Recursos de colección

Repositorio Institucional UN (129,841 recursos)

Repositorio de acceso abierto de la Universidad Nacional de Colombia, en el cual se administran, preservan y difunden todas las obras monográficas que la Universidad ha producido a través de su historia, incluyendo libros, tesis y trabajos de grado, trabajos docentes, entre otros

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Mostrando recursos 141 - 160 de 182

  1. Matrices de estudios de caso comuna nororiental de Medellín - Mapa 29: Sector A - Vivienda No. A-1

  2. Matrices de estudios de caso comuna nororiental de Medellín - Mapa 22: Sector B - Grupo de viviendas - Identificación de las viviendas

  3. Matrices de estudios de caso comuna nororiental de Medellín - Mapa 8: Sector A - Usos no residenciales

  4. Matrices de estudios de caso comuna nororiental de Medellín - Mapa 41: Sector A - Vivienda No. A-6

    Morfología y uso, aspectos constructivos, infraestructura y dominios de la vivienda número A-6, ubicada en el área de estudio sector A de la comuna nororiental.

  5. Imágenes del Portal de Revistas UN

    Biblioteca, Digital UN
    Banderas y banners del Portal de Revistas UN

  6. Imágenes del Repositorio Institucional UN

    Biblioteca, Digital UN
    Banners y bandera del Repositorio Institucional UN

  7. Aquatic insects as target organisms for the study of effects of projected climate change in the British Isles

    Elliott, J.M.
    One of the objectives of the Terrestrial Initiative in Global Environmental Research is to assess the sensitivity of British plant and animal species to climate change. The first phase of the program involved the identification of criteria for selecting species suitable for the study of effects of projected climate change in the British Isles. Apart from shallow ponds, annual temperature ranges of 0 to 25 C in temperate freshwater habitats are narrower than those in most temperate terrestrial habitats. Although freshwater organisms have to exist within a narrower range than their terrestrial equivalents, few species can survive throughout their life...

  8. Quality changes in canned tilapia stored at ambient and accelerated temperatures

    Akande, G.R.; Eyo, A.A.; Adelowo, E.O.
    Changes in the quality of canned tilapia packed in oil and tomato sauce at ambient and accelerated temperatures were examined by microbiological and sensory evaluation. Canned tilapia were found to be microbiologically stable and organoleptically acceptable after six months storage period. Total viable count (TVC) were generally low (2.5 x 10 super(2)). Thermophilic organisms (Clostridium) were absent in all samples. The yield of edible part of tilapia was 72% after dressing. Pre-cooking of tilapia resulted in a loss of 21.5% of its dressed weight. Comparison of canned tilapia with available canned fishes (geisha and bonga) showed similar trends in the...

  9. Die Tiefseegarnele Pandalus borealis im Nordostatlantik. Biologie, Bestandssituation und fischereiliche Nutzung

    Schöne, Rüdiger
    One of the most common decapode in the North Atlantic is the “Northern” or “Pink shrimp” Pandalus borealis (Kröyeri). Due to decreasing fish stocks and catches the shrimp fishery was intensified during most recent years. In the North-East Atlantic, a profitable fishery on this species has been carried out by Norway and USSR/ Russia off Norway, in the Barents Sea and off Spitsbergen for about 30 years. For the first time, Germany started a shrimp fishery with FMV “Hannover” in this area in spring/summer 1999. This article gives information on the biology of Pandalus borealis. A brief description of the problems in stock analyses, stock assessment, and the TACs (Total Allowable Catches)...

  10. Einfluss der Verarbeitung auf lipophile chlororganische Rückstände in Fischen

    Karl, Horst
    Influence of fish processing methods on changes of chlordane and toxaphene residue concentrations were studied in various fishery products. Investigation included smoking, marinating and canning of fish. Smoking of Greenland halibut and ocean perch led to an increase in chlordane and toxaphene residue amounts in the edible part in relation to the raw material. A similar increase was observed during the marinating process of herring fillets. In both cases, loss of water was responsible for the observed changes in residue contents. The fat and thus the lipophilic organochlorine compounds remained completely in the products. Canning of herring fillets in tomato sauce reduced the residue concentration of the final product due to dilution by the...

  11. Welche Faktoren beeinflussen die Stärke der Dorsch-Jahresklassen?

    Oeberst, Rainer; Bleil, Martina
    In the previous years extensive investigations were carried out concerning the reproduction biology of cod in the Baltic Sea. The analyses showed that the year class strength of the eastern Baltic cod stock is decisively determined by the bad oxygen conditions during the spawning season in the summer and by sprat as predator of the cod eggs. In the western Baltic Sea these factors have no importance. The year classes are mainly determined by the strong variations of the portions of female cods, which participated in the spawning activities in the region. The individuals within the length range from 35 cm to 45 cm have a special importance at this time, caused...

  12. Intestinal absorption by Sarotherodon galilaeus (syn Tilapia galilaea ) of Lake Kainji, Nigeria

    Akintunde, E.A.
    Carbohydrates, protein, lipid and crude fibre were found to reduce in amount from the anterior to posterior regions along the gut of Sarotherodon galilaeus collected from Lake Kainji. Different regions of the gut exhibited different absorptive powers and all the compounds were differently absorbed in amount. Different sizes of fish showed different absorptive capacity

  13. The age and growth of the tongue sole Cynoglossus canariensis (Steind 1882)

    Ajayi, T.O.
    The geometric mean regression equation for the weight; length relationship of Cynoglossus canariensis was W = 0.0025 L super(3.1770). The Von Bertalanffy constants Woo, Loo, K, and to were 507.5852 g, 47.3683 cm, 0.3333 and 0.1397 for males and 839.0753 g, 54.4720 cm, 0.3062 and 0.1737 for females. Total mortality coefficient Z ranged from 0.6482 and 0.8021

  14. The growth of Sarotherodon (Tilapia) niloticus L. in Opa Reservoir, University of Ife, Ile-Ife, Nigeria

    Arawomo, G.A.O.
    The growth of Sarotherodon (Tilapia) niloticus in Opa reservoir, University of Ife was determined from the fish scales. Compared with the growth in other similar water bodies the growth was comparatively faster in this newly-impounded reservoir

  15. Preliminary investigation on growth responses of Cyprinus carpio L. fed on locally formulated artificial diets

    Ejike, C.; Ofojekwu,, P.C.
    The growth rate and feed conversion ratios of the common carp, Cyprinus carpio were measured for five test diets in 14-day replicate laboratory studies. The young carp were fed with artificial test diets with crude protein contents ranging from 14.50 to 21.42 per cent. Within this range of feed characteristic optimum growth rates were obtained with diets containing 20.25 and 21.42 per cent crude protein. The study of the effect of varying ration levels showed that growth rates increased with increases of ration size, but the food conversion efficiency and protein efficiency ratios decreased markedly as ration size was increased

  16. Vergleichende Eislagerung von ausgenommenen und unausgenommenen Schleien

    Karl, Horst; Meyer, Carsten
    New regulations of the German “Fisch-Hygiene-Verordnung” lay down that all fish except pelagic species have to be gutted immediately after catch or killing, especially fresh water fish from aquaculture. Only gutted fish should be sold to the consumer. At the present time, however, it is not unusual to sell ungutted fish like tropical or mediterranean species from foreign countries, even the EC area. In this investigation the influence of gutting on the fish quality during storage on ice was tested in tench (Tinca tinca) as a model. Quality changes were controlled by sensory, chemical, physical and microbiological assessment. It was...

  17. Saisonale und regionale Unterschiede zwischen den 0-Gruppen-Schollen-Discards in der deutschen Garnelenfischerei

    Purps, Martin; Damm, Ulrich
    Shrimping in the waddensea is frequently considered to significantly reduce the numbers of juvenile plaice . This investigation aims to reveal the seasonal and regional differences regarding discards in the German waddensea and sets the results in relation to the bycatch projects with German participation. Furthermore, methodological aspects are evaluated to find possible effects on the estimation of the netted numbers. The bycatch problem exists predominantly throughout the summer season, but high catches of juvenile plaice can occur occasionally in autumn. The discard issue seems to be most important in the East Frisian region, while the Elbe and Schleswig-Holstein areas...

  18. Die europäischen Krabbenanlandungen der letzten Jahre: Deutschland Nr. 1

    Neudecker, Thomas
    Fishery on brown shrimp has developed towards one of the most important fisheries in the North Sea area in economic terms. Statistical data on European wide landings have been gathered by a working group of the International Council for the Exploration of the Sea. They show relatively stable shares of approximately 50% for Germany, 38% for the Netherlands and 8% for Denmark. Further production originates from Great Britain, France and Belgium. The new log-book regulation of the EU will give similar data improved by better information on fishing areas and fishing effort.

  19. Geographical distribution of yellowfin and skipjack tuna catches in the Eastern Pacific Ocean, and fleet and total catch statistics, 1971-1974

    Calkins, Thomas P.
    ENGLISH: Logbook records of purse seiners and baitboats fishing for yellowfin and skipjack tunas in the eastern Pacific Ocean were used to prepare charts showing the distribution of catches by l-degree area and quarter of the year for each gear and regulation status, for the years 1971-1974. Changes in geographical distribution of the catch over the four-year period are discernible. Information on annual catch statistics and fleet composition by country is presented. SPANISH: Los registros de bitácora de los cerqueros y clíperes (barcos de carnada) que pescan atún aleta amarilla y barrilete en el Océano Pacífico oriental se emplearon para...

  20. TUNPOP, a computer simulation model of the yellowfin tuna population and the surface tuna fishery of the Eastern Pacific Ocean

    Francis, Robert C.
    ENGLISH: Mathematical documentation of TUNP0P, an age-structured computer simulation model of the yellowfin tuna population and surface tuna fishery of the eastern Pacific Ocean, is described. Example runs of the model are presented and discussed, and the sensitivity of the model output to changes in various parameters is examined. SPANISH: Se describe la documentación matemática de TUNP0P, un modelo computador de simulación basado en la edad de la población del atún aleta amarilla y de la pesca atunera epipelágíca del Océano Pacífico oriental. Se presentan y se discuten ejemplos de las pasadas del modelo, y se examina la sensibilidad de...

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