Goertler instability in compressible boundary layers along curved surfaces with suction and cooling

The Goertler instability of the laminar compressible boundary layer flows along concave surfaces is investigated. The linearized disturbance equations for the three-dimensional, counter-rotating streamwise vortices in two-dimensional boundary layers are presented in an orthogonal curvilinear coordinate. The basic approximation of the disturbance equations, that includes the effect of the growth of the boundary layer, is considered and solved numerically. The effect of compressibility on critical stability limits, growth rates, and amplitude ratios of the vortices is evaluated for a range of Mach numbers for 0 to 5. The effect of wall cooling and suction of the boundary layer on the development of Goertler vortices is investigated for different Mach numbers

Computation of Kolmogorov's Constant in Magnetohydrodynamic Turbulence

In this paper we calculate Kolmogorov's constant for magnetohydrodynamic turbulence to one loop order in perturbation theory using the direct interaction approximation technique of Kraichnan. We have computed the constants for various $E^u(k)/E^b(k)$, i.e., fluid to magnetic energy ratios when the normalized cross helicity is zero. We find that $K$ increases from 1.47 to 4.12 as we go from fully fluid case $(E^b=0)$ to a situation when $E^u/E^b=0.5$, then it decreases to 3.55 in a fully magnetic limit $(E^u=0)$. When $E^u/E^b=1$, we find that $K=3.43$.Comment: Latex, 10 pages, no figures, To appear in Euro. Phys. Lett., 199

Immunological behaviour in fishes

Over the last 25 years, aquaculture has grown into a very significant industry. Fish hatcheries and farms are becoming increasingly important as part of the industry in supplementing food production. Fishes are farmed intensively and under such a high population density, infectious diseases remain a constant threat

Frequency of fungi at different heights of Dongargarh, India

Frequency of fungi at different height of Dongargarh was studied with the help of Petriplate method. Total 389 fungal colonies represented 31 fungal types from altitude and 18 fungal floras were isolated from ground level during the present investigation period. The fungal species were Cladosporium oxysporium, Fusarium Mycelia sterilia, Aspergillus, Penicillium, Curvularia, Cladosporium, Rhizopus,Trichoderma species were observed. Aspergillus niger observed as most frequent fungi from both side, altitude (83.33%) as well as ground level (75%). While minimum percentage frequency (8.33%) is observed for Neosartorya fischeri and A.terreus. on hill-top and A. oryzae, Dictyochlamydospora, Fusarium pallidoroseum at ground level

Study on Control Strategies of Cascaded Solar Module System

Solar photovoltaic (PV) systems have mainly been used in the past decade. Inverter-powered photovoltaic grid topologies are prominently used to meet electricity demand and to integrate renewable forms of energy into power grids. Coping with the growing demand for electricity is currently a major challenge. This article presents the basic architecture of a photovoltaic system and the characteristic performance curve of the photovoltaic generator. The description of DC voltage regulation in this paper

Far-infrared observations of Circinus and NGC 4945 galaxies

Circinus and NGC 4945 are two galaxies luminous in the infrared and are characterized by compact non thermal radio nuclei, deep silicate absorption features and unusually strong water vapor maser luminosities. Moorwood and Glass (1984) have observed these galaxies extensively in the 1 to 20 micron range. In the far-infrared, observations up to 100 microns are available from the Infrared Astronomy Satellite (IRAS). In order to study the cool dust component of these galaxies, researchers observed them at 150 microns using the Tata Institute of Fundamental Research (TIFR) 100 cm balloon-borne telescope. Here, they report observations along with deconvolved maps at 50 and 100 microns obtained from the Chopped Photometric Channel (CPC) on board IRAS