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Sample records for aquaculture system electronic

  1. PECONIC BAY SYSTEM AQUACULTURE

    Science.gov (United States)

    PECONIC BAY SYSTEM AQUACULTURE This reference document serves as the aquaculture sub-section for Phase II of a four-phase series of economic studies being conducted by Economic Analysis, Inc., for the Peconic Estuary Program. It provides an evaluation of the history, current stat...

  2. Sustainable aquaculture systems

    Energy Technology Data Exchange (ETDEWEB)

    Brune, D.E.

    1994-08-01

    The goal of this paper is to examine and assess the technical feasibility of the integration of plant and/or animal aquaculture systems into a sustainable agriculture. Although most researchers tend to avoid a precise definition of sustainable aquaculture, the implication that one gets from `reading between the lines` is that a sustainable agro-ecosystem is one which recycles materials at maximum energy efficiency. The `unspoken` standard against which comparisons of sustainability are often made is that of a mature natural ecosystem at a steady state. Cost comparisons of alternative systems will be used whenever possible, however, in many cases, conventional cost/benefit analysis will be of limited value in such an analysis. For aquaculture, such an analysis can best be conducted by analyzing the possibilities of integrating nutrients, water, and energy flow from aquaculture systems both to and from, conventional agricultural systems. The various aquaculture options are then qualitatively compared as their potential, limitations, environmental soundness, productivity, socio-economic viability and the availability of supporting technology. It is important to realize that the usefulness or applicability of any sustainable or integrated aquaculture practice is highly site specific.

  3. Aquaculture Thesaurus: Descriptors Used in the National Aquaculture Information System.

    Science.gov (United States)

    Lanier, James A.; And Others

    This document provides a listing of descriptors used in the National Aquaculture Information System (NAIS), a computer information storage and retrieval system on marine, brackish, and freshwater organisms. Included are an explanation of how to use the document, subject index terms, and a brief bibliography of the literature used in developing the…

  4. Aquaculture Farm Facility Loss Management System

    Science.gov (United States)

    Choi, Hyung-Rim; Park, Byoung-Kwon; Park, Yong-Sung; Lee, Chang-Sup; Choi, Ki-Nam; Park, Chang-Hyun; Jo, Yong-Hyun; Lee, Byung-Ha

    The loss of aquaculture farm facilities occurring from natural disasters of accidents can cause not only property damage but also marine environmental pollution and vessel safety accidents. When aquaculture farm facilities have been lost to sink down to the bottom of the water, those should be picked up through direct searches but it is difficult to find them because they cannot be visually identified and they are in the sea. In this study, a system that can efficiently manage aquaculture farm facility loss using a new technology IP-RFID will be presented. By attaching IP-Tags to aquaculture farm facilities, this technology enables the transmission of facility information and locations to diverse users in real time through the IPs and through this, the efficiency of aquaculture farm facility management and supervision can be improved and marine environmental pollution can be reduced.

  5. Optimization of aquaculture systems in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo, M. [Instituto Ciencias de la Construccion Eduardo Torroja, Madrid (Spain); Carrillo, M. [Instituto de Acuicultura de Torre la Sal, Castellon (Spain)

    1997-12-31

    An analysis of present heat production systems, using fossil fuel combustion, employed for sea water heating in Spanish hatcheries is given in this paper and compared to a technical solution based on the employment of a heat pump. Price per unit of produced energy is calculated for each system using liquid and gaseous fuels, and then these prices are compared to the price obtained for a heat pump. The heat pump system is also compared, from the point of view of its precision in maintaining temperatures, to the systems used at the present. A project prototype for thermal conditioning and temperature control in aquaculture rearing tanks is described. (author)

  6. Anammox bacteria in different compartments of recirculating aquaculture systems.

    Science.gov (United States)

    van Kessel, Maartje A H J; Harhangi, Harry R; Flik, Gert; Jetten, Mike S M; Klaren, Peter H M; Op den Camp, Huub J M

    2011-12-01

    Strict environmental restrictions force the aquaculture industry to guarantee optimal water quality for fish production in a sustainable manner. The implementation of anammox (anaerobic ammonium oxidation) in biofilters would result in the conversion of both ammonium and nitrite (both toxic to aquatic animals) into harmless dinitrogen gas. Both marine and freshwater aquaculture systems contain populations of anammox bacteria. These bacteria are also present in the faeces of freshwater and marine fish. Interestingly, a new planctomycete species appears to be present in these recirculation systems too. Further exploitation of anammox bacteria in different compartments of aquaculture systems can lead to a more environmentally friendly aquaculture practice. PMID:22103532

  7. Aquaculture and geothermal heat pump systems

    Energy Technology Data Exchange (ETDEWEB)

    Chiasson, Andrew

    2005-01-01

    The objective of this study is to examine the feasibility of aquaculture tank heating with geothermal heat pump (GHP) systems. Both closed- and open-loop GHP systems are examined for heating uncovered and greenhouse-covered tanks at three locations across the U.S. A net present value analysis is conducted for a 20-year life-cycle for various GHP base-load fractions with natural gas-fired boiler peaking. The fraction of GHP capacity to the peak load yielding the lowest life-cycle cost is plotted at various GHP installation costs and natural gas rates. Heating load calculations show that covering aquaculture tanks with a greenhouse-type structure reduces the heating requirements by over 50%. Economic analyses for closed-loop GHP systems show that the lowest life-cycle cost at natural gas rates of $1.00/therm ($0.35/m3), is observed when the GHP system is sized for 10%-20% of the peak load. At that fraction, 30-55% of the total annual heating load could be handled. At low loop installation costs of $4/ft-$6/ft ($13/m-$20/m), approximately 55-70% of the annual heating load could be handled. Open-loop GHP systems show considerably more favorable economics than closed-loop systems. In all situations examined, at natural gas prices of $1.00/therm ($0.35/m3), the lowest life-cycle cost is observed when the open-loop system is sized for about 40% of the peak load. At that size, the GHP system can handle over 80% of the annual heating requirements. At low to moderate installation costs of $200-$700/ton ($57/kW-$200/kW), over 90% of the annual heating load could be handled. Of course, open-loop systems would need to be sited at locations with sufficient ground water supply.

  8. In-tank aeration, a necessary compliment of loaded systems in an airlift recirculating aquaculture system

    Science.gov (United States)

    Water treatment components in recirculating aquaculture systems in generally address solids removal, nitrification, circulation, aeration, and degasification. Airlift pumps in a recirculating aquaculture system can address water circulation, aeration, and degasification. Recent data indicates oxygen...

  9. TOXIC ALGAE IN SOUTHEASTERN AQUACULTURE SYSTEMS

    Science.gov (United States)

    Toxin-producing algae are common in aquaculture facilities. Three divisions of algae have been identified as producing toxins: cyanobacteria, prymnesiophytes, and euglenoid algae. Cyanobacteria produce the most diverse forms including hepatic and neurologic forms. Prymnesin toxin is confined to ...

  10. Production of cobia in recirculating aquaculture systems

    Science.gov (United States)

    Interest in cobia Rachycentron canadum aquaculture in the US has increased greatly in the last decade due to their excellent consumer appeal, extremely rapid growth rates, and the observed success of rearing this species in Taiwan and other southeastern Asian countries. Because most cobia are grown...

  11. Water quality management in shrimp aquaculture ponds using remote water quality logging system

    Digital Repository Service at National Institute of Oceanography (India)

    Sreepada, R.A.; Kulkarni, S.; Suryavanshi, U.; Ingole, B.S.; Drensgstig, A.; Braaten, B.

    management in shrimp aquaculture ponds using remote water quality logging system R. A. Sreepada, Shantanu KuZkamil, Udhau Suryavanshi2, B. S. Ingole, Asbjorn Drensgstigl, Bjoern Braa ten2 Aquaculture Lclboratory, National Institute of O~eanogra~nhy. Dona...

  12. ECONOMIC ASSESSMENT OF WASTE WATER AQUACULTURE TREATMENT SYSTEMS

    Science.gov (United States)

    This study attempted to ascertain the economic viability of aquaculture as an alternative to conventional waste water treatment systems for small municipalities in the Southwestern region of the United States. A multiple water quality objective level cost-effectiveness model was ...

  13. Technology assessment of aquaculture systems for municipal waste water treatment

    Energy Technology Data Exchange (ETDEWEB)

    Hyde, H.C.; Ross, R.S.; Sturmer, L.

    1984-08-01

    The innovative and alternative technology provisions of the Clean Water Act of 1977 (PL 95-217) provide financial incentives to communities that use wastewater treatment alternatives to reduce costs or energy consumption over conventional systems. Some of these technologies have been only recently developed and are not in widespread use in the United States. This document discusses the applicability and technical and economic feasibility of using aquaculture systems for municipal wastewater treatment facilities.

  14. Solar Thermal Aquaculture System Controller Based on Artificial Neural Network

    OpenAIRE

    Doaa M. Atia; Faten H Fahmy; Ninet M Ahmed; Hassen T. Dorrah

    2011-01-01

    Temperature is one of the most principle factors affects aquaculture system. The water temperature is very important parameter for shrimp growth. It can cause stress and mortality or superior environment for growth and reproduction. The required temperature for optimal growth is 34oC, if temperature increase up to 38oC it causes death of the shrimp, so it is important to control water temperature. Solar thermal water heating system is designed to ...

  15. ALTERNATIVE PRACTICE FROM COASTAL POND TO RECIRCULATION AQUACULTURE SYSTEM

    Directory of Open Access Journals (Sweden)

    Ludi Parwadani Aji

    2012-02-01

    Full Text Available Coastal pond aquaculture used solar energy to produce oxygen via phytoplankton with their cultivation can be extensive such as the culture of low value cultured animals. Pond encompasses a larger culture area for juvenile or grow-out culture which is depending on their carrying capacity of the pond. There is no feeding and the amount of food available depends on pond management which can be increased by manuring. As well as in hatcheries that require a very well environmental control, Recirculation aquaculture systems (RAS tend to occupy a small area to culture high value species at high densities. The key parameter affecting RAS is the biological filtration system that removes metabolic and other waste products. This contains bacteria which break down the ammonia and nitrite in the water. Moreover, the food from RAS is supplied externally from cultured or formulated feed. Recirculation systems offer the advantage over pond aquaculture of being able to control the environment and water quality parameters to optimise fish health. For production of commodity food fish that are low in price, pond aquaculture is better than recirculation system due to their lower overheads and production cost as the environment acts as a natural water reconditioning system compared to money spent on water recirculation technology. In developing countries, pond will still remain dominant due to the ease of culture and the low initial investments. While, in developed countries, the growing concern about environmentally friendly discharges, the high labour costs and the need for controlling niche markets will result in the adoption of recirculation technology and the production of high value species at high densities. In comparison to pond culture, RAS offered more control and independent from the environment influence.

  16. Microscreen effects on water quality in replicated recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Fernandes, Paulo; Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg

    2015-01-01

    This study investigated the effects of three microscreen mesh sizes (100, 60 and 20 ?m) on water quality and rainbow trout (Oncorhynchus mykiss) performance compared to a control group without microscreens, in triplicated recirculating aquaculture systems (RAS). Operational conditions were kept constant during a 6-week period where the microscreens were manually rinsed three times a day. The effects of microscreen cleaning frequency and nitrification performance were subsequently assessed. Compa...

  17. Nutrient reusing capacity of a combined pond aquaculture system

    Directory of Open Access Journals (Sweden)

    Dénes Gál

    2010-12-01

    Full Text Available The investigated combined intensive-extensive system (IES as a production system operatedin a close interaction of the intensive and extensive production units. The key element of the properoperation was the treatment capacity of the extensive unit; hence the investigations were focused on theperiphyton application on the nutrient utilisation and water quality of the production system. Resultsproved that combination of intensive aquaculture with extensive fishponds enhances the nutrientutilisation efficiency and fish production in IES. The combined fish production resulted in higher proteinutilisation by 26%; even this ratio can be increased by 40% with periphyton application.

  18. Tracing dissolved organic matter (DOM) from land-based aquaculture systems in North Patagonian streams

    DEFF Research Database (Denmark)

    Nimptsch, Jorge; Woelfl, Stefan; Osorio, Sebastian; Ebersbach, Paul; von Tümpling, Wolf; Palma, Rodrigo; Encina, Francisco; Figueroa, David; Kamjunke, Norbert; Graeber, Daniel

    2015-01-01

    Chile is the second largest producer of salmonids worldwide. The first step in the production of salmonids takes place in land-based aquacultures. However, the effects of the discharge from these aquacultures on stream dissolved organic matter (DOM) content, molecular composition and degradability are unknown. The aim of this study was thus to investigate the inputs of anthropogenic DOM from land-based aquaculture to the predominantly pristine river systems of North Patagonia. We hypothesized, t...

  19. Control methodologies based on geothermal recirculating aquaculture system

    International Nuclear Information System (INIS)

    One of the most common uses of geothermal heat is in RAS (recirculation aquaculture systems) where the water temperature is accurately controlled for optimum growing conditions for sustainable and intensive rearing of marine and freshwater fish. This paper presents a design for RAS rearing tank and plate type heat exchanger to be used with geothermal energy as a source of heating water. A well at Umm Huweitat on the Red Sea is used as a source of geothermal energy. The heat losses from the RAS tank are calculated using Geo Heat Center Software. Then a plate type heat exchanger is designed using the epsilon–NTU (number of transfer units) analysis method. For optimal growth and abundance of production, a different techniques of control system are applied to control the water temperature. The total system is built in MATLAB/SIMULINK to study the overall performance of control unit. Finally, a comparison between PI, Fuzzy-PID, and Fuzzy Logic Control has been done. - Highlights: • Design recirculating aquaculture system using geothermal energy. • Design a PI controller for water temperature control. • Design a Fuzzy logic controller for water temperature control. • Design a Fuzzy-PID controller for water temperature control. • Comparison between different control systems

  20. Comparative performance of CO2 measuring methods: Marine aquaculture recirculation system application

    Science.gov (United States)

    Many methods are available for the measurement of dissolved carbon dioxide in an aqueous environment. Standard titration is the typical field method for measuring dissolved CO2in aquaculture systems. However, titrimetric determination of dissolved CO2 in marine water aquaculture systems is unsuitabl...

  1. Exergetic performance analysis of a recirculating aquaculture system

    Energy Technology Data Exchange (ETDEWEB)

    Kucuk, Haydar [Mechanical Engineering Department, Guemueshane University, 29000 Guemueshane (Turkey); Midilli, Adnan [Energy Division, Mechanical Engineering Department. Nigde University, 51000 Nigde (Turkey); Oezdemir, Atilla; Cakmak, Eyuep [Central Fisheries Research Institute, Ministry of Agricultural and Rural Affairs, Trabzon (Turkey); Dincer, Ibrahim [Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ont. (Canada)

    2010-05-15

    This paper examines exergetic aspects of a Recirculation Aquaculture System (RAS) for Black Sea trout (Salmo trutta labrax) fingerling rearing at the Trabzon Central Fisheries Research Institute, Turkey. In its thermodynamic analysis, each component of the RAS is treated as a steady-state steady flow system and its exergetic efficiencies are studied. In addition, the following parameters are measured and recorded in experiments: the mass flow rates, inlet and outlet temperatures and of the system components, surrounding temperatures, and electrical work utilized by the components in the RAS. Based on these experimental data, inlet and outlet exergy values, exergy losses, and exergetic efficiencies of each component in the system are determined to assess their performance. Moreover, the overall system exergy efficiency is determined. The results show that exergy efficiencies of the system components are highly affected by varying input exergy flows as a function of the surrounding temperature and chiller's operating period. (author)

  2. Exergetic performance analysis of a recirculating aquaculture system

    International Nuclear Information System (INIS)

    This paper examines exergetic aspects of a Recirculation Aquaculture System (RAS) for Black Sea trout (Salmo trutta labrax) fingerling rearing at the Trabzon Central Fisheries Research Institute, Turkey. In its thermodynamic analysis, each component of the RAS is treated as a steady-state steady flow system and its exergetic efficiencies are studied. In addition, the following parameters are measured and recorded in experiments: the mass flow rates, inlet and outlet temperatures and of the system components, surrounding temperatures, and electrical work utilized by the components in the RAS. Based on these experimental data, inlet and outlet exergy values, exergy losses, and exergetic efficiencies of each component in the system are determined to assess their performance. Moreover, the overall system exergy efficiency is determined. The results show that exergy efficiencies of the system components are highly affected by varying input exergy flows as a function of the surrounding temperature and chiller's operating period.

  3. Tracing dissolved organic matter (DOM) from land-based aquaculture systems in North Patagonian streams.

    DEFF Research Database (Denmark)

    Nimptsch, Jorge; Woelfl, Stefan

    2015-01-01

    Chile is the second largest producer of salmonids worldwide. The first step in the production of salmonids takes place in land-based aquacultures. However, the effects of the discharge from these aquacultures on stream dissolved organic matter (DOM) content, molecular composition and degradability are unknown. The aim of this study was thus to investigate the inputs of anthropogenic DOM from land-based aquaculture to the predominantly pristine river systems of North Patagonia. We hypothesized, that i) DOM exported from land-based aquaculture mainly consists of protein-like fluorescence (tyrosine and tryptophan) released from fish feces and food remains, and that ii) this DOM is highly degradable and therefore rapidly turned-over within the receiving streams. In the North Patagonian region we conducted a screening of ten land-based aquacultures and an intensive sampling campaign for one aquaculture. This was combined with longitudinal transects and a degradation experiment in order to couple the composition ofDOM exported from land-based aquacultures to its degradability in streams. We measured dissolved organic carbon (DOC) concentration by high-temperature catalytic oxidation and DOM composition by fluorescence spectroscopy and parallel factor analysis. In the effluent of the ten screened aquacultures and in the repeated sampling of one aquaculture, we consistently found an increase of DOC concentrations and a dominance of protein-like fluorescence. The protein-like fluorescence rapidly disappeared downstream of the aquacultures, and in the degradation experiment. 21 % of the DOC export from the repeatedly sampled aquaculture resulted from food addition and 76% from fish production. We conclude that large amounts of degradable DOM are exported from land-based aquacultures. This probably has strong effects on the ecological structure and function of North Patagonian streams, and similarly affected streams worldwide.

  4. Tracing dissolved organic matter (DOM) from land-based aquaculture systems in North Patagonian streams.

    Science.gov (United States)

    Nimptsch, Jorge; Woelfl, Stefan; Osorio, Sebastian; Valenzuela, Jose; Ebersbach, Paul; von Tuempling, Wolf; Palma, Rodrigo; Encina, Francisco; Figueroa, David; Kamjunke, Norbert; Graeber, Daniel

    2015-12-15

    Chile is the second largest producer of salmonids worldwide. The first step in the production of salmonids takes place in land-based aquacultures. However, the effects of the discharge from these aquacultures on stream dissolved organic matter (DOM) content, molecular composition and degradability are unknown. The aim of this study was thus to investigate the inputs of anthropogenic DOM from land-based aquaculture to the predominantly pristine river systems of North Patagonia. We hypothesized, that i) DOM exported from land-based aquaculture mainly consists of protein-like fluorescence (tyrosine and tryptophan) released from fish feces and food remains, and that ii) this DOM is highly degradable and therefore rapidly turned-over within the receiving streams. In the North Patagonian region we conducted a screening of ten land-based aquacultures and an intensive sampling campaign for one aquaculture. This was combined with longitudinal transects and a degradation experiment in order to couple the composition of DOM exported from land-based aquacultures to its degradability in streams. We measured dissolved organic carbon (DOC) concentration by high-temperature catalytic oxidation and DOM composition by fluorescence spectroscopy and parallel factor analysis. In the effluent of the ten screened aquacultures and in the repeated sampling of one aquaculture, we consistently found an increase of DOC concentrations and a dominance of protein-like fluorescence. The protein-like fluorescence rapidly disappeared downstream of the aquacultures, and in the degradation experiment. 21% of the DOC export from the repeatedly sampled aquaculture resulted from food addition and 76% from fish production. We conclude that large amounts of degradable DOM are exported from land-based aquacultures. This probably has strong effects on the ecological structure and function of North Patagonian streams, and similarly affected streams worldwide. PMID:26282747

  5. Best Management Practices for Freshwater Pond Aquaculture

    Science.gov (United States)

    This chapter in the book “Environmental Best Management Practices for Aquaculture” describes freshwater pond aquaculture systems and management practices to reduce environmental impacts of pond aquaculture. Pond aquaculture systems for channel catfish, crawfish, baitfish, hybrid striped bass, and o...

  6. Future of recirculating systems in the US aquaculture industry

    Energy Technology Data Exchange (ETDEWEB)

    Malone, R.F.

    1994-08-01

    Recirculating systems consist of a culture unit, a recirculating pump, and a treatment block which facilitate extended re-use of water in the rearing of aquatic animals. As water re-use is extended from a few hours to months or even years, the complexity of the treatment block increases. Classified as either `open` with greater than 10 percent water replacement per day or `closed` with less than 10 percent daily replacement, most recirculating systems include aerators, clarifiers, and biofilters as key core elements. The aquaculture industry is increasingly facing a variety of socio-economic issues which will dramatically influence its future development. These problems range from increased competition for water rights through price depression and foreign imports to predation by protected migratory birds. As water-use, environmental, and conservation conflicts grow, the cost differences between the flow-through and closed production technologies will narrow, increasing the industry`s use of recirculating systems.

  7. The evaluation of oxygen and carbon dioxide transfer associated with airlifts in recirculating aquaculture systems

    Science.gov (United States)

    Airlifts in recirculating aquaculture systems (RAS) provide aeration, degasification, and water circulation. They allow the simplification of systems, and if designed properly, can reduce the capital costs and minimize operation and maintenance associated with alternative pumping systems. In order t...

  8. Modeling of TAN in recirculating aquaculture systems by AQUASIM

    DEFF Research Database (Denmark)

    Arvin, Erik; Pedersen, Lars-Flemming

    2011-01-01

    Modeling of total ammonium nitrogen (TAN) in recirculating aquaculture systems (RAS) contribute to identifying and quantifying the most important processes and their relative contribution to removal of TAN. AQUASIM is a flexible modular simulation system for water quality in natural and technical systems developed by EAWAG (Reichert, 1994). AQUASIM allows simulating complex biological, chemical and physical processes in standardized hydraulic systems. We used AQUASIM to model the steady state TAN concentrations in 12 experimental recirculating aquaculture systems (RAS) operated by DTU AQUA in Hirtshals, Denmark (Pedersen et al., 2009). Water from the fish rearing tank is treated in a sedimentation tank and subsequently by biological treatment in a submerged biofilter and in a trickling filter. Generally, the performance of the biological treatment was very well and average TAN concentrations in the RAS were in the range 0.1-0.4 mg TAN/L depending on the cumulative feed load. The average nitrite concentrationswere a little higher than the average TAN concentrations, in the range 0.2-0.6 mg N/L. Our TAN model simulated TAN removal by the following processes: 1 & 2: Nitrification in the biofilm in the submerged biofilter and in the trickling filter, 3. nitrification by suspended nitrifyers (flocs) in all compartments of the RAS, and 4. TAN assimilation associated to biomass growth. The simulation model was able to describe the measured TAN concentration very well after least square optimization of the nitrification rate constants in the biofilm and in the suspended biomass. Thus, it was demonstrated that AQUASIM is a very useful simulation tool that can be applied to improving process understanding as well as to contributing to fish production optimization

  9. Aquaculture Industry Potential and Issues: A Case from Cage Culture System Entrepreneurs: Suggestions for Intensification of Aquaculture Industry

    Directory of Open Access Journals (Sweden)

    A. N.A. Faiz

    2010-01-01

    Full Text Available Problem statement: Cage culture has become a popular aquaculture system nowadays. In the recent statistics provided by DOF, the cage culture system has generated almost USD 400 m (RM 1.39 b of income per year. In order to further intensify this economic activity the Ministry of Agriculture and Agro-based Industry (MOA through the DOF has zoned the aquaculture industry via Aquaculture Industry Zone (ZIA Programs throughout Malaysia. Cage culture system seems to have the ability to be a catalyst in enhancing the economy level of local people but it is well known that certain problems must be overcome first before the potential can be clearly seen. Thus the main focus of this study is to clarify all the potentials and problems faced by the cage culture system entrepreneurs in running their aquaculture activity. Approach: The research approach for this study was a qualitative case study that provided an in-depth description of potentials and issues in aquaculture industry in the district of Kuala Pahang, Malaysia. Data was gained using a Focus Group Discussion (FGD among the cage culture system entrepreneurs guided by an interview guide. A total of 10 cage culture entrepreneurs were selected as the FGD members. The questions served as a guide, but allowed respondents freedom and flexibility in their answers. The findings were in descriptive analysis. Results: The cage culture system was found to provide better income that lead to a higher quality of life for the entrepreneurs, positive intangible values existed among the entrepreneurs; experiences have taught them to become self independent. There were problems identified such as no independence in selecting the fingerlings, environmental problems seem to burden them, unstable pellet price, no official agreement between them and the government emphasizing the portion of the river is given to them for running their business and lot of bureaucracies that the entrepreneurs need to face. Conclusion/Recommendations: Based on the results gained, it can be concluded that even though cage culture industry proved to enhance the level of income and quality of life, a number of problems must be overcome first to further enhance their level of income and quality of life. Therefore, it is a need that the related agencies to provide more financial supports help to solve the environmental problems and further develop their administration aspects to reduce issues such as bureaucracy and official agreement.

  10. Effect of Wind-solar Complementary Increasing Oxygen System in Aquaculture

    Directory of Open Access Journals (Sweden)

    Guodong You

    2013-12-01

    Full Text Available In order to explore a sustainable aquaculture methodology, water was increased oxygen by a wind-solar power which was tested in a production period of the Penaeus vannamei in paper. The result shows that, compareing with the conventional aerating comparison, the system could improve water environment in ponds and dissolved oxygen, temperature, pH value and the content of nitrite stably and uniformly change; make full use of wind energy and solar energy clean energy, save 100% on power consumption, 15.9% on bait, 46.0% on drug; save aquaculture costs, increase income 282%. Using "Wind-solar" complementary increasing oxygen can improve water environment, save power, reduce aquaculture costs, increase aquaculture production and income, provide a new thought and method for green and ecological aquaculture, so it has high value of practical application.

  11. Characterising organic matter in recirculating aquaculture systems with fluorescence EEM spectroscopy

    DEFF Research Database (Denmark)

    Hambly, Adam; Arvin, Erik; Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg; Seredynska-Sobecka, Bozena; Stedmon, Colin

    2015-01-01

    The potential of recirculating aquaculture systems (RAS) in the aquaculture industry is increasingly being acknowledged. Along with intensified application, the need to better characterise and understand the accumulated dissolved organic matter (DOM) within these systems increases. Mature RASs, stocked with rainbow trout and operated at steady state at four feed loadings, were analysed by dissolved organic carbon (DOC) analysis and fluorescence excitation-emission matrix (EEM) spectroscopy. The ...

  12. Bacterial resistance to oxytetracycline in different life stages of Indian freshwater carp aquaculture system

    OpenAIRE

    Singh A.K.; Rathore G.; Singh V.; Mani I.; Singh R.K.; Mishra S.K.; Mishra B.N.; Verma O.P.

    2009-01-01

    In India antibiotics are frequently used for preventing and controlling bacterial pathogens incarp aquaculture system, yet no studies have been performed to evaluate the ecological impact of itsintensive and prolonged use. In this work the frequency of oxytetracycline-resistant bacteria from water,palletized feed and different life stages of fish from Indian freshwater carp aquaculture system as well asthe level of resistance of selected strains was investigated. Viable as well as antibiotic-...

  13. Microscreen effects on water quality in replicated recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Fernandes, Paulo; Pedersen, Lars-Flemming

    2015-01-01

    This study investigated the effects of three microscreen mesh sizes (100, 60 and 20 ?m) on water quality and rainbow trout (Oncorhynchus mykiss) performance compared to a control group without microscreens, in triplicated recirculating aquaculture systems (RAS). Operational conditions were kept constant during a 6-week period where the microscreens were manually rinsed three times a day. The effects of microscreen cleaning frequency and nitrification performance were subsequently assessed. Compared to the control group, microscreens removed particles, reduced particulate organic matter, and increased ?-values. Particulate parameters reached steady-state in all treatment groups having microscreens at the end of the trial. The time to reach equilibrium seemingly increased with increasing mesh size but the three treatment groups (100, 60 and 20 ?m) did not significantly differ at the end of the trial. Increased backwashing frequency over a 24-h period had no further significant effects on the parameters measured. The results demonstrated the role and importance of a microscreen, and showed that mesh size, within the range tested, is less important at long operations under constant conditions. Fish performed similarly in all treatments. Preliminary screening of trout gills did not reveal any pathological changes related to microscreen filtration and the resulting water quality. Biofilter performance was also unaffected, with 0?-order nitrification rates (k0a) being equivalent for all twelve systems (0.148 ± 0.022 g N m?2 d?1). Mechanisms for RAS equilibrium establishment, within and between systems with different mesh sizes, are discussed

  14. Participatory Monitoring and Feedback System: An Important Entry Towards Sustainable Aquaculture in Bolinao, Northern Philippines

    Directory of Open Access Journals (Sweden)

    Lailany Verceles

    2000-12-01

    Full Text Available The aquaculture industry in Caquiputan Channel contributed P2.3M to municipal revenues in 1998. However, the uncontrolled construction of fish pens and fish cages have contributed to the deterioration of the water quality in the Caquiputan Channel. Despite monitoring of parameters (e.g. DO, salinity, and temperature, low production was implicated because of limited dissolved oxygen supply.A participatory monitoring of fish pens and fish cages was facilitated to pave the way for sustainable aquaculture. A system for monitoring and disseminating information on water quality, production and zonation of pens and cages, has been pursued to assess the situation and identify mechanisms to regulate aquaculture activities. The feedback system adopted has raised and facilitated environmental awareness, issue identification, and implementation, of solutions to some major issues. Furthermore, the results have resulted in policy reforms, as embodied in the provisions on aquaculture in the Municipal Fisheries Ordinance.

  15. The Usage of Aquatic Floating Macrophytes (Lemna And Wolffia) as Biofilter in Recirculation Aquaculture System (RAS)

    OpenAIRE

    Velichkova, Katia Naneva; Sirakov, Ivaylo Nikolaev

    2013-01-01

    Conventional water treatment in recirculation aquaculture systems (RAS) is a limited technology to answer the challenges of so called "sustainable aquaculture". This is why new and innovative technologies need to be invented and introduced in RAS. The aim of the conducted study was to determine the possible advantages of using two macrophytic plants - Lemna minor and Wolffia arrhiza and their quality as biological filter in a RAS for the cultivation of fingerlings from common ca...

  16. Aquaculture; Acquacoltura

    Energy Technology Data Exchange (ETDEWEB)

    De Murtas, I.D. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente

    1998-12-01

    This paper attempts an overview of the progress made in the field of aquaculture. Aquaculture is a system of techniques strongly influenced by natural environmental conditions. Aquaculture as a biological technique oriented towards the production of useful aquatic organisms, is reaching a stage of consolidation which will place it on an equal footing which agriculture and animal husbandry. Aquaculture provides important economic and nutritional benefits to many regions of developing world. In 1994, over 90 percent of total aquaculture production was in Asia, with China, India, Japan, Indonesia, Thailand, Philippines and Republic of Korea as the seven leader producers. [Italiano] L`acquacoltura, vale a dire l`arte di riprodurre artificialmente pesci, alghe, molluschi e crostacei ed altri organismi acquatici utili all`uomo, si presenta oggi come un`attivita` di assoluto rilievo nell`insieme dei vari comparti di produzione alimentare. L`aumento della produzione e` costante anche se cinque paesi asiatici (Cina, India, Giappone, Filippine e Corea del Sud) contribuiscono per l`80% al volume della produzione mondiale. Nel presente lavoro vengono descritti lo stato dell`acquacoltura e della maricoltura nel mondo e le filiere di allevamento delle principali specie.

  17. Design, loading, and water quality in recirculating systems for low salinity finfish species at the USDA /ARS Sustainable Marine Aquaculture Systems facility (Fort Pierce, FL)

    Science.gov (United States)

    The USDA ARS Sustainable Marine Aquaculture System Facility was established by the USDA ARS in collaboration with Harbor Branch Oceanographic Institute / Florida Atlantic University to improve the efficiency and sustainability of inland warmwater marine fish culture in recirculating aquaculture syst...

  18. Application of airlift technology in recirculation aquaculture systems

    Science.gov (United States)

    Marine hatcheries implementing recirculating aquaculture technology require pristine water quality and must be designed to provide a disease free environment as much as possible to limit disease transmission. Given the aggressive nature of a variety of marine pathogens, design considerations with re...

  19. ALTERNATIVE PRACTICE FROM COASTAL POND TO RECIRCULATION AQUACULTURE SYSTEM

    OpenAIRE

    Ludi Parwadani Aji

    2012-01-01

    Coastal pond aquaculture used solar energy to produce oxygen via phytoplankton with their cultivation can be extensive such as the culture of low value cultured animals. Pond encompasses a larger culture area for juvenile or grow-out culture which is depending on their carrying capacity of the pond. There is no feeding and the amount of food available depends on pond management which can be increased by manuring. As well as in hatcheries that require a very well environmental control, Recirc...

  20. Recirculating Systems for Pollution Prevention in Aquaculture Facilities

    OpenAIRE

    Maribel Quezada-Cruz; Gabriela Vázquez-Rodríguez; Elizabeth Contreras-López; Claudia Coronel-Olivares; R. Icela Beltrán-Hernández; Juan Ramírez-Godínez

    2013-01-01

    As all other forms of livestock production, fish farming has numerous environmental impacts. Water pollution is one of the most significant outcomes, since aquaculture effluents contain non-ingested food and fish dregs that affect the receiving water bodies when discharged without any treatment. Conventional pollutants (suspended solids, dissolved organic matter and nutrients), as well as pesticides, heavy metals and emerging pollutants (as antibiotics and hormones), are commonly found in th...

  1. An integrated fish-plankton aquaculture system in brackish water

    OpenAIRE

    Gilles, S.; Fargier, L.; Lazzaro, X.; Baras, E.; De Wilde, Nicolas; Drakides, C.; Amiel, C.; Rispal, B.; Blancheton, Jean-paul

    2013-01-01

    Integrated Multi-Trophic Aquaculture takes advantage of the mutualism between some detritivorous fish and phytoplankton. The fish recycle nutrients by consuming live (and dead) algae and provide the inorganic carbon to fuel the growth of live algae. In the meanwhile, algae purify the water and generate the oxygen required by fishes. Such mechanism stabilizes the functioning of an artificially recycling ecosystem, as exemplified by combining the euryhaline tilapia Sarotherodon melanotheron heu...

  2. Development of a seaweed species-selection index for successful culture in a seaweed-based integrated aquaculture system

    Science.gov (United States)

    Kang, Yun Hee; Hwang, Jae Ran; Chung, Ik Kyo; Park, Sang Rul

    2013-03-01

    Integrated multi-trophic aquaculture (IMTA) has been proposed as a concept that combines the cultivation of fed aquaculture species ( e.g., finfish/shrimp) with extractive aquaculture species ( e.g., shellfish/seaweed). In seaweed-based integrated aquaculture, seaweeds have the capacity to reduce the environmental impact of nitrogen-rich effluents on coastal ecosystems. Thus, selection of optimal species for such aquaculture is of great importance. The present study aimed to develop a seaweed species-selection index for selecting suitable species in seaweed-based integrated aquaculture system. The index was synthesized using available literature-based information, reference data, and physiological seaweed experiments to identify and prioritize the desired species. Undaria pinnatifida, Porphyra yezoensis and Ulva compressa scored the highest according to a seaweed-based integrated aquaculture suitability index (SASI). Seaweed species with the highest scores were adjudged to fit the integrated aquaculture systems. Despite the application of this model limited by local aquaculture environment, it is considered to be a useful tool for selecting seaweed species in IMTA.

  3. Pumping performance of a slow-rotating paddlewheel for split-pond aquaculture systems

    Science.gov (United States)

    Commercial catfish farmers are intensifying production by retrofitting ponds with variations of the partitioned aquaculture system (PAS). The split-pond system is the most common variation used commercially. The split-pond consists of a small fish-holding basin connected to a waste treatment lagoon ...

  4. BIOFILTERS IN AQUACULTURE

    OpenAIRE

    Ivo Šari?; Marina Barilo; Ana Gavrilovi?; Jurica Jug-Dujakovi?

    2010-01-01

    Recirculating aquaculture is one of the solutions to an environmentally sustainable and economically feasible aquaculture production, and can be established in either urban or rural communities. Controlled conditions enable optimal growth conditions suitable for the species in question during the whole growth process, as well as the shortening of the process itself, when compared to open uncontrolled systems. Recirculating systems are now one of the most researched fields of aquaculture, and ...

  5. Mass transfer coefficients for carbon dioxide and oxygen for a polygeyser biofilter using airlift in an aquaculture reuse system

    Science.gov (United States)

    Aquaculture is a rapidly growing industry, accounting for over one-third of all direct fisheries consumption. In recirculating aquaculture systems the primary technology being used is energy intensive because water must be moved continuously through the culture and treatment units to remove wastes ...

  6. Design and performance characteristics of a low-head recirculating aquaculture tank system for low salinity finfish production

    Science.gov (United States)

    Water treatment components of a recirculating aquaculture system (RAS) consist mainly of: solid removal devices, biofiltration, aeration, degassing units, and water distribution. For each component, multiple options are available and the selection is based on system volume, system hydrodynamics, fis...

  7. Biodiesel Production by the Green Microalga Scenedesmus obliquus in a Recirculatory Aquaculture System

    Science.gov (United States)

    Mandal, Shovon

    2012-01-01

    Biodiesel production was examined with Scenedesmus obliquus in a recirculatory aquaculture system with fish pond discharge and poultry litter to couple with waste treatment. Lipid productivity of 14,400 liter ha?1 year?1 was projected with 11 cultivation cycles per year. The fuel properties of the biodiesel produced adhered to Indian and international standards. PMID:22660702

  8. Particle sieve analysis for solids removal efficiency for recirculating aquaculture system components

    Science.gov (United States)

    As the aquaculture industry develops, opportunites for small-scale farms to become an integral part of the industry will become more prevalent. For small-scale operations it is important to have a system design that is efficient in water and energy use. If such operations decide to utilize recircula...

  9. DEVELOPMENT OF SUSTAINABLE INTEGRATED AQUACULTURE SYSTEMS WITH ASSESSMENT OF ENVIRONMENTAL, SOCIAL, AND ECONOMIC IMPLICATIONS

    Science.gov (United States)

    The successful completion of this project was achieved using a multi-disciplinary approach in the design, testing, and implementation of a re-circulating integrated aquaculture production system. Graduate students were individually selected for this project based on their ex...

  10. Disinfection of water in recirculating aquaculture systems with peracetic acid (PAA)

    Science.gov (United States)

    The disinfection behaviour of peracetic acid (PAA) in recirculating aquaculture systems (RAS) was investigated. Peracetic acid is a strong oxidizing agent found in various concentrations in different products. Three Wofasteril PAA products (E400 (c), Lspecical; AC 150) were tested in vitro for the...

  11. Practical design and application of airlift technology for aquaculture reuse systems

    Science.gov (United States)

    Air-lift technology to support water movement in low-head water treatment units for recirculating aquacultures systems provides an energy efficient alternative to the use of centrifugal pumps. The benefits of air-lift are further realized when electrical requirements for aeration, CO2 degassing, and...

  12. Observations on side-swimming rainbow trout Oncorhynchus mykiss in water recirculation aquaculture systems

    Science.gov (United States)

    During a controlled 6-month study using six replicated water recirculation aquaculture systems (WRAS), it was observed that rainbow trout Oncorhynchus mykiss in all WRAS exhibited a higher-than-normal prevalence of side-swimming (i.e. controlled, forward swimming, but with misaligned orientation suc...

  13. Biodiesel Production by the Green Microalga Scenedesmus obliquus in a Recirculatory Aquaculture System

    OpenAIRE

    Mandal, Shovon; Mallick, Nirupama

    2012-01-01

    Biodiesel production was examined with Scenedesmus obliquus in a recirculatory aquaculture system with fish pond discharge and poultry litter to couple with waste treatment. Lipid productivity of 14,400 liter ha?1 year?1 was projected with 11 cultivation cycles per year. The fuel properties of the biodiesel produced adhered to Indian and international standards.

  14. Evaluation of commercial marine fish feeds for production of juvenile cobia in recirculating aquaculture systems

    Science.gov (United States)

    The effect of feeding three commercially available diets manufactured by three U.S. feed companies on production characteristics and body composition of juvenile cobia Rachycentron canadum reared in recirculating aquaculture systems (RAS) was evaluated in a 57 d growth trial. Juvenile cobia (26.7 +...

  15. Purification Performance and Production of a Re-circulating Pond Aquaculture System Based on Paddy Field

    Directory of Open Access Journals (Sweden)

    Gu Li

    2012-10-01

    Full Text Available Developing improved aquaculture systems with a more efficient use of water and less environmental impact is becoming a crying need. A re-circulating aquaculture system consisting of paddy field and fish pond is a new culture mode due to aquaculture combing with agriculture. The present study focused on the purification capacity of the paddy field on nitrogen, phosphorus and organic matter, the fluctuation trend of water quality conditions during the whole rearing process and the culture efficacy of the main culture species of grass carp (Ctenopharyngodon idella. The results were as follows: under a flow rate of 1.4-5.5 m3/h for the recirculation treatment, the average removal rate of ammonia nitrogen, nitrate nitrogen, total nitrogen, total phosphorus and biochemical oxygen demand for the aquaculture effluent amounted to 40.5, 43.5, 31.9, 23.9, 20.7 and 52.4%, respectively, But the dissolved oxygen content in the rice fields increased obviously. During the whole process of fish rearing, the main physicochemical parameters of water quality for the experimental ponds were all maintained at a suitable level for the growth of the grass carp. In addition, there were significant differences (p<0.05 in DO, TSS, NH4+ -N, NO--N, BOD5 and Chl-&alpha between the experimental and control ponds. As far as the yield per unit and survival rate was concerned, the level of the experimental ponds was obviously higher than that of the control, while the feed conversion ratio displayed the opposite trend. Overall, the new aquaculture system realized the double aims of water reuse and the reduction of waste water discharge.

  16. Daily micro particle distribution of an experimental recirculating aquaculture system – A case study

    DEFF Research Database (Denmark)

    Fernandes, Paulo; Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg

    2014-01-01

    The particle size distribution (PSD) in a recirculating aquaculture system (RAS) was investigated duringa 24-h cycle. PSD was analyzed in water sampled at several locations in a recirculation loop containing a60-m drum filter, a submerged fixed-bed biofilter and a trickling filter.In relation to total counts, the system was dominated by micro-particles with particles smaller than20 m comprising >94% of the distribution in all samples. However, the system presented a substantialvolumetric influen...

  17. Colonised Coasts : Aquaculture and Emergy Flows in the World System: Cases from Sri Lanka and the Philippines

    OpenAIRE

    Bergquist, Daniel A.

    2008-01-01

    This thesis conceives aquaculture as a transfer of resources within and between different parts of the world system. It is argued that due to inappropriate human-nature interactions, resources tend to flow from the South to the North, as a process of coastal colonisation. To study this resource transfer, coastal aquaculture is ap-proached from a transdisciplinary perspective, integrating natural, social, economic and spatial aspects. By combining world system theory and general systems theory...

  18. Recent advances within intensive Recirculated Aquaculture System cultivation of the calanoid copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Jepsen, Per Meyer; HØjgaard, Jacob Kring

    Danish aquaculture has within recent years focused upon rearing of new marine fish species. A major challenge for rearing of marine fish species is relevant diets for their fish larvae. Copepods and their larvae stage “nauplii” are well documented as the ideal live feed for a variety of marine aquaculture species. Copepodites and nauplii are superior as live feed compared to rotifers and Artemia both in terms of nutritional value, behaviour and prey size. In 1980s the copepod Acartia tonsa (Dana) was isolated in the Danish strait of Øresund and has been studied and kept in cultures ever since. An interesting trait with the species is that the eggs can be provoked into a resting stage, where the egg can be stored for one year, similar to Artemia cysts. This is the most promising storage technique for distribution of copepod eggs to aquaculture facilities worldwide. The eggs can be hatched and the nauplii can be feed to marine fish larvae. A restriction is that copepod cultures for producing eggs are after 30years of research still not stable and in large enough scale for bulk production of eggs. Recently a unique copepod Recirculated Aquaculture System (RAS) at Roskilde University (Denmark) was constructed as a part of the IMPAQ project “IMProvement of AQuaculture high quality fish fry production”. We present recent advance within RAS culture for copepods, and lesson learned from rearing the specie. Further we present physical and biological culture restrictions in terms of water quality (NH3), chemical and physical copepod densities, and its effects on copepod egg production (fecundity). We found that NH3 affect nauplii cultures negatively at levels above 30 ?g NH3 L-1, and adult cultures at levels above 477 ?g NH3 L-1. In terms of chemical and physical densities egg production was limited at densities above 2000 adults L-1.

  19. A ZigBee Wireless Sensor Network for Monitoring an Aquaculture Recirculating System

    OpenAIRE

    Francisco J. Espinosa-Faller; Guillermo E. Rendón-Rodríguez

    2012-01-01

    A ZigBee wireless sensor network was developed for monitoring an experimental aquaculture recirculating system.Temperature, dissolved oxygen, water and air pressure as well as electric current sensors were included in the setup.The high fish densities required in these systems to become economically viable present a case where sensornetworks can be applied to preserve a healthy livestock and to reduce the risk of failures that end up in the loss ofproduction. Modules for reading and transmitt...

  20. Degradation and effect of hydrogen peroxide in small-scale recirculation aquaculture system biofilters

    OpenAIRE

    Møller, Martin Sune; Arvin, Erik; Pedersen, Lars-Flemming

    2009-01-01

    From an environmental point of view, hydrogen peroxide (HP) has beneficial attributes compared with other disinfectants in terms of its ready degradation and neutral by-products. The rapid degradation of HP can, however, cause difficulties with regard to safe and efficient water treatment when applied in different systems. In this study, we investigated the degradation kinetics of HP in biofilters from water recirculating aquaculture systems (RAS). The potential effect of HP on the nitrificat...

  1. Low-dose hydrogen peroxide application in closed recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Good, C.; Pedersen, Per Bovbjerg

    2012-01-01

    The aim of the present work was to simulate water treatment practices with hydrogen peroxide (HP) in recirculating aquaculture systems (RAS). Six identical 1,700-L pilot-scale RAS were divided into two experimental groups based on daily feed allocation and operated under constant conditions for a period of 3 months. The organic and nitrogenous loadings of the systems differed fourfold between the two groups and were achieved by predefined constant daily feed loads and constant additions of water...

  2. End-of-pipe single-sludge denitrification in pilot-scale recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Suhr, Karin Isabel; Pedersen, Lars-Flemming; Nielsen, J.L.

    2014-01-01

    A step toward environmental sustainability of recirculat aquaculture systems (RAS) is implementation ofsingle-sludge denitrification, a process eliminating nitrate from the aqueous environment while reduc-ing the organic matter discharge simultaneously. Two 1700 L pilot-scale RAS systems each with a 85 Ldenitrification (DN) reactor treating discharged water and hydrolyzed solid waste were setup to testthe kinetics of nitrate and COD removal. Nitrate removal and COD reduction efficiency was measu...

  3. Degradation and effect of hydrogen peroxide in small-scale recirculation aquaculture system biofilters

    DEFF Research Database (Denmark)

    Møller, Martin Sune; Arvin, Erik; Pedersen, Lars-Flemming

    2010-01-01

    From an environmental point of view, hydrogen peroxide (HP) has beneficial attributes compared with other disinfectants in terms of its ready degradation and neutral by-products. The rapid degradation of HP can, however, cause difficulties with regard to safe and efficient water treatment when applied in different systems. In this study, we investigated the degradation kinetics of HP in biofilters from water recirculating aquaculture systems (RAS). The potential effect of HP on the nitrification...

  4. Electronics and electronic systems

    CERN Document Server

    Olsen, George H

    1987-01-01

    Electronics and Electronic Systems explores the significant developments in the field of electronics and electronic devices. This book is organized into three parts encompassing 11 chapters that discuss the fundamental circuit theory and the principles of analog and digital electronics. This book deals first with the passive components of electronic systems, such as resistors, capacitors, and inductors. These topics are followed by a discussion on the analysis of electronic circuits, which involves three ways, namely, the actual circuit, graphical techniques, and rule of thumb. The remaining p

  5. Treatment of turtle aquaculture effluent by an improved multi-soil-layer system.

    Science.gov (United States)

    Song, Ying; Huang, Yu-ting; Ji, Hong-fang; Nie, Xin-jun; Zhang, Zhi-yuan; Ge, Chuan; Luo, An-cheng; Chen, Xin

    2015-02-01

    Concentrated turtle aquaculture effluent poses an environmental threat to water bodies, and therefore needs to be treated prior to disposal. This study was conducted to assess the effect of multi-soil-layer (MSL) systems treating turtle aquaculture effluent with adding different amounts of sludge. Four MSL systems were constructed with dry weight ratios of sludge with 0%, 5%, 10%, and 20% (MSL 1, MSL 2, MSL 3, and MSL 4, respectively). The turtle aquaculture effluent had an average chemical oxygen demand (COD), ammonia nitrogen (NH4(+)-N) and total nitrogen (TN) concentration of 288.4, 213.4, and 252.0 mg/L, respectively. The COD/TN (C/N) ratio was 1.2. The results showed that the four MSL systems could effectively treat the COD, NH4(+)-N, and TN, and MSL 4 showed significantly improved NH4(+)-N removal efficiency, suggesting the potential of sludge addition to improve the turtle aquaculture effluent treatment. The average COD, TN, and NH4(+)-N removal ef?ciencies of MSL 4 were 70.3%, 66.5%, and 72.7%, respectively. To further interpret the contribution of microorganisms to the removal, the microbial community compositions and diversities of the four MSL systems were measured. Comparisons of the denaturing gradient gel electrophoresis (DGGE) profiles revealed that the amount of nitrifying bacteria and diversity in MSL 4 were higher than those in the other three systems. We concluded that adding 20% of sludge improved the NH4(+)-N removal and stability of the system for nitrification, due to the enrichment of the nitrifying bacteria in MSL 4. PMID:25644469

  6. Aerobic and anoxic growth and nitrate removal capacity of a marine denitrifying bacterium isolated from a recirculation aquaculture system

    OpenAIRE

    Borges, Maria-Teresa; Sousa, André; de Marco, Paolo; De Matos, Ana,; Hönigova, Petra; Castro, Paula M. L

    2008-01-01

    Bacterial biofilters used in marine recirculation aquaculture systems need improvements to enhance nitrogen removal efficiency. Relatively little is known about biofilter autochthonous population structure and function. The present study was aimed at isolating and characterizing an Autochthonous denitrifying bacterium from a marine biofilter installed at a recirculation aquaculture system. Colonization of four different media in a marine fish farm was followed by isolation of various denit...

  7. Wastewater Utilization for Poly-?-Hydroxybutyrate Production by the Cyanobacterium Aulosira fertilissima in a Recirculatory Aquaculture System?

    OpenAIRE

    Samantaray, Shilalipi; Nayak, Jitendra Kumar; Mallick, Nirupama

    2011-01-01

    Intensive aquaculture releases large quantities of nutrients into aquatic bodies, which can lead to eutrophication. The objective of this study was the development of a biological recirculatory wastewater treatment system with a diazotrophic cyanobacterium, Aulosira fertilissima, and simultaneous production of valuable product in the form of poly-?-hydroxybutyrate (PHB). To investigate this possible synergy, batch scale tests were conducted under a recirculatory aquaculture system in fiber-re...

  8. A ZigBee Wireless Sensor Network for Monitoring an Aquaculture Recirculating System

    Directory of Open Access Journals (Sweden)

    Francisco J. Espinosa-Faller

    2012-06-01

    Full Text Available A ZigBee wireless sensor network was developed for monitoring an experimental aquaculture recirculating system.Temperature, dissolved oxygen, water and air pressure as well as electric current sensors were included in the setup.The high fish densities required in these systems to become economically viable present a case where sensornetworks can be applied to preserve a healthy livestock and to reduce the risk of failures that end up in the loss ofproduction. Modules for reading and transmitting sensor values through a ZigBee wireless network were developedand tested. The modules were installed in an aquaculture recirculating system to transmit sensor values to thenetwork coordinator. A monitoring program was created in order to display and store sensor values and to comparethem with reference limits. An alert is emitted in case reference limits have been reached. E-mail and an SMSmessage alert can also be sent to the cellular phone of the system administrator, so immediate action can be taken. Aweb interface allows Internet access to the sensor values. The present work demonstrates the applicability of ZigBeewireless sensor network technology to aquaculture recirculating systems.

  9. Use of Barley for the Purification of Aquaculture Wastewater in a Hydroponics System

    Directory of Open Access Journals (Sweden)

    A. M. Snow

    2008-01-01

    Full Text Available Barley was examined for its ability to remove nutrients from aquaculture wastewater. The effects of seed sterilization using ethanol and bleach and seed density on germination and plant growth were investigated. Surface sterilization of barley seeds had a negative impact on germination. Increasing the ethanol concentration and/or the bleach concentration reduced the germination percentage. Barley seeds were first germinated in water in the hydroponics system. The seedlings then received wastewater from an aquaculture system stocked with Arctic charr. During the experiment, the crops grew rapidly and fairly uniformly and showed no signs of mineral deficiency or disease. The average crop height at harvest was 25.5 cm and the yield varied from 25 to 59 t ha?1, depending on the seed density. The hydroponically grown barley was able to significantly reduce the pollution load of the aquaculture wastewater. The TS, COD, NH4+-N, NO2--N, NO3--N, and PO43--P reductions ranged from 52.7 to 60.5%, from 72.9 to 83.1%, from 76.0 to 76.0%, from 97.6 to 99.2%, from 76.9 to 81.6% and from 87.1 to 95.1%, respectively. However, the effluent produced from the hydroponics system had slightly higher levels of TS (420-485 mg L?1 than the 480 mg L?1 recommended for aquatic animals. A sedimentation/filtration unit should be added to the hydroponics system.

  10. Fixed-biofilm reactors applied to waste water treatment and aquacultural water recirculating systems.

    OpenAIRE

    Bovendeur, J.

    1989-01-01

    Fixed-biofilm waste water treatment may be regarded as one of the oldest engineered biological waste water treatment methods. With the recent introduction of modern packing materials, this type of reactor has received a renewed impuls for implementation in a wide field of water treatment.In this thesis the possibilities are presented for fixed-film post-treatment of anaerobically digested domestic sewage and water reconditioning in aquacultural water recirculation systems. Emphasis is put on ...

  11. Peracetic acid degradation in freshwater aquaculture systems and possible practical implications

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Meinelt, Thomas; Straus, David L.

    2013-01-01

    Peracetic acid (PAA) is a highly reactive peroxygen compound with wide-ranging antimicrobial effects and is considered an alternative sanitizer to formaldehyde. Products containing PAA are available in solution with acetic acid and hydrogen peroxide to maintain the stability of the chemical, and it decays rapidly when applied to freshwater in aquaculture systems. The rapid decay is beneficial in an environmental context but a challenge to aquaculturists. To assess the impact of organic matter co...

  12. Recirculating aquaculture system for high density production of the calanoid copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Vu, Minh Thi Thuy; Øie, Gunvor; Reinertsen, Helge

    2013-01-01

    The calanoid copepod Acartia tonsa (Dana) is one of the most promising copepod species for marine larviculture. This species has a wide tolerance to temperature and salinity, small size, can produce resting eggs. All their nauplii, copepodites and adults can be use as excellent feeds for marine fish larvae. Yet, the biomass and egg production of A. tonsa has been limited mainly due to the challanges to culture them at high density. The development of recirculating aquaculture system (RAS) in rec...

  13. Observations on Side-Swimming Rainbow Trout in Water Recirculation Aquaculture Systems

    OpenAIRE

    Good, Christopher; Davidson, John; Kinman, Christin; Kenney, P. Brett; Bæverfjord, Grete; Summerfelt, Steven

    2014-01-01

    During a controlled 6-month study using six replicated water recirculation aquaculture systems (WRASs), it was observed that Rainbow Trout Oncorhynchus mykiss in all WRASs exhibited a higher-than-normal prevalence of side swimming (i.e., controlled, forward swimming but with misaligned orientation such that the fish's sagittal axis is approximately parallel to the horizontal plane). To further our understanding of this abnormality, a substudy was conducted wherein side swimmers and normally s...

  14. Systemic granuloma observed in Atlantic salmon Salmo salar raised to market size in a freshwater recirculation aquaculture system

    Science.gov (United States)

    Systemic granuloma was observed in sampled adult Atlantic salmon Salmo salar raised to harvest size in a freshwater recirculation aquaculture system. The prevalence of this condition was estimated at 10-20% of the population, with affected individuals grossly demonstrating pathology in varying degre...

  15. Identification of Bacterial Community Composition in Freshwater Aquaculture System Farming of Litopenaeus vannamei Reveals Distinct Temperature-Driven Patterns

    OpenAIRE

    Yuyi Tang; Peiying Tao; Jianguo Tan; Haizhen Mu; Li Peng; Dandan Yang; Shilu Tong; Lanming Chen

    2014-01-01

    Change in temperature is often a major environmental factor in triggering waterborne disease outbreaks. Previous research has revealed temporal and spatial patterns of bacterial population in several aquatic ecosystems. To date, very little information is available on aquaculture environment. Here, we assessed environmental temperature effects on bacterial community composition in freshwater aquaculture system farming of Litopenaeus vannamei (FASFL). Water samples were collected over a one-ye...

  16. Bacterial resistance to oxytetracycline in different life stages of Indian freshwater carp aquaculture system

    Directory of Open Access Journals (Sweden)

    Singh A.K.

    2009-06-01

    Full Text Available In India antibiotics are frequently used for preventing and controlling bacterial pathogens incarp aquaculture system, yet no studies have been performed to evaluate the ecological impact of itsintensive and prolonged use. In this work the frequency of oxytetracycline-resistant bacteria from water,palletized feed and different life stages of fish from Indian freshwater carp aquaculture system as well asthe level of resistance of selected strains was investigated. Viable as well as antibiotic-resistant bacterialcounts were performed by spread plate method in culture media supplemented with the oxytetracycline.Sixty two resistant Gram negative isolates which represented the oxytetracycline-resistant bacterialpopulation, were randomly selected on nutrient agar supplemented with oxytetracycline (50?g/ml fromcarp farms and feed pellet samples. Among these bacterial isolates Flavobacterium (21%, Alcaligenes(14.5%, Aeromonas (11%, Pseudomonas (10% and Enterobacteriace (19% were the most frequent.The Escherichia, Serratia, Citrobacter, Enterobacter, Shigella and Proteus from Enterobacteriace wererecovered. Twelve isolates of oxytetracycline resistant bacteria were mainly dominated in adult fishes bythe genus Flavobacterium (23% and Enterobacteriace(41%. Selected strains exhibited high levels ofoxytetracycline resistance with minimum inhibitory concentrations (MICs ranging from 50 to600?g/ml.This study shows the presence of an important population of oxytetracycline-resistant bacteriain the microflora of Indian carp aquaculture farms. Therefore the environment of these farms might playimportant roles as reservoirs of bacteria carrying genetic determinants for high level tetracyclineresistance, prompting an important risk to public health.

  17. Fate of water borne therapeutic agents and associated effects on nitrifying biofilters in recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming

    2009-01-01

    Recent discharge restrictions on antibiotics and chemotherapeutant residuals used in aquaculture have several implications to the aquaculture industry. Better management practices have to be adopted, and documentation and further knowledge of the chemical fate is required for proper administration and to support the ongoing development of a sustainable aquaculture industry. A focal point of this thesis concerns formaldehyde (FA), a commonly used chemical additive with versatile aquaculture applications. FA is safe for use with fish and has a high treatment efficiency against fungal and parasite infections; however, current treatment practices have proven difficult to comply with existing discharge regulations. Hydrogen peroxide (HP) and peracetic acid (PAA) are potential candidates to replace FA, as they have similar antimicrobial effects and are more easily degradable than FA, but empirical aquaculture experience is limited. The two main objectives of this Ph.D. project were to 1) investigate the fate of FA in nitrifying aquaculture biofilters, focusing on factors influencing degradation rates, and 2) investigate the fate of HP and PAA in nitrifying aquaculture biofilters and evaluate the effects of these agents on biofilter nitrification performance. All experiments were conducted through addition of chemical additives to closed pilot scale recirculating aquaculture systems (RAS) with fixed media submerged biofilters under controlled operating conditions with rainbow trout (Oncorhynchus mykiss) in a factorial design with true replicates. Biofilter nitrification performances were evaluated by changes in chemical processes, and nitrifying populations were identified by fluorescence in situ hybridisation (FISH) analysis. FA was degraded at a constant rate immediately after addition, and found to positively correlate to temperature, available biofilter surface-area, and the frequency of FA-exposure. Prolonged biofilter exposure to FA did not negatively affect nitrification, and could therefore be a method to optimize FA treatment in RAS and reduce FA discharge. HP degradation was rapid and could be described as a concentration-dependent exponential decay. HP was found to be enzymatically eliminated by microorganisms, with degradation rates correlated to organic matter content and microbial abundance. Nitrification performance was not affected by HP when applied in dosages less than 30 mg/L, whereas prolonged multiple HP dosages at 10 mg/L were found to inhibit nitrite oxidation in systems with low organic loading. PAA decay was found to be concentration-dependent. It had a considerable negative effect on nitrite oxidation over a prolonged period of time when applied at a dosage ?2 mg/L. PAA and HP decay patterns were significantly affected by water quality parameters, i.e. at low organic matter content HP degradation was impeded due to microbial inhibition. FISH analysis on biofilm samples from two different types of RAS showed that Nitrosomonas oligotropha was the dominant ammonia oxidizing bacteria, whereas abundant nitrite oxidizing bacteria consisted of Nitrospira spp. In conclusion, measures to reduce FA have been documented, and investigations of HP and PAA have reflected a relatively narrow safety margin when applied to biofilters

  18. Effects of temperature on nitrous oxide (N2O) emission from intensive aquaculture system.

    Science.gov (United States)

    Paudel, Shukra Raj; Choi, Ohkyung; Khanal, Samir Kumar; Chandran, Kartik; Kim, Sungpyo; Lee, Jae Woo

    2015-06-15

    This study examines the effects of temperature on nitrous oxide (N2O) emissions in a bench-scale intensive aquaculture system rearing Koi fish. The water temperature varied from 15 to 24 °C at interval of 3 °C. Both volumetric and specific rate for nitrification and denitrification declined as the temperature decreased. The concentrations of ammonia and nitrite, however, were lower than the inhibitory level for Koi fish regardless of temperature. The effects of temperature on N2O emissions were significant, with the emission rate and emission factor increasing from 1.11 to 1.82 mg N2O-N/d and 0.49 to 0.94 mg N2O-N/kg fish as the temperature decreased from 24 to 15 °C. A global map of N2O emission from aquaculture was established by using the N2O emission factor depending on temperature. This study demonstrates that N2O emission from aquaculture is strongly dependent on regional water temperatures as well as on fish production. PMID:25747359

  19. Use of planted biofilters in integrated recirculating aquaculture-hydroponics systems in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Trang, N.T.D.; Brix, Hans

    2014-01-01

    The feasibility of using planted biofilters for purification of recirculated aquaculture water in the Mekong Delta of Vietnam was assessed. The plant trenches were able to clean tilapia aquaculture water and to maintain good water quality in the fish tanks without renewal of the water. NH4-N was removed efficiently in the plant trenches, particularly in the trenches with Canna glauca L., probably because of plant uptake and nitrification-denitrification. Plant uptake constituted 6% of N and 7% of P in the input feed. Approximately 1.0 m3 of water was needed per kg of fish produced, and 370, 97 and 2842 g fresh aboveground biomass of Ipomoea aquatica Forssk., Lactuca sativa L. and C. glauca, respectively, were produced. The leafy vegetables provide some extra income besides fish products, whereas C. glauca provides nice flowers and contributes to a significant nutrient removal with annual uptake rates of 725 kg N and 234 kg P ha-1 year-1. This research demonstrates that integrated recirculating aquaculture-hydroponics (aquaponics) systems provide significant water savings and nutrient recycling as compared with traditional fish ponds. © 2012 John Wiley & Sons Ltd.

  20. Long term/low dose formalin exposure to small-scale recirculation aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg

    2010-01-01

    Repetitive long term formalin application at low dose was investigated to determine the effect on formaldehyde removal rate, biofilter nitrification and the microbial composition in small-scale recirculation aquaculture biofilters. Six pilot-scale recirculation aquaculture systems holding rainbow trout (Oncorhynchus mykiss) were designated to formalin treatments (C-0 at 10 and 20mg/L formaldehyde) on a daily or weekly basis. Formaldehyde removal rates were measured over 10 weeks, during which biofilter nitrification rates were measured in terms of standardized NH4Cl spiking events. The rates were positively correlated to the amount and frequency of formalin treatment. In systems with regularly low formalin dosage, the formaldehyde removal rate increased up to tenfold from 0.19 +/- 0.05 to 1.81 +/- 0.13 mg/(L h). Biofilter nitrification was not impaired in systems treated with formalin on a daily basis as compared to untreated systems. In systems intermittently treated with formalin, increased variation and minor reductions of ammonium and nitrite oxidation rates were observed. Nitrifying bacteria were screened by specific gene probes using fluorescence in situ hybridization and quantified by digital image analysis. The relative abundance of ammonia-oxidizing bacteria (AOB) was up to 5.4% of all Bacteria (EUB) positive cells, predominantly Nitrosomonas oligotropha. Nitrite-oxidizing bacteria (NOB), mainly consisting of Nitrospira sp. were found in all biofilm samples up to 2.9%, whereas Nitrobacter sp. was not detected. The relative abundances of AOB and NOB in the untreated system were generally higher compared to the system exposed to formalin. Low dose formalin in recirculated aquaculture systems proved to be a possible treatment strategy, as the effect on nitrification was minimal. Since formaldehyde was steadily removed by microorganisms, available biofilter surface area, hydraulic retention time a:id temperature can be used to predict removal and hence estimate e.g. effluent concentration, (C) 2009 Elsevier B.V. All rights reserved.

  1. Background paper on aquaculture research

    DEFF Research Database (Denmark)

    Wenblad, Axel; Jokumsen, Alfred

    2013-01-01

    The Board of MISTRA established in 2012 a Working Group (WG) on Aquaculture to provide the Board with background information for its upcoming decision on whether the foundation should invest in aquaculture research. The WG included Senior Advisor Axel Wenblad, Sweden (Chairman), Professor Ole Torrissen, Norway, Senior Advisory Scientist Unto Eskelinen, Finland and Senior Advisory Scientist Alfred Jokumsen, Denmark. The WG performed an investigation of the Swedish aquaculture sector including interviews with a range of stakeholders within aquaculture research, farming organisations, authorities, NGOs and the Ministry of Rural Affairs. The term aquaculture corresponds to the Swedish term Vattenbruk. Aquaculture is the cultivation of fish, shellfish or plants in fresh water (FW) or sea water (SW). Aquaculture has become the fastest growing food producing sector currently producing totally about 80 million tonnes accounting for close to 50 % of all aquatic food destined for the global human consumption. The Swedish aquaculture production currently includes about 11,000 tonnes rainbow trout in FW and SW, 1,100 tonnes arctic char (FW), 90 tonnes eel (FW), 1,500 tonnes mussels (SW) and a few tonnes of crayfish altogether corresponding to a total value of SEK 328 million in 2011. Further about 1,000 tonnes of fish and crustaceans were produced for restocking as well as about 3 million fry of salmon and trout were released into rivers. Swedish aquaculture research was overall assessed to be of very high quality and highly acknowledged at international level. However, integration of the research issues with the main stakeholders in the aquaculture sector needs focus; i.e. integration of the political frameworks, regional administrations, the aquaculture producers and the research groups on aquaculture. A closer connection and dialogue between the stakeholders may be facilitated through the regional aquaculture centres interconnected through the National Competence Centre for Aquaculture, and the National Aquaculture Council being established. These structures may create a common and focused platform for cooperation on research and education, exchange and transfer of knowledge from research to aquaculture practice. Further, integration of biological and technological research combined with education and training of skilled professionals as well as authority staff dealing with aquaculture is strongly called upon. Hence, a strong integration of the stakeholders within the aquaculture sector is assessed to be an important platform for a trans-disciplinary research and development program for strategic and efficient development of Swedish Aquaculture. Sweden has large potentials for aquaculture due to the availability of vast water resources of good quality (both marine and fresh water), a high veterinary status and generally well developed public infrastructure. Swedish aquaculture has the potential to develop into a green business producing environmentally sustainable healthy food with low ecosystem and climate impact. Swedish import of aquaculture products may be reduced by increased domestic production. Further Swedish aquaculture may be a driving force in the development of employment, infrastructures and improvement of economic and social conditions in rural areas. Swedish 4 • mistra aquaculture has the potential to contribute significantly to food security. It is therefore important that aquaculture becomes an integrated part of the food production system, i.e. being accepted as an equal food producing sector in line with the agricultural sector.Innovative development of Swedish aquaculture requires production systems with minimal environmental impact, e.g. recirculation technology, efficient feeds and waste management. Although the nutrient-poor hydropower dams in northern Sweden may tolerate nutrient load the strategy for the required development of Swedish aquaculture has to include technologies and strategies to minimize the environmental impact, in particular to the Baltic Sea. Swedish aquaculture may develop to be an env

  2. Fate of water borne therapeutic agents and associated effects on nitrifying biofilters in recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming

    2009-01-01

    Recent discharge restrictions on antibiotics and chemotherapeutant residuals used in aquaculture have several implications to the aquaculture industry. Better management practices have to be adopted, and documentation and further knowledge of the chemical fate is required for proper administration and to support the ongoing development of a sustainable aquaculture industry. A focal point of this thesis concerns formaldehyde (FA), a commonly used chemical additive with versatile aquaculture appli...

  3. The OMEGA system for marine bioenergy, wastewater treatment, environmental enhancement, and aquaculture

    Science.gov (United States)

    Trent, J. D.

    2013-12-01

    OMEGA is an acronym for Offshore Membrane Enclosure for Growing Algae. The OMEGA system consists of photobioreactors (PBRs) made of flexible, inexpensive clear plastic tubes attached to floating docks, anchored offshore in naturally or artificially protected bays [1]. The system uses domestic wastewater and CO2 from coastal facilities to provide water, nutrients, and carbon for algae cultivation [2]. The surrounding seawater maintains the temperature inside the PBRs and prevents the cultivated (freshwater) algae from becoming invasive species in the marine environment (i.e., if a PBR module accidentally leaks, the freshwater algae that grow in wastewater cannot survive in the marine environment). The salt gradient between seawater and wastewater is used for forward osmosis (FO) to concentrate nutrients and facilitate algae harvesting [3]. Both the algae and FO clean the wastewater, removing nutrients as well as pharmaceuticals and personal-care products [4]. The offshore infrastructure provides a large surface area for solar-photovoltaic arrays and access to offshore wind or wave generators. The infrastructure can also support shellfish, finfish, or seaweed aquaculture. The economics of the OMEGA system are supported by a combination of biofuels production, wastewater treatment, alternative energy generation, and aquaculture. By using wastewater and operating offshore from coastal cities, OMEGA can be located close to wastewater and CO2 sources and it can avoid competing with agriculture for water, fertilizer, and land [5]. By combining biofuels production with wastewater treatment and aquaculture, the OMEGA system provides both products and services, which increase its economic feasibility. While the offshore location has engineering challenges and concerns about the impact and control of biofouling [6], large OMEGA structure will be floating marine habitats and will create protected 'no-fishing' zones that could increase local biodiversity and fishery productivity. Potential test sites for the next phase of OMEGA (1-hectare integrated system) will be discussed.

  4. Bioremediation of aquaculture wastes.

    Science.gov (United States)

    Chávez-Crooker, Pamela; Obreque-Contreras, Johanna

    2010-06-01

    Environmental impacts of wastes from large-scale, intensive aquaculture are substantial and can lead to complex ecosystem changes. The application of known and new technologies can capture inorganic nitrogen from water and reduce organic enrichment of sediments. Biological methods, including Integrated Multi-trophic Aquaculture are now gaining interest for increasing in situ removal of nitrogen and other nutrients at sea cage sites. Several studies on biological nitrogen removal through nitrification, denitrification and anaerobic ammonium oxidation (anammox) have been reported and a number of bacterial groups active in this regard have been described. Nevertheless, additional efforts need to be focused on remediation of aquaculture wastewater and marine sediments. Conventional treatment systems have several disadvantages. Development of more efficient reactor systems and a holistic, integrated approach to waste treatment would allow more environmentally balanced aquaculture practices. PMID:20430609

  5. The formation of a risk management system for projects in the field of aquaculture innovative development in the Kaliningrad region: a case study

    OpenAIRE

    Serbulov A. V.; Stepanov A. Yu.; Polyakov O. A.

    2012-01-01

    This article sets out to develop the concept and the principal scheme of the formation of a risk management system for innovative economic development projects in the field of aquaculture. The research carried out by the authors helps identify the main problems and characteristics of risk management projects for the development of aquaculture in presentday Russia. The authors outline the status and features of aquaculture development projects in the North-western...

  6. Effects of feed loading on nitrogen balances and fish performance in replicated recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Suhr, Karin Isabel; Dalsgaard, Anne Johanne Tang; Pedersen, Per Bovbjerg; Arvin, Erik

    2012-01-01

    This study investigated the effects of applying four fixed feed loadings to three replicated recirculating aquaculture systems (RAS) on water quality changes, nitrogenous balances and growth performance of rainbow trout (Oncorhynchus mykiss).Feed loadings ranged from 1.6 to 6.3kgfeed/m3 make-up water, with a constant make-up water renewal of 4.7% of total water volume per day in all twelve RAS. Fish densities ranged from 14 to 92kg/m3 during the prolonged trial of 10weeks. Selected water quality...

  7. Aquaculture in bio-regenerative life support systems (BLSS): Considerations

    Science.gov (United States)

    Gonzales, John M.

    2009-04-01

    A significant amount of research has been invested into understanding the effects of including fish culture in bio-regenerative life support systems (BLSS) for long duration space habitation. While the benefits of fish culture as a sub-process for waste treatment and food production continue to be identified, other pressing issues arise that affect the overall equivalent system mass associated with fish culture in a BLSS. This paper is meant to provide insight into several issues affecting fish culture in a BLSS that will require attention in the future if fish meant for consumption are to be cultured in a BLSS.

  8. TECHNOLOGY ASSESSMENT OF AQUACULTURE SYSTEMS FOR MUNICIPAL WASTEWATER TREATMENT

    Science.gov (United States)

    The innovative and alternative technology provisions of the Clean Water Act of 1977 (PL 95-217) provide financial incentives to communities that use wastewater treatment alternatives to reduce costs or energy consumption over conventional systems. Some of these technologies have ...

  9. Characterising organic matter in recirculating aquaculture systems with fluorescence EEM spectroscopy

    DEFF Research Database (Denmark)

    Hambly, Adam; Arvin, Erik

    2015-01-01

    The potential of recirculating aquaculture systems (RAS) in the aquaculture industry is increasingly being acknowledged. Along with intensified application, the need to better characterise and understand the accumulated dissolved organic matter (DOM) within these systems increases. Mature RASs, stocked with rainbow trout and operated at steady state at four feed loadings, were analysed by dissolved organic carbon (DOC) analysis and fluorescence excitation-emission matrix (EEM) spectroscopy. The fluorescence dataset was then decomposed by PARAFAC analysis using the drEEM toolbox. This revealed that the fluorescence character of the RAS water could be represented by five components, of which four have previously been identified in fresh water, coastal marine water, wetlands and drinking water. The fluorescence components as well as the DOC showed positive correlations with feed loading, however there was considerable variation between the five fluorescence components with respect to the degree of accumulation with feed loading. The five components were found to originate from three sources: the feed; the influent tap water (groundwater); and processes related to the fish and the water treatment system. This paper details the first application of fluorescence EEM spectroscopy to assess DOM in RAS, and highlights the potential applications of this technique within future RAS management strategies

  10. Characterising organic matter in recirculating aquaculture systems with fluorescence EEM spectroscopy.

    Science.gov (United States)

    Hambly, A C; Arvin, E; Pedersen, L-F; Pedersen, P B; Seredy?ska-Sobecka, B; Stedmon, C A

    2015-10-15

    The potential of recirculating aquaculture systems (RAS) in the aquaculture industry is increasingly being acknowledged. Along with intensified application, the need to better characterise and understand the accumulated dissolved organic matter (DOM) within these systems increases. Mature RASs, stocked with rainbow trout and operated at steady state at four feed loadings, were analysed by dissolved organic carbon (DOC) analysis and fluorescence excitation-emission matrix (EEM) spectroscopy. The fluorescence dataset was then decomposed by PARAFAC analysis using the drEEM toolbox. This revealed that the fluorescence character of the RAS water could be represented by five components, of which four have previously been identified in fresh water, coastal marine water, wetlands and drinking water. The fluorescence components as well as the DOC showed positive correlations with feed loading, however there was considerable variation between the five fluorescence components with respect to the degree of accumulation with feed loading. The five components were found to originate from three sources: the feed; the influent tap water (groundwater); and processes related to the fish and the water treatment system. This paper details the first application of fluorescence EEM spectroscopy to assess DOM in RAS, and highlights the potential applications of this technique within future RAS management strategies. PMID:26141427

  11. Assessement of Growth Performances of Juvenile Sterlet Acipenser ruthenus Raised in a Recirculating Aquaculture System (RAS

    Directory of Open Access Journals (Sweden)

    M?rioara Nicula

    2015-10-01

    Full Text Available The study was conducted within the recirculating aquaculture system for sturgeon rearing in Herneacova village, Timis County, on a population of juvenile sterlet (Acipenser ruthenus aged between 346-431 days. Specimens were housed in five round tanks (Ø=3 m, V=6 m3, h=100 cm and fed with commercial extruded pellets (3 mm granulation, 48% CP, and 10% EE. Fish from each tank were individually weighed and measured once every two weeks. Bioproductive indices such body weight gain (BW, specific growth rate (SGR, and feed conversion ratio (FCR were calculated at the end of an 85 days experimental period. Statistical analysis was performed using the SPPS IBM 22 and Minitab 16 software. Data were reported as Mean±Sx at a significant level of p<0.05. Testing differences between means was realized by ANOVA completed with post-hoc Tukey test. The results obtained indicate that the growth performance of juvenile Acipenser ruthenus seems to be similar and even better than that of other sturgeons species reared in recirculating aquaculture system.

  12. Peracetic acid degradation in freshwater aquaculture systems and possible practical implications

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Meinelt, Thomas

    2013-01-01

    Peracetic acid (PAA) is a highly reactive peroxygen compound with wide-ranging antimicrobial effects and is considered an alternative sanitizer to formaldehyde. Products containing PAA are available in solution with acetic acid and hydrogen peroxide to maintain the stability of the chemical, and it decays rapidly when applied to freshwater in aquaculture systems. The rapid decay is beneficial in an environmental context but a challenge to aquaculturists. To assess the impact of organic matter content and temperature on PAA decay, twenty-four batch experiments were set up using PAA doses ranging from 0 to 2.0 mg/l. The results revealed that increasing organic matter content significantly facilitated PAA decay, and positive temperature-decay correlations were found. Instantaneous PAA consumption above 0.2 mg/l was observed, and PAA half-lives were found to be in the order of a few minutes. The relative PAA recovery, calculated as measured PAA concentration over time compared to the PAA concentration applied, decreased with declining dose. Measurements of PAA residuals during water treatment scenarios at three different freshwater fish farms revealed moderate to substantial PAA consumption, documenting a large discrepancy between delivered quantities and realized residuals. Recent investigations of PAA application to manage parasitic diseases in aquaculture are briefly reviewed, and practical implication and guidelines are addressed

  13. Recirculating aquaculture system for high density production of the calanoid copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Vu, Minh Thi Thuy; Øie, Gunvor

    The calanoid copepod Acartia tonsa (Dana) is one of the most promising copepod species for marine larviculture. This species has a wide tolerance to temperature and salinity, small size, can produce resting eggs. All their nauplii, copepodites and adults can be use as excellent feeds for marine fish larvae. Yet, the biomass and egg production of A. tonsa has been limited mainly due to the challanges to culture them at high density. The development of recirculating aquaculture system (RAS) in recent decades has opened a new culturing system that is expected to provide more stable environmental conditions to favor the production of A. tonsa at high density. The current study was initiated to preliminarily apply a recircultating aquaculture system (RAS) for A. tonsa production. A flow through aquaculture system (FTAS) was also run in parallel to evaluate the capacity of RAS compared to the FTAS. Both RAS and FTAS (3 replicates per system) were set up in the same room to ensure the equal condition. The initial densities of copepods were 20000 nauplii L-1 for investigation of growth and development in the early phase and 5000 ind L-1 in the copepodite and adult stages for testing reproduction capacity. A. tonsa fed the unicellular algae Rhodomonas baltica were registered for four weeks in triplicate 50 L tanks in each system. Water quality parameters were recorded daily for temperature, oxygen, pH, salinity, particles and every five days for nitrogenous waste and bacteria through the experimental period in both systems. Unexpectedly, the hatching ratio of eggs was lower in RAS compared to FTAS that may be explained by a higher concentration of nitrite, nitrate and bacteria including Vibrio spp., haemolytic bacteria and fast growing bacteria. A. tonsa cultured in both RAS and FTAS had the similar survival, growth, and reproduction, yet the nauplii developed into copepodites faster in RAS (110h) compared to FTAS (158h). This can be an indication for the potential for culturing or maintaining A. tonsa nauplii and early copepodite stages at higher densities before feeding larvae of marine species. The RAS also needs a further optimisation of water quality by a denitrifying filter component to stabilize for copepod cultivation and an implementation of disease control treatment is also required.

  14. Fate of water borne therapeutic agents and associated effects on nitrifying biofilters in recirculating aquaculture systems

    OpenAIRE

    Pedersen, Lars-Flemming

    2009-01-01

    Recent discharge restrictions on antibiotics and chemotherapeutant residuals used in aquaculture have several implications to the aquaculture industry. Better management practices have to be adopted, and documentation and further knowledge of the chemical fate is required for proper administration and to support the ongoing development of a sustainable aquaculture industry. A focal point of this thesis concerns formaldehyde (FA), a commonly used chemical additive with versat...

  15. A ZigBee Wireless Sensor Network for Monitoring an Aquaculture Recirculating System

    Scientific Electronic Library Online (English)

    Francisco J., Espinosa-Faller; Guillermo E., Rendón-Rodríguez.

    2012-12-01

    Full Text Available Se desarrolló una red de sensores inalámbrica con el protocolo ZigBee para monitorear un sistema experimental acuícola con recirculación de agua. La red incluye sensores de temperatura, oxígeno disuelto, presión de agua y aire, así como de corriente eléctrica. La alta densidad de organismos requerid [...] a para que estos sistemas sean económicamente viables nos presentan un caso donde las redes de sensores pueden ser aplicadas para preservar un stock de peces saludable reduciendo las probabilidades de fallas que conlleven pérdidas en la producción. Se desarrollaron y probaron módulos para la toma y transmisión de datos a través de una red ZigBee y se implementaron en una granja acuícola experimental. Se desarrolló un programa de monitoreo para desplegar los valores de los sensores y emitir alertas cuando se rebasen los límites de referencia especificados. Una alerta por medio de un mensaje SMS y un correo electrónico pueden ser emitidas. Una interfase WEB permite el acceso a los valores de los sensores. El presente trabajo demuestra la aplicabilidad de las redes inalámbricas ZigBee al monitoreo de sistemas acuícolas. Abstract in english A ZigBee wireless sensor network was developed for monitoring an experimental aquaculture recirculating system. Temperature, dissolved oxygen, water and air pressure as well as electric current sensors were included in the setup. The high fish densities required in these systems to become economical [...] ly viable present a case where sensor networks can be applied to preserve a healthy livestock and to reduce the risk of failures that end up in the loss of production. Modules for reading and transmitting sensor values through a ZigBee wireless network were developed and tested. The modules were installed in an aquaculture recirculating system to transmit sensor values to the network coordinator. A monitoring program was created in order to display and store sensor values and to compare them with reference limits. An alert is emitted in case reference limits have been reached. E-mail and an SMS message alert can also be sent to the cellular phone of the system administrator, so immediate action can be taken. A web interface allows Internet access to the sensor values. The present work demonstrates the applicability of ZigBee wireless sensor network technology to aquaculture recirculating systems.

  16. Holographic Aquaculture

    Science.gov (United States)

    Ian, Richard; King, Elisabeth

    1988-01-01

    Proposed is an exploratory study to verify the feasibility of an inexpensive micro-climate control system for both marine and freshwater pond and tank aquaculture, offering good control over water temperature, incident light flux, and bandwidth, combined with good energy efficiency. The proposed control system utilizes some familiar components of passive solar design, together with a new holographic glazing system which is currently being developed by, and proprietary to Advanced Environmental Research Group (AERG). The use of solar algae ponds and tanks to warm and purify water for fish and attached macroscopic marine algae culture is an ancient and effective technique, but limited seasonally and geographically by the availability of sunlight. Holographic Diffracting Structures (HDSs) can be made which passively track, accept and/or reject sunlight from a wide range of altitude and azimuth angles, and redirect and distribute light energy as desired (either directly or indirectly over water surface in an enclosed, insulated structure), effectively increasing insolation values by accepting sunlight which would not otherwise enter the structure.

  17. The potential use of constructed wetlands in a recirculating aquaculture system for shrimp culture

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Y.-F.; Jing, S.-R.; Lee, D.-Y

    2003-05-01

    Constructed wetlands improved water qualities and consequently increased the shrimp growth and survival in a recirculating system. - A pilot-scale constructed wetland unit, consisting of free water surface (FWS) and subsurface flow (SF) constructed wetlands arranged in series, was integrated into an outdoor recirculating aquaculture system (RAS) for culturing Pacific white shrimp (Litopenaeus vannamei). This study evaluated the performance of the wetland unit in treating the recirculating wastewater and examined the effect of improvement in water quality of the culture tank on the growth and survival of shrimp postlarvae. During an 80-day culture period, the wetland unit operated at a mean hydraulic loading rate of 0.3 m/day and effectively reduced the influent concentrations of 5-day biochemical oxygen demand (BOD{sub 5}, 24%), suspended solids (SS, 71%), chlorophyll a (chl-a, 88%), total ammonium (TAN, 57%), nitrite nitrogen (NO{sub 2}-N, 90%) and nitrate nitrogen (NO{sub 3}-N, 68%). Phosphate (PO{sub 4}-P) reduction was the least efficient (5.4%). The concentrations of SS, Chl-a, turbidity and NO{sub 3}-N in the culture tank water in RAS were significantly (P{<=}0.05) lower than those in a control aquaculture system (CAS) that simulated static pond culture without wetland treatment. However, no significant difference (P{<=}0.05) in BOD{sub 5}, TAN and NO{sub 2}-N was found between the two systems. At the end of the study, the harvest results showed that shrimp weight and survival rate in the RAS (3.8{+-}1.8 g/shrimp and 90%) significantly (P{<=}0.01) exceeded those in the CAS (2.3{+-}1.5 g/shrimp and 71%). This study concludes that constructed wetlands can improve the water quality and provide a good culture environment, consequently increasing the shrimp growth and survival without water exchange, in a recirculating system.

  18. The potential use of constructed wetlands in a recirculating aquaculture system for shrimp culture

    International Nuclear Information System (INIS)

    Constructed wetlands improved water qualities and consequently increased the shrimp growth and survival in a recirculating system. - A pilot-scale constructed wetland unit, consisting of free water surface (FWS) and subsurface flow (SF) constructed wetlands arranged in series, was integrated into an outdoor recirculating aquaculture system (RAS) for culturing Pacific white shrimp (Litopenaeus vannamei). This study evaluated the performance of the wetland unit in treating the recirculating wastewater and examined the effect of improvement in water quality of the culture tank on the growth and survival of shrimp postlarvae. During an 80-day culture period, the wetland unit operated at a mean hydraulic loading rate of 0.3 m/day and effectively reduced the influent concentrations of 5-day biochemical oxygen demand (BOD5, 24%), suspended solids (SS, 71%), chlorophyll a (chl-a, 88%), total ammonium (TAN, 57%), nitrite nitrogen (NO2-N, 90%) and nitrate nitrogen (NO3-N, 68%). Phosphate (PO4-P) reduction was the least efficient (5.4%). The concentrations of SS, Chl-a, turbidity and NO3-N in the culture tank water in RAS were significantly (P?0.05) lower than those in a control aquaculture system (CAS) that simulated static pond culture without wetland treatment. However, no significant difference (P?0.05) in BOD5, TAN and NO2-N was found between the two systems. At the end of the study, the harvest results showed that shrimp weight and survival rate in the RAS (3.8±1.8 g/shrimp and 90%) significantly (P?0.01) exceeded those in the CAS (2.3±1.5 g/shrimp and 71%). This study concludes that constructed wetlands can improve the water quality and provide a good culture environment, consequently increasing the shrimp growth and survival without water exchange, in a recirculating system

  19. Production characteristics of Florida pompano reared to market size at two different densities in low salinity recirculating aquaculture systems

    Science.gov (United States)

    The Florida pompano Trachinotus carolinus, a high-value carangid, is widely recognized as an excellent candidate for commercial mariculture. While results of a recent study indicated that pompano can be successfully reared to market size in small scale recirculating aquaculture systems (RAS) at low...

  20. The impact of water exchange rate on the health and performance of rainbow trout Oncorhynchus mykiss in recirculation aquaculture systems

    Science.gov (United States)

    Fish mortality in recirculating aquaculture systems (RAS) has been observed by the authors to increase when RAS are managed at low makeup water exchange rates with relatively high feed loading. The precise etiology of this elevated mortality was unknown, all typical water quality parameters were wit...

  1. Abnormal swimming behavior and increased deformities in rainbow trout Oncorhynchus mykiss cultured in low exchange water recirculation aquaculture systems

    Science.gov (United States)

    Two studies were conducted to determine if accumulating water quality parameters would negatively impact rainbow trout Oncorhynchus mykiss health and welfare within water recirculation aquaculture systems (WRAS) that were operated at low and near-zero water exchange, with and without ozonation, and ...

  2. The Cost and Effectiveness of Solids Thickening Technologies for Treating Backwash and Recovering Nutrients from Intensive Aquaculture Systems

    Science.gov (United States)

    The cost and effectiveness of three solids thickening processes, i.e., gravity thickening settlers (GTS), inclined belt filters (IBF), geotextile bag filters (GBF), were individually evaluated with the biosolids backwash produced in intensive aquaculture systems equipped with microscreen drum filter...

  3. Electron beam irradiation, oxygen, and temperature effects on nucleotide degradation in stored aquaculture hybrid striped bass fillets

    International Nuclear Information System (INIS)

    Skinless fillets from commercially-grown aquaculture hybrid striped bass (Morone saxatilis x M. chrysops) were electron beam-irradiated in the presence of air or vacuum-packaged and stored at 4C and -20C for 14 days. A mean low dose level of 2.0 or 3.0 kGy (+/- 0.5 kGy) and high dose level of 20 kGy (+/- 4 kGy) were used for irradiated samples. Hypoxanthine (Hx) concentrations, Ki-values ([(INO + Hx)/(IMP + INO + Hx)] x 100), and H-values ([(Hx)/(IMP + INO + Hx)] x 100) indicated that irradiation did not influence the rate of nucleotide degradation compared with nonirradiated controls at either refrigerated or frozen temperatures. Vacuum packaging or freezing of stored samples resulted in lower H-values and Hx contents compared with nonirradiated controls regardless of irradiation treatment

  4. BIOFILTERS IN AQUACULTURE

    Directory of Open Access Journals (Sweden)

    Ivo Šari?

    2010-07-01

    Full Text Available Recirculating aquaculture is one of the solutions to an environmentally sustainable and economically feasible aquaculture production, and can be established in either urban or rural communities. Controlled conditions enable optimal growth conditions suitable for the species in question during the whole growth process, as well as the shortening of the process itself, when compared to open uncontrolled systems. Recirculating systems are now one of the most researched fields of aquaculture, and biofiltration as the reduction of the poisonous ammonia compounds generated by digestion of proteins, is one of its most important parts. The aim of this study was to stress the importance of biofiltration, and to describe different designs of biofilters. Many biofilters are being used in commercial and research aquaculture facilities with differences in choice of working organism, design, material, price and etc. For the proper choice of biofilter it is necessary to know characteristics of each recirculating aquaculture system, because there are still no strict criteria for categorizing and applying different biofilter designs.

  5. Inland marine fish culture in low-salinity recirculating aquaculture systems

    Science.gov (United States)

    A growing and increasingly health-conscious population, coupled with declining capture fisheries is driving an increased global demand for farm-raised seafood that can only be met through expansion of aquaculture. In 2007, aquaculture represented 33% of total global seafood production and is projec...

  6. Sea water well and aquaculture preserve, and the combination with a power generation system

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, B.K.

    1988-02-23

    In combination, this patent describes: (a) a power generation apparatus including (1) a system having (i) an evaporator means, (ii) a condenser means, and (iii) an expansion means, and (2) fluid flow means including (i) a first inlet conduit for communicating sea water at a first temperature to the evaporator means, (ii) a second inlet conduit for communicating sea water at a second temperature to the condenser means, and (iii) an outlet conduit for sea water connecting with the evaporator means and the condenser means, (3) well means forming the second inlet conduit, (4) an aquaculture preserved in the form of a reservoir for retention of sea water and marine life to be cultivated.

  7. Low-dose hydrogen peroxide application in closed recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Good, C.

    2012-01-01

    The aim of the present work was to simulate water treatment practices with hydrogen peroxide (HP) in recirculating aquaculture systems (RAS). Six identical 1,700-L pilot-scale RAS were divided into two experimental groups based on daily feed allocation and operated under constant conditions for a period of 3 months. The organic and nitrogenous loadings of the systems differed fourfold between the two groups and were achieved by predefined constant daily feed loads and constant additions of water. The fixed cumulative feed burden was 1.6 × 103 mg feed/L in the low-intensity RAS and 6.3 × 103 mg/L in the high-intensity RAS. The decay of HP in rearing tanks and disconnected biofilter units was investigated by means of HP spiking experiments. The decay in high-intensity RAS rearing units and biofilters was orders of magnitude faster than that in low-intensity units. The application of HP impaired biofilter nitrite oxidation in low-intensity RAS but not in high-intensity RAS. The impact of HP exposure time on biofilter nitrification capacity was then assessed in biofilter bench-scale experiments with nitrite spiking. Exposure time was found to significantly affect nitrite oxidation. Compared with unexposed biofilter elements, nitrite oxidation was reduced more than 90% following 3 h of exposure to 15 mg HP/L, whereas 30 min of exposure had only minor negative effects on nitrite oxidation. The findings of this study demonstrate the potential for developing HP water treatment practices for RAS and contradict prevailing notions that HP cannot be used safely in RAS that employ biofiltration. The development of effective new HP treatment protocols for recirculating aquaculture could reduce the current dependence on formalin to improve water quality and control parasitic loads

  8. Direct utilization of geothermal heat in cascade application to aquaculture and greenhouse systems at Navarro College. Annual report, January 1984-September 1984

    Energy Technology Data Exchange (ETDEWEB)

    Smith, K.

    1984-09-01

    Progress is reported on a project to use the 130/sup 0/F geothermal resource in central Texas. The system for cascading geothermal energy through aquaculture and greenhouse systems was completed and the first shrimp harvest was held. (MHR)

  9. Daily micro particle distribution of an experimental recirculating aquaculture system – A case study

    DEFF Research Database (Denmark)

    Fernandes, Paulo; Pedersen, Lars-Flemming

    2014-01-01

    The particle size distribution (PSD) in a recirculating aquaculture system (RAS) was investigated duringa 24-h cycle. PSD was analyzed in water sampled at several locations in a recirculation loop containing a60-m drum filter, a submerged fixed-bed biofilter and a trickling filter.In relation to total counts, the system was dominated by micro-particles with particles smaller than20 m comprising >94% of the distribution in all samples. However, the system presented a substantialvolumetric influence of larger particles, reflected by a PSD derivate ?-value of 3.40 ± 0.18. Overall ?-valuesthroughout the compartments (p = 0.584) and experimental period (p = 0.217) were not significantlydifferent, although specific components seemed to marginally affect the PSD.A high internal water turnover rate (one system passage every 50 min) promoted the rapid removalof large particles from the system. Permanent volumetric particle removal above 60 m (31% reductionin the relative contribution from each size by the drum filter)per passage, but marginal productionand removal of particles throughout the rest of the system further support the ?-value stability andconsequent PSD equilibrium.The results showed a stable ?-value in the mature RAS. The ?-value is influenced by the containedcompartments and system configuration, and may be used as a system performance-predicting tool.Mechanisms of particle influence on system and fish performance should be addressed in future studies,and are herein discussed

  10. Nitrogen and Phosphorus Removal in the Recirculating Aquaculture System with Water Treatment Tank containing Baked Clay Beads and Chinese Cabbage

    OpenAIRE

    Aeknarin Thanakitpairin; Wiboonluk Pungrasmi; Sorawit Powtongsook

    2014-01-01

    This research aims to describe the nitrogen and phosphorus removal in Recirculating Aquaculture System (RAS) by crop plants biomass production. The 3 experiment systems consisted of 1 treatment (fish tank + baked clay beads + Chinese cabbage) and 2 controls as control-1 (fish tank only) and control-2 (fish tank + baked clay beads), were performed. With all experimental RAS, Nile tilapia (Oreochromis niloticus) was cultured at 2 kg/m3 density. The baked clay beads (8-16 mm in diameter) were fi...

  11. The role of a fish pond in optimizing nutrient flows in integrated agriculture-aquaculture farming systems

    OpenAIRE

    Nhan, D.K.

    2007-01-01

      In the Mekong delta, the Vietnamese government promoted integrated agriculture-aquaculture (IAA) farming systems as an example of sustainable agriculture. An important advantage of IAA-farming is the nutrient linkage between the pond and terrestrial components within a farm, which allows to improve resource use efficiency and income while reducing environmental impacts. This study monitored and analyzed water use in and nutrient flows through ponds that are part of an IAA-farming system. Th...

  12. An efficient water conditioning system for land-based abalone aquaculture

    Energy Technology Data Exchange (ETDEWEB)

    Davis, C.P. [University of Edinburgh (United Kingdom). School of GeoSciences; Carrington, C.G. [University of Otago, Dunedin (New Zealand). Dept. of Physics

    2005-07-01

    Data collected from a single grow-out tank in an abalone farm in southern New Zealand has highlighted hygiene maintenance problems in the use of semi-closed water conditioning systems for the aquaculture of New Zealand black foot abalone Haliotis iris. The data shows that semi-closed systems can have high concentrations of un-ionized ammonia, which is harmful to the animals. In this paper an alternative open flow-through system is suggested where energy demand is limited by heat recovery at the grow-out tank outlet. Using temperature data collected over 1 year, and a previously obtained expression for standing losses, a simple energy model is presented for an open system with heat recovery. To compliment the energy model, a function has been established for abalone production with respect to the concentration of un-ionized ammonia and water temperature. The energy model and production function are combined to determine the impact of plant design and tank conditions on the economics of the operation for the southern New Zealand climate. It is demonstrated that temperature control is financially preferable to an open system with no temperature control, and estimates of optimum operating conditions are given. (author)

  13. Aquaculture system diversity and sustainable development: fish farms and their representation

    OpenAIRE

    Lazard, Jerome; Baruthio, Aurele; Mathe, Syndhia; Rey-valette, Helene; Chia, Eduardo; Clement, Olivier; Aubin, Joel; Morissens, Pierre; Mikolasek, Olivier; Legendre, Marc (ed.); Levang, Patrice; Blancheton, Jean-paul; Rene, Francois

    2010-01-01

    Initiatives for the sustainable development of aquaculture have so far focused on the production of codes of conduct, of best management practices, of standards etc., most of which have been developed by international organisations, the industrial sector and non governmental organisations. They were, to a large extent, produced using a "top down" process and inspired by models from intensive industrial shrimp and sea fish farming (mainly salmon). However, most of global aquaculture production...

  14. Application and analytical verification of peracetic acid use in different types of freshwater aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming

    2011-01-01

    Peracetic acid (PAA) is a highly reactive peroxygen compound with wide-ranging antimicrobial effects. PAA has recently gained substantial attention, due to additional beneficial attributes such as easily degradability and harmless disinfection byproducts. However, PAA is only sporadically used by the aquaculture industry as it is difficult to apply in correct dosages. This study describes the degradation kinetics of PAA when used as an aquaculture disinfectant. Effects of temperature, organic ma...

  15. Recent advances within intensive Recirculated Aquaculture System cultivation of the calanoid copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Jepsen, Per Meyer; Højgaard, Jacob Kring; Drillet, Guillaume; Mahjoub, Mohamed-Sofiane; Rais, Mouloud; Novac, Aliona; Schjelde, Johannes; Andersen, Claus V. B.; Hansen, Benni Winding

    2014-01-01

    Danish aquaculture has within recent years focused upon rearing of new marine fish species. A major challenge for rearing of marine fish species is relevant diets for their fish larvae. Copepods and their larvae stage “nauplii” are well documented as the ideal live feed for a variety of marine aquaculture species. Copepodites and nauplii are superior as live feed compared to rotifers and Artemia both in terms of nutritional value, behaviour and prey size. In 1980s the copepod Acartia tonsa (Dana...

  16. Use of planted biofilters in integrated recirculating aquaculture-hydroponics systems in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Trang, N.T.D.; Brix, Hans

    2014-01-01

    The feasibility of using planted biofilters for purification of recirculated aquaculture water in the Mekong Delta of Vietnam was assessed. The plant trenches were able to clean tilapia aquaculture water and to maintain good water quality in the fish tanks without renewal of the water. NH4-N was removed efficiently in the plant trenches, particularly in the trenches with Canna glauca L., probably because of plant uptake and nitrification-denitrification. Plant uptake constituted 6% of N and 7% o...

  17. Aquaculture Information Package

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, T.; Rafferty, K. [editors

    1998-01-01

    This package of information is intended to provide background to developers of geothermal aquaculture projects. The material is divided into eight sections and includes information on market and price information for typical species, aquaculture water quality issues, typical species culture information, pond heat loss calculations, an aquaculture glossary, regional and university aquaculture offices and state aquaculture permit requirements.

  18. Estimation of primary productivity from diel nitrate uptake measurements of the water hyacinth Eichhornia crassipes in an aquaculture system

    Energy Technology Data Exchange (ETDEWEB)

    Hanisak, M.D.

    1980-01-01

    The primary productivity of the water hyacinth Eichhornia crassipes was estimated from diel measurements of NO/sub 3/-N uptake in an aquaculture system using a continuous, automated nutrient analyzer apparatus. Productivity values obtained by this method agreed favorably with those made by directly harvesting the biomass. Since productivity measurements based on harvesting methods would be impractical on a large scale, the use of diel nutrient uptake measurements would be a significant improvement for proper management of aquatic macrophytes in an aquaculture system. There were few diel changes in NO/sub 3/-N uptake by Eichhornia, a fact which is potentially beneficial to this species not only to its ecological success in its natural ecosystem, but also to its ability to remove nutrients as a component in tertiary sewage treatment.

  19. Enhancing the resilience of inland fisheries and aquaculture systems to climate change

    Directory of Open Access Journals (Sweden)

    Edward H Allison

    2007-12-01

    Full Text Available Some of the most important inland fisheries in the World are found in semi-arid regions. Production systems and livelihoods in arid and semi-arid areas are at risk from future climate variability and change; their fisheries are no exception. This paper reviews the importance of fisheries to livelihoods in ‘wetlands in drylands’, with a focus on case-studies in Africa. We examine the threats posed by climate change to the traditional ‘tri-economy’ of fishing, farming and livestock herding. Although both livelihood strategies and local institutions are highly adapted to cope with, and benefit from, climate-induced variability, weaknesses in the wider governance and macro-economic environment mean that the overall adaptive capacity of these regions is low and the farmer-herder-fishers are vulnerable to projected climate change. In order to maintain the important nutritional, economic, cultural and social benefits of fisheries in the face of climate change, planned adaptation at scales from the local to the regional (trans-national is required. We use the concept of resilience in linked social-ecological systems to examine how such responses may be developed and promoted. Key strategies include facilitating people’s geographical and occupational mobility, improving intersectoral water and land-use planning, and promoting forms of aquaculture that help build resilience of farming systems to seasonal and episodic water deficits.

  20. Managing sea cucumber fisheries and aquaculture : Studies of social-ecological systems in the Western Indian Ocean

    OpenAIRE

    Eriksson, Hampus

    2012-01-01

    Collecting sea cucumbers to supply the high value Chinese dried seafood market is a livelihood activity available to many people in the Western Indian Ocean (WIO), making it an important part of local economies. These fisheries are generally not successfully managed and tropical sea cucumber fisheries show continuing signs of decline. This thesis takes a social-ecological systems approach to guide better management of sea cucumber fisheries and aquaculture in the WIO. Papers 1 and 2 analyse t...

  1. Performance evaluation of the compact aquaculture system integrating submerged fibrousnitrifying biofilters

    Directory of Open Access Journals (Sweden)

    Sorawit Powtongsook

    2012-02-01

    Full Text Available This experiment assessed the performance of submerged fibrous nitrifying biofilters (SFNBs to carry out the zerowaterexchange tilapia cultivation. Without biofilter cleaning, the SFNBs (21 m of biofilter length were susceptible tohydrogen sulfide production when operating beyond the aquaculture density of 13.62 kg/m3. The SFNBs were able tomaintain total ammonia nitrogen (TAN and nitrite below 1.0 mg N/L throughout the experiment and could handle inorganicnitrogen loading as high as 38.6 mg N/L/day when the solid removal from biofilters was performed biweekly. Ammoniumdegradation rate measured at the end of this study was 380±66 mg N/m2/day for biofilters subjected to cleaning. A significantlylower rate of 41.4±2.86 mg N/m2/day was associated with biofilters without any solid removal. Finally, the SFNBsshould be attractive for budget-limited farmers since they are simple to build and operate and can provide alternatives tocage-cultured systems.

  2. Mathematical modelling of nutrient balance of a goldfish (Carassius auratus Linn. recirculating aquaculture system (GRAS

    Directory of Open Access Journals (Sweden)

    Sudeep Puthravilakom Sadasivan Nair

    2010-08-01

    Full Text Available In the present study, a goldfish (Carassius auratus Linn. recirculating aquaculture system (GRAS has been developed. The GRAS consisted of a culture tank, a screen filter and a foam fractionator for removal of particulate and dissolved solids and a trickling filter for conversion of ammonium- and nitrite-nitrogen to relatively harmless nitrate-nitrogen. The culture of goldfish at a stocking density of 1.08 kg/m3 was continued for a period of two and half months. Based on mass balance analysis of ammonium- and nitrate-nitrogen and assuming the trickling filter to be a plug flow reactor, a model was formulated to determine the necessary recirculation flow rate at different times of culture for maintaining the major nutrients, viz., ammonium- and nitrate-nitrogen below their permissible limits. The model was calibrated and validated using the real time data obtained from the experimental run. The high values of coefficient of determination and low values of root mean square error show the effectiveness of the model.

  3. Observations on side-swimming rainbow trout in water recirculation aquaculture systems.

    Science.gov (United States)

    Good, Christopher; Davidson, John; Kinman, Christin; Kenney, P Brett; Bæverfjord, Grete; Summerfelt, Steven

    2014-12-01

    During a controlled 6-month study using six replicated water recirculation aquaculture systems (WRASs), it was observed that Rainbow Trout Oncorhynchus mykiss in all WRASs exhibited a higher-than-normal prevalence of side swimming (i.e., controlled, forward swimming but with misaligned orientation such that the fish's sagittal axis is approximately parallel to the horizontal plane). To further our understanding of this abnormality, a substudy was conducted wherein side swimmers and normally swimming fish were selectively sampled from each WRAS and growth performance (length, weight), processing attributes (fillet yield, visceral index, ventrum [i.e., thickness of the ventral "belly flap"] index), blood gas and chemistry parameters, and swim bladder morphology and positioning were compared. Side swimmers were found to be significantly smaller in length and weight and had less fillet yield but higher ventrum indices. Whole-blood analyses demonstrated that, among other things, side swimmers had significantly lower whole-blood pH and higher Pco2. Side swimmers typically exhibited swim bladder malformations, although the positive predictive value of this subjective assessment was only 73%. Overall, this study found several anatomical and physiological differences between side-swimming and normally swimming Rainbow Trout. Given the reduced weight and fillet yield of market-age side swimmers, producers would benefit from additional research to reduce side-swimming prevalence in their fish stocks. PMID:25250476

  4. An optimized and simplified method for analysing urea and ammonia in freshwater aquaculture systems

    DEFF Research Database (Denmark)

    Larsen, Bodil Katrine; Dalsgaard, Anne Johanne Tang

    2015-01-01

    This study presents a simple urease method for analysis of ammonia and urea in freshwater aquaculture systems. Urea is hydrolysed into ammonia using urease followed by analysis of released ammonia using the salicylate-hypochlorite method. The hydrolysis of urea is performed at room temperature and without addition of a buffer. A number of tests were performed on water samples obtained from a commercial rainbow trout farm to determine the optimal urease concentration and time for complete hydrolysis. One mL of water sample was spiked with 1.3 mL urea at three different concentrations: 50 lg L 1, 100 lg L 1 and 200 lg L 1 urea-N. In addition, five concentrations of urease were tested, ranging from 0.1 U mL 1 to 4 U mL 1. Samples were hydrolysed for various time periods ranging from 5 to 120 min. A urease concentration of 0.4 U mL 1 and a hydrolysis period of 120 min gave the best results, with 99.6–101% recovery of urea-N in samples spiked with 100 or 200 lg L 1 urea-N. The level of accurate quantification of ammonia using the method is 50 lg L 1 NH4 +-N, and the detection level is 5–10 lg L 1 NH4 +-N

  5. Conditioning of broodstock of tiger grouper, Epinephelus fuscoguttatus, in a recirculating aquaculture system

    Directory of Open Access Journals (Sweden)

    Saleem Mustafa

    2015-11-01

    Full Text Available Closing the cycle of commercial species of fish in a recirculating aquaculture system is gaining importance for a number of practical advantages. Founder broodstock originating from the wild population is conditioned to live in hatchery tanks under suitable environmental and feeding conditions and is induced to breed. The juveniles are grown to maturity and facilitated to spawn in captivity to close the life cycle in the hatchery. This experiment was carried out on tiger grouper (Epinephelus fuscoguttatus. After preliminary observations, it was possible to identify appropriate environmental conditions in terms of water quality parameters, volume of broodstock tanks and ration. Growth was nearly isometric (growth exponent = 2.9185 and the condition factor = 1.86. This reflected good management conditions. Cues that trigger sex reversal in this protogynous fish in the hatchery were different from those that operate in nature. It appears that the differentiation of some individuals of a cohort into male sex is linked to socio-demographic cues as well as internal condition of the fish because it related to age and physiological condition. This view was reinforced by a lack of response in young fish to similar cues. The information generated through this study defines what is required for optimum conditioning of tiger grouper broodstock and explains the cues involved in sex differentiation.

  6. Perceptions of shellfish aquaculture in British Columbia and implications for well-being in marine social-ecological systems

    Directory of Open Access Journals (Sweden)

    Linda M. D'Anna

    2015-03-01

    Full Text Available Shellfish aquaculture is often positioned as an adaptive alternative to traditional resource industries, but the social and cultural effects of expanding production on coastal/marine social-ecological systems are unclear. Reporting on a multimethods study, we present perceptions about shellfish aquaculture collected through interviews, participant-employed photography, and a household survey in British Columbia, Canada. With an approach focused on local preferences for social-ecological conditions and the ways in which those conditions may be enhanced or diminished, we indicate that perceptions of the effects of aquaculture on the environment, economy, and lived experience are composed of both objective and subjective components. Interview responses and survey opinions varied widely and included bimodal responses. Industry interviewees tended to focus on environmental and economic benefits while acknowledging concerns about the environment and lived experience. Nonindustry interviewees typically questioned the environmental effects while underscoring economic benefits and negative effects on experience. Most survey participants felt positively about the effects on the economy, expressed negativity and uncertainty about effects on the environment, and demonstrated the greatest variability in opinions about effects on lived experience. Findings revealed uncertainty and alienation across all dimensions. Our findings, used as an analytical lens, support the usefulness of the concept of well-being in attempts like this one to understand the dynamics of coastal communities by providing a framework for deciphering what is important to individuals and societies experiencing change and considering adaptations.

  7. Identification of Bacterial Community Composition in Freshwater Aquaculture System Farming of Litopenaeus vannamei Reveals Distinct Temperature-Driven Patterns

    Directory of Open Access Journals (Sweden)

    Yuyi Tang

    2014-08-01

    Full Text Available Change in temperature is often a major environmental factor in triggering waterborne disease outbreaks. Previous research has revealed temporal and spatial patterns of bacterial population in several aquatic ecosystems. To date, very little information is available on aquaculture environment. Here, we assessed environmental temperature effects on bacterial community composition in freshwater aquaculture system farming of Litopenaeus vannamei (FASFL. Water samples were collected over a one-year period, and aquatic bacteria were characterized by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE and 16S rDNA pyrosequencing. Resulting DGGE fingerprints revealed a specific and dynamic bacterial population structure with considerable variation over the seasonal change, suggesting that environmental temperature was a key driver of bacterial population in the FASFL. Pyrosequencing data further demonstrated substantial difference in bacterial community composition between the water at higher (WHT and at lower (WLT temperatures in the FASFL. Actinobacteria, Proteobacteria and Bacteroidetes were the highest abundant phyla in the FASFL, however, a large number of unclassified bacteria contributed the most to the observed variation in phylogenetic diversity. The WHT harbored remarkably higher diversity and richness in bacterial composition at genus and species levels when compared to the WLT. Some potential pathogenenic species were identified in both WHT and WLT, providing data in support of aquatic animal health management in the aquaculture industry.

  8. Identification of bacterial community composition in freshwater aquaculture system farming of Litopenaeus vannamei reveals distinct temperature-driven patterns.

    Science.gov (United States)

    Tang, Yuyi; Tao, Peiying; Tan, Jianguo; Mu, Haizhen; Peng, Li; Yang, Dandan; Tong, Shilu; Chen, Lanming

    2014-01-01

    Change in temperature is often a major environmental factor in triggering waterborne disease outbreaks. Previous research has revealed temporal and spatial patterns of bacterial population in several aquatic ecosystems. To date, very little information is available on aquaculture environment. Here, we assessed environmental temperature effects on bacterial community composition in freshwater aquaculture system farming of Litopenaeus vannamei (FASFL). Water samples were collected over a one-year period, and aquatic bacteria were characterized by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and 16S rDNA pyrosequencing. Resulting DGGE fingerprints revealed a specific and dynamic bacterial population structure with considerable variation over the seasonal change, suggesting that environmental temperature was a key driver of bacterial population in the FASFL. Pyrosequencing data further demonstrated substantial difference in bacterial community composition between the water at higher (WHT) and at lower (WLT) temperatures in the FASFL. Actinobacteria, Proteobacteria and Bacteroidetes were the highest abundant phyla in the FASFL, however, a large number of unclassified bacteria contributed the most to the observed variation in phylogenetic diversity. The WHT harbored remarkably higher diversity and richness in bacterial composition at genus and species levels when compared to the WLT. Some potential pathogenenic species were identified in both WHT and WLT, providing data in support of aquatic animal health management in the aquaculture industry. PMID:25105725

  9. Developing a Water Temperature Observation Network based on a Ubiquitous Buoy System to Support Aquacultures

    Directory of Open Access Journals (Sweden)

    Masashi Toda

    2008-10-01

    Full Text Available

    The authors have been working on the support of the fishery industry using the information and communication technology. A water temperature observation network is proposed for supporting aquacultures, and a ubiquitous buoy system developed for this purpose is described. The ubiquitous buoy system was created by leveraging ubiquitous sensing technology with water temperature observation buoys that can be executed for $1,000, a figure designed to meet the demands of scallop cultivation fishermen. Since there are no base stations and gateways in marine environments, we selected mobile phones for the Internet connection to send the water temperature data by email. The ubiquitous buoys developed are light weight and of a compact design, and can be easily installed in marine fishery environments. Furthermore, the economic cost allows the buoys to be used in multiple point observation systems. Consequently, not only does the system allow water temperature observations in real time, but it can also be used in future applications to build water temperature observation networks using multiple ubiquitous buoys that share water temperature data and allow analysis of multipoint, multi-layer water temperature data, and thus facilitate efforts to visualize the makeup of water temperature distributions below the surface. Forty ubiquitous buoys have been placed in scallop cultivation regions along the coast of Hokkaido, and the water temperature data is starting to be used.

  10. Errors in experimental design and statistical analysis of aquaculture diet evaluation studies induced by filtration systems

    Directory of Open Access Journals (Sweden)

    Michael F. Tlusty

    2010-07-01

    Full Text Available While single factor diet studies appear to be of simple design, the space constraints in aquaculture caused by the need to filter the aqueous media often c reate constraints on the implementation of the experimental design. A number of papers have been published in which the experimental design and subsequent analysis is incorrect. This paper reviews the principles of experimental design as it related to single factor diet evaluation studies in aquaculture. By adhering tosimple design principles to ensure that experimental units are independent, the data generated by future experiments will be of high quality and results more robust.

  11. Is growth retardation present in Nile tilapia Oreochromis niloticus cultured in low water exchange recirculating aquaculture systems?

    OpenAIRE

    Martins, C. I.; Ochola, D.; Ende, S.S.W.; Eding, E.H.; Verreth, J. A. J.

    2009-01-01

    It has been suggested that fish cultured in recirculating aquaculture systems (RAS) grow less as compared with fish cultured in flow-through systems due to the accumulation of substances. In the Netherlands, the commercial culture of Nile tilapia Oreochromis niloticus in 300 and 600 MT's systems is done exclusively in RAS operated at water exchange ratesas low as 30 L/kg feed/day due to nitrate control by single-sludge denitrification reactors. The use of such nearly closed RAS raises the que...

  12. Public Health Perspectives on Aquaculture

    OpenAIRE

    Gormaz, Juan G.; Fry, Jillian P; Erazo, Marcia; Love, David C.

    2014-01-01

    Nearly half of all seafood consumed globally comes from aquaculture, a method of food production that has expanded rapidly in recent years. Increasing seafood consumption has been proposed as part of a strategy to combat the current non-communicable disease (NCD) pandemic, but public health, environmental, social, and production challenges related to certain types of aquaculture production must be addressed. Resolving these complicated human health and ecologic trade-offs requires systems thi...

  13. Degradation and effect of hydrogen peroxide in small-scale recirculation aquaculture system biofilters

    DEFF Research Database (Denmark)

    MØller, Martin Sune; Arvin, Erik

    2010-01-01

    From an environmental point of view, hydrogen peroxide (HP) has beneficial attributes compared with other disinfectants in terms of its ready degradation and neutral by-products. The rapid degradation of HP can, however, cause difficulties with regard to safe and efficient water treatment when applied in different systems. In this study, we investigated the degradation kinetics of HP in biofilters from water recirculating aquaculture systems (RAS). The potential effect of HP on the nitrification process in the biofilters was also examined. Biofilter elements from two different pilot-scale RAS were exposed to various HP treatments in batch experiments, and the HP concentration was found to follow an exponential decay. The biofilter ammonia and nitrite oxidation processes showed quick recuperation after exposure to a single dose of HP up to 30 mg L?1. An average HP concentration of 10–13 mg L?1 maintained over 3 h had a moderate inhibitory effect on the biofilter elements from one of the RAS with relatively high organic loading, while the nitrification was severely inhibited in the pilot-scale biofilters from the other RAS with a relatively low organic loading. A pilot-scale RAS, equipped with two biofilter units, both a moving-bed (Biomedia) and a fixed-bed (BIO-BLOK®) biofilter, was subjected to an average HP concentration of ?12 mg L?1 for 3 h. The ammonium- and nitrite-degrading efficiencies of both the Biomedia and the BIO-BLOK® filters were drastically reduced. The filters had not reverted to pre-HP exposure efficiency after 24 h, suggesting a possible long-term impact on the biofilters.

  14. End-of-pipe single-sludge denitrification in pilot-scale recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Suhr, Karin Isabel; Pedersen, Lars-Flemming

    2014-01-01

    A step toward environmental sustainability of recirculat aquaculture systems (RAS) is implementation ofsingle-sludge denitrification, a process eliminating nitrate from the aqueous environment while reduc-ing the organic matter discharge simultaneously. Two 1700 L pilot-scale RAS systems each with a 85 Ldenitrification (DN) reactor treating discharged water and hydrolyzed solid waste were setup to testthe kinetics of nitrate and COD removal. Nitrate removal and COD reduction efficiency was measured attwo different DN-reactor sludge ages (high X: 33–42 days and low X: 17–23 days). Nitrate and total N(NO3?+ NO2?+ NH4+) removal of the treated effluent water ranged from 73–99% and 60–95% during theperiods, respectively, corresponding to an overall maximum RAS nitrate removal of approximately 75%.The specific nitrate removal rate increased from 17 to 23 mg NO3?-N (g TVS d)?1and the maximal poten-tial DN rate (measured at laboratory ideal conditions) increased correspondingly from 64–68 mg NO3?-N(g TVS d)?1to 247–294 mg NO3?-N (g TVS d)?1at high and low X, respectively. Quantification of denitri-fiers in the DN-reactors by qPCR showed only minor differences upon the altered sludge removal practice.The hydrolysis unit improved the biodegradability of the solid waste by increasing volatile fatty acid CODcontent 74–76%. COD reductions in the DN-reactors were 64–70%. In conclusion, this study showed thatsingle-sludge denitrification was a feasible way to reduce nitrate discharge from RAS, and higher DN rateswere induced at lower sludge age/increased sludge removal regime. Improved control and optimizationof reactor DN-activity may be achieved by further modifying reactor design and management scheme asindicated by the variation in and between the two DN-reactors.

  15. Inland marine fish culture in low-salinity recirculating aquaculture systems

    Science.gov (United States)

    Expansion of marine aquaculture is challenged by the high cost and limited availability of coastal land and water resources, effluent concerns, high production costs, restricted growing seasons, lack of quality seedstock, and inadequate regulatory and permitting processes. Many of these constraints...

  16. Overview of sustainable marine aquaculture systems engineering projects with emphasis on biofiltration

    Science.gov (United States)

    The rate of ammonia removal for moving bed and static bed biofilters with plastic media was determined for various feed loading rates, flow rates, and salinity. Ammonia removal rates in the eight propeller-wash floating plastic bead filters (0.71 m3) utilized in the 45 m3 recirculating aquaculture ...

  17. Expanded concept of aquaculture

    Directory of Open Access Journals (Sweden)

    Melnikov Victor Nickolaevich

    2012-11-01

    Full Text Available A new expanded definition of the concept "aquaculture" is offered; according to it aquaculture includes fishery, commercial fishing, processing of hydrobionts and ecology of aquaculture. The general concepts, the structure of aquaculture types and the major theoretical and applied problems are considered.

  18. The influence of pellets quality on the growth of sterlet, in recirculating aquaculture system

    Directory of Open Access Journals (Sweden)

    Corina Sion

    2011-04-01

    Full Text Available The paper presents some aspects regarding the influence of food quality on the breeding of sterlet, Acipenser ruthenus Linnaeus, 1758, in a recirculating aquaculture system (RAS. The experiment took place over 30 days, in four pilot breeding units type aquaria of 300 liters in volume. Two kind of variants were compared, with repetition, V1 with 46% crude protein and V2 with 30% crude protein, respectively. The stocking density was of 14 fish/unit. The same feeding level of 8 g/kg metabolic weight (1.5% from total biomass was used in every unit. The technological indicators that showed up at the end of the experiment revealed the following: the mean biomass gain in V1 was of 0.74 kg/m3 compared to 0.39 kg/m3in V2; this was nearly perfectly correlated with the food quality. The growth rate (GR variated from 6.70 to 8.13 g/day in V1 and 3.63-4.17 g/day in V2; the specific growth rate (SGR, calculated as a mean value of the two repetitions of each variant, was of 1.11 g%/day in V1 and 0.63 g%/day in V2; the feed conversion ratio (FCR, calculated as the mean value of the two repetitions from the two variants, was of 1.49 in V1 and of 2.81 in V2. The parameters of fish breeding showed that changing the quality of fodder, the fish growing was positively influenced. This experiment showed also that sterlet is a sturgeon with a moderate growth rate and it is possible to obtain an increase of fish biomass using pellets with 30-46 % crude protein.

  19. Aquaculture information package

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, T.; Rafferty, K.

    1998-08-01

    This package of information is intended to provide background information to developers of geothermal aquaculture projects. The material is divided into eight sections and includes information on market and price information for typical species, aquaculture water quality issues, typical species culture information, pond heat loss calculations, an aquaculture glossary, regional and university aquaculture offices and state aquaculture permit requirements. A bibliography containing 68 references is also included.

  20. Effectiveness of Floating Micro-Bead Bio-Filter for Ornamental Fish in a Re-Circulating Aquaculture System

    OpenAIRE

    R Fadhil

    2011-01-01

    Bio-filtration has been widely used in re-circulating aquaculture system to remove waste and to convert toxic ammonia andnitrite into safe end products ornamental fish and other aquatic organisms. However, the study of micro-bead usage as the filter medium has not yet been broadened and thoroughly developed. Therefore, the aim of this study is to construct a biological filter made from polyethylene micro-bead as the filter medium and to analyze its effectiveness in removingwaste as well as in...

  1. ECONOMIC ANALYSIS OF FRESHWATER AQUACULTURE PRODUCTION: A COMPARATIVE ANALYSIS OF DIFFERENT PRODUCTION SYSTEMS

    Directory of Open Access Journals (Sweden)

    H. Kumar

    2013-01-01

    Full Text Available India produced 8.29 million tonnes of fish in 2010-2011. The industry contributes nearly INR 200 trillion to the national economy, forming 1.4 percent of national gross domestic product (GDP and 5.4 percent of Agricultural GDP. At present, almost 84 percent of the total inland fish production, in the country is contributed by freshwater aquaculture amounting to 3.9 million tonnes in 2008-09. Further, the potential of the vast freshwater resources covering 6.7 million hectare is yet to be fully realized. The freshwater aquaculture which began as small scale activity of stocking ponds with fish seed collected from riverine sources during early fifties in rural Bengal has now transformed into a major economic activity in almost all states. There is a further need to make the sector more vibrant so as to achieve the predicted target of 15 kg per capita fish availability in the country by 2030.

  2. Participatory Monitoring and Feedback System: An Important Entry Towards Sustainable Aquaculture in Bolinao, Northern Philippines

    OpenAIRE

    Lailany Verceles; Liana Talaue-McManus; Porfirio Aliño

    2000-01-01

    The aquaculture industry in Caquiputan Channel contributed P2.3M to municipal revenues in 1998. However, the uncontrolled construction of fish pens and fish cages have contributed to the deterioration of the water quality in the Caquiputan Channel. Despite monitoring of parameters (e.g. DO, salinity, and temperature), low production was implicated because of limited dissolved oxygen supply.A participatory monitoring of fish pens and fish cages was facilitated to pave the way for sustainable a...

  3. [Treatment of marine-aquaculture effluent by the multi-soil-layer (MSL) system and subsurface flow constructed wetland].

    Science.gov (United States)

    Song, Ying; Huang, Yu-ting; Ge, Chuan; Zhang, Hao; Chen, Xin; Zhang, Zhi-jianz; Luo, An-cheng

    2014-09-01

    To evaluate the feasibility of using multi-soil-layer (MSL) system and subsurface flow constructed wetland to treat the wastewater of marine cultured Penaeus vannamei and to determine the suitable process for the local aquaculture wastewater pollution characteristics. In this study, MSL system and four constructed wetland systems with Spartina anglica, Phragmites australis, Typha latifolia and unplanted system were evaluated for their potentials of pollutants removal capacity. The results showed the average removal rates of chemical oxygen demand (COD), total phosphorus (TP), total nitrogen (TN), ammonia nitrogen (NH(4)+ -N) and nitrate (NO-(3) -N) by MSL system were 80. 38% ± 2. 14% , 68. 14% ± 3.51% , 40.79% ± 3. 10% , 42. 68% ± 2.90% and 54. 19% ± 5. 15% , respectively. Additionally, the ability of pollutants removal of other four wetland systems decreased in the order: Spartina anglica, Phragmites australis, Typha latifolia and unplanted system. PMID:25518662

  4. Osnovy formirovanija sistemy upravlenija riskami proektov innovacionnogo razvitija akvakul'tury v regione (Na primere Kaliningradskoj oblasti [The formation of a risk management system for projects in the field of aquaculture innovative development in the Kaliningrad region: a case study

    Directory of Open Access Journals (Sweden)

    Serbulov Alexey

    2012-01-01

    Full Text Available This article sets out to develop the concept and the principal scheme of the formation of a risk management system for innovative economic development projects in the field of aquaculture. The research carried out by the authors helps identify the main problems and characteristics of risk management projects for the development of aquaculture in presentday Russia. The authors outline the status and features of aquaculture development projects in the North-western federal district and the Kaliningrad region. The article formulates and justifies the concept of “risk management projects in innovative development of aquaculture in the region” focusing on the classification of aquaculture risks in relation to innovative development projects, which expands the conceptual framework of risk management in view of the specific risks relating to economic development projects in the field of aquaculture. The authors characterize modern methods and approaches to risk management projects and organizations in the context of their application in the framework of aquaculture development projects and offer mechanisms for risk management of aquaculture development projects, which make it possible to include risk management activity in the general context of activities of parent project organizations. The authors develop the concept and principal scheme of the formation of risk management system for innovative development projects in aquaculture.

  5. Effects of feed loading on nitrogen balances and fish performance in replicated recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Suhr, Karin Isabel

    2012-01-01

    This study investigated the effects of applying four fixed feed loadings to three replicated recirculating aquaculture systems (RAS) on water quality changes, nitrogenous balances and growth performance of rainbow trout (Oncorhynchus mykiss).Feed loadings ranged from 1.6 to 6.3kgfeed/m3 make-up water, with a constant make-up water renewal of 4.7% of total water volume per day in all twelve RAS. Fish densities ranged from 14 to 92kg/m3 during the prolonged trial of 10weeks. Selected water quality parameters were measured during two intensive sampling campaigns, evaluating biofilter nitrification performance and diurnal patterns of total ammonia nitrogen (TAN) and nitrite concentrations. No fish mortality occurred during the study. Feed conversion ratios varied between 0.91±0.04 and 0.95±0.02, and were unaffected by feeding load. Mean nitrate-nitrogen levels ranged from 54±7 to 196±10mg/L at steady state, and the concentration of nitrogenous compounds and organic matter were all positively correlated to feed loading.The TAN loading to the RAS from the specific feed type was assessed in a separate mass-balance study and used as input in a descriptive mathematical model (AQUASIM® software) developed to simulate processes affecting N mass-balances in the RAS. Nitrification kinetic rate constants were applied to the biofilter, and fractions of nitrifiers in suspended solids in the water phase were estimated based on existing information from waste water treatment processes. Two model scenarios successfully simulated the measured TAN concentration in the experimental RAS. The first model scenario applied a first-order area-based nitrification rate (k1a) constant of 0.2m/d, estimating a fraction of active nitrifiers (fN) in the water phase of 4% of the total suspended solids. The second model scenario used a k1a of 0.1, estimating a fN of 8% with similar predictability as in the first scenario. Overall, this study provided new information on fish performance and resulting water quality during steady state RAS operation. Furthermore, the study demonstrated that kinetic modeling can be applied to simulate measured TAN concentrations in experimental RAS.

  6. Effectiveness of Floating Micro-Bead Bio-Filter for Ornamental Fish in a Re-Circulating Aquaculture System

    Directory of Open Access Journals (Sweden)

    R Fadhil

    2011-01-01

    Full Text Available Bio-filtration has been widely used in re-circulating aquaculture system to remove waste and to convert toxic ammonia andnitrite into safe end products ornamental fish and other aquatic organisms. However, the study of micro-bead usage as the filter medium has not yet been broadened and thoroughly developed. Therefore, the aim of this study is to construct a biological filter made from polyethylene micro-bead as the filter medium and to analyze its effectiveness in removingwaste as well as in converting the toxic organic matter into stable substances. The bio-filter was constructed under a rotational molding process. The tubes, hoses, and piping were made from polyvinyl chloride (PVC while the fasteners were made from stainless steel and other non-corrosive materials. The effectiveness of this bio-filter was measured by using biochemical oxygen demand (BOD and total suspended solids (TSS analysis. Results indicated that this bio-filter is efficient enough to remove suspended solids and BOD. Therefore, this floating micro-bead bio-filter can be used in aquaculture systems.

  7. Phosphatase activity and specific methanogenic activity in an anaerobic reactor treating sludge from a brackish recirculation aquaculture system.

    Science.gov (United States)

    Zhang, Xuedong; Ferreira, Rui B; Spanjers, Henri; van Lier, Jules B

    2013-01-01

    Anaerobic treatment of high salinity sludge from marine/brackish recirculation aquaculture systems is potentially limited by inhibition of enzymatic activities and cell lysis resulting from high osmotic pressures. To further address these limitations the following investigations were conducted: effect of salinity on phosphatase activity (PA), soluble microbial products (SMP) production, and presence of extracellular polymeric substances (EPS); effect of iron (III) chloride (FeCl3) on PA and specific methanogenic activity (SMA); effect of addition of the compatible solute glycine betaine (GB) and potassium on PA, as well as on SMP and EPS production, all under saline conditions. The results show that salinity has different effects on PA of anaerobes under starvation and feeding conditions. FeCl3 increased the SMA of the sludge by 22.5% at 100 mg FeCl3/L compared with a control group (0 mg FeCl3/L). Furthermore, results of analysis of variance tests show that betaine increased the polysaccharide content of EPS and polypeptide content of SMP. However, addition of 1 mM potassium chloride did not show a significant effect on EPS and SMP composition. In conclusion, anaerobic digestion of salty sludges from a brackish aquaculture recirculation system may not be negatively affected by FeCl3 addition to concentrate waste streams, whereas GB boosts the production of SMP and EPS. PMID:23863432

  8. Foam fractionation efficiency for particulate matter removal from a low salinity, lowhead recirculating aquaculture system utilized for the culture of red drum, Sciaenops ocellatus

    Science.gov (United States)

    In recirculating aquaculture systems (RAS), the water which is treated and reused must be of such quality to maintain the culture organism in a healthy and fast growing condition, especially as such systems are intensified. Managing particulate matter and different chemical compounds is a key factor...

  9. Prototype recirculating aquaculture system design for juvenile red drum production as part of the Florida Fish and Wildlife Conservation commission’s Hatchery Network Initative

    Science.gov (United States)

    A prototype recirculating aquaculture system for the production of red drum (Sciaenops ocellatus) includes four 10-foot diameter by four foot height tanks for a tank volume of approximately 300 ft3 each (2200 gallons). Water flow for the system is provided for by a low head propeller pump which prov...

  10. Public, animal, and environmental health implications of aquaculture.

    OpenAIRE

    Garrett, E. S.; dos Santos, C L; Jahncke, M. L.

    1997-01-01

    Aquaculture is important to the United States and the world's fishery system. Both import and export markets for aquaculture products will expand and increase as research begins to remove physiologic and other animal husbandry barriers. Overfishing of wild stock will necessitate supplementation and replenishment through aquaculture. The aquaculture industry must have a better understanding of the impact of the "shrouded" public and animal health issues: technology ignorance, abuse, and neglec...

  11. An Overview of Aquaculture in the Nordic Countries

    DEFF Research Database (Denmark)

    Paisley, Larry; Ariel, Ellen; Lyngstad, T. M.; Jónsson, G.; Vennerström, P.; Hellström, A.; Østergaard, P.

    2010-01-01

    The goal of this review was to describe in some detail the Nordic aquaculture industries in order to illuminate the similarities and differences. Information that was gathered for each country includes aquaculture history, aquaculture acts and regulations, production and production systems, environmental concerns, organic aquaculture and outlook for the future. The information will be useful for risk assessments, design of risk-based surveillance programs and for construction of comparative risk...

  12. The influence of different stocking densities on biochemical composition of rainbow trout meat reared in a recirculating aquaculture system

    Directory of Open Access Journals (Sweden)

    Mirela Cretu

    2014-05-01

    Full Text Available The aim of this study is to evaluate the biochemical composition of rainbow trout meat, reared in a recirculating aquaculture system, at different stocking densities (DS1-2,64 kg/m3, DS2-5,16 kg/m3, DS3-7,12 kg/m3, DS4-9,42 kg/m3. The analyses were performed in the research laboratory of Aquaculture, Environmental Science and Cadastre Department – Faculty of Food Science and Engineering, from ,,Dunarea de Jos’’University of Galati. The content of meat proteins, fats, dry substance and ash was determined. After a 33 days experimental trial, the biochemical analysis of meat from all four experimental variants shows that protein content was higher in DS1 and DS4 variants, while the smallest amount of fats was quantified at DS1 and DS2 variants, without significant differences (p >0.05 for none of the biochemical compounds analyzed, at the mean comparison on experimental variants. Thus, it can be concluded that biochemical composition of rainbow trout meat was not influenced by the tested stocking densities.

  13. Future prospects for prophylactic immune stimulation in crustacean aquaculture - the need for improved metadata to address immune system complexity.

    Science.gov (United States)

    Hauton, Chris; Hudspith, Meggie; Gunton, Laetitia

    2015-02-01

    Future expansion of the crustacean aquaculture industry will be required to ensure global food security. However, this expansion must ensure: (a) that natural resources (including habitat use and fish meal) are sustainably exploited, (b) that the socio-economic development of producing nations is safeguarded, and (c) that the challenge presented by crustacean diseases is adequately met. Conventionally, the problem of disease in crustacean aquaculture has been addressed through prophylactic administration of stimulants, additives or probiotics. However, these approaches have been questioned both experimentally and philosophically. In this review, we argue that real progress in the field of crustacean immune stimulants has now slowed, with only incremental advances now being made. We further contend that an overt focus on the immune effector response has been misguided. In light of the wealth of new data reporting immune system complexity, a more refined approach is necessary - one that must consider the important role played by pattern recognition proteins. In support of this more refined approach, there is now a much greater requirement for the reporting of essential metadata. We propose a broad series of recommendations regarding the 'Minimum Information required to support a Stimulant Assessment experiment' (MISA guidelines) to foster new progression within the field. PMID:24796867

  14. Contamination and growth of the shrimp, Penaeus stylirostris Stimpson, cultured in a seawater/wastewater aquaculture system

    Energy Technology Data Exchange (ETDEWEB)

    Landau, M.; Pierce, R.H.; Williams, L.D.; Norris, D.R.

    1985-10-01

    Many commercial mariculture operations have failed because of the costs associated with rearing animals in high density cultures. One of the most significant costs is feed. The costs of culturing marine animals could be lowered by reducing the stocking densities used in the ponds and substituting nutrient-rich, treated wastewater for commercial feeds. However, an aquaculture system which is based on wastewater may not only have a different production profile than a system based on prepared feeds, but the animals may also be subject to contamination. The authors have monitored the growth of shrimp cultured in a seawater/wastewater system and have analyzed water and tissue samples for several likely organic and inorganic contaminants.

  15. Molecular Research in Aquaculture

    Science.gov (United States)

    Molecular research and biotechnology have long been fields of study with applications useful to aquaculture and other animal sciences. Molecular Research in Aquaculture looks to provide an understanding of molecular research and its applications to the aquaculture industry in a format that allows in...

  16. Production characteristics of body composition of Florida pompano reared to market size at two different densities in low salinity recirculating aquaculture systems

    Science.gov (United States)

    The effect of culture density on production characteristics and body composition of Florida pompano Trachinotus carolinus reared to market size using recirculating aquaculture systems (RAS) at a salinity of 5 g/L was evaluated in a 110 day growth trial (water temperature, 27.0-28.5 C). Juvenile pom...

  17. Evaluation of ozonation on levels of the off-flavor compounds geosmin and 2-methylisoborneol in water and rainbow trout Oncorhynchus mykiss from water recirculation aquaculture systems

    Science.gov (United States)

    Common “off-flavors” in fish cultured in water recirculation aquaculture systems (WRAS) are “earthy” and “musty” due to the presence of the off-flavor metabolites geosmin and 2-methylisoborneol (MIB), respectively. Previously, ozone addition has been applied to WRAS at relatively low doses to break...

  18. Flavobacterium branchiophilum and F. succinicans associated with bacterial gill disease in rainbow trout Oncorhynchus mykiss (Walbaum) in water recirculation aquaculture systems

    Science.gov (United States)

    Raised rainbow trout Oncorhynchus mykiss in six replicated water recirculation aquaculture systems (WRAS), and manipulated environmental conditions to promote bacterial gill disease (BGD). For each episode of BGD, gill tissue was sampling from affected fish, unaffected fish within the same WRAS, and...

  19. The impact of water exchange rate and treatment processes on water-borne hormones in recirculation aquaculture systems containing sexually maturing Atlantic salmon Salmo salar

    Science.gov (United States)

    A controlled seven-month study was conducted in six replicated water recirculation aquaculture systems (WRAS) to assess post-smolt Atlantic salmon (Salmo salar) performance in relation to WRAS water exchange rate. Unexpectedly high numbers of precocious sexually mature fish were observed in all WRAS...

  20. The influence of stocking density on the growth of common carp, Cyprinus carpio, in a recirculating aquaculture system

    Directory of Open Access Journals (Sweden)

    Ionica Enache

    2011-04-01

    Full Text Available The paper presents some aspects regarding the influence of stocking density on the breeding of the common carp in a recirculating aquaculture system (RAS. The experiment covered a 30 dayperiod. It was conducted in four aquaculture tanks, 500 L/tank, in the recirculating aquaculture pilot system of “Dunarea de Jos” University of Gala?i. Two kind of stocking density variants were compared: 64 kg/m3 in V1 (B1, B3 and 32 kg/m3 in V2 (B2, B4. The stocking density was: 491 fish in B1, average weight - 65 g/ fish; 245 fish in B2, average weight - 66 g/ fish; 211 fish in B3, average weight - 152 g/fish; 107 fish in B4, average weight - 150 g/fish. The technological indicators obtained revealed the following: the specific growth rate (SGR, calculated as a mean value on the two repetitions, was 1.28%/day in V1 and 1.49 %/day in V2, indicating better growth in V2; the food conversion ratio (FCR, calculated as the mean value of the two repetitions, was 1.28 in V1 and 1.06 in V2, expressing a higher efficiency in capitalization of food in V2. The mean biomass gain in V1 was 30.46 kg/m3 as compared to 18.55 kg/m3 in V2, almost perfectly correlated with the stocking density. The daily growth rate (DGR varied in a similar way, from 494.57 to 520.90 g/day in V1 and 302.4 to 315.9 g/day in V2. The experiment demonstrated a remarkable technological plasticity in both experimental variants, whereas, in terms of technological performance indicators, it was found that the application of lower stocking densities lead to higher crop biomass. The high stocking density means, therefore, large amounts of metabolic waste, removed from the breeding units through their effluent, the recirculating flow of which is 4m3/h, enough to ensure the whole volume of water in a growth tank to be changed every half hour.

  1. Development and design of a fluidized bed/upflow sand filter configuration for use in recirculating aquaculture systems

    Energy Technology Data Exchange (ETDEWEB)

    Burden, D.G.

    1988-01-01

    A fluidized bed/upflow sand filter configuration, was developed and designed for utilization in recirculating aquaculture system, specifically the soft-shell crab and soft-shell crawfish industries. These filters were selected and designed because of their ability to withstand clogging and still maintain high levels of water quality for aquaculture production. The effectiveness of sand grain size was used to evaluate fluidized bed filter performance with filter loadings ranging from 16 to 1285 pounds of crawfish per cubic foot of filter sand. A coarse sand grain size was recommended as a filter media because of it's ability to shear excessive biofilm growth from the and, thus prohibiting clogging from occurring within the filter bed. The fluidized bed/upflow sand filter combination was evaluated in terms of nitrification and oxygen consumption when used with a recirculating crab shedding system. The filter combination's carrying capacity (700 crabs per cubic foot of sand media) exceeded that observed with the submerged rock filter by more than 20 times and was largely explained by the filter's solids removal ability which significantly reduced the filter's oxygen loading rate (OLR). Nitrification rates with the filter combination were extremely high as total ammonia and nitrite levels remained below 1.0 mg-N/l. Verification of a volumetric loading criteria (150 pounds per cubic foot) for this filter combination was further established with performance data obtained from a commercial soft-shell crawfish facility. Water quality monitoring results indicated that the filters maintained total ammonia and nitrite levels below 1.0 mg-N/l under typical operating conditions. Shock loading, pH control, and over-feeding, rather than filter capacity, dominated water quality fluctuations, thereby indicating that the loading criteria was sufficient for commercial operation.

  2. Desarrollo de Sistemas de Vigilancia Tecnológica en la Acuicultura Española / Development of Technological Vigilance Systems in Spanish Aquaculture

    Scientific Electronic Library Online (English)

    Francisco Javier, Sánchez Sellero; Montserrat, Cruz González.

    2012-10-01

    Full Text Available En este artículo caracterizamos el proceso de vigilancia tecnológica como respuesta empresarial a la necesaria adaptación a entornos turbulentos y como origen de ventajas competitivas. En este sentido realizamos una recensión teórica, un análisis estratégico de la referida vigilancia como herramient [...] a para el desarrollo competitivo de la empresa en sectores involucrados con la investigación, el desarrollo y la innovación (I+D+i), así como una adaptación secuencial al desarrollo de la acuicultura. Sobre dicha base hemos realizado una aplicación al sector de la acuicultura en España, mediante el contraste de tres hipótesis relacionadas con el nivel global de desarrollo de los sistemas, los factores y agentes del entorno y la utilización de fuentes de información, todas ellas a través del programa estadístico SPSS 18. Como conclusión hemos identificado patrones globales para la vigilancia en el sector y especificidades por subsector, actividad, área geográfica o tipo de cultivo. Abstract in english In this paper we characterize the process of technological monitoring like enterprise answer to the necessary adjustment to turbulent environments and like origin of competitive advantages. In this respect we fulfil a theoretical critique, a strategic analysis of the above-mentioned monitoring like [...] tool for the competitive development of the company in sectors involved with the research, development and innovation (R+D+i), as well as a sequential adjustment to the development of aquaculture. On the above mentioned base we have realized an application to the Spanish Aquaculture, by means of the resistance of three hypotheses related to the global level of development of the systems, the factors and agents of the environment and the use of sources of intelligence, all of them through statistical program SPSS 18. Since conclusion we have identified global patterns for the monitoring in the sector and specificities by subsector, activity, geographical area or type of crop.

  3. Marketing Netcoatings for Aquaculture

    OpenAIRE

    Martin, Robert J.

    2014-01-01

    Unsustainable harvesting of natural fish stocks is driving an ever growing marine aquaculture industry. Part of the aquaculture support industry is net suppliers who provide producers with nets used in confining fish while they are grown to market size. Biofouling must be addressed in marine environments to ensure maximum product growth by maintaining water flow and waste removal through the nets. Biofouling is managed with copper and organic biocide based net coatings. The aquaculture indust...

  4. Aquaculture-fisheries interactions

    OpenAIRE

    Mikkelsen, Eirik

    2006-01-01

    Assuming externalities from aquaculture to fisheries, we use a Verhulst-Schaefer model of fish population-dynamics and production, coupled with an aquaculture production model, to investigate effects on open-access and rent-maximising fisheries. Externalities are modelled by letting carrying capacity, intrinsic growth rate or catchability coefficient in the fishery depend on aquaculture production. We find that the different externalities can give opposite effects on steady sta...

  5. The effect of recirculating aquaculture systems on the concentrations of heavy metals in culture water and tissues of Nile tilapia Oreochromis niloticus

    OpenAIRE

    Martins, C. I.; Eding, E.H.; Verreth, J. A. J.

    2011-01-01

    To date, farming fish in recirculating aquaculture systems (RAS) is one of the most environmentally friendly ways of producing fish. However, with the trend towards intensification, and consequently decrease in water exchange rates, these systems may accumulate substances, such as heavy metals, in the water and fish. Inductively-coupled plasma-optical emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectroscope (ICP-MS) were used to determine Al, As, Cd, Cr, Cu, Fe, Mn, Ni...

  6. Geothermal aquaculture in Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Birk, S.

    1987-06-01

    Work in geothermal aquaculture and vertically integrated agriculture is undertaken by Washoe Aquaculture Limited, Gourmet Prawnz Inc., General Managing Partners. This approach to agriculture is researched at the integrated Prototype Aquaculture Facility (IPAF) at Hobo Hot Springs, Nevada. The principal objective at the IPAF is to use geothermal aquifers to commercially raise food, plants, and ornamental fish. At the IPAF, the feasibility of geothermal aquaculture has been demonstrated. The company has implemented many demonstration projects, including the cultivation of freshwater prawns, native baitfish, exotic tropical species, and commercially important aquatic plants.

  7. Hydrogen peroxide decomposition kinetics in aquaculture water

    DEFF Research Database (Denmark)

    Arvin, Erik; Pedersen, Lars-Flemming

    2015-01-01

    Hydrogen peroxide (HP) is used in aquaculture systems where preventive or curative water treatments occasionally are required. Use of chemical agents can be challenging in recirculating aquaculture systems (RAS) due to extended water retention time and because the agents must not damage the fish reared or the nitrifying bacteria in the biofilters at concentrations required to eliminating pathogens. This calls for quantitative insight into the fate of the disinfectant residuals during water treat...

  8. Disease in marine aquaculture

    Science.gov (United States)

    Sindermann, C. J.

    1984-03-01

    It has become almost a truism that success in intensive production of animals must be based in part on development of methods for disease diagnosis and control. Excellent progress has been made in methods of diagnosis for major pathogens of cultivated fish, crustacean and molluscan species. In many instances these have proved to be facultative pathogens, able to exert severe effects in populations of animals under other stresses (marginal physical or chemical conditions; overcrowding). The concept of stress management as a critical prophylactic measure is not new, but its significance is being demonstrated repeatedly. The particular relationship of water quality and facultative pathogens such as Vibrio, Pseudomonas and Aeromonas species has been especially apparent. Virus diseases of marine vertebrates and invertebrates — little known two decades ago — are now recognized to be of significance to aquaculture. Virus infections of oysters, clams, shrimps and crabs have been described, and mortalities have been attributed to them. Several virus diseases of fish have also been recognized as potential or actual problems in culture. In some instances, the pathogens seem to be latent in natural populations, and may be provoked into patency by stresses of artificial environments. One of the most promising approaches to disease prophylaxis is through immunization. Fish respond well to various vaccination procedures, and new non-stressing methods have been developed. Vibriosis — probably the most severe disease of ocean-reared salmon — has been controlled to a great extent through use of a polyvalent bacterin, which can be modified as new pathogenic strains are isolated. Prophylactic immunization for other bacterial diseases of cultivated fish has been attempted, especially in Japan, with some success. There is also some evidence that the larger crustaceans may be immunologically responsive, and that at least short-term protection may be afforded to cultured populations. Some progress has been made in marine disease control through chemical treatment in intensive culture systems, principally through application and modification of methods developed for freshwater aquaculture. Major constraints to use of chemicals are restrictions due to public health concerns about food contamination, and the negative effects of some chemicals on biological filters and on algal food production. There is a continuing need, however, for development of specific treatments for acute disease episodes — such as the nitrofurans, developed in Japan, which are effective for some bacterial diseases. The history of aquaculture — freshwater as well as marine — has been characterized by transfers and introductions of species to waters beyond their present ranges. The process continues, and carries with it the possibility of transfers of pathogens to native species and to the recipient culture environments. International groups are attempting to define codes of practice to govern such mass movements, but examples of introductions of real or potential pathogens already exist. The most recent and the most dramatic is the world wide transfer of a virus pathogen of penaeid shrimps. Earlier examples include the introduction of a protozoan pathogen of salmonids to the western hemisphere, and the introduction of a parasitic copepod from the Far East to the west coast of North America and to France. The conclusion is inevitable — diseases are substantial deterrents to aquaculture production. Diagnostic and control procedures are and will be important components of emerging aquaculture technology.

  9. Effect of hydraulic loading rate on the efficiency of effluent treatment in a recirculating puffer aquaculture system coupled with constructed wetlands

    Science.gov (United States)

    Xu, Jiabo; Shi, Yonghai; Zhang, Genyu; Liu, Jianzhong; Zhu, Yazhu

    2013-11-01

    Constructed wetlands (CWs) were integrated into an indoor recirculating aquaculture system of obscure puffer (Takifugu obscurus) for effluent treatment. The effect of hydraulic loading rate (HLR) on the efficiency of effluent treatment by CWs was examined for over a month. The CWs were operated under brackish conditions (salinity 7.4-7.6) at 3 different HLRs (0.762, 0.633, and 0.458 m d-1) 3 times, 10 days each. Overall, the CWs exhibited high efficiency in removal of total ammonium nitrogen (by 81.03-92.81%) and nitrite nitrogen (by 99.40%-99.68%). The efficiency of CWs in removal of total ammonium nitrogen, nitrate nitrogen, total Kjeldahl nitrogen, total phosphorous, and total suspended solids (TSS) increased with the decrease of HLR. The CWs operated at the 3 HLRs in a decreasing trend proves to be effective, providing a useful method for effluent treatment in commercial puffer aquaculture systems.

  10. RESEARCHES REGARDING THE TECHNOLOGICAL PERFORMANCES OF CARP REARING DURING WINTER PERIOD IN THE CONDITIONS OF A RECIRCULATING AQUACULTURE SYSTEM

    Directory of Open Access Journals (Sweden)

    G. STEFAN

    2013-12-01

    Full Text Available The techniques of carp culture are highly diversified, ranging from the extensive production in pond or open water with no fertilization or supplemental feeding to highly intensive systems in concrete tanks or cages. Among the different carp species, common carp is the best species reared in intensive monoculture, the others (Chinese and Indian carps being usually cultivated in polyculture (P. Kestemont, 1995. An experiment was conducted in inside recirculation system conditions to identify the technological performances on carp growth and survival at the Fishing and Aquaculture Department, Galati, during winter period (February, 2007 – March, 2007. The 1-year-old carp (Cyprinus carpio 4792g; 4594 g; 4561 g and 4525 g (total weight grew to 7384g; 7017g; 6924g and 7125 g in 44 days in aquarium 1, 2, 3 and 4, respectively. In all aquariums, the fish appeared healthy and no mortality was observed. Feed conversion efficiencies (FCE had similar values among all aquariums, the highest FCE being found in B4 aquarium with 1, 57 value. Water quality parameters were acceptable range for fish culture. Results show that the carp rearing during winter period in the inside recirculation system is a very good economic solution.

  11. Trophic structure in a pilot system for the integrated multi-trophic aquaculture off the east coast of Korean peninsula as determined by stable isotopes.

    Science.gov (United States)

    Park, Hyun Je; Han, Eunah; Lee, Won Chan; Kwak, Jung Hyun; Kim, Hyung Chul; Park, Mi Seon; Kang, Chang-Keun

    2015-06-15

    To assess the potential for nutritional exploitation of caged-fish-derived waste through the use of extractive co-cultured species in a pilot system for an integrated multi-trophic aquaculture (IMTA), we compared their C and N stable isotope ratios with those of uncultured macroinvertebrates in and around the system. Black rockfish were co-cultured with sea cucumber, oyster, and two macroalgae as extractive species. Isotope signatures of the co-cultured sea cucumber at the IMTA site differed from those at the control site, indicating their assimilation of aquaculture wastes. In contrast, ?(13)C and ?(15)N of individual taxa of the cultured oyster and uncultured invertebrates were consistent between sites, suggesting a minor contribution of the aquaculture waste to benthic and pelagic food chains in and around the IMTA system. These results provide evidence of the suitability of using sea cucumber as an extractive species to reduce the impact of a monoculture system on the ambient environment. PMID:25916198

  12. Economic values of growth and feed efficiency for fish farming in recirculating aquaculture system with density and nitrogen output limitations: a case study with African catfish (Clarias gariepinus)

    OpenAIRE

    Besson, M.; Komen, H.; Aubin, J.; Boer, I.J.M. de; Poelman, M.; Quillet, Edwige; Vancoillie, C.; Vandeputte, Marc; van Arendonk, J. A. M.

    2014-01-01

    In fish farming, economic values (EV) of breeding goal traits are lacking, even though they are key parameters when defining selection objectives. The aim of this study was to develop a bioeconomic model to estimate EV of 2 traits representing production performances in fish farming: the thermal growth coefficient (TGC) and the feed conversion ratio (FCR). This approach was applied to a farm producing African catfish (Clarias gariepinus) in a recirculating aquaculture system (RAS). In the RAS...

  13. Leaf vegetables for use in integrated hydroponics and aquaculture systems: Effects of root flooding on growth, mineral composition and nutrient uptake

    DEFF Research Database (Denmark)

    Trang, Ngo Thuy Diem; Schierup, Hans-Henrik; Brix, Hans

    2010-01-01

    In recirculating aquaculture and hydroponics systems, the waste products from fish production are used to produce vegetables or other crops of economic value, and the water is recirculated to the fish tanks. We studied growth, productivity and nutrient uptake of four leaf vegetable species (Lactuca sativa, Ipomoea aquatica, Brassica rapa var. chinensis and Brassica rapa var. parachinensis) in a controlled growth experiment with three root flooding treatments (drained, half-flooded and flooded) t...

  14. Aquaculture activities in Fiji

    OpenAIRE

    Vereivalu, T

    1989-01-01

    Fiji has no aquaculture tradition, but the Government is engaged in aquaculture production since 1969, with the help of other countries and international organization like F.A.O. Some species have been tested: Fishes: Grass carp (Ctenopharyngodon idellus ) and Tilapia ; Molluscs: Oyster (Crassostrea echinata ) and Mussel (Mytilus viridis ); Crustacean: freshwater prawn (Macrobrachium rosenbergii ) and shrimps (Penaeus monodon, P. indicus, P. stylirostris ).

  15. Aquaculture in New Zealand

    OpenAIRE

    Hayden, B.

    1989-01-01

    Aquaculture is a relatively new activity in New Zealand. The indigenous rock oyster (Saccostrea glomerata ) was the first target for aquaculture in the 1930's although it was not intensively cultured until the 1960's. The faster growing Pacific oyster (Crassostrea gigas ) appeared in 1969/70 and now comprises virtually all the farmed oysters in New Zealand.

  16. Isotopes in aquaculture research

    International Nuclear Information System (INIS)

    The applications of isotopes in aquaculture research include areas like aquatic production process, nutrient cycles and food chain dynamics, fish nutrition, fish physiology, genetics and immunology. The radioisotopes commonly used are beta emitters. The use of different radioisotopes in aquaculture research are presented. 2 tabs

  17. Impact of water boundary layer diffusion on the nitrification rate of submerged biofilter elements from a recirculating aquaculture system

    DEFF Research Database (Denmark)

    Prehn, Jonas; Waul, Christopher Kevin

    2012-01-01

    Total ammonia nitrogen (TAN) removal by microbial nitrification is an essential process in recirculating aquaculture systems (RAS). In order to protect the aquatic environment and fish health, it is important to be able to predict the nitrification rates in RAS’s. The aim of this study was to determine the impact of hydraulic film diffusion on the nitrification rate in a submerged biofilter. Using an experimental batch reactor setup with recirculation, active nitrifying biofilter units from a RAS were exposed to a range of hydraulic flow velocities. Corresponding nitrification rates were measured following ammonium chloride, NH4Cl, spikes and the impact of hydraulic film diffusion was quantified. The nitrification performance of the tested biofilter could be significantly increased by increasing the hydraulic flow velocity in the filter. Area based first order nitrification rate constants ranged from 0.065 m d?1 to 0.192 m d?1 for flow velocities between 2.5 m h?1 and 40 m h?1 (18 °C). This study documents that hydraulic film diffusion may have a significant impact on the nitrification rate in fixed film biofilters with geometry and hydraulic flows corresponding to our experimental RAS biofilters. The results may thus have practical implications in relation to the design, operational strategy of RAS biofilters and how to optimize TAN removal in fixed film biofilter systems

  18. Genomic approaches in aquaculture and fisheries

    DEFF Research Database (Denmark)

    Cancela, M. Leonor; Bargelloni, Luca; Boudry, Pierre; Boulo, Viviane; Dias, Jorge; Huvet, Arnaud; Laize, Vincent; Lapegue, Sylvie; Leite, Ricardo; Mira, Sara; Eg Nielsen, Einar; Planas, Josep V.; Roher, Nerea; Sarropoulou, Elena; Volckaert, Filip A. M.; Cock, JM; TessmarRaible, K; Boyen, C; Viard, F

    2010-01-01

    Despite the enormous input into the worldwide development of fish and shellfish farming in the recent decades, in part as an attempt to minimize the impact of fishing on already overexploited natural populations, the application of genomics to aquaculture and fisheries remains poorly developed. Improving state-of-the-art genomics research in various aquaculture systems, as well as its industrial applications, remains one of the major challenges in this area and should be the focus of well develo...

  19. Biological denitrification using poly(butylene succinate) as carbon source and biofilm carrier for recirculating aquaculture system effluent treatment.

    Science.gov (United States)

    Zhu, Song-Ming; Deng, Ya-Le; Ruan, Yun-Jie; Guo, Xi-Shan; Shi, Ming-Ming; Shen, Jia-Zheng

    2015-09-01

    Nitrate removal is essential for the sustainable operation of recirculating aquaculture system (RAS). This study evaluated the heterotrophic denitrification using poly(butylene succinate) as carbon source and biofilm carrier for RAS wastewater treatment. The effect of varied operational conditions (influent type, salinity and nitrate loading) on reactor performance and microbial community was investigated. The high denitrification rates of 0.53 ± 0.19 kg NO3(-)-N m(-3) d(-1) (salinity, 0‰) and 0.66 ± 0.12 kg NO3(-)-Nm(-3) d(-1) (salinity, 25‰) were achieved, and nitrite concentration was maintained below 1mg/L. In addition, the existence of salinity exhibited more stable nitrate removal efficiency, but caused adverse effects such as excessive effluent dissolved organic carbon (DOC) and dissimilation nitrate reduce to ammonia (DNRA) activity. The degradation of PBS was further confirmed by SEM and FTIR analysis. Illumina sequencing revealed the abundance and species changes of functional denitrification and degradation microflora which might be the primary cause of varied reactor performance. PMID:26093254

  20. Depletion of florfenicol amine in tilapia (Oreochromis sp.) maintained in a recirculating aquaculture system following Aquaflor®-medicated feed therapy

    Science.gov (United States)

    Gaikowski, Mark P.; Whitsel, Melissa K.; Charles, Shawn; Schleis, Susan M.; Crouch, Louis S.; Endris, Richard G.

    2015-01-01

    Aquaflor® [50% w w?1 florfenicol (FFC)], is approved for use in freshwater-reared warmwater finfish which include tilapia Oreochromis spp. in the United States to control mortality from Streptococcus iniae. The depletion of florfenicol amine (FFA), the marker residue of FFC, was evaluated after feeding FFC-medicated feed to deliver a nominal 20 mg FFC kg?1 BW d?1 dose (1.33× the label use of 15 mg FFC kg?1 BW d?1) to Nile tilapia O. niloticus and hybrid tilapia O. niloticus × O. aureus held in a recirculating aquaculture system (RAS) at production-scale holding densities. Florfenicol amine concentrations were determined in fillets taken from 10 fish before dosing and from 20 fish at nine time points after dosing (from 1 to 240 h post-dosing). Water samples were assayed for FFC before, during and after the dosing period. Parameters monitored included daily feed consumption and biofilter function (levels of ammonia, nitrite and nitrate). Mean fillet FFA concentration decreased from 13.77 ?g g?1 at 1-h post dosing to 0.39 ?g g?1 at 240-h post dosing. Water FFC concentration decreased from a maximum of 1400 ng mL?1 at 1 day post-dosing to 847 ng mL?1 at 240 h post-dosing. There were no adverse effects noted on fish, feed consumption or biofilter function associated with FFC-medicated feed administration to tilapia.

  1. Application of CFD modeling to hydrodynamics of CycloBio fluidized sand bed in recirculating aquaculture systems

    Science.gov (United States)

    Liu, Yao; Song, Xiefa; Liang, Zhenlin; Peng, Lei

    2013-11-01

    To improve the efficiency of a CycloBio fluidized sand bed (CB FSB) in removal of dissolved wastes in recirculating aquaculture systems, the hydrodynamics of solid-liquid flow was investigated using computational fluid dynamics (CFD) modeling tools. The dynamic characteristics of silica sand within the CB FSB were determined using three-dimensional, unsteady-state simulations with the granular Eulerian multiphase approach and the RNG k-? turbulence model, and the simulation results were validated using available lab-scale measurements. The bed expansion of CB FSB increased with the increase in water inflow rate in numerical simulations. Upon validation, the simulation involving 0.55 mm particles, the Gidaspow correlation for drag coefficient model and the Syamlal-O'Brien correlation for kinetic granular viscosity showed the closest match to the experimental results. The volume fraction of numerical simulations peaked as the wall was approached. The hydrodynamics of a pilot-scale CB FSB was simulated in order to predict the range of water flow to avoid the silica sand overflowing. The numerical simulations were in agreement with the experimental results qualitatively and quantitatively, and thus can be used to study the hydrodynamics of solid-liquid multiphase flow in CB FSB, which is of importance to the design, optimization, and amplification of CB FSBs.

  2. Importance of kelp-derived organic carbon to the scallop Chlamys farreri in an integrated multi-trophic aquaculture system

    Science.gov (United States)

    Xu, Qiang; Gao, Fei; Yang, Hongsheng

    2015-10-01

    Bivalves and seaweeds are important cleaners that are widely used in integrated multi-trophic aquaculture (IMTA) systems. A beneficial relationship between seaweed and bivalve in the seaweedbased IMTA system has been confirmed, but the trophic importance of seaweed-derived particulate organic materials to the co-cultured bivalve is still unclear. We evaluated the trophic importance of the kelp Saccharina japonica to the co-cultured scallop Chlamys farreri in a typical IMTA farm in Sungo Bay (Weihai, North China). The dynamics of detritus carbon in the water were monitored during the culturing period. The proportion of kelp-derived organic matter in the diet of the co-cultured scallop was assessed via the stable carbon isotope method. Results showed that the detritus carbon in the water ranged from 75.52 to 265.19 ?g/L, which was 25.6% to 73.8% of total particulate organic carbon (TPOC) during the study period. The amount of detritus carbon and its proportion in the TPOC changed throughout the culture cycle of the kelp. Stable carbon isotope analysis showed that the cultured scallop obtained 14.1% to 42.8% of its tissue carbon from the kelp, and that the percentages were closely correlated with the proportion of detritus carbon in the water (F=0.993, P=0.003). Evaluation showed that for 17 000 tons (wet weight) of annual scallop production, the kelp contributed about 139.3 tons of carbon (535.8 tons of dry mass). This confirms that cultured kelp plays a similar trophic role in IMTA systems as it does in a natural kelp bed. It is a major contributor to the detritus pool and supplies a vital food source to filter-feeding scallops in the IMTA system, especially during winter and early spring when phytoplankton are scarce.

  3. Environmental constraints and aquaculture development

    OpenAIRE

    Paquotte, Philippe; Bailly, Denis

    1994-01-01

    Aquaculture is an economic activit y which is characterised by a great dependence on environmental conditions. Therefore, aquaculture development is subdued to institutional context which defines the rules for use and conservation of natural resources. This paper analyses the impact of marine environment regulations on economic operating of aquaculture enterprises and on industrial d ynamics. Because aquaculture enterprises use common goods, an economic approach of aquaculture has to take int...

  4. Nitrogen and Phosphorus Removal in the Recirculating Aquaculture System with Water Treatment Tank containing Baked Clay Beads and Chinese Cabbage

    Directory of Open Access Journals (Sweden)

    Aeknarin Thanakitpairin

    2014-01-01

    Full Text Available This research aims to describe the nitrogen and phosphorus removal in Recirculating Aquaculture System (RAS by crop plants biomass production. The 3 experiment systems consisted of 1 treatment (fish tank + baked clay beads + Chinese cabbage and 2 controls as control-1 (fish tank only and control-2 (fish tank + baked clay beads, were performed. With all experimental RAS, Nile tilapia (Oreochromis niloticus was cultured at 2 kg/m3 density. The baked clay beads (8-16 mm in diameter were filled as a layer of 10 cm in the water treatment tank of control-2. While in the treatment tank, Chinese cabbage (Brassica pekinensis was planted at 334 plants/m2 in baked clay beads layer. During 35 days of experiment, the average fish wet-weight in control-1, control-2 and treatment systems increased from 16.31±1.49, 15.18±1.28 and 11.31±1.49 g to 29.43±7.06, 28.65±3.12 and 27.20±6.56 g, respectively. It was found that the growth rate of 0.45±0.15 g-wet weight/day in a treatment tank was higher than in those 2 controls, which were rather similar at 0.37±0.16 and 0.38±0.05 g-wet weight/day, respectively. The fish survival rate of all experimental units was 100%. The average Chinese cabbage wet-weight in treatment system increased from 0.15±0.02 g to 1.00±0.38 g. For water quality, all parameters were within the acceptable range for aquaculture. The assimilation inorganic nitrogen in a treatment tank showed a slower rate and lower nitrite accumulation relative to those in control tanks. The nitrogen and phosphorus balance analysis illustrated that most of the nitrogen and phosphorus input in all systems was from feed (82-87% and 21-87% while at the final day of experiments, nitrogen and phosphorus in tilapia culture revealed at 15-19% and 4-13%. The accumulation of nitrogen and phosphorus in the water, up to 56% and 70%, was found in control-1 while water in the tank with baked clay beads had substantial lower nitrogen and phosphorus concentration. The most important part was unaccounted nitrogen and phosphorus as high as 60% and 17% in treatment and 53% and 10% in control-2 systems. Nitrogen and phosphorus incorporated in plant (treatment was only 1.31% and 0.11%, respectively. It can be implied from the results that the assimilation in plant was a minor process for nutrient removal in this RAS. On the other hand, the nitrification and denitrification occurred in the sediment layer of baked clay beads tank were the major treatment processes to maintain water quality in the recirculating system. Without baked clay bead, nitrogen waste was accumulated as nitrate in the water while in treatment tank with backed clay beads, nitrogen was significantly removed by denitrification process.

  5. Aquaculture development in Asia :current status, economics and future outlook

    OpenAIRE

    Dey, Madan Mohan; Sheriff, Natasja; Bjørndal, Trond

    2006-01-01

    The purpose of this article is to analyse aquaculture development in selected Asian countries. The contribution of Asia to world aquaculture will be documented. In Asia, different culture systems are practised and numerous species are farmed, and these will be surveyed. Patterns of fish supply, demand and trade are described, followed by an analysis of economic conditions in aquaculture. Finally, a number of scenarios for future development are analysed.

  6. Zebrafish as animal model for aquaculture nutrition research

    OpenAIRE

    Ulloa, Pilar E.; Medrano, Juan F; Feijoo, Carmen G.

    2014-01-01

    The aquaculture industry continues to promote the diversification of ingredients used in aquafeed in order to achieve a more sustainable aquaculture production system. The evaluation of large numbers of diets in aquaculture species is costly and requires time-consuming trials in some species. In contrast, zebrafish (Danio rerio) can solve these drawbacks as an experimental model, and represents an ideal organism to carry out preliminary evaluation of diets. In addition, zebrafish has a sequen...

  7. Electronics circuits and systems

    CERN Document Server

    Bishop, Owen

    2011-01-01

    The material in Electronics - Circuits and Systems is a truly up-to-date textbook, with coverage carefully matched to the electronics units of the 2007 BTEC National Engineering and the latest AS and A Level specifications in Electronics from AQA, OCR and WJEC. The material has been organized with a logical learning progression, making it ideal for a wide range of pre-degree courses in electronics. The approach is student-centred and includes: numerous examples and activities; web research topics; Self Test features, highlighted key facts, formulae and definitions. Ea

  8. Electronics circuits and systems

    CERN Document Server

    Bishop, Owen

    2007-01-01

    The material in Electronics - Circuits and Systems is a truly up-to-date textbook, with coverage carefully matched to the electronics units of the 2007 BTEC National Engineering and the latest AS and A Level specifications in Electronics from AQA, OCR and WJEC. The material has been organized with a logical learning progression, making it ideal for a wide range of pre-degree courses in electronics. The approach is student-centred and includes: numerous examples and activities; web research topics; Self Test features, highlighted key facts, formulae and definitions. Each chapter ends with a set

  9. Aquaculture in Sweden : Sustainability of land-based recirculation aquaculture as a future alternative for Swedish fish farmers

    OpenAIRE

    van der Blom, Daan Wilhelmus

    2013-01-01

    With the world’s population expanding rapidly and estimated to reach nine billion in 2050, the demand for food will increase. Therefore the need for more sustainable ways of food production, in particular meat, poultry and fish are needed. Aquaculture can significantly contribute to this. This thesis focuses on Swedish aquaculture and in particular the increasingly used method of food fish farming in Recirculation Aquaculture Systems (RAS). The aim of the thesis is to analyze and discern the ...

  10. MUNICIPAL WASTEWATER AQUACULTURE

    Science.gov (United States)

    The developmental status of the aquacultural alternative for treatment and reuse of municipal wastewater is reviewed. Major emphasis is given to the reduction or fate of pollutants in such areas as organics, solids, nutrients, heavy metals, residual hydrocarbons, and potentially ...

  11. Danish Aquaculture 2005

    OpenAIRE

    Højgaard, Jonas K.; Jepsen, Per M.; Jørgensen, Anders T.

    2005-01-01

    In this project, the development of the three main aquaculture production methods were evaluated through case studies, and analysed in regards of the environmental impacts of the productions. In addition, trends and tendencies within the development of the sectors were analysed through interviews. It was found that the Danish aquaculture sector as a whole has been stagnated since the early nineties. This stagnation was partly induced by legislative requests more or less corresponding with the...

  12. Microalgae for aquaculture

    OpenAIRE

    Michels, M.H.A.

    2015-01-01

    In 2007, the project ‘Zeeuwse Tong’ (Zeeland Sole) was founded with support of the province of Zeeland, the Netherlands. The aim of the Zeeuwse Tong project was to establish an innovative land-based integrated multi-trophic aquaculture sector, which is producing sole, ragworms, algae, shellfish and saline crops in close harmony with nature. The project was divided into two sub-projects: The integrated saline aquaculture farm and the integrated nursery. The research described in this thesis re...

  13. Molecular genetics in aquaculture

    OpenAIRE

    Liliana Di Stasio; Claudio Lisa; Rossella Lo Presti

    2009-01-01

    Great advances in molecular genetics have deeply changed the way of doing research in aquaculture, as it has already done in other fields. The molecular revolution started in the 1980’s, thanks to the widespread use of restriction enzymes and Polymerase Chain Reaction technology, which makes it possible to easily detect the genetic variability directly at the DNA level. In aquaculture, the molecular data are used for several purposes, which can be clustered into two main groups. The fir...

  14. Mechanisms of quorum sensing and strategies for quorum sensing disruption in aquaculture pathogens.

    Science.gov (United States)

    Zhao, J; Chen, M; Quan, C S; Fan, S D

    2015-09-01

    In many countries, infectious diseases are a considerable threat to aquaculture. The pathogenicity of micro-organisms that infect aquaculture systems is closely related to the release of virulence factors and the formation of biofilms, both of which are regulated by quorum sensing (QS). Thus, QS disruption is a potential strategy for preventing disease in aquaculture systems. QS inhibitors (QSIs) not only inhibit the expression of virulence-associated genes but also attenuate the virulence of aquaculture pathogens. In this review, we discuss QS systems in important aquaculture pathogens and focus on the relationship between QS mechanisms and bacterial virulence in aquaculture. We further elucidate QS disruption strategies for targeting aquaculture pathogens. Four main types of QSIs that target aquaculture pathogens are discussed based on their mechanisms of action. PMID:25219871

  15. Single-sludge denitrification in recirculating aquaculture systems: Effects of pre-fermentation and pH

    DEFF Research Database (Denmark)

    Suhr, Karin Isabel; Letelier Gordo, Carlos Octavio

    2014-01-01

    Single-sludge denitrification (DN) reactors in aquaculture utilize the solid fish waste produced in the system to reduce the nitrate load discharged. The solid waste is available for denitrifiers when present in soluble readily biodegradable form. A transformation accomplished by bacterial hydrolysis (and fermentation). The objective of this study was to quantify the effect of pre-fermentation of the solid fish waste on single-sludge DN-reactor efficiency. Pre-fermentation times tested were; 0 (no pre-fermentation), 1 d, 5 d, and 10 d. The efficiency was quantified as the potential DN-rates in laboratory assessments. Results showed that the highest DN-rate obtained was achieved by 1 d pre-fermentation. The volumetric DN-rate measured in decreasing order was; 23.4 ± 0.00 (1 d); 20.5 ± 0.35 (5 d); 17.0 ± 0.47 (10 d); 14.2 ± 0.24 (0 d) mg NO3-N (L?h)-1 It was suspected that the poor utilization of sCOD in 5 and 10 d pre-fermentation treatments were due to low start pH (below 7). Subsequently, the experiments were repeated in 0.1 M HEPES buffer pH=7.1, and showed a clear correlation between specific DN-rate and soluble COD content. Overall, the highest increase in potential specific DN-rate was achieved by applying pre-fermentation, e.g. from 0 d to 1 d the increase was 85 % and 106 % at unadjusted pH and pH 7.1, respectively. Additional 20 % increase was achieved at pH 7.1 by prolonging the pre-fermentation time to 5 d. At unadjusted pH conditions, the higher sCOD obtained by longer pre-fermentation was futile due to inhibitory effect of low pH

  16. Electronic components and systems

    CERN Document Server

    Dennis, W H

    2013-01-01

    Electronic Components and Systems focuses on the principles and processes in the field of electronics and the integrated circuit. Covered in the book are basic aspects and physical fundamentals; different types of materials involved in the field; and passive and active electronic components such as capacitors, inductors, diodes, and transistors. Also covered in the book are topics such as the fabrication of semiconductors and integrated circuits; analog circuitry; digital logic technology; and microprocessors. The monograph is recommended for beginning electrical engineers who would like to kn

  17. Improving the oscillating grid method to characterize aquaculture biosolids using a laser beam and image analysis

    OpenAIRE

    Masaló Llorà, Ingrid; Ruiz, Joan Ramon; Oca Baradad, Joan

    2014-01-01

    Quick removal of biosolids in aquaculture facilities, and specially in recirculating aquaculture systems (RAS), is one of the most important step in waste management . Sedimentation dynamics of biosolids in an aquaculture tank will determine their accumulation at the bottom of the tank .

  18. Intensification of landbased aquaculture production in single pass and reuse systems

    OpenAIRE

    Blancheton, J.P.; R. Piedrahita; Eding, E.H.; Roque d'orbcastel, D.E.; Lemarié, G.; Bergheim, A.; Fivelstad, S.

    2007-01-01

    Over the last 20 years, the productivity in hatcheries and farms producing fry and smolt of trout and salmon has increased substantially. These land-based farms are mainly situated along the coast and discharge effluent water directly to the sea. Such production is the basis of the recruitment of marine salmon and trout cage farms in Chile, Scotland, Norway and some other temperate countries with a coastline. Similarly, productivity and use of recirculation systems for the production of both ...

  19. 2-Methylisoborneol and geosmin uptake by organic sludge derived from a recirculating aquaculture system.

    Science.gov (United States)

    Guttman, Lior; van Rijn, Jaap

    2009-02-01

    In a previous study on a recirculating fish culture system, levels of geosmin and 2-methylisoborneol were found to decrease when culture water was recirculated through the anaerobic sludge digestion treatment stage of the system. This finding led us to the present study in which the geosmin and 2-methylisoborneol removal capacity of the sludge derived from this treatment stage was examined in vitro. It was found that reduction of off-flavor compounds by the sludge was mediated by both chemical/physical sorption and biological degradation. At geosmin and 2-methylisoborneol concentrations within the range of those experienced in fish culture systems, chemical/physical sorption by the sludge was found to account for a 93% reduction in geosmin and a 79% reduction in 2-methylisoborneol from the overlying water within 48h of incubation. Combined with the biological degradation taking place in the sludge, a complete removal of these compounds from the water phase occurred within 9 days of incubation. By means of repeated washing of the geosmin and 2-methylisoborneol contaminate sludge with clean water, relatively small amounts of these compounds were released from the sludge, a possible indication for the fact that absorption, rather than adsorption, underlies the chemical/physical removal process. PMID:18986667

  20. Fuzzy logic based control system for fresh water aquaculture: A MATLAB based simulation approach

    Directory of Open Access Journals (Sweden)

    Rana Dinesh Singh

    2015-01-01

    Full Text Available Fuzzy control is regarded as the most widely used application of fuzzy logic. Fuzzy logic is an innovative technology to design solutions for multiparameter and non-linear control problems. One of the greatest advantages of fuzzy control is that it uses human experience and process information obtained from operator rather than a mathematical model for the definition of a control strategy. As a result, it often delivers solutions faster than conventional control design techniques. The proposed system is an attempt to apply fuzzy logic techniques to predict the stress factor on the fish, based on line data and rule base generated using domain expert. The proposed work includes a use of Data acquisition system, an interfacing device for on line parameter acquisition and analysis, fuzzy logic controller (FLC for inferring the stress factor. The system takes stress parameters on the fish as inputs, fuzzified by using FLC with knowledge base rules and finally provides single output. All the parameters are controlled and calibrated by the fuzzy logic toolbox and MATLAB programming.

  1. Electron beam processing system

    International Nuclear Information System (INIS)

    Electron beam Processing Systems (EPS) are used as useful and powerful tools in many industrial application fields such as the production of cross-linked wire, rubber tire, heat shrinkable film and tubing, curing, degradation of polymers, sterilization and environmental application. In this paper, the feature and application fields, the selection of machine ratings and safety measures of EPS will be described. (author)

  2. Enhancing the resilience of inland fisheries and aquaculture systems to climate change

    OpenAIRE

    Edward H Allison; Neil L Andrew; Jamie Oliver

    2007-01-01

    Some of the most important inland fisheries in the World are found in semi-arid regions. Production systems and livelihoods in arid and semi-arid areas are at risk from future climate variability and change; their fisheries are no exception. This paper reviews the importance of fisheries to livelihoods in ‘wetlands in drylands’, with a focus on case-studies in Africa. We examine the threats posed by climate change to the traditional ‘tri-economy’ of fishing, farming and livestock herding. Alt...

  3. Application of a fluidized bed reactor charged with aragonite for control of alkalinity, pH and carbon dioxide in marine recirculating aquaculture systems

    Science.gov (United States)

    Paul S Wills, PhD; Pfeiffer, Timothy; Baptiste, Richard; Watten, Barnaby J.

    2015-01-01

    Control of alkalinity, dissolved carbon dioxide (dCO2), and pH are critical in marine recirculating aquaculture systems (RAS) in order to maintain health and maximize growth. A small-scale prototype aragonite sand filled fluidized bed reactor was tested under varying conditions of alkalinity and dCO2 to develop and model the response of dCO2 across the reactor. A large-scale reactor was then incorporated into an operating marine recirculating aquaculture system to observe the reactor as the system moved toward equilibrium. The relationship between alkalinity dCO2, and pH across the reactor are described by multiple regression equations. The change in dCO2 across the small-scale reactor indicated a strong likelihood that an equilibrium alkalinity would be maintained by using a fluidized bed aragonite reactor. The large-scale reactor verified this observation and established equilibrium at an alkalinity of approximately 135 mg/L as CaCO3, dCO2 of 9 mg/L, and a pH of 7.0 within 4 days that was stable during a 14 day test period. The fluidized bed aragonite reactor has the potential to simplify alkalinity and pH control, and aid in dCO2 control in RAS design and operation. Aragonite sand, purchased in bulk, is less expensive than sodium bicarbonate and could reduce overall operating production costs.

  4. Criterios hidrodinámicos para el diseño de sistemas de recirculación en acuicultura / Hydrodynamic Criteria to Design Water Recirculation Systems for Aquaculture

    Scientific Electronic Library Online (English)

    Juan A., García-Aragón; Humberto, Salinas-Tapia; Víctor, Díaz-Palomarez; Boris M., López-Rebollar; Javier, Moreno-Guevara; Leonarda M., Flores-Gutiérrez.

    2014-10-01

    Full Text Available Con el objetivo de hacer más eficiente el uso del agua se ha desarrollado la técnica de sistemas cerrados de recirculación de agua (SRA) para acuicultura. Un aspecto que se ha relegado, en cuanto a los estudios de calidad de agua y biológicos, es el relativo a la hidrodinámica de esos tanques de rec [...] irculación. En este trabajo se describe una investigación experimental llevada a cabo en un modelo en plexiglass a escala reducida de dichos tanques de recirculación. En un tanque circular se utilizó comida para peces; los flóculos resultantes sirvieron de trazadores para establecer las características de sedimentación. Por medio de técnicas ópticas, velocimetría por imágenes de partículas (PIV), se pudo determinar una distribución óptima de difusores para lograr diferentes velocidades en el tanque, a fin de facilitar los procesos de floculación y, a su vez, los de sedimentación. Igualmente se propone un diseño del sedimentador central en función de las características de los flóculos y de su comportamiento hidrodinámico, en especial su velocidad de caída. Para calcular las velocidades de caída de los flóculos se utilizó la técnica de velocimetría por rastreo de partículas (PTV). Los resultados experimentales permitieron calibrar un modelo matemático de velocidades de caída de flóculos. Abstract in english Closed water recirculation systems (WRS) have been developed for aquaculture in order to more efficiently use water. In terms of water quality and biological studies, the hydrodynamics of recirculation tanks is an aspect that has been least studied. The work herein describes an experimental investig [...] ation carried out with a reduced-scale plexiglass model of these tanks. Fish food was used in one tank in which the resulting flocs served as tracers to determine sedimentation characteristics. Using optical techniques ¾ particle image velocimetry (PIV)¾ it was possible to determine the optimal distribution of diffusers to obtain different velocities in the tank in order to facilitate the flocculation and sedimentation processes. A design for a central settling basin is also proposed based on the characterization of the flocs and their hydrodynamic behavior, particularly the fall velocity. Particle trace velocimetry (PTV) was used to calculate the fall velocity of the flocs. The experimental results enabled calibrating a mathematical model for fall velocities of flocs.

  5. MDT DCS Electronics System

    CERN Document Server

    Tsarouchas, Charilaos; Gazis, Evangelos; Tsipolitis, Georgios

    This note has the aim to present the Detector Control System for the Monitor- ing of the electronics values of MDT chambers in ATLAS experiment in CERN. This system is decided to be called in short ELTX. The principal task of DCS is to enable and ensure the coherent and safe oper- ation of the detector. The interaction of detector expers, users or shifters to the detector hardware is also done via DCS. This is the responsible system of moni- toring the operational parameters and the overall state of the detector, the alarm generation and handling, the connection of hardware values to databases and the interaction with the DAQ system. Through this thesis, one can see what ELTX system has to offer as a Detector Control System and in detail, what is the hardware to be controlled and monitored. Moreover it is presented the mainstream of central Atlas DCS concerning the active interfaces.ELTX is a system following these standards.

  6. Cooling system for electronic components

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, William James; Colgan, Evan George; Gerken, James Dorance; Marroquin, Christopher Michael; Tian, Shurong

    2015-12-15

    Embodiments of the present invention provide for non interruptive fluid cooling of an electronic enclosure. One or more electronic component packages may be removable from a circuit card having a fluid flow system. When installed, the electronic component packages are coincident to and in a thermal relationship with the fluid flow system. If a particular electronic component package becomes non-functional, it may be removed from the electronic enclosure without affecting either the fluid flow system or other neighboring electronic component packages.

  7. An Overview of Aquaculture in the Nordic Countries

    DEFF Research Database (Denmark)

    Paisley, Larry; Ariel, Ellen

    2010-01-01

    The goal of this review was to describe in some detail the Nordic aquaculture industries in order to illuminate the similarities and differences. Information that was gathered for each country includes aquaculture history, aquaculture acts and regulations, production and production systems, environmental concerns, organic aquaculture and outlook for the future. The information will be useful for risk assessments, design of risk-based surveillance programs and for construction of comparative risk profiles for endemic and exotic diseases affecting aquaculture in the Nordic countries. Aquaculture in the Nordic countries has a long history; beginning in the 1850s when hatcheries for restocking of salmon and trout were established in Norway. Nowadays, Atlantic salmon is the dominant cultured species in Norway and the Faroe Islands, whereas rainbow trout dominate in Denmark, Finland, and Sweden. Arctic char and cod are most important in Iceland. Other important cultured species include eel and blue mussels. There is much diversity in Nordic aquaculture industries in terms of production, farmed species, and production systems. Although the vast majority of the Nordic aquaculture production is for human consumption, significant numbers of fish are grown for restocking of rivers, lakes, or other bodies of freshwater or seawater.

  8. Preliminary research on the anammox process and control of nitrogen compounds in a recirculating aquaculture system

    Directory of Open Access Journals (Sweden)

    Savin Cristian

    2013-01-01

    Full Text Available Using anammox process in biological filtration of technological water within recirculatingaquaculture system is an alternative to nitrification / denitrification process which can reduce productioncosts, especially energy by replacing aerobic biological processes that require high oxygen consumption,provided through the addition for optimal function of biofilter (conversion of N-NH4 and N-NO2. Aim ofthis paper is to highlight the first steps in the control of nitrogen compounds in recirculating aquaculturesystems using anammox process. Data shown are obtained after 78 researching days (research stillongoing, the results being encouraging, registering an ammonium removal efficiency of 77% in SC1 andof 32% in SC2. Nitrites registered an increase in SC1 and a decrease in SC2 and there are allprerequisites showing that in SC2 anammox activity is more advanced than in SC1. The average ofoxygen consumption rate was 0.73 mgL-1 in SC1 smaller than 0.99 mgL-1 from SC2, which reinforces theidea that there are anammox process in SC2.

  9. Certify Sustainable Aquaculture?

    OpenAIRE

    Bush, S.R.; Belton, B.; Hall, D.; Vandergeest, P.; Murray, F. J.; Ponte, S.; Oosterveer, P.J.M.; Islam, M S; Mol, A.P.J.; Hatanaka, M.; Kruijssen, F.; Ha, T.T.T.; Little, D.C.; Kusumawati, R.

    2013-01-01

    Aquaculture, the farming of aquatic organisms, provides close to 50% of the world's supply of seafood, with a value of U.S. $125 billion. It makes up 13% of the world's animal-source protein (excluding eggs and dairy) and employs an estimated 24 million people (1). With capture (i.e., wild) fisheries production stagnating, aquaculture may help close the forecast global deficit in fish protein by 2020 (2). This so-called “blue revolution” requires addressing a range of environmental and social...

  10. PROTEOMICS in aquaculture

    DEFF Research Database (Denmark)

    Rodrigues, Pedro M.; Silva, Tomé S.; Dias, Jorge; Jessen, Flemming

    2012-01-01

    Over the last forty years global aquaculture presented a growth rate of 6.9% per annum with an amazing production of 52.5million tonnes in 2008, and a contribution of 43% of aquatic animal food for human consumption. In order to meet the world's health requirements of fish protein, a continuous growth in production is still expected for decades to come. Aquaculture is, though, a very competitive market, and a global awareness regarding the use of scientific knowledge and emerging technologies to...

  11. Certify Sustainable Aquaculture?

    DEFF Research Database (Denmark)

    Bush, Simon; Belton, Ben; Hall, Derek; Vandergeest, Peter; Murray, Francis J.; Ponte, Stefano; Oosterveer, Peter; Islam, Muhammad Saidul; Mol, Arthur P. J.; Hatanaka, Maki; Kruijssen, Froukje; Ha, Tran Thi Thu; Little, David C.; Kusumawati, Rini

    2013-01-01

    Aquaculture, the farming of aquatic organisms, provides close to 50% of the world's supply of seafood, with a value of U.S. $125 billion. It makes up 13% of the world's animal-source protein (excluding eggs and dairy) and employs an estimated 24 million people (1). With capture (i.e., wild) fisheries production stagnating, aquaculture may help close the forecast global deficit in fish protein by 2020 (2). This so-called “blue revolution” requires addressing a range of environmental and social pr...

  12. Certify Sustainable Aquaculture?

    DEFF Research Database (Denmark)

    Bush, Simon; Belton, Ben

    2013-01-01

    Aquaculture, the farming of aquatic organisms, provides close to 50% of the world's supply of seafood, with a value of U.S. $125 billion. It makes up 13% of the world's animal-source protein (excluding eggs and dairy) and employs an estimated 24 million people (1). With capture (i.e., wild) fisheries production stagnating, aquaculture may help close the forecast global deficit in fish protein by 2020 (2). This so-called “blue revolution” requires addressing a range of environmental and social problems, including water pollution, degradation of ecosystems, and violation of labor standards.

  13. Disordered Electron Systems

    CERN Document Server

    Castro, C D; Castro, Carlo Di; Raimondi, Roberto

    2004-01-01

    These lectures provide an introduction to the theory of disordered interacting electron systems. In particular, we concentrate on those aspects which are fundamental for the problem of the metal-insulator transition due to the interplay of disorder and interaction. After reviewing the problem of disordered non-interacting electrons, we examine the past and recent experimental urgency to take into account interaction effects. We describe, by using the language of standard perturbation theory, how these interactions effects lead to the picture of the renormalized disordered Fermi liquid. This allows us to obtain the renormalization group equations for the disordered interacting electron liquid. The group equations are then discussed by the light of the existing experimental evidence.

  14. The influence of stocking density on growth performance and hematological profile of stellate sturgeon (A. stellatus, Pallas, 1771, reared in an industrial ,, flow-through’’ aquaculture system

    Directory of Open Access Journals (Sweden)

    Desimira Maria Dicu Stroe

    2013-10-01

    Full Text Available 800x600 The aim of this paper is to evaluate the influence of four different stocking densities, ranging from 18.7 to 28.6 kg m3, on growth performance and welfare of juvenile stellate sturgeons, reared in an industrial ,,flow-through’’ aquaculture system. At the end of 60 days experimental period, a survival rate of 98% and a stocking density that ranged from 32.5 to 39.8 kg m-3 were registered. The physiological state of biological material is characterized by the values ??of hematological indices, that are not significant from the statistical point of view (p> 0.05, both at the beginning and at the end of experimental period, as well as between experimental variants. To assess the biological material growth performance, feed conversion ratio (FCR, specific growth rate (SGR and profile index were calculated. Regarding the growth performance parameters, better value are encountered at B1 (18.7 kg m-3 and B3 (23.3 kg m-3, appreciable values ??at B2 (20.4 kg m-3 and low values at B4 (28.6 kg m-3. As conclusion, it can be assert that the initial stocking density of 28.6 kg m-3 is not optimal for rearing juvenile stellate sturgeons in an industrial ,,flow-through’’ aquaculture system. Normal 0 21 false false false RO X-NONE X-NONE MicrosoftInternetExplorer4

  15. Confinement Aquaculture. Final Report.

    Science.gov (United States)

    Delaplaine School District, AR.

    The Delaplaine Agriculture Department Confinement Project, begun in June 1988, conducted a confinement aquaculture program by comparing the growth of channel catfish raised in cages in a pond to channel catfish raised in cages in the Black River, Arkansas. The study developed technology that would decrease costs in the domestication of fish, using…

  16. Aquaculture. Teacher Edition.

    Science.gov (United States)

    Walker, Susan S.

    This color-coded guide was developed to assist teachers in helping interested students plan, build, stock, and run aquaculture facilities of varied sizes. The guide contains 15 instructional units, each of which includes some or all of the following basic components: objective sheet, suggested activities for the teacher, instructor supplements,…

  17. Reduced photoperiod (18 h light vs 24 h light) during first-year rearing associated with increased early male maturation in Atlantic salmon Salmo salar cultured in a freshwater recirculation aquaculture system

    Science.gov (United States)

    Early male sexual maturation in Atlantic salmon Salmo salar is undesirable for a number of reasons related to production efficiency, and it appears that precocious maturation is a particular problem when raising this species to market size in water recirculation aquaculture systems (RAS). We investi...

  18. Hydrogen peroxide decomposition kinetics in aquaculture water

    DEFF Research Database (Denmark)

    Arvin, Erik; Pedersen, Lars-Flemming

    2015-01-01

    Hydrogen peroxide (HP) is used in aquaculture systems where preventive or curative water treatments occasionally are required. Use of chemical agents can be challenging in recirculating aquaculture systems (RAS) due to extended water retention time and because the agents must not damage the fish reared or the nitrifying bacteria in the biofilters at concentrations required to eliminating pathogens. This calls for quantitative insight into the fate of the disinfectant residuals during water treatment. This paper presents a kinetic model that describes the HP decomposition in aquaculture water facilitated by microbial enzyme activity. The model describes how the hydrogen peroxide removal declines and eventually stops at relatively low chemical oxygen demand (COD) concentrations. It is hypothesized that this is due to an enzyme deficit because it is destructed due to the reactive radicals created during the HP decomposition. The model assumes that the enzyme decay is controlled by an inactivation stoichiometry related to the HP decomposition. In order to make the model easily applicable, it is furthermore assumed that the COD is a proxy of the active biomass concentration of the water and thereby the enzyme activity. This was, however, not measured. The model developed successfully described the removal of HP in aquaculture water from three types of RAS and model parameters are estimated. The model and the model parameters provide new information and are valuable tools to improve HP application in RAS by addressing disinfection demand and identify efficient and safe water treatment routines.

  19. Research on Aquaculture in China

    OpenAIRE

    Zhou, Ang; Wang, Dong; Wang, Di

    2013-01-01

    This paper analyzes the state and conditions of aquaculture in South China Sea both from technological and economic perspectives. We state from the basic marginal cost analysis and construct a two sector model for this issue. Base on the comparison on the cost between aquaculture sector and traditional agricultural sector, we conclude that China has a big potential in aquaculture and the government should impulse this industry by necessary policy instrument.

  20. Background paper on aquaculture research

    DEFF Research Database (Denmark)

    Wenblad, Axel; Jokumsen, Alfred; Eskelinen, Unto; Torrissen, Ole

    2013-01-01

    The Board of MISTRA established in 2012 a Working Group (WG) on Aquaculture to provide the Board with background information for its upcoming decision on whether the foundation should invest in aquaculture research. The WG included Senior Advisor Axel Wenblad, Sweden (Chairman), Professor Ole Torrissen, Norway, Senior Advisory Scientist Unto Eskelinen, Finland and Senior Advisory Scientist Alfred Jokumsen, Denmark. The WG performed an investigation of the Swedish aquaculture sector including int...

  1. L'aquaculture au Sénégal

    OpenAIRE

    Belot, J.; Niamadio, I.

    1988-01-01

    Aquaculture in Senegal. Different projects of aquaculture in Senegal are reviewed. In Senegal, the productions in aquaculture are : culture of oysters in Joal Fadiouth (about 6, 000 dozens/year) a test of shrimp production (Penaeusj in Casamance, the first one in West Africa (0.5 T to 4.5 T/ha/year) culture of Tilapia nilotica long the Senegal river in the north and Anambe in the south. Problems about these projects are discussed.

  2. Heterotrophic denitrification of aquaculture effluent using fluidized sand biofilters

    Science.gov (United States)

    The ability to consistently and cost-effectively reduce nitrate-nitrogen loads in effluent from recirculating aquaculture systems would enhance the industry's environmental stewardship and allow improved facility proximity to large markets in sensitive watersheds. Heterotrophic denitrification techn...

  3. Literature review of the potential effects of hydrogen peroxide on nitrogen oxidation efficiency of the biofilters of recirculating aquaculture systems (RAS) for freshwater finfish

    Science.gov (United States)

    Fredricks, Kim T.

    2015-01-01

    A comprehensive literature review was done for the effects of hydrogen peroxide (HP) on biofilter function in recirculating aquaculture systems (RAS) using these databases: ISI/Web of Knowledge, Scopus, and Pubmed. Inclusion and exclusion criteria were developed as the literature review was conducted. The initial search produced 5,748 potential citations. Once the literature search was complete, these 5,748 titles were screened for applicable papers using the inclusion and exclusion criteria. If the title contained any of the inclusion terms, it was retained. Titles of the remaining papers were then screened for exclusion terms. If the title contained one or more of the exclusion terms, it was eliminated from further consideration. This refined search produced 1,405 papers.

  4. Literature review of the potential effects of formalin on nitrogen oxidation efficiency of the biofilters of recirculating aquaculture systems (RAS) for freshwater finfish

    Science.gov (United States)

    Fredricks, Kim T.

    2015-01-01

    A comprehensive literature review was done for the effects of formalin on biofilter function in recirculating aquaculture systems (RAS) using these databases: ISI/Web of Knowledge, Scopus, and Pubmed. Inclusion and exclusion criteria were developed as the literature review was conducted. The initial search produced 5,682 potential citations. Once the literature search was complete, these 5,682 titles were screened for applicable papers using the inclusion and exclusion criteria. If the title contained any of the inclusion terms, it was retained. Titles of the remaining papers were then screened for exclusion terms. If the title contained one or more of the exclusion terms, it was eliminated from further consideration. This refined search produced 1,287 papers.

  5. Direct utilization of geothermal heat in cascade application to aquaculture and greenhouse systems at Navarro College. Final report, March 1, 1979-September 30, 1984

    Energy Technology Data Exchange (ETDEWEB)

    Smith, K.

    1984-09-01

    This final report documents the Navarro College geothermal use project, which is one of nineteen direct-use geothermal projects funded principally by DOE. The six-year project encompassed a broad range of technical, institutional, and economic activities including: resource and environmental assessment; well drilling and completion; system design, construction, and monitoring; economic analysis; and public awareness programs. Some of the project conclusions are that: (1) the 130/sup 0/F Central Texas geothermal resource can support additional geothermal development; (2) private sector economic incentives currently exist which encourage commercial development of this geothermal resource; (3) potential uses for this geothermal resource include water and space heating, aquacultural and agricultural heating uses, and fruit and vegetable dehydration; (4) high maintenance costs arising from the geofluids' scaling and corrosion characteristics can be avoided through proper analysis and design.

  6. Electronic Nicotine Delivery Systems.

    Science.gov (United States)

    2015-11-01

    Electronic nicotine delivery systems (ENDS) are rapidly growing in popularity among youth. ENDS are handheld devices that produce an aerosolized mixture from a solution typically containing concentrated nicotine, flavoring chemicals, and propylene glycol to be inhaled by the user. ENDS are marketed under a variety of names, most commonly electronic cigarettes and e-cigarettes. In 2014, more youth reported using ENDS than any other tobacco product. ENDS pose health risks to both users and nonusers. Nicotine, the major psychoactive ingredient in ENDS solutions, is both highly addictive and toxic. In addition to nicotine, other toxicants, carcinogens, and metal particles have been detected in solutions and aerosols of ENDS. Nonusers are involuntarily exposed to the emissions of these devices with secondhand and thirdhand aerosol. The concentrated and often flavored nicotine in ENDS solutions poses a poisoning risk for young children. Reports of acute nicotine toxicity from US poison control centers have been increasing, with at least 1 child death reported from unintentional exposure to a nicotine-containing ENDS solution. With flavors, design, and marketing that appeal to youth, ENDS threaten to renormalize and glamorize nicotine and tobacco product use. There is a critical need for ENDS regulation, legislative action, and counter promotion to protect youth. ENDS have the potential to addict a new generation of youth to nicotine and reverse more than 50 years of progress in tobacco control. PMID:26504128

  7. ECOLOGICAL CAPABILITY EVALUATION FOR AQUACULTURE ACTIVITIES BY GIS

    OpenAIRE

    M. Reyahi Khoram, M. Shariat, N. Moharamnejad, A. Azar and H. Mahjub

    2005-01-01

    Geographic Information System (GIS) is the best suitable system for land evaluation. In this research, at the first step, the Makhdoum's model is introduced‚ and then Hamadan Province, from aquaculture point of view and capabilities of the lands to fulfill aquaculture activities is evaluated. GIS was used for the mentioned purposes. The software used was Arc View (version 3.2 a), with the UTM projection. For evaluation, Mc Hark method of Maps overlaying was utilized. According to the results,...

  8. Nutrients valorisation via duckweed-based wastewater treatment and aquaculture

    OpenAIRE

    El-Shafai, S.A.A.M.

    2004-01-01

    Development of a sustainable wastewater treatment scheme to recycle sewage nutrients and water in tilapia aquaculture was the main objective of this PhD research. Use of an Integrated UASB-duckweed ponds system for domestic wastewater treatment linked to tilapia aquaculture was investigated. The treatment system was efficiënt in organic matter removal during the entire year, while nitrogen, phosphorus and faecal coliform removal were negatively affected by the decline in temperat...

  9. Contact zoonotic risks for aquaculture professionals in warm water aquaculture

    Science.gov (United States)

    Aquaculture production and consumption of aquacultural products increases. This growth enhances an increase in zoonotic infection from either handling or ingestion of these products. The principal pathogens acquired topically from fish or shellfish through spine/pincer puncture or open wounds are A...

  10. Leaf vegetables for use in integrated hydroponics and aquaculture systems: Effects of root flooding on growth, mineral composition and nutrient uptake

    DEFF Research Database (Denmark)

    Trang, Ngo Thuy Diem; Schierup, Hans-Henrik

    2010-01-01

    In recirculating aquaculture and hydroponics systems, the waste products from fish production are used to produce vegetables or other crops of economic value, and the water is recirculated to the fish tanks. We studied growth, productivity and nutrient uptake of four leaf vegetable species (Lactuca sativa, Ipomoea aquatica, Brassica rapa var. chinensis and Brassica rapa var. parachinensis) in a controlled growth experiment with three root flooding treatments (drained, half-flooded and flooded) to assess their preferred hydroponic growth requirements, biomass production and nutrient removal capacities. Growth of the two Brassica varieties was clearly best at drained root conditions, while L. sativa and I. aquatica grew best with half-flooded and flooded roots. I. aquatica took up 3 times more N, P and K per plant than L. sativa, and 4 to 6 times more than the two Brassica varieties. At a plant density of 30 plants/m2, I. aquatica produced 146 g DW/m2 aboveground biomass during a 30-day cultivation period containing 2.8, 0.9 and 6.8 g/m2 of N, P and K, respectively. L. sativa produced 115 g DW/m2 of aboveground DW during a 60-day cultivation period, containing 2.2, 0.6 and 4.6 g/m2 of N, P and K, respectively. The two Brassica varieties produced much less aerial biomass (50-54 g DW/m2 during a 60-day period). Both I. aquatica and L. sativa are promising species to be included in integrated hydroponic and aquaculture facilities, with I. aquatica showing the most promise because of its higher growth and nutrient uptake capacity. © 2010 Academic Journals

  11. Environmental comparison of intensive and integrated agriculture-aquaculture systems for striped catfish production in the Mekong Delta, Vietnam, based on two existing case studies using life cycle assessment

    OpenAIRE

    Kluts, I.N.; Potting, J.M.B.; R. H. Bosma; Phong, L.T.; Udo, H. M. J.

    2012-01-01

    Vietnam is the largest producer for the export of striped catfish. Traditionally striped catfish production in the Mekong Delta took place in integrated agriculture–aquaculture systems, but has shifted recently to intensive systems to meet increasing export demands. A recent study quantified the environmental impact of intensive striped catfish production in Vietnam. Another did the same for integrated systems. Both studies used life cycle assessment, covered similar environmental impact cate...

  12. Disease and health management in Asian aquaculture.

    Science.gov (United States)

    Bondad-Reantaso, Melba G; Subasinghe, Rohana P; Arthur, J Richard; Ogawa, Kazuo; Chinabut, Supranee; Adlard, Robert; Tan, Zilong; Shariff, Mohamed

    2005-09-30

    Asia contributes more than 90% to the world's aquaculture production. Like other farming systems, aquaculture is plagued with disease problems resulting from its intensification and commercialization. This paper describes the various factors, providing specific examples, which have contributed to the current disease problems faced by what is now the fastest growing food-producing sector globally. These include increased globalization of trade and markets; the intensification of fish-farming practices through the movement of broodstock, postlarvae, fry and fingerlings; the introduction of new species for aquaculture development; the expansion of the ornamental fish trade; the enhancement of marine and coastal areas through the stocking of aquatic animals raised in hatcheries; the unanticipated interactions between cultured and wild populations of aquatic animals; poor or lack of effective biosecurity measures; slow awareness on emerging diseases; the misunderstanding and misuse of specific pathogen free (SPF) stocks; climate change; other human-mediated movements of aquaculture commodities. Data on the socio-economic impacts of aquatic animal diseases are also presented, including estimates of losses in production, direct and indirect income and employment, market access or share of investment, and consumer confidence; food availability; industry failures. Examples of costs of investment in aquatic animal health-related activities, including national strategies, research, surveillance, control and other health management programmes are also provided. Finally, the strategies currently being implemented in the Asian region to deal with transboundary diseases affecting the aquaculture sector are highlighted. These include compliance with international codes, and development and implementation of regional guidelines and national aquatic animal health strategies; new diagnostic and therapeutic techniques and new information technology; new biosecurity measures including risk analysis, epidemiology, surveillance, reporting and planning for emergency response to epizootics; targeted research; institutional strengthening and manpower development (education, training and extension research and diagnostic services). PMID:16099592

  13. Aquaculture. Second Edition. Teacher Edition.

    Science.gov (United States)

    Walker, Susan S.; Crummett, Dan

    This teacher and student guide for aquaculture contains 15 units of instruction that cover the following topics: (1) introduction to aquaculture; (2) the aquatic environment; (3) fundamental fish biology; (4) marketing; (5) site selection; (6) facility design and layout; (7) water quality management; (8) fish health management; (9) commercial…

  14. Aquaculture: global status and trends.

    Science.gov (United States)

    Bostock, John; McAndrew, Brendan; Richards, Randolph; Jauncey, Kim; Telfer, Trevor; Lorenzen, Kai; Little, David; Ross, Lindsay; Handisyde, Neil; Gatward, Iain; Corner, Richard

    2010-09-27

    Aquaculture contributed 43 per cent of aquatic animal food for human consumption in 2007 (e.g. fish, crustaceans and molluscs, but excluding mammals, reptiles and aquatic plants) and is expected to grow further to meet the future demand. It is very diverse and, contrary to many perceptions, dominated by shellfish and herbivorous and omnivorous pond fish either entirely or partly utilizing natural productivity. The rapid growth in the production of carnivorous species such as salmon, shrimp and catfish has been driven by globalizing trade and favourable economics of larger scale intensive farming. Most aquaculture systems rely on low/uncosted environmental goods and services, so a critical issue for the future is whether these are brought into company accounts and the consequent effects this would have on production economics. Failing that, increased competition for natural resources will force governments to allocate strategically or leave the market to determine their use depending on activities that can extract the highest value. Further uncertainties include the impact of climate change, future fisheries supplies (for competition and feed supply), practical limits in terms of scale and in the economics of integration and the development and acceptability of new bio-engineering technologies. In the medium term, increased output is likely to require expansion in new environments, further intensification and efficiency gains for more sustainable and cost-effective production. The trend towards enhanced intensive systems with key monocultures remains strong and, at least for the foreseeable future, will be a significant contributor to future supplies. Dependence on external feeds (including fish), water and energy are key issues. Some new species will enter production and policies that support the reduction of resource footprints and improve integration could lead to new developments as well as reversing decline in some more traditional systems. PMID:20713392

  15. General Counsel Electronic Management System

    Data.gov (United States)

    Department of Homeland Security — The General Counsel Electronic Management System (GEMS) supports the Office of the Principle Legal Advisor (OPLA) and serves as a central repository for immigration...

  16. Green and technical efficient growth in Danish fresh water aquaculture

    DEFF Research Database (Denmark)

    Nielsen, Rasmus

    2011-01-01

    Aquaculture is the fastest growing animal food processing sector in the world. Nevertheless, growth inside the Organization for Economic Co-operation and Development has been stagnating, with few exceptions. The main reason is strict environmental regulations. This study investigates if green growth can be achieved by introducing new environmentally friendly water purification systems in Danish fresh water aquaculture. Data Envelopment Analysis is used to investigate whether different water puri...

  17. European aquaculture 1991

    OpenAIRE

    Shaw, S

    1991-01-01

    Aquaculture, the farming of aquatic animals and plants in marine and freshwater, has become a major industry in the Member States of the European Community. It is estimated that total production in 1989 amounted to over 847,000 tonnes and was worth over 7,900 million ECUs. We forecast that in 1991 production will be over 900,000 tonnes representing 8,500 million ECUs. This represents around 12% of total EC fish supplies. There are no accurate figures of employment available but we have identi...

  18. Reliability of electronic systems

    International Nuclear Information System (INIS)

    Reliability techniques have been developed subsequently as a need of the diverse engineering disciplines, nevertheless they are not few those that think they have been work a lot on reliability before the same word was used in the current context. Military, space and nuclear industries were the first ones that have been involved in this topic, however not only in these environments it is that it has been carried out this small great revolution in benefit of the increase of the reliability figures of the products of those industries, but rather it has extended to the whole industry. The fact of the massive production, characteristic of the current industries, drove four decades ago, to the fall of the reliability of its products, on one hand, because the massively itself and, for other, to the recently discovered and even not stabilized industrial techniques. Industry should be changed according to those two new requirements, creating products of medium complexity and assuring an enough reliability appropriated to production costs and controls. Reliability began to be integral part of the manufactured product. Facing this philosophy, the book describes reliability techniques applied to electronics systems and provides a coherent and rigorous framework for these diverse activities providing a unifying scientific basis for the entire subject. It consists of eight chapters plus a lot of statistical tables and an extensive annotated bibliography. Chapters embrace the following topics: 1- Introduction to Reliability; 2- Basic Mathematical Concepts; 3- Catastrophic Failure Models; 4-Parametric Failure Models; 5- Systems Reliability; 6- Reliability in Design and Project; 7- Reliability Tests; 8- Software Reliability. This book is in Spanish language and has a potentially diverse audience as a text book from academic to industrial courses. (author)

  19. Japanese aquaculture with thermal water from power plants

    International Nuclear Information System (INIS)

    The present level of thermal aquaculture, utilizing thermal water which is waste cooling water from nuclear power plant, in Japan is reported. There are 13 major potential areas for thermal aquaculture in cooperation with conventional type thermal power plants, seven of which are actually operating. Aquaculture facilities of all these are on land, none in the sea. Of these seven centers, those that have already commercialized their nursery methods or are approaching that stage of research and development, are Tohoku Hatsuden Kogyo Ltd., Tsuruga Hama Land Ltd. and Kyushu Rinsan Ltd. Major problems faced specialists in Japanese thermal aquaculture are water temperature, water quality, radioactivity and costs. For keeping the water temperature constant all seasons, cooling or heating by natural sea water may be used. Even negligible amounts of radioactivity that nuclear power plants release into the sea will concentrate in the systems of marine life. A strict precautionary checking routine is used to detect radioactivity in marine life. (Kobatake, H.)

  20. Electrodynamics of correlated electron systems

    OpenAIRE

    Armitage, N. P.

    2009-01-01

    Physical and chemical systems can be characterized by their natural frequency and energy scales. It is hardly an exaggeration that most of what we know about such systems, from the acoustics of a violin to the energy levels of atoms, comes from their response to perturbations at these natural frequencies. It is of course the same situation in `correlated' electron materials. We can learn about the novel effects of strong electron-electron interactions and the properties of c...

  1. Aquaculture: International examples of success and failure and their lessons for the United States

    Energy Technology Data Exchange (ETDEWEB)

    Katz, A.

    1994-06-01

    To help assess ways to strengthen U.S. aquaculture, the Office of Technology Assessment (OTA) has sponsored a five-part study of aquaculture to: (1) review data and literature on the current state scientific understanding and technological development in aquacultural production in the United States; (2) identify promising new and emerging technologies with potential to influence U.S. aquacultural development; (3) identify new approaches from case studies of aquacultural production systems and policy structures in select foreign countries; (4) assess current and potential roles of federal, state, and private organizations in the development and implementation of technologies; and (5) develop policy options for Congress. This paper represents part 3 of the above outline of the study, identification of new approaches from case studies of aquacultural production systems and policy structures in select foreign countries and their relevance to the United States.

  2. Aquaponics and its potential aquaculture wastewater treatment and human urine treatment

    OpenAIRE

    Sánchez, Henrique Junior Aiveca

    2014-01-01

    The main objective of this thesis is to study the developing fields of aquaponics and its potential for aquaculture wastewater treatment and human urine treatment. Aquaponics is a food production system which combines fish farming (aquaculture) with soilless crop farming (hydroponics). In this thesis the concept of aquaponics and the underlying processes are explained. Research on aquaculture wastewater and human urine wastewater is reviewed and its potential application with aquaponic sys...

  3. Shrimp aquaculture in New Caledonia

    OpenAIRE

    Galinie, C

    1989-01-01

    In New Caledonia, there is no indigenous shrimp species for commercial aquaculture and it is necessary to control the complete cycle in captivity. Since 1973 and the creation of the Station d'Aquaculture de Saint-Vincent (S.A.S.V.), a joint project between IFREMER, France-Aquaculture and the territory of New Caledonia, nine species have been tested and for one of these, P. stylirostris , (introduced in 1980), we are now in a commercial scale production with the tenth generation obtained in ca...

  4. Electronic Resource Management Systems

    Directory of Open Access Journals (Sweden)

    Mark Ellingsen

    2004-10-01

    Full Text Available Computer applications which deal with electronic resource management (ERM are quite a recent development. They have grown out of the need to manage the burgeoning number of electronic resources particularly electronic journals. Typically, in the early years of e-journal acquisition, library staff provided an easy means of accessing these journals by providing an alphabetical list on a web page. Some went as far as categorising the e-journals by subject and then grouping the journals either on a single web page or by using multiple pages. It didn't take long before it was recognised that it would be more efficient to dynamically generate the pages from a database rather than to continually edit the pages manually. Of course, once the descriptive metadata for an electronic journal was held within a database the next logical step was to provide administrative forms whereby that metadata could be manipulated. This in turn led to demands for incorporating more information and more functionality into the developing application.

  5. Electron microscope image recording system

    International Nuclear Information System (INIS)

    In an image recording system, for example an electron microscope, a specimen is scanned by an electron beam and a resulting video signal from a semiconducting photosensitive surface, such as a solar cell, in contact with the specimen is displayed on a monitor in synchronism with the scanning. The solar cell detects both electrons and X-rays produced in the specimen. To produce an entirely X-ray image, the specimen is covered with a thin metal foil. (author)

  6. Economic values of growth and feed efficiency for fish farming in recirculating aquaculture system with density and nitrogen output limitations: a case study with African catfish (Clarias gariepinus).

    Science.gov (United States)

    Besson, M; Komen, H; Aubin, J; de Boer, I J M; Poelman, M; Quillet, E; Vancoillie, C; Vandeputte, M; van Arendonk, J A M

    2014-12-01

    In fish farming, economic values (EV) of breeding goal traits are lacking, even though they are key parameters when defining selection objectives. The aim of this study was to develop a bioeconomic model to estimate EV of 2 traits representing production performances in fish farming: the thermal growth coefficient (TGC) and the feed conversion ratio (FCR). This approach was applied to a farm producing African catfish (Clarias gariepinus) in a recirculating aquaculture system (RAS). In the RAS, 2 factors could limit production level: the nitrogen treatment capacity of the biofilter or the fish density in rearing tanks at harvest. Profit calculation includes revenue from fish sales, cost of juveniles, cost of feed, cost of waste water treatment, and fixed costs. In the reference scenario, profit was modeled to zero. EV were calculated as the difference in profit per kilogram of fish between the current population mean for both traits (µt) and the next generation of selective breeding (µt+?t) for either TGC or FCR. EV of TGC and FCR were calculated for three generations of hypothetical selection on either TGC or FCR (respectively 6.8% and 7.6% improvement per generation). The results show that changes in TGC and FCR can affect both the number of fish that can be stocked (number of batches per year and number of fish per batch) and the factor limiting production. The EV of TGC and FCR vary and depend on the limiting factors. When dissolved NH3-N is the limiting factor for both µt and µt+?t, increasing TGC decreases the number of fish that can be stocked but increases the number of batches that can be grown. As a result, profit remains constant and EVTGC is zero. Increasing FCR, however, increases the number of fish stocked and the ratio of fish produced per kilogram of feed consumed ("economic efficiency"). The EVFCR is 0.14 €/kg of fish, and profit per kilogram of fish increases by about 10%. When density is the limiting factor for both µt and µt+?t, the number of fish stocked per batch is fixed; therefore, extra profit is obtained by increasing either TGC, which increases the annual number of batches, or by decreasing FCR, which decreases annual feed consumption. EVTGC is 0.03 €/kg of fish and EVFCR is 0.05-0.06 €/kg of fish. These results emphasize the importance of calculating economic values in the right context to develop efficient future breeding programs in aquaculture. PMID:25414104

  7. Efficiency of bioaugmentation in the removal of organic matter in aquaculture systems / Eficiência da bioadição na remoção de matéria orgânica em sistemas aquaculturais

    Scientific Electronic Library Online (English)

    RB, Lopes; RA., Olinda; BAI, Souza; JEP, Cyrino; CTS, Dias; JF, Queiroz; LHS, Tavares.

    2011-05-01

    Full Text Available Existem diversas tecnologias para tratamento de efluentes, o processo de bioadição consiste em uma vertente da biorremediação e tem sido empregado na melhoria da qualidade dos efluentes através do tratamento da água de produção. Esta tecnologia consiste basicamente na adição de microrganismos com a [...] capacidade de degradar ou remover compostos poluentes, especialmente matéria orgânica e nutrientes. Este estudo objetivou avaliar os efeitos da suplementação de composto bioativo sobre alguns parâmetros de matéria orgânica e de desempenho de juvenis de tilápias em um sistema intensivo de produção aquacultural. Foi empregada a combinação de dois consórcios bacterianos em delineamento inteiramente aleatorizado, em um esquema fatorial com dois fatores. As diferenças estatísticas entre os tratamentos foram analisadas por meio da análise de variância (ANOVA) e do teste de Tukey ao nível de 5%. Verificou-se neste estudo, que a bioadição heterotrófica foi capaz de reduzir em 23% a demanda bioquímica de oxigênio (DBO); em 83,7%, o carbono orgânico dissolvido (COD); e em 43%, a biomassa fitoplanctônica. Por outro lado, não se observou nenhum prejuízo com relação aos parâmetros físico-químicos de qualidade de água bem como ao desempenho de crescimento para juvenis de tilápias avaliados neste estudo. Abstract in english Several techniques are currently used to treat effluents. Bioaugmentation is a new bioremediation strategy and has been employed to improve effluent quality by treating the water during the production process. This technology consists basically of the addition of microorganisms able to degrade or re [...] move polluting compounds, especially organic matter and nutrients. The objective of this study was to assess the effects of bioaugmentation on some parameters of organic matter and on the performance of juvenile tilapias in an intensive aquaculture production system. The combination of two bacterial consortiums in a complete randomized design was employed in a factorial analysis with two factors. Statistical differences between treatments were analyzed by the analysis of variance (ANOVA) and Tukey test at the 5% level. One of the treatments, heterotrophic bacterial supplementation, was able to reduce biochemical oxygen demand (BOD) by 23%, dissolved organic carbon (DOC) by 83.7% and phytoplanktonic biomass by 43%. On the other hand, no damage was done to either the physical-chemical indicators of water quality or to the growth performance of juvenile tilapias assessed in this study.

  8. Electronic system hardening methodology

    International Nuclear Information System (INIS)

    The notion of hardened systems can be found in several applications (nuclear power plants, alarm systems, research installations..). Their development correspond to the functional necessity to take into account a specific radiative environment. The starting point of each hardening study is the definition of the radiative environmental constraints representative of the application. In addition to these external constraints, the specific functional characteristics of each system are considered: control or interface systems in nuclear industry, in-board control systems, remote handling systems, etc. This paper summarizes the methodology followed according to the experience gained in previous studies and anticipating the future needs. (J.S.). 6 refs., 5 figs

  9. Use of Probiotics in Aquaculture

    OpenAIRE

    Patricia Martínez Cruz; Ana L. Ibáñez; Oscar A. Monroy Hermosillo; Hugo C. Ramírez Saad

    2012-01-01

    The growth of aquaculture as an industry has accelerated over the past decades; this has resulted in environmental damages and low productivity of various crops. The need for increased disease resistance, growth of aquatic organisms, and feed efficiency has brought about the use of probiotics in aquaculture practices. The first application of probiotics occurred in 1986, to test their ability to increase growth of hydrobionts (organisms that live in water). Later, probiotics were used to impr...

  10. Potential use of power plant reject heat in commercial aquaculture

    International Nuclear Information System (INIS)

    Current research and commercial activities in aquaculture operations have been reviewed. An aquaculture system using mostly herbivorous species in pond culture is proposed as a means of using waste heat to produce reasonably priced protein. The system uses waste water streams, such as secondary sewage effluent, animal wastes, or some industrial waste streams as a primary nutrient source to grow algae, which is fed to fish and clams. Crayfish feed on the clam wastes thereby providing a clean effluent from the aquaculture system. Alternate fish associations are presented and it appears that a carp or tilapia association is desirable. An aquaculture system capable of rejecting all the waste heat from a 1000-MW(e) power station in winter can accommodate about half the summer heat rejection load. The aquaculture facility would require approximately 133 ha and would produce 4.1 x 105 kg/year of fish, 1.5 x 106 kg/year of clam meat, and 1.5 x 104 kg/year of live crayfish. The estimated annual pretax profit from this operation is one million dollars. Several possible problem areas have been identified. However, technical solutions appear to be readily available to solve these problems. The proposed system shows considerable economic promise. Small scale experiments have demonstrated the technical feasibility of various components of the system. It therefore appears that a pilot scale experimental facility should be operated

  11. Potential use of power plant reject heat in commercial aquaculture

    Energy Technology Data Exchange (ETDEWEB)

    Olszewski, M.

    1977-01-01

    Current research and commercial activities in aquaculture operations have been reviewed. An aquaculture system using mostly herbivorous species in pond culture is proposed as a means of using waste heat to produce reasonably priced protein. The system uses waste water streams, such as secondary sewage effluent, animal wastes, or some industrial waste streams as a primary nutrient source to grow algae, which is fed to fish and clams. Crayfish feed on the clam wastes thereby providing a clean effluent from the aquaculture system. Alternate fish associations are presented and it appears that a carp or tilapia association is desirable. An aquaculture system capable of rejecting all the waste heat from a 1000-MW(e) power station in winter can accommodate about half the summer heat rejection load. The aquaculture facility would require approximately 133 ha and would produce 4.1 x 10/sup 5/ kg/year of fish, 1.5 x 10/sup 6/ kg/year of clam meat, and 1.5 x 10/sup 4/ kg/year of live crayfish. The estimated annual pretax profit from this operation is one million dollars. Several possible problem areas have been identified. However, technical solutions appear to be readily available to solve these problems. The proposed system shows considerable economic promise. Small scale experiments have demonstrated the technical feasibility of various components of the system. It therefore appears that a pilot scale experimental facility should be operated.

  12. Temperature effects on biomass, geosmin, and 2-methylisoborneol production and cellular activity by Nocardia spp. and Streptomyces spp. isolated from rainbow trout recirculating aquaculture systems.

    Science.gov (United States)

    Schrader, Kevin K; Harries, Marcuslene D; Page, Phaedra N

    2015-05-01

    Isolates of Nocardia cummidelens, Nocard ia fluminea, Streptomyces albidoflavus, and Streptomyces luridiscabiei attributed as the cause of "earthy-musty" off-flavor in rainbow trout (Oncorhynchus mykiss) raised in recirculating aquaculture systems (RAS) were evaluated for the effect of temperature (10-30 °C) on biomass, geosmin, and 2-methylisoborneol (MIB) production and cellular activity. Cultures of these isolates were monitored over 7 days by measuring culture dry weight, geosmin, and MIB production using solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS), and ATP production via a luminometer. Compared to the other isolates, S. luridiscabiei had significantly (P < 0.05) higher biomass (8.17 ± 0.35 mg/mL) at 15 °C (water temperature in the RAS) after 7 days incubation. In addition, S. luridiscabiei produced significantly (P < 0.05) higher geosmin (69,976 ± 15,733 ng/L) at 15 °C. At 25 °C and 30 °C, S. albidoflavus produced significantly (P < 0.05) higher geosmin (182,074 ± 60,272 ng/L and 399,991 ± 102,262 ng/L, respectively). All isolates produced MIB at 15 °C, but S. luridiscabiei produced significantly (P < 0.05) higher MIB (97,143 ± 28,972 ng/L) and ATP after 7 days. Therefore, S. luridiscabiei appears to be a likely contributor of geosmin and MIB in the RAS. PMID:25724337

  13. Effects of spectral composition, photoperiod and light intensity on the gonadal development of Atlantic salmon Salmo salar in recirculating aquaculture systems (RAS)

    Science.gov (United States)

    Qiu, Denggao; Xu, Shihong; Song, Changbin; Chi, Liang; Li, Xian; Sun, Guoxiang; Liu, Baoliang; Liu, Ying

    2015-01-01

    Artificial lighting regimes have been successfully used to inhibit sexual maturity of Atlantic salmon in confinement. However, when these operations are applied in commercial recirculating aquaculture systems (RAS) using standard lighting technology, sexual maturation is not suppressed. In this study, an L9 (33) orthogonal design was used to determine the effects of three factors (spectral composition, photoperiod, and light intensity) on the gonadal development of Atlantic salmon in RAS. We demonstrated that the photoperiod at the tested levels had a much greater effect on the gonadosomatic index and female Fulton condition factor than spectral composition and light intensity. The photoperiod had a significant effect on the secretion of sex steroids and melatonin ( P0.05). The optimum lighting levels in female and male Atlantic salmon were LD 8:16, 455 nm (or 625 nm), 8.60 W/m2; and LD 8:16, 8.60 W/m2, 455 nm respectively. These conditions not only delayed gonadal development, but also had no negative effects on Atlantic salmon growth in RAS. These results demonstrate that a combination of spectral composition, photoperiod and light intensity is effective at delaying the gonadal development of both male and female salmon in RAS.

  14. Evaluation of feed and feeding regime on growth performance, flesh quality and fecal viscosity of Atlantic salmon ( Salmo salar L.) in recirculating aquaculture systems

    Science.gov (United States)

    Sun, Guoxiang; Liu, Ying; Li, Yong; Li, Xian; Wang, Shunkui

    2015-10-01

    The effects of different feeds and feeding regimes on growth performance, flesh quality and fecal viscosity of Atlantic salmon ( Salmo salar L.) in recirculating aquaculture systems (RAS) were investigated. Fish (initial body weight of 1677 g ± 157 g) were fed with four commercial feeds (Nosan salmon-NS, Aller gold-AG, Skretting salmon-SS and Han ye-HY) in two feeding regimes (80% and 100% satiation) for 78 d. The results showed that salmon specific growth ratio (SGR) and weight gain ratio (WGR) were significantly affected by feed type and feeding regime ( P < 0.05). Feed conversion ratio (FCR) varied between 0.93 and 3.40, which was significantly affected by feed type ( P < 0.05), and slightly improved with increased satiation degree. The activities of digestive enzymes including protease, lipase and amylase were also significantly affected by feed type and feeding regime ( P < 0.05), increasing with satiation degree. Flesh qualities for vitamin E, hydroxyproline (HYP), liquid loss and muscle pH among all groups showed significant differences ( P < 0.05), ranging from 26.67 to 29.67, while no obvious difference was found in flesh color. Fecal viscosity for different treatments showed no significant difference, though improvement was found in 100% satiation group. From present experiment, it was concluded that both feed type and feeding regime can affect the important quality attributes of Atlantic salmon.

  15. Ecosystem-based approach to aquaculture management

    Directory of Open Access Journals (Sweden)

    Patrick White

    2008-12-01

    Full Text Available Ecosystems have real thresholds and limits which, when exceeded, can affect major system restructuring. Once thresholds and limits have been exceeded, changes can be irreversible. Diversity is important to ecosystem functioning. The ecosystem approach is a strategy for the integrated management of land, water, and living resources that promotes conservation and sustainable use in an equitable way. The application of the ecosystem approach will help to reach a balance of the three main objectives: conservation, sustainable use, and a fair and equitable sharing of the benefits and use of the natural resources. Aquaculture development needs to be within the carrying capacity of the water resource so that it is sustainable and does not greatly impact the environment. The determination of the carrying capacity needs to be science-based. The planning of development in ecosystems has been done for freshwater ecosystems within the PAMB (Protected Area Management Board framework, but in many cases this does not give the correct significance to the impact of aquaculture on the water resources in the ecosystem. It also needs to be extended to river basins and estuaries, brackishwater areas, and inland bays, and seas. The planning and management of aquaculture needs to be undertaken at the local government unit (LGU level in a coordinated manner by all the LGUs that have a part of the water resource. The co-management of aquaculture, in terms of monitoring of the environment, monitoring of production, and monitoring of licenses, needs to be funded out of license fees and non-compliance fines collected by the LGUs. A number of these management activities need to be undertaken jointly (monitoring the environment and others separately but in a coordinated manner (e.g., checking licenses and checking compliance.

  16. FTU bolometer electronic system upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Pollastrone, Fabio, E-mail: fabio.pollastrone@enea.it [Associazione EURATOM-ENEA sulla Fusione, Via Enrico Fermi 45, 00044 Frascati, Rome (Italy); Neri, Carlo; Florean, Marco; Ciccone, Giovanni [Associazione EURATOM-ENEA sulla Fusione, Via Enrico Fermi 45, 00044 Frascati, Rome (Italy)

    2013-10-15

    Highlights: ? Design and realization of a new bolometer electronic system. ? Many improvements over the actual commercial system. ? Architecture based on digital electronic hardware with minimal analog front end. ? Auto off-set correction, real time visualization features and small system size. ? Test results for the electronic system. -- Abstract: The FTU (Frascati Tokamak Upgrade) requires a bolometer diagnostic in order to measure the total plasma radiation. The current diagnostic architecture is based on a full analog multichannel AC bolometer system, which uses a carrier frequency amplifier with a synchronous demodulation. Taking into account the technological upgrades in the field of electronics, it was decided to realize an upgrade for the bolometric electronic system by using a hybrid analog/digital implementation. The new system developed at the ENEA Frascati laboratories has many improvements, and mainly a massive system volume reduction, a good measurement linearity and a simplified use. The new hardware system consists of two subsystems: the Bolometer Digital Control and the Bolometer Analog System. The Bolometer Digital Control can control 16 bolometer bridges through the Bolometer Analog System. The Bolometer Digital Control, based on the FPGA architecture, is connected via Ethernet with a PC; therefore, it can receive commands settings from the PC and send the stream of bolometric measurements in real time to the PC. In order to solve the cross-talk between the bridges and the cables, each of the four bridges in the bolometer head receives a different synthesized excitation frequency. Since the system is fully controlled by a PC GUI (Graphic User Interface), it is very user friendly. Moreover, some useful features have been developed, such as: auto off-set correction, bridge amplitude regulation, software gain setting, real time visualization, frequency excitation selection and noise spectrum analyzer embedded function. In this paper, the hardware and software system architectures are described and some tests of the developed system are presented, with a related statistical analysis.

  17. FTU bolometer electronic system upgrade

    International Nuclear Information System (INIS)

    Highlights: ? Design and realization of a new bolometer electronic system. ? Many improvements over the actual commercial system. ? Architecture based on digital electronic hardware with minimal analog front end. ? Auto off-set correction, real time visualization features and small system size. ? Test results for the electronic system. -- Abstract: The FTU (Frascati Tokamak Upgrade) requires a bolometer diagnostic in order to measure the total plasma radiation. The current diagnostic architecture is based on a full analog multichannel AC bolometer system, which uses a carrier frequency amplifier with a synchronous demodulation. Taking into account the technological upgrades in the field of electronics, it was decided to realize an upgrade for the bolometric electronic system by using a hybrid analog/digital implementation. The new system developed at the ENEA Frascati laboratories has many improvements, and mainly a massive system volume reduction, a good measurement linearity and a simplified use. The new hardware system consists of two subsystems: the Bolometer Digital Control and the Bolometer Analog System. The Bolometer Digital Control can control 16 bolometer bridges through the Bolometer Analog System. The Bolometer Digital Control, based on the FPGA architecture, is connected via Ethernet with a PC; therefore, it can receive commands settings from the PC and send the stream of bolometric measurements in real time to the PC. In order to solve the cross-talk between the bridges and the cables, each of the four bridges in the bolometer head receives a different synthesized excitation frequency. Since the system is fully controlled by a PC GUI (Graphic User Interface), it is very user friendly. Moreover, some useful features have been developed, such as: auto off-set correction, bridge amplitude regulation, software gain setting, real time visualization, frequency excitation selection and noise spectrum analyzer embedded function. In this paper, the hardware and software system architectures are described and some tests of the developed system are presented, with a related statistical analysis

  18. Component reliability for electronic systems

    CERN Document Server

    Bajenescu, Titu-Marius I

    2010-01-01

    The main reason for the premature breakdown of today's electronic products (computers, cars, tools, appliances, etc.) is the failure of the components used to build these products. Today professionals are looking for effective ways to minimize the degradation of electronic components to help ensure longer-lasting, more technically sound products and systems. This practical book offers engineers specific guidance on how to design more reliable components and build more reliable electronic systems. Professionals learn how to optimize a virtual component prototype, accurately monitor product reliability during the entire production process, and add the burn-in and selection procedures that are the most appropriate for the intended applications. Moreover, the book helps system designers ensure that all components are correctly applied, margins are adequate, wear-out failure modes are prevented during the expected duration of life, and system interfaces cannot lead to failure.

  19. Analytical purpose electron backscattering system

    International Nuclear Information System (INIS)

    In this work an analytical purposes electron backscattering system improved at the Center of Applied Studies for Nuclear Development is described. This system can be applied for fast, exact and nondestructive testing of binary and AL/Cu, AL/Ni in alloys and for other applications

  20. Instabilities of multiorbital electron systems

    OpenAIRE

    Uebelacker, Stefan Andreas

    2013-01-01

    In the present thesis, we consider interaction induced instabilities in different electronic models consisting of multiple orbitals. We employ the functional renormalization group method, to tackle the many-particle problem. The main goal of this work is the identification of leading instabilities of different interacting electron systems and the relevant energy scales for the onset of correlations. First, we recapitulate the functional renormalization group formalism and discuss details of i...

  1. 40 CFR 122.25 - Aquaculture projects (applicable to State NPDES programs, see § 123.25).

    Science.gov (United States)

    2010-07-01

    ... of CWA, and in accordance with 40 CFR part 125, subpart B. (b) Definitions. (1) Aquaculture project... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Aquaculture projects (applicable to... DISCHARGE ELIMINATION SYSTEM Permit Application and Special NPDES Program Requirements § 122.25...

  2. Aquaculture practices and the coastal marine environment

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.; Ansari, Z.A.; Sreepada, R.A.

    Aquaculture has the potential for causing environmental harm as well as for improving livelihood and nutrition. Aquaculture development, therefore requires to be seen in the wider context of aquatic resource use, land use development and its...

  3. Effect of culture density on production characteristics and body composition of market size cobia reared from juveniles in recirculating aquaculture systems

    Science.gov (United States)

    Interest regarding cobia Rachycentron canadum aquaculture in the US has increased greatly in the last decade due to their excellent consumer appeal, extremely rapid growth rates, and the observed success of rearing this species in Taiwan and other southeastern Asian countries. Because the principal...

  4. World Aquaculture: Environmental Impacts and Troubleshooting Alternatives

    OpenAIRE

    Martinez-Porchas, Marcel; Martinez-Cordova, Luis R.

    2012-01-01

    Aquaculture has been considered as an option to cope with the world food demand. However, criticisms have arisen around aquaculture, most of them related to the destruction of ecosystems such as mangrove forest to construct aquaculture farms, as well as the environmental impacts of the effluents on the receiving ecosystems. The inherent benefits of aquaculture such as massive food production and economical profits have led the scientific community to seek for diverse strategies to minimize th...

  5. ISO/TC 234, Fisheries and Aquaculture

    OpenAIRE

    Ramona I. Costea

    2009-01-01

    The largest standard developing organization, ISO, works these days at International Standards for Fisheries and Aquaculture. They created a technical committee divided in six work groups that will have to establish cage technology, aquaculture environmental management, aquaculture technology, food safety for aquaculture farms, traceability of fishery products and environmental monitoring on the seabed’s impact from marine finfish farms. These standards will promote the sustainable developmen...

  6. Portable digital electronic radiography system

    International Nuclear Information System (INIS)

    Radiography is a standard nondestructive technique in the industrial testing of materials and components. It is routinely used during the construction, maintenance and repair of nuclear plants. Traditionally, radiography is performed using photographic film (film radiography, FR). Recent developments in solid-state area imaging radiation detectors, miniature electronics and computer software/hardware techniques have brought electronic alternatives to FR. In recent years various electronic radiography (ER) techniques have served as alternatives to FR, these proved beneficial in some applications. While originally developed to provide real time imaging, ER may offer other advantages over FR, depending on the application. Work was undertaken at CRL to review progress in ER techniques and evaluate the possibility of constructing a portable DER (digital electronic radiography) system, for the inspection of power plant components. A suitable DER technique has been developed and a proof of principle portable system constructed. As this paper demonstrates, a properly designed ER system can be small and compact, while providing radiographic examination with acceptable image quality and the benefits of ER imaging. The CRL DER system can operate with radioactive sources typical of FR. While it does not replace FR, our DER system is expected to be beneficial in specific applications for Candu maintenance, reducing cost, labour and time. Practical, cost saving applications of this system are expected to include valve monitoring and foreign object location during maintenance at Candu reactors

  7. Aquaculture Engineering: Status and Roles in the Growth of Aquaculture Industry in Nigeria

    OpenAIRE

    Mrs. Nene A. Jamabo; P.U. Uzukwu and O.S. George

    2010-01-01

    This study reviews the role of aquaculture engineering in Nigeria’s aquaculture sub-sector. The focus was on solving site selection problems due to environmental, Climatic and hydrological factors, equipment selection and fabrication, and site specific engineering problems. The poor growth of the aquaculture industry in Nigeria in the past is attributed to the poor status of aquaculture engineering. Also emphasis was placed on the shortage of qualified manpower, aquaculture engineers, in Nige...

  8. Application of Machine Learning Techniques in Aquaculture

    OpenAIRE

    Akhlaqur Rahman; Sumaira Tasnim

    2014-01-01

    In this paper we present applications of different machine learning algorithms in aquaculture. Machine learning algorithms learn models from historical data. In aquaculture historical data are obtained from farm practices, yields, and environmental data sources. Associations between these different variables can be obtained by applying machine learning algorithms to historical data. In this paper we present applications of different machine learning algorithms in aquaculture...

  9. Exploring Aquaculture. Curriculum Guide for Agriscience 282.

    Science.gov (United States)

    Texas A and M Univ., College Station. Dept. of Agricultural Education.

    This curriculum guide provides materials for teachers to use in developing a course in "Exploring Aquaculture, Agriscience 282," one of 28 semester courses in agricultural science and technology for Texas high schools. This introductory course is designed to acquaint students with the growing industry of aquaculture; it includes aquaculture career…

  10. United States Aquaculture and the Environment

    Science.gov (United States)

    This is the introductory chapter to the book “Environmental Best Management Practices for Aquaculture.” The chapter broadly focuses on interactions between aquaculture and the environment. The first sections describe global and United States aquaculture, including a detailed summary of U.S. aquacu...

  11. PREFACE: Strongly correlated electron systems Strongly correlated electron systems

    Science.gov (United States)

    Saxena, Siddharth S.; Littlewood, P. B.

    2012-07-01

    This special section is dedicated to the Strongly Correlated Electron Systems Conference (SCES) 2011, which was held from 29 August-3 September 2011, in Cambridge, UK. SCES'2011 is dedicated to 100 years of superconductivity and covers a range of topics in the area of strongly correlated systems. The correlated electronic and magnetic materials featured include f-electron based heavy fermion intermetallics and d-electron based transition metal compounds. The selected papers derived from invited presentations seek to deepen our understanding of the rich physical phenomena that arise from correlation effects. The focus is on quantum phase transitions, non-Fermi liquid phenomena, quantum magnetism, unconventional superconductivity and metal-insulator transitions. Both experimental and theoretical work is presented. Based on fundamental advances in the understanding of electronic materials, much of 20th century materials physics was driven by miniaturisation and integration in the electronics industry to the current generation of nanometre scale devices. The achievements of this industry have brought unprecedented advances to society and well-being, and no doubt there is much further to go—note that this progress is founded on investments and studies in the fundamentals of condensed matter physics from more than 50 years ago. Nevertheless, the defining challenges for the 21st century will lie in the discovery in science, and deployment through engineering, of technologies that can deliver the scale needed to have an impact on the sustainability agenda. Thus the big developments in nanotechnology may lie not in the pursuit of yet smaller transistors, but in the design of new structures that can revolutionise the performance of solar cells, batteries, fuel cells, light-weight structural materials, refrigeration, water purification, etc. The science presented in the papers of this special section also highlights the underlying interest in energy-dense materials, which make use of 'small' electrons packed to the highest possible density. These are by definition 'strongly correlated'. For example: good photovoltaics must be efficient optical absorbers, which means that photons will generate tightly bound electron-hole pairs (excitons) that must then be ionised at a heterointerface and transported to contacts; efficient solid state refrigeration depends on substantial entropy changes in a unit cell, with large local electrical or magnetic moments; efficient lighting is in a real sense the inverse of photovoltaics; the limit of an efficient battery is a supercapacitor employing mixed valent ions; fuel cells and solar to fuel conversion require us to understand electrochemistry on the scale of a single atom; and we already know that the only prospect for effective high temperature superconductivity involves strongly correlated materials. Even novel IT technologies are now seen to have value not just for novel function but also for efficiency. While strongly correlated electron systems continue to excite researchers and the public alike due to the fundamental science issues involved, it seems increasingly likely that support for the science will be leveraged by its impact on energy and sustainability. Strongly correlated electron systems contents Strongly correlated electron systemsSiddharth S Saxena and P B Littlewood Magnetism, f-electron localization and superconductivity in 122-type heavy-fermion metalsF Steglich, J Arndt, O Stockert, S Friedemann, M Brando, C Klingner, C Krellner, C Geibel, S Wirth, S Kirchner and Q Si High energy pseudogap and its evolution with doping in Fe-based superconductors as revealed by optical spectroscopyN L Wang, W Z Hu, Z G Chen, R H Yuan, G Li, G F Chen and T Xiang Structural investigations on YbRh2Si2: from the atomic to the macroscopic length scaleS Wirth, S Ernst, R Cardoso-Gil, H Borrmann, S Seiro, C Krellner, C Geibel, S Kirchner, U Burkhardt, Y Grin and F Steglich Confinement of chiral magnetic modulations in the precursor region of FeGeH Wilhelm, M Baenitz, M Schmidt, C Naylor, R Lortz, U

  12. Applications of probiotic in aquaculture

    Directory of Open Access Journals (Sweden)

    Seval Bahad?r Koca

    2011-10-01

    Full Text Available Ecological impacts including emergence of a large variety of pathogens and bacterial resistance is caused in increase of productivity in aquaculture. This negatively effects are seen as a results of made applications in production cycles (such as randomly use kemoteropatik. Using probi¬otic in aquaculture is a new approach to reduce these negatively effects. In this study is submi¬ted, definition of the concept probiotic, effect mechanisms of probiotics, colonization to host, selection of probiotics, use probiotic in fish, crustacean, the mollusk and the live feed.

  13. Status of Irish Aquaculture 2004

    OpenAIRE

    Institute, Marine; Mhara, Bord Iascaigh; Teo, Taighde Mara

    2005-01-01

    This report is the second annual report on the status of Irish aquaculture (see Parsons et al., 2004). It has been produced in collaboration with the three main State agencies that provide support services in the areas of research and development to the industry – Bord Iascaigh Mhara (BIM), the Marine Institute and Taighde Mara. The aims of the report are to: (1) provide an objective and comprehensive source of information on the status of Irish aquaculture in 2004; (2) show the main trends i...

  14. EDITORIAL: Strongly correlated electron systems Strongly correlated electron systems

    Science.gov (United States)

    Ronning, Filip; Batista, Cristian

    2011-03-01

    Strongly correlated electrons is an exciting and diverse field in condensed matter physics. This special issue aims to capture some of that excitement and recent developments in the field. Given that this issue was inspired by the 2010 International Conference on Strongly Correlated Electron Systems (SCES 2010), we briefly give some history in order to place this issue in context. The 2010 International Conference on Strongly Correlated Electron Systems was held in Santa Fe, New Mexico, a reunion of sorts from the 1989 International Conference on the Physics of Highly Correlated Electron Systems that also convened in Santa Fe. SCES 2010—co-chaired by John Sarrao and Joe Thompson—followed the tradition of earlier conferences, in this century, hosted by Buzios (2008), Houston (2007), Vienna (2005), Karlsruhe (2004), Krakow (2002) and Ann Arbor (2001). Every three years since 1997, SCES has joined the International Conference on Magnetism (ICM), held in Recife (2000), Rome (2003), Kyoto (2006) and Karlsruhe (2009). Like its predecessors, SCES 2010 topics included strongly correlated f- and d-electron systems, heavy-fermion behaviors, quantum-phase transitions, non-Fermi liquid phenomena, unconventional superconductivity, and emergent states that arise from electronic correlations. Recent developments from studies of quantum magnetism and cold atoms complemented the traditional subjects and were included in SCES 2010. 2010 celebrated the 400th anniversary of Santa Fe as well as the birth of astronomy. So what's the connection to SCES? The Dutch invention of the first practical telescope and its use by Galileo in 1610 and subsequent years overturned dogma that the sun revolved about the earth. This revolutionary, and at the time heretical, conclusion required innovative combinations of new instrumentation, observation and mathematics. These same combinations are just as important 400 years later and are the foundation of scientific discoveries that were discussed during SCES 2010. As we learned, past dogmas about strongly correlated materials and phenomena must be re-examined with an open and inquisitive mind. Invited speakers and respected leaders in the field were invited to contribute to this special issue and we have insisted that they present new data, ideas, or perspectives, as opposed to simply an overview of their past work. As with the conference, this special issue touches upon recent developments of strongly correlated electron systems in d-electron materials, such as Sr3Ru2O7, graphene, and the new Fe-based superconductors, but it is dominated by topics in f-electron compounds. Contributions reflect the growing appreciation for the influence of disorder and frustration, the need for organizing principles, as well as detailed investigations on particular materials of interest and, of course, new materials. As this special issue could not possibly capture the full breadth and depth that the conference had to offer, it is being published simultaneously with an issue of Journal of Physics: Conference Series containing 157 manuscripts in which all poster presenters at SCES 2010 were invited to contribute. Since this special issue grew out of the 2010 SCES conference, we take this opportunity to give thanks. This conference would not have been possible without the hard work of the SCES 2010 Program Committee, International and National Advisory Committees, Local Committee, and conference organizers, the New Mexico Consortium. We thank them as well as those organizations that generously provided financial support: ICAM-I2CAM, Quantum Design, Lakeshore, the National High Magnetic Field Laboratory and the Department of Energy National Laboratories at Argonne, Berkeley, Brookhaven, Los Alamos and Oak Ridge. Of course, we especially thank the participants for bringing new ideas and new results, without which SCES 2010 would not have been possible. Strongly correlated electron systems contents Spin-orbit coupling and k-dependent Zeeman splitting in strontium ruthenate Emil J Rozbicki, James F Annett, Jean-René Souquet an

  15. Aquaculture, ecological engineering: Lessons from China

    Energy Technology Data Exchange (ETDEWEB)

    Chan, G.L. (Kowloon, Hong Kong (Hong Kong))

    1993-01-01

    Economic development and urbanization worldwide have led to many pollution problems as a result of growing input to the environment of organic wastes and inorganic nutrients. Even the developed countries have not been able to solve this problem satisfactorily. The situation is especially problematical in developing countries where raw wastes are disrupting the coastal ecosystems that are the main source of food protein. This article describes how these problems are addressed in China, using aquaculture and ecological engineering not only to solve waste problems, but also to optimize food and energy production by completely recycling wastes in integrated farming systems. 8 refs, 2 figs

  16. Studies on wels catfish (Silurus glanis development during cold season as an auxiliary species in sturgeon recirculated aquaculture systems

    Directory of Open Access Journals (Sweden)

    Radu Muscalu

    2010-12-01

    Full Text Available The research had the purpose to establish if the wels catfish is suitable for growing in closedrecirculated system designed for sturgeon farming, because during the cold season the system does notneed to reach high temperatures such as for other fish species. Our studies showed that the wels catfishcan survive during the cold season from a recirculated system, and furthermore they accept feeds attemperatures as low as 17°C, and even have a slight body weight increase during this season. The welscatfish entered the spring in our experiment at a mean body weight of 72.5 grams, while the wels catfishfrom semi-intensive system after wintering in earthern ponds entered the winter at a mean body weighof 30 grams. Our experiments also studied the effect of stocking density on fish development in theseconditions.

  17. Generative electronic background music system

    Energy Technology Data Exchange (ETDEWEB)

    Mazurowski, Lukasz [Faculty of Computer Science, West Pomeranian University of Technology in Szczecin, Zolnierska Street 49, Szczecin, PL (Poland)

    2015-03-10

    In this short paper-extended abstract the new approach to generation of electronic background music has been presented. The Generative Electronic Background Music System (GEBMS) has been located between other related approaches within the musical algorithm positioning framework proposed by Woller et al. The music composition process is performed by a number of mini-models parameterized by further described properties. The mini-models generate fragments of musical patterns used in output composition. Musical pattern and output generation are controlled by container for the mini-models - a host-model. General mechanism has been presented including the example of the synthesized output compositions.

  18. Generative electronic background music system

    International Nuclear Information System (INIS)

    In this short paper-extended abstract the new approach to generation of electronic background music has been presented. The Generative Electronic Background Music System (GEBMS) has been located between other related approaches within the musical algorithm positioning framework proposed by Woller et al. The music composition process is performed by a number of mini-models parameterized by further described properties. The mini-models generate fragments of musical patterns used in output composition. Musical pattern and output generation are controlled by container for the mini-models - a host-model. General mechanism has been presented including the example of the synthesized output compositions

  19. Electronic imaging system and technique

    Science.gov (United States)

    Bolstad, J.O.

    1984-06-12

    A method and system for viewing objects obscurred by intense plasmas or flames (such as a welding arc) includes a pulsed light source to illuminate the object, the peak brightness of the light reflected from the object being greater than the brightness of the intense plasma or flame; an electronic image sensor for detecting a pulsed image of the illuminated object, the sensor being operated as a high-speed shutter; and electronic means for synchronizing the shutter operation with the pulsed light source.

  20. DNA vaccines for aquacultured fish

    DEFF Research Database (Denmark)

    Lorenzen, Niels; LaPatra, S.E.

    2005-01-01

    Deoxyribonucleic acid (DNA) vaccination is based on the administration of the gene encoding the vaccine antigen, rather than the antigen itself. Subsequent expression of the antigen by cells in the vaccinated hosts triggers the host immune system. Among the many experimental DNA vaccines tested in various animal species as well as in humans, the vaccines against rhabdovirus diseases in fish have given some of the most promising results. A single intramuscular (IM) injection of microgram amounts of DNA induces rapid and long-lasting protection in farmed salmonids against economically important viruses such as infectious haematopoietic necrosis virus (IHNV) and viral haemorrhagic septicaemia virus (VHSV). DNA vaccines against other types of fish pathogens, however, have so far had limited success. The most efficient delivery route at present is IM injection, and suitable delivery strategies for mass vaccination of small fish have yet to be developed. In terms of safety, no adverse effects in the vaccinated fishhave been observed to date. As DNA vaccination is a relatively new technology, various theoretical and long-term safety issues related to the environment and the consumer remain to be fully addressed, although inherently the risks should not be any greater than with the commercial fish vaccines that are currently used. Present classification systems lack clarity in distinguishing DNA-vaccinated animals from genetically modified organisms (GMOs), which could raise issues in terms of licensing and public acceptance of the technology. The potential benefits of DNA vaccines for farmed fish include improved animal welfare, reduced environmental impacts of aquaculture activities, increased food quality and quantity, and more sustainable production. Testing under commercial production conditions has recently been initiated in Canada and Denmark.

  1. Multimedia electronic medical record systems.

    Science.gov (United States)

    Lowe, H J

    1999-02-01

    A wide range of imaging technologies are becoming increasingly important to the practice of medicine. In addition, many medical specialties are highly visual, independent of their use of new imaging modalities. Because today's medical record contains text, images, and physiologic signals, it is inherently multimedia in nature. However, most electronic medical record systems handle only the textual portion of the patient record, resulting in a fragmentation of the database that physicians need to make timely, effective clinical decisions. Advances in database-, storage-, data-compression, and networking technologies will facilitate the development of multimedia electronic medical record systems for the 21st century. These systems will become widely used over the next decade, and in addition to enhancing patient care, will also present new opportunities for using clinical imaging data for biomedical research and education. PMID:10065056

  2. Vertex detector electronics : L1 electronics system issues

    CERN Document Server

    Ermoline, Y

    2001-01-01

    This note describes the application of general requirements to LHCb L1 front-end electronics [1] to the vertex detector L1 electronics, mainly system aspects like initialisation, resets, event identification, data formats and throttling.

  3. Field reliability of electronic systems

    International Nuclear Information System (INIS)

    This report investigates, through several examples from the field, the reliability of electronic units in a broader sense. That is, it treats not just random parts failure, but also inadequate reliability design and (externally and internally) induced failures. The report is not meant to be merely an indication of the state of the art for the reliability prediction methods we know, but also as a contribution to the investigation of man-machine interplay in the operation and repair of electronic equipment. The report firmly links electronics reliability to safety and risk analyses approaches with a broader, system oriented view of reliability prediction and with postfailure stress analysis. It is intended to reveal, in a qualitative manner, the existence of symptom and cause patterns. It provides a background for further investigations to identify the detailed mechanisms of the faults and the remedical actions and precautions for achieving cost effective reliability. (author)

  4. Comparing Denitrification Rates and Carbon Sources in Commercial Scale Upflow Denitrification Biological Filters in Aquaculture

    Science.gov (United States)

    Aerobic biological filtration systems employing nitrifying bacteria to remediate excess ammonia and nitrite concentrations are common components of recirculating aquaculture systems (RAS). However, significant water exchange may still be necessary to reduce nitrate concentrations to acceptable leve...

  5. Aquaculture Engineering: Status and Roles in the Growth of Aquaculture Industry in Nigeria

    Directory of Open Access Journals (Sweden)

    Mrs. Nene A. Jamabo

    2010-11-01

    Full Text Available This study reviews the role of aquaculture engineering in Nigeria’s aquaculture sub-sector. The focus was on solving site selection problems due to environmental, Climatic and hydrological factors, equipment selection and fabrication, and site specific engineering problems. The poor growth of the aquaculture industry in Nigeria in the past is attributed to the poor status of aquaculture engineering. Also emphasis was placed on the shortage of qualified manpower, aquaculture engineers, in Nigeria, and suggestions were made for the short, medium and long term solutions. It is hoped that this review article will elicit a positive shift in policy towards aquaculture engineering in Nigeria and beyond.

  6. 76 FR 9210 - Draft DOC National Aquaculture Policy

    Science.gov (United States)

    2011-02-16

    ... DOC National Aquaculture Policy AGENCY: Commerce. ACTION: Notice of availability of draft aquaculture... draft national aquaculture policy that supports sustainable aquaculture in the United States. The intent of the policy is to guide DOC's actions and decisions on aquaculture and to provide a...

  7. Produção do híbrido "cachadia" em diferentes densidades de estocagem em sistema de recirculação de água / Production of cachadia hybrid at different densities in a recirculating aquaculture system

    Scientific Electronic Library Online (English)

    P.M.C, Faria; R.K, Luz; S.A, Prado; E.M, Turra; T.B.F, Jorge; A.M.Q, Lana; E.A, Teixeira.

    2011-10-01

    Full Text Available Avaliou-se o efeito da densidade de estocagem na produção de "cachadia" (Pseudoplatystoma fasciatum x Leiarius marmoratus) em sistema de recirculação de água. Nas duas primeiras fases, com duração de 27 e 40 dias e usando animais com média de peso inicial de 31 e 57g, respectivamente, foram testados [...] 20, 40, 60 e 80 peixes/m³. Na terceira e quarta fase, usando peixes com média de peso de 169 e 399g durante 41 e 99 dias, respectivamente, foram testados 10, 20, 30 e 40 peixes/m³. A taxa de sobrevivência foi acima de 92%, sem diferenças significativas entre tratamentos. Verificou-se redução no ganho de peso diário com redução com o incremento da densidade na segunda e na quarta fase experimental. A biomassa final apresentou relação direta com a densidade em todas as fases. Taxas de conversão alimentar entre 0,8 e 1,3:1 foram registradas. O "cachadia" atingiu 1,1kg em 207 dias de cultivo, mostrando-se promissor para a piscicultura intensiva. Abstract in english The aim of this study was to investigate the effect of different stocking densities on cachadia production (Pseudoplatystoma fasciatum x Leiarius marmoratus) in recirculating aquaculture system. In the two first phases for 27 and 40 days using fish with average weight of 31 and 57g, respectively, de [...] nsities 20, 40, 60, and 80 fish/m³ were tested. In the third and fourth trial, using fish with an average weight of 169 and 399g during 41 and 99 days, respectively, densities 10, 20, 30, and 40 fish/m³ were tested. Survival rate was higher than 92%, without stocking density differences between the treatments. Daily weight gain showed reduction with the increase of the density in the second and fourth trial. However, final biomass presented direct relationship with increase density in all trials. Feed conversion rates ranged 0.8 from 1.3:1 were registered. Cachadia hybrid reached 1.1kg in approximately seven months of rearing indicating promise for intensive production.

  8. Nutrient discharge from China’s aquaculture industry and associated environmental impacts

    Science.gov (United States)

    Zhang, Ying; Bleeker, Albert; Liu, Junguo

    2015-04-01

    China’s aquaculture industry accounts for the largest share of the world’s fishery production, and provides a principal source of protein for the nation’s booming population. However, the environmental effects of the nutrient loadings produced by this industry have not been systematically studied or reviewed. Few quantitative estimates exist for nutrient discharge from aquaculture and the resultant nutrient enrichment in waters and sediments. In this paper, we evaluate nutrient discharge from aquacultural systems into aquatic ecosystems and the resulting nutrient enrichment of water and sediments, based on data from 330 cases in 51 peer-reviewed publications. Nitrogen use efficiency ranged from 11.7% to 27.7%, whereas phosphorus use efficiency ranged from 8.7% to 21.2%. In 2010, aquacultural nutrient discharges into Chinese aquatic ecosystems included 1044 Gg total nitrogen (184 Gg N from mariculture; 860 Gg N freshwater culture) and 173 Gg total phosphorus (22 Gg P from mariculture; 151 Gg P from freshwater culture). Water bodies and sediments showed high levels of nutrient enrichment, especially in closed pond systems. However, this does not mean that open aquacultural systems have smaller nutrient losses. Improvement of feed efficiency in cage systems and retention of nutrients in closed systems will therefore be necessary. Strategies to increase nutrient recycling, such as integrated multi-trophic aquaculture, and social measures, such as subsidies, should be increased in the future. We recommend the recycling of nutrients in water and sediments by hybrid agricultural-aquacultural systems and the adoption of nutrient use efficiency as an indicator at farm or regional level for the sustainable development of aquaculture; such indicators; together with water quality indicators, can be used to guide evaluations of technological, policy, and economic approaches to improve the sustainability of Chinese aquaculture.

  9. Advanced uncooled infrared system electronics

    Science.gov (United States)

    Neal, Henry W.

    1998-07-01

    Over the past two decades, Raytheon Systems Company (RSC), formerly Texas Instruments Defense Systems & Electronics Group, developed a robust family of products based on a low- cost, hybrid ferroelectric (FE) uncooled focal-plane array (FPA) aimed at meeting the needs for thermal imaging products across both military and commercial markets. Over the years, RSC supplied uncooled infrared (IR) sensors for applications such as in combat vehicles, man-portable weaponry, personnel helmets, and installation security. Also, various commercial IR systems for use in automobiles, boats, law enforcement, hand-held applications, building/site security, and fire fighting have been developed. These products resulted in a high degree of success where cooled IR platforms are too bulky and costly, and other uncooled implementations are less reliable or lack significant cost advantage. Proof of this great success is found in the large price reductions, the unprecedented monthly production rates, and the wide diversity of products and customers realized in recent years. The ever- changing needs of these existing and potential customers continue to fuel the advancement of both the primary technologies and the production capabilities of uncooled IR systems at RSC. This paper will describe a development project intended to further advance the system electronics capabilities of future uncooled IR products.

  10. Techniques to Assess Fish Productivity in Aquaculture Farms and Small Fisheries: An Overview of Algebraic Methods

    Directory of Open Access Journals (Sweden)

    G.M. Soto-Zarazua

    2012-01-01

    Full Text Available The main goal of aquaculture and small fisheries is the bioaccumulation of chemical elements in edible tissue. Fish, shellfish, decapods and/or algae are commonly cultivated organisms in marine and freshwater aquaculture systems. Total biomass is the best indicator of production system performance. However, due to the high variation of technologies and methods used in aquaculture, special techniques are required to make thorough studies. The present study is a summary of algebraic fish biometric techniques to assess fish biomass production. Numerical computations were carried out for didactical purposes.

  11. Genomic approaches in aquaculture and fisheries

    DEFF Research Database (Denmark)

    Cancela, M. Leonor; Bargelloni, Luca

    2010-01-01

    Despite the enormous input into the worldwide development of fish and shellfish farming in the recent decades, in part as an attempt to minimize the impact of fishing on already overexploited natural populations, the application of genomics to aquaculture and fisheries remains poorly developed. Improving state-of-the-art genomics research in various aquaculture systems, as well as its industrial applications, remains one of the major challenges in this area and should be the focus of well developed strategies to be implemented in the next generation of projects. This chapter will first provide an overview of the genomic tools and resources available, then discuss the application of genomic approaches to the improvement of fish and shellfish farming (e.g. breeding, reproduction, growth, nutrition and product quality), including the evaluation of stock diversity and the use of selection procedures. The chapter will also discuss the use of genomic approaches to study and monitor natural fish and shellfish populations and to understand interactions within their ecosystems.

  12. 76 FR 9209 - Draft NOAA National Aquaculture Policy

    Science.gov (United States)

    2011-02-16

    ...Draft NOAA National Aquaculture Policy and Draft DOC National Aquaculture Policy; Notices Federal Register / Vol...Administration RIN 0648-XA214 Draft NOAA National Aquaculture Policy AGENCY: National Marine...

  13. 76 FR 9210 - Draft DOC National Aquaculture Policy

    Science.gov (United States)

    2011-02-16

    ...OF COMMERCE Draft DOC National Aquaculture Policy AGENCY: Commerce. ACTION: Notice of availability of draft aquaculture policy; request for comments...public comment on a draft national aquaculture policy that supports...

  14. Reliability of Power Electronic Converter Systems

    DEFF Research Database (Denmark)

    2015-01-01

    The main aims of power electronic converter systems (PECS) are to control, convert, and condition electrical power flow from one form to another through the use of solid-state electronics. This book outlines current research into the scientific modeling, experimentation, and remedial measures for advancing the reliability, availability, system robustness, and maintainability of PECS at different levels of complexity. Drawing on the experience of an international team of experts, this book explores the reliability of PECS covering topics including an introduction to reliability engineering in power electronic converter systems; anomaly detection and remaining-life prediction for power electronics; reliability of DC-link capacitors in power electronic converters; reliability of power electronics packaging; modeling for life-time prediction of power semiconductor modules; minimization of DC-link capacitance in power electronic converter systems; wind turbine systems; smart control strategies for improved reliability of power electronics system; lifetime modelling; power module lifetime test and state monitoring; tools for performance and reliability analysis of power electronics systems; fault-tolerant adjustable speed drive systems; mission profile oriented reliability design in wind turbine and photovoltaic systems; reliability of power conversion systems in photovoltaic applications; power supplies for computers; and high-power converters. Reliability of Power Electronic Converter Systems is essential reading for researchers, professionals and students working with power electronics and their applications, particularly those specializing in the development and application of power electronic converters and systems.

  15. Status of Irish Aquaculture 2006

    OpenAIRE

    Institute, Marine; Mhara, Bord Iascaigh; Teo, Taighde Mara

    2007-01-01

    This is the fourth annual report reviewing the status of Irish aquaculture (see Parsons et al. 2004, Parsons et al. 2005, and Browne et al. 2006). As with the previous reports it has been produced in collaboration with the three main State agencies that provide support services in the areas of research and development to the industry – Bord Iascaigh Mhara (BIM), the Marine Institute (MI) and Údarás na Gaeltachta/ Taighde Mara Teoranta (TMT). The objectives of this report are: (1) To provide a...

  16. Market interactions for aquaculture products

    OpenAIRE

    Asche, Frank; Bjørndal, Trond; James A. Young

    2001-01-01

    During the last two decades there has been a tremendous growth in the production of intensively farmed fish. This growth has been accompanied by a substantial reduction in prices. As this enhances the competitiveness of farmed fish, concerns are often raised with respect to the market impact of new aquaculture species. In this paper we investigate what we know about market interactions for three groups of successfully farmed fish species salmon, catfish and sea bass/sea bream. We also provide...

  17. Aquaculture: global status and trends

    OpenAIRE

    Bostock, John; McAndrew, Brendan; Richards, Randolph; Jauncey, Kim; Telfer, Trevor; Lorenzen, Kai; Little, David; Ross, Lindsay; Handisyde, Neil; Gatward, Iain; Corner, Richard

    2010-01-01

    Aquaculture contributed 43 per cent of aquatic animal food for human consumption in 2007 (e.g. fish, crustaceans and molluscs, but excluding mammals, reptiles and aquatic plants) and is expected to grow further to meet the future demand. It is very diverse and, contrary to many perceptions, dominated by shellfish and herbivorous and omnivorous pond fish either entirely or partly utilizing natural productivity. The rapid growth in the production of carnivorous species such as salmon, shrimp an...

  18. QTL mapping designs for aquaculture.

    OpenAIRE

    Massault, C.; Bovenhuis, H; Haley, C. S.; De Koning, D.J.

    2008-01-01

    Rapid development of genomics technology is providing new opportunities for genetic studies, including QTL mapping, in many aquaculture species. This paper investigates the strengths and limitations of QTL mapping designs for fish and shellfish under three different controlled breeding schemes. For each controlled breeding scheme, the potential and limitations are described for typical species and are illustrated by three different designs using interval mapping. The results show that, regard...

  19. Status of Irish Aquaculture 2005

    OpenAIRE

    Institute, Marine; Mhara, Bord Iascaigh; Teo, Taighde Mara

    2006-01-01

    This is the third annual report on the status of Irish aquaculture (see Parsons et al., 2003, Parsons et al., 2004). As with the previous reports it has been produced in collaboration with the three main State agencies that provide support services in the areas of research and development to the industry – Bord Iascaigh Mhara (BIM), the Marine Institute (MI) and Taighde Mara Teo (TMT). The objectives of this report are: (1) To provide a useful, objective and comprehensive source of informatio...

  20. Application of Machine Learning Techniques in Aquaculture

    Directory of Open Access Journals (Sweden)

    Akhlaqur Rahman

    2014-04-01

    Full Text Available In this paper we present applications of different machine learning algorithms in aquaculture. Machine learning algorithms learn models from historical data. In aquaculture historical data are obtained from farm practices, yields, and environmental data sources. Associations between these different variables can be obtained by applying machine learning algorithms to historical data. In this paper we present applications of different machine learning algorithms in aquaculture applications.

  1. Significance of Pigmentation and Use in Aquaculture

    OpenAIRE

    *(1), ?brahim Diler; (2), Kamil Dilek

    2002-01-01

    Aquaculture is a rapidly growing global industry, comprising cultivation of various freshwater and marine species of finfish, prawn, and ornamental fish. By the year 2000, as much as 20% of the world 3% of the Turkey production of fish will be based on aquaculture. Properly formulated feeds and pigmentation are a significant part of successful aquaculture. Carotenoids play a major role in culture of some species i.e. salmon and rainbow trout, gold fish, red and gilthead sea bream. Various bio...

  2. Probiotics in aquaculture: importance and future perspectives

    OpenAIRE

    Sahu, Maloy Kumar; Swarnakumar, N. S.; K.Sivakumar; Thangaradjou, T.; Kannan, L.

    2008-01-01

    Aquaculture is one of the fastest developing growth sectors in the world and Asia presently contributes about 90% to the global production. However, disease outbreaks are constraint to aquaculture production thereby affects both economic development of the country and socio-economic status of the local people in many countries of Asia-Pacifi c region. Disease control in aquaculture industry has been achieved by following different methods using traditional ways, synthetic chemicals and antibi...

  3. REVIEW OF AQUACULTURE GENETIC RESEARCHES IN THAILAND

    OpenAIRE

    UTHAIRAT NA-NAKORN

    1992-01-01

    Aquaculture business has been well established in Thailand for more than 40 years. The most recent data indicated a total production of 260 380 tons. Sixty-five percent of the total production came from coastal aquaculture, mainly tiger prawn (Penaeus monodon) culture. Other important species for coastal aquaculture are banana prawn (P. merguensis), cockle (Anadara granosa), green mussel (Perna viridis), oyster (Crassostrea belcheri, Saccostrea commercialis), sea bass (Lates calcarifer) and g...

  4. A theory of electron baths: One-electron system dynamics

    International Nuclear Information System (INIS)

    The second-quantized, many-electron, atomic, and molecular Hamiltonian is partitioned both by the identity or labeling of the spin orbitals and by the dynamics of the spin orbitals into a system coupled to a bath. The electron bath is treated by a molecular time scale generalized Langevin equation approach designed to include one-electron dynamics in the system dynamics. The bath is formulated as an equivalent chain of spin orbitals through the introduction of equivalent-chain annihilation and creation operators. Both the dynamics and the quantum grand canonical statistical properties of the electron bath are examined. Two versions for the statistical properties of the bath are pursued. Using a weak bath assumption, a bath statistical average is defined which allows one to achieve a reduced dynamics description of the electron system which is coupled to the electron bath. In a strong bath assumption effective Hamiltonians are obtained which reproduce the dynamics of the bath and which lead to the same results as found in the weak bath assumption. The effective (but exact) Hamiltonian is found to be a one-electron Hamiltonian. A reduced dynamics equation of motion for the system population matrix is derived and found to agree with a previous version. This equation of motion is useful for studying electron transfer in the system when coupled to an electron bath

  5. Modeling of power electronic systems with EMTP

    Science.gov (United States)

    Tam, Kwa-Sur; Dravid, Narayan V.

    1989-01-01

    In view of the potential impact of power electronics on power systems, there is need for a computer modeling/analysis tool to perform simulation studies on power systems with power electronic components as well as to educate engineering students about such systems. The modeling of the major power electronic components of the NASA Space Station Freedom Electric Power System is described along with ElectroMagnetic Transients Program (EMTP) and it is demonstrated that EMTP can serve as a very useful tool for teaching, design, analysis, and research in the area of power systems with power electronic components. EMTP modeling of power electronic circuits is described and simulation results are presented.

  6. Sustainable Treatment of Aquaculture Effluents—What Can We Learn from the Past for the Future?

    OpenAIRE

    Ariel E. Turcios; Jutta Papenbrock

    2014-01-01

    Many aquaculture systems generate high amounts of wastewater containing compounds such as suspended solids, total nitrogen and total phosphorus. Today, aquaculture is imperative because fish demand is increasing. However, the load of waste is directly proportional to the fish production. Therefore, it is necessary to develop more intensive fish culture with efficient systems for wastewater treatment. A number of physical, chemical and biological methods used in conventional wastewater treatme...

  7. Ocean modelling for aquaculture and fisheries in Irish waters

    Science.gov (United States)

    Dabrowski, T.; Lyons, K.; Cusack, C.; Casal, G.; Berry, A.; Nolan, G. D.

    2015-06-01

    The Marine Institute, Ireland, runs a suite of operational regional and coastal ocean models. Recent developments include several tailored products that focus on the key needs of the Irish aquaculture sector. In this article, an overview of the products and services derived from the models are presented. A shellfish model that includes growth and physiological interactions of mussels with the ecosystem and is fully embedded in the 3-D numerical modelling framework has been developed at the Marine Institute. This shellfish model has a microbial module designed to predict levels of coliform contamination in mussels. This model can also be used to estimate the carrying capacity of embayments, assess impacts of pollution on aquaculture grounds and help to classify shellfish waters. The physical coastal model of southwest Ireland provides a three day forecast of shelf water movement in the region. This is assimilated into a new harmful algal bloom alert system used to inform end-users of potential toxic shellfish events and high biomass blooms that include fish killing species. Further services include the use of models to identify potential sites for offshore aquaculture, to inform studies of potential cross-contamination in farms from the dispersal of planktonic sea lice larvae and other pathogens that can infect finfish and to provide modelled products that underpin the assessment and advisory services on the sustainable exploitation of the marine fisheries resources. This paper demonstrates that ocean models can provide an invaluable contribution to the sustainable blue growth of aquaculture and fisheries.

  8. Ocean modelling for aquaculture and fisheries in Irish waters

    Directory of Open Access Journals (Sweden)

    T. Dabrowski

    2015-06-01

    Full Text Available The Marine Institute, Ireland, runs a suite of operational regional and coastal ocean models. Recent developments include several tailored products that focus on the key needs of the Irish aquaculture sector. In this article, an overview of the products and services derived from the models are presented. A shellfish model that includes growth and physiological interactions of mussels with the ecosystem and is fully embedded in the 3-D numerical modelling framework has been developed at the Marine Institute. This shellfish model has a microbial module designed to predict levels of coliform contamination in mussels. This model can also be used to estimate the carrying capacity of embayments, assess impacts of pollution on aquaculture grounds and help to classify shellfish waters. The physical coastal model of southwest Ireland provides a three day forecast of shelf water movement in the region. This is assimilated into a new harmful algal bloom alert system used to inform end-users of potential toxic shellfish events and high biomass blooms that include fish killing species. Further services include the use of models to identify potential sites for offshore aquaculture, to inform studies of potential cross-contamination in farms from the dispersal of planktonic sea lice larvae and other pathogens that can infect finfish and to provide modelled products that underpin the assessment and advisory services on the sustainable exploitation of the marine fisheries resources. This paper demonstrates that ocean models can provide an invaluable contribution to the sustainable blue growth of aquaculture and fisheries.

  9. Continuous host-macroparasite models with application to aquaculture

    Directory of Open Access Journals (Sweden)

    Catherine Bouloux Marquet

    2004-11-01

    Full Text Available We study a continuous deterministic host-macroparasite system which involves populations of hosts, parasites, and larvae. This system leads to a countable number of partial differential equations that under certain hypotheses, is reduced to finitely many equations. Also we assume hypotheses to close the system and to define the global dynamics for the hosts. Then, we analyze the spatially homogeneous model without demography (aquaculture hypothesis, and show some preliminary results for the spatially structured model.

  10. Computer Aided Control and Monitoring of Aquaculture Plants

    OpenAIRE

    Erik Hansen

    1987-01-01

    A computer system for control and monitoring of aquaculture plants has been developed by the Norwegian company NODEC. The system is based on a local area network which interfaces a computer system to the primary instruments located at various sites in the plant. Special software modules have been developed to handle different tasks such as data gathering, automatic control, alarming, logging, trend analysis and reporting. Special effort has been made to develop a user-friendly high level man-...

  11. Green and technical efficient growth in Danish fresh water aquaculture

    DEFF Research Database (Denmark)

    Nielsen, Rasmus

    2011-01-01

    Aquaculture is the fastest growing animal food processing sector in the world. Nevertheless, growth inside the Organization for Economic Co-operation and Development has been stagnating, with few exceptions. The main reason is strict environmental regulations. This study investigates if green growth can be achieved by introducing new environmentally friendly water purification systems in Danish fresh water aquaculture. Data Envelopment Analysis is used to investigate whether different water purification systems and farm size influence technical efficiency. The empirical results indicate that different water purification systems have no significant influence, although it increases with farm size. The policy implications are that green growth is possible by implementing the new water purification systems, but farmers have no incentive to adopt the new systems under the present regulation. If green growth should be achieved, the present regulation needs to be changed, providing the farmers with an incentive to adopt environmentally friendly production methods.

  12. Sediment quality and production data of black tiger shrimp (Penaeus monodon culture under Code of Conduct for Responsible Shrimp Aquaculture (CoC system and ordinary system of intensive shrimp farms

    Directory of Open Access Journals (Sweden)

    Klaysri, S.

    2005-02-01

    Full Text Available The study of sediment qualities and production data of black tiger shrimp (Penaeus monodon culture was carried out in 5 ponds practised following CoC guideline (CoC: “Code of Conduct for Responsible Shrimp Aquaculture” and in 10 ponds practised following common guideline of ordinary intensive farm (OIF. All the ponds were located in Songkhla and Nakhon Si Thammarat provinces and the study period was during March 2003-January 2004. It was found that sediment qualities (organic matter as %ignition loss, TN andTOC and pH of OIF system were significantly higher (p<0.05 than those of the CoC system only during the period 30-60 days of culture which was the most critical period of shrimp culture. This evidence suggests a significant effect on deterioration of the pond bottom causing an unsuitable ecological condition for shrimp living on the pond bottom. Our result on production data showed that the production and variable cost of production were about 794 kg/rai, and 114.6 baht/kg in the CoC system, while those of the OIF were 377 kg/ rai and 185.6 baht/kg, respectively.

  13. Polyurethane-flexible foam oil barrier production system for the protection of harbours, shorelines, and aquaculture projects. Final report. Barriere aus Polyurethanweichschaum zum Schutz gegen auslaufendes Rohoel bei Tanker-Havarien bzw. zum Schutz von Haefen, Straenden und Aquakulturanlagen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Dietzel, K.

    1987-01-01

    Among several sponsored projects concerning the combat of oil pollution a method and a prototyp of an oil barrier production system has been developed. This method produces continuously a barrier of flexible polyurethane foam at any length needed at the place of an oil spill off board a ship for the protection of harbours, shorelines or aquaculture facilities. The modulus system permits to build units of any size needed. The production speed of a barrier is, independent of temperatures and weather conditions, 250-400 metres per hour; a method and a prototype of a semiautomatic sewing device for the production of the skin, surrounding the floating element made up of flexible polyurethane foam. The production speed for this type of skin is about 1200 metres a day (24 working hours per day). With 17 refs., 1 tab., 17 figs.

  14. Differentiated Use of Electronic Case Management Systems

    Directory of Open Access Journals (Sweden)

    Erwin Rooze

    2010-11-01

    Full Text Available ICT is used to support and automate case management practices of courts. This use of ICT is here referred to as electronic case management systems. These systems can be applied at different levels of sophistication, on different types of caseflows and with different components. This article introduces the term "differentiated electronic case management systems", since the development and deployment of these electronic systems differs widely in level of sophistication and provided functionality and since these systems are capable of supporting the contingent use of differentiated case management. An overview of functionality of electronic case management systems found in research is given, using a distinction in four components. The lens of the contingency theory is used to discuss what relevance the different types of caseflows, components and levels of sophistication have for the differentiated use and development of electronic case management systems. Also discussed is what courts can do to harvest potential benefits of electronic case management systems.

  15. Sustainable Treatment of Aquaculture Effluents—What Can We Learn from the Past for the Future?

    Directory of Open Access Journals (Sweden)

    Ariel E. Turcios

    2014-02-01

    Full Text Available Many aquaculture systems generate high amounts of wastewater containing compounds such as suspended solids, total nitrogen and total phosphorus. Today, aquaculture is imperative because fish demand is increasing. However, the load of waste is directly proportional to the fish production. Therefore, it is necessary to develop more intensive fish culture with efficient systems for wastewater treatment. A number of physical, chemical and biological methods used in conventional wastewater treatment have been applied in aquaculture systems. Constructed wetlands technology is becoming more and more important in recirculating aquaculture systems (RAS because wetlands have proven to be well-established and a cost-effective method for treating wastewater. This review gives an overview about possibilities to avoid the pollution of water resources; it focuses initially on the use of systems combining aquaculture and plants with a historical review of aquaculture and the treatment of its effluents. It discusses the present state, taking into account the load of pollutants in wastewater such as nitrates and phosphates, and finishes with recommendations to prevent or at least reduce the pollution of water resources in the future.

  16. Differentiated Use of Electronic Case Management Systems

    OpenAIRE

    Erwin Rooze

    2010-01-01

    ICT is used to support and automate case management practices of courts. This use of ICT is here referred to as electronic case management systems. These systems can be applied at different levels of sophistication, on different types of caseflows and with different components. This article introduces the term "differentiated electronic case management systems", since the development and deployment of these electronic systems differs widely in level of sophistication and provided functionalit...

  17. Vets and aquaculture: an evolving relationship.

    Science.gov (United States)

    Soutar, Ronnie

    2015-09-12

    Aquaculture is one of the largest farming sectors in the UK, particularly in Scotland. Although veterinary involvement remains small, vets have proved their worth in the industry. As part of Veterinary Record's continuing series of articles discussing the state of different sectors of the veterinary profession, Ronnie Soutar describes the growth of aquaculture and the evolving relationship between the industry and profession. PMID:26358450

  18. Feed Additives for Aquaculture and Aquarium Culture

    OpenAIRE

    Barata, Eduardo N.; Velez, Zélia

    2011-01-01

    The presente invention refers of feed additives for aquaculture and aquarium culture. These additives comprise the amino acid, 1-methyl-L-tryptophane, or its isomers with the objective of improving the attractiveness of feeds used in aquaculture and aquaria for fish, as well as other aquatic organisms, under culture conditions. Therefore, this invention has applications in the agriculture-food industry.

  19. Environmental Best Management Practices for Aquaculture

    Science.gov (United States)

    The book “Environmental Best Management Practices for Aquaculture” provides technical guidance to improve the environmental performance of fish and shellfish farming. The book is the only comprehensive guide to mitigation of environmental impacts of aquaculture. Topics include the histiory and use...

  20. Influence of environmental variables in the efficiency of phage therapy in aquaculture

    OpenAIRE

    Yolanda J. Silva; Costa, Liliana; Pereira, Carla; Cunha, Ângela; Calado, Ricardo; Newton C.M. Gomes; Almeida, Adelaide

    2014-01-01

    Aquaculture facilities worldwide continue to experience significant economic losses because of disease caused by pathogenic bacteria, including multidrug-resistant strains. This scenario drives the search for alternative methods to inactivate pathogenic bacteria. Phage therapy is currently considered as a viable alternative to antibiotics for inactivation of bacterial pathogens in aquaculture systems. While phage therapy appears to represent a useful and flexible tool for microbiological deco...

  1. Status of Irish Aquaculture 2007

    OpenAIRE

    Institute, Marine; Mhara, Bord Iascaigh; Gaeltachta, U?dara?s na

    2008-01-01

    This is the fifth annual report to review the status of Irish aquaculture (see Parsons et al., 2004, Parsons et al., 2005, Browne et al., 2006, and Browne et al., 2007). As with previous editions it has been produced in collaboration with the three main State agencies that provide support services in the areas of research and development to the industry – Bord Iascaigh Mhara (BIM), the Marine Institute (MI) and Údarás na Gaeltachta. The objectives of this and previous reports are: (1) To prov...

  2. Status of Irish Aquaculture 2003

    OpenAIRE

    Institute, Marine; Mhara, Bord Iascaigh; Teo, Taighde Mara

    2004-01-01

    This is the first joint report on the status of Irish aquaculture, which has been produced in collaboration by the three main State agencies that provide support services in the areas of research and development to the industry – Bord Iascaigh Mhara, the Marine Institute and Taighde Mara. The value of industry output was over €1 billion in the period from 1990 to 2003 and this represents a significant socio economic impact in the coastal areas of the south and west coast. The aims of the repo...

  3. Micro-Electronic Nose System

    Science.gov (United States)

    Zee, Frank C.

    2011-12-01

    The ability to "smell" various gas vapors and complex odors is important for many applications such as environmental monitoring for detecting toxic gases as well as quality control in the processing of food, cosmetics, and other chemical products for commercial industries. Mimicking the architecture of the biological nose, a miniature electronic nose system was designed and developed consisting of an array of sensor devices, signal-processing circuits, and software pattern-recognition algorithms. The array of sensors used polymer/carbon-black composite thin-films, which would swell or expand reversibly and reproducibly and cause a resistance change upon exposure to a wide variety of gases. Two types of sensor devices were fabricated using silicon micromachining techniques to form "wells" that confined the polymer/carbon-black to a small and specific area. The first type of sensor device formed the "well" by etching into the silicon substrate using bulk micromachining. The second type built a high-aspect-ratio "well" on the surface of a silicon wafer using SU-8 photoresist. Two sizes of "wells" were fabricated: 500 x 600 mum² and 250 x 250 mum². Custom signal-processing circuits were implemented on a printed circuit board and as an application-specific integrated-circuit (ASIC) chip. The circuits were not only able to measure and amplify the small resistance changes, which corresponded to small ppm (parts-per-million) changes in gas concentrations, but were also adaptable to accommodate the various characteristics of the different thin-films. Since the thin-films were not specific to any one particular gas vapor, an array of sensors each containing a different thin-film was used to produce a distributed response pattern when exposed to a gas vapor. Pattern recognition, including a clustering algorithm and two artificial neural network algorithms, was used to classify the response pattern and identify the gas vapor or odor. Two gas experiments were performed, one at low gas concentrations between 100 and 600 ppm for two gas vapors and the other at high gas concentrations between 2000 ppm and the saturated vapor pressure of three gas vapors. The array of sensors and circuits were able to uniquely detect and measure these gas vapors and showed a linear response to their concentration levels for both experiments. The results also demonstrated that a reduction in the sensor area by two orders of magnitude (from 4.32 mm² to 0.0625 mm²) did not affect the sensor response. By applying pattern-recognition algorithms, the electronic nose system was able to correctly identify the different gas vapors from the pattern responses of the sensor array.

  4. 76 FR 9209 - Draft NOAA National Aquaculture Policy

    Science.gov (United States)

    2011-02-16

    ... National Aquaculture Policy and Draft DOC National Aquaculture Policy; Notices #0;#0;Federal Register / Vol... and Atmospheric Administration RIN 0648-XA214 Draft NOAA National Aquaculture Policy AGENCY: National...: Notice of availability of draft aquaculture policy; request for comments. SUMMARY: NOAA is seeking...

  5. Understanding electronic systems in semiconductor quantum dots

    International Nuclear Information System (INIS)

    Systems of confined electrons are found everywhere in nature in the form of atoms where the orbiting electrons are confined by the Coulomb attraction of the nucleus. Advancement of nanotechnology has, however, provided us with an alternative way to confine electrons by using artificial confining potentials. A typical structure of this nature is the quantum dot, a nanoscale system which consists of few confined electrons. There are many types of quantum dots ranging from self-assembled to miniaturized semiconductor quantum dots. In this work we are interested in electrostatically confined semiconductor quantum dot systems where the electrostatic confining potential that traps the electrons is generated by external electrodes, doping, strain or other factors. A large number of semiconductor quantum dots of this type are fabricated by applying lithographically patterned gate electrodes or by etching on two-dimensional electron gases in semiconductor heterostructures. Because of this, the whole structure can be treated as a confined two-dimensional electron system. Quantum confinement profoundly affects the way in which electrons interact with each other, and external parameters such as a magnetic field. Since a magnetic field affects both the orbital and the spin motion of the electrons, the interplay between quantum confinement, electron–electron correlation effects and the magnetic field gives rise to very interesting physical phenomena. Thus, confined systems of electrons in a semiconductor quantum dot represent a unique opportunity to study fundamental quantum theories in a controllable atomic-like setup. In this work, we describe some common theoretical models which are used to study confined systems of electrons in a two-dimensional semiconductor quantum dot. The main emphasis of the work is to draw attention to important physical phenomena that arise in confined two-dimensional electron systems under various quantum regimes. (comment)

  6. REVIEW OF AQUACULTURE GENETIC RESEARCHES IN THAILAND

    Directory of Open Access Journals (Sweden)

    UTHAIRAT NA-NAKORN

    1992-01-01

    Full Text Available Aquaculture business has been well established in Thailand for more than 40 years. The most recent data indicated a total production of 260 380 tons. Sixty-five percent of the total production came from coastal aquaculture, mainly tiger prawn (Penaeus monodon culture. Other important species for coastal aquaculture are banana prawn (P. merguensis, cockle (Anadara granosa, green mussel (Perna viridis, oyster (Crassostrea belcheri, Saccostrea commercialis, sea bass (Lates calcarifer and grouper (Epinephelus tauvina. Freshwater aquaculture, although produced only 35% of the annual production, provides major protein source for people in rural areas. Important freshwater species are Nile tilapia (Oreochromis niloticus, tawes (Puntius gonionotus, sepat Siam (Trichogasterpectoralis, walking catfish (Glorias spp., stripped catfish (Pangasius sutchi and giant freshwater prawn (Macrobrachium rosenbergii. Optimum aquacultural practises, namely stocking density, nutrition requirement and water quality have been obtained in most cultured species. But genetic approach has not been considered, thus resulting in deterioration in economic traits which might be due to excessive inbreeding (reviewed by Uraiwan 1989 and/or negative selection (Wongsangchan 1985. The history of researches on genetics in aquaculture in Thailand started in 1982 when the aquaculture genetic programme in form of a network has been established at the National Inland Fisheries Institute, Department of Fisheries. This programme was supported by the International Development Research Centre (IDRC, Canada in cooperation with Dalhousie University, Canada (Uraiwan 1989. In the same year a genetic improvement programme aiming at improving economic characters of some economic fish species has been conducted at the Department of Aquaculture, Kasetsart University. Paralelly a course in Fish Genetics has been offered. Since then different approaches of genetics have been applied with final objectives on improving aquaculture production of the country. Researches being conducted are reviewed according to the following fish species.

  7. PROBLEMS OF BIOFOULING ON FISH–CAGE NETS IN AQUACULTURE

    OpenAIRE

    Merica Sliškovi?; Gorana Jeli?

    2002-01-01

    Biofouling on fish–cage netting is a serious technical and economical problem to aquaculture worldwide. Compensation for the effects of biofouling must be included in cage system design and planning, as fouling can dramatically increase both weight and drag. Settlements of sessile plants and animals, with accumulation of the detritus diminish the size of mesh and can rapidly occlude mesh. Negative effect of smaller mesh size is changing in water flow trough the cages. Biofouling problems nece...

  8. Scenarios for Resilient Shrimp Aquaculture in Tropical Coastal Areas

    OpenAIRE

    Willem F. de Boer; Roel Bosma; Han van Dijk; Leontine Visser; Paul A.M. van Zwieten; Simon R. Bush; Marc Verdegem

    2010-01-01

    We contend there are currently two competing scenarios for the sustainable development of shrimp aquaculture in coastal areas of Southeast Asia. First, a landscape approach, where farming techniques for small-scale producers are integrated into intertidal areas in a way that the ecological functions of mangroves are maintained and shrimp farming diseases are controlled. Second, a closed system approach, where problems of disease and effluent are eliminated in closed recirculation ponds behind...

  9. Electrons at the surface of quantum systems

    OpenAIRE

    Leiderer, Paul

    1992-01-01

    Electrons can be trapped at the surfaces and interfaces of the condensed phases of quantum matter (in particular hydrogen and helium), where they form classical two-dimensional Coulomb systems. Apart from studying the intrinsic properties of these nearly ideal systems, like the transition from an electron gas to a Wigner solid, one can use the electrons also as a sensitive probe to investigate the surface of quantum liquids and solids. The examples presented here include the surface of solid ...

  10. Application of Information Systems in Electronic Insurance

    OpenAIRE

    Payman Salami; Hojat Ahmadi

    2010-01-01

    Information Systems (IS) and some of the application software are very important for developing electronic insurance. In this research we try to determine and investigate the Inform ation Systems and their application software, which are effective for electronic insurance development. The electronic insurance parameter that we consider in our research are quality of services, human resources, customer benefit, increased customer services, integrated customer information, integrated customer o...

  11. Electron beam welding complex diagnostics automated system

    Directory of Open Access Journals (Sweden)

    ?. ?. ?????????

    2013-07-01

    Full Text Available The structure of the system of technical diagnostics is investigated. The algorithm of technical diagnostic of electron beam welding complex, which serves as the basis for creation of automated system for technical diagnostics, is proposed

  12. Electronic Resource Management Systems in Practice

    Science.gov (United States)

    Grogg, Jill E.

    2008-01-01

    Electronic resource management (ERM) systems have inundated the library marketplace. Both integrated library systems (ILS) vendors and subscription agents are now offering products and service enhancements that claim to help libraries efficiently manage their electronic resources. Additionally, some homegrown and open-source solutions have emerged…

  13. Electronic Money: A Viable Payment System?

    OpenAIRE

    Guadamuz, Andres

    2003-01-01

    This paper explores some of the legal and practical issues related to the implementation of electronic money placed in smart cards as a viable online payment system. This is a subject of particular importance as many there are many hopes from the financial industry about the implementation of an electronic currency system will create a great method for small transactions, both online and offline.

  14. Electronic Official Personnel Folder System

    Data.gov (United States)

    US Agency for International Development — The eOPF is a digital recreation of paper personnel folder that stores electronic personnel data spanning an individual's Federal career. eOPF allows employees to...

  15. Characterization and significance of indicator bacteria in commercial aquaculture production facilities

    Energy Technology Data Exchange (ETDEWEB)

    Fiederlein, R.J.; Davis, E.M.; Mathewson, J.J. [Univ. of Texas School of Public Health, Houston, TX (United States)

    1996-11-01

    Catfish production is the single largest segment of the domestic aquaculture industry. Waste discharges from aquaculture operations are regulated at both the federal and state level. The federal government regulates surface water discharges from aquaculture facilities using regulations promulgated under the Clean Water Act. These regulations designate concentrated aquatic animal production facilities as point sources of pollution, thus subjecting them to National Pollution Discharge Elimination Systems (NPDES) permit requirements. Previous studies of aquaculture effluents have primarily characterized the organic, chemical, and physical components of discharged wastewater and have only characterized to a limited extent the microbial component of discharged wastewater. This study was initiated to examine the levels of four wastewater indicator bacteria groups and to examine to the genus level the members of one of these groups in wastewater, or potential wastewater, from aquaculture facilities over the course of the growout season of several different species of fish. This study also examined the relationships between these bacterial levels and other water quality parameters and operational variables and enumerated and characterized Aeromonas hydrophila complex bacteria, members of which are potential water-borne pathogens. The effectiveness of waste stabilization ponds in the treatment of aquaculture wastewaters was also evaluated.

  16. Stensund wastewater aquaculture. Studies of key factors for its optimization

    Energy Technology Data Exchange (ETDEWEB)

    Guterstam, B.; Forsberg, L.E. [Stensund Ecological Center, Stensunds Fold Center, S-61991 Trosa (Sweden); Buczynska, A. [Faculty of Process and Environmental Engineering, Technical University of Lodz, 175 Wolczanska strasse, PL-90942 Lodz (Poland); Frelek, K. [Department of Analytical Chemistry, Medical University of Gdansk, Al. Gen. J. Hallera 107, PL-80416 Gdansk (Poland); Pilkaityte, R. [Natural Science Faculty, University of Klaipeda, LT-5813 Klaipeda (Lithuania); Reczek, L. [Department of Water Supply and Sewage Systems, Warsaw Agricultural University, 166 Nowoursynowska strasse, PL-02787 Warsaw (Poland); Rucevska, I. [Latvian Environmental Data Center, Straumes 2, Jurmala LV 2015 (Latvia)

    1998-10-21

    This paper is a summary of an in-depth study of key factors in the function of a 7-year-old aquaculture system designed for treatment and recycling of domestic wastewater at Stensund, Trosa, Sweden. The reported areas are: wastewater flows, reduction of biochemical oxygen demand (BOD), chemical oxygen demand (COD), phosphorus, nitrogen, and fecal bacteria. Plant production is recorded as harvested biomass, and energy results are given as generated heat and electricity consumption. Special studies were conducted on the reduction of copper by anaerobic treatment. Nitrification was studied with different filter media. Microalgal autofocculation of phosphorus was studied in relation to pH and water hardness for the green algal genus Scenedesmus. Limiting factors for the growth of Daphnia magna in the zooplankton step of the constructed aquatic food-web was studied in a specially designed reproduction test. The results are analyzed in order to optimize the function of the wastewater aquaculture

  17. Liposarcoma in clownfish, Amphiprion ocellaris Cuvier, produced in indoor aquaculture.

    Science.gov (United States)

    Sharon, G; Benharroch, D; Kachko, L; Reis-Hevlin, N; Zilberg, D

    2015-06-01

    Clownfish, Amphiprion ocellaris Cuvier, produced and grown in an experimental indoor aquaculture facility, presented with lipomatous tumours. A total of 14 affected fish were examined. Based on the total number of fish at the aquaculture facility at the time of outbreak of this pathology, the scope of the incident is estimated to be 1 of 300 fish. The tumours were characterized by the presence of mature adipocytes of variable sizes, lipoblasts and by an invasive behaviour, which affected internal organs, muscle, central nervous system and, in one case, an eye. Detailed macroscopic and histopathological features are presented. The suggested diagnosis is that of a well-differentiated liposarcoma, a diagnosis so far never applied to fish. The limited outbreak of the neoplasm lasted a few months in 2011 and did not recur. Possible factors leading to this phenomenon, notably the metastasis, are discussed. PMID:24917512

  18. Carbon dioxide stripping in aquaculture. part 1: terminology and reporting

    Science.gov (United States)

    Colt, John; Watten, Barnaby; Pfeiffer, Tim

    2012-01-01

    The removal of carbon dioxide gas in aquacultural systems is much more complex than for oxygen or nitrogen gas because of liquid reactions of carbon dioxide and their kinetics. Almost all published carbon dioxide removal information for aquaculture is based on the apparent removal value after the CO2(aq) + HOH ? H2CO3 reaction has reached equilibrium. The true carbon dioxide removal is larger than the apparent value, especially for high alkalinities and seawater. For low alkalinity freshwaters (<2000 ?eq/kg), the difference between the true and apparent removal is small and can be ignored for many applications. Analytical and reporting standards are recommended to improve our understanding of carbon dioxide removal.

  19. Biogeochemical ecology of aquaculture ponds

    Energy Technology Data Exchange (ETDEWEB)

    Weisburd, R.S.J.

    1988-01-01

    Two methods to determine rates of organic matter production and consumption were applied in shrimp aquaculture ponds. Several questions were posed: can net rates of organic matter production and consumption be determined accurately through application of dissolved inorganic carbon (DIC) mass balance in a pond with high advective through-put Are organically loaded aquaculture ponds autotrophic How do rates of organic production vary temporally Are there diurnal changes in respiration rates Four marine ponds in Hawaii have been evaluated for a 53 day period through the use of geochemical mass balances. All fluxes of DIC into and out of the ponds were considered. DIC was calculated from hourly pH measurements and weekly alkalinity measurements. Average uptake of DIC from the pond water, equivalent to net community production, revealed net autotrophy in all cases. Hourly and longer period variations in organic matter production rates were examined. The daily cycle dominated the variation in rates of net community production. Maximal rates of net community production were maintained for four to six hours starting in mid-morning. Respiration rates decreased rapidly during the night in two of the ponds and remained essentially constant in the others. A similar pattern of decreasing respiration at night was seen in freshwater shrimp ponds which were studied with incubations. A new method involving isotope dilution of {sup 14}C-labeled DIC was used to measure respiration rates in light and dark bottles. This method is an inexpensive and convenient procedure which should also be useful in other environments. The incubations demonstrated that plankton respiration rates peak at or soon after solar noon and vary over the course of the day by about a factor of two.

  20. Biogeochemical ecology of aquaculture ponds

    International Nuclear Information System (INIS)

    Two methods to determine rates of organic matter production and consumption were applied in shrimp aquaculture ponds. Several questions were posed: can net rates of organic matter production and consumption be determined accurately through application of dissolved inorganic carbon (DIC) mass balance in a pond with high advective through-put? Are organically loaded aquaculture ponds autotrophic? How do rates of organic production vary temporally? Are there diurnal changes in respiration rates? Four marine ponds in Hawaii have been evaluated for a 53 day period through the use of geochemical mass balances. All fluxes of DIC into and out of the ponds were considered. DIC was calculated from hourly pH measurements and weekly alkalinity measurements. Average uptake of DIC from the pond water, equivalent to net community production, revealed net autotrophy in all cases. Hourly and longer period variations in organic matter production rates were examined. The daily cycle dominated the variation in rates of net community production. Maximal rates of net community production were maintained for four to six hours starting in mid-morning. Respiration rates decreased rapidly during the night in two of the ponds and remained essentially constant in the others. A similar pattern of decreasing respiration at night was seen in freshwater shrimp ponds which were studied with incubations. A new method involving isotope dilution of 14C-labeled DIC was used to measure respiration rates in light and dark bottles. This method is an inexpensive and convenient procedure which should also be useful in other environments. The incubations demonstrated that plankton respiration rates peak at or soon after solar noon and vary over the course of the day by about a factor of two

  1. High perveance electron gun for the electron cooling system

    Science.gov (United States)

    Korotaev, Yu; Meshkov, I.; Petrov, A.; Sidorin, A.; Smirnov, A.; Syresin, E.; Titkova, I.

    2000-02-01

    The cooling time in the electron cooling system is inversely proportional to the beam current. To obtain high current of the electron beam the control electrode of the gun is provided with a positive potential and an electrostatic trap for secondary electrons appears inside the electron gun. This leads to a decrease in the gun perveance. To avoid this problem, the adiabatic high perveance electron gun with the clearing control electrode is designed in JINR (J. Bosser, Y. Korotaev, I. Meshkov, E. Syresin et al., Nucl. Instr. and Meth. A 391 (1996) 103. Yu. Korotaev, I. Meshkov, A. Sidorin, A. Smirnov, E. Syresin, The generation of electron beams with perveance of 3-6 ?A/ V3/2, Proceedings of SCHEF'99). The clearing control electrode has a transverse electric field, which clears secondary electrons. Computer simulations of the potential map were made with RELAX3D computer code (C.J. Kost, F.W. Jones, RELAX3D User's Guide and References Manual).

  2. High perveance electron gun for the electron cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Korotaev, Yu.; Meshkov, I.; Petrov, A.; Sidorin, A.; Smirnov, A.; Syresin, E.; Titkova, I. E-mail: kitti@nusun.jinr.ru

    2000-02-21

    The cooling time in the electron cooling system is inversely proportional to the beam current. To obtain high current of the electron beam the control electrode of the gun is provided with a positive potential and an electrostatic trap for secondary electrons appears inside the electron gun. This leads to a decrease in the gun perveance. To avoid this problem, the adiabatic high perveance electron gun with the clearing control electrode is designed in JINR (J. Bosser, Y. Korotaev, I. Meshkov, E. Syresin et al., Nucl. Instr. and Meth. A 391 (1996) 103. Yu. Korotaev, I. Meshkov, A. Sidorin, A. Smirnov, E. Syresin, The generation of electron beams with perveance of 3-6 {mu}A/V{sup 3/2}, Proceedings of SCHEF'99). The clearing control electrode has a transverse electric field, which clears secondary electrons. Computer simulations of the potential map were made with RELAX3D computer code (C.J. Kost, F.W. Jones, RELAX3D User's Guide and References Manual)

  3. High perveance electron gun for the electron cooling system

    International Nuclear Information System (INIS)

    The cooling time in the electron cooling system is inversely proportional to the beam current. To obtain high current of the electron beam the control electrode of the gun is provided with a positive potential and an electrostatic trap for secondary electrons appears inside the electron gun. This leads to a decrease in the gun perveance. To avoid this problem, the adiabatic high perveance electron gun with the clearing control electrode is designed in JINR (J. Bosser, Y. Korotaev, I. Meshkov, E. Syresin et al., Nucl. Instr. and Meth. A 391 (1996) 103. Yu. Korotaev, I. Meshkov, A. Sidorin, A. Smirnov, E. Syresin, The generation of electron beams with perveance of 3-6 ?A/V3/2, Proceedings of SCHEF'99). The clearing control electrode has a transverse electric field, which clears secondary electrons. Computer simulations of the potential map were made with RELAX3D computer code (C.J. Kost, F.W. Jones, RELAX3D User's Guide and References Manual)

  4. High perveance electron gun for the electron cooling system

    CERN Document Server

    Korotaev, Yu V; Petrov, A; Sidorin, A; Smirnov, A; Syresin, E M; Titkova, I

    2000-01-01

    The cooling time in the electron cooling system is inversely proportional to the beam current. To obtain high current of the electron beam the control electrode of the gun is provided with a positive potential and an electrostatic trap for secondary electrons appears inside the electron gun. This leads to a decrease in the gun perveance. To avoid this problem, the adiabatic high perveance electron gun with the clearing control electrode is designed in JINR (J. Bosser, Y. Korotaev, I. Meshkov, E. Syresin et al., Nucl. Instr. and Meth. A 391 (1996) 103. Yu. Korotaev, I. Meshkov, A. Sidorin, A. Smirnov, E. Syresin, The generation of electron beams with perveance of 3-6 mu A/V sup 3 sup / sup 2 , Proceedings of SCHEF'99). The clearing control electrode has a transverse electric field, which clears secondary electrons. Computer simulations of the potential map were made with RELAX3D computer code (C.J. Kost, F.W. Jones, RELAX3D User's Guide and References Manual).

  5. A simple electron-beam lithography system

    DEFF Research Database (Denmark)

    MØlhave, Kristian; Madsen, Dorte NØrgaard

    2005-01-01

    A large number of applications of electron-beam lithography (EBL) systems in nanotechnology have been demonstrated in recent years. In this paper we present a simple and general-purpose EBL system constructed by insertion of an electrostatic deflector plate system at the electron-beam exit of the column of a scanning electron microscope (SEM). The system can easily be mounted on most standard SEM systems. The tested setup allows an area of up to about 50 x 50 pm to be scanned, if the upper limit for acceptable reduction of the SEM resolution is set to 10 run. We demonstrate how the EBL system can be used to write three-dimensional nanostructures by electron-beam deposition. (C) 2004 Elsevier B.V. All rights reserved.

  6. State of the art of Italian aquaculture

    OpenAIRE

    Melotti, P.; A. Roncarati

    2010-01-01

    According to aquaculture production statistics published by FEAP (2007), Italy is the fifth largest fish producer in the European Union having a total quantity for 2006 estimated around 60,000 t. This data is exclusively referred to rainbow trout (Oncorhynchus mykiss), seabream (Sparus aurata), seabass (Dicentrarchus labrax) and European eel (Anguilla anguilla) but even if we consider the total aquaculture production elaborated by ISMEA (2006) through year 2005 including sturgeons, carps, str...

  7. Aquaculture and Poultry Industry, Useful Learned Lessons

    OpenAIRE

    Y.M. Abdelhadi

    2012-01-01

    The historical development of aquaculture and poultry industry in Egypt was reviewed starting from the 60's of the 20th century up to 2011. Several and different stages of historical development for both sectors were described starting from the late 70's of the 20th century until the year 2011. Production figures, market prices, advantages and disadvantages of poultry industry compared with aquaculture were discussed. Many useful practices applied in poultry industry and could be applied also...

  8. Advances in genomics for flatfish aquaculture

    OpenAIRE

    Cerdà, Joan; Manchado, Manuel

    2012-01-01

    Fish aquaculture is considered to be one of the most sustainable sources of protein for humans. Many different species are cultured worldwide, but among them, marine flatfishes comprise a group of teleosts of high commercial interest because of their highly prized white flesh. However, the aquaculture of these fishes is seriously hampered by the scarce knowledge on their biology. In recent years, various experimental ‘omics’ approaches have been applied to farmed flatfishes to increment the g...

  9. Consumer behaviour and preferences for aquaculture products

    DEFF Research Database (Denmark)

    Brunsø, Karen; Scholderer, Joachim; Verbeke, Wim; Olsen, Svein Ottar

    2006-01-01

    During the last decades, the proportion of aquaculture products in the market place has increased dramatically and this trend seems to continue in the future as well. While both the producers of aquaculture products as well as the distribution channels are aware of this change in product composition, still little is known about the effect this has on consumer preferences and product choices. In connection with the SEAFOODplus project CONSUMERSURVEY, which aims at explaining seafood consumption, ...

  10. Increased competition for aquaculture from fisheries

    DEFF Research Database (Denmark)

    Jensen, Frank; Nielsen, Max; Nielsen, Rasmus

    2014-01-01

    The global fisheries sector has been characterized by three main trends over the last 2–3 decades; fish stocks have been overexploited and supply from wild fisheries is stagnating; fisheries management has improved slowly with the aims of achieving biological sustainability and rent maximization; and supplies from aquaculture have grown continuously. In this paper, the impact of improved fisheries management on aquaculture growth is studied assuming perfect substitution between farmed and wild f...

  11. Economics of aquaculture development in greece

    OpenAIRE

    Bailly, Denis

    1987-01-01

    (OCR non controlé) General terms of reference for the project and conclusions reached by other consultants point out that Greece offers good opportunities to develop aquaculture to the level of a socially and economically significant industry. Aquaculture development is stated to contribute to Government aims such as food security, preservation of foreign exchange, social and economic development of remote rural areas and contribution to the gross national product by rational use of water res...

  12. Risks of Using Antifouling Biocides in Aquaculture

    OpenAIRE

    José Meseguer; Maria Angeles Esteban; Francisco Antonio Guardiola; Alberto Cuesta

    2012-01-01

    Biocides are chemical substances that can deter or kill the microorganisms responsible for biofouling. The rapid expansion of the aquaculture industry is having a significant impact on the marine ecosystems. As the industry expands, it requires the use of more drugs, disinfectants and antifoulant compounds (biocides) to eliminate the microorganisms in the aquaculture facilities. The use of biocides in the aquatic environment, however, has proved to be harmful as it has toxic effects on the ma...

  13. Reproduction of European Eel in Aquaculture (REEL)

    DEFF Research Database (Denmark)

    Tomkiewicz, Jonna; Tybjerg, Lars; Støttrup, Josianne; McEvoy, Fintan; Ravn, Peter; Sørensen, Sune Riis; Lauesen, Peter; Graver, Christian; Munk, Peter; Holst, Lars K.; Vestbö, Bjarne; Svalastoga, Eiliv; Jacobsen, Charlotte; Holst, Bjørn; Steenfeldt, Svend Jørgen; Buelund, Lene; Hornum, Thomas; Kofoed, Tanja

    2012-01-01

    Project aim: Enhance methods and technology applied to produce and culture European eel larvae as basis for the development of a future self-sustained eel aquaculture. Background: The severe decline of the European eel stock calls for conservation measures including national eel management plans and establishment of a self-sustained eel aquaculture. In 2005, the National Institute of Aquatic Resources at the Technical University of Denmark (DTU Aqua), the Faculty of Life Sciences at Copenhagen U...

  14. Current status of federal involvement in US aquaculture. Background paper

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    The United States lacks a strong national aquaculture policy and supporting federal presence. Over the years, levels and focii of agency involvement in aquaculture development have shifted in response to legislation and its differing interpretations. The National Aquaculture Act (NAA), the primary piece of aquaculture-related legislation, is slated for reauthorization of the NAA and related legislation is the federal role in research and regulation of this emerging industry. Congress requested this Background Paper to provide information on technology issues of immediate importance to the U.S. aquaculture industry. This is a companion piece to the Background Paper on Selected Technology Issues in U.S. Aquaculture.

  15. Corrosion Reliability of Electronic Systems

    DEFF Research Database (Denmark)

    Ambat, Rajan; Jensen, Stine G.; Møller, Per

    2008-01-01

    Inherently two factors namely multi-material usage and potential bias makes electronic devices susceptible to corrosion if exposed to humid conditions. The problem is compounded today due to miniaturization and contamination effects. The reduction in size of the components and close spacing on a Printed Circuit Board (PCB) for high density packing has greatly increased the risk of corrosion under humid conditions. An important issue is the failures due to electrolytic metal migration. This paper...

  16. Preparation of targets using electron gun systems

    International Nuclear Information System (INIS)

    Most targets of isotopes with very low vapor pressure can only be fabricated by vacuum deposition using an electron gun system or a heavy ion sputtering system. Heavy ion sputtering is a very new technique with many unsolved problems. Therefore it seems to be easier to work with an electron gun. Different commercially available electron guns, which are all designed for the high evaporation rates used in industry, are examined for their qualification in processing small amounts of material as used in fabrication of isotope targets. Electron backscattering and the associated efficiency of the electron beam power is strongly dependent on the atomic number Z of the evaporant and the incident angle of the electron beam on the surface of the evaporant. This dependence leads also to the undesired effects to the target layers from electrons and ions. Some precautions are necessary against the effects of the electrons and ions, which are formed in the plasma directly over the beam impact point. Beam power and beam density have to be chosen to get a constant evaporation rate and a low enough condensation rate in order not to overheat the target substrates. To evaporate some metals it may be helpful to pulse the electron beam

  17. Protecting industrial control systems from electronic threats

    CERN Document Server

    Weiss, Joseph

    2010-01-01

    This book is meant to help both the novice and expert in Information Technology (IT) security and industrial control systems (ICS) gain a better understanding of protecting ICSs from electronic threats. The term ""ICS"" was chosen as ICSs include Supervisory Control and Data Acquisition (SCADA), Distributed Control Systems (DCS), Programmable Logic Controllers (PLCs), Remote Terminal Units (RTUs), Intelligent Electronic Devices (IEDs), field controllers, sensors, and drives, emission controls, building controls including fire suppression, thermostats, and elevator controls, and meters includin

  18. Towards environmentally sustainable aquaculture: Exploiting fermentation products from anaerobic sludge digestion for fueling nitrate removal in RAS

    DEFF Research Database (Denmark)

    Suhr, Karin Isabel; Pedersen, Per Bovbjerg

    2011-01-01

    Aquaculture is the world’s fastest growing food production sector (FAO, 2007). The continuous growth in many countries, however, relies heavily on the ability to reduce the emission of nutrients and chemicals from the fish farms. A way to manage and treat the nutrient aquaculture wastes is by production in recirculating aquaculture systems (RAS). In Denmark, more than 50 % of total fresh-water rainbow trout production is made in semi-intensive RAS, called ModelTroutFarms (MTF). MTF efficiently r...

  19. Nitrosomonas Nm143-like ammonia oxidizers and Nitrospira marina -like nitrite oxidizers dominate the nitrifier community in a marine aquaculture biofilm

    DEFF Research Database (Denmark)

    Foesel, Bärbel U.; Gieseke, Armin; Schwermer, Carsten; Stief, Peter; Koch, Liat; Cytryn, Eddie; de la Torré, José R.; van Rijn, Jaap; Minz, Dror; Drake, Harold L.; Schramm, Andreas

    2008-01-01

    Zero-discharge marine aquaculture systems are an environmentally friendly alternative to conventional aquaculture. In these systems, water is purified and recycled via microbial biofilters. Here, quantitative data on nitrifier community structure of a trickling filter biofilm associated with a recirculating marine aquaculture system are presented. Repeated rounds of the full-cycle rRNA approach were necessary to optimize DNA extraction and the probe set for FISH to obtain a reliable and comprehe...

  20. Electron beam size measurements in the Fermilab Electron Cooling System

    Energy Technology Data Exchange (ETDEWEB)

    Kroc, T.K.; Burov, A.V.; Bolshakov, T.B.; Shemyakin, A.; /Fermilab; Seletskiy, S.M.; /Rochester U.

    2005-09-01

    The Fermilab Electron Cooling Project requires a straight trajectory and constant beam size to provide maximum cooling of the antiprotons in the Recycler. A measurement system was developed using movable apertures and steering bumps to measure the beam size in a 20m long, nearly continuous, solenoid. This paper will focus on results of these measurements of the beam size and the difficulties in making those measurements.

  1. Quantum-based electronic devices and systems selected topics in electronics and systems, v.14

    CERN Document Server

    Dutta, Mitra

    1998-01-01

    This volume includes highlights of the theories and experimental findings that underlie essential phenomena occurring in quantum-based devices and systems as well as the principles of operation of selected novel quantum-based electronic devices and systems. A number of the emerging approaches to creating new types of quantum-based electronic devices and systems are also discussed.

  2. Bioactivity of phytochemicals in some lesser-known plants and their effects and potential applications in livestock and aquaculture production systems.

    Science.gov (United States)

    Makkar, H P S; Francis, G; Becker, K

    2007-10-01

    Livestock and aquaculture production is under political and social pressure, especially in the European Union (EU), to decrease pollution and environmental damage arising due to animal agriculture. The EU has banned the use of antibiotics and other chemicals, which have been shown to be effective in promoting growth and reducing environment pollutants because of the risk caused to humans by chemical residues in food and by antibiotic resistance being passed on to human pathogens. As a result of this, scientists have intensified efforts in exploiting plants, plant extracts or natural plant compounds as potential natural alternatives for enhancing the livestock productivity. This paper discusses work on the effects of various phytochemicals and plant secondary metabolites in ruminant and fish species. The focus is on (i) plants such as Ananas comosus (pine apple), Momordica charantia (bitter gourd) and Azadirachta indica (neem) containing anthelmintic compounds and for their use for controlling internal parasites; (ii) plants containing polyphenols and their applications for protecting proteins from degradation in the rumen, increasing efficiency of microbial protein synthesis in rumen and decreasing methane emission; for using as antioxidants, antibacterial and antihelmintic agents; and for changing meat colour and for increasing n-3 fatty acids and conjugated linoleic acid in meat; (iii) saponin-rich plants such as quillaja, yucca and Sapindus saponaria for increasing the efficiency of rumen fermentation, decreasing methane emission and enhancing growth; for producing desired nutritional attributes such as lowering of cholesterol in monogastric animals; for increasing growth of fish (common carp and Nile tilapia) and for changing male to female ratio in tilapia; and for use as molluscicidal agents; (iv) Moringa oleifera leaves as a source of plant growth factor(s), antioxidants, beta-carotene, vitamin C, and various glucosinolates and their degraded products for possible use as antibacterial, antioxidant, anticarcinogenic and antipest agents; (v) Jatropha curcas toxic variety with high levels of various phytochemicals such as trypsin inhibitor, lectin, phytate and phorbol esters in seeds limiting the use of seed meal in fish and livestock diets; and the use of phorbol esters as bio-pesticidal agent; and (vi) lesser-known legumes such as Entada phaseoloides seeds containing high levels of trypsin inhibitor and saponins, Sesbania aculeate seeds rich in non-starch polysaccharides and Mucuna pruriens var. utilis seeds rich in l-3,4-dihydroxyphenylalanine and their potential as fish feed; Cassia fistula seeds as a source of antioxidants; and the use of Canavalia ensiformis, C. gladiata and C. virosa seeds containing high levels of trypsin inhinitor, lectins and canavanine. The paper also presents some challenges and future areas of work in this field. PMID:22444893

  3. THE STATUS OF AQUACULTURE IN THE WORLD AND IN EUROPE

    OpenAIRE

    Nikola Fijan

    2002-01-01

    During the past few years, several authors have presented the production data and the problems in Croatian aquaculture and suggested measures for improvements. Some of these authors referred to some sectors of aquaculture in the world. This paper reports basic statistical data of the Food and Agriculture Organization (FAO, United Nations) of the world aquaculture during the period of 1990–1999. The annual growth rate in that period averaged about 10%, and in the year 1999 the aquaculture prov...

  4. Debugging at the Electronic System Level

    CERN Document Server

    Rogin, Frank

    2010-01-01

    Debugging becomes more and more the bottleneck to chip design productivity, especially while developing modern complex integrated circuits and systems at the Electronic System Level (ESL). Today, debugging is still an unsystematic and lengthy process. Here, a simple reporting of a failure is not enough, anymore. Rather, it becomes more and more important not only to find many errors early during development but also to provide efficient methods for their isolation. In "Debugging at the Electronic System Level" the state-of-the-art of modeling and verification of ESL designs is review

  5. An overview of strongly correlated electron systems

    International Nuclear Information System (INIS)

    This work provides an overview of strongly correlated electron systems. Taking a historical point of view, this work emphasizes early papers and general concepts that have remained relevant over the 50-year development of the field. Selected experimental results are given that illustrate different phenomena. The subjects discussed include concentrated Kondo systems, anomalous gapless superconductivity, non-Fermi liquid behavior, and quantum phase transitions

  6. An overview of strongly correlated electron systems

    Energy Technology Data Exchange (ETDEWEB)

    Edelstein, A.S. E-mail: edelstein@arl.army.mil

    2003-01-01

    This work provides an overview of strongly correlated electron systems. Taking a historical point of view, this work emphasizes early papers and general concepts that have remained relevant over the 50-year development of the field. Selected experimental results are given that illustrate different phenomena. The subjects discussed include concentrated Kondo systems, anomalous gapless superconductivity, non-Fermi liquid behavior, and quantum phase transitions.

  7. Electron-optical systems for Mott polarimeters

    International Nuclear Information System (INIS)

    Electron-optical systems, forming polarized electron beams from solid and gaseous sources at a Mott detector with operating potentials of 20 and 50 kV, have been theoretically investigated. The integral EOS creates a beam <2.6 nm in diameter at the target of the Mott detector for secondary electrons with energies of 1-20 eV and exit angles of 0 -60 . The differential EOS provides an energy resolution of 2-6% within the range of 3-2000 eV, the illumination being 5-13% for a 4? angle; at the target of the Mott detector it creates a beam of 1-6 mm in diameter. Both systems have been constructed at the laboratory of Spin-polarized Electron Spectroscopy (Department of Experimental Physics) at St. Petersburg State Technical University. ((orig.))

  8. 7 CFR 1437.303 - Aquaculture, including ornamental fish.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Aquaculture, including ornamental fish. 1437.303... ASSISTANCE PROGRAM Determining Coverage Using Value § 1437.303 Aquaculture, including ornamental fish. (a) Aquaculture is a value loss crop and is compensable only in accord with restrictions set in this...

  9. Electron-phonon interactions in correlated systems

    International Nuclear Information System (INIS)

    There exist attempts to describe the superconducting mechanism operating in HTS as based on antiferromagnetic fluctuations. It is not our intention to dwell on the superconducting mechanism, even though this is very a important issue. The main aim is to discuss the problem of interplay between electron-phonon and electron-electron interactions in correlated systems. We believe such analysis can be of importance for various materials and not only HTS'S. We shall however mainly refer to experiments on this last class of superconductors. Severe complications are to be expected by studying the problem. As is well known electron correlations are very important in narrow band systems, where the relevant electronic scale EF is quite small. In those circumstances, the phonon energy scale ?D is of comparable magnitude, with the ratio ?D/EF of order 1 signalling a possible break down of the Migdal - Eliashberg description of the electron-phonon interaction in metals. Here we shall assume the validity of the Migdal-Eliashberg approximation and concentrate on the mutual influence of electron and phonon subsystems. In the next section we shall discuss experimental motivation for and theoretical work related to the present problem. Section 3 contains a brief discussion of our theory. It is a self-consistent theory a la Migdal with strong correlations treated with an auxiliary boson technique. We conclude with results and their discussion. (orig.)

  10. Electronic nicotine delivery systems: a research agenda

    OpenAIRE

    Etter, Jean-François; Bullen, Chris; Flouris, Andreas D; Laugesen, Murray; Eissenberg, Thomas

    2011-01-01

    Electronic nicotine delivery systems (ENDS, also called electronic cigarettes or e-cigarettes) are marketed to deliver nicotine and sometimes other substances by inhalation. Some tobacco smokers report that they used ENDS as a smoking cessation aid. Whether sold as tobacco products or drug delivery devices, these products need to be regulated, and thus far, across countries and states, there has been a wide range of regulatory responses ranging from no regulation to complete bans. The empiric...

  11. VHDL Model of Electronic-Lock System

    Directory of Open Access Journals (Sweden)

    J. Noga

    2000-04-01

    Full Text Available The paper describes the design of an electronic-lock system which wascompleted as part of the Basic VHDL course in the Department of Controland Measurement Faculty of Electrical Engineering and Informatics,Technical University of Ostrava, Czech Republic in co-operation withthe Department if Electronic Engineering, University of Hull, GreatBritain in the frame of TEMPUS project no. S_JEP/09468-95.

  12. Electronic relaxation and dissipation in mesoscopic systems

    OpenAIRE

    Houshang Pour Islam, Kamran

    2000-01-01

    This thesis is concerned with the theoretical study of the transport in small conductors at low temperatures. Our aim is to elucidate the interplay between the statistical environment and mesoscopic systems, and its effect on electronic features in the domain of transport. In a first phenomenological approach based on the Landauer picture of transport, we study de transport properties of a mesoscopic sample connected to electronic reservoirs. The infl...

  13. Information entropies of many-electron systems

    International Nuclear Information System (INIS)

    The Boltzmann-Shannon (BS) information entropy S? = - ? ?(r)log ?(r) dr measures the spread or extent of the one-electron density ?(r), which is the basic variable of the density function theory of the many electron systems. This quantity cannot be analytically computed, not even for simple quantum mechanical systems such as, e.g., the harmonic oscillator (HO) and the hydrogen atom (HA) in arbitrary excited states. Here, we first review (i) the present knowledge and open problems in the analytical determination of the BS entropies for the HO and HA systems in both position and momentum spaces and (ii) the known rigorous lower and upper bounds to the position and momentum BS entropies of many-electron systems in terms of the radial expectation values in the corresponding space. Then, we find general inequalities which relate the BS entropies and various density functionals. Particular cases of these results are rigorous relationships of the BS entropies and some relevant density functionals (e.g., the Thomas-Fermi kinetic energy, the Dirac-Slater exchange energy, the average electron density) for finite many-electron systems. 28 refs

  14. Aquaculture and climate change in Canada

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-05-01

    Oceans and large bodies of water have the ability to absorb and distribute heat, which would indicate that changes related to climate may be more gradual and less apparent than those occurring in the atmosphere. The possible impact of temperature rise on aquaculture has not been studied in great detail. The species suitable for farming in any specified area would be affected by temperature changes. Temperature changes would also have an indirect impact on oxygen, pests, and the occurrence of toxic algal blooms. A rise in sea level would gradually impact some types of aquaculture. In addition, an increase in extreme weather patterns and storms represents a hazard to the industry. This document examines several possible scenarios in an effort to promote discussion among industry operators. An overview of the aquaculture industry in Canada was provided. The possible impacts of climate change were discussed, along with environmental factors, impacts and mitigation. A brief look at technological advances was presented. 1 tab., 1 fig.

  15. Vertical Integration in the Taiwan Aquaculture Industry

    Directory of Open Access Journals (Sweden)

    Tzong-Ru Lee (Jiun-Shen

    2011-12-01

    Full Text Available The study aims to improve the distribution channels in the Taiwanaquaculture industry through a better vertical integration. This studyis derived from a need to improve the distribution performance ofagricultural-based industries in response to increasing food demandsin Asia and elsewhere. Based on a four-by-eight matrix derived fromboth a value chain and a service profit chain, thirty different strategiesare developed. This development is based on key success factors andstrategies for vertical integration interviewed and cited in the literatures.The findings are identified by applying the Gray Relational Analysis(GRA. For this study, the key success factors for aquaculture wholesalemarkets include the communication, integration and cohesion ofopinion within the wholesale market; government support; andmutualtrust between members of the vertical integration scheme. The suitablevertical integration strategies are an improved safety and hygiene inspectionof aquaculture products, accuracy of aquaculture product categorization,and precision in product weighing.

  16. Capturing Ecosystem Services, Stakeholders' Preferences and Trade-Offs in Coastal Aquaculture Decisions: A Bayesian Belief Network Application

    OpenAIRE

    Schmitt, Laetitia Helene Marie; Brugere, Cecile

    2013-01-01

    Aquaculture activities are embedded in complex social-ecological systems. However, aquaculture development decisions have tended to be driven by revenue generation, failing to account for interactions with the environment and the full value of the benefits derived from services provided by local ecosystems. Trade-offs resulting from changes in ecosystem services provision and associated impacts on livelihoods are also often overlooked. This paper proposes an innovative application of Bayesian...

  17. Security in Electronic Payment Systems

    Directory of Open Access Journals (Sweden)

    Roxana Turcu

    2014-12-01

    Full Text Available The payment security becomes fundamental in our days. Based on this statement I have decided to deepen this subject and to study the online payment systems and the connection between them. I have observed that this area becomes the hackers’ attraction and I have realized how important the security of the ecommerce is. Also I have done a research of the possible attacks and I have searched for the countermeasures of this attacks. The result of my research is my payment gateway solution presented in the following lines.

  18. A Flexible Electronic Commerce Recommendation System

    Science.gov (United States)

    Gong, Songjie

    Recommendation systems have become very popular in E-commerce websites. Many of the largest commerce websites are already using recommender technologies to help their customers find products to purchase. An electronic commerce recommendation system learns from a customer and recommends products that the customer will find most valuable from among the available products. But most recommendation methods are hard-wired into the system and they support only fixed recommendations. This paper presented a framework of flexible electronic commerce recommendation system. The framework is composed by user model interface, recommendation engine, recommendation strategy model, recommendation technology group, user interest model and database interface. In the recommender strategy model, the method can be collaborative filtering, content-based filtering, mining associate rules method, knowledge-based filtering method or the mixed method. The system mapped the implementation and demand through strategy model, and the whole system would be design as standard parts to adapt to the change of the recommendation strategy.

  19. Perception of Alabama Science and Career Technology Teachers Concerning Teaching the Alabama Aquaculture Course of Study

    Science.gov (United States)

    Cline, David John

    The purpose of this study was to improve teachers' ability to effectively use aquaculture as a tool to teach math and science. The study population included Alabama science and career tech teachers that were certified to teach the Alabama aquaculture course of study. The teachers were electronically surveyed regarding their perceptions of the importance of the aquascience elective and aquaculture science course content standards, their knowledge of those topics and how they perceived the quality of available teaching materials. While all of the content standards were rated above average in importance, aquaculture career awareness and safety concerns were rated the highest by teachers. Teachers were most knowledgeable about career opportunities, categorization of aquaculture species, and the adaptations of aquatic organisms. The average materials ratings were below average for all content standards. The highest rated materials were for career opportunities, categorization of species and safety topics. Using Borich's (1980) model of mean weighted discrepancy scores, the control of diseases and pests in the aquatic environment and concepts associated with health management of aquacrops were identified as top priorities for in-service teacher training. Aquaculture industry infrastructure and the effects of the fishing industry were also identified as priority training topics. Teachers were self-divided into 3 categories those that taught science (SCI), career tech (CTE) and those that taught both (BOTH). They were further divided by their level of experience. A multivariate analysis of variance (MANOVA) revealed a significant effect between teacher types but there was no significant interaction effect between (a) teacher type and experience level or (b) the two levels of experience. A follow-up analysis of variance (ANOVA) indicated that the science teachers thought significantly less of the available materials than either the CTE or BOTH groups.

  20. Cultivable intestinal microbiota of yellowtail juveniles (Seriola lalandi) in an aquaculture system / Microbiota intestinal cultivable de juveniles de dorada (Seriola lalandi) en un sistema de acuicultura

    Scientific Electronic Library Online (English)

    Eduardo, Aguilera; Gabriel, Yany; Jaime, Romero.

    2013-07-01

    Full Text Available La dorada ("yellowtail", Seriola lalandi) ha sido cultivada durante los últimos años, y su expansión se ha debido al mayor conocimiento científico-técnico así como a la creciente demanda, convirtiéndose en una promisoria especie para la acuicultura. Dado que el conocimiento de la microbiota intestin [...] al de esta especie es muy limitado, el objetivo de este estudio es describir las poblaciones bacterianas asociadas al tracto intestinal de Seriola lalandi cultivada en Chile. La composición de la microbiota fue analizada en dos etapas de crecimiento diferenciadas por peso y parámetros como SGR y FCR. Los juveniles (peso inicial promedio 7.33 ± 0.30 g) y pre-adultos (81.7 ± 19.0 g) fueron alimentados con dieta comercial por 33 y 50 días, respectivamente. Las primeras muestras fueron recolectadas al término del primer ensayo en ejemplares de 50 g app., y la segunda muestra fue tomada al término del segundo ensayo en peces de 370 g app. La composición de la microbiota fue examinada mediante aislamiento convencional en medio de cultivo de Agar Tripticasa Soya (TSA) seguido de secuenciación e identificación por 16S rRNA. Un total de dieciséis géneros fueron identificados, donde Pseudomonas, Vibrio y Staphylococcus fueron los géneros predominantes en peces de 50 g, mientras que Microbacterium y Francisella fueron los géneros predominantes en los peces de 370 g. Se determinó que la composición de la microbiota se ajustó a diferentes arreglos en función del tamaño del hospedero, donde los únicos géneros compartidos fueron Bacillus y Vibrio. El conocimiento de la microbiota intestinal de Seriola lalandi es el primer paso para explorar el adecuado manejo de la misma, así como el desarrollo de probióticos y también obtener referencias de la microbiota de peces sanos en condiciones de cultivo. Abstract in english The yellowtail (Seriola lalandi) has been farmed for many years and is becoming a promising aquaculture species. Knowledge of the intestinal microbiota of this species is very limited. Thus, the aim of this study is to describe the bacterial populations associated with the intestinal tract of Seriol [...] a lalandi reared in Chile. The microbiota composition was analyzed at two growth stages distinguished by weight and parameters such as Specific Growth Rate (SGR) and Feed Conversion Ratio (FCR). Juveniles (mean initial weight 7.33 ± 0.30 g) and pre-adults (81.7 ± 19.0 g) were fed with commercial diet for 33 and 50 days, respectively. The first intestinal samples were collected at the end of Trial 1 from specimens weighing approximately 50 g while the second samples were obtained at the end of Trial 2 from specimens weighing approximately 370 g. The microbiota composition was examined using conventional isolation in Tryptic Soy Agar (TSA) followed by 16S rRNA sequencing and identification. In total, 16 genera were identified. Pseudomonas, Vibrio and Staphylococcus were the predominant genera in fish at the 50 g stage, whereas Microbacterium and Francisella were the predominant genera in the 370 g stage. The microbiota composition showed different assemblages, depending on host size, with Bacillus and Vibrio being the only genera that were shared. Knowledge of the intestinal microbiota of Seriola lalandi is the first step in the exploration of microbiota management and the development of probiotics, as well as in the identification of the bacterial populations in healthy fish under cultured conditions.

  1. Electronic instrumentation system for pulsed neutron measurements

    International Nuclear Information System (INIS)

    An essential point of pulsed neutron measurement of thermal neutron parameters for different materials is the registration of the thermal neutron die-away curve after a fast neutron bursts have been injected into the system. An electronic instrumentation system which is successfully applied for pulsed neutron measurements is presented. An important part of the system is the control unit which has been designed and built in the Laboratory of Neutron Parameters of Materials. (author)

  2. Electronic system of TBR tokamak device

    International Nuclear Information System (INIS)

    The electronics developed as a part of the TBR project, which involves the construction of a small tokamak at the Physics Institute of the University of Sao Paulo, is described. On the basis of tokamak parameter values, the electronics for the toroidal field, ohmic/heating and vertical field systems is presented, including capacitors bank, switches, triggering circuits and power supplies. A controlled power oscilator used in discharge cleaning and pre-ionization is also described. The performance of the system as a function of the desired plasma parameters is discussed. (Author)

  3. Prognostics for Electronics Components of Avionics Systems

    Science.gov (United States)

    Celaya, Jose R.; Saha, Bhaskar; Wysocki, Philip F.; Goebel, Kai F.

    2009-01-01

    Electronics components have and increasingly critical role in avionics systems and for the development of future aircraft systems. Prognostics of such components is becoming a very important research filed as a result of the need to provide aircraft systems with system level health management. This paper reports on a prognostics application for electronics components of avionics systems, in particular, its application to the Isolated Gate Bipolar Transistor (IGBT). The remaining useful life prediction for the IGBT is based on the particle filter framework, leveraging data from an accelerated aging tests on IGBTs. The accelerated aging test provided thermal-electrical overstress by applying thermal cycling to the device. In-situ state monitoring, including measurements of the steady-state voltages and currents, electrical transients, and thermal transients are recorded and used as potential precursors of failure.

  4. Probiotic effects on cobia Rachycentron canadum larvae reared in a recirculating aquaculture system / Efectos probióticos sobre las larvas de cobia Rachycentron canadum criadas en un sistema de recirculación de agua

    Scientific Electronic Library Online (English)

    M. Angélica, Garrido-Pereira; Michael, Schwarz; Brendan, Delbos; Ricardo V, Rodrigues; Luis, Romano; Luís, Sampaio.

    2014-11-01

    Full Text Available Cobia (Rachycentron canadum) es una especie de pez marino con buen potencial para la maricultura. Este estudio analiza los efectos del probiótico Bacillus spp. sobre el desempeño de las larvas de cobia criadas en un sistema de recirculación de agua (RAS). Las larvas fueron sembradas en dos RAS indep [...] endientes durante 26 días después de la eclosión. Uno de los sistemas (tratamiento experimental) recibió la adición de un probiótico comercial que consiste en B. subtilis, B. licheniformis y B. pumilus directamente en el agua y por alimento vivo. La sobrevivencia, peso final y calidad del agua no se vieron afectados por los probióticos. Los resultados mostraron que las larvas del tratamiento probiótico presentaron una mayor resistencia al estrés por estrés salino. El análisis inmunohistoquímico mostró una mayor expresión de CD4 en el tratamiento probiótico. Estos resultados sugieren que estos probióticos utilizados en las larvas de cobia en RAS tienen un potencial impacto estimulante sobre la diferenciación del sistema inmunológico y aumenta la resistencia al estrés de las larvas de cobia. Abstract in english Cobia (Rachycentron canadum) is a marine finfish with good potential for mariculture. This study analyzes the effects of probiotic Bacillus spp. on the performance of cobia larvae reared in a recirculating aquaculture system (RAS). Larvae were stocked into two independent RAS for 26 days after hatch [...] ing. One of the systems (Probiotic treatment) received the addition of a commercial probiotic consisting of B. subtilis, B. licheniformis and B. pumilus directly into the water and by live feed. Survival, final weight and water quality were not affected by probiotics. Results showed larvae of the probiotic treatment demonstrated a greater resistance to salinity stress. Immunohistochemical analysis showed a higher expression of CD4 in probiotic treatment. These results suggest that Bacillus spp. probiotics used in RAS have a potential stimulating impact on immune system differentiation and increases salinity stress resistance of cobia larvae.

  5. THE STATUS OF AQUACULTURE IN THE WORLD AND IN EUROPE

    Directory of Open Access Journals (Sweden)

    Nikola Fijan

    2002-06-01

    Full Text Available During the past few years, several authors have presented the production data and the problems in Croatian aquaculture and suggested measures for improvements. Some of these authors referred to some sectors of aquaculture in the world. This paper reports basic statistical data of the Food and Agriculture Organization (FAO, United Nations of the world aquaculture during the period of 1990–1999. The annual growth rate in that period averaged about 10%, and in the year 1999 the aquaculture provided 31.7% of the world needs for aquatic products. The total production and industrialization of aquaculture will continue. Planning of aquaculture development in Croatia and the preparations for joining the European Economic Community must take into account the status of aquaculture and trends in the world, the common fishery policy of EEC (green document, the production in EEC member states and EEC–candidate states and especially the production in neighboring countries. The number, the size and the strength of organizational structures helping the development of aquaculture in EEC are showing these factors to be of decisive importance for the future of sustainable aquaculture in Croatia, too. The very low fish consumption in the country is a negative health factor for the Croatian citizens and it emphasizes the importance of faster development of aquaculture. The paper is intended to stimulate improvements in the aquaculture development strategy, to promote more positive approach towards this food production sector and to speed up its successfulness in Croatia.

  6. Electronic Subsystems For Laser Communication System

    Science.gov (United States)

    Long, Catherine; Maruschak, John; Patschke, Robert; Powers, Michael

    1992-01-01

    Electronic subsystems of free-space laser communication system carry digital signals at 650 Mb/s over long distances. Applicable to general optical communications involving transfer of great quantities of data, and transmission and reception of video images of high definition.

  7. Enhancement of existing geothermal resource utilization by cascading to intensive aquaculture

    Energy Technology Data Exchange (ETDEWEB)

    Zachritz, W.H., II; Polka, R.; Schoenmackers

    1996-04-01

    A demonstration high rate aquaculture production system utilizing a cascaded geothermal resource was designed, constructed and operated to fulfill the objectives of this project. Analysis of the energy and water balances for the system indicated that the addition of an Aquaculture Facility expanded the use of the existing resource. This expanded use in no way affected the up- stream processes. Analysis of the system`s energy and water requirements indicated that the present resource was under-utilized and could be expanded. Energy requirements appeared more limiting than water use, but the existing system could be expanded to a culture volume of 72,000 gal. This system would have a potential production capacity of 93,600 lb/yr with a potential market value of $280,00/yr. Based on the results of this study, the heat remaining in the geothermal fluid from one square foot of operating greenhouse is sufficient to support six gallons of culture water for a high density aquaculture facility. Thus, the over 1.5M ft{sup 2} of existing greenhouse space in New Mexico, has the potential to create an aquaculture industry of nearly 9M gal. This translates to an annual production potential of 11.7M lb with a market value of $35.lM.

  8. The use of probiotics in aquaculture.

    Science.gov (United States)

    Hai, N V

    2015-10-01

    This study aims to present comprehensive notes for the use of probiotics in aquaculture. Probiotics have been proven to be positive promoters of aquatic animal growth, survival and health. In aquaculture, intestines, gills, the skin mucus of aquatic animals, and habitats or even culture collections and commercial products, can be sources for acquiring appropriate probiotics, which have been identified as bacteria (Gram-positive and Gram-negative) and nonbacteria (bacteriophages, microalgae and yeasts). While a bacterium is a pathogen to one aquatic animal, it can bring benefits to another fish species; a screening process plays a significant role in making a probiotic species specific. The administration of probiotics varies from oral/water routine to feed additives, of which the latter is commonly used in aquaculture. Probiotic applications can be either mono or multiple strains, or even in combination with prebiotic, immunostimulants such as synbiotics and synbiotism, and in live or dead forms. Encapsulating probiotics with live feed is a suitable approach to convey probiotics to aquatic animals. Dosage and duration of time are significant factors in providing desired results. Several modes of actions of probiotics are presented, while some others are not fully understood. Suggestions for further studies on the effects of probiotics in aquaculture are proposed. PMID:26119489

  9. Aquaculture in Hawaii: Past, present, and future

    OpenAIRE

    Wyban, J; Wyban, C

    1989-01-01

    Hawaii's aquaculture industry has a long and colorful history. When Cook arrived in Hawaii in 1778, over 350 fishponds were in operation. Future prospects for Hawaii's industry are bright. Expanded R&D activities have the greatest growth potential with technology transfer through international consulting and training likely. Commercial activities will focus on intensive culture of shrimp, finfish and seaweeds.

  10. Inverness College: Innovations in Aquaculture Training.

    Science.gov (United States)

    Regional Technology Strategies, Inc., Carrboro, NC.

    This paper describes the aquaculture program developed at Inverness College in Scotland. Inverness is located in the Scottish Highlands and serves an area roughly the size of Belgium, but with a population of only 300,000. The regional infrastructure and human capital resources in the Highlands are relatively weak due to inadequate transportation,…

  11. Application of physics technology in aquaculture

    International Nuclear Information System (INIS)

    Experiments show that after hydrobiology stimulation by a certain dosage of a physical field such as electromagnetic, laser, or neutron irradiation, hydorbiological activity can be improved, and consequently yield and quality enhanced. Recent advances in the application of physical fields in aquaculture are summarized, and prospects for future developments presented

  12. BENEFICIAL USE OF ATTENUATED VACCINES IN AQUACULTURE

    Science.gov (United States)

    The success of safe and effective vaccines in controlling disease and enhancing profitability in livestock production has been profound. Because fish farmers operate on narrow profit margins, cost effectiveness is of paramount importance in any vaccination program. In aquaculture, the best vaccines ...

  13. Recirculation technology – The future of aquaculture

    Science.gov (United States)

    The production of farmed fish is eclipsing that of wild caught fish and will be supplying half of the total fish and shellfish for human consumption. With limited resources to increase the wild harvest fishing industry, the U. S. and foreign countries are expanding their aquaculture production. Betw...

  14. PROTEOMICS in aquaculture : Applications and trends

    DEFF Research Database (Denmark)

    Rodrigues, Pedro M.; Silva, Tomé S.

    2012-01-01

    Over the last forty years global aquaculture presented a growth rate of 6.9% per annum with an amazing production of 52.5million tonnes in 2008, and a contribution of 43% of aquatic animal food for human consumption. In order to meet the world's health requirements of fish protein, a continuous growth in production is still expected for decades to come. Aquaculture is, though, a very competitive market, and a global awareness regarding the use of scientific knowledge and emerging technologies to obtain a better farmed organism through a sustainable production has enhanced the importance of proteomics in seafood biology research. Proteomics, as a powerful comparative tool, has therefore been increasingly used over the last decade to address different questions in aquaculture, regarding welfare, nutrition, health, quality, and safety. In this paper we will give an overview of these biological questions and the role of proteomics in their investigation, outlining the advantages, disadvantages and future challenges. A brief description of the proteomics technical approaches will be presented. Special focus will be on the latest trends related to the aquaculture production of fish with defined nutritional, health or quality properties for functional foods and the integration of proteomics techniques in addressing this challenging issue. This article is part of a Special Issue entitled: Farm animal proteomics.

  15. The SLAC polarized electron source laser system

    International Nuclear Information System (INIS)

    The Stanford Linear Collider (SLC) has operated a polarized photocathode electron source and titanium sapphire laser for high energy physics collisions for over 6500 hours of nearly continuous operation. The laser system for the source has demonstrated >98.5% total uptime for the duration of the experiment. The laser system uses a pair of titanium sapphire oscillators pumped by frequency doubled YAG lasers to produce 2ns, 250 ?J pulses at wavelengths from 740 nm to 870 nm

  16. Soft errors in modern electronic systems

    CERN Document Server

    Nicolaidis, Michael

    2010-01-01

    This book provides a comprehensive presentation of the most advanced research results and technological developments enabling understanding, qualifying and mitigating the soft errors effect in advanced electronics, including the fundamental physical mechanisms of radiation induced soft errors, the various steps that lead to a system failure, the modelling and simulation of soft error at various levels (including physical, electrical, netlist, event driven, RTL, and system level modelling and simulation), hardware fault injection, accelerated radiation testing and natural environment testing, s

  17. Using Metadata Description for Agriculture and Aquaculture Papers

    Directory of Open Access Journals (Sweden)

    P. S?imek, J. Vane?k, V. Oc?ena?s?ek, M. Stoc?es, T. Vogeltanzova

    2012-12-01

    Full Text Available The paper deals with the most used metadata formats and thesauri suitable for describing scientific and research papers in the domains agriculture, food industry, aquaculture, environment and rural areas. These include the Dublin Core (DC, Metadata Object Description Schema (MODS, Virtual Open Access Agriculture and Aquaculture Repository Metadata Application Profile (VOA3R AP and the AGROVOC thesaurus. Having analyzed the metadata formats and research paper lifecycle, the authors would recommend that each paper should entail metadata description as soon as it is published. The metadata are to describe the content and properties of the paper. One of the most suitable metadata formats is the VOA3R AP that is partially patterned on the DC and combined with the AGROVOC thesaurus. As a result, an effective description, availability and automatic data exchange between and among local and central repositories should be attained.The knowledge and data presented in the present paper were obtained as a result of the following research programs and grant schemes: the Grant No. 20121044 of the Internal Grant Agency titled „Using Automatic Metadata Generation for Research Papers“, the Grant agreement No. 250525 funded by the European Commission corresponding to the VOA3R Project (Virtual Open Access Agriculture & Aquaculture Repository: Sharing Scientific and Scholarly Research related to Agriculture, Food, and Environment, http://voa3r.eu and the Research Program titled „Economy of the Czech Agriculture Resources and their Efficient Use within the Framework of the Multifunctional Agrifood Systems“ of the Czech Ministry of Education, Youth and Sport number VZ MSM 6046070906.

  18. Evaluation on Biofilter in Recirculating Integrated Multi-Trophic Aquaculture

    Directory of Open Access Journals (Sweden)

    Asfie Maidie

    2013-06-01

    Full Text Available Integrated multi-trophic aquaculture pays more attention as a bio-integrated food production system that serves as a model of sustainable aquaculture, minimizes waste discharge, increases diversity and yields multiple products. The objectives of this research were to analyze the efficiency of total ammonia nitrogen biofiltration and its effect on carrying capacity of fish rearing units. Pilot-scale bioreactor was designed with eight run-raceways (two meters of each that assembled in series. Race 1-3 were used to stock silky worm (Tubifex sp as detrivorous converter, then race 4-8 were used to plant three species of leaf-vegetable as photoautotrophic converters, i.e; spinach (Ipomoea reptana, green mustard (Brassica juncea and basil (Ocimum basilicum. The three plants were placed in randomized block design based on water flow direction. Mass balance of nutrient analysis, was applied to figure out the efficiency of bio-filtration and its effect on carrying capacity of rearing units. The result of the experiment showed that 86.5 % of total ammonia nitrogen removal was achieved in 32 days of culturing period. This efficiency able to support the carrying capacity of the fish tank up to 25.95 kg/lpm with maximum density was 62.69 kg/m3 of fish biomass productionDoi: http://dx.doi.org/10.12777/ijse.4.2.2013.80-85 [How to cite this article: Sumoharjo, S.  and Maidie, A. (2013. Evaluation on Biofilter in Recirculating Integrated Multi-Trophic Aquaculture.  International Journal of  Science and Engineering, 4(2,80-85. Doi: http://dx.doi.org/10.12777/ijse.4.2.2013.80-85

  19. Electronic Document Management Using Inverted Files System

    OpenAIRE

    Suhartono Derwin; Setiawan Erwin; Irwanto Djon

    2014-01-01

    The amount of documents increases so fast. Those documents exist not only in a paper based but also in an electronic based. It can be seen from the data sample taken by the SpringerLink publisher in 2010, which showed an increase in the number of digital document collections from 2003 to mid of 2010. Then, how to manage them well becomes an important need. This paper describes a new method in managing documents called as inverted files system. Related with the electronic based document, the i...

  20. Laser system for a subpicosecond electron linac

    International Nuclear Information System (INIS)

    At the Argonne Chemistry Division efforts are underway to develop a sub-picosecond electron beam pulse radiolysis facility for chemical studies. The target output of the accelerator is to generate electron pulses that can be adjusted from 3nC in .6ps to 100nC in 45ps. In conjunction with development of the accelerator a state-of-the-art ultrafast laser system is under construction that will drive the linac's photocathode and provide probe pulses that are tunable from the UV to IR spectral regions

  1. Design for Reliability of Power Electronic Systems

    DEFF Research Database (Denmark)

    Wang, Huai; Ma, Ke

    2012-01-01

    Advances in power electronics enable efficient and flexible processing of electric power in the application of renewable energy sources, electric vehicles, adjustable-speed drives, etc. More and more efforts are devoted to better power electronic systems in terms of reliability to ensure high availability, long lifetime, sufficient robustness, low maintenance cost and low cost of energy. However, the reliability predictions are still dominantly according to outdated models and terms, such as MIL-HDBK-217F handbook models, Mean-Time-To-Failure (MTTF), and Mean-Time-Between-Failures (MTBF). A collection of methodologies based on Physics-of-Failure (PoF) approach and mission profile analysis are presented in this paper to perform reliability-oriented design of power electronic systems. The corresponding design procedures and reliability prediction models are provided. Further on, a case study on a 2.3 MW wind power converter is discussed with emphasis on the reliability critical components IGBTs. Different aspects of improving the reliability of the power converter are mapped. Finally, the challenges and opportunities to achieve more reliable power electronic systems are addressed.

  2. Electron Dynamics in Finite Quantum Systems

    Science.gov (United States)

    McDonald, Christopher R.

    The multiconfiguration time-dependent Hartree-Fock (MCTDHF) and multiconfiguration time-dependent Hartree (MCTDH) methods are employed to investigate nonperturbative multielectron dynamics in finite quantum systems. MCTDHF is a powerful tool that allows for the investigation of multielectron dynamics in strongly perturbed quantum systems. We have developed an MCTDHF code that is capable of treating problems involving three dimensional (3D) atoms and molecules exposed to strong laser fields. This code will allow for the theoretical treatment of multielectron phenomena in attosecond science that were previously inaccessible. These problems include complex ionization processes in pump-probe experiments on noble gas atoms, the nonlinear effects that have been observed in Ne atoms in the presence of an x-ray free-electron laser (XFEL) and the molecular rearrangement of cations after ionization. An implementation of MCTDH that is optimized for two electrons, each moving in two dimensions (2D), is also presented. This implementation of MCTDH allows for the efficient treatment of 2D spin-free systems involving two electrons; however, it does not scale well to 3D or to systems containing more that two electrons. Both MCTDHF and MCTDH were used to treat 2D problems in nanophysics and attosecond science. MCTDHF is used to investigate plasmon dynamics and the quantum breathing mode for several electrons in finite lateral quantum dots. MCTDHF is also used to study the effects of manipulating the potential of a double lateral quantum dot containing two electrons; applications to quantum computing are discussed. MCTDH is used to examine a diatomic model molecular system exposed to a strong laser field; nonsequential double ionization and high harmonic generation are studied and new processes identified and explained. An implementation of MCTDHF is developed for nonuniform tensor product grids; this will allow for the full 3D implementation of MCTDHF and will provide a means to investigate a wide variety of problems that cannot be currently treated by any other method. Finally, the time it takes for an electron to tunnel from a bound state is investigated; a definition of the tunnel time is established and the Keldysh time is connected to the wavefunction dynamics.

  3. Emerging research priorities for the aquaculture sector in sub-Saharan Africa - a case study of Nigeria

    Directory of Open Access Journals (Sweden)

    Kafayat A. Fakoya

    2009-10-01

    Full Text Available This paper reviews the role of aquaculture research in Nigeria. The achievements and limitations of research in aquaculture development are discussed. It identifies strategic prioritization of research objectives in three phases namely; the short term, medium term and long term to properly foster real growth in the aquaculture sector with the dawn of privatization in the country. Ex post assessments are also fundamental in evaluating the viability and effectiveness of past research activities. Participatory approach in research prioritization and process, increased private funding of research and extension, programmes of intervention by the government are required to maximize the untapped potentials in aquaculture for its rapid transformation to a full-fledged economically viable sector. Thus, profitable, sustainable ecological aquaculture and ‘water smart’ culture systems consistent with different geographical zones of the country must be designed with potentials for sequestration of anthropogenic carbon and nutrients. Adoption of Guidelines on Best Management and Practices in Aquaculture Schemes is a necessity. Above all is the question of an enabling institutional framework, autonomy and pragmatic sector - specific policies without which nothing can be realistically achieved.

  4. Determination of melamine in aquaculture feed samples based on molecularly imprinted solid-phase extraction.

    Science.gov (United States)

    Lian, Ziru; Liang, Zhenlin; Wang, Jiangtao

    2015-10-01

    This research highlights the application of highly efficient molecularly imprinted solid-phase extraction for the preconcentration and analysis of melamine in aquaculture feed samples. Melamine-imprinted polymers were synthesized employing methacrylic acid and ethylene glycol dimethacrylate as functional monomer and cross-linker, respectively. The characteristics of obtained polymers were evaluated by scanning electron microscopy, Fourier transform infrared spectroscopy and binding experiments. The imprinted polymers showed an excellent adsorption ability for melamine and were applied as special solid-phase extraction sorbents for the selective cleanup of melamine. An off-line molecularly imprinted solid-phase extraction procedure was developed for the separation and enrichment of melamine from aquaculture feed samples prior to high-performance liquid chromatography analysis. Optimum molecularly imprinted solid-phase extraction conditions led to recoveries of the target in spiked feed samples in the range 84.6-96.6% and the relative standard deviation less than 3.38% (n = 3). The aquaculture feed sample was determined, and there was no melamine found. The results showed that the molecularly imprinted solid-phase extraction protocols permitted the sensitive, uncomplicated and inexpensive separation and pre-treatment of melamine in aquaculture feed samples. PMID:26304786

  5. Temperature measurement systems in wearable electronics

    Science.gov (United States)

    Walczak, S.; Go?ebiowski, J.

    2014-08-01

    The aim of this paper is to present the concept of temperature measurement system, adapted to wearable electronics applications. Temperature is one of the most commonly monitored factor in smart textiles, especially in sportswear, medical and rescue products. Depending on the application, measured temperature could be used as an initial value of alert, heating, lifesaving or analysis system. The concept of the temperature measurement multi-point system, which consists of flexible screen-printed resistive sensors, placed on the T-shirt connected with the central unit and the power supply is elaborated in the paper.

  6. NASA Electronic Library System (NELS) optimization

    Science.gov (United States)

    Pribyl, William L.

    1993-01-01

    This is a compilation of NELS (NASA Electronic Library System) Optimization progress/problem, interim, and final reports for all phases. The NELS database was examined, particularly in the memory, disk contention, and CPU, to discover bottlenecks. Methods to increase the speed of NELS code were investigated. The tasks included restructuring the existing code to interact with others more effectively. An error reporting code to help detect and remove bugs in the NELS was added. Report writing tools were recommended to integrate with the ASV3 system. The Oracle database management system and tools were to be installed on a Sun workstation, intended for demonstration purposes.

  7. Test software for BESIII MDC electronics system

    International Nuclear Information System (INIS)

    This paper presents the design of Test System Software for BESIII MDC Electronics. Two kinds of test systems, SBS VP7 based and PowerPC based systems, and their corresponding test software are introduced. The software is developed in LabVIEW 7.1 and Microsoft Visual C++ 6.0, some test functions of the software, as well as their user interfaces, are described in detail. The software has been applied in hardware debugging, performance test and long term stability test. (authors)

  8. Effects of aquaculture noise on hearing, growth, and disease resistance of rainbow trout Oncorhynchus mykiss

    Science.gov (United States)

    Intensive aquaculture production often utilizes equipment (e.g., aerators, air and water pumps, harvesters, blowers, filtration systems, and maintenance machinery) that increases noise levels in fish culture tanks. Consequently, chronic exposure to elevated noise levels in tanks could negatively imp...

  9. Constructed wetlands for freshwater and saline aquaculture wastewater treatment: a microcosm experience

    OpenAIRE

    Jesus, J. M.; Borges, M. T.; Calheiros, Cristina S. C.; Castro, Paula M. L

    2011-01-01

    The aquaculture industry discharges large volumes of nutrient rich wastewater, contributing to eutrophication events. Recent culture intensification methodologies such as recirculation (RAS) and shallow raceway (SRS) systems discharge wastewater with even higher nutrient concentrations, though at lower volumes (Rana et al., 2005). Hence, efluent treatment options are of vital importance. Constructed wetlands (CWs) are a possible but underexplored treatment solution even for hig...

  10. Two-speed deflection system for electron micropattern generator

    Science.gov (United States)

    Malmberg, P. R.

    1972-01-01

    Development of dual speed deflection system for electron beam micropattern generator system is discussed. Factors affecting application of electron beam lithography are analyzed. Procedure for using two speed deflection system is described.

  11. Secondary electron yields of solar system ices

    Science.gov (United States)

    Suszcynsky, David M.; Borovsky, Joseph E.; Goertz, Christoph K.

    1992-01-01

    The secondary electron yields of H2O, CO2, NH3, and CH3OH ices have been measured as a function of electron beam energy in the 2- to 30-keV energy range. The ices were produced on a liquid-nitrogen-cooled cold finger and transferred under vacuum to a SEM where the yield measurements were made. The imaging capabilities of the SEM provide a means of correlating the yield measurements with the morphology of the ices and are also used to monitor charging effects. The yields were determined by measuring the amplified current from a secondary electron detector and calibrating this current signal with the amplified current signal from samples of metals with known secondary electron yields. Each of the measured yields is found to decrease with an increase in energy in the 2- to 30-keV range. Estimates are given for the maximum secondary electron yield Y(max) of each ice and the energy at which this maximum yield occurs. Implications for the charging of solar system ice grains are discussed.

  12. Electronic Information Systems Elektronik Bilgi Sistemleri

    Directory of Open Access Journals (Sweden)

    Birgül Egeli

    1995-09-01

    Full Text Available Users can retrieve information that is increasing continuously, using new technologies and new systems such as electronic information systems. The aim of electronic information systems is to share accumulation and production of universal information equally within every society. This requires the use of CD-ROM and hypermedia; the new storage and retrieval environments created by developing technologies. The use of these environments creates new problems for the researchers to work on. Electronic information systems can achieve a desired level of performance and service the users appropriately based upon the results of such research. Geli?en teknoloji ve artan bilgi miktar? ile birlikte kullan?c?n?n bilgiye istenilen yerden ve kolayl?kla eri?ebilmesini sa?layacak yeni sistemler gerekmektedir. Bu sistemlerin en önemlilerinden biri elektronik bilgi sistemleridir. Eldeki evrensel bilgi birikimi ve üretiminin bütün toplumlar taraf?ndan e?it ko?ullarda payla??lmas?n? sa?lama amac?nda olan elektronik bilgi sistemleri etkin olabilmek için geli?en teknolojileri kullanmak zorundad?r. Geli?en teknolojilerin yaratt??? yeni kay?t ortamlar? olan CD-ROM ve hipermedya beraberlerinde baz? sorunlar? da getirmekte ve bu sorunlar?n çözümü ile ilgili olarak yeni ara?t?rma konular? ortaya ç?kmaktad?r. Bu ara?t?rmalar sonucunda elektronik bilgi sistemleri istenilen düzeye eri?ebilecek ve kullan?c?ya en iyi hizmeti verebilecek duruma gelecektir.

  13. Imaging Characteristics Of Electronic Imaging Systems

    Science.gov (United States)

    Kriss, Michael A.

    1989-03-01

    Electronic imaging in the form of television has served the public for over 40 years. Television cameras have up to now used mostly photoconductive tubes to capture the live image. However, the last ten years have seen the advances in microelectronics, including VLSI technology, introduce newer, more flexible ways to record images via the solid state sensor. One version of the solid state sensor, the charge coupled device (CCD) has found its way into consumer electronic imaging, replacing the Super 8 movie system, and today, portable, commercial television cameras are starting to use CCD arrays instead of the more conventional photoconductive tubes. There are several electronic still cameras (ESC) on the market using solid state sensors, but due to the limited number of imaging sites or pixels on these imaging sensors, the quality is far below that of present photographic-based systems. This paper will consider imaging characteristics of photoconductive tubes (solid state imaging sensors) and how they compare to photographic film. Also, based on a system analysis, the requirements for a solid state sensor that will provide image quality equal to current photographic systems will be defined. The importance of digital image processing and digital image compression will also be discussed.

  14. Quantum frustrated and correlated electron systems

    Directory of Open Access Journals (Sweden)

    P Thalmeier

    2008-06-01

    Full Text Available  Quantum phases and fluctuations in correlated electron systems with frustration and competing interactions are reviewed. In the localized moment case the S=1/2 J1 - J2 - model on a square lattice exhibits a rich phase diagram with magnetic as well as exotic hidden order phases due to the interplay of frustration and quantum fluctuations. Their signature in magnetocaloric quantities and the high field magnetization are surveyed. The possible quantum phase transitions are discussed and applied to layered vanadium oxides. In itinerant electron systems frustration is an emergent property caused by electron correlations. It leads to enhanced spin fluctuations in a very large region of momentum space and therefore may cause heavy fermion type low temperature anomalies as in the 3d spinel compound LiV2O4 . Competing on-site and inter-site electronic interactions in Kondo compounds are responsible for the quantum phase transition between nonmagnetic Kondo singlet phase and magnetic phase such as observed in many 4f compounds. They may be described by Kondo lattice and simplified Kondo necklace type models. Their quantum phase transitions are investigated by numerical exact diagonalization and analytical bond operator methods respectively.

  15. Electronic Document Management Using Inverted Files System

    Directory of Open Access Journals (Sweden)

    Suhartono Derwin

    2014-03-01

    Full Text Available The amount of documents increases so fast. Those documents exist not only in a paper based but also in an electronic based. It can be seen from the data sample taken by the SpringerLink publisher in 2010, which showed an increase in the number of digital document collections from 2003 to mid of 2010. Then, how to manage them well becomes an important need. This paper describes a new method in managing documents called as inverted files system. Related with the electronic based document, the inverted files system will closely used in term of its usage to document so that it can be searched over the Internet using the Search Engine. It can improve document search mechanism and document save mechanism.

  16. An ecosystem-based approach and management framework for the integrated evaluation of bivalve aquaculture impacts

    DEFF Research Database (Denmark)

    Cranford, Peter J.; Kamermans, Pauline

    2012-01-01

    An ecosystem-based approach to bivalve aquaculture management is a strategy for the integration of aquaculture within the wider ecosystem, including human aspects, in such a way that it promotes sustainable development, equity, and resilience of ecosystems. Given the linkage between social and ecological systems, marine regulators require an ecosystem-based decision framework that structures and integrates the relationships between these systems and facilitates communication of aquaculture–environment interactions and policy-related developments and decisions. The Drivers-Pressures-State Change-Impact-Response (DPSIR) management framework incorporates the connectivity between human and ecological issues and would permit available performance indicators to be identified and organized in a manner that facilitates different regulatory needs. Suitable performance indicators and modeling approaches, which are used to assess DPSIR framework components, are reviewed with a focus on the key environmental issues associated with bivalve farming. Indicator selection criteria are provided to facilitate constraining the number of indicators within the management framework. It is recommended that an ecosystem-based approach for bivalve aquaculture be based on a tiered indicator monitoring system that is structured on the principle that increased environmental risk requires increased monitoring effort. More than 1 threshold for each indicator would permit implementation of predetermined impact prevention and mitigation measures prior to reaching an unacceptable ecological state. We provide an example of a tiered monitoring program that would communicate knowledge to decision-makers on ecosystem State Change and Impact components of the DPSIR framework

  17. Advanced Photonic and Electronic Systems WILGA 2010

    OpenAIRE

    Romaniuk, R S

    2010-01-01

    SPIE – PSP WILGA Symposium gathers two times a year in January and in May new adepts of advanced photonic and electronic systems. The event is oriented on components and applications. WILGA Symposium on Photonics and Web Engineering is well known on the web for its devotion to “young research” promotion under the eminent sponsorship of international engineering associations like SPIE and IEEE and their Poland Sections or Counterparts. WILGA is supported by the most important national professi...

  18. Power Electronics for Renewable Energy Systems

    DEFF Research Database (Denmark)

    Choi, U. M.; Lee, K. B.; Blaabjerg, Frede

    2012-01-01

    The use of renewable energy sources are increased because of the depletion of natural resources and the increasing pollution level from energy production. The wind energy and the solar energy are most widely used among the renewable energy sources. Power electronics is needed in almost all kinds of renewable energy system. It controls the renewable source and interfaces with the load effectively, which can be grid-connected or van work in stand-alone mode. In this presentation, overview of wind ...

  19. Quantum phase transitions in electronic systems

    OpenAIRE

    Kirkpatrick, T. R.; Belitz, D.

    1997-01-01

    Zero-temperature or quantum phase transitions in itinerant electronic systems both with and without quenched disordered are discussed. Phase transitions considered include, the ferromagnetic transition, the antiferromagnetic transition, the superconductor-metal transition, and various metal-insulator transitions. Emphasis is placed on how to determine the universal properties that characterize these quantum phase transitions. For the first three of the phase transitions list...

  20. Synthesizing cognition in neuromorphic electronic systems

    OpenAIRE

    Neftci, E.; Binas, J; U. Rutishauser; Chicca, E; Indiveri, G.; R. Douglas

    2013-01-01

    The quest to implement intelligent processing in electronic neuromorphic systems lacks methods for achieving reliable behavioral dynamics on substrates of inherently imprecise and noisy neurons. Here we report a solution to this problem that involves first mapping an unreliable hardware layer of spiking silicon neurons into an abstract computational layer composed of generic reliable subnetworks of model neurons and then composing the target behavioral dynamics as a “soft state machine” runni...

  1. Design of the BEPCII electron gun system

    International Nuclear Information System (INIS)

    BEPCII upgrading project needs a new high current electron gun. The design stage such as physical design, mechanical design and control system design of this new electron gun is described. The emission current is designed to be higher than 10 A for the pulse width of 1 ns with repetition rate of 50 Hz. The gun will operate with a pulsed high voltage power supply which can provide up to 200 kV high voltage. Computer simulations and optimizations have been carried out in the design stage, including the gun geometry and beam transport. EGUN and DGUN codes are used to simulate the gun geometry, and the results show that the perveance is about 0.22 ?A·V-3/2, and the emittance at gun exit is about 16 ?·mm·mrad. PARMELA code shows that the electron beam can be easily transported to the end of the first accelerating tube with a capture efficiency of 67% and root mean square emittance of 25 mm·mrad. New scheme of the gun control system based on EPICS is also presented. Two-bunch operation mode and 2.5 ?s long pulse operation mode are available in the control system. (authors)

  2. Electronic Integrated Disease Surveillance System and Pathogen Asset Control System

    Scientific Electronic Library Online (English)

    Tom G., Wahl; Aleksey V., Burdakov; Andrey O., Oukharov; Azamat K., Zhilokov.

    Full Text Available Electronic Integrated Disease Surveillance System (EIDSS) has been used to strengthen and support monitoring and prevention of dangerous diseases within One Health concept by integrating veterinary and human surveillance, passive and active approaches, case-based records including disease-specific c [...] linical data based on standardised case definitions and aggregated data, laboratory data including sample tracking linked to each case and event with test results and epidemiological investigations. Information was collected and shared in secure way by different means: through the distributed nodes which are continuously synchronised amongst each other, through the web service, through the handheld devices. Electronic Integrated Disease Surveillance System provided near real time information flow that has been then disseminated to the appropriate organisations in a timely manner. It has been used for comprehensive analysis and visualisation capabilities including real time mapping of case events as these unfold enhancing decision making. Electronic Integrated Disease Surveillance System facilitated countries to comply with the IHR 2005 requirements through a data transfer module reporting diseases electronically to the World Health Organisation (WHO) data center as well as establish authorised data exchange with other electronic system using Open Architecture approach. Pathogen Asset Control System (PACS) has been used for accounting, management and control of biological agent stocks. Information on samples and strains of any kind throughout their entire lifecycle has been tracked in a comprehensive and flexible solution PACS. Both systems have been used in a combination and individually. Electronic Integrated Disease Surveillance System and PACS are currently deployed in the Republics of Kazakhstan, Georgia and Azerbaijan as a part of the Cooperative Biological Engagement Program (CBEP) sponsored by the US Defense Threat Reduction Agency (DTRA).

  3. Electronic integrated disease surveillance system and pathogen asset control system.

    Science.gov (United States)

    Wahl, Tom G; Burdakov, Aleksey V; Oukharov, Andrey O; Zhilokov, Azamat K

    2012-01-01

    Electronic Integrated Disease Surveillance System (EIDSS) has been used to strengthen and support monitoring and prevention of dangerous diseases within One Health concept by integrating veterinary and human surveillance, passive and active approaches, case-based records including disease-specific clinical data based on standardised case definitions and aggregated data, laboratory data including sample tracking linked to each case and event with test results and epidemiological investigations. Information was collected and shared in secure way by different means: through the distributed nodes which are continuously synchronised amongst each other, through the web service, through the handheld devices. Electronic Integrated Disease Surveillance System provided near real time information flow that has been then disseminated to the appropriate organisations in a timely manner. It has been used for comprehensive analysis and visualisation capabilities including real time mapping of case events as these unfold enhancing decision making. Electronic Integrated Disease Surveillance System facilitated countries to comply with the IHR 2005 requirements through a data transfer module reporting diseases electronically to the World Health Organisation (WHO) data center as well as establish authorised data exchange with other electronic system using Open Architecture approach. Pathogen Asset Control System (PACS) has been used for accounting, management and control of biological agent stocks. Information on samples and strains of any kind throughout their entire lifecycle has been tracked in a comprehensive and flexible solution PACS.Both systems have been used in a combination and individually. Electronic Integrated Disease Surveillance System and PACS are currently deployed in the Republics of Kazakhstan, Georgia and Azerbaijan as a part of the Cooperative Biological Engagement Program (CBEP) sponsored by the US Defense Threat Reduction Agency (DTRA). PMID:23327375

  4. Electronic Integrated Disease Surveillance System and Pathogen Asset Control System

    Directory of Open Access Journals (Sweden)

    Tom G. Wahl

    2012-06-01

    Full Text Available Electronic Integrated Disease Surveillance System (EIDSS has been used to strengthen and support monitoring and prevention of dangerous diseases within One Health concept by integrating veterinary and human surveillance, passive and active approaches, case-based records including disease-specific clinical data based on standardised case definitions and aggregated data, laboratory data including sample tracking linked to each case and event with test results and epidemiological investigations. Information was collected and shared in secure way by different means: through the distributed nodes which are continuously synchronised amongst each other, through the web service, through the handheld devices. Electronic Integrated Disease Surveillance System provided near real time information flow that has been then disseminated to the appropriate organisations in a timely manner. It has been used for comprehensive analysis and visualisation capabilities including real time mapping of case events as these unfold enhancing decision making. Electronic Integrated Disease Surveillance System facilitated countries to comply with the IHR 2005 requirements through a data transfer module reporting diseases electronically to the World Health Organisation (WHO data center as well as establish authorised data exchange with other electronic system using Open Architecture approach. Pathogen Asset Control System (PACS has been used for accounting, management and control of biological agent stocks. Information on samples and strains of any kind throughout their entire lifecycle has been tracked in a comprehensive and flexible solution PACS.Both systems have been used in a combination and individually. Electronic Integrated Disease Surveillance System and PACS are currently deployed in the Republics of Kazakhstan, Georgia and Azerbaijan as a part of the Cooperative Biological Engagement Program (CBEP sponsored by the US Defense Threat Reduction Agency (DTRA.

  5. Biofilter treatment of aquaculture water for reuse applications.

    Science.gov (United States)

    Yang, L; Chou, L S; Shieh, W K

    2001-09-01

    Biotreatment of aquaculture water for recirculation purposes is a sensible mean to support the further growth of aquaculture industry without excessive water demands that are environmentally unsustainable. This study evaluates the efficacy of biofilter treatment of an eel (Anguilla japonica) culture pond water using different filter media and flow scheme arrangements. The experimental results demonstrate that biofilter systems packed with suitable filter media are capable of improving the quality of effluents for recirculation applications. The characteristics of the filter media appear to be more critical than biofilter flow scheme arrangements in affecting the efficacy of the biofilter treatment. Filter media with surface and structural characteristics are conducive to the development of biofilms and the capture of organic suspended matter are desirable to ensure good and consistent biofilter performance. Under such circumstances the bacterial "consortia" in the biofilter are capable of utilizing the captured organic suspended matter as an alternative substrate to support their metabolic activities when the concentration of the primary substrate (i.e., BOD) is low. For the eel pond water, a biofilter packed with filter media having cross-link structures and a high bed porosity, followed by another biofilter packed with a type of filter media having rough surfaces, produced the best results under the conditions tested. Moreover, a preliminary cost-benefit analysis confirms its cost advantages. PMID:11487106

  6. PROBLEMS OF BIOFOULING ON FISH–CAGE NETS IN AQUACULTURE

    Directory of Open Access Journals (Sweden)

    Merica Sliškovi?

    2002-09-01

    Full Text Available Biofouling on fish–cage netting is a serious technical and economical problem to aquaculture worldwide. Compensation for the effects of biofouling must be included in cage system design and planning, as fouling can dramatically increase both weight and drag. Settlements of sessile plants and animals, with accumulation of the detritus diminish the size of mesh and can rapidly occlude mesh. Negative effect of smaller mesh size is changing in water flow trough the cages. Biofouling problems necessitating purchase of a second sets of nets or more, and frequent cleaning and changing of biofouling. Changing and cleaning frequency depend on many factors such as: location of cages (near the coast or off shore, productivity of that location, time of the year, time period in which the cages are placed on that location (cause of loading of phosphorus and nitrogen from the unconsumed food in the sediment. Net changing and cleaning procedures are labor and capital intensive. Process of the cleaning of the nets is inadequate, especially when there isnžt adequate equipment available as it is case in smaller aquaculture industry. Chemical control of biofouling e. g. use of antifoulants is questioningly cause of their possible negative effects on breeding species and environment.

  7. Scenarios for Resilient Shrimp Aquaculture in Tropical Coastal Areas

    Directory of Open Access Journals (Sweden)

    Willem F. de Boer

    2010-06-01

    Full Text Available We contend there are currently two competing scenarios for the sustainable development of shrimp aquaculture in coastal areas of Southeast Asia. First, a landscape approach, where farming techniques for small-scale producers are integrated into intertidal areas in a way that the ecological functions of mangroves are maintained and shrimp farming diseases are controlled. Second, a closed system approach, where problems of disease and effluent are eliminated in closed recirculation ponds behind the intertidal zone controlled by industrial-scale producers. We use these scenarios as two ends of a spectrum of possible interactions at a range of scales between the ecological, social, and political dynamics that underlie the threat to the resilience of mangrove forested coastal ecosystems. We discuss how the analytical concepts of resilience, uncertainty, risk, and the organizing heuristic of scale can assist us to understand decision making over shrimp production, and in doing so, explore their use in the empirical research areas of coastal ecology, shrimp health management and epidemiology, livelihoods, and governance in response to the two scenarios. Our conclusion focuses on a series of questions that map out a new interdisciplinary research agenda for sustainable shrimp aquaculture in coastal areas.

  8. Electronic journal management systems experiences from the field

    CERN Document Server

    Ives, Gary W

    2013-01-01

    Discover how to manage your library's electronic journals?with tips from those who've already met the challenge!The explosive growth of electronic journals presents unique challenges for libraries. Electronic Journal Management Systems: Experiences from the Field comprehensively examines these complex topics, including explanations of the automated systems libraries have developed or adopted, licensing issues, and the provision of access to electronic journals. Respected library professionals discuss their own experiences in the implementation and use of electronic journal management systems,

  9. Electronics of LHCb calorimeter monitoring system

    CERN Document Server

    Konoplyannikov, A

    2008-01-01

    All calorimeter sub-detectors in LHCb, the Scintillator Pad Detector (SPD), the Preshower detector (PS), the Electromagnetic Calorimeter (ECAL) and the Hadron Calorimeter (HCAL) are equipped with the Hamamatsu photomultiplier tubes (PMT) as devices for light to electrical signal conversion [1]. The PMT gain behaviour is not stable in a time, due to changes in the load current and due to ageing. The calorimeter light emitting diode (LED) monitoring system has been developed to monitor the PMT gain over time during data taking. Furthermore the system will play an important role during the detector commissioning and during LHC machine stops, in order to perform tests of the PMTs, cables and FE boards and measurements of relative time alignment. The aim of the paper is to describe the LED monitoring system architecture, some technical details of the electronics implementation based on radiation tolerant components and to summarize the system performance.

  10. New aquaculture drugs under FDA review

    Science.gov (United States)

    Bowker, James D.; Gaikowski, Mark P.

    2012-01-01

    Only eight active pharmaceutical ingredients available in 18 drug products have been approved by the U.S. Food and Drug Administration for use in aquaculture. The approval process can be lengthy and expensive, but several new drugs and label claims are under review. Progress has been made on approvals for Halamid (chloramine-T), Aquaflor (florfenicol) and 35% PeroxAid (hydrogen peroxide) as therapeutic drugs. Data are also being generated for AQUI-S 20E, a fish sedative.

  11. Prediction of Suitable Harvest Time in Aquaculture

    OpenAIRE

    Zhaotang Shang; Lin Cheng; Mengsen Luo; Lang He; Zhigang Lu

    2013-01-01

    A model is provided to predict the prawn’s harvest in aquaculture through analytical research in agrometeorology, mathematical statistics, synoptic meteorology and et al. It is found out that the Benefit Analysis of the Best Harvest is one of the most ideal ways. The models for the breeding objects, climate prediction and analysis of market quotation should be set up and perfected continuously. Only when the dynamic numerical simulation of the growth is accurate and the short-term weather fo...

  12. PCR AS DIAGNOSTIC METHOD IN AQUACULTURE

    OpenAIRE

    Ivan?ica Strunjak-Perovi?; Natalija Topi? Popovi?

    1999-01-01

    PCR is an acronym for »polymerase chain reaction«, a technique based on detection and amplification of specific DNA and RNA sequences. It can be applied in diagnostics of hereditary diseases, forensics, population genetics, systematics, bioengineering, evolution biology, and also aquaculture. With this method it is possible to diagnose an array of viral, bacterial and parasitic diseases of fish, shellfish and crustaceans. The advantages of the technique are manifested in rapid obtaining of re...

  13. Organic matter decomposition in simulated aquaculture ponds

    OpenAIRE

    Torres Beristain, B.

    2005-01-01

    Different kinds of organic and inorganic compounds (e.g. formulated food, manures, fertilizers) are added to aquaculture ponds to increase fish production. However, a large part of these inputs are not utilized by the fish and are decomposed inside the pond. The microbiological decomposition of the organic matter is a critical factor for water quality control and nutrient recycle. Usually, management practices are developed to control the survival and health of the cultured animals and to mai...

  14. Genomics in Eels — Towards Aquaculture and Biology

    OpenAIRE

    Minegishi, Yuki; Henkel, Christiaan V.; Dirks, Ron P.; van den Thillart, Guido E. E. J. M.

    2012-01-01

    Freshwater eels (genus Anguilla), especially the species inhabiting the temperate areas such as the European, American and Japanese eels, are important aquaculture species. Although artificial reproduction has been attempted since the 1930s and large numbers of studies have been conducted, it has not yet fully succeeded. Problems in eel artificial breeding are highly diverse, for instance, lack of basic information about reproduction in nature, no appropriate food for larvae, high mortality, ...

  15. Probiotics as control agents in aquaculture

    Science.gov (United States)

    Geovanny D, Gómez R.; Balcázar, José Luis; Ma, Shen

    2007-01-01

    Infectious diseases constitute a limiting factor in the development of the aquaculture production, and control has solely concentrated on the use of antibiotics. However, the massive use of antibiotics for the control of diseases has been questioned by acquisition of antibiotic resistance and the need of alternative is of prime importance. Probiotics, live microorganisms administered in adequate amounts that confer a healthy effect on the host, are emerging as significant microbial food supplements in the field of prophylaxis.

  16. Productivity in organic and conventional salmon aquaculture

    OpenAIRE

    Reithe, Siv; Tveterås, Ragnar

    2000-01-01

    This report provides a comparative analysis of productivity in conventional and organic salmon aquaculture. Regulations in organic salmon farming impose several restrictions on production that are not present in conventional salmon farming. We have analysed the effect of a fish density regulation on the economic performance of salmon farms. A fish density regulation has two possible consequences. First, with a given cage volume, it leads to a reduction in total production at the farm. Second,...

  17. Biotechnology and aquaculture: the role of cell cultures.

    Science.gov (United States)

    Bols, N C

    1991-01-01

    Cell culturing complements recombinant DNA technology in the application of biotechnology to aquaculture. Cell cultures can be prepared from the three main groups of multicellular organisms in aquaculture: fish, shellfish, and seaweeds. These cultures can contribute indirectly to the successful farming of these organisms by providing basic insights into how their growth, reproduction, and health can be understood and manipulated. Finally, they can be a direct source of diverse biochemical products for use in aquaculture, medicine and the food industry. PMID:14543738

  18. On the relationship between aquaculture and reduction fisheries

    OpenAIRE

    Asche, Frank; Tveterås, Sigbjørn

    2000-01-01

    Traditional aquaculture has to a large extent used herbivore species with limited requirements for additional feeding. However, in intensive aquaculture production one farm carnivore species like salmon and also feeds herbivore species with fishmeal as this increase growth. This has lead to a growing concern that increased aquaculture production poses an environmental threat to the species targeted in reduction fisheries as increased demand increase fishing pressure. In this paper we address ...

  19. National activities in the field of Aquaculture: Ireland

    OpenAIRE

    Griffith, David de G.

    1996-01-01

    This document was prepared in May 1995 by a group of invited aquaculture experts drawn from the Irish aquaculture industry, the Fisheries Research Centre, An Bord Iascaigh Mhara, Salmon Research Agency, Veterinary Research Laboratory, the Marine Institute and from University RTD laboratories. It was drafted as a contribution to the 1995 meeting of Directors of Fisheries Research Organisations of the European Union, and as a response to a review by DG XIV entitled "European Aquaculture Researc...

  20. Electronic key system using alpha detection

    International Nuclear Information System (INIS)

    We have developed the new electronic key system utilizes random pulse from alpha-particle detection with PIN photo diode. The random pulse by natural decay of alpha source is stable under the every outside environment like as temperature, pressure, an electromagnetic wave, and so on. The stable and un-predicted signals of the random pulses are the most suitable as a source of authentication signal for the electric key system. The program made of manufacture side forms the key code under current electronic key. Therefore, the manufacture must keep the code data secret for long time. The new electronic key always identify between key body and each key by the original pulse data from alpha particles. It is reduce the control cost of security remarkably. Moreover, back ground noise can be ignored in the circuit and it doesn't need to enlarge a total number of activity. The activity of the alpha source is about 10-100 Bq in one module. (author)

  1. Evaluation of three types of structured floating plastic media in moving bed biofilters for total ammonia nitrogen removal in a low salinity hatchery recirculating aquaculture system

    Science.gov (United States)

    Three different commercially available structural plastic media were evaluated in triplicate in moving bed toriod filters under low salinity (11-12 ppt) warm water culture conditions and two different feed loading rates. The culture system consisted of nine separate modules that include a double dra...

  2. State of the art of Italian aquaculture

    Directory of Open Access Journals (Sweden)

    P. Melotti

    2010-04-01

    Full Text Available According to aquaculture production statistics published by FEAP (2007, Italy is the fifth largest fish producer in the European Union having a total quantity for 2006 estimated around 60,000 t. This data is exclusively referred to rainbow trout (Oncorhynchus mykiss, seabream (Sparus aurata, seabass (Dicentrarchus labrax and European eel (Anguilla anguilla but even if we consider the total aquaculture production elaborated by ISMEA (2006 through year 2005 including sturgeons, carps, striped bass, catfish and ornamental fish, Italy ranks fourth with 69,100 t after Norway (655,364 t, Great Britain (141,793 t and Greece (83,600 t. Over the last 15 years, Italian finfish production has known a decrease related to all the species mainly reared (trout, eel, carps, catfish except for the eurhyaline species that have had an important expansion (Table 1. Based on these considerations, in this work we describe the main features of fish aquaculture in Italy focalizing the attention to the single sectors of the farmed species and their trend for the future.

  3. Probiotics in shrimp aquaculture: avenues and challenges.

    Science.gov (United States)

    Ninawe, A S; Selvin, Joseph

    2009-01-01

    As an alternative strategy to antibiotic use in aquatic disease management, probiotics have recently attracted extensive attention in aquaculture. However, the use of terrestrial bacterial species as probiotics for aquaculture has had limited success, as bacterial strain characteristics are dependent upon the environment in which they thrive. Therefore, isolating potential probiotic bacteria from the marine environment in which they grow optimally is a better approach. Bacteria that have been used successfully as probiotics belong to the genus Vibrio and Bacillus, and the species Thalassobacter utilis. Most researchers have isolated these probiotic strains from shrimp culture water, or from the intestine of different penaeid species. The use of probiotic bacteria, based on the principle of competitive exclusion, and the use of immunostimulants are two of the most promising preventive methods developed in the fight against diseases during the last few years. It also noticed that probiotic bacteria could produce some digestive enzymes, which might improve the digestion of shrimp, thus enhancing the ability of stress resistance and health of the shrimp. However, the probiotics in aquatic environment remain to be a controversial concept, as there was no authentic evidence / real environment demonstrations on the successful use of probiotics and their mechanisms of action in vivo. The present review highlights the potential sources of probiotics, mechanism of action, diversity of probiotic microbes and challenges of probiotic usage in shrimp aquaculture. PMID:19514908

  4. Risks of using antifouling biocides in aquaculture.

    Science.gov (United States)

    Guardiola, Francisco Antonio; Cuesta, Alberto; Meseguer, José; Esteban, Maria Angeles

    2012-01-01

    Biocides are chemical substances that can deter or kill the microorganisms responsible for biofouling. The rapid expansion of the aquaculture industry is having a significant impact on the marine ecosystems. As the industry expands, it requires the use of more drugs, disinfectants and antifoulant compounds (biocides) to eliminate the microorganisms in the aquaculture facilities. The use of biocides in the aquatic environment, however, has proved to be harmful as it has toxic effects on the marine environment. Organic booster biocides were recently introduced as alternatives to the organotin compounds found in antifouling products after restrictions were imposed on the use of tributyltin (TBT). The replacement products are generally based on copper metal oxides and organic biocides. The biocides that are most commonly used in antifouling paints include chlorothalonil, dichlofluanid, DCOIT (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, Sea-nine 211(®)), Diuron, Irgarol 1051, TCMS pyridine (2,3,3,6-tetrachloro-4-methylsulfonyl pyridine), zinc pyrithione and Zineb. There are two types of risks associated with the use of biocides in aquaculture: (i) predators and humans may ingest the fish and shellfish that have accumulated in these contaminants and (ii) the development of antibiotic resistance in bacteria. This paper provides an overview of the effects of antifouling (AF) biocides on aquatic organisms. It also provides some insights into the effects and risks of these compounds on non-target organisms. PMID:22408407

  5. Risks of Using Antifouling Biocides in Aquaculture

    Directory of Open Access Journals (Sweden)

    José Meseguer

    2012-02-01

    Full Text Available Biocides are chemical substances that can deter or kill the microorganisms responsible for biofouling. The rapid expansion of the aquaculture industry is having a significant impact on the marine ecosystems. As the industry expands, it requires the use of more drugs, disinfectants and antifoulant compounds (biocides to eliminate the microorganisms in the aquaculture facilities. The use of biocides in the aquatic environment, however, has proved to be harmful as it has toxic effects on the marine environment. Organic booster biocides were recently introduced as alternatives to the organotin compounds found in antifouling products after restrictions were imposed on the use of tributyltin (TBT. The replacement products are generally based on copper metal oxides and organic biocides. The biocides that are most commonly used in antifouling paints include chlorothalonil, dichlofluanid, DCOIT (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, Sea-nine 211®, Diuron, Irgarol 1051, TCMS pyridine (2,3,3,6-tetrachloro-4-methylsulfonyl pyridine, zinc pyrithione and Zineb. There are two types of risks associated with the use of biocides in aquaculture: (i predators and humans may ingest the fish and shellfish that have accumulated in these contaminants and (ii the development of antibiotic resistance in bacteria. This paper provides an overview of the effects of antifouling (AF biocides on aquatic organisms. It also provides some insights into the effects and risks of these compounds on non-target organisms.

  6. Plasma Oscillations and Electron-Elecron Interactions in 2D Electron Systems

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, A B, E-mail: abd@rioo.r, E-mail: abd-69@mail.r [Ryazan Institute of Open Education, 2 Bronnaya str., Ryazan, 390010 (Russian Federation); Ryazan State Radio Technical University, 59/2 Gagarin str., Ryazan, 39005 (Russian Federation)

    2010-11-01

    Electron-electron interactions in a single highly doped heterojunction are considered taking into account both transitions. Expressions are derived for the time of electron-electron interaction, matrix elements of the full screening potential and dynamic dielectric function in 2D electron system with fine structure of energy spectrum, and for the electron density spatial distribution. The calculated dependences provide a good description of the experimental times of Landau levels collisional broadening.

  7. Inelastic electron lifetime in disordered mesoscopic systems

    CERN Document Server

    Blanter, Ya M

    1996-01-01

    Inelastic quasiparticle lifetime due to the electron-electron interaction (out-scattering time in the kinetic equation formalism) is calculated for finite metallic diffusive systems (quantum dots) in the whole range of parameters. Both cases of ``continuous'' (the inelastic level broadening much exceeds the mean level spacing) and ``discrete'' spectrum are analyzed. In particular, crossover between one- and zero-dimensional regimes is studied in details. In the case of continuous spectrum the out-scattering time is shown to be the same as the inelastic time entering expressions for universal conductance fluctuations and persistent currents. It is also found to be shorter than the phase-breaking time in two- and one-dimensional systems, while in zero-dimensional systems these two times coincide. In the case of discrete spectrum for small enough systems a universal behavior of the scattering time is obtained. For temperatures below the mean level spacing the out-scattering rate is shown to be vanishingly small.

  8. Stretchable interconnections for flexible electronic systems.

    Science.gov (United States)

    Jianhui, Lin; Bing, Yan; Xiaoming, Wu; Tianling, Ren; Litian, Liu

    2009-01-01

    Sensors, actuators and integrated circuits (IC) can be encapsulated together on an elastic substrate, which makes a flexible electronic system. In this system, electrical interconnections that can sustain large and reversible stretching are in great need. This paper is devoted to the fabrication of highly stretchable metal interconnections. Transfer printing technology is utilized, which mainly involves the transfer of 100-nm-thick gold ribbons from silicon wafers to pre-stretched elastic substrates. After the elastic substrates relax from the pre-strain, the gold ribbons buckle and form wavy geometries. These wavy geometries change in shapes to accommodate the applied strain and can be reversely stretched without cracks or fractures occurring, which will greatly raise the stretchability of the gold ribbons. As an application example, some of these wavy ribbons can accommodate high levels of stretching (up to 100%) and bending (with curvature radius down to 1.20 mm). Moreover, the efficiency and reliability of the transfer, especially for slender ribbons, have been increased due to the improvement of the technology. All the characteristics above will permit making stretchable gold conductors as interconnections for flexible electronic systems such as implantable medical systems and smart clothes. PMID:19963807

  9. Solar aquaculture: A wintering technique for parent prawns

    Energy Technology Data Exchange (ETDEWEB)

    Cao Jin Long [Aquaculture Res. Inst., Shandong Province (China)

    1994-09-01

    A new method of providing the warm water needed for parent prawn wintering using solar energy is described. Using solar energy for prawn wintering involves heat collection, heat storage and temperature maintenance. The system designed provides sufficient energy for the safe wintering of prawns with suitable water temperatures. The temperature control facilities consist of three parts: a salt gradient solar pond, a shallow solar pond and a plastic house. The technique involves use of a shallow solar pond for collection and storage of heat. The average temperature in the wintering pond plastic house was 11 degrees C and the minimum temperature in January was 5.4 degrees C. This system allowed the wintering process to be conducted using solar energy alone and may extend aquaculture to higher latitudes. The ratio of net profit with the solar energy system over investment is 1.5 which makes it economically viable.

  10. Freshwater aquaculture in the United States: Complying with environmental protection law and policy

    OpenAIRE

    Noble, M.

    1993-01-01

    The author deal with the relations between the freshwater fish culture and the many regulations of the environmental protection in USA. The author develops the federal and state administrative frameworks (federal government administration of aquaculture, the state government administration of aquaculture), the freshwater aquaculture and water rights, the freshwater aquaculture and wetlands regulation, the freshwater aquaculture and water quality regulation, the freshwater aquaculture and wild...

  11. New Electron Gun System for BEPCII

    CERN Document Server

    Liu, Bo; Long Chi, Yun; Zhang, Chuang

    2005-01-01

    The new electron gun system for BEPCII has been put into operation since Nov. 2004. The article describes the design, experiment and operation of this new system. The design current of the gun is 10 A for the pulse lengths of 1 ns, 2.5 ns and 1 ?s with repetition rate of 50 Hz. The gun is operated with a pulsed high voltage power supply which can provide up to 200 kV high voltage. Computer simulations have been carried out in the design stage, including simulation of the gun geometry and beam transportation. Some important relation curves are obtained during the experiment. Two-bunch operation is available and some elementary tests have been performed. New scheme of the gun control system based on EPICS is also presented. The real operation shows that the design and manufacturing is basically successful.

  12. Expert system for WDS Electron Probe Microanalysis

    International Nuclear Information System (INIS)

    The electron microprobe is a complex tool for elemental micro-characterisation. The expert system developed during this thesis is a software to help and to advice the operator and its aim is to simplify the procedures, to improve the accuracy of the results and to control the analysis time. The starting point of the system is an interactive questionnaire regarding the sample,( i.e. what is already known), and about the expectations on the analysis,( i.e. the accuracy of the results required by the operator). Then, the system performs a semi-quantitative analysis of the sample. Based on the acquisition of a wavelength qualitative spectrum, this method is a way to obtain the sample composition in a short time with a reasonable accuracy. The results at the end of this first phase give a good idea of the present elements and the sample composition. All the information obtained in this first step are necessary to the system to optimise all the parameters of an accurate quantitative measure. For this study, we developed specific algorithms of simulation, in particular the X radiation emitted by an unknown under the electron beam, and the response of the microprobe for this emission. Then, we have developed models to calculate the intensity, the shape of the x-ray lines and of the continuum as they would be measured by the microprobe. These models were validated by comparison with measures. Moreover, they are created to be adapted to all kind of microprobe. These simulations give to the system expert the possibility to consider all the analysis configurations for the tested sample and to optimise the microprobe parameters in agreement with the operator's expectations. The final configuration proposed by the expert system is the one which better satisfies the expectations and which needs the minimal time of measure for each point. (author)

  13. Recirculation-aeration: Bibliography for aquaculture. Bibliographies and literature of agriculture (Final)

    Energy Technology Data Exchange (ETDEWEB)

    Perschbacher, P.W.; Powell, R.V.; Freeman, D.W.; Lorio, W.J.; Hanfman, D.T.

    1993-08-01

    The bibliography includes literature citations through 1992 related to water recirculation and aeration in aquaculture. The focus is on filtration, aeration, and circulation techniques in various aquaculture situations.

  14. Chemical and Sensory Quantification of Geosmin and 2-Methylisoborneol in Rainbow Trout (Oncorhynchus mykiss) from Recirculated Aquacultures in Relation to Concentrations in Basin Water

    DEFF Research Database (Denmark)

    Petersen, Mikael A.; Hyldig, Grethe; Strobel, Bjarne W.; Henriksen, Niels H.; Jørgensen, Niels O. G.

    2011-01-01

    Globally, aquaculture systems with water recirculation experience increasing problems with microbial taste and odor compounds (TOCs) such as geosmin and 2-methylisoborneol (MIB). This study investigated the content of geosmin and MIB in water and the flesh of 200 rainbow trouts from eight recirculated aquaculture systems in Denmark. TOC content in the fish flesh was measured by a dynamic headspace extraction method and was evaluated by a sensory panel. The results showed significant correlations...

  15. Structural dynamics of electronic and photonic systems

    CERN Document Server

    Suhir, Ephraim; Steinberg, David S

    2011-01-01

    The proposed book will offer comprehensive and versatile methodologies and recommendations on how to determine dynamic characteristics of typical micro- and opto-electronic structural elements (printed circuit boards, solder joints, heavy devices, etc.) and how to design a viable and reliable structure that would be able to withstand high-level dynamic loading. Particular attention will be given to portable devices and systems designed for operation in harsh environments (such as automotive, aerospace, military, etc.)  In-depth discussion from a mechanical engineer's viewpoint will be conducte

  16. Doniach Diagram in Disordered Electrons System

    Science.gov (United States)

    Lee, Hyunyong; Kettemann, Stefan

    2013-03-01

    We have derived the quantum phase diagram of disordered electron systems with magnetic impurities. The competition between RKKY interaction, JRKKY, and Kondo effect gives rise to a rich quantum phase diagram, or Doniach diagram. We present numerical results for disordered 2D electron systems which show that both Kondo temperature, TK and JRKKY are widely distributed and quantum critical point is extended to a critical region. We find a sharp cutoff in the distribution of their ratio, JRKKY /TK , and from that critical density of magnetic impurity below which Kondo always wins. We find that the spin coupled phase grows at the expense of Kondo phase as increasing disorder.The spin coupled phase shows a succession of 3 phases: 1. a Griffiths phase with anomalous power laws determined by distribution of JRKKY, 2. spin glass phase, 3. long range magnetic ordered phase. We report the results on graphene where we find that spin coupled phase is more stable against Kondo screening, but is more easily destroyed by disorder into a paramagnetic phase. We have derived the quantum phase diagram of disordered electron systems with magnetic impurities. The competition between RKKY interaction, JRKKY, and Kondo effect gives rise to a rich quantum phase diagram, or Doniach diagram. We present numerical results for disordered 2D electron systems which show that both Kondo temperature, TK and JRKKY are widely distributed and quantum critical point is extended to a critical region. We find a sharp cutoff in the distribution of their ratio, JRKKY /TK , and from that critical density of magnetic impurity below which Kondo always wins. We find that the spin coupled phase grows at the expense of Kondo phase as increasing disorder.The spin coupled phase shows a succession of 3 phases: 1. a Griffiths phase with anomalous power laws determined by distribution of JRKKY, 2. spin glass phase, 3. long range magnetic ordered phase. We report the results on graphene where we find that spin coupled phase is more stable against Kondo screening, but is more easily destroyed by disorder into a paramagnetic phase. National Research Foundation of Korea funded by the Ministry of Education, Science and Technology(R31-2008-000-10059-0), Division of Advanced Materials Science

  17. Effect of electron-electron interaction on thermal conductivity of disordered systems

    International Nuclear Information System (INIS)

    Arfi presents a calculation of a correction to the thermal conductivity due to the inclusion of electron-electron interaction in a disordered metallic system. He finds that, to the first order in electron-electron interaction, the Wiedemann-Franz law is not satisfied

  18. Broodstock management of the fine flounder Paralichthys adspersus (Steindachner, 1867) using recirculating aquaculture systems / Manejo de reproductores del lenguado Paralichthys adspersus (Steindachner, 1867) usando sistemas de recirculación en acuicultura

    Scientific Electronic Library Online (English)

    Lili, Carrera; Noemí, Cota; Melissa, Montes; Enrique, Mateo; Verónica, Sierralta; Teresa, Castro; Angel, Perea; Cristian, Santos; Christian, Catcoparco; Carlos, Espinoza.

    2013-03-01

    Full Text Available El presente trabajo, describe la metodología desarrollada en IMARPE para la captura, aclimatación y acondicionamiento de ejemplares adultos de P. adspersus en sistemas de recirculación (SRA), con la finalidad de formar un stock de reproductores. El SRA permitió manejar parámetros medioambientales es [...] tables durante el periodo de acondicionamiento, como: temperatura del agua (17,2±1°C), oxígeno disuelto (8,1±0,7 mg L-1), pH (7,3±0,2), amonio (0,004±0,003 mg L-1), nitrito (0,52±0,2 mg L-1) y nitrato (3,45±2,6 mg L-1). Se dio inicio a la alimentación el día 15 post-captura, utilizando alimento vivo (Odonthestes regia regia, Mugil cephalus), crustáceos (Emerita analoga), alimento fresco (Engraulis ringens y Dosidicus gigas) y artificial semihúmedo. Durante los primeros días de acondicionamiento los peces mostraron una disminución en el peso, hasta su adaptación a las condiciones de cultivo, luego de lo cual se produjo un incremento continuo en ambos sexos. La tasa específica de crecimiento fue positiva a partir del tercer mes y la tasa de crecimiento relativo mostró que en agosto 2010, el peso promedio se incrementó 24,5% en machos y 16,2% en hembras. Se realizó un análisis patológico a los ejemplares capturados y se observó la presencia de diferentes parásitos internos y externos, entre ellos predominaron Entobdella sp. y Philometra sp. Abstract in english The present study describes the methodology used at IMARPE for the capture, acclimation and management of P. adspersus broodstock using recirculating aquaculture systems (RAS). RAS improved the water quality and maintained the environmental parameters during the acclimation period, temperature (17.2 [...] ±1°C), oxygen (8.1±0.7 mg L-1), pH (7.3±0.2), ammonia (0.004±0.003 mg L-1), nitrite (0.52±0.2 mg L-1) and nitrate (3.45±2.6 mg L-1). Fish began to be fed normally from day 15 post-capture, once or twice a day using live fish (Odonthestes regia regia, Mugil cephalus), crustacean (Emerita analoga), fresh food (Engraulis ringens and Dosidicus gigas) and artificial feed. A significant loss in the weight of the fish was registered during the first days of captivity, followed by a continuous increase in both sexes. The specific growth rate was positive from the third month of captivity, being the relative growth rate 24.5% and 16.2% in August 2010 in males and females, respectively. Different internal and external parasites were detected in the fish, being Entobdella sp. and Philometra sp. the prevailing parasites observed during samplings.

  19. The impact of level of the stocking density on the haematological parameters of rainbow trout (Oncorhynchus mykiss reared in recirculating aquaculture systems

    Directory of Open Access Journals (Sweden)

    Angelica Docan

    2011-10-01

    Full Text Available Hematological indices are important parameters for the evaluation of fish physiological status.The purpose of this experiment was to evaluate how level of the stocking density influence the bloodphysiology of of juvenile rainbow trout (Oncorhynchus mykiss reared in a recirculating system. Theexperiment was conducted over a period of 33 days. A number of 254 rainbow trout with an averageweight of 29.51 ± 1.32 g were divided into four rearing units in order to create different stockingdensities: in B1-2.64 kg/m3, with an average weight of 31.68 g/ex, B2 – 5.16 kg/m3 with an averageweight of 30.39 g/ex, B3 – 7.12 kg/m3 with an average weight of 28.52 g/ex and B4- 9.42 kg/m3 with anaverage weight of 27.46 g. The sampling of O. mykiss blood from the four variants before and after theexperimental trial allowed determination of hematological indices. Red blood cell counts (RBCc,haematocrit values (Ht, haemoglobin concentration (Hb, mean corpuscular volume (MCV, meancorpuscular haemoglobin (MCH and mean corpuscular haemoglobin concentration (MCHC weremeasured and analyzed, with routine methods used in fish hematology (Blaxhall & Daisley 1973;Svobodova 2001. Some hematological indicators (Hb, MCV, MCH had been influenced by the stockingdensity. The results of our research provide a contribution to the knowledge of the hematologicalparameters of the rainbow trout reared in different level of stocking densities, under the recirculatingsystems condition.

  20. Energy transformation in molecular electronic systems

    International Nuclear Information System (INIS)

    Our new optical pumping spectroscopy (steady state, and double-laser pulse) allows the production and study of the unstable rare tautomer in its ground and excited states, including picosecond dynamic studies. Molecules under study here included 7-azaindole (model for biological purines), 3-hydroxyflavone (model for plant flavones), lumichrome, and other heterocyclics. New detailed molecular mechanisms for proton transfer are derived, especially with catalytic assisting molecules. A new proton-transfer laser of extraordinary efficiency has become a side dividend, possibly worth of industrial development. The excited and highly reactive singlet molecular oxygen species 1?/sub g/) has proven to be ubiquitous in chemical peroxide systems and in physically excited sensitizer-oxygen systems. Hyperbaric oxygen mechanisms in biology probably involve singlet oxygen. We have undertaken a spectroscopic study of tris - dibenzoylmethane chelates of Al, Gd, Eu, and Yb trivalent ions. These chelates offer a variety of electronic behaviors, from Z-effects on ?-electron spin-orbital coupling (Al, Gd) to Weissman intramolecular energy transfer to 4f mestable levels (Eu, Gd). Elegant new spectroscopic resolution at 77K permits separation of tautomeric, parasitic self-absorption, dissociation, and cage effects to be resolved. 18 refs., 4 figs

  1. Radiation Risks and Mitigation in Electronic Systems

    CERN Document Server

    Todd, B

    2015-01-01

    Electrical and electronic systems can be disturbed by radiation-induced effects. In some cases, radiation-induced effects are of a low probability and can be ignored; however, radiation effects must be considered when designing systems that have a high mean time to failure requirement, an impact on protection, and/or higher exposure to radiat ion. High-energy physics power systems suffer from a combination of these effects: a high mean time to failure is required, failure can impact on protection, and the proximity of systems to accelerators increases the likelihood of radiation-induced events. This paper presents the principal radiation-induced effects, and radiation environments typical to high-energy physics. It outlines a procedure for designing and validating radiation-tolerant systems using commercial off-the-shelf components. The paper ends with a worked example of radiation-tolerant power converter controls that are being developed for the Large Hadron Collider and High Luminosity-Large Hadron Colli...

  2. Fisheries And Aquaculture Resources And Their Interactions With Environment in Turkey

    Science.gov (United States)

    Deniz, H.

    2003-04-01

    Turkey, with 8333 km of coast line, 151 080 sq. km economic sea area, many rivers with 177 714 total length, nearly, 1 million ha of natural lakes, 500 000 ha of dam reservoirs has rich marine and inland aquatic resource potential. Despite of these large resources, Turkish fisheries has the characteristics of small-scale fisheries and in general it can be considered as coastal fisheries. There is also great potential for inland fisheries and aquaculture. Being in half closed position, these seas have different characteristics in respect of biological, physical, chemical and ecological points. In addition; Turkey has favourable geographic position between the Black Sea and Mediterranean Sea. Nevertheless, this potential seems not to be fully utilised and therefore fisheries is not a major sector in the economy. According to the statistics of the fisheries for 2000 published by the Turkish government, Turkey's total fisheries production was 582.376 tons. Total catch consists sea fish (441 690 tons, crustaceans and molluscs (18 831 tons), freshwater fish (42.824 tons) and aquaculture (79. 031 tons). The Ministry of Agriculture and Rural Affairs (MARA) is the Ministry responsible for the overall fisheries and aquaculture development, administration, regulation, promotion and technical assistance. In the past two decades, marine fish farming using net cages has developed in the coastal waters throughout Turkey. Such fish farming has allowed the production of large amounts of valuable fish and their supply to the internal and external markets on a regular basis. However, fish farming is sometimes fallowed by organic pollution of the water and bottom sediment in the vicinity of the cages. A comprehensive land and coastal planning survey of almost the whole coast of Turkey is currently being conducted. This master plan designates areas to be developed for forestry, agriculture, industry, urbanisation, environmentally protected areas, etc. The plan was undertaken before the potential of aquaculture was fully realised and there were, therefore, no areas specifically designated for aquaculture. Aquaculture development is therefore being restricted by the loss of access to some of the best sites. The most common conflicts occur with environmental protection, tourism, recreation, urbanisation, archaeology and navigation. In order to prevent such conflicts and minimise the environmental impacts the open sea fishery, offshore mariculture systems, and echo-friendly technologies have to be adopted. In addition to that integrated coastal management models must be developed and implemented. Key words: fisheries and aquaculture resources, environment, interaction, tourism, protected areas, mangement and sustainability.

  3. Decoding Spatial Complexity in Strongly Correlated Electronic Systems

    OpenAIRE

    Carlson, E. W.; Liu, S.; Phillabaum, B.; Dahmen, K. A.

    2014-01-01

    Inside the metals, semiconductors, and magnets of our everyday experience, electrons are uniformly distributed throughout the material. By contrast, electrons often form clumpy patterns inside of strongly correlated electronic systems (SCES) such as colossal magnetoresistance materials and high temperature superconductors. In copper-oxide based high temperature superconductors, scanning tunneling microscopy (STM) has detected an electron nematic on the surface of the materia...

  4. Perception of Aquaculture Education to Support Further Growth of Aquaculture Industry in Victoria, Australia

    Science.gov (United States)

    Awal, Sadiqul; Christie, Andrew; Watson, Matthew; Hannadige, Asanka G. T.

    2012-01-01

    Purpose: The central aim of this study was to determine the perception of aquaculture educational provisions in the state of Victoria, and whether they are sufficient to ultimately support further growth of the industry. Design/methodology/approach: Questionnaires were formulated and distributed to participants in a variety of ways, including via…

  5. Water Quality Monitoring and Control for Aquaculture Based on Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Daudi S. Simbeye

    2014-04-01

    Full Text Available We have designed and presented a wireless sensor network monitoring and control system for aquaculture. The system can detect and control water quality parameters of temperature, dissolved oxygen content, pH value, and water level in real-time. The sensor nodes collect the water quality parameters and transmit them to the base station host computer through ZigBee wireless communication standard. The host computer is used for data analysis, processing and presentation using LabVIEW software platform. The water quality parameters will be sent to owners through short messages from the base station via the Global System for Mobile (GSM module for notification. The experimental evaluation of the network performance metrics of quality of communication link, battery performance and data aggregation was presented. The experimental results show that the system has great prospect and can be used to operate in real world environment for optimum control of aquaculture environment

  6. Application of Medicinal Herbs to Aquaculture in Asia

    OpenAIRE

    Sataporn DIREKBUSARAKOM

    2004-01-01

    Aquaculture has increased greatly in Asia, but there are various problems associated with acquacultural production one of which is the use of antimicrobial agents resulting in more resistant bacterial strains which adversely affect human health and the natural environment. This paper presents information on the role and application of herbs for aquaculture in Asia.

  7. Aqua-Topics. Aquaculture for Youth and Youth Educators.

    Science.gov (United States)

    McVey, Eileen

    This booklet contains information on aquaculture and ideas for aquaculture projects. The information provided is for students at upper elementary through high school learning levels. Recommended activities at the end of the text are organized by level of difficulty. The activities can be modified depending on area and availability of resources. A…

  8. A Review of Alternative Protein Sources in Aquaculture Feeds

    Science.gov (United States)

    With a global sea food production of about 51.7 million tonnes in 2006, and an annual growth rate of 6.9% from 1970 to 2006, aquaculture is one of the fastest growing sectors in the food industry. Feed represents 40% to 70% of operating costs for aquaculture operations. Fish diets typically contain ...

  9. Guide to Using Drugs, Biologics, and Other Chemicals in Aquaculture

    Science.gov (United States)

    The Guide to Using Drugs, Biologics, and Other Chemicals in Aquaculture (Guide) describes regulated products that are approved for use in U.S. aquaculture. The Guide also describes drugs that are not yet approved for use in the U. S. but that can be used under an Investigational New Animal Drug (INA...

  10. Mechanisms of antimicrobial resistance in finfish aquaculture environments

    Directory of Open Access Journals (Sweden)

    PatriciaL.Keen

    2013-08-01

    Full Text Available Consumer demand for affordable fish drives the ever-growing global aquaculture industry. The intensification and expansion of culture conditions in the production of several finfish species has been coupled with an increase in bacterial fish disease and the need for treatment with antimicrobials. Understanding the molecular mechanisms of antimicrobial resistance prevalent in aquaculture environments is important to design effective disease treatment strategies, to prioritize the use and registration of antimicrobials for aquaculture use, and to assess and minimize potential risks to public health. In this brief article we provide an overview of the molecular mechanisms of antimicrobial resistance mechanisms in finfish aquaculture environments and highlight specific research that should provide the basis of sound, science-based policies for the use of antimicrobials in aquaculture.

  11. DIAGNOSIS OF AQUACULTURE IN THE MUNICIPALITY OF ALVARADO VERACRUZ, MEXICO

    Directory of Open Access Journals (Sweden)

    Lenin Rangel-López

    2014-07-01

    Full Text Available This research aims to analyze the current situation of aquaculture farms in the Municipality of Alvarado, Veracruz, Mexico. During this study, 29 interviews were conducted aimed to the units of aquaculture producers; 24 variables were analyzed within the aspects of the socio-economic, technical, marketing and legal framework. The most relevant results within the legal framework: 21% of units has “National Registration of Fisheries and Aquaculture” (RNPyA and 7% has “Federal Taxpayer Register” (RFC; in the socio-economic aspects: 187 jobs are generated; on technical aspects: the average area for cultivation is 410.11 ha, 79% of production is Tilapia (Oreochromis spp.. The aquaculture activity on Alvarado, Veracruz, it is in a learning process, therefore strategies are needed in order to the development of the activity and increasing production; improving cultivation methodologies and training producers on managing their aquaculture units.

  12. Welfare of farmed fish : towards a sustainable development of European aquaculture

    OpenAIRE

    Immink, V.M.

    2009-01-01

    The European project FASTFISH has developed a fish behaviour monitoring system for aquaculture to ensure that fish production continues to be legitimised by society and remains competitive in production performance. Adoption of the monitoring system in society is a political process of choices and strategies, requiring experience and capacity from all stakeholders. The main challenge of FASTFISH is to combine learning processes as well as accountability for retailers and non-governmental orga...

  13. The current status of extensive and semi-intensive aquaculture practices in Southern Europe

    OpenAIRE

    Anras, L.; Boglione, Clara; Cataudella, Stefano; Dinis, M. T.; Makridis, Pavlos; Marino, G.; Ramalho Ribeiro, Ana; Yúfera, Manuel

    2010-01-01

    In less than 30 years, intensive fish farming has become the main provider of marine farmed products. Yet, extensive and semi-intensive systems1 still represent significant amounts of production and use large places along the southern Europe coastal zones. These include confined areas of coastal lagoons, natural and managed deltas, and semi closed bays and estuaries, encompassing polders with earthen ponds. The farming systems studied are aquaculture stricto sensu and capture fisheries ...

  14. Water Quality Monitoring and Control for Aquaculture Based on Wireless Sensor Networks

    OpenAIRE

    Daudi S. Simbeye; Shi Feng Yang

    2014-01-01

    We have designed and presented a wireless sensor network monitoring and control system for aquaculture. The system can detect and control water quality parameters of temperature, dissolved oxygen content, pH value, and water level in real-time. The sensor nodes collect the water quality parameters and transmit them to the base station host computer through ZigBee wireless communication standard. The host computer is used for data analysis, processing and presentation using LabVIEW software pl...

  15. Periphyton boosts production in pond aquaculture systems

    OpenAIRE

    Azim, E.A.; Verdegem, M.C.J.; Wahab, M.A.; Dam, A.A., van; M. C. M. Beveridge

    2001-01-01

    Silver perch (Bidyanus bidyanus, Mitchell) of 65 g average weight were reared at high density under controlled conditions on diets containing 24.8nd 40.6?rotein. Diets were fed at 2?r 4?f the fish biomass day1. Both protein concentrations and feeding level of the diet influenced growth and proximate composition of the fish at the end of the 50-day growth trial. Energy requirement for maintenance for these fish was found to be 77 cal BW0.8 and for each unit of energy retained 3.78 cal BW0.8 ne...

  16. 36 CFR 1236.26 - What actions must agencies take to maintain electronic information systems?

    Science.gov (United States)

    2010-07-01

    ...agencies take to maintain electronic information systems? 1236.26 ...agencies take to maintain electronic information systems? (a) Agencies must maintain inventories of electronic information systems and...

  17. Aquaculture in Africa = La pisciculture en Afrique

    OpenAIRE

    Jackson, P.N.B.

    1988-01-01

    L'élevage des poissons proprement dit est d'origine récente en Afrique et n'a débuté qu'avec l'importation de techniques utilisées dans d'autres régions. C'est le cas pour la carpe introduite en 1859 en Afrique du Sud et pour le premier élevage des tilapias au Kenya en 1924 ... Après une période durant laquelle l'intérêt pour l'aquaculture s'est ralenti (les causes en sont discutées ici), il y a maintenant une forte demande dans beaucoup de pays africains. Les poissons indigènes les plus inté...

  18. Survey and Alignment of the Fermilab Electron Cooling System

    Energy Technology Data Exchange (ETDEWEB)

    Oshinowo, Babatunde O' Sheg; Leibfritz, Jerry

    2006-09-01

    The goal of achieving the Tevatron luminosity of 3 x 10{sup 32} cm{sup -2}s{sup -1} requires Electron Cooling in the Recycler Ring to provide an increased flux of antiprotons. The Fermilab Electron Cooling system has been designed to assist accumulation of antiprotons for the Tevatron collider operations. The installation along with the survey and alignment of the Electron Cooling system in the Recycler Ring were completed in November 2004. The Electron Cooling system was fully commissioned in May 2005 and the first cooling of antiprotons was achieved in July 2005. This paper discusses the alignment methodology employed to survey and align the Electron Cooling system.

  19. Development of the electron gun control system of SSRF

    International Nuclear Information System (INIS)

    An electron gun is the key part of a linac, the beam quality of which depends on beam quality of the electron gun, hence the need of a stable control system of the electron gun to ensure its safe operation.In this paper, we report our progresses in developing the linac's electron gun control system of Shanghai Synchrotron Radiation Facility (SSRF). It uses PLC as the device controllers, with the monitoring software developed on EPICS. The whole system is connected by Ethernet. The PLC and Ethernet technology ensures good reliability and easy maintenance of the electron gun control system. (authors)

  20. Electron-optical systems for planar gyrotrons

    Energy Technology Data Exchange (ETDEWEB)

    Manuilov, V. N.; Zaslavsky, V. Yu.; Ginzburg, N. S.; Glyavin, M. Yu. [Institute of Applied Physics of the Russian Academy of Sciences, 46 Ul' yanov St., Nizhny Novgorod 603950 (Russian Federation); Nizhny Novgorod State University, 23 Gagarin Ave., Nizhny Novgorod 603950 (Russian Federation); Kuftin, A. N.; Zotova, I. V. [Institute of Applied Physics of the Russian Academy of Sciences, 46 Ul' yanov St., Nizhny Novgorod 603950 (Russian Federation)

    2014-02-15

    The methodology of designing an electron-optical system (EOS) that forms sheet helical electron beams (HEBs) for high-power gyrotrons is developed. As an example, we consider the EOS for a 140-GHz gyrotron operated at the first harmonic of the cyclotron frequency with an accelerating voltage of 50?kV, a beam current of 30?A, and a magnetic field compression of 36. A planar geometry of the magnetron-injection gun (MIG) is suggested. The adiabatic theory of MIGs modified for the planar geometry of EOS is used for preliminary estimations of MIG parameters. Numerical simulation of the HEB properties based on the CST STUDIO SUITE 3D code is performed to find the optimal configuration of a planar MIG. The accuracy of the calculated data is discussed. The main factors that affect the HEB quality are considered. It is shown that a sheet HEB with a pitch-factor of 1.3 and velocity spread not exceeding 25%–30% can be formed; this is quite acceptable for high-efficiency operation of modern gyrotrons. Calculation of the beam-wave interaction with the obtained HEB parameters proved that a high output power with a sufficiently good efficiency of about 20% can be reached. Simulations show the feasibility of the experimental implementation of a novel planar EOS and its use in short-wave planar gyrotrons. The developed technique can be used for the study and optimization of planar gyrotrons of different frequency bands and power levels.

  1. DNA vaccines for aquacultured fish

    DEFF Research Database (Denmark)

    Lorenzen, Niels; LaPatra, S.E.

    2005-01-01

    Deoxyribonucleic acid (DNA) vaccination is based on the administration of the gene encoding the vaccine antigen, rather than the antigen itself. Subsequent expression of the antigen by cells in the vaccinated hosts triggers the host immune system. Among the many experimental DNA vaccines tested in various animal species as well as in humans, the vaccines against rhabdovirus diseases in fish have given some of the most promising results. A single intramuscular (IM) injection of microgram amounts ...

  2. T-3 electron-beam-excited laser system

    International Nuclear Information System (INIS)

    A laser system specifically designed to study the kinetics of electron-beam driven systems is described. Details of the system are given along with measurements of the electron-beam uniformity and deposition in the laser medium. Some HF laser results obtained with this system are also given

  3. Advanced Photonic and Electronic Systems WILGA 2010

    CERN Document Server

    Romaniuk, R S

    2010-01-01

    SPIE – PSP WILGA Symposium gathers two times a year in January and in May new adepts of advanced photonic and electronic systems. The event is oriented on components and applications. WILGA Symposium on Photonics and Web Engineering is well known on the web for its devotion to “young research” promotion under the eminent sponsorship of international engineering associations like SPIE and IEEE and their Poland Sections or Counterparts. WILGA is supported by the most important national professional organizations like KEiT PAN and PSP-Photonics Society of Poland. The Symposium is organized since 1998 twice a year. It has gathered over 4000 young researchers and published over 2000 papers mainly internationally, including more than 900 in 10 published so far volumes of Proc. SPIE. This paper is a digest of WILGA Symposium Series and WILGA 2010 summary. Introductory part treats WILGA Photonics Applications characteristics over the period 1998-2010. Following part presents a short report on the XXVth and XXVI...

  4. Electronic Switching Spherical Array (ESSA) antenna systems

    Science.gov (United States)

    Hockensmith, R. P.

    1984-01-01

    ESSA (Electronic Switching Spherical Array) is an antenna system conceived, developed and qualified for linking satellite data transmissions with NASA's tracking and data relay satellites (TDRSS) and tracking and data acquisition satellites (TDAS). ESSA functions in the S band frequency region, cover 2 pi or more steradians with directional gain and operates in multiple selectable modes. ESSA operates in concert with the NASA's TDRS standard transponder in the retrodirective mode or independently in directional beam, program track and special modes. Organizations and projects to the ESSA applications for NASA's space use are introduced. Coverage gain, weight power and implementation and other performance information for satisfying a wide range of data rate requirements are included.

  5. CERN Sells its Electronic Document Handling System

    CERN Multimedia

    2001-01-01

    The EDH team. Left to right: Derek Mathieson, Rotislav Titov, Per Gunnar Jonsson, Ivica Dobrovicova, James Purvis. Missing from the photo is Jurgen De Jonghe. In a 1 MCHF deal announced this week, the British company Transacsys bought the rights to CERN's Electronic Document Handling (EDH) system, which has revolutionised the Laboratory's administrative procedures over the last decade. Under the deal, CERN and Transacsys will collaborate on developing EDH over the coming 12 months. CERN will provide manpower and expertise and will retain the rights to use EDH, which will also be available freely to other particle physics laboratories. This development is an excellent example of the active technology transfer policy CERN is currently pursuing. The negotiations were carried out through a fruitful collaboration between AS and ETT Divisions, following the recommendations of the Technology Advisory Board, and with the help of SPL Division. EDH was born in 1991 when John Ferguson and Achille Petrilli of AS Divisi...

  6. Unpaired electrons as probes of catalytic systems.

    Science.gov (United States)

    Rhodes, Christopher J

    2014-01-01

    An overview is provided of the importance of molecular species containing unpaired electrons in catalytic systems, as revealed using ESR spectroscopy. The review aims to demonstrate the considerable extent of scientific progress that has been made in this broad topic during the past few decades. Studies of catalytically active surfaces, including zeolites, are surveyed, and the detection of radical species, formed as intermediates in their reactions, using matrix isolation and spin-trapping techniques. Radical cation formation in zeolites is discussed, and the employment of muon spin rotation and relaxation techniques to study the mobility of labelled radicals in various porous and catalytic media. Among the specific types of catalytic media considered are those for photocatalysis, water splitting, degradation of environmental pollutants, hydrocarbon conversions, fuel cells and sensor devices employing graphene. The review concludes with recent developments in the study of enzymes and their reactions, using ESR-based methods. PMID:25642491

  7. Wavefunctions for large systems as basis for electronic structure calculations

    CERN Document Server

    Fulde, Peter

    2015-01-01

    Electronic structure calculations for solids based on many-electron wavefunctions have been hampered by the argument that for large electron numbers wavefunctions are not a legitimate scientific concept, because they face an exponential wall problem. We show that this problem can be avoided by using cumulant techniques in formulating wavefunctions. Therefore calculations for solids based on many-electron functions are possible and useful. This includes also systems with strongly correlated electrons.

  8. Enhancement of existing geothermal resource utilization by cascading to intensive aquaculture

    Energy Technology Data Exchange (ETDEWEB)

    Zachritz, W.H. II; Polka, R.; Schoenmackers, R.

    1995-12-04

    Aquaculture, the farming and husbandry of freshwater and marine organisms, is the newest and fastest growing US agricultural sector. In New Mexico, low winter temperatures and limited freshwater sources narrow culture production possibilities; however, it has long been recognized that the state has abundant supplies of both saline and geothermal ground waters. The purpose of this project was to demonstrate the achievable energy savings and value enhancement of the byproduct geothermal energy by cascading fluids for the production of commercial aquaculture species. Specifically the project involved evaluating the heating systems performance in terms of heating budget for the geothermal assist, determine the total quantity of water used for culture and heating, amount of geothermal byproduct heat extracted, and ability of the system to maintain culture water temperatures during critical heating periods of the year. In addition, an analysis was conducted to determine the compatibility of this new system with existing greenhouse heating requirements.

  9. CHANGING PHENOMENON OF AQUACULTURE LAND THROUGH SPACE AND TIME USING GEOINFORMATICS TECHNIQUES: A CASE STUDY OF MOYNAAND NANDAKUMAR BLOCK, PURBA MEDINIPUR, WEST BENGAL, INDIA

    Directory of Open Access Journals (Sweden)

    Nirupam Acharyya

    2015-03-01

    Full Text Available Aquaculture basically known as aqua farming that means the farming of aquatic organisms such as fish. This can be considered a sustainable land use in the same way as like the conventional terrestrial agriculture.It involves with raising fish commercially in tanks, ponds which is mainly for nutrition. Which is a highly regulated industry, and these regulations may well keep fish farming. Numbers of peoples are becoming dependent on the aquaculture system. Fundamentally, agricultural land provides space and opportunities for livelihood systems,however in many ways peoples are over-exploited land and water resources. In the present study an attempt has been made to identification and quantification of aquaculture zone occurring in the inland area of Moyna and Nandakumar Block, Purba Medinipur, West Bengal, India by using space-born Remote Sensing (RS technology, which has a good potentiality for change detection and good data availability and is consequently; well suited for the monitoring of land use change over a gap time period. The benefits of Geographic Information Systems (GIS application in aquaculture have promoted its quick expansion and as a most advantage to compare with the ground reality. The present study describes an efficient and scientific approach for aquaculture changing phenomenon with suitable illustrations of map to point out insight the respect of ground reality. The aquaculture area is delineated from satellite images through image processing technique and aquaculture zone are specially highlighted from spatially high resolution satellite images. Finally the study can shows that, the agriculture lands are highly vulnerable due to regular flooding and that land specially converted to aquaculture land

  10. Electron-electron interactions in a weakly screened two-dimensional electron system

    OpenAIRE

    Karakurt, I.; Dahm, A. J.

    2002-01-01

    We probe the strength of electron-electron interactions using magnetoconductivity measurements of two-dimensional non-degenerate electrons on liquid helium at 1.22 K. Our data extend to electron densities that are two orders of magnitude smaller than previously reported. We span both the independent-electron regime where the data are qualitatively described by the self-consistent Born approximation (SCBA), and the strongly-interacting electron regime. At finite fields we obs...

  11. Immune–potentiators for the Aquaculture

    Directory of Open Access Journals (Sweden)

    Rocmira Pérez

    2014-04-01

    Full Text Available Aquaculture represents one of the fastest–growing animal food–producing sectors worldwide. One of the main challenges is to obtain high–volume production with the highest possible quality, this leads to reduce the use of antibiotics and chemotherapeutics. A promising solution to these problems is the application of immune– potentiatiors mainly in intensive farming. This article aims to review the main immune–potentiators, as well as the trends and challenges of global use of them. It summarizes the main molecular and functional characteristics with emphasis on those most studied such as levamisole, ß-glucans, lipopolysaccharide, vitamin C, plant extracts and hormones. All these heterogeneous compounds, mostly affect the innate immunity of fish, strengthening and enhancing disease resistance and some of them additionally have anti–stress effect and promote fish growth. We conclude that immune–potentiators are a viable strategy to reduce losses for health problems in aquaculture field, however, aspects such as administration route and appropriate immunization phase for each species remains to be solved.

  12. Genomic Approaches in Marine Biodiversity and Aquaculture

    Scientific Electronic Library Online (English)

    Jorge A, Huete-Pérez; Fernando, Quezada.

    Full Text Available Recent advances in genomic and post-genomic technologies have now established the new standard in medical and biotechnological research. The introduction of next-generation sequencing, NGS,has resulted in the generation of thousands of genomes from all domains of life, including the genomes of compl [...] ex uncultured microbial communities revealed through metagenomics. Although the application of genomics to marine biodiversity remains poorly developed overall, some noteworthy progress has been made in recent years. The genomes of various model marine organisms have been published and a few more are underway. In addition, the recent large-scale analysis of marine microbes, along with transcriptomic and proteomic approaches to the study of teleost fishes, mollusks and crustaceans, to mention a few, has provided a better understanding of phenotypic variability and functional genomics. The past few years have also seen advances in applications relevant to marine aquaculture and fisheries. In this review we introduce several examples of recent discoveries and progress made towards engendering genomic resources aimed at enhancing our understanding of marine biodiversity and promoting the development of aquaculture. Finally, we discuss the need for auspicious science policies to address challenges confronting smaller nations in the appropriate oversight of this growing domain as they strive to guarantee food security and conservation of their natural resources.

  13. Genomic Approaches in Marine Biodiversity and Aquaculture

    Directory of Open Access Journals (Sweden)

    Jorge A Huete-Pérez

    2013-01-01

    Full Text Available Recent advances in genomic and post-genomic technologies have now established the new standard in medical and biotechnological research. The introduction of next-generation sequencing, NGS,has resulted in the generation of thousands of genomes from all domains of life, including the genomes of complex uncultured microbial communities revealed through metagenomics. Although the application of genomics to marine biodiversity remains poorly developed overall, some noteworthy progress has been made in recent years. The genomes of various model marine organisms have been published and a few more are underway. In addition, the recent large-scale analysis of marine microbes, along with transcriptomic and proteomic approaches to the study of teleost fishes, mollusks and crustaceans, to mention a few, has provided a better understanding of phenotypic variability and functional genomics. The past few years have also seen advances in applications relevant to marine aquaculture and fisheries. In this review we introduce several examples of recent discoveries and progress made towards engendering genomic resources aimed at enhancing our understanding of marine biodiversity and promoting the development of aquaculture. Finally, we discuss the need for auspicious science policies to address challenges confronting smaller nations in the appropriate oversight of this growing domain as they strive to guarantee food security and conservation of their natural resources.

  14. Power electronic converter systems for direct drive renewable energy applications

    DEFF Research Database (Denmark)

    Chen, Zhe

    2013-01-01

    This chapter presents power electronic conversion systems for wind and marine energy generation applications, in particular, direct drive generator energy conversion systems. Various topologies are presented and system design optimization and reliability are briefly discussed.

  15. Halophyte filter beds for treatment of saline wastewater from aquaculture.

    Science.gov (United States)

    Webb, J M; Quintã, R; Papadimitriou, S; Norman, L; Rigby, M; Thomas, D N; Le Vay, L

    2012-10-15

    The expansion of aquaculture and the recent development of more intensive land-based marine farms require efficient and cost-effective systems for treatment of highly nutrient-rich saline wastewater. Constructed wetlands with halophytic plants offer the potential for waste-stream treatment combined with production of valuable secondary plant crops. Pilot wetland filter beds, constructed in triplicate and planted with the saltmarsh plant Salicornia europaea, were evaluated over 88 days under commercial operating conditions on a marine fish and shrimp farm. Nitrogen waste was primarily in the form of dissolved inorganic nitrogen (TDIN) and was removed by 98.2 ± 2.2% under ambient loadings of 109-383 ?mol l(-1). There was a linear relationship between TDIN uptake and loading over the range of inputs tested. At peak loadings of up to 8185 ± 590 ?mol l(-1) (equivalent to 600 mmol N m(-2) d(-1)), the filter beds removed between 30 and 58% (250 mmol N m(-2) d(-1)) of influent TDIN. Influent dissolved inorganic phosphorus levels ranged from 34 to 90 ?mol l(-1), with 36-89% reduction under routine operations. Dissolved organic nitrogen (DON) loadings were lower (11-144 ?mol l(-1)), and between 23 and 69% of influent DON was removed during routine operation, with no significant removal of DON under high TDIN loading. Over the 88-day study, cumulative nitrogen removal was 1.28 mol m(-2), of which 1.09 mol m(-2) was retained in plant tissue, with plant uptake ranging from 2.4 to 27.0 mmol N g(-1) dry weight d(-1). The results demonstrate the effectiveness of N and P removal from wastewater from land-based intensive marine aquaculture farms by constructed wetlands planted with S. europaea. PMID:22818948

  16. Gender training in aquaculture in northern Vietnam. A report.

    Science.gov (United States)

    Voeten, J; Ottens, B J

    1997-01-01

    Described is a pilot project that integrated gender and technology in training and analysis in Vietnam. Many farmers in Vietnam use the VAC system of fishing, farming, and animal husbandry, which makes efficient use of resources and requires low inputs. Excess products are sold locally. Plants are used for food, fiber, and fuel. Waste products are recycled. Small ponds (under 0.5 ha) are created using rainwater. 2-8 tons/ha/year of fish are produced. The dug-out soil is used to build up gardens and house foundations as protection against flooding. Fresh water for the household comes from wells. Garden plots contain various intercropped species. Fruit trees and tuber crops are cultivated in shady areas. Timber trees and rattan are planted to form tree fences. Taro is planted around the ponds, and marsh lentils are planted on pond surfaces. Various fish feed in the top, middle, and bottom portions of ponds. Gourd is grown on trellises above the ponds. Pig manure is used for plant and fish food. Pond water, which is rich in nutrients and sludge, is used to fertilize gardens. During 1995-96, a pilot program provided training in aquaculture for poor rural women in the villages of My Xa and My Tan in Nam Ha province and Tuan Chinh and Yen Dong in Vihn Phu province in the north. The analysis identified gender relations in management, control of aquaculture, decision-making, and use of benefits. The concept of gender was explained to women in the training program. Women were more concerned with the technical training. The position of women improved in participation, decision-making, and control over benefits. The technical transfer of knowledge was viewed as less important than gender awareness. The aim to improve women's position should be clearly identified. Community participation in the training of trainers was beneficial. Follow-up activities continued during 1997-99. PMID:12179940

  17. Feasibility analysis of the utilization of moderator heat for agricultural and aquacultural purposes, Bruce nuclear power development

    International Nuclear Information System (INIS)

    A study is presented of the feasibility of using moderator reject heat from the Bruce nuclear power development either to heat greenhouses or to aid in a warm water hatchery or aquaculture operation. The study examines heat extraction and delivery plans, reliability of supply, pricing schedules, the Ontario greenhouse industry, site selection criteria, water transmission and distribution, costs, approvals required, and a construction timetable. Total system analysis shows that a greenhouse facility would be viable but the aquaculture/hatchery scheme is more cost-effective. (E.C.B.)

  18. Salmon aquaculture and antimicrobial resistance in the marine environment.

    Science.gov (United States)

    Buschmann, Alejandro H; Tomova, Alexandra; López, Alejandra; Maldonado, Miguel A; Henríquez, Luis A; Ivanova, Larisa; Moy, Fred; Godfrey, Henry P; Cabello, Felipe C

    2012-01-01

    Antimicrobials used in salmon aquaculture pass into the marine environment. This could have negative impacts on marine environmental biodiversity, and on terrestrial animal and human health as a result of selection for bacteria containing antimicrobial resistance genes. We therefore measured the numbers of culturable bacteria and antimicrobial-resistant bacteria in marine sediments in the Calbuco Archipelago, Chile, over 12-month period at a salmon aquaculture site approximately 20 m from a salmon farm and at a control site 8 km distant without observable aquaculture activities. Three antimicrobials extensively used in Chilean salmon aquaculture (oxytetracycline, oxolinic acid, and florfenicol) were studied. Although none of these antimicrobials was detected in sediments from either site, traces of flumequine, a fluoroquinolone antimicrobial also widely used in Chile, were present in sediments from both sites during this period. There were significant increases in bacterial numbers and antimicrobial-resistant fractions to oxytetracycline, oxolinic acid, and florfenicol in sediments from the aquaculture site compared to those from the control site. Interestingly, there were similar numbers of presumably plasmid-mediated resistance genes for oxytetracycline, oxolinic acid and florfenicol in unselected marine bacteria isolated from both aquaculture and control sites. These preliminary findings in one location may suggest that the current use of large amounts of antimicrobials in Chilean aquaculture has the potential to select for antimicrobial-resistant bacteria in marine sediments. PMID:22905164

  19. Key Performance Characteristics of Organic Shrimp Aquaculture in Southwest Bangladesh

    Directory of Open Access Journals (Sweden)

    Christian Reinhard Vogl

    2012-05-01

    Full Text Available In Bangladesh, black tiger shrimp (Penaeus monodon; Fabricius, 1798 aquaculture has come to be one of the most important sectors in both the rural and national economies. Likewise, organic shrimp aquaculture has emerged as an alternative farming enterprise for farmers especially in the southwestern districts of Bangladesh. The present study aims to show key performance characteristics of organic shrimp farmers and farming in a prototypical shrimp farming area in Bangladesh. Data was collected in 2009 from organic shrimp farmers in the Kaligonj and Shyamnagar sub-districts through questionnaire interviews, transect walks and focus group discussions. The mean productivity of organic shrimp farming in the area is 320 kg ha?1 yr?1 (ranging from 120 to 711 kg ha?1year?1. Organic farmers are more likely to have a higher monthly income and less aquaculture experience. Moreover, suitable landholdings and classified labor distribution have been found to play an important role in the development of organic shrimp aquaculture. The most common assets of organic shrimp aquaculture are high yield, low production cost, available post larvae and high market prices. Small business farmers are likely to earn more income benefits from organic shrimp aquaculture than their larger-scale counterparts. Finally, the paper suggests that more research is needed to stimulate the success of organic shrimp aquaculture.

  20. Duke Electronic Mail Post Office A Practical Mail Linking System*

    OpenAIRE

    Dryfoos, James D.; Hammond, William E; Spero, Laurence A.; Rabold, Jean S.; Straube, Mark J.; Stead, William W

    1988-01-01

    This paper describes a system designed to integrate the many different electronic mail systems in use throughout Duke University. The Duke Electronic Mail Post Office project is part of Duke University Medical Center's model for Achieving an Integrated Academic Information Management System (IAIMS).