37 resultados para hydrographical and sedimentary parameters
Resumo:
In the present work, Indigenous polymer coated Tin Free Steel cans were analyzed fortheir suitability for thermal processing and storage of fish and fish products following standard methods. The raw materials used for the development of ready to eat thermally processed fish products were found to be of fresh condition. The values for various biochemical and microbiological parameters of the raw materials were well within the limits. Based on the analysis of commercial sterility, instrumental colour, texture, WB-shear force and sensory parameters, squid masala processed to F0 value of 8 min with a total process time of 38.5 min and cook value of 92 min was chosen as the optimum for squid masala in tin free steel cans while shrimp curry processed to F0 7 min with total process time of 44.0 min and cook value of 91.1 min was found to be ideal and was selected for storage study. Squid masala and shrimp curry thermally processed in indigenous polymer coated TFS cans were found to be acceptable even after one year of storage at room temperaturebased on the analysis of various sensory and biochemical parameters. Analysis of the Commission Internationale d’ Eclirage L*, a* and b* color values showed that the duration of exposure to heat treatment influenced the color parameters: the lightness (L*) and yellowness (b*)decreased, and the redness (a*) significantly increased with the increase in processing time or reduction in processing temperature.Instrumental analysis of texture showed that hardness-1 & 2 decreased with reduction in retort temperature while cohesiveness value did not show any appreciable change with decrease in temperature of processing. Other texture profile parameters like gumminess, springiness and chewiness decreased significantly with increase of processing time. W-B shear force values of mackerel meat processed at 130 °C were significantly higher than those processed at 121.1 and 115 °C. HTST processing of mackerel in brine helped in reducing the process time and improving the quality.The study also indicated that indigenous polymer coated TFS cans with easy openends can be a viable alternative to the conventional tin and aluminium cans. The industry can utilize these cans for processing ready to eat fish and shell fish products for both domestic and export markets. This will help in reviving the canning industry in India.
Resumo:
TRMM Microwave Imager (TMI) is reported to be a useful sensor to measure the atmospheric and oceanic parameters even in cloudy conditions. Vertically integrated specific humidity, Total Precipitable Water (TPW) retrieved from the water vapour absorption channel (22GHz.) along with 10m wind speed and rain rate derived from TMI is used to investigate the moisture variation over North Indian Ocean. Intraseasonal Oscillations (ISO) of TPW during the summer monsoon seasons 1998, 1999, and 2000 over North Indian Ocean is explored using wavelet analysis. The dominant waves in TPW during the monsoon periods and the differences in ISO over Arabian Sea and Bay of Bengal are investigated. The northward propagation of TPW anomaly and its coherence with the coastal rainfall is also studied. For the diagnostic study of heavy rainfall spells over the west coast, the intrusion of TPW over the North Arabian Sea is seen to be a useful tool.
Resumo:
The present study is an attempt to find out the ralation between RNA/DNA ratio, protein,percentage growth rate and specific growth rate of prawn,Penaeus indicus with respect to Nervous system, Eyestalk and Muscle tissues during ontogenesis. We have isolated and purified a natural agglutinin in the hemolymph of P.indicus with antigenecity, agglutinating, hemolytic and antibacterial properties. The influence of growth and environmental parameters on the level of agglutinin in the hemolymph was studied. Agglutinin concentration during normal growth process was compared. The agglutinin concentration in the hemolymph was quantified through developing ELISA, which is useful in health monitoring studies of individual species. Complete amino acid composition of both the subunits of P.indicus agglutinin were analysed. P.indicus agglutinin showed similarity to those proteins having antigenecity,hemolytic and agglutinating properties.Hence, agglutinin was considered as a natural defence protein in the hemolymph of P.indicus responsible for immune surveillance. The humoral defence mechanism of agglutinin was a co-operative effort with hemocytes and complement system. The composition of isolated agglutinin of P.indicus amino acids will be helpful in the synthesis of new antibacterial analogues which can be used against disease causing organisms.
Resumo:
Advent of lasers together with the advancement in fiber optics technology has revolutionized the sensor technology. Advancement in the telemetric applications of optical fiber based measurements is an added bonus. The present thesis describes variety of fiber based sensors using techniques like micro bending, long period grating and evanescent waves. Sensors to measure various physical and chemical parameters are described in this thesis.
Resumo:
The present study focused on the quality of rainwater at various land use locations and its variations on interaction with various domestic rainwater harvesting systems.Sampling sites were selected based upon the land use pattern of the locations and were classified as rural, urban, industrial and sub urban. Rainwater samples were collected from the south west monsoon of May 2007 to north east monsoon of October 2008, from four sampling sites namely Kothamangalam, Emakulam, Eloor and Kalamassery, in Ernakulam district of the State of Kerala, which characterized typical rural, urban, industrial and suburban locations respectively. Rain water samples at various stages of harvesting were also collected. The samples were analyzed according to standard procedures and their physico-chemical and microbiological parameters were determined. The variations of the chemical composition of the rainwater collected were studied using statistical methods. It was observed that 17.5%, 30%, 45.8% and 12.1% of rainwater samples collected at rural, urban, industrial and suburban locations respectively had pH less than 5.6, which is considered as the pH of cloud water at equilibrium with atmospheric CO,.Nearly 46% of the rainwater samples were in acidic range in the industrial location while it was only 17% in the rural location. Multivariate statistical analysls was done using Principal Component Analysis, and the sources that inf1uence the composition of rainwater at each locations were identified .which clearly indicated that the quality of rain water is site specific and represents the atmospheric characteristics of the free fall The quality of harvested rainwater showed significant variations at different stages of harvesting due to deposition of dust from the roof catchment surface, leaching of cement constituents etc. Except the micro biological quality, the harvested rainwater satisfied the Indian Standard guide lines for drinking water. Studies conducted on the leaching of cement constituents in water concluded that tanks made with ordinary portland cement and portland pozzolana cement could be safely used for storage of rain water.
Resumo:
The Setschenow parameter and thermodynamic parameters of transfer of 2-, 3-, and 4-methylbenzoic acids from water to salt solutions have been reported. The data have been rationalized by considering the structure breaking effects of the ions of the salts, the localized hydrolysis model, and the internal pressure theory.
Resumo:
We present a novel approach to computing the orientation moments and rheological properties of a dilute suspension of spheroids in a simple shear flow at arbitrary Peclct number based on a generalised Langevin equation method. This method differs from the diffusion equation method which is commonly used to model similar systems in that the actual equations of motion for the orientations of the individual particles are used in the computations, instead of a solution of the diffusion equation of the system. It also differs from the method of 'Brownian dynamics simulations' in that the equations used for the simulations are deterministic differential equations even in the presence of noise, and not stochastic differential equations as in Brownian dynamics simulations. One advantage of the present approach over the Fokker-Planck equation formalism is that it employs a common strategy that can be applied across a wide range of shear and diffusion parameters. Also, since deterministic differential equations are easier to simulate than stochastic differential equations, the Langevin equation method presented in this work is more efficient and less computationally intensive than Brownian dynamics simulations.We derive the Langevin equations governing the orientations of the particles in the suspension and evolve a procedure for obtaining the equation of motion for any orientation moment. A computational technique is described for simulating the orientation moments dynamically from a set of time-averaged Langevin equations, which can be used to obtain the moments when the governing equations are harder to solve analytically. The results obtained using this method are in good agreement with those available in the literature.The above computational method is also used to investigate the effect of rotational Brownian motion on the rheology of the suspension under the action of an external force field. The force field is assumed to be either constant or periodic. In the case of con- I stant external fields earlier results in the literature are reproduced, while for the case of periodic forcing certain parametric regimes corresponding to weak Brownian diffusion are identified where the rheological parameters evolve chaotically and settle onto a low dimensional attractor. The response of the system to variations in the magnitude and orientation of the force field and strength of diffusion is also analyzed through numerical experiments. It is also demonstrated that the aperiodic behaviour exhibited by the system could not have been picked up by the diffusion equation approach as presently used in the literature.The main contributions of this work include the preparation of the basic framework for applying the Langevin method to standard flow problems, quantification of rotary Brownian effects by using the new method, the paired-moment scheme for computing the moments and its use in solving an otherwise intractable problem especially in the limit of small Brownian motion where the problem becomes singular, and a demonstration of how systems governed by a Fokker-Planck equation can be explored for possible chaotic behaviour.
Resumo:
In this thesis, we explore the design, computation, and experimental analysis of photonic crystals, with a special emphasis on structures and devices that make a connection with practically realizable systems. First, we analyze the propenies of photonic-crystal: periodic dielectric structures that have a band gap for propagation. The band gap of periodically loaded air column on a dielectric substrate is computed using Eigen solvers in a plane wave basis. Then this idea is extended to planar filters and antennas at microwave regime. The main objectives covered in this thesis are:• Computation of Band Gap origin in Photonic crystal with the abet of Maxwell's equation and Bloch-Floquet's theorem • Extension of Band Gap to Planar structures at microwave regime • Predict the dielectric constant - synthesized dieletric cmstant of the substrates when loaded with Photonic Band Gap (PBG) structures in a microstrip transmission line • Identify the resonant characteristic of the PBG cell and extract the equivalent circuit based on PBG cell and substrate parameters for microstrip transmission line • Miniaturize PBG as Defected Ground Structures (DGS) and use the property to be implemented in planar filters with microstrip transmission line • Extended the band stop effect of PBG / DGS to coplanar waveguide and asymmetric coplanar waveguide. • Formulate design equations for the PBG / DGS filters • Use these PBG / DGS ground plane as ground plane of microstrip antennas • Analysis of filters and antennas using FDID method
Resumo:
This study was aimed at to characterize the spatio-temporal trends in the distributional characteristics of various species of nitrogen and phosphorus as well as to elucidate the factors and processes aflecting these nutrients in the dissolved, particulate and sedimentary phases of a river estuarine system. The main area of study is Chalakudy river in Kerala, which is a fresh water system originating from Anamalai hills and ending at Arabian Sea. Its basin is between I00 05 ’ to I00 35’ North latitude and 76” 15 ’ to 760 55’ East longitude. Being a riparian bufler zone, the dynamics of nutrient mobility tend to be more complex and variable in this river-estuarine system.The diflerent species of nitrogen estimated from the filtrate were nitrite-N, nitrateN, ammonia-N, urea-N, total nitrogen and residual nitrogen. The diflerent forms of phosphorus estimated from the filtrate were phosphate-P, total-P and residualP. Pre weighed sediments as well as particulate matter were analysed for quantijying nitrite-N, nitrate-N, ammonia-N and urea-N. Total nitrogen was estimated after digestion with potassium persulfate. Fractionation of phosphorus in sediment/particulate matter was performed by applying sequential extraction procedure. The dijferent forms of phosphorus thus estimated were loosely bound (exchangeable) P, Fe/Al bound P, polyphosphates, Ca bound P and refractory P. Sedimental total P was also measured directly by applying digestion method.The analyses carried out in this bimonthly annual survey have revealed specific information on the latent factors influencing the water quality pattern ofthe river. There was dependence among the chemical components of the river sediment and suspended matter, reflecting the water quality. A period of profound environmental change occurred and changes in various species had been noted in association with seasonal variations in the waterway, especially following enhanced river runoff during the monsoon. The results also successfully represented the distribution trend of nutrients during the rainy as well as dry season. Thus, the information gathered in this work will also be beneficial for those interested or involved in river management, conservation, regulation and policy making in regional and national levels.
Resumo:
This thesis Entitled macrobenthos of the continental margin (200-1000m) of south eastern arabian sea with special reference to polychaetes. The continental margins are geologically complex and hydrodynamically active regions of the ocean, where vital biogeochemical processes take place from a global perspective. The Eastern Arabian Sea is one of the most productive regions of the world, and as a result, vast amount of organic matter is supplied to the sub surface waters and sea bed of the Arabian Sea. In this study, data on faunal abundance, standing crop and faunal composition, together with sedimentary and environmental parameters were collected from three depths (200m, 500m & 1000m) in nine bathymetric transects along the South Eastern Arabian Sea (from Cape Comorin to Karwar) during three surveys. In the present study, five textural classes of sediments were identified from the SEAS margin, viz. sand, silty sand, sandy silt, clayey silt and admixture of sand, silt and clay. The composition of sand was higher in the southern region and decreased progressively towards the north. On the shelf edge and upper slope regions in the south (Cape to Kollam) in particular, sandy sediments dominated .
Resumo:
The Doctoral thesis focuses on the factors that influence the weather and climate over Peninsular Indias. The first chapter provides a general introduction about the climatic features over peninsular India, various factors dealt in subsequent chapters, such as solar forcing on climate, SST variability in the northern Indian Ocean and its influence on Indian monsoon, moisture content of the atmosphere and its importance in the climate system, empirical formulation of regression forecast of climate and some aspects of regional climate modeling. Chapter 2 deals with the variability in the vertically integrated moisture (VIM) over Peninsular India on various time scales. The third Chapter discusses the influence of solar activity in the low frequency variability in the rainfall of Peninsular India. The study also investigates the influence of solar activity on the horizontal and vertical components of wind and the difference in the forcing before and after the so-called regime shift in the climate system before and after mid-1970s.In Chapter 4 on Peninsular Indian Rainfall and its association with meteorological and oceanic parameters over adjoining oceanic region, a linear regression model was developed and tested for the seasonal rainfall prediction of Peninsular India.
Resumo:
Trawling, despite being heavily energy expensive, still continues to be the most energy expensive fishing method particularly so in View of the export oriented nature of the Indian seafood industry. This study therefore aims at analyzing the efficiency of trawls operation from Cochin, an important fishing center along the southwest coast of India. The analysis is made along two perspectives - economic and technological. Even though technological efficiency complement economic efficiency, in the fishing parlance, parameters like the size composition of the catch, selectivity factors, etc., will have a direct bearing on the technological qualities of the trawl, and which parameters will have a significant impact on the effective exploitation of a fishery stock. Whereas the technological analysis aims at improving the efficiency with regard to the effective utilization of fuel and fishery stocks, economic analysis ascertains the present status of the trawling operations from the commercial angle.
Resumo:
The objective of the preset work is to develop optical fiber sensors for various physical and chemical parameters. As a part of this we initially investigated trace analysis of silica, ammonia, iron and phosphate in water. For this purpose the author has implemented a dual wavelength probing scheme which has many advantages over conventional evanescent wave sensors. Dual wavelength probing makes the design more reliable and repeatable and this design makes the sensor employable for concentration, chemical content, adulteration level, monitoring and control in industries or any such needy environments. Use of low cost components makes the system cost effective and simple. The Dual wavelength probing scheme is employed for the trace analysis of silica, iron, phosphate, and ammonia in water. Such sensors can be employed for the steam and water quality analysers in power plants. Few samples from a power plant are collected and checked the performance of developed system for practical applications.
Resumo:
The pollutants discharged into the estuaries are originate from two main sources-industrial and sewage. The former may be toxic which includes heavy metals, residues from antifouling paint particles and pesticides, while large discharges of sewage will contain pathogenic microorganisms. The contamination is enough to destroy the amenities of the waterfront, and the toxic substances may completely destroy the marine life and damage to birds, fishes and other marine organisms. Antifouling biocides are a type of chemical used in marine structure to prevent biofouling. These antifouling biocides gradually leach from the ships and other marine structures into water and finally settled in sediments. Once a saturation adsorption is reached they desorbed into overlying water and causes threat to marine organisms. Previous reports explained the imposex and shell thickening in bivalves owing to the effect of biocides. So bivalves are used as indicator organisms to understand the status of pollution. The nervous system is one of the best body part to understand the effect of toxicant. Acetylcholine esterase enzyme which is the main neurotransmitter in nervous was used to understand the effect of pollutants. Present study uses Acetylcholine esterase enzyme as pollution monitoring indicator
Resumo:
Eight hundred and eighty-¢ve strains of bacterial isolates fromvarious samples associatedwith the natural habitat ofMacrobrachiumrosenbergii were screened for their probiotic potential. Two putative probionts namely Bacillus NL110 and Vibrio NE17 isolated from the larvae and egg samples, respectively, were selected for experimental studies and were introduced to the juveniles of M. rosenbergii (0.080 0.001g) through di¡erent modes such as through feed, water and both. The probiotic potential of the above bacteria in terms of improvements inwater quality, growth, survival, speci¢c growth rate (SGR), feed conversion ratio and immune parameters was evaluated. The treatment groups showed a signi¢cant improvement in SGR and weight gain (Po0.001). Survival among di¡erent treatment groups was better than that in the control group. There were also signi¢cant improvements in the water quality parameters such as the concentration of nitrate and ammonia in the treatment groups (Po0.05). Improvements in immune parameters such as the total haemocyte count (Po0.05), phenoloxidase activity and respiratory burst were also signi¢cant (Po0.001). It is concluded that screening of the natural micro£ora of cultured ¢sh and shell¢sh for putative probionts might yield probiotic strains of bacteria that could be utilized for an environment-friendly and organic mode of aquaculture.