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1

High rate algal pond treatment for water reuse in a marine fish recirculation system: Water purification and fish health  

Microsoft Academic Search

Regardless of the degree of closure of a recirculation system, effluents are produced and replacement water is needed, which limits the possibility of locating a seawater production system away from the shoreline. At the Palavas Ifremer station, in the south of France, a High Rate Algal Pond (HRAP) was operated during several years to treat the effluent from a recirculating

E. Metaxa; G. Deviller; P. Pagand; C. Alliaume; C. Casellas; J. P. Blancheton

2006-01-01

2

Stream cleaning for specific foulants in open recirculating cooling water systems  

Microsoft Academic Search

Together with corrosion, fouling is the most predominant problem in open recirculating cooling water systems. There are basically 5 different types of fouling deposits which form in cooling water systems, as follows: (1) inorganic scale deposits arising from the mineral content of the makeup water; (2) iron salts and oxides consisting of corrosion products from active corrosion sites in the

D. R. Sexsmith; E. Q. Petrey

1971-01-01

3

Design and Evaluation of Recirculating Water Systems for Maintenance and Propagation of Freshwater Mussels  

Microsoft Academic Search

A complete system for culturing, rearing, and holding juvenile and adult freshwater mussels (Unionidae) was designed and evaluated for use at hatcheries and research facilities. The system includes air delivery, water conditioning and delivery, algal culturing and automated algal feed delivery, and air-driven water-recirculating units. These systems are appropriate for holding and conditioning adult mussels for spawning, as well as

William F. Henley; Lora L. Zimmerman; Richard J. Neves; Mark R. Kidd

2001-01-01

4

Design of multifamily solar domestic hot water systems using recirculating distribution  

SciTech Connect

This paper describes a study designed to quantify the effect of daily domestic hot water loads and system design on the performance of solar domestic hot water systems employing a recirculating distribution system. A solar domestic hot water system judged representative of the systems funded by the HUD Solar Demonstration Program, along with a modification to this system, was modeled using the TRNSYS simulation computer program. Results of simulations over a representative climatic period show that daily domestic hot water usage significantly affects solar system performance. Notable improvement in system performance can be obtained by the use of a recirculation return to solar storage system configuration within a specific range of daily domestic hot water loads. An optimum system was developed from parametric variations of system design and modeled on an annual basis. Comparison is made to modeled system performance of the original design.

Wedekind, D.R.

1982-01-01

5

Use of Hydroponics to Maintain Quality of Recirculated Water in a Fish Culture System  

Microsoft Academic Search

Fish production, biofiltration, and hydroponics were linked in a closed system of recirculating water. Fish tanks were stocked with channel catfish (Ictalurus punctatus) and the fish were fed daily. A revolving plate-type biofilter was used. Three field varieties of tomatoes (Lycopericon esculentum) were planted in outdoor hydroponic tanks. Three production units were operated during the 1976 growing season. All significant

William M. Lewis; John H. Yopp; Harold L. Schramm JR; Alan M. Brandenburg

1978-01-01

6

Biofouling reduction in recirculating cooling systems through biofiltration of process water.  

PubMed

Biofouling is a serious problem in industrial recirculating cooling systems. It damages equipment, through biocorrosion, and causes clogging and increased energy consumption, through decreased heat transfer. In this research a fixed-bed biofilter was developed which removed assimilable organic carbon (AOC) from process water, thus limiting the major substrate for the growth of biofouling. The biofilter was tested in a laboratory model recirculating cooling water system, including a heat exchanger and a cooling tower. A second identical model system without a biofilter served as a reference. Both installations were challenged with organic carbon (sucrose and yeast extract) to provoke biofouling. The biofilter improved the quality of the recirculating cooling water by reducing the AOC content, the ATP concentration, bacterial numbers (30-40 fold) and the turbidity (OD660). The process of biofouling in the heat exchangers, the process water pipelines and the cooling towers, was monitored by protein increase, heat transfer resistance, and chlorine demanded for maintenance. This revealed that biofouling was lower in the system with the biofilter compared to the reference installation. It was concluded that AOC removal through biofiltration provides an attractive, environmental-friendly means to reduce biofouling in industrial cooling systems. PMID:12688686

Meesters, K P H; Van Groenestijn, J W; Gerritse, J

2003-02-01

7

Nitrification in brackish water recirculating aquaculture system integrated with activated packed bed bioreactor.  

PubMed

Recirculation aquaculture systems (RAS) depend on nitrifying biofilters for the maintenance of water quality, increased biosecurity and environmental sustainability. To satisfy these requirements a packed bed bioreactor (PBBR) activated with indigenous nitrifying bacterial consortia has been developed and commercialized for operation under different salinities for instant nitrification in shrimp and prawn hatchery systems. In the present study the nitrification efficiency of the bioreactor was tested in a laboratory level recirculating aquaculture system for the rearing of Penaeus monodon for a period of two months under higher feeding rates and no water exchange. Rapid setting up of nitrification was observed during the operation, as the volumetric total ammonia nitrogen removal rates (VTR) increased with total ammonia nitrogen (TAN) production in the system. The average Volumetric TAN Removal Rates (VTR) at the feeding rate of 160 g/day from 54-60th days of culture was 0.1533+/-0.0045 kg TAN/m(3)/day. The regression between VTR and TAN explained 86% variability in VTR (P<0.001). The laboratory level RAS demonstrated here showed high performance both in terms of shrimp biomass yield and nitrification and environmental quality maintenance. Fluorescent in-situ Hybridization analysis of the reactor biofilm ensured the presence of autotrophic nitrifier groups such as Nitrosococcus mobilis lineage, Nitrobacter spp and phylum Nitrospira, the constituent members present in the original consortia used for activating the reactors. This showed the stability of the consortia on long term operation. PMID:20150717

Rejish Kumar, V J; Joseph, Valsamma; Philip, Rosamma; Bright Singh, I S

2010-01-01

8

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

9

An integrated recirculating aquaculture system (RAS) for land-based fish farming: The effects on water quality and fish production  

Microsoft Academic Search

To mitigate the serious water pollution caused by the rapid expansion of the aquaculture industry in recent years, the development of improved aquaculture systems with more efficient water usage and less environmental impact has become essential. In this study, a land-based recirculating aquaculture system (RAS) was established that consisted of purification units (i.e., a primary biological pond, two parallel horizontal

Shi-Yang Zhang; Gu Li; Hui-Bi Wu; Xing-Guo Liu; Yan-Hong Yao; Ling Tao; Huang Liu

10

The effects of ozone and water exchange rates on water quality and rainbow trout Oncorhynchus mykiss performance in replicated water recirculating systems  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rainbow trout Oncorhynchus mykiss performance and water quality were evaluated and compared within six replicated 9.5 cubic meter water recirculating aquaculture systems (WRAS) operated with and without ozone at various water exchange rates. Three separate studies were conducted: 1) low water exchan...

11

The effects of ozone and water exchange rates on water quality and rainbow trout Oncorhynchus mykiss performance in replicated water recirculating systems  

Microsoft Academic Search

Rainbow trout Oncorhynchus mykiss performance and water quality were evaluated and compared within six replicated 9.5m3 water recirculating aquaculture systems (WRAS) operated with and without ozone at various water exchange rates. Three separate studies were conducted: (1) low water exchange (0.26% of the total recycle flow) with and without ozone; (2) low water exchange with ozone versus high water exchange

John Davidson; Christopher Good; Carla Welsh; Steven Summerfelt

2011-01-01

12

Microbial and physicochemical parameters associated with Legionella contamination in hot water recirculation systems.  

PubMed

Hot water recirculation systems (HWRS) in hotels and nursing homes, which are common in countries such as Spain, have been related to outbreaks of legionellosis. To establish the relationships of microbial and physicochemical parameters, especially protozoa, with the occurrence of Legionella in HWRS, 231 samples from hotels and nursing homes were analysed for Legionella, protozoa, heterotrophic plate counts (HPC) at 22 and 37 °C, Pseudomonas, metals, temperature and others. Legionella pneumophila was the dominant species isolated, and 22 % were sg. 1. The sampling method became particularly important in order to define which factors were involved on the occurrence of Legionella. Results showed that the bacteria and the accompanying microbiota were more abundant in the first flush water whose temperature was lower. The bacteria occurred in those samples with high HPC and were inversely correlated with high temperatures. Multivariate regression showed that a concentration above 1 × 10(5) CFU/100 mL of HPC at 37 °C, Fe above 0.095 ppm and the presence of protozoa increased significantly the risk of Legionella colonization, while univariant regression showed that the presence of Cu above 0.76 ppm and temperature above 55 °C diminished it. Therefore, to reduce the risk associated with Legionella occurrence in HWRS these parameters should be taken into consideration. PMID:23436060

Serrano-Suárez, Alejandra; Dellundé, Jordi; Salvadó, Humbert; Cervero-Aragó, Sílvia; Méndez, Javier; Canals, Oriol; Blanco, Silvia; Arcas, Antoni; Araujo, Rosa

2013-02-23

13

Fundamental Aspects of Ozone Chemistry in Recirculating Cooling Water Systems — Data Evaluation Needs  

Microsoft Academic Search

Proposed uses of ozone for stand-alone cooling water treatment raise critical questions as to what happens chemically. These questions are of more significance to industrial cooling water systems, which typically have higher temperatures and cooling ranges than do comfort cooling systems. When applying ozone to cooling waters, it is very important for the user to understand many fundamental aspects of

Rip G. Rice; J. Fred Wilkes

1992-01-01

14

Preoperational test report, recirculation condenser cooling systems  

SciTech Connect

This represents a preoperational test report for Recirculation Condenser Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The four system provide condenser cooling water for vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102. Each system consists of a valved piping loop, a pair of redundant recirculation pumps, a closed-loop evaporative cooling tower, and supporting instrumentation; equipment is located outside the farm on concrete slabs. Piping is routed to the each ventilation condenser inside the farm via below-grade concrete trenches. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

Clifton, F.T.

1997-11-04

15

A low energy, bio-secure, 'hybrid' recirculation system incorporating air lift pumps for water circulation, aeration, and CO2 degassing  

Technology Transfer Automated Retrieval System (TEKTRAN)

A ‘Hybrid’ recirculating aquaculture system design utilizes elements of both a ‘Centralized’ design concept with a single water treatment system for a number of fish tanks and the ‘Modular’ design concept which employs a individual treatment system for each fish culture tank. The ‘Hybrid’ recirculat...

16

Pioneer colonizer microorganisms in biofilm formation on galvanized steel in a simulated recirculating cooling-water system.  

PubMed

Some bacteria have a higher tendency to produce biofilm than others. Especially, Pseudomonas and Aeromonas strains are acknowledged to be pioneer colonizers and are predominant in biofilm formation. We examined biofilm formation and first attachment maintance of biofilms of Pseudomonas spp., Pseudomonas aeruginosa, Aeromonas spp, sulphate reducing bacteria and filamentous fungi. A simulated recirculating cooling-water system was used. Heterotrophic bacteria counts on galvanized steel and glass surfaces rose during the tidy period of 720 hours. In addition, we determined that although Pseudomonas spp., Pseudomonas aeruginosa and Aeromonas spp. were the pioneer colonizers, they surprisingly could not be determined in the biofilms on both types of surface after 456 hours. Sulphate reducing bacteria were observed in biofilms on both surfaces from the outset of the experiments. Filamentous fungi were seen on the galvanized steel and glass surfaces after 0.5 h. PMID:19455520

Do?ruöz, Nihal; Göksay, Duygu; Ilhan-Sungur, Esra; Cotuk, Ay?in

2009-09-01

17

Use of Produced Water in Recirculated Cooling Systems at Power Generating Facilities  

SciTech Connect

Tree ring studies indicate that, for the greater part of the last three decades, New Mexico has been relatively 'wet' compared to the long-term historical norm. However, during the last several years, New Mexico has experienced a severe drought. Some researchers are predicting a return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters to supplement current fresh water supplies for power plant operation and cooling and other uses. The U.S. Department of Energy's National Energy Technology Laboratory sponsored three related assessments of water supplies in the San Juan Basin area of the four-corner intersection of Utah, Colorado, Arizona, and New Mexico. These were (1) an assessment of using water produced with oil and gas as a supplemental supply for the San Juan Generating Station (SJGS); (2) a field evaluation of the wet-surface air cooling (WSAC) system at SJGS; and (3) the development of a ZeroNet systems analysis module and an application of the Watershed Risk Management Framework (WARMF) to evaluate a range of water shortage management plans. The study of the possible use of produced water at SJGS showed that produce water must be treated to justify its use in any reasonable quantity at SJGS. The study identified produced water volume and quality, the infrastructure needed to deliver it to SJGS, treatment requirements, and delivery and treatment economics. A number of produced water treatment alternatives that use off-the-shelf technology were evaluated along with the equipment needed for water treatment at SJGS. Wet surface air-cooling (WSAC) technology was tested at the San Juan Generating Station (SJGS) to determine its capacity to cool power plant circulating water using degraded water. WSAC is a commercial cooling technology and has been used for many years to cool and/or condense process fluids. The purpose of the pilot test was to determine if WSAC technology could cool process water at cycles of concentration considered highly scale forming for mechanical draft cooling towers. At the completion of testing, there was no visible scale on the heat transfer surfaces and cooling was sustained throughout the test period. The application of the WARMF decision framework to the San Juan Basis showed that drought and increased temperature impact water availability for all sectors (agriculture, energy, municipal, industry) and lead to critical shortages. WARMF-ZeroNet, as part of the integrated ZeroNet decision support system, offers stakeholders an integrated approach to long-term water management that balances competing needs of existing water users and economic growth under the constraints of limited supply and potential climate change.

C. McGowin; M. DiFilippo; L. Weintraub

2006-06-30

18

Use of Produced Water in Recirculating Cooling Systems at Power Generating Facilities  

SciTech Connect

The purpose of this study is to evaluate produced water as a supplemental source of water for the San Juan Generating Station (SJGS). This study incorporates elements that identify produced water volume and quality, infrastructure to deliver it to SJGS, treatment requirements to use it at the plant, delivery and treatment economics, etc. SJGS, which is operated by Public Service of New Mexico (PNM) is located about 15 miles northwest of Farmington, New Mexico. It has four units with a total generating capacity of about 1,800 MW. The plant uses 22,400 acre-feet of water per year from the San Juan River with most of its demand resulting from cooling tower make-up. The plant is a zero liquid discharge facility and, as such, is well practiced in efficient water use and reuse. For the past few years, New Mexico has been suffering from a severe drought. Climate researchers are predicting the return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters. This deliverable describes possible test configurations for produced water demonstration projects at SJGS. The ability to host demonstration projects would enable the testing and advancement of promising produced water treatment technologies. Testing is described for two scenarios: Scenario 1--PNM builds a produced water treatment system at SJGS and incorporates planned and future demonstration projects into the design of the system. Scenario 2--PNM forestalls or decides not to install a produced water treatment system and would either conduct limited testing at SJGS (produced water would have to be delivered by tanker trucked) or at a salt water disposal facility (SWD). Each scenario would accommodate demonstration projects differently and these differences are discussed in this deliverable. PNM will host a demonstration test of water-conserving cooling technology--Wet Surface Air Cooling (WSAC) using cooling tower blowdown from the existing SJGS Unit 3 tower--during the summer months of 2005. If successful, there may be follow-on testing using produced water. WSAC is discussed in this deliverable. Recall that Deliverable 4, Emerging Technology Testing, describes the pilot testing conducted at a salt water disposal facility (SWD) by the CeraMem Corporation. This filtration technology could be a candidate for future demonstration testing and is also discussed in this deliverable.

Kent Zammit; Michael N. DiFilippo

2005-07-01

19

Future of recirculating systems in the US aquaculture industry  

SciTech Connect

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

Malone, R.F.

1994-08-01

20

Processes to improve energy efficiency during pumping and aeration of recirculating water in circular tank systems  

Technology Transfer Automated Retrieval System (TEKTRAN)

Conventional gas transfer technologies for aquaculture systems occupy a large amount of space, require considerable capital investment, and can contribute to high electricity demand. In addition, diffused aeration in a circular tank can interfere with the hydrodynamics of water rotation and the spee...

21

Recirculating cooling water solute depletion models  

SciTech Connect

Chromates have been used for years to inhibit copper corrosion in the plant Recirculating Cooling Water (RCW) system. However, chromates have become an environmental problem in recent years both in the chromate removal plant (X-616) operation and from cooling tower drift. In response to this concern, PORTS is replacing chromates with Betz Dianodic II, a combination of phosphates, BZT, and a dispersant. This changeover started with the X-326 system in 1989. In order to control chemical concentrations in X-326 and in systems linked to it, we needed to be able to predict solute concentrations in advance of the changeover. Failure to predict and control these concentrations can result in wasted chemicals, equipment fouling, or increased corrosion. Consequently, Systems Analysis developed two solute concentration models. The first simulation represents the X-326 RCW system by itself; and models the depletion of a solute once the feed has stopped. The second simulation represents the X-326, X-330, and the X-333 systems linked together by blowdown. This second simulation represents the concentration of a solute in all three systems simultaneously. 4 figs.

Price, W.T.

1990-03-16

22

Biofouling characteristics and identification of preponderant bacteria at different nutrient levels in batch tests of a recirculating cooling water system.  

PubMed

Understanding the influence of nutrient levels on biofouling control is an important requirement for management strategies in a recirculating cooling water system. Nutrient limitation may be one way to control biofouling development without increasing biocide dosing. Therefore, this study was carried out to investigate the effects of nutrient levels on biofouling characteristics and to identify the preponderant bacteria in the batch tests with a simulated cooling water system. The biofouling characteristics were assessed by varying the biofoulant mass and the bacteria respiratory activity, which was estimated by measuring oxygen uptake rates. According to the results obtained in nutrient factor experiments, the biofouling could be better controlled at carbon, nitrogen and phosphorus concentrations of 30 mg N/L, 8 mg N/L and 1.0 mg P/L, respectively. Increasing carbon concentrations shortened the biofouling initial growth period and resulted in higher biofoulant mass. The preponderant bacteria strains involved in biofouling under two culture conditions were identified by applying both physiological and biochemical tests and further molecular biology techniques with phylogenetic affiliation analysis. Enterobacter (family Enterobacteriaceae), Staphylococcus (family Micrococcaceae), Bacillus (family Bacillaceae), Proteus (family Enterobacteriaceae), Neisseria (family Neisseriaceae) and Pseudomonas (family Pseudomonadaceae) were dominant in the conditions of lower carbon concentration (30 mg/L). Enterobacter are autotrophs, but the other five bacteria are all heterotrophs. In the conditions of higher carbon concentration (70 mg/L), Klebsiella (family Enterobacteriaceae), Enterobacter and Microbacterium (family Microbacteriaceae) were dominant; Enterobacter and Microbacterium are heterotrophs. PMID:21879565

Liu, Fang; Zhao, Chao-Cheng; Xia, Lu; Yang, Fei; Chang, Xin; Wang, Yong-Qiang

23

Hexachlorobenzene Uptake by Fathead Minnows and Macroinvertebrates in Recirculating Sediment/Water Systems.  

National Technical Information Service (NTIS)

Fathead minnow (Pimephales promelas), the worm, Lumbriculus variegatus, and the amphipods Hyalella azteca and Gammarus lacustris were exposed to hexachlorobenzene (HCB) in water with and without a bed of HCB-spiked sediment. Water HCB concentrations were ...

G. S. Schuytema D. F. Krawczyk W. L. Griffis A. V. Nebeker M. L. Robideaux

1990-01-01

24

USE OF PRODUCED WATER IN RECIRCULATING COOLING SYSTEMS AT POWER GENERATING FACILITIES  

Microsoft Academic Search

The purpose of this study is to evaluate produced water as a supplemental source of water for the San Juan Generating Station (SJGS). This study incorporates elements that identify produced water volume and quality, infrastructure to deliver it to SJGS, treatment requirements to use it at the plant, delivery and treatment economics, etc. SJGS, which is operated by Public Service

Kent Zammit; Michael N. DiFilippo

2005-01-01

25

USE OF PRODUCED WATER IN RECIRCULATING COOLING SYSTEMS AT POWER GENERATING FACILITIES  

Microsoft Academic Search

The purpose of this study is to evaluate produced water as a supplemental source of water for the San Juan Generating Station (SJGS). This study incorporates elements that identify produced water volume and quality, infrastructure to deliver it to SJGS, treatment requirements to use it at the plant, delivery and treatment economics, etc. SJGS, which is operated by Public Service

Michael N. DiFilippo

2004-01-01

26

USE OF PRODUCED WATER IN RECIRCULATING COOLING SYSTEMS AT POWER GENERATING FACILITIES  

SciTech Connect

The purpose of this study is to evaluate produced water as a supplemental source of water for the San Juan Generating Station (SJGS). This study incorporates elements that identify produced water volume and quality, infrastructure to deliver it to SJGS, treatment requirements to use it at the plant, delivery and treatment economics, etc. SJGS, which is operated by Public Service of New Mexico (PNM) is located about 15 miles northwest of Farmington, New Mexico. It has four units with a total generating capacity of about 1,800 MW. The plant uses 22,400 acre-feet of water per year from the San Juan River with most of its demand resulting from cooling tower make-up. The plant is a zero liquid discharge facility and, as such, is well practiced in efficient water use and reuse. For the past few years, New Mexico has been suffering from a severe drought. Climate researchers are predicting the return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters. Deliverable 1 presents a general assessment of produced water generation in the San Juan Basin in Four Corners Area of New Mexico. Oil and gas production, produced water handling and disposal, and produced water quantities and chemistry are discussed. Legislative efforts to enable the use of this water at SJGS are also described.

Michael N. DiFilippo

2004-08-01

27

USE OF PRODUCED WATER IN RECIRCULATING COOLING SYSTEMS AT POWER GENERATING FACILITIES  

SciTech Connect

The purpose of this study is to evaluate produced water as a supplemental source of water for the San Juan Generating Station (SJGS). This study incorporates elements that identify produced water volume and quality, infrastructure to deliver it to SJGS, treatment requirements to use it at the plant, delivery and treatment economics, etc. SJGS, which is operated by Public Service of New Mexico (PNM) is located about 15 miles northwest of Farmington, New Mexico. It has four units with a total generating capacity of about 1,800 MW. The plant uses 22,400 acre-feet of water per year from the San Juan River with most of its demand resulting from cooling tower make-up. The plant is a zero liquid discharge facility and, as such, is well practiced in efficient water use and reuse. For the past few years, New Mexico has been suffering from a severe drought. Climate researchers are predicting the return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters. Deliverable 2 focuses on transportation--the largest obstacle to produced water reuse in the San Juan Basin (the Basin). Most of the produced water in the Basin is stored in tanks at the well head and must be transported by truck to salt water disposal (SWD) facilities prior to injection. Produced water transportation requirements from the well head to SJGS and the availability of existing infrastructure to transport the water are discussed in this deliverable.

Michael N. DiFilippo

2004-08-01

28

USE OF PRODUCED WATER IN RECIRCULATING COOLING SYSTEMS AT POWER GENERATING FACILITIES  

SciTech Connect

The purpose of this study is to evaluate produced water as a supplemental source of water for the San Juan Generating Station (SJGS). This study incorporates elements that identify produced water volume and quality, infrastructure to deliver it to SJGS, treatment requirements to use it at the plant, delivery and treatment economics, etc. SJGS, which is operated by Public Service of New Mexico (PNM) is located about 15 miles northwest of Farmington, New Mexico. It has four units with a total generating capacity of about 1,800 MW. The plant uses 22,400 acre-feet of water per year from the San Juan River with most of its demand resulting from cooling tower make-up. The plant is a zero liquid discharge facility and, as such, is well practiced in efficient water use and reuse. For the past few years, New Mexico has been suffering from a severe drought. Climate researchers are predicting the return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters. Produced water is generated nationally as a byproduct of oil and gas production. Seven states generate 90 percent of the produced water in the continental US. About 37 percent of the sources documented in the US Geological Survey's (USGS) Produced Waters Database have a TDS of less than 30,000 mg/l. This is significant because produced water treatment for reuse in power plants was found to be very costly above 30,000 mg/l TDS. For the purposes of this report, produced water treatment was assessed using the technologies evaluated for the San Juan Generating Station (SJGS) in Deliverable 3, Treatment and Disposal Analysis. Also, a methodology was developed to readily estimate capital and operating costs for produced water treatment. Two examples are presented to show how the cost estimating methodology can be used to evaluate the cost of treatment of produced water at power plants close to oil and gas production.

Kent Zammit; Michael N. DiFilippo

2005-01-01

29

HEXACHLOROBENZENE UPTAKE BY FATHEAD MINNOWS AND MACRO INVERTEBRATES IN RECIRCULATING SEDIMENT/WATER SYSTEMS  

EPA Science Inventory

Fathead minnow (Pimephales promelas), the worm, Lumbriculus variegatus, and the amphipods Hyalella azteca and Gammarus lacustris were exposed to hexachlorobenzene (HCB) in water with and without a bed of HCB-spiked sediment. ater HCB concentrations were maintained by recirculatio...

30

Common carp ( Cyprinus carpio ) response to two pieces of music (“Eine Kleine Nachtmusik” and “Romanza”) combined with light intensity, using recirculating water system  

Microsoft Academic Search

The objective of this study was to further investigate the effects of music on fish physiology, bearing in mind available\\u000a information regarding the involvement of endogenous and exogenous factors in fish farming. Therefore, Cyprinus carpio (50.5 ± 0.36 g) were reared in a recirculating water system under 80 and 200 lux and subjected to no music at all (control,\\u000a ambient noise only), 4 h of

Sofronios E. Papoutsoglou; Nafsika Karakatsouli; Eustratios S. Papoutsoglou; Georgios Vasilikos

2010-01-01

31

Re-circulating linac vacuum system  

Microsoft Academic Search

The vacuum system for a proposed 2.5 GeV, 10?A re-circulating linac synchrotron light source is readily achievable with conventional vacuum hardware and established fabrication processes. Some of the difficult technical challenges associated with synchrotron light source storage rings are sidestepped by the relatively low beam current and short beam lifetime requirements of a re-circulating linac. This minimal lifetime requirement leads

Russell P. Wells; John N. Corlett; Alexander A. Zholents

2003-01-01

32

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

33

Closed recirculating system for shrimp-mollusk polyculture  

Microsoft Academic Search

This paper deals with a new system of aquaculture, i.e., a closed recirculating system for shrimp-mollusk polyculture. The\\u000a culture system consisted of several shrimp ponds, a mollusk water-purifying pond and a reservoir. During the production cycle,\\u000a water circulated between the shrimp and mollusk ponds, and the reservoir compensated for water loss from seepage and evaporation.\\u000a Constricted tagelus,Sinonovacula constricta, was selected

Xiongfei Wu; Zhidong Zhao; Deshang Li; Kangmei Chang; Zhuanshang Tong; Liegang Si; Kaichong Xu; Bailin Ge

2005-01-01

34

Developments in recirculation systems for Mediterranean fish species  

Microsoft Academic Search

Nowadays, most European commercial hatcheries use recirculating water systems for all the different stages of Mediterranean fish rearing, from breeders to fingerlings several grams in weight. Despite a higher initial investment relative to flow-through systems, this technology reduces production costs mainly because much less energy is required for heating and the survival rate of the fingerlings is much higher. The

Jean Paul Blancheton

2000-01-01

35

Production of cobia in recirculating systems  

Technology Transfer Automated Retrieval System (TEKTRAN)

Only limited information exists with respect to rearing juvenile cobia Rachycentron canadum to stocker and marketable sizes using recirculating aquaculture systems (RAS). To investigate this topic, two rearing trials were conducted using commercial scale RAS. In Trial 1, juvenile cobia (29 g) we...

36

Pressure mediated diesel engine exhaust gas recirculation control system  

Microsoft Academic Search

A diesel engine includes an air intake system, an exhaust system , and an exhaust gas recirculation conduit which leads from the exhaust system to the intake system. An exhaust gas recirculation control valve, which includes a first diaphragm chamber, is mounted in the exhaust gas recirculation conduit so as to regulate the flow of exhaust gas through it. The

1983-01-01

37

Hydraulics of recirculating well pairs for ground water remediation.  

PubMed

Recirculating well pairs are a proven means of implementing bioremediation and may also be useful for applying other in situ ground water remediation technologies. A bromide tracer test was performed to characterize the hydraulic performance of a recirculating well pair installed at Moffett Field, California. In particular, we estimate two important properties of the recirculating well pair: (1) the fraction of captured water that is recycled between the wells, and (2) the travel-time distribution of ground water in the induced zone of recirculation. We also develop theoretical estimates of these two properties and demonstrate they depend upon a dimensionless pumping rate, denoted xi. The bromide breakthrough curve predicted from theory agrees well with that determined experimentally at Moffett Field. The minimum travel time between the wells is denoted t(min). In theory, t(min) depends inversely on Q, the pumping rate in the recirculating wells, and is proportional to a2, the square of the distance between the wells. Both the experimental and theoretical travel-time distributions indicate that at least half the recirculating water travels between the wells along fast flowpaths (travel time < 2*t(min)). Therefore, when designing recirculating well pairs, engineers should ensure that t(min) will be sufficiently high to allow biologically mediated reactions (or other in situ remediation processes) sufficient time to proceed. PMID:15584301

Cunningham, Jeffrey A; Hoelen, Thomas P; Hopkins, Gary D; Lebrón, Carmen A; Reinhard, Martin

38

Re-circulating linac vacuum system  

SciTech Connect

The vacuum system for a proposed 2.5 GeV, 10{Mu}A recirculating linac synchrotron light source [1] is readily achievable with conventional vacuum hardware and established fabrication processes. Some of the difficult technical challenges associated with synchrotron light source storage rings are sidestepped by the relatively low beam current and short beam lifetime requirements of a re-circulating linac. This minimal lifetime requirement leads directly to relatively high limits on the background gas pressure through much of the facility. The 10{Mu}A average beam current produces very little synchrotron radiation induced gas desorption and thus the need for an ante-chamber in the vacuum chamber is eliminated. In the arc bend magnets, and the insertion devices, the vacuum chamber dimensions can be selected to balance the coherent synchrotron radiation and resistive wall wakefield effects, while maintaining the modest limits on the gas pressure and minimal outgassing.

Wells, Russell P.; Corlett, John N.; Zholents, Alexander A.

2003-05-09

39

Effects of Elevated Atmospheric Carbon Dioxide Concentrations on Water and Acid Requirements of Soybeans Grown in a Recirculating Hydroponic System.  

National Technical Information Service (NTIS)

Establishing mass budgets of various crop needs, i.e. water and nutrients, in different environments is essential for the Controlled Ecological Life Support System (CELSS). The effects of CO2 (500 and 1000 umol mol (exp -1)) on water and acid use (for pH ...

C. L. Mackowiak R. M. Wheeler W. Lowery J. C. Sager

1990-01-01

40

Effect of oxidizing and non-oxidizing biocides on biofilm at different substrate levels in the model recirculating cooling water system  

Microsoft Academic Search

With the reducing of water resources, using advanced treated refinery wastewater as recirculating cooling water is an effective\\u000a method to save water and to reduce the pollution of petroleum and petrochemical industry. However, the control of biofilm\\u000a is a bottleneck in the application of this technology. To resolve the problem of biofilm formation and development, antimicrobial\\u000a characteristics of chlorine dioxide

Fang Liu; Xin Chang; Fei Yang; Yongqiang Wang; Feiyang Wang; Wenwen Dong; Chaocheng Zhao

41

Exhaust gas recirculation system for an internal combustion engine  

DOEpatents

An exhaust gas recirculation system for an internal combustion engine comprises an exhaust driven turbocharger having a low pressure turbine outlet in fluid communication with an exhaust gas conduit. The turbocharger also includes a low pressure compressor intake and a high pressure compressor outlet in communication with an intake air conduit. An exhaust gas recirculation conduit fluidly communicates with the exhaust gas conduit to divert a portion of exhaust gas to a low pressure exhaust gas recirculation branch extending between the exhaust gas recirculation conduit and an engine intake system for delivery of exhaust gas thereto. A high pressure exhaust gas recirculation branch extends between the exhaust gas recirculation conduit and the compressor intake and delivers exhaust gas to the compressor for mixing with a compressed intake charge for delivery to the intake system.

Wu, Ko-Jen

2013-05-21

42

Water recirculation and good management: potential methods to avoid disease outbreaks with Flavobacterium psychrophilum.  

PubMed

Flavobacterium psychrophilum infections cause high mortality among rainbow trout, Oncorhynchus mykiss, fry in Danish fish farms and hatcheries. Hatcheries based entirely on bore-hole water recirculation systems have been suggested as a possibility for eliminating F. psychrophilum or at least keeping the amount of this bacterium low. The occurrence of the bacterium in a bore-hole water recirculation system was compared with a combined bore-hole water and stream water flow-through system in a hatchery where outbreaks of rainbow trout fry syndrome caused by F. psychrophilum often occurred. Broodfish, unfertilized and fertilized eggs, eyed eggs and fry, as well as water samples from the tanks/troughs with broodfish/fry, were examined. Suspect yellow bacterial colonies were either confirmed or rejected as F. psychrophilum by growth characteristics and by PCR. As both virulent and less virulent F. psychrophilum isolates are known, isolates were characterized. The isolates were ribotyped and grouped according to ribotyping patterns. Representatives of the groups were serotyped. Fry isolates were very homogeneous whereas isolates from broodfish were heterogeneous, whether the isolates originated from external surfaces of the fish (mucus from skin and gills, haemorrhages and ulcers) or internal organs. Flavobacterium psychrophilum was isolated from broodfish in both water systems; 56% of investigated broodfish from the borehole/flowthrough system and 36% from the recirculation facility harboured the bacterium. In the recirculation system, the bacterium was isolated from fish (ulcers, milt, liver, abdominal cavity) kept in the system for 11 months. Flavobacterium psychrophilum was found in milt and ovarian fluid as well as on the surface of fertilized eggs, but not inside the eggs. Fry also harboured F. psychrophilum, but in the water recirculation system the bacterium was first isolated from the fry after they had been graded. Flavobacterium psychrophilum was found regularly in other parts of the hatchery (outside the recirculation facility), including at the time of grading, suggesting that the occurrence of F. psychrophilum in the fry recirculation facility was due to contamination from the borehole/flow-through hatchery. It is suggested that the combination of bore-hole water recirculation systems and good management procedures (including egg disinfection) is a possible method for hatcheries to avoid disease outbreaks due to F. psychrophilum. PMID:19238756

Madsen, L; Dalsgaard, I

2008-11-01

43

Use of Produced Water In Recirculating Cooling Systems at Power Generating Facilities. Semi-Annual Technical Progress Report.  

National Technical Information Service (NTIS)

The purpose of this study is to evaluate produced water as a supplemental source of water for the San Juan Generating Station (SJGS). This study incorporates elements that identify produced water volume and quality, infrastructure to deliver it to SJGS, t...

2005-01-01

44

Recirculating Molten Metal Supply System And Method  

DOEpatents

The melter furnace includes a heating chamber (16), a pump chamber (18), a degassing chamber (20), and a filter chamber (22). The pump chamber (18) is located adjacent the heating chamber (16) and houses a molten metal pump (30). The degassing chamber (20) is located adjacent and in fluid communication with the pump chamber (18), and houses a degassing mechanism (36). The filter chamber (22) is located adjacent and in fluid communication with the degassing chamber (20). The filter chamber (22) includes a molten metal filter (38). The melter furnace (12) is used to supply molten metal to an externally located holder furnace (14), which then recirculates molten metal back to the melter furnace (12).

Kinosz, Michael J. (Apollo, PA); Meyer, Thomas N. (Murrysville, PA)

2003-07-01

45

Growth and survival of juvenile cobia, Rachycentron canadum, at different salinities in a recirculating aquaculture system  

Microsoft Academic Search

Cobia (Rachycentron canadum) is an emerging aquaculture candidate for both offshore cage culture and land-based systems such as recirculating aquaculture systems. The ability to grow cobia at salinities other than oceanic (?34 ppt) could present culturists with additional production opportunities with this species. Culture at low salinities could also reduce the incidence of disease and simplify water management. In two

Matthew J. Resley; Kenneth A. Webb; G. Joan Holt

2006-01-01

46

An Inexpensive Recirculating Aquaculture System with Multiple Use Capabilities.  

ERIC Educational Resources Information Center

|Describes the construction of an inexpensive recirculating aquaculture system that can hold up to 46 pounds of fish, invertebrates, and mussels for classroom use. The system is versatile, requires little maintenance, and can be used for both teaching and research purposes. (WRM)|

Scurlock, Gerald Don, Jr.; Cook, S. Bradford; Scurlock, Carrie Ann

1999-01-01

47

An Inexpensive Recirculating Aquaculture System with Multiple Use Capabilities.  

ERIC Educational Resources Information Center

Describes the construction of an inexpensive recirculating aquaculture system that can hold up to 46 pounds of fish, invertebrates, and mussels for classroom use. The system is versatile, requires little maintenance, and can be used for both teaching and research purposes. (WRM)

Scurlock, Gerald Don, Jr.; Cook, S. Bradford; Scurlock, Carrie Ann

1999-01-01

48

Design of a computerized, temperature-controlled, recirculating aquaria system  

USGS Publications Warehouse

We built a recirculating aquaria system with computerized temperature control to maintain static temperatures, increase temperatures 1 ??C/day, and maintain diel temperature fluctuations up to 10 ??C. A LabVIEW program compared the temperature recorded by thermocouples in fish tanks to a desired set temperature and then calculated the amount of hot or cold water to add to tanks to reach or maintain the desired temperature. Intellifaucet?? three-way mixing valves controlled temperature of the input water and ensured that all fish tanks had the same turnover rate. The system was analyzed over a period of 50 days and was fully functional for 96% of that time. Six different temperature treatments were run simultaneously in 18, 72 L fish tanks and temperatures stayed within 0.5 ??C of set temperature. We used the system to determine the upper temperature tolerance of fishes, but it could be used in aquaculture, ecological studies, or other aquatic work where temperature control is required. ?? 2005 Elsevier B.V. All rights reserved.

Widmer, A. M.; Carveth, C. J.; Keffler, J. W.; Bonar, S. A.

2006-01-01

49

CHEMICAL EXPERIENCE WITH THE RECIRCULATION COOLING SYSTEM OF THE NRX THERMAL SHIELDS  

Microsoft Academic Search

The mild steel thermal shields in the NRX reactor were cooled for the ; first eight years by Ottawa River water with added phosphate, alkali and ; chlorine, on a once-through basis. In the summer of 1955 the cooling system was ; changed to recirculation, and this report deals with chemical and corrosion ; results obtained since that time. Considerable

Allison

1959-01-01

50

NET DISSOLVED ORGANIC CARBON PRODUCTION IN RECIRCULATING SALMONID CULTURE SYSTEM  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ozonating a coldwater recirculating system (RAS) can help control the accumulation of fine suspended solids, micro-organisms, and components of dissolved organic carbon (DOC) that can negatively impact fish health and production efficiency. Ozone can oxidize relatively large non-biodegradable organ...

51

Exhaust gas recirculation control system for an internal combustion engine  

Microsoft Academic Search

An exhaust gas recirculation control system is disclosed for particular application to a diesel engine, which includes a combination of a fuel injection pump having a movable fuel amount determining element whose position regulates the amount of fuel injected, a conversion device having a fixed orifice and a variable orifice provided downstream of the fixed orifice and whose effective opening

1981-01-01

52

A continuous recirculating culture system for planktonic copepods  

Microsoft Academic Search

The calanoid copepods, Acartia clausiGiesbrecht and Acartia tonsaDana, are maintained at high densities in continuous culture at 15°C. Synthetic sea-water medium is recirculated through filters and a foam tower which limits accumulation of dissolved wastes and various metabolites. The ciliate Euplotes vannusMüller is associated in culture with the copepods, and effectively controls bacterial population and accumulation of algal debris. The

E. J. Zillioux

1969-01-01

53

Potential and limitations of ozone for the removal of ammonia, nitrite, and yellow substances in marine recirculating aquaculture systems  

Microsoft Academic Search

The high levels of water-reuse in intensive recirculating aquaculture systems (RAS) require an effective water treatment in order to maintain good water quality. In order to reveal the potential and limitations of ozonation for water quality improvement in marine RAS, we tested ozone's ability to remove nitrite, ammonia, yellow substances and total bacterial biomass in seawater, considering aspects such as

J. P. Schroeder; P. L. Croot; B. Von Dewitz; U. Waller; R. Hanel

2011-01-01

54

Exhaust gas recirculation control system for a compression-ignition internal combustion engine  

Microsoft Academic Search

An exhaust gas recirculation control system for a compression ignition internal combustion engine or diesel engine including an intake throttle valve in an intake passage and an exhaust gas recirculation passage opening downstream of the intake throttle valve, comprises a shut-off valve in the exhaust gas recirculation passage so that the shut-off valve is closed in the proximity of a

H. Fujii; M. Shinzawa; J. Teranuma; S. Yasuhara

1981-01-01

55

RECIRCULATING - REDUCING AND ALKALINITY PRODUCING SYSTEM (RERAPS) FOR THE TREATMENT OF ACIDIC COAL PILE RUNOFF 1  

Microsoft Academic Search

The treatment of acidic coal pile runoff (CPR) using an alternative constructed wetland design was evaluated. This alternative design, which provided improved wetland performance, was based on the partial re-circulation of treated water into a detention basin located immediately upstream from a Reducing and Alkalinity Producing System (RAPS). This modification created a semi-passive RAPS-based system we refer to as a

William E. Garrett; Alfred A. Bartolucci; Robert R. Pitt; Michael E. Vermace

2002-01-01

56

Exhaust recirculation  

Microsoft Academic Search

An exhaust gas recirculation system for the reduction of nitrogen oxides in automobile exhaust is described that provides for the reduction of recirculation during engine idling without the prior-art complexities of moving parts. The system also achieves preheating and improved mixing and carburetion of the fuel-air mixture in the inlet header. Exhaust gases are recycled by means of a swirl

Sarto

1974-01-01

57

Characterization of a biofilm bacterium from a recirculation system for European lobster ( Homarus gammarus)  

Microsoft Academic Search

The European lobster (Homarus gammarus) is often stored live in re-circulation systems. Previously bio-films and fouling has been reported to occur during storage of live aquatic animals. This investigation profiled a bacterium isolated from a bio-film observed on the carapace of live lobster and on the sub-water surfaces of the holding facility. Molecular analysis using a universal 16s rRNA primer

Jennifer E. Welsh; Pauline A. King; Eugene MacCarthy

2011-01-01

58

Combination of a bead filter and rotating biological contactor in a recirculating fish culture system  

Microsoft Academic Search

The performance of the combination of a floating bead filter and an RBC employing 1-inch diameter N?orpac® tube media was evaluated in an intensive pilot scale recirculating system stocked with tilapia. The combination maintained favorable water quality, attaining practically complete TAN and NO2-N removal. The average overall removal across the FBF-RBC combination was 60·6 g TAN\\/day and 59·6 g NO2-N\\/day,

Aurelio A. delos Reyes; Thomas B. Lawson

1996-01-01

59

A Sodium Bicarbonate Dosing Methodology for pH Management in Freshwater-Recirculating Aquaculture Systems  

Microsoft Academic Search

High-density water-recirculating aquaculture systems with hydraulic retention times above about 5 d must be monitored for alkalinity, and in the vast majority of cases, the alkalinity must be adjusted upwards to assure maintenance of desirable pH levels. Sodium bicarbonate is the preferred additive for increasing alkalinity because it is inexpensive, dissolves rapidly, and is safe for both personnel and fish.

J. Clay Loyless; Ronald F. Malone

1997-01-01

60

Xenon recirculation systems for next-generation lithography tools  

NASA Astrophysics Data System (ADS)

Next generation lithography tools designed to pattern critical dimensions at <45nm will require extreme ultraviolet (EUV) light sources. Xenon is currently a strong candidate for the source medium for production of EUV light at 13.5nm. A consistent supply of ultra high purity xenon is required for efficient light source production. Several factors must be considered in the overall operating costs of the EUV tool: The high cost of xenon (typically ~$4/litre); The quantities required for EUV source production, which are typically 4slpm for Laser Produced Plasma (LPP) and 300sccm for Gas Discharge Produced Plasma (GDPP). On the basis of these figures the annual xenon cost would typically be approximately $11M/year for LPP, $1M/year for GDPP. Therefore recycling of xenon offers a significant operating cost reduction. This type of re-circulation system is not restricted to high xenon throughput applications, but can be scaled in size, and hence cost, for application to lower throughput process applications. Additional applications in mainstream silicon processing including a new development in dielectric etch using xenon could also benefit from re-circulation. Present research indicates that for a typical recipe, 675sccm xenon is required per wafer pass, this equates to an annual cost of $0.6M. BOC Edwards has designed & built a series of five fully integrated xenon re-circulation systems for lithography applications. Each system has been custom designed to exact application requirements, including liquid/solid xenon filament production. Additionally, an important footprint reduction has been achieved during the design evolution, which ideally suits dielectric etch applications.

Greenwood, Joanne R.; Mennie, Darren; Hughes, Carolyn; Lee, Ron

2004-05-01

61

Recirculation regeneration  

Microsoft Academic Search

Disclosed are improved recirculating sorption bed systems of the type in which one sorption bed is in sorption duty while another is being regenerated thermally by a recirculating regeneration loop. The regeneration loop includes a cooler\\/condenser, a heater, and a tertiary sorption bed. The tertiary bed takes up sorbate from the coolant stream that may contain sorbate as a result

Oliker

1984-01-01

62

Polyculture of Endangered Bonytails and Razorback Suckers in Recirculated Water  

Microsoft Academic Search

Bonytails Gila elegans and razorback suckers Xyrauchen texanus are imperiled fish species that are endemic to the Colorado River system in the southwestern United States. Captive propagation is a component of the recovery plan for each species, which are sometimes cultured together indoors in water reuse systems. A 3 × 2 factorial design was selected for examining the co-culture of

James P. Henne; Matthew M. Romero; Gary J. Carmichael

2007-01-01

63

NITRIFICATION PERFORMANCE OF A PROPELLER-WASHED BEAD CLARIFIER SUPPORTING A FLUIDIZED SAND BIOFILTER IN A RECIRCULATING WARMWATER FISH SYSTEM  

Technology Transfer Automated Retrieval System (TEKTRAN)

A propeller-wash bead filter (PWBF) and a fluidized sand filter (FSF) on a 28 m3 recirculating system stocked with tilapia maintained favorable water quality at five different feed rates, ranging from 0.9 to 4.5 kg feed per day. TAN removal rates ranged up to about 200 g TAN per m3 of media per day ...

64

Flow and recirculation of Antarctic Intermediate Water across the Rio Grande Rise  

NASA Astrophysics Data System (ADS)

The flow of the low-salinity Antarctic Intermediate Water (AAIW) at 700-1150 m depth across the Rio Grande Rise and the lower Santos Plateau is studied under the auspices of the World Ocean Circulation Experiment (WOCE) in the context of the Deep Basin Experiment. Our data set consists of several hydrographic sections, a collection of 15 RAFOS float trajectories, and records from 14 moored current meters. The data were gathered during different intervals between 1990 and 1994. The inferred flow field strongly supports a basinwide anticyclonic recirculation cell in the subtropical South Atlantic underneath the wind-driven gyre. Its center, which appears to be southeast of the Rio Grande Rise, separates the eastward advection of AAIW below the South Atlantic Current from the westward flowing, recirculating AAIW. The two near-shelf limbs closing the circumference of AAIW flow are formed in the east by the deep Benguela Current, potentially modulated by salty inflow of Indian Ocean Intermediate Water, and in the west by the Brazil Current system. Further important circulation elements are the Brazil-Falkland (Malvinas) Confluence Zone at 40°S and an unnamed divergence at 28°S close to the 1000 m isobath. The resulting broad southward flow of AAIW augments the share of modified, i.e., saltier, intermediate water in the source region of the South Atlantic Current, while the smaller northward flow marks the source of a narrow equatorward Western Intermediate Boundary Current, ultimately leaving the South Atlantic. This shelf-trapped jet is clearly documented in hydrographic data from 19°S and in nearby current meter records. The jet contrasts a sluggish flow across this latitude east of 35°W. A continuous flow of AAIW from its subpolar region in the southwestern Argentine Basin all along the western slope toward the equator appears unlikely between 35°S and 25°S.

Boebel, Olaf; Schmid, Claudia; Zenk, Walter

1997-09-01

65

Exhaust gas recirculation control system for a diesel engine and control method therefor  

Microsoft Academic Search

In an exhaust gas recirculation control system in which a fuel injection quantity is determined on the basis of engine speed and engine load, a throttle-closed range is determined on the basis of engine speed and fuel injection quantity. An exhaust gas recirculation control valve has an electromagnetically operable valve actuator, the duty cycle of which is controlled by a

Y. Kawamura; T. Nakagawa; M. Nakajima; G. Shioyama

1984-01-01

66

EVALUATING THE IMPACT OF WATER CHEMISTRY ON CUPROSOLVENCY AND COPPER CORROSION BY-PRODUCT USING A SIMPLE COPPER PIPE RECIRCULATING LOOP SYSTEM  

EPA Science Inventory

1991, EPA publicized the Lead and Copper Rule (LCR),which set regulations to minimize the amount of lead copper in drinking water. The LCR set the copper action level at 1.3 mg/L in more then 10% of customer?s first-draw taps sampled. Potential health effects of copper include vo...

67

DEVELOPMENT OF A NOVEL STRATEGY FOR CLEARING FISH PATHOGENS FROM RECIRCULATING AQUACULTURE SYSTEMS USING BACTERIOPHAGE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Biosecurity is more easily managed in environmentally controlled recirculating aquaculture systems (RAS) facilities. However, pathogenic organisms still invade systems and result in significant losses. Current RAS disinfection strategies include delivering medicated feeds to culture animals, incre...

68

TO RATING FIXED-FILM BIOFILTERS USED IN RECIRCULATING AQUACULTURE SYSTEMS  

Technology Transfer Automated Retrieval System (TEKTRAN)

A standardized methodology for evaluating and rating biofilters is proposed to simplify design of recirculating systems. This methodology will allow engineers to compare biofilters options and accurately predict performance before construction. The methodology is based upon an increasing recognized ...

69

Analysis of the sodium recirculation theory of solute-coupled water transport in small intestine  

PubMed Central

Our previous mathematical model of solute-coupled water transport through the intestinal epithelium is extended for dealing with electrolytes rather than electroneutral solutes. A 3Na+–2K+ pump in the lateral membranes provides the energy-requiring step for driving transjunctional and translateral flows of water across the epithelium with recirculation of the diffusible ions maintained by a 1Na+-1K+–2Cl? cotransporter in the plasma membrane facing the serosal compartment. With intracellular non-diffusible anions and compliant plasma membranes, the model describes the dependence on membrane permeabilities and pump constants of fluxes of water and electrolytes, volumes and ion concentrations of cell and lateral intercellular space (lis), and membrane potentials and conductances. Simulating physiological bioelectrical features together with cellular and paracellular fluxes of the sodium ion, computations predict that the concentration differences between lis and bathing solutions are small for all three ions. Nevertheless, the diffusion fluxes of the ions out of lis significantly exceed their mass transports. It is concluded that isotonic transport requires recirculation of all three ions. The computed sodium recirculation flux that is required for isotonic transport corresponds to that estimated in experiments on toad small intestine. This result is shown to be robust and independent of whether the apical entrance mechanism for the sodium ion is a channel, a SGLT1 transporter driving inward uphill water flux, or an electroneutral Na+–K+–2Cl? cotransporter.

Larsen, Erik Hviid; S?rensen, Jakob Balslev; S?rensen, Jens N?rkaer

2002-01-01

70

Temporal and spatial pore water pressure distribution surrounding a vertical landfill leachate recirculation well.  

PubMed

Addition of liquids into landfilled waste can result in an increase in pore water pressure, and this in turn may increase concerns with respect to geotechnical stability of the landfilled waste mass. While the impact of vertical well leachate recirculation on landfill pore water pressures has been mathematically modeled, measurements of these systems in operating landfills have not been reported. Pressure readings from vibrating wire piezometers placed in the waste surrounding a liquids addition well at a full-scale operating landfill in Florida were recorded over a 2-year period. Prior to the addition of liquids, measured pore pressures were found to increase with landfill depth, an indication of gas pressure increase and decreasing waste permeability with depth. When liquid addition commenced, piezometers located closer to either the leachate injection well or the landfill surface responded more rapidly to leachate addition relative to those far from the well and those at deeper locations. After liquid addition stopped, measured pore pressures did not immediately drop, but slowly decreased with time. Despite the large pressures present at the bottom of the liquid addition well, much smaller pressures were measured in the surrounding waste. The spatial variation of the pressures recorded in this study suggests that waste permeability is anisotropic and decreases with depth. PMID:21655145

Kadambala, Ravi; Townsend, Timothy G; Jain, Pradeep; Singh, Karamjit

2011-05-24

71

Electron recirculation in electrostatic multicusp systems: II. System performance scaling of one-dimensional rollover wells  

Microsoft Academic Search

In an earlier paper a comprehensive study was made of the recirculation and losses of electrons in their flow through simple inverse power-law potential wells bounded by similarly inverse power-law dependent magnetic fields. This study examined electron flow and loss behavior in the simplest approximation invoked to describe Polywell confinement systems. The importance of this study, and of the present

R. W. Bussard; K. E. King

1992-01-01

72

Recirculation pump discharge line break tests at ROSA-III for a boiling water reactor  

Microsoft Academic Search

Three loss-of-coolant accident (LOCA) tests were conducted at the Rig of Safety Assessment (ROSA)-III test facility, which simulates boiling water reactor (BWR)\\/6-251 with a volumetric scaling factor of 1\\/424. The fundamental features of the recirculation pump discharge line break LOCA and the effects of break areas on the features are investigated. It has been confirmed experimentally that the LOCA phenomena

M. Suzuki; Y. Anoda; H. Kumamaru; H. Nakamura; M. Shiba; K. Tasaka

1985-01-01

73

Internal dust recirculation system for a fluidized bed heat exchanger  

Microsoft Academic Search

A fluidized bed heat exchanger in which air is passed through a bed of particulate material containing fuel disposed in a housing. A steam\\/water natural circulation system is provided in a heat exchange relation to the bed and includes a steam drum disposed adjacent the bed and a tube bank extending between the steam drum and a water drum. The

Robert L. Gamble; Juan A. Garcia-Mallol

1981-01-01

74

Performance of a constructed wetland in treating brackish wastewater from commercial recirculating and super-intensive shrimp growout systems.  

PubMed

A recirculating aquaculture system was developed for treating Pacific white shrimp (Litopenaeus vannamei) production wastewater using an integrated vertical-flow (IVF) and five connected integrated horizontal flow (IHF) constructed wetlands as water treatment filters for mesohaline conditions (8.25‰-8.26‰ salinity). The constructed wetlands demonstrated the ability to reduce total nitrogen, total ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, total phosphorous, chemical oxygen demand, and total suspended solids to levels significantly lower than those in effluents from culture tanks. Various water quality parameters in the culture tanks were deemed suitable for shrimp culture. The actual ratio of wetland area (A(w)) to culture tank area (A(t)) was 1.1439, and the estimated optimal ratio A(w)/A(t) was approximately 1. The IVF-IHF wetlands showed flexibility and reliability in consistently removing the main pollutants from commercial recirculating and super-intensive shrimp growout systems throughout the culture period. PMID:21852127

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

2011-07-26

75

Comparison of aerobically-treated and untreated crop residue as a source of recycled nutrients in a recirculating hydroponic system  

Microsoft Academic Search

This study compared the growth of potato plants on nutrients recycled from inedible potato biomass. Plants were grown for 105 days in recirculating, thin-film hydroponic systems containing four separate nutrient solution treatments: 1) modified half-strength Hoagland's (control), 2) liquid effluent from a bioreactor containing inedible potato biomass, 3) filtered (0.2 ?m) effluent, and 4) the water soluble fraction of inedible

C. L. Mackowiak; J. L. Garland; R. F. Strayer; B. W. Finger; R. M. Wheeler

1996-01-01

76

Experimental Study of a Recirculating Water Jet ice Drill  

Microsoft Academic Search

A need has been stated for oceanographic measurements made through the ice cover by an unmanned, microcomputer controlled air deployed system. A novel ice drilling concept has been identified to provide a highly efficient means of penetrating ice surfaces up to 15m thick with a 15cm diameter hole. In support of a computer program modeling the drilling process, a series

Corydon B. Pierson

1980-01-01

77

Intensive mass production of Artemia in a recirculated system  

Microsoft Academic Search

An outdoor closed system for intensive Artemia biomass production was evaluated. The system integrates the use of inexpensive agro-techno products and photosynthesis to create an improved diet for culturing adult Artemia. The diet in the initial days of culture consists of microalgae, followed by a mixture of torula yeast and soy protein. No water or solids are discharged from the

Odi Zmora; Muki Shpigel

2006-01-01

78

Branching of Atlantic Water within the Greenland-Spitsbergen Passage: An estimate of recirculation  

NASA Astrophysics Data System (ADS)

Atlantic Water (AW) supplies the largest source of heat, mass, and salt to the Arctic Ocean via Fram Strait (Greenland-Spitsbergen Passage), yet it represents only a fraction of the Atlantic Water that resides in the Greenland, Iceland, Norwegian, and Barents Seas. This is a result of both the branching of the central core of AW along its northward flow and the modification of its T-S signature through air-sea-ice interactions and internal mixing. This paper addresses the quantitative analysis of the three dominant Atlantic Water cores within Fram Strait and north of 76°N using an 11-year (1977 to 1987) hydrographic database. Spatial variations of heat, volume, and salt along its flow path of some 600 km showed that the major core of Atlantic Water that directly enters the Arctic Ocean (Svalbard branch) did not extend past 20°E. Of the 9719 km3 of Atlantic Water existing within the region, one third resided within the Svalbard branch; the remainder, 22% and 45%, were held within the Return Atlantic Current and the Yermak branches, respectively. Restricting the analysis to a southern limit of 79°N effectively removed the Return Atlantic Current and showed a nearly equal split between the two remaining branches. Work completed by Bourke et al. (1988) indicated that the Yermak branch is largely recirculated to the south; if true, this analysis supports Rudels' (1987) model estimate of a 50% recirculation of AW within this region.

Manley, T. O.

1995-10-01

79

Effects of Flue-Gas Recirculation on NOx Production and Performance of Pulse Combustion Hot-Water Boilers  

Microsoft Academic Search

Two hot-water boilers with rated inputs of 147 and 220 kW had NOx emissions near 40 and 50 ppm (3% O2), respectively, without flue-gas recirculation. With recirculation, NOx was reduced to 20-25 ppm for the larger boiler and to less than 20 ppm for the smaller one. Emissions of CO were not correlated with NOx; they depended on overall equivalence

Y. MICHEL; F. E. BELLES

1993-01-01

80

A computer model of the energy-current loss instabilities in a recirculating accelerator system  

NASA Astrophysics Data System (ADS)

The computer program called ESRA (energy stability in a recirculating accelerator FELs) has been written to model bunches of particles in longitudinal phase space traversing a recirculating accelerator and the associated rf changes and aperture current losses. This code addresses stability issues and determines the transport, noise, feedback and other parameters for which these FEL systems are stable or unstable. A representative system is modeled, the Novosibirisk high power FEL race-track microtron for photochemical research. The system is stable with prudent choice of parameters.

Edighoffer, J. A.; Kim, K.-J.

1995-02-01

81

Determination of nitrate ion content in recirculating water in petroleum refineries and petrochemical plants  

SciTech Connect

A method for determining nitrate ions, using a 2,6-diacetaminopyridine solution in concentrated sulfuric acid, was investigated. Potassium nitrate solutions with nitrate ion contents of 1 mg/ml, including a 2% aqueous solution of sulfamic acid, a 0.5% solution of antimony trioxide in concentrated sulfuric acid, were used. The solutions were mixed with a 1-4 ml sample of recirculating water in two 25 ml flasks. The optical density of the solution was measured relative to the zero standard of the scale of the calibration curve. Nitrate ion content was measured by the calibration curve, from data obtained in a series of 25-ml volumetric flasks.

Sukhova, N.S.; Bokova, Z.I.

1987-11-01

82

A semi-recirculating, integrated system for the culture of fish and seaweed  

Microsoft Academic Search

Biofiltration allows for environmentally sustainable mariculture. An intensive, biofiltered recirculating integrated system producing fish and seaweed on a semi-commercial scale was evaluated with respect to production and to nutrient and heat budgets. The system consisted of abalone (Haliotis discus hannai) and sea urchin (Paracentrotus lividus) tanks, an intensive fishpond (Sparus aurata), and a three-stage Ulva lactuca biofilter, which cleaned and

Andreas Schuenhoff; Muki Shpigel; Ingrid Lupatsch; Arik Ashkenazi; Flower E Msuya; Amir Neori

2003-01-01

83

Fulminant hepatic failure following marijuana drug abuse: Molecular adsorbent recirculation system therapy  

PubMed Central

Marijuana is used for psychoactive and recreational purpose. We report a case of fulminant hepatic failure following marijuana drug abuse who recovered following artificial support systems for acute liver failure. There is no published literature of management of marijuana intoxication with molecular adsorbent recirculation system (MARS). MARS is effective and safe in patients with fulminant hepatic failure following marijuana intoxication.

Swarnalatha, G.; Pai, S.; Ram, R.; Dakshinamurty, K. V.

2013-01-01

84

Fulminant hepatic failure following marijuana drug abuse: Molecular adsorbent recirculation system therapy.  

PubMed

Marijuana is used for psychoactive and recreational purpose. We report a case of fulminant hepatic failure following marijuana drug abuse who recovered following artificial support systems for acute liver failure. There is no published literature of management of marijuana intoxication with molecular adsorbent recirculation system (MARS). MARS is effective and safe in patients with fulminant hepatic failure following marijuana intoxication. PMID:24049281

Swarnalatha, G; Pai, S; Ram, R; Dakshinamurty, K V

2013-09-01

85

Growth and survival of larval and juvenile cobia Rachycentron canadum in a recirculating raceway system  

Microsoft Academic Search

Cobia Rachycentron canadum is a fast-growing, pelagic marine species that has recently attracted aquaculturists in both the research and commercial sectors. The typical method of grow-out for this species is in outdoor systems where production is limited to locations and seasons conducive for adequate growth and survival. Expanding the culture of cobia to indoor recirculating aquaculture systems (RAS) would allow

Cynthia K. Faulk; Jeffrey B. Kaiser; G. Joan Holt

2007-01-01

86

Development of low cost all glass recirculation systems for environmental applications.  

PubMed

Some simple glassware has been developed for recirculation of liquid medium. These glassware have wider applications and have been tested in experiments involving leaching, biodegradation, and desulfurization. The fabrication cost is minimum and can be developed in a small glassware workshop. Such a development has certain advantages as no separate mechanical devices are needed, the flow can be easily monitored due to transparency of the apparatus, acidic or alkaline medium can also be circulated. The paper discusses the development, design and fabrication of some specialized glass recirculation systems and its environmental applications. PMID:13677063

Kshirsagar, P S; Pandya, G H

2002-10-01

87

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

Microsoft Academic Search

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

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

2011-01-01

88

Response of Bacterial Biofilms in Recirculating Aquaculture Systems to Various Sanitizers  

Microsoft Academic Search

Pathogenic microorganisms may be incorporated into biofilms found in aquaculture systems, causing recurring exposure to potential disease agents. Aerobic plate counts, the presence of Enterobacteriaceae, and the presence of Escherichia coli, modified to express a green fluorescent protein (GFP E. coli), was used to evaluate the effectiveness of various sanitizers in decreasing bacterial incorporation into newly generated biofilms in recirculating

Robin K. King; George J. Flick Jr; Stephen A. Smith; Merle D. Pierson; Gregory D. Boardman; Charles W. Coale Jr

2008-01-01

89

A nucleonic oil debris monitor for detecting metal in recirculating lubricating systems  

Microsoft Academic Search

Metallic debris sensors have been developed for recirculating oil lubrication systems. The in-line monitors apply the principle of X-ray fluorescence. The nucleonic oil debris monitors (ODM's) have been designed and fabricated for use with test cell operations involving aircraft transmissions and gear boxes. ODM's were tested to evaluate their sensitivity, accuracy, and response to lubricant temperature over the range of

R. W. Harman

1974-01-01

90

Control system for engine exhaust gas recirculation according to engine opertional condition  

Microsoft Academic Search

A control system comprising a flow control valve provided in an exhaust gas recirculation passage, an electromechanical valve-actuator for actuating the flow control valve and a control circuit including function generators and an adder, optionally combined with a multiplier, for producing a control signal to operate the valve-actuator. Each function generator receives a signal representing one of several variables related

Aono

1978-01-01

91

Growth of juvenile cobia, Rachycentron canadum, at three different densities in a recirculating aquaculture system  

Microsoft Academic Search

Cobia (Rachycentron canadum) is an excellent aquaculture candidate and culture of this species continues to develop worldwide. Current culture practices generally include larviculture and production of early juveniles on land with final growout occurring in ocean cages. Data indicate that production and\\/or growout of juveniles in land based recirculating systems may be hampered by growth depression in fish held at

Kenneth A. Webb; Glenn M. Hitzfelder; Cynthia K. Faulk; G. Joan Holt

2007-01-01

92

[Performance of recirculating aquaculture systems in the intensive farming of Pacú Piaractus mesopotamicus (Characiformes: Characidae)].  

PubMed

An alternative to intensify fish production, reducing the environmental impact and production costs are recirculating aquaculture systems (RAS). The performance of a RAS was evaluated, as fish growth and water quality conditions, in a culture of Piaractus mesopotamicus reared for ornamental purposes. Two commercial food brands with different protein contents (18%-T1 and 28%-T2), were given to juvenile fishes during an eight weeks period. Growth was measured bi-weekly: standard length (Lp), peak height (A), weight and multiple condition factor (KM). The evaluation of water parameters included: dissolved oxygen, NH3-NH4, pH, NO2, NO3, KH carbonate hardness and PO4. NH3-N rate production was analyzed following Timmons-Ebeling model. Results demonstrated significant differences in weight only, and T2 showed a 7.5% higher value than T1; nevertheless, treatment T1 had a higher KM. In general, water quality values were suitable for growth: OD=T1: 4.23 +/- 1.23; T2: 4.13 +/- 0.86; NH3=T1: 0.02 +/- 0.02; T2: 0.06 +/- 0.10; however, pH was an exception (T1: 6.95 +/- 0.98; T2: 7.11 +/- 1.03), displaying lethal rates (<5) by the fifth week. Systems NH3 removal had a 99.4% to 100% efficiency. Final fish biomass was 22.03kg for T1 and 27.49kg for T2. We concluded that the systems were able to maintain suggested density up to the experimental fifth week. Water quality parameters remained in suitable levels, with the pH exception. Cultured fishes reached their commercial size (10cm) in eight weeks. PMID:22458232

Domínguez Castanedo, Omar; Martínez Espinosa, David Alberto

2012-03-01

93

A study on the optimal hydraulic loading rate and plant ratios in recirculation aquaponic system.  

PubMed

The growths of the African catfish (Clarias gariepinus) and water spinach (Ipomoea aquatica) were evaluated in recirculation aquaponic system (RAS). Fish production performance, plant growth and nutrient removal were measured and their dependence on hydraulic loading rate (HLR) was assessed. Fish production did not differ significantly between hydraulic loading rates. In contrast to the fish production, the water spinach yield was significantly higher in the lower hydraulic loading rate. Fish production, plant growth and percentage nutrient removal were highest at hydraulic loading rate of 1.28 m/day. The ratio of fish to plant production has been calculated to balance nutrient generation from fish with nutrient removal by plants and the optimum ratio was 15-42 gram of fish feed/m(2) of plant growing area. Each unit in RAS was evaluated in terms of oxygen demand. Using specified feeding regime, mass balance equations were applied to quantify the waste discharges from rearing tanks and treatment units. The waste discharged was found to be strongly dependent on hydraulic loading rate. PMID:19819130

Endut, Azizah; Jusoh, A; Ali, N; Wan Nik, W B; Hassan, A

2009-10-09

94

Performance and operation of a rotating biological contactor in a tilapia recirculating aquaculture system  

Microsoft Academic Search

This paper describes the performance characteristics of an industrial-scale air-driven rotating biological contactor (RBC) installed in a recirculating aquaculture system (RAS) rearing tilapia at 28°C. This three-staged RBC system was configured with stages 1 and 2 possessing approximately the same total surface area and stage 3 having approximately 25% smaller. The total surface area provided by the RBC equaled 13,380m2.

Brian L. Brazil

2006-01-01

95

Recirculating loop for experimental evaluation of EDFA saturated regime effects on optical communication systems  

Microsoft Academic Search

We demonstrate an optical-fiber recirculating loop for experimental simulation of long-haul optical communication systems using cascaded erbium-doped fiber amplifiers (EDFA's) operating in the gain saturation regime. The loop contains sections of dispersion shifted fibers (DSF's), standard fiber, and a set of in-line devices, such as tuning filters, optical amplifiers, polarization controllers, and a variable attenuator. The main results presented here

Claudio Mazzali; Hugo L. Fragnito

1998-01-01

96

Noncardiogenic pulmonary edema induced by a molecular adsorbent recirculating system: case report  

Microsoft Academic Search

Noncardiogenic pulmonary edema is a well-recognized manifestation of acute lung injury which has been related, among others, to blood or blood-product transfusion, intravenous contrast injection, air embolism, and drug ingestion. We describe two cases of noncardiogenic pulmonary edema after use of a molecular adsorbent recirculating system, a cell-free dialysis technique. Patients in this series presented at our institution to be

Cataldo Doria; Lucio MandalÀ; Victor L. Scott; Ignazio R. Marino; Salvatore Gruttadauria; Roberto Miraglia; Claudio H. Vitale; Jan Smith

2003-01-01

97

Transmission of tobacco mosaic virus in recirculating hydroponic system  

Microsoft Academic Search

The possible pathway of transmission of tobacco mosaic virus (TMV) from diseased plants to healthy plants in two hydroponic systems, deep flow culture (DFC) and container culture (CC), was investigated in this study. The tested plants were tobacco (Nicotiana tabacum cv. Samsun-nn and cv. Xanthi), tomato (Lycopersicon esculentum cv. Alchan), and hot pepper (Capsicum annuum cv. Dahong). The longevity in

Won Mok Park; Gung Pyo Lee; Ki Hyun Ryu; Kuen Woo Park

1999-01-01

98

Prediction of central recirculation zone size for a complete burner-quarl-furnace system  

SciTech Connect

In the swirl flow burning process of fuels, the central recirculation zone plays an important role in flame stabilization by providing a hot flow of recirculated combustion products, which reduce both the length of flame and the stabilized flame distance from the burner mouth. In this paper, a new modified swirl number, S exp xx, related to the characteristic size of the burner quarl, is introduced to correlate the isothermal and burning flows. Using a well-known two-dimensional computational model, the isothermal flow pattern in a complete burner-quarl-furnace system is computed. On this basis, the theoretical swirl number S exp xx is calculated and used as a correlation parameter for predicting the central recirculation zone size in burning flow conditions. Experimental tests for both nonreacting and reacting flows on the same complete burner-quarl-furnace system, for comparing the theoretical and experimental swirl number s exp xx, have been conducted, and the validity of this new correlation parameter has been proved. 11 references.

Cristea, E.B.

1987-03-01

99

[Ecological effect of recirculated landfill leachate with different hydraulic loading on plant-soil system].  

PubMed

The ecological effect of irrigating recirculated leachate with different hydraulic loading on bermudagrass (Cynodon dactylon) and soil system was evaluated. The results show that leachate irrigation with hydraulic loading of 2.77-12.00 mm d(-1) leads to high chlorophyll content, low proline (Pro) content, as well as low malondialdehyde (MDA) and H2O2 content. Soil enzyme activities, respirations, microbial biomass and ratio of biomass carbon to organic carbon (Cmic/Corg) are rather higher. Among leachte irrigation group, leachate irrigation with hydraulic loading of 6.46-10.15 mm x d(-1) leads to declined proline, increased chlorophyll content, low POD activity and low content of MDA and H2O2. Soil bio-activity related parameters, such as soil enzyme activities, respirations, microbial biomass and Cmic/Corg are all enhanced at 6.46-10.15 mm x d(-1) of hydraulic loading. However, when hydraulic loading increases to 12.00 mm x d(-1) or declines to 2.77-4.16 mm x d(-1), the stress of irrigation on bermudagrass is aggravated, and soil bioactivity declines. The results reveal that leachate irrigation could alleviate the stress of environment on bermudagrass and improve the bio-activity of soil. The positive effect of leachate irrigation on the plant-soil system might be contributed to changes of soil water and physico-chemical property after leachate irrigated to the soil. The experimental results suggest that leachate irrigation could benefit plant-soil system, especially when controlled at suitable hydraulic loading. PMID:16850839

Wang, Ru-yi; He, Pin-jing; Shao, Li-ming; Yuan, Li; Li, Guo-jian

2006-05-01

100

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

PubMed

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

101

Recirculation in the Fram Strait and transports of water in and north of the Fram Strait derived from CTD data  

NASA Astrophysics Data System (ADS)

The volume, heat and freshwater transports in the Fram Strait are estimated from geostrophic computations based on summer hydrographic data from 1984, 1997, 2002 and 2004. In these years, in addition to the usually sampled section along 79° N, a section between Greenland and Svalbard was sampled further north. Quasi-closed boxes bounded by the two sections and Greenland and Svalbard can then be formed. Applying conservation constraints on these boxes provides barotropic reference velocities. The net volume flux is southward and varies between 2 and 4 Sv. The recirculation of Atlantic water is about 2 Sv. Heat is lost to the atmosphere and the heat loss from the area between the sections averaged over the four years is about 10 TW. The net heat (temperature) transport is 20 TW northward into the Arctic Ocean, with large interannual differences. The mean net freshwater added between the sections is 40 mSv and the mean freshwater transport southward across 79° N is less than 60 mSv, indicating that most of the liquid freshwater leaving the Arctic Ocean through Fram Strait in summer is derived from sea ice melt in the northern vicinity of the strait. In 1997, 2001 and 2003 meridional sections along 0° longitude were sampled and in 2003 two smaller boxes can be formed, and the recirculation of Atlantic water in the strait is estimated by geostrophic computations and continuity constraints. The recirculation is weaker close to 80° N than close to 78° N, indicating that the recirculation is mainly confined to the south of 80° N. This is supported by the observations in 1997 and 2001, when only the northern part of the meridional section, from 79° N to 80° N, can be computed with the constraints applied. The recirculation is found strongest close to 79° N.

Marnela, M.; Rudels, B.; Houssais, M.-N.; Beszczynska-Möller, A.; Eriksson, P. B.

2013-05-01

102

Production Characteristics and Body Composition of Florida Pompano Reared to Market Size at Two Different Densities in Low-Salinity Recirculating Aquaculture Systems  

Microsoft Academic Search

The effect of culture density on production characteristics and body composition of Florida pompano Trachinotus carolinus reared to market size using recirculating aquaculture systems (RASs) maintained at a salinity of 5‰ was evaluated in a 110-d growth trial (water temperature = 27.0–28.5°C). Juvenile Florida pompano (mean weight ± SE = 259.0 ± 3.0 g) were stocked into two tanks from

Charles R. Weirich; Paul S. Wills; Richard M. Baptiste; Peter N. Woodward; Marty A. Riche

2009-01-01

103

Bacterial diversity, community structure and function associated with biofilm development in a biological aerated filter in a recirculating marine aquaculture system  

Microsoft Academic Search

A biological aerated filter (100 l), filled with bamboo ball media, was set up for treatment of low ammonia-containing recirculating\\u000a water in a marine aquaculture system. Chemical analysis showed that it took 70 days to establish a stable efficiency, at which\\u000a more than 30% of the ammonia was removed. During the biofilm development, bacterial diversity and community structure were\\u000a determined by construction

Xi-Yan Gao; Yang Xu; Ying Liu; Zhi-Pei Liu

104

Electron recirculation in electrostatic multicusp systems: II. System performance scaling of one-dimensional rollover wells  

SciTech Connect

In an earlier paper a comprehensive study was made of the recirculation and losses of electrons in their flow through simple inverse power-law potential wells bounded by similarly inverse power-law dependent magnetic fields. This study examined electron flow and loss behavior in the simplest approximation invoked to describe Polywell confinement systems. The importance of this study, and of the present paper, is that the power balance in Polywell systems is determined entirely by the rate of electron losses; if these are large, then the system can not yield net power. Thus it is of interest to determine those conditions that results in small losses, and to design experiments and systems to attempt to achieve and operate at these most favorable conditions, in order to test and prove the efficacy of the system for the generation of net power from fusion reactions. The outline and summary of this problem presented is generally repeated here, with some modifications to clarify particular physics issues of most concern, in order to avoid having to refer to the earlier document for this general description. As noted, a large body of work has been undertaken over the past 35 or so years in the study of general cusp confinement of plasmas. Nearly all of this has examined single particle electron (or ion) motion or the motion of particles in neutral plasmas within cusped magnetic systems, generally without internal electric potential fields.**INVALID KEYWORDS: controlled nuclear fusion, electron flux, plasma devices, confinement, performance, engineering, scaling factor, multicusp systems, polywell systems

Bussard, R.W.; King, K.E.

1992-01-01

105

Improving Hollow Fiber Dialyzer Efficiency with a Recirculating Dialysate System II: Comparison Against Two-Chamber Dialysis Systems  

Microsoft Academic Search

The theoretical basis of the nonregenerated recirculating dialysate system (RDS) was derived in Part I of this work [M. Prado,\\u000a L. M. Roa, A. Palma, and J. A. Milán, Ann. Biomed. Eng. (2005)]. This system pursues the maximization of the clearance of hollow fiber dialyzers whose performance is controlled\\u000a by diffusion, as occurred in standard hemodialysis. In this second part

Manuel Prado; Laura M. Roa; Alfonso Palma; José A. Milán

2005-01-01

106

An implantable centrifugal blood pump with a recirculating purge system (Cool-Seal system).  

PubMed

A compact centrifugal blood pump has been developed as an implantable left ventricular assist system. The impeller diameter is 40 mm, and pump dimensions are 55 x 64 mm. This first prototype, fabricated from titanium alloy, resulted in a pump weight of 400 g including a brushless DC motor. The weight of a second prototype pump was reduced to 280 g. The entire blood contacting surface is coated with diamond like carbon (DLC) to improve blood compatibility. Flow rates of over 7 L/min against 100 mm Hg pressure at 2,500 rpm with 9 W total power consumption have been measured. A newly designed mechanical seal with a recirculating purge system (Cool-Seal) is used for the shaft seal. In this seal system, the seal temperature is kept under 40 degrees C to prevent heat denaturation of blood proteins. Purge fluid also cools the pump motor coil and journal bearing. Purge fluid is continuously purified and sterilized by an ultrafiltration unit which is incorporated in the paracorporeal drive console. In vitro experiments with bovine blood demonstrated an acceptably low hemolysis rate (normalized index of hemolysis = 0.005 +/- 0.002 g/100 L). In vivo experiments are currently ongoing using calves. Via left thoracotomy, left ventricular (LV) apex descending aorta bypass was performed utilizing an expanded polytetrafluoroethylene (ePTFE) vascular graft with the pump placed in the left thoracic cavity. In 2 in vivo experiments, the pump flow rate was maintained at 5-9 L/min, and pump power consumption remained stable at 9-10 W. All plasma free Hb levels were measured at less than 15 mg/dl. The seal system has demonstrated good seal capability with negligible purge fluid consumption (<0.5 ml/day). In both calves, the pumps demonstrated trouble free continuous function over 6 month (200 days and 222 days). PMID:9650667

Yamazaki, K; Litwak, P; Tagusari, O; Mori, T; Kono, K; Kameneva, M; Watach, M; Gordon, L; Miyagishima, M; Tomioka, J; Umezu, M; Outa, E; Antaki, J F; Kormos, R L; Koyanagi, H; Griffith, B P

1998-06-01

107

Improving hollow fiber dialyzer efficiency with a recirculating dialysate system. I: Theory and applicability.  

PubMed

The mathematical theory that underlies a novel non-regenerated recirculating dialysate system (RDS) for improving diffusive clearance in hemodialyzers is presented. The theory states the conditions that hemodialyzers must meet to be suitable in RDS optimization. We have verified the applicability of the RDS for several Cuprophan and polysulfone (PS) commercial dialyzers, showing that PS (synthetic) membranes achieve the highest increments of diffusive clearance. A numerical simulation analysis over more general conditions defined by the dimensionless groups of the system demonstrated that the highest diffusive clearance improvements are achieved in dialyzers operating with a low value of the diffusive mass-transfer area/blood flow rate ratio. This study has provided the base for the assessment of the performance of the RDS as compared to several high-efficiency systems, presented in Part II of this work [M. Prado, L. M. Roa, A. Palma, and J. A. Milan, Ann. Biomed. Eng. (2004) submitted]. PMID:15981864

Prado, Manuel; Roa, Laura M; Palma, Alfonso; Milán, José A

2005-05-01

108

Electron Recirculation in Electrostatic Multicusp Systems: II - System Performance Scaling of One-Dimensional 'Rollover' Wells.  

National Technical Information Service (NTIS)

In an earlier paper a comprehensive study was made of the recirculation and losses of electrons in their flow through simple inverse power-law potential wells bounded by similarly inverse power-law dependent magnetic fields. This study examined electron f...

R. W. Bussard K. E. King

1992-01-01

109

Characterization of the microbial community and nitrogen transformation processes associated with moving bed bioreactors in a closed recirculated mariculture system  

Microsoft Academic Search

The microbial consortium of a moving bed bioreactor (MBB) connected to a marine recirculating aquaculture system was examined by denaturing gradient gel electrophoresis (DGGE) of amplified 16S rRNA gene fragments. Both ammonia and nitrite oxidizers, Nitrosomonas cryotolerans and Nitrospira marina, respectively, were found associated with the marine system as well as a number of heterotrophic bacteria, including Pseudomonas sp. and

Yossi Tal; Joy E. M. Watts; Susan B. Schreier; Kevin R. Sowers; Harold J. Schreier

2003-01-01

110

Advances in rearing cobia Rachycentron canadum larvae in recirculating aquaculture systems: Live prey enrichment and greenwater culture  

Microsoft Academic Search

Cobia Rachycentron canadum is a relatively hardy species which exhibits high rates of growth during the larval and juvenile periods. Currently, this species is considered to be a good candidate for commercial production in recirculating aquaculture systems. However, little information is available regarding the nutritional requirements of cobia larvae in such systems, and this information is required to advance commercial

Cynthia K. Faulk; G. Joan Holt

2005-01-01

111

A Mathematical Model of Solute Coupled Water Transport in Toad Intestine Incorporating Recirculation of the Actively Transported Solute  

PubMed Central

A mathematical model of an absorbing leaky epithelium is developed for analysis of solute coupled water transport. The non-charged driving solute diffuses into cells and is pumped from cells into the lateral intercellular space (lis). All membranes contain water channels with the solute passing those of tight junction and interspace basement membrane by convection-diffusion. With solute permeability of paracellular pathway large relative to paracellular water flow, the paracellular flux ratio of the solute (influx/outflux) is small (2–4) in agreement with experiments. The virtual solute concentration of fluid emerging from lis is then significantly larger than the concentration in lis. Thus, in absence of external driving forces the model generates isotonic transport provided a component of the solute flux emerging downstream lis is taken up by cells through the serosal membrane and pumped back into lis, i.e., the solute would have to be recirculated. With input variables from toad intestine (Nedergaard, S., E.H. Larsen, and H.H. Ussing, J. Membr. Biol. 168:241–251), computations predict that 60–80% of the pumped flux stems from serosal bath in agreement with the experimental estimate of the recirculation flux. Robust solutions are obtained with realistic concentrations and pressures of lis, and with the following features. Rate of fluid absorption is governed by the solute permeability of mucosal membrane. Maximum fluid flow is governed by density of pumps on lis-membranes. Energetic efficiency increases with hydraulic conductance of the pathway carrying water from mucosal solution into lis. Uphill water transport is accomplished, but with high hydraulic conductance of cell membranes strength of transport is obscured by water flow through cells. Anomalous solvent drag occurs when back flux of water through cells exceeds inward water flux between cells. Molecules moving along the paracellular pathway are driven by a translateral flow of water, i.e., the model generates pseudo-solvent drag. The associated flux-ratio equation is derived.

Larsen, Erik Hviid; S?rensen, Jakob Balslev; S?rensen, Jens N?rkaer

2000-01-01

112

Comparison of aerobically-treated and untreated crop residue as a source of recycled nutrients in a recirculating hydroponic system  

NASA Astrophysics Data System (ADS)

This study compared the growth of potato plants on nutrients recycled from inedible potato biomass. Plants were grown for 105 days in recirculating, thin-film hydroponic systems containing four separate nutrient solution treatments: 1) modified half-strength Hoagland's (control), 2) liquid effluent from a bioreactor containing inedible potato biomass, 3) filtered (0.2 ?m) effluent, and 4) the water soluble fraction of inedible potato biomass (leachate). Approximately 50% of the total nutrient requirement in treatments 2 - 4 were provided (recycled) from the potato biomass. Leachate had an inhibitory effect on leaf conductance, photosynthetic rate, and growth (50% reduction in plant height and 60% reduction in tuber yield). Plants grown on bioreactor effluent (filtered or unfiltered) were similar to the control plants. These results indicated that rapidly degraded, water soluble organic material contained in the inedible biomass, i.e., material in leachate, brought about phytotoxicity in the hydroponic culture of potato. Recalcitrant, water soluble organic material accumulated in all nutrient recycling treatments (650% increase after 105 days), but no increase in rhizosphere microbial numbers was observed.

Mackowiak, C. L.; Garland, J. L.; Strayer, R. F.; Finger, B. W.; Wheeler, R. M.

1996-01-01

113

Production characteristics and body composition of juvenile cobia fed three different commercial diets in recirculating aquaculture systems  

Technology Transfer Automated Retrieval System (TEKTRAN)

The effect of feeding three commercial diets on production characteristics and body composition of juvenile cobia Rachycentron canadum reared using recirculating aquaculture systems (RAS) was evaluated in a 56 d growth trial. Juvenile cobia (29.2 +/= 0.7 g, mean weight +/= SE) were stocked into thr...

114

Preliminary studies on the depuration of common off-flavors from fish raised in recirculating aquaculture systems  

Technology Transfer Automated Retrieval System (TEKTRAN)

“Off-flavor” problems can adversely impact the growth of the aquaculture industry. Fish raised in recirculating systems have the potential to develop the common off-flavors “earthy” and “musty” due to accumulation of the microbial metabolites geosmin and 2-methylisoborneol (MIB) in the fish flesh. ...

115

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

116

Transport behavior of surrogate biological warfare agents in a simulated landfill: effect of leachate recirculation and water infiltration.  

PubMed

An understanding of the transport behavior of biological warfare (BW) agents in landfills is required to evaluate the suitability of landfills for the disposal of building decontamination residue (BDR) following a bioterrorist attack on a building. Surrogate BW agents, Bacillus atrophaeus spores and Serratia marcescens, were spiked into simulated landfill reactors that were filled with synthetic building debris (SBD) and operated for 4 months with leachate recirculation or water infiltration. Quantitative polymerase chain reaction (Q-PCR) was used to monitor surrogate transport. In the leachate recirculation reactors, <10% of spiked surrogates were eluted in leachate over 4 months. In contrast, 45% and 31% of spiked S. marcescens and B. atrophaeus spores were eluted in leachate in the water infiltration reactors. At the termination of the experiment, the number of retained cells and spores in SBD was measured over the depth of the reactor. Less than 3% of the total spiked S. marcescens cells and no B. atrophaeus spores were detected in SBD. These results suggest that significant fractions of the spiked surrogates were strongly attached to SBD. PMID:20973546

Saikaly, Pascal E; Hicks, Kristin; Barlaz, Morton A; de Los Reyes, Francis L

2010-10-25

117

Performance of solar energy hot water systems  

NASA Astrophysics Data System (ADS)

A comparative analysis of solar energy hot water systems installed in sites monitored by the National Solar Data Network is presented. Two single family and two multi-family residences were selected for evaluation. These systems represent different types of hot water systems: passive hot water, active hot water with space heating, hot water with recirculation, and hot water thermosiphon. The data is provided in a number of forms including average monthly performance values for each hot water system, average monthly values for the summer and winter seasons, and estimated operational dollar savings. The conclusions are directed at both solar and conventional design features that cause good or bad performance.

Cramer, M. A.; Evans, K. D.; Rosenbusch, J. M.; Weinstein, R. A.

118

Graywater processing in recirculating hydroponic systems: phytotoxicity, surfactant degradation, and bacterial dynamics  

Microsoft Academic Search

Incorporation of human hygiene water (graywater) into hydroponic plant production systems, and subsequent recovery of the water transpired by the plants, is one potential means for water purification and recycling in bioregenerative life support systems under development for long duration space missions. Surfactant phytotoxicity and the potential for growth of human-associated microorganisms were assessed in studies of wheat and lettuce

J. L Garland; L. H Levine; N. C Yorio; J. L Adams; K. L Cook

2000-01-01

119

Molecular Adsorbent Recirculating System Technique for Liver Failure due to Cardiogenic Shock.  

PubMed

Background Systematic data on clinical outcome in patients with liver failure due to cardiogenic shock are scarce.Methods We performed a monocentric retrospective data analysis in 197 cardiogenic shock patients with serum bilirubin levels above 102 µmol/L receiving molecular adsorbent recirculating system (MARS). We assessed clinical outcome, recorded laboratory parameters, and tried to assess risk factors for survival.Results The median duration of MARS was 87 hours (range, 20-315 hours) during a median time period of 9 days (range, 3-736 days). During MARS, 48 to 75% of patients developed infections and gastrointestinal, respiratory, and neurological complications, respectively. Inhospital mortality was 66% (n = 129). Baseline bilirubin levels were comparable between survivors and non-survivors. During MARS, bilirubin values decreased significantly in survivors but not in non-survivors. Of various clinical and biochemical parameters assessed at baseline, the sepsis-related Organ Failure Assessment score remained the only independent predictor of inhospital mortality.Conclusion Inhospital mortality is still unsatisfyingly high in cardiogenic shock patients with liver failure. Future studies should clarify whether MARS can definitively improve survival in these patients. PMID:23055403

Zittermann, Armin; Engel, Markus; Hohnemann, Sigrid; Kizner, Lukasz; Gummert, Jan F

2012-10-10

120

Advanced Horizontal Well Recirculation Systems for Geothermal Energy Recovery in Sedimentary Formations  

SciTech Connect

There is increased recognition that geothermal energy resources are more widespread than previously thought, with potential for providing a significant amount of sustainable clean energy worldwide. Recent advances in drilling, completion, and production technology from the oil and gas industry can now be applied to unlock vast new geothermal resources, with some estimates for potential electricity generation from geothermal energy now on the order of 2 million megawatts. Terralog USA, in collaboration with the University of California, Irvine (UCI), are currently investigating advanced design concepts for paired horizontal well recirculation systems, optimally configured for geothermal energy recovery in permeable sedimentary and crystalline formations of varying structure and material properties. This two-year research project, funded by the US Department of Energy, includes combined efforts for: 1) Resource characterization; 2) Small and large scale laboratory investigations; 3) Numerical simulation at both the laboratory and field scale; and 4) Engineering feasibility studies and economic evaluations. The research project is currently in its early stages. This paper summarizes our technical approach and preliminary findings related to potential resources, small-scale laboratory simulation, and supporting numerical simulation efforts.

Mike Bruno; Russell L. Detwiler; Kang Lao; Vahid Serajian; Jean Elkhoury; Julia Diessl; Nicky White

2012-09-30

121

[Analysis of the changes of microbial community structure on bio-carrier of recirculating aquaculture systems (RAS)].  

PubMed

In order to study the variation of microbial community structure and the mechanism of denitrification on bio-carrier in recirculating aquaculture systems (RAS) during the periods of bio-film formation and operation the systems, traditional microbiological methods were applied to count the quantity of heterotrophic bacteria, ammonia oxidize bacteria and nitrite oxidize bacteria. The amplified products of variable V3 region of bacterial 16S rDNA were separated by using denaturing gradient gel electrophoresis (DGGE). And bacterial community DNA fingerprint was obtained. The sequences retrieved from the DGGE bands were used for homology analysis and construction of phylogenetic tree. It presented a trend that the quantity of the three types of bacteria increased gradually to a top and then fallen slowly to a stable level. The composition of microbial community of bio-carrier was very abundant in all periods, and the Shannon index was 1.53, 1.44, 1.57, 1.08, 1.27 and 1.30, respectively. During different periods, there was a certain shift in the microbial community structure, while the C(s) value (similar index) in two adjacent periods was high, indicating the variation and succession of the microbial community was slow and regular. Several bacteria had an effect on removal of pollutants for farming water and the effluent water quality could meet the requirements of high-density culture. Among them, Proteobacteria and Flavobacteria were main communities. The Nitrosomonas and some other facultative anaerobic bacteria (Flavobacteriaceae bacterium) were identified, which indicated that there may be coexisted pathways of nitrification and denitrification in bio-filter. PMID:21404692

Zhang, Hai-Geng; Ma, Shao-Sai; Li, Qiu-Fen; Fu, Xue-Jun; Zhang, Yan; Qu, Ke-Ming

2011-01-01

122

Hematologic and plasma biochemical values of healthy hybrid tilapia (Oreochromis aureus x Oreochromis nilotica) maintained in a recirculating system.  

PubMed

Tilapia are cultured worldwide and are increasing in popularity among aquaculturalists in the United States; however, data regarding normal health parameters are limited. Few hematologic and plasma biochemical values of clinically normal tilapia have been reported, but these data may be key for identifying and managing disease issues in recirculating systems. Therefore, blood was collected from clinically normal hybrid tilapia (Oreochromis aureus x Oreochromis nilotica) housed in recirculating systems for the purpose of establishing normal hematologic and plasma biochemical reference ranges. Using standard clinical techniques the following hematologic values were determined: packed cell volume, plasma protein, leukocyte counts, leukocyte differentials, and thrombocyte counts. Additionally, the following plasma biochemical values were determined: albumin, total protein, globulins, albumin/globulin ratio, aspartate aminotransferase, alkaline phosphatase, glucose, uric acid, calcium, phosphorus, magnesium, sodium, potassium, chloride, urea nitrogen, and creatinine. The condition of the sample was also noted (lipemic, hemolysis, and icterus). The reference ranges reported in this study can be used in the management of cultured tilapia in recirculating systems. PMID:17939351

Mauel, Michael J; Miller, Debra L; Merrill, Anita L

2007-09-01

123

Effects of Diet and Temperature on Growth and Mortality of the Blue Crab, 'Callinectes sapidus', Maintained in a Recirculating Culture System.  

National Technical Information Service (NTIS)

Blue crab growth parameters were measured over a sixty-day period in a recirculating culture system, with each crab in physical isolation. Dependent variables were molt interval, increase in carapace width per molt, percent molt and mortality. No consista...

R. R. Winget C. E. Epifanio T. Runnels P. Austin

1976-01-01

124

Two-dimensional hydraulics of recirculating ground-water remediation wells in unconfined aquifers  

Microsoft Academic Search

A technique for remediating and protecting ground-water and drinking-water wells from contamination is presented. A ground-water remediation well design is proposed in which ground water is drawn into the well bottom, treated in the well casing, and returned clean to the aquifer at the well top. The hydraulics of ground-water circulation around imperfectly penetrating wells were examined experimentally in pilot-scale

W. M. Stallard; K. C. Wu; N. Shi; M. Yavuz Corapcioglu

1996-01-01

125

Evaluation of a recirculating pond system for rearing juvenile freshwater mussels at White Sulphur Springs National Fish Hatchery, West Virginia, U.S.A.  

USGS Publications Warehouse

A recirculating double-pond system at White Sulphur Springs National Fish Hatchery in West Virginia, U.S.A., was evaluated for suitability for culturing juvenile freshwater mussels. Newly metamorphosed juveniles of Villosa iris and Lampsilis fasciola were placed in the system, and their growth and survival were evaluated for 94 days. Throughout the study, parameters of water quality remained within ranges suitable for mussel survival. Planktonic algal densities in the pond system ranged from 2850 to 6892 cells/ml. Thirty-seven algal taxa were identified, primarily green algae (Chlorophyta), diatoms (Bacillariophyceae), and blue-green algae (Cyanoprokaryota). Over the culture period, juveniles of L. fasciola experienced significantly lower (p < 0.001) survival (6.3% ?? 4.5) than those of V. iris (49.8% ?? 14.5). The very low survival rate of L. fasciola may indicate a failure of the flow-through pond environment to meet its habitat requirements or that variable microhabitat conditions within culture containers existed. Growth did not differ significantly between the species (p = 0.13). Survival of V. iris and growth of both species were similar to previous trials to culture juvenile mussels. Survival rates as high as 66.4% at 93 days for V. iris suggest that juveniles of some riverine species can be successfully cultured in a recirculating pond environment.

Mummert, A.; Newcomb, T. J.; Neves, R. J.; Parker, B.

2006-01-01

126

Simultaneous water desalination and electricity generation in a microbial desalination cell with electrolyte recirculation for pH control.  

PubMed

A recirculation microbial desalination cell (rMDC) was designed and operated to allow recirculation of solutions between the anode and cathode chambers. This recirculation avoided pH imbalances that could inhibit bacterial metabolism. The maximum power density was 931±29mW/m(2) with a 50mM phosphate buffer solution (PBS) and 776±30mW/m(2) with 25mM PBS. These power densities were higher than those obtained without recirculation of 698±10mW/m(2) (50mM PBS) and 508±11mW/m(2) (25mM PBS). The salt solution (20g/L NaCl) was reduced in salinity by 34±1% (50mM) and 37±2% (25mM) with recirculation (rMDC), and by 39±1% (50mM) and 25±3% (25mM) without recirculation (MDC). These results show that electrolyte recirculation using an rMDC is an effective method to increase power and achieve efficient desalination by eliminating pH imbalances. PMID:22200556

Qu, Youpeng; Feng, Yujie; Wang, Xin; Liu, Jia; Lv, Jiangwei; He, Weihua; Logan, Bruce E

2011-11-25

127

In vitro comparison of the molecular adsorbent recirculation system (MARS) and single-pass albumin dialysis (SPAD).  

PubMed

The detoxification capacities of single-pass albumin dialysis (SPAD), the molecular adsorbents recirculation system, (MARS) and continuous veno-venous hemodiafiltration (CVVHDF) were compared in vitro. In each experiment 4,100 mL of toxin-loaded human plasma was processed for 6.5 hours. MARS treatment (n = 6) was undertaken in combination with CVVHDF. For SPAD (n = 6) and CVVHDF (n = 6) a high-flux hollow fiber hemodiafilter (identical to the MARS filter) was used. Levels of ammonia, urea, creatinine, bilirubin, and bile acids were determined. Concentrations before and after application of detoxification procedures were expressed as differences and were compared using the Kruskal-Wallis test. Post hoc comparisons for pairs of groups were adjusted according to Bonferroni-Holm. Time, group, and interaction effects were tested using the nonparametric ANOVA model for repeated measurements. SPAD and CVVHDF induced a significantly greater reduction of ammonia levels than MARS. No significant differences were found among SPAD, MARS, and CVVHDF with respect to other water-soluble substances. SPAD induced a significantly greater reduction in bilirubin levels than MARS. Reductions in bile acid levels were similar for SPAD and MARS. When operating MARS in continuous veno-venous hemodialysis mode, as recommended by the manufacturer, no significant differences in the removal of bilirubin, bile acids, urea, and creatinine were found. However, MARS in continuous veno-venous hemodialysis mode was significantly less efficient in removing ammonia than MARS in CVVHDF mode. In conclusion, the detoxification capacity of SPAD is similar to or even greater than that of MARS. PMID:15122770

Sauer, Igor M; Goetz, Max; Steffen, Ingo; Walter, Gesa; Kehr, Daniel C; Schwartlander, Ruth; Hwang, Yoon J; Pascher, Andreas; Gerlach, Joerg C; Neuhaus, Peter

2004-05-01

128

Molecular Adsorbent Recirculating System (MARS(®)) removal of piperacillin/tazobactam in a patient with acetaminophen-induced acute liver failure.  

PubMed

The objective of this study was to illustrate the pharmacokinetic removal of piperacillin/tazobactam in an anuric patient on Molecular Adsorbent Recirculating System (MARS(®)). The patient was a 32-year-old woman who presented to a medical intensive care unit with acute liver failure secondary to an acetaminophen overdose. While awaiting transplant, she was started on MARS therapy as a bridge to liver transplant and empirically started on piperacillin/tazobactam therapy. MARS is an extracorporeal hemofiltration device, which incorporates a continuous venovenous hemofiltration (CVVHD) machine linked to an albumin-enriched dialysate filter to normalize excess electrolytes, metabolic waste, and protein-bound toxins. In addition to protein-bound waste, MARS removes water-soluble, low molecular-weight molecules. The patient received piperacillin/tazobactam 4.5 g infused intravenously over 3 h. A steep decline in serum levels occurred between hours 4 and 6 while MARS continued and no antibiotic was infused. The elimination rate constant (k(e)) for the removal of piperacillin in this patent was 0.453 h(-1) and the half-life (?) was 1.53 h. The k(e) was 2.9-fold higher than with CVVHD alone and the ? was 3.7-fold shorter. Low levels of piperacillin are achieved during MARS therapy, but in the treatment of more resistant organisms, such as Pseudomonas aeruginosa, these low levels may not be adequate to achieve bactericidal activity. Drug levels following a standard infusion of 30 min would likely be even lower. Formalized pharmacokinetic studies of piperacillin/tazobactam removal in patients on MARS therapy are necessary to make clear dosing recommendations. PMID:23279615

Ruggero, M A; Argento, A C; Heavner, M S; Topal, J E

2012-12-28

129

Water Quality Monitoring in a Pilot Marine Integrated Aquaculture System  

Microsoft Academic Search

Land based aquaculture systems are growing in popularity, and there is a drive to improve the efficiency of their energy and water systems for both economic and environmental benefit. Recirculating Aquaculture Systems (RAS) generally refer to systems that recycle their wastewater streams to be more or less a zero discharge facility. A more sustainable approach is emerging in the form

Alex W. Kruglick

2012-01-01

130

Preoperational test report, raw water system  

SciTech Connect

This represents the preoperational test report for the Raw Water System, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system supplies makeup water to the W-030 recirculation evaporative cooling towers for tanks AY1O1, AY102, AZ1O1, AZ102. The Raw Water pipe riser and associated strainer and valving is located in the W-030 diesel generator building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

Clifton, F.T.

1997-10-29

131

Anaerobic Ammonium-Oxidizing (Anammox) Bacteria and Associated Activity in Fixed-Film Biofilters of a Marine Recirculating Aquaculture System  

PubMed Central

Microbial communities in the biological filter and waste sludge compartments of a marine recirculating aquaculture system were examined to determine the presence and activity of anaerobic ammonium-oxidizing (anammox) bacteria. Community DNA was extracted from aerobic and anaerobic fixed-film biofilters and the anaerobic sludge waste collection tank and was analyzed by amplifying 16S rRNA genes by PCR using anammox-selective and universal GC-clamped primers. Separation of amplified PCR products by denaturing gradient gel electrophoresis and sequencing of the different phylotypes revealed a diverse biofilter microbial community. While Planctomycetales were found in all three communities, the anaerobic denitrifying biofilters contained one clone that exhibited high levels of sequence similarity to known anammox bacteria. Fluorescence in situ hybridization studies using an anammox-specific probe confirmed the presence of anammox Planctomycetales in the microbial biofilm from the denitrifying biofilters, and anammox activity was observed in these biofilters, as detected by the ability to simultaneously consume ammonia and nitrite. To our knowledge, this is the first identification of anammox-related sequences in a marine recirculating aquaculture filtration system, and our findings provide a foundation for incorporating this important pathway for complete nitrogen removal in such systems.

Tal, Yossi; Watts, Joy E. M.; Schreier, Harold J.

2006-01-01

132

Improving hollow fiber dialyzer efficiency with a recirculating dialysate system II: comparison against two-chamber dialysis systems.  

PubMed

The theoretical basis of the nonregenerated recirculating dialysate system (RDS) was derived in Part I of this work [M. Prado, L. M. Roa, A. Palma, and J. A. Milán, Ann. Biomed. Eng. (2005)]. This system pursues the maximization of the clearance of hollow fiber dialyzers whose performance is controlled by diffusion, as occurred in standard hemodialysis. In this second part we perform a comparison by digital simulation of the RDS against three well-known two-chamber dialysis systems. As a major outcome, the efficiency of the RDS increased by a factor of five-eight with respect to the efficiency of a single dialyzer operating with a number of transfer units equal to 0.1, that is when the diffusive mass-transfer of the dialyzer is exhausted. Present low-flux dialyzers do not take advantage of the full potential of this technique, but the functional domain where high-flux and high-area dialyzers operate could be more suitable to exploit this technique. We conclude that RDS can be a competitive efficient technique for optimizing the dialysis efficiency. PMID:16341926

Prado, Manuel; Roa, Laura M; Palma, Alfonso; Milán, José A

2005-11-01

133

Dynamics of microorganism populations in recirculating nutrient solutions  

Microsoft Academic Search

This overview covers the basic microbial ecology of recirculating hydroponic solutions. Examples from NASA and Soviet CELSS tests and the commercial hydroponic industry will be used. The sources of microorganisms in nutrient solutions include air, water, seeds, plant containers and plumbing, biological vectors, and personnel. Microbial fates include growth, death, and emigration. Important microbial habitats within nutrient delivery systems are

R. F. Strayer

1994-01-01

134

A Recirculating Sea Water Benthic Chamber for the Study of the Biogeochemistry of Petroleum Components at the Sediment Water Interface.  

National Technical Information Service (NTIS)

The experimental benthic chamber was designed to conduct both laboratory and in situ investigations on the transport and degradation of petroleum type hydrocarbons at the sediment water interface, and to investigate the sediment/water/organism interaction...

C. L. Winget

1978-01-01

135

Blood chemistry of healthy, nephrocalcinosis-affected and ozone-treated tilapia in a recirculation system, with application of discriminant analysis  

Microsoft Academic Search

Blood chemistry parameters of Nile tilapia (pure strain Oreochromis niloticus) raised in a recirculation system were studied. Plasma samples were collected from 30 healthy tilapia every 3 months during a 1-year period. An additional 30 tilapia affected with nephrocalcinosis, and 30 fish from a system treated with ozone were also examined. Significant differences among healthy groups were observed in all

Chun-Yao Chen; Gregory A Wooster; Rodman G Getchell; Paul R Bowser; Michael B Timmons

2003-01-01

136

Control of a turbocharged Diesel engine fitted with high pressure and low pressure exhaust gas recirculation systems  

Microsoft Academic Search

Exhaust gas recirculation is an effective way for reducing nitric oxides emissions in Diesel engine achieving low temperature combustion (LTC). Two strategies can be applied to recirculate burnt gas in a turbocharged Diesel engine using the high pressure loop or the low pressure loop. This paper describes a generic model based control structure for Diesel engines with dual-loop exhaust gas

Olivier Grondin; Philippe Moulin; Jonathan Chauvin

2009-01-01

137

Efficient random subcloning of DNA sheared in a recirculating point-sink flow system.  

PubMed Central

Based on a high-performance liquid chromatographic pump, we have built a device that allows recirculation of DNA through a 63-microm orifice with ensuing fractionation to a minimum fragment size of approximately 300 base pairs. Residence time of the DNA fragments in the converging flow created by a sudden contraction was found to be sufficiently long to allow extension of the DNA molecules into a highly extended conformation and, hence, breakage to occur at midpoint. In most instances, 30 passages sufficed to obtain a narrow size distribution, with >90% of the fragments lying within a 2-fold size distribution. The shear rate required to achieve breakage was found to be inversely proportional to the 1.0 power of the molecular weight. Compared with a restriction digest, up to 40% of all fragments could be cloned directly, with only marginal improvements in cloning efficiency having been observed upon prior end repair with Klenow, T4 polymerase or T4 polynucleotide kinase. Sequencing revealed a fairly random distribution of the fragments.

Oefner, P J; Hunicke-Smith, S P; Chiang, L; Dietrich, F; Mulligan, J; Davis, R W

1996-01-01

138

SET UP AND OPERATION OF A RECIRCULATING WETTED RIGID MEDIA EVAPORATIVE COOLER INSTALLED IN A GAS TURBINE COMBUSTION INLET AIR SYSTEM  

Microsoft Academic Search

A procedure for setting up and operating a recirculating evaporative cooler installed in the combustion air inlet system of a gas turbine is described. The procedure includes a recommendation for selecting the ambient operating wet and dry bulb temperatures. A description of the parameters used in the procedure and calculation methods are shown. In response to frequent inquiries about the

R. S. Johnson

139

Comparative performance of CO2 measuring methods: marine aquaculture recirculation system application  

USGS Publications Warehouse

Many methods are available for the measurement of dissolved carbon dioxide in an aqueous environment. Standard titration is the typical field method for measuring dissolved CO2 in aquaculture systems. However, titrimetric determination of dissolved CO2 in marine water aquaculture systems is unsuitable because of the high dissolved solids, silicates, and other dissolved minerals that interfere with the determination. Other methods used to measure dissolved carbon dioxide in an aquaculture water included use of a wetted CO2 probe analyzer, standard nomographic methods, and calculation by direct measurements of the water's pH, temperature, and alkalinity. The determination of dissolved CO2 in saltwater based on partial pressure measurements and non-dispersive infra-red (NDIR) techniques with a CO2 gas analyzer are widely employed for oceanic surveys of surface ocean CO2 flux and are similar to the techniques employed with the head space unit (HSU) in this study. Dissolved carbon dioxide (DC) determination with the HSU using a infra-red gas analyzer (IRGA) was compared with titrimetric, nomographic, calculated, and probe measurements of CO2 in freshwater and in saltwater with a salinity ranging from 5.0 to 30 ppt, and a CO2 range from 8 to 50 mg/L. Differences in CO2 measurements between duplicate HSUs (0.1–0.2 mg/L) were not statistically significant different. The coefficient of variation for the HSU readings averaged 1.85% which was better than the CO2 probe (4.09%) and that for the titrimetric method (5.84%). In all low, medium and high salinity level trials HSU precision was good, averaging 3.39%. Differences existed between comparison testing of the CO2 probe and HSU measurements with the CO2 probe readings, on average, providing DC estimates that were higher than HSU estimates. Differences between HSU and titration based estimates of DC increased with salinity and reached a maximum at 32.2 ppt. These differences were statistically significant (P < 0.05) at all salinity levels greater than 0.3 ppt. Results indicated reliable replicated results from the head space unit with varying salinity and dissolved carbon dioxide concentrations.

Pfeiffer, T. J.; Summerfelt, S. T.; Watten, B. J.

2011-01-01

140

Molecular adsorbent recirculating system is ineffective in the management of type 1 hepatorenal syndrome in patients with cirrhosis with ascites who have failed vasoconstrictor treatment  

Microsoft Academic Search

BackgroundThe pathogenetic mechanism of hepatorenal syndrome (HRS) is paradoxical renal vasoconstriction consequent upon systemic and splanchnic arterial vasodilatation. Molecular adsorbent recirculating system (MARS) is a specialised form of dialysis that clears albumin-bound substances, including vasodilators, and therefore can potentially reduce systemic vasodilatation in cirrhosis.ObjectiveTo assess the efficacy of MARS in improving systemic and renal haemodynamics in patients with cirrhosis with

Florence Wong; Nilima Raina; Robert Richardson

2009-01-01

141

Isolation of Legionella pneumophila from water systems: methods and preliminary results  

Microsoft Academic Search

A preliminary survey of water systems in hospitals and hotels showed that Legionella pneumophila may be found in water storage and distribution systems as well as in the recirculating cooling water of air-conditioning plants. Altogether 42 isolates of L pneumophila were made from 31 establishments, six of which were associated with cases of legionnaires' disease but in 25 of which

J O Tobin; R A Swann; C L Bartlett

1981-01-01

142

Water Systems  

NSDL National Science Digital Library

Water cycle concepts and basics including the distribution of water on the planet in oceans, rivers and lakes, glaciers and atmosphere. Defines basic terms: states of water, evaporation, transpiration, condensation, precipitation, melting. Good illustrations, maps and photos. Excellent list itemizes human uses and impacts on water and the water cycle. Links to more detailed references are provided, case studies illustrate current concerns and issues in Ontario, Canada.

143

Fuel cell stack with an integral ejector for reactant gas recirculation  

Microsoft Academic Search

A stack of fuel cells operating on gaseous reactants includes an ejector in integral heat exchange relationship with the stack for recirculating one of the reactant gases through the cells of the stack. The recirculating reactant is continuously heated by waste heat from the cells as it recirculates thereby preventing condensation of water from the recirculating reactant gas and thereby

Grasso

1976-01-01

144

Recirculating Electron Beam Linac.  

National Technical Information Service (NTIS)

One method to achieve a high gradient, linear induction accelerator is to recirculate the electron beam in phase with a repeating accelerating voltage. A two-cavity recirculating accelerator has been designed and operated in a single-pass mode. The protot...

W. K. Tucker S. L. Shope D. E. Hasti

1987-01-01

145

Evaluation of a Revolving Plate Type Biofilter for Use in Recirculated Fish Production and Holding Units  

Microsoft Academic Search

Based on information gained from a pilot model, two identical revolving plate filters were designed to be evaluated for use in a recirculated fish production system. Each unit consisted of a fiberglass tank containing 787 liters of water; a biofilter having 60 plates, each 51 cm in diameter, rotated at 6 rpm; and a settling tank. The total water volume

William M. Lewis; Gerard L. Buynak

1976-01-01

146

The structure and function of microbial communities in recirculating hydroponic systems  

NASA Astrophysics Data System (ADS)

Strategies to control the microbial community associated with plant growth systems need to be based on a fundamental understanding of the factors which structure and regulate the community. Spatial and temporal patterns in the abundance and production rate of microorganisms in hydroponic systems containing wheat were examined to evaluate how root-derived carbon is processed. The relevance of results to monitoring and control strategies is discussed.

Garland, J. L.

1994-11-01

147

Recirculating rotary gas compressor  

DOEpatents

A positive displacement, recirculating Roots-type rotary gas compressor which operates on the basis of flow work compression. The compressor includes a pair of large diameter recirculation conduits (24 and 26) which return compressed discharge gas to the compressor housing (14), where it is mixed with low pressure inlet gas, thereby minimizing adiabatic heating of the gas. The compressor includes a pair of involutely lobed impellers (10 and 12) and an associated port configuration which together result in uninterrupted flow of recirculation gas. The large diameter recirculation conduits equalize gas flow velocities within the compressor and minimize gas flow losses. The compressor is particularly suited to applications requiring sustained operation at higher gas compression ratios than have previously been feasible with rotary pumps, and is particularly applicable to refrigeration or other applications requiring condensation of a vapor.

Weinbrecht, John F. (601 Oakwood Loop, NE., Albuquerque, NM 87123)

1992-01-01

148

Recirculating rotary gas compressor  

DOEpatents

A positive displacement, recirculating Roots-type rotary gas compressor is described which operates on the basis of flow work compression. The compressor includes a pair of large diameter recirculation conduits which return compressed discharge gas to the compressor housing, where it is mixed with low pressure inlet gas, thereby minimizing adiabatic heating of the gas. The compressor includes a pair of involutely lobed impellers and an associated port configuration which together result in uninterrupted flow of recirculation gas. The large diameter recirculation conduits equalize gas flow velocities within the compressor and minimize gas flow losses. The compressor is particularly suited to applications requiring sustained operation at higher gas compression ratios than have previously been feasible with rotary pumps, and is particularly applicable to refrigeration or other applications requiring condensation of a vapor. 12 figs.

Weinbrecht, J.F.

1992-02-25

149

Effects of non-uniform root zone salinity on water use, Na+ recirculation, and Na+ and H+ flux in cotton  

PubMed Central

A new split-root system was established through grafting to study cotton response to non-uniform salinity. Each root half was treated with either uniform (100/100?mM) or non-uniform NaCl concentrations (0/200 and 50/150?mM). In contrast to uniform control, non-uniform salinity treatment improved plant growth and water use, with more water absorbed from the non- and low salinity side. Non-uniform treatments decreased Na+ concentrations in leaves. The [Na+] in the ‘0’ side roots of the 0/200 treatment was significantly higher than that in either side of the 0/0 control, but greatly decreased when the ‘0’ side phloem was girdled, suggesting that the increased [Na+] in the ‘0’ side roots was possibly due to transportation of foliar Na+ to roots through phloem. Plants under non-uniform salinity extruded more Na+ from the root than those under uniform salinity. Root Na+ efflux in the low salinity side was greatly enhanced by the higher salinity side. NaCl-induced Na+ efflux and H+ influx were inhibited by amiloride and sodium orthovanadate, suggesting that root Na+ extrusion was probably due to active Na+/H+ antiport across the plasma membrane. Improved plant growth under non-uniform salinity was thus attributed to increased water use, reduced leaf Na+ concentration, transport of excessive foliar Na+ to the low salinity side, and enhanced Na+ efflux from the low salinity root.

Kong, Xiangqiang; Luo, Zhen; Dong, Hezhong; Eneji, A. Egrinya

2012-01-01

150

Systems and methods for reactive distillation with recirculation of light components  

DOEpatents

Systems and methods for producing gas-to-liquids products using reactive distillation are provided. The method for producing gas-to-liquids products can include reacting a feedstock in a column having a distillation zone and a reaction zone to provide a bottoms stream and an overhead stream. A first portion of the overhead stream can be recycled to the column at the top of the reaction zone and second portion of the overhead stream can be recycled to the column at the bottom of the reaction zone.

Stickney, Michael J. (Nassau Bay, TX); Jones, Jr., Edward M. (Friendswood, TX)

2011-07-26

151

Addition of Molecular Adsorbent Recirculating System (MARS®) Albumin Dialysis for the Preoperative Management of Jaundiced Patients with Hilar Cholangiocarcinoma  

PubMed Central

The preoperative management of hilar cholangiocarcinoma (HC) with jaundice focuses on decreasing the total serum bilirubin level (SBL) by performing preoperative biliary drainage (PBD). However, it takes about 6–8 weeks for the SBL to fall at a sufficient extent. The objective of this preliminary study was to evaluate the impact of Molecular Adsorbent Recirculating System (MARS®) dialysis (in association with PBD) on SBL decrease. From January 2010 to January 2011, we prospectively selected all jaundiced patients admitted to our university hospital for resectable HC and requiring PBD prior to major hepatectomy. The PBD was followed by 3 sessions of MARS dialysis over a period of 72 h. A total of 10 patients with HC were screened and two of them were included (Bismuth-Corlette stage IIIa, gender ratio 1, median age 68 years). The initial SBL in the two patients was 328 and 242 ?mol/l, respectively. After three MARS dialysis sessions, the SBL had fallen by 30 and 52%, respectively. After the end of each session, there was a SBL rebound of about 10 ?mol/l. The MARS decreased the serum creatinine level, the platelet count and the prothrombin index, but did not modify the serum albumin level. Pruritus disappeared after one and two sessions, respectively. MARS-related morbidity included hypotension (n = 1), tachycardia (n = 1), thrombocytopenia (n = 2) and anaemia (n = 1). When combined with PBD, MARS dialysis appears to accelerate the decrease in SBL and thus may enable earlier surgery. This hypothesis must be validated in a larger study.

Regimbeau, Jean-Marc; Fuks, David; Chapuis-Roux, Emilie; Yzet, Thierry; Cosse, Cyril; Bartoli, Eric; N'Guyen-Khac, Eric; Robert, Brice; Lobjoie, Eric

2013-01-01

152

Addition of Molecular Adsorbent Recirculating System (MARS(®)) Albumin Dialysis for the Preoperative Management of Jaundiced Patients with Hilar Cholangiocarcinoma.  

PubMed

The preoperative management of hilar cholangiocarcinoma (HC) with jaundice focuses on decreasing the total serum bilirubin level (SBL) by performing preoperative biliary drainage (PBD). However, it takes about 6-8 weeks for the SBL to fall at a sufficient extent. The objective of this preliminary study was to evaluate the impact of Molecular Adsorbent Recirculating System (MARS(®)) dialysis (in association with PBD) on SBL decrease. From January 2010 to January 2011, we prospectively selected all jaundiced patients admitted to our university hospital for resectable HC and requiring PBD prior to major hepatectomy. The PBD was followed by 3 sessions of MARS dialysis over a period of 72 h. A total of 10 patients with HC were screened and two of them were included (Bismuth-Corlette stage IIIa, gender ratio 1, median age 68 years). The initial SBL in the two patients was 328 and 242 ?mol/l, respectively. After three MARS dialysis sessions, the SBL had fallen by 30 and 52%, respectively. After the end of each session, there was a SBL rebound of about 10 ?mol/l. The MARS decreased the serum creatinine level, the platelet count and the prothrombin index, but did not modify the serum albumin level. Pruritus disappeared after one and two sessions, respectively. MARS-related morbidity included hypotension (n = 1), tachycardia (n = 1), thrombocytopenia (n = 2) and anaemia (n = 1). When combined with PBD, MARS dialysis appears to accelerate the decrease in SBL and thus may enable earlier surgery. This hypothesis must be validated in a larger study. PMID:24163652

Regimbeau, Jean-Marc; Fuks, David; Chapuis-Roux, Emilie; Yzet, Thierry; Cosse, Cyril; Bartoli, Eric; N'guyen-Khac, Eric; Robert, Brice; Lobjoie, Eric

2013-09-10

153

Containment system for supercritical water oxidation reactor  

DOEpatents

A system is described for containment of a supercritical water oxidation reactor in the event of a rupture of the reactor. The system includes a containment for housing the reaction vessel and a communicating chamber for holding a volume of coolant, such as water. The coolant is recirculated and sprayed to entrain and cool any reactants that might have escaped from the reaction vessel. Baffles at the entrance to the chamber prevent the sprayed coolant from contacting the reaction vessel. An impact-absorbing layer is positioned between the vessel and the containment to at least partially absorb momentum of any fragments propelled by the rupturing vessel. Remote, quick-disconnecting fittings exterior to the containment, in cooperation with shut-off valves, enable the vessel to be isolated and the system safely taken off-line. Normally-closed orifices throughout the containment and chamber enable decontamination of interior surfaces when necessary. 2 figures.

Chastagner, P.

1994-07-05

154

Thermal and bifurcation characteristics of heat-recirculating conversion of gaseous fuels  

NASA Astrophysics Data System (ADS)

The paper investigates the possibility of utilisation of heat-recirculating systems for fuel conversions having low net thermal effect. The experimental part is conducted with an electrically heated heat exchanger. It is shown that heat-recirculating systems can operate under superadiabatic conditions. Their thermal characteristics are provided by means of the dependencies of heat recirculation ratio on process parameters. Further, the heat-recirculating catalytic combustion system is characterised via combustion bifurcation diagrams. The similarities and differences of both those heat-recirculating systems are qualitatively compared and explained. Bifurcation characteristics proves to be useful tools in concise description of practical complex heat-recirculating fuel conversion systems in energy generation.

Budzianowski, Wojciech

2010-07-01

155

Rescue of a marginal liver graft by sequential treatment with molecular adsorbent recirculating system and transjugular intrahepatic portosystemic shunt: a case report.  

PubMed

A 53-year-old man with alcoholic liver cirrhosis underwent orthotopic liver transplantation (OLT) using a marginal graft. Persistent cholestasis post-OLT was successfully treated using a molecular adsorbent recirculating system (MARS). Afterwards, the patient developed refractory ascites, which was controlled by a transjugular intrahepatic portosystemic shunt (TIPS). TIPS reduction and eventually occlusion was necessary due to the development of encephalopathy. Despite TIPS occlusion, the ascites did not relapse probably because of the onset of other adaptive mechanisms. MARS and TIPS used sequentially were capable of rescuing a liver graft, thereby avoiding the morbidity and mortality associated with early retransplantation and sparing a liver graft from the donor pool. PMID:19857762

Darius, T; Monbaliu, D; Aerts, R; Laleman, W; Roskams, T; Van Steenbergen, W; Cassiman, D; Verslype, C; Maleux, G; Nevens, F; Pirenne, J

2009-10-01

156

Energy conservation by partial recirculation of peanut drying air  

SciTech Connect

Conventional, recirculating, and intermittent type peanut dryers were compared in a three-year study. Comparisons indicate that partial recirculation of peanut drying air may reduce energy consumption per unit of water removed by approximately 25% while also reducing required drying time and maintaining high quality.

Young, J.H.

1983-06-01

157

Exhaust gas recirculation apparatus  

Microsoft Academic Search

Apparatus is disclosed for recirculating combustion exhaust gases to the burner region of a Stirling cycle hot-gas engine to lower combustion temperature and reduct NO\\/sub x\\/ formation includes a first wall separating the exhaust gas stream from the inlet air stream, a second wall separating the exhaust gas stream from the burner region, and low flow resistance ejectors formed in

R. A. Egnell; B. L. Hansson

1981-01-01

158

Biodiversity of N-cycle bacteria in nitrogen removing moving bed biofilters for freshwater recirculating aquaculture systems  

Microsoft Academic Search

Maintenance of optimal water quality and removal of nitrogen compounds pose challenges to aquaculture worldwide. Presence and activity of different bacteria involved in nitrogen cycling in the biofilm of a moving bed biofilm reactor (MBBR) connected to a Koi carp tank were investigated experimentally. For this MBBR system, a nitrogen removing rate of 3.5g nitrogen per day was found in

Maartje A. H. J. van Kessel; Harry R. Harhangi; Katinka van de Pas-Schoonen; J. L. C. M. van de Vossenberg; Gert Flik; Mike S. M. Jetten; Peter H. M. Klaren

2010-01-01

159

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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 ...

160

Iodine and selenium supplementation increased survival and changed thyroid hormone status in Senegalese sole (Solea senegalensis) larvae reared in a recirculation system.  

PubMed

To test how iodine and both iodine and selenium supplementation affected the thyroid status as well as growth and survival in Senegalese sole, larvae were reared in a recirculation system from 15 to 34 DAH. Sets of three tanks were assigned to each of the following three diets: control (C), iodine (I) and iodine and selenium (I + Se). Samples were collected at 15, 27 and 34 DAH to determine dry weight, iodine and selenium levels, GPx and ORD activities, thyroid hormone levels and thyroid follicles histology. At 34 DAH, fish from the control (C) treatment suffered from hyperplasia of the thyroid follicles (goitre), whereas iodine-treated larvae did not (I and I + Se). Lower survival rates in the C groups were probably a consequence of the hyperplasia. Moreover, there was an improvement in thyroid hormone status in I- and I + Se-treated larvae, showing that further supplementation of live feed with iodine can be crucial for fish at early life stages, as it seems to sustain normal larval development, when reared in a recirculation system. Selenium did not affect the results. Together with previous results, this indicates selenium supplement is more important at younger life stages. PMID:21932022

Ribeiro, A R A; Ribeiro, L; Sæle, O; Dinis, M T; Moren, M

2011-09-20

161

Toluene removal in membrane bioreactors under recirculating and non-recirculating liquid conditions  

Microsoft Academic Search

A single-, dual- and multiple-tube dense phase silicone rubber membrane bioreactor were investigated for control of toluene-contaminated\\u000a air under circulating and non-recirculating liquid conditions. A mathematical model was developed to describe the system.\\u000a The reactors were seeded with a mixed bacterial consortium isolated from activated sludge and capable of aromatic biodegradation.\\u000a After operating with recirculating liquid nutrient solution, the reactors

Ellen England; Mark W. Fitch; Melanie Mormile; Michael Roberts

2005-01-01

162

Geothermal hot water system  

SciTech Connect

Geothermal hot water system including a hot water tank and a warm water tank which are heated independently of each other by a close loop freon system. The closed loop freon system includes a main condenser which heats water for the warm water tank and a super-heated condenser which heats water for the hot water tank, and where the freon passes through a water evaporator which is heated by water such as from a well or other suitable source. The water evaporator in the closed loop freon system passes the water through but no environmental change to the water. An electrical circuit including aquastats in the warm water tank connected therethrough controls operation of the closed loop freon system including respective pumps on the super-heated condenser and main condenser for pumping water. Pumps pump water through the main condenser for the warm tank and through the super-heated condenser for the hot tank. The system provides for energy conservation in that the head pressure of the compressor is kept in the lower operating ranges as determined by the discharge flow of the main condenser which varies by the head pressure and temperature flow control which varies by temperature. The geothermal hot water system uses a least amount of energy in heating the water in the hot tank as well as the warm tank.

Dittell, E.W.

1983-05-10

163

Household hot water systems  

Microsoft Academic Search

An arrangement for combination with the conventional hot water system of a house or building in which the water is conventionally heated and stored in a tank, the arrangement comprising a solar energy panel (at an upper level) with a thermostatic valve and a supplementary cold water tank, connected into the system in such a way that hot water is

Tacchi

1983-01-01

164

Sulfide-induced nitrate reduction in the sludge of an anaerobic digester of a zero-discharge recirculating mariculture system  

Microsoft Academic Search

The anaerobic digester is a vital component in a zero-discharge mariculture system as therein most of the organic matter is mineralized and nitrogen-containing compounds are converted to gaseous N2. Although denitrification is a major respiratory process in this nitrate-rich treatment stage, also sulfate respiration takes place and may cause undesirable high sulfide concentrations in the effluent water. To examine the

Yonatan Sher; Kenneth Schneider; Carsten U. Schwermer; Jaap van Rijn

2008-01-01

165

Vapor-liquid equilibria of the water + 1,3-propanediol and water + 1,3-propanediol + lithium bromide systems  

Microsoft Academic Search

Vapor-liquid equilibrium data of the water + 1,3-propanediol and water + 1,3-propanediol + lithium bromide systems were measured at 60, 160, 300, and 760 mmHg at temperatures ranging from 315 to 488 K. The apparatus used in this work is a modified still especially designed for the measurement of low-pressure VLE, in which both liquid and vapor are continuously recirculated.

S. Y. Mun; Huen Lee

1999-01-01

166

A volumetric lysimeter system (VLS): an alternative to weighing lysimeters for plant–water relations studies  

Microsoft Academic Search

A closed, recirculating volumetric lysimeter system (VLS) consisting of 24 experimental plant growth units was constructed. The VLS measured irrigation and drainage volumes with pressure transducer trace analysis of irrigation reservoir\\/sump water elevation. To estimate crop evapotranspiration (ET), changes in soil moisture storage in the plant growth boxes were obtained with neutron probe measurements and were combined with the transducer

J. A. Poss; W. B. Russell; P. J. Shouse; R. S. Austin; S. R. Grattan; C. M. Grieve; J. H. Lieth; L. Zeng

2004-01-01

167

THE BMI16 RECIRCULATING GAS LOOP INSTALLED AT THE ETR  

Microsoft Academic Search

A developmental program was conducted to provide and in-pile loop ; facility for use in evaluating gas-cooledreactor fuel asubassemblies. The ; program included the design, construction, and installation of a recirculating ; gas loop which is located in a 6 by 6-in. facility in the aluminum reflector of ; the ETR. The loop system was designed to recirculate the primary

J. V. Baum; G. A. Francis

1960-01-01

168

Leachate Recirculation Using Permeable Blankets in Engineered Landfills  

Microsoft Academic Search

Subsurface leachate recirculation or liquid injection methods for municipal solid waste MSW landfills are horizontal trenches, vertical wells, and permeable blankets. In this study, results of field-scale testing and numerical modeling of a recently developed subsurface leachate recirculation system called permeable blankets have been presented. In the field, at a MSW landfill located in Michigan, the travel of injected leachate

Mazen M. Haydar; Milind V. Khire

2007-01-01

169

Dynamics of Microorganism Populations in Recirculating Nutrient Solutions.  

National Technical Information Service (NTIS)

This overview covers the basic microbial ecology of recirculating hydroponic solutions. Examples from NASA and Soviet CELSS tests and the commercial hydroponic industry will be used. The sources of microorganisms in nutrient solutions include air, water, ...

R. F. Strayer

1994-01-01

170

The Role of Water Chemistry in Marine Aquarium Design: A Model System for a General Chemistry Class  

ERIC Educational Resources Information Center

Water chemistry is central to aquarium design, and it provides many potential applications for discussion in undergraduate chemistry and engineering courses. Marine aquaria and their life support systems feature many chemical processes. A life support system consists of the entire recirculation system, as well as the habitat tank and all ancillary…

Keaffaber, Jeffrey J.; Palma, Ramiro; Williams, Kathryn R.

2008-01-01

171

The Role of Water Chemistry in Marine Aquarium Design: A Model System for a General Chemistry Class  

ERIC Educational Resources Information Center

|Water chemistry is central to aquarium design, and it provides many potential applications for discussion in undergraduate chemistry and engineering courses. Marine aquaria and their life support systems feature many chemical processes. A life support system consists of the entire recirculation system, as well as the habitat tank and all…

Keaffaber, Jeffrey J.; Palma, Ramiro; Williams, Kathryn R.

2008-01-01

172

Water Purification Systems.  

National Technical Information Service (NTIS)

Clearwater Pool Technologies employs NASA-developed silver/copper ionization to purify turtle and dolphin tanks, cooling towers, spas, water recycling systems, etc. The pool purifier consists of a microcomputer to monitor water conditions, a pair of metal...

1994-01-01

173

Hydraulic study on recirculation loops using computational fluid dynamics (CFD). Design optimization and turbulence reduction  

Microsoft Academic Search

A full scope study of the recirculation system flow of a BWR6 nuclear plant is essential, to completing the characterisation and understanding the dynamics of the flow and specially the bistable flow in the recirculation loop.The finite element model serves to study the sensitivity of the design and to reduce turbulence at the connection between the recirculation pump impulsion piping

Carlos Julián Gavilán Moreno

2009-01-01

174

Closeout of IE Compliance Bulletin 86-03: Potential failure of multiple ECCS (Emergency Core Cooling System) pumps due to single failure of air-operated valve in minimum flow recirculation line  

Microsoft Academic Search

Documentation is provided in this report for the closeout of IE Compliance Bulletin 86-03 regarding the potential failure of multiple Emergency Core Cooling System (ECCS) pumps due to a single failure of an air-operated valve in a minimum flow recirculation line. Closeout is based on the implementation and verification of four actions required by the bulletin. Evaluation of utility responses

W. J. Foley; R. S. Dean; A. Hennick

1990-01-01

175

NGL recovery being hiked by natural-gasoline recirculation  

SciTech Connect

Construction will be completed later this year at two compression plants operated by Lagoven, S.A., to install natural-gasoline recirculation to improve NGL recovery. The project is the result of a study of condensate-stream recirculation and absorber operations at the compression plants Tia Juana 2 (PCTJ-2) and Tia Juana 3 (PCTJ-3), offshore Lake Maracaibo in western Venezuela. The PCTJ-2 and PCTJ-3 gas compression plants have two systems: gas compression and NGL extraction. Previous analysis of the NGL extraction and fractionation processes of Lagoven determined that there are two practical and attractive alternatives for the recirculation of the condensate streams in PCTJ-2 and 3: recirculation of natural gasoline from the Ule LPG plant; recirculation of a conditioned condensate from the de-ethanizer tower of each plant. Both alternatives are discussed. Also described are fractionation capacity, and modifications for adding absorption and fractionation.

Rivas M, M.; Bracho, J.L. [Lagoven S.A., Maracaibo (Venezuela); Murray, J.E. [Murray (James E.), Corpus Christi, TX (United States)

1997-07-07

176

Exhaust gas recirculation control valve  

Microsoft Academic Search

An exhaust gas recirculation control valve for preventing carbon and the like contained in the exhaust gas from attaching to the inner wall surface of exhaust gas paths, through which the exhaust gas from an engine of a motor car passes, thus decreasing the diameters of the paths with time. This exhaust gas recirculation control valve is provided in a

Masuda

1982-01-01

177

Recirculation-aeration: Bibliography for aquaculture. Bibliographies and literature of agriculture (Final)  

SciTech Connect

The bibliography includes literature citations through 1992 related to water recirculation and aeration in aquaculture. The focus is on filtration, aeration, and circulation techniques in various aquaculture situations.

Perschbacher, P.W.; Powell, R.V.; Freeman, D.W.; Lorio, W.J.; Hanfman, D.T.

1993-08-01

178

Airlift recirculation well test results -- Southern sector  

SciTech Connect

Chlorinated solvents used in the A and M-Areas at the Savannah River Site (SRS) from 1952--1982 have contaminated the groundwater under the site. A plume of groundwater contaminated with trichloroethylene (TCE) and perchloroethylene (PCE) in the Lost Lake aquifer is moving generally southward with the natural flow of groundwater. To comply with the requirements of the current SCDHEC Part B Permit, a series of wells is being installed to contain and treat the plume. Airlift Recirculation Wells (ARW) are a new and innovative technology with potential for more cost effective implementation than conventional pump and treat systems. Two Airlift Recirculation Wells have been installed and tested to quantify performance parameters needed to locate a line of these wells along the leading edge of the contaminant plume. The wells proved to be very sensitive to proper development, but after this requirement was met, performance was very good. The Zone of Capture has been estimated to be within a radius of 130--160 ft. around the wells. Thus a line of wells spaced at 250 ft. intervals could intercept the contaminant plume. At SSR-012, TCE was stripped from the groundwater at approximately 1.2 lb./day. The longer term effect of the recirculation wells upon the plume and the degree of recirculation within the aquifer itself will require additional data over a longer time period for an accurate review. Data collection is ongoing.

White, R.M.; Hiergesell, R.A.

1997-08-01

179

Water Table Control Systems  

Technology Transfer Automated Retrieval System (TEKTRAN)

Water table control systems for agricultural cropland are installed primarily to reduce or eliminate the effects of water related factors that limit crop production, and to control losses of applied agrochemicials in subsurface drainage discharge and surface runoff. System design objectives are to i...

180

Regeneration of granular activated carbon saturated with acetone and isopropyl alcohol via a recirculation process under H 2O 2\\/UV oxidation  

Microsoft Academic Search

This study examines a water-based system, coupling an adsorber and a photoreactor, for regeneration of granular activated carbon (GAC) saturated with acetone and isopropyl alcohol (IPA). Through water recirculation the regeneration reaction was operated in both intermittent and continuous ultraviolet illumination modes. With a periodic dosage of hydrogen peroxide not only was regeneration efficient but it was also catalyzed by

Richard S. Horng; I.-Chin Tseng

2008-01-01

181

Nitric Oxide Formation in Combustion Processes with Strong Recirculation.  

National Technical Information Service (NTIS)

The principal objective of the combustion experiments was to obtain information on the nitric oxide formation process in a continuous flow combustion system in which the flame is stabilized by recirculation. Specifically, the factors affecting nitric oxid...

C. T. Bowman L. S. Cohen M. N. Director

1973-01-01

182

Exhaust gas recirculation apparatus  

SciTech Connect

Apparatus is disclosed for recirculating combustion exhaust gases to the burner region of a Stirling cycle hot-gas engine to lower combustion temperature and reduct NO/sub x/ formation includes a first wall separating the exhaust gas stream from the inlet air stream, a second wall separating the exhaust gas stream from the burner region, and low flow resistance ejectors formed in the first and second walls for admitting the inlet air to the burner region and for entraining and mixing with the inlet air portion of the exhaust gas stream. In a preferred embodiment the ejectors are arranged around the periphery of a cylindrical burner region and oriented to admit the air/exhaust gas mixture tangentially to promote mixing. In another preferred embodiment a single annular ejector surrounds and feeds the air/exhaust gas mixture to a cylindrical burner region. The annular ejector includes an annular plate with radially-directed flow passages to provide an even distribution of the air/exhaust gas mixture to the burner region.

Egnell, R.A.; Hansson, B.L.

1981-07-14

183

Method for reducing water corrosivity in circulating water systems of petroleum refineries  

SciTech Connect

Under the conditions of recirculating water systems with mixed oxygen/hydrogen depolarization, the authors advise using nontoxic passivating inhibitors, among which the most promising are phosphorus containing reagents, particularly polyphosphates and their combinations with inorganic and organic additives, which give a high level of protection even at concentrations of 15-20 mg/liter. At the Odessa Petroleum Refinery, a combination of sodium nitrite and sodium tripolyphosphate (TPP) has made it possible to achieve more than 85% protection (St3 steel) with a total component concentration of 100-200 mg/liter, with practically no local corrosion in the system. TPP is especially promising when the change is made to industrial installations with closed water systems with combined treatment of water.

Sorochenko, V.F.; Kozlikovskii, Y.B.; Suprunchuk, V.I.

1986-05-01

184

Dogbone geometry for recirculating accelerators.  

National Technical Information Service (NTIS)

Most scenarios for accelerating muons require recirculating acceleration. A racetrack shape for the accelerator requires particles with lower energy in early passes to traverse almost the same length of arc as particles with the highest energy. This extra...

S. Berg Johnstone Summers

2001-01-01

185

Vapor–liquid–liquid equilibrium and vapor–liquid equilibrium for the quaternary system water–ethanol–cyclohexane–toluene and the ternary system water–cyclohexane–toluene. Isobaric experimental determination at 101.3 kPa  

Microsoft Academic Search

Experimental isobaric vapor–liquid–liquid and vapor–liquid equilibrium data for the ternary system water (1)–cyclohexane (2)–toluene (3) and the quaternary system water (1)–ethanol (2)–cyclohexane (3)–toluene (4) were measured at 101.3kPa. An all-glass, dynamic recirculating still equipped with an ultrasonic homogenizer was used to determine the VLLE. The results obtained show that the system does not present quaternary azeotropes. The point-by-point method by

Ana Pequenín; Juan Carlos Asensi; Vicente Gomis

2011-01-01

186

Optimal mixing in recirculation zones  

Microsoft Academic Search

Coarse-scale mixing in a recirculation zone is described with a simple vortex model. Time-dependent forcing is employed to change the vortex motion and mixing properties. An optimal mixing problem is defined in which the flux across the recirculation region shall be maximized under the side-constraints of bounded vortex motion and bounded actuation. Concepts of control theory and chaotic advection are

Bernd R. Noack; Igor Mezic; Gilead Tadmor; Andrzej Banaszuk

2004-01-01

187

Monitoring of Leachate Recirculation in a Bioreactor Using Electrical Resistivity  

NASA Astrophysics Data System (ADS)

The bioreactor is a concept of waste landfill management consisting in speeding up the biodegradation by optimizing the moisture content through leachate recirculation. Electrical resistivity tomography (ERT) is carried out with fast resistivity-meter (Syscal Pro, IRIS Instruments, developed in the framework of the research project CERBERE 01V0665-69, funded by the French Research Ministry) to monitor leachate recirculation. During a recirculation period waste moisture increases, so that electrical resistivity may decrease, but at the same time temperature and mineralization of both waste and leachate become intermixed. If waste temperature is much higher than leachate temperature electrical resistivity will not decrease as much as if the temperature difference was smaller. If leachate mineralization (i.e. leachate conductivity) is higher than that of wet waste in the landfill, electrical resistivity will tend to decrease. Otherwise for example after an addition of rain water into the leachate storage or in case of very wet waste, the resistivities of each medium (leachate and wet waste) can be almost the same, so that leachate mineralization will not have a great influence on waste resistivity. Resistivity measurements were performed during 85 minutes injection trials (with a discharge of 20 m3 h-1) where leachate was injected through a vertical borehole perforated between 1.85 and 4.15 m. Three first measurements are made during the injection (3, 30 and 60 minutes from the beginning of the injection) and the two other after the injection period (8 and 72 minutes after the end of the injection). Apparent and interpreted resistivity variations that occurred during injection trials, expressed as the relative differences (in %) between apparent, respectively interpreted, resistivity during injection and apparent, respectively interpreted, resistivity before injection (reference measurement) show the formation of a plume (a negative anomaly: resistivity decreases with increasing moisture content). The positive anomaly could be explained by an increasing of biogas proportion in waste porosity. For this experiment, leachate temperature is relatively cold (between 5 and 10° C, as the injection trials take place at the end of October), leachate conductivity is about 9200 ? S cm-1 (i.e. a resistivity of 1.1 ? m) and waste resistivity in the borehole region is about 80 ? m. This is a situation where the temperature difference between waste and leachate is large and the resistivity difference between waste and leachate is high. The resistivity variation is essentially due to waste moisture increase. ERT method allows leachate diffusion to be seen through the waste mass and the influence zone of the leachate recirculation system to be determined.

Grellier, S.; Bureau, N.; Robain, H.; Tabbagh, A.; Camerlynck, C.; Guerin, R.

2004-05-01

188

Operating experience of natural circulation core cooling in boiling water reactors  

Microsoft Academic Search

General Electric (GE) has proposed an advanced boiling water reactor, the Simplified Boiling Water Reactor (SBWR), which will utilize passive, gravity-driven safety systems for emergency core coolant injection. The SBWR design includes no recirculation loops or recirculation pumps. Therefore the SBWR will operate in a natural circulation (NC) mode at full power conditions. This design poses some concerns relative to

C. Kullberg; K. Jones; C. Heath

1993-01-01

189

Validation for a recirculation model.  

PubMed

Recent Clean Air Act regulations designed to reduce volatile organic compound (VOC) emissions have placed new restrictions on painting operations. Treating large volumes of air which contain dilute quantities of VOCs can be expensive. Recirculating some fraction of the air allows an operator to comply with environmental regulations at reduced cost. However, there is a potential impact on employee safety because indoor pollutants will inevitably increase when air is recirculated. A computer model was developed, written in Microsoft Excel 97, to predict compliance costs and indoor air concentration changes with respect to changes in the level of recirculation for a given facility. The model predicts indoor air concentrations based on product usage and mass balance equations. This article validates the recirculation model using data collected from a C-130 aircraft painting facility at Hill Air Force Base, Utah. Air sampling data and air control cost quotes from vendors were collected for the Hill AFB painting facility and compared to the model's predictions. The model's predictions for strontium chromate and isocyanate air concentrations were generally between the maximum and minimum air sampling points with a tendency to predict near the maximum sampling points. The model's capital cost predictions for a thermal VOC control device ranged from a 14 percent underestimate to a 50 percent overestimate of the average cost quotes. A sensitivity analysis of the variables is also included. The model is demonstrated to be a good evaluation tool in understanding the impact of recirculation. PMID:11318387

LaPuma, P T

2001-04-01

190

Automatic hot water recovery system  

Microsoft Academic Search

A heat recovery system recovers hot water to an insulated tank through reciprocally variable volume chambers which are biased to draw water from hot water lines when the pressure throughout the system is equalized. One-way valving means permits continuous water flow when desired through the hot water tank to the hot water outlet. In a specific embodiment, bias is effected

Haws

1985-01-01

191

Development of a Vertical Recirculation Well System for the A/M Area of the Savannah River Site  

SciTech Connect

The objective of this work is to examine and develop a remediation scenario to provide long term hydraulic control and remediation of the dissolved chlorinated solvent plume within the Western and Southern Sectors of the A/M Area. This scope includes the development and siting of a remediation system that will contain the 500 part per billion trichloroethylene isoconcentration contour within each sector.

Jackson, D.G. Jr. [Westinghouse Savannah River Company, AIKEN, SC (United States); Looney, B.B.

1996-09-13

192

Recirculating, suppressor T cells in transplantation tolerance  

PubMed Central

An adoptive transfer system was used to examine the capacity of cellular inocula from rats fully tolerant of Ag-B antigens to transfer tolerance to irradiated recipients. Permanent tolerance in these irradiated recipients involved specific suppression of the regenerating immune response. Cells obtained from tissues rich in recirculating lymphocytes were the most effective suppressors. Highly purified inocula of T cells from tolerant donors were potent suppressors in irradiated hosts, but were not capable of direct suppression of peripheral antigen-sensitive T cells.. The role of the thymus in maintaining the complement of recirculating suppressor T cells in tolerant animals was examined after adult thymectomy. Thymectomized tolerant rats did not reject their tolerated grafts, and the longevity of the suppression in tolerant rats was confirmed by showing that adoptive transfer of cells from thymectomized tolerant donors was effective in suppressing irradiated recipients up to 180 days after thymectomy. Cellular inocula from these donors appeared to lose their suppressor function marginally faster than they lost effector function (as measured by their capacity to mediate rejection of third party control grafts). Thymectomy made tolerant rats more vulnerable to the termination of tolerance by challenge with normal cells. Transplantation tolerance is maintained in adult rats by long-lived rapidly recirculating suppressor T cells. The target for the suppressor action of these cells is probably the precursor of alloantigen- sensitive lymphocytes, and the effect of suppression may be deletion or inactivation of the relevant clone of these cells.

1977-01-01

193

Identification of Bacteria Potentially Responsible for Oxic and Anoxic Sulfide Oxidation in Biofilters of a Recirculating Mariculture System  

Microsoft Academic Search

Bacteria presumably involved in oxygen- or nitrate-dependent sulfide oxidation in the biofilters of a recir- culating marine aquaculture system were identified using a new application of reverse transcription-PCR denaturing gradient gel electrophoresis (DGGE) analysis termed differential-transcription (DT)-DGGE. Bio- filter samples were incubated in various concentrations of sulfide or thiosulfate (0 to 5 mM) with either oxygen or nitrate as the

Eddie Cytryn; Jaap van Rijn; Andreas Schramm; Armin Gieseke; Dirk de Beer; Dror Minz

2005-01-01

194

Safety system consideration of a supercritical-water cooled fast reactor with simplified PSA  

Microsoft Academic Search

The probabilistic safety of the supercritical-water cooled fast reactor (SCFR) is evaluated with the simplified probabilistic safety assessment (PSA) methodology. SCFR has a once-through direct cycle where all feedwater flows through the core to the turbine at supercritical pressure. There are no recirculation loops in the once-through direct cycle system, which is the most important difference from the current light

J. H Lee; Y Oka; S Koshizuka

1999-01-01

195

Identification and origin of plant pathogenic microorganisms in recirculating nutrient solutions  

NASA Astrophysics Data System (ADS)

Avoidance of root-infecting microorganisms was originally considered one of the advantages of cultivation of crops in a soilless, recirculating nutrient solution. However, to date, four viral, three bacterial and 21 fungal pathogens have been identified as causal agents of root disease in hydroponically-grown crops. Root-infecting fungi, particularly those which produce a motile stage known as a zoospore, have been the primary pathogens associated with extensive crop losses. Documented sources of these root pathogens in hydroponic systems include peat, surface water such as rivers and streams, and insects. The severity of disease caused by these introduced root pathogens is primarily governed by the genetic susceptibility of each crop and the temperature of the recirculating nutrient solution.

Stanghellini, M. E.; Rasmussen, S. L.

1994-11-01

196

Some Loop Experiments in NRX Reactor to Study The Corrosion of Mild Steel by Flowing Water at 90 deg F  

Microsoft Academic Search

This work was undertaken to find the water conditions necessary for minimum corrosion in the mild steel thermal shield recirculating systems in NRX and NRU. This report contains the chemical and corrosion results obtained by operating three mild steel loops in which water at 85-95 deg F was recirculated through test sections located in J-rod positions in the NRX reactor.

Allison

1956-01-01

197

Dynamics of microorganism populations in recirculating nutrient solutions.  

PubMed

This overview covers the basic microbial ecology of recirculating hydroponic solutions. Examples from NASA and Soviet CELSS tests and the commercial hydroponic industry will be used. The sources of microorganisms in nutrient solutions include air, water, seeds, plant containers and plumbing, biological vectors, and personnel. Microbial fates include growth, death, and emigration. Important microbial habitats within nutrient delivery systems are root surfaces, hardware surfaces (biofilms), and solution suspension. Numbers of bacteria on root surfaces usually exceed those from the other habitats by several orders of magnitude. Gram negative bacteria dominate the microflora with fungal counts usually much lower. Trends typically show a decrease in counts with increasing time unless stressed plants increase root exudates. Important microbial activities include carbon mineralization and nitrogen transformations. Important detrimental interactions include competition with plants, and human and plant pathogenesis. PMID:11540206

Strayer, R F

1994-11-01

198

Recycling crop residues for use in recirculating hydroponic crop production.  

PubMed

As part of bioregenerative life support feasibility testing by NASA, crop residues are being used to resupply elemental nutrients to recirculating hydroponic crop production systems. Methods for recovering nutrients from crop residues have evolved from water soaking (leaching) to rapid aerobic bioreactor processing. Leaching residues recovered the majority of elements but it also recovered significant amounts of soluble organics. The high organic content of leachates was detrimental to plant growth. Aerobic bioreactor processing reduced the organic content ten-fold, which reduced or eliminated phytotoxic effects. Wheat and potato production studies were successful using effluents from reactors having with 8- to 1-day retention times. Aerobic bioreactor effluents supplied at least half of the crops elemental mass needs in these studies. Descriptions of leachate and effluent mineral content, biomass productivity, microbial activity, and nutrient budgets for potato and wheat are presented. PMID:11541570

Mackowiak, C L; Garland, J L; Sager, J C

1996-12-01

199

Dynamics of microorganism populations in recirculating nutrient solutions  

NASA Astrophysics Data System (ADS)

This overview covers the basic microbial ecology of recirculating hydroponic solutions. Examples from NASA and Soviet CELSS tests and the commercial hydroponic industry will be used. The sources of microorganisms in nutrient solutions include air, water, seeds, plant containers and plumbing, biological vectors, and personnel. Microbial fates include growth, death, and emigration. Important microbial habitats within nutrient delivery systems are root surfaces, hardware surfaces (biofilms), and solution suspension. Numbers of bacteria on root surfaces usually exceed those from the other habitats by several orders of magnitude. Gram negative bacteria dominate the microflora with fungal counts usually much lower. Trends typically show a decrease in counts with increasing time unless stressed plants increase root exudates. Important microbial activities include carbon mineralization and nitrogen transformations. Important detrimental interactions include competition with plants, and human and plant pathogenesis.

Strayer, R. F.

1994-11-01

200

Smart Water: Energy-Water Optimization in Drinking Water Systems  

EPA Science Inventory

This project aims to develop and commercialize a Smart Water Platform â?? Sensor-based Data-driven Energy-Water Optimization technology in drinking water systems. The key technological advances rely on cross-platform data acquisition and management system, model-based real-time sys...

201

Quaternary isobaric (vapor + liquid + liquid) equilibrium and (vapor + liquid) equilibrium for the system (water + ethanol + cyclohexane + heptane) at 101.3 kPa  

Microsoft Academic Search

Experimental isobaric (vapor+liquid+liquid) and (vapor+liquid) equilibrium data for the ternary system {water (1)+cyclohexane (2)+heptane (3)} and the quaternary system {water (1)+ethanol (2)+cyclohexane (3)+heptane (4)} were measured at 101.3kPa. An all-glass, dynamic recirculating still equipped with an ultrasonic homogenizer was used to determine the VLLE. The results obtained show that the system does not present quaternary azeotropes. The point-by-point method by

Ana Pequenín; Juan Carlos Asensi; Vicente Gomis

2011-01-01

202

Investigation of sludge re-circulating clarifiers design and optimization through numerical simulation.  

PubMed

In steam thermal power plants (TPP) with open re-circulating wet cooling towers, elimination of water hardness and suspended solids (SS) is performed in clarifiers. Most of these clarifiers are of high efficiency sludge re-circulating type (SRC) with capacity between 500-1,500 m3/hr. Improper design and/or mal-operation of clarifiers in TPPs results in working conditions below design capacity or production of soft water with improper quality (hardness and S.S.). This causes accumulation of deposits in heat exchangers, condenser tubes, cooling and service water pipes and boiler tubes as well as increasing the ionic load of water at the demineralizing system inlet. It also increases the amount of chemical consumptions and produces more liquid and solid waste. In this regard, a software program for optimal design and simulation of SRCs has been developed. Then design parameters of existing SRCs in four TPPs in Iran were used as inputs to developed software program and resulting technical specifications were compared with existing ones. In some cases improper design was the main cause of poor outlet water quality. In order to achieve proper efficiency, further investigations were made to obtain control parameters as well as design parameters for both mal-designed and/or mal-operated SRCs. PMID:14753549

Davari, S; Lichayee, M J

2003-01-01

203

Field evaluation of a horizontal well recirculation system for groundwater treatment: Field demonstration at X-701B Portsmouth Gaseous Diffusion Plant, Piketon, Ohio  

SciTech Connect

This report describes the field-scale demonstration performed as part of the project, In Situ Treatment of Mixed Contaminants in Groundwater. This project was a 3{1/2} year effort comprised of laboratory work performed at Oak Ridge National Laboratory and fieldwork performed at the US Department of Energy (DOE) Portsmouth Gaseous Diffusion Plant (PORTS). The overall goal of the project was to evaluate in situ treatment of groundwater using horizontal recirculation coupled with treatment modules. Specifically, horizontal recirculation was tested because of its application to thin, interbedded aquifer zones. Mixed contaminants were targeted because of their prominence at DOE sites and because they cannot be treated with conventional methods. The project involved several research elements, including treatment process evaluation, hydrodynamic flow and transport modeling, pilot testing at an uncontaminated site, and full-scale testing at a contaminated site. This report presents the results of the work at the contaminated site, X-701B at PORTS. Groundwater contamination at X-701B consists of trichloroethene (TCE) (concentrations up to 1800 mg/L) and technetium-998 (Tc{sup 99}) (activities up to 926 pCi/L).

Korte, N.; Muck, M.; Kearl, P.; Siegrist, R.; Schlosser, R.; Zutman, J. [Oak Ridge National Lab., TN (United States)] [Oak Ridge National Lab., TN (United States); Houk, T. [Lockheed Martin Energy Systems, Piketon, OH (United States). Portsmouth Gaseous Diffusion Plant] [Lockheed Martin Energy Systems, Piketon, OH (United States). Portsmouth Gaseous Diffusion Plant

1998-08-01

204

Classification of lymphocytes recirculating in the spleen.  

PubMed Central

After washing out remaining blood cells using cold perfusate, pig spleens were connected to a closed-circuit normothermic perfusion system. Recirculating lymphocytes migrated out and rapidly established an equilibrium with the splenic extravascular lymphoid tissues. Comparison of the subpopulations among these lymphocytes with those in the blood at time of removal of the spleen, showed the absence of Null cells and reduced numbers of weakly E-rosetting cells among splenic emigrants. The proportion of other B- and T-cell subpopulations were increased in a way which might be explained by non-recirculation of these two subpopulations. Autologous blood lymphocytes labelled with fluorescein isothiocyanate and introduced into spleen perfusions rapidly established equilibrium (approximately 15%-25%, well within 1 hr) and at the end of perfusion were concentrated in the marginal zones. The fluorescent lymphocytes remaining in the perfusate showed a marked enrichment of Null cells suggesting that these cells do not home to splenic extravascular lymphoid tissues in agreement with the hypothesis that Null cells are absent from splenic emigrants because they are nonrecirculating cells. Images Figure 1 Figure 2

Binns, R M; Pabst, R; Licence, S T

1981-01-01

205

Classification of lymphocytes recirculating in the spleen.  

PubMed

After washing out remaining blood cells using cold perfusate, pig spleens were connected to a closed-circuit normothermic perfusion system. Recirculating lymphocytes migrated out and rapidly established an equilibrium with the splenic extravascular lymphoid tissues. Comparison of the subpopulations among these lymphocytes with those in the blood at time of removal of the spleen, showed the absence of Null cells and reduced numbers of weakly E-rosetting cells among splenic emigrants. The proportion of other B- and T-cell subpopulations were increased in a way which might be explained by non-recirculation of these two subpopulations. Autologous blood lymphocytes labelled with fluorescein isothiocyanate and introduced into spleen perfusions rapidly established equilibrium (approximately 15%-25%, well within 1 hr) and at the end of perfusion were concentrated in the marginal zones. The fluorescent lymphocytes remaining in the perfusate showed a marked enrichment of Null cells suggesting that these cells do not home to splenic extravascular lymphoid tissues in agreement with the hypothesis that Null cells are absent from splenic emigrants because they are nonrecirculating cells. PMID:6795107

Binns, R M; Pabst, R; Licence, S T

1981-10-01

206

Automation of Water Supply Systems.  

National Technical Information Service (NTIS)

The report provides an engineering evaluation of the capabilities of various commercially available water quality sensing devices and automated control systems adapted to water treatment plant operation. This state-of-the-art survey was accomplished throu...

W. F. Echelberger M. W. Tenney D. C. Withey B. P. J. Higgins

1975-01-01

207

Water Entry System.  

National Technical Information Service (NTIS)

The present invention relates to water entry of unmanned underwater vehicles and more specifically to suppression of cavity formation upon entry of such vehicles into the water. Underwater vehicles, such as torpedoes, are generally designed for speed, rel...

R. Kuklinski

2009-01-01

208

Exhaust gas recirculation valve assembly  

SciTech Connect

This paper describes an exhaust gas recirculation valve assembly. It comprises: a base having an exhaust gas chamber through which exhaust gas passes; a pintle valve assembly having a valve member disposed within the exhaust gas chamber and a valve stem extending outwardly of the chamber through an opening therein; an actuator, maintained in a fixed relationship to the base, coupling means, extending between the valve stem and the armature and configured to allow lateral movement of the valve stem relative to the armature to compensate for misalignment of the actuator relative to the base thereby preventing the misalignment from affecting the reciprocal operation of the pintle valve assembly relative to the base.

Grey, T.J.; Braun, C.N.; Palmer, D.O.

1991-06-04

209

Recirculation in multiple wave conversions  

SciTech Connect

A one-dimensional multiple wave-conversion model is constructed that allows energy recirculation in ray phase space. Using a modular eikonal approach, the connection coefficients for this model are calculated by ray phase-space methods. Analytical results (confirmed numerically) show that all connection coefficients exhibit interference effects that depend on an interference phase, calculated from the coupling constants and the area enclosed by the intersecting rays. This conceptual model, which focuses on the topology of intersecting rays in phase space, is used to investigate how mode conversion between primary and secondary waves is modified by the presence of a tertiary wave.

Brizard, A. J. [Department of Chemistry and Physics, Saint Michael's College, Colchester, Vermont 05439 (United States); Kaufman, A. N. [Department of Physics and Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 (United States); Tracy, E. R. [Department of Physics, College of William and Mary, Williamsburg, Virginia 23187-8795 (United States)

2008-08-15

210

Recirculation in multiple wave conversions  

SciTech Connect

A one-dimensional multiple wave-conversion model is constructed that allows energy recirculation in ray phase space. Using a modular eikonal approach, the connection coefficients for this model are calculated by ray phase-space methods. Analytical results (confirmed numerically) show that all connection coefficients exhibit interference effects that depend on an interference phase, calculated from the coupling constants and the area enclosed by the intersecting rays. This conceptual model, which focuses on the topology of intersecting rays in phase space, is used to investigate how mode conversion between primary and secondary waves is modified by the presence of a tertiary wave.

Kaufman, A. N.; Brizard, A.J.; Kaufman, A.N.; Tracy, E.R.

2008-07-30

211

10 Commercially Feasible Urban Recirculating Aquaculture: Addressing the Marine Sector  

Microsoft Academic Search

With the global collapse of marine fisheries and the environmental issues associated with net-pen aquaculture practices, there is a pressing need to develop fully contained and environmentally sus- tainable approaches to producing seafood. Recirculating aquaculture systems (RAS), which provide this approach, have been widely used over the last two decades to farm freshwater species. However, the cost associated with the

Yonathan Zohar; Yossi Tal; Harold Schreier; Colin Steven; John Stubblefield

212

PATHFINDER ATOMIC POWER PLANT PROTOTYPE RECIRCULATION PUMP REPORT  

Microsoft Academic Search

The development and testing of a centrifugal pump suitable for use in ; the recirculation system which forces core coolant and moderator through the core ; at a high rate are described. The prototype is a vertical single-stage ; centrifugal pump driven by a 400-hp induction motor. The pump has an overhung ; impeller which contains a journal for a

R. A. Haugen; D. J. Nolan

1962-01-01

213

Vapor-liquid equilibria of the water + 1,3-propanediol and water + 1,3-propanediol + lithium bromide systems  

SciTech Connect

Vapor-liquid equilibrium data of the water + 1,3-propanediol and water + 1,3-propanediol + lithium bromide systems were measured at 60, 160, 300, and 760 mmHg at temperatures ranging from 315 to 488 K. The apparatus used in this work is a modified still especially designed for the measurement of low-pressure VLE, in which both liquid and vapor are continuously recirculated. For the analysis of salt-containing solutions, a method incorporating refractometry and gravimetry was used. From the experimental measurements, the effect of lithium bromide on the VLE behavior of water + 1,3-propanediol was investigated. The experimental data of the salt-free system were successfully correlated using the Wilson, NRTL, and UNIQUAC models. In addition, the extended UNIQUAC model of Sander et al. was applied to the VLE calculation of salt-containing mixtures.

Mun, S.Y.; Lee, H.

1999-12-01

214

In Situ Biotreatment of TBA with Recirculation/Oxygenation  

PubMed Central

The potential for in situ biodegradation of tert-butyl alcohol (TBA) by creation of aerobic conditions in the subsurface with recirculating well pairs was investigated in two field studies conducted at Vandenberg Air Force Base (VAFB). In the first experiment, a single recirculating well pair with bromide tracer and oxygen amendment successfully delivered oxygen to the subsurface for 42 days. TBA concentrations were reduced from approximately 500 ?g/L to below the detection limit within the treatment zone and the treated water was detected in a monitoring transect several meters downgradient. In the second experiment, a site-calibrated model was used to design a double recirculating well pair with oxygen amendment, which successfully delivered oxygen to the subsurface for 291 days and also decreased TBA concentrations to below the detection limit. Methylibium petroleiphilum strain PM1, a known TBA-degrading bacterium, was detectable at the study site but addition of oxygen had little impact on the already low baseline population densities, suggesting that there was not enough carbon within the groundwater plume to support significant new growth in the PM1 population. Given favorable hydrogeologic and geochemical conditions, the use of recirculating well pairs to introduce dissolved oxygen into the subsurface is a viable method to stimulate in situ biodegradation of TBA or other aerobically-degradable aquifer contaminants.

North, Katharine P.; Mackay, Douglas M.; Kayne, Julian S.; Petersen, Daniel; Rasa, Ehsan; Rastegarzadeh, Laleh; Holland, Reef B.; Scow, Kate M.

2012-01-01

215

Gas recirculator for acyclic machines  

NASA Astrophysics Data System (ADS)

The present invention relates to acyclic machines of the type using liquid metal collectors, and more particularly to an improvement for retaining the liquid metal in such machines. Radial type acyclic motors and generators generally include a metallic disk rotor rotating on a shaft between electromagnetic stator poles excited by field coils wound concentric with the shaft. Instead of solid brush, current collectors at the rotor periphery, liquid metal collectors are sometimes used to close the electrical current loop between the shaft and the rotor, and an inert pressurized cover gas fills the gaps between the rotating components and the stationary housing. A cover has recirculator in an acyclic generator having liquid metal collectors for reducing entrainment of the liquid metal in the gas. Radial passages in the stator housing provide natural recirculating paths for the cover gas to flow radially outward along the sides of the rotor and return inwardly through the passages. Scoops or lips located inward of the liquid metal collector divert the outward gas flow into the passages to minimize contact of the gas with the liquid metal.

Balsa, T. F.

1985-05-01

216

Integrity of Interconnected Water Systems.  

National Technical Information Service (NTIS)

Various theoretical and applied network theory approaches for assessing the reliability of water delivery systems are examined including signal flow methodology and connectivity as well as structural integrity in a utility-type power system network. Probl...

R. Schinzinger L. D. Nyirenda M. Saeb A. Peiravi

1983-01-01

217

Energy utilization and recirculation of currant-finishing wastewater.  

PubMed

In this study, a new method for the treatment of currant-finishing wastewater was proposed in the context of the "clean technology" concept. This method consisted of two stages. In the first stage, the currant-finishing wastewater was recirculated in the currant-wash process and in the second stage this wastewater was utilized for the production of energy through anaerobic digestion. Recycling ratios from 0 to 95% were examined. By increasing the recycling ratio, effluent's COD increased from 3808 to 43,722mg/l, effluent's BOD from 681 to 5378mg/l, total sugars from 2.57 to 42.13g/l, total phosphorous from 0.79 to 5.14mg/l and total Kjeldahl nitrogen from 7.36 to 51.9mg/l while fresh water addition decreased from 6 to 0.3kg per kg of currants processed. The optimum recycling ratio range for the wastewater energy utilization proved to be 30-40%. In this range, the mass of COD and sugars digested was maximized resulting in the highest biogas production. Thus, the proposed system could be promising since water consumption is minimized and wastewater energy utilization is achieved rendering the process almost energetically self-sufficient. PMID:17316987

Vlyssides, A G; Barampouti, E M P; Mai, S T

2007-01-18

218

Water preheater system  

SciTech Connect

A heat transfer liquid collects heat in a solar collector and transfers the heat to water in a preheater heat exchanger. Use of a negative-pressure collector by means of an ejector and pressure relief valve allows inexpensive and readily available materials to be used in the collector. Preferably, the preheat heat exchanger is a converted gas hot water heater in which the heat transfer liquid is sprayed onto a portion of the storage tank and is collected in a reservoir. The negative-pressure solar collector can also be used to heat swimming pool water.

Dunstan, Ph.E.

1985-03-12

219

Design of Small Water Systems.  

National Technical Information Service (NTIS)

This manual provides guidance and criteria for the design of small water supply, treatment, and distribution systems. For the purpose of this manual, small water systems shall be those having average daily design flow rates of 380,000 liters per day (100 ...

A. J. Genetti

1999-01-01

220

Water Electrolysis Propulsion System Testing.  

National Technical Information Service (NTIS)

A twenty-four month program was conducted to demonstrate the life capability of a water electrolysis propulsion system and to develop flightweight 5-lbf and 0.1-lbf GO2/GH2 thrusters. A water electrolysis propulsion system was tested for 33 weeks at an ac...

J. G. Campbell R. C. Stechman

1974-01-01

221

Water Treatment Technology - Distribution Systems.  

ERIC Educational Resources Information Center

One of twelve water treatment technology units, this student manual on distribution systems provides instructional materials for six competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: types of pipe for distribution systems, types…

Ross-Harrington, Melinda; Kincaid, G. David

222

Assessing Global Water System Research  

NASA Astrophysics Data System (ADS)

Rapid growth of global change science has led to improved knowledge about interdependencies in the global water cycle and recognition that the global water system consists of physical, human, and biogeochemical components [Vörösmarty et al., 2004]. Traditionally, water research is spread over a number of scientific disciplines. However, for water science to effectively inform policy for sustainable water management, research about the dynamics of water in the context of global change needs to be holistic, must integrate the existing knowledge base, and should synthesize knowledge about how the interactions between nature and society at various scales are affecting the global water system. This article assesses the level of interdisciplinarity in water science programs by comparing the activities of international waterrelated projects with the Global Water System Project (GWSP) activity profile (http://www.gwsp.org). The GWSP is a project of the Earth System Science Partnership (ESSP) comprising the International Geosphere-Biosphere Programme (http:// www.igbp.kva.se/cgi-bin/php/frameset.php), the International Human Dimension Programme on Global Environmental Change (www.ihdp.org), the World Climate Research Programme (http://www.wmo.ch/web/wcrp/wcrp-home.html), and the DIVERSITAS international program on biodiversity science (http://www.diversitasinternational.org/). GWSP's attributes include its scientific and policy-informing orientation, global perspective, integrative and interdisciplinary approach, and multitemporal investigation of human impacts on water resources.

Braimoh, Ademola K.; Craswell, Eric T.

2006-04-01

223

Operational Management System for Regulated Water Systems  

NASA Astrophysics Data System (ADS)

Most of the Dutch large rivers, canals and lakes are controlled by the Dutch water authorities. The main reasons concern safety, navigation and fresh water supply. Historically the separate water bodies have been controlled locally. For optimizating management of these water systems an integrated approach was required. Presented is a platform which integrates data from all control objects for monitoring and control purposes. The Operational Management System for Regulated Water Systems (IWP) is an implementation of Delft-FEWS which supports operational control of water systems and actively gives advice. One of the main characteristics of IWP is that is real-time collects, transforms and presents different types of data, which all add to the operational water management. Next to that, hydrodynamic models and intelligent decision support tools are added to support the water managers during their daily control activities. An important advantage of IWP is that it uses the Delft-FEWS framework, therefore processes like central data collection, transformations, data processing and presentation are simply configured. At all control locations the same information is readily available. The operational water management itself gains from this information, but it can also contribute to cost efficiency (no unnecessary pumping), better use of available storage and advise during (water polution) calamities.

van Loenen, A.; van Dijk, M.; van Verseveld, W.; Berger, H.

2012-04-01

224

Water Supply Infrastructure System Surety  

SciTech Connect

The executive branch of the United States government has acknowledged and identified threats to the water supply infrastructure of the United States. These threats include contamination of the water supply, aging infrastructure components, and malicious attack. Government recognition of the importance of providing safe, secure, and reliable water supplies has a historical precedence in the water works of the ancient Romans, who recognized the same basic threats to their water supply infrastructure the United States acknowledges today. System surety is the philosophy of ''designing for threats, planning for failure, and managing for success'' in system design and implementation. System surety is an alternative to traditional compliance-based approaches to safety, security, and reliability. Four types of surety are recognized: reactive surety; proactive surety, preventative surety; and fundamental, inherent surety. The five steps of the system surety approach can be used to establish the type of surety needed for the water infrastructure and the methods used to realize a sure water infrastructure. The benefit to the water industry of using the system surety approach to infrastructure design and assessment is a proactive approach to safety, security, and reliability for water transmission, treatment, distribution, and wastewater collection and treatment.

EKMAN,MARK E.; ISBELL,DARYL

2000-01-06

225

Wind Effect, Recirculation and Thermal Flow Field of a Direct Air-cooled Condenser for a Large Power Plant  

NASA Astrophysics Data System (ADS)

The thermal effect experiments were carried out of a direct air-cooled system in the low speed wind tunnel. The influence of effect factors on recirculation is also discussion, after that the relationship between the thermal flow field structure and recirculation ratio under the cooling tower is analyzed. At last, the engineering measures to reduce or avoid recirculation are proposed. For certain conditions the experimental measurement shows close agreement with numerical values.

Zhao, W. L.; Liu, P. Q.; Duan, H. S.; Zhu, J. Y.

2011-09-01

226

A dynamic simulation of a two-phase anaerobic digestion system for solid wastes.  

PubMed

In this article, a two-phase system for the digestion of wastes with a high solid content is simulated. The solids are charged to the hydrolyzer and then leachate recirculation is activated until biodegradation is nearly complete. Several parameters are tested, namely moisture, leachate recirculation flow rate, and hydrolyzer-methanizer volume ratio. The results show that recirculation rate is an important parameter subject to optimization, with optimal values corresponding to hydrolyzer hydraulic retention times below 1 day. The quantity of recirculating water must be the highest possible. As a consequence, the organic load to the methanizer is reduced, making thus possible the use of a smaller methanizer volume. PMID:18581519

Mata-Alvarez, J

1987-11-01

227

Systems and Components Fuel Delivery System, Water Delivery System, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Systems and Components - Fuel Delivery System, Water Delivery System, Derrick Crane System, and Crane System Details - Marshall Space Flight Center, F-1 Engine Static Test Stand, On Route 565 between Huntsville and Decatur , Huntsville, Madison County, AL

228

Lattice Design for the LHEC Recirculating Linac  

SciTech Connect

In this paper, we present a lattice design for the Large Hadron Electron Collider (LHeC) recirculating linac. The recirculating linac consists of one roughly 3-km long linac hosting superconducting RF (SRF) accelerating cavities, two arcs and one transfer line for the recirculation. In two passes through a pulsed SRF linac the electron beam can get a maximum energy of 140 GeV. Alternatively, in the Energy Recovery Linac (ERL) option the beam passes through a CW linac four times (two passes for acceleration and two for deceleration) for a maximum energy of 60 GeV.

Sun, Yipeng; /CERN; Eide, Anders; /CERN; Zimmermann, Frank; /CERN; Adolphsen, Chris; /SLAC

2011-05-20

229

SMALL DRINKING WATER SYSTEMS RESEARCH  

EPA Science Inventory

There are 159,796 Community Water Systems (CWSs) in the United States. Ninety-three percent of CWSs are considered very small to medium-sized systems that serve roughly 19% of the CWS population. In contrast, large to very large systems comprise just 7% of CWSs, but serve 81% of ...

230

Cyclone reactor with internal separation and axial recirculation  

DOEpatents

A cyclone combustor apparatus contains a circular partition plate containing a central circular aperture is described. The partition plate divides the apparatus into a cylindrical precombustor chamber and a combustor chamber. A coal-water slurry is passed axially into the inlet end of the precombustor chamber, and primary air is passed tangentially into said chamber to establish a cyclonic air flow. Combustion products pass through the partition plate aperture and into the combustor chamber. Secondary air may also be passed tangentially into the combustor chamber adjacent the partition plate to maintain the cyclonic flow. Flue gas is passed axially out of the combustor chamber at the outlet end and ash is withdrawn tangentially from the combustor chamber at the outlet end. A first mixture of flue gas and ash may be tangentially withdrawn from the combustor chamber at the outlet end and recirculated to the axial inlet of the precombustor chamber with the coal-water slurry. A second mixture may be tangentially withdrawn from the outlet end and passed to a heat exchanger for cooling. Cooled second mixture is then recirculated to the axial inlet of the precombustor chamber. In another embodiment a single cyclone combustor chamber is provided with both the recirculation streams of the first mixture and the second mixture. 10 figs.

Becker, F.E.; Smolensky, L.A.

1988-07-19

231

Research on leachate recirculation from different types of landfills  

SciTech Connect

Landfills can produce a great amount of leachate containing highly concentrated organic matter. This is especially true for the initial leachate from landfilled municipal solid wastes (MSW) that generally has concentrations of COD{sub Cr} and BOD{sub 5} up to 80,000 and 50,000 mg/L, respectively. The leachate could be disposed by means of recirculating technique, which decomposes the organics through the action of proliferating microorganisms and thereby purifies the leachate, and simultaneously accelerates organic decomposition through water saturation control. Data from experimental results indicated that leachate recirculating could reduce the organic concentration considerably, with a maximum reduction rate of COD{sub Cr} over 95%; and, using a semi-aerobic process, NH{sub 3}-N concentration of treated leachate could be under 10 mg/L. In addition, the organic concentration in MSW decreased greatly.

Wang Qi [Research Institute of Solid Waste Management, Chinese Research Academy of Environmental Sciences, No. 8 of Dayangfang, Chaoyang District, Beijing 100012 (China) and Faculty of Engineering, Fukuoka University, 8-19-1 Nanakuma, Johnan-ku, Fukuoka 814-0180 (Japan)]. E-mail: wangqi@craes.org.cn; Matsufuji, Yasushi [Faculty of Engineering, Fukuoka University, 8-19-1 Nanakuma, Johnan-ku, Fukuoka 814-0180 (Japan); Dong Lu [Research Institute of Solid Waste Management, Chinese Research Academy of Environmental Sciences, No. 8 of Dayangfang, Chaoyang District, Beijing 100012 (China); Huang Qifei [Research Institute of Solid Waste Management, Chinese Research Academy of Environmental Sciences, No. 8 of Dayangfang, Chaoyang District, Beijing 100012 (China); Hirano, Fumiaki [Faculty of Engineering, Fukuoka University, 8-19-1 Nanakuma, Johnan-ku, Fukuoka 814-0180 (Japan); Tanaka, Ayako [Faculty of Engineering, Fukuoka University, 8-19-1 Nanakuma, Johnan-ku, Fukuoka 814-0180 (Japan)

2006-07-01

232

Picosecond Pulse Recirculation for High Average Brightness Thomson Scattering-based Gamma-ray Sources  

SciTech Connect

Pulse recirculation has been successfully demonstrated with the interaction laser system of LLNL's Thomson-Radiated Extreme X-ray (T-REX) source. The recirculation increased twenty-eight times the intensity of the light coming out of the laser system, demonstrating the capability of increasing the gamma-ray flux emitted by T-REX. The technical approach demonstrated could conceivably increase the average gamma-ray flux output by up to a hundred times.

Semenov, V

2009-05-28

233

Clean Water Systems in Mexico  

NSDL National Science Digital Library

In this video segment adapted from Rx for Survival, learn about the importance of clean water and sanitation systems. Hear the story of how, in the early 1990s, Mexico's entry into a North American trade agreement was threatened by a cholera epidemic. Find out how the Mexican government rebuilt the water and sanitation system to stop the spread of the disease and how the investment in clean water helped the country win the trade agreement. A background essay, discussion questions, and standards correlations are also provided.

2010-08-31

234

Recirculating cross-correlation detector  

DOEpatents

A digital cross-correlation detector is provided in which two time-varying signals are correlated by repetitively comparing data samples stored in digital form to detect correlation between the two signals. The signals are sampled at a selected rate converted to digital form, and stored in separate locations in separate memories. When the memories are filled, the data samples from each memory are first fed word-by-word through a multiplier and summing circuit and each result is compared to the last in a peak memory circuit and if larger than the last is retained in the peak memory. Then the address line to leading signal memory is offset by one byte to affect one sample period delay of a known amount in that memory and the data in the two memories are then multiplied word-by-word once again and summed. If a new result is larger than a former sum, it is saved in the peak memory together with the time delay. The recirculating process continues with the address of the one memory being offset one additional byte each cycle until the address is shifted through the length of the memory. The correlation between the two signals is indicated by the peak signal stored in the peak memory together with the delay time at which the peak occurred. The circuit is faster and considerably less expensive than comparable accuracy correlation detectors.

Andrews, W.H. Jr.; Roberts, M.J.

1985-01-18

235

High Power Picosecond Laser Pulse Recirculation.  

National Technical Information Service (NTIS)

We designed and constructed a nonlinear crystal-based short pulse recirculation cavity that traps the second harmonic of an incident high power laser. This scheme aims to increase the efficiency of Compton-scattering based light sources.

C. Brown D. Gibson F. Hartemann I. Jovanovic M. Y. Shverdin S. Anderson

2007-01-01

236

Assessment System for Water Conservation Society Based on Water Footprint  

Microsoft Academic Search

The assessment system for the water conservation is of vital significance to construct a water conservation society that is one of the most important strategies in the harmous development of social economy and ecological environment. According to the idea of ecological water footprint available, the evaluation system is established for the assessment of water conservation society based on water quality

Jing Chen; Shuying He; Kai Yang

2010-01-01

237

Recirculation control valve replacement cuts maintenance costs  

Microsoft Academic Search

This article describes how replacement of boiler feed pump recirculation control valves solves a maintenance problem on Baldwin Unit 3. All three of Illinois Power`s Baldwin power plant units had the same boiler feed pump (BFP) valve design when they went into commercial operation. The original BFP recirculation valves were a top-guided plug, single-port cage design using a tapered plug

M. E. Liefer; H. L. Miller; R. E. Katz

1995-01-01

238

Control solids in cooling water to cut makeup requirements  

Microsoft Academic Search

A pilot program demonstrates effectiveness of reverse osmosis and electrodialysis in increasing the cycles of concentration of recirculating-water systems. The team performed its study with the help of the Department of Interior's mobile demineralization treatment system, which houses both a reverse-osmosis and an electrodialysis desalting system. Their results indicate that both systems can produce product water of higher quality than

R. Osantowski; J. Kane

1984-01-01

239

Thermoelectric power systems and the energy-water nexus  

NASA Astrophysics Data System (ADS)

The goal of this Thesis is the development of a comprehensive methodology to evaluate the total cost of water use in the recirculating cooling loops of thermoelectric power plants. This methodology expands upon the work presented in the literature to improve estimations of the economic impact of condenser fouling. The methods developed in this Thesis are incorporated into a user friendly Combined Cost Model (CCM) interface that will allow future researchers, students and plant personnel to perform the same comparative analyses presented herein. The objective of this Thesis is the application of the CCM to determine the economic viability of treated municipal wastewater (MWW) use to replace freshwater for cooling in power plants with recirculating cooling systems. To accomplish this objective, a set of case study evaluations are included to (1) evaluate the sensitivity of the economic impact of fouling to condenser design and operation, (2) determine the cost of treated MWW use in pulverized coal power plants, and (3) compare the relative cost of degraded water use in advanced power systems such as IGCC and oxy-combustion. The results of these evaluations show that current freshwater prices do not provide an economic incentive to switch to the use of treated MWW water. However, results indicate that the breakeven differential price of freshwater, at which the total costs of using freshwater and treated MWW are equal, is only 0.52 /1000Gal. (USD 2009). In addition, the use of treated MWW for cooling is shown to be a better economic alternative to dry air cooling technology (DACT) for the conservation of freshwater resources. Cost-to-conservation estimates of treated MWW use are 1.1 /1000 Gal., in contrast to 5.6 $/1000 Gal. for DACT. This Thesis also presents a novel, hybrid coal conversion concept, the dry gasification oxy-combustion (DGOC) power cycle. This process is similar to oxy-combustion, in that it maintains a concentrated CO2 flue stream and does not utilize a complex separation step. However, coal conversion and sulfur removal are performed within a gasification unit. It is estimated to achieve CCS goals with a higher efficiency than the leading alternative strategies.

Walker, Michael Edward

240

The global water systems project  

NASA Astrophysics Data System (ADS)

The Global Water System (GWS) plays a central and integrative role in the dynamics of the Earth system. It is a regulator of biogeophysical and biogeochemical processes, and it is also is essential for sustenance of human societies. The GWS is increasingly modified by humans and through climate effects (facets of it have moved well outside the range of natural variability), without adequate understanding of how the system works. For understanding the changes, feedbacks and potentially critical thresholds within the Earth system, and eventually for better managing the GWS, new synthetic knowledge is required. The Global Water System Project (GWSP) is a new activity being undertaken jointly by the World Climate Research Programme (WCRP), International Geophshere-Biosphere Program (IGBP), International Human Dimensions Program (IHP), and Diversitas. It will address the GWS in a comprehensive fashion at the global scale, building upon the emerging new consolidated Earth systems data sets, global monitoring tools, and predictive and coupled modeling capabilities. The central scientific question that motivates the GWSP is: "How are humans changing the global water cycle, the associated biogeochemical cycles, and the biological components of the GWS, and what are the social feedbacks arising from these changes?" GWSP will be structured around three "framing questions": a) What are the relative magnitudes of global-scale changes in the global water system that are attributable to changing human activities, and to environmental factors such as climate variability and change?; b) What are the main mechanisms by which human activities are affecting the global water system; and c) To what extent is the global water system resilient to global change? Examples of issues that might be addressed under each of these questions are provided.

Hoff, H.; Jaeger, C.; Leveque, C.; Lettenmaier, D.; Lins, H.; Meybeck, M.; Niasse, M.; Vorosmarty, C.

2003-04-01

241

Evidence for sediment recirculation on an ebb-tidal delta of the East Frisian barrier-island system, southern North Sea  

NASA Astrophysics Data System (ADS)

The Otzum ebb-tidal delta, located between Langeoog and Spiekeroog islands along the East Frisian barrier-island coast, southern North Sea, was investigated with respect to its morphological evolution, sediment distribution patterns and internal sedimentary structures. Bathymetric charts reveal that, over the last 50 years, the size of the Otzum ebb-tidal delta has slightly shrunk, while sediment has accreted on the ebb-delta lobe to the east of the main inlet channel (west of Spiekeroog). Swash bars superimposed on the eastern ebb-tidal shoal (Robben Plate) have migrated south or south-eastwards, i.e. towards the inlet throat. The main ebb-delta body is composed of fine quartz sand, whereas the superimposed swash bars and the inlet channel bed consist of medium-grained quartz sand containing high proportions of coarser bioclastic material. Internal sedimentary structures in short box-cores (up to 30 cm long) are dominated by flood-oriented cross-beds. Longer vibro-cores (up to 1.5 m long) show that, at depth, the sediment is dominated by storm-generated parallel (upper plane bed) laminations with intercalated shell layers and dune cross-bedding. The cross-bedded sands in both box-cores and vibro-cores from the ebb-delta shoal predominantly dip towards the south or southeast, indicating transport towards the inlet throat by the flood current. The observations demonstrate that, contrary to previous contentions, the sediments of the highly mobile swash bars do not bypass the inlet but are instead being continually recirculated by the combined action of tidal currents and waves. In this model, the cycle begins with both fine and medium sands, including shell hash, being transported seawards in the main ebb channel until they reach the shallow ebb-delta front. From here, the sediment is pushed onto the eastern ebb-delta shoal by the flood current assisted by waves, becoming strongly size-sorted in the process. The medium sands together with the shell hash are formed into swash bars which migrate along arcuate paths over a base of fine sand back to the main ebb channel located south of the ebb delta. By the same token, the fine sand between the swash bars is transported south-eastwards by the flood current in the form of small dunes until it cascades into the large flood channel located to the west of Spiekeroog. From here, the fine sand is fed back into the main ebb channel, thus completing the cycle. No evidence was found on the ebb delta for alongshore sediment bypassing.

Son, Chang Soo; Flemming, Burghard W.; Bartholomä, Alexander

2011-04-01

242

Closed loop system lowers service water temperature  

Microsoft Academic Search

This article describes, Gulf States Utilities completed conversion of the service water system at River Bend station to a treated demineralized water closed loop system. The modification to this 63,000-gpm system required separating service water from the larger circulating water cooling system that cools the main condenser. New service water pumps were installed along with eight parallel plate and frame

DeWeese

1993-01-01

243

Parasite infections in recirculated rainbow trout ( Oncorhynchus mykiss) farms  

Microsoft Academic Search

Parasite infections in recirculated rainbow trout farms were monitored through 22 months. Parameters such as temperature, mortality, pH, nitrite and ammonia-concentrations, use of formalin, mortality and feed conversion ratio were also monitored. Due to introduction of rainbow trout from traditional earth ponds into the new systems, all farms were found to be infected with a number of parasitic organisms known from

Thomas R. Jørgensen; Thomas B. Larsen; Kurt Buchmann

2009-01-01

244

Combining dialysate and blood recirculation to boost uremic toxin removal: theory and simulation study.  

PubMed

Emerging concepts in renal replacement therapies such as daily hemodialysis (HD) and wearable artificial kidney (WAK) meet the challenges derived from the aging of renal disease population. The successful results of blood recirculation to improve the dialysis clearance of medium-high uremic toxins suggest that this technique could be used both in daily HD and WAK. However, blood recirculation induces a reduction of small solutes clearance. This work analyzes the ability of a nonregenerated recirculating dialysate technique to avoid that reduction. The study uses in silico simulations with in vitro data from several commercial dialyzers and very compact dialyzer models derived from them. The resulting combined optimization system (recirculating blood-dialysate system [RBDS]) reached low solute dialysance improvements above 100% in different scenarios. Our outcomes show the RBDS performs best with very compact dialyzers, in agreement with the requirements of daily HD and WAK. PMID:17924986

Prado, Manuel; Roa, Laura

2007-10-08

245

21 CFR 884.6170 - Assisted reproduction water and water purification systems.  

Code of Federal Regulations, 2010 CFR

...Assisted reproduction water and water purification systems. 884.6170 Section...Assisted reproduction water and water purification systems. (a) Identification. Assisted reproduction water purification systems are devices...

2009-04-01

246

21 CFR 884.6170 - Assisted reproduction water and water purification systems.  

Code of Federal Regulations, 2010 CFR

...Assisted reproduction water and water purification systems. 884.6170 Section...Assisted reproduction water and water purification systems. (a) Identification. Assisted reproduction water purification systems are devices...

2010-04-01

247

21 CFR 884.6170 - Assisted reproduction water and water purification systems.  

Code of Federal Regulations, 2013 CFR

...Assisted reproduction water and water purification systems. 884.6170 Section...Assisted reproduction water and water purification systems. (a) Identification. Assisted reproduction water purification systems are devices...

2013-04-01

248

Screening reactor steam\\/water piping systems for water hammer  

Microsoft Academic Search

A steam\\/water system possessing a certain combination of thermal, hydraulic and operational states, can, in certain geometries, lead to a steam bubble collapse induced water hammer. These states, operations, and geometries are identified. A procedure that can be used for identifying whether an unbuilt reactor system is prone to water hammer is proposed. For the most common water hammer, steam

1997-01-01

249

Flume simulation of sedimentation in recirculating flow  

SciTech Connect

A 4-m-wide flume at the University of Tsukuba Environmental Research Center was used to simulate flow conditions near debris fans in bedrock gorges. Flow was constricted to 2 m by a semicircular obstruction. During the authors experiments (discharge = 600 L/sec; Froude number of constricted flow = 1) a zone of recirculating current extended 25-30 m downstream from the separation point at the constriction. The pattern and velocity of surface flow was determined using time-lapse photography; subsurface velocity was measured with a two-dimensional electromagnetic current meter. During 32-hr of run time, a fine, very coarse sand mixture was fed into the flow at a rate between 0.5-1 kg/sec. Oscillation ripples developed beneath the separation surface that bounds the recirculation zone, and upstream-migrating dunes and ripples developed within the recirculation zone upstream from the reattachment point. A mid-channel expansion bar was deposited downstream from the reattachment point. Sedimentation within the recirculation zone continued by vertical aggradation and by upstream migration of dunes and ripples. Sediments within the recirculation zone were areally sorted with the finest sediment deposited near the separation point. These patterns are consistent with field observations of bars along the Colorado River in the Grand Canyon.

Schmidt, J.C. (Middlebury College, VT (USA)); Rubin, D.M. (Geological Survey, Menlo Park, CA (USA)); Ikeda, H. (Univ. of Tsukuba (Japan))

1990-05-01

250

Corps Water Management System (CWMS).  

National Technical Information Service (NTIS)

As part of its Civil works mission, the US Army Corps of Engineers designs, builds and operates a variety of water resources projects. Projects include, multi-use storage reservoirs, navigation dams and locks, and levee systems with closure structures. Co...

A. F. Pabst

2000-01-01

251

WATER QUALITY MODELING DISTRIBUTION SYSTEMS  

EPA Science Inventory

This paper reviews the use of models for predicting water quality in distribution systems. esults of an extensive field study conducted by the USEPA and North Penn Mater Authority are examined. A case study of the model application to a waterborne disease outbreak in Cabool, Miss...

252

Manual for Regulating Water Systems.  

National Technical Information Service (NTIS)

Practical aspects of regulation are detailed as a guide to commissioning engineers and designers. Regulation is defined as a process during which the flow of water through a distribution system is measured and adjusted to achieve the design flows within a...

1979-01-01

253

Velocity characteristics of a swirling recirculating flow  

SciTech Connect

The isothermal recirculating flow downstream of a model swirl burner is studied making use of a laser-Doppler velocimeter. The arrangement was designed to incorporate the injection of liquid fuel into a gas flame characterized by a large recirculation zone attached to the burner head and to allow a detailed analysis of turbulent transport processes in a strongly swirled recirculating flow. The results show that turbulent mixing in the present flow is not dominated by large-scale motions or precession. The production of turbulent kinetic energy depends upon mechanisms of shear-generated turbulence but is influenced by streamline curvature in the zone of mean shear. Inspection of the terms in the conservation equations for the turbulent stresses allows quantification of the extent to which the interaction of normal stresses and normal strains influence the flow and suggests the likely magnitude of turbulent diffusion and dissipation. 53 refs.

Heitor, M.V.; Moreira, A.L.N. (Karlsruhe, Universitaet (Germany))

1992-05-01

254

Generating electricity along municipal water supply systems  

Microsoft Academic Search

In addition to providing water supply for municipalities, water mains can serve as conduits for small hydro plants. Examples of several such projects illustrate a practical, cost-effective way to meet growing electricity demands. A typical water supply system for a municipality consists of one or more reservoirs of water, a pipeline, and a water treatment plant. As the water flows

E. J. Busse; T. W. Haag; L. D. Coupe

1992-01-01

255

Experiments With Recirculating Target for F-18 Production  

NASA Astrophysics Data System (ADS)

Approximately 10 ml of O-18 water was loaded in an apparatus containing a 5 ml storage vessel, pump, silver target attached to a cyclotron, filter, backpressure regulator, conductivity meter, several valves and ion exchange cartridges. The water was continuously pumped through the target during proton bombardment at a rate 5 ml/min. Continuous irradiation with beam current ranging from 10 to 50 uA was conducted while pressure, temperature and conductivity were continuously monitored. The results indicate that recirculating of the target water can increase production of F-18 in relation to consumed O-18 water material. It can also increase productivity by eliminating idle periods for re-filling the target. A backpressure regulator can precisely control target pressure. This method also allows for continuous monitoring of the target material temperature, pressure, conductivity and accumulated radioactivity. Results of these observations provide important information about target performance and physical processes taking place inside the target.

Kiselev, M. Y.

2003-08-01

256

Total Water Management, the New Paradigm for Urban Water Systems  

EPA Science Inventory

There is a growing need for urban water managers to take a more holistic view of their water resource systems as population growth, urbanization, and current resource management practices put different stresses on local water resources and urban infrastructure. Total Water Manag...

257

Security of Water Infrastructure Systems  

NASA Astrophysics Data System (ADS)

This paper formulates the security problem in critical water infrastructure systems for diagnosing quality faults. The proposed scheme is based on the discretized equations of advection and reaction of contaminant concentrations in pipes and tanks, expressed in a state-space form. Faults are signals affecting the states, and their impact is measured based on certain epidemiological dynamics. A multi-objective optimization problem is formulated for minimizing various risk-related objectives.

Eliades, Demetrios G.; Polycarpou, Marios M.

258

MINIMIZATION OF WATER USE IN LEAFY VEGETABLE WASHERS  

EPA Science Inventory

This project was undertaken to construct and test an improved leafy greens washing system employing water recirculation, to characterize the quality of the wash water and waste stream and to make comparisons to conventional washers. The prototype system produced a cleaner product...

259

33 CFR 159.127 - Safety coliform count: Recirculating devices.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Safety coliform count: Recirculating devices...Testing § 159.127 Safety coliform count: Recirculating devices...device must have less than 240 fecal coliform bacteria per 100 milliliters....

2009-07-01

260

33 CFR 159.127 - Safety coliform count: Recirculating devices.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Safety coliform count: Recirculating devices...Testing § 159.127 Safety coliform count: Recirculating devices...device must have less than 240 fecal coliform bacteria per 100 milliliters....

2010-07-01

261

Longitudinal dynamics in high frequency ffag recirculating accelerators..  

National Technical Information Service (NTIS)

A recirculating accelerator accelerates the beam by passing through accelerating cavities multiple times. An FFAG recirculating accelerator uses a single arc to connect the linacs together, as opposed to multiple arcs for the different energies. For most ...

S. Berg

2002-01-01

262

Fuel evaporation rate in intense recirculation zones  

Microsoft Academic Search

An expression is derived for the mean liquid fuel concentration in a flow region with intense recirculation rates. The expression makes it possible to evaluate liquid fuel evaporation rates. Finite fuel concentrations are predicted even for residence times greater than the critical value for single drops. The mean fuel evaporation rate may, therefore, be significantly smaller than that for single

I. T. Osgerby

1975-01-01

263

Interaction between an organic dye in water and sand packs in a flume system.  

PubMed

The sorption kinetics of methylene blue (MB), a standard compound in the American Society for Testing and Materials tests, on natural sand in a batch system at a reciprocal shaking speed of 120 rpm is fast, with equilibrium and surface coverage attained in minutes. When the same experiment is carried out in a recirculating flume, adsorption is much slower, with lifetimes increasing up to several months in the flume. Sorption retardation is dependent on the diffusion coefficient of the dye and on the depth of penetration of the MB layer in sand. The experimental results suggest that, in field experiments, formation of thin films dramatically inhibits the sorption kinetics and, in a closed system, such as a lake or reservoir, contaminants will remain in the water column for long periods, with very slow penetration in the sediment layer. In rivers, the contaminant will travel farther with less penetration into the sediment layer, compared to more static systems. PMID:20862753

Nome, Rene A; Souza, Aloisio J; Nome, Carlos A; Souza, Bruno S; Nome, Faruk; Fiedler, Haidi D

2010-11-01

264

Stealthy deception attacks on water SCADA systems  

Microsoft Academic Search

This article investigates the vulnerabilities of Supervisory Control and Data Acquisition (SCADA) systems which monitor and control the modern day irrigation canal systems. This type of monitoring and control infrastructure is also common for many other water distribution systems. We present a linearized shallow water partial differential equation (PDE) system that can model water flow in a network of canal

Saurabh Amin; Xavier Litrico; S. Shankar Sastry; Alexandre M. Bayen

2010-01-01

265

Screening Reactor Steam/Water Piping Systems for Water Hammer.  

National Technical Information Service (NTIS)

A steam/water system possessing a certian combination of thermal, hydraulic and operational states, can, in certain geometries, lead to a steam bubble collapse induced water hammer. These states, operations, and geometries are identified. A procedure that...

P. Griffith

1997-01-01

266

Modeling Leakage in Water Distribution Systems  

Microsoft Academic Search

Due to the continuous need to improve water supply sources, water operators are looking towards ways to conserve water and protect water quality through leakage protection. Currently computer generated models have been used to try to identify leakage areas and develop a relationship between leakage and pressure variations in water systems. The method of the leakage prediction has used both

Kristin Brown

2007-01-01

267

Heat pump system using waste water heat  

Microsoft Academic Search

A practical and economical heat pump system stacks the evaporator, compressor, condenser, and expander to use heat from household waste water more efficiently and effectively. A novel waste water storage tank treats the waste water to remove particulates while it supplies its warmest water to the evaporator to provide heat to the refrigerant in the heat pump unit. Heated water

Dunstan

1984-01-01

268

Ozone Treatment in Cooling Water Systems  

Microsoft Academic Search

Ozone treatment for preventing the biofouling in cooling water systems is investigated.In the fresh water system, the separating effect of the ozonated water on the microorganisms such as the sphaerotilus and the zoogloea which adhere to the piping and form the slime is recognized. When the ozonated water is supplied intermittently to the piping without stopping the flow of the

N. Kaiga; T. Seki; K. Iyasu

1989-01-01

269

Water: Life's Elixir in the Solar System  

NSDL National Science Digital Library

This article discusses the possible occurrence of water in our solar system. Topics include the necessity of liquid water for life, distribution of water throughout the solar system, and the possibility that there may be liquid water on Mars or on some of Jupiter's moons.

270

Low NOx Combustion of DME by Means of Flue Gas Recirculation  

NASA Astrophysics Data System (ADS)

This study focuses on the fundamental characteristics of DME (Dimethyl Ether) combustion aiming at development of low-NOx combustion technology with flue gas recirculation, FGR. The flue gas is recirculated into the combustion chamber to reduce the oxygen concentration and to suppress the combustion gas temperature, so that NOx emission is significantly reduced. The fuel gas recirculation at high mixing ratio, however, may lead to unstable combustion of conventional fuels, methane or city gas. On the other hand, DME has very high potential of applicability for the flue gas recirculation even at high mixing ratio because of its high burning velocity and low ignition temperature. Combustion tests were conducted with laboratory-scale 11kW combustor. The maximum FGR ratio is 85% at the initial air ratio of 1.5 with preheated diluted air about 600K. The NOx emission reduced to 13ppm at 0%-O2, which corresponds to about 9% of NOx emission at FGR=0%. The stable combustion is sustained even in the low oxygen concentration by preheating diluted-air up to near the auto-ignition temperature of DME. Finally, the effect of the flue gas recirculation on the NOx and CO emission is discussed with reference to the industrial-scale water-tube boilers.

Matsumoto, Ryosuke; Ozawa, Mamoru; Terada, Shinya; Iio, Takenori

271

Solid Polymer Electrolyte Water Electrolysis System Development.  

National Technical Information Service (NTIS)

Solid polymer electrolyte technology used in a water electrolysis system (WES) to generate oxygen and hydrogen for manned space station applications was investigated. A four-man rated, low pressure breadboard water electrolysis system with the necessary i...

1975-01-01

272

General Public Notification for Public Water Systems.  

National Technical Information Service (NTIS)

The Handbook is for owners, operators, and managers of public water systems, and discusses federal public notification regulations. Public water systems are required to comply with the federal regulations from the effective date of the rule (April 28, 198...

1989-01-01

273

The influence of different electrical conductivity values in a simplified recirculating soilless system on inner and outer fruit quality characteristics of tomato.  

PubMed

Irrigation with saline water affects tomato fruit quality. While total fruit yield decreases with salinity, inner quality characterized by taste and health-promoting compounds can be improved. For a detailed description of this relationship, the influence of three different salt levels [electrical conductivity (EC) 3, 6.5, and 10] in hydroponically grown tomatoes was investigated. Rising salinity levels in the nutrient solution significantly increased vitamin C, lycopene, and beta-carotene in fresh fruits up to 35%. The phenol concentration was tendentiously enhanced, and the antioxidative capacity of phenols and carotenoids increased on a fresh weight basis. Additionally, the higher EC values caused an increase of total soluble solids and organic acids, parameters determining the taste of tomatoes. Total fruit yield, single fruit weight, and firmness significantly decreased with rising EC levels. Regression analyses revealed significant correlations between the EC level and the dependent variables single fruit weight, total soluble solids, titrable acids, lycopene, and antioxidative capacities of carotenoids and phenols, whereas vitamin C and phenols correlated best with truss number, and beta-carotene correlated best with temperature. Only pressure firmness showed no correlation with any of the measured parameters. As all desirable characteristics in the freshly produced tomato increased when exposed to salinity, salinity itself constitutes an alternative method of quality improvement. Moreover, it can compensate for the loss of yield by the higher inner quality due to changing demands by the market and the consumer. This investigation is to our knowledge the first comprehensive overview regarding parameters of outer quality (yield and firmness), taste (total soluble solids and acids), nutritional value (vitamin C, carotenoids, and phenolics), as well as antioxidative capacity in tomatoes grown under saline conditions. PMID:16417302

Krauss, Sandra; Schnitzler, Wilfried H; Grassmann, Johanna; Woitke, Markus

2006-01-25

274

A prospective randomized open-label crossover trial of regional citrate anticoagulation vs. anticoagulation free liver dialysis by the Molecular Adsorbents Recirculating System  

PubMed Central

Introduction The Molecular Adsorbent Recycling System (MARS) is used to treat patients with liver failure. Observational data suggest that citrate anticoagulation during MARS is feasible. Comparative studies on the optimal anticoagulation regimen during MARS are lacking. The aim of the current study was to evaluate two heparin-free anticoagulation regimens. Methods We performed a prospective randomized open-label crossover study of regional citrate anticoagulation against no anticoagulation. Ten patients (age 55 ± 11 years) with liver failure undergoing MARS treatment were included. The primary endpoint was completion of MARS sessions. Secondary endpoints included treatment efficacy and safety. Longevity of MARS treatment was plotted as a Kaplan-Meier estimate. Fisher's exact test was used for contingency table analysis. Results Of a total of 27 6-hour sessions, four sessions had to be terminated prematurely, three due to occlusive clotting of the extracorporeal circuit and one due to uncontrollable bleeding from the vascular access site. All four events occurred in the group without anticoagulation. Between group comparison demonstrated citrate anticoagulation to significantly increase the likelihood of completed MARS treatment (Fisher's exact test, P 0.04). This translates into higher bilirubin reduction ratios when citrate was applied (reduction ratio 0.25 vs. 0.15, P 0.02). Systemic ionized calcium concentrations were significantly reduced during citrate anticoagulation (P < 0.001) but remained within a safe range. We observed no major adverse events. Conclusions Regional citrate anticoagulation in patients with liver failure is feasible. Citrate anticoagulation provides superior patency of the extracorporeal circuit. Avoidance of anticoagulation during MARS results in significant loss of treatment efficacy, due to treatment downtime. Additional studies are required to identify the optimal anticoagulation regimen for extracorporeal circulation in patients with liver failure.

2012-01-01

275

WATER QUALITY EFFECTS RELATED TO BLENDING WATERS IN DISTRIBUTION SYSTEMS  

EPA Science Inventory

This study was conducted to evaluate the effects of blending two or more waters of different quality and to relate their composition to the corrosive effects and calcium carbonate deposition tendency of the water on distribution systems. The EPA mobile water quality monitoring la...

276

Recirculation Gyres In The Labrador Sea and Their Influence On Deep Convection  

NASA Astrophysics Data System (ADS)

Recent observations in the Labrador and Irminger Seas have revealed energetic, weakly sheared cyclonic recirculation gyres just offshore of the boundary currents that flow around the subpolar North Atlantic. The data suggest that these features, which dominate the circulation in the interior of the Labrador and Irminger Seas, play an active role in isolating deep convection. The driving mechanism for these recircula- tion gyres and their influence on the formation and circulation of water masses within the Labrador and Irminger Seas are the main subjects of this study. To investigate these issues, a regional numerical model of the area of interest is used, which is idealized but designed to retain the essential features of the Labrador and Irminger Seas. The recirculation gyres appear to be predominantly forced by intense cyclonic wind events that develop along the east coast of Greenland during winter. The resulting oceanic response is a so-called beta-plume: an elongated cyclonic gyre that follows the topography around Greenland and into the Labrador Sea. Recirculations develop in the Irminger and Labrador Seas, in crude agreement with the observations. Despite the strong seasonality of the forcing the circulation persists year-round, as a consequence of slow Rossby-wave adjustment and interaction with the continental slope. Having established a plausible forcing mechanism for the recirculation gyres, we sub- sequently incorporate buoyancy forcing to investigate the influence of the recirculation gyres on deep convection. Key features of the recirculations that may result in favor- able conditions for localized deep convection, like the trapping of water masses and preconditioning of the stratification, are addressed.

Spall, M. A.; Katsman, C. A.; Pickart, R. S.

277

Pilot-scale cooling tower to evaluate corrosion, scaling, and biofouling control strategies for cooling system makeup water.  

PubMed

Pilot-scale cooling towers can be used to evaluate corrosion, scaling, and biofouling control strategies when using particular cooling system makeup water and particular operating conditions. To study the potential for using a number of different impaired waters as makeup water, a pilot-scale system capable of generating 27,000 kJ?h heat load and maintaining recirculating water flow with a Reynolds number of 1.92 × 10(4) was designed to study these critical processes under conditions that are similar to full-scale systems. The pilot-scale cooling tower was equipped with an automatic makeup water control system, automatic blowdown control system, semi-automatic biocide feeding system, and corrosion, scaling, and biofouling monitoring systems. Observed operational data revealed that the major operating parameters, including temperature change (6.6 °C), cycles of concentration (N = 4.6), water flow velocity (0.66 m?s), and air mass velocity (3660 kg?h m(2)), were controlled quite well for an extended period of time (up to 2 months). Overall, the performance of the pilot-scale cooling towers using treated municipal wastewater was shown to be suitable to study critical processes (corrosion, scaling, biofouling) and evaluate cooling water management strategies for makeup waters of complex quality. PMID:22380105

Chien, S H; Hsieh, M K; Li, H; Monnell, J; Dzombak, D; Vidic, R

2012-02-01

278

Recirculation control valve replacement cuts maintenance costs  

SciTech Connect

This article describes how replacement of boiler feed pump recirculation control valves solves a maintenance problem on Baldwin Unit 3. All three of Illinois Power`s Baldwin power plant units had the same boiler feed pump (BFP) valve design when they went into commercial operation. The original BFP recirculation valves were a top-guided plug, single-port cage design using a tapered plug and seat arrangement. This design failed in Unit 1 during the first year of operation, so a redesigned set of internals was installed in 1973. The new internals used a drilled-hole cage and were designed to resist cavitation and erosion. This same design was initially installed in the Unit 2 and Unit 3 valves. During initial unit startup and throughout the years, cavitation and erosion of the valve internals resulted in leaks.

Liefer, M.E.; Miller, H.L.; Katz, R.E.

1995-07-01

279

Recirculation of process streams in fuel ethanol production from softwood based on simultaneous saccharification and fermentation.  

PubMed

The effect of process stream recirculation on ethanol production from steam- pretreated softwood based on simultaneous saccharification and fermentation (SSF) was investigated for two process configurations. In the first configuration, a part of the stillage stream after distillation was recycled and, in the second configuration, the liquid after SSF was recycled. The aim was to minimize the energy consumption in the distillation of the fermentation broth and in the evaporation of the stillage, as well as the use of fresh water. However, recirculation leads to an increased concentration of nonvolatiles in the first configuration, and of both volatiles and nonvolatiles in the second configuration. These substances might be inhibitory to the enzymes and the yeast in SSF. When 60% of the fresh water was replaced by stillage, the ethanol yield and the productivity were the same as for the configuration without recirculation. The ethanol production cost was reduced by 17%. In the second configuration, up to 40% of the fresh water could be replaced without affecting the final ethanol yield, although the initial ethanol productivity decreased. The ethanol production cost was reduced by 12%. At higher degrees of recirculation, fermentation was clearly inhibited, resulting in a decrease in ethanol yield while hydrolysis seemed unaffected. PMID:12018307

Alkasrawi, Malek; Galbe, Mats; Zacchi, Guido

2002-01-01

280

Hybrid heat exchange for the compression capture of CO2 from recirculated flue gas  

SciTech Connect

An approach proposed for removal of CO2 from flue gas cools and compresses a portion of a recirculated flue-gas stream, condensing its volatile materials for capture. Recirculating the flue gas concentrates SOx, H2O and CO2 while dramatically reducing N2 and NOx, enabling this approach, which uses readily available industrial components. A hybrid system of indirect and direct-contact heat exchange performs heat and mass transfer for pollutant removal and energy recovery. Computer modeling and experimentation combine to investigate the thermodynamics, heat and mass transfer, chemistry and engineering design of this integrated pollutant removal (IPR) system.

Oryshchyn, Danylo B.; Ochs, Thomas L.; Summers, Cathy A.

2004-01-01

281

High Power Picosecond Laser Pulse Recirculation  

SciTech Connect

We demonstrate a nonlinear crystal-based short pulse recirculation cavity for trapping the second harmonic of an incident high power laser pulse. This scheme aims to increase the efficiency and flux of Compton-scattering based light sources. We demonstrate up to 36x average power enhancement of frequency doubled sub-millijoule picosecond pulses, and 17x average power enhancement of 177 mJ, 10 ps, 10 Hz pulses.

Shverdin, M Y; Jovanovic, I; Semenov, V A; Betts, S M; Brown, C; Gibson, D J; Shuttlesworth, R M; Hartemann, F V; Siders, C W; Barty, C P

2010-04-12

282

BIOFILM IN DRINKING WATER DISTRIBUTION SYSTEMS  

EPA Science Inventory

Throughout the world there are millions of miles of water distribution pipe lines which provide potable water for use by individuals and industry. Some of these water distribution systems have been in service well over one hundred years. Treated water moving through a distributio...

283

Water purification system using a heat pump  

Microsoft Academic Search

This paper presents a way to produce purified water with the same quality from the conventional water distiller and the advantage of saving energy and cooling water. Purified water was obtained by air dehumidifying with the aid of a heat pump and an adiabatic humidification system. The designed equipment is composed of two parts: a vapor compression heat pump and

Lorena Aires Lombardi Queiroz; Mariana de Oliveira Carvalho; João Borges Laurindo; Vivaldo Silveira Júnior

2011-01-01

284

Molecular Determinants Controlling Homeostatic Recirculation and Tissue-Specific Trafficking of Lymphocytes  

Microsoft Academic Search

The homeostasis of the immune system is maintained by the recirculation of naïve lymphocytes through the secondary lymphoid tissues, such as the lymph nodes, Peyer’s patches, and spleen. Upon insult by pathogens or antigens, lymphocytes become activated, and the regulated trafficking of these cells results in the integration of systemic and regional immune responses. The exquisite specificity of such lymphocyte

Toshiyuki Tanaka; Yukihiko Ebisuno; Naotoshi Kanemitsu; Eiji Umemoto; Bo-gie Yang; Myoung-ho Jang; Masayuki Miyasaka

2004-01-01

285

Beneficial effects on water management of simple hydraulic structures in wetland systems: the Vallevecchia case study, Italy.  

PubMed

Conflicting water uses in coastal zones demand integrated approaches to achieve sustainable water resources management, protecting water quality while allowing those human activities which rely upon aquatic ecosystem services to thrive. This case study shows that the creation and simple management of hydraulic structures within constructed wetlands can markedly reduce the non-point pollution from agriculture and, simultaneously, benefit agricultural activities, particularly during hot and dry periods. The Vallevecchia wetland system is based on a reclaimed 900 ha-large drainage basin in Northern Italy, where droughts recently impacted agriculture causing water scarcity and saltwater intrusion. Rainwater and drained water are recirculated inside the system to limit saltwater intrusion, provide irrigation water during dry periods and reduce the agricultural nutrient loads discharged into the bordering, eutrophic Adriatic Sea. Monitoring (2003-2009) of water quality and flows highlights that the construction (ended in 2005) of a gated spillway to control the outflow, and of a 200,000 m3 basin for water storage, dramatically increased the removal of nutrients within the system. Strikingly, this improvement was achieved with a minimal management effort, e.g., each year the storage basin was filled once: a simple management of the hydraulic structures would greatly enhance the system efficiency, and store more water to irrigate and limit saltwater intrusion. PMID:22053478

Carrer, G M; Bonato, M; Smania, D; Barausse, A; Comis, C; Palmeri, L

2011-01-01

286

Alternative Water Treatment Systems Using Flotation Technology.  

National Technical Information Service (NTIS)

Feasibility study was conducted for a parallel comparison between conventional water treatment system and innovative flotation system (KROFTA SANDFLOAT). It was concluded that the innovative system is technically feasible for removal of turbidity, color, ...

M. Krofta L. K. Wang

1982-01-01

287

Flow Field Features of the Induced Recirculation Zone using Planar Jet Injection.  

NASA Astrophysics Data System (ADS)

The objective of the present work is to study the recirculation bubble induced by injecting a planar jet in to a channel flow. The work is motivated by the desire to provide a flame stabilization environment for ramjet engines without the use of a sudden expansion or bluff-body which incurs drag penalties. A planar jet issuing into a cross flow is used to create a recirculation zone reminiscent of the flow field created downstream of a rearward-facing step configuration which is used in a current ramjet/scramjet systems. The effect of confinement at high momentum flux ratios leads to a saturation of the control of the recirculation bubble size and strength. Comparison to a rearward-facing step flow shows the current method produces higher turbulence levels and larger integral length scales. It is clear that the flow field produced with fluidic injection has potential for flame anchoring and enhancing combustion rates.

Ahmed, Kareem; Forliti, David; Moody, Jack

2006-11-01

288

Corrosion control in water injection systems  

SciTech Connect

Corrosion control in water injection systems encompasses a wide range of technologies, including chemicals (corrosion inhibitors, biocides, and oxygen scavengers); corrosion-resistant materials (metallic and nonmetallic); internal coatings and linings; mechanical removal of dissolved oxygen; velocity control; and prevention of oxygen entry and galvanic couples. This article reviews the way that these technologies are used in modern water-injection systems (both seawater and produced water) to provide an acceptable service life and high-quality injection water.

Patton, C.C. (C.C. Patton and Associates Inc., Dallas, TX (United States))

1993-08-01

289

Purification of Aquacultural Water: Conventional and New Membrane-based Techniques  

Microsoft Academic Search

Removing solids is an essential task when recirculating water an aquaculture system. Dissolved solids production directly from particulate solids as well as by fish is a function of time. These contaminants can indirectly affect the fish both biologically and physically. The flaws of conventional water treatment on seawater aquaculture systems are reviewed in this paper. Then a new technology for

Rosalam Sarbatly

2011-01-01

290

MUST Waste Water Treatment System.  

National Technical Information Service (NTIS)

The purpose of this program was to develop a second-generation water treatment unit that would treat liquid wastes (except human) from the MUST Hospital and produce (1) water, safe for ground discharge, and (2) potable water. As the previous flotation sys...

C. A. Bryce J. A. Heist R. Leon R. J. Daley R. D. Holyer Black

1973-01-01

291

Effect of room air recirculation delay on the decay rate of tracer gas concentration  

SciTech Connect

Tracer gas measurements are commonly used to estimate the fresh air exchange rate in a room or building. Published tracer decay methods account for fresh air supply, infiltration, and leaks in ductwork. However, the time delay associated with a ventilation system recirculating tracer back to the room also affects the decay rate. We present an analytical study of tracer gas decay in a well-mixed, mechanically-ventilated room with recirculation. The analysis shows that failing to account for delays can lead to under- or over-estimates of the fresh air supply, depending on whether the decay rate calculation includes the duct volume.

Kristoffersen, A.R.; Gadgil, A.J.; Lorenzetti, D.M.

2004-05-01

292

Impact of nitrate-enhanced leachate recirculation on gaseous releases from a landfill bioreactor cell.  

PubMed

This study evaluates the impact of nitrate injection on a full scale landfill bioreactor through the monitoring of gaseous releases and particularly N(2)O emissions. During several weeks, we monitored gas concentrations in the landfill gas collection system as well as surface gas releases with a series of seven static chambers. These devices were directly connected to a gas chromatograph coupled to a flame ionisation detector and an electron capture detector (GC-FID/ECD) placed directly on the field. Measurements were performed before, during and after recirculation of raw leachate and nitrate-enhanced leachate. Raw leachate recirculation did not have a significant effect on the biogas concentrations (CO(2), CH(4) and N(2)O) in the gas extraction network. However, nitrate-enhanced leachate recirculation induced a marked increase of the N(2)O concentrations in the gas collected from the recirculation trench (100-fold increase from 0.2 ppm to 23 ppm). In the common gas collection system however, this N(2)O increase was no more detectable because of dilution by gas coming from other cells or ambient air intrusion. Surface releases through the temporary cover were characterized by a large spatial and temporal variability. One automated chamber gave limited standard errors over each experimental period for N(2)O releases: 8.1 +/- 0.16 mg m(-2) d(-1) (n = 384), 4.2 +/- 0.14 mg m(-2) d(-1) (n = 132) and 1.9 +/- 0.10 mg m(-2) d(-1) (n = 49), during, after raw leachate and nitrate-enhanced leachate recirculation, respectively. No clear correlation between N(2)O gaseous surface releases and recirculation events were evidenced. Estimated N(2)O fluxes remained in the lower range of what is reported in the literature for landfill covers, even after nitrate injection. PMID:19297142

Tallec, G; Bureau, C; Peu, P; Benoist, J C; Lemunier, M; Budka, A; Presse, D; Bouchez, T

2009-03-17

293

The impact of recirculation, ventilation and filters on secondary organic aerosols generated by indoor chemistry  

NASA Astrophysics Data System (ADS)

This study examined the impact of recirculation rates (7 and 14 h -1), ventilation rates (1 and 2 h -1), and filtration on secondary organic aerosols (SOAs) generated by ozone of outdoor origin reacting with limonene of indoor origin. Experiments were conducted within a recirculating air handling system that serviced an unoccupied, 236 m 3 environmental chamber configured to simulate an office; either no filter, a new filter or a used filter was located downstream of where outdoor air mixed with return air. For otherwise comparable conditions, the SOA number and mass concentrations at a recirculation rate of 14 h -1 were significantly smaller than at a recirculation rate of 7 h -1. This was due primarily to lower ozone concentrations, resulting from increased surface removal, at the higher recirculation rate. Increased ventilation increased outdoor-to-indoor transport of ozone, but this was more than offset by the increased dilution of SOA derived from ozone-initiated chemistry. The presence of a particle filter (new or used) strikingly lowered SOA number and mass concentrations compared with conditions when no filter was present. Even though the particle filter in this study had only 35% single-pass removal efficiency for 100 nm particles, filtration efficiency was greatly amplified by recirculation. SOA particle levels were reduced to an even greater extent when an activated carbon filter was in the system, due to ozone removal by the carbon filter. These findings improve our understanding of the influence of commonly employed energy saving procedures on occupant exposures to ozone and ozone-derived SOA.

Fadeyi, M. O.; Weschler, C. J.; Tham, K. W.

294

Liquid flow focused by a gas: Jetting, dripping, and recirculation  

NASA Astrophysics Data System (ADS)

The liquid cone-jet mode can be produced upon stimulation by a coflowing gas sheath. Most applications deal with the jet breakup, leading to either of two droplet generation regimes: Jetting and dripping. The cone-jet flow pattern is explored by direct axisymmetric volume of fluid (VOF) numerical simulation; its evolution is studied as the liquid flow rate is increased around the jetting-dripping transition. As observed in other focused flows such as electrospraying cones upon steady thread emission, the flow displays a strong recirculating pattern within the conical meniscus; it is shown to play a role on the stability of the system, being a precursor to the onset of dripping. Close to the minimum liquid flow rate for steady jetting, the recirculation cell penetrates into the feed tube. Both the jet diameter and the size of the cell are accurately estimated by a simple theoretical model. In addition, the transition from jetting to dripping is numerically analyzed in detail in some illustrative cases, and compared, to good agreement, with a set of experiments.

Herrada, Miguel A.; Gañán-Calvo, Alfonso M.; Ojeda-Monge, Antonio; Bluth, Benjamin; Riesco-Chueca, Pascual

2008-09-01

295

SAFE DRINKING WATER INFORMATION SYSTEM (STATE)  

EPA Science Inventory

Resource Purpose: The Safe Drinking Water Information System (STATE) (SDWIS/STATE) is an information system OGWDW is developing for states and EPA regions to manage their water industry. SDWIS/STATE is not an information system for which EPA HQ is using to store or retrie...

296

DISTRIBUTION SYSTEM RESEARCH (WATER SUPPLY AND WATER RESOURCES DIVISION)  

EPA Science Inventory

Two water distribution system simulators(DSSs)are now in operation at the USEPA Test and Evaluation (T&E) Facility in Cincinnati, OH. EPA's T&E Facility is a multifaceted research resource in which a wide variety of water treatment and other environmental protection technologies ...

297

Raw water pre-treatment methods in pharmaceutical water systems  

Microsoft Academic Search

The use of pre-treatment methods for the raw water used to produce pharmaceutical grade water is growing in popularity, especially when it results in better operating reliability and a longer operating lifetime of the downstream treatment plant and equipment. Andreas Müller and Thomas Menzel, Christ AG, Switzerland, discuss the background to pre-treatment, and explain when such systems are necessary and

Andreas Müller; Thomas Menzel

2004-01-01

298

Monitoring of Leachate Recirculation in a Bioreactor Using Electrical Resistivity  

Microsoft Academic Search

The bioreactor is a concept of waste landfill management consisting in speeding up the biodegradation by optimizing the moisture content through leachate recirculation. Electrical resistivity tomography (ERT) is carried out with fast resistivity-meter (Syscal Pro, IRIS Instruments, developed in the framework of the research project CERBERE 01V0665-69, funded by the French Research Ministry) to monitor leachate recirculation. During a recirculation

S. Grellier; N. Bureau; H. Robain; A. Tabbagh; C. Camerlynck; R. Guerin

2004-01-01

299

FULL-SCALE EXPERIENCES WITH LEACHATE RECIRCULATING LANDFILLS: CASE STUDIES  

Microsoft Academic Search

Leachate recirculation has been shown in lysimeter, pilot-scale and full-scale investigations to reduce the time required for waste stabilization, improve leachate quality, provide the opportunity for leachate volume reduction, and to enhance the rate of gas production. New generation full-scale landfills are implementing recirculation as a leachate management tool with increasing frequency. Leachate recirculation techniques used at full-scale landfills include

Debra R. Reinhart

1996-01-01

300

Interpretation of corrosion potential data from boiling-water reactors under hydrogen water chemistry conditions  

SciTech Connect

A method was devised to estimate electrochemical conditions at the entrance to the recirculation piping of a boiling water reactor under hydrogen water chemistry (HWC) conditions from electrochemical corrosion potential (ECP) measurements made in remote autoclaves. The technique makes use of the mixed potential model to estimate ECP in the autoclaves and compares estimates to measured values in an optimization on the concentrations of hydrogen peroxide and oxygen in the recirculation system. The algorithm recognizes that H{sub 2}O{sub 2} decomposes in sampling lines and that transit times between the recirculation system and monitoring points depend upon flow rates and sampling line diameters. An analysis was made of ECP data from three monitoring locations in the Barseback BWR in Sweden, as a function of H{sub 2} concentration in the feedwater for two flow rates (5,500 kg/s and 6,300 kg/s for the four recirculation loops). HWC did not displace ECP below a critical value of {minus}0.23 V{sub SHE} at the lower flow rate until the reactor water [H{sub 2}] exceeded 0.15 ppm, corresponding to a feedwater H{sub 2} level of > 0.93 ppm. At the higher flow rate of 6,300 kg/s (divided equally between four recirculation loops), protection was not predicted until the feedwater [H{sub 2}] exceeded 1.2 ppm, corresponding to a reactor water [H{sub 2}] of {approximately} 0.195 ppm. The difference was attributed to the greater persistence of H{sub 2}O{sub 2} at high feedwater [H{sub 2}] at the higher flow rate, possibly because of the lower transit time from the core to the recirculation system.

Macdonald, D.D.; Urquidi-Macdonald, M. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science

1996-09-01

301

Recirculating Linear Accelerators for Future Muon Facilities  

SciTech Connect

Neutrino Factories (NF) and Muon Colliders (MC) require rapid acceleration of short-lived muons to multi-GeV and TeV energies. A Recirculating Linear Accelerator (RLA) that uses superconducting RF structures can provide exceptionally fast and economical acceleration to the extent that the focusing range of the RLA quadrupoles allows each muon to pass several times through each high-gradient cavity. A new concept of rapidly changing the strength of the RLA focusing quadrupoles as the muons gain energy is being developed to increase the number of passes that each muon will make in the RF cavities, leading to greater cost effectiveness.

S.A. Bogacz, K.B.Beard, R.P. Johnson

2010-05-01

302

Practice review of five bioreactor/recirculation landfills.  

PubMed

Five landfills were analyzed to provide a perspective of current practice and technical issues that differentiate bioreactor and recirculation landfills in North America from conventional landfills. The bioreactor and recirculation landfills were found to function in much the same manner as conventional landfills, with designs similar to established standards for waste containment facilities. Leachate generation rates, leachate depths and temperatures, and liner temperatures were similar for landfills operated in a bioreactor/recirculation or conventional mode. Gas production data indicate accelerated waste decomposition from leachate recirculation at one landfill. Ambiguities in gas production data precluded a definitive conclusion that leachate recirculation accelerated waste decomposition at the four other landfills. Analysis of leachate quality data showed that bioreactor and recirculation landfills generally produce stronger leachate than conventional landfills during the first two to three years of recirculation. Thereafter, leachate from conventional and bioreactor landfills is similar, at least in terms of conventional indicator variables (BOD, COD, pH). While the BOD and COD decreased, the pH remained around neutral and ammonia concentrations remained elevated. Settlement data collected from two of the landfills indicate that settlements are larger and occur much faster in landfills operated as bioreactors or with leachate recirculation. The analysis also indicated that more detailed data collection over longer time periods is needed to draw definitive conclusions regarding the effects of bioreactor and recirculation operations. For each of the sites in this study, some of the analyses were limited by sparseness or ambiguity in the data sets. PMID:16766174

Benson, C H; Barlaz, M A; Lane, D T; Rawe, J M

2006-06-12

303

Phase-noise suppression in an interferometric fiber optic sensor with recirculating paths  

Microsoft Academic Search

We report a modified all-fiber Mach-Zehnder interferometer configuration incorporating recirculating fiber paths in both the signal and reference arms. This system can be operated using a time-division based interrogation approach to yield a self phase-noise compensated sensor.

Michael J. Marrone; Alan D. Kersey

1992-01-01

304

A Tracer Method for Evaluating Recirculation of Pollutant Releases in Buildings  

Microsoft Academic Search

A method is introduced for evaluating recirculation in a building ventilation system from pollutant emissions in or near the building. Tracer was released at a known rate at the point of pollutant emission. Using measured tracer concentrations, the tracer release rate, and an estimate of the pollutant release rate, pollutant concentrations were estimated at the locations in the building where

James P. Rydock; Ove Hermansen

2002-01-01

305

Selective Withdrawal in Oil\\/water system  

Microsoft Academic Search

We study the process of selective withdrawal in oil\\/water system. A layer of oil is placed on the top of a layer of water. The oil is being withdrawn at a constant rate through the tube; the tube's end is situated above the undisturbed oil\\/water interface. If the oil withdrawal rate is small, only the oil enters the tube (single

Itai Cohen; Sidsney Nagel; Todd Dupont; Vachtang Putkaradze

1998-01-01

306

Grey water treatment systems: A review  

Microsoft Academic Search

This review aims to discern a treatment for grey water by examining grey water characteristics, reuse standards, technology performance and costs. The review reveals that the systems for treating grey water, whatever its quality, should consist of processes that are able to trap pollutants with a small particle size and convert organic matter to mineralized compounds. For efficient, simple and

L. N. A. H. Abu-Ghunmi; G. Zeeman; M. Fayyad; Lier van J. B

2011-01-01

307

Grey Water Treatment Systems: A Review  

Microsoft Academic Search

This review aims to discern a treatment for grey water by examining grey water characteristics, reuse standards, technology performance and costs. The review reveals that the systems for treating grey water, whatever its quality, should consist of processes that are able to trap pollutants with a small particle size and convert organic matter to mineralized compounds. For efficient, simple and

Lina Abu Ghunmi; Grietje Zeeman; Manar Fayyad; Jules B. van Lier

2011-01-01

308

Hot water heating system having minimum hot water use based on minimum water temperatures and time of heating  

Microsoft Academic Search

This patent describes a water heater control system for constantly controlling the heating and use of hot water from a water heater unit of the type having water heater means with a water heater control means therefor converting between on for heating water and off free of heating water. The control system comprises a water inlet means for feeding water

T. R. Vandermeyden; O. R. Dufau; F. J. Blau

1986-01-01

309

Water Quality Management and Information Systems.  

National Technical Information Service (NTIS)

A data management system is presented that will aid planners in the implementation of a decision support system which addresses the technical aspects of areawide water quality planning. The basis is the systematic study of the information flows and their ...

A. B. Whinston

1975-01-01

310

Recirculating Planar Magnetron Modeling and Experiments  

NASA Astrophysics Data System (ADS)

We present simulations and initial experimental results of a new class of crossed field device: Recirculating Planar Magnetrons (RPM) [1]. Two geometries of RPM are being explored: 1) Dual planar-magnetrons connected by a recirculating section with axial magnetic field and transverse electric field, and 2) Planar cathode and anode-cavity rings with radial magnetic field and axial electric field. These RPMs have numerous advantages for high power microwave generation by virtue of larger area cathodes and anodes. The axial B-field RPM can be configured in either the conventional or inverted (faster startup) configuration. Two and three-dimensional EM PIC simulations show rapid electron spoke formation and microwave oscillation in pi-mode. Smoothbore prototype axial-B RPM experiments are underway using the MELBA accelerator at parameters of -300 kV, 1-20 kA and pulselengths of 0.5-1 microsecond. Implementation and operation of the first RPM slow wave structure, operating at 1GHz, will be discussed. [4pt] [1] Patent pending

Franzi, Matthew; Gilgenbach, Ronald; Hoff, Brad; French, Dave; Lau, Y. Y.

2011-11-01

311

Recirculating linac free-electron laser driver  

NASA Astrophysics Data System (ADS)

This paper describes the design of a recirculating linac as a driver for the suite of seeded free-electron lasers (FELs) proposed in the UK New Light Source (NLS) project. The choice of superconducting technology for NLS is required in order to deliver bunches at high repetition rates up to 1 MHz. This raises the question of whether a shorter linac in recirculating mode can deliver the beam quality required for seeded FELs. To design such a facility, careful layout choices and optimizations must be made to ensure emittance growth is minimized. Effects leading to emittance dilution include chromatic transport terms, incoherent and coherent synchrotron radiation. The design outlined here is based on a modular philosophy to separate beam injection and extraction from a three stage compression scheme. The design uses many novel design concepts and optimizations to deliver the necessary high peak currents while preserving beam quality for seeded FELs. Start-to-end simulations including the FELs show that the necessary pulse coherence and output power can be provided from the beam thus generated.

Williams, Peter H.; Angal-Kalinin, Deepa; Dunning, David J.; Jones, James K.; Thompson, Neil R.

2011-05-01

312

Automated Water Analyser Computer Supported System (AWACSS)  

Microsoft Academic Search

A novel analytical system AWACSS (Automated Water Analyser Computer Supported System) based on immunochemical technology has been evaluated that can measure several organic pollutants at low nanogram per litre level in a single few-minutes analysis without any prior sample pre-concentration or pre-treatment steps.Having in mind actual needs of water-sector managers related to the implementation of the Drinking Water Directive (DWD)

Jens Tschmelak; Guenther Proll; Johannes Riedt; Joachim Kaiser; Peter Kraemmer; Luis Bárzaga; James S. Wilkinson; Ping Hua; J. Patrick Hole; Richard Nudd; Michael Jackson; Ram Abuknesha; Damià Barceló; Sara Rodriguez-Mozaz; Maria J. López de Alda; Frank Sacher; Jan Stien; Jaroslav Slobodník; Peter Oswald; Helena Kozmenko; Eva Korenková; Lívia Tóthová; Zoltan Krascsenits; Guenter Gauglitz

2005-01-01

313

Tokyo's modern water system celebrates its centennial  

Microsoft Academic Search

In 1898, Tokyo, Japan, modernized its then 300-year-old water supply system by building a slow sand filtration plant. The modernized system has come a long way and is celebrating its one hundredth anniversary in 1998. This article highlights the triumphs and tribulations Tokyo has faced over the years in delivering drinking water to its citizens. It covers the development of

Kazunori Kawakita

1998-01-01

314

Basics of Solar Heating & Hot Water Systems.  

ERIC Educational Resources Information Center

|In presenting the basics of solar heating and hot water systems, this publication is organized from the general to the specific. It begins by presenting functional and operational descriptions of solar heating and domestic hot water systems, outlining the basic concepts and terminology. This is followed by a description of solar energy…

American Inst. of Architects, Washington, DC.

315

Simulation in operation of water supply systems  

Microsoft Academic Search

Simulation techniques in the operation of water supply systems have the following advantages: (a) enables the engineer to evaluate the efficiency of his design options and so attain maximum efficiency; (b) enables the operators to monitor the hydraulic feasibility of heuristic or optimized operation schedules; and (c) enables the forecasting of water flows through the hydraulic system. In Mekorot two

Y. Kadar; E. Damelin

316

Basics of Solar Heating & Hot Water Systems.  

ERIC Educational Resources Information Center

In presenting the basics of solar heating and hot water systems, this publication is organized from the general to the specific. It begins by presenting functional and operational descriptions of solar heating and domestic hot water systems, outlining the basic concepts and terminology. This is followed by a description of solar energy utilization…

American Inst. of Architects, Washington, DC.

317

A revised land hydrology in the ECMWF model: A step towards water fluxes prediction in a fully-closed water cycle  

Microsoft Academic Search

Predictions of the global water cycle involve accurate atmospheric analyses and forecasts and a realistic representation of land surface processes for correctly timing water recirculation. A river routing mechanism is then needed to simulate rivers transport back into the oceans. Physical parameterizations of the ECMWF Integrated Forecast System (IFS) involved in the predictions of soil moisture and snow have been

G. Balsamo; E. Dutra; F. Pappenberger; P. Viterbo; B. van den Hurk

2009-01-01

318

'GIARDIA' DETECTION IN WATER SYSTEMS  

EPA Science Inventory

A method has been developed combining immunofluorescence and phase-contrast to microscopically locate and identify Giardia cysts among particulates filtered from water samples. Selective staining of cysts with anti-Giardia antiserum and a fluorochrom enhances the contrast between...

319

Reuse of Treated Internal or External Wastewaters in the Cooling Systems of Coal-Based Thermoelectric Power Plants  

Microsoft Academic Search

This study evaluated the feasibility of using three impaired waters - secondary treated municipal wastewater, passively treated abandoned mine drainage (AMD), and effluent from ash sedimentation ponds at power plants - for use as makeup water in recirculating cooling water systems at thermoelectric power plants. The evaluation included assessment of water availability based on proximity and relevant regulations as well

Radisav Vidic; David Dzombak; Ming-Kai Hsieh; Heng Li; Shih-Hsiang Chien; Yinghua Feng; Indranil Chowdhury; Jason Monnell

2009-01-01

320

The water portal: a decision support system for water governance  

Microsoft Academic Search

The World Water Assessment Programme (WWAP) is a UN-system wide programme involving all agencies and convention secretariats concerned with freshwater. It responds to the 1998 call by the UN Commission for sustainable development for the UN system to undertake period assessments of \\

M. del Pilar Gonzalez Meyaui

2004-01-01

321

An Ice Storage System using Supercooled Water  

NASA Astrophysics Data System (ADS)

The economic aspects of an ice storage system employing supercooled water were compared with those of a chilled water system. In this analysis, the characteristics of the thermal storage tank and the system-COP were selected as technological factors, that have particular relevance to the economic issues at introduction of tharmal storage systems. The following results were obtained : (1) The cooling rate of the ice storage system was comparable with the rate of a chilled water storage system. (2) The cooling rate of the ice storage system was not hardly influenced by the cost of thermal storage tank. (3) In the hybrid thermal storage system, the ice storage system could surely satisfy the requirement for large peak shift.

Tanino, Masayuki; Iribe, Masatake; Okonogi, Tokio; Kozawa, Yoshiyuki

322

Recirculation subtraction for analysis of left-to-right-cardiac shunts: concise communication  

SciTech Connect

The object of this study is to improve the techniques for describing the lung dilution curve for shunt quantification by separating the effects of systemic recirculation on the curve from those of direct shunt return. The time of the systemic recirculation peak was estimated by determination of transit times from the right and left ventricles and lung. A gamma variate fit based on the distribution of points at that segment was applied to the recirculation curve and subtracted from the original lung dilution curve. Similar gamma variate fitting was performed for both primary and shunt curves. Rather than fitting the gamma variate of the shunt curve by the leading edge only, a larger portion could now be used since the trailing edge of the curve is clearer following recirculation subtraction. The algorithm is completely automatic, requiring no operator intervention or selection of curve-fitting regions. The correlation coefficient for comparison of the dilution-curve analysis with oximetry determinations was 0.92 in a series of 29 patients.

Houser, T.S.; MacIntyre, W.J.; Cook, S.A.; Go, R.T.; Moodie, D.S.; Ceimo, J.; Gallagher, J.H.

1981-12-01

323

Water recycle method for washing alkali-refined soybean oil  

Microsoft Academic Search

Vegetable oil refineries are faced today with cutting down on pollution caused by their waste water. A method was developed\\u000a for washing alkali-refined soybean oil with treated, recirculated wash water. In this method, wash water passes through a\\u000a cation exchange resin that removes Na, and the slightly acid water goes back into the system for continuous reuse. The disposal\\u000a problem

R. A. Eisenhauer; R. E. Beal; E. L. Griffin

1970-01-01

324

Analysis and prevention of corrosion in T o chopper systems  

Microsoft Academic Search

To neutron choppers at Oak Ridge National Laboratory's Spallation Neutron Source will stop prompt pulses of high-energy neutrons outside the target moderator. Choppers are cooled internally by recirculated distilled water maintained at 15°C. Numerous metallic components are used to fabricate the choppers and cooling system; water contacts many of these components, establishing a corrosion cell. To chopper system corrosion products

Laura R. Skubal; David B. Chojnowski; Raymond Ziegler

2008-01-01

325

The benefits of flue gas recirculation in waste incineration  

Microsoft Academic Search

Flue gas recirculation in the incinerator combustion chamber is an operative technique that offers substantial benefits in managing waste incineration. The advantages that can be obtained are both economic and environmental and are determined by the low flow rate of fumes actually emitted if compared to the flue gas released when recirculation is not conducted. Simulations of two incineration processes,

Giuseppe Liuzzo; Nicola Verdone; Marco Bravi

2007-01-01

326

Energy savings from air recirculation in peanut curing  

SciTech Connect

A thin-layer peanut drying simulation model was adapted to incorporate air recirculation. Laboratory crop dryers were designed and constructed to conduct experiments to verify the model. Five batches of peanuts were dried using different recirculation strategies. The model successfully predicted the results.

Cook, D.F.; Cundiff, J.S.; Vaughan, D.H.

1982-12-01

327

Longitudinal dynamics in high frequency ffag recirculating accelerators  

Microsoft Academic Search

A recirculating accelerator accelerates the beam by passing through accelerating cavities multiple times. An FFAG recirculating accelerator uses a single arc to connect the linacs together, as opposed to multiple arcs for the different energies. For most scenarios using high-frequency RF, it is impractical to change the phase of the RF on each pass, at least for lower energy accelerators.

S. Berg

2002-01-01

328

Activated seawater waste water treatment system  

SciTech Connect

A waste water treatment system for use in treating household waste water particularly for tidal coastal areas where seawater is plentiful and fresh water may be scarce. The system uses a source of seawater, preferably from a central storage location, to which hydrogen peroxide has been added. Individual households are provided with the seawater-hydrogen peroxide mixture as flush water directly into the toilet flush tanks. The discharge from each household, including wastes from toilets, bathing, wash and kitchen units, is fed to a series of two or three reaction chambers, and a filter unit before being drained back into the tidal waters. The system includes also a bypass line independent of the flushing mechanisms to provide a continuous source of the seawater-hydrogen peroxide mixture directly into the reaction chambers to insure continuous aerobic biochemical reaction with solids in the reaction chambers thus providing for continuous reaction independent of fluctuating rate of usage of the household waste systems.

Rehm, R.H.

1984-04-10

329

Screening reactor steam/water piping systems for water hammer  

SciTech Connect

A steam/water system possessing a certain combination of thermal, hydraulic and operational states, can, in certain geometries, lead to a steam bubble collapse induced water hammer. These states, operations, and geometries are identified. A procedure that can be used for identifying whether an unbuilt reactor system is prone to water hammer is proposed. For the most common water hammer, steam bubble collapse induced water hammer, six conditions must be met in order for one to occur. These are: (1) the pipe must be almost horizontal; (2) the subcooling must be greater than 20 C; (3) the L/D must be greater than 24; (4) the velocity must be low enough so that the pipe does not run full, i.e., the Froude number must be less than one; (5) there should be void nearby; (6) the pressure must be high enough so that significant damage occurs, that is the pressure should be above 10 atmospheres. Recommendations on how to avoid this kind of water hammer in both the design and the operation of the reactor system are made.

Griffith, P. [Massachusetts Inst. of Tech., Cambridge, MA (United States)

1997-09-01

330

Seaweed biofilters as regulators of water quality in integrated fish-seaweed culture units  

Microsoft Academic Search

The water-quality characteristics of a new system for the integrated culture of fish (Sparus aurata L.) and seaweed (Ulva lactuca L.) were examined. Seawater was recirculated between intensive fishponds and seaweed ponds. The seaweed removed most of the ammonia excreted by the fish and oxygenated the water. A model consisting of several tanks and a pilot consisting of two 100-m3,

Amir Neori; Michael D. Krom; Steve P. Ellner; Claude E. Boyd; Dan Popper; Ruth Rabinovitch; Patrick J. Davison; Orit Dvir; Daniel Zuber; Michal Ucko; Dror Angel; Hillel Gordin

1996-01-01

331

Recirculating Linac Accelerators For Future Muon Facilities  

SciTech Connect

Neutrino Factories (NF) and Muon Colliders (MC) require rapid acceleration of shortlived muons to multi-GeV and TeV energies. A Recirculating Linear Accelerator (RLA) that uses superconducting RF structures can provide exceptionally fast and economical acceleration to the extent that the focusing range of the RLA quadrupoles allows each muon to pass several times through each high-gradient cavity. A new concept of rapidly changing the strength of the RLA focusing quadrupoles as the muons gain energy is being developed to increase the number of passes that each muon will make in the RF cavities, leading to greater cost effectiveness. We discuss the optics and technical requirements for RLA designs, using RF cavities capable of simultaneous acceleration of both m+ and m- species. The design will include the optics for the multi-pass linac and droplet-shaped return arcs.

Yves Roblin, Alex Bogacz, Vasiliy Morozov, Kevin Beard

2012-04-01

332

Mixing in a stratified recirculating flow  

SciTech Connect

Experiments were conducted to study the mixing processes and circulation patterns in a stratified, lid-driven cavity flow. This flow is different from those reported in the literature in three ways, viz., recirculation is a dominant feature, temperature is used as the stratification device, and the upper and lower boundaries are held at different constant temperatures. For the geometric configuration used entrainment rate E is proportional to Ri/sup -7/5/. Taylor-Goertler-like vortices above the thermocline are significant contributors to the mixing process. In addition, the number of circulation cells expected in this stratified flow can be estimated by use of the bulk Richardson number Ri/sub b/.

Koseff, J.R.; Rhee, H.; Street, R.L.

1983-01-01

333

The ultra pure water system: Final report  

SciTech Connect

The design, building and the testing of an Ultra Pure Water Generation System that was funded by the Department of Energy (DOE) after first being evaluated by the National Bureau of Standards is covered. This system will accept water that is highly polluted with both suspended and dissolved solids. The purification and sterilization is performed in stages. As the water is pumped in, it is first forced through a set of three filters. These filters collect 99% of the particles. The water is then sent through the ion-exchange section which extracts 99.9% of the dissolved solids. The water is then sent through a mixed ion-exchange column and into the the last micro filter. It then is sent to a two gallon holding tank. While in the tank the pure water is polished with ozone gas. The flow through the complete purification system is 2 gallons per minute, therefore, its exposure time to ozone in this holdup tank is about 5 minutes. During the time any oxidizable matter, bacteria or viruses left will be destroyed. An important cycle of this unit is the back flush system. After each use of the water purification system, the unit reverses the flow of water through the larger particle filters.

Karlson, E.L.

1988-03-01

334

Near-surface recirculation over Georges Bank  

NASA Astrophysics Data System (ADS)

Satellite-tracked drifters with drogues centered near-surface (5 m) and below the seasonal thermocline (50 m) were launched during late winter and spring of 1988 and 1989 in the northern Great South Channel in the western Gulf of Maine to investigate the regional circulation as part of the South Channel Ocean Productivity Experiment (SCOPEX). Many of the near-surface drifters became entrained in the clockwise gyre over Georges Bank, and eight drifters made a total of 16 complete circuits around the bank during the stratified season. The average recirculation period of these eight drifters was 48 days, and the average drifter speed around the bank was 12 cm s -1. There is no clear evidence from the drifter data that the strength of the clockwise gyre over the bank increased with time during the stratified season. On average, these drifters (i) followed a relatively narrow path around the bank, except over the eastern end of the bank where three preferred paths were observed, (ii) moved fastest over the northern and southern flanks of the bank, (iii) did not enter a core area of 3500 km 2 centered at 41°17'N, 68°00'W, approximately 30 km southwest of the topographic center of the bank, and (iv) stopped circling the bank by the end of November, due in part to strong wind events that appeared to drive drifters off the bank. Curiously, none of the near-surface drifters moved from the southern flank of Georges Bank onto the New England shelf as might be expected from continuity of flow along the outer shelf; instead, the drifters that circled the bank tended to move off the bank along its southern flank. None of the drifters with drogues centered at 50 m appeared to recirculate around Georges Bank.

Limeburner, Richard; Beardsley, Robert C.

335

Optimal monitoring of water distribution systems  

NASA Astrophysics Data System (ADS)

The supervisory control and data acquisition (SCADA) technology is commonly used in water distribution systems in recently years. Monitoring is one of the most important steps in SCADA's implementation, and in reality monitoring stations used for water pressure are usually decided by experience or simply evenly distributed. For the purpose of more efficient monitoring, a method for optimal monitoring of water pressure in a water distribution system is proposed in this paper, in which, a sensitivity analysis is conducted for determining the sensitivity equation, and the sensitivity equation is then solved by a least-square method. It is found from examples that the method provides an efficient and practical way in which optimal monitoring scheme of water distribution system may be decided.

Liang, Jianwen; Xiao, Di; Zhang, Hongwei; Zhao, Xinhua

2003-08-01

336

Captive Water Current Power System  

SciTech Connect

Current energy is converted into shaft power in two stages; First, buoyant power units with stationary hydrofoil wings reach faster than the current speed by sweeping out a captive path. Second, turbines at said power units convert the fast relative local current into shaft power. Power units sweeping along the water surface, using cycloidal turbine methods, as well as power units sweeping on a submerged path, using axial flow turbine methods, are described.

Wuenscher, H. F.; Wuenscher, H. A.

1984-01-31

337

Army Energy and Water Reporting System Assessment  

Microsoft Academic Search

There are many areas of desired improvement for the Army Energy and Water Reporting System. The purpose of system is to serve as a data repository for collecting information from energy managers, which is then compiled into an annual energy report. This document summarizes reported shortcomings of the system and provides several alternative approaches for improving application usability and adding

Peggy C. Deprez; Michael J. Giardinelli; John S. Burke; Linda M. Connell

2011-01-01

338

Deep water riser system for offshore drilling  

Microsoft Academic Search

A buoyant riser system for use in a deep water offshore drilling environment is anchored by a system of compliant guys below the active weather zone of the sea. A controllably buoyant housing of the system is submerged at a depth that is readily accessible to divers and includes a blow-out preventer (BOP) from which a suspended sub-riser leads to

1984-01-01

339

U.S. Nuclear Regulatory Commission Guide Series. Division 1. Power Reactors (Regulatory Guide 1.82, Revision 4). Water Sources for Long-Term Recirculation Cooling Following a Loss-of Coolant Accident.  

National Technical Information Service (NTIS)

This guide describes methods that the staff of the U.S. Nuclear Regulatory Commission (NRC) considers acceptable for use in implementing requirements regarding the sumps and suppression pools that provide water sources for emergency core cooling, containm...

2012-01-01

340

Biofilm formation and multiplication of Legionella in a model warm water system with pipes of copper, stainless steel and cross-linked polyethylene.  

PubMed

Legionella pneumophila was grown in a model warm water system with pipes of copper (Cu), stainless steel (SS) and cross-linked polyethylene (PEX) during recirculation of tap water at 25--35 degrees C. Subsequently, domestic use of warm (37 degrees C) water was simulated using tap water with a low AOC concentration (<10 microg C/L). Two times each week the temperature of the water in the electric heaters (not in the pipes) was elevated to 70 degrees C for 30 min. ATP concentrations in the water sampled from the pipes over a 2-year period were significantly different for the pipe materials, with median values of 2.1 ng/l (Cu), 2.5 ng/l (SS) and 4.5 ng/l (PEX), respectively. Median values of the biofilm concentration were similar on Cu and SS (about 630 pg ATP/cm(2)) and 1870 pg ATP/cm(2) on PEX. Legionella multiplied in these biofilms and median values of Legionella concentrations in water were 1500 CFU/l (Cu) and about 4300 CFU/l for SS and PEX. Legionella to ATP ratios in water had median values of about 0.8 CFU/pg. Hot water flushing (70 degrees C) of the pipes on day 552, followed by 2 weeks of recirculation at 37 degrees C, caused strongly increased concentrations of ATP (up to 300 ng/l) and Legionella (>10(7)CFU/l), with about 100 CFU/pg ATP. Concentrations declined to original levels within 1 week of domestic water use, etc. Legionella concentrations in water and biofilms were at the same levels for all materials after 2 years. Hence, copper temporarily limited the growth of Legionella under the applied conditions and a rapid biomass development strongly increased the Legionella to ATP ratio. PMID:16019051

van der Kooij, Dick; Veenendaal, Harm R; Scheffer, Will J H

2005-08-01

341

Management of Water Distribution System Components.  

National Technical Information Service (NTIS)

The purpose of the study is to (1) analyze main break failures and (2) incorporate other drinking water distribution system components into a data base management structure for reliability analyses. Reliability analysis should be a part of an overall oper...

J. A. Goodrich C. P. S. Frebis E. J. Read R. M. Clark

1987-01-01

342

Vulnerability of the Albuquerque Water Supply System.  

National Technical Information Service (NTIS)

This report assesses the vulnerability of the Albuquerque water supply system to damage from a hypothetical nuclear weapon attack. Probable damage to facilities and casualties to personnel are considered, as well as the possible loss of support from inter...

R. L. Nevin

1969-01-01

343

CONCENTRATION OF POLIOVIRUS IN WATER BY MOLECULAR FILTRATION  

EPA Science Inventory

The efficiency of concentrating poliovirus 1 from distilled water samples was determined by using a recirculating-flow molecular filtration system. The most efficient recoveries were achieved against membranes with a 10,000 nominal molecular weight limit pretreated with flocculat...

344

Decision support system for drinking water management  

NASA Astrophysics Data System (ADS)

The problems in drinking water management are complex and often solutions must be reached under strict time constrains. This is especially distinct in case of environmental accidents in the catchment areas of the wells that are used for drinking water supply. The beneficial tools that can help decision makers and make program of activities more efficient are decision support systems (DSS). In general they are defined as computer-based support systems that help decision makers utilize data and models to solve unstructured problems. The presented DSS was developed in the frame of INCOME project which is focused on the long-term stable and safe drinking water supply in Ljubljana. The two main water resources Ljubljana polje and Barje alluvial aquifers are characterized by a strong interconnection of surface and groundwater, high vulnerability, high velocities of groundwater flow and pollutant transport. In case of sudden pollution, reactions should be very fast to avoid serious impact to the water supply. In the area high pressures arising from urbanization, industry, traffic, agriculture and old environmental burdens. The aim of the developed DSS is to optimize the activities in cases of emergency water management and to optimize the administrative work regarding the activities that can improve groundwater quality status. The DSS is an interactive computer system that utilizes data base, hydrological modelling, and experts' and stakeholders' knowledge. It consists of three components, tackling the different abovementioned issues in water management. The first one utilizes the work on identification, cleaning up and restoration of illegal dumpsites that are a serious threat to the qualitative status of groundwater. The other two components utilize the predictive capability of the hydrological model and scenario analysis. The user interacts with the system by a graphical interface that guides the user step-by-step to the recommended remedial measures. Consequently, the acquisition of information to support the water management's decisions is simplified and faster, thus contributing to more efficient water management and a safer supply of drinking water.

Janža, M.

2012-04-01

345

Investigation of groundwater recirculation for the removal of RDX from the Pantex Plant perched aquifer  

SciTech Connect

The Pantex Plant near Amarillo, Texas, is a US Department of Energy (DOE) facility that has been in operation since 1942. Past and present operations at Pantex include the creation of chemical high explosives components for nuclear weapons and assembly and disassembly of nuclear weapons. The Pantex Plant is underlain by the Ogallala aquifer, which in this area, consists of the main water-bearing unit and a perched water zone. These are separated by a fine-grained zone of low permeability. Multiple contaminant plumes containing high explosive (HE) compounds have been detected in the perched aquifer beneath the plant. The occurrence of these contaminants is the result of past waste disposal practices at the facility. RDX is an HE compound, which has been detected in the groundwater of the perched aquifer at significant concentrations. A pilot-scale, dual-phase extraction treatment system has been installed at one location at the plant, east of Zone 12, to test the effectiveness of such a system on the removal of these contaminants from the subsurface. A tracer test using a conservative tracer, bromide (Br), was conducted at the treatment site in 1996. In addition to the bromide, RDX and water elevations in the aquifer were monitored. Using data from the tracer test and other relevant data from the investigations at Pantex, flow and contaminant transport in the perched aquifer were simulated with groundwater models. The flow was modeled using MODFLOW and the transport of contaminants in the aqueous phase was modeled using MT3D. Modeling the perched aquifer had been conducted to characterize the flow in the perched aquifer; estimate RDX retardation in the perched aquifer; and evaluate the use of groundwater re-circulation to enhance the extraction of RDX from the perched aquifer.

Woods, A.L. [ed.; Barnes, D.L. [Amarillo National Resource Center for Plutonium, TX (United States); Boles, K.M.; Charbeneau, R.J. [Univ. of Texas, Austin, TX (United States); Black, S.; Rainwater, K. [Texas Tech Univ., Lubbock, TX (United States). Water Resources Center

1998-07-01

346

The Water Quality Emergency Monitoring System Based on GIS and RS for Urban Drinking Water Source  

Microsoft Academic Search

With more and more serious problem on water pollution, it is significant to monitor the water quality and get to know the trend of the water quality change for water source management and water environment protection. Urban drinking water source quality monitoring system is based on GIS and remote sensing technology. This relatively integrated system comprises water source quality information

Mu Fengyun; Wu Xiaochun

2010-01-01

347

Partitioning of polychlorinated biphenyls in octanol\\/water, triolein\\/water, and membrane\\/water systems  

Microsoft Academic Search

The use of the octanol\\/water partition constant (Kow) as a surrogate parameter for lipid\\/water partitioning of persistent organic pollutants (POPs) was reassessed by comparing the measured Kow of 12 selected polychlorinated biphenyl congeners (PCBs) with partition constants in triolein\\/water (Ktw) and membrane\\/water (Kmw) systems. Kow and Ktw were measured by the slow-stirring method. Kmw was measured by an adaptation of

Thomas W. Jabusch; Deborah L. Swackhamer

2005-01-01

348

Dynamic weighting system for water quality index.  

PubMed

Water quality standards are developed world over by National and International agencies for pollution control decision-making. Use-based water quality classification criteria and Water Quality Indices (WQIs) also play important role in assessment of water resources for their suitability with reference various uses. Formulation of value function curves and weights assigned to parameters in WQIs are often defined by local water experts and hence WQIs are known to inherit subjectivity. Assignment of weights a priori to various water quality parameters results in misclassification of water quality by WQI. A method of dynamic weighting has been developed in the present work to assign weights to water quality parameters with due consideration to their pollution effect at a particular site. Application of a methodology to Overall Index of Pollution (OIP) provides water quality classification of Indian rivers as "Polluted", "Acceptable", and "Slightly Polluted", which is comparable with the reported CPCB classification as well as with the statistical index CCME-WQI. The methodology developed is general and can be applied to any subjective index. This is exemplified by dynamically weighting the parameters in NSF-WQI for Red and Waikato rivers. Dynamic weighting system provides a true representation to comprehend water quality classification and to achieve River Quality Objectives. PMID:18845865

Sargaonkar, Aabha P; Gupta, Apurba; Devotta, Sukumar

2008-01-01

349

Estimation of hydrogen peroxide decomposition rates in the boiling water reactor primary coolant circuit  

SciTech Connect

In a boiling water reactor primary coolant circuit, the coolant flow velocities and volume-to-surface ratios at various locations are taken into account for the estimation of the decomposition rate of hydrogen peroxide in the system. The decomposition half-times are estimated ranging from a few seconds in the core region to a few minutes in the recirculation piping system.

Lin, Chien C. (GE Nuclear Energy, Pleasanton, CA (United States). Vallecitos Nuclear Center.)

1993-08-01

350

Estimation of hydrogen peroxide decomposition rates in the boiling water reactor primary coolant circuit  

Microsoft Academic Search

In a boiling water reactor primary coolant circuit, the coolant flow velocities and volume-to-surface ratios at various locations are taken into account for the estimation of the decomposition rate of hydrogen peroxide in the system. The decomposition half-times are estimated ranging from a few seconds in the core region to a few minutes in the recirculation piping system.

Lin; Chien C

1993-01-01

351

21 CFR 1250.42 - Water systems; constant temperature bottles.  

Code of Federal Regulations, 2013 CFR

...and Air Conveyances § 1250.42 Water systems; constant temperature bottles. (a) The water system, whether of the pressure or gravity type, shall be complete...for protected vent openings. The water system shall be protected...

2013-04-01

352

30 CFR 75.1101-6 - Water sprinkler systems; general.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Water sprinkler systems; general. 75.1101-6 Section... Fire Protection § 75.1101-6 Water sprinkler systems; general. Water sprinkler systems may be installed to protect main...

2013-07-01

353

Water Electrolysis System Refurbishment and Testing.  

National Technical Information Service (NTIS)

The electrolytic oxygen generator for the back-up water electrolysis system in a 90-day manned test was refurbished, improved and subjected to a 182-day bench test. The performance of the system during the test demonstrated the soundness of the basic elec...

B. M. Greenough

1972-01-01

354

Distilled Water Distribution Systems. Laboratory Design Notes.  

ERIC Educational Resources Information Center

|Factors concerning water distribution systems, including an evaluation of materials and a recommendation of materials best suited for service in typical facilities are discussed. Several installations are discussed in an effort to bring out typical features in selected applications. The following system types are included--(1) industrial…

Sell, J.C.

355

Distilled Water Distribution Systems. Laboratory Design Notes.  

ERIC Educational Resources Information Center

Factors concerning water distribution systems, including an evaluation of materials and a recommendation of materials best suited for service in typical facilities are discussed. Several installations are discussed in an effort to bring out typical features in selected applications. The following system types are included--(1) industrial…

Sell, J.C.

356

Blow-by gas recirculating apparatus  

SciTech Connect

A blow-by gas recirculating apparatus for returning blow-by gases from the crankcase of an internal combustion engine to an intake passage thereof is described comprising: a cylinder head; a cylinder head cover mounted on the engine cylinder head; a DOHC valve mechanism housed in the cylinder head; a shield panel attached to the cylinder head cover in substantially covering relation to the DOHC valve mechanism; a breather chamber defined between the cylinder head cover and the shield panel and communicating with both the interior of the cylinder head and an air intake unit of the internal combustion engine; the breather chamber extending longitudinally of the cylinder head cover and comprising a central first, second and third chamber sections each extending longitudinally substantially the full length of the cylinder head; and the second and third breather chamber sections being located one on each side of the first breather chamber section, the first through third breather chamber sections being interconnected by passages for causing blow-by gas passing from the interior of the cylinder head to flow longitudinally for substantially the entire length of the cylinder head cover through each of the first, second and third breather chambers, in that order, to the intake unit of the internal combustion engine.

Kato, H.

1988-01-26

357

Radiation buildup control in BWR recirculation piping  

SciTech Connect

Boiling water nuclear reactors (BWRs) employ stainless steel (Type 304 or 316 NG) pipes in which high-purity water at temperatures in the vicinity of 275/sup 0/C are circulated. Various components of the system, such as valves and bearings, often contain hard facing metal alloys such as Stellite-6. These components, along with the stainless steel tubing and feedwater, serve as sources of /sup 59/Co. The presence of even small amounts of /sup 60/Co on the walls of the cooling water system is the dominant contributor to inplant radiation levels. Typical long-term surface activities due to this isotope on the walls of the cooling pipes range from 2.7 to 24 ..mu..Ci/cm/sup 2/. The resulting radiation field limits the allowable exposure time of maintenance and inspection personnel. The object of the research was twofold: (a) to form a thin film diffusion barrier against the outward diffusion of cobalt from a cobalt-containing surface and (b) to prevent the growth of a /sup 60/Co-containing corrosion film. The latter goal was most important since most of the radioactive cobalt will originate from sources other than the stainless steel piping itself. To meet these objectives, an experimental program was carried out using stainless steel rods to simulate the BWR piping and then exposing the rods to simulated BWR conditions in the General Electric Vallecitos /sup 60/Co test loop. It has been shown that the use of protective thin film coatings will reduce /sup 60/Co pickup. Many coatings were tried, but the three best were palladium, nickel, and gold prepared in various ways.

Meyer, W.; Wood, R.M.; Rao, T.V.; Vook, R.W.

1987-01-01

358

Recirculating Peritoneal Dialysis with a Subcutaneous Peritoneal Catheter.  

National Technical Information Service (NTIS)

Ten end stage renal disease patients, 9 of whom were diabetic, were treated with peritoneal dialysis via a subcutaneous peritoneal catheter. Three dialysis formats were used: Intermittent peritoneal dialysis (IPD), recirculating peritoneal dialysis (RPD),...

R. L. Stephen S. C. Jacobsen C. Kablitz W. J. Kolff

1977-01-01

359

In-situ continuous water monitoring system  

DOEpatents

An in-situ continuous liquid monitoring system for continuously analyzing volatile components contained in a water source comprises: a carrier gas supply, an extraction container and a mass spectrometer. The carrier gas supply continuously supplies the carrier gas to the extraction container and is mixed with a water sample that is continuously drawn into the extraction container by the flow of carrier gas into the liquid directing device. The carrier gas continuously extracts the volatile components out of the water sample. The water sample is returned to the water source after the volatile components are extracted from it. The extracted volatile components and the carrier gas are delivered continuously to the mass spectrometer and the volatile components are continuously analyzed by the mass spectrometer. 2 figs.

Thompson, C.V.; Wise, M.B.

1998-03-31

360

Geothermal hot water transportation and utilization system  

SciTech Connect

A geothermal hot water transportation system is described for transporting geothermal hot water from underground to above ground. The system consists of: means for pressurizing and pumping hot water from a geothermal production well to a location above ground including a downhole pump for installation in the geothermal production well, and a long downhole pump shaft; a pump casing having a below surface end connected to the downhole pump and an above surface end; means for separating steam and hot water brought to the surface from the well by the downhole pump through the pump casing, including an above ground rotary separation two-phase flow turbine communicating with the above surface end of the pump casing, the two-phase flow turbine having a power output shaft means for directly powering the downhole pump through the downhole pump shaft.

Yamaoka, K.

1986-03-18

361

Energy optimization of water distribution system  

SciTech Connect

In order to analyze pump operating scenarios for the system with the computer model, information on existing pumping equipment and the distribution system was collected. The information includes the following: component description and design criteria for line booster stations, booster stations with reservoirs, and high lift pumps at the water treatment plants; daily operations data for 1988; annual reports from fiscal year 1987/1988 to fiscal year 1991/1992; and a 1985 calibrated KYPIPE computer model of DWSD`s water distribution system which included input data for the maximum hour and average day demands on the system for that year. This information has been used to produce the inventory database of the system and will be used to develop the computer program to analyze the system.

Not Available

1993-02-01

362

Water injected fuel cell system compressor  

DOEpatents

A fuel cell system including a dry compressor for pressurizing air supplied to the cathode side of the fuel cell. An injector sprays a controlled amount of water on to the compressor's rotor(s) to improve the energy efficiency of the compressor. The amount of water sprayed out the rotor(s) is controlled relative to the mass flow rate of air inputted to the compressor.

Siepierski, James S. (Williamsville, NY); Moore, Barbara S. (Victor, NY); Hoch, Martin Monroe (Webster, NY)

2001-01-01

363

The Pebble Recirculation Experiment (PREX) for the AHTR  

SciTech Connect

Conceptual design studies for the liquid-salt cooled Advanced High Temperature Reactor (AHTR) have identified three candidate TRISO fuel geometries: prismatic, pebble, and stringer fuels. This paper presents experimental results from the integral Pebble Recirculation Experiment (PREX) that verifies the viability of pebble recirculation in a Pebble Bed AHTR (PB-AHTR). The experiments conducted include injection and extraction of buoyant pebbles, measurements of packing density and pressure losses, and observations of pebble landing dynamics and bed formation. (authors)

Bardet, P.; An, J.Y.; Franklin, J.T.; Huang, D.; Lee, K.; Mai, A.; Toulouse, M.; Peterson, P.F. [Department of Nuclear Engineering, University of California, Berkeley, CA 94720-1730 (United States)

2007-07-01

364

A changing framework for urban water systems.  

PubMed

Urban water infrastructure and the institutions responsible for its management have gradually evolved over the past two centuries. Today, they are under increasing stress as water scarcity and a growing recognition of the importance of factors other than the cost of service provision are forcing a reexamination of long-held ideas. Research and development that supports new technological approaches and more effective management strategies are needed to ensure that the emerging framework for urban water systems will meet future societal needs. PMID:23650975

Hering, Janet G; Waite, T David; Luthy, Richard G; Drewes, Jörg E; Sedlak, David L

2013-05-08

365

Water Resources Data System State Climate Office  

NSDL National Science Digital Library

The Water Resources Data System is a "clearinghouse of hydrological and climatological data for the State of Wyoming" provided by the University of Wyoming. Online data include a water quality database, climatological data (such as snow depth and precipitation), and earthquake and landslide data. A water library link contains research briefs, publications, a reference shelf, newsletters, and other related documents. Additional links on the main page include US Geological Survey stream flow conditions, the state climatologist office, data clearinghouses, and other Wyoming-specific informational sites.

366

Thermal-hydraulic tests of a recirculation cooling installation for the Rostov nuclear power station  

NASA Astrophysics Data System (ADS)

Results obtained from thermal-hydraulic tests of the recirculation cooling installation used as part of the air cooling system under the containments of the Rostov nuclear power station Units 3 and 4 are presented. The operating modes of the installation during normal operation (air cooling on the surface of finned tubes), under the conditions of anticipated operational occurrences (air cooling and steam condensation from a steam-air mixture), and during an accident (condensation of pure steam) are considered. Agreement is obtained between the results of tests and calculations carried out according to the recommendations given in the relevant regulatory documents. A procedure of carrying out thermal calculation for the case of steam condensation from a steam-air mixture on the surface of fins is proposed. The possibility of efficient use of the recirculation cooling installation in the system for reducing emergency pressure under the containment of a nuclear power station is demonstrated.

Balunov, B. F.; Balashov, V. A.; Il'in, V. A.; Krayushnikov, V. V.; Lychakov, V. D.; Meshalkin, V. V.; Ustinov, A. N.; Shcheglov, A. A.

2013-09-01

367

Humans transforming the global water system  

NASA Astrophysics Data System (ADS)

Fresh water figures prominently in the machinery of the Earth system and is key to understanding the full scope of global change. Greenhouse warming with a potentially accelerated hydrologic cycle is already a well-articulated science issue, with strong policy implications. A broad array of other anthropogenic factors—widespread land cover change, engineering of river channels, irrigation and other consumptive losses, aquatic habitat disappearance, and pollution—also influences the water system in direct and important ways. A rich history of site-specific research demonstrates the clear impact of such factors on local environments. Evidence now shows that humans are rapidly intervening in the basic character of the water cycle over much broader domains. The collective significance of these many transformations on both the Earth system and human society remains fundamentally unknown [Framing Committee of the GWSP, 2004].

Vörösmarty, C.; Lettenmaier, D.; Leveque, C.; Meybeck, M.; Pahl-Wostl, C.; Alcamo, J.; Cosgrove, W.; Grassl, H.; Hoff, H.; Kabat, P.; Lansigan, F.; Lawford, R.; Naiman, R.

2004-11-01

368

The Kuroshio Extension Northern Recirculation Gyre: Profiling Float Measurements and Forcing Mechanism  

Microsoft Academic Search

Middepth, time-mean circulation in the western North Pacific Ocean (28°-45°N, 140°-165°E) is investi- gated using drift information from the profiling floats deployed in the Kuroshio Extension System Study (KESS) and the International Argo programs. A well-defined, cyclonic recirculation gyre (RG) is found to exist north of the Kuroshio Extension jet, confined zonally between the Japan Trench (?145°E) and the Shatsky

Bo Qiu; Shuiming Chen; Peter Hacker; Nelson G. Hogg; Steven R. Jayne; Hideharu Sasaki

2008-01-01

369

Heat and mass transfer in turbulent flows with several recirculated flow eddies  

Microsoft Academic Search

Numerical modeling of the concentration and temperature distribution in axial symmetrical systems with several recirculated flow eddies, which is based on various 2D stationary k-? models and commercial codes, e.g. ANSYS and FLUENT, leads to results, which are significantly different from experimental data. Therefore additional user-defined subroutines were included in the commercial program code to improve the turbulent heat and

E. Baake; B. Nacke; A. Jakovics; A. Umbrashko

2001-01-01

370

The effects of ozonation on performance, health and welfare of rainbow trout Oncorhynchus mykiss in low-exchange water recirculation aquaculture systems  

Technology Transfer Automated Retrieval System (TEKTRAN)

A controlled four-month trial was conducted to compare the effects of ozonation (oxidation-reduction potential setpoint = 250 mV) versus no ozonation on rainbow trout Oncorhynchus mykiss performance, health, and welfare in replicated WRAS operated at low exchange rates (0.26% of the total recirculat...

371

Safety Features Comparative Study between Advanced Boiling Water Reactor and Supercritical Water-Cooling Reactor  

Microsoft Academic Search

Supercritical water-cooling reactor is one of the advanced nuclear power plants as the fourth generation reactor of internationally recognized. The plant system design is once-through cycle, feed-water flow rate are provided from pressure head by pump through the reactor core became steam, and directly into the turbine. There is not a recirculation loop in this cycle, this is the the

Hangding Wang; Tao Zhou; Zhousen Hou

2011-01-01

372

Colorado Springs Utilities Case Study: Water System Calibration\\/Optimization  

Microsoft Academic Search

Colorado Springs Utilities (Utility) provides water service to a rapidly growing population of 400,000. The Utility also owns and operates the Green Mountain Falls (GMF) water system located several miles outside of city limits. The GMF water system, serving 937 customers, is a separate water system consisting of small diameter cast iron and ductile iron water pipes. A significant portion

Istvan Lippai

373

Competition for water for the food system  

PubMed Central

Although the global agricultural system will need to provide more food for a growing and wealthier population in decades to come, increasing demands for water and potential impacts of climate change pose threats to food systems. We review the primary threats to agricultural water availability, and model the potential effects of increases in municipal and industrial (M&I) water demands, environmental flow requirements (EFRs) and changing water supplies given climate change. Our models show that, together, these factors cause an 18 per cent reduction in the availability of worldwide water for agriculture by 2050. Meeting EFRs, which can necessitate more than 50 per cent of the mean annual run-off in a basin depending on its hydrograph, presents the single biggest threat to agricultural water availability. Next are increases in M&I demands, which are projected to increase upwards of 200 per cent by 2050 in developing countries with rapidly increasing populations and incomes. Climate change will affect the spatial and temporal distribution of run-off, and thus affect availability from the supply side. The combined effect of these factors can be dramatic in particular hotspots, which include northern Africa, India, China, parts of Europe, the western US and eastern Australia, among others.

Strzepek, Kenneth; Boehlert, Brent

2010-01-01

374

Accelerated landfill waste decomposition by external leachate recirculation from an old landfill cell.  

PubMed

This research is focused on the management of moisture regime for a young landfill site in terms of leachate recirculation which entails the containment, collection and reinjection of leachate back into the landfill to promote in situ anaerobic biological treatment. Moreover, an innovative leachate management strategy was developed by using leachate recirculation from a mature landfill site into a young landfill site to provide accelerated waste stabilization. For this purpose, two reactors simulating young and old landfills were used in the laboratory. These reactors were loaded with shredded and compacted municipal solid waste with a typical composition determined for Istanbul Region. Both reactors were operated in a constant temperature room at 32 degrees C to enhance the growth of anaerobic microorganisms. Moreover, water was added to the reactors in order to simulate the annual rainfall. The reactor having the properties of old landfills was used as a control reactor. The reactor which represented the characteristics of young landfill was operated under four operational stages to enhance the activity of methanogenic population and accelerate waste stabilization. Results of this study indicated that the utilization of leachate recirculation enhanced waste stabilization in the young landfill by increasing the uniformity, and providing additional substrate and nutrients. Additions of buffer solutions of KOH and Na2CO3 together with leachate recirculation enhanced further waste stabilization and prevented possible acid inhibition. The utilization of external leachate recycled from the old landfill having desired acclimated anaerobic microorganisms, low organic content and higher buffer capacity into a young landfill could be a promising leachate management strategy for faster and controlled waste stabilization. PMID:12926691

Suna Erses, A; Onay, T T

2003-01-01

375

Stimulation of conversion rates and bacterial activity in a silage-fed two-phase biogas process by initiating liquid recirculation  

Microsoft Academic Search

The effects of liquid recirculation on a liquefaction-acidogenic reactor in an anaerobic two-phase digesting system operating with grass-clover silage was studied during 40 days after initiating recirculation of effluent from the methanogenic reactor to the liquefaction-acidogenic reactor. An increase in alkalinity and, thus, an increase in pH from 5.2 to 6.0 occurred in the liquefaction-acidogenic reactor. During the same period,

Åsa Jarvis; Åke Nordberg; Berit Mathisen; Bo H. Svensson

1995-01-01

376

Control solids in cooling water to cut makeup requirements  

SciTech Connect

A pilot program demonstrates effectiveness of reverse osmosis and electrodialysis in increasing the cycles of concentration of recirculating-water systems. The team performed its study with the help of the Department of Interior's mobile demineralization treatment system, which houses both a reverse-osmosis and an electrodialysis desalting system. Their results indicate that both systems can produce product water of higher quality than makeup water drawn from the Colorado River. Capital cost of a full-scale treatment system with 75% product-water recovery is estimated at $3.6 million. Annual operating cost would be about $822,000.

Osantowski, R.; Kane, J.

1984-07-01

377

21 CFR 1240.86 - Protection of pier water system.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Protection of pier water system. 1240.86 Section 1240.86...CONTROL OF COMMUNICABLE DISEASES Source and Use of Potable Water § 1240.86 Protection of pier water system. No vessel engaged in...

2013-04-01

378

21 CFR 1250.42 - Water systems; constant temperature bottles.  

Code of Federal Regulations, 2010 CFR

... Water systems; constant temperature bottles. 1250.42 Section... Water systems; constant temperature bottles. (a) The...water. (e) Constant temperature bottles and other containers...and shall be subjected to effective bactericidal treatment...

2010-04-01

379

Providing Safe Drinking Water In America. 2003 National Public Water Systems Compliance Report.  

National Technical Information Service (NTIS)

The National Public Water Systems Compliance Report for 2003 describes how the Environmental Protection Agency (EPA) and its state and tribal partners are meeting the goal of ensuring that Americans receive safe drinking water from public water systems. S...

2005-01-01

380

Removal of sodium chloride from human urine via batch recirculation electrodialysis at constant applied voltage.  

PubMed

The removal of sodium chloride (NaCl) from human urine using a six-compartment electrodialysis cell with batch recirculation mode of operation for use in advanced life support systems (ALSS) was studied. From the results obtained, batch recirculation at constant applied voltage yields high values (approximately 94% of NaCl removal. Based on the results, the initial rate of NaCl removal was correlated to a power function of the applied voltage: -r=2.0 x 10(-4)E(3.8). With impedance spectroscopy methods, it was also found that the anion membranes were more affected by fouling with an increase of the ohmic resistance of almost 11% compared with 7.4% for the cationic ones. PMID:14632001

Gordils-Striker, Nilda E; Colon, Guillermo

2003-01-01

381

Optimal monitoring of water distribution systems (II)  

NASA Astrophysics Data System (ADS)

The supervisory control and data acquisition (SCADA) technology has been used in water distribution systems in recently years, in which, waterhead at some nodes and/or flowrate in some links in the water distribution systems are monitored by radio or internet, and the waterhead and flowrate monitoring stations are usually determined by experience or simply evenly distributed. For the purpose of more efficient monitoring, optimal monitoring of waterhead in a water distribution system was developed by the authors, and as the second part of the study, this paper has proposed a method for optimal monitoring of flowrate in a water distribution system. A perturbation analysis is conducted to determine the sensitivity matrix, and the sensitivity equation is solved by a least square method, and the optimal monitoring of flowrate is then decided. The optimal monitoring solution is compared with the evenly distributed case, and it is found the optimal monitoring provides a more efficient and practical scheme if the number of monitoring stations is specified.

Xiao, Di; Liang, Jianwen; Zhao, Xinhua; Zhang, Hongwei

2004-07-01

382

PREDICTING WATER QUALITY IN DISTRIBUTION SYSTEMS  

EPA Science Inventory

The quality of a public water supply although acceptable when it leaves the treatment plant, may deteriorate before it reaches the user. Deterioration may be caused by either chemical or biological transformations or by a loss of system integrity. There have been a growing number...

383

Water quality requirements for reuse systems  

Microsoft Academic Search

Water quality criteria for aquaculture systems have typically considered parameters such as temperature, dissolved oxygen, total gas pressure, ammonia, and nitrite. Many of the published criteria are derived for environmental protection of a wide range of species and life stages. These criteria may not be appropriate for a single species and life stage, especially in commercial applications. The value of

John Colt

2006-01-01

384

Falluja Waste Water Treatment System, Falluja, Iraq.  

National Technical Information Service (NTIS)

In July 2008, the U.S. Ambassador became 'extremely concerned' that the Falluja Waste Water Treatment System had 'gone so far off track and for so long.' This project was originally planned to cost $32.5 million, be completed in 18 months in January 2006 ...

A. Johnston K. O'Connor T. Criswell

2008-01-01

385

LIGHTWEIGHT GREEN ROOF WATER RETENTION SYSTEM  

EPA Science Inventory

During Phase I, we have forged numerous necessary partnerships, which will allow us to begin our implementation tests. Working with the Philadelphia Water Department (PWD) and Drexel Smart House (DSH) we have 3 to 4 prime test sites for our system. We plan to execute our insta...

386

SMALL WATER SYSTEMS: ROLE OF TECHNOLOGY  

EPA Science Inventory

Over 90% of the nation's water supplies serve fewer than 10,000 people, less than 25% of the total population. Many of these small systems have problems. One of the major problems is their lack of operating revenues. They cannot benefit from economies of scale as do large urban s...

387

Microorganism Removal for Small Water Systems.  

National Technical Information Service (NTIS)

This document is designed primarily for use by owners and operators of small water systems, those producing 500,000 gallons per day or less and serving less than 5,000 persons. Other expected users are municipal managers and consulting engineers retained ...

1983-01-01

388

MANAGEMENT OF WATER DISTRIBUTION SYSTEM COMPONENTS  

EPA Science Inventory

The purpose of the study is to (1) analyze main break failures and (2) incorporate other drinking water distribution system components into a data base management structure for reliability analyses. Reliability analysis should be a part of an overall operation and maintenance str...

389

Systems Analysis for Urban Water Management.  

National Technical Information Service (NTIS)

The major purpose of the study was to indicate that the goals of urban water management, with respect to the use and further development of systems analysis tools explored, are attainable. It was primarily a technical enterprise to demonstrate that a comp...

W. C. Ackermann J. C. Geyer C. F. Izzard S. W. Jens D. E. Jones

1970-01-01

390

Rural Water Supply Systems: Improved Planning Strategies through Systems Analysis.  

National Technical Information Service (NTIS)

Research was carried out to assess the state-of-the-art of planning strategies currently used by institutions and consultants in planning rural water supply systems, and to explore systems analysis techniques for improving the planning/design/operation/ma...

T. A. Austin R. S. Schulz R. B. Robinson

1982-01-01

391

Water delivery in the early Solar System  

NASA Astrophysics Data System (ADS)

As part of the national scientific network 'Pathways to Habitable Worlds' the delivery of water onto terrestrial planets is a key question since water is essential for the development of life as we know it. After summarizing the state of the art we show some first results of the transport of water in the early Solar System for scattered main belt objects. Hereby we investigate the questions whether planetesimals and planetesimal fragments which have gained considerable inclination due to the strong dynamical interactions in the main belt region around 2 AU can be efficient water transporting vessels. The Hungaria asteroid group is the best example that such scenarios are realistic. Assuming that the gas giants and the terrestrial planets are already formed, we monitor the collisions of scattered small bodies containing water (in the order of a few percent) with the terrestrial planets. Thus we are able to give a first estimate concerning the respective contribution of such bodies to the actual water content in the crust of the Earth.

Dvorak, Rudolf; Eggl, Siegfried; Süli, Áron; Sándor, Zsolt; Galiazzo, Mattia; Pilat-Lohinger, Elke

2012-08-01

392

Biotreatment of red water with fungal systems  

SciTech Connect

Red water generated during the manufacture of trinitrotoluene (TNT) is an environmental concern because it contaminates ground surfaces and groundwaters. Past methods for the management of this hazardous waste stream did not meet pollution compliance or were not cost effective. Biodegradation of TNT by bacteria has been reported, but no conclusive evidence supports its biotransformation to harmless products or its complete mineralization. The lignin peroxidase (ligninase) secreted by the white rot fungus (Phanerochaete chrysosporium) has been shown to degrade a broad spectrum of organic pollutants. In this study, the efficacy of treating red water with the P. chrysosporium system was investigated.

Tsai, TenLin S.; Turner, R.J.; Sanville, C.J.

1990-01-01

393

Recirculating Linac Acceleration - End-to-End Simulation  

SciTech Connect

A conceptual design of a high-pass-number Recirculating Linear Accelerator (RLA) for muons is presented. The scheme involves three superconducting linacs (201 MHz): a single pass linear Pre-accelerator followed by a pair multi-pass (4.5-pass)'Dogbone' RLAs. Acceleration starts after ionization cooling at 220 MeV/c and proceeds to 12.6 GeV. The Pre-accelerator captures a large muon phase space and accelerates muons to relativistic energies, while adiabatically decreasing the phase-space volume, so that effective acceleration in the RLA is possible. The RLA further compresses and shapes up the longitudinal and transverse phase-spaces, while increasing the energy. Appropriate choice of multi-pass linac optics based on FODO focusing assures large number of passes in the RLA. The proposed 'Dogbone' configuration facilitates simultaneous acceleration of both mu{sup +}- species through the requirement of mirror symmetric optics of the return 'droplet' arcs. Finally, presented end-to-end simulation validates the efficiency and acceptance of the accelerator system.

Bogacz, S. Alex [Center for Advanced Studies of Accelerators, Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States)

2010-03-30

394

Recirculating Linac Acceleration-End-to-End Simulation  

NASA Astrophysics Data System (ADS)

A conceptual design of a high-pass-number Recirculating Linear Accelerator (RLA) for muons is presented. The scheme involves three superconducting linacs (201 MHz): a single pass linear Pre-accelerator followed by a pair multi-pass (4.5-pass) `Dogbone' RLAs. Acceleration starts after ionization cooling at 220 MeV/c and proceeds to 12.6 GeV. The Pre-accelerator captures a large muon phase space and accelerates muons to relativistic energies, while adiabatically decreasing the phase-space volume, so that effective acceleration in the RLA is possible. The RLA further compresses and shapes up the longitudinal and transverse phase-spaces, while increasing the energy. Appropriate choice of multi-pass linac optics based on FODO focusing assures large number of passes in the RLA. The proposed `Dogbone' configuration facilitates simultaneous acceleration of both ?+/- species through the requirement of mirror symmetric optics of the return `droplet' arcs. Finally, presented end-to-end simulation validates the efficiency and acceptance of the accelerator system.

Bogacz, S. Alex

2010-03-01

395

Recent advances in AMTEC recirculating test cell performance  

NASA Astrophysics Data System (ADS)

The alkali metal thermal to electric converter (AMTEC) is an electrochemical device for the direct conversion of thermal energy to electrical energy with efficiencies potentially near Carnot. The future usefulness of AMTEC for space power conversion depends on the efficiency of the devices. Systems studies have projected from 15% to 35% thermal to electric conversion efficiencies, and one experiment has demonstrated 19% efficiency for a short period of time. A recent experiment in a recirculating test cell (RCT) has demonstrated sustained conversion efficiencies as high as 13.2%. The cell was operated at lower current and 12% efficiency for over 1700 hours at the time of this writing. The cell required a maturation period of 355 hours at high temperature. During this period, the cell was operated once at 12% efficiency but was generally operated at lower powers. The maturation period ended with the formation of a reflective sodium film on the condenser surface which reduced the parasitic thermal losses in the cell. After maturation, the cell demonstrated the first experimental demonstration of the maximum efficiency occuring at a lower current than the maximum power. The cell also demonstrated an unexpected decrease in parasitic loss with increasing cell current. The decrease in parasitic loss resulted from the development of a more reflective sodium film at higher sodium fluxes.

Underwood, Mark L.; Williams, Roger M.; Ryan, Margaret A.; Jeffries-Nakamura, Barbara; O'Connor, Dennis

1993-01-01

396

Deep water riser system for offshore drilling  

SciTech Connect

A buoyant riser system for use in a deep water offshore drilling environment is anchored by a system of compliant guys below the active weather zone of the sea. A controllably buoyant housing of the system is submerged at a depth that is readily accessible to divers and includes a blow-out preventer (BOP) from which a suspended sub-riser leads to a well bore to which the sub-riser is coupled. Above the housing, a riser suspended from a floating drill rig is coupled to the BOP thereby communicating the drill rig directly with the well bore for drilling and well completion operations.

Potts, H.L.

1984-05-15

397

Deficiencies in drinking water distribution systems in developing countries  

Microsoft Academic Search

Rapidly growing populations and migration to urban areas in developing countries has resulted in a vital need for the establishment of centralized water systems to disseminate potable water to residents. Protected source water and modern, well-maintained drinking water treatment plants can provide water adequate for human consumption. However, ageing, stressed or poorly maintained distribution systems can cause the quality of

Ellen J. Lee; Kellogg J. Schwab

2005-01-01

398

Load control system for nuclear power plant  

Microsoft Academic Search

A load control system for a boiling water reactor power plant. A recirculating pump speed demand signal and a total steam flow demand signal are derived on the basis of combination of a first control signal produced in accordance with a power difference signal representative of difference between an actual value of an output power of an electric generator and

J. Tanji; M. Izumi

1984-01-01

399

Influence of leachate recirculation on aerobic and anaerobic decomposition of solid wastes.  

PubMed

In this study, the effect of leachate recirculation on aerobic and anaerobic degradation of municipal solid wastes is determined by four laboratory-scale landfill reactors. The options studied and compared with the traditional anaerobic landfill are: leachate recirculation, landfill aeration, and aeration with leachate recirculation. Leachate quality is regularly monitored by the means of pH, alkalinity, total dissolved solids, conductivity, oxidation-reduction potential, chloride, chemical oxygen demand, ammonia, and total Kjeldahl nitrogen, in addition to generated leachate quantity. Aerobic leachate recirculated landfill appears to be the most effective option in the removal of organic matter and ammonia. The main difference between aerobic recirculated and non-recirculated landfill options is determined at leachate quantity. Recirculation is more effective on anaerobic degradation of solid waste than aerobic degradation. Further studies are going on to determine the optimum operational conditions for aeration and leachate recirculation rates, also with the operational costs of aeration and recirculation. PMID:17023112

Bilgili, M Sinan; Demir, Ahmet; Ozkaya, Bestamin

2006-09-10

400

Water resources development and environmental protection in Poyang Lake water system  

Microsoft Academic Search

The sustainable use of water resources has become an strategic issue involving economic and social development in China. This article presented the situation and characteristics of Poyang Lake water system in Jiangxi province, analyzed the existing problems in exploitation and utilization of water resources and put forward some countermeasures to water environmental protection in Poyang Lake Water System from the

Shuzhen Zou; Zhiqiang Wu; Biaohong Tao; Yingping Xiao

2010-01-01

401

Agricultural-to-hydropower water transfers: sharing water and benefits in hydropower-irrigation systems  

Microsoft Academic Search

This paper presents a methodology to assess agricultural-to-hydropower water transfers in water resources systems where irrigation crop production and hydropower generation are the main economic activities. In many countries, water for crop irrigation is often considered as a static asset: irrigation water is usually allocated by a system of limited annual rights to use a prescribed volume of water. The

A. Tilmant; Q. Goor; D. Pinte

2009-01-01

402

Army Energy and Water Reporting System Assessment  

SciTech Connect

There are many areas of desired improvement for the Army Energy and Water Reporting System. The purpose of system is to serve as a data repository for collecting information from energy managers, which is then compiled into an annual energy report. This document summarizes reported shortcomings of the system and provides several alternative approaches for improving application usability and adding functionality. The U.S. Army has been using Army Energy and Water Reporting System (AEWRS) for many years to collect and compile energy data from installations for facilitating compliance with Federal and Department of Defense energy management program reporting requirements. In this analysis, staff from Pacific Northwest National Laboratory found that substantial opportunities exist to expand AEWRS functions to better assist the Army to effectively manage energy programs. Army leadership must decide if it wants to invest in expanding AEWRS capabilities as a web-based, enterprise-wide tool for improving the Army Energy and Water Management Program or simply maintaining a bottom-up reporting tool. This report looks at both improving system functionality from an operational perspective and increasing user-friendliness, but also as a tool for potential improvements to increase program effectiveness. The authors of this report recommend focusing on making the system easier for energy managers to input accurate data as the top priority for improving AEWRS. The next major focus of improvement would be improved reporting. The AEWRS user interface is dated and not user friendly, and a new system is recommended. While there are relatively minor improvements that could be made to the existing system to make it easier to use, significant improvements will be achieved with a user-friendly interface, new architecture, and a design that permits scalability and reliability. An expanded data set would naturally have need of additional requirements gathering and a focus on integrating with other existing data sources, thus minimizing manually entered data.

Deprez, Peggy C.; Giardinelli, Michael J.; Burke, John S.; Connell, Linda M.

2011-09-01

403

Soil Water and Temperature System (SWATS) Handbook  

SciTech Connect

The soil water and temperature system (SWATS) provides vertical profiles of soil temperature, soil-water potential, and soil moisture as a function of depth below the ground surface at hourly intervals. The temperature profiles are measured directly by in situ sensors at the Central Facility and many of the extended facilities of the SGP climate research site. The soil-water potential and soil moisture profiles are derived from measurements of soil temperature rise in response to small inputs of heat. Atmospheric scientists use the data in climate models to determine boundary conditions and to estimate the surface energy flux. The data are also useful to hydrologists, soil scientists, and agricultural scientists for determining the state of the soil.

Bond, D

2005-01-01

404

Biofouling and biocorrosion in industrial water systems.  

PubMed

Corrosion associated with microorganisms has been recognized for over 50 years and yet the study of microbiologically influenced corrosion (MIC) is relatively new. MIC can occur in diverse environments and is not limited to aqueous corrosion under submerged conditions, but also takes place in humid atmospheres. Biofouling of industrial water systems is the phenomenon whereby surfaces in contact with water are colonized by microorganisms, which are ubiquitous in our environment. However, the economic implications of biofouling in industrial water systems are much greater than many people realize. In a survey conducted by the National Association of Corrosion Engineers of the United States ten years ago, it was found that many corrosion engineer did not accept the role of bacteria in corrosion, and many of then that did, could not recognize and mitigate the problem. Biofouling can be described in terms of its effects on processes and products such as material degradation (bio-corossion), product contamination, mechanical blockages, and impedance of heat transfer. Microorganisms distinguish themselves from other industrial water contaminants by their ability to utilize available nutrient sources, reproduce, and generate intra- and extracellular organic and inorganic substances in water. A sound understanding of the molecular and physiological activities of the microorganisms involved is necessary before strategies for the long term control of biofouling can be format. Traditional water treatment strategies however, have largely failed to address those factors that promote biofouling activities and lead to biocorrosion. Some of the major developments in recent years have been a redefinition of biofilm architecture and the realization that MIC of metals can be best understood as biomineralization. PMID:16417202

Coetser, S E; Cloete, T E

2005-01-01

405

Water Resources Planning Using Integrated Systems of Marketable Water Rights and Reservoir Design and Operation.  

National Technical Information Service (NTIS)

In the study, management techniques to integrate marketable water rights systems with systems for the design and operation of a single reservoir are developed. Three kinds of rights may be found in such integrated systems; Natural flowing water rights, re...

B. D. C. Wong J. W. Eheart

1985-01-01

406

Absorption cold and warm water system utilizing solar heat  

Microsoft Academic Search

An absorbtion cold and warm water system utilizing solar heat is disclosed. Heat source water is obtained by heating water by the solar heat and a main heating source. The system is selectively made to function as a warm water system, a first heat pump and a second heat pump in accordance with temperature conditions associated with the heat source

Y. Hibino; K. Kamejima; Y. Nara

1985-01-01

407

Particle capture by turbulent recirculation zones measured using long-time Lagrangian particle tracking  

NASA Astrophysics Data System (ADS)

We have measured the trajectories of particles into, and around, the recirculation zone formed in water flowing through a sudden pipe expansion with radius ratio 1:3.7, at Reynolds numbers between 5,960 and 41,700 over a range of particle Stokes number (here defined as St = {{T_{{f}} }/{tau_{{p} }}} , where T f is an appropriate mean or turbulent timescale of the fluid flow and a particle relaxation time, ?p,) between 6.2 and 51 and drift parameter between 0.3 and 2.8. The particles were thus weakly inertial but nevertheless heavy with a diameter about an order of magnitude larger than the Kolmogorov scale. Trajectories of particles, released individually into the flow, were taken in a Lagrangian framework by a three-dimensional particle tracking velocimeter using a single 25 Hz framing rate intensified CCD camera. Trajectories are quantified by the axial distribution of the locations of particle axial velocity component reversal and the probability distributions of trajectory angle and curvature. The effect of increasing the drift parameter was to reduce the tendency for particles to enter the recirculation zone. For centreline release, the proportion of particles entering the recirculation zone and acquiring a negative velocity decreased from about 80% to none and from about 66% to none, respectively, as the drift parameter increased from 0.3 to 2.8. Almost half of the particles experienced a relatively large change of direction corresponding to a radius of curvature of their trajectory comparable to, or smaller than, the radius of the downstream pipe. This was due to the interaction between these particles and eddies of this size in the downstream pipe and provides experimental evidence that particles are swept by large eddies into the recirculation zone over 1.0 < Z^{*} < 2.5, where Z^{*} is axial distance from the expansion plane normalized by the downstream pipe diameter, which was well upstream of the reattachment point at the wall ( Z^{*} ? 3. 5 ). Once inside the recirculation zone, the particle motion was governed more by the drift parameter than by the Stokes number.

Siu, Y. W.; Taylor, A. M. K. P.

2011-07-01

408

System Identification and Multi-Level Optimization of Integrated Ground Water Systems.  

National Technical Information Service (NTIS)

Conjunctive surface water and ground water systems are analyzed using the techniques of system identification and multi-level optimization. Mathematical models describing the behavior of the ground water regime are developed. Given historic ground water l...

J. A. Dracup

1974-01-01

409

Effects of organic loading rate and effluent recirculation on the performance of two-stage anaerobic digestion of vegetable waste.  

PubMed

The effects of organic loading rates (OLR) and effluent recirculation on dynamics of acidogenic and methanogenic processes in two-stage anaerobic digestion of vegetable waste were investigated. Two systems were performed at OLRs of 1.3, 1.7, 2.1 and 2.6gVS/L/d. One system recirculated the effluent from the methanogenic reactor to acidogenic reactor. With increasing OLRs, total volatile fatty acid (VFA) concentration increased to approximately 8500mg/L in acidogenic digester, where pH decreased from 6.4 to 5.2. Daily biogas production and methane content in methanogenic reactor increased from 1.2 to 4.4L/d and from 27.4% to 60.5%, respectively. However, inhibition of hydrolysis in acidogenic reactor was demonstrated under the OLR of 2.6gVS/L/d without recirculation, thus indicating system overloading. Effluent recirculation shown a considerable positive effect on alleviating VFA inhibition and improving biogas production in acidogenic reactor because of the effect of dilution and pH adjustment, particularly at high OLRs. PMID:23973975

Zuo, Zhuang; Wu, Shubiao; Zhang, Wanqin; Dong, Renjie

2013-08-02

410

Acceleration schedules for a recirculating heavy-ion accelerator  

SciTech Connect

Recent advances in solid-state switches have made it feasible to design programmable, high-repetition-rate pulsers for induction accelerators. These switches could lower the cost of recirculating induction accelerators, such as the ''small recirculator'' at Lawrence Livermore National Laboratory (LLNL), by substantially reducing the number of induction modules. Numerical work is reported here to determine what effects the use of fewer pulsers at higher voltage would have on the beam quality of the LLNL small recirculator. Lattices with different numbers of pulsers are examined using the fluid/envelope code CIRCE, and several schedules for acceleration and compression are compared for each configuration. For selected schedules, the phase-space dynamics is also studied using the particle-in-cell code WARP3d.

Sharp, W.M.; Grote, D.P.

2002-05-01

411

Integrated mine cooling and water conditioning system  

SciTech Connect

A method is described comprising: cooling an aqueous liquid at ground level, by means of a refrigeration system which rejects heat, to produce an aqueous ice slurry of ice crystals in the aqueous liquid; separating ice from some of the aqueous ice slurry produced at ground level, washing the ice and melting the ice to produce potable water at ground level, and using the potable water hydrostatic energy to power hydraulic machinery at the location below ground level; feeding the aqueous ice slurry from ground level to a location substantially below ground level to cool that location by heat exchange with the slurry, thereby producing warm aqueous liquid; withdrawing the warm aqueous liquid from the location, returning it to ground level and then cooling the aqueous liquid by means of the refrigeration system to again convert it to an aqueous ice slurry; and recycling the slurry to the location substantially below ground level.

Husain, M.; Nail, J.A.

1988-06-14

412

Process water system integrity: A metallurgical evaluation  

Microsoft Academic Search

This memorandum summarizes metallurgical data and analyses that demonstrate the continued reliability of the piping and components in the process water systems of SRP reactors. The principle structural materials in primary, DâO, moderator\\/coolant pressure boundary are Type 304 and CF-8 austenitic stainless steels. These tough, weldable, corrosion resistant alloys are exposed to relatively pure moderator (pD 5.1, DâO) at temperatures

Louthan; M. R. Jr

1989-01-01

413

The response of a bacterial biofilm community in a simulated industrial cooling water system to treatment with an anionic dispersant.  

PubMed

The effect of a dispersant on the microbial community in a simulated open recirculating cooling water system was determined by continuous operation of the system over two consecutive periods of 196 and 252 d, respectively. An open recirculating cooling water system feeding a modified Robbin's Device with synthetic cooling water to simulate the environment of an industrial cooling water system was set up. Planktonic and biofilm (mild steel and Nylon(R)) samples were taken weekly in 1997 (196-d period) and fortnightly in 1998 (252-d period). Each biofilm was scraped off and diluted in 10-ml 1 x phosphate-buffered saline (PBS). Serial dilutions were performed and plated onto R2A agar (pH 8.0) to obtain the predominant culturable bacteria. The diversity was determined by allocating groups according to colony morphology, diameter and colour. Diversity was calculated according to the Shannon-Weaver Index. During the first run (1997), dispersant was added on day 57 to a final concentration of 15 mg l-1 for 49 d, stopped for 49 d and dosed at 30 mg l-1 for 41 d. The second run entailed adding dispersant to a final concentration of 30 mg l-1 on day 98 for 70 d, stopping dosing for 56 d and resuming dosing at 30 mg l-1 for another 28 d. The 2-year evaluation period demonstrated that the biofilm-removing action of the dispersant decreased to a point where it was not effective at all. Our results showed that the synthetic dispersant evaluated was only effective initially, but was ineffective in controlling biofouling on Nylon, and to a lesser degree on mild steel at the recommended (15 mg l-1) as well as at double the recommended concentration in the long term. The release of cells from biofilms observed when dispersant dosing was terminated, supports the notion that a community attaching in the presence of the surface active agent was selected for. The decreased efficacy may therefore be due to a selection of strains able to remain attached and/or attach in the presence of the dispersant as demonstrated by shifts in the biofilm communities on both Nylon and mild steel. PMID:10971754

MacDonald, R; Santa, M; Brözel, V S

2000-08-01

414

Economic uncertainties in chilled water system design  

SciTech Connect

The analysis described here examines how uncertainties in engineering and economic assumptions made during chilled water system design translate to uncertainty in commonly used design decision metrics. The metric used is the benefit-cost ratio based on discounted cash flow. This analysis was performed as part of a project that is developing engineering tools for use in selecting energy-efficient chilled water system components, controls, and operating strategies. These tools include cooling thermal load prediction capabilities and performance data and models for chillers and cooling towers. The purpose of this study is to estimate accuracy requirements for the load and performance data that will be provided as part of the chilled water system tools. The logic is that there is inherent uncertainty in the decision metric due to uncertainty in inputs other than load and equipment performance, and, consequently, there is a limit below which further improvements in the accuracy of the load and equipment performance do not appreciably improve the quality of information available to the decision maker.

Kammerud, R.; Gillespie, K.L. Jr.; Hydeman, M.M.

1999-07-01

415

Technological Advance in Cooling Systems at U.S. Power Plants  

Microsoft Academic Search

Prior to adoption of the 1972 Clean Water Act (CWA) most U.S. power plants used once-through cooling water systems that discharged large quantities of warm water and resulted in significant amounts of thermal pollution in neighboring bodies of water. The CWA essentially mandated recirculating systems for most new facilities. This paper investigates whether there was either cost-saving or performance enhancing

Allen S Bellas; Duane Finney; Ian Lange

2011-01-01

416

Preliminary Study on Emittance Growth in the LHEC Recirculating Linac  

SciTech Connect

In this paper, we estimate the emittance growth in the LHeC recirculating Linac, the lattice design of which is presented in another paper of IPAC10 proceedings. The possible sources for emittance growth included here are: energy spread from RF acceleration in the SRF (superconducting RF) linac together with large chromatic effects from the lattice, and synchrotron radiation (SR) fluctuations in the recirculating arcs. 6-D multi-particle tracking is launched to calculate the emittance from the statistical point of view. The simulation results are also compared with a theoretical estimation.

Sun, Yi-Peng; Adolphsen, Chris; /SLAC; Zimmermann, Frank; /CERN

2011-05-20

417

Microbial Contamination of Potable Water in Distribution Systems.  

National Technical Information Service (NTIS)

Drinking water from two sites in Vermont were sampled and analyzed to examine the relationships among water source, prevailing treatment practices and the quantity and identity of the microorganisms in the distribution systems. Samples of raw water or set...

D. R. Hemenway

1983-01-01

418

WATER DISTRIBUTION SYSTEM ANALYSIS: FIELD STUDIES, MODELING AND MANAGEMENT  

EPA Science Inventory

The user?s guide entitled ?Water Distribution System Analysis: Field Studies, Modeling and Management? is a reference guide for water utilities and an extensive summarization of information designed to provide drinking water utility personnel (and related consultants and research...

419

Assessing Microbially Mediated Water Quality Problems in Distribution Systems.  

National Technical Information Service (NTIS)

This research sought to provide a review of various aspects of water quality problems that develop in distribution systems during water transmission by surveying water utility problems and responses to customer complaints and by conducting field monitorin...

W. R. Knocke G. D. Boardman

1982-01-01

420

A simple high efficiency solar water purification system  

Microsoft Academic Search

A new passive solar water pasteurization system based on density difference flow principles has been designed, built and tested. The system contains no valves and regulates flow based on the density difference between two columns of water. The new system eliminates boiling problems encountered in previous designs. Boiling is undesirable because it may contaminate treated water. The system with a

William S. Duff; David A. Hodgson

2005-01-01

421

Viability of hydrogen water chemistry for protecting in-vessel components of boiling water reactors  

SciTech Connect

This paper reports that a mixed potential model (MPM) has been developed for calculating electrochemical potential (ECP) data for boiling water reactor (BWR) in-vessel components and recirculation piping using compositional data obtained from radiolysis water chemistry models. The calculated core component ECPs for the Duane-Arnold BWR are in good agreement with limited in-plant data. The calculated ECP data suggest that hydrogen water chemistry (HWC) will be effective in protecting the core inlet and the recirculation system of Duane-Arnold against intergranular stress corrosion cracking (IGSCC) but that it may be effective for this purpose in Dresden-2 because of the higher concentrations of radiolysis products predicted to exist in this reactor. Furthermore, the MPM predicts that HWC will be ineffective in protecting various in-vessel components such as the upper plenum, fuel channels, core bypass structure, and the downcomer.

Macdonald, D.D. (Center for Advanced Materials, Pennsylvania State Univ., University Park, PA (US))

1992-03-01

422

Water-spray systems for mitigating accidental indoor releases of water-soluble gasesq  

Microsoft Academic Search

Water-spray systems have been designed for mitigating accidental outdoor releases of water-soluble gases. This paper describes the new application of water systems to mitigating indoor releases. The performance of spray systems is studied by using models of atmospheric release and spray mitigation, having adjusted them for the indoor environment. A case study is presented of a mitigation system for a

Vasilis M. Fthenakis

423

SMALL SYSTEM STUDIES (WATER SUPPLY AND WATER RESOURCES DIVISION)  

EPA Science Inventory

To support and help in the struggle to improve the quality of drinking water in the U.S. and abroad (China and South America), the National Risk Management Research Laboratory's Water Supply and Water Resources Division (WSWRD) uses the USEPA Test and Evaluation (T&E) Facility lo...

424

Safe Drinking Water Act Cost Impacts on Selected Water Systems.  

National Technical Information Service (NTIS)

Detailed site visits were made to eight U.S. water utilities to assess the capital and O and M costs of meeting the requirements of the Safe Drinking Water Act (SDWA). New treatment facilities were constructed at each of the utilities to correct water qua...

B. E. Burris R. C. Gumerman

1987-01-01

425

Microbial growth control in water hydraulic systems by conventional filtration  

Microsoft Academic Search

Water hydraulic systems use water as a pressure medium instead of oil. One of the factors limiting the applicability of water hydraulics is microbial growth in the pressure medium and on the surfaces of the system. The aim of this work was to study the potential of conventional hydraulic filters and different filter materials in controlling microbial growth in water

SH Varjus; H Riipinen; SM Soini; KT Koskinen; MJ Vilenius; JA Puhakka

2004-01-01

426

SURFACE WATER MONITORING SYSTEM INSTALLED ON BOARD THE ICEBREAKER SHIRASE  

Microsoft Academic Search

A surface water monitoring system was designed and installed on board the icebreaker SHIRASE. The system consists of sensors unit, navigation information terminal and control unit. Water pumped up from an intake of hull (8 m depth) is led into the sensors unit so as to measure flow rate of water, water temperature, conductivity, dissolved oxygen, fluorescence intensity, size com

Mitsuo FUKUCHI; Hiroshi HATTORI

427

BENEFITS OF MAINTAINING A CHLORINE RESIDUAL IN WATER SUPPLY SYSTEMS  

EPA Science Inventory

The protection afforded the water consumer by the maintenance of a chlorine residual in water distribution systems was evaluated in laboratory holding tanks and reservoirs and existing municipal water distribution systems. In the laboratory studies, tap water, adjusted to the app...

428

SOURCE WATER ASSESSMENT USING GEOGRAPHIC INFORMATION SYSTEMS  

EPA Science Inventory

The 1996 amendments to Section 1453 of the Safe Drinking Water Act require the states to establish and implement a Source Water Assessment Program (SWAP). Source water is the water taken from rivers, reservoirs, or wells for use as public drinking water. Source water assessment i...

429

Water management. Part 3. What to do about closed water systems  

Microsoft Academic Search

Scale problems generally are more severe in closed systems because they usually handle subsurface waters-- supply water and water produced with oil. Deep-well waters are often brines that contain high levels of dissolved gases, such as carbon dioxide, hydrogen sulfide, ad natural gas. Pumping these waters to the surface produces a large pressure reduction causing the dissolved gases to escape

J. H. Holben; A. W. Baumgartner

1970-01-01

430

Impacts of residence time during storage on potential of water saving for grey water recycling system  

Microsoft Academic Search

Grey water recycling has been generally accepted and is about to move into practice in terms of sustainable development. Previous research has revealed the bacteria re-growth in grey water and reclaimed municipal water during storage. However, in most present grey water recycling practices, impacts of water quality changes during storage on the system's performance and design regulation have not been

S. Liu; D. Butler; F. A. Memon; C. Makropoulos; L. Avery; B. Jefferson

2010-01-01

431

Study on Water Quality Chemical Stability of Desalinated Seawater in Municipal Water Supply Systems  

Microsoft Academic Search

The ldquoyellow waterrdquo phenomenon often appears when desalinated seawater entered the old ferruginous water supply systems. Therefore, different tubing water pipe-nets were used to simulate the desalinated seawater distribution process, change of water quality between raw water and pipe water was analyzed as well as the mechanism of ldquoyellow waterrdquo phenomenon. Also, the control indexes of desalinated seawater quality chemical

Bijun Luo; Xinhua Zhao; Baoshuang Liang; Guofeng Dong

2009-01-01

432

Dynamic tuning of optical waveguides with electrowetting pumps and recirculating fluid channels  

NASA Astrophysics Data System (ADS)

We have developed an approach for using electrowetting actuation in recirculating fluidic channels to achieve dynamic tuning of optical fiber structures. The electrically controlled and fully reversible motion of the fluids and lubricants in these channels alters the refractive index profile experienced by the optical waveguide modes of the fiber. When combined with in-fiber gratings and etched fibers, this fluidic system yields dynamically adjustable narrow and broadband fiber filters, respectively. The nonmechanical operation of these systems, their ability to support switching speeds on the order of milliseconds, and their excellent optical characteristics indicate a promising potential for electrowetting-actuated fluidic tuning in optical fiber devices and other photonic components.

Mach, P.; Krupenkin, T.; Yang, S.; Rogers, J. A.

2002-07-01

433

Pyrosequencing Analysis of Bacterial Biofilm Communities in Water Meters of a Drinking Water Distribution System? †  

PubMed Central

The applicability of 454 pyrosequencing to characterize bacterial biofilm communities from two water meters of a drinking water distribution system was assessed. Differences in bacterial diversity and composition were observed. A better understanding of the bacterial ecology of drinking water biofilms will allow for effective management of water quality in distribution systems.

Hong, Pei-Ying; Hwang, Chiachi; Ling, Fangqiong; Andersen, Gary L.; LeChevallier, Mark W.; Liu, Wen-Tso

2010-01-01

434

Amplified recirculating circuits for pseudo-continuous wave generation  

Microsoft Academic Search

An analysis of amplified recirculating structures for producing a pseudo-continuous wave, PCW, signal is presented. Experimentations with amplification provided by EDFA and SOA are shown. Both the hold-on function and the switch-off function are analyzed. The comparison between structures with different amplifiers shows better duration performances for EDFAs, but faster all-optical operation capabilities for SOAs.

Paola Parolari; Lucia Marazzi; Pierpaolo Boffi; Mario Martinelli

1999-01-01

435

EVALUATION OF A PAINT SPRAY BOOTH UTILIZING AIR RECIRCULATION  

EPA Science Inventory

The objective of this project was to evaluate the effectiveness of the recirculating air spray booth process at the Deere and Company facility in Davenport, Iowa. The effort involved a field measurement program and subsequent analysis of flow rates and emission data from the spra...

436

Wastewater Renovation in Buried and Recirculating Sand Filters  

Microsoft Academic Search

A replicated, multiyear field study was conducted to assess the re- duction of N, P and microbial indicators by a recirculating sand filter (RSF) and bu ried mu ltilayer sa nd filter patterned after the RU CK filter. The RSF's received 38 L m -~ d-1 of septic tank effluent, while the buried sand filters were loaded at 76 L

A. J. Gold; B. E. Lamb; G. W. Loomis; J. R. Boyd; V. J. Cabelli; C. G. McKiel

1992-01-01

437

PROTOTYPE RECIRCULATION PUMP TESTS. PATHFINDER ATOMIC POWER PLANT SUMMARY REPORT  

Microsoft Academic Search

Results of tests performed on the Pathfinder Atomic Power Plant ; recirculation prototype pump and its components are presented. Tests included a ; preliminary seal test, a serrated bushing test, a cold performance test, and a ; hot loop test. Results indicated thut the pump should give trouble-free service ; in the field if operated as intended and within the

R. Haugen; D. J. Nolan

1961-01-01

438

Using exhaust gas recirculation in internal combustion engines: a review  

Microsoft Academic Search

The aim of this work is to review the potential of exhaust gas recirculation (EGR) to reduce the exhaust emissions, particularly NOX emissions, and to delimit the application range of this technique. A detailed analysis of previous and current results of EGR effects on the emissions and performance of Diesel engines, spark ignition engines and duel fuel engines is introduced.

G. H. Abd-Alla

2002-01-01

439

Selecting materials for recirculation valves used in secondary recovery service  

Microsoft Academic Search

It would be desirable to recommend an optimum combination of trim materials for use in recirculating valves handling seawater and\\/or hydrogen sulfide, but each application must be judged independently. The design engineer on each project must determine what materials will be best in the application, depending on the problem expected. Valve cavitation can be eliminated by using the proper valve

M. Schumacher; J. Gossett

1983-01-01

440

21 CFR 876.5665 - Water purification system for hemodialysis.  

Code of Federal Regulations, 2013 CFR

A water purification system for hemodialysis is a device that is intended for use with a hemodialysis system and that is intended to remove organic and inorganic substances and microbial contaminants from water used to dilute dialysate concentrate to form...

2013-04-01

441

21 CFR 876.5665 - Water purification system for hemodialysis.  

Code of Federal Regulations, 2010 CFR

A water purification system for hemodialysis is a device that is intended for use with a hemodialysis system and that is intended to remove organic and inorganic substances and microbial contaminants from water used to dilute dialysate concentrate to form...

2009-04-01

442

21 CFR 876.5665 - Water purification system for hemodialysis.  

Code of Federal Regulations, 2010 CFR

A water purification system for hemodialysis is a device that is intended for use with a hemodialysis system and that is intended to remove organic and inorganic substances and microbial contaminants from water used to dilute dialysate concentrate to form...

2010-04-01

443

21 CFR 1250.82 - Potable water systems.  

Code of Federal Regulations, 2013 CFR

...from any part of the potable water system, including treatment devices, discharging to a drain...protected against backflow. (f) Water systems shall be cleaned, disinfected...Food and Drugs shall find such treatment necessary to prevent the...

2013-04-01

444

High-pressure phase equilibria for the carbon dioxide + 3-pentanol and carbon dioxide + 3-pentanol + water systems  

SciTech Connect

High-pressure vapor-liquid equilibria for the binary carbon dioxide + 3-pentanol system were measured at 313.2 K. The phase equilibrium apparatus used in this work was of the circulation type in which the coexisting phases were recirculated, on-line sampled, and analyzed. The critical pressure and corresponding mole fraction of carbon dioxide at 313.2 K were found to be 8.22 MPa and 0.974, respectively, for this binary system. The phase equilibria for the ternary carbon dioxide + 3-pentanol + water system were also measured at 313.2 K and pressures of 2.00, 4.00, 6.00, 8.00, and 8.25 MPa. This ternary system showed the liquid-liquid-vapor (LLV) phase behavior over the range of pressure up to the critical pressure of 8.25 MPa. The binary equilibrium data were all reasonably well-correlated with the Redlich-Kwong, Soave-Redlich-Kwong, Peng-Robinson, and Patel-Teja equations of state incorporated with the eight different mixing rules: the van der Waals, Panagiotopoulos-Reic, and six modified Huron-Vidal mixing rules with UNIQUAC parameters. For the prediction of high-pressure phase equilibria for the systems containing carbon dioxide and alcohols, the SRK-MHV2 might reproduce many features of the measured behavior although further tests are needed with other systems.

Lee, H.S.; Mun, S.Y.; Lee, H. [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of). Dept. of Chemical Engineering

1999-05-01

445

Recirculating flow and sedimentation in the Colorado River in Grand Canyon, Arizona  

Microsoft Academic Search

Debris fans debouching into the bottom of Grand Canyon create rapids and flow separation in the Colorado River. The patterns of flow and the behavior of recirculation zones formed by flow separation are consistent throughout the Canyon's length. Zones of recirculating flow occur along the margin of channel expansions. Recirculation zones are comprised of one primary eddy; secondary eddies and

John C. Schmidt

1990-01-01

446

Low NOx Combustion of DME by Means of Flue Gas Recirculation  

Microsoft Academic Search

This study focuses on the fundamental characteristics of DME (Dimethyl Ether) combustion aiming at development of low-NOx combustion technology with flue gas recirculation, FGR. The flue gas is recirculated into the combustion chamber to reduce the oxygen concentration and to suppress the combustion gas temperature, so that NOx emission is significantly reduced. The fuel gas recirculation at high mixing ratio,

Ryosuke Matsumoto; Mamoru Ozawa; Shinya Terada; Takenori Iio

2008-01-01

447

Water Quality Evaluation System to Assess the Brantas River Water  

Microsoft Academic Search

Water quality degradation in the Brantas’ river will increase from the year to year due to increasing of the wastewater production\\u000a as well as forests and land degradations resulting from population growth, urbanization and economic and industrial developments.\\u000a Assessment of river water pollution is usually conducted by a comparison between the effective water quality and the standards\\u000a regulated by law.

Mohamad Ali Fulazzaky

2009-01-01

448

46 CFR 154.1105 - Exterior water spray system: General.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Exterior water spray system: General. 154.1105... Firefighting § 154.1105 Exterior water spray system: General. Each liquefied...liquefied toxic gas vessel must have an exterior water spray system that meets §§...

2012-10-01

449

46 CFR 154.1105 - Exterior water spray system: General.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Exterior water spray system: General. 154.1105... Firefighting § 154.1105 Exterior water spray system: General. Each liquefied...liquefied toxic gas vessel must have an exterior water spray system that meets §§...

2011-10-01

450

Consolidation as a Regulatory Compliance Strategy: Small Drinking Water Systems and the Safe Drinking Water Act  

Microsoft Academic Search

Despite extensive research and policy initiatives to increase the technical, financial, and managerial capacity of small drinking water systems, there has been little research focusing on understanding how consolidation can increase the overall capacity of the drinking water industry. Consolidation of water systems may be a mechanism that increases regulatory compliance by removing poorly performing systems from the industry and

Min-Yang A. Lee; John B. Braden

2007-01-01

451

K West integrated water treatment system subproject safety analysis document  

SciTech Connect

This Accident Analysis evaluates unmitigated accident scenarios, and identifies Safety Significant and Safety Class structures, systems, and components for the K West Integrated Water Treatment System.

SEMMENS, L.S.

1999-02-24

452

Rainwater Harvesting and Grey Water Recycling Systems  

Microsoft Academic Search

The benefits of water efficiency measures, rainwater harvesting and greywater reuse are principally water savings and reduced volume of consumption. Cost savings can accrue to the water supplier and water user. These benefits can be felt at a local level. Only with widespread use of such technology will reduced pressure on water resources and the supply infrastructure be realised. These

Liam McCarton; Sean O hOgain

2003-01-01

453

WATER QUALITY EARLY WARNING SYSTEMS FOR SOURCE WATER PROTECTION  

EPA Science Inventory

Source waters of the U.S. are vulnerable to natural and anthropogenic factors affecting quality for use as both a drinking water and ecological media. Important factors include physical parameters such as increased turbidity, ecological cycles such as algal blooms, and episodic ...

454

Family of Packaged Water/Packaged Water System.  

National Technical Information Service (NTIS)

The purpose of this project was to determine the feasibility of and a method to package potable water on the battlefield for use by the individual soldier or small groups of soldiers, in support of the airland battle concept. Water packaged in expendable ...

D. M. Wood

1994-01-01

455

Investigation of Water Quality in Domestic Water Systems.  

National Technical Information Service (NTIS)

The objective of the research was to determine the metal contents (zinc, copper, lead, cadmium and iron) in drinking waters transmitted by galvanized steel pipes and copper pipes. Water samples were taken from 17 buildings in New Jersey, New York and Mass...

L. K. Wang D. B. Aulenbach W. Y. W. Chan

1984-01-01

456

Biological and Synthetic Systems for Production of Hydrogen from Water.  

National Technical Information Service (NTIS)

Two systems were developed for the production of hydrogen and oxygen by the biophotolysis of water. The first system uses intact hydrogenase-containing algae which do not require isolated biological systems or enzymes. The second system consists of isolat...

A. I. Krasna

1978-01-01

457

Systems for Recycling Water in Poultry Processing.  

National Technical Information Service (NTIS)

The study was conducted to identify effective and economical water treatments, including disinfection, to meet the U.S. Department of Agriculture's standards for the recycling of poultry chiller water. Reconditioned chiller water meeting these criteria wa...

R. E. Carawan B. W. Sheldon

1988-01-01

458

Prototype Solar Domestic Hot Water Systems.  

National Technical Information Service (NTIS)

Construction of a double wall heat exchanger using soft copper tube coiled around a hot water storage tank was completed and preliminary tests were conducted. Solar transport water to tank potable water heat exchange tests were performed with a specially ...

1978-01-01

459

STANDARDIZED COSTS FOR WATER SUPPLY DISTRIBUTION SYSTEMS  

EPA Science Inventory

Presented within the report are cost data for construction and operation/maintenance of domestic water distribution and transmission pipelines, domestic water pumping stations, and domestic water storage reservoirs. To allow comparison of new construction with rehabilitation of e...

460

STANDARDIZED COSTS FOR WATER SUPPLY DISTRIBUTION SYSTEMS  

EPA Science Inventory

Presented within this report are cost data for construction and operation/maintenance of domestic water distribution and transmission pipelines, domestic water pumping stations, and domestic water storage reservoirs. ipeline cost data include costs for commonly utilized pipe mate...

461

Studies on water retention and water release from some protein systems  

Microsoft Academic Search

The hydrogen-bond properties (WBI index), water retention and water release from the protein-water systems gluten-water, soya protein- water and casein-water, have been investigated using differential scanning calorimetry in the temperature range 223–423 K. The proteins were characterized by their isoelectric point, contents of carboxyl groups and sulfur-containing groups, and readiness of undergo chloromethylation. It was concluded that the marked difference

R. Silvonen; J. J. Lindberg; C. Seppälä; M. Ervasti; C. Hauta-Aho

1982-01-01

462

Conceptual design study of geothermal district heating of a thirty-house subdivision in Elko, Nevada, using existing water-distribution systems, Phase III. Final technical report, October 1, 1979-September 30, 1980  

SciTech Connect

A conceptual design study for district heating of a 30-home subdivision located near the southeast extremity of the city of Elko, Nevada is presented. While a specific residential community was used in the study, the overall approach and methodologies are believed to be generally applicable for a large number of communities where low temperature geothermal fluid is available. The proposed district heating system utilizes moderate temperature, clean domestic water and existing community culinary water supply lines. The culinary water supply is heated by a moderate temperature geothermal source using a single heat exchanger at entry to the subdivision. The heated culinary water is then pumped to the houses in the community where energy is extracted by means of a water supplied heat pump. The use of heat pumps at the individual houses allows economic heating to result from supply of relatively cool water to the community, and this precludes the necessity of supplying objectionably hot water for normal household consumption use. Each heat pump unit is isolated from the consumptive water flow such that contamination of the water supply is avoided. The community water delivery system is modified to allow recirculation within the community, and very little rework of existing water lines is required. The entire system coefficient of performance (COP) for a typical year of heating is 3.36, exclusive of well pumping energy.

Pitts, D.R.

1980-09-30

463

Occurrence of Legionella in hot water systems of single-family residences in suburbs of two German cities with special reference to solar and district heating.  

PubMed

A total of 452 samples from hot water systems of randomly selected single family residences in the suburbs of two German cities were analysed for the occurrence of Legionella. Technical data were documented using a standardized questionnaire to evaluate possible factors promoting the growth of the bacterium in these small plumbing systems. All houses were supplied with treated groundwater from public water works. Drinking water quality was within the limits specified in the German regulations for drinking water and the water was not chlorinated. The results showed that plumbing systems in private houses that provided hot water from instantaneous water heaters were free of Legionella compared with a prevalence of 12% in houses with storage tanks and recirculating hot water where maximum counts of Legionella reached 100,000 CFU/100ml. The presence of L. pneumophila accounted for 93.9% of all Legionella positive specimens of which 71.8% belonged to serogroup 1. The volume of the storage tank, interrupting circulation for several hours daily and intermittently raising hot water temperatures to >60 degrees C had no influence on Legionella counts. Plumbing systems with copper pipes were more frequently contaminated than those made of synthetic materials or galvanized steel. An inhibitory effect due to copper was not present. Newly constructed systems (<2 years) were not colonized. The type of hot water preparation had a marked influence. More than 50% of all houses using district heating systems were colonized by Legionella. Their significantly lower hot water temperature is thought to be the key factor leading to intensified growth of Legionella. Although hot water systems using solar energy to supplement conventional hot water supplies operate at temperatures 3 degrees C lower than conventional systems, this technique does not seem to promote proliferation of the bacterium. Our data show convincingly that the temperature of the hot water is probably the most important or perhaps the only determinant factor for multiplication of Legionella. Water with a temperature below 46 degrees C was most frequently colonized and contained the highest concentrations of legionellae. It is evident that the same factors affecting colonization by Legionella in large buildings also exist in small residential water systems. If temperatures are low there is no difference between large and small systems and Legionella counts are high in both. Since private residences are an important source of community-acquired legionellosis, these findings emphasize the need for preventive control measures in small residential buildings. In some situations it may be necessary to install filtration devices at the point-of-use. PMID:17409022

Mathys, Werner; Stanke, Juliane; Harmuth, Margarita; Junge-Mathys, Elisabeth

2007-04-03

464

40 CFR 142.303 - Which size public water systems can receive a small system variance?  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Which size public water systems can receive...Provisions § 142.303 Which size public water systems can receive...variance to public water systems serving 3,300 or fewer persons...variance to public water systems serving more than 3,300 persons...

2013-07-01

465

A Learning Progression for Water in Socio-Ecological Systems  

ERIC Educational Resources Information Center

|Providing model-based accounts (explanations and predictions) of water and substances in water moving through environmental systems is an important practice for environmental science literacy and necessary for citizens confronting global and local water quantity and quality issues. In this article we present a learning progression for water in…

Gunckel, Kristin L.; Covitt, Beth A.; Salinas, Ivan; Anderson, Charles W.

2012-01-01

466

Optimization of coagulant dosing process in water purification system  

Microsoft Academic Search

In the water purification plant, chemicals are injected for quick purification of raw water. The amount of chemicals intrinsically depends on the water quality such as turbidity, temperature, pH and alkalinity, etc. This paper presents the method of deriving the optimum dosing rate of coagulant in water purification system. A fuzzy model for normal condition and a neural network model

Tae-Hwan Han; Eui-Suck Nahm; Kwang-Bang Woo; C. J. Kim; Jeong-Woong Ryu

1997-01-01

467

Estimation Energy and Water Losses in Residential Hot Water Distribution Systems.  

National Technical Information Service (NTIS)

Residential single family building practice currently ignores the losses of energy and water caused by the poor design of hot water systems. These losses include; the waste of water while waiting for hot water to get to the point of use; the wasted heat a...

J. Lutz

2005-01-01

468

COST COMPARISIONS OF WATER TREATMENT SYSTEMS TO IMPROVE WATER QUALITY FOR MUNICIPAL USE  

Microsoft Academic Search

Drinking water quality is the key factor for sustainability of life and well being of the human population. The quality of water in Texas High Plains generally is suitable for irrigation but doesn't meet the drinking water standards with respect to certain dissolved constituents (dissolved solids\\/salinity, fluorides, chlorides and sulfate). Water treatment systems are costly and local communities have financial

Naveen C Adusumilli; Lal K. Almas

469

EPRI Water Supply Data Base System. Final Report, December 1978.  

National Technical Information Service (NTIS)

This is the final report for RP762, Water Supply Data Base for R and D Planning. The result of this study is the EPRI water data system--a data base, or data dictionary, that describes water data collection efforts. The system has two components: (1) a ma...

1978-01-01

470

Use of ozone for Legionella reduction in water systems  

Microsoft Academic Search

Ozone is reported to be effective against Legionella in water systems such cooling towers and tap water pipelines. Until now, most of the studies performed to asses the efficiency of disinfectants against Legionella were made in vitro or in existing water systems. In vitro studies do not take into account the higher resistance of this bacterium to biocides due to

B. Ruiz; J. Bauzá; J. Benito; A. Pascual

471

Water desalination with concentrating photovoltaic\\/thermal (CPVT) systems  

Microsoft Academic Search

A coupled system is proposed, comprised of a concentrating photovoltaic\\/thermal collector field and a multi-effect evaporation desalination plant. The combined system produces solar electricity and simultaneously exploits the waste heat of the photovoltaic cells to desalinate water. A detailed simulation was performed to compute the annual production of electricity and water. The cost of desalinated water was estimated and compared

Gur Mittelman; Abraham Kribus; Ornit Mouchtar; Abraham Dayan

2009-01-01

472

Running Hot Water: A Systems Approach to Energy Conservation.  

National Technical Information Service (NTIS)

Ways to conserve energy in domestic hot water systems are discussed. Examination of the Swedish situation shows that centralized systems, where water heating is a subsidiary of space heating, waste energy because water cools in the pipes after use, and th...

P. Wulff

1982-01-01

473

Water quality monitoring system based on robotic dolphin  

Microsoft Academic Search

To meet the demands of online, safe and overall monitoring of the water quality, a water quality monitoring system based on robotic dolphin is developed, enlightened by the dolphin's swimming ability with high efficiency and good maneuverability. The system is composed of fixed monitoring nodes, robotic dolphin node and a console, and the water quality parameters such as PH value,

Fei Shen; Changming Wei; Zhiqiang Cao; Chao Zhou; De Xu; Weiyi Zhang

2011-01-01

474

33 CFR 127.1507 - Water systems for fire protection.  

Code of Federal Regulations, 2013 CFR

...distributing and applying the water to protect personnel...cargo, and vessels. Each water system must include on the pier...to the vessel. (b) Each water system must fully and simultaneously...at their designed flow and pressure for the worst single...

2013-07-01

475

Financing Assistance Available for Small Public Water Systems  

Microsoft Academic Search

Many small and very small drinking water systems require repair and upgrading if they are to comply with the Safe Drinking Water Act of 1974 and its amendments. Often, dispersed population makes infrastructure expensive on a per-capita basis. Funding shortages at the federal, state, and water system levels compound the problem, leading to budget deficits, layoffs, and furloughs that affect

Susan Campbell; Benjamin W. Lykins Jr.; James A. Goodrich

1993-01-01

476

Effect of the distribution system on drinking-water quality  

Microsoft Academic Search

The Safe Drinking Water Act and its Amendments has focused interest on the factors that cause the deterioration of water between the treatment plant and the consumer. The distribution system itself can contribute to this deterioration. Numerous examples of waterborne disease outbreaks have demonstrated the importance of the distribution system in preventing disease. Water-quality propagation models can be used to

R. M. Clark; J. A. Goodrich; L. J. Wymer

1993-01-01

477

RETURN FLOW TO GROUND WATER FROM ONSITE WASTEWATER SYSTEMS  

Microsoft Academic Search

Ground water pumped for potable supply is often beneficially used only once, discharged into a centralized sewer system, and released after treatment into a different hydrologic system such as a river that flows into an ocean. These and other anthropogenic transfers of water from continental aquifers into oceans are resulting in ground-water depletion and a small contribution to rising sea

Dennis McQuillan; Eugene Bassett

478

A hybrid solar desalination and water heating system  

Microsoft Academic Search

The hybrid character of a solar desalination system consisting of a “greenhouse”- type conventional solar still coupled with a solar collector field and hot water storage tank was investigated. This system shows significantly higher distilled water output compared with that of an uncoupled still, and moreover has the advantage of supplying hot water from its storage tank. Through experimental data

K. Voropoulos; E. Mathioulakis; V. Belessiotis

2004-01-01

479

Control of water levels of regional water systems using reinforcement learning  

Microsoft Academic Search

Real-time control (RTC) of the regulating structures such as pumping stations, weirs, inlets etc. in a regional water system ensures efficient water management. In practice, dynamic programming is mostly used with the help of a physically-based model to determine the optimal control strategy. For complex water systems the required computation time for optimisation may prohibit its use in RTC. In

B. Bhattacharya; A. H. Lobbrecht; D. P. Solomatine

2002-01-01

480

Summary of Operating Experience with Recirculating Steam Generators.  

National Technical Information Service (NTIS)

Operating problems have occurred in the steam generators of each of the three manufacturers of pressurized water reactors (PWR) nuclear steam supply systems (NSSS): Babcock & Wilcox, Combustion Engineering, and Westinghouse Electric Corporation. This repo...

D. G. Eisenhut B. D. Liaw J. Stronsnider

1979-01-01