993 resultados para depositional environment


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Distribution of the marine life in relation to the extent of pollution at and outside Mahim Bay was studied. A poor marine fauna at stations A and B was associated with a relatively high intensity of pollution accompanied by high BOD and nutrients and low DO levels. A distinct deterioration in the marine life and water quality along the northern part of the bay as compared to the southern part was evident. An increasing trend in the marine fauna with decreasing intensity of pollution from inside to outside the bay was noticed.

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Vast barren lands are lying vacant in the semi-arid zone of India, which can effectively be utilised for fish farming. Experiments conducted in semi-arid conditions at Damdama indicated that it is possible to breed Indian major carps and common carp under controlled conditions of modern carps hatchery CIFE D-80 without depending on rain.

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A semi-arid environment is a major constraint for production of carp seed through hypophysation. At a water temperature above 31 degree C fishes often fail to respond to induced breeding or produce partial or full eggs with fairly less fertilization, leading to their mortality during embryonic development. Field trials with Labee rohita and Cyprinus carpio communis prove that hypophysation followed by stripping and hatching in a water medium with reduced temperature (below 31 degree C) through controlled use of ice-water and water showers can result in 50-60% fertilization of eggs and 50-72% hatching for L. rohita, and 40-90% fertilization and 49-77% hatching for C. carpio communis. Simultaneous breeding experiments of the species in normal water temperature (>31 degree C) showed negative results.

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Available of carp breeders in their prim state of maturity is a major constraint in hypophysation. Experiments conducted in a fish farm at Naihati, West Bengal, for two consecutive years, 1983-84 and 1984-85, clearly prove that by manipulation of environmental parameters such as metabolites, dissolved oxygen, running water conditions, as also of stock densities and quality and quantity of feed. Catla catla, Hypophythalmichthys molitrix, Labeo rohita, Cirrhina mrigala and Ctenopharyngodon idella can be made to attain better maturity and spawning stage much earlier than normal i.e. even in summer months and the entire stock spawned during the period from March to September. Percentage of successful breeding, quantities of eggs released and fertilised in relation to the body weight of all the species, were also found to be more in comparison to the brood stock raised through the conventional methods.

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The marine environment near Karachi, particularly the Baba channel, Chari Kundi channel and Manora channel have been found contaminated with industrial effluents discharged by Malir and Lyari rivers, since they carry a high concentration of toxic heavy metals viz. Pb, Zn, Cu and Mn emanating from the industrial area and are received and discharged by the Lyari river. Out of 60 seawater samples collected from the above mentioned areas, Pb was present in 55 samples and Zn in 58 samples. The concentration of Pb was between 0.04 and 59.2ppm and the concentration of Zn was between 0.05 and 1.9ppm. Similarly all the 60 sludge samples collected from Lyari outfall and its adjoining area have been found to contain Pb and Zn in alarmingly high concentratios, which for Pb was between 15.4 and 3209.9ppm while for Zn was between 87 and 111.3ppm. Cu and Mn were also found in all the above samples.

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This report deals with the application of knowledge of mangrove ecosystems from around the world to the understanding of the present status of mangroves ecosystems in Pakistan.

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Fish culture in deep-water-rice (DWR) environment using net pen and polder systems was evaluated. In net pen rohu and Thai silver barb were cultured, whereas a 5-species combination (rohu, mrigal, common carp, grass carp and Thai silver barb) were cultured with BR3 rice variety and DWR. Boro-fish production system produced 2.8 t/ha of fish and 7.33 t/ha of rice in polder system with 5-species combinations.

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The experiment was conducted at BRRI Regional Station, Habiganj during 1994-95 to evaluate the growth and economic performance of Nile tilapia, Oreochromis niloticus, fish reared in the field of irrigated boro rice with different fertilizer levels. Grain yield of rice was not affected by fish culture. It was observed that 50% of recommended fertilizer was enough to produce increased rice yield (8-10 t/ha) at floodplain environment and additional yield was obtained with the increasing fertilizer rates. Results further indicated that O. niloticus could successfully be reared in the field of irrigated boro rice with recommended fertilizer level. Larger size of fingerlings at release had improved recovery percent, body weight gain and higher fish yield. Results also revealed that rice + fish production system produced higher net return than the system with rice alone.

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An engineering design environment should allow users to design complex engineering systems, to manage and coordinate the designs as they proceed, and to develop and modify the software tools used for designs. These requirements call for a programming environment with an integrated set of software tools of different functionalities. The required functionalities are mainly: the provision of design algorithms based on suitable numeric software, appropriate data structures for the application area, a user-friendly interface, and the provision of a design database for the long term management of the designs generated. The provision of such an integrated design environment in a functional programming environment with particular emphasis on the provision of appropriate control-theoretic data structures and data model is described. Object-orientation is used to model entities in the application domain, which are represented by persistent objects in the database. Structural properties, relationships and operations on entities are modelled through objects and functions classified into strict types with inheritance semantics and a recursive structure.

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Raising design quality and value in the built environment requires continuous improvement, drawing on feedback from clients or occupiers and other industry players. The challenging task for architectural and engineering designers has always been to use their intellectual knowledge to deliver both forms of benefits, tangibles and intangibles, in the built environment. Increasingly as clients demand best value for money, there is a greater need to understand the potential from intangibles, to see projects not as ends in themselves but as means to improved quality of life and wealth creation. As we begin to understand more about how - through the design of the built environment - to deliver these improvements in outcomes, clients will be better placed to expect their successful delivery from designers, and designers themselves will be better placed to provide them. This paper discusses cross-disciplinary issues about intangibles and is aimed at designers, clients, investors and entrepreneurs within the built environment. It presents some findings from a minuscule study that investigated intangible benefits in a new primary school. © 2004 IEEE.

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Source of the Nile Fish farm (SON) is located at Bugungu area in Napoleon Gulf, northern Lake Victoria. The proprietors of the farm and the National Fisheries Resources Research Institute (NaFIRRI) have an established collaborative arrangement where NaFIRRI provides technical back‐stopping to enable quarterly environment monitoring of the cage site as a mandatory requirement of the National Environment Management Authority (NEMA). The agreed study areas are selected physical‐chemical factors (water depth, water transparency/secchi depth, water temperature, dissolved oxygen, pH, conductivity, and nutrient status), algal community (including primary production), aquatic invertebrates (zooplankton and macro‐benthos) and the fish community. This report presents field observations made during the fourth quarter (October‐December) field survey undertaken during December 2013; along with scientific interpretation and discussion of the results in reference to possible impacts of the cage facility to the water environment quality and aquatic biota.

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Lake victoria is the second largest lake in the world.the lake is shatred between three East African countries (Kenya,Uganda and Tanzania) the lake basin is estimatedto have about 30 million people who depend on it as a source of fish for food,employment,income and recreation.the lake is transport locally and regionally is used for recreation and is recongnised internationally for its high fish species diversity of ecological and scientific value. This document in the first in a series to be produced on different fish production systems in Uganda and should stimulate discussions and comments to guide application of scientific findings into the policy environment.