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ISSN: 2333-9721




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匹配条件: “S. K. Mukhopadhyay” ,找到相关结果约422916条。
Effect of rotation and relaxation times on plane waves in generalized thermo-visco-elasticity
S. K. Roychoudhuri,Santwana Mukhopadhyay
International Journal of Mathematics and Mathematical Sciences , 2000, DOI: 10.1155/s0161171200001356
Abstract: The generalized dynamical theory of thermo-elasticity proposed by Green and Lindsay is applied to study the propagation of harmonically time-dependent thermo-visco-elastic plane waves of assigned frequency in an infinite visco-elastic solid of Kelvin-Voigt type, when the entire medium rotates with a uniform angular velocity. A more general dispersion equation is deduced to determine the effects of rotation, visco-elasticity, and relaxation time on the phase-velocity of the coupled waves. The solutions for the phase velocity and attenuation coefficient are obtained for small thermo-elastic couplings by the perturbation technique. Taking an appropriate material, the numerical values of the phase velocity of the waves are computed and the results are shown graphically to illustrate the problem.
L-Tryptophan Production by Auxotrophic and Analogue Resistant Mutants of Aureobacterium flavescens
A. Roy and S.K. Mukhopadhyay
International Journal of Tryptophan Research , 2012, DOI: 10.4137/IJTR.S5984
Abstract: A number of tyrosine plus phenylalanine double auxotrophic mutants were isolated by N-methyl-N-nitro-N-nitrosoguanidine (MNNG) treatment of a locally isolated strain of Aureobacterium flavescens of which 11A39 and 11A17 were selected on the basis of their tryptophan production in a mineral salt medium over other isolated mutant strains. The mutational block in the aromatic amino acid biosynthetic pathway of the selected double auxotrophs were determined. By controlling pH of the production medium to near neutrality, the active growth period could be extended up to 72 h and more tryptophan was accumulated compared to pH unregulated culture where the active growth ceased after 48 h. Further improvement of the tryptophan production has been achieved by stepwise isolation of a mutant strain resistant to the tryptophan analogues p-fluorotryptophan (FT) and 5-methyl tryptophan (MT) from the 11A39. Demand for L-tryptophan as food additive and therapeutic agent is increasing day by day throughout the World, particularly in the underdeveloped and developing countries like India. Still to date India depends on other countries for L-tryptophan. The aim of this work is to develop a potent high yielding, feed back insensitive mutant strain and optimization of its medium pH for maximum production of tryptophan.
Magneto-thermoelastic waves induced by a thermal shock in a finitely conducting elastic half space
S. K. Roychoudhuri,Santwana Banerjee (Mukhopadhyay)
International Journal of Mathematics and Mathematical Sciences , 1996, DOI: 10.1155/s0161171296000208
Abstract: The propagation of magneto-thermoelastic disturbances produced by a thermal shock in a finitely conducting elastic half-space in contact with vacuum is investigated. The boundary of the half-space is subjected to a normal load. Lord-Shulman theory of thermoelasticity [1] is used to account for the interaction between the elastic and thermal fields. Laplace transform on time is used to obtain the short-time approximations of the solutions because of the short duration of 'second sound' effects. It is found that in the half-space the displacement is continuous at the modified dilational and thermal wavefronts, whereas the perturbed magnetic field, stress and the temperature suffer discontinuities at these locations. The perturbed magnetic field, is, however, discontinuous at the Alf'ven-acoustic wavefront in vacuum.
MTHFR gene polymorphisms analyzed in population from Kolkata, West Bengal
Mukhopadhyay K,Dutta S,Das Bhomik
Indian Journal of Human Genetics , 2007,
International Journal of Agriculture Sciences , 2012,
Abstract: The physicochemical properties of soil (0-0.20 m) were analysed to evaluate the characteristics of tea growing soils under three different locations of West Bengal (India), considering the age and elevation of tea plantation. The soil samples of Dooars and Terai region of West Bengal were collected on the basis of age (young, medium and old) of the tea plants, while that from Darjeeling region as organic and non-organic tea growing soils. The organic and non-organic tea soils were collected on the basis of elevations of the sites. The soils of the Dooars region were clay to sandy loam in texture whereas, soils of Terai and Darjeeling were sandy loam in texture. The selected soils were strong to moderately acidic in reaction with low electrical conductivity (EC), Ca+2 and Mg+2 content. The organic carbon content of different regions was found medium to high, but very little variation was obtained with organic tea growing regions of Darjeeling. The soil available N and P content were low to medium in all the regions but higher available K content were found with the soils of Dooars and Terai regions. The cation exchange capacity (CEC) of soils varied from low to medium. The correlation study indicated that CEC, available N and K were influenced by soil organic carbon content, while the available P, Ca+2 and Mg+2 content by the soil pH. The available N, K, EC and CEC were negatively influenced by sand content of the soils.
L-Tryptophan Production by Auxotrophic and Analogue Resistant Mutants of Aureobacterium flavescens
A. Roy,S.K. Mukhopadhyay
International Journal of Tryptophan Research , 2011,
Dynamic elastic properties and magnetic susceptibility across the austenite-martensite transformation in site-disordered ferromagnetic Ni-Fe-Al alloy
P. K. Mukhopadhyay,S. N. Kaul
Physics , 2007, DOI: 10.1063/1.2896649
Abstract: Besides permitting an accurate determination of the ferromagnetic-to-paramagnetic phase transition temperature and the characteristic temperatures for the beginning and end of the growth of martensite (austenite) phase at the expense of austenite (martensite) phase while cooling (heating), the results of an extensive ac susceptibility, sound velocity and internal friction investigation of the thermoelastic martensitic transformation in melt-quenched (site-disordered) Ni55Fe20Al25 alloy provide a clear experimental evidence for the following. Irreversible thermoelastic changes (thermal hysteresis) occur in the austenite phase in the premartensitic regime. In the heating cycle, the system retains the "memory" of the initiation and subsequent growth of the martensitic phase (at the expense of the parent austenite phase) that had taken place during the cooling cycle in the austenite-martensite phase coexistence region. We report and discuss these novel findings in this communication.
Backcross Breeding and Directional Selection of Two Multivoltines, N+p and Np of Silkworm, Bombyx mori L. for Higher Viability and Productivity in Eastern India
T. K. Mukhopadhyay,S. S. Bhattacharya,J. K. Kundu
Journal of Entomology and Zoology Studies , 2013,
Abstract: A new superior multivoltine breed of Bombyx mori L. (D+p) has been developed by crossing between two strains of Nistari Plain (Np) and Nistari Marked (N+p) which are the two most preferred strains of multivoltine breed at the farmer’s level of eastern India. Through standard breeding plan this needbased new breed, D+p was developed by adopting three steps: i) Development of Recurrent Backcross Line through backcross breeding for initial eight generations; ii) Improvement of developed RBL following directional selection process for the next twenty generations and ultimately iii) stabilization for next eight generations upto F40 generation at normal environmental conditions. Study of nine quantitative characters related to viability and productivity of the new breed in relation to its parents have been studied statistically and Heterosis%.
Status of lymphatic filariasis in parts of East Godavari district of Andhra Pradesh, India
A.K. Mukhopadhyay; S.K. Patnaik ; Satya Babu
Journal of Vector Borne Diseases , 2007,
Effect of mass drug administration programme on microfilaria carriers in East Godavari district of Andhra Pradesh
A.K. Mukhopadhyay ; S.K. Patnaik
Journal of Vector Borne Diseases , 2007,

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