WorldWideScience
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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...

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Partitioned pond aquaculture systems  

Science.gov (United States)

World aquaculture is dominated by the use of simple earthen ponds in which suitable water quality is maintained by photosynthetic processes. Relying upon sunlight to maintain water quality offers the lowest cost and most sustainable approach to fish or shellfish production, which explains the popula...

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

Science.gov (United States)

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…

Lanier, James A.; And Others

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Aquaculture and geothermal heat pump systems  

Energy Technology Data Exchange (ETDEWEB)

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.

Chiasson, Andrew

2005-01-01

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The potential of periphyton-based aquaculture production systems  

OpenAIRE

Key words : Periphyton; Biofilm; Artificial substrates; Pond productivity; Tropical aquaculture; Monoculture; Polyculture; Fertilization; Proximate composition; Stocking ratio; Stable isotope ratio; Nutrient efficiency; Production economics; Indian major carps; Catla catla ; Labeo rohita ; Labeo gonius ; Labeo calbasu . The overall objective of this study was to determine the technical and economical performance of periphyton-based aquaculture systems in Bangladesh. It thus addressed one of ...

Ul Azim, M. E.

2001-01-01

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Aquaculture Network Information Center  

Science.gov (United States)

Given the declining schools of fish in many of the world's oceans, interest in aquaculture has grown exponentially in the past few years. The Aquaculture Network Information Center (ANIC) serves as an electronic gateway to thousands of online aquaculture-related resources, and is hosted by Purdue University and the University of Illinois through the Illinois - Indiana Sea Grant College Program. ANIC was started in 1994, and currently contains links to hundreds of aquaculture publications from around the globe, visual media (such as Power Point presentations), calendars of germane conferences and events, and specialty sections for species and production systems. From the ANIC home page, visitors may join discussion groups about aquaculture (organized by species), learn about different aquaculture cultivation systems, and peruse recent and archive publications from the relevant federal, state, and international agencies. For aquaculture neophytes, a FAQ section will answer ever quandary possible about the world of pond management, the perplexity of pond construction, and the inevitable debates surrounding which form of aquaculture production is most appropriate for different regions of the world.

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ALTERNATIVE PRACTICE FROM COASTAL POND TO RECIRCULATION AQUACULTURE SYSTEM  

Directory of Open Access Journals (Sweden)

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.

Ludi Parwadani Aji

2012-02-01

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Solar energy system design for a lobster aquaculture facility  

Energy Technology Data Exchange (ETDEWEB)

In aquaculture, as in most manufacturing processes, the operating cost is greatly dependent upon the cost of energy. The objectives were to: (a) analyze the power requirements for a lobster aquaculture plant, and (b) to evaluate the use of solar energy as a cost reduction measure in plant operation. A flat plate collector system capable of supplying heat alone was compared with a total energy system in which both electrical power and heat were supplied. The flat plate collector was not cost effective because when heat was needed in December, the least amount of heat was available from solar radiation. Therefore, the collector area and cost were prohibitive. However, the total energy system was cost effective when the capital investment was amortized over ten or more years. The optimum solar power plant was designed to provide 100% of the average yearly power demands, or 60% of the December power requirement. This plant would consist of 60,000 square feet of mirror surface (3.5 acres of land for 40% packing density) which would concentrate 1500 to 2000 suns on a receiver mounted on an 85 foot tower. In the tower would be the three storage stoves which would contain the heat required to operate a 343 KWe Brayton gas turbine engine and alternator for 27 hours. Equipment to generate 3 million kw-hr annually will cost an estimated $1.3 million.

1977-09-30

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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.

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

Directory of Open Access Journals (Sweden)

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.

A. N.A. Faiz

2010-01-01

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Effect of Wind-solar Complementary Increasing Oxygen System in Aquaculture  

Directory of Open Access Journals (Sweden)

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.

Guodong You

2013-12-01

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Microscreen effects on water quality in replicated recirculating aquaculture systems  

DEFF Research Database (Denmark)

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

Fernandes, Paulo; Pedersen, Lars-Flemming

2014-01-01

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Microbial communities of recirculating aquaculture facilities: interaction between heterotrophic and autotrophic bacteria and the system itself  

OpenAIRE

Les systèmes d'aquaculture en circuit recirculé (Recirculating Aquaculture Systems, RAS) peuvent être considérés comme une alternative à la technologie de l'aquaculture en milieu ouvert et en bassins (en consommant moins d'eau pour un même rendement de production) ou peuvent être intégrés dans une chaîne de production avec des systèmes d'enclos en filet. L'intérêt des RAS est dû à leurs avantages intrinsèques comme la réduction des besoins en surface et en eau, le haut ni...

Michaud, Luigi

2007-01-01

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Nutrient fate in aquacultural systems for waste treatment  

Energy Technology Data Exchange (ETDEWEB)

Twelve small, recirculating aquacultural systems were operated for livestock waste treatment to determine nutrient fate. Each system consisted of a 730-L fish tank coupled in a recirculating loop with three sand beds (serving as biofilters) in parallel. Fish (Tilapia species) were grown in the tanks while cattails, reed canary grass, and tomatoes were grown in separate sand beds. Swine waste was added to the fish tanks every other day at average rates of 50, 72, 95, and 118 kg-COD/ha/day of fish tank surface (three replications of each loading rate). Water from the fish tanks was filtered through the sand beds three times per day with 20% of the tank volume passing through the sand each day. The systems were operated in a greenhouse for eight months (21 July to 8 March). Aboveground plant matter was harvested at eight-week intervals. The fish were removed after four months and the tanks were restocked with fingerlings. Initial and final nitrogen (N), phosphorus (P), and potassium (K) contents of the system components, as well as that of the harvested plants and fish, were determined. Nutrient balance calculations revealed that 30 to 68% of added N was lost from the systems, probably via denitrification. Nutrient removal by plants was 6 to 18% for N, 8 to 21% for P, and 25 to 71% for K, with tomatoes (foliage and fruit) accounting for the majority of the removal. Plant growth was limited by growing conditions (particularly day length), not be nutrient availability. Fish growth was limited by temperature; thus nutrient extraction by the fish was minimal. Under the conditions of this experiment, the system required supplemental aeration.

Dontje, J.H.; Clanton, C.J.

1999-08-01

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Geothermal aquaculture project: Real Property Systems Inc. , Harney Basin, Oregon  

Energy Technology Data Exchange (ETDEWEB)

Real Property Systems Inc., (RPS) owns two parcels in the vicinity of Harney Lake, Oregon. One parcel is 120 acres in size, the other is 200 acres. A study concludes that the 200 acre parcel has the greater potential for geothermal development. RPS is interested in an aquaculture operation that produces fresh water prawns, (Macrobrachium rosenbergii) for the market. To supply the heat necessary to maintain the ideal temperature of 82/sup 0/F desired for these prawns, a geothermal resource having a 150/sup 0/F temperature or higher, is needed. The best estimate is that 150/sup 0/F water can be found from a minimum 1090 feet depth to 2625 feet, with no absolute assurances that sufficient quantities of geothermal waters exist without drilling for the same. This study undertakes the preliminary determination of project economics so that a decision can be made whether or not to proceed with exploratory drilling. The study is based on 10 acres of ponds, with a peak requirement of 2500 gpm of 150/sup 0/F geothermal water.

1981-08-14

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LCA and emergy accounting of aquaculture systems: towards ecological intensification.  

Science.gov (United States)

An integrated approach is required to optimise fish farming systems by maximising output while minimising their negative environmental impacts. We developed a holistic approach to assess the environmental performances by combining two methods based on energetic and physical flow analysis. Life Cycle Assessment (LCA) is a normalised method that estimates resource use and potential impacts throughout a product's life cycle. Emergy Accounting (EA) refers the amount of energy directly or indirectly required by a product or a service. The combination of these two methods was used to evaluate the environmental impacts of three contrasting fish-farming systems: a farm producing salmon in a recirculating system (RSF), a semi-extensive polyculture pond (PF1) and an extensive polyculture pond (PF2). The RSF system, with a low feed-conversion ratio (FCR = 0.95), had lower environmental impacts per tonne of live fish produced than did the two pond farms, when the effects on climate change, acidification, total cumulative energy demand, land competition and water dependence were considered. However, RSF was clearly disconnected from the surrounding environment and depended highly on external resources (e.g. nutrients, energy). Ponds adequately incorporated renewable natural resources but had higher environmental impacts due to incomplete use of external inputs. This study highlighted key factors necessary for the successful ecological intensification of fish farming, i.e., minimise external inputs, lower the FCR, and increase the use of renewable resources from the surrounding environment. The combination of LCA and EA seems to be a practical approach to address the complexity of optimising biophysical efficiency in aquaculture systems. PMID:23531606

Wilfart, Aurélie; Prudhomme, Jehane; Blancheton, Jean-Paul; Aubin, Joël

2013-05-30

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Aquaculture; Acquacoltura  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1998-12-01

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An integrated fish-plankton aquaculture system in brackish water.  

Science.gov (United States)

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 heudelotii and the unicellular alga Chlorella sp. Feed addition in this ecosystem results in faster fish growth but also in an increase in phytoplankton biomass, which must be limited. In the prototype described here, the algal population control is exerted by herbivorous zooplankton growing in a separate pond connected in parallel to the fish-algae ecosystem. The zooplankton production is then consumed by tilapia, particularly by the fry and juveniles, when water is returned to the main circuit. Chlorella sp. and Brachionus plicatilis are two planktonic species that have spontaneously colonized the brackish water of the prototype, which was set-up in Senegal along the Atlantic Ocean shoreline. In our system, water was entirely recycled and only evaporation was compensated (1.5% volume/day). Sediment, which accumulated in the zooplankton pond, was the only trophic cul-de-sac. The system was temporarily destabilized following an accidental rotifer invasion in the main circuit. This caused Chlorella disappearance and replacement by opportunist algae, not consumed by Brachionus. Following the entire consumption of the Brachionus population by tilapias, Chlorella predominated again. Our artificial ecosystem combining S. m. heudelotii, Chlorella and B. plicatilis thus appeared to be resilient. This farming system was operated over one year with a fish productivity of 1.85 kg/m2 per year during the cold season (January to April). PMID:23031842

Gilles, S; Fargier, L; Lazzaro, X; Baras, E; De Wilde, N; Drakidès, C; Amiel, C; Rispal, B; Blancheton, J-P

2013-02-01

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ALTERNATIVE PRACTICE FROM COASTAL POND TO RECIRCULATION AQUACULTURE SYSTEM  

OpenAIRE

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...

Ludi Parwadani Aji

2012-01-01

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Measuring System for Growth Control of the Spirulina Aquaculture  

Science.gov (United States)

It describes the workings of a data-logging instrument that measures growth levels of the Spirulina aquaculture. The Spirulina is a very delicate algae and its culture may be suddenly lost due to overgrowth. This kind of instrument is not at present available in the market. The transduction is a submergible laser device whose measuring margin of error is near to 0.28%. The advantage of this new instrument is the improvement in the measurement and the low cost. The future application of this work is related to the industrial production of food and fuel from micro algae culture, for the growing world population.

Ponce S., Claudio; Ponce L., Ernesto; Bernardo S., Barraza

2008-11-01

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Low-dose hydrogen peroxide application in closed recirculating aquaculture systems  

Science.gov (United States)

The aim of the present work was to simulate water treatment practice with hydrogen peroxide (HP) in recirculating aquaculture systems (RAS). Six identical 1700 L pilot scale RAS were divided into two experimental groups based on daily feed allocation and were operated under constant conditions durin...

22

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

OpenAIRE

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.

Mandal, Shovon; Mallick, Nirupama

2012-01-01

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Biodiesel production by the green microalga Scenedesmus obliquus in a recirculatory aquaculture system.  

Science.gov (United States)

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

Mandal, Shovon; Mallick, Nirupama

2012-08-01

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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...

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

Directory of Open Access Journals (Sweden)

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.

Gu Li

2012-10-01

26

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

DEFF Research Database (Denmark)

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.

Jepsen, Per Meyer; HØjgaard, Jacob Kring

27

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

OpenAIRE

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...

Bergquist, Daniel A.

2008-01-01

28

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

Science.gov (United States)

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 efficiencies 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

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

2015-01-01

29

A ZigBee Wireless Sensor Network for Monitoring an Aquaculture Recirculating System  

Directory of Open Access Journals (Sweden)

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.

Francisco J. Espinosa-Faller

2012-06-01

30

Electronics and electronic systems  

CERN Document Server

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

Olsen, George H

1987-01-01

31

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

Directory of Open Access Journals (Sweden)

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.

A. M. Snow

2008-01-01

32

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

OpenAIRE

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 waste...

Snow, A. M.; Ghaly, Abdel E.

2008-01-01

33

In situ estimation of water quality parameters in freshwater aquaculture ponds using hyperspectral imaging system  

Science.gov (United States)

Knowledge of water quality parameters is integral to sustainability of freshwater aquaculture operations that raise ornamental fish. Our objective in this study is to evaluate the ability of a mobile, ground-based hyperspectral (HS) imaging sensor to determine chlorophyll-a (Chl-a) concentrations in working aquaculture ponds, which represent manipulated, shallow, nutrient-rich systems, and to determine the effect of using submerged reflectance targets on the accuracy of Chl-a estimation. We collected Chl-a measurements from aquaculture ponds ranging from 0.8 to 494 ?g/L. Chl-a measurements showed a strong correlation with two-band and three-band spectral indices computed from the HS image reflectance. Coefficient of determination ( R2) values of 0.975 and 0.982 were obtained for the two- and three-band models, respectively, using spectra captured from the submerged target at 10 cm depth. Using spectra captured from water (no submerged targets), R2 values were slightly lower at 0.833 and 0.862 for two- and three-band models. Data from the submerged target at 30 cm depth had the lowest correlation with measured chlorophyll-a concentrations, potentially due to variations in water column properties and shadows cast by the platform. Modeling total Phosphorous (P) and Nitrogen (N) concentrations of the collected samples with the spectral indices sensitive to Chl-a concentrations showed a moderate level of correlation. Removing a model outlier (observation with maximum N and P concentrations) led to a significant increase in the models' coefficient of determination ( e.g. from 0.478 to 0.823 for the P model using three-band index values), which highlighted the possibility of using HS imagery to estimate N and P concentrations and the need for more research to model the interrelationships between Chl-a and nutrient concentrations in aquaculture water systems.

Abd-Elrahman, Amr; Croxton, Matthew; Pande-Chettri, Roshan; Toor, Gurpal S.; Smith, Scot; Hill, Jeffrey

34

Aquaculture Production and Biodiversity Conservation  

Science.gov (United States)

This overview examines the status and trends of seafood production, and the positive and negative impacts of aquaculture on biodiversity conservation. Capture fisheries have been stabilized at about 90 million metric tons since the late 1980s, whereas aquaculture increased from 12 million metric tons in 1985 to 45 million metric tons by 2004. Aquaculture includes species at any trophic level that are grown for domestic consumption or export. Aquaculture has some positive impacts on biodiversity; for example, cultured seafood can reduce pressure on overexploited wild stocks, stocked organisms may enhance depleted stocks, aquaculture often boosts natural production and species diversity, and employment in aquaculture may replace more destructive resource uses. On the negative side, species that escape from aquaculture can become invasive in areas where they are nonnative, effluents from aquaculture can cause eutrophication, ecologically sensitive land may be converted for aquaculture use, aquaculture species may consume increasingly scarce fish meal, and aquaculture species may transmit diseases to wild fish. Most likely, aquaculture will continue to grow at significant rates through 2025, and will remain the most rapidly increasing food production system.

James Diana (University of Michigan; School of Natural Resources and Environment)

2009-01-01

35

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

DEFF Research Database (Denmark)

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

Pedersen, Lars-Flemming

2009-01-01

36

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

DEFF Research Database (Denmark)

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.

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

2014-01-01

37

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

DEFF Research Database (Denmark)

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 matter content and initial PAA dosage on the chemical fate of PAA is reported. Furthermore, investigations of water sanitation with PAA application were used to analytically verify actual PAA concentration under real conditions at different kinds of aquaculture systems. A characteristic instant disinfection demand was found to be significantly positively related to water COD content, and PAA half-lives were found to be in the order of a few minutes. The study revealed that PAA degrades so rapidly that insufficient disinfection is a likely outcome. The observations have applications for optimizing water treatment strategies with PAA. The investigations also indicated that the rapid degradation and hence swift presence of PAA in RAS made raceway disinfection possible without bypassing the biofilters. Future perspectives, benefits and drawbacks on the use of PAA in RAS are discussed

Pedersen, Lars-Flemming

2011-01-01

38

Background paper on aquaculture research  

DEFF Research Database (Denmark)

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

Wenblad, Axel; Jokumsen, Alfred

2013-01-01

39

A Model for an Intelligent Support Decision System in Aquaculture  

OpenAIRE

The paper purpose an intelligent software system agents–based to support decision in aquculture and the approach of fish diagnosis with informatics methods, techniques and solutions. A major purpose is to develop new methods and techniques for quick fish diagnosis, treatment and prophyilaxis at infectious and parasite-based known disorders, that may occur at fishes raised in high density in intensive raising systems. But, the goal of this paper is to presents a model of an intelligent agent...

Novac Ududec, Cornelia C.

2009-01-01

40

Particle size distribution in the tilapia Recirculating Aquaculture System  

OpenAIRE

This study was to evaluate methods for measuring and describing particle size distribution from three different spots in Tilapia recirculating system at University of Life Ccience in Ås, Norway. For this purpose serial filtration over different mesh size and parallel filtration over different mesh size methods were compared. Water samples were taken from before drum filter, after drum filter and after bio-filter (MBBR) and filtrated through eight different mesh size classes and calculated in...

Stokic, Jelena

2012-01-01

41

Removal efficiency and balance of nitrogen in a recirculating aquaculture system integrated with constructed wetlands.  

Science.gov (United States)

The nitrogen (N) balance for aquaculture is an important aspect, especially in China, and it is attributed to the eutrophication in many freshwater bodies. In recent years, constructed wetlands (CWs) have been widely used in wastewater treatment and ecosystem restoration. A recirculating aquaculture system (RAS) consisting of CWs and 4 fish ponds was set up in Wuhan, China. Channel catfish (Ictalurus punctatus) fingerlings were fed for satiation daily for 168 days with 2 diets containing 5.49 % and 6.53 % nitrogen, respectively. The objectives of this study were to investigate the N budget in the RAS, and try to find out the feasibility of controlling N accumulation in the fish pond. It is expected that the study can provide a mass balance for the fate of N in the eco-friendly treatment system to avoid eutrophication. The results showed that the removal rates of ammonia (NH(+)(4)-N), sum of nitrate & nitrite (NO(-)(X)-N), and total nitrogen (TN) by the CWs were 20-55%, 38-84 % and 39-57 %, respectively. Denitrification in the CWs was the main pathway of nitrogen loss (41.67 %). Nitrogen accumulation in pond water and sediment accounted for 3.39 % and 12.65 % of total nitrogen loss, respectively. The nitrogen removal efficiency and budget showed that the CW could be used to control excessive nitrogen accumulation in fish ponds. From the viewpoint of the nitrogen pollution control, the RAS combined with the constructed wetland can be applied to ensure the sustainable development for aquaculture. PMID:21644158

Zhong, Fei; Liang, Wei; Yu, Tao; Cheng, Shui P; He, Feng; Wu, Zhen B

2011-01-01

42

Program to monitor and evaluate a passive solar greenhouse/aquaculture system. Final report  

Energy Technology Data Exchange (ETDEWEB)

A temperature monitoring program of Amity's solar greenhouse demonstrated that air, soil, and water temperatures can be maintained at optimal levels without supplemental heat. A foil reflector placed in front of the greenhouse glazing at an angle of between 0 and 5/sup 0/ above horizontal enhanced direct light entering the greenhouse by as much as 22%. Aquaculture in the water heat storage of a solar greenhouse has been a success. Fish reached harvest size in about seven months. The two species that were received the best by the public were African perch (Tilapia mossambica) and channel catfish (Ictalurus punctatus). Although carp (Cyprinus carpio) were the fastest growers they were not well received by the public. Linking hydroponics to greenhouse aquaculture shows a lot of promise. Different support medias were examined and tomatoes and European cucumbers were raised successfully. A savonius windmill was successfully linked to an aquaculture aeration system but because of the wind pattern in the Willamette valley the windmill system did not provide air in the evening when it was needed most. Alternate designs are discussed. Locally grown fish diets were evaluated for their ability to promote fish growth. Diets such as water hyacinth, duckweed, earthworms, beans, and comfrey were raised on the Amity site, pelleted with a hand grinder and solar dried. Duckweed and earthworms appear to hold promise for a nutritous, easy to grow and pelletize, food source. Amity's solar greenhouse, three coldframe designs and a PVC tunnel cloche were compared in a vegetable growing trial. Most impressive was the cloche design because it provided adequate protection, was inexpensive and very easy to build.

1982-01-01

43

Aquaculture Network Information Center (AquaNIC)  

Science.gov (United States)

Links to national and international level electronic resources for aquaculture information including: scientific institutions, agencies, industries, news, newsletters, job listings, discussion groups, courses, species, publications, and commercial products. Goals include: providing self-paced aquaculture instruction to the aquaculture industry, and obtaining user input in directing AquaNIC services. A version in Spanish is being prepared.

44

The accumulation of substances in Recirculating Aquaculture Systems (RAS) affects embryonic and larval development in common carp Cyprinus carpio  

OpenAIRE

The accumulation of substances in Recirculating Aquaculture Systems (RAS) may impair the growth and welfare of fish. To test the severity of contaminants accumulated in RAS, early-life stages of fish were used. Ultrafiltered water from two Recirculating Aquaculture Systems (RAS), one RAS with a high accumulation of substances (water exchange rate 30 L/kg feed/day) and one RAS with a low accumulation of substances (water exchange rate 1500 L/kg feed/day), was used to incubate eggs and rear lar...

Martins, C. I.; Pristin, M. G.; Ende, S. S. W.; Eding, E. H.; Verreth, J. A. J.

2009-01-01

45

Abundance, diversity and seasonal dynamics of predatory bacteria in aquaculture zero discharge systems.  

Science.gov (United States)

Standard aquaculture generates large-scale pollution and strains water resources. In aquaculture using zero discharge systems (ZDS), highly efficient fish growth and water recycling are combined. The wastewater stream is directed through compartments in which beneficial microbial activities induced by creating suitable environmental conditions remove biological and chemical pollutants, alleviating both problems. Bacterial predators, preying on bacterial populations in the ZDS, may affect their diversity, composition and functional redundancy, yet in-depth understanding of this phenomenon is lacking. The dynamics of populations belonging to the obligate predators Bdellovibrio and like organisms (BALOs) were analyzed in freshwater and saline ZDS over a 7-month period using QPCR targeting the Bdellovibrionaceae, and the Bacteriovorax and Bacteriolyticum genera in the Bacteriovoracaeae. Both families co-existed in ZDS compartments, constituting 0.13-1.4% of total Bacteria. Relative predator abundance varied according to the environmental conditions prevailing in different compartments, most notably salinity. Strikingly, the Bdellovibrionaceae, hitherto only retrieved from freshwater and soil, also populated the saline system. In addition to the detected BALOs, other potential predators were highly abundant, especially from the Myxococcales. Among the general bacterial population, Flavobacteria, Bacteroidetes, Fusobacteriaceae and unclassified Bacteria dominated a well mixed but seasonally fluctuating diverse community of up to 238 operational taxonomic units, as revealed by 16S rRNA gene sequencing. PMID:24749684

Kandel, Prem P; Pasternak, Zohar; van Rijn, Jaap; Nahum, Ortal; Jurkevitch, Edouard

2014-07-01

46

Oxygen Consumption of Tilapia and Preliminary Mass Flows through a Prototype Closed Aquaculture System  

Science.gov (United States)

Performance of NASA's prototype CELSS Breadboard Project Closed Aquaculture System was evaluated by estimating gas exchange quantification and preliminary carbon and nitrogen balances. The total system oxygen consumption rate was 535 mg/hr kg/fish (cv = 30%) when stocked with Tilapia aurea populations (fresh weights of 97 +/- 19 to 147 +/- 36 g/fish for various trials). Oxygen consumption by T. aurea (260 mg/hr kg/fish) contributed to approximately one-half of total system demand. Continuous carbon dioxide quantification methods were analyzed using the,relation of carbon dioxide to oxygen consumption. Overall food conversion rates averaged 18.2 +/- 3.2%. Major pathways for nitrogen and carbon in the system were described with preliminary mass closure of 60-80% and 60% for nitrogen and carbon.

Muller, Matthew S.; Bauer, Clarence F.

1994-01-01

47

Peracetic acid degradation in freshwater aquaculture systems and possible practical implications  

DEFF Research Database (Denmark)

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

Pedersen, Lars-Flemming; Meinelt, Thomas

2013-01-01

48

A ZigBee Wireless Sensor Network for Monitoring an Aquaculture Recirculating System  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: English Abstract in spanish 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.

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

2012-12-01

49

Holographic Aquaculture  

Science.gov (United States)

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.

Ian, Richard; King, Elisabeth

1988-01-01

50

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 harvess. 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

51

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

52

Low-dose hydrogen peroxide application in closed recirculating aquaculture systems  

DEFF Research Database (Denmark)

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

Pedersen, Lars-Flemming; Good, C.

2012-01-01

53

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

DEFF Research Database (Denmark)

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

Fernandes, Paulo; Pedersen, Lars-Flemming

2014-01-01

54

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)

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)

Smith, K.

1984-09-01

55

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

OpenAIRE

  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. T...

Nhan, D. K.

2007-01-01

56

Biomass production and nitrogen dynamics in an integrated aquaculture/agriculture system  

Science.gov (United States)

A combined aquaculture/agriculture system that brings together the three major components of a Controlled Ecological Life Support System (CELSS) - biomass production, biomass processing, and waste recycling - was developed to evaluate ecological processes and hardware requirements necessary to assess the feasibility of and define design criteria for integration into the Kennedy Space Center (KSC) Breadboard Project. The system consists of a 1 square meter plant growth area, a 500 liter fish culture tank, and computerized monitoring and control hardware. Nutrients in the hydrophonic solution were derived from fish metabolites and fish food leachate. In five months of continuous operation, 27.0 kg of lettuce tops, 39.9 kg of roots and biofilm, and 6.6 kg of fish (wet weights) were produced with 12.7 kg of fish food input. Based on dry weights, a biomass conversion index of 0.52 was achieved. A nitrogen budget was derived to determine partitioning of nitrogen within various compartments of the system. Accumulating nitrogen in the hypoponic solution indicated a need to enlarge the plant growth area, potentially increasing the biomass production and improving the biomass conversion index.

Owens, L. P.; Hall, C. R.

1990-01-01

57

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

OpenAIRE

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...

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

2010-01-01

58

Aquaculture Knowledge Environment  

Science.gov (United States)

An information and communication resource for aquaculture professionals. Advances knowledge and information sharing about the science, policy, and practice of aquaculture. Includes an aquaculture documents library, with technical resources and publications from several countries, research consortia and academic journals. Topics covered include aquaculture species, practices and technology, aquaculture research, policy and regulation issues.

59

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

Directory of Open Access Journals (Sweden)

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.

Edward H Allison

2007-12-01

60

Improving methane production and phosphorus release in anaerobic digestion of particulate saline sludge from a brackish aquaculture recirculation system.  

Science.gov (United States)

In this study, batch tests were conducted to examine the effects of trehalose and glycine betaine as well as potassium on the specific methanogenic activity (SMA), acid and alkaline phosphatase activity of anaerobic biomass and phosphorus release in anaerobic digestion of saline sludge from a brackish recirculation aquaculture system. The results of ANOVA and Tukey's HSD (honestly significant difference) tests showed that glycine betaine and trehalose enhanced SMA of anaerobic biomass and reactive phosphorus release from the particulate waste. Moreover, SMA tests revealed that methanogenic sludge, which was long-term acclimatized to a salinity level of 17 g/L was severely affected by the increase in salinity to values exceeding 35 g/L. Addition of compatible solutes, such as glycine betaine and trehalose, could be used to enhance the specific methane production rate and phosphorus release in anaerobic digestion from particulate organic waste produced in marine or brackish aquaculture recirculation systems. PMID:24785791

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

2014-06-01

61

Inorganic nitrogen control in a novel zero-water exchanged aquaculture system integrated with airlift-submerged fibrous nitrifying biofilters.  

Science.gov (United States)

This work examined the feasibility of applying shrimp diets to establish nitrification on submerged fibrous biofilters. It also investigated the performance of a proposed zero-water exchanged aquaculture system, which integrated growing of aquatic stocks and operation of acclimated biofilters in the same environment. Addition of shrimp diets fully established nitrification within 3 weeks as indicated by continuous increase of nitrate and trivial levels of ammonium and nitrite. A series of batch experiment revealed an average ammonium degradation rate of 24.1mg Nm(-2) day(-1). Zero-water discharged tilapia cultivation could be carried out in the proposed aquaculture system for at least 44 days when daily inorganic loadings increased from 1.24 to 10.78mg Nl(-1) day(-1). The corresponding daily growth rates of tilapia from the proposed aquaculture systems integrated with acclimated biofilters varied from 3.01 to 3.35g day(-1), which was approximately 7-16% better than numbers from the systems using non-acclimated biofilters. PMID:19036581

Sesuk, Thanathon; Powtongsook, Sorawit; Nootong, Kasidit

2009-03-01

62

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

OpenAIRE

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...

Eriksson, Hampus

2012-01-01

63

Building and Using a Hydroponic/Aquaculture System in the Classroom  

Science.gov (United States)

Details for constructing a hydroponic / aquaculture system are shared. I have used the apparatus for the past six years in my class with excellent results. A 100 gallon aquarium serves as our fish farm. Teams of students monitor the change in biomass of the fish population, (usually Tilapia). They also maintain records of the amount of high protein floating fish food consumed. As aquaculturists they try to develop a feeding regime that will maximize the fishes' growth. Water from this tank containing the fishes' metabolic wastes is pumped every thirty minutes through a series of five hydroponic tubes filled with lava rock. Seedlings in Jiffy 7 peat pots are inserted into circular holes in the tubes. This soil-less garden can support about forty plants. We have grown many varieties of lettuce, spinach, herbs, tomatoes, cucumbers, jalapeno peppers, as well as many types of flowers. In addition, climbing plants such as morning glories or four o'clocks or nasturtia are grown directly from the surface of the aquarium by inserting Jiffy 7 pots into floating Styrofoam. These are supported so they arch across the ceiling. While in use the system can be used to visually demonstrate many important scientific principles from a variety of disciplines such as, animal and plant physiology, microbiology, and, of course, ecology.

Ernest Nicol (Newton North High School REV)

1995-06-30

64

Escherichia coli contamination of fish raised in integrated pig-fish aquaculture systems in Vietnam.  

Science.gov (United States)

Integrated livestock-fish aquaculture utilizes animal excreta and urine as pond fertilizers to enhance growth of plankton and other microorganisms eaten by the fish. In Vietnam, pigs are commonly integrated with fish and horticulture in household-based VAC systems (vuon = garden; ao = pond; chuong = pigsty), but the level of fecal contamination in the fish produced is unknown. This study was carried out to assess the level Escherichia coli contamination of fish meat and gut contents of grass carp (Ctenopharyngodon idellus), silver carp (Hypophthalmichthys molitrix), and rohu (Labeo rohita) cultured in randomly selected five VAC ponds (with pig manure) and five non-VAC ponds (without pig manure) at sites in periurban Hanoi, Vietnam. Fish muscle tissue samples contained E. coli at carp, grass carp, and rohu, respectively, about 100 times higher than the contamination of fish from the control ponds. The results indicate that muscle tissue of fish raised in VAC systems has a low level of fecal contamination despite high levels of E. coli in their gut. Thus, a critical point to control food safety of such fish is the prevention of fecal cross-contamination during degutting and cleaning of the fish at markets and in the home. PMID:22980016

Dang, Son Thi Thanh; Dalsgaard, Anders

2012-07-01

65

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

Directory of Open Access Journals (Sweden)

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.

Sudeep Puthravilakom Sadasivan Nair

2010-08-01

66

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

Science.gov (United States)

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

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

2014-12-01

67

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

DEFF Research Database (Denmark)

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.

MØller, Martin Sune; Arvin, Erik

2010-01-01

68

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

DEFF Research Database (Denmark)

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.

Suhr, Karin Isabel; Pedersen, Lars-Flemming

2014-01-01

69

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

Directory of Open Access Journals (Sweden)

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.

Corina Sion

2011-04-01

70

Expanded concept of aquaculture  

Directory of Open Access Journals (Sweden)

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.

Melnikov Victor Nickolaevich

2012-11-01

71

Aquaculture information package  

Energy Technology Data Exchange (ETDEWEB)

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.

Boyd, T.; Rafferty, K.

1998-08-01

72

Effect of oxidation–reduction potential on performance of European sea bass (Dicentrarchus labrax) in recirculating aquaculture systems  

OpenAIRE

The direct impact of oxidation–reduction potential (ORP) on fish welfare and water quality in marine recirculating aquaculture systems (RAS) is poorly documented. In this study, the effects of the fish size (S1, S2, S3) and ORP level (normal, four successive levels) on the performance of European sea bass (Dicentrarchus labrax) were investigated. Three size fish were distributed into two RAS (RAS and RAS O3). Ozone was injected into RAS O3 to increase the ORP level. The ORP was stabilized t...

Li, Xian; Blancheton, Jean-paul; Liu, Ying; Triplet, Sebastien; Michaud, Luigi

2014-01-01

73

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

OpenAIRE

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...

Fadhil, R.

2011-01-01

74

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

Directory of Open Access Journals (Sweden)

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.

H. Kumar

2013-01-01

75

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

Science.gov (United States)

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

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

2014-09-01

76

Effect of stocking density on performances of juvenile turbot ( Scophthalmus maximus) in recirculating aquaculture systems  

Science.gov (United States)

Limited information has been available about the influence of loading density on the performances of Scophthalmus maximus, especially in recirculating aquaculture systems (RAS). In this study, turbot (13.84±2.74 g; average weight±SD) were reared at four different initial densities (low 0.66, medium 1.26, sub-high 2.56, high 4.00 kg/m2) for 10 weeks in RAS at 23±1°C. Final densities were 4.67, 7.25, 14.16, and 17.47 kg/m2, respectively, which translate to 82, 108, 214, and 282 percent coverage of the tank bottom. Density had both negative and independent impacts on growth. The final mean weight, specific growth rate (SGR), and voluntary feed intake significantly decreased and the coefficient of variation (CV) of final body weight increased with increase in stocking density. The medium and sub-high density groups did not differ significantly in SGR, mean weight, CV, food conversion rate (FCR), feed intake, blood parameters, and digestive enzymes. The protease activities of the digestive tract at pH 7, 8.5, 9, and 10 were significantly higher for the highest density group, but tended to be lower (not significantly) at pH 4 and 8.5 for the lowest density group. The intensity of protease activity was inversely related to feed intake at the different densities. Catalase activity was higher (but not significantly) at the highest density, perhaps because high density started to induce an oxidative effect in turbot. In conclusion, turbot can be cultured in RAS at a density of less than 17.47 kg/m2. With good water quality and no feed limitation, initial density between 1.26 and 2.56 kg/m2 (final: 7.25 and 14.16 kg/m2) would not negatively affect the turbot cultured in RAS. For culture at higher density, multi-level feeding devices are suggested to ease feeding competition.

Li, Xian; Liu, Ying; Blancheton, Jean-Paul

2013-05-01

77

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)

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.

Serbulov Alexey

2012-01-01

78

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

Directory of Open Access Journals (Sweden)

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.

R Fadhil

2011-01-01

79

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

Science.gov (United States)

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

Hauton, Chris; Hudspith, Meggie; Gunton, Laetitia

2015-02-01

80

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)

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.

Mirela Cretu

2014-05-01

81

Public, animal, and environmental health implications of aquaculture.  

OpenAIRE

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...

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

1997-01-01

82

Electron beam focusing system  

Energy Technology Data Exchange (ETDEWEB)

The high energy electron cooling requires a very cold electron beam. Thus, the electron beam focusing system is very important for the performance of electron cooling. A system with and without longitudinal magnetic field is presented for discussion. Interaction of electron beam with the vacuum chamber as well as with the background ions and stored antiprotons can cause the coherent electron beam instabilities. Focusing system requirements needed to suppress these instabilities are presented.

Dikansky, N.; Nagaitsev, S.; Parkhomchuk, V.

1997-09-01

83

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...

84

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...

85

Group-selective enrichment and determination of pyrethroid insecticides in aquaculture seawater via molecularly imprinted solid phase extraction coupled with gas chromatography-electron capture detection.  

Science.gov (United States)

Two types of molecularly imprinted polymers (MIPs) for the simultaneous determination of six pyrethroid insecticides have been developed using deltamethrin (D-MIPs) and cypermethrin (C-MIPs) as template molecules. A comparison of the performance of D-MIPs, C-MIPs, and the corresponding non-imprinted polymers (NIPs) were conducted. Stronger group-selective interactions between the C-MIPs and the six pyrethroid insecticides were achieved. The MISPE method based on the C-MIPs displayed higher extraction recoveries (86.4-96.0%) with RSD values ranging from 2.4 to 7.8% for the six pyrethroid insecticides in aquaculture seawater. After the C-MIP cartridge procedure, the limits of detection and quantification for fenvalerate, deltamethrin, cypermethrin, cyfluthrin, and bifenthrin were in the 16.6-37.0 and 55.3-109.1 ng L?¹ ranges, respectively, and 0.68 and 2.26 ?g L?¹ for phenothrin, respectively. The proposed MISPE method coupled with gas chromatography-electron capture detection was successfully used for the determination of the six pyrethroid insecticides in aquaculture seawater. PMID:22265776

Shi, Xizhi; Liu, Jinghua; Sun, Aili; Li, Dexiang; Chen, Jiong

2012-03-01

86

Aquaculture and food crisis: opportunities and constraints.  

Science.gov (United States)

Fish farming, now well known as aquaculture, has been well recognized since the ancient era. The first written document on fish culture was published in China in 475 BC, and the first koi pond was constructed at the Japanese Imperial Palace grounds during 71-130 AD. In recent years, aquaculture has progressively played an important role in the provision of: animal protein and gourmet cuisines, job opportunities, and foreign currency for developing countries. Asian countries produce around 91 percent of the world's total aquaculture production. Among the top ten aquaculture-producing countries, nine are from Asia. The current global population consist of more than 6.5 billion individuals; over one billion of which face hunger problem. In the highly populated Asia-Pacific region with moderately high-productivity, 642 million people are still facing hunger. Being a proficient and potential source of animal protein, aquaculture will play an increasing and important role in solving the world food problem in the future. This paper discusses both the opportunities and constraints in the aquaculture industry, specifically in the Asia-Pacific region, and its possible role in solving the current global food crisis. Strategies including promotion and adoption of traceability and HACCP systems for food safety, and marketing management for aquaculture products are also suggested. It is hoped that traditional administration of aquaculture management for survival, profit, as well as food safety will successfully match sustainability management to meet the urgent global need for food. PMID:19965349

Liao, I Chiu; Chao, Nai-Hsien

2009-01-01

87

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish 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.

Francisco Javier, Sánchez Sellero; Montserrat, Cruz González.

2012-10-01

88

Aquaculture-fisheries interactions  

OpenAIRE

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...

Mikkelsen, Eirik

2006-01-01

89

Marketing Netcoatings for Aquaculture  

OpenAIRE

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...

Martin, Robert J.

2014-01-01

90

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

OpenAIRE

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...

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

2011-01-01

91

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)

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.

G. STEFAN

2013-12-01

92

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

93

Aquaculture activities in Fiji  

OpenAIRE

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 ).

Vereivalu, T.

1989-01-01

94

Ammonia-oxidizing archaea and nitrite-oxidizing nitrospiras in the biofilter of a shrimp recirculating aquaculture system.  

Science.gov (United States)

This study analysed the nitrifier community in the biofilter of a zero discharge, recirculating aquaculture system (RAS) for the production of marine shrimp in a low density (low ammonium production) system. The ammonia-oxidizing populations were examined by targeting 16S rRNA and amoA genes of ammonia-oxidizing bacteria (AOB) and archaea (AOA). The nitrite-oxidizing bacteria (NOB) were investigated by targeting the 16S rRNA gene. Archaeal amoA genes were more abundant in all compartments of the RAS than bacterial amoA genes. Analysis of bacterial and archaeal amoA gene sequences revealed that most ammonia oxidizers were related to Nitrosomonas marina and Nitrosopumilus maritimus. The NOB detected were related to Nitrospira marina and Nitrospira moscoviensis, and Nitrospira marina-type NOB were more abundant than N. moscoviensis-type NOB. Water quality and biofilm attachment media played a role in the competitiveness of AOA over AOB and Nitrospira marina-over N. moscoviensis-type NOB. PMID:22775980

Brown, Monisha N; Briones, Aurelio; Diana, James; Raskin, Lutgarde

2013-01-01

95

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

Science.gov (United States)

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.

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

2013-11-01

96

Potentials and limitations of biomethane and phosphorus recovery from sludges of brackish/marine aquaculture recirculation systems: a review.  

Science.gov (United States)

Brackish/marine recirculation aquaculture systems (RAS) produce a relatively small but concentrated waste stream. The produced waste is perceived as a constraint for sustainable development of brackish/marine RAS. Appropriate disposal of sludge or waste from brackish/marine RAS is of great importance for widespread acceptance and implementation. Anaerobic stabilization of RAS sludge is considered as a potential cost-effective methodology to achieve effective sludge reduction and biogas production. Therefore, this review presents an overview of studies conducted on anaerobic digestion of sludge from brackish/marine RAS. Several researchers have shown that specific methane yield (SMY) of anaerobic digestion of sludges from brackish/marine RAS is relatively low, mainly in the range of 0.001-0.184 m(3) CH4 (STP)/kg COD of sludge added. The possible reasons for low SMY are reviewed in this work and can be mainly attributed to applied experimental set-ups, particularly improper inoculum, and high salinity, mainly resulting from high sodium cation levels. This review also evaluates the potentials and limitations for phosphorus recovery from the waste streams. Additionally, corresponding approaches to enhance specific methanogenic activities are proposed, particularly about the need for further thickening sludges from brackish/marine RAS in order to increase SMY from the wastes and downsize the anaerobic digestion units. PMID:24140486

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

2013-12-15

97

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

Science.gov (United States)

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.

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

2013-01-01

98

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)

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.

Aeknarin Thanakitpairin

2014-01-01

99

Environmental constraints and aquaculture development  

OpenAIRE

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...

Paquotte, Philippe; Bailly, Denis

1994-01-01

100

Zebrafish as animal model for aquaculture nutrition research  

OpenAIRE

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...

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

2014-01-01

101

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 ...

102

Molecular genetics in aquaculture  

OpenAIRE

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...

Liliana Di Stasio; Claudio Lisa; Rossella Lo Presti

2009-01-01

103

Florida Seafood & Aquaculture  

Science.gov (United States)

Official web site of the Bureau of Seafood and Aquaculture Marketing, offering seafood information for both consumers and the industry to help buy, sell and market Florida seafood and aquaculture products. Provides promotional materials, supplier directories, and training for retailers, food service, wholesalers, processors, fishermen and aquaculturists. Also includes internet links, recipes, news, calendar of seafood festivals, brochures, clip art, audio and video. Includes both freshwater and marine species culture.

104

Modelling studies of fish production in integrated agriculture-aquaculture systems.  

OpenAIRE

The general objective of this thesis is to formulate a general model for fish production in integrated ponds and ricefields as a means of obtaining a better understanding of these production systems. Integrated culture systems produce fish without large industrial energy inputs and have positive effects on the whole farm system. A main characteristic is their environmental variability, notably dissolved oxygen concentration and temperature. A systems approach using mathematical models is advo...

Dam, A. A.

1995-01-01

105

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

OpenAIRE

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 th...

Blom, Daan Wilhelmus

2013-01-01

106

Electronics circuits and systems  

CERN Document Server

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

Bishop, Owen

2011-01-01

107

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

DEFF Research Database (Denmark)

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

Suhr, Karin Isabel; Letelier Gordo, Carlos Octavio

2014-01-01

108

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

Science.gov (United States)

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

Zhao, J; Chen, M; Quan, Cs; Fan, Sd

2014-09-15

109

Capacity building improve Malaysia's inspection and monitoring system for aquaculture and fishery products  

OpenAIRE

The project aimed to help build a credible inspection and monitoring system that can guarantee safe quality products of Ministry of Health (MoH) and Department of Fisheries (DoF) by upgrading the analytical capacity of the laboratory staff directly involved in the analysis and detection of forbidden substances. Two training courses were implemented in 2011 in the Bio Security Centre in Kuantan, Malaysia. The first training course on 'Marine lipophilic toxins using LC-MS/MS has been implemente...

Gevers, G. J. M.; Zoontjes, P. W.; Essers, M. L.; Klijnstra, M.; Gerssen, A.

2012-01-01

110

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

OpenAIRE

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 herd...

Allison, Edward H.; Andrew, Neil L.; Jamie Oliver

2007-01-01

111

Handbook for aquaculture water quality  

Science.gov (United States)

Efficient aquaculture production depends upon maintaining acceptable water quality conditions in culture units. This handbook discusses background information from chemistry, physics, biology, and engineering necessary for understanding the principles of water quality management in aquaculture. It a...

112

Contact zoonosis related to aquaculture: a growing concern  

Science.gov (United States)

Aquaculture develops fast worldwide, with new cultured species and increased global transport of live aquaculture products. There is a growing recognition of zoonotic disease agents causing epidemics and carrier states in cultured fish and shellfish, especially from warm water systems, transmitted t...

113

Strongly correlated electron systems  

International Nuclear Information System (INIS)

These Proceedings of the Anniversary Adriatico Research Conference and Workshop on Strongly Correlated Electron Systems, held at the International Centre for Theoretical Physics, Trieste, Italy, 19 June - 21 July 1989, and published in this Volume 23 of ''Progress in High Temperature Superconductivity'', contain 30 papers on the solid state quantum theory of strongly correlated electron systems relevant to the understanding of high-temperature superconductivity. The volume is divided into the following parts: (1) Two-dimensional models - various techniques; (2) Two-dimensional models - Numerical Studies; (3) Hole Motion in a Quantum Antiferromagnet; (4) Flux Phases and Anyon Superconductivity; (5) Superconductivity Phenomenology and Related Topics; and (6) Low and High Dimensional Models

114

Phylogenetic diversity of ammonia-oxidizing archaea and bacteria in biofilters of recirculating aquaculture systems.  

Science.gov (United States)

We constructed ammonia monooxygenase alpha subunit (amoA) gene clone libraries of ammonia-oxidizing archaea (AOA) and bacteria (AOB) from three biofiltration tanks used for closed marine fish culture systems. The number of operational taxonomic units (OTUs) found in any one place was 76%-80% of the total OTUs in each tank for AOA and 100% for AOB when OUTs were defined on the basis of a 5% nucleotide difference. In a phylogenetic tree, all of the AOA amoA sequences fell into a cluster, which contained Candidatus Nitrosopumilus maritimus. All of the AOB amoA sequences were related to the Nitrosospira lineage. These results indicated that different ammonia oxidizers were present in different tanks, but that the dominant phylogenetic types were stable. In a biofiltration tank to which a high concentration of ammonium chloride was added periodically to condition the biofilter materials, most of the AOA amoA sequences were different from the dominant one observed in the fish culture tanks. The AOB amoA sequences were also different, and were similar to those of Nitrosomonas aestuarii. These findings suggest that high concentration ammonia loads have a considerable affect on ammonia-oxidizer community composition. PMID:22897959

Sakami, Tomoko; Andoh, Tadashi; Morita, Tetsuo; Yamamoto, Yoshihisa

2012-09-01

115

Aquaculture report 1976  

Energy Technology Data Exchange (ETDEWEB)

Growth of channel catfish (Ictalurus punctatus) and Tilapia zillii in the Reft River Geothermal Area (RRGT) geothermal waters can equal or surpass that in a commercial aquaculture facility. Fish and prawn mortality over the course of the intermediate term preliminary study did not appear to be related to any inherent geothermal water chemistry conditions. Temperature control was a problem but does not appear to be beyond design control. The absence of temperature-related mortality in channel catfish, Tilapia zilli, and yellow perch (Perca flavescens) indicates increased survival and suggests reduced expenditures for disease control. It may also allow higher fish densities in commercial aquaculture operations using geothermal water. Results of this study indicate potential for commercial aquaculture development at the Raft River Geothermal Testing Site.

Campbell, D.K.; Watson, L.; Kent, J.C.; Johnson, D.W.

1977-04-08

116

Programmable electronic safety systems  

International Nuclear Information System (INIS)

Traditionally safety systems intended for protecting personnel from electrical and radiation hazards at particle accelerator laboratories have made extensive use of electromechanical relays. These systems have the advantage of high reliability and allow the designer to easily implement fail-safe circuits. Relay based systems are also typically simple to design, implement, and test. As systems, such as those presently under development at the Superconducting Super Collider Laboratory (SSCL), increase in size, and the number of monitored points escalates, relay based systems become cumbersome and inadequate. The move toward Programmable Electronic Safety Systems is becoming more widespread and accepted. In developing these systems there are numerous precautions the designer must be concerned with. Designing fail-safe electronic systems with predictable failure states is difficult at best. Redundancy and self-testing are prime examples of features that should be implemented to circumvent and/or detect failures. Programmable systems also require software which is yet another point of failure and a matter of great concern. Therefore the designer must be concerned with both hardware and software failures and build in the means to assure safe operation or shutdown during failures. This paper describes features that should be considered in developing safety systems and describes a system recently installed at the Accelerator Systems String Test (ASST) facility of the SSCLtring Test (ASST) facility of the SSCL

117

Certify Sustainable Aquaculture?  

DEFF Research Database (Denmark)

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.

Bush, Simon; Belton, Ben

2013-01-01

118

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)

119

Electron-electron interactions in disordered systems  

CERN Document Server

``Electron-Electron Interactions in Disordered Systems'' deals with the interplay of disorder and the Coulomb interaction. Prominent experts give state-of-the-art reviews of the theoretical and experimental work in this field and make it clear that the interplay of the two effects is essential, especially in low-dimensional systems.

Efros, AL

1985-01-01

120

An Overview of Aquaculture in the Nordic Countries  

DEFF Research Database (Denmark)

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.

Paisley, Larry; Ariel, Ellen

2010-01-01

121

Granular Electronic Systems  

CERN Document Server

A granular metal is an array of metallic nano-particles imbedded into an insulating matrix. Tuning the intergranular coupling strength a granular system can be transformed into either a good metal or an insulator and, in case of superconducting particles, experience superconductor-insulator transition. The ease of adjusting electronic properties of granular metals makes them most suitable for fundamental studies of disordered solids and assures them a fundamental role for nanotechnological applications. This Review discusses recent important theoretical advances in the study of granular metals, emphasizing on the interplay of disorder, quantum effects, fluctuations and effects of confinement in formation of electronic transport and thermodynamic properties of granular materials.

Beloborodov, I S; Lopatin, A V; Vinokur, V M

2006-01-01

122

Confinement Aquaculture. Final Report.  

Science.gov (United States)

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…

Delaplaine School District, AR.

123

Delaware Aquaculture Resource Center  

Science.gov (United States)

An archive of information about aquaculture in the Mid-Atlantic states: Delaware, New Jersey, New York, Maryland, Pennsylvania, Virginia, West Virginia, and North Carolina. Expanding list of resources and other useful information including contacts, news, meetings, conferences, workshops, publications, and jobs.

124

Aquaculture. Teacher Edition.  

Science.gov (United States)

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,…

Walker, Susan S.

125

Electronic Nose System  

Science.gov (United States)

The Jet Propulsion Laboratory has designed and built an electronic nose system -- ENose -- to take on the duty of staying alert for smells that could indicate hazardous conditions in a closed spacecraft environment. Its sensors are tailored so they conduct electricity differently when an air stream carries a particular chemical across them. JPL has designed and built a 3-pound flight version (shown with palm-size control and data computer). The active parts are 32 sensors, each with a different mix of polymers saturated with carbon. When certain chemicals latch onto a sensor, they change how the sensor conducts electricity. This signal tells how much of a compound is in the air. The electronic nose flown aboard STS-95 in 1998 was capable of successfully detecting 10 toxic compounds.

2003-01-01

126

Electronic Nose System Sensors  

Science.gov (United States)

The Jet Propulsion Laboratory has designed and built an electronic nose system -- ENose -- to take on the duty of staying alert for smells that could indicate hazardous conditions in a closed spacecraft environment. Its sensors (shown here) are tailored so they conduct electricity differently when an air stream carries a particular chemical across them. JPL has designed and built a 3-pound flight version. The active parts are 32 sensors, each with a different mix of polymers saturated with carbon. When certain chemicals latch onto a sensor, they change how the sensor conducts electricity. This signal tells how much of a compound is in the air. The electronic nose flown aboard STS-95 in 1998 was capable of successfully detecting 10 toxic compounds.

2003-01-01

127

Marketing Netcoatings for Aquaculture  

Directory of Open Access Journals (Sweden)

Full Text Available 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 industry provides a case study for business issues related to entry of improved fouling management technology into the marketplace. Several major hurdles hinder entry of improved novel technologies into the market. The first hurdle is due to the structure of business relationships. Net suppliers can actually cut their business profits dramatically by introducing improved technologies. A second major hurdle is financial costs of registration and demonstration of efficacy and quality product with a new technology. Costs of registration are prohibitive if only the net coatings market is involved. Demonstration of quality product requires collaboration and a team approach between formulators, net suppliers and farmers. An alternative solution is a vertically integrated business model in which the support business and product production business are part of the same company.

Robert J. Martin

2014-10-01

128

Marketing netcoatings for aquaculture.  

Science.gov (United States)

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 industry provides a case study for business issues related to entry of improved fouling management technology into the marketplace. Several major hurdles hinder entry of improved novel technologies into the market. The first hurdle is due to the structure of business relationships. Net suppliers can actually cut their business profits dramatically by introducing improved technologies. A second major hurdle is financial costs of registration and demonstration of efficacy and quality product with a new technology. Costs of registration are prohibitive if only the net coatings market is involved. Demonstration of quality product requires collaboration and a team approach between formulators, net suppliers and farmers. An alternative solution is a vertically integrated business model in which the support business and product production business are part of the same company. PMID:25329615

Martin, Robert J

2014-01-01

129

Marketing Netcoatings for Aquaculture  

Science.gov (United States)

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 industry provides a case study for business issues related to entry of improved fouling management technology into the marketplace. Several major hurdles hinder entry of improved novel technologies into the market. The first hurdle is due to the structure of business relationships. Net suppliers can actually cut their business profits dramatically by introducing improved technologies. A second major hurdle is financial costs of registration and demonstration of efficacy and quality product with a new technology. Costs of registration are prohibitive if only the net coatings market is involved. Demonstration of quality product requires collaboration and a team approach between formulators, net suppliers and farmers. An alternative solution is a vertically integrated business model in which the support business and product production business are part of the same company. PMID:25329615

Martin, Robert J.

2014-01-01

130

L'aquaculture au Sénégal  

OpenAIRE

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.

Belot, J.; Niamadio, I.

1988-01-01

131

Research on Aquaculture in China  

OpenAIRE

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.

Zhou, Ang; Wang, Dong; Wang, Di

2013-01-01

132

Hydrogen peroxide decomposition kinetics in aquaculture water  

DEFF Research Database (Denmark)

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.

Arvin, Erik; Pedersen, Lars-Flemming

2015-01-01

133

Nitrous oxide (N2O) emission from aquaculture: a review.  

Science.gov (United States)

Nitrous oxide (N(2)O) is an important greenhouse gas (GHG) which has a global warming potential 310 times that of carbon dioxide (CO(2)) over a hundred year lifespan. N(2)O is generated during microbial nitrification and denitrification, which are common in aquaculture systems. To date, few studies have been conducted to quantify N(2)O emission from aquaculture. Additionally, very little is known with respect to the microbial pathways through which N(2)O is formed in aquaculture systems. This review suggests that aquaculture can be an important anthropogenic source of N(2)O emission. The global N(2)O-N emission from aquaculture in 2009 is estimated to be 9.30 × 10(10) g, and will increase to 3.83 × 10(11)g which could account for 5.72% of anthropogenic N(2)O-N emission by 2030 if the aquaculture industry continues to increase at the present annual growth rate (about 7.10%). The possible mechanisms and various factors affecting N(2)O production are summarized, and two possible methods to minimize N(2)O emission, namely aquaponic and biofloc technology aquaculture, are also discussed. The paper concludes with future research directions. PMID:22594516

Hu, Zhen; Lee, Jae Woo; Chandran, Kartik; Kim, Sungpyo; Khanal, Samir Kumar

2012-06-19

134

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)

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

Trang, Ngo Thuy Diem; Schierup, Hans-Henrik

2010-01-01

135

Nutrients valorisation via Duckweed-based wastewater treatment and aquaculture:  

OpenAIRE

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 tempera...

El-shafai, S. A. A. M.

2004-01-01

136

Aquaculture. Second Edition. Teacher Edition.  

Science.gov (United States)

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…

Walker, Susan S.; Crummett, Dan

137

Phenotypic and molecular characterisation of fish-borne Flavobacterium johnsoniae-like isolates from aquaculture systems in South Africa.  

Science.gov (United States)

Fish infections caused by pathogenic Flavobacterium species are a major problem in the aquaculture industry worldwide, often leading to large economic losses. Thirty-two Flavobacterium spp. isolates, obtained from various diseased fish species and biofilm growth, were characterised genetically using 16S rDNA PCR restriction fragment length polymorphism (RFLP), randomly amplified polymorphic DNA (RAPD) PCR, repetitive extragenic palindromic (REP) element PCR, plasmid profiling, whole cell protein (WCP) and outer membrane protein (OMP) analyses. Although the Flavobacterium spp. isolates displayed a high degree of genetic heterogeneity when differentiated by RAPD-PCR, REP-PCR and OMP fingerprinting techniques, isolates appeared very homogeneous by plasmid profiling and WCP analysis. No specific correlation was observed between the RAPD, REP and/or OMP profiles and fish host, site of isolation, geographic location or date of isolation of the Flavobacterium spp. isolates. Experimental infection of tilapia fish revealed variable levels of virulence and pathogenicity by isolates following handling stress and could not be linked to specific molecular types. This is the first reported isolation and characterisation of Flavobacterium johnsoniae-like spp. isolated from diseased fish in Southern Africa. PMID:17113757

Flemming, Leonard; Rawlings, Douglas; Chenia, Hafizah

2007-01-01

138

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

OpenAIRE

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–...

Cranford, Peter J.; Kamermans, Pauline; Krause, Gesche; Mazurie?, Joseph; Buck, Bela H.; Dolmer, Per; Fraser, David; Nieuwenhove, Kris; O’beirn, Francis X.; Sanchez-mata, Adoracio?n; Thorarinsdo?ttir, Gudrun G.; Strand, Øivind

2012-01-01

139

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 follod 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)

140

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.)

141

Electrodynamics of correlated electron systems  

OpenAIRE

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...

Armitage, N. P.

2009-01-01

142

Novel electron gas systems  

International Nuclear Information System (INIS)

We review recent progress on the physics of electrons in the bilayered electron gas, relevant to coupled quantum wells in GaAs/AIGaAs heterostructures. First we focus on the phase diagram of a symmetric bilayer at T = B = 0, obtained by diffusion Monte Carlo (DMC) simulations. It is found that inter-layer correlations stabilize crystalline structures at intermediate inter-layer separation, while favoring a liquid phase at smaller distance. Also, the available DMC evidence is in contrast with the recently (Hartree-Fock) predicted total charge transfer (TCT), whereby all the electron spontaneously jump in one layer. In fact, one can show that such a TCT state is never stable in the ideal bilayer with no tunneling. We finally comment on ongoing DMC investigations on the electron-hole bilayer, where excitonic condensation is expected to take place. (Copyright (1998) World Scientific Publishing Co. Pte. Ltd)

143

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)

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

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

144

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)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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.

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

2011-05-01

145

The ALS Gun Electronics system  

International Nuclear Information System (INIS)

The ALS Gun Electronics system has been designed to accommodate gun with a custom made socket and high speed electronics circuit which is capable of producing single and multiple electron bunches with time jitters measured at better than 50 PS. The system generates the gated RF signal at ground level before sending it up to the 120 KV-biased gun deck via a fiber optic cable. The current pulse width as a function of grid bias, using an Eimac 8847A planar triode simulating an electron gun, was measured to show the relationship between the two parameters

146

Realization of dynamical electronic systems  

OpenAIRE

This article gives an overview of a methodology for building dynamical electronic systems. As an example a part of a system for epileptic seizure prediction is used, which monitors EEG signals and continuously calculates the largest short-term Lyapunov exponents. In dynamical electronic systems, the cost of exploitation, for instance energy consumption, may vary substantially with the values of input signals. In addition, the functions describing the variations are not known at the time the s...

Hammari Elena; Catthoor Francky; Iasemidis Leonidas; Gunnar Kjeldsberg Per; Huisken Jos; Tsakalis Konstantinos

2014-01-01

147

Use of Probiotics in Aquaculture  

OpenAIRE

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...

Patricia Martínez Cruz; Ib Amp Xe Amp Xf Ez, Ana L.; Monroy Hermosillo, Oscar A.; Ram Amp Xed Rez Saad, Hugo C.

2012-01-01

148

Application of chemical coagulation aids for the removal of suspended solids (TSS) and phosphorus from the microscreen effluent discharge of an intensive recirculating aquaculture system  

Science.gov (United States)

An evaluation of two commonly used coagulation-flocculation aids (alum and ferric chloride) was conducted to determine optimum conditions for treating the backwash effluent from microscreen filters in an intensive recirculating aquaculture system. Tests were carried out to evaluate the dosages and conditions (mixing and flocculation stirring speeds, durations, and settling times) required to achieve optimum waste capture. The orthophosphate removal efficiency for alum and ferric chloride were greater than 90% at a dosage of 60 mg/L. Optimum turbidity removal was achieved with a 60-mg/L dosage for both alum and ferric chloride. Both alum and ferric chloride demonstrated excellent removal of suspended solids from initial total suspended solid values of approximately 320 mg/L to approximately 10 mg/L at a dosage of 60 mg/L. Flocculation and mixing speed and duration played only a minor role in the removal efficiencies for both orthophosphates and suspended solids. Both coagulation-flocculation aids also exhibited excellent settling characteristics, with the majority of the floc quickly settling out in the first 5 min.

Ebeling, J.M.; Ogden, S.R.; Sibrell, P.L.; Rishel, K.L.

2004-01-01

149

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)

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 ( Psex steroid and melatonin level increases. The three test factors had no significant effects on the survival rate, specific growth rate, relative weight gain, and male Fulton condition factor ( P>0.05). 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.

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

2015-01-01

150

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)

151

A Portable Electron Radiography System  

CERN Document Server

The technique of charged particle radiography has been developed and proven with 800 MeV protons at LANSCE and 24 GeV protons at the AGS. Recent work at Los Alamos National Laboratory in collaboration with the Idaho Accelerator Center has extended this diagnostic technique to electron radiography through the development of an inexpensive and portable electron radiography system. This system has been designed to use 30 MeV electrons to radiograph thin static and dynamic systems. The system consists of a compact 30 MeV pulsed electron linear accelerator coupled to a quadrupole lens magnifier constructed from permanent magnet quadrupoles. The design features and operational characteristics of this radiography system are presented as well as the radiographic performance parameters.

Merrill, Frank E; Harmon, Frank; Hunt, Alan W; King, B J; Morris, Christopher

2005-01-01

152

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

153

Potential use of power plant reject heat in commercial aquaculture  

Energy Technology Data Exchange (ETDEWEB)

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.

Olszewski, M.

1977-01-01

154

Issues, impacts, and implications of shrimp aquaculture in Thailand  

Science.gov (United States)

Water quality impacts to and from intensive shrimp aquaculture in Thailand are substantial. Besides the surface and subsurface salinization of freshwaters, loadings of solids, oxygen-consuming organic matter, and nutrients to receiving waters are considerable when the cumulative impacts from water exchange during the growout cycle, pond drainage during harvesting, and illegal pond sediment disposal are taken into account. Although just beginning to be considered in Thailand, partial recirculating and integrated intensive farming systems are producing promising, if somewhat limited, results. By providing on-site treatment of the effluent from the shrimp growout ponds, there is less reliance on using outside water supplies, believed to be the source of the contamination. The explosion in the number of intensively operated shrimp farms has not only impacted the coastal zone of Thailand, but has also resulted in an unsustainable aquaculture industry. Abandonment of shrimp ponds due to either drastic, disease-caused collapses or more grandual, year-to-year reductions in the productivity of the pond is common. To move Thailand towards a more sustainable aquaculture industry and coastal zone environment, integrated aquaculture management is needed. Components of integrated aquaculture management are technical and institutional. The technical components involve deployment of wastewater treatment and minimal water-use systems aimed at making aquaculture operations more hydraulically closed. Before this is possible, technical and economic feasibility studies on enhanced nitrification systems and organic solids removal by oxidation between production cycles and/or the utilization of plastic pond liners need to be conducted. The integration of semi-intensive aquaculture within mangrove areas also should be investigated since mangrove losses attributable to shrimp aquaculture are estimated to be between 16 and 32% of the total mangrove area destroyed betweeen 1979 and 1993. Government policy needs to devote as much attention to sustainability issues as it has on promoting intensive pond culture. Such a balanced policy would include training and education monitoring and enforcement, rehabilitating abandoned ponds, managing land use within the coastal zone, more community involvement, and government reorganization to eliminate overlapping jurisdictions among agencies. As integrated aquaculture management becomes more the practice than the exception, less risk of crop failure to the industry and reduced discharge loadings from intensively managed shrimp ponds to receiving waters can be expected. Projected limitations on growing and marketing shrimp in the future, such as scarcity of land and broodstock, continued disease outbreaks, negative publicity, regulatory enforcement, water treatment and solids disposal costs, and increased competition from growers in other Asian countries will also drive the government and the industry towards adopting integrated aquaculture management.

Dierberg, Forrest E.; Kiattisimkul, Woraphan

1996-09-01

155

Ecosystem-based approach to aquaculture management  

Directory of Open Access Journals (Sweden)

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.

Patrick White

2008-12-01

156

Kerberos Based Electronic Tender system  

OpenAIRE

An electronic tender (e-tender) system is a system in which selling, buying and providing contract by the government with the help of online software. In this system the tender data is recorded, stored and processed primarily as digital information. In the modern world e-tender system is increasing speedily and the popularity of e-tender system need quality and security. In this paper a ‘KBETS’ is proposed which provides user to participating in tender nevertheless of the ...

NITISH KUMAR SINGH; SUBNUM BEGUM

2014-01-01

157

Avermectin use in aquaculture.  

Science.gov (United States)

The main indication for use of avermectins in aquaculture-produced fish is infestations with ectoparasitic copepods. The compounds ivermectin and emamectin benzoate are predominantly used as in-feed formulations on salmonid fish against copepods in the family Caligidae: Lepeophtheirus salmonis, Caligus elongatus and C. rogercresseyi. These agents are well-documented as very effective on all developmental stages of the parasites. The duration of effect can be up to 10 weeks. The safety margin for ivermectin is narrow, but better for emamectin benzoate. Environmental impact from these chemicals on bottom-dwelling and sediment-dwelling organisms occurs, but these are restricted to the immediate area around the production site. Avermectins are incompletely absorbed from the intestine of the fish and slowly excreted. They penetrate the blood-brain barrier of the fish, ivermectin more than emamectin benzoate. Resistance has developed against these agents in L. salmonis in almost all major salmon producing areas. The situation must be viewed as serious and can render these agents completely ineffective for salmon lice control. PMID:22039799

Horsberg, Tor E

2012-05-01

158

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

159

Electronic control systems for teleoperated mining systems  

Energy Technology Data Exchange (ETDEWEB)

The Bureau of Mines has been investigating electronic control systems for teleoperated mining since the late 1970s. Electronic control systems used for teleoperated mining promote safety by removing the operator from a hazardous area and placing him/her at a safe distance. The electronic control systems used for the first teleoperated machine were based on a simple eight bit microprocessor. In the mid-eighties, eight bit microcontrollers were integrated into a large, distributed, control system. In the early nineties, the use of multiprocessor systems was started. These control systems use both the thirty-two bit Motorola 68020 microprocessor and the thirty-two bit Intel 80386 microprocessor. The current electronic control system consists of a master and slave controller. With this electronic control system, machine functions are activated about ten times faster than the distributed microcontroller system it replaced. This system provides near real-time control of mining machinery which is out of line of sight. 5 refs., 7 figs., 2 tabs.

Monaghan, W.D.; Kwitowski, A.J.; Brautigam, A.L. (US Bureau of Mines, Pittsburgh, PA (USA))

1992-01-01

160

Component reliability for electronic systems  

CERN Document Server

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.

Bajenescu, Titu-Marius I

2010-01-01

161

ISO/TC 234, Fisheries and Aquaculture  

OpenAIRE

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 developm...

Costea, Ramona I.

2009-01-01

162

World Aquaculture: Environmental Impacts and Troubleshooting Alternatives  

OpenAIRE

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...

Martinez-porchas, Marcel; Martinez-cordova, Luis R.

2012-01-01

163

Exploring Aquaculture. Curriculum Guide for Agriscience 282.  

Science.gov (United States)

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…

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

164

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

OpenAIRE

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 Ni...

Jamabo, Nene A.; George, P. U. Uzukwu And O. S.

2010-01-01

165

Realization of dynamical electronic systems  

Science.gov (United States)

This article gives an overview of a methodology for building dynamical electronic systems. As an example a part of a system for epileptic seizure prediction is used, which monitors EEG signals and continuously calculates the largest short-term Lyapunov exponents. In dynamical electronic systems, the cost of exploitation, for instance energy consumption, may vary substantially with the values of input signals. In addition, the functions describing the variations are not known at the time the system is designed. As a result, the architecture of the system must accommodate for the worst case exploitation costs, which rapidly exceed the available resources (for instance battery life) when accumulated over time. The presented system scenario methodology solves these challenges by identifying at design time groups of possible exploitation costs, called system scenarios, and implementing a mechanism to detect system scenarios at run time and re-configure the system to cost-efficiently accommodate them. During reconfiguration, the optimized system architecture settings for the active system scenario are selected and the total exploitation cost is reduced. When the dynamic behavior is due to input data variables with a large number of possible values, current techniques for bottom-up scenario identification and detection becomes too complex. A new top-down technique, based on polygonal regions, is presented in this paper. The results for the example system indicate that with 10 system scenarios the average energy consumption of the system can be reduced by 28% and brought within 5% of the theoretically best solution.

Hammari, Elena; Catthoor, Francky; Iasemidis, Leonidas; Kjeldsberg, Per Gunnar; Huisken, Jos; Tsakalis, Konstantinos

2014-04-01

166

Realization of dynamical electronic systems  

Directory of Open Access Journals (Sweden)

Full Text Available This article gives an overview of a methodology for building dynamical electronic systems. As an example a part of a system for epileptic seizure prediction is used, which monitors EEG signals and continuously calculates the largest short-term Lyapunov exponents. In dynamical electronic systems, the cost of exploitation, for instance energy consumption, may vary substantially with the values of input signals. In addition, the functions describing the variations are not known at the time the system is designed. As a result, the architecture of the system must accommodate for the worst case exploitation costs, which rapidly exceed the available resources (for instance battery life when accumulated over time. The presented system scenario methodology solves these challenges by identifying at design time groups of possible exploitation costs, called system scenarios, and implementing a mechanism to detect system scenarios at run time and re-configure the system to cost-efficiently accommodate them. During reconfiguration, the optimized system architecture settings for the active system scenario are selected and the total exploitation cost is reduced. When the dynamic behavior is due to input data variables with a large number of possible values, current techniques for bottom-up scenario identification and detection becomes too complex. A new top-down technique, based on polygonal regions, is presented in this paper. The results for the example system indicate that with 10 system scenarios the average energy consumption of the system can be reduced by 28% and brought within 5% of the theoretically best solution.

Hammari Elena

2014-04-01

167

Applications of probiotic in aquaculture  

Directory of Open Access Journals (Sweden)

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.

Seval Bahad?r Koca

2011-10-01

168

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)

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.

Radu Muscalu

2010-12-01

169

DNA vaccines for aquacultured fish  

DEFF Research Database (Denmark)

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.

Lorenzen, Niels; LaPatra, S.E.

2005-01-01

170

PREFACE: Strongly correlated electron systems Strongly correlated electron systems  

Science.gov (United States)

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

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

2012-07-01

171

Use of recirculating aquaculture systems to increase production and quality of hatchery reared juvenile red drum for marine stock enhancement  

Science.gov (United States)

The abundance of economically important marine sportfish has declined in Florida’s waters due to factors such as over-fishing and critical habitat disturbance. Hatchery production and enhancement stocking has traditionally been used in freshwater systems as a means of mitigating for effects such as ...

172

Power electronic systems Walsh analysis with Matlab  

CERN Document Server

A Totally Different Outlook on Power Electronic System AnalysisPower Electronic Systems: Walsh Analysis with MATLAB® builds a case for Walsh analysis as a powerful tool in the study of power electronic systems. It considers the application of Walsh functions in analyzing power electronic systems, and the advantages offered by Walsh domain analysis of power electronic systems. Solves Power Electronic Systems in an Unconventional WayThis book successfully integrates power electronics as well as systems and control. Incorporating a complete orthonormal function set very much unlike the sine-cosin

Deb, Anish

2014-01-01

173

Development of a GIS-Based Tool for Aquaculture Siting  

Directory of Open Access Journals (Sweden)

Full Text Available Nearshore aquaculture siting requires the integration of a range of physical, environmental, and social factors. As a result, the information demand often presents coastal managers with a range of complex issues regarding where specific types of aquaculture should be ideally located that reduce environmental and social impacts. Here we provide a framework and tool for managers faced with these issues that incorporate physical and biological parameters along with geospatial infrastructure. In addition, the development of the tool and underlying data included was undertaken with careful input and consideration of local population concerns and cultural practices. Using Hawai?i as a model system, we discuss the various considerations that were integrated into an end-user tool for aquaculture siting.

Noelani Puniwai

2014-06-01

174

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)

175

Genomic approaches in aquaculture and fisheries  

DEFF Research Database (Denmark)

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.

Cancela, M. Leonor; Bargelloni, Luca

2010-01-01

176

REVIEW OF AQUACULTURE GENETIC RESEARCHES IN THAILAND  

OpenAIRE

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...

UTHAIRAT NA-NAKORN

1992-01-01

177

7 CFR 1437.303 - Aquaculture, including ornamental fish.  

Science.gov (United States)

...false Aquaculture, including ornamental fish. 1437.303 Section 1437...303 Aquaculture, including ornamental fish. (a) Aquaculture is...consumed by humans; and (3) Ornamental fish propagated and reared in an...

2010-01-01

178

76 FR 9209 - Draft NOAA National Aquaculture Policy  

Science.gov (United States)

...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...

2011-02-16

179

76 FR 9210 - Draft DOC National Aquaculture Policy  

Science.gov (United States)

...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...

2011-02-16

180

Multilocus Sequence Analysis of the Marine Bacterial Genus Tenacibaculum Suggests Parallel Evolution of Fish Pathogenicity and Endemic Colonization of Aquaculture Systems  

Science.gov (United States)

The genus Tenacibaculum, a member of the family Flavobacteriaceae, is an abundant component of marine bacterial ecosystems that also hosts several fish pathogens, some of which are of serious concern for marine aquaculture. Here, we applied multilocus sequence analysis (MLSA) to 114 representatives of most known species in the genus and of the worldwide diversity of the major fish pathogen Tenacibaculum maritimum. Recombination hampers precise phylogenetic reconstruction, but the data indicate intertwined environmental and pathogenic lineages, which suggests that pathogenicity evolved independently in several species. At lower phylogenetic levels recombination is also important, and the species T. maritimum constitutes a cohesive group of isolates. Importantly, the data reveal no trace of long-distance dissemination that could be linked to international fish movements. Instead, the high number of distinct genotypes suggests an endemic distribution of strains. The MLSA scheme and the data described in this study will help in monitoring Tenacibaculum infections in marine aquaculture; we show, for instance, that isolates from tenacibaculosis outbreaks in Norwegian salmon farms are related to T. dicentrarchi, a recently described species. PMID:24973065

Habib, Christophe; Houel, Armel; Lunazzi, Aurélie; Bernardet, Jean-François; Olsen, Anne Berit; Nilsen, Hanne; Toranzo, Alicia E.; Castro, Nuria; Nicolas, Pierre

2014-01-01

181

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)

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.

Klaysri, S.

2005-02-01

182

Continuous host-macroparasite models with application to aquaculture  

Directory of Open Access Journals (Sweden)

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.

Catherine Bouloux Marquet

2004-11-01

183

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

OpenAIRE

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...

Turcios, Ariel E.; Jutta Papenbrock

2014-01-01

184

Green and technical efficient growth in Danish fresh water aquaculture  

DEFF Research Database (Denmark)

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.

Nielsen, Rasmus

2011-01-01

185

Feed Additives for Aquaculture and Aquarium Culture  

OpenAIRE

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.

Barata, Eduardo N.; Velez, Ze?lia

2011-01-01

186

Fishing the Future: The Need For Aquaculture  

Science.gov (United States)

The issue-focused, reviewed, student article illustrates how aquaculture, or seafood farming, may be the best solution to dwindling food supplies. Its development is urgently needed because: overpopulation has exceeded Earth's capacity to feed us, fisheries have been exploited to a dangerous level, and aquaculture is a reliable, safe, and inexpensive source of food.

Ronald Hsu (West Shore Jr./Sr. High School in Melbourne, FL; )

2001-07-01

187

World aquaculture: environmental impacts and troubleshooting alternatives.  

Science.gov (United States)

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 the negative impacts, rather than just prohibiting the activity. Aquaculture is a possible panacea, but at present is also responsible for diverse problems related with the environmental health; however the new strategies proposed during the last decade have proven that it is possible to achieve a sustainable aquaculture, but such strategies should be supported and proclaimed by the different federal environmental agencies from all countries. Additionally there is an urgent need to improve legislation and regulation for aquaculture. Only under such scenario, aquaculture will be a sustainable practice. PMID:22649291

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

2012-01-01

188

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

Directory of Open Access Journals (Sweden)

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.

Ariel E. Turcios

2014-02-01

189

Ecotoxicity assessment in aquaculture system using the test organism Pseudokirchneriella subcapitata (Chlorophyceae - doi: 10.4025/actascibiolsci.v34i4.9391  

Directory of Open Access Journals (Sweden)

Full Text Available The purpose of this study is to perform toxicity tests with microalgae Pseudokirchneriella subcapitata (Chlorophyceae using inland water samples to evaluate the impact caused by aquaculture. Six field samples were collected ranged November 2006 to March 2007, at Experimental Station, Pindamonhangaba, State of São Paulo. Abiotic factors pointed out to the mesotrophic and eutrophic characteristics already observed at the fish pond and its effluent. The results of ecotoxicological tests carried out with the microalgae Pseudokirchneriella subcapitata showed that the fish pond effluent was potential enough to stimulate the algal growth, therefore eutrophication, to the extent that it is naturally diluted to at least 12.5% of its initial concentration. This type of test can be a tool to be used by environmental managers in attempts to measure the extents of the impacts of effluent discharges from fish farming and to propose treatments based on qualitative and quantitative information.  

Julio Vicente Lombardi

2012-09-01

190

Micro-Electronic Nose System  

Science.gov (United States)

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.

Zee, Frank C.

2011-12-01

191

REVIEW OF AQUACULTURE GENETIC RESEARCHES IN THAILAND  

Directory of Open Access Journals (Sweden)

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.

UTHAIRAT NA-NAKORN

1992-01-01

192

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)

193

Knowledge and Skill Guidelines for Aquaculture Technicians  

Science.gov (United States)

The Marine Advanced Technology Education Center (MATE) has provided this overview of knowledge and skill guidelines for aquaculture technicians. The report begins with detailing the background of the creation of these guidelines, which occurred at the third annual Rhode Island Aquaculture Conference in Warwick, Rhode Island. Competency areas for aquaculture technicians outlined in the report are laboratory skills, math skills, knowledge of basic chemistry, field experience, knowledge of basic biology, mechanical skills, communication skills, analytical skills, internship experience, time management skills, computer skills, basic business skills and staying up-to-date.

194

PROBLEMS OF BIOFOULING ON FISH–CAGE NETS IN AQUACULTURE  

OpenAIRE

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 ne...

Merica Sliškovi?; Gorana Jeli?

2002-01-01

195

Scenarios for Resilient Shrimp Aquaculture in Tropical Coastal Areas  

OpenAIRE

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...

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

2010-01-01

196

Electronic document management in office systems  

OpenAIRE

This paper summarizes the main aspects concerning the management of electronic documents, that is, documents as they are represented inside the automated office. An electronic document is a multimedia data object which is an aggregation of text, images, attribute, and audio components. A system for the management of electronic documents will be constituted by a number of electronic document servers operating in a network environment together with the user workstations, which are the source of...

Rabitti, Fausto

1985-01-01

197

Electronic structure and symmetry in conjugated ?-electron systems.  

Science.gov (United States)

The continuous symmetry measures (CSM) method has been used to study the ?-electron systems for a diverse set of molecules, illustrating the capabilities of this new analytical tool to quantify the changes in the electronic structure of molecules upon symmetry breaking perturbations induced either by geometry modifications or chemical substitutions. The symmetry analysis applied to the Hamiltonian, the molecular orbitals or the electron density obtained from a simple Hückel model for these compounds reveals the basic relations between symmetry and the electronic structure. Calculation of continuous symmetry measures from ab initio calculations confirms these relations, allowing at the same time a much more accurate description of the influence of symmetry on the electronic structure of these compounds. PMID:22161743

Alemany, Pere; Casanova, David; Dryzun, Chaim

2011-12-23

198

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 respiratC-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

199

NATIONAL ELECTRONIC DISEASE SURVEILLANCE SYSTEM (NEDSS)  

Science.gov (United States)

The National Electronic Disease Surveillance System (NEDSS) project is a public health initiative to provide a standard-based, integrated approach to disease surveillance and to connect public health surveillance to the burgeoning clinical information systems infrastructure. NEDS...

200

Electronic Resource Management Systems in Practice  

Science.gov (United States)

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…

Grogg, Jill E.

2008-01-01

201

Pseudopotentials for correlated electron systems  

CERN Document Server

A scheme is developed for creating pseudopotentials for use in correlated-electron calculations. Pseudopotentials for the light elements H, Li, Be, B, C, N, O, and F, are reported, based on data from high-level quantum chemical calculations. Results obtained with these correlated electron pseudopotentials (CEPPs) are compared with data for atomic energy levels and the dissociation energies, molecular geometries and zero-point vibrational energies of small molecules obtained from coupled cluster single double triple (CCSD(T)) calculations with large basis sets. The CEPPs give better results in correlated-electron calculations than Hartree-Fock-based pseudopotentials available in the literature.

Trail, J R

2013-01-01

202

Risks of Using Antifouling Biocides in Aquaculture  

OpenAIRE

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...

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

2012-01-01

203

Acartia Bifilosa viability in freshwater aquacultures  

OpenAIRE

Abstract A lot of research has been given to the use of copepods in saltwater aquacultures; however there is also a demand for freshwater fish that could also potentially benefit from being fed copepods. Acartia bifilosa is a robust species in regards to their salinity stress and are as such potential candidates to utilize in freshwater aquacultures if they are capable of hatching and surviving for long enough to allow the fish larvae to ingest them. Sediment from Umeå, Sweden, was inv...

Olsson, Malthe Mathias; Adlouni, Yasmin; Højgaard, Heidi Charlotte

2014-01-01

204

Aquaculture: Environmental, toxicological, and health issues.  

Science.gov (United States)

Aquaculture is one of the fastest growing food-producing sectors, supplying approximately 40% of the world's fish food. Besides such benefit to the society, the industry does have its problems. There are occupational hazards and safety concerns in the aquaculture industry. Some practices have caused environmental degradation. Public perception to farmed fish is that they are "cleaner" than comparable wild fish. However, some farmed fish have much higher body burden of natural and man-made toxic substances, e.g. antibiotics, pesticides, and persistent organic pollutants, than wild fish. These contaminants in fish can pose health concerns to unsuspecting consumers, in particular pregnant or nursing women. Regulations and international oversight for the aquaculture industry are extremely complex, with several agencies regulating aquaculture practices, including site selection, pollution control, water quality, feed supply, and food safety. Since the toxicological, environmental, and health concerns of aquaculture have not been adequately reviewed recently, we are providing an updated review of the topic. Specifically, concerns and recommendations for improving the aquaculture industry, and for protection of the environment and the consumers will be concisely presented. PMID:18790671

Cole, David W; Cole, Richard; Gaydos, Steven J; Gray, Jon; Hyland, Greg; Jacques, Mark L; Powell-Dunford, Nicole; Sawhney, Charu; Au, William W

2009-07-01

205

Focused electron and ion beam systems  

Science.gov (United States)

An electron beam system is based on a plasma generator in a plasma ion source with an accelerator column. The electrons are extracted from a plasma cathode in a plasma ion source, e.g. a multicusp plasma ion source. The beam can be scanned in both the x and y directions, and the system can be operated with multiple beamlets. A compact focused ion or electron beam system has a plasma ion source and an all-electrostatic beam acceleration and focusing column. The ion source is a small chamber with the plasma produced by radio-frequency (RF) induction discharge. The RF antenna is wound outside the chamber and connected to an RF supply. Ions or electrons can be extracted from the source. A multi-beam system has several sources of different species and an electron beam source.

Leung, Ka-Ngo; Reijonen, Jani; Persaud, Arun; Ji, Qing; Jiang, Ximan

2004-07-27

206

Electron transport in molecular systems  

International Nuclear Information System (INIS)

Large-scale quantum electronic structure calculations coupled with nonequilibrium Green function theory are employed for determining quantum conductance on practical length scales. The combination of state-of-the-art quantum mechanical methods, efficient numerical algorithms, and high performance computing allows for realistic evaluation of properties at length scales that are routinely reached experimentally. Two illustrations of the method are presented. First, quantum chemical calculations using up to 104 basis functions are used to investigate the amphoteric doping of carbon nanotubes by encapsulation of organic molecules. As a second example, we investigate the electron transport properties of a Si/organic molecule/Si junction using a numerically optimized basis

207

Evaluation of Pacific White Shrimp (Litopenaeus vannamei) Health during a Superintensive Aquaculture Growout Using NMR-Based Metabolomics  

OpenAIRE

Success of the shrimp aquaculture industry requires technological advances that increase production and environmental sustainability. Indoor, superintensive, aquaculture systems are being developed that permit year-round production of farmed shrimp at high densities. These systems are intended to overcome problems of disease susceptibility and of water quality issues from waste products, by operating as essentially closed systems that promote beneficial microbial communities (biofloc). The re...

Schock, Tracey B.; Duke, Jessica; Goodson, Abby; Weldon, Daryl; Brunson, Jeff; Leffler, John W.; Bearden, Daniel W.

2013-01-01

208

High performance electron processing systems  

International Nuclear Information System (INIS)

Many of the processes of immediate interest for commercial electron curing require large, single pass doses at high speed. The machine designer is faced with some practical upper limits to the dose rate (or electron current density) which can be used efficiently by the chemistry being initiated in the product. In addition, he must pay attention to the temperature excursions in the product due to the relatively low glass transition temperatures or softening temperatures in the substrates of interest. A new family of processors is described capable of delivering up to one megarad at 1500 meters per minute (typically 10 megarads at 150 m/minute). Product temperature excursions are controlled by the use of a shielded drum located within the processor Selfshield. Considerations of the real time diagnosis and control of these processors in production application are discussed, along with typical uniformity and penetration performance in the product

209

High performance electron processing systems  

International Nuclear Information System (INIS)

Many of the processes of immediate interest for commercial electron curing require large, single pass doses at high speed. The machine designer is faced with some practical upper limits to the dose rate (or electron current density) which can be used efficiently by the chemistry being initiated in the product. In addition, he must pay attention to the temperature excursions in the product due to the relatively low glass transition temperatures or softening temperatures in the substrates of interest. A new family of processors is described capable of delivering up to one megarad at 1500 meters per minute (typically 10 megarads at 150 m/minute). Product temperature excursions are controlled by the use of a shielded drum located within the processor. Considerations of the real time diagnosis and control of these processors in production application are discussed, along with typical uniformity and penetration performance in the product. (author)

210

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

Science.gov (United States)

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

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

2007-10-01

211

Ecotoxicity assessment in aquaculture system using the test organism Pseudokirchneriella subcapitata (Chlorophyceae=Avaliação da ecotoxicidade em sistema de aquicultura utilizando o organismo-teste Pseudokirchneriella subcapitata (Chlorophyceae  

Directory of Open Access Journals (Sweden)

Full Text Available The purpose of this study is to perform toxicity tests with microalgae Pseudokirchneriella subcapitata (Chlorophyceae using inland water samples to evaluate the impact caused by aquaculture. Six field samples were collected ranged November 2006 to March 2007, at Experimental Station, Pindamonhangaba, State of São Paulo. Abiotic factors pointed out to the mesotrophic and eutrophic characteristics already observed at the fish pond and its effluent. The results of ecotoxicological tests carried out with the microalgae Pseudokirchneriella subcapitata showed that the fish pond effluent was potential enough to stimulate the algal growth, therefore eutrophication, to the extent that it is naturally diluted to at least 12.5% of its initial concentration. This type of test can be a tool to be used by environmental managers in attempts to measure the extents of the impacts of effluent discharges from fish farming and to propose treatments based on qualitative and quantitative information.O objetivo deste trabalho foi realizar testes ecotoxicológicos com a microalga Pseudokirchneriella subcapitata (Chlorophyceae em amostras de água de piscicultura continental, para avaliar impactos gerados pela atividade. Seis campanhas amostrais foram realizadas entre novembro de 2006 e março de 2007 na piscicultura experimental, Pindamonhangaba, Estado de São Paulo. Os fatores abióticos apontaram para características mesotróficas e eutróficas do viveiro e do efluente. Os testes com amostras brutas indicaram que mesmo após o encontro do efluente com o corpo de água receptor, a carga orgânica do viveiro foi capaz de estimular crescimento algáceo. Os resultados obtidos nos ensaios ecotoxicológicos realizados com a microalga Pseudokirchneriella subcapitata demonstraram que o efluente do viveiro de piscicultura exerceu um risco de eutrofização do meio até o ponto em que o mesmo estiver naturalmente diluído a 12,5% da sua concentração no corpo hídrico receptor. Ficou demonstrado que este tipo de ensaio pode ser uma ferramenta passível de utilização por gestores ambientais nas tentativas de mensurar as extensões dos impactos dos lançamentos de efluentes de piscicultura e de propor tratamentos com base em informações qualitativas e quantitativas.

Cacilda Thais Janson Mercante

2012-10-01

212

Electronic states in systems of reduced dimensionality  

International Nuclear Information System (INIS)

This report briefly discusses the following research: magnetically modulated systems, inelastic magnetotunneling, ballistic transport review, screening in reduced dimensions, raman and electron energy loss spectroscopy; and ballistic quantum interference effects. (LSP)

213

Graphics System in Vehicle Electronics  

OpenAIRE

In this thesis three problems areas are studied related to embedded system and device driver programming: a GPS driver, the CAN Bus and study of graphics libraries suitable for embedded systems. The thesis has two parts: an academic study and an implementation phase based on the academic study. The Freescale i.MX31ADS development board together with ENEA's operating system OSE is used as a basis for the study and it is shown that OpenGL ES is best suited for the platform. Further the system c...

Kjellgren, Andreas

2009-01-01

214

A Comparative Assessment of Hydroponically Grown Cereal Crops for the Purification of Aquaculture Wastewater and the Production of Fish Feed  

OpenAIRE

Hydroponically grown wheat, barley and oats were examined for their ability to remove nutrients from aquaculture wastewater. Wheat, barley and oats seeds were germinated in water in a 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 although fungal growth was evident. The average crop heights and yields at harvest were 19....

Snow, A. M.; Ghaly, Abdel E.

2008-01-01

215

User oriented software system for electron microprobes  

International Nuclear Information System (INIS)

A user-oriented software system for electron microprobes is described. The TASK automation program which provides instrument control and data collection is also capable of calling auxiliary programs which can provide quantitative data reduction, editing, plotting, summary, and statistical analysis capabilities. Qualitative analysis auxiliary capabilities include digital electronic scanning of the beam, mechanical scanning of the stage and the wavelength dispersive (WDS) spectrometers, identification of energy dispersive (EDS) peaks, low magnification x-ray mapping (which requires synchronous scanning of the spectrometers and the electron beam) and particle characterization. A disk operating system facilitates loading, exchanging, and saving of programs and data

216

Electronic Student Attendance Recording System  

Directory of Open Access Journals (Sweden)

Full Text Available Bluetooth technology is offering a very robust way to transfer data in faster rates within a short range wireless communication local network. Wireless and radio communication technologies are giving organizations and users many benefits such as portability and flexibility, increased productivity, and lower the installation costs.  Register the attendance and absence for students in the classroom of all educational institutions is one of the most intensive daily operations. In this paper, we are interesting to use the free wireless communication via Bluetooth technology that is available in most mobile phones and computer systems to build a computerized wireless clients-server network system. The client side will be a mobile phone that used to fill the list of attendance and absence for students in a classroom of educational institutions in an easy and fast way.  Server side will contain the centralized database and monitoring attendance system for the distributing clients connected to the system. The idea of this system is developed and implemented on real educational institution. The recorded results show that the system saves a costs and efforts and helps the educational institution to get a more effective system than the old one.

Dr. AkramAbedelKarim Ahmad AbdelQader

2013-03-01

217

Corrosion Reliability of Electronic Systems  

DEFF Research Database (Denmark)

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 describes an investigation of the electrolytic migration of Sn-Pb solder lines on PCBs in humid environments under applied potential conditions. Studies were carried out using two electrode potentiostatic polarization experiments and measuring the resulting current due to electrolytic migration. The surface morphology of the electrodes before and after migration testing was investigates using SEM and EDS. An in-service failure of a Ceramic Capacitor due to electrolytic migration in humid environments is also presented.

Ambat, Rajan; Jensen, Stine G.

2008-01-01

218

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

CERN Document Server

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.

Dutta, Mitra

1998-01-01

219

THE STATUS OF AQUACULTURE IN THE WORLD AND IN EUROPE  

OpenAIRE

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 pr...

Nikola Fijan

2002-01-01

220

Investigation into the sustainability of organic aquaculture of Atlantic cod (Gadus morhua  

Directory of Open Access Journals (Sweden)

Full Text Available Wild stocks of Atlantic cod (Gadus morhua are low. With fisheries in decline, continued demand for cod has led to a fledgling aquaculture industry and current forecasts call for rapid growth. However, critics blame aquaculture of carnivorous species for further depleting fish stocks and for its wider effects on the marine environment. We examine the activities of Johnson Seafarms, a sea-cage organic cod farming facility in the Shetland Islands, to investigate whether “organic” cod farming can be environmentally, economically, and socially sustainable. Data were collected via public questionnaires and interviews with aquaculture experts. The results show that, before it closed in 2008, Johnson Seafarms was addressing the environmental concerns traditionally associated with aquaculture of carnivorous species and that economic viability is possible as a market exists for organically farmed cod at prices higher than for wild fish. We conclude that organic cod farming, as was practiced in the Shetland Islands, is sustainable on that scale. While the industry has room for measured expansion, overexpansion would increase pressure on natural systems, undermining environmental and, ultimately, social and economic sustainability. Producers and regulators should consider alternative techniques, including land-based or integrated aquaculture systems. Any development should be accompanied by further research regarding the industry’s sustainability.

Benjamin Birt

2009-09-01

221

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)

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.

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

2013-07-01

222

Vertical Integration in the Taiwan Aquaculture Industry  

Directory of Open Access Journals (Sweden)

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.

Tzong-Ru Lee (Jiun-Shen

2011-12-01

223

Increased competition for aquaculture from fisheries : does improved fisheries management limit aquaculture growth?  

DEFF Research Database (Denmark)

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 fish. We find that improved fisheries management, ceteris paribus, reduces the growth potential of global aquaculture in markets where wild fisheries constitute a large share of total supply.

Jensen, Frank; Nielsen, Max

2014-01-01

224

Harry K. Dupree Stuttgart National Aquaculture Research Center  

Science.gov (United States)

Aquaculture (fish farming) has played an ever-increasing role in providing people with fish, shrimp, and shellfish. Aquaculture is currently the fastest growing sector of global food production and in 2011 totaled 60 million tons valued at $119 billion. The production of food-fish from aquaculture...

225

Electronics applied to buildings lighting systems  

Energy Technology Data Exchange (ETDEWEB)

Progress in the introduction of electronics into building lighting systems has allowed the use of more architecturally interesting lighting components to enhance overall building architecture, the creation of more pleasant and safer working environments, and the adoption of intelligent building energy management systems to reduce energy consumption. ENEL (Italian National Electricity Board), through extensive energy conservation studies on building lighting systems, has now begun a campaign of information dissemination to educate consumers on how to efficiently manage building lighting and to make effective use of innovative electronic lighting equipment.

Bellato, G.

1990-08-01

226

Water budgets for freshwater aquaculture ponds with reference to effluent volume  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents the consumptive water use for freshwater pond aquaculture for semi-intensive carps farming practices. The consumptive use of water includes evaporation loss, seepage loss and water exchanges requirements. The water requirement has been estimated to be10.3 m3/Kg of fish production under present study for semi-intensive culture and with supplemental feeding. Out of which7.6 m3/Kg of fish production is system associated requirement. On an average the evaporation loss from the pond is1498.3 mm/year and seepage loss per year is about1182.60 mm/year. Seepage and water exchange losses recharge the ground water aquifers and if they are treated and recycled, the water use in aquaculture can be reduced significantly. A further reduction in fresh water use in pond aquaculture is possible through development of intensive and superintensive culture systems and aqua feeds.

K. K. Sharma

2013-07-01

227

Bioinspired electron-transfer systems and applications  

International Nuclear Information System (INIS)

Bioinspired electron-transfer systems including artificial photosynthesis and respiration are presented herein together with some of their applications. First, multi-step electron-transfer systems composed of electron donor-acceptor ensembles have been developed, mimicking functions of the photosynthetic reaction center. However, a significant amount of energy is lost during the multi-step electron-transfer processes. Then, as an alternative to conventional charge-separation functional molecular models based on multi-step long-range electron transfer within redox cascades, simple donor-acceptor dyads have been developed to attain along-lived and high energy charge-separated state without significant loss of excitation energy, by fine control of the redox potentials and of the geometry of donor-acceptor dyads that have small reorganization energies of electron transfer. Such simple molecular dyads, capable of fast charge separation but extremely slow charge recombination, have significant advantages with regard to synthetic feasibility, providing a variety of applications including construction of organic solar cells and development of efficient photo-catalytic systems for the solar energy conversion. An efficient four-electron reduction of dioxygen to water by one-electron reductants such as ferrocene derivatives as well as by an NADH analog has also been achieved as a respiration model by using a cofacial dicobalt porphyrin that can form the ?-peroxo Co(III)-O2hat can form the ?-peroxo Co(III)-O2Co(III) complex. The catalytic mechanism of the four-electron reduction of dioxygen has been clarified based on the detailed kinetic study and the detection of the intermediate. (author)

228

Electron transport through molecular bridge systems  

OpenAIRE

Electron transport characteristics are investigated through some molecular chains attached to two non-superconducting electrodes by the use of Green's function method. Here we do parametric calculations based on the tight-binding formulation to characterize the electron transport through such bridge systems. The transport properties are significantly influenced by (a) the length of the molecular chain and (b) the molecule-to-electrodes coupling strength and here we focus are...

Maiti, Santanu K.

2009-01-01

229

Tomography system with electronic control device  

International Nuclear Information System (INIS)

The system for tomography utilises a source of X-radiation or gamma radiation and an electronic control unit. The radiation source, object carrier, slit forming masks and detector unit are spatially arranged on opposite sides of each other in groups. The electronic control circuit uses a drive mode circuit with a connection to the input window of the video camera. The tube has means for beam deflection in both the horizontal and vertical modes. (G.C.)

230

Exact duality relations in correlated electron systems  

OpenAIRE

Using gauge transformations on electron bond operators, we derive exact duality relations between various order parameters for correlated electron systems. Applying these transformations, we find two duality relations in the generalized two-leg Hubbard ladder at arbitrary filling. The relations show that unconventional density-wave orders such as staggered flux or circulating spin-current are dual to conventional density-wave orders and there are direct mappings between dual...

Momoi, Tsutomu; Hikihara, Toshiya

2003-01-01

231

Inelastic Electron Lifetime in Disordered Mesoscopic Systems  

OpenAIRE

The 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 detail. In the case of co...

Blanter, Yaroslav M.

1996-01-01

232

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)

Full Text Available SciELO Chile | Language: English Abstract in spanish 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.

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

1169-11-01

233

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

Science.gov (United States)

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.

Cline, David John

234

A Flexible Electronic Commerce Recommendation System  

Science.gov (United States)

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.

Gong, Songjie

235

Implementation of an Electronic Media Security System  

Energy Technology Data Exchange (ETDEWEB)

Recent security lapses within the Department of Energy Laboratories prompted the establishment and implementation of additional procedures and training for operations involving classified removable electronic media (CREM) storage. In addition, the definition of CREM has been expanded and the number of CREM has increased significantly. Procedures now require that all CREM be inventoried and accounted for on a weekly basis. Weekly inventories consist of a physical comparison of each item against the reportable inventory listing. Securing and accounting for CREM is a continuous challenge for existing security systems. To address the challenge, Pacific Northwest National Laboratory (PNNL) has developed an automated Electronic Media Security System (EMSS) for a weekly CREM inventory collection and reporting system. The EMSS approach is to tag the CREM with an electronically readable unique identification code and automatically collect data on the inventory in each security container or vault at a user-defined interval and upon detection of an access event; thus eliminating the need for hand-written inventory sheets while allowing automated transfer of the collected inventory data to an electronic reporting system. An electronic log of CREM access events is maintained, providing enhanced accountability for daily/weekly checks, routine audits, and follow-up investigations. The key attributes of the EMSS include improved accountability, reduced risk of human error, improved accuracy and timeliness of inventory data, and reduced costs as a result of man-hour reductions.

Silvers, Kurt L.; Burghard, Brion J.; Skorpik, James R.; Clark, Dave A.

2005-09-01

236

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)

237

Prognostics for Electronics Components of Avionics Systems  

Science.gov (United States)

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.

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

2009-01-01

238

PROTEOMICS in aquaculture : Applications and trends  

DEFF Research Database (Denmark)

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.

Rodrigues, Pedro M.; Silva, Tomé S.

2012-01-01

239

Aquaculture in Hawaii: Past, present, and future  

OpenAIRE

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.

Wyban, J.; Wyban, C.

1989-01-01

240

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

241

Inverness College: Innovations in Aquaculture Training.  

Science.gov (United States)

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,…

Regional Technology Strategies, Inc., Carrboro, NC.

242

THE STATUS OF AQUACULTURE IN THE WORLD AND IN EUROPE  

Directory of Open Access Journals (Sweden)

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.

Nikola Fijan

2002-06-01

243

Electron-drag effects in coupled electron systems  

CERN Document Server

The advancement of fabrication and lithography techniques of semiconductors have made it possible to study bi-layer systems made of two electronic layers separated by distances of several hundred Angstroms. In this situation the electrons in layer 1 are distinguishable from those in layer 2, and can communicate through the direct inter-layer Coulomb interaction. In particular, if a current is applied to one of the layers, the electrons in th e second will be dragged giving rise to a transresistance $\\rho_D$. In this article we review recent theoretical and experimental developments in the understanding of this effect. At very low temperatures it turns out that phonons dominate the transresistance. The direct Coulomb interaction and plasmon excitations are important at temperatures $T>0.1T_F$, with $T_F$ the Fermi temperature. If a magnetic field is applied the transresistance is increased, in a very interesting interplay between $\\rho_D$ and Landau quantization. The non-dissipative drag is also reviewed.

Rojo, A G

1999-01-01

244

Method of fabricating a cooled electronic system  

Science.gov (United States)

A method of fabricating a liquid-cooled electronic system is provided which includes an electronic assembly having an electronics card and a socket with a latch at one end. The latch facilitates securing of the card within the socket. The method includes providing a liquid-cooled cold rail at the one end of the socket, and a thermal spreader to couple the electronics card to the cold rail. The thermal spreader includes first and second thermal transfer plates coupled to first and second surfaces on opposite sides of the card, and thermally conductive extensions extending from end edges of the plates, which couple the respective transfer plates to the liquid-cooled cold rail. The extensions are disposed to the sides of the latch, and the card is securable within or removable from the socket using the latch without removing the cold rail or the thermal spreader.

Chainer, Timothy J; Gaynes, Michael A; Graybill, David P; Iyengar, Madhusudan K; Kamath, Vinod; Kochuparambil, Bejoy J; Schmidt, Roger R; Schultz, Mark D; Simco, Daniel P; Steinke, Mark E

2014-02-11

245

Spectral properties of Dirac electron system  

Science.gov (United States)

We present the extension of our previous G0W0 approach to the two-dimensional system of massless Dirac electrons interacting via the long-range Coulomb interaction. We determine the one-particle spectral function taking into account only a partially filled linear band above the Dirac point. The electron self-energy is calculated, paying particular attention to the contribution coming from the collective plasmon mode through the dynamically screened Coulomb electron-electron interaction. The obtained results show a dispersing feature in the spectral function and a low energy quasi-particle with the renormalized spectral weight. We expect the results obtained to be qualitatively in agreement with spectral properties of monolayer of MoS2 which has the large direct band gap between the valence and conduction bands. We also discuss the influence of the underlying substrate on the obtained results.

Bona?i? Loši?, Ž.

2015-03-01

246

Ferromagnetism in p-electron system  

International Nuclear Information System (INIS)

We demonstrate the origin of the unexpected exotic ferromagnetism in p-electron system, Ca1-xLaxB6, using high resolution ultraviolet photoemission spectroscopy (UPS). We have carried out a comparative UPS study of the parent compounds, CaB6 and LaB6. Magnetic measurements indicate high temperature ferromagnetism in CaB6 but LaB6 remains paramagnetic down to the lowest temperature studied. Temperature dependent UPS valence band spectra exhibits finite density of states at the Fermi energy (?F) and distinct localized features below ?F at low temperatures in case of CaB6. However, the valence band in LaB6 does not show signature of localization, instead it shows disorder induced pseudogap at ?F at low temperatures. Spectral analysis of the localized features in CaB6 suggest that they originate from partial localization of B 2p electrons constituting the valence band. We conclude from our results that both disorder in the boron lattice and dilute conduction electron density are needed to achieve ferromagnetism in these systems. Our results thus suggest that the controversial magnetism in this p-electron system is not entirely extrinsic as was believed earlier but there exists an intrinsic source for this exotic p-electron ferromagnetism. (author)

247

Total and inorganic arsenic in natural and aquacultural freshwater fish in Thailand: a comparative study.  

Science.gov (United States)

Total and inorganic arsenic were determined in 108 samples of four freshwater fish species collected from natural water sources and aquaculture systems in the central region of Thailand between March and May 2010. Concentrations of total and inorganic arsenic (dry wt) and percentages of inorganic arsenic in four aquacultural fish species were not significantly different from those found in natural fish. Inorganic arsenic levels found in the four fish species from both sources in this study were much lower than the Thai regulatory standard of 2 ?g/g, and hence are considered safe for human consumption. PMID:23073739

Ruangwises, Nongluck; Saipan, Piyawat; Ruangwises, Suthep

2012-12-01

248

Enhancement of existing geothermal resource utilization by cascading to intensive aquaculture  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1996-04-01

249

The DIAMANT electronics and data acquisition system  

International Nuclear Information System (INIS)

We describe the electronics and data acquisition system of the 4? light particle multidetector array DIAMANT. This system has been conceived to be very modular with regard to both the kind and number of detectors. The whole system is designed to run either with a few additional ancillary detectors (Ge) or linked to 4? ? arrays such as EUROGAM. Part of the electronics has been designed using SMD devices; the acquisition is based on CAMAC ADCs and VME units for data acquisition, data transfer is handled via a 32 bit ECL bus (DT32) used for EUROGAM. The data acquisition, distributed on a network, is based on the VxWorks real time kernel and the UNIX operating system. (orig.)

250

Networked Training: An Electronic Education System.  

Science.gov (United States)

Presents perspectives on networked training based on the development of an electronic education system at the Westinghouse Savannah River Company that integrated motion video, text, and data information with multiple audio sources. The technology options of compact disc, digital video architecture, and digital video interactive are discussed. (LRW)

Ryan, William J.

1993-01-01

251

NATIONAL ELECTRONIC INJURY SURVEILLANCE SYSTEM (NEISS)  

Science.gov (United States)

The National Center for Injury Prevention and Control (NCIPC), Centers for Disease Control and Prevention (CDC) is collaborating with the U.S. Consumer Product Safety Commission (CPSC) to expand the National Electronic Injury Surveillance System (NEISS) to collect data on all typ...

252

Using Metadata Description for Agriculture and Aquaculture Papers  

Directory of Open Access Journals (Sweden)

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.

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

2012-12-01

253

Evaluation on Biofilter in Recirculating Integrated Multi-Trophic Aquaculture  

Directory of Open Access Journals (Sweden)

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

Asfie Maidie

2013-06-01

254

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

255

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

OpenAIRE

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 ...

Radu Muscalu; Cristina Muscalu; Mihai Nagy; Marian Bura; Zoltan-Tibor Szelei

2010-01-01

256

Application of Information Systems in Electronic Insurance  

Directory of Open Access Journals (Sweden)

Full Text Available 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 order information, standardized registration processes, speed up registration processes, customer contact, and electronic registration organization management. According to the result of our research, ERP can apply magic effect to the registration organization processes. CRM helps registration organization to use technology and human resources to gain insight into the behaviors of customers and the value of those customers. DSS can help manager to take a good decision about quality of their services and also improve electronic registration organization management. MIS has more effect on integrated customer information, and integrated customer order information, respectively. EDI allows us to send and receive information at any time thereby tremendous improving registration organizations are able to communicate quickly and efficiently. Internet is the most effective on registration organization development parameters. Database application is m ore useful to integrate customer information. According to the results networking is very effective to speed up registration processes in registration organization.

Payman Salami

2010-05-01

257

Electron gun system for NSC KIPT linac  

CERN Document Server

In NSC KIPT linac, a neutron source based on a subcritical assembly driven by a 100MeV/100kW electron linear accelerator is under design and development. The linear accelerator needs a new high current electron gun. In this paper, the physical design, mechanical fabrication and beam test of this new electron gun are described. The emission current is designed to be higher than 2A for the pulse width of 3us with repetition rate of 50 Hz. The gun will operate with a DC high voltage power supply which can provide a high voltage up to 150 kV. . Computer simulations and optimizations have been carried out in the design stage, including the gun geometry and beam transport line. The test results of high voltage conditioning and beam test are presented. The operation status of the electron gun system is also included. The basic test results show that the design, manufacture and operation of the new electron system are basically successful.

Zhou, Zusheng; Chi, Yunlong

2013-01-01

258

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

259

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

Directory of Open Access Journals (Sweden)

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.

Kafayat A. Fakoya

2009-10-01

260

Electron Dynamics in Finite Quantum Systems  

Science.gov (United States)

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.

McDonald, Christopher R.

261

Constructed Wetlands for freshwater and saline aquaculture wastewater treatment: a microcosm experience  

OpenAIRE

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...

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

2012-01-01

262

Minimizing noise in fiberglass aquaculture tanks: Noise reduction potential of various retrofits  

Science.gov (United States)

Equipment used in intensive aquaculture systems, such as pumps and blowers can produce underwater sound levels and frequencies within the range of fish hearing. The impacts of underwater noise on fish are not well known, but limited research suggests that subjecting fish to noise could result in imp...

263

Zope based electronic operation log system - Zlog  

International Nuclear Information System (INIS)

Since January 2004, the Zope based electronic operation logging system, named Zlog, has been running at the KEKB and AR accelerator facilities. Since Zope is the python based open source web application server software and python language is familiar for the members in the KEKB accelerator control group, we have developed the Zlog system rapidly. In this paper, we report the development history and the present status of Zlog system. Also we show some general plug-in components, called Zope products, have been useful for our Zlog development. (author)

264

Electron radiographic system with liquid absorber  

International Nuclear Information System (INIS)

An electron radiographic system is presented for making x-ray pictures by producing an electrostatic image on a dielectric sheet suitable for development by xerographic techniques. A pair of electrodes has a liquid filled gap therebetween, with the liquid taking several forms. A dielectric sheet is positioned at an electrode and x-rays are directed past the object to the liquid for producing electrons and positive ions in the gap. The electrons and positive ions are attracted toward the respective electrodes for deposit on the dielectric sheet to produce the latent electrostatic image. The liquid is x-ray opaque and electrically nonconducting and may be a solvent with a gas or nonionic metallic compounds dissolved therein, or may be a liquified gas. (Auth.)

265

Electron correlations in narrow band systems  

International Nuclear Information System (INIS)

The effect of the electron correlations in narrow bands, such as d(f) bands in the transition (rare earth) metals and their compounds and the impurity bands in doped semiconductors is studied. The narrow band systems is described, by the Hubbard Hamiltonian. By proposing a local self-energy for the interacting electron, it is found that the results are exact in both atomic and band limits and reduce to the Hartree Fock results for U/? ? 0, where U is the intra-atomic Coulomb interaction and ? is the bandwidth of the noninteracting electrons. For the Lorentzian form of the density of states of the noninteracting electrons, this approximation turns out to be equivalent to the third Hubbard approximation. A simple argument, based on the mean free path obtained from the imaginary part of the self energy, shows how the electron correlations can give rise to a discontinous metal-nonmetal transition as proposed by Mott. The band narrowing and the existence of the satellite below the Fermi energy in Ni, found in photoemission experiments, can also be understood. (Author)

266

Secondary electron yields of solar system ices  

Science.gov (United States)

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.

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

1992-01-01

267

Electronic Document Management Using Inverted Files System  

Directory of Open Access Journals (Sweden)

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.

Suhartono Derwin

2014-03-01

268

Magnetic impurity in correlated electrons system  

CERN Document Server

We study a magnetic impurity embedded in a correlated electron system using the density-matrix renormalization group method. The correlated electron system is described by the one-dimensional Hubbard model. At half filling, we confirm that the binding energy of the singlet bound state increases exponentially in the weak-coupling regime and decreases inversely proportional to the correlation in the strong-coupling regime. The spin-spin correlation shows an exponential decay with distance from the impurity site. The correlation length becomes smaller with increasing the correlation strength. We find discontinuous reduction of the binding energy and of spin-spin correlations with hole doping. The binding energy is reduced by hole doping; however, it remains of the same order of magnitude as for the half-filled case.

Nishimoto, S

2007-01-01

269

Productivity in organic and conventional salmon aquaculture  

OpenAIRE

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,...

Reithe, Siv; Tvetera?s, Ragnar

2000-01-01

270

Probiotics as control agents in aquaculture  

Science.gov (United States)

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.

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

2007-01-01

271

Organic matter decomposition in simulated aquaculture ponds  

OpenAIRE

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...

Torres Beristain, B.

2005-01-01

272

Scenarios for Resilient Shrimp Aquaculture in Tropical Coastal Areas  

Directory of Open Access Journals (Sweden)

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.

Willem F. de Boer

2010-06-01

273

Synthesizing cognition in neuromorphic electronic systems  

OpenAIRE

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” r...

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

2013-01-01

274

Requirement specifications for electronic voting systems  

OpenAIRE

This paper presents an analysis of the requirements specification in electronic voting systems. In particular, it poses a specification that assumes a physical distributed architecture model with two networked intelligent units (Voting Terminal and Authorities Terminal). State Transition Diagrams and Use Cases are used in the modeling of the requirements. Finally, the model adaptation to two classes of different elections is analyzed: a national election of closed daily cycle and a university...

Pesado, Patricia; Feierherd, Guillermo Eugenio; Pasini, Ariel C.

2005-01-01

275

Integration of thermal and food processing residuals into a system for commercial culture of freshwater shrimp (power plant waste heat utilization in aquaculture). Volume I. Final report 1 Jul 74-31 Oct 76  

Energy Technology Data Exchange (ETDEWEB)

The primary objective of this study was to establish the bilogical feasibility of rearing the freshwater shrimp Macrobrachium rosenbergii and rainbow trout Salmo gairdneri in the thermal effluents from PSEandG's Mercer Generating Station. A new approach in aquaculture involving semiannual grow-out periods, diseasonal aquaculture was the result of the large seasonal variation in Delaware River temperature (0.2 to 29/sup 0/C), since it was determined that no commercially important species could take this wide temperature range. Secondary objectives of this study were to make preliminary evaluations of the engineering and economic feasibility of rearing the above-mentioned species in thermal effluents, and to obtain a preliminary assessment of product quality.

Guerra, C.R.; Godfriaux, B.L.; Eble, A.F.; Farmanfarmian, A.F.

1977-01-01

276

Risks of using antifouling biocides in aquaculture.  

Science.gov (United States)

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

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

2012-01-01

277

Risks of Using Antifouling Biocides in Aquaculture  

Directory of Open Access Journals (Sweden)

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.

José Meseguer

2012-02-01

278

Vaccination strategies in freshwater salmonid aquaculture.  

Science.gov (United States)

The focus of this chapter is antibacterial vaccines. The main salmonid species in freshwater aquaculture is the rainbow trout. Other salmonid species are produced on a limited scale. The most important bacterial fish diseases in European freshwater aquaculture are the rainbow trout fry syndrome-RTFS-(Flavobacterium psychrophilum) and enteric redmouth disease-ERM-(Yersinia ruckeri) which are widespread and cause serious epizootics, while furunculosis (Aeromonas salmonicida) is endemic, only giving overt disease under extremely stressing conditions. In the hatchery, there is a need for vaccination against RTFS (not commercially available) and ERM; in the ponds it is urgent to vaccinate against ERM, while the importance of furunculosis vaccination is not clear. The fish for ongrowing in saltwater should be vaccinated against ERM, furunculosis and vibriosis. Commercial vaccines are available against these diseases, either as single component or combination vaccines for immersion and injection-and oral vaccines are under registration. Hitherto, there has not been much strategic research on vaccination in freshwater; however recent results suggest that with the regime of vaccines available (and soon available), fish should be vaccinated with an ERM immersion vaccine in the hatchery approximately four weeks before transfer to the ponds. To cover the growth period in fresh water an oral booster should be given two to three months later. There is a need for development and research in strategic use of an RTFS and a furunculosis vaccine in freshwater aquaculture. PMID:9270868

Larsen, J L; Pedersen, K

1997-01-01

279

State of the art of Italian aquaculture  

Directory of Open Access Journals (Sweden)

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.

P. Melotti

2010-04-01

280

Importation of aquaculture seedlings to Japan.  

Science.gov (United States)

Japan is one of the largest consumers of fishery products in the world. Importation of various fishery commodities - including larvae and eggs for aquaculture - is increasing due to high consumer demand. Elvers of Anguilla anguilla have been imported from Europe since the late 1960s. Eyed eggs of coho salmon (Oncorhynchus kisutch) are imported from North America. During the last decade, over-production caused the price of Japanese amberjack (or 'yellowtail') (Seriola quinqueradiata) and Japanese seabream (Pagrus major) to drop, forcing farmers to venture into the culture of other species. A variety of marine fish seedlings are now imported from Asian countries. Almost all aquaculture production of coho salmon, greater amberjack (Seriola dumerili), seabass (Lateolabrax japonicus), rockfish (Sebastes spp.) and groupers (Epinephlus septemfaciatus, etc.) depends on imported seedlings. These species accounted for approximately 9% by value of marine finfish production in Japan in 1993. Apart from ubiquitous or endemic pathogens, a considerable number of exotic microorganisms and parasites are suspected to have accompanied fish eggs and larvae imported for aquaculture purposes. On a voluntary basis, 80-90% of imported salmon eggs are being examined for bacterial kidney disease and salmon viruses by semi-governmental organisation. Voluntary inspections are also being conducted on some other fish species imported from foreign countries. No legislation exists, however, for the control of exotic fish pathogens. PMID:8890372

Wakabayashi, H

1996-06-01

281

National activities in the field of Aquaculture: Ireland  

OpenAIRE

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...

Griffith, David G.

1996-01-01

282

On the relationship between aquaculture and reduction fisheries  

OpenAIRE

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 ...

Asche, Frank; Tvetera?s, Sigbjørn

2000-01-01

283

Advanced Electronic Systems. Curriculum Guide for Technology Education.  

Science.gov (United States)

This curriculum for a 1-semester or 1-year course in electronics is designed to take students from basic through advanced electronic systems. It covers several electronic areas, such as digital electronics, communication electronics, industrial process control, instrumentation, programmable controllers, and robotics. The guide contains…

Patrick, Dale R.

284

Analysis of economic and biological factors of waste heat aquaculture  

Energy Technology Data Exchange (ETDEWEB)

A waste heat aqualculture system using extensive culture techniques is currently under investigation at the Oak Ridge National Lab. The system uses nutrients in waste water streams to grow algae and zooplankton which provide feed for fish and clams. A tilapia polyculture association and the freshwater clam Corbicula are the animals cultured in the system. The investigations detailed in this study have been performed to determine the economic and biological fesibility of the system and to examine energy utilization. The economic study indicated that fish producion costs of $0.24/lb were possible. This cost, however, depends upon the fish production rate and food conversion efficiency and could rise to as much as $0.75/lb. The biological studies have examined growth relationships and production potential of the cultured organisms. In the laboratory, growth-temperature optima have been deinfed (32/sup 0/C, with good growth rates between 26 and 34/sup 0/C) for tilapia hybrids. Using cage culture techniques in sewage oxidation ponds, we have obtained production estimates in excess of 50,000 lb/acre/yr. The energy utilization study indicated that, when all energy costs are included, fish from the aquaculture system may require only 35% of the net energy now required for fish products from the ocean. However, the energy requirements also depend on system parameters and could be large as those required for ocean-caught products. The analyses indicate that the system is economically feasible. They also indicate that significant energy savings are possible if waste heat aquaculture products replace ocean-caught products.

Suffern, J. S.; Olszewski, M.

1978-01-01

285

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

Science.gov (United States)

...2010-07-01 2010-07-01 false Aquaculture projects (applicable to State NPDES...Program Requirements § 122.25 Aquaculture projects (applicable to State NPDES...Permit requirement. Discharges into aquaculture projects, as defined in this...

2010-07-01

286

Electron density profile in multilayer systems  

International Nuclear Information System (INIS)

Complete text of publication follows. Electron energy loss spectroscopy (EELS) has been used extensively to study the multilayer systems, where the thickness of layers are in the nanometer range. These studies has received considerable attention because of its technological interest, for example in the nanotechnology. On the most fundamental level, its importance is derived from the basic physics that is involved. One key quantities of interest is the response of a many-body system to an external perturbation: How act and how modify the interface between the solid-solid or solid-vacuum the excitations in the solid and in the vicinity of the interfaces. In this work, as a starting point of such investigations we calculated the electron density profile for multilayer systems. Our approach employs the time-dependent density functional theory (TDDFT), that is, the solution of a time-dependent Schroedinger equation in which the potential and forces are determined selfconsistently from the dynamics governed by the Schroedinger equation. We treat the problem in TDDFT at the level of the local-density approximation (LDA). Later, the comparison of experimentally obtained loss functions and the theory, based on our TDDFT calculations can provide deeper understanding of surface physics. We performed the calculations for half-infinite samples characterized by rs=1.642 and rs=1.997. We also performed the calculations for double layer systems. The substrate wafor double layer systems. The substrate was characterized by rs=1.997 and the coverage by rs=1.642. Fig. 1. shows the obtained electron density profile in LDA approximation. Because of the sharp cutoff of electronic wave vectors at the Fermi surface, the densities in the interior exhibit slowly decaying Friedel oscillations. To highlight the Friedel oscillation we enlarged the electron density profile in Fig. 1a. and Fig. 1b. The work was supported by the Hungarian Scientific Research Found: OTKA No. T038016, the grant 'Bolyai' from the Hungarian Academy of Sciences, and TeT Grant Nos. CHN-3/2004,and A-15/04. (author)

287

Electronic journal management systems experiences from the field  

CERN Document Server

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,

Ives, Gary W

2013-01-01

288

Freshwater aquaculture in the United States: Complying with environmental protection law and policy  

OpenAIRE

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...

Noble, M.

1993-01-01

289

Diet breadth variation and trophic plasticity behavior of the African bonytongue Heterotis niloticus (Cuvier, 1829 in the Sô River-Lake Hlan aquatic system (Benin, West Africa: Implications for species conservation and aquaculture development  

Directory of Open Access Journals (Sweden)

Full Text Available The African bonytongue, Heterotis niloticus (Pisces: Osteoglossidae, is an omnivore foraging mainly on aquatic insects, microcrustacea, seeds and detritus. We examined the diet breadth and the trophic plasticity behavior of this species (1461 specimens in the S? River and Lake Hlan water system located in the southern Benin (West Africa. Overall, the mean diet breadths of the two populations of Heterotis from both habitats were not significantly (p ? 0.05 different and were not associated with seasons. However, in Lake Hlan, mean diet breadths tended to increase with size (r = 0.81 and gut length (r = 0.82 indicating that bonytongues ingest a broader range of food resources as they grow. In both habitats, the positive correlation of both standard length (Log SL and gut length (Log GL with the volumetric proportions of detritus and with the volumetric proportions of seeds suggests that the consumption of these two food resources increased with the size of Heterotis and with the development of the digestive tract. Likewise, the negative correlation of both (Log SL and (Log GL with the volumetric proportions of aquatic insects and with the volumetric proportions of microcrustacea suggests that the consumption of these two food categories decreased as the size and the gut length of Heterotis increased. The differences in the consumption of microcrustacea (13.77% in Lake Hlan versus 2.63% in S? River and mollusks (0.73% in Lake Hlan versus 4.91% in S? River evidenced that Heterotis shifts his trophic structure according to resource availlability in the habitat. This foraging behavior suggests a degree of trophic plasticity in Heterotis. The specialized morphological structure of Heterotis, mainly the presence of a relatively high number of gill rakers (42 - 94 rakers on the first branchial arch during its whole life, allowing sieving of zooplankton and other microcrustacea, and the presence of the gizzard favored this trophic plasticity. The broader diet breadth coupled with the trophic plasticity behavior is probably an advantage because it enables Heterotis not only to colonize and to adapt to unstable and changing aquatic habitats, but also to invade and to well-establish in various ecosystems, such as freshwater lakes, swamps, inundated plains, streams, rivers and fish farming ponds. As a result, the wider diet breadths and the trophic plasticity behavior depicted are useful eco-ethological tool for the conservation and the aquaculture development of H. niloticus.

Alphonse Adite

2013-12-01

290

Multipole ordering in f-electron systems  

Energy Technology Data Exchange (ETDEWEB)

In order to investigate multipole ordering in f-electron systems from a microscopic viewpoint, we study the so-called {gamma}{sub 8} models on three kinds of lattices, simple cubic (sc), bcc, and fcc, based on a j-j coupling scheme with f-electron hopping integrals through (ff{sigma}) bonding. From the {gamma}{sub 8} model, we derive an effective model for each lattice structure by using the second-order perturbation theory with respect to (ff{sigma}). By further applying mean-field theory to the effective model, we find a {gamma}{sub 3g} antiferro-quadrupole transition for the sc lattice, a {gamma}{sub 2u} antiferro-octupole transition for the bcc lattice, and a longitudinal triple-q{gamma}{sub 5u} octupole transition for the fcc lattice.

Kubo, Katsunori [Advanced Science Research Center, Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan)]. E-mail: kubo.katsunori@jaea.go.jp; Hotta, Takashi [Advanced Science Research Center, Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan)

2006-05-01

291

Multipole ordering in f-electron systems  

International Nuclear Information System (INIS)

In order to investigate multipole ordering in f-electron systems from a microscopic viewpoint, we study the so-called ?8 models on three kinds of lattices, simple cubic (sc), bcc, and fcc, based on a j-j coupling scheme with f-electron hopping integrals through (ff?) bonding. From the ?8 model, we derive an effective model for each lattice structure by using the second-order perturbation theory with respect to (ff?). By further applying mean-field theory to the effective model, we find a ?3g antiferro-quadrupole transition for the sc lattice, a ?2u antiferro-octupole transition for the bcc lattice, and a longitudinal triple-q?5u octupole transition for the fcc lattice

292

Multipole ordering in f-electron systems  

CERN Document Server

In order to investigate multipole ordering in f-electron systems from a microscopic viewpoint, we study the so-called \\Gamma_8 models on three kinds of lattices, simple cubic (sc), bcc, and fcc, based on a j-j coupling scheme with f-electron hopping integrals through (ff\\sigma) bonding. From the \\Gamma_8 model, we derive an effective model for each lattice structure by using the second-order perturbation theory with respect to (ff\\sigma). By further applying mean-field theory to the effective model, we find a \\Gamma_{3g} antiferro-quadrupole transition for the sc lattice, a \\Gamma_{2u} antiferro-octupole transition for the bcc lattice, and a longitudinal triple-q \\Gamma_{5u} octupole transition for the fcc lattice.

Kubo, K; Kubo, Katsunori; Hotta, Takashi

2005-01-01

293

SCOPE AND LIMITATION OF ELECTRONIC VOTING SYSTEM  

Directory of Open Access Journals (Sweden)

Full Text Available Electronic Voting are now being performed using World Wide Web in many countries of theworld due to this advancement a voter need not to visit the polling place. But has to just logging on thecomputer with an internet connection. Also, this voting requires an access code for the e-voting through theadvance report of a voter. To reduce these disadvantages, we suggest a process in which a voter, who has thewireless certificate issued in advance, uses its own mobile phone for an e-voting without the uniqueregistration for a vote. In this paper, a polling scheme by means of mobile technology is resented as mostfundamental application of GSM based Personal Response System, which allows a voter to cast his vote insimple and convenient way without the limit of time and location by integrating an electronic voting methodwith the GSM infrastructure.

Atiya Parveen

2013-05-01

294

The EH101 Electronic Instrument Systems  

Directory of Open Access Journals (Sweden)

Full Text Available This paper describes the background to the introduction of an electronic instrument system on the Anglo-Italian EH101 helicopter. The demanded flexibility to accommodate the display needs of several roles leading logically to the adoption of full colour multi-purpose display surfaces and the drive to achieve maximum commonality between military and civil variants is discussed. The configurations arrived at for both variants are described together with the operating philosophy and display formats developed during an ongoing simulator program. The paper also deals with a detailed description of the hardware implementation of the EIS including the fully integrated systems architecture and details of the symbol generators (SGs, display units (DUs and display mode selectors (DMSs. Emphasis is placed on the robust integrity characteristics and reversionary switching philosophy of the system."

Kieth N. Atkin

2013-04-01

295

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)

296

Assessing and modelling farmers' decision-making on integrating aquaculture into agriculture in the Mekong Delta  

OpenAIRE

Contrary to the global trend of specialization within agriculture, the rice-based Vietnamese production systems have diversified into integrated agriculture¿aquaculture systems. Economic liberalization in 1986 resulted in an explosive increase in rice production and a rapid diversification. This paper describes the history and dynamics of these systems in the Mekong Delta, and the farmers¿ decisionmaking in this process. Subsequently, we use fuzzy logic to simulate farmers¿ decisions to op...

Bosma, R. H.; Le Thanh Phong; Kaymak, U.; Berg, J.; Udo, H. M. J.; Mensvoort, M. E. F.; Le Quang Tri

2006-01-01

297

Hy914, an electronic equipment test system  

International Nuclear Information System (INIS)

The article introduced the needs for thorough testing of electronic equipment with comparison between manual testing and automatic testing. An electronic equipment test system -HY914- which was used to test one network communication system was discussed in detail. HY914, which is able to do both black box testing and white box testing, is a integrated automatic test platform that provides rich features including test script, function testing, load testing, abnormal behaviour checking, application status monitoring, hardware resource monitoring and etc. HY914 also provides capability for doing complicated testing in short period and it helps to cut both labour cost and hours spent greatly. In between testing of the network communication system, engineers found and fixed a lot of software bugs such as device hanging, downgrading of voice quality and etc. By just doing minor changes of the test scripts, HY914 also provides the capability for users to test the device with minimum effort before a new software version is released. HY914 is designed to be used as a generic test platform and automatic testing of various products can be done by customising the test scripts, platform virtual machine, and virtual device driver. (authors)

298

76 FR 43206 - Electronic Tariff Filing System (ETFS)  

Science.gov (United States)

...10-141; FCC 11-92] Electronic Tariff Filing System (ETFS...over the Internet, using the Electronic Tariff Filing System (ETFS...sought; (3) A showing of good cause; and (4) The appropriate...Washington, DC 20554.'' The Electronic Tariff Filing System...

2011-07-20

299

Water Diagnosis in Shrimp Aquaculture based on Neural Network  

Science.gov (United States)

In many countries, the shrimp aquaculture has not advanced computational systems to supervise the artificial habitat of the farms and laboratories. A computational system of this type helps significantly to improve the environmental conditions and to elevate the production and its quality. The main idea of this study is the creation of a system using an artificial neural network (ANN), which can help to recognize patterns of problems and their evolution in shrimp aquaculture, and thus to respond with greater rapidity against the negative effects. Bad control on the shrimp artificial habitat produces organisms with high stress and as consequence losses in their defenses. It generate low nutrition, low reproduction or worse still, they prearrange to acquire lethal diseases. The proposed system helps to control this problem. Environmental variables as pH, temperature, salinity, dissolved oxygen and turbidity have an important effect in the suitable growth of the shrimps and influence in their health. However, the exact mathematical model of this relationship is unspecified; an ANN is useful for establishing a relationship between these variables and to classify a status that describes a problem into the farm. The data classification is made to recognize and to quantify two states within the pool: a) Normal: Everything is well. b) Risk: One, some or all environmental variables are outside of the allowed interval, which generates problems. The neural network will have to recognize the state and to quantify it, in others words, how normal or risky it is, which allows finding trend of the water quality. A study was developed for designing a software tool that allows recognizing the status of the water quality and control problems for the environment into the pond.

Carbajal Hernández, J. J.; Sánchez Fernández, L. P.

2007-05-01

300

BPM System for Electron Cooling in the Fermilab Recycler Ring  

International Nuclear Information System (INIS)

We report a VXI based system used to acquire and process BPM data for the electron cooling system in the Fermilab Recycler ring. The BPM system supports acquisition of data from 19 BPM locations in five different sections of the electron cooling apparatus. Beam positions for both electrons and anti-protons can be detected simultaneously with a resolution of ±50 ?m. We calibrate the system independently for each beam type at each BPM location. We describe the system components, signal processing and modes of operation used in support of the electron-cooling project and present experimental results of system performance for the developmental electron cooling installation at Fermilab

301

Structural dynamics of electronic and photonic systems  

CERN Document Server

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

Suhir, Ephraim; Steinberg, David S

2011-01-01

302

The VERITAS Flash ADC Electronics System  

Science.gov (United States)

? The VERITAS-4 atmospheric Cerenkov telescope (ACT) array will employ PMT cameras with high-sp eed waveform-capture electronics based on 500 Msps Flash Analog to Digital Converters (FADCs). The deep memory of the FADCs provide a true first level array trigger capability that minimizes deadtime and reduces the trigger threshold. An auto-sensing gain switch and a low jitter constant fraction discriminator will minimize the effective FADC gate. This new system will result in a reduction in the energy threshold of the VERITAS-4 array.

Rebillot, P. F.; Buckley, J.H.; Dowkontt, P.; Kosack, K.

2003-07-01

303

Electron scattering and few nucleon systems  

International Nuclear Information System (INIS)

Recent result obtained by electron scattering in the few-nucleon systems (A 3He charge and magnetic form factors are discussed. New theoretical results indicate that three body forces improve considerably the saturation properties of 3He, 4He and nuclear matter, but are not able to reconcile experiment and theory for the charge form factors of 3He and 4He. Calculations of meson exchange effects with different theoretical approaches bring the theory into reasonable agreement with the experimental charge and magnetic form factor fo 3He. Recent results of the measurements of the two and three body break-up of 3He are discussed

304

Analysis of economic and energy utilization aspects for waste heat aquaculture  

Energy Technology Data Exchange (ETDEWEB)

A waste heat aquaculture system using extensive culture techniques to produce fin and shellfish is currently under investigation at the Oak Ridge National Laboratory. The system uses nutrients in waste water streams to grow algae and zooplankton which are fed to fish and clams. A tilapia polyculture association and the freshwater clam Corbicula are the animals cultured in the system. The investigations were performed to determine the economic feasibility of the system and examine energy utilization in the system. A net energy analysis was performed to identify the energy saving potential for the system. This analysis includes all energy costs (both direct and indirect) associated with building and operating the system. The results of the economic study indicated that fish production costs of $0.55/kg ($0.25/lb) were possible. This cost, however, depends upon the fish production rate and food conversion efficiency and could rise to as much as $1.65/kg ($0.75/lb). Clam production costs were found to be in the neighborhood of $0.37/kg of clam meat ($1.24/bushel). The energy utilization study results indicated that, when all energy costs are included, fish from the aquaculture system may require only 35% of the net energy now required for fish products from the ocean. However, the energy requirements also depend on system parameters and could be as large as the energy required for ocean caught products. Clams can be produced in the aquaculture system using only about 25% of the net energy required by traditional means. The results of the analysis indicate that the system appears to be economically feasible. They also indicate that significant energy savings are possible if waste heat aquaculture products replace ocean caught products.

Olszewski, M.; Wilson, J. V.

1978-01-01

305

Perception of Aquaculture Education to Support Further Growth of Aquaculture Industry in Victoria, Australia  

Science.gov (United States)

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…

Awal, Sadiqul; Christie, Andrew; Watson, Matthew; Hannadige, Asanka G. T.

2012-01-01

306

Periphyton boosts production in pond aquaculture systems  

OpenAIRE

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 BW...

Azim, E. A.; Verdegem, M. C. J.; Wahab, M. A.; Dam, A. A.; Beveridge, M. C. M.

2001-01-01

307

Vacuum system of TRISTAN electron ring  

International Nuclear Information System (INIS)

The conceptual design and developing studies of the vacuum system in the 30 GeV electron/positron collision ring which belongs to the phase I of TRISTAN program have been continued so far. In June, 1980, the conceptual design for the phase I has become concrete, which included the 6 to 8 GeV accumulator ring having the 2.5 GeV electron linac in the radiated light experiment facility now under construction as the injector, and the 30 GeV super-large TRISTAN ring. The pressure required is on the average 5 x 10-9 Torr if beam life is assumed as 48 hours. The main pump for the beam duct is the distributed ion pump. The beam duct is made of aluminum alloy, and composed of pump room, cooling channels and heater groove and others. In the beam duct, the standardized deflection magnet section, quadrupole magnet section, straight run portion, etc. are jointed by full automatic welding with the bellows having the same cross-sectional shape without using flanges. This satisfies the requirements of high reliability, sharp cut of cost, smaller space factor, beam impedance matching, reduction of residual radioactivity, and simplification and light weight. The auxiliary ion pump is provided to maintain the ultrahigh vacuum even during the interruption of operation. Further, roughing pump, gate valve, heater and heat insulation, vacuum gauge, monitor, collision experiment section, septum magnet chamber for beam injection and extraction, electron/positron separateand extraction, electron/positron separater chamber, radiated light channel are described, respectively. (Wakatsuki, Y.)

308

Superconductivity and Strongly Correlated Electron Systems  

Science.gov (United States)

The Table of Contents for the book is as follows: * Preface * Towards a theory of copper-oxides metals * The Mott transition: mean field theories and real materials * The boson-fermion scenario for high-Tc superconductivity * Bipolaronic Bose-liquid in high-Tc superconductors: arguments against and evidence for * Superconductivity and density waves in high dimensions * Theory of dynamical screening effects in the exciton and bipolaron formation: an application to strongly photoexcited semiconductors and to the bipolaron model for high-Tc superconductivity * On the NMR properties of the quasi-2D Heisenberg antiferromagnet doped with real space pairs * Composite operator method for strongly correlated electron systems * Second order approximation for optical polarons in the strong coupling case * Fermion-spin transformation and strong coupling behavior of two-coupled t-J chains * t-J model and quasiparticles in NiO and in CuO2 * Electronic structure and pairing of strongly correlated fermions: Fermi liquid versus spin liquid * A multiple-subband solution of the t-t'-J model * Novel symmetries in condensed matter physics: quantum symmetry and the Hubbard model with phonons * Hubbard models: a Quantum Monte-Carlo study * Electron-hole asymmetry in a generalized one-band Hubbard model * The Hubbard model as a paradigm for strongly correlated electron systems * A study of La2Cu1-cZncO4 with implications for Fermi liquid models of high temperature superconductivity * Analysis of the Hubbard model by composite operator method in a generalized mean field approximation * Condensed particle structure in the inhomogeneous BCS-model and a mean field Hubbard model * A field theoretical investigation of the Hubbard hamiltonian * Magnetic and non-magnetic states of heavy fermion systems * Kinematical mechanism of superconductivity in the periodic Anderson model * Correlation effects in high-Tc superconductors and heavy fermion compounds * Are anyons relevant to condensed matter? Maybe * Fractional statistics in 2+1 dimensional U(1)-scalar-Chern-Simons gauge field theory * Weak disorder and phase transitions in unconventional superconductors * Fluctuation effects in superconductors with random-field-like quenched disorder * oscopic quantum theoretic approach to superconductive electrodynamics

Scarpetta, G.; Noce, C.; Romano, A.

1994-10-01

309

Major bacterial diseases in aquaculture and their vaccine development  

Science.gov (United States)

Aquaculture is emerging as the fastest growing food-producing industry in the world due to the increasing demand for food fish consumption. However, the intensive culture of food fish has led to outbreaks of various bacterial diseases, resulting in annual economic losses to the aquaculture industry ...

310

Application of Medicinal Herbs to Aquaculture in Asia  

OpenAIRE

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.

Direkbusarakom, Sataporn

2004-01-01

311

Aqua-Topics. Aquaculture for Youth and Youth Educators.  

Science.gov (United States)

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…

McVey, Eileen

312

Fisheries And Aquaculture Resources And Their Interactions With Environment in Turkey  

Science.gov (United States)

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.

Deniz, H.

2003-04-01

313

Water Quality Monitoring and Control for Aquaculture Based on Wireless Sensor Networks  

Directory of Open Access Journals (Sweden)

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

Daudi S. Simbeye

2014-04-01

314

Experimental system of ejected electron spectroscopy with ECR ion source  

Energy Technology Data Exchange (ETDEWEB)

The experiment of analyzing energy spectrum of electrons ejected from multiple electron capture process on ion-atom collision is carried out using ECR (Electron Cyclotron Resonance) ion source. An old collision system using gas atoms as target and a new system using vapour atoms are developed. In this report, the developments and exploitations of the experimental systems for the ejected electron spectroscopy with ECR Ion source are presented. (author).

Kitazawa, Sin-iti [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1995-09-01

315

In Brief: Environmental standards needed for offshore marine aquaculture  

Science.gov (United States)

The U.S. Congress should enact legislation that sets strong environmental standards for offshore marine aquaculture, the Marine Aquaculture Task Force recommended in a recent report. Aquaculture now accounts for about half of all seafood consumed in the world, and the industry is rapidly growing and expanding into regions offshore (more than 3 nautical miles from the coast) that are controlled by the federal government. The task force, which was organized by researchers from the Woods Hole Oceanographic Institution, examined the risks and benefits of marine aquaculture. They proposed that the U.S. National Oceanic and Atmospheric Administration be appointed the lead agency responsible for regulation of offshore marine aquaculture and for providing incentives for research and development. The main environmental standard proposed by the task force was to limit farming only to native species with local genetics unless the potential harm of escaped fish to local populations would be negligible.

Zielinski, Sarah

2007-01-01

316

Mechanisms of antimicrobial resistance in finfish aquaculture environments  

Directory of Open Access Journals (Sweden)

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.

PatriciaL.Keen

2013-08-01

317

Development of integrated aquaculture : agriculture with brackish and salt water, Egypt  

OpenAIRE

This report describes the development of an integrated saltwater aquaculture – agriculture farming system at Wadi El Natroun, Egypt. During the first two years of the project promising salt-tolerant plant species were identified, the methods for seed germination and growing of three salt-tolerant plant species with potential for human consumption and animal fodder were developed, and the culture of red tilapia in a so-called biofloc system with salt water was tested. Report number CDI-13-004

Heijden, P. G. M.; Blom-zandstra, G.; Sadek, S.; Elsamadony, E.; Eweas, M.; El-dib, H.; Sabry, M.

2013-01-01

318

Universal detector system for backscattered electrons, transmitted electrons and cathodoluminescence  

International Nuclear Information System (INIS)

The design concept of a multi-function detector is presented. It basically consists of a photomultiplier tube coupled via an optical switch towards two flexible fiber optic light guides. The optical switch allows coupling of each light guide to the photomultiplier separately. For backscattered electrons there is a scintillator attached to the other end of the fibers, for transmitted electrons a scintillator plus a 45 degree mirror and for cathodoluminescence a small light lens. The basic concept is illustrated with a typical design example. (C.F.)

319

NMR study of strongly correlated electron systems  

International Nuclear Information System (INIS)

Various types of ground states in strongly correlated electron systems have been systematically investigated by means of NMR/NQR at low temperatures under high magnetic field and pressure. We focus on two well-known heavy-electron families, CeCu2X2 (X=Si and Ge) (Ce(122)) and UM2Al3 (M=Ni and Pd) (U(123)). The Cu NQR experiments on CeCu2X2 under high pressure indicate that the physical property of CeCu2Ge2 at high pressure, i.e. above the transition at 7.6GPa from antiferromagnetic (AF) to superconductivity, are clearly related to that of CeCu2Si2 at ambient pressure. In addition to the H-T phase diagram established below 7T, NMR and specific heat experiments on polycrystal CeCu2.05Si2 have revealed the presence of a new phase above 7T. In a high-quality polycrystal of UPd2Al3 with a record high-Tc of 2K at ambient pressure and the narrowest Al NQR line width, the nuclear-spin lattice relaxation rate, 27(1/T1) measured in zero field has been found to obey the T3 law down to 0.13K, giving strong evidence that the energy gap vanishes along lines on the Fermi surface. Thus it seems that all heavy-electron superconductors exhibit lines of zero gap, regardless of their different magnetic properties. ((orig.))

320

75 FR 48629 - Electronic Tariff Filing System (ETFS)  

Science.gov (United States)

...10-141; FCC 10-127] Electronic Tariff Filing System (ETFS...the initiation of mandatory electronic filing. * * * * * 7. Section...sought; (3) A showing of good cause; and (4) The appropriate...Washington, DC 20554.'' The Electronic Tariff Filing System...

2010-08-11

321

75 FR 38118 - In the Matter of Certain Electronic Devices With Image Processing Systems, Components Thereof...  

Science.gov (United States)

...Certain Electronic Devices With Image Processing Systems, Components Thereof...certain electronic devices with image processing systems, components thereof...certain electronic devices with image processing systems, components...

2010-07-01

322

Immune–potentiators for the Aquaculture  

Directory of Open Access Journals (Sweden)

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.

Rocmira Pérez

2014-04-01

323

Genomic Approaches in Marine Biodiversity and Aquaculture  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english 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.

Jorge A, Huete-Pérez; Fernando, Quezada.

324

Enhancement of existing geothermal resource utilization by cascading to intensive aquaculture  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1995-12-04

325

Characteristics of the beam injection system in an electron LINAC  

International Nuclear Information System (INIS)

The main characteristics of an electron beam injection system are described; the system is used for injecting and focusing electron beams into the acceleration structure of an 10 MeV linear electron accelerator. The beam injection system consists of a Pierce convergent diode-type electron gun with pulse modulator for power supply and a thin axially symmetric lens. The perveance and the capture coefficient were optimized by the analogical resistors network. This type of injection system was used in the linear electron accelerators: ALIN – 3 MeV, ALIN – 10 MeV and ALID ? 8 MeV, performed at NILPRP? Bucharest, Romania.

326

Survey and Alignment of the Fermilab Electron Cooling System  

Energy Technology Data Exchange (ETDEWEB)

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.

Oshinowo, Babatunde O' Sheg; Leibfritz, Jerry

2006-09-01

327

Characteristics of the beam injection system in an electron LINAC  

Energy Technology Data Exchange (ETDEWEB)

The main characteristics of an electron beam injection system are described; the system is used for injecting and focusing electron beams into the acceleration structure of an 10 MeV linear electron accelerator. The beam injection system consists of a Pierce convergent diode-type electron gun with pulse modulator for power supply and a thin axially symmetric lens. The perveance and the capture coefficient were optimized by the analogical resistors network. This type of injection system was used in the linear electron accelerators: ALIN - 3 MeV, ALIN - 10 MeV and ALID - 8 MeV, performed at NILPRP{sup Asterisk-Operator} Bucharest, Romania.

Baltateanu, N., E-mail: nicolaebaltateanu@yahoo.com [Hyperion University, Hyperion Research and Development Institute Bucharest, 169 Calea Calarasilor, Bucharest 3, CP 030615 (Romania); Gheorghiu, A. [Hyperion University, Hyperion Research and Development Institute Bucharest, 169 Calea Calarasilor, Bucharest 3, CP 030615 (Romania); Jurba, M. [Electrooptic Components SRL, 171 A Atomistilor str, Magurele-Ilfov (Romania); Popescu, E., E-mail: elop@elop.ro [Electrooptic Components SRL, 171 A Atomistilor str, Magurele-Ilfov (Romania)

2011-12-15

328

Synthesizing cognition in neuromorphic electronic systems.  

Science.gov (United States)

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" running on these reliable subnets. In the first step, the neural networks of the abstract layer are realized on the hardware substrate by mapping the neuron circuit bias voltages to the model parameters. This mapping is obtained by an automatic method in which the electronic circuit biases are calibrated against the model parameters by a series of population activity measurements. The abstract computational layer is formed by configuring neural networks as generic soft winner-take-all subnetworks that provide reliable processing by virtue of their active gain, signal restoration, and multistability. The necessary states and transitions of the desired high-level behavior are then easily embedded in the computational layer by introducing only sparse connections between some neurons of the various subnets. We demonstrate this synthesis method for a neuromorphic sensory agent that performs real-time context-dependent classification of motion patterns observed by a silicon retina. PMID:23878215

Neftci, Emre; Binas, Jonathan; Rutishauser, Ueli; Chicca, Elisabetta; Indiveri, Giacomo; Douglas, Rodney J

2013-09-10

329

The ALTA cosmic ray experiment electronics system  

International Nuclear Information System (INIS)

Understanding the origin and propagation of high-energy cosmic rays is a fundamental area of astroparticle physics with major unanswered questions. The study of cosmic rays with energy more than 1014 eV, probed only by ground-based experiments, has been restricted by the low particle flux. The Alberta Large-area Time-coincidence Array (ALTA) uses a sparse array of cosmic ray detection stations located in high schools across a large geographical area to search for non-random high-energy cosmic ray phenomena. Custom-built ALTA electronics is based on a modular board design. Its function is to control the detectors at each ALTA site allowing precise measurements of event timing and energy in the local detectors as well as time synchronization of all of the sites in the array using the global positioning system

330

Analysis of an Electronic Voting System  

Science.gov (United States)

A potential flaw in a kind of electronic voting machine used in several U.S. states was discovered and publicized by researchers from Johns Hopkins and Rice Universities. It purportedly can make the machine vulnerable to security breaches that would allow a single individual to cast multiple votes. The conclusions of the researchers are outlined in a 24-page study. After providing an overview of the voting system in question, which requires users to insert a smart card to cast a vote, the report suggests that homemade smart cards could be used to gain an unacceptable level of access. Examples of violations include, as was mentioned above, the ability to submit multiple ballots, as well as "viewing partial results and terminating the election early."

Kohno, Tadayoshi

331

Advanced Photonic and Electronic Systems WILGA 2010  

CERN Document Server

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...

Romaniuk, R S

2010-01-01

332

CERN Sells its Electronic Document Handling System  

CERN Multimedia

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...

2001-01-01

333

Electron beam accelerator energy control system  

International Nuclear Information System (INIS)

A control system has been developed for the energy control of the electron beam accelerator using PLC. The accelerating voltage of 3 MV has been obtained by using parallel coupled voltage multiplier circuit. A autotransformer controlled variable 0-10 KV DC is fed to a tube based push pull oscillator to generate 120 Khz, 10 KV AC. Oscillator output voltage is stepped up to 0-300 KV/AC using a transformer. 0-300 KVAC is fed to the voltage multiplier column to generate the accelerating voltage at the dome 0-3 MV/DC. The control system has been designed to maintain the accelerator voltage same throughout the operation by adjusting the input voltage in close loop. Whenever there is any change in the output voltage either because of beam loading or arcing in the accelerator. The instantaneous accelerator voltage or energy is a direct proportional to 0-10 KVDC obtained from autotransformer. A PLC based control system with user settable energy level has been installed for 3 MeV, EB accelerator. The PLC takes the user defined energy value through a touch screen and compares it to the actual accelerating voltage (obtained using resistive divider). Depending upon the error the PLC generates the pulses to adjust the autotransformer to bring the actual voltage to the set value within the window of error (presently set to +/- 0.1%). (author)

334

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)

Full Text Available SciELO Chile | Language: English Abstract in spanish 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.

Lili, Carrera; Noemí, Cota; Melissa, Montes; Enrique, Mateo; Verónica, Sierralta; Teresa, Castro; Angel, Perea; Cristian, Santos; Christian, Catcoparco; Carlos, Espinoza.

2013-03-01

335

Correlated-Electron Systems and High-Temperature Superconductivity  

OpenAIRE

We present recent theoretical results on superconductivity in correlated-electron systems, especially in the two-dimensional Hubbard model and the three-band d-p model. The mechanism of superconductivity in high-temperature superconductors has been extensively studied on the basis of various electronic models and also electron-phonon models. In this study, we investigate the properties of superconductivity in correlated-electron systems by using numerical methods such as the variational Mont...

Takashi Yanagisawa; Mitake Miyazaki; Kunihiko Yamaji

2013-01-01

336

Correlated-Electron Systems and High Temperature Superconductivity  

OpenAIRE

We present recent theoretical results on superconductivity in correlated-electron systems, especially in the two-dimensional Hubbard model and the three-band d-p model. The mechanism of superconductivity in high-temperature superconductors has been extensively studied on the basis of various electronic models and also electron-phonon models. In this study we investigate the properties of superconductivity in correlated-electron systems by using numerical methods such as the ...

Yanagisawa, Takashi; Miyazaki, Mitake; Yamaji, Kunihiko

2013-01-01

337

Organic Thin Film Transistors for Electronic Systems  

Science.gov (United States)

The surge of interest in organic thin film transistors (TFTs) has been motivated, on the one hand, by fundamental questions concerning the energetics and transport of localized carriers, and, on the other hand, by the practical advantages of electronic systems fabricated at low temperatures on flexible substrates. The overriding consideration for the usefulness of organic thin-film transistors for electronic systems has been the field-effect mobility. In this paper I will discuss materials-related factors other than mobility that influence the usefulness of organic TFTs. The subthreshold slope determines the voltage excursion that must take place below the threshold voltage to fully turn off the transistor. Typical organic TFTs have subthreshold slopes that are small compared to silicon devices, due to strongly localized states in energy gap between the more extended levels. The excursion required below threshold often has about the same magnitude as that required above threshold to reach a given level of on-current, and the speed of the system, as well as the power supply requirements, can be adversely affected by the additional required voltage swing. Organic TFTs use metallic or conducting polymer contacts that overlap the gate region, unlike the doped source and drain regions that are self-aligned to the gate in high-performance silicon technologies. A self-aligned process has not been developed for organic TFTs, and, as a result, in organic TFTs there are large parasitic capacitances that can limit system performance. If the amount of overlap is fixed by registration capabilities and can not be reduced as channel length L is reduced, the well-known silicon scaling law in which the upper frequency limit fmax scales as 1/L^2 is modified to fmax ˜ 1/L, altering significantly the economics of increased integration. The usefulness of organic TFTs is hindered by the lack of a technology that provides complementary n-channel and p-channel transistors on the same substrate. A good case can be made that the benefits of a complementary technology outweigh the gains achieved from modest improvements in single-channel device mobility, and that more effort to develop organic CMOS is warranted.

Kane, Michael

2005-03-01

338

Transmission Phase and Electron-Electron Interactions in Mesoscopic Systems  

International Nuclear Information System (INIS)

In a series of beautiful experiments by Yacobi, Schuster, Heiblum, Buksi Mahalu, Umansky and Shtrikman, the (relative) phase of an electron beam transmitted through a quantum dot has been measured. A high degree of correlation of this phase has been observed as consecutive transmission resonances through the dot were scanned (by varying a gate voltage). Notwithstanding a considerable theoretical effort, this result has not yet been accounted for. In particular, an independent electron picture cannot provide such correlations. We propose a model combining the effects of disorder and charging energy which results in generic phase correlations. We identify a large dimensionless parameter in tile theory which provides for such correlations. Possible experimental tests are proposed. The work has been supported by German-Israeli Foundation (GIF), by Israel Science Foundation founded by Israel Academy of Science and humanities- Centres of Excellence program, and by the Minerva foundation. Y.G. was an EPSRC fellow under grant GR/L67103

339

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

Science.gov (United States)

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 decontamination of aquaculture effluents, the effect of physical and chemical properties of culture waters on the efficiency of this technology has never been reported. The present study aimed to evaluate the effect of physical and chemical properties of aquaculture waters (e.g. pH, temperature, salinity and organic matter content) on the efficiency of phage therapy under controlled experimental conditions in order to provide a basis for the selection of the most suitable protocol for subsequent experiments. A bioluminescent genetically transformed Escherichia coli was selected as a model microorganism to monitor real-time phage therapy kinetics through the measurement of bioluminescence, thus avoiding the laborious and time-consuming conventional method of counting colony-forming units (CFU). For all experiments, a bacterial concentration of ? 10(5) CFU ml(-1) and a phage concentration of ? 10(6-8) plaque forming unit ml(-1) were used. Phage survival was not significantly affected by the natural variability of pH (6.5-7.4), temperature (10-25 °C), salinity (0-30 g NaCl l(-1) ) and organic matter concentration of aquaculture waters in a temperate climate. Nonetheless, the efficiency of phage therapy was mostly affected by the variation of salinity and organic matter content. As the effectiveness of phage therapy increases with water salt content, this approach appears to be a suitable choice for marine aquaculture systems. The success of phage therapy may also be enhanced in non-marine systems through the addition of salt, whenever this option is feasible and does not affect the survival of aquatic species being cultured. PMID:24841213

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

2014-09-01

340

Salmon aquaculture and antimicrobial resistance in the marine environment.  

Science.gov (United States)

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

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

341

Key Performance Characteristics of Organic Shrimp Aquaculture in Southwest Bangladesh  

Directory of Open Access Journals (Sweden)

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.

Christian Reinhard Vogl

2012-05-01

342

Power electronic converter systems for direct drive renewable energy applications  

DEFF Research Database (Denmark)

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.

Chen, Zhe

2013-01-01

343

Electron-electron interactions in a weakly screened two-dimensional electron system  

OpenAIRE

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...

Karakurt, I.; Dahm, A. J.

2002-01-01

344

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.)

345

THE FISHERIES AND AQUACULTURE COMPONENT OF RURAL DEVELOPMENT  

Directory of Open Access Journals (Sweden)

Full Text Available Fisheries and aquaculture can provide a key contribution to food security and poverty alleviation. Fisheries and aquaculture policy is an instrument for the conservation and management of fisheries and aquaculture. It was created with the aims of managing a common resource. Fisheries policies and management strategies the world over is in a state of flux, continued attempts to use fisheriesas the key to solving a complex web of social and economic issues threaten to overwhelm the basic fact that, if this resources are overfished, they will not sustain either social or development.

Adrian ZUGRAVU

2006-01-01

346

Operation of Doublet III electron cyclotron system  

International Nuclear Information System (INIS)

The first phase of operation of the Doublet III 60 GHz ECH system has been completed. In this phase, the power from two gyrotrons which put out a total of 340 kW for pulse lengths to 85 msec was used to launch the ordinary wave from the low field side of the plasma. The gyrotrons were Varian VGE-8060 tubes designed for 100 msec pulses; the gyrotrons which will be used for subsequent experimental phases at total power up to 2 MW are Varian VGE-8006 cw tubes, for pulse lengths up to 5 sec. (Pulse lengths are limited by the power supply.) The high voltage system used to power up to ten gyrotrons is shown. The power source is an 80 kV,.100 A power supply that was designed for neutral beam operation and which was modified for negative polarity as required for gyrotron operation. This power supply provided a single series modulator/regulator for the entire system, with individual gyrotron operation controlled by a low power switch tube (Thompson 5185) and compensated resistive voltage divider. The voltage divider determines the voltage on the gyrotron gun anode, which acts as a control grid for the gyrotron electron gun. The individual gyrotrons are isolated from each other by 100 ? series resisters. This approach to gyrotron control has proved to be effective in operation of at least two gyrotrons simultaneously; it is also highly cost-effective compared to providing a series modulator/regulator for each gyrotron. Cross-talk between gyrotrons either through the power suppn gyrotrons either through the power supply or through the waveguide has not been a problem

347

Establishment of a mobile electron beam treatment system  

International Nuclear Information System (INIS)

The main goal of the project was the construction of mobile electron beam treatment system. The system of mobile electron beam was needed against the environmental problem that was not able to be figured out by the conventional treatment technologies. The mobile electron beam system was constructed for the field demonstration of treatment and remediation of various contaminated environments to obtain New Environmental Technology (NET) of Ministry of Environment (MOE)

348

Power electronics system integration for electric and hybrid vehicles  

OpenAIRE

The paper gives an overview of the basic requiremensts, concepts, and trends regarding a system intergration of power electronics in hybrid (HEV) an electric vehicles (EV). A site-of-action system integration of the various power electronics subsystems minimizes costs and construction space requirements. New technologies that foster a system integration of power electronics and a merging with the mechanical environment are presented. The focus is on power modules and passive components.

Ma?rz, M.; Schletz, A.; Eckardt, B.; Engelkraut, S.; Rauh, H.

2010-01-01

349

Angle-Resolved Spectroscopy of Electron-Electron Scattering in a 2D System  

OpenAIRE

Electron-beam propagation experiments have been used to determine the energy and angle dependence of electron-electron (ee) scattering a two-dimensional electron gas (2DEG) in a very direct manner by a new spectroscopy method. The experimental results are in good agreement with recent theories and provide direct evidence for the differences between ee-scattering in a 2DEG as compared with 3D systems. Most conspicuous is the increased importance of small-angle scattering in a...

Yanovsky, A. V.; Predel, H.; Buhmann, H.; Gurzhi, R. N.; Kalinenko, A. N.; Kopeliovich, A. I.; Molenkamp, L. W.

2000-01-01

350

Raft River aquaculture project. Final report  

Energy Technology Data Exchange (ETDEWEB)

The commercial potential for geothermal aquaculture was evaluated for 2 years at the Department of Energy's Raft River geothermal site in southcentral Idaho. Common carp '(Cyprinus carpio) and channel catfish (Ictalurus punctatus) were selected as culture species. Objectives of the study included investigation of: (1) growth rates; (2) nutrition trials; (3) histological and physiological parameters; (4) bioaccumulation of heavy metals; and (5) reproductive capacity. The second year project efforts were primarily studying the effects of geothermal water on the reproductive capacity of common carp by: (1) determining the effects of geothermal water on gonadal development of common carp; and (2) determining the effects of geothermal water on common carp embryogenesis.

Beleau, M.H.; Woiwode, J.G.

1980-07-01

351

Electronic upgrade of the pneumatic Finnish system 'Rabbit'  

International Nuclear Information System (INIS)

This paper describes the development of a new electronic module for control of the Finnish pneumatic system 'Rabbit', which usually use to send samples to RP-10 reactor core. The original analog electronic control is very old and replacement parts are very hard to obtain. Because of this, the system frequently was inoperative. A new electronic control system, fully digital, has been developed in the Electronic Development Laboratory of Huarangal Nuclear Center. This system is configurable, reliable and easier to use. Design details, operating considerations and its results are shown here. (orig.)

352

Performance of a constructed wetland treating intensive shrimp aquaculture wastewater under high hydraulic loading rate  

International Nuclear Information System (INIS)

A water treatment unit, mainly consisting of free water surface (FWS) and subsurface flow (SF) constructed wetland cells, was integrated into a commercial-scale recirculating aquaculture system for intensive shrimp culture. This study investigated performance of the treatment wetlands for controlling water quality. The results showed that the FWS-SF cells effectively removed total suspended solids (55-66%), 5-day biochemical oxygen demand (37-54%), total ammonia (64-66%) and nitrite (83-94%) from the recirculating water under high hydraulic loading rates (1.57-1.95 m/day). This led to a water quality that was suitable for shrimp culture and effluent that always satisfied the discharge standards. The area ratios of wetlands to culture tank being demonstrated (0.43) and calculated (0.096) in this study were both significantly lower than the reported values. Accordingly, a constructed wetland was technically and economically feasible for managing water quality of an intensive aquaculture system. - A constructed wetland was found to be technically and economically feasible for managing water quality of an intensive recirculating aquaculture system

353

Hund's Rule in Two-Electron Atomic Systems  

Science.gov (United States)

A model proposed by Rioux to explain Hund's rule is investigated. Although the largest contribution to the singlet-triplet splitting in the two-electron atomic systems is the nuclear attraction term, this arises from different optimum scale factors in the two states and that difference is driven by the electron-electron exchange term. The…

Harriman, John E.

2008-01-01

354

Temperature dependent effective mass renormalization in 2D electron systems  

OpenAIRE

We calculate, as a function of temperature and density, the electron-electron interaction induced quasiparticle effective mass renormalization in 2D electron systems within the leading-order dynamically screened Coulomb interaction expansion. We find an unexpected nonanalyticity and nonmonotonicity in the temperature dependent effective mass with the renormalized mass linearly increasing with temperature at low temperatures for all densities.

Sarma, S. Das; Galitski, Victor; Zhang, Ying

2003-01-01

355

Switched Control of Electron Nuclear Spin Systems  

OpenAIRE

In this article, we study control of electron-nuclear spin dynamics at magnetic field strengths where the Larmor frequency of the nucleus is comparable to the hyperfine coupling strength. The quantization axis for the nuclear spin differs from the static B_0 field direction and depends on the state of the electron spin. The quantization axis can be switched by flipping the state of electron spin, allowing for universal control on nuclear spin states. We show that by performi...

Khaneja, Navin

2007-01-01

356

Local electronic properties in nanoscale systems  

OpenAIRE

The local electronic structure on nanoscale chains is investigated theoretically. We propose a mechanism to explain the even-odd oscillation of length distribution of atom chains. We study the spatial peak structure as obtained by scanning tunneling microscopy (STM) constant-current topography as a function of the electron-electron interaction, band filling and temperature. The site-dependent magnetic moment is also examined.

Souza, Andre M. C.; Herrmann, Hans

2007-01-01

357

Electronic transport in quantum confined systems  

OpenAIRE

With the advent of nanotechnology, a broad range of materials can be shaped with nanometer scale dimensions involving different methods, and the integration of nanostructures into electronic devices needs to characterize their electronic structure. Scanning tunnelling microscopy is a well appropriate technique for such purpose because it allows a precise positioning of the probe above the nanostructures and has the ability to resolve their electronic structure. Through this work, we report on...

Berthe, M.

2007-01-01

358

Multifunctionalized cantilever systems for electronic nose applications.  

Science.gov (United States)

Multiple target detection using a cantilever is essential for biosensor, chemical sensor, and electronic nose systems. We report a novel microcantilever array chip that includes four microreaction chambers in a chip, which consequently contains four different functionalized surfaces for multitarget detection. For model tests, we designed microcantilever chips and demonstrated the ability of binding of 2,4-dinitrotoluene (DNT) targets onto four different surfaces. We used peptide receptors that are known to have highly selective binding. By simply using four microreaction chambers, we immobilized DNT specific peptide (HPNFSKYILHQRC; SP), DNT nonspecific peptide (TSMLLMSPKHQAC; NSP), and self-assembled monolayer (SAM) as well as a bare cantilever. After flowing DNT gases through the cantilever chip, we could monitor the four different binding signals simultaneously. The shifts in NSP provided information as a negative control because it contained information of temperature fluctuations and mechanical vibration from gas flow. By utilizing the differential signal of the SP and NSP, we acquired 7.5 Hz in resonant responses that corresponds with 160 part per billion (ppb) DNT concentration, showing the exact binding response by eliminating the inevitable thermal noise, vibration noise, as well as humidity effects on the peptide surface. PMID:22947095

Yoo, Yong Kyoung; Chae, Myung-Sic; Kang, Ji Yoon; Kim, Tae Song; Hwang, Kyo Seon; Lee, Jeong Hoon

2012-10-01

359

Aquaculture applications of a thermal effluent and considerations on geothermal water use  

Energy Technology Data Exchange (ETDEWEB)

Aquaculture may benefit from the use of thermal discharges from power plants or geothermal waters. Fish culture technology applicable to use of heated effluents should also apply generally to geothermal water sources. In the early 1970's the Tennessee Valley Authority and a private cooperator pumped thermal effluent from the discharge canal of the Gallatin Steam Plant near Nashville, TN, through a raceway facility, to evaluate an intensive culture system for catfish. Water tempertures averaged 5/sup 0/C above ambient plant intake water. Results demonstrated the potential of heated water to extend the growing season, enhance growth rates, and increase production. Numerous constraints hindering commercial use of thermal effluents for aquaculture were also identified.

Hubert, W.A.; Meriwether, J.

1977-11-16

360

What shapes food value chains? Lessons from aquaculture in Asia  

DEFF Research Database (Denmark)

In this article, we explain what shapes food value chains through the analysis of selected aquaculture industries in four key Asian producing countries. Worldwide production of aquatic resources has grown rapidly in the past few decades, and aquaculture production in Asia has played a decisive role in this growth. We examine the main forms of coordination found along these value chains and the role that institutional frameworks play in governing them. We observe that negative publicity, driven by NGO and media campaigns, has led to increased use of third-party certification and the adoption of public and private standards. We find that the most sophisticated aquaculture operations in Asia are found in value chains led by retailers and branded processors and where the quality of domestic institutional frameworks has facilitated compliance with increasing demands from buyers overseas. Finally, we reflect on the sustainability challenges of aquaculture and provide four broad observations on the governance of food value chains.

Jespersen, Karen Sau; Kelling, I

2014-01-01

361

What Shapes Food Value Chains? : Lessons from Aquaculture in Asia  

DEFF Research Database (Denmark)

In this article, we explain what shapes food value chains through the analysis of selected aquaculture industries in four key Asian producing countries. Worldwide production of aquatic resources has grown rapidly in the past few decades, and aquaculture production in Asia has played a decisive role in this growth. We examine the main forms of coordination found along these value chains and the role that institutional frameworks play in governing them. We observe that negative publicity, driven by NGO and media campaigns, has led to increased use of third-party certification and the adoption of public and private standards. We find that the most sophisticated aquaculture operations in Asia are found in value chains led by retailers and branded processors and where the quality of domestic institutional frameworks has facilitated compliance with increasing demands from buyers overseas. Finally, we reflect on the sustainability challenges of aquaculture and provide four broad observations on the governance of food value chains.

Jespersen, Karen Sau; Kelling, Ingrid

2014-01-01

362

Diagnostic Neural Network Systems for the Electronic Circuits  

International Nuclear Information System (INIS)

Neural Networks is one of the most important artificial intelligent approaches for solving the diagnostic processes. This research concerns with uses the neural networks for diagnosis of the electronic circuits. Modern electronic systems contain both the analog and digital circuits. But, diagnosis of the analog circuits suffers from great complexity due to their nonlinearity. To overcome this problem, the proposed system introduces a diagnostic system that uses the neural network to diagnose both the digital and analog circuits. So, it can face the new requirements for the modern electronic systems. A fault dictionary method was implemented in the system. Experimental results are presented on three electronic systems. They are: artificial kidney, wireless network and personal computer systems. The proposed system has improved the performance of the diagnostic systems when applied for these practical cases

363

Single and combined genotoxic and cytotoxic effects of two xenobiotics widely used in intensive aquaculture.  

Science.gov (United States)

Several chemicals are used in aquaculture to prevent or to treat disease outbreaks. These substances are mainly administered by two different routes: by prolonged immersion or by mixing into the diet. In the case of intensive aquaculture, the chemicals that are most frequently applied by immersion are formaldehyde (FA) 37% and oxytetracycline (OTC). The first is highly effective against most protozoa, as well as some of the most common parasites such as monogenetic trematodes. OTC presents a large spectrum of antibacterial activities and is used to treat systemic bacterial infections that affect fish. Under therapeutic use, FA (37%) is applied prophylactically at 200ml/m(3), whereas OTC is used curatively at 40g/m(3). The goal of the present study is to assess genotoxic and cytotoxic effects associated with exposure of the European sea bass (Dicentrarchus labrax) to FA37% and OTC under the same conditions as those applied in intensive aquaculture systems. To this end the micronucleus (MN) assay was applied in erythrocytes. Our results show that both tested chemicals present genotoxic and cytotoxic potential following a time-dependent pattern. Remarkably, the combined treatment induces a cumulative effect, which is particularly pronounced after 15 days of exposure. This suggests the critical hazards associated with exposure to FA and OTC when applied or released together. PMID:21621636

Jerbi, Mohamed Ali; Ouanes, Zouhour; Besbes, Raouf; Achour, Lotfi; Kacem, Adnen

2011-09-18

364

Agonistic behaviour in juvenile southern rock lobster, Jasus edwardsii (Decapoda, Palinuridae): implications for developing aquaculture  

Science.gov (United States)

Abstract The Southern rock lobster, Jasus edwardsii, is a temperate species of spiny lobster with established well managed fisheries in Australia and New Zealand. It has also been under consideration as a species with aquaculture potential. Agonistic behaviour has important consequences under aquaculture conditions that encompass direct effects, such as damage or death of protagonists, and indirect effects on growth that relate to resource access, principally food and refuge. This study aimed to identify and characterize behaviours and to make a preliminary investigation of their occurrence under tank culture. Juvenile Jasus edwardsii were examined in a flow-through seawater system using a remote video camera system. Twenty-nine behaviours were divided into three sub-groups: aggressive (11), avoidance (6) and others (12). Aggressive behaviours included attacks, pushing, lifting, clasping and carrying an opponent. Avoidance behaviours included moving away in a backwards-, forwards- or side-stepping motion as well as with more vigorous tail flips. These behaviours were components of twelve behavioural groups that described contact, attack and displacement between individuals. Activity was crepuscular with two clear peaks, one in the morning and the other in the evening. The occurrence of behavioural groups was not different between the morning and evening. The frequency of aggressive behaviours was not affected by changes made to stocking density or access to food. The implications of agonistic behaviours are discussed further in relation to developing aquaculture. PMID:25561845

Carter, Chris G.; Westbury, Heath; Crear, Bradley; Simon, Cedric; Thomas, Craig

2014-01-01

365

Salmon Aquaculture and Antimicrobial Resistance in the Marine Environment  

OpenAIRE

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 s...

Buschmann, Alejandro H.; Tomova, Alexandra; Lo?pez, Alejandra; Maldonado, Miguel A.; Henri?quez, Luis A.; Ivanova, Larisa; Moy, Fred; Godfrey, Henry P.; Cabello, Felipe C.

2012-01-01

366

The social and economic impact of aquaculture : a European review  

OpenAIRE

This paper undertakes a preliminary evaluation of the social and economic impact of aquaculture from both empirical and theoretical standpoints. Drawing initially on background information collected for the Commission of the European Communities (CEC) in a recent study by the European Association of Fisheries Economists (EAFE), a number of important indicators and trends (e.g. production, employment, market structure) are examined which indicate that aquaculture is of increasing significance ...

Neiland, A. E.; Shaw, S. A.; Bailly, Denis

1991-01-01

367

High quality flux control system for electron gun evaporation  

International Nuclear Information System (INIS)

This paper reports on a high quality flux control system for electron gun evaporation developed and tested for the MBE growth of high temperature superconductors. The system can be applied to any electron gun without altering the electron gun itself. Essential elements of the system are a high bandwidth mass spectrometer, control electronics and a high voltage modulator to sweep the electron beam over the melt at high frequencies. the sweep amplitude of the electron beam is used to control the evaporation flux at high frequencies. The feedback loop of the system has a bandwidth of over 100 Hz, which makes it possible to grow superlattices and layered structures in a fast and precisely controlled manner

368

Content formation method in the electronic content commerce systems  

OpenAIRE

In the given article content is forming method as the content life cycle stage in electronic commerce systems is proposed. The method implements the information resources processing in electronic content commerce systems and automation technology simplifies the commercial content formation. In the given article the main problems of electronic content commerce and functional services of commercial content forming are analyzed. The proposed method gives an opportunity to create an instrument of...

Berko, Andriy; Vysotska, Victoria; Chyrun, Lyubomyr

2013-01-01

369

Electronic Liquid Crystal Phases in Strongly Correlated Systems  

OpenAIRE

In this lectures I discuss the electronic liquid crystal (ELC) phases in correlated electronic systems, what these phases are and in what context they arise. I will go over the strongest experimental evidence for these phases in a variety of systems: the two-dimensional electron gas in magnetic fields, the bilayer material Sr$_3$Ru$_2$O$_7$ (also in magnetic fields), and a set of phenomena in the cuprate superconductors (and more recently in the pnictide materials) that can ...

Fradkin, Eduardo

2010-01-01

370

Frictional magnetodrag between spatially separated two-dimensional electron systems: Coulomb versus phonon mediated electron-electron interaction  

OpenAIRE

We study the frictional drag due to Coulomb and phonon mediated electron-electron interaction in a double layer electron system exposed to a perpendicular magnetic field. Within the random phase approximation we calculate the dispersion relation of the intra Landau level magnetoplasmons at finite temperatures and distinguish their contribution to the magnetodrag. We calculate the transresistivity $\\rho_{Drag}$ as a function of magnetic field $B$, temperature $T$, and interla...

Badalyan, Samvel M.; Kim, Chang Sub

2003-01-01

371

A control system for a free electron laser experiment  

International Nuclear Information System (INIS)

The general layout of a control and data acquisition system for a Free Electron Laser experiment will be discussed. Some general considerations about the requirements and the architecture of the whole system will be developed. (author)

372

Security analysis of electronic voting and online banking systems  

OpenAIRE

The main focus of this dissertation is on security analysis of electronic voting and online banking systems. Six papers form the basis of the thesis and include the following topics: a model for analysis of voting systems, a case study where we apply the proposed model, a new scheme for remote electronic voting, and three case studies of commercial online banking solutions in Norway.

Tjøstheim, Thomas

2007-01-01

373

Electron gun system for NSC KIPT linac  

OpenAIRE

In NSC KIPT linac, a neutron source based on a subcritical assembly driven by a 100MeV/100kW electron linear accelerator is under design and development. The linear accelerator needs a new high current electron gun. In this paper, the physical design, mechanical fabrication and beam test of this new electron gun are described. The emission current is designed to be higher than 2A for the pulse width of 3us with repetition rate of 50 Hz. The gun will operate with a DC high vo...

Zhou, Zusheng; He, Dayong; Chi, Yunlong

2013-01-01

374

ELECTRONIC STRUCTURE OF MIXED VALENT SYSTEMS  

OpenAIRE

The electronic structure of Tm and Sm monochalcogenides, SmB6 and Yb4As3 is theoretically investigated from the first principles, using the fully relativistic Dirac LMTO band structure method. The electronic structure is obtained using the local spin-density approximation (LSDA), as well as the so-called LSDA+U approach. While the standard LSDA approach is incapable of correctly describing the electronic structure of such materials due to the strong on-site Coulomb repulsion, the LSDA+U appro...

Antonov, V. N.; Shpak, A. P.; Yaresko, A. N.

2004-01-01

375

Electron mass shift in nonthermal systems  

CERN Document Server

The electron mass is known to be sensitive to local fluctuations in the electromagnetic field, and undergoes a small shift in a thermal field. It was claimed recently that a very large electron mass shift should be expected near the surface of a metal hydride [{\\it Eur. Phys. J. C}, {\\bf 46} 107 (2006)]. We examine the shift using a formulation based on the Coulomb gauge, which leads to a much smaller shift. The maximization of the electron mass shift under nonequilibrium conditions seems nonetheless to be an interesting problem. We consider a scheme in which a current in a hollow wire produces a large vector potential in the wire center. Fluctuations in an LC circuit with nearly matched loss and gain can produce large current fluctuations; and these can increase the electron mass shift by orders of magnitude over its room temperature value.

Hagelstein, Peter L

2008-01-01

376

NFC-based Electronic Data Capture Systems  

OpenAIRE

In this paper, we present a Near Field Communication (NFC)-based electronic data capture prototype for patient self-reported rating scales. Such scales are valuable feedback for medical treatment and care processes. As traditional paper-based questionnaires are time- and cost-consuming and may be affected by low patient compliance, our prototype allows patient monitoring and electronic data acquisition directly from the patient's home. It enables real time representation and analysis of ...

Prinz, A.; Menschner, P.; Jan Marco Leimeister

2012-01-01

377

Thermodynamic potential of electrons and phonons system of disordered alloy  

CERN Document Server

The cluster decomposition for the delayed two-time Green functions and the disordered crystal dynamic potential is obtained with an account of the electron-phonon and electron-electron interactions. The system electron states are described within the frames of the multizone strong coupling model. The calculations are based on the diagram technique for the Green temperature functions. The coherent potential approximation is chosen as the zero mononode approximation in this cluster decomposition method. It is shown that the processes of the contributions of the elementary excitations scattering on the clusters decrease with the cluster nodes number growth in the cluster in correspondence with certain small parameters. The analytical evaluations of the electron-phonon interaction impact on the electron energy spectrum of the ordering alloy are made in the monozone model. The possibility of applying the obtained results for describing the strong electron correlations impact on the electron structure and propertie...

Repetskij, S P

2002-01-01

378

Importance of Initial Electronic State in Two-Dimensional Electron System for Electron Transport from Two-Dimensional Electron Gas to Quantum Dot  

OpenAIRE

We have theoretically investigated the time-evolution of electron transport from a two-dimensional electron system (2DES) to a quantum dot (QD). We clearly showed that the coherent electron transport is remarkably modified depending on the initial electronic state in the 2DES. The electron transport from the 2DES to the QD is strongly enhanced when the initial state of electron in the 2DES is localized below the QD. We indicate that these features should be obtained in other...

Muraguchi, Masakazu; Takada, Yukihiro; Nomura, Shintaro; Endoh, Testuo; Shiraishi, Kenji

2008-01-01

379

EU sampling strategies for the detection of veterinary drug residues in aquaculture species: are they working?  

Science.gov (United States)

Over the past 50 years, the culture of aquatic species in controlled conditions to enhance production has grown in importance and now provides nearly 50% of the world's seafood supply. In part, this expansion has been made possible by the use of antibiotics, antifungals, and other veterinary medicines to control disease and improve welfare. Despite guidelines being available, the sampling programmes for drug residue surveillance of aquaculture products recommended by the CODEX Alimentarius Commission were withdrawn in 2008 and put under review. Directive 96/23/EC sets out legislation to govern how sampling programmes for drug residue surveillance should be conducted within the EU. This directive applies both to produce raised within the EU and also imported products from third countries. This communication examines the existing EU sampling regimen for aquaculture products and comments on its possible application in a global context. We examine UK statutory sampling data that, while indicating the effectiveness of the directive, also suggests that the directive may lead to unnecessary sampling. Regarding imports, examination of the Rapid Alert System for Food and Feed (RASFF) database using process control charts and statistical modelling suggests that the sampling regimen described in the directive is effective but not sufficiently flexible for the range of aquaculture practices that exist. Limitations of the directive, datasets, and practices are further discussed. PMID:22851354

Morris, D J; Gray, A J; Kay, J F; Gettinby, G

2012-08-01

380

Review of solutions for 3D hydrodynamic modeling applied to aquaculture in South Pacific atoll lagoons.  

Science.gov (United States)

A workshop organized in French Polynesia in November 2004 allowed reviewing the current methods to model the three-dimensional hydrodynamic circulation in semi-enclosed atoll lagoons for aquaculture applications. Mollusk (e.g. pearl oyster, clam) aquaculture is a major source of income for South Pacific countries such as French Polynesia or Cook Islands. This aquaculture now requires a better understanding of circulation patterns to improve the spatial use of the lagoons, especially to define the best area to set larvae collectors. The pelagic larval duration of the relevant species (remote sensing and in situ data collection) to accurately represent the different components of the lagoon system and its specific boundary conditions. We review here the current methods and tools used to address these different components for a hypothetical atoll of the Tuamotu Archipelago (French Polynesia), representative of the semi-closed lagoons of the South Pacific Ocean. We hope this paper will serve as a guide for similar studies elsewhere and we provide guidelines in terms of costs for all the different stages involved. PMID:16987532

Andréfouët, S; Ouillon, S; Brinkman, R; Falter, J; Douillet, P; Wolk, F; Smith, R; Garen, P; Martinez, E; Laurent, V; Lo, C; Remoissenet, G; Scourzic, B; Gilbert, A; Deleersnijder, E; Steinberg, C; Choukroun, S; Buestel, D

2006-10-01

381

Tocopherols in Seafood and Aquaculture Products.  

Science.gov (United States)

ABSTRACT Fish products contain various nutritionally beneficial components, namely, ?3 polyunsaturated fatty acids (?3-PUFA), minerals, and vitamins. Particularly, tocopherols (?-, ?-, ?-, and ?-tocopherol) can be provided by seafood and aquaculture products. Hence, this review shows the various aspects of tocopherols in seafood and aquaculture products. For tocopherol determination in these products, HPLC methods coupled with diode array detection in the UV area of the spectrum or fluorescence detection have been shown as sensitive and accurate. These newest methods have helped in understanding tocopherols fate upon ingestion by seafood organisms. Tocopherols pass through the intestinal mucosa mainly by the same passive diffusion mechanism as fats. After absorption, the transport mechanism is thought to consist of two loops. The first loop is dietary, including chylomicrons and fatty acids bound to carrier protein, transporting lipids mainly to the liver. The other is the transport from the liver to tissues and storage sites. Moreover, tocopherol levels in fish organisms correlate with diet levels, being adjusted in fish body depending on diet concentration. For farmed fish species, insufficient levels of tocopherols in the diet can lead to poor growth performance or to nutritional disease. The tocopherol quantity needed as a feed supplement depends on various factors, such as the vitamer mixture, the lipid level and source, the method of diet preparation, and the feed storage conditions. Other ingredients in diet may be of great importance, it has been proposed that ?-tocopherol may behave as a prooxidant synergist at higher concentrations when prooxidants such as transition metals are present. However, the antioxidant action of tocopherols outweighs this prooxidant effect, provided that adequate conditions are used. In fact, muscle-based foods containing higher levels of tocopherol show, for instance, higher lipid stability. Besides, tocopherols are important not only from the nutritional point of view but also from the physiological one, since they are involved in many metabolic processes in the human organism. Moreover, synergistic interactions with selenium and ascorbic acid have been reported. It deserves attention that there is evidence tocopherols taken with food can prevent heart disease, while no such evidence was found for ?-tocopherol as supplement. From this perspective, eating fish is advisable, since, for instance, a 100 g serving of salmon may provide nearly 14 % of recommended dietary allowance. PMID:24915325

Afonso, Cláudia; Bandarra, Narcisa M; Nunes, Leonor; Cardoso, Carlos

2013-10-11

382

Electron Gamma Shower Code System-4 (EGS4)  

International Nuclear Information System (INIS)

EGS Code system is a package of computer programs to simulate the transport behavior of a primary electron, positron or a gamma photon and all it's descendents (electron/positron/photon) in a medium using Monte Carlo technique. Electron and positron will be commonly called electron unless a distinction is warranted. The code ignores nuclear absorption processes/fission such as (?,n), (?,p) (?,f) etc. The code is thus developed to solve coupled electron gamma transport problems encountered in a large variety of areas such as radiological, medical physics, shielding calculations in radiation installations and high-energy research applications etc

383

A Layman's Guide to Geothermal Aquaculture  

Energy Technology Data Exchange (ETDEWEB)

The following paper is designed as an aid to anyone contemplating a venture into commercially raising giant freshwater prawns, Macrobrachium rosenbergii. Oregon Institute of Technology has been actively involved in a research program to determine the feasibility of such a venture and results to date have been very encouraging. This aquaculture research was initiated in 1975 and was developed as an effort to utilize excess energy from the school’s geothermal heating system. Therefore, most of the information gathered here, will apply to flow-through systems which use geothermal water to maintain a suitable environment for the animals. A study of the market potential for freshwater prawns has been conducted and a favorable response received from wholesale distributors in the Pacific Northwest. Not only is a good market available, but distributors have suggested paying from $4.50 to $5.00 per pound for whole prawns in the size category of 16 to 20 tails to the pound, for a constant fresh supply. By maintaining constant temperatures of 27 degrees Celsius (80 degrees Fahrenheit) ± 1 degree Celsius in our research ponds, we have been able to produce this size prawn in 6 to 8 months.

Smith, Kenan C.

1981-01-01

384

Electron energy recovery system for negative ion sources  

Science.gov (United States)

An electron energy recovery system for negative ion sources is provided. The system, employs crossed electric and magnetic fields to separate the electrons from ions as they are extracted from a negative ion source plasma generator and before the ions are accelerated to their full kinetic energy. With the electric and magnetic fields oriented 90.degree. to each other, the electrons are separated from the plasma and remain at approximately the electrical potential of the generator in which they were generated. The electrons migrate from the ion beam path in a precessing motion out of the ion accelerating field region into an electron recovery region provided by a specially designed electron collector electrode. The electron collector electrode is uniformly spaced from a surface of the ion generator which is transverse to the direction of migration of the electrons and the two surfaces are contoured in a matching relationship which departs from a planar configuration to provide an electric field component in the recovery region which is parallel to the magnetic field thereby forcing the electrons to be directed into and collected by the electron collector electrode. The collector electrode is maintained at a potential slightly positive with respect to the ion generator so that the electrons are collected at a small fraction of the full accelerating supply voltage energy.

Dagenhart, William K. (Oak Ridge, TN); Stirling, William L. (Oak Ridge, TN)

1982-01-01

385

RHIC electron lens beam transport system design considerations  

International Nuclear Information System (INIS)

To apply head-on beam-beam compensation for RHIC, two electron lenses are designed and will be installed at IP10. Electron beam transport system is one of important subsystem, which is used to transport electron beam from electron gun side to collector side. This system should be able to change beam size inside superconducting magnet and control beam position with 5 mm in horizontal and vertical plane. Some other design considerations for this beam transport system are also reported in this paper. The head-on beam-beam effect is one of important nonlinear source in storage ring and linear colliders, which have limited the luminosity improvement of many colliders, such as SppS, Tevatron and RHIC. In order to enhance the performance of colliders, beam-beam effects can be compensated with direct space charge compensation, indirect space charge compensation or betatron phase cancellation scheme. Like other colliders, indirect space charge compensation scheme (Electron Lens) was also proposed for Relativistic Heavy Ion Collider (RHIC) beam-beam compensation at Brookhaven National Laboratory. The two similar electron lenses are located in IR10 between the DX magnets. One RHIC electron lens consists of one DC electron gun, one superconducting magnet, one electron collector and beam transport system.

386

Electron beam sterilization using an integrated systems approach  

International Nuclear Information System (INIS)

The sterilization of medical disposables is a complex process and requires a sophisticated system to meet today's stringent requirements. Such a system is in use today using electron beam sterilization from a Dynamitron accelerator. The process system components are described as is their functionality as part of an integrated system. Certain information is omitted to observe the confidentiality of the user. (orig.)

387

Correlated electrons systems on the Apollonian network  

CERN Document Server

Strongly correlated electrons on an Apollonian network are studied using the Hubbard model. Ground-state and thermodynamic properties, including specific heat, magnetic susceptibility, spin-spin correlation function, double occupancy and one-electron transfer, are evaluated applying direct diagonalization and quantum Monte Carlo. The results support several types of magnetic behavior. In the strong-coupling limit, the quantum anisotropic spin 1/2 Heisenberg model is used and the phase diagram is discussed using the renormalization group method. For ferromagnetic coupling, we always observe the existence of long-range order. For antiferromagnetic coupling, we find a paramagnetic phase for all finite temperatures.

Souza, A M C; Souza, Andre M. C.; Herrmann, Hans

2006-01-01

388

Secure electronic commerce communication system based on CA  

Science.gov (United States)

In this paper, we introduce the situation of electronic commercial security, then we analyze the working process and security for SSL protocol. At last, we propose a secure electronic commerce communication system based on CA. The system provide secure services such as encryption, integer, peer authentication and non-repudiation for application layer communication software of browser clients' and web server. The system can implement automatic allocation and united management of key through setting up the CA in the network.

Chen, Deyun; Zhang, Junfeng; Pei, Shujun

2001-07-01

389

Handbook of power systems engineering with power electronics applications  

CERN Document Server

Formerly known as Handbook of Power System Engineering, this second edition provides rigorous revisions to the original treatment of systems analysis together with a substantial new four-chapter section on power electronics applications. Encompassing a whole range of equipment, phenomena, and analytical approaches, this handbook offers a complete overview of power systems and their power electronics applications, and presents a thorough examination of the fundamental principles, combining theories and technologies that are usually treated in separate specialised fields, in a single u

Hase, Yoshihide

2012-01-01

390

Quality Control of Coffee Using an Electronic Nose System  

Directory of Open Access Journals (Sweden)

Full Text Available An electronic nose system for quality control of coffee is designed and tested. The system uses the Figaro TGS800 series sensors with an integrated heating element. The testing of the system is carried out using different types of coffee where it is proved successful in classifying the tested coffees and actual discrimination of ingredients into different classes[10]. Database based software is designed to interface the built hardware and to process the electronic nose signals before being classified.

Nidal F. Shilbayeh

2004-01-01

391

Quality Control of Coffee Using an Electronic Nose System  

OpenAIRE

An electronic nose system for quality control of coffee is designed and tested. The system uses the Figaro TGS800 series sensors with an integrated heating element. The testing of the system is carried out using different types of coffee where it is proved successful in classifying the tested coffees and actual discrimination of ingredients into different classes[10]. Database based software is designed to interface the built hardware and to process the electronic nose signals before being cl...

Shilbayeh, Nidal F.; Iskandarani, Mahmoud Z.

2004-01-01

392

Propagation of electron-acoustic radiation in a relativistic electron-beam plasma system  

International Nuclear Information System (INIS)

The effects of a relativistic electrons on the amplitude and width of small amplitude electron acoustic radiation are examined in an unmagnetized collisionless four components plasma system. The Korteweg-de Vries (KdV) equation has been derived using a reductive perturbation theory. Finally solitary solution is obtained

393

The electronic identification, signature and security of information systems  

Directory of Open Access Journals (Sweden)

Full Text Available The contribution deals with the actual methods and technologies of information and communication systems security. It introduces the overview of electronic identification elements such as static password, dynamic password and single sign-on. Into this category belong also biometric and dynamic characteristics of verified person. Widespread is authentication based on identification elements ownership, such as various cards and authentication calculators. In the next part is specified a definition and characterization of electronic signature, its basic functions and certificate categories. Practical utilization of electronic signature consists of electronic signature acquirement, signature of outgoing email message, receiving of electronic signature and verification of electronic signature. The use of electronic signature is continuously growing and in connection with legislation development it exercises in all resorts.

Horovèák Pavel

2002-12-01

394

DNA and microfluidics: Building molecular electronics systems  

Energy Technology Data Exchange (ETDEWEB)

The development of molecular electronics using DNA molecules as the building blocks and using microfluidics to build nanowire arrays is reviewed. Applications of DNA conductivity to build sensors and nanowire arrays, and DNA conjugation with other nanostructures, offers an exciting opportunity to build extremely small analytical devices that are suitable for single-molecule detection and also target screening.

Ye Yun [Chemical Sensors Group, Department of Chemical and Physical Sciences, University of Toronto at Mississauga, 3359 Mississauga Road North, Mississauga, Ont., L5L 1C6 (Canada); Chen Lu [Chemical Sensors Group, Department of Chemical and Physical Sciences, University of Toronto at Mississauga, 3359 Mississauga Road North, Mississauga, Ont., L5L 1C6 (Canada); Liu Xuezhu [Chemical Sensors Group, Department of Chemical and Physical Sciences, University of Toronto at Mississauga, 3359 Mississauga Road North, Mississauga, Ont., L5L 1C6 (Canada); Krull, Ulrich J. [Chemical Sensors Group, Department of Chemical and Physical Sciences, University of Toronto at Mississauga, 3359 Mississauga Road North, Mississauga, Ont., L5L 1C6 (Canada)]. E-mail: ukrull@utm.utoronto.ca

2006-05-24

395

Designing an Electronic Medication Reconciliation System  

OpenAIRE

Unintended medication discrepancies at hospital admission and discharge potentially harm patients. Explicit medication reconciliation (MR) can prevent unintended discrepancies among care settings and is mandated by JCAHO for 2005. Enterprise-wide, we are linking pre-admission and discharge medication lists in our outpatient electronic health records (EHR) with our inpatient order entry ...

Hamann, Claus; Poon, Eric; Smith, Sandra; Coley, Christopher; Graydon-baker, Erin; Gandhi, Tejal; Chueh, Henry C.; Poikonen, John; Hallisey, Robert K.; Putten, Cheryl; Broverman, Carol; Blumenfeld, Barry; Middleton, Blackford

2005-01-01

396

DNA and microfluidics: Building molecular electronics systems  

International Nuclear Information System (INIS)

The development of molecular electronics using DNA molecules as the building blocks and using microfluidics to build nanowire arrays is reviewed. Applications of DNA conductivity to build sensors and nanowire arrays, and DNA conjugation with other nanostructures, offers an exciting opportunity to build extremely small analytical devices that are suitable for single-molecule detection and also target screening

397

Orbital ordering phenomena in $d$- and $f$-electron systems  

OpenAIRE

In recent decades, novel magnetism of $d$- and $f$-electron compounds has been discussed very intensively both in experimental and theoretical research fields of condensed matter physics. It has been recognized that those material groups are in the same category of strongly correlated electron systems, while the low-energy physics of $d$- and $f$-electron compounds has been separately investigated rather in different manners. One of common features of both $d$- and $f$-elect...

Hotta, Takashi

2006-01-01

398

Projected density functional theory of strongly correlated electron systems  

CERN Document Server

Combining the Hohenberg-Kohn theorem with the Gutzwiller projection, we develop a density functional theory of strongly correlated electron systems. The optimization of the energy functional leads to a thoroughly unrestricted self-consistent re-normalized mean field theory. Applying the theory to high-$T_c$ superconductors, we discuss the issues of electronic inhomogeneity, the superfluid density, and in particular the local electron density of states. The results account for many intriguing aspects of the phenomenology.

Wang, Q H; Chen, Y; Zhang, F C; Wang, Qiang-Hua; Chen, Yan; Zhang, Fu-Chun

2006-01-01

399

Development of an economical electron backscattering diffraction system for an environmental scanning electron microscope  

Science.gov (United States)

A low cost, highly versatile electron backscattering diffraction system has been developed for an ElectroScan E3 Environmental Scanning Electron Microscope (ESEM). A P20 phosphor coated screen is placed in the microscope environment to image electron backscattering diffraction patterns (EBSP's). A CCD TV camera is used to view the patterns through a leaded glass port in the microscope specimen chamber. This system has a spatial resolution approaching 5 micron and yields analyzable patterns at pressures of up to 6 Torr. With minor modifications this system may be adapted to fit any scanning electron microscope. Comparison of analyses of the grain boundary misorientation of a Ni-16Cr-9Fe alloy with this system and by selected area channeling patterns (SACP's), performed in a standard SEM, yielded excellent agreement between the two techniques.

Thaveeprungsriporn, V.; Mansfield, J. F.; Was, G. S.

1994-07-01

400

Effect of radiosensitizing agents on electron transport systems  

International Nuclear Information System (INIS)

Experiments have been carried out to study the interaction between chemical radiosensitizing agents and model electron transport systems. Using an NAD(P)H:O2 oxidoreductase enzyme as such a model, it was demonstrated that radiosensitizers can act as intermediates in the transfer of electrons from NADH to O2, even in the presence of classical inhibitors of electron transport, with an efficiency related to both their redox potentials and their radiosensitizing abilities. This work which was further confirmed in mammalian mitochondria and microsomes as well as in a cultured cell system indicated that these sensitizers can accept electrons from a variety of organelle systems. This action was shown to be related to the concentration of reduced pyridine nucleotides present both in vivo and in vitro. Of the electron-affinic agents tested, those whose redox potential was more negative than -0.39 V may possibly serve as better radiotherapeutic mediators. (author)

401

Electronic accelerator pedal optimal design of intelligent test system  

Science.gov (United States)

Developed an intelligent test system for the electronic accelerator pedal, and optimized it. The system uses the three-dimensional motion platform driven by servo motor to realize to control the movement of the electronic accelerator pedal automatically and uses the least squares method to optimize the data for the electronic accelerator pedal which is integrated with linear Hall sensors. Carried on the test experiment to the double electric potential signal output electron accelerator pedal and the results show that the system has excellent dynamic and static performance, and the change of motor parameters and load disturbances has strong robustness. Performance indicators have reached the Euro III emission standard configuration of the electronic accelerator pedal and the new technical requirements.

Li, Quailing; Lin, Min; Guo, Bin; Luo, Zai

2010-12-01

402

Life cycle of the electronic encyclopedia as the information system  

OpenAIRE

The paper dwells on the integral aspect of the electronic encyclopedia, namely its life cycle. There is a generalized system of the electronic encyclopedia formation in this article. It reveals the essence of the each life cycle stage. It is justified the choice of knowledge extraction from open texts for the encyclopedic conten formation.

Zhezhnych, Pavlo; Hirnyak, Mariya

2013-01-01

403

Determining conversion electron yields in a liquid scintillation system  

International Nuclear Information System (INIS)

This paper demonstrates the capabilities of a liquid scintillation system to measure conversion electron yields. The conversion electrons, being monoenergetic, can be measured with 100 percent efficiency if the energy is significantly greater than the threshold (a few keV for unquenched samples). Examples are given using cobalt 57 and chromium 51 decays

404

The electronics readout system for the OPAL Vertex Drift Chamber  

International Nuclear Information System (INIS)

The Vertex Drift Chamber for the OPAL experiment at LEP provides high quality track co-ordinates using multi-hit sub-nanosecond timing to detect the drifted electrons. This paper explains the electronic techniques that have been devised and implemented for the detector. The overall performance of the system is demonstrated with measurements from the final OPAL chamber. (author)

405

Scaffolding Strategies in Electronic Performance Support Systems: Types and Challenges  

Science.gov (United States)

In the study described in this paper, the major components of an electronic performance support system are described and the use of scaffolding techniques within such electronic environments is explored. Four different types of scaffolding are discussed: "conceptual" (supportive) scaffolding, "metacognitive" (reflective) scaffolding, "procedural"…

Cagiltay, Kursat

2006-01-01

406

Use of Geothermal Energy for Aquaculture Purposes - Phase III  

Energy Technology Data Exchange (ETDEWEB)

This project, financed by the Pacific Northwest Regional Commission (PNRC), was designed to provide information to evaluate the best methods to use for intensive aquaculture of freshwater prawns, Macrobrachium rosenbergii, using geothermal energy. The freshwater prawn is a tropical organism and is native to southeast Asia. Earlier projects at Oregon Institute of Technology have shown the feasibility of culturing this aquatic animal in geothermal water. This phase of the project was designed to investigate intensive culture of this animal as well as the advantages of growing rainbow trout, ornamental tropical fin fish, and mosquito fish, Gambusia affnis, for vector control using geothermal energy. The research data collected on the prawns was obtained from the stocking and sampling of two 0.2- ha (half-acre) ponds constructed as a part of the project. The ponds are equipped with recording monitors for temperature and flow. The geothermal energy used is the geothermal effluent from the Oregon Institute of Technology heating system. This water is of potable quality and ranges in temperature from 50 to 70oC. The geothermal water used in the ponds is controlled at 27oC, ± 2oC, by using thermostats and solenoid valves. A small building next to the ponds contains facilities for hatching larvae prawns and tanks for growing post-larvae prawns. The hatchery facility makes the project self-sustaining. The hatchery was obtained as part of an earlier PNRC project.

Johnson, W.C.; Smith, K.C.

1981-09-01

407

Human Health Consequences of Use of Antimicrobial Agents in Aquaculture  

DEFF Research Database (Denmark)

Intensive use of antimicrobial agents in aquaculture provides a selective pressure creating reservoirs of drug-resistant bacteria and transferable resistance genes in fish pathogens and other bacteria in the aquatic environment. From these reservoirs, resistance genes may disseminate by horizontal gene transfer and reach human pathogens, or drug-resistant pathogens from the aquatic environment may reach humans directly. Horizontal gene transfer may occur in the aquaculture environment, in the food chain, or in the human intestinal tract. Among the antimicrobial agents commonly used in aquaculture, several are classified by the World Health Organisation as critically important for use in humans. Occurrence of resistance to these antimicrobial agents in human pathogens severely limits the therapeutic options in human infections. Considering the rapid growth and importance of aquaculture industry in many regions of the world and the widespread, intensive, and often unregulated use of antimicrobial agents in thisarea of animal production, efforts are needed to prevent development and spread of antimicrobial resistance in aquaculture to reduce the risk to human health.

Heuer, Ole Eske; Kruse, H.

2009-01-01

408

Possibilities for marker-assisted selection in aquaculture breeding schemes  

International Nuclear Information System (INIS)

FAO estimates that there are around 200 species in aquaculture. However, only a few species have ongoing selective breeding programmes. Marker-assisted selection (MAS) is not used in any aquaculture breeding scheme today. The aim of this chapter, therefore, is to review briefly the current status of aquaculture breeding schemes and to evaluate the possibilities for MAS of aquaculture species. Genetic marker maps have been published for some species in culture. The marker density of these maps is, in general, rather low and the maps are composed of many amplified fragment length polymorphism (AFLP) markers anchored to few microsatellites. Some quantitative trait loci (QTL) have been identified for economically important traits, but they are not yet mapped at a high density. Computer simulations of within-family MAS schemes show a very high increase in genetic gain compared with conventional family-based breeding schemes, mainly due to the large family sizes that are typical for aquaculture breeding schemes. The use of genetic markers to identify individuals and their implications for breeding schemes with control of inbreeding are discussed. (author)

409

Variables Affecting Two Electron Transport System Assays  

OpenAIRE

Several methodological variables were critical in two commonly used electron transport activity assays. The dehydrogenase assay based on triphenyl formazan production exhibited a nonlinear relationship between formazan production (dehydrogenase activity) and sediment dilution, and linear formazan production occurred for 1 h in sediment slurries. Activity decreased with increased time of sediment storage at 4°C. Extraction efficiencies of formazan from sediment varied with alcohol type; metha...

Burton, G. Allen; Lanza, Guy R.

1986-01-01

410

Electronic system for Langmuir probe measurements.  

Czech Academy of Sciences Publication Activity Database

Ro?. 356, ?. 1 (2012), s. 012008. ISSN 1742-6588. [InternationalSummerSchoolonVacuum,Electron, and IonTechnologies(VEIT2011)/17./. Sunny Beach, 19.09.2011-23.09.2011] Institutional research plan: CEZ:AV0Z20430508 Keywords : Plasma * tokamak * diagnostics * electric probe Subject RIV: BL - Plasma and Gas Discharge Physics http://iopscience.iop.org/1742-6596/356/1/012008/pdf/1742-6596_356_1_012008.pdf

Mitov, M.; Bankova, A.; Dimitrova, M.; Ivanova, P.; Tutulkov, K.; Djermanova, N.; Dejarnac, Renaud; Stöckel, Jan; Popov, Tsv.K.

2012-01-01

411

Energy Transformation in Molecular Electronic Systems  

Energy Technology Data Exchange (ETDEWEB)

This laboratory has developed many new ideas and methods in the electronic spectroscopy of molecules. This report covers the contract period 1993-1995. A number of the projects were completed in 1996, and those papers are included in the report. The DOE contract was terminated at the end of 1995 owing to a reorganizational change eliminating nationally the projects under the Office of Health and Environmental Research, U. S. Department of Energy.

Kasha, Michael

1999-05-17

412

Boundary conditions for many-electron systems  

OpenAIRE

It is shown that natural boundary conditions for non-relativistic wave functions are of periodic or of homogeneous Robin type. Using asymptotic central symmetry of Hamiltonian and theory of singular differential equations the many-electron wave function is expanded in series both in the vicinity of Coulomb singularities and at infinity. Hydrogenic angular dependence of three leading terms of expansion about Coulomb singularities is found. Exact first- and second-order cusp c...

To?th, Pe?ter V.

2010-01-01

413

F-electron systems: Pushing band theory  

Energy Technology Data Exchange (ETDEWEB)

The f-electron orbitals have always been the incomplete atomic shell acting as a local moment weakly interacting with the remaining electronic structure'' in the minds of most people. So examining them using a band theory where one views them as itinerant once was -- and to some extent even today still is -- considered with some skepticism. Nonetheless, a very significant community has successfully utilized band theory as a probe of the electronic structure of the appropriate actinides and rare earths. Those people actually using the approach would be the first to declare that it is not the whole solution. Instead, one is pushing and even exceeding its limits of applicability. However, the appropriate procedure is to push the model consistently to its limits, patch where possible, and then look to see where discrepancies remain. I propose to offer a selected review of past developments (emphasizing the career to date of A. J. Freeman in this area), offer a list of interesting puzzles for the future, and then make some guesses as to the techniques one might want to use. 27 refs.

Koelling, D.D.

1990-08-01

414

Does pond water reflectance influence double-crested cormorant selection of aquaculture pond?  

Science.gov (United States)

Double-crested cormorants (Phalacrocorax auritus) are a frequent and major avian predator on channel catfish (Ictalurus punctatus) and other aquaculture species throughout the southeastern USA. Although cormorant movements and occurrence within the aquaculture production region are understood, no s...

415

14 CFR 23.1311 - Electronic display instrument systems.  

Science.gov (United States)

...indicator, and attitude instrument or individual electronic...system. These secondary instruments may be installed in panel positions that are displaced...parameter that is located in the instrument panel such that the pilot...

2010-01-01

416

Automotive mechatronics automotive networking, driving stability systems, electronics  

CERN Document Server

As the complexity of automotive vehicles increases this book presents operational and practical issues of automotive mechatronics. It is a comprehensive introduction to controlled automotive systems and provides detailed information of sensors for travel, angle, engine speed, vehicle speed, acceleration, pressure, temperature, flow, gas concentration etc. The measurement principles of the different sensor groups are explained and examples to show the measurement principles applied in different types. Contents Basics of mechatronics.- Architecture.- Electronic control unit.- Software development.- Basic principles of networking.- Automotive networking.- Bus systems.- Automotive sensors.- Sensor measuring principles.- Sensor types.- Electric actuators.- Electrohydraulic actuators.- Electronic transmission control.- Electronic transmission control unit.- Modules for transmission control.- Antilock braking system.- Traction control system.- Electronic stability program.- Automatic brake functions.- Hydraulic modu...

2015-01-01

417

Power Electronics and Reliability in Renewable Energy Systems  

DEFF Research Database (Denmark)

Power Electronics are needed in almost all kind of renewable energy systems. It is used both for controlling the renewable source and also for interfacing to the load, which can be grid-connected or working in stand-alone mode. More and more efforts are put into making renewable energy systems better in terms of reliability in order to ensure a high availability of the power sources, in this case the knowledge of mission profile of a certain application is crucial for the reliability evaluation/design of power electronics. In this paper an overview on the power electronic circuits behind the most common converter configurations for wind turbine and photovoltaic is done. Next different aspects of improving the system reliability are mapped. Further on examples of how to control the chip temperature in different power electronic configurations as well as operation modes for wind power generation systems are given in order to reduce the temperature cycling.

Blaabjerg, Frede; Ma, Ke

2012-01-01

418

Limiting electron beam currents in co-axial systems  

International Nuclear Information System (INIS)

The problem of limiting currents in cylindrical coaxial systems of coaxial diode or coaxial drift space type is investigated. Exact and approximated analytical formulae for stationary limiting currents in such systems are derived, and numeric simulation of non-stationary injection and electron acceleration problems in coaxial systems and comparison of numeric results with analytic ones are performed as well. 2 refs., 9 figs

419

Monitoring and control system of the Saclay electron linear accelerator  

International Nuclear Information System (INIS)

A description is given of the automatic monitoring and control system of the 60MeV electron linear accelerator of the Centre d'Etudes Nucleaires de Saclay. The paper is mostly concerned with the programmation of the system. However, in a real time device, there is a very close association between computer and electronics, the latter are therefore described in details and make up most of the paper

420

Electronic-enthalpy functional for finite systems under pressure  

OpenAIRE

We introduce the notion of electronic enthalpy for first-principles structural and dynamical calculations of finite systems under pressure. An external pressure field is allowed to act directly on the electronic structure of the system studied via the ground-state minimization of the functional $E+PV_{q}$, where $V_{q}$ is the quantum volume enclosed by a charge isosurface. The Hellmann-Feynman theorem applies, and assures that the ionic equations of motion follow an isoenth...

Cococcioni, Matteo; Mauri, Francesco; Ceder, Gerbrand; Marzari, Nicola

2005-01-01

421

Why are Prices in Wild Catch and Aquaculture Industries so Different?  

OpenAIRE

Through a comparative analysis of prices in capture fisheries and aquaculture sectors, the objectives of this paper are a) to investigate three the trends in prices of forage catches to feed the aquaculture species, b) to analyze the amount of fish species need to feed aquaculture species in order to assess the level of efficiency in resource use, and c) to examine the degree of economic concentration either in wild-catch industry and aquaculture sectors. The results show that prices of culti...

Villasante, Sebastia?n; Rodri?guez-gonza?lez, David; Antelo, Manel; Rivero-rodri?guez, Susana; Lebranco?n-nieto, Joseba

2013-01-01

422

Genetic considerations for mollusk production in aquaculture: current state of knowledge  

OpenAIRE

In 2012, world mollusk production in aquaculture reached a volume of 15,171,000 tons, representing 23% of total aquaculture production and positioning mollusks as the second most important category of aquaculture products (fishes are the first). Clams and oysters are the mollusk species with the highest production levels, followed in descending order by mussels, scallops, and abalones. In view of the increasing importance attached to genetic information on aquaculture, which can help with goo...

Astorga, Marcela P.

2014-01-01

423

The effects of aquaculture production noise on the growth, condition factor, feed conversion, and survival of rainbow trout, Oncorhynchus mykiss  

Science.gov (United States)

Intensive aquaculture systems, particularly recirculating systems, utilize equipment such as aerators, air and water pumps, blowers, and filtration systems that inadvertently increase noise levels in fish culture tanks. Sound levels and frequencies measured within intensive aquaculture systems are within the range of fish hearing, but species-specific effects of aquaculture production noise are not well defined. Field and laboratory studies have shown that fish behavior and physiology can be negatively impacted by intense sound. Therefore, chronic exposure to aquaculture production noise could cause increased stress, reduced growth rates and feed conversion efficiency, and decreased survival. The objective of this study was to provide an in-depth evaluation of the long term effects of aquaculture production noise on the growth, condition factor, feed conversion efficiency, and survival of cultured rainbow trout, Oncorhynchus mykiss. Rainbow trout were cultured in replicated tanks using two sound treatments: 117??dB re 1????Pa RMS which represented sound levels lower than those recorded in an intensive recycle system and 149??dB re 1????Pa RMS, representing sound levels near the upper limits known to occur in recycle systems. To begin the study mean fish weights in the 117 and 149??dB tanks were 40 and 39??g, respectively. After five months of exposure no significant differences were identified between treatments for mean weight, length, specific growth rates, condition factor, feed conversion, or survival (n = 4). Mean final weights for the 117 and 149??dB treatments were 641 ?? 3 and 631 ?? 10??g, respectively. Overall specific growth rates were equal, i.e. 1.84 ?? 0.00 and 1.84 ?? 0.01%/day. Analysis of growth rates of individually tagged rainbow trout indicated that fish from the 149??dB tanks grew slower during the first month of noise exposure (p < 0.05); however, fish acclimated to the noise thereafter. This study further suggests that rainbow trout growth and survival are unlikely to be affected over the long term by noise levels common to intensive aquaculture systems. ?? 2008 Elsevier B.V.

Davidson, J.; Bebak, J.; Mazik, P.

2009-01-01

424

ANALYSIS OF ELECTRONIC VOTING SYSTEM IN VARIOUS COUNTRIES  

Directory of Open Access Journals (Sweden)

Full Text Available India is the world’s largest democracy with a population of more than 1 billion; India has an electorate of more than 668 million and covers 543 parliamentary constituencies. Voting is the bridge between the governed and government. The last few years have brought a renewed focus on to the technology used in the voting process. The current voting system has many security holes, and it is difficult to prove even simple security properties about them. A voting system that can be proven correct has many concerns. There are some reasons for a government to use electronic systems are to increase elections activities and to reduce the elections expenses. Still there is some scope of work in electronic voting system because there is no way of identification by the electronic voting system whether the user is authentic or not and securing electronic voting machine from miscreants. This paper provides an overview of the experiences of other countries using electronic voting machine. The comparative focus is on the adoption of electronic voting systems adopted at the international level.

Sanjay Kumar,

2011-05-01

425

Power electronics for renewable energy systems, transportation and industrial applications  

CERN Document Server

Compiles current research into the analysis and design of power electronic converters for industrial applications and renewable energy systems, presenting modern and future applications of power electronics systems in the field of electrical vehicles With emphasis on the importance and long-term viability of Power Electronics for Renewable Energy this book brings together the state of the art knowledge and cutting-edge techniques in various stages of research.  The topics included are not currently available for practicing professionals and aim to enable the reader to directly apply the know

Abu-Rub, Haitham; Al-Haddad, Kamal

2014-01-01

426

Electronic control system TVER for 220 MW steam turbines  

International Nuclear Information System (INIS)

The electronic turbine output governor is an electronic part of an electronic and hydraulic control system of one pair of 220 MW turbo-set. It consists of the following function assemblies: a turbine output governor, a condenser steam pressure controller, a module for evaluating the temperature stress of the turbine critical point, a pressure controller in gland circuits, a digital speedometer, logic control circuits for safe control of nonsteady-state and accident system conditions, sensors and actuators. The operation of the individual elements is described in detail. The device has fully been proven in practice. (J.B.). 9 figs., 4 refs

427

Advanced Power Electronic Interfaces for Distributed Energy Systems Part 1: Systems and Topologies  

Energy Technology Data Exchange (ETDEWEB)

This report summarizes power electronic interfaces for DE applications and the topologies needed for advanced power electronic interfaces. It focuses on photovoltaic, wind, microturbine, fuel cell, internal combustion engine, battery storage, and flywheel storage systems.

Kramer, W.; Chakraborty, S.; Kroposki, B.; Thomas, H.

2008-03-01

428

Bæreevne i norsk akvakultur – CANO :Carrying Capacity in Norwegian Aquaculture – CANO  

OpenAIRE

In aquaculture the carrying capacity may be defined as the maximum amount of an aquaculture organism that can be produced in an area without the environmental effects exceeding accepted levels. The CANO project will contribute to determine the carrying capacity and ensure a sustainable aquaculture industry.

Ervik, Arne; Hansen, Pia Kupka; Strand, Øivind; Agnalt, Ann-lisbeth

2009-01-01

429

77 FR 50082 - Notice of Opportunity To Submit Content Request for the 2013 Census of Aquaculture  

Science.gov (United States)

...Content Request for the 2013 Census of Aquaculture AGENCY: National Agricultural Statistics...content requests for the 2013 Census of Aquaculture. This census is required by law under...The results of the 2005 Census of Aquaculture were released in October 2006....

2012-08-20

430

Electronic readout system in L3 Cosmics  

International Nuclear Information System (INIS)

The L3 Cosmics experiment will use the unique muon spectrometer of L3 at CERN to measure cosmic muon. the read-out system of this experiment is a advanced system. It is designed with VHDL, and uses EPLD, FPGA, the special TDC chip and JTAG technology

431

NASA three-laser airborne differential absorption lidar system electronics  

Science.gov (United States)

The system control and signal conditioning electronics of the NASA three laser airborne differential absorption lidar (DIAL) system are described. The multipurpose DIAL system was developed for the remote measurement of gas and aerosol profiles in the troposphere and lower stratosphere. A brief description and photographs of the majority of electronics units developed under this contract are presented. The precision control system; which includes a master control unit, three combined NASA laser control interface/quantel control units, and three noise pulse discriminator/pockels cell pulser units; is described in detail. The need and design considerations for precision timing and control are discussed. Calibration procedures are included.

Allen, R. J.; Copeland, G. D.

1984-12-01

432

Intelligent Systems for Self-Healing Electronics  

Science.gov (United States)

For long duration missions it is imperative to be able to monitor and record critical information. The data acquisition systems used must therefore be fault tolerant. This usually meant having redundant copies of critical channels. Since each channel usually consists of various components, the parts count, cost, weight and complexity of the system could be very high. The Advanced Data Acquisition System (ADAS) has been developed as a proof of concept. The purpose was to demonstrate an architecture where individual spare parts can replace defective ones to repair a channel. By so doing entire channels do not need replication. This reduces the need of total redundancy and reduces the parts count. This has the added feature that in addition to spare parts, good components of a failed channel can be used as spares in another channel. In addition to reducing parts count and cost, this configuration, with an intelligent decision maker, can improve the reliability of the overall system. Another unique feature of ADAS is that it uses reconfigurable analog filters. These components can be programmed, by the smart system to meet the specific needs of the part they are to replace. This way one part can serve as spare for many different components. The hardware was built and now serves as a platform for developing intelligent algorithms. Another related project was a wireless data acquisition system. I was invited to participate in the meetings and issue suggestions. A brief description of this system will also be included.

Latino, Carl D.

2001-01-01

433

Large magnetocapacitance in electronic ferroelectric manganite systems  

International Nuclear Information System (INIS)

We have observed a sizable positive magnetocapacitance (?5%–90%) in perovskite Pr0.55Ca0.45MnO3 and bilayer Pr(Sr0.1Ca0.9)2Mn2O7 system under 5?T magnetic field across 20–100?K below the magnetic transition point TN. The magnetodielectric effect, on the other hand, exhibits a crossover: (a) from positive to negative for the perovskite system and (b) from negative to positive for the bilayer system over the same temperature range. The bilayer Pr(Sr0.1Ca0.9)2Mn2O7 system exhibits a sizable anisotropy as well. We have also noticed the influence of magnetic field on the dielectric relaxation characteristics of these systems. These systems belong to a class of improper ferroelectrics and are expected to exhibit charge/orbital order driven ferroelectric polarization below the transition point TCO. Large magnetocapacitance in these systems shows a typical multiferroic behavior even though the ferroelectric polarization is small in comparison to that of other ferroelectrics

434

Terrestrial radiation effects in ULSI devices and electronic systems  

CERN Document Server

A practical guide on how mathematical approaches can be used to analyze and control radiation effects in semiconductor devices within various environments Covers faults in ULSI devices to failures in electronic systems caused by a wide variety of radiation fields, including electrons, alpha -rays, muons, gamma rays, neutrons and heavy ions. Readers will learn the environmental radiation features at the ground or avionics altitude. Readers will also learn how to make numerical models from physical insight and what kind of mathematical approaches should be implemented to analyze the radiation effects. A wide variety of mitigation techniques against soft-errors are reviewed and discussed. The author shows how to model sophisticated radiation effects in condensed matter in order to quantify and control them. The book provides the reader with the knowledge on a wide variety of radiation fields and their effects on the electronic devices and systems. It explains how electronic systems including servers and rout...

Ibe, Eishi H

2015-01-01

435

Electronic specific heats in metal--hydrogen systems  

International Nuclear Information System (INIS)

The electronic specific heats of metals and metal--hydrogen systems can in many cases be evaluated from the measured specific heats at constant pressure, C/sub p/, in the temperature range 1 to 10 K. For the simplest case, C/sub p/ = ?T + ?T3, where ?T represents the specific heat contribution associated with the conduction electrons, and ?T3 represents lattice specific heat contribution. The electronic specific heat coefficient, ?, is important because it is proportional to electron density of states at the Fermi surface. A short description of a low temperature calorimetric cryostat employing a 3He/4He dilution refrigeration is given. Various considerations and complications encountered in the evaluation of ? from specific heat data are discussed. Finally, the experimental values of ? for the V--Cr--H system and for the Lu--H system are summarized and the variations of ? as function of alloy composition are discussed

436

Electron Transfer in Donor-Acceptor Systems: Many-Particle Effects and Influence of Electronic Correlations  

CERN Document Server

We investigate electron transfer processes in donor-acceptor systems with a coupling of the electronic degrees of freedom to a common bosonic bath. The model allows to study many-particle effects and the influence of the local Coulomb interaction U between electrons on donor and acceptor sites. Using the non-perturbative numerical renormalization group approach we find distinct differences between the electron transfer characteristics in the single- and two-particle subspaces. We calculate the critical electron-boson coupling alpha_c as a function of $U$ and show results for density-density correlation functions in the whole parameter space. The possibility of many-particle (bipolaronic) and Coulomb-assisted transfer is discussed.

Tornow, S; Bulla, R; Tornow, Sabine; Tong, Ning-Hua; Bulla, Ralf

2006-01-01

437

78 FR 13546 - Defense Federal Acquisition Regulation Supplement; Electronic Subcontracting Reporting System  

Science.gov (United States)

...Regulation Supplement; Electronic Subcontracting Reporting System AGENCY: Defense...procedures related to the Electronic Subcontracting Reporting System. DATES: Effective...policies related to the Electronic Subcontracting Reporting System (eSRS)....

2013-02-28

438

36 CFR 1236.26 - What actions must agencies take to maintain electronic information systems?  

Science.gov (United States)

...take to maintain electronic information systems? 1236.26 Section 1236...take to maintain electronic information systems? (a) Agencies must maintain inventories of electronic information systems and review the...

2010-07-01

439

Data Acquisition System for Electron Energy Loss Coincident Spectrometers  

Science.gov (United States)

A Data Acquisition System (DAQ) for electron energy loss coincident spectrometers (EELCS) has been developed. The system is composed of a Multiplex Time-Digital Converter (TDC) that measures the flying time of positive and negative ions and a one-dimension position-sensitive detector that records the energy loss of scattering electrons. The experimental data are buffered in a first-in-first-out (FIFO) memory module, then transferred from the FIFO memory to PC by the USB interface. The DAQ system can record the flying time of several ions in one collision, and allows of different data collection modes. The system has been demonstrated at the Electron Energy Loss Coincident Spectrometers at the Laboratory of Atomic and Molecular Physics, USTC. A detail description of the whole system is given and experimental results shown.

Zhang, Chi; Yu, Xiaoqi; Yang, Tao

2005-12-01

440

Coulomb Ordering in Anderson-Localized Electron Systems  

CERN Document Server

The ground state of a 2D/3D Anderson-localized electron system has been considered taking into account mutual Coulomb repulsion of the electrons. It has been shown that at sufficiently low electron densities the Coulomb forces bring about ordering of the electrons into a Wigner crystal lattice slightly disturbed by random displacements of electrons from the electron crystal sites, the ordering taking place over a wide parameter range. The residual randomness is an inevitable consequence of the disorder that is intrinsic to the system. It is of a sort of a dipole glass whose ground state posseses a multi-valley degeneration akin to that in spin glass. Conduction in the Coulomb ordered Anderson-localized system has been found to be of a pure activation character, not by the long-range hopping. With the electron density increasing, the ordered state turns, depending on a degree of the disorder, into a glassy state that is essentially different from Fermi-glass or into a state which results from self-localization...

Slutskin, A A; Kovtun, H A

2001-01-01