1,227 research outputs found
Can one identify non-equilibrium in a three-state system by analyzing two-state trajectories?
For a three-state Markov system in a stationary state, we discuss whether, on
the basis of data obtained from effective two-state (or on-off) trajectories,
it is possible to discriminate between an equilibrium state and a
non-equilibrium steady state. By calculating the full phase diagram we identify
a large region where such data will be consistent only with non-equilibrium
conditions. This regime is considerably larger than the region with oscillatory
relaxation, which has previously been identified as a sufficient criterion for
non-equilibrium.Comment: 4 pages, 2 figures, J. Chem. Phys. (2010) (in press
Interaction of silica with polystyrene: mechanical properties, polymer/filler adhesion and failure behavior
Composites of polystyrene with different loading of silica were prepared by melt mixing in a Brabender Plasticorder at a rotor speed of 60 rpm. The mechanical properties of the composites such as tensile behavior, impact strength, and flexural properties were studied as a function of filler loading. The tensile moduli of the composites increased with silica content. To improve adhesion between the filler and the matrix, an amino silane coupling agent was used. The composites with coupling agents showed enhanced mechanical properties. Thermal properties were measured using differential scanning calorimetry (DSC), thermogravimetry (TGA) and flammability tests. Composites with 15 wt.% and 0.5 wt.% coupling agent showed optimum properties. Scanning electron microscopy (SEM) studies of the tensile fractured samples revealed the extent of filler dispersion and filler/matrix interaction. Finally, experimental results were compared with theoretical predictions
Impact of environment variables on pelagic fish landings: Special emphasis on Indian oil sardine off Tiruchendur coast, Gulf of Mannar
Results of the present study reported the correlation of various environmental variables such as dissolved oxygen (DO), chlorophyll тАШaтАЩ, primary productivity (PP), salinity, sea surface temperature (SST) and meteorological parameters such as air temperature (AT), air pressure (AP), relative humidity (RH), wind pattern, sunshine hours (SSH) and rainfall (RF) during January, 2008 to December, 2010 with that of the sardine fish landing along the Tiruchendur coast in Gulf of Mannar. The landings of the pelagic fishes like sardine, anchovy and Indian mackerel were high during south-west monsoon months extending from July to September in Tiruchendur coast. Sardines, which contribute 18.24% of the total fish catch, were recorded throughout the study period with a minimum occurrence during January and maximum in August. Large sized fishes were caught during October. It was found that, moderate temperature, high chlorophyll тАШaтАЩ concentration and phytoplankton abundance are primary factors that enhance sardine fishery. Weather changes, influences fisheries through the modification of habitat characteristics, affecting the organisms to the extent that the physical, chemical and biological conditions that influence their productivity, development, nourishment and reproduction distribution are altered. Subtle changes in key environmental variables can drastically modify the abundance, distribution, and availability of fish populations
Dendrilla nigra, a marine sponge, as potential source of antibacterial substances for managing shrimp diseases
Secondary metabolites of marine sponge Dendrilla nigra were tested for determining the efficacy of controlling shrimp bacterial pathogens. Based on the exploratory experiments, the chosen dose of D. nigra (500 mg/kg of shrimp) was used for pilot experiment. The percent relative protection (PRP) of shrimps treated with Dendrilla feed and challenged with various concentrations of bacterial pathogen was evaluated. Dendrilla feed elicited complete protection (100% survival) against the most common shrimp pathogens such as luminescent Vibrio harveyi and Vibrio alginolyticus. Results of combined bacterial challenge indicated that Dendrilla was a broad spectrum vibriostatic agent. Invariably, the survival of treated shrimp against the bacterial infection was significant at p<0.01 level. Based on the present findings, it could be inferred that the secondary metabolites of D. nigra form an excellent source for developing potent antibacterial agents to combat bacterial diseases of shrimp and replace the conventional antibiotic
Shrimp disease management using bioactive marine secondary metabolites: an ecofriendly approach
Vibriosis caused by opportunistic and secondary bacterial pathogens is still a serious disease problem in aquaculture
of the black tiger shrimp Panaeus monodon. Attempts were made for controlling shrimp bacterial diseases using marine Secondary Metabolites (MSMs). Findings indicated that the MSMs of seaweed Ulva fasciata and sponge Dendrilla nigra are effective for controlling shrimp bacterial pathogen
Methods for the rapid diagnosis and control of bacterial diseases in shellfishes and finfishes
The culture of finfish and shellfish are often threatened by disease causing bacteria. At times it is difficult to distinguish between infection with a pathogen and disease that may result from such infections. In addition, the stressed animals (physiological or environmental) are easily predisposed to encounter bacterial infections as well as diseases
Immunomodulatory potential of marine secondary metabolites against bacterial diseases of shrimp
Shrimp disease management using bioactive marine secondary metabolites (MSMs) was developed as a package of practice for the sustainable shrimp farming. Therefore, the effect of MSMs on the host defense factors of shrimp was evaluated in the present study. Findings indicated that Ulva diet significantly increase the defense factors such as haemogram, agglutination index, phagocytic rate, bacterial clearance and serum bactericidal activity of treated shrimps over the control group. Based on the gut bacterial load, Ulva diet was considered as proactive drug whereas Dendrilla diet was determined as a curative agent
Pathogenicity, antibiogram and biochemical characteristics of Luminescent Vibrio harveyi, associated with 'Black Shell Disease' of Penaeus monodon
Bacterial isolation was made from shrimps Penaeus monodon showing characteristic
external symptoms of 'black shell disease' from shrimp farms located in southeast coast of India.
The isolates were screened on TeBS agar plates and 0/129 for the selective isolation of Vibrio
sp. Based on the morphological, biochemical and physiological characteristics, the isolate (RJM5)
was characterized as luminescent Vibrio harveyi." Antibiogram of V. Imrueyi indicated that it was
highly sensitive to chloramphenicol. ciprofloxacin, nalidixic acid and streptomycin. The
pathogenicity studies confirmed that the isolate (V.harveyi) was moderately virulent
FABRICATION AND ELECTROCHEMICAL EVALUATION OF THE LITHIUM BATTERY, Li0.5La0.5TiO3/LiFePO4-C INTERFACE
The Li0.5La0.5TiO3 and LiFePO4/C has been prepared using sol-gel method for its interface analysis towards its application for all solid state assembly. The LiFePO4cathode material and Li0.5La0.5TiO3 solid electrolyte has been individually tested for its electrochemical reversibility. The thin film battery assembly shows severe capacity fading, which results in electrochemically non active with the chosen anode materials. In order to verify the electrochemical activity and interaction of Li0.5La0.5TiO3-LiFePO4/C interface the mixture has been tested for its electrochemical reversibility. The Li0.5La0.5TiO3-LiFePO4/C interface exhibits well resolved oxidation-reduction hype which verifies its suitability towards all solid state assemblies
Optimization and characterization of a new lipopeptide biosurfactant produced by marine Brevibacterium aureum MSA 13 in solid state culture
The biosurfactant production of a marine actinobacterium Brevibacterium aureum MSA 13 was optimized using industrial and agroindustrial solid waste residues as substrates in solid state culture
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