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An analytical study of linear and non-linear convection in Boussinesq-Stokes suspensions
The Rayleigh-Benard situation in Boussinesq-Stokes suspensions is investigated using both linear and non-linear stability analyses. The linear and non-linear analyses are based on a normal mode solution and minimal representation of double Fourier series, respectively. The effect of suspended particles on convection is delineated against the background of the results of the clean fluid. The realm of non-linear convection warrants the quantification of heat transfer and this has been achieved on the Rayleigh-Nusselt plane. Possibility of aperiodic convection is discussed. 2003 Elsevier Science Ltd. All rights reserved. -
Study of 1s internal bremsstrahlung spectrum from 57Co
The internal bremsstrahlung contribution from the electron capture of 57Co has been measured in coincidence with K-X-ray of the residual atom. The end-point energy (EPE) is extracted from the data using the linearised Jauch plot. The transition energy obtained using the (EPE) is 842.7keV, which is close to the value given by Audi and Wapstra. The measured intensity and shape factor from 300 to 600keV are found to be in good agreement with the Glauber and Martin theory. 2002 Elsevier Science Ltd. All rights reserved. -
Unique helical conformation of the fourth cytoplasmic loop of the CB1 cannabinoid receptor in a negatively charged environment
The proximal portion of the C-terminus of the CB1 cannabinoid receptor is a primary determinant for G-protein activation. A 17 residue proximal C-terminal peptide (rodent CB1 401-417), the intracellular loop 4 (IL4) peptide, mimicked the receptor's G-protein activation domain. Because of the importance of the cationic amino acids to G-protein activation, the three-dimensional structure of the IL4 peptide in a negatively charged sodium dodecyl sulfate (SDS) micellar environment has been studied by two-dimensional proton nuclear magnetic resonance (2D 1H NMR) spectroscopy and distance geometry calculations. Unambiguous proton NMR assignments were carried out with the aid of correlation spectroscopy (DQF-COSY and TOCSY) and nuclear Overhauser effect spectroscopy (NOESY and ROESY) experiments. The distance constraints were used in torsion angle dynamics algorithm for NMR applications (DYANA) to generate a family of structures which were refined using restrained energy minimization and dynamics. In water, the IL4 peptide prefers an extended conformation, whereas in SDS micelles, 310-helical conformation is induced. The predominance of 310-helical domain structure in SDS represents a unique difference compared with structure in alternative environments, which can significantly impact global electrostatic surface potential on the cytoplasmic surface of the CB1 receptor and might influence the signal to the G-proteins. 2007 Elsevier Inc. All rights reserved. -
Effect of temperature/gravity modulation on the onset of magneto-convection in electrically conducting fluids with internal angular momentum
The effect of time-periodic temperature/gravity modulation on the onset of magneto-convection in electrically conducting fluids with internal angular momentum is investigated by making a linear stability analysis. The results of the present study are presented against the background of the results of weak electrically conducting fluids. The qualitative findings of Siddheshwar and Pranesh are found to be true in the present case also except that the eigenvalue is found to be magnitudewise less than that obtained in the case of a weak electrically conducting fluid. -
Growth of some urinary crystals and studies on inhibitors and promoters. II. X-ray studies and inhibitory or promotery role of some substances
Best conditions were established for the gel growth of three urinary crystals viz., calcium oxalate monohydrate, calcium hydrogen phosphate dihydrate and ammonium magnesium phosphate hexahydrate. The crystals grown were characterized using single crystal X-ray diffraction techniques and density measurements. Crystal growth experiments were carried out by incorporating the extracts or juices of some natural products in the gel media. By carefully observing the changes in the growth of crystals (compared to control experiments carried out at the same conditions), results about the inhibitory or promotery role of the substance incorporated were obtained. It was found that the extracts or juices of many of the naturally occurring substances have interesting inhibitory or promotery effects. These results may have useful applications in the treatment of recurrent stone patients. -
Magnetoconvection in a micropolar fluid
The problem of Rayleigh-Bard convection in an electrically conducting micropolar fluid layer permeated by a uniform, vertical magnetic field is investigated with free-free, isothermal, spin-vanishing boundaries. The influence of the various micropolar fluid parameters and magnetic field on the onset of stationary convection has been analysed. It is observed that the electrically conducting micropolar fluid layer heated from below is more stable as compared with the classical electrically conducting Newtonian fluid. The critical wave number is found to be insensitive to the changes in the micropolar fluid parameters, but sensitive to the Chandrasekhar number. 1998 Elsevier Science Ltd. All rights reserved. -
Suction-injection effects on the onset of Rayleigh-Bard-Marangoni convection in a fluid with suspended particles
The effect of Suction-Injection-Combination (SIC) on the linear stability of Rayleigh-Bard Marangoni convection in a horizontal layer of an Boussinesq fluid with suspended particles confined between an upper free adiabatic boundary and a lower rigid isothermal/adiabatic boundary is considered. The Rayleigh-Ritz technique is used to obtain the eigenvalues. The influence of various parameters on the onset of convection has been analysed. It is found that the effect of Prandtl number on the stability of the system is dependent on the SIC being pro-gravity or anti-gravity. A similar Pre-sensitivity is found in respect of the critical wave number. It is observed that the fluid layer with suspended particles heated from below is more stable compared to the classical fluid layer without suspended particles. The problem has possible applications in microgravity situations. -
Assault on religion from modern behavioural and natural sciences
[No abstract available] -
Effect of temperature/gravity modulation on the onset of magneto-convection in weak electrically conducting fluids with internal angular momentum
The effect of time-periodic temperature/gravity modulation at the onset of magneto-convection in weak electrically conducting fluids with internal angular momentum is investigated by making a linear stability analysis. The Venezian approach is adopted in arriving at the critical Rayleigh and wave numbers for small amplitude temperature/gravity modulation. The temperature modulation is shown to give rise to sub-critical motion and gravity modulation leads to delayed convection. An asymptotic analysis is also presented for small and large frequencies. 1999 Elsevier Science B.V. -
Impact of people management practices on organizational performance: Analysis of a causal model
Although researchers in strategic human resource management have established a relationship between HRM practices and organizational performance, the intervening process connecting HRM system and organizational performance remains unexplored. This paper, based on a study on Indian software companies, is an attempt to develop and test a causal model linking HRM with organizational performance through an intervening process. The study has found that not even a single HRM practice has direct causal connection with organizational financial performance. At the same time, it has been found that each and every HRM practice under study has an indirect influence on the operational and financial performance of the organization. Further, HRM practices such as training, job design, compensation and incentives directly affect the operational performance parameters, viz., employee retention, employee productivity, product quality, speed of delivery and operating cost. -
Effects of suction-injection-combination (SIC) on the onset of Rayleigh-Benard magnetoconvection in a micropolar fluid
The effects of suction-injection-combination (SIC) and magnetic field on the linear stability analysis of Rayleigh-Benard convection in a horizontal layer of an Boussinesq micropolar fluid is studied using a Rayleigh-Ritz techinque. The eigenvalues are obtained for free-free, rigid-free and rigid-rigid velocity boundary combinations with isothermal and adiabatic temperature conditions on the spin-vanishing boundaries. The eigenvalues are also obtained for lower rigid isothermal and upper free adiabatic boundaries with vanishing spin. The influence of various micropolar fluid parameters on the onset of convection has been analysed. It is found that the effect of Prandtl number on the stability of the system is dependent on the SIC being pro-gravity or anti-gravity. A similar Pe-sensitivity is found in respect of the critical wave number. It is observed that the micropolar fluid layer heated from below is more stable compared to the classical fluid layer. 2003 Elsevier Science Ltd. All rights reserved.