भारतीय समुद्रों के पालिमोनिडे कुटुम्ब के समुद्री झींगों की विविधता

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Description of a new species of Caridina H. M. Edwards from the hill streams of southern Western Ghats, Tamil Nadu, India

The paper describes a new species, Caridina mathiassi sp. nov., from the hill streams of Mahendragiri Estate, part of southern Western Ghats, Kanyakumari District, Tamil Nadu, India (8o 27’ 32.27" N and 77o 23’ 32.50" E) collected during summer months of 1999 and 2000. This species is abundant and closely related to Caridina jalihali Mariappan and Richard, 2006 and Caridina gurneyi Jalihal et al., 1984. The diagnosis of the species include: shrimps of genus Caridina having a moderately long rostrum with 11-20 dorsal (4-6 post-orbital) and 2-7 ventral teeth; telson not ending in a median spine but with 4-10 spinules at distal and 3-5 pairs of spines at dorsal regions; carpus of first pereiopod deeply excavated anteriorly; fourth pereiopod with merus having 2-4, carpus having 1 large and 3-5 small spines and dactylus ending in a sharp spine and 5-7 spinules; fifth pereiopod with merus having 2-4, carpus with 1 large and sometimes 3-4 small spines and dactylus having 30-40 spinules; endopod of first pleopod with long appendix interna subterminal, curved inwards; appendix masculina double the size of appendix interna or a little longer of male second pleopod; diaeresis of uropod with 16-22 spines; size of eggs ranging from 0.53-0.61 X 0.86-1.04 mm and fecundity ranging from 122-181

Managing Mental Health During COVID- 19 Pandemic and Beyond

The novel coronavirus disease 2019 (COVID?19) pandemic is a global public health crisis of a scale not previously experienced in modern times. The whole of humanity is sharing a problem that is changing the world, and humans are living under more uncertainty. Most people have been feeling intense anxiety related to COVID-19 and the aftermath the world will leave in its wake. The paper intends to put up a deeper understanding of the anxiety reaction about various aspects of current life. Clear strategies for managing and turning off the anxiety response for short periods is developed based on the understanding of how one's brain reacts to crises along with some powerful tools for managing the pandemic.  The paper explores some of the strategies to address mental health during COVID-19

Simulation of Thermo-fluid Interactions in Cryogenic Stage Turbine Startup System Using AUSM+-UP-based Higher-order Accurate Flow Solver

High-speed turbines are used in upper stage liquid engines of launch vehicles and the most common ones include LH2 and LOX turbines used in the cryogenic stages. The main constraints in the design of turbine system for a liquid engine are thermal loads, mass flow and pressure drops in various systems ahead of the turbine inlet. The temperature of the combustion products/gases reaching the turbine blades must be well below the melting point of the turbine blade material and the mass flow rate must be sufficient to generate the required power. Turbine can be started in two ways, by generating gases using a solid propellant-based spinner motor, and using compressed gases stored in gas bottles. The first method involves design challenges but requires less space and weight. On the other hand, second method is simple but requires more space. Because of the space and weight constraints associated with the upper stages, first method is preferred and discussed in this paper. It consists of a solid propellant-based spinner motor with a convergent-divergent nozzle, a guiding duct connecting nozzle exit, and the turbine inlet manifold in the form of a torroid with nozzle block having 39 guiding nozzles. The combustion products generated by the spinner motor are guided to the manifold through the guiding duct. Inlet manifold acts as a reservoir and supplies hot gases uniformly to the turbine through 39 nozzles. This study addresses the role of  computational fluid dynamics in the design of turbine startup system using unstructured cell-centered AUSM+-UP-based finite volume solver with the twoequation turbulence model. The flow and the thermal characteristics of the solid motor with a convergentdivergent nozzle were studied to evaluate the gas temperature, operating pressure, and flow velocities. The guiding duct along with the inlet manifold was analysed separately to find the drop in temperature and pressure within the system. From the simulation results, the mass flow through each guiding nozzle, and hence, energy available could be evaluated to ensure proper functioning of the turbine.Defence Science Journal, 2009, 59(3), pp.215-229, DOI:http://dx.doi.org/10.14429/dsj.59.151

Sequential sporadic-E layers at low latitudes in the Indian sector

International audienceA study of the formation and movement of sequential Sporadic-E layers observed during the night-time hours at two Indian low-latitude stations, SHAR (dip 10°N) and Waltair (dip 20°N) shows that the layer are formed around 19:00 h. IST at altitudes of ~180 km. They descend to the normal E-region altitude of about 100 km in three to four hours and becomes blanketing type of Es before they disappear. However, the absence of these descending layers at an equatorial station, Trivandrum (dip 2°N) gives the experimental evidence for wind shear theory. The meridional neutral wind derived from the height variation of the F-layer showed significant poleward wind during the descent of these layers. Hence it is inferred that these layers are formed as a consequence of the convergence of plasma by the poleward wind and the equatorward propagating gravity waves (inferred from the height fluctuations of F-layer)

Optimal configuration of microstructure in ferroelectric materials by stochastic optimization

An optimization procedure determining the ideal configuration at the microstructural level of ferroelectric (FE) materials is applied to maximize piezoelectricity. Piezoelectricity in ceramic FEs differ significantly from that of single crystals because of the presence of crystallites (grains) possessing crystallographic axes aligned imperfectly. The piezoelectric properties of a polycrystalline (ceramic) FE is inextricably related to the grain orientation distribution (texture). The set of combination of variables, known as solution space, which dictates the texture of a ceramic is unlimited and hence the choice of the optimal solution which maximizes the piezoelectricity is complicated. Thus a stochastic global optimization combined with homogenization is employed for the identification of the optimal granular configuration of the FE ceramic microstructure with optimum piezoelectric properties. The macroscopic equilibrium piezoelectric properties of polycrystalline FE is calculated using mathematical homogenization at each iteration step. The configuration of grains characterised by its orientations at each iteration is generated using a randomly selected set of orientation distribution parameters. Apparent enhancement of piezoelectric coefficient $d_{33}$ is observed in an optimally oriented BaTiO$_3$ single crystal. A configuration of crystallites, simultaneously constraining the orientation distribution of the c-axis (polar axis) while incorporating ab-plane randomness, which would multiply the overall piezoelectricity in ceramic BaTiO$_{3}$ is also identified. The orientation distribution of the c-axes is found to be a narrow Gaussian distribution centred around ${45^\circ}$. The piezoelectric coefficient in such a ceramic is found to be nearly three times as that of the single crystal.Comment: 11 pages, 7 figure

Production of Diamino propionic acid ammonia lyase by a new strain of Salmonella typhimurium PU011

BACKGROUND: Seeds of the legume plant Lathyrus sativus, which is grown in arid and semi arid tropical regions, contain Diamino Propionic acid (DAP). DAP is a neurotoxin, which, when consumed, causes a disease called Lathyrism. Lathryrism may manifest as Neurolathyrism or Osteolathyrism, in which the nervous system, and bone formation respectively, are affected. DAP ammonia lyase is produced by a few microorganisms such as Salmonella typhi, Salmonella typhimurium and Pseudomonas, and is capable of detoxifying DAP. RESULTS: S. typhimurium PU011, a non-virulent bacterial strain isolated in our lab, was found to produce DAP ammonia lyase enzyme when grown in minimal medium containing DAP. There was a direct correlation between biomass yield and enzyme activity, until 16 h post inoculation in minimal medium containing DAP. Following ammonium sulphate precipitation and passing through Sephadex G100, CM-Sephadex and DEAE-Sephacel for crude enzyme extract preparation, about 68-fold enzyme purity was obtained. The purified enzyme gave maximum activity at pH 8.0 and was stable up to 45 degrees C. The Km value for the substrate was found to be 0.685mM, calculated from a Line Weaver Burk plot. CONCLUSION: A new bacterial strain, S.typhimurium PU 011, which is capable of producing DAP ammonia lyase, was isolated

Small-angle neutron scattering studies on water soluble complexes of poly(ethylene glycol)-based cationic random copolymer and SDS

The interaction of cationic random copolymers of methoxy poly(ethylene glycol) monomethacrylate and (3-(methacryloylamino)propyl) trimethylammonium chloride with oppositely charged surfactant, sodium dodecyl sulphate, and the influence of surfactant association on the polymer conformation have been investigated by small-angle neutron scattering. SANS data showed a positive indication of the formation of RCPSDS complexes. Even though the complete structure of the polyion complexes could not be ascertained, the results obtained give us the information on the local structure in these polymer-surfactant systems. The data were analysed using the log-normal distribution of the polydispersed spherical aggregate model for the local structure in these complexes. For all the systems the median radius and the polydispersity were found to be in the range of 20 ± 2 Å and 0.6 ± 0.05, respectively