid distillates of rice bran, soybean, coconut, palm kernel and palm oil. Initially, fermentation study was carried out in shake flasks for 144 h. Products were isolated and identified by GLC analysis. Finally, fermentation was carried out in a 2 L jar fermenter, which yielded 62 g/L and 48 g/L of total dibasic acids from rice bran oil fatty acid distillate and coconut oil fatty acid distillate respectively. FADs can be effectively utilized to produce DCAs of various chain lengths by biooxidation process.

A novel investigation on size reduction of a frequency selective surface

Abstract: The study presents theoretical and experimental investigation of a novel, reduced size Microstrip Frequency Selective Surface The novel design is achieved by cutting some rectangular slots at four sides of a square patch Compared with conventional square patch Frequency Selective Surface (FSS), this slotted square patch Microstrip FSS can achieve reduction in patch area of 36% The structure acts like a band pass filter with a resonant frequency 8 GHz Both theoretical and experimental investigations are done Theoretical investigation is done by IE3D software Experimental investigation is performed using standard microwave test bench © 2007 Wiley Periodicals, Inc Microwave Opt Technol Lett 49: 2820–2821, 2007; Published online in Wiley InterScience (wwwintersciencewileycom) DOI 101002/mop22833

MHD instability due to non-homogeneity and non-uniformity of magnetic field in gravitating medium and its consequences in the central region of galaxies

Abstract: The MHD wave instabilities due to non-uniform magnetic field and non-homogeneity of density have been studied. The reference (coordinate) system considered here is cylindrical type. The General Dispersion Relation (GDR) for the wave propagation in a gravitating but non-relativistic region has been derived. Similar to common knowledge, the said non-uniformities have been found to be responsible for the instability of the system. But interestingly many instability factors are produced due to presence of two types of non-uniformities simultaneously. This theory may add more clues for the event of instabilities, formation of hot plasma-bed in Galactic Central Region, and mass out-flow from there. Many conditions for instabilities could be obtained from GDR deduced here. However, a few conditions for critical wavelength of the MHD wave have been obtained in terms of system parameters (like gradient of magnetic field and rotation).