973 resultados para Chemistry of the water
Resumo:
In this reservoir, the parameters being assessed are very important in the aspect of fish culture. These parameters are: physical parameters which includes temperature (O), Transparency (M).Chemical parameters include: Dissolve oxygen (mg/l) pH concentration and the Biological Parameters which include phytoplankton and zooplankton. The phytoplankton and zooplankton identification and estimation were carried out in the NIFFR Limnology Laboratory, (Green House), New Bussa. Each identified zooplankton and phytoplankton species was placed according to its major group e.g. zooplankton was grouped into three families, Roifera, Cladocera and Copepods. During this study period it was observed that copepods have the highest total number of zooplankton both beside the poultry and monk (station 'A'&'B'). Water temperature of station 'A' (beside the poultry house) ranges from 27 C-29, 5 c also same station 'B' (near the monk). Dissolve oxygen station 'A' range from 6.30mg/l-7.40mg/l while that of station 'B' ranges from 6.20mg/7.50mg/l, turbidity reading of station A'ranges from 0.19m-0.3m while station 'B' ranges from 0.22m-0.37m. The last parameter, which is pH concentration, in both stations 8.2 was observed this is an indication that the pH was constant. According to some literature review all the water parameter figures obtained were good for fish culture
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This dataset provides raw data of chemical analyses made during studies on seasonal variations of some major ions in the stream water of the River Duddon in Cumbria. Measurements of sodium, calcium, potassium, magnesium and chloride ions and pH were taken at 5 stations in the River Duddon between January 1970 and August 1974.
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This dataset provides raw data of chemical analyses made during studies on seasonal variations of some major ions in the stream water of the upper basin of the River Duddon in Cumbria. Measurements of sodium, calcium, potassium, magnesium and chloride ions and pH were taken at 26 stations in the River Duddon basin between 1972 and 1974.
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We examined the potential for water chemistry to affect the width of daily increments in reef fish otoliths using both mensurative and manipulative methods. We found significant differences in the widths of increments in otoliths of the neon damselfish (Pomacentrus coelestis) collected in different habitats at One Tree Island on the Great Barrier Reef. We then used manipulative experiments to determine if natural water masses (ocean water vs. lagoon plume) could produce different incremental widths in otoliths in the absence of potentially confounding factors. Fish exposed to ocean water had significantly wider otolith increments for two of the three experiments. Elemental analyses indicated that Ba/Ca ratios were significantly correlated with increment widths for two of the three experiments and Sr/Ca ratios did not correlate with increment width for any experimental period. Variation in crystal-lattice orientation did not explain differences in increment width between treatments. Differences in water chemistry can affect increment widths in otoliths of reef fishes, potentially confounding patterns previously attributed to growth rate or condition alone.
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A practical guide is given to help aquaculture researchers identify and correct common problems associated with the colorimetric analysis of water. Hints in making standard solutions, choosing standard concentrations for making a standard curve and making measurements are included. Various types of standard curves and some problems are outlined and details provided regarding the evaluation of standard curves.
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For some time pollution of the waters of the Delaware River by municipal and industrial wastes has been suspected of playing a major role in the decline of the shad fishery. Accordingly, studies were planned to ascertain whether any conditions of water quality caused by stream pollution and harmful or lethal to shad were existant in the waters of the Delaware River during the migration periods of the shad.
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Fat and water contents of the muscles and gonads in relation to gonad growth in Otolithus argentes from Karwar are reported. Water content showed an inverse relationship to lipid in both the sexes. Variation in somatic body weight was found associated with the fluctuations in lipid contents.
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Corn starch, gelatin, sago palm starch, agar, and bread flour were tested for their binding capacity in pelleted diets for Penaeus monodon . Agar was found to be good binder, but it costs too much, while bread flour was also good but as it's commonly used for human comsumption its use for animal feed should be minimized. The use of 20% bread flour, or a combination of 5% sago palm starch or corn starch with 15% bread flour is recommended, depending on the cost and availability. Basic composition of the formulated diet is tabulated, as is water stability of 2 and 4 mm diameter steamed pellets after 2, 6 and 18 h.
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A study was conducted to determine the comparative effectiveness of purified, semipurified and crude starch of sago as binders for pelleted shrimp diets. The diet containing semipurified sago starch had the highest water stability (79.1%). The values were nearly the same for the pellets bound with purified and crude sago starch. Reasons for the low binding capacity of purified and crude sago could be that the gel of purified sago is weakened due to purification, and that of the crude sago is due to the spongy material present in the product. Thus, semipurified sago starch is a better source of binder and purified crude sago. From the economic viewpoint, the cost of purified sago is prohibitive for use as binder. Both semipurified and crude sago palm starch are acceptable. Composition of shrimp diets containing various sources of sago palm starch, and binder cost and water stability of shrimp diets containing various sources of sago palm starch tested at 3, 6 and 12 hours, are tabulated.
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The water stability of shrimp (Penaeus monodon) diets with various polysaccharides as binding agents were tested without steaming. The diet with alginate showed the best water stability and did not completely disintegrate in 24 hours. However, the use of alginate is dependent on cost and availability, so alternate choices may be a combination of sago palm starch and wheat flour or glutinous rice flour.
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We investigate the formation of microstructured polymer networks known as Breath Figure templated structures created by the presence of water vapour over evaporating polymer solutions. We use a highly controlled experimental approach to examine this dynamic and non-equilibrium process to uniquely compare pure solvent systems with polymer solutions and demonstrate using a combination of optical microscopy, focused ion-beam milling and SEM analysis that the porous polymer microstructure is completely controlled by the interfacial forces that exist between the water droplet and the solvent until a final drying dilation of the imprints. Water droplet contact angles are the same in the presence or absence of polymer and are independent of size for droplets above 5 μm. The polymer acts a spectator that serves to trap water droplets present at the air interface, and to transfer their shape into the polymer film. For the smallest pores, however, there are unexpected variations in the contact angle with pore size that are consistent with a possible contribution from line tension at these smaller dimensions. © The Royal Society of Chemistry.
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The molar heat capacity of the azeotropic mixture composed of water and benzene was measured by an adiabatic calorimeter in the temperature range from 80 to 320 K. The phase transitions took place in the temperature range from 265.409 to 275.165 K and 275.165 to 279.399 K. The phase transition temperatures were determined to be 272.945 and 278.339 K, which were corresponding to the solid-liquid phase transitions of water and benzene, respectively. The thermodynamic functions and the excess thermodynamic functions of the mixture relative to standard temperature 298.15 K were derived from the relationships of the thermodynamic functions and the function of the measured heat capacity with respect to temperature.
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A series Of pyrrolidine-triazole based dendritic catalysts have been synthesized and applied directly in the asymmetric Michael addition of ketones to nitroolefins without the use of an organic solvent. Good yields (up to 99%), and high diastereoselectivities (up to syn/anti = 45:1) and enantioselectivities (up to 95% ee) have been obtained. Furthermore. the third generation catalyst can be reused at least five times without significant loss of catalytic activity. (C) 2008 Elsevier Ltd. All rights reserved.
Resumo:
A novel supramolecular inclusion complex of alpha-CD/C-60 was synthesized using anionic C-60. The reaction progress was monitored in situ by visible and near-IR spectroscopy. The obtained complex was characterized by UV-vis, C-13 NMR, MALDI-TOF, and cyclic voltammetry. The induction and dispersion forces are considered to be the major driving forces for the formation of a resulting alpha-CD/C-60(.-) inclusion complex.