1,218 research outputs found
Purse-seines off Goa
The design, construction and operational details of the purse-seines operated from Goa, for sardines and mackerel are reported briefly. The deck equipment and details of vessel along with the fishing season, fishing grounds and catches are briefly accounted. The design has been compared with Japanese purse-seines operated for the same species of fishes. Based on the findings an improved design of purse-seine has been presented
Economics of gill netting and two boat midwater trawling
The paper deals with the economic aspects of operation of gill netting and two boat midwater trawling conducted off Cochin. The data collected on two boat midwater trawling and gill netting during 1979 and 1980-81 are presented. Gill netting was profitable at the range of 17.5 and 25.2% while two midwater trawling was profitable at the rate of 18.5 %
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Poor choices: the limits of competitive markets in the provision of essential services to low-income consumers
A major study of the problems faced by the poor in the market for seven essential services in the UK - energy, food, housing, water, telecoms, transport, and financial services. Together these represent 60% of spending by the poorest 30% of households
Effect of Processing and Storage on the Trace Metal Concentration and Freshness Quality of Catfish (Clarias gariepinus)
The freshness quality of fish is altered by enzymatic and microbial activities, necessitating the application of fish preservation technology. This study assessed trace metals concentration and freshness quality of Catfish (Clarias gariepinus) preserved by oven-drying, brining/oven drying and smoking. The fish were processed to average moisture contents of 15 ± 5 %. Processed fish samples were stored in perforated plastic containers for 11 successive weeks at room temperature and assessed weekly for levels of trace metals (Fe, Zn, Cd, Pb) and physical attributes of odour, flavour and texture. Microbial load was assessed by total viable count (TVC) and biochemical activity by total volatile nitrogen (TVN). The freshness quality of processed fish decreased with increasing storage time and all samples preserved using the three preservation methods contained levels of trace metals below the recommended limits for trace metals in fish and are therefore safe for human consumption. Keywords: Preservation, trace metals, freshness quality, total viable count, total volatile nitroge
DFT calculation of the intermolecular exchange interaction in the magnetic Mn dimer
The dimeric form of the single-molecule magnet
[MnOCl(OCEt)(py)] recently revealed interesting
phenomena: no quantum tunneling at zero field and tunneling before magnetic
field reversal. This is attributed to substantial antiferromagnetic exchange
interaction between different monomers. The intermolecular exchange
interaction, electronic structure and magnetic properties of this molecular
magnet are calculated using density-functional theory within
generalized-gradient approximation. Calculations are in good agreement with
experiment.Comment: 4 page
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Advanced Material Distribution Measurement in Multiphase Flows: A Case Study
A variety of tomographic techniques that have been applied to multiphase flows are described. The methods discussed include electrical impedance tomography (EIT), magnetic resonance imaging (MRI), positron emission tomography (PET), gamma-densitometry tomography (GDT), radiative particle tracking (RDT), X-ray imaging, and acoustic tomography. Also presented is a case study in which measurements were made with EIT and GDT in two-phase flows. Both solid-liquid and gas-liquid flows were examined. EIT and GDT were applied independently to predict mean and spatially resolved phase volume fractions. The results from the two systems compared well
A New Class of Exact Hairy Black Hole Solutions
We present a new class of black hole solutions with minimally coupled scalar
field in the presence of a negative cosmological constant. We consider a
one-parameter family of self-interaction potentials parametrized by a
dimensionless parameter . When , we recover the conformally invariant
solution of the Martinez-Troncoso-Zanelli (MTZ) black hole. A non-vanishing
signals the departure from conformal invariance. All solutions are
perturbatively stable for negative black hole mass and they may develop
instabilities for positive mass. Thermodynamically, there is a critical
temperature at vanishing black hole mass, where a higher-order phase transition
occurs, as in the case of the MTZ black hole. Additionally, we obtain a branch
of hairy solutions which undergo a first-order phase transition at a second
critical temperature which depends on and it is higher than the MTZ
critical temperature. As , this second critical temperature diverges.Comment: 18 pages, 6 figures, minor changes, references added, published
versio
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Comparison of gamma-densitometry tomography and electrical-impedance tomography for determining material distribution in liquid-solid flows
The spatial distribution of materials in multiphase flows is of importance to many industrial processes. For example, in indirect coal liquefaction, a reactive gas is bubbled through a catalyst-laden liquid (slurry), and a spatially nonuniform gas distribution can reduce process efficiency by inducing large-scale buoyancy-driven recirculating flows. Gamma-densitometry tomography (GDT) and electrical-impedance tomography (EIT) are techniques with the potential of providing spatially resolved information on material distribution in multiphase flows. GDT and EIT have both been applied to a liquid-solid flow for comparison purposes. The experiment consisted of a cylinder (19 cm diameter) filled with water, in which 80 {micro}m glass spheres were suspended by a mixer to achieve solid volume fractions of 0.01, 0.02, and 0.03. Both GDT and EIT revealed a relatively uniform distribution of solids in the measurement plane, and the average solid volume fractions from both techniques were in good agreement
Uptake of gases in bundles of carbon nanotubes
Model calculations are presented which predict whether or not an arbitrary
gas experiences significant absorption within carbon nanotubes and/or bundles
of nanotubes. The potentials used in these calculations assume a conventional
form, based on a sum of two-body interactions with individual carbon atoms; the
latter employ energy and distance parameters which are derived from empirical
combining rules. The results confirm intuitive expectation that small atoms and
molecules are absorbed within both the interstitial channels and the tubes,
while large atoms and molecules are absorbed almost exclusively within the
tubes.Comment: 9 pages, 12 figures, submitted to PRB Newer version (8MAR2K). There
was an error in the old one (23JAN2K). Please download thi
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