Screening-level ecological and human health risk assessment of polycyclic aromatic hydrocarbons in stormwater detention pond sediments of Coastal South Carolina, USA

Energy Technology Data Exchange (ETDEWEB)

Weinstein, John E., E-mail: john.weinstein@citadel.edu [Department of Biology, The Citadel, Charleston, SC (United States); Crawford, Kevin D. [Department of Chemistry, University of Wisconsin-Oshkosh, Oshkosh, WI (United States); Garner, Thomas R. [Institute of Environmental Toxicology, Clemson University, Pendleton, SC (United States); Flemming, Alan J. [South Carolina Department of Health and Environmental Control, Charleston, SC (United States)

2010-06-15

Screening-level ecological and human health assessments were performed for polycyclic aromatic hydrocarbon (PAH) contamination in the sediments of 19 stormwater detention ponds located in coastal South Carolina. For ecological screening benchmarks, we used threshold and probable effect concentrations (TEC and PEC) derived from consensus-based sediment quality guidelines for individual PAH analytes and equilibrium partitioning sediment benchmarks-toxic units ({Sigma}ESB-TU) derived for PAH mixtures. For human health benchmarks, we used preliminary remediation goals (PRGs). Sediments of five stormwater ponds (four commercial ponds and one residential pond with a large drainage area) exceeded PEC values for several PAH analytes and the {Sigma}ESB-TU safe value of 1 for PAH mixtures. These same five stormwater ponds also exceeded the PRG values for five carcinogenic PAH analytes. These results suggest that the PAH levels in sediments from certain commercial and residential ponds have the potential to pose moderate to high risks for adverse, chronic effects to benthic organisms in situ and an increased risk of cancer to humans ex situ following excavation and on-site disposal. We recommend that sediment from these stormwater ponds be tested prior to excavation to determine the appropriate method of disposal. We also recommend that regulatory agencies enforce guidelines for periodic sediment removal as this should reduce both in situ and ex situ risks resulting from sediment PAH exposure.

Screening-level ecological and human health risk assessment of polycyclic aromatic hydrocarbons in stormwater detention pond sediments of Coastal South Carolina, USA

International Nuclear Information System (INIS)

Weinstein, John E.; Crawford, Kevin D.; Garner, Thomas R.; Flemming, Alan J.

2010-01-01

Screening-level ecological and human health assessments were performed for polycyclic aromatic hydrocarbon (PAH) contamination in the sediments of 19 stormwater detention ponds located in coastal South Carolina. For ecological screening benchmarks, we used threshold and probable effect concentrations (TEC and PEC) derived from consensus-based sediment quality guidelines for individual PAH analytes and equilibrium partitioning sediment benchmarks-toxic units (ΣESB-TU) derived for PAH mixtures. For human health benchmarks, we used preliminary remediation goals (PRGs). Sediments of five stormwater ponds (four commercial ponds and one residential pond with a large drainage area) exceeded PEC values for several PAH analytes and the ΣESB-TU safe value of 1 for PAH mixtures. These same five stormwater ponds also exceeded the PRG values for five carcinogenic PAH analytes. These results suggest that the PAH levels in sediments from certain commercial and residential ponds have the potential to pose moderate to high risks for adverse, chronic effects to benthic organisms in situ and an increased risk of cancer to humans ex situ following excavation and on-site disposal. We recommend that sediment from these stormwater ponds be tested prior to excavation to determine the appropriate method of disposal. We also recommend that regulatory agencies enforce guidelines for periodic sediment removal as this should reduce both in situ and ex situ risks resulting from sediment PAH exposure.

Carbonate deposition on tail feathers of ruddy ducks using evaporation ponds

Science.gov (United States)

Euliss, N.H.; Jarvis, R.L.; Gilmer, D.S.

1989-01-01

Substantial carbonate deposits were observed on rectrices of Ruddy Ducks (Oxyura jamaicensis) collected during 1982-1984 on evaporation ponds in the San Joaquin Valley, California. Carbonate deposits were composed of about 75% aragonite and 25% calcite, both polymorphous forms of CaCO3. Significantly more carbonate deposits were observed on Ruddy Ducks as length of exposure to agricultural drain water increased, during the 1983-1984 field season when salt concentrations in the ponds were higher, and in certain evaporation-pond systems.

Effectiveness of a stormwater collection and detention system for reducing constituent loads from bridge runoff in Pinellas County, Florida

Science.gov (United States)

Stoker, Y.E.

1996-01-01

The quantity and quality of stormwater runoff from the Bayside Bridge were evaluated to determine the effectiveness of the stormwater collection and detention pond system of the bridge in reducing constituent loads to Old Tampa Bay. Water-quality samples of stormwater runoff from the bridge and outflow from the detention pond were collected during and after selected storms. These samples were used to compute loads for selected constituents. Stormwater on the Bayside Bridge drained rapidly during rain events. The volume of stormwater runoff from 24 storms measured during the study ranged from 4,086 to 103,705 cubic feet. Storms were most frequent during July through September and were least frequent from February through May. Concentrations of most constituents in stormwater runoff before the bridge opened to traffic were less than or equal to concentrations measured after the bridge was opened to traffic. However, concentrations of arsenic in the outflow from the detention pond generally were greater before the bridge opened than concentrations after, and concentrations of orthophosphorus in the stormwater runoff and outflow from the pond were greater before the bridge opened than during over half the sampled storms after the bridge opened. Concentrations of most constituents measured in stormwater runoff from the bridge were greatest at the beginning of the storm and decreased as the storm continued. Variations in suspended solids, nutrients, and trace element concentrations were not always concurrent with each other. The source of the measured constituent (rainfall or road debris) and the phase of the constituent (suspended or dissolved) probably affected the timing of concentration changes. The quality of stormwater runoff from the Bayside Bridge varied with total runoff volume, with the length of the dry period before the storm, and with season. Average concentrations of suspended solids, ammonia plus organic nitrogen, nitrite plus nitrate nitrogen

Halite depositional facies in a solar salt pond: A key to interpreting physical energy and water depth in ancient deposits?

Science.gov (United States)

Robertson Handford, C.

1990-08-01

Subaqueous deposits of aragonite, gypsum, and halite are accumulating in shallow solar salt ponds constructed in the Pekelmeer, a sea-level sauna on Bonaire, Netherlands Antilles. Several halite facies are deposited in the crystallizer ponds in response to differences in water depth and wave energy. Cumulate halite, which originates as floating rafts, is present only along the protected, upwind margins of ponds where low-energy conditions foster their formation and preservation. Cornet crystals with peculiar mushroom- and mortarboard-shaped caps precipitate in centimetre-deep brine sheets within a couple of metres of the upwind or low-energy margins. Downwind from these margins, cornet and chevron halite precipitate on the pond floors in water depths ranging from a few centimetres to ˜60 cm. Halite pisoids with radial-concentric structure are precipitated in the swash zone along downwind high-energy shorelines where they form pebbly beaches. This study suggests that primary halite facies are energy and/or depth dependent and that some primary features, if preserved in ancient halite deposits, can be used to infer physical energy conditions, subenvironments such as low- to high-energy shorelines, and extremely shallow water depths in ancient evaporite basins.

Impact of beaver ponds on river discharge and sediment deposition along the Chevral River, Ardennes, Belgium

Science.gov (United States)

Nyssen, Jan; Frankl, Amaury; Pontzeele, Jolien; De Visscher, Maarten; Billi, Paolo

2013-04-01

With the recovery of the European beaver (Castor fiber) and their capacity to engineer fluvial landscapes, questions arise as to how they influence river discharge and sediment transport. The Chevral river (Ardennes, Belgium) contains two beaver dam sequences which appeared in 2004 and count now about 30 dams. Flow discharges and sediment fluxes were measured at the in- and outflow of each dam sequence. Volumes of sediment deposited behind the dams were measured. Between 2004 and 2011, peak flows were topped off, and the magnitude of extreme events decreased. 1710 m³ of sediment were deposited behind the beaver dams, with an average sediment thickness of 25 cm. The thickness of the sediment layer is related to the area of the beaver ponds. Along the stream, beaver pond sediment thickness displayed a sinusoidal deposition pattern, in which ponds with thick sediment layers were preceded by a series of ponds with thinner sediment layers. A downstream textural coarsening in the dam sequences was also observed, probably due to dam failures subsequent to surges. Differences in sediment flux between the in- and outflow at the beaver pond sequence were related to the river hydrograph, with deposition taking place during the rising limbs and slight erosion during the falling limbs. The seven-year-old sequences have filtered 190 tons of sediment out of the Chevral river, which is of the same order of magnitude as the 374 tons measured in pond deposits, with the difference between the values corresponding to beaver excavations (60 tons), inflow from small tributaries, and runoff from the valley flanks. Hydrogeomorphic effects of C. fiber and C. canadensis activity are similar in magnitude. The detailed analysis of changes to hydrology in beaver pond sequences confirms the potential of beavers to contribute to river and wetland restoration and catchment management.

Nutrient and metal uptake in wetland plants at stormwater detension ponds

DEFF Research Database (Denmark)

Istenic, Darja; Arias, Carlos Alberto; Brix, Hans

2011-01-01

Nutrients and metals were analysed in tissues of various wetland plants growing in stormwater detention ponds in Denmark. Nutrient and metal concentrations in below and aboveground tissues were compared to the concentrations of the adjacent sediment. The results showed accumulation of heavy metal...

Relationship Between Accumulation and Influx of Pollutants in Highway Ponds

DEFF Research Database (Denmark)

Bentzen, Thomas Ruby; Larsen, Torben; Rasmussen, Michael R.

The paper discusses the long term mass balance of pollutants in highway ponds. The accumulations of five polycyclic aromatic hydrocarbons (PAHs) and six heavy metals have been measured in eight Danish detention ponds, which receive runoff from highways only. For each pollutant the accumulation has...... been compared to the long-term influx, estimated from short-term measurements of concentrations in highway runoff. The results show that a large proportion of the incoming heavy metals in short-term runoff events has accumulated in the ponds. This is not the case for the toxic organic compounds....... The results also show that the accumulation rates for the heavy metals depend significantly on the relative pond area (pond area divided by catchment area). The conclusion is that the mass balances of heavy metals and PAHs in highway ponds can be estimated with acceptable accuracy from a combination of short...

Modeling the eutrophication of two mature planted stormwater ponds for runoff control

DEFF Research Database (Denmark)

Wium-Andersen, Tove; Nielsen, A.H.; Hvitved-Jacobsen, Thorkild

2013-01-01

A model, targeting eutrophication of stormwater detention ponds was developed and applied to sim-ulate pH, dissolved oxygen and the development of algae and plant biomass in two mature plantedwetponds for run off control. The model evaluated algal and plant biomass growth into three groupsnamely;...

Agricultural runoff pollution control by a grassed swales coupled with wetland detention ponds system: a case study in Taihu Basin, China.

Science.gov (United States)

Zhao, Jinhui; Zhao, Yaqian; Zhao, Xiaoli; Jiang, Cheng

2016-05-01

The performance of a field grassed swales (GSs) coupled with wetland detention ponds (WDPs) system was monitored under four typical rainfall events to assess its effectiveness on agricultural runoff pollution control in Taihu Basin, China. The results indicated that suspended solids (SS) derived from the flush process has significant influence on pollution loads in agricultural runoff. Determination of first flush effect (FFE) indicated that total suspended solids (TSS) and total phosphorus (TP) exhibited moderate FFE, while chemical oxygen demand (COD) and total nitrogen (TN) showed weak FFE. Average removal efficiencies of 83.5 ± 4.5, 65.3 ± 6.8, 91.6 ± 3.8, and 81.3 ± 5.8 % for TSS, COD, TN, and TP were achieved, respectively. The GSs played an important role in removing TSS and TP and acted as a pre-treatment process to prevent clogging of the subsequent WDPs. Particle size distributions (PSDs) analysis indicated that coarse particles larger than 75 μm accounted for 80 % by weight of the total particles in the runoff. GSs can effectively reduce coarse particles (≥75 μm) in runoff, while its removal efficiency for fine particles (runoff pollution control.

Taphonomic and sedimentological aspects from PICOS II paleontological site, a quaternary pond deposit of Alagoas, Brazil

Science.gov (United States)

Asakura, Yumi; Silva, Jorge Luiz Lopes da; Silva, Ana Paula Lopes da; Silva, Elaine Pollyanne Alves da; Omena, Érica Cavalcante

2016-11-01

The Picos II Paleontological Site (PIIPS), located in the city of Piranhas, in Alagoas State, is a fossil deposit with a pond-like geomorphological feature, a kind of peculiar deposit for the Quaternary of Northeast Brazil. A detailed taphonomic study is presented about the PIIPS assemblage, from material collection to the laboratory analysis. The conservation state of the collected fossils in PIIPS is different from that found in other tank deposits, showing a high degree of specimen preservation. Two taxa of pleistocenic mammals have been identified: Eremotherium laurillardi and Notiomastodon platensis, and fragments of an avian bone, whose taxonomic identification was not possible. The taphonomic analysis indicates that the deposited material experienced a short transportation in high-energy event, with a short period of subaerial exposure before the final burial, where at least the final disarticulation occurred in situ, which explains the high conservation level of the material. The sedimentological analysis made in each layer of the deposit corroborates the information related to the transport of the material, which were obtained in taphonomic analysis. Regarding these aspects, PIIPS reflects nearly non-biased biocenotic patterns. The well-preserved material found in PIIPS demonstrates the great potential of deposits with pond-like geomorphological features, with sidelines that are less steep than traditional tanks, providing smoother transport and accommodation for skeletal elements, which is a distinguishing factor in preserving fossils of vertebrates.

Predictions of Resuspension of Highway Detention Pond Deposits in Interrain Event Periods due to Wind-Induced Currents and Waves

DEFF Research Database (Denmark)

Bentzen, Thomas Ruby; Larsen, Torben; Rasmussen, Michael R.

2009-01-01

-shear stress induced by the return flow near the bed and waves both generated by the wind. Wind statistics for 30 years have been applied for prediction of the annual discharged bulk of suspended solids and associated pollutants; fluoranthene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo......(a,h)anthracene and indeno(1,2,3-cd)pyrene (PAHs) and the heavy metals of cadmium, chromium, copper, lead, nickel, and zinc. The current and wave-generated bed-shear stresses entail a discharged bulk of pollutants corresponding to approximately 10% of the annual accumulation of pollutants in the present pond due...

Samples of Asteroid Surface Ponded Deposits in Chondritic Meteorites

Science.gov (United States)

Zolensky, M. E.; Lee, R.; Le, L.

2004-01-01

One of the many unexpected observations of asteroid 433 Eros by the Near Earth Asteroid Rendezvous (NEAR) mission was the many ponds of fine-grained materials [1-3]. The ponds have smooth surfaces, and define equipotential surfaces up to 10's of meters in diameter [4]. The ponds have a uniformly sub-cm grain size and appear to be cohesive or indurated to some degree, as revealed by slumping. The ponds appear to be concentrated within 30 degrees of the equator of Eros, where gravity is lowest. There is some insight into the mineralogy and composition of the ponds surfaces from NEAR spectroscopy [2,4,5,6]. Compared to the bulk asteroid, ponds: (1) are distinctly bluer (high 550/760 nm ratio), (2) have a deeper 1um mafic band, (3) have reflectance elevated by 5%.

Vanishing Ponds and Regional Water Resources in Taoyuan, Taiwan

Directory of Open Access Journals (Sweden)

Yuei-An Liou

2015-01-01

Full Text Available Taiwan has a Subtropic to Tropical climate, but its precipitation varies widely in response to seasonal effects and weather events such as Typhoon and Meiyu systems. Precipitation must be held back in reservoirs to provide and regulate sufficient water supply. Balancing the irregular precipitation and increasing water demands generates tremendous pressure on water resources management for the water stored in the Shihmen Reservoir, which is the major unitary water supply system in the Greater Taoyuan Area. Such pressure will be significantly enlarged due to the huge 17 billion USD Taoyuan Aerotropolis Project. In earlier days many small artificial ponds (a common terminology in this article, including irrigation ponds, fishery ponds and others, were built to cope with water shortages in Taoyuan County. These small storage ponds provided a solution that resolved seasonal precipitation shortages. Unfortunately, these ponds have been vanishing one after another one due to regional industrialization and urbanization in recent decades and less than 40% of them still remain today. There is great urgency and importance to investigating the link between vanishing ponds and water resources management. Remote sensing technology was used in this study to monitor the environmental consequences in the Taoyuan area by conducting multi-temporal analysis on the changes in water bodies, i.e., ponds. SPOT satellite images taken in 1993, 2003, and 2010 were utilized to analyze and assess the importance of small-scale ponds as water conservation facilities. It was found that, during the seventeen years from 1993 - 2010, the number of irrigation ponds decreased by 35.94%. These ponds can reduce the burden on the major reservoir and increase the water recycling rate if they are properly conserved. They can also improve rainfall interception and surface detention capabilities, and provide another planning advantage for regional water management.

21 CFR 800.55 - Administrative detention.

Science.gov (United States)

2010-04-01

... obtained and confirmed by written memorandum within FDA as soon as possible. (f) Labeling or marking a...) Issuance of detention order. (1) The detention order shall be issued in writing, in the form of a detention... permitted under paragraph (h) of this section, without the written permission of an authorized FDA...

Nogales flood detention study

Science.gov (United States)

Norman, Laura M.; Levick, Lainie; Guertin, D. Phillip; Callegary, James; Guadarrama, Jesus Quintanar; Anaya, Claudia Zulema Gil; Prichard, Andrea; Gray, Floyd; Castellanos, Edgar; Tepezano, Edgar; Huth, Hans; Vandervoet, Prescott; Rodriguez, Saul; Nunez, Jose; Atwood, Donald; Granillo, Gilberto Patricio Olivero; Ceballos, Francisco Octavio Gastellum

2010-01-01

Flooding in Ambos Nogales often exceeds the capacity of the channel and adjacent land areas, endangering many people. The Nogales Wash is being studied to prevent future flood disasters and detention features are being installed in tributaries of the wash. This paper describes the application of the KINEROS2 model and efforts to understand the capacity of these detention features under various flood and urbanization scenarios. Results depict a reduction in peak flow for the 10-year, 1-hour event based on current land use in tributaries with detention features. However, model results also demonstrate that larger storm events and increasing urbanization will put a strain on the features and limit their effectiveness.

Questions over alternatives to detention programmes

Directory of Open Access Journals (Sweden)

Stephanie J Silverman

2013-09-01

Full Text Available Alternative to detention programmes may be less restrictive and less expensive than formal detention but they may still have drawbacks. The provision of competent legal advice appears to be key to low rates of absconding.

8 CFR 241.3 - Detention of aliens during removal period.

Science.gov (United States)

2010-01-01

... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Detention of aliens during removal period. 241.3 Section 241.3 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED Post-hearing Detention and Removal § 241.3 Detention of...

Refugee children's sandplay narratives in immigration detention in Canada.

Science.gov (United States)

Kronick, Rachel; Rousseau, Cécile; Cleveland, Janet

2018-04-01

Asylum seeking children arriving in Canada regularly face incarceration in medium-security-style immigration detention centres. Research demonstrates the human cost of detaining migrant children and families and the psychiatric burden linked with such imprisonment. This study aims to understand the lived experiences of children aged 3-13 held in detention. Informed by a qualitative methodology of narrative inquiry, child participants created worlds in the sand and generated stories to express their subjective experience. Results suggest that children's sandplay confirms the traumatic nature of immigration detention while also revealing children's sometimes conflicting understanding of the meaning of detention and their own migration. The results are contextualized by a description of detention conditions and the psychiatric symptoms associated with immigration incarceration. The study highlights the need for more research examining the impact of immigration detention on children's mental health, while also underlining how refugee children's voices provide important direction for policy change.

Can we close the long term mass balanceequation for pollutants in highway ponds?

DEFF Research Database (Denmark)

Bentzen, Thomas Ruby; Larsen, Torben; Rasmussen, Michael R.

2006-01-01

The paper discusses the prospects of finding the long term mass balance on basis of short term simulations. A step in this process is to see to which degree the mass balance equation can be closed by measurements. Accordingly the total accumulation of heavy metals and PAH's in 8 Danish detention...... ponds only receiving runoff from highways have been measured. The result shows that the incoming mass of heavy metals from short term runoff events is accumulated. This is not observable in the same magnitude for the toxic organic compounds. The results also show that the accumulation rates...

Identifying Farm Pond Habitat Suitability for the Common Moorhen (Gallinula chloropus: A Conservation-Perspective Approach

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Chun-Hsien Lai

2018-04-01

Full Text Available The purpose of this study was to establish a habitat-suitability assessment model for Gallinula chloropus, or the Common Moorhen, to be applied to the selection of the most suitable farm pond for habitat conservation in Chiayi County, Taiwan. First, the fuzzy Delphi method was employed to evaluate habitat selection factors and calculate the weights of these factors. The results showed that the eight crucial factors, by importance, in descending order, were (1 area ratio of farmlands within 200 m of the farm pond; (2 pond area; (3 pond perimeter; (4 aquatic plant coverage of the pond surface; (5 drought period; (6 coverage of high and low shrubs around the pond bank; (7 bank type; and (8 water-surface-to-bank distance. Subsequently, field evaluations of 75 farm ponds in Chiayi County were performed. The results indicated that 15 farm ponds had highly-suitable habitats and were inhabited by unusually high numbers of Common Moorhens; these habitats were most in need of conservation. A total of two farm ponds were found to require habitat-environment improvements, and Common Moorhens with typical reproductive capacity could be appropriately introduced into 22 farm ponds to restore the ecosystem of the species. Additionally, the habitat suitability and number of Common Moorhens in 36 farm ponds were lower than average; these ponds could be used for agricultural irrigation, detention basins, or for recreational use by community residents. Finally, the total habitat suitability scores and occurrence of Common Moorhens in each farm pond were used to verify the accuracy of the habitat-suitability assessment model for the Common Moorhen. The overall accuracy was 0.8, and the Kappa value was 0.60, which indicates that the model established in this study exhibited high credibility. To sum up, this is an applicable framework not only to assess the habitat suitability of farm ponds for Common Moorhens, but also to determine whether a particular location may

HIV/AIDS knowledge in detention in Hunan province, China

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Chen Xi

2010-04-01

Full Text Available Abstract Background Injection drug use (IDU is one of the major modes of HIV transmission in China. Drug use is illegal in China, all identified drug users are registered by Public Security Bureau, and most were sent to detention; most detainees engaged in high risk behaviours. In order to well understand the HIV/AIDS knowledge among detainees, a survey was conducted in different detention settings in Hunan province in 2008 to assess knowledge and attitudes about HIV among detainees and to provide useful information for HIV prevention and intervention strategies in detention centers. Methods A cross-sectional survey was conducted in 10 detentions in Hunan province, China, and demographic information along with knowledge and attitude of HIV/AIDS was collected through standardized interviews. Descriptive statistics were used to describe HIV knowledge, attitudes, and education services among detainees. Results There were 956 detainees interviewed from 10 detention centers. The male to female ratio was 2.24:1. The majority detainees received nine years of compulsory education, accounting for 51.5%. There were nine questions to assess HIV/AIDS knowledge of detainees, and 35.7% of those surveyed answered all nine questions correctly. There were 92.3% (882/956 who consented to be informed about the HIV antibody test results when tested, and 81% (774/956 elected that their family members were also informed. All detention centers had an organized HIV/AIDS education program. Conclusion This study gives us an overview about HIV/AIDS knowledge in detention in Hunan province, and all detention sites in the study provided HIV/AIDS intervention services among detainees that focused on HIV/AIDS knowledge, attitude, and health behaviors.

CFD analysis of sludge accumulation and hydraulic performance of a waste stabilization pond.

Science.gov (United States)

Alvarado, Andres; Sanchez, Esteban; Durazno, Galo; Vesvikar, Mehul; Nopens, Ingmar

2012-01-01

Sludge management in waste stabilization ponds (WSPs) is essential for safeguarding the system performance. Sludge accumulation patterns in WSPs are strongly influenced by the pond hydrodynamics. CFD modeling was applied to study the relation between velocity profiles and sludge deposition during 10 years of operation of the Ucubamba WSP in Cuenca (Ecuador). One tracer experiment was performed and three sludge accumulation scenarios based on bathymetric surveys were simulated. A residence time distribution (RTD) analysis illustrated the decrease of residence times due to sludge deposition. Sludge accumulation rates were calculated. The influence of flow pattern on the sludge deposition was studied, enabling better planning of future pond operation and desludging.

Can we close the long term mass balance equation for pollutants in highway ponds?

DEFF Research Database (Denmark)

Bentzen, Thomas Ruby; Larsen, Torben; Rasmussen, Michael R.

2007-01-01

The paper discusses the prospects of finding the long term mass balance on basis of short term simulations. A step in this process is to see to which degree the mass balance equation can be closed by measurements. Accordingly the total accumulation of heavy metals and PAH's in 8 Danish detention...... ponds only receiving runoff from highways have been measured. The result shows that the incoming mass of heavy metals from short term runoff events is accumulated. This is not observable in the same magnitude for the toxic organic compounds. The results also show that the accumulation rates...

27 CFR 26.194 - Detention of articles.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Detention of articles. 26..., DEPARTMENT OF THE TREASURY LIQUORS LIQUORS AND ARTICLES FROM PUERTO RICO AND THE VIRGIN ISLANDS Shipment of... Detention of articles. (a) Upon receiving a notification in accordance with § 26.193(b), the appropriate TTB...

Preliminary results of sedimentation study in SMART, Kg. Berembang holding pond

International Nuclear Information System (INIS)

Jeremy Andy Dominic; Wan Zakaria Wan Md Tahir; Lakam Mejus; Juhari Mohd Yusuf; Kamaruzaman Mohamad; Mod Omar Hassan

2010-01-01

Full text: Spatial variations of the sediment bulk density profile in the Storm water Management And Road Tunnel (SMART) holding pond were measured at every 20 metre intervals along six cross section lines with a total of 72 sampling points using a Cs-137 nuclear backscatter probe. The bulk density profile at each sampling points were vertically measured at every 2 inches increment in an upward direction. The thickness of the deposited sediment varies spatially with a gradual increase towards the centre of the holding pond. The highest sediment deposition areas are located near the baffle walls, the centre and the south east corner of the holding pond. The maximum thickness of the deposited sediment adjacent to the baffle walls is 22 inch and at both the centre and south east area are 18 inch. The sediment bulk density profile varies from 1,010 kg.m -3 to 1,400 kg.m -3 . Spatial density variations are in correlation with the active and inactive zone in the pond area. The potential of sediment deposition and consolidation process is higher in the inactive zone compare to the active zone, therefore the bulk density value the inactive zone is much higher. (author)

The Record of Tsunamis and Storms in a Coastal Mangrove Pond, NW Puerto Rico

Science.gov (United States)

Jaffe, B. E.; Buckley, M. L.; Watt, S. G.; Moya, J. C.; Richmond, B. M.; Gelfenbaum, G. R.; La Selle, S.

2017-12-01

The written record of tsunamis in the Caribbean extends back over 500 years, yet, is incomplete. In particular, it is not known whether great earthquakes or submarine landslides near the Puerto Rico Trench have generated large tsunamis that impact the north coast of Puerto Rico. We cored a coastal mangrove pond in NW Puerto Rico to search for tsunami deposits. The pond extends from 150 to 350 m from the shoreline, and is 0.5 m above sea level. The area between the pond and the ocean presently has a high of 3 m above sea level, but had dunes up to 10 m high before they were mined for sand beginning in the 1960s. Pond sediments are predominately mud or mangrove peat and contain prominent sand layers. At the sediment surface, a tabular sandy overwash deposit up to 40 cm thick extends inland approximately 30 m from the pond's seaward edge and abruptly ends. This sand layer contains no evidence of vertical grading and was likely formed by one or more recent hurricanes, which with the removal of coastal dunes in the 1960s are able to flood the pond. In contrast, underlying the overwash deposit and mangrove peat at a depth of approximately 60 cm is a thin (1 - 7 cm thick) sand layer extending to the landward limit of the pond. This layer has features of a tsunami deposit, including suspension grading, which is a specific type of normal grading where the entire grain-size distribution shifts to finer sizes upward that is created when sediment settles out of suspension as a high-speed flow wanes, an erosive basal contact, and an organic cap. In addition, couplets or triplets of sand inter-layered with mud are present within the thin sandy layer at some locations. Alternation of sand and mud layers at this scale is a signature of series of tsunami waves. Radiocarbon dates from organic material above and below the thin sand layer constrain deposition as occurring sometime from 1446 to 1919 AD. We present the features of the coastal mangrove pond deposits and evaluate whether

Copper mobilization affected by weather conditions in a stormwater detention system receiving runoff waters from vineyard soils (Champagne, France)

Energy Technology Data Exchange (ETDEWEB)

Banas, D., E-mail: damien.banas@u-psud.f [Univ. Reims Champagne-Ardenne, Lab. Eco-Toxicologie, BP 1039, F-51687 Reims Cedex 2 (France); Univ. Nancy, UR-AFPA, INRA, 2 Av. Foret Haye, F-54505 Vandoeuvre-les-Nancy (France); Marin, B., E-mail: beatrice.marin@univ-reims.f [Univ. Reims Champagne-Ardenne, EA3795 GEGENA, 2 Esplanade Roland Garros, F-51100 Reims (France); Skraber, S., E-mail: skraber@lippmann.l [Centre de Recherche Public, Gabriel Lippmann, Department of Environment and Agro-biotechnologies (EVA), 41 rue du Brill, L-4422 Belvaux (Luxembourg); Chopin, E.I.B., E-mail: chopin@oakland.ed [Oakland University, Department of Chemistry, Rochester, MI 48309 (United States); Zanella, A., E-mail: augusto.zanella@unipd.i [Univ. Padova, Facolta di Agraria, Viale dell' Universita 16, I-35020 Legnaro (Italy)

2010-02-15

Copper, a priority substance on the EU-Water Framework Directive list, is widely used to protect grapevines against fungus diseases. Many vineyards being located on steep slopes, large amounts of Cu could be discharged in downstream systems by runoff water. The efficiency of stormwater detention basins to retain copper in a vineyard catchment was estimated. Suspended solids, dissolved (Cu{sub diss}) and total Cu (Cu{sub tot}) concentrations were monitored in runoff water, upstream, into and downstream from a detention pond. Mean Cu{sub tot} concentrations in entering water was 53.6 mug/L whereas it never exceeded 2.4 mug/L in seepage. Cu{sub tot} concentrations in basin water (>100 mug/L in 24% of the samples) exceeded LC{sub 50} values for several aquatic animals. Copper was principally sequestered by reduced compounds in the basin sediments (2/3 of Cu{sub tot}). Metal sequestration was reversible since sediment resuspension resulted in Cu remobilization. Wind velocity controlled resuspension, explained 70% of Cu{sub diss} variability and could help predicting Cu mobilization. - Copper in stormwater basin is efficiently retained but can be released during windy events or after dredging.

Copper mobilization affected by weather conditions in a stormwater detention system receiving runoff waters from vineyard soils (Champagne, France)

International Nuclear Information System (INIS)

Banas, D.; Marin, B.; Skraber, S.; Chopin, E.I.B.; Zanella, A.

2010-01-01

Copper, a priority substance on the EU-Water Framework Directive list, is widely used to protect grapevines against fungus diseases. Many vineyards being located on steep slopes, large amounts of Cu could be discharged in downstream systems by runoff water. The efficiency of stormwater detention basins to retain copper in a vineyard catchment was estimated. Suspended solids, dissolved (Cu diss ) and total Cu (Cu tot ) concentrations were monitored in runoff water, upstream, into and downstream from a detention pond. Mean Cu tot concentrations in entering water was 53.6 μg/L whereas it never exceeded 2.4 μg/L in seepage. Cu tot concentrations in basin water (>100 μg/L in 24% of the samples) exceeded LC 50 values for several aquatic animals. Copper was principally sequestered by reduced compounds in the basin sediments (2/3 of Cu tot ). Metal sequestration was reversible since sediment resuspension resulted in Cu remobilization. Wind velocity controlled resuspension, explained 70% of Cu diss variability and could help predicting Cu mobilization. - Copper in stormwater basin is efficiently retained but can be released during windy events or after dredging.

Open Drainage and Detention Basin Combined System Optimization

Directory of Open Access Journals (Sweden)

M. E. Banihabib

2017-01-01

Full Text Available Introduction: Since flooding causes death and economic damages, then it is important and is one of the most complex and destructive natural disaster that endangers human lives and properties compared to any other natural disasters. This natural disaster almost hit most of countries and each country depending on its policy deals with it differently. Uneven intensity and temporal distribution of rainfall in various parts of Iran (which has arid and semiarid climate causes flash floods and leads to too much economic damages. Detention basins can be used as one of the measures of flood control and it detains, delays and postpones the flood flow. It controls floods and affects the flood directly and rapidly by temporarily storing of water. If the land topography allows the possibility of making detention basin with an appropriate volume and quarries are near to the projects for construction of detention dam, it can be used, because of its faster effect comparing to the other watershed management measures. The open drains can be used alone or in combination with detention basin instead of detention basin solitarily. Since in the combined system of open and detention basin the dam height is increasing in contrast with increasing the open drainage capacity, optimization of the system is essential. Hence, the investigation of the sensitivity of optimized combined system (open drainage and detention basin to the effective factors is also useful in appropriately design of the combined system. Materials and Methods: This research aims to develop optimization model for a combined system of open drainage and detention basins in a mountainous area and analyze the sensitivity of optimized dimensions to the hydrological factors. To select the dam sites for detention basins, watershed map with scale of 1: 25000 is used. In AutoCAD environment, the location of the dam sites are assessed to find the proper site which contains enough storage volume of the detention

Experimental analysis of green roof substrate detention characteristics.

Science.gov (United States)

Yio, Marcus H N; Stovin, Virginia; Werdin, Jörg; Vesuviano, Gianni

2013-01-01

Green roofs may make an important contribution to urban stormwater management. Rainfall-runoff models are required to evaluate green roof responses to specific rainfall inputs. The roof's hydrological response is a function of its configuration, with the substrate - or growing media - providing both retention and detention of rainfall. The objective of the research described here is to quantify the detention effects due to green roof substrates, and to propose a suitable hydrological modelling approach. Laboratory results from experimental detention tests on green roof substrates are presented. It is shown that detention increases with substrate depth and as a result of increasing substrate organic content. Model structures based on reservoir routing are evaluated, and it is found that a one-parameter reservoir routing model coupled with a parameter that describes the delay to start of runoff best fits the observed data. Preliminary findings support the hypothesis that the reservoir routing parameter values can be defined from the substrate's physical characteristics.

Detente: A Role for U.S.-Soviet Exchanges?

Science.gov (United States)

Herman, Paul F., Jr.

The contribution of international exchanges (e.g., cultural activities, tourism, student exchange) to detente enhancement is assessed. International exchanges have a capacity for engendering trust and for providing cultural, political, and economic benefit, two characteristics of policy acts which tend to enhance detente. A comparison of four very…

Are healthcare professionals working in Australia's immigration detention centres condoning torture?

Science.gov (United States)

Isaacs, David

2016-07-01

Australian immigration detention centres are in secluded locations, some on offshore islands, and are subject to extreme secrecy, comparable with 'black sites' elsewhere. There are parallels between healthcare professionals working in immigration detention centres and healthcare professionals involved with or complicit in torture. In both cases, healthcare professionals are conflicted between a duty of care to improve the health of patients and the interests of the government. While this duality of interests has been recognised previously, the full implications for healthcare professionals working in immigration detention have not been addressed. The Australian Government maintains that immigration detention is needed for security checks, but the average duration of immigration detention has increased from 10 weeks to 14 months, and detainees are not informed of the progress of their application for refugee status. Long-term immigration detention causes major mental health problems, is illegal in international law and arguably fulfils the recognised definition of torture. It is generally accepted that healthcare professionals should not participate in or condone torture. Australian healthcare professionals thus face a major ethical dilemma: patients in immigration detention have pressing mental and physical health needs, but providing healthcare might support or represent complicity in a practice that is unethical. Individual healthcare professionals need to decide whether or not to work in immigration detention centres. If they do so, they need to decide for how long and to what extent restrictive contracts and gagging laws will constrain them from advocating for closing detention centres. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Development of cloud-operating platform for detention facility design

Science.gov (United States)

Tun Lee, Kwan; Hung, Meng-Chiu; Tseng, Wei-Fan; Chan, Yi-Ping

2017-04-01

In the past 20 years, the population of Taiwan has accumulated in urban areas. The land development has changed the hydrological environment and resulted in the increase of surface runoff and shortened the time to peak discharge. The change of runoff characteristics increases the flood risk and reduces resilient ability of the city during flood. Considering that engineering measures may not be easy to implement in populated cities, detention facilities set on building basements have been proposed to compromise the increase of surface runoff resulting from development activities. In this study, a web-based operational platform has been developed to integrate the GIS technologies, hydrological analyses, as well as relevant regulations for the design of detention facilities. The design procedure embedded in the system includes a prior selection of type and size of the detention facility, integrated hydrological analysis for the developing site, and inspection of relevant regulations. After login the platform, designers can access the system database to retrieve road maps, land use coverages, and storm sewer information. Once the type, size, inlet, and outlet of the detention facility are assigned, the system can acquire the rainfall intensity-duration-frequency information from adjacent rain gauges to perform hydrological analyses for the developing site. The increase of the runoff volume due to the development and the reduction of the outflow peak through the construction of the detention facility can be estimated. The outflow peak at the target site is then checked with relevant regulations to confirm the suitability of the detention facility design. The proposed web-based platform can provide a concise layout of the detention facility and the drainageway of the developing site on a graphical interface. The design information can also be delivered directly through a web link to authorities for inspecting to simplify the complex administrative procedures.

Discussion on the source survey method in a natural evaporation pond

International Nuclear Information System (INIS)

Dai Xiaoshu; Fan Chengrong; Fu Yunshan

2014-01-01

A natural evaporation pond intended to be decommissioned. The survey of the pond focused on investigating radioactive contamination distribution and estimating the total amount of deposits in the pond, in order to provide support for subsequent decommissioning activities. Based on the source survey in the pond, this paper introduced how to implement radiation measurements and sampling (such as water and sediment) in the water. The movable work platform was built on the pond to facilitate sampling and measurement. In addition, a sludge sampler had been designed so as to accurately determine the amount of sampling and its depth. This paper also described the distribution of sampling points. (authors)

A Community Standard: Equivalency of Healthcare in Australian Immigration Detention.

Science.gov (United States)

Essex, Ryan

2017-08-01

The Australian government has long maintained that the standard of healthcare provided in its immigration detention centres is broadly comparable with health services available within the Australian community. Drawing on the literature from prison healthcare, this article examines (1) whether the principle of equivalency is being applied in Australian immigration detention and (2) whether this standard of care is achievable given Australia's current policies. This article argues that the principle of equivalency is not being applied and that this standard of health and healthcare will remain unachievable in Australian immigration detention without significant reform. Alternate approaches to addressing the well documented issues related to health and healthcare in Australian immigration detention are discussed.

Ecological conditions of ponds situated on blast furnace slag deposits located in South Gare Site of Special Scientific Interest (SSSI), Teesside, UK.

Science.gov (United States)

Raper, E; Davies, S; Perkins, B; Lamb, H; Hermanson, M; Soares, A; Stephenson, T

2015-06-01

Slag, a by-product from the iron and steel industry, has a range of applications within construction and is used in wastewater treatment. Historically considered a waste material, little consideration was given to the environmental impacts of its disposal. South Gare (a Site of Special Scientific Interest) located at the mouth of the Tees estuary, UK, formed on slag deposits used to create a sea wall and make the land behind permanent. Over time, ponds formed in depressions with the water chemistry, being significantly impacted by the slag deposits. Calcium levels reached 504 mg/L, nitrate 49.0 mg/L and sulphate 1,698 mg/L. These levels were also reflected in the composition of the sediment. pH (5.10-9.90) and electrical conductivity (2,710-3,598 µS/cm) were variable but often notably high. Pb, Cu and Cd were not present within the water, whilst Zn ranged from 0.027 to 0.37 mg/L. Heavy metal levels were higher in surface sediments. Zinc was most dominant (174.3-1,310.2 mg/L) followed by Pb (9.9-431 mg/L), Cu (8.4-41.8 mg/L) and Cd (0.4-1.1 mg/L). A sediment core provided a historical overview of the ponds. The ponds were unfavourable for aquatic biodiversity and unsuitable for drinking water abstraction.

Economics in Detention

Science.gov (United States)

Elonge, Michael

2013-01-01

Economics in Detention is a University of Maryland Extension program that teaches inmates essential principles of economics as a foundation to a spectrum of decision making. Also, the program includes an emphasis on starting a small business after incarceration. The idea of this program emanates from an invitation by the Baltimore City Detention…

Mercury concentrations in pond fish in relation to a coal-fired power plant

International Nuclear Information System (INIS)

Logan, D.T.; Wilson, H.T.; Pinkney, A.E.

1994-01-01

Although many studies have reported that atmospheric mercury is the primary cause for bioaccumulation in fish from remote lakes, few data are available on the effects of possible near-field deposition on fish from nearby waters. The authors surveyed mercury concentrations in fish from 23 ponds in the vicinity of the coal-burning Dickerson Power Plant (Dickerson, MD). A stratified random sampling design was used to select ponds within zones delineated by concentric rings mapped at 3, 7, 10, and 15 km from the plant. For each pond, mercury concentrations were measured by cold vapor atomic absorption spectrometry in sunfish (bluegill, pumpkin seed, or green sunfish), and largemouth bass, which were present in 14 of the ponds. Mean concentrations in the ponds ranged from 0.03 to 0.38 ppm for sunfish and from 0.04 to 0.43 ppm for bass. Alkalinity, pH, conductivity, hardness, and fish length were measured. Stepwise multiple regression identified variables related to tissue concentrations. Differences between strata were tested with ANCOVA. The pattern of concentrations was compared to the pattern of wet deposition predicted by a model. The predicted pattern of local wet deposition did not match the observed pattern of mercury bioaccumulation. This research was sponsored by the Maryland Department of Natural Resources, Power Plant Research Program

Unlocking Human Dignity: A Plan to Transform the US Immigrant Detention System

Directory of Open Access Journals (Sweden)

Migration and Refugee Services/ United States Conference of Catholic Bishops

2015-05-01

Full Text Available Unlocking Human Dignity: A Plan to Transform the US Immigrant Detention System addresses one of the most troubled features of the US immigration system and highlights the need for fundamental changes to it. The report comes six years since the inception of the Obama administration’s detention reform initiative. In the interim, the number of immigrant detainees per year has risen to more than 400,000, the administration has opened immense new family detention centers, and the overwhelming majority of persons in the custody of the Department of Homeland Security (DHS have remained in prisons, jails and other secure facilities where they are subject to standards designed for criminal defendants and, in many ways, treated more harshly than criminals.The report’s overarching recommendation is that the US immigrant detention system be dismantled and replaced with a network of supervised release, case management, and community support programs, designed to ensure court appearances. It recognizes that detention may be necessary for short periods and in certain cases, but it rejects detention as a central immigrant “management” tool, and argues that detention should only be used as a last resort if less harmful strategies and programs—viewed on a continuum beginning with the least restrictive and moving to release programs with different levels of supervision, monitoring, and support—cannot reasonably ensure court appearances or (in rare cases protect the public. It opposes the detention of pregnant and nursing women, bona fide asylum seekers, the very ill, the disabled, the elderly, and other vulnerable persons. It calls for the substantial contraction of detention facilities and “bed space.”As the first step in this process, the report urges Congress to commission a comprehensive study on the benefits, challenges, cost, and time frame for creating a civil immigration detention system. It also proposes that the administration create a

9 CFR 11.4 - Inspection and detention of horses.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Inspection and detention of horses. 11... AGRICULTURE ANIMAL WELFARE HORSE PROTECTION REGULATIONS § 11.4 Inspection and detention of horses. For the purpose of effective enforcement of the Act: (a) Each horse owner, exhibitor, trainer, or other person...

LGBTI migrants in immigration detention

Directory of Open Access Journals (Sweden)

Shana Tabak

2013-04-01

Full Text Available As states increasingly use detention as a means of controllingmigration flows, sexual minority migrants find themselves in detentionfacilities where they may face multiple violations of their human rights.

The Restorative Justice Center: An Alternative to School Detention

Science.gov (United States)

Ashworth, Julie; Van Bockern, Steve; Ailts, Julie; Donnelly, Jason; Erickson, Kelsey; Woltermann, Jenna

2008-01-01

The traditional "stay silent, sit still, do nothing" school detention approach is a punitive and ineffective way to change behavior. It does little to create positive school climates. For children who have been traumatized through fear, isolation, and emotional abuse, poorly managed detention can add to that trauma. A restorative justice approach…

Fish Scale Evidence for Rapid Post Glacial Colonization of an Atlantic Coastal Pond

Science.gov (United States)

Daniels, R. A.; Peteet, Dorothy

1996-01-01

Fish scales from the sediment of Allamuchy Pond, New Jersey, USA, indicate that fishes were present in the pond within 400 years of the time of the first deposition of organic material, at approximately 12,600 yrs BP. The earliest of the scales, from a white sucker, Catostomus commersoni, appears in sediment dated 12,260 +/- 220 yrs BP. Presence of scales in sediment deposited before I 0,000 yrs BP indicates that Atlantic salmon, Salmo salar, sunfish, Lepomis sp., and yellow perch, Perca flavescens, also were early inhabitants of the pond. The timing of the arrival of each of these fishes suggests that they migrated out from Atlantic coastal refugia. A minnow scale, referred to Phoxininae, was also retrieved; it could not be matched to any cyprinid currently found in northeastern North America. The species present historically in this pond are from five families found currently in ponds throughout the Northeast and sugoest that the lentic palaeo-enviromnent was similar to present mid-elevation or high-latitude lentic systems.

Pond-aquifer flow and water availability in the vicinity of two coastal area seepage ponds, Glynn and Bulloch Counties, Georgia

Science.gov (United States)

Clarke, John S.; Rumman, Malek Abu

2005-01-01

Pond-aquifer flow and water availability at excavated seepage pond sites in Glynn County and in southern Bulloch County, Georgia, were evaluated to determine their potential as sources of water supply for irrigation. Excavated seepage ponds derive water primarily from ground water seeping into the pond, in a manner similar to a dug well completed in a surficial aquifer. The availability of water from seepage ponds is controlled by the permeability of surficial deposits, the amount of precipitation recharging the ground-water system, and the volume of water stored in the pond. The viability of seepage ponds as supplies for irrigation is limited by low seepage rates and high dependence on climatic conditions. Ponds will not refill unless there is adequate precipitation to recharge the surficial aquifer, which subsequently drains (seeps) into the pond. Ground-water seepage was estimated using a water-budget approach that utilized on-site climatic and hydrologic measurements, computing pond-volume changes during pond pumping tests, and by digital simulation using steady-state and transient ground-water flow models. From August 1999 to May 2000, the Glynn County pond was mostly losing water (as indicated by negative net seepage); whereas from October 2000 to June 2001, the Bulloch County pond was mostly gaining water. At both sites, most ground-water seepage entered the pond following major rainfall events that provided recharge to the surficial aquifer. Net ground-water seepage, estimated using water-budget analysis and simulation, ranged from -11.5 to 15 gallons per minute (gal/min) at the Glynn County pond site and from -55 to 31 gal/min at the Bulloch County pond site. Simulated values during pumping tests indicate that groundwater seepage to both ponds increases with decreased pond stage. At the Glynn County pond, simulated net ground-water seepage varied between 7.8 gal/min at the beginning of the test (high pond stage and low hydraulic gradient) and 103 gal

DETENTION TANKS AS A MEANS OF URBAN STORM WATER ...

African Journals Online (AJOL)

sewers and detention tanks. That is, for sewers the peak value, t,, and for detention tanks the total, t-i, is used, which are computed as follows: • = Maxq. P. Maxr. (3) ..... infrastructure, like water supply, power supply, storm and wastewater management, etc. A change or new development in the mode of settlement of a certain ...

Sensitivity to acidification of subalpine ponds and lakes in north-western Colorado

Science.gov (United States)

Campbell, D.H.; Muths, E.; Turk, J.T.; Corn, P.S.

2004-01-01

Although acidifying deposition in western North America is lower than in many parts of the world, many high-elevation ecosystems there are extremely sensitive to acidification. Previous studies determined that the Mount Zirkel Wilderness Area (MZWA) has the most acidic snowpack and aquatic ecosystems that are among the most sensitive in the region. In this study, spatial and temporal variability of ponds and lakes in and near the MZWA were examined to determine their sensitivity to acidification and the effects of acidic deposition during and after snowmelt. Within the areas identified as sensitive to acidification based on bedrock types, there was substantial variability in acid-neutralizing capacity (ANC), which was related to differences in hydrological flowpaths that control delivery of weathering products to surface waters. Geological and topographic maps were of limited use in predicting acid sensitivity because their spatial resolution was not fine enough to capture the variability of these attributes for lakes and ponds with small catchment areas. Many of the lakes are sensitive to acidification (summer and autumn ANC pH value was 5·4, and pH generally remained less than 6·0 throughout early summer in the most sensitive ponds, indicating that biological effects of acidification are possible at levels of atmospheric deposition that occurred during the study. The aquatic chemistry of lakes was dominated by atmospheric deposition and biogeochemical processes in soils and shallow ground water, whereas the aquatic chemistry of ponds was also affected by organic acids and biogeochemical processes in the water column and at the sediment–water interface. These results indicate that conceptual and mechanistic acidification models that have been developed for lakes and streams may be inadequate for predicting acidification in less-understood systems such as ponds.

Examining the everyday micro-economies of migrant detention in the United States

OpenAIRE

D. Conlon; N. Hiemstra

2014-01-01

Securitization of immigration, the rise of interior immigration policing, and forces of carceral privatization have occasioned a remarkable expansion of immigrant detention throughout the United States. Previous studies have drawn attention to the importance of the daily rates paid by the federal government to individual facilities in driving the emphasis on detention. This paper, in contrast, argues that tracing the political and economic geography of money inside detention...

Preventive Detention: A Necessity

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Jaya Mishra

2017-08-01

Full Text Available State, ever since, its emergence, has been concerned with the maintenance of law and order and protecting people from external aggression and internal threats, thereby, ensuring safety and security to its inhabitants. The authority to maintain law and order empowers the state to use coercive power. It also emanates from various laws that are enacted from time to time. More often than not, coercive laws are self-contradictory because on the one hand they guarantee rights to people and on the other hand, they take away the right of a person or persons. Therefore, it is not wrong to say that modern states are repository of contradictions and India is no exception. There are several undemocratic provisions in the Indian Constitution; preventive detention is one of them. It seeks to detain a person to prevent him/her from indulging in any activity which is likely to pose a threat to the security of the State. In Britain and America this provision was used during World War II while, in India it can be used even in peacetime. This provision has been extensively used against the political dissidents during the post-colonial period. Justice Mahajan of the Supreme Court of India has held that ‘preventive detention laws are repugnant to democratic constitution and they cannot be found to exist in any of the democratic countries of the world’. The question that one can ask at this juncture is that why did the Government of ‘independent’ India retain preventive detention laws? And further, framed new ones. This research contribution examines the circumstances which compelled the Government to frame ‘preventive detention’ laws, and its use during national emergency and peace time.

Quality of life among immigrants in Swedish immigration detention centres: a cross-sectional questionnaire study

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Soorej J. Puthoopparambil

2015-07-01

Full Text Available Background: Detention of immigrants negatively affects their health and well-being. Quality of life (QOL is a broad concept incorporating the self-evaluation of one's own health and well-being that can provide an understanding of the health and well-being of immigrant detainees. The aim of this study was to estimate QOL among immigrant detainees in Sweden and to assess its relationship with the services provided in detention centres and with the duration of detention. Design: All immigrants in all five existing Swedish detention centres (N=193 were invited to participate in the study (n=127. In this cross-sectional study, QOL was measured using the WHOQOL-BREF questionnaire, which was administered by the first author. The questionnaire contained four additional questions measuring participants’ satisfaction with the services provided in detention. Associations between QOL domain scores and service satisfaction scores were assessed using regression analysis. The Spearman's rank correlation coefficient was calculated to measure the degree of association between the duration of detention and QOL scores. Results: The mean QOL domain scores (out of 100 were 47.0, 57.5, 41.9, and 60.5 for the environmental, physical, psychological, and social domains, respectively. The level of support detainees received from detention staff was significantly positively associated with detainees’ physical (βadjusted 3.93, confidence interval [CI] 0.06–7.80 and psychological (βadjusted 5.72, CI 1.77–9.66 domain scores. There was also significant positive association between detainees’ satisfaction with the care they received from detention staff and the domain scores. The general health score in the WHOQOL-BREF was significantly associated with the detainees’ ability to understand the Swedish or English languages. Although not statistically significant, a longer duration of detention was negatively correlated with QOL scores. Conclusion: Immigrant

Pond Hockey on Whitmore Lacus: the Formation of Ponds and Ethane Ice Deposits Following Storm Events on Titan

Science.gov (United States)

Steckloff, Jordan; Soderblom, Jason M.

2017-10-01

Cassini ISS observations reveled regions, later identified as topographic low spots (Soderblom et al. 2014, DPS) on Saturn’s moon Titan become significantly darker (lower albedo) following storm events (Turtle et al. 2009, GRL; 2011, Science), suggesting pools of liquid hydrocarbon mixtures (predominantly methane-ethane-nitrogen). However, these dark ponds then significantly brighten (higher albedo relative to pre-storm albedo), before fading to their pre-storm albedos (Barnes et al. 2013 Planet. Sci; Soderblom et al. 2014, DPS). We interpret these data to be the result of ethane ice formation, which cools from evaporation of methane. The formation of ethane ices results from a unique sequence of thermophysical processes. Initially, the methane in the ternary mixture evaporates, cooling the pond. Nitrogen, dissolved primarily in the methane, exsolves, further cooling the liquid. However, because nitrogen is significantly more soluble in cooler methane-hydrocarbon mixtures, the relative concentration of nitrogen in the solution increases as it cools. This increased nitrogen fraction increases the density of the pond, as nitrogen is significantly more dense thane methane or ethane (pure ethane’s density is intermediate to that of methane and nitrogen). At around ~85 K the mixture is as dense as pure liquid ethane. Thus, further evaporative methane loss and cooling at the pond’s surface leads to a chemical stratification, with an increasingly ethane rich epilimnion (surface layer) overlying a methane rich hypolimnion (subsurface layer). Further evaporation of methane from the ethane-rich epilimnion drives its temperature and composition toward the methane-ethane-nitrogen liquidus curve, causing pure ethane ice to precipitate out of solution and settle to the bottom of the pool. This settling would obscure the ethane ice from Cassini VIMS and ISS, which would instead continue to appear as a dark pond on the surface. As the ethane precipitates out completely, a

Commentary (Pre-Trial Detention in the Extraordinary Chambers in the Courts of Cambodia )

DEFF Research Database (Denmark)

Marchuk, Iryna

2015-01-01

Most international criminal courts and tribunals find provisional detention absolutely necessary to ensure the swift delivery of justice. A decision on pre-trial detention must be in conformity with well-recognized human rights standards, thus respecting the person’s right to a fair trial...... and upholding the presumption of evidence. Although the general assumption in criminal law is that pre-trial detention is the exception and not the rule, a number of factors, such as the gravity of the crimes, as well as heightened flight risk of the accused, appear to have reversed the test employed...... in international criminal courts and tribunals. To date, all provisional detention orders against former members of the inner circle of Pol Pot, except for one, have been re-affirmed on appeal in the ECCC. This commentary appraises the ECCC case law on pre-trial detention from the standpoint of its conformity...

Transportation and Bioavailability of Copper and Zinc in a Storm Water Retention Pond

Science.gov (United States)

Camponelli, K.; Casey, R. E.; Wright, M. E.; Lev, S. M.; Landa, E. R.

2006-05-01

Highway runoff has been identified as a non-point source of metals to storm water retention ponds. Zinc and copper are major components of tires and brake pads, respectively. As these automobile parts degrade, they deposit particulates onto the roadway surface. During a storm event, these metal containing particulates are washed into a storm water retention pond where they can then accumulate over time. These metals may be available to organisms inhabiting the pond and surrounding areas. This study focuses on tracking the metals from their deposition on the roadway to their transport and accumulation into a retention pond. The retention pond is located in Owings Mills, MD and collects runoff from an adjacent four lane highway. Pond sediments, background soils, road dust samples, and storm events were collected and analyzed. Copper and zinc concentrations in the pond sediments are higher than local background soils indicating that the pond is storing anthropogenically derived metals. Storm event samples also reveal elevated levels of copper and zinc transported through runoff, along with a large concentration of total suspended solids. After looking at the particulate and dissolved fractions of both metals in the runoff, the majority of the Zn and Cu are in the particulate fraction. Changes in TSS are proportional with changes in particulate bound Zn, indicating that the solid particulates that are entering into the pond are a major contributor of the total metal loading. Sequential extractions carried out on the road dust show that the majority of zinc is extracted in the second and third fractions and could become available to organisms in the pond. There is a small amount of Cu that is being released in the more available stages of the procedure; however the bulk of the Cu is seen in the more recalcitrant steps. In the pond sediments however, both Cu and Zn are only being released from the sediments in the later steps and are most likely not highly available.

Geohydrology and limnology of Walden Pond, Concord, Massachusetts

Science.gov (United States)

Colman, John A.; Friesz, Paul J.

2001-01-01

The trophic ecology and ground-water contributing area of Walden Pond, in Concord and Lincoln, Mass., were investigated by the U.S. Geological Survey in cooperation with the Massachusetts Department of Environmental Management from April 1997 to July 2000. Bathymetric investigation indicated that Walden Pond (24.88 hectares), a glacial kettle-hole lake with no surface inlet or outlet, has three deep areas. The maximum depth (30.5 meters) essentially was unchanged from measurements made by Henry David Thoreau in 1846. The groundwater contributing area (621,000 square meters) to Walden Pond was determined from water-table contours in areas of stratified glacial deposits and from land-surface contours in areas of bedrock highs. Walden Pond is a flow-through lake: Walden Pond gains water from the aquifer along its eastern perimeter and loses water to the aquifer along its western perimeter. Walden Pond contributing area also includes Goose Pond and its contributing area. A water budget calculated for Walden Pond, expressed as depth of water over the lake surface, indicated that 45 percent of the inflow to the lake was from precipitation (1.215 meters per year) and 55 percent from ground water (1.47 meters per year). The groundwater inflow estimate was based on the average of two different approaches including an isotope mass-balance approach. Evaporation accounted for 26 percent of the outflow from the lake (0.71 meters per year) whereas lake-water seepage to the groundwater system contributed 74 percent of the outflow (1.97 meters per year). The water-residence time of Walden Pond is approximately 5 years. Potential point sources of nutrients to ground water, the Concord municipal landfill and a trailer park, were determined to be outside the Walden Pond groundwater contributing area. A third source, the septic leach field for the Walden Pond State Reservation facilities, was within the groundwater contributing area. Nutrient budgets for the lake indicated that

There and Back Again: On the Diffusion of Immigration Detention

Directory of Open Access Journals (Sweden)

Michael Flynn

2014-07-01

Full Text Available From Mexico to the Bahamas, Mauritania to Lebanon, Turkey to Saudi Arabia, South Africa to Indonesia, Malaysia to Thailand, immigration-related detention has become an established policy apparatus that counts on dedicated facilities and burgeoning institutional bureaucracies. Until relatively recently, however, detention appears to have been largely an ad hoc tool, employed mainly by wealthy states in exigent circumstances. This paper uses concepts from diffusion theory to detail the history of key policy events in several important immigration destination countries that led to the spreading of detention practices during the last 30 years and assesses some of the motives that appear to have encouraged this phenomenon. The paper also endeavors to place the United States at the center of this story because its policy decisions appear to have played an important role in encouraging the process of policy innovation, imitation, and imposition that has helped give rise to today’s global immigration detention phenomenon. Nevertheless, many US offshore practices have not received nearly the same attention as those of other important destination countries.  More broadly, in telling this story, this paper seeks to flesh out some of the larger policy implications of the externalization of immigration control regimes. Just as offshore interdiction and detention schemes raise important questions about custody, accountability, and sovereignty, they should also spur questions over where responsibility for the wellbeing of migrants begins and ends. 

Prediction of local effects of proposed cooling ponds

International Nuclear Information System (INIS)

Hicks, B.B.

1978-01-01

A Fog Excess Water (FEW) Index has been shown to provide a good measure of the likelihood for steam fog to occur at specific cooling pond installations. The FEW Index is derived from the assumption that the surface boundary layer over a cooling pond will be strongly convective, and that highly efficient vertical transport mechanisms will result in a thorough mixing of air saturated at surface temperature with ambient air aloft. Available data support this assumption. An extension of this approach can be used to derive a simple indicator for use in predicting the formation of rime ice in the immediate downwind environs of a cooling pond. In this case, it is supposed that rime ice will be deposited whenever steam fog and sub-freezing surface temperatures are predicted. This provides a convenient method for interpreting pre-existing meteorological information in order to assess possible icing effects while in the early design stages of the planning process. However, it remains necessary to derive accurate predictions of the cooling pond water surface temperature. Once a suitable and proven procedure for this purpose has been demonstrated, it is then a simple matter to employ the FEW Index in evaluations of the relative merits of alternative cooling pond designs, with the purpose of minimizing overall environmental impact

[Factors to be considered in decision making for quarantine detention with emergence of a novel influenza virus].

Science.gov (United States)

Wada, Koji; Ohta, Hiroshi; Sakaguchi, Hiroko

2011-04-01

In the early phase of the emergence of influenza A (H1N1) 2009 abroad, quarantine detention measures based on exposure assessment of infected persons at airports were enacted in Japan. Detention, while being a step needed to protect safety and health of citizens, restricts healthy individuals' activities for several days until they can be confirmed to be not infected. Thus, the number of persons detained must be minimized in the interest of human rights. In this study, we reviewed factors to be considered in decision-making to carry out optimal detention in the early phase of emergence of a novel influenza virus in the future. We reviewed manuscripts on contagiousness of influenza, cases of infections in public transportation such as airplanes, and the effectiveness of detention, and interviewed persons who were involved in detentions in the early phase of the influenza A(H1N1) 2009 pandemic. When a decision is made about detention, it is essential to assess the necessity of detention, the measures for minimizing the scope of individuals to be detained, the measures for ensuring the human rights of individuals affected, and possible means to substitute for detention. Assessment of the necessity of detention should cover the following: (1) whether or not the novel influenza is a sufficiently severe threat to public health to justify detention; (2) whether or not detention at a given point of time can delay the beginning of a domestic epidemic; and (3) who is responsible and how revision of the once decided detentions should be made. Regarding measures for minimizing the scope of individuals to be detained, discussions are needed as to: (1) giving advice to the nation to refrain from getting aboard an airplane when aware of flu-like symptoms so that exposure of people to infected individuals may be avoided; and (2) whether or not selection of individuals to be detained is going to be made, taking into account the level of exposure to infected individuals. To ensure

Waste Stabilisation Ponds

OpenAIRE

Von Sperling, Marcos

2007-01-01

"Waste Stabilisation Ponds is the third volume in the series Biological Wastewater Treatment. The major variants of pond systems are fully covered, namely: facultative ponds anaerobic ponds aerated lagoons maturation ponds The book presents in a clear and informative way the main concepts, working principles, expected removal efficiencies, design criteria, design examples, construction aspects, operational guidelines and sludge managment for pond systems. About the series: The series is...

Youth Empowerment Through the Use of Prison Libraries: Case Studies of the Tangerang Juvenile Detention Center Library and the Salemba Detention Center Library in Indonesia

Directory of Open Access Journals (Sweden)

Rahmi Rahmi

2015-01-01

Full Text Available It is widely acknowledged that libraries play a positive and important role in the lives of prisoners, just as they do with other people.  They do not only provide resources to support various educational, recreational and welfare programs, but they also create opportunities for prisoners to acquire new skills, skills that they may need once they leave prison.  In addition, prison libraries also help address various psychological issues, attitude problems, as well as other difficulties in coping with prison life.  According to the Ministry of Law and Human Rights of Indonesia, as of 2013, there are 4,622 children in 16 different prisons in Indonesia.  Such statistics show that there is a great need for well-resourced and well-staffed libraries inside these prisons in order to support the educational, recreational, and psychological needs of imprisoned children.  It is evident that the existence of prison libraries and its library collections, facilities, as well as other services could serve as effective rehabilitation for the prisoners and the detainees – to help them develop awareness of their own actions, as well as associated risks and consequences. The purpose of this study is to examine the practical, social, recreational, educational, psychological, and spiritual needs of detained juvenile delinquents in regards to using the collections, facilities and services at the Tangerang Juvenile Detention Center Library and the Salemba Detention Center Library. This study is based on informational interviews conducted with the Head Librarians at the Tangerang Juvenile Detention Center Library (JDC and the Salemba Detention Center Library.  During these interviews, various problems and challenges related to ethics, professionalism, and other professional issues associated to working as a prison librarian, were discussed.  Other issues related to staffing, organizational structure, facilities and the resource situation of the Tangerang

76 FR 66073 - Guidance for Industry on What You Need to Know About Administrative Detention of Foods; Availability

Science.gov (United States)

2011-10-25

...] Guidance for Industry on What You Need to Know About Administrative Detention of Foods; Availability AGENCY... guidance for industry entitled ``What You Need to Know About Administrative Detention of Foods,'' which... administrative detention order, what food may be subject to administrative detention, who receives a copy of an...

Modeling a ponded infiltration experiment at Yucca Mountain, NV

International Nuclear Information System (INIS)

Hudson, D.B.; Guertal, W.R.; Flint, A.L.

1994-01-01

Yucca Mountain, Nevada is being evaluated as a potential site for a geologic repository for high level radioactive waste. As part of the site characterization activities at Yucca Mountain, a field-scale ponded infiltration experiment was done to help characterize the hydraulic and infiltration properties of a layered dessert alluvium deposit. Calcium carbonate accumulation and cementation, heterogeneous layered profiles, high evapotranspiration, low precipitation, and rocky soil make the surface difficult to characterize.The effects of the strong morphological horizonation on the infiltration processes, the suitability of measured hydraulic properties, and the usefulness of ponded infiltration experiments in site characterization work were of interest. One-dimensional and two-dimensional radial flow numerical models were used to help interpret the results of the ponding experiment. The objective of this study was to evaluate the results of a ponded infiltration experiment done around borehole UE25 UZN number-sign 85 (N85) at Yucca Mountain, NV. The effects of morphological horizons on the infiltration processes, lateral flow, and measured soil hydaulic properties were studied. The evaluation was done by numerically modeling the results of a field ponded infiltration experiment. A comparison the experimental results and the modeled results was used to qualitatively indicate the degree to which infiltration processes and the hydaulic properties are understood. Results of the field characterization, soil characterization, borehole geophysics, and the ponding experiment are presented in a companion paper

Sediment remediation of the Hespeler Mill Pond, Cambridge, Ontario

Energy Technology Data Exchange (ETDEWEB)

Angeloni, D.; Eby, M.; Jarvis, S.; Martin, P. [Univ. of Guelph, School of Engineering, Guelph, Ontario (Canada)]. E-mail: danielle.angeloni@earthtech.ca

2002-06-15

'Full text:' Low dissolved oxygen levels and large accumulated sediment remediation alternatives were examined to assemble the Hespeler Mill Pond, Cambridge (HMP) into a healthier and more desirable recreational area in the City of Cambridge. The theory that a large amount of sediment has been deposited into the HMP from the Speed River upstream over a number of years predicts the depressed oxygen levels, high nutrient-loading rates and the odour problems in the summer months. The initial phase in the remediation plan for this project involved extensive background research and investigation. The focus was on determining the characteristics of the sediment and the history of the pond, to ultimately decide if the sediment was the source of the issues. Dissolved oxygen field tests and sediment sampling were conducted to get information on the magnitude of the problem and the environmental hazards potentially present in the pond. The pond was modelled utilising the Streeter-Phelps oxygen-sag model to predict the oxygen deficit. Biochemical Oxygen Demand (BOD{sub 5}) testing was completed to determine the oxygen demand in the pond. These tests were conducted by using water samples obtained from various sample points at the pond. The proposed solution is a combined dredging and aeration approach. Mechanical dredging using a clamshell bucket and the installation of aerators is expected to solve the dissolved oxygen and water quality issues. (author)

Aerial radiological surveys of Steed Pond, Savannah River Site: Dates of surveys, 1984--1989

International Nuclear Information System (INIS)

Fritzsche, A.E.; Jobst, J.E.

1993-09-01

From June 1984 to August 1985, three aerial radiological surveys were conducted over Steed Pond at the Savannah River Site in South Carolina. In addition, Steed Pond was included in larger-area surveys of the Savannah River Site in subsequent years. The surveys were conducted by the Remote Sensing Laboratory of EG ampersand G Energy Measurements, Inc., Las Vegas, Nevada, for the US Department of Energy. Airborne measurements were obtained for both natural and man-made gamma radiation over Steed Pond and surrounding areas. The first survey was conducted when the pond was filled to normal capacity for the time of the year. On September 1, 1984, the Steed Pond dam spillway failed causing the pond to drain. The four subsequent surveys were conducted with the pond drained. The second survey and the third were conducted to study silt deposits exposed by the drop in water level after the spillway's opening. Steed Pond data from the February 1987 and April 1989 Savannah River Site surveys have been included to bring this study up to date

The Impact of Detention on the Health of Asylum Seekers

DEFF Research Database (Denmark)

Filges, Trine; Montgomery, Edith; Kastrup, Marianne

2016-01-01

Objectives: This review assesses the evidence about the effects of detention on the mental and physical health and social functioning of asylum seekers. Method and Analysis: We followed Campbell Collaboration guidelines to conduct a systematic review. Meta-analytic methods were used...... to quantitatively synthesize the study results.  Results: Primary study effect sizes for post-traumatic stress disorder, depression, and anxiety, while the asylum seekers were still detained lies in the range 0.35–0.99, all favoring the nondetained asylum group. Author’s Conclusions: There is some evidence...... to suggest an independent adverse effect of detention on the mental health of asylum seekers. The conclusions should however be interpreted with caution as they are based on few studies. More research is needed in order to fully investigate the effect of detention on mental health....

A Demography and Taxonomy of Long-term Immigration Detention in Australia

Directory of Open Access Journals (Sweden)

Melissa Bull

2013-04-01

Full Text Available The practice of long-term immigration detention is a relatively recent aspect of Australian Government policy. There has been much debate about the wisdom of such policy, raising concerns regarding the health of detainees, the dereliction of human rights, and the legal robustness of such practice. Despite considerable interest, little detail is available describing who is being held and the reasons for their long-term detention. This paper addresses this noticeable gap through a systematic analysis of the Commonwealth Ombudsman’s Immigration Reports over the period 2005 through 2009. From such reporting it has been possible to produce a demographic profile of people held in Australian detention and to develop a taxonomy of the reasons contributing to the ongoing containment.

Seal Formation Mechanism Beneath Animal Waste Holding Ponds

Science.gov (United States)

Cihan, A.; Tyner, J. S.; Wright, W. C.

2005-12-01

Infiltration of animal waste from holding ponds can cause contamination of groundwater. Typically, the initial flux from a pond decreases rapidly as a seal of animal waste particulates is deposited at the base of the pond. The purpose of this study was to investigate the mechanism of the seal formation. Twenty-four soil columns (10-cm diameter by 43-cm long) were hand-packed with sand, silty loam or clay soils. A 2.3 m column of dairy or swine waste was applied to the top of the each column. The leakage rate from each column was measured with respect to time to analyze the effect of seal formation on different soil textures and animal waste types. We tested our hypothesis that seal growth and the subsequent decrease of leachate production adheres to a filter cake growth model. Said model predicts that the cumulative leakage rate is proportional to the square root of time and to the square root of the height of the waste.

Contamination of settling ponds of coal mines caused by natural radionuclides

International Nuclear Information System (INIS)

Michalik, B.; Chalupnik, S.; Skubacz, K.; Wysocka, M.; Mielnikow, A.

2002-01-01

As a result of a discharge of the radium-bearing waters from coal mines into settlement ponds and later into rivers a significant increase of radium concentration in bottom sediments can be observed. Sometimes also a contamination of river banks, soils and vegetation occurs. Mine waters contain mainly radium isotopes i.e. 226 Ra from uranium series and 228 Ra from thorium series. Due to chemical properties of such brines, these waters contain usually no uranium, no thorium and rather seldom elevated concentration of other isotopes as lead ( 210 Pb) and polonium ( 210 Po). The deposition or adsorption of radium on bottom sediments may take place on a distance of several kilometers from the discharge points. After a deposition or adsorption of radium isotopes the built-up of the activity of their progeny begins. Therefore concentrations of radium isotopes are higher than the decay products. We are able to measure the disequilibrium in 226 Ra decay chain as well as in 228 Ra decay chain, which shows the approximate age of the deposit. The paper describes results of investigation of sediments with enhanced natural radioactivity occurring in settlement ponds, where mine waters have been dumped. The results of measurements show that these deposits contain mainly 226 Ra and 228 Ra and their progeny. Influence of bottom sediments with enhanced radium concentration on the natural environment in the vicinity of settlement ponds was studied on the example of two different water reservoirs where radium-bearing mine waters type A and B are released. The results show clearly enhanced radioactivity of bottom sediments and water in the settling ponds and in the rivers, but no evident enhancement was found in the adjacent land. Both coal mines are located in the drainage area of Vistula river, and bottom sediments with enhanced radium concentrations were found in Vistula up to 70 km downstream from the discharge point. (author)

Modelling the impact of retention-detention units on sewer surcharge and peak and annual runoff reduction.

Science.gov (United States)

Locatelli, Luca; Gabriel, Søren; Mark, Ole; Mikkelsen, Peter Steen; Arnbjerg-Nielsen, Karsten; Taylor, Heidi; Bockhorn, Britta; Larsen, Hauge; Kjølby, Morten Just; Blicher, Anne Steensen; Binning, Philip John

2015-01-01

Stormwater management using water sensitive urban design is expected to be part of future drainage systems. This paper aims to model the combination of local retention units, such as soakaways, with subsurface detention units. Soakaways are employed to reduce (by storage and infiltration) peak and volume stormwater runoff; however, large retention volumes are required for a significant peak reduction. Peak runoff can therefore be handled by combining detention units with soakaways. This paper models the impact of retrofitting retention-detention units for an existing urbanized catchment in Denmark. The impact of retrofitting a retention-detention unit of 3.3 m³/100 m² (volume/impervious area) was simulated for a small catchment in Copenhagen using MIKE URBAN. The retention-detention unit was shown to prevent flooding from the sewer for a 10-year rainfall event. Statistical analysis of continuous simulations covering 22 years showed that annual stormwater runoff was reduced by 68-87%, and that the retention volume was on average 53% full at the beginning of rain events. The effect of different retention-detention volume combinations was simulated, and results showed that allocating 20-40% of a soakaway volume to detention would significantly increase peak runoff reduction with a small reduction in the annual runoff.

Effects of pond draining on biodiversity and water quality of farm ponds.

Science.gov (United States)

Usio, Nisikawa; Imada, Miho; Nakagawa, Megumi; Akasaka, Munemitsu; Takamura, Noriko

2013-12-01

Farm ponds have high conservation value because they contribute significantly to regional biodiversity and ecosystem services. In Japan pond draining is a traditional management method that is widely believed to improve water quality and eradicate invasive fish. In addition, fishing by means of pond draining has significant cultural value for local people, serving as a social event. However, there is a widespread belief that pond draining reduces freshwater biodiversity through the extirpation of aquatic animals, but scientific evaluation of the effectiveness of pond draining is lacking. We conducted a large-scale field study to evaluate the effects of pond draining on invasive animal control, water quality, and aquatic biodiversity relative to different pond-management practices, pond physicochemistry, and surrounding land use. The results of boosted regression-tree models and analyses of similarity showed that pond draining had little effect on invasive fish control, water quality, or aquatic biodiversity. Draining even facilitated the colonization of farm ponds by invasive red swamp crayfish (Procambarus clarkii), which in turn may have detrimental effects on the biodiversity and water quality of farm ponds. Our results highlight the need for reconsidering current pond management and developing management plans with respect to multifunctionality of such ponds. Efectos del Drenado de Estanques sobre la Biodiversidad y la Calidad del Agua en Estanques de Cultivo. © 2013 Society for Conservation Biology.

A Case of Mixed Motives? : Formal and Informal Functions of Administrative Immigration Detention

NARCIS (Netherlands)

A.S. Leerkes (Arjen); D.W.J. Broeders (Dennis)

2010-01-01

textabstractIn most EU countries and the United States, immigration detention is defined as an administrative, non-punitive measure to facilitate expulsion. This paper argues that immigration detention in the Netherlands serves three informal functions in addition to its formal function as an

78 FR 15017 - Guidance for Industry: What You Need To Know About Administrative Detention of Foods; Small...

Science.gov (United States)

2013-03-08

...] Guidance for Industry: What You Need To Know About Administrative Detention of Foods; Small Entity... ``What You Need to Know About Administrative Detention of Foods; Small Entity Compliance Guide'' (SECG... order, what food may be subject to administrative detention, who receives a copy of an administrative...

High Rates of Police Detention Among Recently Released HIV-infected Prisoners in Ukraine: Implications for Health Outcomes

Science.gov (United States)

Izenberg, Jacob M.; Bachireddy, Chethan; Soule, Michael; Kiryazova, Tetiana; Dvoryak, Sergey; Altice, Frederick L.

2013-01-01

Background Ukraine’s HIV epidemic, primarily affecting people who inject drugs (PWID), is expanding and transitioning despite free opioid substitution therapy (OST) and antiretroviral therapy (ART), two effective ways to reduce HIV transmission. Police detention not resulting in imprisonment, defined as police harassment, of PWID is common, but its prevalence and impact on health is not known. Method HIV-infected individuals (N=97) released from prison within one year were recruited and surveyed in two HIV-endemic Ukrainian cities about post-release police detention experiences. Data on the frequency of police detention, related adverse events, and impact on OST and ART continuity were collected, and correlates of detention were examined using logistic regression. Results Detention responses were available for 94 (96.9%) participants, of which 55 (58.5%) reported police detentions (mean=9.4 per person-year). For those detained while prescribed OST (N=28) and ART (N=27), medication interruption was common (67.9% and 70.4%, respectively); 23 of 27 participants prescribed OST (85.2%) were detained en route to/from OST treatment. Significant independent correlates of detention without charges included post-release ART prescription (AOR 4.98, p=0.021), current high-risk injection practices (AOR 5.03, p=0.011), male gender (AOR 10.88, p=0.010), and lower lifetime months of imprisonment (AOR 0.99, p=0.031). Conclusions HIV-infected individuals recently released from prison in Ukraine experience frequent police detentions, resulting in withdrawal symptoms, confiscation of syringes, and interruptions of essential medications, including ART and OST. Structural changes are urgently needed to reduce police detentions in order to control HIV transmission and improve both individual and public health. PMID:23769160

Alternatives to detention: open family units in Belgium

Directory of Open Access Journals (Sweden)

Liesbeth Schockaert

2013-09-01

Full Text Available Preliminary outcomes of an alternative to detention programme in Belgium, based on case management and individual ‘coaches’ for families, are positive and merit consideration by other countries.

21 CFR 1.378 - What criteria does FDA use to order a detention?

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false What criteria does FDA use to order a detention? 1.378 Section 1.378 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL GENERAL ENFORCEMENT REGULATIONS Administrative Detention of Food for Human or Animal Consumption...

Geology and lithogeochemistry of hydrothermal mudstones from the upper block near the Duck Pond volcanogenic massive sulfide (VMS) deposit, Newfoundland, Canada: evidence for low-temperature venting into oxygenated mid-Cambrian seawater

Science.gov (United States)

Piercey, Stephen J.; Squires, Gerry; Brace, Terry

2018-02-01

Pyrite- and pyrrhotite-rich mudstones are spatially associated with Cambrian ( 512-509 Ma) volcanogenic massive sulfide (VMS) deposits throughout the Tally Pond group, central Newfoundland, Canada. At the Duck Pond mine, sulfide-rich mudstones are hosted within a weakly mineralized upper block that structurally overlies the deposit but is older ( 513 versus 509 Ma). The mudstones are laminated, 10-30-cm thick, and pyrite- and pyrrhotite-rich and occur along pillow lava selvages, or in between pillow lavas, rhyolite flows, and volcaniclastic rocks. The mudstones are laterally extensive and proximal to the mudstone host rocks are hydrothermally altered to epidote-quartz-chlorite (basalt host) and sericite-quartz (rhyolite host). Lithogeochemical data for the sulfide-rich mudstones reflect the varying contributions of elements from sedimentary detritus, hydrothermal discharge, and hydrogenous scavenging from middle Cambrian seawater. The mudstones have minor detrital element abundances and significant hydrothermal element enrichments (i.e., elevated Fe2O3, S, Pb, Zn, Cu, and Ba concentrations, high Fe/Al ratios). The hydrothermal mudstones are also enriched in oxyanions (i.e., P2O5, U, V, Cr, Ni, Co, and Hg), interpreted to have been enriched via oxidative scavenging from seawater by Fe-oxide/oxyhydroxide particles. The mudstones also have REE-Y signatures similar to modern oxygenated seawater with high Y/Ho and negative Ce anomalies (Ce/Ce* = 0.40-0.86; average = 0.58), which correlate with adsorbed oxyanion concentrations. The low Eu/Eu* (1.02-1.86; average = 1.22) in the mudstones suggest that they were deposited from low-temperature (residence time to scavenge oxyanions from seawater and inherit a middle Cambrian seawater signature. The predominant seawater REE-Y-oxyanion signature in the Duck Pond upper block sulfide-rich mudstones suggests that they are distal hydrothermal sedimentary rocks that could have formed up to 10 km from their original vent sources

8 CFR 241.14 - Continued detention of removable aliens on account of special circumstances.

Science.gov (United States)

2010-01-01

... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Continued detention of removable aliens on account of special circumstances. 241.14 Section 241.14 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED Post-hearing...

Environmental Problems Associated with Decommissioning of Chernobyl Power Plant Cooling Pond

Science.gov (United States)

Foley, T. Q.; Oskolkov, B. Y.; Bondarkov, M. D.; Gashchak, S. P.; Maksymenko, A. M.; Maksymenko, V. M.; Martynenko, V. I.; Jannik, G. T.; Farfan, E. B.; Marra, J. C.

2009-12-01

Decommissioning of nuclear power plants and other nuclear fuel cycle facilities associated with residual radioactive contamination is a fairly pressing issue. Significant problems may result from decommissioning of cooling ponds. The Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond is one of the largest self-contained bodies of water in the Chernobyl Region and Ukrainian Polesye with a water surface area of 22.9 km2. The major hydrological feature of the ChNPP Cooling Pond is that its water level is 6-7 m higher than the water level in the Pripyat River and water losses due to seepage and evaporation are replenished by pumping water from the Pripyat River. In 1986, the accident at the ChNPP #4 Reactor Unit significantly contaminated the ChNPP Cooling Pond. According to the 2001 data, the total radionuclide inventory in the ChNPP Cooling Pond bottom deposits was as follows: 16.28 ± 2.59 TBq for 137Cs; 2.4 ± 0.48 TBq for 90Sr, and 0.00518 ± 0.00148 TBq for 239+240Pu. Since ChNPP is being decommissioned, the ChNPP Cooling Pond of such a large size will no longer be needed and cost effective to maintain. However, shutdown of the water feed to the Pond would expose the contaminated bottom deposits and change the hydrological features of the area, destabilizing the radiological and environmental situation in the entire region in 2007 - 2008, in order to assess potential consequences of draining the ChNPP Cooling Pond, the authors conducted preliminary radio-ecological studies of its shoreline ecosystems. The radioactive contamination of the ChNPP Cooling Pond shoreline is fairly variable and ranges from 75 to 7,500 kBq/m2. Three areas with different contamination levels were selected to sample soils, vegetation, small mammals, birds, amphibians, and reptilians in order to measure their 137Cs and 90Sr content. Using the ERICA software, their dose exposures were estimated. For the 2008 conditions, the estimated dose rates were found to be as follows: amphibians - 11

The legal nature of administrative detention

Directory of Open Access Journals (Sweden)

Adrian ALDEA

2012-01-01

Full Text Available Administrative or constabulary detention is the first measure involving deprivation of liberty that the police officers applies in extenso when initiating criminal investigations. Following the amendment of the jurisprudence of the European Court of Human Rights a more rigorous regulation of the circumstances and situations in which such a measure becomes effective is required

Modeling Nitrogen Decrease in Water Lettuce Ponds from Waste Stabilization Ponds

Science.gov (United States)

Putri, Gitta Agnes; Sunarsih

2018-02-01

This paper presents about the dynamic modeling of the Water Lettuce ponds as a form of improvement from the Water Hyacinth ponds. The purpose of this paper is to predict nitrogen decrease and nitrogen transformation in Water Lettuce ponds integrated with Waste Stabilization Ponds. The model consists of 4 mass balances, namely Dissolved Organic Nitrogen (DON), Particulate Organic Nitrogen (PON), ammonium (NH4+), Nitrate and Nitrite (NOx). The process of nitrogen transformation which considered in a Water Lettuce ponds, namely hydrolysis, mineralization, nitrification, denitrification, plant and bacterial uptake processes. Numerical simulations are performed by giving the values of parameters and the initial values of nitrogen compounds based on a review of previous studies. Numerical results show that the rate of change in the concentration of nitrogen compounds in the integration ponds of waste stabilization and water lettuce decreases and reaches stable at different times.

9 CFR 93.324 - Detention for quarantine.

Science.gov (United States)

2010-01-01

... CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND CERTAIN ANIMAL, BIRD, AND POULTRY PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Horses Mexico 18 § 93.324 Detention for quarantine. Horses intended for importation from Mexico shall be quarantined until they qualify for release from such...

Migration-related detention centers: the challenges of an ecological perspective with a focus on justice.

Science.gov (United States)

Esposito, Francesca; Ornelas, José; Arcidiacono, Caterina

2015-06-06

In recent years, border control and migration-related detention have become increasingly widespread practices affecting the lives of undocumented migrants, their families, and communities at large. In spite of the concern within academia, few studies have directly witnessed the life and experiences of people confined to migration-related detention centers. In the medical and psychological fields, a considerable body of research has demonstrated the pathogenic nature of detention in terms of mental health, showing an association between length of detention and severity of distress. Nevertheless, it was limited to the assessment of individuals' clinical consequences, mainly focusing on asylum seekers. There currently exists a need to adopt an ecological perspective from which to study detained migrants' experiences as context-dependent, and influenced by power inequalities. This paper addresses this gap. Drawing upon advances in community psychology, we illustrate an ecological framework for the study of migration-related detention contexts, and their effects on the lives of detained migrants and all people exposed to them. Making use of existing literature, Kelly's four principles (interdependence, cycling of resources, adaptation, succession) are analyzed at multiple ecological levels (personal, interpersonal, organizational, communal), highlighting implications for future research in this field. A focus on justice, as a key-dimension of analysis, is also discussed. Wellbeing is acknowledged as a multilevel, dynamic, and value-dependent phenomenon. In presenting this alternative framework, the potential for studying migration-related detention through an ecological lens is highlighted, pointing the way for future fields of study. We argue that ecological multilevel analyses, conceptualized in terms of interdependent systems and with a focus on justice, can enhance the comprehension of the dynamics at play in migration-related detention centers, providing an

MODELLING OF RADIONUCLIDE MIGRATION IN THE SYSTEM OF NUCLEAR POWER PLANT BIOLOGICAL PONDS

Directory of Open Access Journals (Sweden)

Ю. Кутлахмедов

2011-04-01

Full Text Available Migration of radionuclide coming from nuclear power plant into the system of biological pondsand then into the water reservoir-cooler is considered in the article. The theme of the work ismodeling of radionuclide migration process in the system of biological ponds on the example of thePivdennoukrainska nuclear power plant using chamber models method. Typical water ecosystemconsisting of three chambers (chamber-water, chamber-biota and chamber-bed silt was the basistaken by the authors. Application of chamber models method allowed authors to develop thedynamic chamber model of radionuclide migration in nuclear power plant biological ponds. Thismodel allows to forecast values and dynamics of radioactive water pollution based on limitedecosystem monitoring data. Thus, parameters of radioactive capacity of nuclear power plantbiological ponds system and water reservoir-cooler were modeled by authors, the estimation andprognosis of radionuclide distribution and accumulation in the system of nuclear power plantbiological ponds were done. Authors also explain the roles of basin water, biomass and bed silt inradionuclide deposition

Intermediate pond sizes contain the highest density, richness, and diversity of pond-breeding amphibians.

Directory of Open Access Journals (Sweden)

Raymond D Semlitsch

Full Text Available We present data on amphibian density, species richness, and diversity from a 7140-ha area consisting of 200 ponds in the Midwestern U.S. that represents most of the possible lentic aquatic breeding habitats common in this region. Our study includes all possible breeding sites with natural and anthropogenic disturbance processes that can be missing from studies where sampling intensity is low, sample area is small, or partial disturbance gradients are sampled. We tested whether pond area was a significant predictor of density, species richness, and diversity of amphibians and if values peaked at intermediate pond areas. We found that in all cases a quadratic model fit our data significantly better than a linear model. Because small ponds have a high probability of pond drying and large ponds have a high probability of fish colonization and accumulation of invertebrate predators, drying and predation may be two mechanisms driving the peak of density and diversity towards intermediate values of pond size. We also found that not all intermediate sized ponds produced many larvae; in fact, some had low amphibian density, richness, and diversity. Further analyses of the subset of ponds represented in the peak of the area distribution showed that fish, hydroperiod, invertebrate density, and canopy are additional factors that drive density, richness and diversity of ponds up or down, when extremely small or large ponds are eliminated. Our results indicate that fishless ponds at intermediate sizes are more diverse, produce more larvae, and have greater potential to recruit juveniles into adult populations of most species sampled. Further, hylid and chorus frogs are found predictably more often in ephemeral ponds whereas bullfrogs, green frogs, and cricket frogs are found most often in permanent ponds with fish. Our data increase understanding of what factors structure and maintain amphibian diversity across large landscapes.

“The Russians are coming, the Russians are coming” – an apology of detente

Directory of Open Access Journals (Sweden)

Ivan Kovačević

2016-02-01

Full Text Available The 1966 film The Russians are coming, the Russians are coming is a film which promotes the politics of detente in America. After cold war era films in which the Soviets are exclusively portrayed as spies endangering America, this is the first film to portray them as positive characters, while ridiculing those who propagate war and confrontation. After the Cuban crisis and the process of stopping the spread of nuclear weapons it was necessary to show the American public the funny face of detente. In the comedy about sailors from a stranded Soviet submarine confrontation is always possible but us avoided through solidarity and communal efforts. This apology of detente, intended to calm the cold war situation and anti-war lobbies in America is one-sided, because there weren’t any such films on the other side. What happened over there during the detente period is evident by the following decade in which the largest number of military interventions by the Soviet and Cuban armies around the world occurred.

19 CFR 12.150 - Merchandise prohibited by economic sanctions; detention; seizure or other disposition; blocked...

Science.gov (United States)

2010-04-01

...; detention; seizure or other disposition; blocked property. 12.150 Section 12.150 Customs Duties U.S. CUSTOMS...; detention; seizure or other disposition; blocked property. (a) Generally. Merchandise from certain countries... the United States shall be detained until the question of its release, seizure, or other disposition...

Health at risk in immigration detention facilities

Directory of Open Access Journals (Sweden)

Ioanna Kotsioni

2013-09-01

Full Text Available Since 2004 Médecins Sans Frontières (MSF has provided medical and psychosocial support for asylum seekers and migrants held in different immigration detention facilities across Europe (in Greece, Malta, Italy and Belgium where the life, health and human dignity of vulnerable people are being put at risk.

Qualitative and quantitative control of the urban runoff with detention basis

Directory of Open Access Journals (Sweden)

Jolival Antônio da Silva Jr.

2007-12-01

Full Text Available Floods in urban areas are responsible for impacts that go from puddles formation to environmental and social disasters. Looking for alternatives to minimize the effects of floods in urban areas, some methodologies have been studied and applied, such as the use of detention basin in high consolidated urban areas. This study analyses the efficiency on flood control of two detention basins, a dry and a wet one. The study approaches both quantitative and qualitative aspects related to runoff from an urban area of Brasilia city, federal district of Brazil. The affluent caught by the detention basins is related to a conventional urban drainage system with a 4.75km2 (dry basin and 6.12km2 (wet basin contribution area. The results showed that the basins can reduce the peak income flow significantly (averaged 62.6% and 74% peak flow reduction, for dry and wet basin, respectively and has positive impact over pollution control, with an average reduction of 1 to 3% for BOD and up to 41 to 74% for Suspended Solids.

Cameroon: UN group finds detention of gay men a violation of human rights.

Science.gov (United States)

Pearshouse, Richard; Klein, Alana

2006-12-01

In an opinion issued on 11 October 2006, the United Nations Working Group on Arbitrary Detention declared that the detention of 11 men in Cameroon on the basis of their presumed sexual orientation constituted an arbitrary deprivation of liberty and a violation of the principle of equal protection of the law. The Working Group called on the Cameroonian government to "examine the possibility of amending the legislation" criminalizing homosexual sex.

The impact of compulsory drug detention exposure on the avoidance of healthcare among injection drug users in Thailand.

Science.gov (United States)

Kerr, Thomas; Hayashi, Kanna; Ti, Lianping; Kaplan, Karyn; Suwannawong, Paisan; Wood, Evan

2014-01-01

Although Thailand has relied on the use of compulsory drug detention centres as a strategy to try to address problematic drug use, little is known about the effects of exposure to these centres on people who inject drugs (IDU). Therefore, we undertook this study to explore whether exposure to compulsory drug detention was associated with avoiding healthcare among Thai IDU. Using Poisson regression analyses, we examined the relationship between compulsory drug detention exposure and avoiding healthcare among participants in the Mitsampan Community Research Project based in Bangkok. 435 IDU participated in this study, including 111 (25.5%) participants who reported avoiding healthcare. In multivariate analyses, avoiding healthcare was positively associated with exposure to compulsory drug detention (adjusted prevalence ratio [APR]=1.60; 95% confidence interval [CI]: 1.16-2.21), having been refused healthcare (APR=3.46; 95% CI: 2.61-4.60), and experiencing shame associated with one's drug use (APR=1.93; 95% CI: 1.21-3.09). Exposure to compulsory drug detention was associated with avoiding healthcare among Thai IDU, suggesting that this system of detention may be contributing to the burden of preventable morbidity among IDU in this setting. Although further research is needed to confirm these findings, the results of this study reinforce previous calls to replace the system of compulsory drug detention with evidence-based public health interventions for IDU. Copyright © 2013 Elsevier B.V. All rights reserved.

Elemental signature of terrigenous sediment runoff as recorded in coastal salt ponds: US Virgin Islands

International Nuclear Information System (INIS)

Larson, Rebekka A.; Brooks, Gregg R.; Devine, Barry; Schwing, Patrick T.; Holmes, Charles W.; Jilbert, Tom; Reichart, Gert-Jan

2015-01-01

A high-resolution, multi-proxy approach is utilized on mm- to cm-scale laminated coastal salt pond sediments from St. John, U.S. Virgin Islands, to determine: (1) the sedimentological signature of depositional events/processes, (2) link this sedimentological signature with known depositional events/processes in the historical (past ∼100 years) record; and, (3) project back into the recent geologic past (past ∼1400 years) to investigate the natural variability of depositional events/processes. High-resolution, short-lived radioisotope geochronology ("2"1"0Pb, "1"3"7Cs, "7Be) combined with high-resolution elemental scanning techniques (scanning XRF and scanning LA-ICP-MS) allows for the direct comparison of well-preserved salt pond deposits to historical records of depositional events (e.g., runoff/rainfall, tropical cyclones, tsunamis) to identify the sedimentary signature of each type of event. There is a robust sedimentary record of terrigenous sediment runoff linked to the frequency of rainfall events that exceed a threshold of ∼12 mm/day (minimum to mobilize and transport sediment) for study sites. This is manifested in the sedimentary record as increases in terrigenous indicator elements (%Al, %Fe, %Ti, %Si), which agree well with rainfall records over the past ∼50 years. Variability in the sedimentary record over the past ∼100 years reflects decadal-scale fluctuations between periods of increased frequency of rainfall events, and decreased frequency of rainfall events. Dm-scale variability in terrigenous indicator elements over the past ∼1400 years represents the natural system variability on a decadal–centennial scale, and provides a high-resolution, long-term baseline of natural variability of rainfall/runoff events. A period of increased terrigenous sediment delivery during the 1700s and 1800s likely indicates increased erosion in response to anthropogenic activities associated with the island’s plantation era, and perhaps increased

Effect of co-culture of Chinese shrimp ( Fenneropenaeus chinensis) and sea cucumber ( Apostichopus japonicus Selenka) on pond environment

Science.gov (United States)

Yu, Haibo; Gao, Qinfeng; Dong, Shuanglin; Sun, Yongjun; Wang, Fang

2016-10-01

Monoculture of sea cucumber (pond S) and polyculture of shrimp with sea cucumber (pond SS) were established to evaluate the effect of shrimp on the environmental conditions of sea cucumber farming pond. Contributions of sediment organic matter (SOM2) resuspended from benthic sediment and the suspended particulate organic matter (SPOM) deposited from the water column to the precipitated organic matter (SOM1) collected with sediment traps were estimated with carbon stable isotope analysis. The results showed that the levels of SPOM and SOM2 in pond SS significantly decreased in comparison with those in pond S at the end of experiment ( P sea cucumber farming pond could purify the farming water. Carbon stable isotope analysis showed that the proportion of SOM2 in SOM1 in pond SS (84.97% ± 0.38%) was significantly lower than that in pond S (95.20% ± 0.30%) ( P < 0.05), suggesting that the resuspension of organic matter from benthic sediment into overlying water was reduced in polyculture pond. In contrast, the proportion of SPOM in SOM1 in pond SS (15.03% ± 0.38%) was significantly higher than that in pond S (4.80% ± 0.30%) ( P < 0.05), indicating that the sedimentation of SPOM from water column was enhanced in pond SS owing to the biodeposition effect of shrimp.

Multimetric Evaluation of Detention Basin Retrofit to Reduce Hydrologic Alteration of Urbanization and Restore Stream Stability

Science.gov (United States)

Abstract: Conventional stormwater detention basins are ubiquitous in the developed portions of U.S., particularly those areas developed since the 1980s. Because most detention basins were designed exclusively for flood control, they are not being utilized to their fullest potent...

Healthcare and complicity in Australian immigration detention.

Science.gov (United States)

Essex, Ryan

2016-06-01

Australian immigration detention has received persistent criticism since its introduction almost 25 years ago. With the recent introduction of offshore processing, these criticisms have intensified. Riots, violence, self-harm, abuse and devastating mental health outcomes are all now well documented, along with a number of deaths. Clinicians have played a central role working in these environments, faced with the overarching issue of delivering healthcare while facilitating an abusive and harmful system. Since the re-introduction of offshore processing a number of authors have begun to discuss the possibility of a boycott. While taking such action may lead to change, further discussion is needed, not only in relation to the impact of a boycott, but whether it is possible for clinicians to engage with this system in more productive, ethical ways. This article utilises a framework proposed by Lepora and Goodin (On complicity and compromise, Oxford University Press, Oxford, 2013) that provides a structured approach to examine complicity and seeks to explore how clinicians have engaged with Australian immigration detention and ultimately whether they should continue to do so.

Par Pond water balance

International Nuclear Information System (INIS)

Hiergesell, R.A.; Dixon, K.L.

1996-06-01

A water budget for the Par Pond hydrologic system was established in order to estimate the rate of groundwater influx to Par Pond. This estimate will be used in modeling exercises to predict Par Pond reservoir elevation and spillway discharge in the scenario where Savannah River water is no longer pumped and discharged into Par Pond. The principal of conservation of mass was used to develop the water budget, where water inflow was set equal to water outflow. Components of the water budget were identified, and the flux associated with each was determined. The water budget was considered balanced when inflow and outflow summed to zero. The results of this study suggest that Par Pond gains water from the groundwater system in the upper reaches of the reservoir, but looses water to the groundwater system near the dam. The rate of flux of groundwater from the water table aquifer into Par Pond was determined to be 13 cfs. The rate of flux from Par Pond to the water table aquifer near the dam was determined to be 7 cfs

New models for alternatives to detention in the US

Directory of Open Access Journals (Sweden)

Megan Bremer

2013-09-01

Full Text Available While there is growing recognition of the value of community-based alternatives to detention in the US, shortfalls in funding and political will are hindering implementation of improved services and best practice.

Holocene closure of Lib Pond, Marshall Islands.

Directory of Open Access Journals (Sweden)

Conor L Myhrvold

Full Text Available Well-preserved sediment from closed water bodies of atolls such as Lib Pond are rare opportunities to reconstruct the past regional climate, which pieced together across a latitude and longitude range identify the range of movement patterns of wider scale climate phenomena such as the Intertropical Convergence Zone (ITCZ and El Niño Southern Oscillation (ENSO. We conducted the first physico-chemical survey of Lib Pond, a shallow, closed-water saline lake located on remote and difficult to access Lib Island in the Marshall Islands at 8° 18' 48.99″ N, 167 22' 51.90″ E in the Pacific Ocean, in July 2009. We performed a bathymetric survey, recorded salinity, dissolved oxygen, pH, and temperature profiles, monitored the tidal variability, and conducted a vegetation survey surrounding the lake. From bathymetric data we calculated the lake volume, which we used to estimate the lake's salt budget, and ultimately the residence time of water in the lake basin. We took a series of sediment cores from the lake, cores which indicate Lib Island's changing environment and climate. Radiocarbon measurements determined sediment age, and reveal significant mixing over the last 2 ka of deposition. We conclude that prior to 3 ka, Lib Island was an atoll with a central lagoon connected to the open ocean, which was then closed off from the open ocean to form the brackish system that exists today. We predict that the sediment accumulation in Lib Pond evident today will continue. As seawater is inhibited from exchanging with fresh water, Lib Pond will become a shallower lake with increasingly fresh water.

Holocene closure of Lib Pond, Marshall Islands.

Science.gov (United States)

Myhrvold, Conor L; Janny, Fran; Nelson, Daniel; Ladd, S Nemiah; Atwood, Alyssa; Sachs, Julian P

2014-01-01

Well-preserved sediment from closed water bodies of atolls such as Lib Pond are rare opportunities to reconstruct the past regional climate, which pieced together across a latitude and longitude range identify the range of movement patterns of wider scale climate phenomena such as the Intertropical Convergence Zone (ITCZ) and El Niño Southern Oscillation (ENSO). We conducted the first physico-chemical survey of Lib Pond, a shallow, closed-water saline lake located on remote and difficult to access Lib Island in the Marshall Islands at 8° 18' 48.99″ N, 167 22' 51.90″ E in the Pacific Ocean, in July 2009. We performed a bathymetric survey, recorded salinity, dissolved oxygen, pH, and temperature profiles, monitored the tidal variability, and conducted a vegetation survey surrounding the lake. From bathymetric data we calculated the lake volume, which we used to estimate the lake's salt budget, and ultimately the residence time of water in the lake basin. We took a series of sediment cores from the lake, cores which indicate Lib Island's changing environment and climate. Radiocarbon measurements determined sediment age, and reveal significant mixing over the last 2 ka of deposition. We conclude that prior to 3 ka, Lib Island was an atoll with a central lagoon connected to the open ocean, which was then closed off from the open ocean to form the brackish system that exists today. We predict that the sediment accumulation in Lib Pond evident today will continue. As seawater is inhibited from exchanging with fresh water, Lib Pond will become a shallower lake with increasingly fresh water.

Modelling the impact of retention–detention units on sewer surcharge and peak and annual runoff reduction

DEFF Research Database (Denmark)

Locatelli, Luca; Gabriel, S.; Mark, O.

2015-01-01

. The impact of retrofitting a retention-detention unit of 3.3 m(3)/100 m(2) (volume/impervious area) was simulated for a small catchment in Copenhagen using MIKE URBAN. The retention-detention unit was shown to prevent flooding from the sewer for a 10-year rainfall event. Statistical analysis of continuous...... simulations covering 22 years showed that annual stormwater runoff was reduced by 68-87%, and that the retention volume was on average 53% full at the beginning of rain events. The effect of different retention-detention volume combinations was simulated, and results showed that allocating 20...

The meaning and mental health consequences of long-term immigration detention for people seeking asylum.

Science.gov (United States)

Coffey, Guy J; Kaplan, Ida; Sampson, Robyn C; Tucci, Maria Montagna

2010-06-01

The aim of the present research was to examine the experience of extended periods of immigration detention from the perspective of previously detained asylum seekers and to identify the consequences of these experiences for life after release. The study sample comprised seventeen adult refugees (sixteen male and one female; average age 42 years), who had been held in immigration detention funded by the Australian government for on average three years and two months. They were interviewed on average three years and eight months following their release and had been granted permanent visa status or such status was imminent. The study employed a combination of qualitative and quantitative methods to explore detention and post-detention experiences, and mental health some years after release. The qualitative component consisted of semi-structured interviews exploring psychological well-being, daily life, significant events, relationships, and ways of coping throughout these periods. This was supplemented with standardised quantitative measures of current mental health and quality of life. All participants were struggling to rebuild their lives in the years following release from immigration detention, and for the majority the difficulties experienced were pervasive. Participants suffered an ongoing sense of insecurity and injustice, difficulties with relationships, profound changes to view of self and poor mental health. Depression and demoralisation, concentration and memory disturbances, and persistent anxiety were very commonly reported. Standardised measures found high rates of depression, anxiety, PTSD and low quality of life scores. The results strongly suggest that the psychological and interpersonal difficulties participants were suffering at the time of interview were the legacy of their adverse experiences while detained. The current study assists in identifying the characteristics of prolonged immigration detention producing long-term psychological harm

Prevention and control of tuberculosis in correctional and detention facilities: recommendations from the CDC

CSIR Research Space (South Africa)

Parsons, S

2006-07-01

Full Text Available and Detention Facilities: Recommendations from CDC Endorsed by the Advisory Council for the Elimination of Tuberculosis, the National Commission on Correctional Health Care, and the American Correctional Association MMWR CONTENTS Introduction... in Correctional and Detention Facilities: Recommendations from CDC Endorsed by the Advisory Council for the Elimination of Tuberculosis, the National Commission on Correctional Health Care, and the American Correctional Association Summary Tuberculosis (TB...

Detention in Kenya: risks for refugees and asylum seekers

OpenAIRE

Lucy Kiama; Dennis Likule

2013-01-01

Refugees and asylum seekers detained in Kenya risk multiple convictions and protracted detention due to poor coordination between immigration officials, police and prison officers, coupled with lack of interpreters and low levels of knowledge among government officers.

River water quality management considering agricultural return flows: application of a nonlinear two-stage stochastic fuzzy programming.

Science.gov (United States)

Tavakoli, Ali; Nikoo, Mohammad Reza; Kerachian, Reza; Soltani, Maryam

2015-04-01

In this paper, a new fuzzy methodology is developed to optimize water and waste load allocation (WWLA) in rivers under uncertainty. An interactive two-stage stochastic fuzzy programming (ITSFP) method is utilized to handle parameter uncertainties, which are expressed as fuzzy boundary intervals. An iterative linear programming (ILP) is also used for solving the nonlinear optimization model. To accurately consider the impacts of the water and waste load allocation strategies on the river water quality, a calibrated QUAL2Kw model is linked with the WWLA optimization model. The soil, water, atmosphere, and plant (SWAP) simulation model is utilized to determine the quantity and quality of each agricultural return flow. To control pollution loads of agricultural networks, it is assumed that a part of each agricultural return flow can be diverted to an evaporation pond and also another part of it can be stored in a detention pond. In detention ponds, contaminated water is exposed to solar radiation for disinfecting pathogens. Results of applying the proposed methodology to the Dez River system in the southwestern region of Iran illustrate its effectiveness and applicability for water and waste load allocation in rivers. In the planning phase, this methodology can be used for estimating the capacities of return flow diversion system and evaporation and detention ponds.

Priority and construction sites of water storage in a watershed in response to climate change

Science.gov (United States)

Lin, Cheng-Yu; Zhang, Wen-Yan; Lin, Chao-Yuan

2014-05-01

Taiwan is located at the Eastern Asia Monsoon climate zone. Typhoons and/or convectional rains occur frequently and result in high intensity storms in the summer season. Once the detention facilities are shortage or soil infiltration rate become worse in a watershed due to land use, surface runoff is easily to concentrate and threaten the protected areas. Therefore, it is very important to examine the functionality of water storage for a watershed. The purpose of this study is to solve the issue of flooding in the Puzi Creek. A case study of Yizen Bridge Watershed, in which the SCS curve number was used as an index to extract the spatial distribution of the strength of water storage, and the value of watershed mean CN along the main channel was calculated using area-weighting method. Therefore, the hotspot management sites were then derived and the priority method was applied to screen the depression sites for the reference of management authorities in detention ponds placement. The results show that the areas of subzone A with the characteristics of bad condition in topography and soil, which results in poor infiltration. However, the areas are mostly covered with forest and are difficult to create the artificial water storage facilities. Detention dams are strongly recommended at the site of depression in the river channel to decrease discharge velocity and reduce impact from flood disaster. The areas of subzone B are mainly located at the agriculture slope land. The topographic depressions in the farmland are the suitable places to construct the farm ponds for the use of flood detention and sediment deposition in the rainy seasons and irrigation in the dry seasons. Areas of subzone C are mainly occupied the gentle slope land with a better ability in water storage due to low CN value. Farm ponds constructed in the riparian to bypass the nearby river channel can create multifunctional wetland to effectively decrease the peak discharge in the downstream during

Application of a Method for Intelligent Multi-Criteria Analysis of the Environmental Impact of Tailing Ponds in Northern Kosovo and Metohija

Directory of Open Access Journals (Sweden)

Gordana Milentijević

2016-11-01

Full Text Available The technological process of exploitation of mineral resources and processing of mined ores to cater to the market results, among other things, in a large amount of tailings deposed on tailing ponds. Because of the chemical composition of the material, the increasing amount of waste, and the mismanagement of recovery and reclamation of ponds, these ponds have become a significant element of negative impact on the surrounding ecosystem. Economics was behind the discharging of this material, resulting in tailing ponds created in inappropriate areas. There is an ongoing process of depositing tailings on old tailing ponds, although no special attention has been paid to the subsequent effect on the environment. Application of intelligent multi-criteria analysis AHP and PROMETHEE has been performed in this paper for the purpose of ranking the degree of negative impact on the environment of tailing ponds. Analysis is performed for five tailing ponds of MMCC (Mining Metallurgy Chemical Combine “Trepča”, whereby two of the ponds are active and three inactive. The ponds are in relatively close proximity to the municipalities of Zvečan and Kosovska Mitrovica, to the north of Kosovo and Metohija, Republic of Serbia. In order to achieve the most objective results, the AHP and PROMETHEE methods were applied. By using these methods for calculations, the following ranking for the flotation tailing waste deposits was obtained, regarding their environmental impact: Žitkovac, Tvrđanski Do, Bostanište, Gornje Polje and Žarkov Potok. This result can contribute to the decision-making process of a prioritizing strategy for rehabilitation and remediation of these five flotation tailings. The analysis illustrates that application of intelligent multi-criteria analysis is a useful environmental management tool to be included in the decision-making process.

Detention in Kenya: risks for refugees and asylum seekers

Directory of Open Access Journals (Sweden)

Lucy Kiama

2013-09-01

Full Text Available Refugees and asylum seekers detained in Kenya risk multiple convictions and protracted detention due to poor coordination between immigration officials, police and prison officers, coupled with lack of interpreters and low levels of knowledge among government officers.

Sexuality education groups in juvenile detention.

Science.gov (United States)

Farrow, J A; Schroeder, E

1984-01-01

Several major studies have described the magnitude and character of adolescent sexual activity and sexual knowledge related to contraception and sexually transmitted diseases (Diepold & Young, 1979; Hass, 1979; Sorenson, 1973; Zelnick & Kantner, 1980). Few systematic studies have been conducted, however, which analyze the attitudes toward sexuality and contraception of delinquent adolescents who are generally school dropouts and who may engage in socially unacceptable behaviors such as running away, drug abuse, and prostitution. Delinquent youths, especially delinquent girls, have been characterized as being more sexually active and less sexually knowledgeable than their nondelinquent peers (Gibbon, 1981; Mannarino & Marsh, 1978). Despite the assumed high-risk nature of this delinquent population, few juvenile detention facilities have offered systematically evaluated coeducational sex education programs. One barrier to implementation of such programs in juvenile detention centers is the lack of a treatment or program orientation of most staff, and/or staff denial of adolescent sexuality in general, an attitude which suppresses the development of healthier sexual values and often promotes pathologic sexual interaction within institutions (Shore & Gochros, 1981). A recent survey of adolescent sexuality (Diepold, 1979) points out that teenagers' feelings about their "sexual selves" impacts greatly upon their general self-image. Low self-esteem is more frequently found among delinquents than nondelinquents (Jones & Swain, 1977; Lund & Salury, 1980), and treatment for delinquent girls often focuses on increasing self-esteem and developing assertiveness skills based on feelings of self-worth (DeLange, Lanahan, & Barton, 1981; NiCarthy, 1981). Two studies carried out with juvenile detainees from a large urban center confirmed that sexual activity among delinquent adolescents is significantly greater than that of the general adolescent population, and that the delinquents

uG-LilyPond - Floating Plant Pond for Microgravity, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The proposed μG-LilyPond is an autonomous environmentally controlled floating plant cultivation system for use in microgravity. The μG-LilyPond concept expands the...

Mental health screening in immigration detention: A fresh look at Australian government data.

Science.gov (United States)

Young, Peter; Gordon, Michael S

2016-02-01

The poor mental health of asylum seekers and refugees in immigration detention has consistently been reported in peer-reviewed literature internationally; however, data on the mental health of asylum seekers and refugees detained in Australian immigration has been very limited. We re-analysed mental health screening data obtained by the Human Rights Commission. Longer time in detention was associated with higher self-reported depression scores, with female individuals being more vulnerable to time in detention than those of male gender. Approximately one-half of the refugee group who agreed to complete the Harvard Trauma Questionnaire had post-traumatic stress disorder symptoms. On clinician-rated measures, one-third of the children, adolescents and adults suffered with clinical symptoms requiring tertiary outpatient assessment. This paper consolidates the findings of the 2014 Australian Human Rights Commission report and it provides an argument for public reporting of refugee data. © The Royal Australian and New Zealand College of Psychiatrists 2016.

Science and the common good: indefinite, non-reviewable mandatory detention of asylum seekers and the research imperative.

Science.gov (United States)

Steel, Zachary; Silove, Derrick

2004-10-01

Despite a strong historical record of resettling and providing care for refugee populations, the Australian Federal Government has increasingly implemented harsh and restrictive policies regarding the treatment and management of asylum seekers. Most controversial of these has been the mandatory detention of asylum seekers, a policy applied indiscriminately and without discretion where individual cases have not been subject to judicial review or time constraints. From the outset health professionals have raised concerns about the possible adverse mental health impacts of prolonged detention. In contrast, government representatives have characterized conditions in detention as benign and comfortable, and have consistently contested criticism of detention, often citing a lack of scientific evidence as tacit support for the continuation of the policy. Nevertheless, requests for access to the detention centres to undertake rigorous scientific investigations have gone unheeded. In this context we argue that the Australian Government has failed to uphold its commitment to good governance by allowing transparency, openness and a willingness to have the impact of its policies scrutinized by scientists. The manifest conflict of interest in the government position leads to a breach in the normal social contract between mental health researchers and those responsible for the policy of detention. There is, we argue, a legitimate moral imperative in such situations for clinical researchers to breach the walls of enforced silence and give a voice to those who are afflicted. This imperative, however, must be carefully balanced against the risks that may face detainees agreeing to participate in such research.

Contesting Institutional Discourse to Create New Possibilities for Understanding Lived Experience: Life-Stories of Young Women in Detention, Rehabilitation, and Education

Science.gov (United States)

Sharma, Suniti

2010-01-01

This research explores autobiographies of young women in detention, rehabilitation, and education as counter-stories to the official, institutional stories of their lives. The context of the study is a private detention facility in the United States; the participants are young women aged 15-19 years in a detention classroom; and data for the study…

Undisclosed U.S. Detention Sites Overseas: Background and Legal Issues

National Research Council Canada - National Science Library

Elsea, Jennifer K; Kim, Julie

2006-01-01

.... detention facility at the Guantanamo Bay Naval Station confirmed the existence of secret U.S. prison facilities abroad, the subject of previously unsubstantiated media allegations and investigations by foreign governments and human rights bodies...

Nature of uranium contamination in the agricultural drainage water evaporation ponds of the San Joaquin Valley, California, USA

International Nuclear Information System (INIS)

Duff, M.C.; Amrhein, C.; Bradford, G.

1997-01-01

Evaporation ponds used for agricultural subsurface drainage water disposal in the Tulare Lake Bed (TLB) of the San Joaquin Valley, California, USA have elevated levels of U. Waterfowl which inhabit and forage the ponds and surrounding areas are threatened by exposure to U. The ponds, which receive irrigation drainage waters and seasonal rain, are subject to wetting and drying periods. The periods result in the accumulation of decaying algae and other organic material in surface sediments. Sediment and waters in the ponds were sampled to determine what factors control U solubility and sediment U concentrations. Data from a 1990 study conducted by Chilcott et al. in 1989 on the TLB ponds were used to help identify what factors may control U solubility. Pond sediment U concentrations decreased abruptly with depth and surface sediment U concentrations were related to dissolved Ca:HCO 3 ratios. Pond algal U bioaccumulation was favored in waters with high Ca:HCO 3 ratios, which had lower pH values and carbonate alkalinities than waters with low CA:HCO 3 ratios. Ponds with high salinities and high carbonate alkalinities contained the highest aqueous U concentrations relative to other TLB ponds. Sediment total organic carbon (TOC) was correlated with sediment U concentrations, suggesting that U is bound to organic matter. The source of TOC is most likely from algae deposition. (author)

Determining the Chemical and Biological Availability of Zinc in Urban Stormwater Retention Ponds

Science.gov (United States)

Camponelli, K.; Casey, R.; Lev, S. M.; Landa, E. R.; Snodgrass, J.

2005-12-01

Highway runoff has the potential to negatively impact receiving systems due to transport of contaminants that accumulate on road surfaces. Metals such as copper and zinc are major components of automobile brake pads and tires, respectively. As these automobile parts are degraded, these metal containing particulates are deposited on the roadway and are washed into storm water retention ponds and surface water bodies during precipitation events. It has been estimated that 15 to 60% of the Zn in urban stormwater runoff comes from tire wear and that tire wear is a significant source of Zn to the environment with release inventories comparable to waste incineration sources. In urban and sub-urban systems, this large source of Zn can accumulate in stormwater retention ponds which serve as habitat for a variety of species. Understanding the chemical and biological availability of Zn to biota is integral to assessing the habitat quality of retention ponds. This study is a first effort to relate the amount and speciation of Zn in a retention pond to Zn inputs through highway-derived runoff events. In addition, results suggest that the chemical speciation and availability of particulate Zn can be related to the bioavailability and toxicity of Zn to pond organisms (i.e. larval amphibians). The study site in Owings Mills, MD is located next to a four-lane highway from which it receives runoff through a single culvert. Five species of anurans are known to utilize the pond as a breeding site and Zn in amphibian tissues and retention pond sediments were highly elevated at this site in 2001 and 2002. A recent analysis of pond sediments, soils, roadway dust and storm water collected at this site suggests that roadway particulate matter transported during runoff events is the dominant source of Zn in this system. Overall, Zn and other trace metals were found to be most abundant in the clay sized faction of pond sediments and soils. The pond cores were found to have higher Zn and Cu

216-B-3 expansion ponds closure plan

International Nuclear Information System (INIS)

1994-10-01

This document describes the activities for clean closure under the Resource Conservation and Recovery Act of 1976 (RCRA) of the 216-B-3 Expansion Ponds. The 216-B-3 Expansion Ponds are operated by the US Department of Energy, Richland Operations Office (DOE-RL) and co-operated by Westinghouse Hanford Company (Westinghouse Hanford). The 216-B-3 Expansion Ponds consists of a series of three earthen, unlined, interconnected ponds that receive waste water from various 200 East Area operating facilities. The 3A, 3B, and 3C ponds are referred to as Expansion Ponds because they expanded the capability of the B Pond System. Waste water (primarily cooling water, steam condensate, and sanitary water) from various 200 East Area facilities is discharged to the Bypass pipe (Project X-009). Water discharged to the Bypass pipe flows directly into the 216-B-3C Pond. The ponds were operated in a cascade mode, where the Main Pond overflowed into the 3A Pond and the 3A Pond overflowed into the 3C Pond. The 3B Pond has not received waste water since May 1985; however, when in operation, the 3B Pond received overflow from the 3A Pond. In the past, waste water discharges to the Expansion Ponds had the potential to have contained mixed waste (radioactive waste and dangerous waste). The radioactive portion of mixed waste has been interpreted by the US Department of Energy (DOE) to be regulated under the Atomic Energy Act of 1954; the dangerous waste portion of mixed waste is regulated under RCRA

216-B-3 expansion ponds closure plan

Energy Technology Data Exchange (ETDEWEB)

1994-10-01

This document describes the activities for clean closure under the Resource Conservation and Recovery Act of 1976 (RCRA) of the 216-B-3 Expansion Ponds. The 216-B-3 Expansion Ponds are operated by the US Department of Energy, Richland Operations Office (DOE-RL) and co-operated by Westinghouse Hanford Company (Westinghouse Hanford). The 216-B-3 Expansion Ponds consists of a series of three earthen, unlined, interconnected ponds that receive waste water from various 200 East Area operating facilities. The 3A, 3B, and 3C ponds are referred to as Expansion Ponds because they expanded the capability of the B Pond System. Waste water (primarily cooling water, steam condensate, and sanitary water) from various 200 East Area facilities is discharged to the Bypass pipe (Project X-009). Water discharged to the Bypass pipe flows directly into the 216-B-3C Pond. The ponds were operated in a cascade mode, where the Main Pond overflowed into the 3A Pond and the 3A Pond overflowed into the 3C Pond. The 3B Pond has not received waste water since May 1985; however, when in operation, the 3B Pond received overflow from the 3A Pond. In the past, waste water discharges to the Expansion Ponds had the potential to have contained mixed waste (radioactive waste and dangerous waste). The radioactive portion of mixed waste has been interpreted by the US Department of Energy (DOE) to be regulated under the Atomic Energy Act of 1954; the dangerous waste portion of mixed waste is regulated under RCRA.

Tsunami Stratigraphy in a Coastal Salt Pond, St. Croix, US Virgin Islands

Science.gov (United States)

Russell, P.; Browning, T. N.; Brooks, G.; Larson, R. A.; Cook, A.; Sawyer, D. E.

2017-12-01

The Caribbean has significant exposure to tsunamis from multiple sources, such as earthquakes, volcanoes, and landslides. Due to the limited historical record in the region, paleotsunami deposits provide important information about the size, location, and sources of these events. In turn, these data inform the public and policymakers about the tsunamigenic threat to their communities. A key challenge is that tsunami deposits are often poorly preserved. However, a good candidate for high preservation potential are coastal salt ponds commonly found on the perimeter of tropical islands. The US Virgin Islands has both high susceptibility to tsunamis and large, low lying salt ponds. The most prominent historical example of a tsunami in the US Virgin Islands is the 1867 event which caused widespread devastation throughout the region, including Puerto Rico. One of the hardest hit locations was Frederiksted, on the western end of St. Croix, US Virgin Islands with 7m runups that beached the USS Monongahela. Frederiksted is also in close proximity to a large coastal salt pond. We targeted this, and older, events by collecting a series of sediment cores at four sites in the salt pond during a summer 2017 field campaign. At each location we acquired a 3" aluminum core and a 4" acrylic companion core to core refusal, which most often occurred at a impenetrable horizon. Maximum core recovery was .79m and the average was .54m. Each 4" core was extruded in 1cm intervals and used to determine grain size, total carbon content, and age dating via radioisotope dating. The 3" core was scanned in a X-Ray CT Lab, split, described, and samples from key layers were targeted for detailed sedimentological analyses. The defining stratigraphic sequence is fine-grained muds interspersed with coarse-grained units that exhibit a fining-upwards trend and contained a variety of marine debris, which we infer to represent tsunami or tropical storm event deposits. However, each core did not exhibit

Metals in pond sediments as archives of anthropogenic activities: a study in response to health concerns

International Nuclear Information System (INIS)

Graney, Joseph R.; Eriksen, Timothy M.

2004-01-01

An environmental geochemistry approach was applied in response to health concerns about present day and past exposure to pollutants within Broome County, New York by determining historical records of anthropogenic activities as preserved in sediment cores. Sediment was collected from a stormwater retention pond adjacent to a warehouse complex in the urban community of Hillcrest as well as from 3 other ponds in rural locations in Broome County. Metal concentrations and decay products of 210 Pb and 137 Cs were measured to determine the timing of source specific differences in the distribution of metals in the sediment cores. Concentrations of Zn, Pb, Ni, Cu, Cr, Cd and As were elevated in the retention pond sediments when compared to sediment from other locations. Topography influenced atmospheric transport and deposition of pollutants within incised river valleys and enhanced runoff from impervious surfaces within an urban watershed contributed to the elevated metal concentrations at Hillcrest. Temporal changes in Pb deposition within retention pond sediment mimic the rise and fall in use of leaded gasoline. Arsenic concentrations decreased following placement of emission controls on nearby coal-fired power plant sources. Superimposed over the temporal trends of Pb and As are co-varying Zn, Ni, Cu, Cr and Cd concentrations; a suite of metals commonly used in metal plating processes by local industries. Analysis of sediment in stormwater retention ponds in other urban areas may provide opportunities for detailed records of pollution history to be obtained in many communities. Residents in urban communities located in incised river valley locations similar to Hillcrest may be particularly prone to enhanced exposure to metals from anthropogenic sources

Heavy metal composition in stormwater and retention in ponds dependent on pond age, design and catchment type

DEFF Research Database (Denmark)

Egemose, Sara; Sønderup, Melanie J.; Grudinina, Anna

2015-01-01

Heavy metals have toxic effects on flora and fauna in the aquatic environments and are of great concern in stormwater. Heavy metal runoff was studied in 37 stormwater ponds in Denmark with varying heavy metal load, catchment type and pond design. The studied metals were Cu, Cr, Cd, Pb, Ni and Zn...... difficult to retain. The removal efficiency in the ponds varied considerably, with the highest retention of Pb, Ni and Zn due to higher particulate fraction. The retention increased with increased pond volume-to-reduced catchment area ratio. In addition, the pond age affected the efficiency; whereas ponds...... less than 1-2 years efficiently removed all metals, 30-40-year-old ponds only removed Pb, Ni and Zn, but steeply decreasing over the years. Physical parameters such as pond size, age and sedimentation patterns were found to play a more significant role in the removal compared with chemical parameters...

Heavy metals in water, sediments and submerged macrophytes in ponds around the Dianchi Lake, China.

Science.gov (United States)

Wang, Zhixiu; Yao, Lu; Liu, Guihua; Liu, Wenzhi

2014-09-01

Through retaining runoff and pollutants such as heavy metals from surrounding landscapes, ponds around a lake play an important role in mitigating the impacts of human activities on lake ecosystems. In order to determine the potential for heavy metal accumulation of submerged macrophytes, we investigated the concentrations of 10 heavy metals (i.e., As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in water, sediments, and submerged macrophytes collected from 37 ponds around the Dianchi Lake in China. Our results showed that both water and sediments of these ponds were polluted by Pb. Water and sediments heavy metal concentrations in ponds received urban and agricultural runoff were not significantly higher than those in ponds received forest runoff. This result indicates that a large portion of heavy metals in these ponds may originate from atmospheric deposition and weathering of background soils. Positive relationships were found among heavy metal concentrations in submerged macrophytes, probably due to the coaccumulation of heavy metals. For most heavy metals, no significant relationships were found between submerged macrophytes and their water and sediment environments. The maximum concentrations of Cr, Fe and Ni in Ceratophyllum demersum were 4242, 16,429 and 2662mgkg(-1), respectively. The result suggests that C. demersum is a good candidate species for removing heavy metals from polluted aquatic environments. Copyright © 2014 Elsevier Inc. All rights reserved.

Using Automatic Control Approach In Detention Storages For Storm Water Management In An Urban Watershed

Science.gov (United States)

Goyal, A.; Yadav, H.; Tyagi, H.; Gosain, A. K.; Khosa, R.

2017-12-01

Increased imperviousness due to rapid urbanization have changed the urban hydrological cycle. As watersheds are urbanized, infiltration and groundwater recharge have decreased, surface runoff hydrograph shows higher peak indicating large volumes of surface runoff in lesser time durations. The ultimate panacea is to reduce the peak of hydrograph or increase the retention time of surface flow. SWMM is widely used hydrologic and hydraulic software which helps to simulate the urban storm water management with the provision to apply different techniques to prevent flooding. A model was setup to simulate the surface runoff and channel flow in a small urban catchment. It provides the temporal and spatial information of flooding in a catchment. Incorporating the detention storages in the drainage network helps achieve reduced flooding. Detention storages provided with predefined algorithms were for controlling the pluvial flooding in urban watersheds. The algorithm based on control theory, automated the functioning of detention storages ensuring that the storages become active on occurrence of flood in the storm water drains and shuts down when flooding is over. Detention storages can be implemented either at source or at several downstream control points. The proposed piece of work helps to mitigate the wastage of rainfall water, achieve desirable groundwater and attain a controlled urban storm water management system.

Comparison between field data and ultimate heat-sink cooling-pond and spray-pond models

International Nuclear Information System (INIS)

Codell, R.

1982-09-01

Two previously published reports, NUREG-0693 and NUREG-0733, presented models and methods by which ultimate heat sink cooling ponds and spray ponds used for safety-related water supplies in nuclear power plants could be analyzed for design-basis conditions of heat load and meteorology. These models were only partially verified with field data. The present report compares the NRC models to data collected for NRC by Battelle Pacific Northwest Laboratories on the performance of small geothermally heated ponds and spray ponds. These comparisons generally support the conclusion that the NRC models are useful tools in predicting ultimate heat sink performance

Lake or Pond WBID

Data.gov (United States)

Vermont Center for Geographic Information — The VT DEC (Vermont Department of Environmental Conservation) manages an inventory of lake and pond information. The "Lakes and Ponds Inventory" stores the Water...

Study on radionuclides transport from natural evaporating ponds to the atmosphere

International Nuclear Information System (INIS)

Liu Keqiang; Zou Changgui

1997-08-01

The results of simulated experiments, field monitoring and radiation health risk evaluation of radionuclides transport to the atmosphere from the natural evaporating ponds of a certain nuclear factory, and the estimating method of releasing source strength are presented. The estimated results of radiation health risk show that the maximum individual annual risk is 6.5 x 10 -9 and the total collective annual risk within a radius of 20 km is 3.2 x 10 -5 person, which are caused by operation of the evaporating ponds. It should be pointed out that the above estimated results only refer to one operating year (1990). If the cumulative effect of radionuclides deposition in ground is considered, the risk will increase a little with time until the dynamic balance is achieved. (5 ref., 8 tabs.)

South Bay Salt Pond Tidal Marsh Restoration at Pond A17 Project

Science.gov (United States)

Information about the SFBWQP South Bay Salt Pond Tidal Marsh Restoration at Pond A17 Project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

Changes in tundra pond limnology: re-sampling Alaskan ponds after 40 years.

Science.gov (United States)

Lougheed, Vanessa L; Butler, Malcolm G; McEwen, Daniel C; Hobbie, John E

2011-09-01

The arctic tundra ponds at the International Biological Program (IBP) site in Barrow, AK, were studied extensively in the 1970s; however, very little aquatic research has been conducted there for over three decades. Due to the rapid climate changes already occurring in northern Alaska, identifying any changes in the ponds' structure and function over the past 30-40 years can help identify any potential climate-related impacts. Current research on the IBP ponds has revealed significant changes in the physical, chemical, and biological characteristics of these ponds over time. These changes include increased water temperatures, increased water column nutrient concentrations, the presence of at least one new chironomid species, and increased macrophyte cover. However, we have also observed significant annual variation in many measured variables and caution that this variation must be taken into account when attempting to make statements about longer-term change. The Barrow IBP tundra ponds represent one of the very few locations in the Arctic where long-term data are available on freshwater ecosystem structure and function. Continued monitoring and protection of these invaluable sites is required to help understand the implications of climate change on freshwater ecosystems in the Arctic.

Discipline and Grievance Procedures: Juvenile Detention and Correctional Facilities.

Science.gov (United States)

Illinois Univ., Champaign. Community Research Center.

The purpose of sound disciplinary practices and grievance procedures in juvenile detention and correctional facilities is outlined and a philosophy on discipline and grievance procedures is discussed. The use of secure confinement or restriction as a means of treatment, and the effects of restriction are considered. The basics of good discipline…

Chromate abatement in the Y-12 Plant's New Hope Pond

International Nuclear Information System (INIS)

DeMonbrum, J.R.; Muenzer, W.A.

1975-01-01

Results are reported from a 15-months field study that utilized four nonchromate-based water-treatment programs in 16 low-temperature (less than 100 0 F) cooling towers using corrosion and deposition studies, microbiological control, and plant effluent creek analyses as evaluation parameters. The study succeeded in bringing the chromate content of effluent of the New Hope Pond at the Oak Ridge Y-12 Plant to the limits established by the Environmental Protection Agency. (auth)

Incommunicado detention and torture in Spain, Part IV: Psychological and psychiatric consequences of ill-treatment and torture: trauma and human worldviews.

Science.gov (United States)

Navarro-Lashaya, Miguel Angel; Pérez-Sales, Pau; Lopez Neyr, Gabriela; Martínez, Maitane Arnoso; Morentin, Benito

2016-01-01

Most literature on psychological consequences of torture is related to prolonged detention. Psychological consequences of intensive physical and psychological torture in brief detention have not been investigated. The aim of this study is to analyse the psychological impact of torture in short-term incommunicado detention. A sample of 45 Basque people who had allegedly been subjected to ill-treatment or torture whilst held in incommunicado detention between two and 11 days in Spain in the period 1980-2012 was analysed. The period between detention and evaluation ranged between two and 12 years. Each case was evaluated by several psychiatrists and psychologists. Clinical interviews which followed the Istanbul Protocol were assessed, as were psychometric tests (Post-traumatic Checklist-Civilian version (PCL-C), Beck Depression Inventory (BDI) and Vital Impact Assessment Questionnaire (VIVO)) and external documentary evidence. A cumulative prevalence of psychiatric diagnosis (ICD-10) from the period of detention was established. Post-traumatic stress disorder (PTSD) was the most frequent diagnosis (53%). Enduring personality change after a catastrophic experience was detected in 11% of subjects. Other diagnoses were depressive disorders (16%) and anxiety disorders (9%). Psychometric evaluation at the time of the study showed symptoms of PTSD in 52% of the subjects (with a tendency for these symptoms to diminish over time) and depressive symptoms in 56%. The VIVO questionnaire discerned two subgroups of survivors: "affected" survivors (36%); and "resilient" survivors (64%). The data demonstrated two important issues: the undervalued damaging effect of intensive torture in short-term detention and the long lasting psychological damage of the same over time.

Pond and Irrigation Model (PIM): a tool for simultaneously evaluating pond water availability and crop irrigation demand

Science.gov (United States)

Ying Ouyang; Gary Feng; Theodor D. Leininger; John Read; Johnie N. Jenkins

2018-01-01

Agricultural ponds are an important alternative source of water for crop irrigation to conserve surface and ground water resources. In recent years more such ponds have been constructed in Mississippi and around the world. There is currently, however, a lack of a tool to simultaneously estimate crop irrigation demand and pond water availability. In this study, a Pond-...

2101-M pond closure plan

International Nuclear Information System (INIS)

1993-06-01

This document describes activities for the closure of a surface impoundment (2101-M Pond) at the Hanford Site. The 2101-H Pond was initially constructed in 1953 to serve as a drainage collection area for the 2101-H Building. (Until the Basalt Waste Isolation Project (BWIP) Laboratory was constructed in the 2101-M Building in 1979--1981, the only source contributing discharge to the pond was condensate water from the 2101-H Building heating, ventilation, and air conditioning (HVAC) system. The drains for the BWIP Laboratory rooms were plumbed into a 4-in., cast-iron, low-pressure drain pipe that carries waste water from the HVAC system to the pond. During the active life of the BWIP Laboratory, solutions of dissolved barium in groundwater samples were discharged to the 2101-M Pond via the laboratory drains. As a result of the discharges, a Part A permit application was initially submitted to the Washington State Department of Ecology (Ecology) in August 1986 which designates the 2101-M Pond as a surface impoundment

Par Pond vegetation status 1996

International Nuclear Information System (INIS)

Mackey, H.E. Jr.; Riley, R.S.

1996-12-01

The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995, and into the early spring and late summer of 1996. Communities similar to the pre-drawdown, Par Pond aquatic plant communities continue to become re-established. Emergent beds of maidencane, lotus, waterlily, watershield, and Pontederia are extensive and well developed. Measures of percent cover, width of beds, and estimates of area of coverage with satellite data indicate regrowth within two years of from 40 to 60% of levels prior to the draw down. Cattail occurrence continued to increase during the summer of 1996, especially in the former warm arm of Par Pond, but large beds common to Par Pond prior to the draw down still have not formed. Lotus has invaded and occupies many of the areas formerly dominated by cattail beds. To track the continued development of macrophytes in Par Pond, future surveys through the summer and early fall of 1997, along with the evaluation of satellite data to map the extent of the macrophyte beds of Par Pond, are planned

Origin of the RNA world: The fate of nucleobases in warm little ponds

Science.gov (United States)

Pearce, Ben K. D.; Pudritz, Ralph E.; Semenov, Dmitry A.; Henning, Thomas K.

2017-10-01

Before the origin of simple cellular life, the building blocks of RNA (nucleotides) had to form and polymerize in favorable environments on early Earth. At this time, meteorites and interplanetary dust particles delivered organics such as nucleobases (the characteristic molecules of nucleotides) to warm little ponds whose wet–dry cycles promoted rapid polymerization. We build a comprehensive numerical model for the evolution of nucleobases in warm little ponds leading to the emergence of the first nucleotides and RNA. We couple Earth's early evolution with complex prebiotic chemistry in these environments. We find that RNA polymers must have emerged very quickly after the deposition of meteorites (less than a few years). Their constituent nucleobases were primarily meteoritic in origin and not from interplanetary dust particles. Ponds appeared as continents rose out of the early global ocean, but this increasing availability of “targets” for meteorites was offset by declining meteorite bombardment rates. Moreover, the rapid losses of nucleobases to pond seepage during wet periods, and to UV photodissociation during dry periods, mean that the synthesis of nucleotides and their polymerization into RNA occurred in just one to a few wet–dry cycles. Under these conditions, RNA polymers likely appeared before 4.17 billion years ago.

Origin of the RNA world: The fate of nucleobases in warm little ponds.

Science.gov (United States)

Pearce, Ben K D; Pudritz, Ralph E; Semenov, Dmitry A; Henning, Thomas K

2017-10-24

Before the origin of simple cellular life, the building blocks of RNA (nucleotides) had to form and polymerize in favorable environments on early Earth. At this time, meteorites and interplanetary dust particles delivered organics such as nucleobases (the characteristic molecules of nucleotides) to warm little ponds whose wet-dry cycles promoted rapid polymerization. We build a comprehensive numerical model for the evolution of nucleobases in warm little ponds leading to the emergence of the first nucleotides and RNA. We couple Earth's early evolution with complex prebiotic chemistry in these environments. We find that RNA polymers must have emerged very quickly after the deposition of meteorites (less than a few years). Their constituent nucleobases were primarily meteoritic in origin and not from interplanetary dust particles. Ponds appeared as continents rose out of the early global ocean, but this increasing availability of "targets" for meteorites was offset by declining meteorite bombardment rates. Moreover, the rapid losses of nucleobases to pond seepage during wet periods, and to UV photodissociation during dry periods, mean that the synthesis of nucleotides and their polymerization into RNA occurred in just one to a few wet-dry cycles. Under these conditions, RNA polymers likely appeared before 4.17 billion years ago.

Pond bank access as an approach for managing toxic cyanobacteria in beef cattle pasture drinking water ponds.

Science.gov (United States)

Wilson, Alan E; Chislock, Michael F; Yang, Zhen; Barros, Mário U G; Roberts, John F

2018-03-25

Forty-one livestock drinking water ponds in Alabama beef cattle pastures during were surveyed during the late summer to generally understand water quality patterns in these important water resources. Since livestock drinking water ponds are prone to excess nutrients that typically lead to eutrophication, which can promote blooms of toxigenic phytoplankton such as cyanobacteria, we also assessed the threat of exposure to the hepatotoxin, microcystin. Eighty percent of the ponds studied contained measurable microcystin, while three of these ponds had concentrations above human drinking water thresholds set by the US Environmental Protection Agency (i.e., 0.3 μg/L). Water quality patterns in the livestock drinking water ponds contrasted sharply with patterns typically observed for temperate freshwater lakes and reservoirs. Namely, we found several non-linear relationships between phytoplankton abundance (measured as chlorophyll) and nutrients or total suspended solids. Livestock had direct access to all the study ponds. Consequently, the proportion of inorganic suspended solids (e.g., sediment) increased with higher concentrations of total suspended solids, which underlies these patterns. Unimodal relationships were also observed between microcystin and phytoplankton abundance or nutrients. Euglenoids were abundant in the four ponds with chlorophyll concentrations > 250 μg/L (and dominated three of these ponds), which could explain why ponds with high chlorophyll concentrations would have low microcystin concentrations. Based on observations made during sampling events and available water quality data, livestock-mediated bioturbation is causing elevated total suspended solids that lead to reduced phytoplankton abundance and microcystin despite high concentrations of nutrients, such as phosphorus and nitrogen. Thus, livestock could be used to manage algal blooms, including toxic secondary metabolites, in their drinking water ponds by allowing them to walk in the

Defendant’s free will in legal collaboration and its relation with pre-trial detention

Directory of Open Access Journals (Sweden)

Antonio Henrique Graciano Suxberger

2017-03-01

Full Text Available The legal collaboration, a type of evidence used on organized crime prosecutions, demands free will of the defendant. Appraising the defendant’s free will, many critics cover the deals made with an arrested defendant during the negotiation of the legal collaboration. These two institutes — legal collaboration and pre-trial detention —, although they do not present themselves as a cause-effect relation, commonly are approached in practice as associated. This essay intends to evaluate the defendant’s free will during pre-trial detention and the legal collaboration’s bargaining. It asserts a strict and clear relation between pre-trial detention and the legal collaboration bargaining. Identifying occasional problems do not imply the conclusion on the existence of a structural problem to legal collaboration institute. This consideration is relevant to avoid superficial solutions that could fragilize even more the held defendant. Methodologically, from a literature review and document analysis about the subject, the paper clarifies what is a “criminal case” and what it means to the study.

Biogeochemical ecology of aquaculture ponds

International Nuclear Information System (INIS)

Weisburd, R.S.J.

1988-01-01

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

HIV and incarceration: prisons and detention.

Science.gov (United States)

Jürgens, Ralf; Nowak, Manfred; Day, Marcus

2011-05-19

The high prevalence of HIV infection among prisoners and pre-trial detainees, combined with overcrowding and sub-standard living conditions sometimes amounting to inhuman or degrading treatment in violation of international law, make prisons and other detention centres a high risk environment for the transmission of HIV. Ultimately, this contributes to HIV epidemics in the communities to which prisoners return upon their release. We reviewed the evidence regarding HIV prevalence, risk behaviours and transmission in prisons. We also reviewed evidence of the effectiveness of interventions and approaches to reduce the risk behaviours and, consequently, HIV transmission in prisons. A large number of studies report high levels of risk behaviour in prisons, and HIV transmission has been documented. There is a large body of evidence from countries around the world of what prison systems can do to prevent HIV transmission. In particular, condom distribution programmes, accompanied by measures to prevent the occurrence of rape and other forms of non-consensual sex, needle and syringe programmes and opioid substitution therapies, have proven effective at reducing HIV risk behaviours in a wide range of prison environments without resulting in negative consequences for the health of prison staff or prisoners.The introduction of these programmes in prisons is therefore warranted as part of comprehensive programmes to address HIV in prisons, including HIV education, voluntary HIV testing and counselling, and provision of antiretroviral treatment for HIV-positive prisoners. In addition, however, action to reduce overcrowding and improve conditions in detention is urgently needed.

[Girls detained under civil and criminal law in juvenile detention centres; psychiatric disorders, trauma and psychosocial problems].

Science.gov (United States)

Hamerlynck, S M J J; Doreleijers, Th A H; Vermeiren, R R J M; Cohen-Kettenis, P T

2009-01-01

As from 2008, juveniles sentenced under civil law and juveniles sentenced under criminal law can no longer be assigned to the same juvenile detention centres. The reasoning runs as follows: the centres are unlikely to provide adequate treatment for the 'civil' group, and the 'criminal' group may exert a negative influence on the 'civil' group. Hitherto, there has been no research into the question of whether the problems and treatment requirements of girls in the two categories call for detention in the same detention centres or in different ones. The aim of this study is to investigate differences between the two groups of girls with regard to offence history, sociodemographic characteristics, contact with the social services, psychiatric disorders and trauma. Investigation of a representative sample of 211 female minors in three juvenile detention centres using standard instruments. results 82% of the girls were detained under civil law, 18% under criminal law. There were strong similarities between the groups. However, the 'criminal' group more often had a violent history of delinquency and a non-Dutch background, whereas the 'civil' group more often had a background of residential placements, oppositional-defiant disorder, suicidality and self-harm. Girls detained under civil and under criminal law differed in characteristics such as criminal record, but there were striking similarities in the girls' behavioural problems and psychiatric disorders. It is argued that assignment to a particular type of detention centre should depend on treatment requirements rather than on measures imposed by civil or criminal law.

Microbiology of solar salt ponds

Science.gov (United States)

Javor, B.

1985-01-01

Solar salt ponds are shallow ponds of brines that range in salinity from that of normal seawater (3.4 percent) through NaCl saturation. Some salterns evaporate brines to the potash stage of concentration (bitterns). All the brines (except the bitterns, which are devoid of life) harbor high concentrations of microorganisms. The high concentrations of microorganisms and their adaptation to life in the salt pond are discussed.

Characterizing bacterial communities in tilapia pond surface sediment and their responses to pond differences and temporal variations.

Science.gov (United States)

Fan, Limin; Barry, Kamira; Hu, Gengdong; Meng, Shunlong; Song, Chao; Qiu, Liping; Zheng, Yao; Wu, Wei; Qu, Jianhong; Chen, Jiazhang; Xu, Pao

2017-01-01

Bacterial community compositions in the surface sediment of tilapia ponds and their responses to pond characteristics or seasonal variations were investigated. For that, three ponds with different stocking densities were selected to collect the samples. And the method of Illumina high-throughput sequencing was used to amplify the bacterial 16S rRNA genes. A total of 662, 876 valid reads and 5649 operational taxonomic units were obtained. Further analysis showed that the dominant phyla in all three ponds were Proteobacteria, Bacteroidetes, Chloroflexi, and Acidobacteria. The phyla Planctomycetes, Firmicutes, Chlorobi, and Spirochaetae were also relatively abundant. Among the eight phyla, the abundances of only Proteobacteria, Bacteroidetes, Firmicutes, and Spirochaetae were affected by seasonal variations, while seven of these (with the exception of Acidobacteria) were affected by pond differences. A comprehensive analysis of the richness and diversity of the bacterial 16S rRNA gene, and of the similarity in bacterial community composition in sediment also showed that the communities in tilapia pond sediment were shaped more by pond differences than by seasonal variations. Linear discriminant analysis further indicated that the influences of pond characteristics on sediment bacterial communities might be related to feed coefficients and stocking densities of genetically improved farmed tilapia (GIFT).

The impact of immigration detention on the mental health of torture survivors is poorly documented--a systematic review.

Science.gov (United States)

Storm, Tania; Engberg, Marianne

2013-11-01

Torture has enduring mental and physical health consequences for survivors. Detention of asylum seekers is an integrated part of the immigration systems in many countries. Among the asylum seekers are vulnerable groups such as survivors of torture and severely traumatized refugees. The aim of the present study is to review the scientific evidence on the mental health consequences of immigration detention for adult survivors of torture. The review was conducted according to a modified version of the PRISMA guidelines. A systematic search was made in: PubMed (Medline), PsychINFO, PILOTS and IBSS, and reference lists were screened. The search yielded 241 results and two records came from additional sources. A total of 15 studies were included. Merely two case studies focused on survivors of torture. Both reported severe effects of detention on the detainees' mental health. High levels of psychological problems were found in studies identifying torture survivors among the asylum seekers. The impact of detention on the mental health of torture survivors is poorly documented, and the available data are insufficient to allow analysis of any specific effects. The studies do report severe mental health issues among detained torture survivors. In general, serious mental health problems are found among the detainees and formerly detained asylum seekers. Systematically identifying torture survivors and other vulnerable groups, and assessing and monitoring mental health issues is crucial. The health risks that detention may pose to the wellbeing of each individual should be carefully considered.

Hatching success in salamanders and chorus frogs at two sites in Colorado, USA: Effects of acidic deposition and climate

Science.gov (United States)

Muths, E.; Campbell, D.H.; Corn, P.S.

2003-01-01

The snowpack in the vicinity of the Mount Zirkel Wilderness Area is among the most acidic in the western United States. We analyzed water chemistry and examined hatching success in tiger salamanders and chorus frogs at ponds there and at nearby Rabbit Ears Pass (Dumont) to determine whether acid deposition affects amphibians or their breeding habitats at these potentially sensitive locations. We found a wide range of acid neutralizing capacity among ponds within sites; the minimum pH recorded during the experiment was 5.4 at one of 12 ponds with all others at pH ??? 5.7. At Dumont, hatching success for chorus frogs was greater in ponds with low acid neutralizing capacity; however, lowest pHs were >5.8. At current levels of acid deposition, weather and pond characteristics are likely more important than acidity in influencing hatching success in amphibian larvae at these sites.

Beaver ponds increase methylmercury concentrations in Canadian shield streams along vegetation and pond-age gradients.

Science.gov (United States)

Roy, Virginie; Amyot, Marc; Carignan, Richard

2009-08-01

Beaver impoundments flood forested areas and may be important production sites for methylmercury (MeHg) because of the resulting enhanced microbial activity and oxygen depletion. The influence of 17 beaver impoundments on streamwater chemistry (total mercury (THg), MeHg, nutrients, cations, and anions)] was investigated by sampling sites located along vegetation and pond-age gradients in southwestern Quebec (Canada). Recently inundated beaver ponds (beaver ponds as suggested by depletions of dissolved oxygen, sulfate and nitrite-nitrate concentrations, and increases in nutrients (e.g., dissolved organic carbon, total phosphorus, and total nitrogen) in outlets compared to inlets. Acidic waters at coniferous sites may have stimulated more MeHg production than in mixed woodland regions. Lower methylation efficiencies in older ponds (> 20 years old) may be due to the degradation of less labile organic matter as ponds age. Beavers actively alter watersheds by building impoundments, and our findings indicate that this landscape disturbance may be a significant source of MeHg to downstream water bodies.

Frozen ponds

DEFF Research Database (Denmark)

Langer, M; Westermann, S.; Anthony, K. Walter

2015-01-01

to a warming climate are complex and only poorly understood. Small waterbodies have been attracting an increasing amount of attention since recent studies demonstrated that ponds can make a significant contribution to the CO2 and CH4emissions of tundra ecosystems. Waterbodies also have a marked effect...... on the thermal state of the surrounding permafrost; during the freezing period they prolong the period of time during which thawed soil material is available for microbial decomposition.  This study presents net CH4 production rates during the freezing period from ponds within a typical lowland tundra landscape...

Leaching of radium from mine deposits - application for planning of ground reclamation

International Nuclear Information System (INIS)

Chalupnik, S.

2002-01-01

Saline waters occurring in underground coal mines in Poland often contain natural radioactive isotopes, mainly 226 Ra from uranium series and 228 Ra from thorium series. Approximately 40% of total amount of radium remains underground in a form of radioactive deposits, but 225 MBq of 226 Ra and 400 MBq of 228 Ra are released daily into the rivers with mine effluents through surface settling ponds. Very peculiar situation is observed in coal mines, where as a result of precipitation of radium from radium-bearing waters radioactive deposits are formed. Sometimes natural radioactivity of such materials is very high, in case of scaling from coal mines radium concentration may reach 400000 Bq/kg - similar activity as for 3% uranium ore. Usually such deposits can be found underground, but sometimes co-precipitation of radium and barium takes place on the surface, in settling pond and in rivers. Therefore maintenance of solid and liquid waste with technologically enhanced natural radioactivity (TENORM) is a very important subject. Lately another problem appeared - due to the decrease of the production in Poland coal industry and dismantling of several coal mines, also the ground reclamation should be done in their vicinity. But in several cases deposits in the ponds contain enhanced levels of radium concentration. Therefore laboratory tests were done to investigate a possibility of the re-entry of radium into ground water or river waters from such deposits. Results show, that in the case of insoluble barium and radium sulphates co-precipitated out from waters type A, re-entry ratio is very small. Different situation can be observed in case of radium, adsorbed on bottom of sediments from waters type B, because re-entry ratio is much higher. Nevertheless, this phenomenon seems to be not so important and significant for the further pollution of the adjacent areas of the settling ponds in the future. (author)

Aquatic studies of Gable Mountain Pond

International Nuclear Information System (INIS)

Cushing, C.E.; Watson, D.G.

1974-12-01

Studies of the biotic and abiotic components of the Gable Mountain Pond (HAPO cooling water disposal pond) ecosystem were undertaken to determine if there was a potential problem for off-site transfer of radioactivity to man originating with the aquatic food web. Most of the 137 Cs in the pond is associated with the sediments which are probably the main source of 137 Cs for uptake by the biota. Generally, highest concentrations of 137 Cs and other radioisotopes were found in the upper two inches of sediments in the northwest end of the pond and in the deeper areas along the long-axis of the pond. Native goldfish had maximum and average 137 Cs concentrations of about 340 and 170 pCi/g dry wt, respectively. Algae, macrophytes, and detritus comprised the main food items of the goldfish, and the 137 Cs levels in the plants were usually higher than the 137 Cs concentration in the fish. The 137 Cs concentrations of wild experimental ducks restricted to Gable Mountain Pond were approximately the same as resident coots, but significantly higher than transient wild ducks. Neither the goldfish nor the waterfowl inhabiting the pond attained concentrations of 137 Cs exceeding acceptable limits. Sediment, however, could be a source of high concentrations of radioactivity or radioactive contamination concern if the concentration of radiocontaminants increased and/or the pond dries up, and the contaminated sediments become windborne. (U.S.)

Estuarine Sediment Deposition during Wetland Restoration: A GIS and Remote Sensing Modeling Approach

Science.gov (United States)

Newcomer, Michelle; Kuss, Amber; Kentron, Tyler; Remar, Alex; Choksi, Vivek; Skiles, J. W.

2011-01-01

Restoration of the industrial salt flats in the San Francisco Bay, California is an ongoing wetland rehabilitation project. Remote sensing maps of suspended sediment concentration, and other GIS predictor variables were used to model sediment deposition within these recently restored ponds. Suspended sediment concentrations were calibrated to reflectance values from Landsat TM 5 and ASTER using three statistical techniques -- linear regression, multivariate regression, and an Artificial Neural Network (ANN), to map suspended sediment concentrations. Multivariate and ANN regressions using ASTER proved to be the most accurate methods, yielding r2 values of 0.88 and 0.87, respectively. Predictor variables such as sediment grain size and tidal frequency were used in the Marsh Sedimentation (MARSED) model for predicting deposition rates for three years. MARSED results for a fully restored pond show a root mean square deviation (RMSD) of 66.8 mm (<1) between modeled and field observations. This model was further applied to a pond breached in November 2010 and indicated that the recently breached pond will reach equilibrium levels after 60 months of tidal inundation.

Post-Depositional Behavior of Cu in a Metal-Mining Polishing Pond (East Lake, Canada)

Science.gov (United States)

Martin, A.J.; Jambor, J.L.; Pedersen, Thomas F.; Crusius, J.

2003-01-01

The post-depositional behavior of Cu in a gold-mining polishing pond (East Lake, Canada) was assessed after mine closure by examination of porewater chemistry and mineralogy. The near-surface (upper 1.5 cm) sediments are enriched in Cu, with values ranging from 0.4 to 2 wt %. Mineralogical examination revealed that the bulk of the Cu inventory is present as authigenic copper sulfides. Optical microscopy, energy-dispersion spectra, and X-ray data indicate that the main Cu sulfide is covellite (CuS). The formation of authigenic Cu-S phases is supported by the porewater data, which demonstrate that the sediments are serving as a sink for dissolved Cu below sub-bottom depths of 1-2 cm. The zone of Cu removal is consistent with the occurrence of detectable sulfide and the consumption of sulfate. The sediments can be viewed as a passive bioreactor that permanently removes Cu as insoluble copper sulfides. This process is not unlike that which occurs in other forms of bioremediation, such as wetlands and permeable reactive barriers. Above the zone of Cu removal, dissolved Cu maxima in the interfacial porewaters range from 150 to 450 ??g L-1 and reflect the dissolution of a Cu-bearing phase in the surface sediments. The reactive phase is thought to be a component of treatment sludges delivered to the lake as part of cyanide treatment. Flux calculations indicate that the efflux of dissolved Cu from the sediments to the water column (14-51 ??g cm-2 yr-1) can account for the elevated levels of dissolved Cu in lake waters (???50 ??g L-1). Implications for lake recovery are discussed.

Rapid surface-water volume estimations in beaver ponds

Science.gov (United States)

Karran, Daniel J.; Westbrook, Cherie J.; Wheaton, Joseph M.; Johnston, Carol A.; Bedard-Haughn, Angela

2017-02-01

Beaver ponds are surface-water features that are transient through space and time. Such qualities complicate the inclusion of beaver ponds in local and regional water balances, and in hydrological models, as reliable estimates of surface-water storage are difficult to acquire without time- and labour-intensive topographic surveys. A simpler approach to overcome this challenge is needed, given the abundance of the beaver ponds in North America, Eurasia, and southern South America. We investigated whether simple morphometric characteristics derived from readily available aerial imagery or quickly measured field attributes of beaver ponds can be used to approximate surface-water storage among the range of environmental settings in which beaver ponds are found. Studied were a total of 40 beaver ponds from four different sites in North and South America. The simplified volume-area-depth (V-A-h) approach, originally developed for prairie potholes, was tested. With only two measurements of pond depth and corresponding surface area, this method estimated surface-water storage in beaver ponds within 5 % on average. Beaver pond morphometry was characterized by a median basin coefficient of 0.91, and dam length and pond surface area were strongly correlated with beaver pond storage capacity, regardless of geographic setting. These attributes provide a means for coarsely estimating surface-water storage capacity in beaver ponds. Overall, this research demonstrates that reliable estimates of surface-water storage in beaver ponds only requires simple measurements derived from aerial imagery and/or brief visits to the field. Future research efforts should be directed at incorporating these simple methods into both broader beaver-related tools and catchment-scale hydrological models.

Effect of detention basin release rates on flood flows - Application of a model to the Blackberry Creek Watershed in Kane County, Illinois

Science.gov (United States)

Soong, David T.; Murphy, Elizabeth A.; Straub, Timothy D.

2009-01-01

The effects of stormwater detention basins with specified release rates are examined on the watershed scale with a Hydrological Simulation Program - FORTRAN (HSPF) continuous-simulation model. Modeling procedures for specifying release rates from detention basins with orifice and weir discharge configurations are discussed in this report. To facilitate future detention modeling as a tool for watershed management, a chart relating watershed impervious area to detention volume is presented. The report also presents a case study of the Blackberry Creek watershed in Kane County, Ill., a rapidly urbanizing area seeking to avoid future flood damages from increased urbanization, to illustrate the effects of various detention basin release rates on flood peaks and volumes and flood frequencies. The case study compares flows simulated with a 1996 land-use HSPF model to those simulated with four different 2020 projected land-use HSPF model scenarios - no detention, and detention basins with release rates of 0.08, 0.10, and 0.12 cubic feet per second per acre (ft3/s-acre), respectively. Results of the simulations for 15 locations, which included the downstream ends of all tributaries and various locations along the main stem, showed that a release rate of 0.10 ft3/s-acre, in general, can maintain postdevelopment 100-year peak-flood discharge at a similar magnitude to that of 1996 land-use conditions. Although the release rate is designed to reduce the 100-year peak flow, reduction of the 2-year peak flow is also achieved for a smaller proportion of the peak. Results also showed that the 0.10 ft3/s-acre release rate was less effective in watersheds with relatively high percentages of preexisting (1996) development than in watersheds with less preexisting development.

Thermal performance experiments on ultimate heat sinks, spray ponds, and cooling ponds

International Nuclear Information System (INIS)

Hadlock, R.K.

1976-12-01

A program of measurement on a Battelle-Northwest (BNW) spray pond has been completed to prove an integrated instrumentation system for application in future field experiments. The measurement programs in the field will produce data of relevance to the design and understanding of performance for ultimate heat sinks as components of emergency core cooling systems. In the absence of active emergency cooling systems, the data will be obtained on analog systems--prime candidates among these are the naturally-occurring hot ponds at Yellowstone National Park and man-made hot cooling ponds at Savannah River National Laboratory as well as spray ponds at various industrial facilities. The proof experiment has provided data that not only illustrate the effectiveness of the instrumentation system but also display interesting site-specific heat transfer processes. The data to be obtained in the field will also be site specific but must be of generic applicability in modeling for design and performance purposes. The integrated instrumentation system will evolve, through modest modifications and substantial supplementation, to provide the requisite data for the more demanding situation of work in and about hot water

100-D Ponds closure plan. Revision 1

International Nuclear Information System (INIS)

Petersen, S.W.

1997-09-01

The 100-D Ponds is a Treatment, Storage, and Disposal (TSD) unit on the Hanford Facility that received both dangerous and nonregulated waste. This Closure Plan (Rev. 1) for the 100-D Ponds TSD unit consists of a RCRA Part A Dangerous Waste Permit Application (Rev. 3), a RCRA Closure Plan, and supporting information contained in the appendices to the plan. The closure plan consists of eight chapters containing facility description, process information, waste characteristics, and groundwater monitoring data. There are also chapters containing the closure strategy and performance standards. The strategy for the closure of the 100-D Ponds TSD unit is clean closure. Appendices A and B of the closure plan demonstrate that soil and groundwater beneath 100-D Ponds are below cleanup limits. All dangerous wastes or dangerous waste constituents or residues associated with the operation of the ponds have been removed, therefore, human health and the environment are protected. Discharges to the 100-D Ponds, which are located in the 100-DR-1 operable unit, were discontinued in June 1994. Contaminated sediment was removed from the ponds in August 1996. Subsequent sampling and analysis demonstrated that there is no contamination remaining in the ponds, therefore, this closure plan is a demonstration of clean closure

Diel changes in water chemistry in an arsenic-rich stream and treatment-pond system

Science.gov (United States)

Gammons, C.H.; Grant, T.M.; Nimick, D.A.; Parker, S.R.; DeGrandpre, M.D.

2007-01-01

Arsenic concentrations are elevated in surface waters of the Warm Springs Ponds Operable Unit (WSPOU), located at the head of the upper Clark Fork River Superfund site, Montana, USA. Arsenic is derived from historical deposition of smelter emissions (Mill and Willow Creeks) and historical mining and milling wastes (Silver Bow Creek). Although long-term monitoring has characterized the general seasonal and flow-related trends in As concentrations in these streams and the pond system used to treat Silver Bow Creek water, little is known about solubility controls and sorption processes that influence diel cycles in As concentrations. Diel (24-h) sampling was conducted in July 2004 and August 2005 at the outlet of the treatment ponds, at two locations along a nearby reconstructed stream channel that diverts tributary water around the ponds, and at Silver Bow Creek 2??km below the ponds. Dissolved As concentration increased up to 51% during the day at most of the stream sites, whereas little or no diel change was displayed at the treatment-pond outlet. The strong cycle in streams is explained by pH- and temperature-dependent sorption of As onto hydrous metal oxides or biofilms on the streambed. Concentrations of dissolved Ca2+ and HCO3- at the stream sites showed a diel temporal pattern opposite to that of As, and geochemical modeling supports the hypothesis that the concentrations of Ca2+ and HCO3- were controlled by precipitation of calcite during the warm afternoon hours when pH rose above 9.0. Nightly increases in dissolved Mn and Fe(II) concentrations were out of phase with concentrations of other divalent cations and are more likely explained by redox phenomena. ?? 2007 Elsevier B.V. All rights reserved.

Detention Outlet Retrofit Improves the Functionality of Existing ...

Science.gov (United States)

Journal Article Provide a stormwater management device for States and watershed management organizations. By discharging excess stormwater runoff at rates that more frequently exceed the critical flow for stream channel erosion, conventional detention basins often contribute to the escalated levels of instability that are common in urban and suburban streams and can be detrimental to aquatic habitat and water quality, as well as adjacent property and infrastructure. However, these ubiquitous assets, valued at ca. $600,000/km2 in a representative suburban watershed in Northern Kentucky, are ideal candidates to aid in reversing such cycles of channel degradation because improving their functionality would not necessarily require property acquisition or heavy construction. The objective of this research was to develop a simple, cost-effective device that could be installed in detention basin outlets to reduce the erosive power of the relatively frequent, but otherwise erosive, storm events (e.g. ~ ≤ 2-yr recurrence) and provide a passive bypass to maintain flood control performance during infrequent storms (e.g. 100-yr recurrence). Results from a pilot installation show that the Detain H2O device can not only meet these goals, but can also contribute to reduced flashiness and prolonged baseflows in receiving streams. When scaling the strategy across a watershed, these results suggest that substantial gains in water quality and stream channel stability could b

Trauma and psychological distress in Latino citizen children following parental detention and deportation.

Science.gov (United States)

Rojas-Flores, Lisseth; Clements, Mari L; Hwang Koo, J; London, Judy

2017-05-01

The mental health impact of parental detention and deportation on citizen children is a topic of increasing concern. Forced parent-child separation and parental loss are potentially traumatic events (PTEs) with adverse effects on children's mental health. This study examines posttraumatic stress disorder (PTSD) symptoms and psychological distress among 91 Latino U.S.-born children (ages 6 to 12), living in mixed-status families with a least 1 undocumented parent at risk for detention or deportation. Multiagent (child, parent, teacher, clinician) and standardized assessments were conducted at baseline to assess for child trauma and psychological distress. Analyses indicate that PTSD symptoms as reported by parent were significantly higher for children of detained and deported parents compared to citizen children whose parents were either legal permanent residents or undocumented without prior contact with immigration enforcement. Similarly, findings revealed differences in child internalizing problems associated with parental detention and deportation as reported by parent as well as differences in overall child functioning as reported by clinician. In addition, teachers reported higher externalizing for children with more exposure to PTEs. These findings lend support to a reconsideration and revision of immigration enforcement practices to take into consideration the best interest of Latino citizen children. Trauma-informed assessments and interventions are recommended for this special population. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Fuel particles in the Chernobyl cooling pond: current state and prediction for remediation options

International Nuclear Information System (INIS)

Bulgakov, A.; Konoplev, A.; Smith, J.; Laptev, G.; Voitsekhovich, O.

2009-01-01

During the coming years, a management and remediation strategy for the Chernobyl cooling pond (CP) will be implemented. Remediation options include a controlled reduction in surface water level of the cooling pond and stabilisation of exposed sediments. In terrestrial soils, fuel particles deposited during the Chernobyl accident have now almost completely disintegrated. However, in the CP sediments the majority of 90 Sr activity is still in the form of fuel particles. Due to the low dissolved oxygen concentration and high pH, dissolution of fuel particles in the CP sediments is significantly slower than in soils. After the planned cessation of water pumping from the Pripyat River to the Pond, significant areas of sediments will be drained and exposed to the air. This will significantly enhance the dissolution rate and, correspondingly, the mobility and bioavailability of radionuclides will increase with time. The rate of acidification of exposed bottom sediments was predicted on the basis of acidification of similar soils after liming. Using empirical equations relating the fuel particle dissolution rate to soil and sediment pH allowed prediction of fuel particle dissolution and 90 Sr mobilisation for different remediation scenarios. It is shown that in exposed sediments, fuel particles will be almost completely dissolved in 15-25 years, while in parts of the cooling pond which remain flooded, fuel particle dissolution will take about a century

Par Pond vegetation status Summer 1995 -- Summary

International Nuclear Information System (INIS)

Mackey, H.E. Jr.; Riley, R.S.

1996-01-01

The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995. Communities similar to the pre-drawdown, Par Pond aquatic plant communities are becoming re-established. Emergent beds of maidencane, lotus, waterlily, and watershield are extensive and well developed. Cattail occurrence continued to increase during the summer, but large beds common to Par Pond prior to the drawdown have not formed. Estimates from SPOT HRV, remote sensing satellite data indicated that as much as 120 hectares of emergent wetlands vegetation may have been present along the Par Pond shoreline by early October, 1995. To track the continued development of macrophytes in Par Pond, future surveys throughout 1996 and 1997, along with the continued evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned

Technical manual for calculating cooling pond performance

International Nuclear Information System (INIS)

Krstulovich, S.F.

1988-01-01

This manual is produced in response to a growing number of requests for a technical aid to explain methods for simulating cooling pond performance. As such, it is a compilation of reports, charts and graphs developed through the years for use in analyzing situations. Section II contains a report summarizing the factors affecting cooling pond performance and lists statistical parameters used in developing performance simulations. Section III contains the graphs of simulated cooling pond performance on an hourly basis for various combinations of criteria (wind, solar, depth, air temperature and humidity) developed from the report in Section II. Section IV contains correspondence describing how to develop further data from the graphs in Section III, as well as mathematical models for the system of performance calculation. Section V contains the formulas used to simulate cooling pond performances in a cascade arrangement, such as the Fermilab Main Ring ponds. Section VI contains the calculations currently in use to evaluate the Main Ring pond performance based on current flows and Watts loadings. Section VII contains the overall site drawing of the Main Ring cooling ponds with thermal analysis and physical data

9 CFR 381.210 - Poultry and other articles subject to administrative detention.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Poultry and other articles subject to..., DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION POULTRY PRODUCTS INSPECTION REGULATIONS Detention; Seizure...

Wintertime Emissions from Produced Water Ponds

Science.gov (United States)

Evans, J.; Lyman, S.; Mansfield, M. L.

2013-12-01

Every year oil and gas drilling in the U.S. generates billions of barrels of produced water (water brought to the surface during oil or gas production). Efficiently disposing of produced water presents a constant financial challenge for producers. The most noticeable disposal method in eastern Utah's Uintah Basin is the use of evaporation ponds. There are 427 acres of produced water ponds in the Uintah Basin, and these were used to evaporate more than 5 million barrels of produced water in 2012, 6% of all produced water in the Basin. Ozone concentrations exceeding EPA standards have been observed in the Uintah Basin during winter inversion conditions, with daily maximum 8 hour average concentrations at some research sites exceeding 150 parts per billion. Produced water contains ozone-forming volatile organic compounds (VOC) which escape into the atmosphere as the water is evaporated, potentially contributing to air quality problems. No peer-reviewed study of VOC emissions from produced water ponds has been reported, and filling this gap is essential for the development of accurate emissions inventories for the Uintah Basin and other air sheds with oil and gas production. Methane, carbon dioxide, and VOC emissions were measured at three separate pond facilities in the Uintah Basin in February and March of 2013 using a dynamic flux chamber. Pond emissions vary with meteorological conditions, so measurements of VOC emissions were collected during winter to obtain data relevant to periods of high ozone production. Much of the pond area at evaporation facilities was frozen during the study period, but areas that actively received water from trucks remained unfrozen. These areas accounted for 99.2% of total emissions but only 9.5% of the total pond area on average. Ice and snow on frozen ponds served as a cap, prohibiting VOC from being emitted into the atmosphere. Emissions of benzene, toluene, and other aromatic VOCs averaged over 150 mg m-2 h-1 from unfrozen pond

Beaver ponds' impact on fluvial processes (Beskid Niski Mts., SE Poland).

Science.gov (United States)

Giriat, Dorota; Gorczyca, Elżbieta; Sobucki, Mateusz

2016-02-15

Beaver (Castor sp.) can change the riverine environment through dam-building and other activities. The European beaver (Castor fiber) was extirpated in Poland by the nineteenth century, but populations are again present as a result of reintroductions that began in 1974. The goal of this paper is to assess the impact of beaver activity on montane fluvial system development by identifying and analysing changes in channel and valley morphology following expansion of beaver into a 7.5 km-long headwater reach of the upper Wisłoka River in southeast Poland. We document the distribution of beaver in the reach, the change in river profile, sedimentation type and storage in beaver ponds, and assess how beaver dams and ponds have altered channel and valley bottom morphology. The upper Wisłoka River fluvial system underwent a series of anthropogenic disturbances during the last few centuries. The rapid spread of C. fiber in the upper Wisłoka River valley was promoted by the valley's morphology, including a low-gradient channel and silty-sand deposits in the valley bottom. At the time of our survey (2011), beaver ponds occupied 17% of the length of the study reach channel. Two types of beaver dams were noted: in-channel dams and valley-wide dams. The primary effect of dams, investigated in an intensively studied 300-m long subreach (Radocyna Pond), was a change in the longitudinal profile from smooth to stepped, a local reduction of the water surface slope, and an increase in the variability of both the thalweg profile and surface water depths. We estimate the current rate of sedimentation in beaver ponds to be about 14 cm per year. A three-stage scheme of fluvial processes in the longitudinal and transverse profile of the river channel is proposed. C. fiber reintroduction may be considered as another important stage of the upper Wisłoka fluvial system development. Copyright © 2015 Elsevier B.V. All rights reserved.

Solar pond conception - experimental and theoretical studies

Energy Technology Data Exchange (ETDEWEB)

Kurt, Huseyin [Zonguldak Karaelmas Univ., Technical Education Faculty, Karabuk (Turkey); Halici, Fethi [Sakarya Univ., Mechanical Engineering Dept., Adapazari (Turkey); Binark, A. Korhan [Marmara Univ., Technical Education Faculty, Istanbul (Turkey)

2000-07-01

A one dimensional transient mathematical model for predicting the thermal performance of the salt gradient solar pond is developed and presented. In this paper, the natural solar ponds and different artificial solar pond systems found in the literature are introduced. Necessary modifications are made on the experimental stand located in Istanbul Technical University, the experimental stand is introduced and natural phenomena produced in the pond by the different solar pond variations under natural conditions are observed. In the theoretical work based on a one dimensional unsteady state heat conduction model with internal heat generation, the energy and mass balance equations for the upper convective zone, the non-convective zone and the lower convective zone, all of which form the solar pond, are written in terms of differential equations. These equations are solved analytically and numerically. The results obtained from the analysis are compared with the experimental results. The temperature and the concentration profiles are separately presented in the figures. (Author)

78 FR 42381 - Administrative Detention of Drugs Intended for Human or Animal Use

Science.gov (United States)

2013-07-15

... to all interested persons in a timely fashion. The 30-day public docket closed on May 9, 2013. FDA... detained drug, may be incurred if FDA revokes the detention order on appeal. Given the history of...

Walden Pond, Massachusetts: Environmental Setting and Current Investigations

Science.gov (United States)

Colman, John A.; Waldron, Marcus C.

1998-01-01

Introduction Walden Pond, in Concord, Massachusetts, is famous among lakes because of its unique social history. Walden was the setting for American naturalist Henry David Thoreau's well-known essay 'Walden; or, Life in the Woods,' first published in 1854. Thoreau lived and wrote at Walden Pond from July 1845 to September 1847. In 'Walden,' Thoreau combined highly admired writing on Transcendental philosophy with pioneering observations of aquatic ecology and physical aspects of limnology, the study of lakes. Because Thoreau also defended so effectively the value of living close to nature in the Walden woods, the pond is considered by many to be the birthplace of the American conservation movement. Visitors come from all over the world to the pond, which has been designated a National Historic Landmark, and its fame has resulted in a major fund drive to preserve the surrounding woods. Walden Pond has no surfacewater inflow or outflow, and much of its ground-water contributing area likely is preserved within the Walden Pond Reservation area (fig. 1). Only 15 miles from Boston, the pond is unusually clear and pristine for an urban-area lake. However, point sources of nutrients near the pond, and a large annual visitor attendance, concentrated during the summer when the swimming beach (fig. 2) is open, may contribute a nutrient load sufficient to change the pond environment. The occurrence of nuisance algal species, a recent beach closing, and an awareness of water-quality problems suffered by other ponds in the region raise concerns about the risk of ecological change at Walden Pond. Despite the role of Walden Pond as a cultural and environmental icon, little is known about the pond's ecological features, such as its internal nutrient cycling or the structure of its food web, nor have consistent measurements been made to determine whether these features are changing or are stable. Production rates of aquatic plants in lakes and ponds naturally undergo a slow increase

Par Pond phytoplankton in association with refilling of the pond: Final Report for sampling from February 1995 -- September 1996

International Nuclear Information System (INIS)

Wilde, E.W.; Johnson, M.A.; Cody, W.C.

1996-01-01

This report describes the results of phytoplankton analyses from Par Pond samples collected between February 1995 and September 1996. The principal objective of the study was to determine the effect of refilling of Par Pond following repair of the dam on the phytoplankton community. Algal blooms are often responsible for fish kills and other detrimental effects in ponds and lakes, and it was postulated that decaying vegetation from formerly exposed sediments might trigger algal blooms that could result in fish kills in Par Pond following the refill. Sporadic algal blooms involving blue-green algae were detected, especially during the summer of 1996. However, the data derived from the study demonstrates that overall, the refilling effort caused no significant negative impact to the pond attributable to phytoplankton dynamics

Par Pond phytoplankton in association with refilling of the pond: Final Report for sampling from February 1995 -- September 1996

Energy Technology Data Exchange (ETDEWEB)

Wilde, E.W.; Johnson, M.A.; Cody, W.C.

1996-12-31

This report describes the results of phytoplankton analyses from Par Pond samples collected between February 1995 and September 1996. The principal objective of the study was to determine the effect of refilling of Par Pond following repair of the dam on the phytoplankton community. Algal blooms are often responsible for fish kills and other detrimental effects in ponds and lakes, and it was postulated that decaying vegetation from formerly exposed sediments might trigger algal blooms that could result in fish kills in Par Pond following the refill. Sporadic algal blooms involving blue-green algae were detected, especially during the summer of 1996. However, the data derived from the study demonstrates that overall, the refilling effort caused no significant negative impact to the pond attributable to phytoplankton dynamics.

The refreezing of melt ponds on Arctic sea ice

Science.gov (United States)

Flocco, Daniela; Feltham, Daniel L.; Bailey, Eleanor; Schroeder, David

2015-02-01

The presence of melt ponds on the surface of Arctic sea ice significantly reduces its albedo, inducing a positive feedback leading to sea ice thinning. While the role of melt ponds in enhancing the summer melt of sea ice is well known, their impact on suppressing winter freezing of sea ice has, hitherto, received less attention. Melt ponds freeze by forming an ice lid at the upper surface, which insulates them from the atmosphere and traps pond water between the underlying sea ice and the ice lid. The pond water is a store of latent heat, which is released during refreezing. Until a pond freezes completely, there can be minimal ice growth at the base of the underlying sea ice. In this work, we present a model of the refreezing of a melt pond that includes the heat and salt balances in the ice lid, trapped pond, and underlying sea ice. The model uses a two-stream radiation model to account for radiative scattering at phase boundaries. Simulations and related sensitivity studies suggest that trapped pond water may survive for over a month. We focus on the role that pond salinity has on delaying the refreezing process and retarding basal sea ice growth. We estimate that for a typical sea ice pond coverage in autumn, excluding the impact of trapped ponds in models overestimates ice growth by up to 265 million km3, an overestimate of 26%.

Transient peat properties in two pond-peatland complexes in the sub-humid Western Boreal Plain, Canada

Directory of Open Access Journals (Sweden)

R.M. Petrone

2008-03-01

Full Text Available In the Canadian Western Boreal Plain (WBP, wetlands (ponds and peatlands comprise up to 50% of the landscape and represent unique habitat where summer precipitation is often outpaced by evapotranspiration and hillslope groundwater position does not follow topography. In this sub-humid location, groundwater fluxes and stores in riparian peatlands influence pond water levels and root zone moisture sources for forested uplands. To accurately describe the transport and retention of water in peat, it is important to consider peat subsidence. This paper quantifies the amount and effect of seasonal subsidence in a riparian peatland in the Utikuma Lake region in north-central Alberta, Canada. Results demonstrate that the deep and poorly decomposed peat deposits are resistant to compression, and that thick (and persistent ground frost hinders pore collapse (shrinkage above the water table until late summer when the ground has thawed. Even then, subsidence is still limited to the top 50 cm and is not closely related to changes in peatland water table or pond water level. Thus the water balance of these ponds and riparian areas appears to be less sensitive to peat volume changes than it is to the persistence of a substantial frost layer well into the snow-free period.

CO₂ efflux from shrimp ponds in Indonesia.

Science.gov (United States)

Sidik, Frida; Lovelock, Catherine E

2013-01-01

The conversion of mangrove forest to aquaculture ponds has been increasing in recent decades. One of major concerns of this habitat loss is the release of stored 'blue' carbon from mangrove soils to the atmosphere. In this study, we assessed carbon dioxide (CO₂) efflux from soil in intensive shrimp ponds in Bali, Indonesia. We measured CO₂ efflux from the floors and walls of shrimp ponds. Rates of CO₂ efflux within shrimp ponds were 4.37 kg CO₂ m⁻² y⁻¹ from the walls and 1.60 kg CO₂ m⁻² y⁻¹ from the floors. Combining our findings with published data of aquaculture land use in Indonesia, we estimated that shrimp ponds in this region result in CO₂ emissions to the atmosphere between 5.76 and 13.95 Tg y⁻¹. The results indicate that conversion of mangrove forests to aquaculture ponds contributes to greenhouse gas emissions that are comparable to peat forest conversion to other land uses in Indonesia. Higher magnitudes of CO₂ emission may be released to atmosphere where ponds are constructed in newly cleared mangrove forests. This study indicates the need for incentives that can meet the target of aquaculture industry without expanding the converted mangrove areas, which will lead to increased CO₂ released to atmosphere.

CO₂ efflux from shrimp ponds in Indonesia.

Directory of Open Access Journals (Sweden)

Frida Sidik

Full Text Available The conversion of mangrove forest to aquaculture ponds has been increasing in recent decades. One of major concerns of this habitat loss is the release of stored 'blue' carbon from mangrove soils to the atmosphere. In this study, we assessed carbon dioxide (CO₂ efflux from soil in intensive shrimp ponds in Bali, Indonesia. We measured CO₂ efflux from the floors and walls of shrimp ponds. Rates of CO₂ efflux within shrimp ponds were 4.37 kg CO₂ m⁻² y⁻¹ from the walls and 1.60 kg CO₂ m⁻² y⁻¹ from the floors. Combining our findings with published data of aquaculture land use in Indonesia, we estimated that shrimp ponds in this region result in CO₂ emissions to the atmosphere between 5.76 and 13.95 Tg y⁻¹. The results indicate that conversion of mangrove forests to aquaculture ponds contributes to greenhouse gas emissions that are comparable to peat forest conversion to other land uses in Indonesia. Higher magnitudes of CO₂ emission may be released to atmosphere where ponds are constructed in newly cleared mangrove forests. This study indicates the need for incentives that can meet the target of aquaculture industry without expanding the converted mangrove areas, which will lead to increased CO₂ released to atmosphere.

The Pond Is Our Laboratory

Science.gov (United States)

Marchewka, Barbara Turco

1978-01-01

This science teacher's laboratory is a pond within walking distance of his school that provides a stimulating environment for exploring the natural world. With simple materials students practice making careful observations, taking measurements and compiling and graphing information for their science studies. They also extend their pond experiences…

Pond of Illusion: Interacting through Mixed Reality

DEFF Research Database (Denmark)

Nobel-Jørgensen, Morten; Nielsen, Jannik Boll; Larsen, Anders Boesen Lindbo

2013-01-01

Pond of Illusion is a mixed reality installation where a virtual space (the pond) is injected between two real spaces. The users are in either of the real spaces, and they can see each other through windows in the virtual space as illustrated in Figure 1(left). The installation attracts people...... to a large display in either of the real spaces by allowing them to feed virtual fish swimming in the pond. Figure 1(middle) shows how a Microsoft Kinect mounted on top of the display is used for detecting throw motions, which triggers virtual breadcrumbs to be thrown into the pond for feeding the nearby...... fish. Of course, the fish may not be available because they are busy eating what people have thrown into the pond from the other side....

The color of melt ponds on Arctic sea ice

Science.gov (United States)

Lu, Peng; Leppäranta, Matti; Cheng, Bin; Li, Zhijun; Istomina, Larysa; Heygster, Georg

2018-04-01

Pond color, which creates the visual appearance of melt ponds on Arctic sea ice in summer, is quantitatively investigated using a two-stream radiative transfer model for ponded sea ice. The upwelling irradiance from the pond surface is determined and then its spectrum is transformed into RGB (red, green, blue) color space using a colorimetric method. The dependence of pond color on various factors such as water and ice properties and incident solar radiation is investigated. The results reveal that increasing underlying ice thickness Hi enhances both the green and blue intensities of pond color, whereas the red intensity is mostly sensitive to Hi for thin ice (Hi 1.5 m), similar to the behavior of melt-pond albedo. The distribution of the incident solar spectrum F0 with wavelength affects the pond color rather than its intensity. The pond color changes from dark blue to brighter blue with increasing scattering in ice, and the influence of absorption in ice on pond color is limited. The pond color reproduced by the model agrees with field observations for Arctic sea ice in summer, which supports the validity of this study. More importantly, the pond color has been confirmed to contain information about meltwater and underlying ice, and therefore it can be used as an index to retrieve Hi and Hp. Retrievals of Hi for thin ice (Hi measurements than retrievals for thick ice, but those of Hp are not good. The analysis of pond color is a new potential method to obtain thin ice thickness in summer, although more validation data and improvements to the radiative transfer model will be needed in future.

Examining Water Quality Variations of Tidal Pond System

Science.gov (United States)

Chui, T. F. M.; Cui, W.

2014-12-01

Brackish tidal shrimp ponds, traditionally referred to as gei wais, have been constructed along coastal areas in many parts of the world. The regular exchange of pond water with the surrounding coastal environment is important as it brings shrimp larvae and nutrients, etc. into and out of the pond. Such a water exchange can reduce the quality of the receiving waters; though there are opposing views recently because farming practices are becoming more sustainable while other sources of pollutions in the surroundings are increasing. This project monitors the water quality of a tidal shrimp pond and its receiving water at high temporal resolution. The pond is located within the wetland complex of Mai Po Nature Reserve in Hong Kong, China. Water quality parameters (i.e., dissolved oxygen, temperature, salinity, pH, water depth and chlorophyll) were recorded at 15-minute interval from December 2013 to March 2014 within the pond and also at its receiving water which is a water channel within a mangrove forest. Data reveals both daily and fortnightly fluctuations. Daily variations in mangrove correspond to both tidal flushing and insolation, whereas those within the pond correspond mainly to insolation. For example, dissolved oxygen in mangrove shows two peaks daily which correlate with tidal elevation, and that within the pond shows only one peak which correlates with sunlight. Dissolved oxygen within the pond also shows a fortnightly pattern that corresponds to the schedule of water exchange. Such high temporal resolution of monitoring reveals the two-way water quality influences between the pond and the mangrove. It sheds insights that can possibly lead to refinement of water exchange practice and water sampling schedule given the temporal variations of the water quality both inside and outside the pond. It thus enables us to take a step closer in adopting more sustainable farming practices despite increasing pollution in the surrounding areas.

Design and Application of a Solar Mobile Pond Aquaculture Water Quality-Regulation Machine Based in Bream Pond Aquaculture.

Science.gov (United States)

Liu, Xingguo; Xu, Hao; Ma, Zhuojun; Zhang, Yongjun; Tian, Changfeng; Cheng, Guofeng; Zou, Haisheng; Lu, Shimin; Liu, Shijing; Tang, Rong

2016-01-01

Bream pond aquaculture plays a very important role in China's aquaculture industry and is the main source of aquatic products. To regulate and control pond water quality and sediment, a movable solar pond aquaculture water quality regulation machine (SMWM) was designed and used. This machine is solar-powered and moves on water, and its primary components are a solar power supply device, a sediment lifting device, a mechanism for walking on the water's surface and a control system. The solar power supply device provides power for the machine, and the water walking mechanism drives the machine's motion on the water. The sediment lifting device orbits the main section of the machine and affects a large area of the pond. Tests of the machine's mechanical properties revealed that the minimum illumination necessary for the SMWM to function is 13,000 Lx and that its stable speed on the water is 0.02-0.03 m/s. For an illumination of 13,000-52,500 Lx, the sediment lifting device runs at 0.13-0.35 m/s, and its water delivery capacity is 110-208 m(3)/h. The sediment lifting device is able to fold away, and the angle of the suction chamber can be adjusted, making the machine work well in ponds at different water depths from 0.5 m to 2 m. The optimal distance from the sediment lifting device to the bottom of the pond is 10-15 cm. In addition, adjusting the length of the connecting rod and the direction of the traction rope allows the SMWM to work in a pond water area greater than 80%. The analysis of water quality in Wuchang bream (Parabramis pekinensis) and silver carp (Hypophthalmichthys molitrix) culture ponds using the SMWM resulted in decreased NH3(+)-N and available phosphorus concentrations and increased TP concentrations. The TN content and the amount of available phosphorus in the sediment were reduced. In addition, the fish production showed that the SMWM enhanced the yields of Wuchang bream and silver carp by more than 30% and 24%, respectively. These results

Artistry in Lockdown: Transformative Music Experiences for Students in Juvenile Detention

Science.gov (United States)

Marcum, Travis

2014-01-01

In 2009, there were approximately 137,000 court-involved minor children in residential detention and rehabilitation facilities in the United States as a result of committing a crime. Most of these children have no opportunity to participate in music education while serving long-term sentences in residential lockdown. A program in Austin, Texas,…

9 CFR 329.1 - Article or livestock subject to administrative detention.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Article or livestock subject to administrative detention. 329.1 Section 329.1 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... of the provisions of Title I of the Act, any other Federal law, or the laws of any State or Territory...

Renewable energy for the aeration of wastewater ponds.

Science.gov (United States)

Hobus, I; Hegemann, W

2003-01-01

The application of a decentralised renewable energy supply for the aeration of wastewater ponds, and the influence of an unsteady oxygen supply on the specific conversion rate and biocoenose was investigated. With the discontinuous aeration the specific conversion rate is increased as compared to facultative ponds. The estimation of the microorganisms consortia was done with in situ hybridisation techniques. A significant shift in the bacteria population with the chosen specific probes for anaerobic, sulphate reducing and nitrifying bacteria could not be detected. Wastewater ponds have sufficient buffer volume to compensate for the fluctuating energy supply. But the efficiency of the energy supply of a photovoltaic plant decreases in shallow lakes (d photovoltaic and wind power plant, energy management, aeration system and wastewater pond, a simulation model was developed and tested. The application of renewable energy for the aeration of wastewater ponds is a useful alternative for the redevelopment of overloaded ponds as well as the construction of new wastewater ponds, especially in areas with an inadequate central electricity grid and a high availability of wind and solar energy.

Quantifying sediment sources in a lowland agricultural catchment pond using {sup 137}Cs activities and radiogenic {sup 87}Sr/{sup 86}Sr ratios

Energy Technology Data Exchange (ETDEWEB)

Le Gall, Marion; Evrard, Olivier [Laboratoire des Sciences et de l' Environnement, UMR 8212 (CEA/CNRS/UVSQ), Université Paris-Saclay, Domaine du CNRS, Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex (France); Foucher, Anthony [E.A 6293, Laboratoire GéoHydrosystèmes Continentaux (GéHCO), Université F. Rabelais de Tours, Faculté des Sciences et Techniques, Parc de Grandmont, 37200 Tours (France); Laceby, J. Patrick [Laboratoire des Sciences et de l' Environnement, UMR 8212 (CEA/CNRS/UVSQ), Université Paris-Saclay, Domaine du CNRS, Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex (France); Salvador-Blanes, Sébastien [E.A 6293, Laboratoire GéoHydrosystèmes Continentaux (GéHCO), Université F. Rabelais de Tours, Faculté des Sciences et Techniques, Parc de Grandmont, 37200 Tours (France); Thil, François; Dapoigny, Arnaud; Lefèvre, Irène [Laboratoire des Sciences et de l' Environnement, UMR 8212 (CEA/CNRS/UVSQ), Université Paris-Saclay, Domaine du CNRS, Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex (France); Cerdan, Olivier [Département Risques et Prévention, Bureau de Recherches Géologiques et Minières, 3 avenue Claude Guillemin, 45060 Orléans (France); and others

2016-10-01

Soil erosion often supplies high sediment loads to rivers, degrading water quality and contributing to the siltation of reservoirs and lowland river channels. These impacts are exacerbated in agricultural catchments where modifications in land management and agricultural practices were shown to accelerate sediment supply. In this study, sediment sources were identified with a novel tracing approach combining cesium ({sup 137}Cs) and strontium isotopes ({sup 87}Sr/{sup 86}Sr) in the Louroux pond, at the outlet of a lowland cultivated catchment (24 km{sup 2}, Loire River basin, France) representative of drained agricultural areas of Northwestern Europe. Surface soil (n = 36) and subsurface channel bank (n = 17) samples were collected to characterize potential sources. Deposited sediment (n = 41) was sampled across the entire surface of the pond to examine spatial variation in sediment deposits. In addition, a 1.10 m sediment core was sampled in the middle of the pond to reconstruct source variations throughout time. {sup 137}Cs was used to discriminate between surface and subsurface sources, whereas {sup 87}Sr/{sup 86}Sr ratios discriminated between lithological sources. A distribution modeling approach quantified the relative contribution of these sources to the sampled sediment. Results indicate that surface sources contributed to the majority of pond (μ 82%, σ 1%) and core (μ 88%, σ 2%) sediment with elevated subsurface contributions modeled near specific sites close to the banks of the Louroux pond. Contributions of the lithological sources were well mixed in surface sediment across the pond (i.e., carbonate sediment contribution, μ 48%, σ 1% and non-carbonate sediment contribution, μ 52%, σ 3%) although there were significant variations of these source contributions modeled for the sediment core between 1955 and 2013. These fluctuations reflect both the progressive implementation of land consolidation schemes in the catchment and the eutrophication of

Results of submerged sediment core sampling and analysis on Par Pond, Pond C, and L Lake: July 1995

International Nuclear Information System (INIS)

Koch, J.W. II; Martin, F.D.; Friday, G.P.

1996-06-01

Sediment cores from shallow and deep water locations in Par Pond, Pond C, and L Lake were collected and analyzed in 1995 for radioactive and nonradioactive constituents. This core analysis was conducted to develop a defensible characterization of contaminants found in the sediments of Par Pond, Pond C, and L Lake. Mercury was the only nonradiological constituent with a nonestimated quantity that was detected above the U.S Environmental Protection Agency Region IV potential contaminants of concern screening criteria. It was detected at a depth of 0.3--0.6 meters (1.0--2.0 feet) at one location in L Lake. Cesium-137, promethium-146, plutonium-238, and zirconium-95 had significantly higher concentrations in Par Pond sediments than in sediments from the reference sites. Cobalt-60, cesium-137, plutonium-238, plutonium-239/240, and strontium-90 had significantly higher concentrations in L-Lake sediments than sediments from the reference sites

Par Pond Fish, Water, and Sediment Chemistry

International Nuclear Information System (INIS)

Paller, M.H.; Wike, L.D.

1996-06-01

The objectives of this report are to describe the Par Pond fish community and the impact of the drawdown and refill on the community, describe contaminant levels in Par Pond fish, sediments, and water and indicate how contaminant concentrations and distributions were affected by the drawdown and refill, and predict possible effects of future water level fluctuations in Par Pond

Par Pond Fish, Water, and Sediment Chemistry

Energy Technology Data Exchange (ETDEWEB)

Paller, M.H. [Westinghouse Savannah River Company, AIKEN, SC (United States); Wike, L.D.

1996-06-01

The objectives of this report are to describe the Par Pond fish community and the impact of the drawdown and refill on the community, describe contaminant levels in Par Pond fish, sediments, and water and indicate how contaminant concentrations and distributions were affected by the drawdown and refill, and predict possible effects of future water level fluctuations in Par Pond.

100-D Ponds groundwater quality assessment

International Nuclear Information System (INIS)

Hartman, M.J.

1996-01-01

The 100-D Ponds facility is regulated under the Resource Conservation and Recovery Act of 1976. The pH of groundwater in a downgradient well is statistically different than local background, triggering an assessment of groundwater contamination under 40 CFR 265.93. Results of a similar assessment, conducted in 1993, show that the elevated pH is caused by the presence of alkaline ash sediments beneath the ponds, which are not part of the RCRA unit. The 100-D Ponds should remain in indicator evaluation monitoring

ANL-W 779 pond seepage test

International Nuclear Information System (INIS)

Braun, D.R.

1992-11-01

The ANL-W 779 sanitary wastewater treatment ponds are located on the Idaho National Engineering Laboratory (INEL), north of the Argonne National Laboratory -- West (ANL-W) site A seepage test was performed for two Argonne National Laboratory -- West (ANL-W) sanitary wastewater treatment ponds, Facility 779. Seepage rates were measured to determine if the ponds are a wastewater land application facility. The common industry standard for wastewater land application facilities is a field-measured seepage rate of one quarter inch per day or greater

The Impact of Parental Detention on the Psychological Wellbeing of Palestinian Children.

Directory of Open Access Journals (Sweden)

Amer Shehadeh

Full Text Available Since 1967, the Palestinian Occupied Territories are marked by a political conflict between Palestinians and Israel. During this conflict, about one fifth of the Palestinian population has been detained; about one quarter of these are parents. Although we know that father's incarceration might impact their children's psychological wellbeing, little is known about the impact of father's imprisonment on young children (under 11 years old, and when the incarceration is framed in contexts of political conflict. Therefore, this study aimed at gaining insight into the impact of parental detention on young children's psychological wellbeing, and the impact of witnessing the detention process itself.Based on the list of imprisoned Palestinian men with children living in the West Bank, a group of 79 (3- to 10-years old children was randomly composed. Above, through schools and health centers, a comparison sample of 99 children who didn't experience imprisonment of a family member was selected. Mothers of these children completed two cross-culturally validated questionnaires on their children's psychological wellbeing, the UCLA-PTSD-Index and the Strength and Difficulties Questionnaire (SDQ.Results showed higher levels of PTSD and general mental health problems associated with father's capturing. Above, when the children watched the arrest process of their fathers, scores still increased further. Younger children tended to show higher SDQ scores, and children living in villages reported higher posttraumatic stress scores compared to children living in urban areas or refugee camps. Little gender differences were found.This study shows the important impact of parental detention on the psychological wellbeing for young children and urges for more psychological care and support for family members--in particular children--of detainees.

Suicidal behaviors among adolescents in juvenile detention: role of adverse life experiences.

Directory of Open Access Journals (Sweden)

Madhav P Bhatta

Full Text Available PURPOSE: The purpose of this study was to assess the influence of multiple adverse life experiences (sexual abuse, homelessness, running away, and substance abuse in the family on suicide ideation and suicide attempt among adolescents at an urban juvenile detention facility in the United States. MATERIALS AND METHODS: The study sample included a total of 3,156 adolescents processed at a juvenile detention facility in an urban area in Ohio between 2003 and 2007. The participants, interacting anonymously with a voice enabled computer, self-administered a questionnaire with 100 items related to health risk behaviors. RESULTS: Overall 19.0% reported ever having thought about suicide (suicide ideation and 11.9% reported ever having attempted suicide (suicide attempt. In the multivariable logistic regression analysis those reporting sexual abuse (Odds Ratio = 2.75; 95% confidence interval  = 2.08-3.63 and homelessness (1.51; 1.17-1.94 were associated with increased odds of suicide ideation, while sexual abuse (3.01; 2.22-4.08, homelessness (1.49; 1.12-1.98, and running away from home (1.38; 1.06-1.81 were associated with increased odds of a suicide attempt. Those experiencing all four adverse events were 7.81 times more likely (2.41-25.37 to report having ever attempted suicide than those who experienced none of the adverse events. CONCLUSIONS: Considering the high prevalence of adverse life experiences and their association with suicidal behaviors in detained adolescents, these factors should not only be included in the suicide screening tools at the intake and during detention, but should also be used for the intervention programming for suicide prevention.

The Impact of Parental Detention on the Psychological Wellbeing of Palestinian Children.

Science.gov (United States)

Shehadeh, Amer; Loots, Gerrit; Vanderfaeillie, Johan; Derluyn, Ilse

2015-01-01

Since 1967, the Palestinian Occupied Territories are marked by a political conflict between Palestinians and Israel. During this conflict, about one fifth of the Palestinian population has been detained; about one quarter of these are parents. Although we know that father's incarceration might impact their children's psychological wellbeing, little is known about the impact of father's imprisonment on young children (under 11 years old), and when the incarceration is framed in contexts of political conflict. Therefore, this study aimed at gaining insight into the impact of parental detention on young children's psychological wellbeing, and the impact of witnessing the detention process itself. Based on the list of imprisoned Palestinian men with children living in the West Bank, a group of 79 (3- to 10-years old) children was randomly composed. Above, through schools and health centers, a comparison sample of 99 children who didn't experience imprisonment of a family member was selected. Mothers of these children completed two cross-culturally validated questionnaires on their children's psychological wellbeing, the UCLA-PTSD-Index and the Strength and Difficulties Questionnaire (SDQ). Results showed higher levels of PTSD and general mental health problems associated with father's capturing. Above, when the children watched the arrest process of their fathers, scores still increased further. Younger children tended to show higher SDQ scores, and children living in villages reported higher posttraumatic stress scores compared to children living in urban areas or refugee camps. Little gender differences were found. This study shows the important impact of parental detention on the psychological wellbeing for young children and urges for more psychological care and support for family members--in particular children--of detainees.

Site-specific health and safety plan 100-D Pond remediation project

International Nuclear Information System (INIS)

Hobbs, B.J.

1996-06-01

The 100-D Ponds are located north of the northern perimeter fence of the 100-D Area. The ponds were excavated in a preexisting basin that had been used for disposal of coal ash. There are two ponds, one used as a settling pond and the other a percolation pond. Liquid effluent from the 100-D process sewers was discharged to the ponds from 1977 through 1987; after 1987 the ponds received backwash and rinsate from the 100-D water treatment facilities. All discharges to the ponds ceased in June 1994, and the ponds were allowed to dry up

Mechanisms for parasites removal in a waste stabilisation pond.

Science.gov (United States)

Reinoso, Roberto; Blanco, Saúl; Torres-Villamizar, Linda A; Bécares, Eloy

2011-04-01

A waste stabilisation pond (WSP) system formed by two anaerobic ponds, a facultative pond and a maturation pond was studied from December 2003 to September 2004 in north-western Spain in order to evaluate its efficiency in the removal of faecal indicator bacteria (total coliforms, Escherichia coli, faecal streptococci), coliphages, helminth eggs and protozoan (oo)cysts (Cryptosporidium and Giardia). Furthermore, sediment samples were collected from the bottom of the ponds to assess the settling rates and thus determine the main pathogen removal mechanisms in the WSPs system. The overall removal ranged from 1.4 log units for coliphages in the cold period to 5.0 log units for E. coli in the hot period. Cryptosporidium oocysts were reduced by an average of 96%, Giardia cysts by 98% and helminth eggs by 100%. The anaerobic ponds showed significantly higher surface removal rates (4.6, 5.2 and 3.7 log (oo)cysts/eggs removed m(-2) day(-1), respectively) than facultative and maturation ponds. Sunlight and water physicochemical conditions were the main factors influencing C. parvum oocysts removal both in the anaerobic and maturation ponds, whereas other factors like predation or natural mortality were more important in the facultative pond. Sedimentation, the most commonly proposed mechanism for cyst removal had, therefore, a negligible influence in the studied ponds.

Greenhouse Gas Exchange in Small Arctic Thaw Ponds

Science.gov (United States)

Laurion, I.; Bégin, P. N.; Bouchard, F.; Preskienis, V.

2014-12-01

Arctic lakes and ponds can represent up to one quarter of the land surface in permafrost landscapes, particularly in lowland tundra landscapes characterized by ice wedge organic polygons. Thaw ponds can be defined as the aquatic ecosystems associated to thawing of organic soils, either resulting from active layer processes and located above low-center peat polygons (hereafter low-center polygonal or LCP ponds), or resulting from thermokarst slumping above melting ice wedges linked to the accelerated degradation of permafrost (hereafter ice-wedge trough or IWT ponds). These ponds can merge together forming larger water bodies, but with relatively stable shores (hereafter merged polygonal or MPG ponds), and with limnological characteristics similar to LCP ponds. These aquatic systems are very small and shallow, and present a different physical structure than the larger thermokarst lakes, generated after years of development and land subsidence. In a glacier valley on Bylot Island, Nunavut, Canada, thermokarst and kettle lakes together represent 29% of the aquatic area, with a thermal profile resembling those of more standard arctic lakes (mixed epilimnion). The IWT ponds (44% of the area) are stratified for a large fraction of the summer despite their shallowness, while LCP and MPG ponds (27% of the area) show a more homogeneous water column. This will affect gas exchange in these diverse aquatic systems, in addition to their unique microbiota and organic carbon lability that control the production and consumption rates of greenhouse gases. The stratification in IWT ponds generates hypoxic conditions at the bottom, and together with the larger availability of organic carbon, stimulates methanogenesis and limits the mitigating action of methanotrophs. Overall, thaw ponds are largely supersaturated in methane, with IWT ponds dominating the emissions in this landscape (92% of total aquatic emissions estimated for the same valley), and they present large variations in

Valuing Multiple Benefits, and the Public Perception of SUDS Ponds

Directory of Open Access Journals (Sweden)

Joy Jarvie

2017-02-01

Full Text Available Understanding how the public perceive and value ponds is fundamental to appreciate the synergy between Sustainable urban Drainage (SUDS ponds and the multiple benefits they provide. This paper investigates this, through the application of a structured postal and online survey, for a case study area of Edinburgh, in the UK. It compares man-made ponds (including SUDS, and ponds with natural origins. The results from Whole Life Cost show that the benefits (based on Contingent Valuation exceed the CAPEX and OPEX costs for three of five artificial ponds studied. Benefits from natural (reference ponds exceed the replacement costs for a pond with the same surface area/catchment. This paper highlights the importance of monetising the multiple benefits from ponds.

Long-term changes in pond permanence, size, and salinity in Prairie Pothole Region wetlands: The role of groundwater-pond interaction

Science.gov (United States)

LaBaugh, James W.; Rosenberry, Donald O.; Mushet, David M.; Neff, Brian; Nelson, Richard D.; Euliss, Ned H.

2018-01-01

Study RegionCottonwood Lake area wetlands, North Dakota, U.S.A.Study FocusFluctuations in pond permanence, size, and salinity are key features of prairie-pothole wetlands that provide a variety of wetland habitats for waterfowl in the northern prairie of North America. Observation of water-level and salinity fluctuations in a semi-permanent wetland pond over a 20-year period, included periods when the wetland occasionally was dry, as well as wetter years when the pond depth and surface extent doubled while volume increased 10 times.New hydrological insights for the study regionCompared to all other measured budget components, groundwater flow into the pond often contributed the least water (8–28 percent) but the largest amount (>90 percent) of specific solutes to the water and solute budgets of the pond. In drier years flow from the pond into groundwater represented > 10 percent of water loss, and in 1992 was approximately equal to evapotranspiration loss. Also during the drier years, export of calcium, magnesium, sodium, potassium, chloride, and sulfate by flow from the pond to groundwater was substantial compared with previous or subsequent years, a process that would have been undetected if groundwater flux had been calculated as a net value. Independent quantification of water and solute gains and losses were essential to understand controls on water-level and salinity fluctuations in the pond in response to variable climate conditions.

Microbial activities and communities in oil sands tailings ponds

Energy Technology Data Exchange (ETDEWEB)

Gieg, Lisa; Ramos, Esther; Clothier, Lindsay; Bordenave, Sylvain; Lin, Shiping; Voordouw, Gerrit; Dong, Xiaoli; Sensen, Christoph [University of Calgary (Canada)

2011-07-01

This paper discusses how the microbial communities and their activity play a vital role in tailings ponds. The ponds contain microorganisms along with metals, hydrocarbon diluent, naphthenic acid and others. The ponds play an important role in mining operations because they store bitumen extraction waste and also allow water to be re-used in the bitumen extraction process. Pond management presents a few challenges that include, among others, gas emissions and the presence of toxic and corrosive acids. Microbial activities and communities help in managing these ponds. Microbial activity measurement in active and inactive ponds is described and analyzed and the results are presented. The conditions for reducing sulfate, nitrate and iron are also presented. From the results it can be concluded that naphthenic acids can potentially serve as substrates for anaerobic populations in tailings ponds.

Musculoskeletal disorder survey for pond workers

Science.gov (United States)

Maryani, A.; Partiwi, S. G.; Dewi, H. N. F.

2018-04-01

Mucsuloskeletal disorder will affect worker performance and become serious injury when ignored, so that workers cannot work normally. Therefore, an effective strategy plan is needed to reduce the risk of musculoskeletal disorder. A pond worker is profession with high risk of physical complain. Four main activities are ponds preparation, seed distribution, pond maintenance, and harvesting. The methods employed in this current musculoskeletal disorder survey are questionnaire and interview. The result from 73 questionnaires shown that most of pond workers were working for 7 days a week. Prevalence physical complain are on neck, shoulders, upper back, lower back, and knees. The level of perceived complaint is moderate pain. However, most of them do not contact therapists or physicians. Therefore it is necessary to improve the working methods to be able to reduce physical complains due to musculoskeletal disorder.

Preventive detention of sex offenders: the American experience versus international human rights norms.

Science.gov (United States)

Janus, Eric S

2013-01-01

Nearly two decades after the birth of American Sexually Violent Predator (SVP) laws and the tolerant review of their legitimacy by American courts, European courts and international bodies are beginning to develop a jurisprudence of their own with regard to preventive detention. Applying international human rights norms, these bodies have been significantly less tolerant of preventive detention, looking not only at their design but also at their implementation. Simultaneously, American courts are showing the beginnings of a second look at SVP laws, inspired and informed not by promises about the future implementation of newly passed SVP laws, but rather by the sorry record of two decades of implementation. This article examines an American SVP scheme as it has been implemented over 20 years, contrasts the international perspective, and offers some speculation about the path of reform for American SVP schemes. Copyright © 2013 John Wiley & Sons, Ltd.

A case study for biogas generation from covered anaerobic ponds treating abattoir wastewater: Investigation of pond performance and potential biogas production

International Nuclear Information System (INIS)

McCabe, Bernadette K.; Hamawand, Ihsan; Harris, Peter; Baillie, Craig; Yusaf, Talal

2014-01-01

Highlights: • We report on the performance of a novel covered anaerobic pond system. • Potential biogas production was estimated using BioWin modelling software. • Ponds maintained stable operation; however, accumulation of crust was an issue. • Modelling indicated that biogas yield can be influenced by decomposition efficiency. • Configuration and operation of ponds can also impact potential biogas production. - Abstract: Covered anaerobic ponds offer significant advantages to the red meat processing industry by capturing methane rich gas as a fuel source for bioenergy while reducing greenhouse gas emissions (GHG). This paper presents the results of a novel-designed anaerobic pond system at an Australian abattoir in relation to pond performance and potential biogas production. Key findings in assessing the effectiveness of the system revealed that the covered ponds are capable of efficient wastewater decomposition and biogas production. The primary issue with the covered ponds at the abattoir was the build-up of fat/crust that prevented the accurate measurement of biogas and effective use of the cover. In the absence of field biogas data the novel application of the computer modelling software BioWin® was carried out to simulate chemical oxygen demand (COD) removal rates and subsequent biogas yield. The unique parameter used to fit field data was the fraction of the inlet COD due to a superficial crust which did not follow anaerobic digestion. Field data effluent COD removal rates were matched to simulated rates predicted by BioWin when measured influent COD was reduced to 30%. Biogas modelling results suggest significant variation in the economic benefit of biogas energy, with the quantity of biogas potentially varying tenfold (from 328 m 3 /d to 3284 m 3 /d) depending on site factors such as pond efficiency, pond configuration and operational practices

226Ra and 228Ra activities associated with agricultural drainage ponds and wetland ponds in the Kankakee Watershed, Illinois-Indiana, USA

International Nuclear Information System (INIS)

Sidle, W.C.; Shanklin, D.; Lee, P.Y.; Roose, D.L.

2001-01-01

Background radioactivity is elevated in many agricultural drainage ponds and also constructed wetland ponds in the Kankakee watershed. During 1995-1999, gross-α and -β activities were measured up to 455 and 1650 mBq L -1 , respectively. 226 Ra and 228 Ra averaged 139 and 192 mBq L -1 in controlled drainage ponds compared to 53 and 58 mBq L -1 for 226 Ra and 228 Ra, respectively, in native wetland ponds. Analyses of applied ammonium phosphate fertilizers near both native and controlled ponds indicate comparable 226 Ra/ 228 Ra and 228 Ra/ 232 Th activity ratios with only the surface waters in the controlled ponds. For example, 226 Ra/ 228 Ra activity ratios in controlled ponds ranged from 0.79 to 0.91 and group with a local fertilizer batch containing FL phosphate compounds with 226 Ra/ 228 Ra activity ratios of 0.83-1.04. Local soils of the Kankakee watershed have 226 Ra/ 228 Ra activity ratios of 0.54-0.70. Calculated Ra fluxes of waters, in drainage ditches associated with these controlled ponds, for 226 Ra ranged from 0.77 to 9.00 mBq cm -2 d -1 and for 228 Ra ranged from 1.22 to 8.43 mBq cm -2 d -1 . Ra activity gradients were measured beneath these controlled ponds both in agricultural landscapes and in constructed wetlands, all being associated with drainage ditches. Ra had infiltrated to the local water table but was below regulatory maximum contaminant limits. Still, measurable Ra activity was measured downgradient of even the constructed wetlands in the Kankakee watershed, suggesting that the attenuation of Ra was low. However, no Ra excess was observed in the riparian zone or the Kankakee River downgradient of the native wetland ponds

UHS, Ultimate Heat Sink Cooling Pond Analysis

International Nuclear Information System (INIS)

Codell, R.; Nuttle, W.K.

1998-01-01

1 - Description of program or function: Three programs model performance of an ultimate heat sink cooling pond. National Weather Service data is read and analyzed to predict periods of lowest cooling performance and highest evaporative loss. The data is compared to local site data for significant differences. Then the maximum pond temperature is predicted. Five programs model performance of an ultimate heat sink spray pond. The cooling performance, evaporative water loss, and drift water loss as a function of wind speed are estimated for a spray field. These estimates are used in conjunction with National Weather Service data to predict periods of lowest cooling performance and highest evaporative loss. This data is compared to local site data for significant differences. Then the maximum pond temperature is predicted. 2 - Method of solution: The transfer of heat and water vapor is modeled using an equilibrium temperature procedure for an UHS cooling pond. The UHS spray pond model considers heat, mass, and momentum transfer from a single water drop with the surrounding air, and modification of the surrounding air resulting from the heat, mass, and momentum transfer from many drops in different parts of a spray field. 3 - Restrictions on the complexity of the problem: The program SPRCO uses RANF, a uniform random number generator which is an intrinsic function on the CDC. All programs except COMET use the NAMELIST statement, which is non standard. Otherwise these programs conform to the ANSI Fortran 77 standard. The meteorological data scanning procedure requires tens of years of recorded data to be effective. The models and methods, provided as useful tool for UHS analyses of cooling ponds and spray ponds, are intended as guidelines only. Use of these methods does not automatically assure NRC approval, nor are they required procedures for nuclear-power-plant licensing

The uranium mine Key Lake, Canada, as an example of final deposition of radioactive tailings

International Nuclear Information System (INIS)

Schmitz, T.

1984-01-01

The main part of that waste handling system is tailing storage. The other parts include the water storage reservoirs and monitoring ponds. Soil conditions and design features of the tailings pond are described in detail as well as the method of tailings disposal. Finally the method of deposition results in a laminated radioactive tailings deposit and the tailings reach a degree of compactness comparable to concrete. The Key Lake Mining Corporation and its consultants have developed a tailings handling program in order to minimize environmental impact and to take advantage of the natural topography and soil materials in the project area. (orig./HP) [de

Flocculation of retention pond water

International Nuclear Information System (INIS)

Hart, B.T.; McGregor, R.J.

1982-05-01

An integral part of the water management strategy proposed by Ranger Uranium Mining Pty. Ltd. involves the collection of runoff water in a series of retention ponds. This water will subsequently be used in the uranium milling plant or released to Magela Creek. Runoff water collected during the wet season caused a section of Magela Creek to become turbid when it was released. The eroded material causing the turbidity was very highly dispersed and showed little tendency to sediment out in the retention ponds. Results of a preliminary study to determine the feasibility of clarifying retention pond water by flocculation with alum are presented. A concentration of 30 Mg/L alum reduced turbidity from an initial 340 NTU to less than 30 NTU in four hours

PERFORMANCES OF TIGER SHRIMP CULTURE IN ENVIRONMENTALLY FRIENDLY PONDS

Directory of Open Access Journals (Sweden)

Taufik Ahmad

2016-10-01

Full Text Available Mangrove ecosystem plays an obvious role in maintaining the biological balance in the coastal environment where shrimp ponds are usually constructed. The removal of mangroves around shrimp ponds has frequently brought about harvest failure. The study evaluated the performance of tiger shrimp culture in ponds provided with water from a water body where there was mangrove vegetation (hereafter mangrove reservoir. Twelve ponds, each measuring 2,500 m2, were filled with seawater from the mangrove reservoir until the water depth of 100 cm and then stocked with 20-40 PL/m2. In the first six ponds, the bottom water was released into the reservoir when the water depth reached 140 cm and then the water depth was maintained at 100 cm. In the second six ponds, the water was released from the ponds until the water depth reached 60 cm and then refilled with reservoir water until a depth of 100 cm. Both treatment ponds received water from the reservoir which also received the wastewater. The feeds for the shrimps were broadcast into the ponds twice a day to meet the 3% shrimp biomass requirement, which adjusted every other week through sampling. The result showed that mangrove  vegetation is capable of removing excessive nutrients, up to 70% for NO3- N and NH4 +-N, reducing PO4 =-P fluctuation, and producing bioactive  compounds. In the second treatment ponds, shrimp mortality started to occur in day 28 and most died by day 54 after stocking due to white spot disease outbreak. Mass mortality took place 54 days after stocking in two out of six of the first treatment ponds.

Seeking asylum in Australia: immigration detention, human rights and mental health care.

Science.gov (United States)

Newman, Louise; Proctor, Nicholas; Dudley, Michael

2013-08-01

The article aims to discuss the impact of mandatory detention and human rights violations on the mental health of asylum seekers and the implications for psychiatrists and health professionals. Advocacy for human rights and engagement in social debate are core ethical and professional responsibilities. Clinicians need to maintain a focus on ethical obligations.

Educational inclusion in values in a detention centre through a Blog

Directory of Open Access Journals (Sweden)

A. Silla

2016-12-01

Full Text Available The purpose of this educational intervention lies in the new technologies inclusion in a detention minor centre. This initiative consists of using an educational blog in a values teaching and learning process carrying out in the basketball activity. An activity which promotes social values (fellowship, encourage player’s self-esteem, autonomy and motivation, moreover it fosters behaviours of equality and health. The sample was 13 players, all of them from the detention centre of Valencia’s city where the basketball activity takes one day per week. The educational blog is a platform which use wordpress technology, with limited access to the pupils of the centre and with their own activity contents about tasks/complementary activities to the work on the court. It is remarkable that all tasks are related to Real Madrid Foundation (FRM and it is framed in the educational project of FRM (Ortega, 2012. The findings warn that the participation and the access interest to the platform have increased as well as during the practice, it has been experienced a knowledge transfer on the values contents worked on the blog.

Transition in the fractal geometry of Arctic melt ponds

Directory of Open Access Journals (Sweden)

C. Hohenegger

2012-10-01

Full Text Available During the Arctic melt season, the sea ice surface undergoes a remarkable transformation from vast expanses of snow covered ice to complex mosaics of ice and melt ponds. Sea ice albedo, a key parameter in climate modeling, is determined by the complex evolution of melt pond configurations. In fact, ice–albedo feedback has played a major role in the recent declines of the summer Arctic sea ice pack. However, understanding melt pond evolution remains a significant challenge to improving climate projections. By analyzing area–perimeter data from hundreds of thousands of melt ponds, we find here an unexpected separation of scales, where pond fractal dimension D transitions from 1 to 2 around a critical length scale of 100 m² in area. Pond complexity increases rapidly through the transition as smaller ponds coalesce to form large connected regions, and reaches a maximum for ponds larger than 1000 m², whose boundaries resemble space-filling curves, with D ≈ 2. These universal features of Arctic melt pond evolution are similar to phase transitions in statistical physics. The results impact sea ice albedo, the transmitted radiation fields under melting sea ice, the heat balance of sea ice and the upper ocean, and biological productivity such as under ice phytoplankton blooms.

Description of work for 216-U-Pond cone penetrometer demonstration

International Nuclear Information System (INIS)

Kelty, G.G.

1993-01-01

This description of work details the Proposed field activities associated with Cone Penetrometer (CPT) work at the 216-U-10 Pond (U-10 Pond) in the 200 West Area and will serve as a field guide for those performing the work. The U-10 Pond was constructed in 1944 to receive low-level liquid effluent from the various chemical reprocessing facilities within the 200 West Area. The U-10 Pond covered 30 acres and received approximately 4.3 x 10 10 gal of contaminated liquid. Sampling conducted in 1980 indicated that the most significant radionuclides were 90 Sr, 137 Cs, plutonium, and uranium (DOE-RL 1993). The pond was deactivated and stabilized in 1985 with clean fill dirt. The thickness of the stabilization cover is variable across the former pond and ranges between 2 ft near the pond margins and delta area to 8 feet in the deepest section of the pond. The purpose of this work is to establish the extent of contamination beneath the U-10 pond

Sexual risk behavior and pregnancy in detained adolescent females: a study in Dutch detention centers

Directory of Open Access Journals (Sweden)

Jansen Lucres MC

2007-06-01

Full Text Available Abstract Background The purpose of this study was to investigate the lifetime prevalence of teenage pregnancy in the histories of detained adolescent females and to examine the relationship between teenage pregnancy on the one hand and mental health and sexuality related characteristics on the other. Methods Of 256 admitted detained adolescent females aged 12–18 years, a representative sample (N = 212, 83% was examined in the first month of detention. Instruments included a semi-structured interview, standardized questionnaires and file information on pregnancy, sexuality related characteristics (sexual risk behavior, multiple sex partners, sexual trauma, lack of assertiveness in sexual issues and early maturity and mental health characteristics (conduct disorder, alcohol and drug use disorder and suicidality. Results Approximately 20% of the participants reported having been pregnant (before detention, although none had actually given birth. Sexuality related characteristics were more prevalent in the pregnancy group, while this was not so for the mental health characteristics. Age at assessment, early maturity, sexual risk behavior, and suicidality turned out to be the best predictors for pregnancy. Conclusion The lifetime prevalence of pregnancy in detained adolescent females is high and is associated with both sexuality related risk factors and mental health related risk factors. Therefore, prevention and intervention programs targeting sexual risk behavior and mental health are warranted during detention.

The laboratory environmental algae pond simulator (LEAPS) photobioreactor: Validation using outdoor pond cultures of Chlorella sorokiniana and Nannochloropsis salina

Energy Technology Data Exchange (ETDEWEB)

Huesemann, M.; Williams, P.; Edmundson, S.; Chen, P.; Kruk, R.; Cullinan, V.; Crowe, B.; Lundquist, T.

2017-09-01

A bench-scale photobioreactor system, termed Laboratory Environmental Algae Pond Simulator (LEAPS), was designed and constructed to simulate outdoor pond cultivation for a wide range of geographical locations and seasons. The LEAPS consists of six well-mixed glass column photobioreactors sparged with CO2-enriched air to maintain a set-point pH, illuminated from above by a programmable multicolor LED lighting (0 to 2,500 µmol/m2-sec), and submerged in a temperature controlled water-bath (-2 °C to >60 °C). Measured incident light intensities and water temperatures deviated from the respective light and temperature set-points on average only 2.3% and 0.9%, demonstrating accurate simulation of light and temperature conditions measured in outdoor ponds. In order to determine whether microalgae strains cultured in the LEAPS exhibit the same linear phase biomass productivity as in outdoor ponds, Chlorella sorokiniana and Nannochloropsis salina were cultured in the LEAPS bioreactors using light and temperature scripts measured previously in the respective outdoor pond studies. For Chlorella sorokiniana, the summer season biomass productivity in the LEAPS was 6.6% and 11.3% lower than in the respective outdoor ponds in Rimrock, Arizona, and Delhi, California; however, these differences were not statistically significant. For Nannochloropsis salina, the winter season biomass productivity in the LEAPS was statistically significantly higher (15.2%) during the 27 day experimental period than in the respective outdoor ponds in Tucson, Arizona. However, when considering only the first 14 days, the LEAPS biomass productivity was only 9.2% higher than in the outdoor ponds, a difference shown to be not statistically significant. Potential reasons for the positive or negative divergence in LEAPS performance, relative to outdoor ponds, are discussed. To demonstrate the utility of the LEAPS in predicting productivity, two other strains – Scenedesmus obliquus and Stichococcus minor

The western pond turtle: Habitat and history. Final report

International Nuclear Information System (INIS)

Holland, D.C.

1994-08-01

The western pond turtle is known from many areas of Oregon. The majority of sightings and other records occur in the major drainages of the Klamath, Rogue, Umpqua, Willamette and Columbia River systems. A brief overview is presented of the evolution of the Willamette-Puget Sound hydrographic basin. A synopsis is also presented of the natural history of the western pond turtle, as well as, the status of this turtle in the Willamette drainage basin. The reproductive ecology and molecular genetics of the western pond turtle are discussed. Aquatic movements and overwintering of the western pond turtle are evaluated. The effect of introduced turtle species on the status of the western pond turtle was investigated in a central California Pond. Experiments were performed to determine if this turtle could be translocated as a mitigation strategy

Bioaccumulation of heavy metals in two wet retention ponds

DEFF Research Database (Denmark)

Søberg, Laila C.; Vollertsen, Jes; Blecken, Godecke-Tobias

2016-01-01

Metal accumulation in stormwater ponds may contaminate the inhabiting fauna, thus jeopardizing their ecosystem servicing function. We evaluated bioaccumulation of metals in natural fauna and caged mussel indicator organisms in two wet retention ponds. Mussel cages were distributed throughout...... the ponds to detect bioaccumulation gradients and obtain a time-integrated measure of metal bioavailability. We further investigated if sediment metal concentrations correlate with those in the fauna and mussels. Metal concentrations in the fauna tended to be higher in the ponds than in a reference lake......, but statistical significance was only shown for Cu. Positive correlations were found for some metals in fauna and sediment. Sediment metal concentrations in one pond decreased from inlet to outlet while no gradients were observed in the mussels in either pond. These findings indicate that metal accumulation...

Solar pond design for Arabian Gulf conditions

Energy Technology Data Exchange (ETDEWEB)

Hassab, M.A.; Tag, I.A.; Jassim, I.A.; Al-Juburi, F.Y.

1987-01-01

Collection and storage of solar energy in salt gradient solar ponds under conditions of high ambient and ground temperatures and all year-round sunny weather are investigated theoretically. A transient model based on measured local environmental conditions is developed to predict solar transmission, temperature distribution and salt distribution inside the pond for any day of the year. In the model the effects of heat dissipation into the ground, bottom reflection, pond dimensions, load extraction and variation of the pond's physical properties with temperature and concentration are investigated. The generated non-linear coupled system of heat and salt concentration equations for the composite media, considered to have isothermal boundary conditions, is solved numerically using the implicit finite-difference scheme.

Cooling pond fog studies

International Nuclear Information System (INIS)

Hicks, B.B.

1978-01-01

The Fog Excess Water Index (FEWI) method of fog prediction has been verified by the use of data obtained at the Dresden cooling pond during 1976 and 1977 and by a reanalysis of observations made in conjunction with a study of cooling pond simulators during 1974. For applications in which the method is applied to measurements or estimates of bulk water temperature, a critical value of about 0.7 mb appears to be most appropriate. The present analyses confirm the earlier finding that wind speed plays little part in determining the susceptibility for fog generation

Hydrology, water quality, and water-supply potential of ponds at Hunter Army Airfield, Chatham County, Georgia, November 2008-July 2009

Science.gov (United States)

Clarke, John S.; Painter, Jaime A.

2010-01-01

The hydrology, water quality, and water-supply potential of four ponds constructed to capture stormwater runoff at Hunter Army Airfield, Chatham County, Georgia, were evaluated as potential sources of supplemental irrigation supply. The ponds are, Oglethorpe Lake, Halstrum Pond, Wilson Gate Pond, and golf course pond. During the dry season, when irrigation demand is highest, ponds maintain water levels primarily from groundwater seepage. The availability of water from ponds during dry periods is controlled by the permeability of surficial deposits, precipitation and evaporation, and the volume of water stored in the pond. Net groundwater seepage (Gnet) was estimated using a water-budget approach that used onsite and nearby climatic and hydrologic data collected during November-December 2008 including precipitation, evaporation, pond stage, and discharge. Gnet was estimated at three of the four sites?Oglethorpe Lake, Halstrum Pond, and Wilson Gate Pond?during November-December 2008. Pond storage volume in the three ponds ranged from 5.34 to 12.8 million gallons. During November-December 2008, cumulative Gnet ranged from -5.74 gallons per minute (gal/min), indicating a net loss in pond volume, to 19 gal/min, indicating a net gain in pond volume. During several periods of stage recovery, daily Gnet rates were higher than the 2-month cumulative amount, with the highest rates of 178 to 424 gal/min following major rainfall events during limited periods. These high rates may include some contribution from stormwater runoff; more typical recovery rates were from 23 to 223 gal/min. A conservative estimate of the volume of water available for irrigation supply from three of the ponds was provided by computing the rate of depletion of pond volume for a variety of withdrawal rates based on long-term average July precipitation and evaporation and the lowest estimated Gnet rate at each pond. Withdrawal rates of 1,000, 500, and 250 gal/min were applied during an 8-hour daily

Long-term changes in pond permanence, size, and salinity in Prairie Pothole Region wetlands: The role of groundwater-pond interaction

Directory of Open Access Journals (Sweden)

James W. LaBaugh

2018-06-01

New hydrological insights for the study region: Compared to all other measured budget components, groundwater flow into the pond often contributed the least water (8–28 percent but the largest amount (>90 percent of specific solutes to the water and solute budgets of the pond. In drier years flow from the pond into groundwater represented > 10 percent of water loss, and in 1992 was approximately equal to evapotranspiration loss. Also during the drier years, export of calcium, magnesium, sodium, potassium, chloride, and sulfate by flow from the pond to groundwater was substantial compared with previous or subsequent years, a process that would have been undetected if groundwater flux had been calculated as a net value. Independent quantification of water and solute gains and losses were essential to understand controls on water-level and salinity fluctuations in the pond in response to variable climate conditions.

Models and observations of Arctic melt ponds

Science.gov (United States)

Golden, K. M.

2016-12-01

During the Arctic melt season, the sea ice surface undergoes a striking transformation from vast expanses of snow covered ice to complex mosaics of ice and melt ponds. Sea ice albedo, a key parameter in climate modeling, is largely determined by the complex evolution of melt pond configurations. In fact, ice-albedo feedback has played a significant role in the recent declines of the summer Arctic sea ice pack. However, understanding melt pond evolution remains a challenge to improving climate projections. It has been found that as the ponds grow and coalesce, the fractal dimension of their boundaries undergoes a transition from 1 to about 2, around a critical length scale of 100 square meters in area. As the ponds evolve they take complex, self-similar shapes with boundaries resembling space-filling curves. I will outline how mathematical models of composite materials and statistical physics, such as percolation and Ising models, are being used to describe this evolution and predict key geometrical parameters that agree very closely with observations.

19 CFR 12.108 - Detention of articles; time in which to comply.

Science.gov (United States)

2010-04-01

... Sculpture and Murals § 12.108 Detention of articles; time in which to comply. If the importer cannot produce... take the sculpture or mural into Customs custody and send it to a bonded warehouse or public store to... sculpture or mural is taken into Customs custody, or such longer period as may be allowed by the port...

QUALITATIVE COMPOSITION OF PHYTOPLANKTONS IN DIFFERENTLY MANURED CARP PONDS

Directory of Open Access Journals (Sweden)

Ljubica Debeljak

1997-04-01

Full Text Available Researches on qualitative composition of phytoplanktons in differently manured fish-ponds "Jelas" were carried out in 1996. The carp fingerling from larve to its second month was nurtured in three fish-ponds (A,B,C with the plantation of larves of 1,000,000 ind.ha-1. Larves and carp fry were nurtured by trouvit and wheat flour. The fish-pond A was controlled but not manured; the fish-pond B was fertilized by the total of 200 kg.ha-1 NPK (15:15:15 and the fish-pond C was fertilized by the total of 75 l.ha-1 of UAN and 75 kg.l-1 of NP (12:52. All fish-ponds had similar water chemism. In the qualitative composition of phytoplanktons there were stated 93 kinds, members of systematic groups Cyanophyta (10%, Euglenophyta (16.2%, Pyrrophyta (2%, Chrysophyta (39.4% and Chlorophyta (32%. All fish-ponds had similar qualitative composition of phytoplanktons with the flora similarity quotient from 65.5% to 72%.

WWER-type NPP spray ponds screen

International Nuclear Information System (INIS)

Nikolova, M.; Jordanov, M.; Denev, J.; Markov, D.

2003-01-01

The objective of this study is to develop a protection screen of WWER-type NPP spray ponds. The screen design is to ensure reduction of the water droplets blown by the wind and, if possible, their return back to the spray ponds. The cooling capacity of the ponds is not to be changed below the design level for safety reasons. Computational fluid dynamics analysis is used to assess the influence of each design variant on the behavior of the water droplets distribution. Two variants are presented here. The one with plants is found not feasible. The second variant, with steel screen and terrain profile modification is selected for implementation. (author)

The evaporation from ponds in the French Midwest

Directory of Open Access Journals (Sweden)

Mohammad AL DOMANY

2013-12-01

Full Text Available This research shows the results of a study about evaporation in five ponds in the Midwest of France. To realize this study we used climate data from the meteorological station of the Limoges-Bellegarde airport and the data of a weather station installed by us near one of the ponds. We used eight different methods to calculate the evaporation rate and we modified the Penman-Monteith method by replacing the air temperature by water temperature. To understand the role of ponds in water loss through evaporation, we proposed a hypothesis that says : if the pond did not exist, what results would we get? Based on this hypothesis we calculated the potential evapotranspiration rate taking into account the percentage of interception by vegetation. In conclusion, this study indicates that the ponds in the French Midwest present a gain of water

Osmotically driven membrane process for the management of urban runoff in coastal regions

KAUST Repository

Li, Zhenyu; Valladares Linares, Rodrigo; Abu-Ghdaib, Muhannad; Zhan, Tong; Yangali-Quintanilla, Victor; Amy, Gary L.

2014-01-01

An osmotic detention pond was proposed for the management of urban runoff in coastal regions. Forward osmosis was employed as a bridge to utilize natural osmotic energy from seawater for concentrating and reusing urban runoff water, and as a barrier

The critical role of islands for waterbird breeding and foraging habitat in managed ponds of the South Bay Salt Pond Restoration Project, South San Francisco Bay, California

Science.gov (United States)

Ackerman, Joshua T.; Hartman, C. Alex; Herzog, Mark P.; Smith, Lacy M.; Moskal, Stacy M.; De La Cruz, Susan E. W.; Yee, Julie L.; Takekawa, John Y.

2014-01-01

The South Bay Salt Pond Restoration Project aims to restore 50–90 percent of former salt evaporation ponds into tidal marsh in South San Francisco Bay, California. However, large numbers of waterbirds use these ponds annually as nesting and foraging habitat. Islands within ponds are particularly important habitat for nesting, foraging, and roosting waterbirds. To maintain current waterbird populations, the South Bay Salt Pond Restoration Project plans to create new islands within former salt ponds in South San Francisco Bay. In a series of studies, we investigated pond and individual island attributes that are most beneficial to nesting, foraging, and roosting waterbirds.

Simple Rules Govern the Patterns of Arctic Sea Ice Melt Ponds

Science.gov (United States)

Popović, Predrag; Cael, B. B.; Silber, Mary; Abbot, Dorian S.

2018-04-01

Climate change, amplified in the far north, has led to rapid sea ice decline in recent years. In the summer, melt ponds form on the surface of Arctic sea ice, significantly lowering the ice reflectivity (albedo) and thereby accelerating ice melt. Pond geometry controls the details of this crucial feedback; however, a reliable model of pond geometry does not currently exist. Here we show that a simple model of voids surrounding randomly sized and placed overlapping circles reproduces the essential features of pond patterns. The only two model parameters, characteristic circle radius and coverage fraction, are chosen by comparing, between the model and the aerial photographs of the ponds, two correlation functions which determine the typical pond size and their connectedness. Using these parameters, the void model robustly reproduces the ponds' area-perimeter and area-abundance relationships over more than 6 orders of magnitude. By analyzing the correlation functions of ponds on several dates, we also find that the pond scale and the connectedness are surprisingly constant across different years and ice types. Moreover, we find that ponds resemble percolation clusters near the percolation threshold. These results demonstrate that the geometry and abundance of Arctic melt ponds can be simply described, which can be exploited in future models of Arctic melt ponds that would improve predictions of the response of sea ice to Arctic warming.

Simple Rules Govern the Patterns of Arctic Sea Ice Melt Ponds.

Science.gov (United States)

Popović, Predrag; Cael, B B; Silber, Mary; Abbot, Dorian S

2018-04-06

Climate change, amplified in the far north, has led to rapid sea ice decline in recent years. In the summer, melt ponds form on the surface of Arctic sea ice, significantly lowering the ice reflectivity (albedo) and thereby accelerating ice melt. Pond geometry controls the details of this crucial feedback; however, a reliable model of pond geometry does not currently exist. Here we show that a simple model of voids surrounding randomly sized and placed overlapping circles reproduces the essential features of pond patterns. The only two model parameters, characteristic circle radius and coverage fraction, are chosen by comparing, between the model and the aerial photographs of the ponds, two correlation functions which determine the typical pond size and their connectedness. Using these parameters, the void model robustly reproduces the ponds' area-perimeter and area-abundance relationships over more than 6 orders of magnitude. By analyzing the correlation functions of ponds on several dates, we also find that the pond scale and the connectedness are surprisingly constant across different years and ice types. Moreover, we find that ponds resemble percolation clusters near the percolation threshold. These results demonstrate that the geometry and abundance of Arctic melt ponds can be simply described, which can be exploited in future models of Arctic melt ponds that would improve predictions of the response of sea ice to Arctic warming.

Heating an aquaculture pond with a solar pool blanket

Energy Technology Data Exchange (ETDEWEB)

Wisely, B; Holliday, J E; MacDonald, R E

1982-01-01

A floating solar blanket of laminated bubble plastic was used to heat a 0.11 ha seawater pond of 1.3 m depth. The covered pond maintained daily temperatures 6 to 9/sup 0/C above two controls. Local air temperatures averaged 14 to 19/sup 0/C. Oysters, prawns, seasquirts, and fish in the covered pond all survived. After three weeks, the blanket separated. This was the result of pond temperatures exceeding 30/sup 0/C, the maximum manufacturer's specification. Floating blankets fabricated to higher specifications would be useful for maintaining above-ambient temperatures in small ponds or tanks in temporary situations during cold winter months and might have a more permanent use.

STORMWATER BEST MANAGEMENT PRACTICES TEST FACILITY - SWALES

Science.gov (United States)

The NRMRL swale evaluation is part of a larger collection of long-term research projects that evaluates many Best Management Practices. EPA has ongoing research examining the performance of constructed wet lands, and detention and retention ponds. Other projects will evaluate ra...

Watershed Scale Impacts of Stormwater Green Infrastructure on Hydrology, Nitrogen Fluxes, and Combined Sewer Overflows in the Baltimore, MD and Washington, DC area

Science.gov (United States)

Despite the increasing use of urban stormwater green infrastructure (SGI), including detention ponds and rain gardens, few studies have quantified the cumulative effects of multiple SGI projects on hydrology and water quality at the watershed scale. To assess the effects of SGI, ...

Observations of the transmittance in two solar ponds

Energy Technology Data Exchange (ETDEWEB)

Almanza, R.; Bryant, M.C.

1983-11-01

A NaCl salt gradient solar pond has been in continuous operation at the University of New Mexico since the fall of 1975; a smaller pond, using KNO/sub 3/ to produce the salinity gradient, was commissioned in the fall of 1981. The distribution of absorbed radiation in the ponds is of key importance in the determination of their efficiencies for collecting and storing solar energy. The absorption coefficient of light in an aqueous solution is very dependent upon wavelength; the spectral distribution of sunlight shifts toward the blue and the amount of solar energy absorbed per unit length of path declines with depth of penetration. The presence of suspended solids and bioforms further complicate the transmittance of sun light through the pond, specially since this contamination tends to vary strongly with depth. Because of its importance to the phytoplankton population , considerable work has been done by oceanographers on the absorption and scattering of light for different wavelengths. However, in a solar pond the big question is the amount of energy reaching the lower convective layer (storage). Several attempts have been made to measure the transmittance in solar ponds, mainly NaCl but the problem is to find a temperature-insensitive submersible pyranometer. Convenient formulas have been offered for the attenuation of solar radiation in pond water by considering it to be divided into spectral bands, or by fitting simple analytical functions, or specifying the extintion coefficient. (For the first method, it is necessary to know the absorption and scattering of light for different lambda.) In this paper some measurements of transmittance in the UNM ponds, are presented thereby exhibiting a simple procedure which may be of interest to others in this field.

Getting out of (self-) harm's way: A study of factors associated with self-harm among asylum seekers in Australian immigration detention.

Science.gov (United States)

Hedrick, Kyli

2017-07-01

The monitoring of self-harm among asylum seekers in Australian immigration detention has not occurred routinely or transparently. Thus whilst concerns regarding rates of self-harm among asylum seekers have been frequently raised, a paucity of systematic information regarding key factors associated with self-harm among asylum seekers exists. The present study was designed therefore to fill a number of gaps in government monitoring by examining the government's own archived self-harm data. Via a descriptive analysis of self-harm incident reports from all operational Australian immigration detention facilities over a 20-month period to May 2011, obtained under Freedom of Information, the present study identified that 959 incidents of self-harm occurred during this period. A gender bias towards men was also found. In addition to this, 10 different methods of self-harm were identified, the four most common being: cutting (47%), attempted hanging (19%), head hitting (12%) and self-poisoning by medication (6%). Seven different precipitating factors for self-harm were also identified, the four most common were: detention conditions (39%), processing arrangements (27%), negative decisions (24%) and family separation (3%). These findings point strongly to the health benefits of considering alternatives to held immigration detention, such as community based processing. Copyright © 2017 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Thermal evolutions of two kinds of melt pond with different salinity

Science.gov (United States)

Kim, Joo-Hong; Wilkinson, Jeremy; Moon, Woosok; Hwang, Byongjun; Granskog, Mats

2016-04-01

Melt ponds are water pools on sea ice. Their formation reduces ice surface albedo and alter surface energy balance, by which the ice melting and freezing processes are regulated. Thus, better understanding of their radiative characteristics has been vital to improve the simulation of melting/freezing of sea ice in numerical models. A melt pond would preserve nearly fresh water if it formed on multi-year ice and no flooding of sea water occurred, whereas a melt pond would contain more salty water if it formed on thinner and porous first-year ice, if there were an inflow of sea water by streams or cracks. One would expect that the fluid dynamic/thermodynamic properties (e.g., turbulence, stability, etc.) of pond water are influenced by the salinity, so that the response of pond water to any heat input (e.g., shortwave radiation) would be different. Therefore, better understanding of the salinity-dependent thermal evolution also has significant potential to improve the numerical simulation of the sea ice melting/freezing response to radiative thermal forcing. To observe and understand the salinity-dependent thermal evolution, two ice mass balance buoys (IMBs) were deployed in two kinds (fresh and salty) of melt pond on a same ice floe on 13 August 2015 during Araon Arctic cruise. The thermistor chain, extending from the air through the pond and ice into the sea water, was deployed through a drilled borehole inside the pond. Besides, the IMBs were also accompanied with three broadband solar radiation sensors (two (up and down) in the air over melt pond and one upward-looking under sea ice) to measure the net shortwave radiation at the pond surface and the penetrating solar radiation through ice. Also, the web camera was installed to observe any updates in the conditions of equipment and surrounding environment (e.g., weather, surface state, etc.). On the date of deployment, the fresh pond had salinity of 2.3 psu, light blue color, lots of slush ice particles which

Enhancing Ecoefficiency in Shrimp Farming through Interconnected Ponds

Directory of Open Access Journals (Sweden)

Ramón Héctor Barraza-Guardado

2015-01-01

Full Text Available The future development of shrimp farming needs to improve its ecoefficiency. The purpose of this study was to evaluate water quality, flows, and nitrogen balance and production parameters on a farm with interconnected pond design to improve the efficiency of the semi-intensive culture of Litopenaeus vannamei ponds. The study was conducted in 21 commercial culture ponds during 180 days at densities of 30–35 ind m−2 and daily water exchange <2%. Our study provides evidence that by interconnecting ponds nutrient recycling is favored by promoting the growth of primary producers of the pond as chlorophyll a. Based on the mass balance and flow of nutrients this culture system reduces the flow of solid, particulate organic matter, and nitrogen compounds to the environment and significantly increases the efficiency of water (5 to 6.5 m3 kg−1 cycle−1, when compared with traditional culture systems. With this culture system it is possible to recover up to 34% of the total nitrogen entering the system, with production in excess of 4,000 kg ha−1 shrimp. We believe that the production system with interconnected ponds is a technically feasible model to improve ecoefficiency production of shrimp farming.

First description of underwater acoustic diversity in three temperate ponds

Directory of Open Access Journals (Sweden)

Camille Desjonquères

2015-11-01

Full Text Available The past decade has produced an increased ecological interest in sonic environments, or soundscapes. However, despite this rise in interest and technological improvements that allow for long-term acoustic surveys in various environments, some habitats’ soundscapes remain to be explored. Ponds, and more generally freshwater habitats, are one of these acoustically unexplored environments. Here we undertook the first long term acoustic monitoring of three temperate ponds in France. By aural and visual inspection of a selection of recordings, we identified 48 different sound types, and according to the rarefaction curves we calculated, more sound types are likely present in one of the three ponds. The richness of sound types varied significantly across ponds. Surprisingly, there was no pond-to-pond daily consistency of sound type richness variation; each pond had its own daily patterns of activity. We also explored the possibility of using six acoustic diversity indices to conduct rapid biodiversity assessments in temperate ponds. We found that all indices were sensitive to the background noise as estimated through correlations with the signal-to-noise ratio (SNR. However, we determined that the AR index could be a good candidate to measure acoustic diversities using partial correlations with the SNR as a control variable. Yet, research is still required to automatically compute the SNR in order to apply this index on a large data set of recordings. The results showed that these three temperate ponds host a high level of acoustic diversity in which the soundscapes were variable not only between but also within the ponds. The sources producing this diversity of sounds and the drivers of difference in daily song type richness variation both require further investigation. Such research would yield insights into the biodiversity and ecology of temperate ponds.

Recovery of aquatic insect-mediated methylmercury flux from ponds following drying disturbance.

Science.gov (United States)

Chumchal, Matthew M; Drenner, Ray W; Greenhill, Frank M; Kennedy, James H; Courville, Ashlyn E; Gober, Charlie A A; Lossau, Luke O

2017-08-01

Small ponds exist across a permanence gradient, and pond permanence is hypothesized to be a primary determinant of insect community structure and insect-mediated methylmercury (MeHg) flux from ponds to the surrounding terrestrial landscape. The present study describes the first experiment examining the recovery of insect-mediated MeHg flux following a drying disturbance that converted permanent ponds with insectivorous fish to semipermanent ponds without fish. Floating emergence traps were used to collect emergent insects for 10 wk in the spring and summer from 5 ponds with fish (permanent) and 5 ponds that were drained to remove fish, dried, and refilled with water (semipermanent). During the 73-d period after semipermanent ponds were refilled, total MeHg flux from semipermanent ponds was not significantly different than total MeHg flux from permanent ponds, indicating that insect-mediated MeHg flux had rapidly recovered in semipermanent ponds following the drying disturbance. Methylmercury fluxes from dragonflies (Odonata: Anisoptera) and phantom midges (Diptera: Chaoboridae) were significantly greater from newly refilled semipermanent ponds than permanent ponds, but the MeHg fluxes from the other 8 emergent insect taxa did not differ between treatments. The present study demonstrates the impact of drying disturbance and the effect of community structure on the cross-system transport of contaminants from aquatic to terrestrial ecosystems. Environ Toxicol Chem 2017;36:1986-1990. © 2017 SETAC. © 2017 SETAC.

Groundwater impact assessment report for the 100-D Ponds

International Nuclear Information System (INIS)

Alexander, D.J.

1993-07-01

The 183-D Water Treatment Facility (WTF) discharges effluent to the 120-0-1 Ponds (100-D Ponds) located north of the 100-D Area perimeter fence. This report satisfies one of the requirements of the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) Milestone M-17-00B as agreed by the US Department of Energy, Washington State Department of Ecology, and the US Environmental Protection Agency. Tri-Party Agreement Milestone M-17-00B includes a requirement to assess impacts to groundwater from disposal of the 183-D WTF effluent to the 100-D Ponds. In addition, the 100-D Ponds are a Resource Conservation and Recovery Act of 1976 treatment, storage, and disposal facility covered by the 100-D Ponds Closure Plan (DOE-RL 1993a). There is evidence of groundwater contamination, primarily nitrate, tritium, and chromium, in the unconfined aquifer beneath the 100-D Area and 100 Areas in general. The contaminant plumes are area wide and are a result of past-practice reactor and disposal operations in the 100-D Area currently being investigated as part of the 100-DR-1 and 100-HR-3 Operable Units (DOE-RL 1992b, 1992a). Based on current effluent conditions, continued operation of the 100-D Ponds will not adversely affect the groundwater quality in the 100-D Area. Monitoring wells near the pond have slightly higher alkaline pH values than wells in the rest of the area. Concentrations of known contaminants in these wells are lower than ambient 100-D Area groundwater conditions and exhibit a localized dilution effect associated with discharges to the pond. Hydraulic impact to the local groundwater system from these discharges is minor. The groundwater monitoring well network for the 100-D Ponds is adequate

Ponds, Flows, and Ejecta of Impact Cratering and Volcanism: A Remote Sensing Perspective of a Dynamic Moon

Science.gov (United States)

Stopar, Julie D.

Both volcanism and impact cratering produce ejecta and associated deposits incorporating a molten rock component. While the heat sources are different (exogenous vs. endogenous), the end results are landforms with similar morphologies including ponds and flows of impact melt and lava around the central crater. Ejecta from both impact and volcanic craters can also include a high percentage of melted rock. Using Lunar Reconnaissance Orbiter Camera Narrow Angle Camera (LROC NAC) images, crucial details of these landforms are finally revealed, suggesting a much more dynamic Moon than is generally appreciated. Impact melt ponds and flows at craters as small as several hundred meters in diameter provide empirical evidence of abundant melting during the impact cratering process (much more than was previously thought), and this melt is mobile on the lunar surface for a significant time before solidifying. Enhanced melt deposit occurrences in the lunar highlands (compared to the mare) suggest that porosity, target composition, and pre-existing topography influence melt production and distribution. Comparatively deep impact craters formed in young melt deposits connote a relatively rapid evolution of materials on the lunar surface. On the other end of the spectrum, volcanic eruptions have produced the vast, plains-style mare basalts. However, little was previously known about the details of small-area eruptions and proximal volcanic deposits due to a lack of resolution. High-resolution images reveal key insights into small volcanic cones (0.5-3 km in diameter) that resemble terrestrial cinder cones. The cones comprise inter-layered materials, spatter deposits, and lava flow breaches. The widespread occurrence of the cones in most nearside mare suggests that basaltic eruptions occur from multiple sources in each basin and/or that rootless eruptions are relatively common. Morphologies of small-area volcanic deposits indicate diversity in eruption behavior of lunar basaltic

2101-M pond closure plan. Volume 1, Revision 2

Energy Technology Data Exchange (ETDEWEB)

Izatt, R. D.; Lerch, R. E.

1993-06-01

This document describes activities for the closure of a surface impoundment (2101-M Pond) at the Hanford Site. The 2101-H Pond was initially constructed in 1953 to serve as a drainage collection area for the 2101-H Building. (Until the Basalt Waste Isolation Project (BWIP) Laboratory was constructed in the 2101-M Building in 1979--1981, the only source contributing discharge to the pond was condensate water from the 2101-H Building heating, ventilation, and air conditioning (HVAC) system. The drains for the BWIP Laboratory rooms were plumbed into a 4-in., cast-iron, low-pressure drain pipe that carries waste water from the HVAC system to the pond. During the active life of the BWIP Laboratory, solutions of dissolved barium in groundwater samples were discharged to the 2101-M Pond via the laboratory drains. As a result of the discharges, a Part A permit application was initially submitted to the Washington State Department of Ecology (Ecology) in August 1986 which designates the 2101-M Pond as a surface impoundment.

Investigation of turbidity effect on exergetic performance of solar ponds

International Nuclear Information System (INIS)

Atiz, Ayhan; Bozkurt, Ismail; Karakilcik, Mehmet; Dincer, Ibrahim

2014-01-01

Highlights: • A comprehensive experimental work on a turbidity of the solar pond. • Percentage transmission evaluation of the turbid and clean salty water of the zones. • Exergy analysis of the inner zones for turbid and clean salty water. • Turbidity effect on exergy efficiencies of the solar pond. • The thermal performance assessment by comparing the exergetic efficiencies of the solar pond. - Abstract: The present paper undertakes a study on the exergetic performance assessment of a solar pond and experimental investigation of turbidity effect on the system performance. There are various types of solar energy applications including solar ponds. One of significant parameters to consider in the assessment of solar pond performance is turbidity which is caused by dirty over time (e.g., insects, leaf, dust and wind bringing parts fall down). Thus, the turbidity in the salty water decreases solar energy transmission through the zones. In this study, the samples are taken from the three zones of the solar pond and analyzed using a spectrometer for three months. The transmission aspects of the solar pond are investigated under calm and turbidity currents to help distinguish the efficiencies. Furthermore, the maximum exergy efficiencies are found to be 28.40% for the calm case and 22.27% with turbidity effects for the month of August, respectively. As a result, it is confirmed that the solar pond performance is greatly affected by the turbidity effect

Legal and Psychological Fundamentals of Extreme Communication in the Conditions of Hostages Detention (Bibliography Review

Directory of Open Access Journals (Sweden)

Zverev V. O.

2014-01-01

Full Text Available An attempt is made to generalize and analyze some accumulated scientific knowledge in the sphere of psychological nuances arising in the process of negotiations with criminals in the conditions of hostages detention, the experience shared by Soviet and Russian scientists

Risks to Ecological Receptors Posed by Contaminants of Potential Concern in the Lower Three Runs Cooling Ponds and Canals

Energy Technology Data Exchange (ETDEWEB)

Paller, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Blas, S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-03-21

The upper portion of Lower Three Runs includes several ponds, reservoirs, and canals that were formerly used as a cooling system for nuclear production reactors. This area was divided into nine exposure areas (EAs) for the assessment of environmental contamination resulting from past reactor operations and other industrial processes. A tiered screening process identified several contaminants of potential concern including aluminum, cyanide, lead, manganese, mercury, DDD, DDE, and DDT. Risks posed by these contaminants to ecological receptors (river otter, belted kingfisher, raccoon, and blue heron) were assessed using contaminant exposure models that estimated contaminant intake resulting from ingestion of food, water, and sediment/ soil and compared these intakes with toxicity reference values (TRVs). The contaminant exposure models showed that the TRVs were not exceeded in the otter model, exceeded by aluminum in EA 7 (Pond 2 and associated canals) in the raccoon model, and exceeded by mercury in EAs 2, 3 (Pond B), 6 (Par Pond), and 8 (Ponds 4 and 5 and Canal to Pond C) in both the kingfisher and blue heron models. Hazard quotients (total exposure dose divided by the TRV) were 2.8 for aluminum and 1.7- 3.6 for mercury. The primary route of exposure for aluminum was the ingestion of soil, and the primary route of exposure for mercury was the ingestion of mercury contaminated fish. Elevated levels of mercury in fish were at least partly the result of the aerial deposition of mercury onto Lower Three Runs and its watershed. The atmospheric deposition of mercury creates pervasive contamination in fish throughout the Savannah River basin. Another possible source of mercury was the discharge of mercury contaminated Savannah River water into the Lower Three Runs cooling ponds and canals during previous years of reactor operation. This contamination originated from industries located upstream of the SRS. The aluminum exceedance for the raccoon was likely the result of

Organic matter decomposition in simulated aquaculture ponds

NARCIS (Netherlands)

Torres Beristain, B.

2005-01-01

Different kinds of organic and inorganic compounds (e.g. formulated food, manures, fertilizers) are added to aquaculture ponds to increase fish production. However, a large part of these inputs are not utilized by the fish and are decomposed inside the pond. The microbiological decomposition of the

Simple intervention to reduce mosquito breeding in waste stabilisation ponds

DEFF Research Database (Denmark)

Ensink, Jeroen H J; Mukhtar, Muhammad; van der Hoek, Wim

2007-01-01

Waste stabilisation ponds (WSP) are the preferred method for treatment of urban wastewater in low-income countries but, especially in arid regions, the pond systems can be important breeding sites for mosquitoes of medical importance. In a WSP system in Faisalabad, Pakistan, we assessed the impact...... of simple environmental interventions on mosquito occurrence and abundance. Reducing the amount of floating matter in the ponds, eliminating emergent vegetation and repairing cracks in the cement structure reduced the number of mosquito-positive samples in the intervention ponds to almost zero, whereas...... the control ponds had a significant number of positive samples. This suggests that a combination of simple low-cost interventions is a feasible environmental management strategy for vector control in WSP systems that are located in areas where medically important mosquitoes may breed in the shallow ponds....

Arctic sea ice melt pond fractal dimension - explained

Science.gov (United States)

Popovic, Predrag

As Arctic sea ice starts to melt in the summer, pools of melt water quickly form on its surface, significantly changing its albedo, and impacting its subsequent evolution. These melt ponds often form complex geometric shapes. One characteristic of their shape, the fractal dimension of the pond boundaries, D, when plotted as a function of pond size, has been shown to transition between the two fundamental limits of D = 1 and D = 2 at some critical pond size. Here, we provide an explanation for this behavior. First, using aerial photographs, we show how this fractal transition curve changes with time, and show that there is a qualitative difference in the pond shape as ice transitions from impermeable to permeable. Namely, while ice is impermeable, maximum fractal dimension is less than 2, whereas after it becomes permeable, maximum fractal dimension becomes very close to 2. We then show how the fractal dimension of a collection of overlapping circles placed randomly on a plane also transitions from D = 1 to D = 2 at a size equal to the average size of a single circle. We, therefore, conclude that this transition is a simple geometric consequence of regular shapes connecting. The one physical parameter that can be extracted from the fractal transition curve is the length scale at which transition occurs. We provide a possible explanation for this length scale by noting that the flexural wavelength of the ice poses a fundamental limit on the size of melt ponds on permeable ice. If this is true, melt ponds could be used as a proxy for ice thickness.

A review of virus removal in wastewater treatment pond systems.

Science.gov (United States)

Verbyla, Matthew E; Mihelcic, James R

2015-03-15

Wastewater treatment ponds (lagoons) are one of the most common types of technologies used for wastewater management worldwide, especially in small cities and towns. They are particularly well-suited for systems where the effluent is reused for irrigation. However, the efficiency of virus removal in wastewater treatment pond systems is not very well understood. The main objective of this paper is to critically review the major findings related to virus removal in wastewater treatment pond systems and to statistically analyze results reported in the literature from field studies on virus removal in these systems. A comprehensive analysis of virus removal reported in the literature from 71 different wastewater treatment pond systems reveals only a weak to moderate correlation of virus removal with theoretical hydraulic retention time. On average, one log10 reduction of viruses was achieved for every 14.5-20.9 days of retention, but the 95th percentile value of the data analyzed was 54 days. The mechanisms responsible for virus removal in wastewater treatment ponds were also reviewed. One recent finding is that sedimentation may not be a significant virus removal mechanism in some wastewater ponds. Recent research has also revealed that direct and indirect sunlight-mediated mechanisms are not only dependent on pond water chemistry and optics, but also on the characteristics of the virus and its genome. MS2 coliphage is considered to be the best surrogate for studying sunlight disinfection in ponds. The interaction of viruses with particles, with other microorganisms, and with macroinvertebrates in wastewater treatment ponds has not been extensively studied. It is also unclear whether virus internalization by higher trophic-level organisms has a protective or a detrimental effect on virus viability and transport in pond systems. Similarly, the impact of virus-particle associations on sunlight disinfection in ponds is not well understood. Future research should focus on

Can terraced pond wetland systems improve urban watershed water quality?

Science.gov (United States)

Li, S.; Ho, M.; Flanagan, N. E.; Richardson, C. J.

2017-12-01

Properly built constructed wetlands are a more economic and efficient way of wastewater treatment compared with traditional methods, although their mechanisms are far from completely understood. As part of the Stream and Wetland Assessment Management Park (SWAMP), which is aimed to improve the water quality of downstream and thereby enhance watershed ecosystem services, a terraced three-pond wetland system was created near Duke University in 2014. This project is expected to promote the retention and settling of pollutants and sediment before runoffs enter downstream flow. The goal of this study is to examine: (1) whether a terraced pond wetland system improves water quality, during both baseline (low flow) and storm events (high flow), which increases pollutant inputs; and (2) how this system functions to remove pollutants, namely what components of this system (plant, soil or water) increase or decrease the level of pollutants. By analyzing a dataset consisting of more than four-year monthly samplings from Pond 1 (first pond in the system) and Pond 3 (last pond in the system), we found that the pond system has reduced total suspended solids (TSS) but only when elevated inputs occur. Dissolved oxygen (DO) is closely related to temperature and macrophytes growth; whereas acidity (pH), total nitrogen (TN), and total phosphorus (TP) did not show retention in the early stages of the system development. This system reaches its optimum for reducing TSS at the second pond, but the third pond has important effects on DO, pH, TN and TP. A monitoring in 2017 shows this pond system significantly reduces TSS while increasing dissolved oxygen and neutralizing pH after a storm event; although greater variations incurred within the system as time progresses after storm, overall retention function remained valid. Retention of the pollutants is primarily accomplished by the settling process, which occurs in stilled waterbody of the ponds and by the filtration of macrophytes. We

Emissions from Produced Water Treatment Ponds, Uintah Basin, Utah, USA

Science.gov (United States)

Mansfield, M. L.; Lyman, S. N.; Tran, H.; O'Neil, T.; Anderson, R.

2015-12-01

An aqueous phase, known as "produced water," usually accompanies the hydrocarbon fluid phases that are extracted from Earth's crust during oil and natural gas extraction. Produced water contains dissolved and suspended organics and other contaminants and hence cannot be discharged directly into the hydrosphere. One common disposal method is to discharge produced water into open-pit evaporation ponds. Spent hydraulic fracturing fluids are also often discharged into the same ponds. It is obvious to anyone with a healthy olfactory system that such ponds emit volatile organics to the atmosphere, but very little work has been done to characterize such emissions. Because oil, gas, and water phases are often in contact in geologic formations, we can expect that more highly soluble compounds (e.g., salts, alcohols, carbonyls, carboxyls, BTEX, etc.) partition preferentially into produced water. However, as the water in the ponds age, many physical, chemical, and biological processes alter the composition of the water, and therefore the composition and strength of volatile organic emissions. For example, some ponds are aerated to hasten evaporation, which also promotes oxidation of organics dissolved in the water. Some ponds are treated with microbes to promote bio-oxidation. In other words, emissions from ponds are expected to be a complex function of the composition of the water as it first enters the pond, and also of the age of the water and of its treatment history. We have conducted many measurements of emissions from produced water ponds in the Uintah Basin of eastern Utah, both by flux chamber and by evacuated canister sampling with inverse modeling. These measurements include fluxes of CO2, CH4, methanol, and many other volatile organic gases. We have also measured chemical compositions and microbial content of water in the ponds. Results of these measurements will be reported.

The Necessary Evil of Preventive Detention: A Plan for a More Moderate and Sustainable Solution

Science.gov (United States)

2008-07-01

Malaysia and Singapore have preventive detention regimes in which they can hold suspects for two-year periods without charge or meaningful court...have the leisure , turn their considerable talents to 212 deliberating how to fix a strained and mismatched legal system, before another cataclysm

Pond dyes are Culex mosquito oviposition attractants

Directory of Open Access Journals (Sweden)

Natali Ortiz Perea

2017-05-01

Full Text Available Background British mosquito population distribution, abundance, species composition and potential for mosquito disease transmission are intimately linked to the physical environment. The presence of ponds and water storage can significantly increase the density of particular mosquito species in the garden. Culex pipiens is the mosquito most commonly found in UK gardens and a potential vector of West Nile Virus WNV, although the current risk of transmission is low. However any factors that significantly change the distribution and population of C. pipiens are likely to impact subsequent risk of disease transmission. Pond dyes are used to control algal growth and improve aesthetics of still water reflecting surrounding planting. However, it is well documented that females of some species of mosquito prefer to lay eggs in dark water and/or containers of different colours and we predict that dyed ponds will be attractive to Culex mosquitoes. Methods Black pond dye was used in oviposition choice tests using wild-caught gravid C. pipiens. Larvae from wild-caught C. pipiens were also reared in the pond dye to determine whether it had any impact on survival. An emergence trap caught any adults that emerged from the water. Water butts (80 L were positioned around university glasshouses and woodland and treated with black pond dye or left undyed. Weekly sampling over a six month period through summer and autumn was performed to quantified numbers of larvae and pupae in each treatment and habitat. Results Gravid female Culex mosquitoes preferred to lay eggs in dyed water. This was highly significant in tests conducted under laboratory conditions and in a semi-field choice test. Despite this, survivorship in black dyed water was significantly reduced compared to undyed water. Seasonal analysis of wild larval and pupal numbers in two habitats with and without dye showed no impact of dye but a significant impact of season and habitat. Mosquitoes were more

Morphology-dependent water budgets and nutrient fluxes in arctic thaw ponds

Science.gov (United States)

Koch, Joshua C.; Gurney, Kirsty; Wipfli, Mark S.

2014-01-01

Thaw ponds on the Arctic Coastal Plain of Alaska are productive ecosystems, providing habitat and food resources for many fish and bird species. Permafrost in this region creates unique pond morphologies: deep troughs, shallow low-centred polygons (LCPs) and larger coalescent ponds. By monitoring seasonal trends in pond volume and chemistry, we evaluated whether pond morphology and size affect water temperature and desiccation, and nitrogen (N) and phosphorus (P) fluxes. Evaporation was the largest early-summer water flux in all pond types. LCPs dried quickly and displayed high early-summer nutrient concentrations and losses. Troughs consistently received solute-rich subsurface inflows, which accounted for 12 to 42 per cent of their volume and may explain higher P in the troughs. N to P ratios increased and ammonium concentrations decreased with pond volume, suggesting that P and inorganic N availability may limit ecosystem productivity in older, larger ponds. Arctic summer temperatures will likely increase in the future, which may accelerate mid-summer desiccation. Given their morphology, troughs may remain wet, become warmer and derive greater nutrient loads from their thawing banks. Overall, seasonal- to decadal-scale warming may increase ecosystem productivity in troughs relative to other Arctic Coastal Plain ponds. 

Health Disparities in Drug- and Alcohol-Use Disorders: A 12-Year Longitudinal Study of Youths After Detention.

Science.gov (United States)

Welty, Leah J; Harrison, Anna J; Abram, Karen M; Olson, Nichole D; Aaby, David A; McCoy, Kathleen P; Washburn, Jason J; Teplin, Linda A

2016-05-01

To examine sex and racial/ethnic differences in the prevalence of 9 substance-use disorders (SUDs)--alcohol, marijuana, cocaine, hallucinogen or PCP, opiate, amphetamine, inhalant, sedative, and unspecified drug--in youths during the 12 years after detention. We used data from the Northwestern Juvenile Project, a prospective longitudinal study of 1829 youths randomly sampled from detention in Chicago, Illinois, starting in 1995 and reinterviewed up to 9 times in the community or correctional facilities through 2011. Independent interviewers assessed SUDs with Diagnostic Interview Schedule for Children 2.3 (baseline) and Diagnostic Interview Schedule version IV (follow-ups). By median age 28 years, 91.3% of males and 78.5% of females had ever had an SUD. At most follow-ups, males had greater odds of alcohol- and marijuana-use disorders. Drug-use disorders were most prevalent among non-Hispanic Whites, followed by Hispanics, then African Americans (e.g., compared with African Americans, non-Hispanic Whites had 32.1 times the odds of cocaine-use disorder [95% confidence interval = 13.8, 74.7]). After detention, SUDs differed markedly by sex, race/ethnicity, and substance abused, and, contrary to stereotypes, did not disproportionately affect African Americans. Services to treat substance abuse--during incarceration and after release--would reach many people in need, and address health disparities in a highly vulnerable population.

Continuous Hydrologic and Water Quality Monitoring of Vernal Ponds.

Science.gov (United States)

Mina, Odette; Gall, Heather E; Chandler, Joseph W; Harper, Jeremy; Taylor, Malcolm

2017-11-13

Vernal ponds, also referred to as vernal pools, provide critical ecosystem services and habitat for a variety of threatened and endangered species. However, they are vulnerable parts of the landscapes that are often poorly understood and understudied. Land use and management practices, as well as climate change are thought to be a contribution to the global amphibian decline. However, more research is needed to understand the extent of these impacts. Here, we present methodology for characterizing a vernal pond's morphology and detail a monitoring station that can be used to collect water quantity and quality data over the duration of a vernal pond's hydroperiod. We provide methodology for how to conduct field surveys to characterize the morphology and develop stage-storage curves for a vernal pond. Additionally, we provide methodology for monitoring the water level, temperature, pH, oxidation-reduction potential, dissolved oxygen, and electrical conductivity of water in a vernal pond, as well as monitoring rainfall data. This information can be used to better quantify the ecosystem services that vernal ponds provide and the impacts of anthropogenic activities on their ability to provide these services.

Pond dynamics and supraglacial-englacial connectivity on debris-covered Lirung Glacier

Science.gov (United States)

Miles, Evan S.; Steiner, Jakob; Willis, Ian; Buri, Pascal; Immerzeel, Walter W.; Chesnokova, Anna; Pellicciotti, Francesca

2017-09-01

The hydrological systems of heavily-downwasted debris-covered glaciers differ from clean-ice glaciers due to the hummocky surface and debris mantle of such glaciers, leading to a relatively limited understanding of drainage pathways. Supraglacial ponds represent sinks within the discontinuous supraglacial drainage system, and have been documented to sporadically drain englacially. To assess pond dynamics, pond water level measurements were made on Lirung Glacier during May and October of 2013 and 2014. The four field seasons coincided with aerial, satellite, and terrestrial orthomosaic images and digital elevation models, which provided snapshots of the ponds and their surroundings. We analysed the glacier's closed surface catchments to identify surface drainage pathways and englacial drainage points, and compared this to field observations of surface discahrge. The ponded area was higher in the pre-monsoon than post-monsoon, with individual ponds filling and draining seasonally associated with the surface exposure of englacial conduit segments. We recorded four pond drainage events, all of which occurred gradually (duration of weeks), observed diurnal fluctuations indicative of varying supply and discharge, and we documented instances of interaction between distant ponds. The DEM drainage analysis identified numerous sinks >3m across the glacier surface, few of which exhibited ponds (23%), while the field survey highlighted surface discharge only explicable via englacial routes. Taken together our observations provide evidence for widespread supraglacial-englacial connectivity for meltwater drainage paths. Results suggest that progressive englacial conduit collapse events, themselves likely driven by supraglacial pond drainage, enable the glacier surface to evolve into a configuration following relict englacial conduit systems. Within this system, ponds form in depressions of reduced drainage efficiency and link the supraglacial and englacial drainage networks.

FROM PONDS TO MAN-MADE SEAS IN RUSSIA

Directory of Open Access Journals (Sweden)

Sergey Gorshkov

2013-01-01

Full Text Available Russia has more than 2200 reservoirs and large ponds. As time went by, ponds lost their importance in some aspects of human life, while newly created man-made seas impacted the nature and the people in two ways. The costs involved in designing, constructing, and operating the artificial seas, especially on the plains, have been too high to consider them as an undisputed achievement of the Soviet scientists transforming the nature. This paper discusses the problem of ponds and man-made seas in Russia.

[Studies on nitrogen, phosphorus and organic matter in ponds around Chaohu Lake].

Science.gov (United States)

Sun, Qing-ye; Ma, Xiu-ling; Yang, Gui-de; Chen, Zheng; Wu, Hong-lin; Xuan, Huai-xiang

2010-07-01

There are a lot of ponds around Chaohu Lake. According to location and runoff supply of ponds, the ponds are divided into three types: ponds inner vellage (PIV), ponds adjacent vellage (PAV) and ponds outer vellage (POV). The samples of water and sediment were collected from 136 ponds around Chaohu Lake and the contents of nitrogen, phosphorus and organic matter in water and sediments were analyzed in this study. The results showed that mean contents of total nitrogen (TN), NH4+ -N, NO3- -N, NO2- -N, total phosphorus (TP), soluble PO4(3-) -P and COD were 2.53, 0.65, 0.18, 0.02, 0.97, 0.38 and 51.58 mg x L(-1) in pond water, respectively; and mean contents of TN, NH4+ -N, NO3- -N, NO2- -N, TP, inorganic phosphorus (IP), organic phosphorus (OP) and loss of ignition (LOI) in pond sediment were 1575.36, 35.73, 13.30, 2.88, 933.19, 490.14, 414.75 mg x kg(-1) and 5.44%, respectively. The ponds of more than 90% presented eutrophication in the contents of total nitrogen and phosphorus in water. The contents of TN and NH4+ -N in water and sediment of PIV were significantly higher than that of POV. And the contents of inorganic nitrogen in pond water and sediment displayed a following order: NH4+ -N > NO3- -N > NO2- -N. Data analysis indicated that there was a significantly positive correlation between organic matter and total nitrogen and phosphorus in water and sediment. The nitrogen, phosphorus and organic matter in ponds mainly sourced farmlands and village land surface. The contents of nitrogen, phosphorus and organic matter in ponds were affected by location and runoff supply of ponds. By retaining nitrogen, phosphorus and organic matter in runoff, the ponds can effectively decrease nutrient content into Chaohu Lake.

Geochemistry of the Upper Parana River floodplain. Study of the Garcas Pond and Patos Pond

International Nuclear Information System (INIS)

Marcelo Bevilacqua Remor; Silvio Cesar Sampaio; Marcio Antonio Vilas Boas; Ralpho Rinaldo dos Reis

2015-01-01

The aim of this study was to investigate the temporal evolution of the supply of chemical elements to the Upper Parana River floodplain and identify trends in the geochemistry of its drainage basin. The primary factor that regulates the supply of chemical elements of the Upper Parana River floodplain is the flood pulse, which can be magnified by the El Nino-Southern Oscillation. Garcas Pond is affected by agriculture, urbanization, discharge of industrial effluents and hydroelectric power production activities. Patos Pond is affected by sugarcane burning, gold mining, agriculture and urbanization. (author)

Poorly known microbial taxa dominate the microbiome of permafrost thaw ponds.

Science.gov (United States)

Wurzbacher, Christian; Nilsson, R Henrik; Rautio, Milla; Peura, Sari

2017-08-01

In the transition zone of the shifting permafrost border, thaw ponds emerge as hotspots of microbial activity, processing the ancient carbon freed from the permafrost. We analyzed the microbial succession across a gradient of recently emerged to older ponds using three molecular markers: one universal, one bacterial and one fungal. Age was a major modulator of the microbial community of the thaw ponds. Surprisingly, typical freshwater taxa comprised only a small fraction of the community. Instead, thaw ponds of all age classes were dominated by enigmatic bacterial and fungal phyla. Our results on permafrost thaw ponds lead to a revised perception of the thaw pond ecosystem and their microbes, with potential implications for carbon and nutrient cycling in this increasingly important class of freshwaters.

Gaming under pre-trial detention: At-risk youth and their digital leisure practices during remand

DEFF Research Database (Denmark)

Nielsen, Rune Kristian; Witkowski, Emma

This paper looks at the practices of young men engaging with digital leisure activities within the physical, social, and psychological setting of a Danish Juvenile Detention Center. The study of young men's digital play prevails in game studies, yet the experiences and lifestyles captured in over...

Numerical modelling of hydro-morphological processes dominated by fine suspended sediment in a stormwater pond

Science.gov (United States)

Guan, Mingfu; Ahilan, Sangaralingam; Yu, Dapeng; Peng, Yong; Wright, Nigel

2018-01-01

Fine sediment plays crucial and multiple roles in the hydrological, ecological and geomorphological functioning of river systems. This study employs a two-dimensional (2D) numerical model to track the hydro-morphological processes dominated by fine suspended sediment, including the prediction of sediment concentration in flow bodies, and erosion and deposition caused by sediment transport. The model is governed by 2D full shallow water equations with which an advection-diffusion equation for fine sediment is coupled. Bed erosion and sedimentation are updated by a bed deformation model based on local sediment entrainment and settling flux in flow bodies. The model is initially validated with the three laboratory-scale experimental events where suspended load plays a dominant role. Satisfactory simulation results confirm the model's capability in capturing hydro-morphodynamic processes dominated by fine suspended sediment at laboratory-scale. Applications to sedimentation in a stormwater pond are conducted to develop the process-based understanding of fine sediment dynamics over a variety of flow conditions. Urban flows with 5-year, 30-year and 100-year return period and the extreme flood event in 2012 are simulated. The modelled results deliver a step change in understanding fine sediment dynamics in stormwater ponds. The model is capable of quantitatively simulating and qualitatively assessing the performance of a stormwater pond in managing urban water quantity and quality.

Surface and subsurface soils at the Pond B dam: July 1998

International Nuclear Information System (INIS)

Halverson, N.V.

1999-01-01

Pond B, 685-13G, is an inactive reactor cooling impoundment built in 1961 on the Savannah River Site (SRS). Between 1961 and 1964, Pond B received R-Reactor cooling water discharges that were contaminated with 137 Cs, 90 Sr and plutonium. Though the pond has not been used since 1964, radionuclides from the contaminated cooling water remain in the water and in the surface sediments of the pond. The current proposal to fix and repair the Pond B dam structure includes installing a new drain system and monitoring equipment. The dam will be reinforced with additional previous material on the downstream face of the dam. The objectives of this report are to describe the sampling methodology used during the July 1998 sampling event at the downstream face of the Pond B dam and in Pond B, present the results of the sampling event, and compare, where possible, these results to related risk-based standards

Seasonality of dipteran-mediated methylmercury flux from ponds.

Science.gov (United States)

Chumchal, Matthew M; Drenner, Ray W; Hall, MacGregor N; Polk, D Kirkland; Williams, Edward B; Ortega-Rodriguez, Celeste L; Kennedy, James H

2018-03-12

Methylmercury (MeHg) is an aquatic contaminant that can be transferred to terrestrial predators by emergent aquatic insects. We assessed the effects of month and pond permanence on dipteran-mediated MeHg flux (calculated as emergent dipteran biomass × dipteran MeHg concentration) in 10 experimental ponds. Emergent dipterans were collected weekly from permanent ponds with bluegill (Lepomis macrochirus; n = 5) and semipermanent ponds without fish (n = 5) over a 7-mo period (February-August, 2015). We detected a significant effect of month on MeHg flux from 6 dipteran taxa and aggregate MeHg flux, with the highest MeHg flux from herbivorous/detritivorous chironomid midges and predatory midges in March; biting midges, phantom midges and herbivorous/detritivorous orthoclad midges in April; and mosquitoes in August. Aggregate dipteran-mediated MeHg flux peaked in April and then declined throughout the remainder of the summer. We did not detect a significant main effect of pond permanence or a significant month × pond permanence interaction effect on MeHg flux for any of the taxa examined in the present study or for aggregate MeHg flux. Given their ubiquity in aquatic systems and their importance in food webs at the land-water interface, dipterans are important taxa that should not be overlooked as a part of the Hg cycle. Environ Toxicol Chem 2018;9999:1-6. © 2018 SETAC. © 2018 SETAC.

Aquatic biodiversity in sedimentation ponds receiving road runoff - What are the key drivers?

Science.gov (United States)

Sun, Zhenhua; Brittain, John E; Sokolova, Ekaterina; Thygesen, Helene; Saltveit, Svein Jakob; Rauch, Sebastien; Meland, Sondre

2018-01-01

Recently, increased attention has been paid to biodiversity conservation provided by blue-green solutions such as engineered ponds that are primarily established for water treatment and flood control. However, little research has been done to analyse the factors that affect biodiversity in such ponds. The purpose of this study was to evaluate the influence of environmental factors on aquatic biodiversity, mainly macroinvertebrate communities, in road sedimentation ponds in order to provide a foundation for recommendations on aquatic biodiversity conservation. Multivariate statistical methods, including unconstrained and constrained analysis, were applied to examine the relationships between organisms and the water quality as well as physical factors (including plant cover). Stepwise multiple regressions indicated that the most important variables governing the variation in the biological community composition were pond size, average annual daily traffic, metals, chloride, distance to the closest pond from study pond, dissolved oxygen, hydrocarbons, and phosphorus. The presence of most taxa was positively correlated with pond size and negatively correlated with metals. Small ponds with high pollutant loadings were associated with a low diversity and dominated by a few pollution tolerant taxa such as oligochaetes. A comprehensive understanding of impacts of various environmental factors on aquatic biodiversity is important to effectively promote and conserve aquatic biodiversity in such sedimentation ponds. Our results indicate that road sedimentation ponds should be designed large enough, because large ponds are likely to provide a more heterogeneous habitat and thus contain a species rich fauna. In addition, larger ponds seem to be less contaminated due to dilution compared to smaller ponds, thereby maintaining a higher biodiversity. Finally, creating some additional ponds in the vicinity of the sedimentation ponds in areas with few water bodies would increase the

Monthly and diurnal variations of limnological conditions of two ponds

Directory of Open Access Journals (Sweden)

AKM Fazlur Rahaman

2017-06-01

Full Text Available A study on monthly and diurnal changes of limnological conditions of two ponds was conducted in the Bangladesh Agricultural University campus, Mymensingh. The research work was performed by studying the limnological parameters such as transparency, temperature, dissolved oxygen, free carbon dioxide, pH, total alkalinity, nitrate-nitrogen, phosphate-phosphorus and plankton. Diurnal variations of physico-chemical factors were studied fortnightly at 6 hrs intervals at 6 a.m., 12 noon, 6 p.m. and 12 midnight. The amounts of transparency, dissolved oxygen and pH were higher during winter months than in summer months in both the ponds. Transparency, water temperature, total alkalinity, NO3-N and PO4-P were higher during summer months than in winter months in both the ponds. But the amount of free carbon dioxide was higher during winter months than in summer months in pond 1 while in pond 2 the amount of free carbon dioxide was higher during summer months than in winter months. Qualitative and quantitative monthly variations of phytoplankton and zooplankton were observed in both the ponds during the study period. The highest amount of dissolved oxygen, pH and total alkalinity were recorded at 6 p.m. and the lowest amounts of those at 6 a.m. in both the ponds. The highest temperature was recorded at 12 noon and the lowest at 12 midnight. But the highest amount of free carbon dioxide was recorded at 6 a.m. and the lowest at 6 p.m. in both the ponds. All the factors showed appreciable diel variations throughout the study period, which indicate that the ponds are productive.

A mathematical procedure to estimate solar absorptance of shallow water ponds

International Nuclear Information System (INIS)

Wu Hongbo; Tang Runsheng; Li Zhimin; Zhong Hao

2009-01-01

In this article, a mathematical procedure is developed for estimating solar absorption of shallow water ponds with different pond floor based on the fact that the solar radiation trapped inside the water layer undergoes multiplicative reflection and absorption and on that the solar absorption of water is selective. Theoretical model indicates that the solar absorption of a water pond is related to the reflectivity of the pond floor, the solar spectrum and the water depth. To validate the mathematical model, a concrete water pond measuring 3 x 3 x 0.24 m was constructed. Experimental results indicate that solar reflectivity calculated based on the mathematical model proposed in this work were in good agreement with those measured. For water ponds with a water-permeable floor, such as concrete floor, theoretical calculations of the solar absorptance of a water pond should be done based on the reflectivity of full wet floor, whereas for water ponds with a non-water-permeable floor, theoretical calculations should be done based on the fact that solar reflection on the floor is neither perfect specular reflection nor prefect isotropic diffuse reflection. Results of numerical calculation show that theoretical calculations of solar absorption of a water pond by dividing solar spectrum into six bands were pretty agreement with those by dividing solar spectrum into 20 bands.

Likelihood and predictors of detention in patients with personality disorder compared with other mental disorders: A retrospective, quantitative study of Mental Health Act assessments.

Science.gov (United States)

Olajide, Kike; Tyrer, Peter; Singh, Swaran P; Burns, Tom; Rugkåsa, Jorun; Thana, Lavanya; Paul, Moli; Islam, Zoebia; Crawford, Mike J

2016-08-01

The UK guidelines on the treatment of personality disorder recommend avoiding compulsory treatment except in extreme situations. Little is known about how often patients with personality disorder are detained or how this compares with the treatment of other mental disorders. Our aim is to test the hypothesis that people with personality disorder are infrequently detained under the Mental Health Act (MHA) and that risk factors associated with detention are the same as those for people with other mental disorders. We used a retrospective, quantitative study of MHA assessments. Of the 2 087 assessments undertaken, 204 (9.8%) patients had a diagnosis of personality disorder; 40.7% of assessments in the personality disorder group resulted in detention, as did 69.7% of patients with other mental disorders. A higher proportion of people with personality disorder received no intervention following assessment compared with those with other mental disorders (20.6% vs. 4.7%, p mental disorders. Detention rates in patients with personality disorder are lower than those for other disorders but are still substantial. Risk factors for detention in patients with personality disorder differ from those with other mental disorders. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Avifauna of waste ponds ERDA Hanford Reservation, Benton County, Washington

International Nuclear Information System (INIS)

Fitzner, R.E.; Rickard, W.H.

1975-06-01

The presence of small ponds on the Hanford 200 Area plateau provides attractive habitats for birds. During a 29-month period, 126 bird species were observed utilizing these ponds, their associated vegetation, and air space. Waterfowls are the important agents of dispersal of radionuclides from waste ponds based on food habits, abundance, migratory habits, and importance as food in the diet of people. Abundance, long residence time, and food habits identify the American coot as the single most important species to be considered in the biological dispersal of radionuclides from waste ponds. (U.S.)

Distribution of transuranic elements in a freshwater pond ecosystem

International Nuclear Information System (INIS)

Emery, R.M.; Klopfer, D.C.

1975-05-01

Preliminary results are reported from a study initiated on the Hanford Reservation concerning the ecological behavior of 238 Pu, 239 Pu, 240 Pu, and 241 Am in a freshwater environment. This study involves a waste pond which has been receiving Pu processing wastes for about 30 years. The pond has a sufficiently established ecosystem to provide an excellent location for limnological characterization. In addition, the ecological distribution of Pu and Am was investigated. The pond is also highly enriched with nutrients, thus supporting a high level of algal and macrophyte production. Seston (30 percent diatoms) appears to be the principal concentrators of Pu transuranics in the pond system. The major sink for Pu and Am in this system is the sediments. Organic floc, overlaying the pond sediments, is also a major concentrator of transuranics in this system []Aside from the seston and floc, no other ecological components of the pond appear to have concentrations significantly greater than those of the sediment. Dragonfly, larvae, watercress, and snails show concentrations which approximate those of the sediments but nearly all other food web components have levels of Pu and Am which are lower than those of the sediments, thus, Pu and Am seem to be relatively immobile in the aquatic ecosystem. (CH)

Estimation of Melt Ponds over Arctic Sea Ice using MODIS Surface Reflectance Data

Science.gov (United States)

Ding, Y.; Cheng, X.; Liu, J.

2017-12-01

Melt ponds over Arctic sea ice is one of the main factors affecting variability of surface albedo, increasing absorption of solar radiation and further melting of snow and ice. In recent years, a large number of melt ponds have been observed during the melt season in Arctic. Moreover, some studies have suggested that late spring to mid summer melt ponds information promises to improve the prediction skill of seasonal Arctic sea ice minimum. In the study, we extract the melt pond fraction over Arctic sea ice since 2000 using three bands MODIS weekly surface reflectance data by considering the difference of spectral reflectance in ponds, ice and open water. The preliminary comparison shows our derived Arctic-wide melt ponds are in good agreement with that derived by the University of Hamburg, especially at the pond distribution. We analyze seasonal evolution, interannual variability and trend of the melt ponds, as well as the changes of onset and re-freezing. The melt pond fraction shows an asymmetrical growth and decay pattern. The observed melt ponds fraction is almost within 25% in early May and increases rapidly in June and July with a high fraction of more than 40% in the east of Greenland and Beaufort Sea. A significant increasing trend in the melt pond fraction is observed for the period of 2000-2017. The relationship between melt pond fraction and sea ice extent will be also discussed. Key Words: melt ponds, sea ice, Arctic

Distribution of transuranic elements in a freshwater pond ecosystem

International Nuclear Information System (INIS)

Emery, R.M.; Klopfer, D.C.

1976-01-01

During the past two years a unique study has been initiated on the Hanford Reservation concerning the ecological behavior of plutonium and americium in a freshwater environment. This study involves a waste pond which has been receiving occasional low-level plutonium processing wastes for about 30 years. The pond has a sufficiently established ecosystem to provide an excellent location for limnological characterization. In addition, the ecological distribution of plutonium and americium is being investigated. The purpose of this work is to explain plutonium and americium concentrations at specific ecological sites, important export routes out of the pond, and potential pathways to man. The pond is also highly enriched with nutrients, thus supporting a high level of algal and macrophyte production. Seston (30 percent diatoms) appears to be the principal concentrator of transuranics in the pond system. The major sink for plutonium and americium in this system is the sediments. Organic floc, overlaying the pond sediments, is also a major concentrator of transuranics in this system. Aside from the seston and floc, no other ecological components of the pond appear to have concentrations significantly greater than those of the sediment. Dragonfly larvae, watercress, and snails show concentrations which approximate those of the sediments but nearly all other food web components have levels of plutonium and americium which are lower than those of the sediments. Thus, plutonium and americium seem to be relatively immobile in the aquatic ecosystem. However, the role of algae as a potential mechanism for the long-range ecological transport of plutonium and americium will receive additional attention

Decontamination and decommissioning of the BORAX-V leach pond. Final report

International Nuclear Information System (INIS)

Smith, D.L.

1985-01-01

This report describes the decontamination and decommissioning (D and D) of the BORAX-V leach pond located at the Idaho National Engineering Laboratory (INEL). The leach pond became radioactively contaminated from the periodic discharge of low-level liquid waste during operation of the Boiling Water Reactor Experiments (BORAX) from 1954 to 1964. This report describes work performed to accomplish the D and D objectives of stabilizing the leach pond and preventing the spread of contamination. D and D of the BORAX-V leach pond consisted to backfilling the pond with clean soil, grading and seeding the area, and erecting a permanent marker to identify very low-level subsurface contamination

Depression, anxiety, and history of substance abuse among Norwegian inmates in preventive detention: Reasons to worry?

Directory of Open Access Journals (Sweden)

Værøy Henning

2011-03-01

Full Text Available Abstract Background Inmates on preventive detention are a small and select group sentenced to an indefinite term of imprisonment. Mood disorders and substance abuse are risk factors for inmate violence and recidivism, so the prevalence of depression, anxiety, and substance abuse was examined in this cohort using psychometric tests. Methods Completion of self-report questionnaires was followed by face-to-face clinical interviews with 26 of the 56 male inmates on preventive detention in Norway's Ila Prison. Substance abuse histories and information about the type of psychiatric treatment received were compiled. To assess anxiety and depression, the Hospital Anxiety and Depression Scale (HADS, the Clinical Anxiety Scale (CAS, and the Montgomery Asberg Depression Rating Scale (MADRS were used. Results Scores on the MADRS revealed that 46.1% of inmates had symptoms of mild depression. The HADS depression subscale showed that 19.2% scored above the cut-off for depression (κ = 0.57. The CAS anxiety score was above the cut-off for 30.7% of the subjects, while 34.6% also scored above the cut-off on the HADS anxiety subscale (κ = 0.61. Almost 70% of all these inmates, and more than 80% of those convicted of sex crimes, had a history of alcohol and/or drug abuse. Conclusions Mild anxiety and depression was found frequently among inmates on preventive detention. Likewise, the majority of the inmates had a history of alcohol and drug abuse. Mood disorders and substance abuse may enhance recidivism, so rehabilitation programs should be tailored to address these problems.

Characterisation and Treatment of Nano-sized Particles, Colloids and Associated Polycyclic Aromatic Hydrocarbons in Stormwater

DEFF Research Database (Denmark)

Nielsen, Katrine

such as pH, Total Suspended Solid(TSS), turbidity, and electrical conductivity.The five sites where stormwater was sampled from used two different methods of stormwater treatment: settling and filtration, and four different treatment techniques: detention ponds, stormwater pond, disc filter and combined...... sedimentation tanks. From all sites, inlet and outlet stormwater were collected,and pollutant concentrations were quantified as well as the removal efficiencies calculated. The colloidal and nano-sized particle-enhanced transportation of pollutants was also scrutinised in the stormwater.The μm-range PSD...

Limnological database for Par Pond: 1959 to 1980

International Nuclear Information System (INIS)

Tilly, L.J.

1981-03-01

A limnological database for Par Pond, a cooling reservoir for hot reactor effluent water at the Savannah River Plant, is described. The data are derived from a combination of research and monitoring efforts on Par Pond since 1959. The approximately 24,000-byte database provides water quality, primary productivity, and flow data from a number of different stations, depths, and times during the 22-year history of the Par Pond impoundment. The data have been organized to permit an interpretation of the effects of twenty years of cooling system operations on the structure and function of an aquatic ecosystem

EXPERIMENTAL INVESTIGATION OF SOLAR POND PERFORMANCE IN KARABUK ENVIRONMENT

Directory of Open Access Journals (Sweden)

Mehmet ÖZKAYMAK

2004-01-01

Full Text Available The solar energy, one of the alternative energy sources, can be economically and cheaply and efficiently collected with solar ponds. In this study, varying concentrations of sodium carbonate dilution in the solar pond in terms of heat storage performance has been examined. Experiment apparatus has been located Zonguldak Karaelmas University Karabük Technical Education Faculty. Five experiments with different density levels have been done and the changes in the temperature and density have been presented graphically within the solar pond. The experiments show that the temperature difference between the bottom and top level of solar pond is max. 21 °C and the highest temperature in lower convective zone (LCZ has been measured as 49 °C.

Lime application methods, water and bottom soil acidity in fresh water fish ponds

Directory of Open Access Journals (Sweden)

Queiroz Julio Ferraz de

2004-01-01

Full Text Available Although some methods for determining lime requirement of pond soils are available and commonly used, there is still no consensus on whether it is more effective to apply liming materials to the bottoms of empty ponds or to wait and apply them over the water surface after ponds are filled. There is also little information on how deep lime reacts in pond sediment over time, and whether the depth of reaction is different when liming materials are applied to the water or to the soil. Therefore, three techniques for treating fish ponds with agricultural limestone were evaluated in ponds with clayey soils at a commercial fish farm. Amounts of agricultural limestone equal to the lime requirement of bottom soils were applied to each of three ponds by: direct application over the pond water surface; spread uniformly over the bottom of the empty pond; spread uniformly over the bottom of the empty pond followed by tilling of the bottom. Effectiveness of agricultural limestone applications did not differ among treatment methods. Agricultural limestone also reacted quickly to increase total alkalinity and total hardness of pond water to acceptable concentrations within 2 weeks after application. The reaction of lime to increase soil pH was essentially complete after one to two months, and lime had no effect below a soil depth of 8 cm. Tilling of pond bottoms to incorporate liming materials is unnecessary, and tilling consumes time and is an expensive practice; filled ponds can be limed effectively.

Treatment of pond sludge at the Rocky Flats Plant

International Nuclear Information System (INIS)

Wienand, J.; Tyler, R.; Baldwin, C.

1992-01-01

The treatment of low-level radioactive/hazardous materials sludges from five inactive solar evaporation settling ponds at the Rocky Flats Plant is discussed. The paper presents information on the following topics: history of the ponds; previous pond cleanout activities; current approach to the problem with respect to water management, sludge management, regulatory actions, and disposal; and future processing technology needs in the areas of polymer solidification, microwave solidification, joule-heated glass melters, and advanced technology incineration

76 FR 25538 - Criteria Used To Order Administrative Detention of Food for Human or Animal Consumption

Science.gov (United States)

2011-05-05

... Consumption AGENCY: Food and Drug Administration, HHS. ACTION: Interim final rule; request for comments... food for human or animal consumption. As required by the FDA Food Safety Modernization Act (FSMA), FDA... provide procedures for administrative detention of food for human or animal consumption under the...

Interconnected ponds operation for flood hazard distribution

Science.gov (United States)

Putra, S. S.; Ridwan, B. W.

2016-05-01

The climatic anomaly, which comes with extreme rainfall, will increase the flood hazard in an area within a short period of time. The river capacity in discharging the flood is not continuous along the river stretch and sensitive to the flood peak. This paper contains the alternatives on how to locate the flood retention pond that are physically feasible to reduce the flood peak. The flood ponds were designed based on flood curve number criteria (TR-55, USDA) with the aim of rapid flood peak capturing and gradual flood retuning back to the river. As a case study, the hydrologic condition of upper Ciliwung river basin with several presumed flood pond locations was conceptually designed. A fundamental tank model that reproducing the operation of interconnected ponds was elaborated to achieve the designed flood discharge that will flows to the downstream area. The flood hazard distribution status, as the model performance criteria, will be computed within Ciliwung river reach in Manggarai Sluice Gate spot. The predicted hazard reduction with the operation of the interconnected retention area result had been bench marked with the normal flow condition.

Validation Hydrodynamic Models of Three Topological Models of Secondary Facultative Ponds

OpenAIRE

Aponte-Reyes Alxander

2014-01-01

A methodology was developed to analyze boundary conditions, the size of the mesh and the turbulence of a mathematical model of CFD, which could explain hydrodynamic behavior on facultative stabilization ponds, FSP, built to pilot scale: conventional pond, CP, baffled pond, BP, and baffled-mesh pond, BMP. Models dispersion studies were performed in field for validation, taking samples into and out of the FSP, the information was used to carry out CFD model simulations of the three topologies. ...

Estimated hydrologic budgets of kettle-hole ponds in coastal aquifers of southeastern Massachusetts

Science.gov (United States)

Walter, Donald A.; Masterson, John P.

2011-01-01

Kettle-hole ponds in southeastern Massachusetts are in good hydraulic connection to an extensive coastal aquifer system that includes the Plymouth-Carver aquifer system on the mainland and aquifers underlying Cape Cod. The ponds receive water from, and contribute water to, the underlying glacial aquifer; ponds also receive water from precipitation and lose water to evaporation from the pond surface. Some ponds are connected to surface-water drainage systems and receive water from or contribute water to streams or adjacent wetlands. The Massachusetts Department of Environmental Protection currently (2011) is developing Total Maximum Daily Loads of phosphorus for the freshwater ponds in the region to maintain the health of pond ecosystems; the amounts and sources of water fluxes into and out of the ponds are important factors in determining the amount of phosphorus that can be assimilated into a pond. To assist in this effort, the U.S. Geological Survey used groundwater-flow models of the coastal aquifer system to estimate hydrologic budgets-including inflows and outflows from the aquifer system and adjacent streams and wetlands, and recharge from precipitation-for 425 ponds in southeastern Massachusetts.

PRODUCTIVITY OF GROWING PONDS WHEN APPLYING THE BACTERIAL FERTILIZER «PHOSPHOBAKTERIN»

Directory of Open Access Journals (Sweden)

Т. Hryhorenko

2017-09-01

Full Text Available Purpose. To investigate the effect of the bacterial fertilizer "Phosphobacterin" on the formation of the hydrochemical regime, development of the natural food supply and fish productivity in the growing ponds. Methodology. The work was conducted according to generally accepted hydrochemical,, microbiological, hydrobiological and fish farming methods. Findings The article presents the results of a study of the productivity of growing ponds with different methods of the application of the bacterial fertilizer "Phosphobacterin". It was found that the hydrochemical regime of the experimental ponds was formed under the effect of the source of water supply and measures aimed at intensifying the development of the natural food supply and was favorable for the development of feed organisms and the cultivation of fish seeds. Application of the bacterial fertilizer at the beginning of the growing season along the water pond surface proved to be little effective for increasing the productivity of the pond ecosystem as a whole. A more effective method of increasing biological productivity, including fish productivity of growing ponds, was the application of "Phosphobacterin" during the growing season both on the bed and on the water surface in combination with the organic fertilizer - cattle humus. In the experimental pond under complex fertilization, the average phytoplankton biomass during the growing season was 1.5 times, bacterioplankton 1.1 times, zoobenthos 2.6 times higher, and the obtained total fish productivity was 1.2 times higher than in the control pond (when applying only cattle humus. Originality. The peculiarities of formation of hydrochemical and hydrobiological (phyto-, bacterio-, zooplankton, zoobenthos regimes of growing ponds and the fishery indices are studied, both for bacterial fertilizer "Phosphobacterin" independently and together with the traditional organic fertilizer - cattle humus. Practical value. Based on the obtained results

Operation of a pond-cooler: the case of Berezovskaya GRES-1

Science.gov (United States)

Morozova, O. G.; Kamoza, T. L.; Koyupchenko, I. N.; Savelyev, A. S.; Pen, R. Z.; Veselkova, N. S.; Kudryavtsev, M. D.

2017-08-01

Pond-coolers at heat and nuclear power stations are natural-technological systems, so the program of their monitoring should include the effect made by the SRPS (state regional power station) on the pond ecosystem, including thermal discharge of cooling water. The objectives of this study were development and implementation of a monitoring program for the cooling pond of Berezovskaya SRPS-1 on the chemical and biological water quality indicators and identification of patterns of the thermal and hydrochemical regime when operating the progressive power plant (from 1996 to 2015). The quality of the cooling water of the pond-cooler BGRES-1 was studied under full-scale conditions by selecting and analyzing the water samples of the pond in accordance with the principles of complexity, systematic observation, and consistency of timing their conduct with the characteristic hydrological phases. Processing of the obtained array of monitoring data by methods of mathematical statistics makes it possible to identify the main factors affecting the water quality of the pond. The data on water quality obtained during their monitoring and mathematical processing over a long time interval are the scientific basis for forecasting the ecological state of the pond, which is necessary to economically ensure the efficient energy production and safety of water use. Recommendations proposed by these authors, including those partially already implemented, have been to prevent the development of eutrophication processes in the pond-cooler: the construction of a dam that cuts off the main peat massif and cleaning the river banks forming the cooling pond.

Heat recovery from ground below the solar pond

NARCIS (Netherlands)

Ganguly, S.; Date, Abhijit; Akbarzadeh, Aliakbar

2017-01-01

The method of heat recovery from the ground below solar ponds is investigated in the present brief note. Solar ponds lose considerable amount of heat from its bottom to the ground due to temperature gradient between them. This waste heat from ground, which is at different temperature at different

Mathematical modeling of dissolved oxygen in fish ponds ...

African Journals Online (AJOL)

Mathematical modeling of dissolved oxygen in fish ponds. WJS Mwegoha, ME Kaseva, SMM Sabai. Abstract. A mathematical model was developed to predict the effects of wind speed, light, pH, Temperature, dissolved carbon dioxide and chemical oxygen demand (COD) on Dissolved Oxygen (DO) in fish ponds. The effects ...

Determination of the algal growth-limiting nutrients in strip mine ponds

International Nuclear Information System (INIS)

Bucknavage, M.J.; Aharrah, E.C.

1984-01-01

Using both a test organism, Ankistrodesmus falcatus, and natural phytoplankton, the Printz Algal Assay Bottle Test was used to determine the algal growth limiting nutrients in two strip mine ponds. Nitrogen, phosphorus, and iron were investigated, singly and in combination, as possible limiting nutrients. A synthetic chelator, Na 2 EDTA, was also used in the assay to test for the presence of metal toxicants and/or trace metal limitation. Because bacteria have a major influence on water chemistry, a separate assay incorporating the natural bacteria population was performed. In both ponds, assay results using test alga indicate phosphorus to be the primary limiting nutrient and nitrogen as a secondary factor. The presence of EDTA in combination with phosphate containing treatment promoted a higher algal concentration in both ponds. Iron was determined to be a secondary limiting nutrient in only one of the ponds. Natural phytoplankton of the two ponds responded in a similar manner to nutrient increases. Only one pond had the same results produced by both assays. Nutrient availability was influenced by the presence of bacteria in one pond but not in the other

THERMAL AND OXYGEN CONDITIONS IN CARP PONDS DURING THE SUMMER PERIOD

Directory of Open Access Journals (Sweden)

Magdalena Wiśnios

2015-11-01

Full Text Available The work presents changes of oxygen indices in carp ponds during the summer season. The basis of the research were regular water tests conducted in two ponds: Mydlniki II intended for carp farming in the second year of fish production cycle and Bocian used for carp farming in the third (final year of breeding. The temperature of pond water in July and August was optimal for development and farming of cyprinid fish and ranged from 16.6 to 30.5 °C. The lowest value of oxygen dissolved in water (6.4 mg·dm-3 was registered in Mydlniki II pond and was higher than the oxygen optimum for carp (5 mg·dm-3. Oxygen saturation in water of fish ponds exceeded the optimum upper limit value (168% on a few dates, however, it posed no lethal threat for fish. In August in Bocian pond oxygen saturation fell within the range of optimal values, creating better conditions for fish development. In the secondary pond (Mydlniki II it was found that oxygen saturation in water on 12 dates was lower than the low optimal value (96%.

78 FR 21085 - Establishment of a Public Docket for Administrative Detention Under the Food and Drug...

Science.gov (United States)

2013-04-09

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Chapter I [Docket No. FDA-2013-N-0365] Establishment of a Public Docket for Administrative Detention Under the Food and Drug Administration Safety and Innovation Act AGENCY: Food and Drug Administration, HHS. ACTION: Establishment of...

Watershed Scale Impacts of Stormwater Green Infrastructure ...

Science.gov (United States)

Despite the increasing use of urban stormwater green infrastructure (SGI), including detention ponds and rain gardens, few studies have quantified the cumulative effects of multiple SGI projects on hydrology and water quality at the watershed scale. To assess the effects of SGI, Baltimore County, MD, Montgomery County, MD, and Washington, DC, were selected based on the availability of data on SGI, water quality, and stream flow. The watershed scale impact of SGI was evaluated by assessing how increased spatial density of SGI correlates with stream hydrology and nitrogen exports over space and time. The most common SGI types were detention ponds (58%), followed by marshes (12%), sand filters (9%), wet ponds (7%), infiltration trenches (4%), and rain gardens (2%). When controlling for watersheds size and percent impervious surface cover, watersheds with greater amounts of SGI (>10% SGI) have 44% lower peak runoff, 26% less frequent runoff events, and 26% less variable runoff than watersheds with lower SGI. Watersheds with more SGI also show 44% less NO3− and 48% less total nitrogen exports compared to watersheds with minimal SGI. There was no significant reduction in combined sewer overflows in watersheds with greater SGI. Based on specific SGI types, infiltration trenches (R2 = 0.35) showed the strongest correlation with hydrologic metrics, likely due to their ability to attenuate flow, while bioretention (R2 = 0.19) and wet ponds (R2 = 0.12) showed stronger

Experimental and modelling of Arthrospira platensis cultivation in open raceway ponds.

Science.gov (United States)

Ranganathan, Panneerselvam; Amal, J C; Savithri, S; Haridas, Ajith

2017-10-01

In this study, the growth of Arthrospira platensis was studied in an open raceway pond. Furthermore, dynamic model for algae growth and CFD modelling of hydrodynamics in open raceway pond were developed. The dynamic behaviour of the algal system was developed by solving mass balance equations of various components, considering light intensity and gas-liquid mass transfer. A CFD modelling of the hydrodynamics of open raceway pond was developed by solving mass and momentum balance equations of the liquid medium. The prediction of algae concentration from the dynamic model was compared with the experimental data. The hydrodynamic behaviour of the open raceway pond was compared with the literature data for model validation. The model predictions match the experimental findings. Furthermore, the hydrodynamic behaviour and residence time distribution in our small raceway pond were predicted. These models can serve as a tool to assess the pond performance criteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

The origin and fate of arsenic in coalbed natural gas-produced water ponds.

Science.gov (United States)

Sowder, J T; Kelleners, T J; Reddy, K J

2010-01-01

Coalbed natural gas (CBNG)-produced water contains small amounts of trace metals that can accumulate over time in produced water retention ponds. Within the Powder River Basin (PRB) of Wyoming, high concentrations of trace metals in pond water and their effect on shallow groundwater are potential concerns. A pond with a maximum As concentration of 146 microg L(-1) was studied in detail to determine the potential for groundwater pollution and to explain the cause for the high concentration of As. Infiltration characteristics, subsurface hydrology, our fall and pond water quality, isotope signatures, and trace metal balances were examined to assess the hydrology and geochemistry of the pond. The results indicated minimum or no infiltration of pond water and no measurable contamination of the shallow groundwater. The high As concentrations in the pond were determined to be the result of semi-continuous inputs of CBNG-produced water with low As concentrations (0.20-0.48 microg L(-1)), exasperated by low pond volumes during drought conditions. Because of reduced infiltration and high evaporation rates, As became concentrated over time. Reduced infiltration was most likely caused by the high sodium concentration and high sodium adsorption ratio of the CBNG-produced water, which disrupt soil structure. The findings for the pond and the techniques used may serve as a template for future impact assessments of other CBNG-produced water ponds and are relevant for the approximately 4000 ponds currently permitted in the PRB and for future ponds. Further studies are recommended in the use of playa landforms to store marginal-quality produced water.

Piecing Together the US Immigrant Detention Puzzle One Night at a Time: An Analysis of All Persons in DHS-ICE Custody on September 22, 2012

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Donald Kerwin

2015-11-01

Full Text Available This paper analyzes a dataset of every person in the custody of the US Department of Homeland Security Immigration and Customs Enforcement (DHS-ICE or ICE on September 22, 2012, and compares this data with an earlier analysis of a similar dataset on detainees in DHS-ICE custody on January 25, 2009. DHS-ICE provided the 2012 and 2009 datasets in response to Freedom of Information Act (FOIA requests from the Boston Globe and Associated Press. The paper sets forth findings related to: (1 the removal adjudication processes to which the detainees were subject; (2 the facilities in which they were held; (3 their length of detention; and (4 their criminal histories, if any. It finds that on September 22, 2012:DHS-ICE held 35,197 people in its custody.18,470 detainees had pending removal cases, 14,674 had been ordered removed, and 2,053 cases included no information on whether or not the detainee had been ordered removed.Thirty-eight percent of detainees were subject to summary, non-court removal processes.Forty percent of detainees were from the Northern Triangle states of Central America and 34 percent from Mexico, compared to 37 percent from Mexico and 28 percent from Central America on January 25, 2009.Detainees were held in 189 facilities, with 77 percent concentrated in nine states and 51 percent in the four states that border Mexico.DHS-ICE held 67 percent of all detainees in facilities owned and/or administered by for-profit prison corporations and 90 percent of detainees in the 21 facilities with the largest detention populations.Forty-seven percent of detainees had been held for less than 30 days, and 4,179 (12 percent had been held for more than six months.Of those ordered removed and continuously detained in the interim, 553 persons had been detained for more than six months after being ordered removed, despite being presumptively eligible for release after six months.Sixty-one percent of detainees had criminal convictions, compared to 42

Assessment of waste stabilization ponds (WSP) efficiency on ...

African Journals Online (AJOL)

This stage is essential for polishing water and nutrient as well as pathogen removal. There is need of frequent awareness campaign to a community for the reuse of wastewater for agriculture and its possible impacts. Ponds should be modified and addition of maturation ponds constructed. Further studies are required for ...

Little Fish in a Big Pond--Time to Get Schooled!

Science.gov (United States)

Moye, Johnny J.

2011-01-01

One technique used by many who fish is to catch a fish in a creek or pond and then release it in a different pond. This satisfies the desire for sport, and it also serves to stock a pond that may need replenishment. Of course this restocking can be a traumatic experience for the new fish. To survive in the new environment, the fish must find its…

Sea Ice Melt Pond Data from the Canadian Arctic

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains observations of albedo, depth, and physical characteristics of melt ponds on sea ice, taken during the summer of 1994. The melt ponds studied...

Ecological behavior of plutonium and americium in a freshwater pond

International Nuclear Information System (INIS)

Emery, R.M.; Klopfer, D.C.; Garland, T.R.; Weimer, W.C.

1976-01-01

A plutonium (Pu) processing waste pond on the Hanford Reservation has been studied since mid-1973 to characterize the pond's limnology and determine the ecological behavior of transuranics in this ecosystem. This ultra-eutrophic pond has a water inflow rate of 10 m 3 /min, of which 95% leaves the pond by percolation. Macrophytes (mainly Potamogeton), algae (mainly Cladophora), benthic invertebrates (mainly dipteran and odonate larvae, hemipterans, amphipods and gastropods) and goldfish are the major biotic components of the system. Sediments appear to be the principal repository of Pu and Am, having mean concentrations for 238 Pu, 239 240 Pu and 241 Am of 112, 121 and 71 pCi/g (dry), respectively. Mean ratios of isotopes in the sediments are 0.85 for 238 Pu to 239 240 Pu, and 0.49 for 241 Am to 239 240 Pu. Algal floc (decomposing algal material) is the major concentrator of Pu and Am in the pond having mean concentrations of 238 Pu of 986 pCi/g, for 239 240 Pu of 615 pCi/g, and for 241 Am of 256 pCi/g. Watercress (Rorippa) had Pu levels about equal to those of the sediments, while dragonfly larvae (Libellula) and snails (Lymnaea) along with watercress had Am levels approximating those of the sediments. The remaining biota had Pu and Am levels which were generally well below those of the sediments.Preliminary in situ experiments indicate that goldfish reach an equilibrium level for Pu of about 15 pCi/g within a few days of exposure to the pond, after which they may remain active in the pond for many months without further accumulation. Experimental goldfish established ratios of 238 Pu to 239 240 Pu and 241 Am to 239 240 Pu that were similar to all other pond biota within 2 weeks of pond residence, suggesting a common source of biologically available Pu and Am

Further contributions to the understanding of nitrogen removal in waste stabilization ponds.

Science.gov (United States)

Bastos, R K X; Rios, E N; Sánchez, I A

2018-06-01

A set of experiments were conducted in Brazil in a pilot-scale waste stabilization pond (WSP) system (a four-maturation-pond series) treating an upflow anaerobic sludge blanket (UASB) reactor effluent. Over a year and a half the pond series was monitored under two flow rate conditions, hence also different hydraulic retention times and surface loading rates. On-site and laboratory trials were carried out to assess: (i) ammonia losses by volatilization using acrylic capture chambers placed at the surface of the ponds; (ii) organic nitrogen sedimentation rates using metal buckets placed at the bottom of the ponds for collecting settled particulate matter; (iii) nitrogen removal by algal uptake based on the nitrogen content of the suspended particulate matter in samples from the ponds' water column. In addition, nitrification and denitrification rates were measured in laboratory-based experiments using pond water and sediment samples. The pond system achieved high nitrogen removal (69% total nitrogen and 92% ammonia removal). The average total nitrogen removal rates varied from 10,098 to 3,849 g N/ha·d in the first and the last ponds, respectively, with the following fractions associated with the various removal pathways: (i) 23.5-45.6% sedimentation of organic nitrogen; (ii) 13.1-27.8% algal uptake; (iii) 1.2-3.1% ammonia volatilization; and (iv) 0.15-0.34% nitrification-denitrification.

The effect of sunny area ratios on the thermal performance of solar ponds

International Nuclear Information System (INIS)

Bozkurt, Ismail; Karakilcik, Mehmet

2015-01-01

Highlights: • The effect of sunny area ratio on model solar ponds in different geometries. • The sunny area ratio was calculated for 8 different cases. • The efficiency of the model solar pond was determined for 8 different cases. • The energy efficiencies of the solar pond are affected by the sizes of the solar pond, strongly. • The results help to select the sizes of the solar pond before construction. - Abstract: In this study, we investigated the effect of the sunny area ratios on thermal efficiency of model solar pond for different cases in Adiyaman, Turkey. For this purpose, we modeled the solar ponds to compute theoretical sunny area ratios of the zones and temperature distributions in order to find the performance of the model solar ponds. Incorporating the finite difference approach, one and two dimensional heat balances were written for inner zones and insulation side walls. Through, careful determination of the dimensions, insulation parameter and incoming solar radiation reaching the storage zone increased the efficiency of the solar pond. The efficiencies of the model solar pond were determined for case1a–2a–3a–4a to be maximum 14.93%, 20.42%, 23.51% and 27.84%, and for case1b–2b–3b–4b to be maximum 12.65%, 16.76%, 21.37% and 23.30% in August, respectively. With the increase of the sunny area ratio, the performance of the solar pond significantly increased. However, with the increasing rate of the surface area, performance increase rate decreased gradually. The results provide a strong perspective to determine the dimensions of the solar pond before starting the project of a solar pond

Social Relation between Businessman and Community in Management of Intensive Shrimp Pond

Science.gov (United States)

Gumay Febryano, Indra; Sinurat, James; Lovinia Salampessy, Messalina

2017-02-01

Expansion of aquaculture, especially shrimp culture, is the primary cause of deforestation of mangrove along coastal zone. This phenomenon is pretty much related to social relation between businessman of intensive shrimp pond and community around coastal zone. The objective of this research is to explain social relation between businessman and community in managing intensive shrimp pond. This research is a kind of qualitative research and the method used is a case study. The result of this research shows that the behaviour of the majority of businessman of intensive shrimp pond is not accordingly with environmental concerns as they compelled conversion of mangrove and they disposed waste of shrimp pond into the sea. Such kind of behaviour caused degradation of water ecosystem and marginalizing local community. Corporate Social Responsibility (CSR) which was implemented by businessman of intensive shrimp pond in the area of social, religion, and education can downgrade the coming up of social turbulence. Otherwise, CSR in enabling economic community and environmental management was not conducted yet. CSR in environmental management can be conducted by businessman of intensive shrimp pond by considering the existence of mangrove and pond management and waste in a better way, so that environment around ponds is not polluted and the sustainability of shrimp pond business as well as income of community can be guaranteed. Accordingly with the result of this research, CSR is not only involving businessman of intensive shrimp pond and community, but also involving local government in terms of right and responsibility of citizen as well as management and development of community.

Deposition By Turbidity Currents In Intraslope Diapiric Minibasins: Results Of 1-D Experiments And Numerical Modeling

Science.gov (United States)

Lamb, M.; Toniolo, H.; Parker, G.

2001-12-01

The slope of the continental margin of the northern Gulf of Mexico is riddled with small basins resulting from salt tectonics. Each such minibasin is the result of local subsidence due to salt withdrawal, and is isolated from neighboring basins by ridges formed due to compensational uplift. The minibasins are gradually filled by turbidity currents, which are active at low sea stand. Experiments in a 1-D minibasin reveal that a turbidity current flowing into a deep minibasin must undergo a hydraulic jump and form a muddy pond. This pond may not spill out of the basin even with continuous inflow. The reason for this is the detrainment of water across the settling interface that forms at the top of the muddy pond. Results of both experiments and numerical modeling of the flow and the evolution of the deposit are presented. The numerical model is the first of its kind to capture both the hydraulic jump and the effect of detrainment in ponded turbidity currents.

Use of cooling ponds and hydraulic turbines to save SRP energy consumption

International Nuclear Information System (INIS)

Price, J.B.

1980-01-01

A substantial amount of energy can be saved by using cooling ponds to supply C and K reactors with cooling water. Hydraulic turbines between the reactor and the cooling pond can recover some of the power used to pump cooling water to the reactors. Cooling ponds would also reduce effluent temperature in the swamps adjacent to the Savannah River. Cooling ponds are evaluated in this memorandum

Pond Dynamics and Supraglacial-Englacial Connectivity on Debris-Covered Lirung Glacier, Nepal

Directory of Open Access Journals (Sweden)

Evan S. Miles

2017-09-01

Full Text Available The hydrological systems of heavily-downwasted debris-covered glaciers differ from those of clean-ice glaciers due to the hummocky surface and debris mantle of such glaciers, leading to a relatively limited understanding of drainage pathways. Supraglacial ponds represent sinks within the discontinuous supraglacial drainage system, and occasionally drain englacially. To assess pond dynamics, we made pond water level measurements on Lirung Glacier, Nepal, during May and October of 2013 and 2014. Simultaneously, aerial, satellite, and terrestrial orthoimages and digital elevation models were obtained, providing snapshots of the ponds and their surroundings. We performed a DEM-based analysis of the glacier's closed surface catchments to identify surface drainage pathways and englacial drainage points, and compared this to field observations of surface and near-surface water flow. The total ponded area was higher in the pre-monsoon than post-monsoon, with individual ponds filling and draining seasonally associated with the surface exposure of englacial conduit segments. We recorded four pond drainage events, all of which occurred gradually (duration of weeks, observed diurnal fluctuations indicative of varying water supply and outflow discharge, and we documented instances of interaction between distant ponds. The DEM drainage analysis identified numerous sinks >3 m in depth across the glacier surface, few of which exhibited ponds (23%, while the field survey highlighted instances of surface water only explicable via englacial routes. Taken together, our observations provide evidence for widespread supraglacial-englacial connectivity of meltwater drainage paths. Results suggest that successive englacial conduit collapse events, themselves likely driven by supraglacial pond drainage, cause the glacier surface drainage system to evolve into a configuration following relict englacial conduit systems. Within this system, ponds form in depressions of

Using nanofluids in enhancing the performance of a novel two-layer solar pond

International Nuclear Information System (INIS)

Al-Nimr, Moh'd A.; Al-Dafaie, Ameer Mohammed Abbas

2014-01-01

A novel two-layer nanofluid solar pond is introduced. A mathematical model that describes the thermal performance of the pond has been developed and solved. The upper layer of the pond is made of mineral oil and the lower layer is made of nanofluid. Nanofluid is known to be an excellent solar radiation absorber, and this has been tested and verified using the mathematical model. Using nanofluid will increase the extinction coefficient of the lower layer and consequently will improve the thermal efficiency and the storage capacity of the pond. The effects of other parameters have been also investigated. - Highlights: • A novel two-layer solar pond is discussed. • Nanofluid as thermal energy storage is used in this pond. • A mathematical model is developed to predict the performance of the pond. • The mathematical model is solved using Green's function. • The pond is simulated for different values of governing parameter

Evaluation of relocation of unionid mussels into artificial ponds

Science.gov (United States)

Newton, T.J.; Monroe, E.M.; Kenyon, R.; Gutreuter, S.; Welke, K.I.; Thiel, P.A.

2001-01-01

Relocation of unionid mussels into refuges (e.g., hatchery ponds) has been suggested as a management tool to protect these animals from the threat of zebra mussel (Dreissena polymorpha) invasion. To evaluate the efficacy of relocation, we experimentally relocated 768 mussels, representing 5 species (Leptodea fragilis, Obliquaria reflexa, Fusconaia flava, Amblema plicata, and Quadrula quadrula) into an earthen pond at a National Fish Hatchery or back into the river. In both locations, mussels were placed into 1 of 4 treatments (mesh bags, corrals, and buried or suspended substrate-filled trays). Mussels were examined annually for survival, growth (shell length and wet mass), and physiological condition (glycogen concentration in foot and mantle and tissue condition index) for 36 mo in the pond or 40 mo in the river. We observed significant differences in mortality rates between locations (mortality was 4 times greater in the pond than in the river), among treatments (lowest mortality in the suspended trays), and among species (lower mortality in the amblemines than lamp-silines). Overall survival in both locations averaged 80% the 1st year; survival in the pond decreased dramatically after that. Although length and weight varied between locations and over time, these changes were small, suggesting that their utility as short-term measures of well being in long-lived unionids is questionable. Mussels relocated to the pond were in poor physiological condition relative to those in the river, but the magnitude of these differences was small compared to the inherent variability in physiological condition of reference mussels. These data suggest that relocation of unionids into artificial ponds is a high-risk conservation strategy; alternatives such as introduction of infected host fish, identification of mussel beds at greatest risk from zebra mussels, and a critical, large-scale assessment of the factors contributing to their decline should be explored.

Fate of Pyrethroids in Farmland Ponds

DEFF Research Database (Denmark)

Mogensen, B. B.; Sørensen, P. B.; Stuer-Lauridsen, F.

Pyrethroids constitute a group of widely used insecticides, which are toxic to aquatic organisms. This report presents the results from a 2-year study of the fate of pyrethroids in ponds, i.e. their distribution in the water column, the sediment and the surface microlayer respectively. The measur......Pyrethroids constitute a group of widely used insecticides, which are toxic to aquatic organisms. This report presents the results from a 2-year study of the fate of pyrethroids in ponds, i.e. their distribution in the water column, the sediment and the surface microlayer respectively...

Thermal performance measurements on ultimate heat sinks--cooling ponds

International Nuclear Information System (INIS)

Hadlock, R.K.; Abbey, O.B.

1977-12-01

The primary objective of the studies described is to obtain the requisite data, with respect to modeling requirements, to characterize thermal performance of heat sinks for nuclear facilities existing at elevated water temperatures in result of experiencing a genuinely large heat load and responding to meteorological influence. The data should reflect thermal performance for combinations leading to worst-case meteorological influence. A geothermal water retention basin has been chosen as the site for the first measurement program and data have been obtained in the first of several experiments scheduled to be performed there. These data illustrate the thermal and water budgets during episodes of cooling from an initially high pond water bulk temperature. Monitoring proceeded while the pond experienced only meteorological and seepage influence. The data are discussed and are presented as a data volume which may be used for calculation purposes. Suggestions for future measurement programs are stated with the intent to maintain and improve relevance to nuclear ultimate heat sinks while continuing to examine the performance of the analog geothermal pond. It is further suggested that the geothermal pond, with some modification, may be a suitable site for spray pond measurements

Monitoring, chemical fate modelling and uncertainty assessment in combination: a tool for evaluating emission control scenarios for micropollutants in stormwater systems

DEFF Research Database (Denmark)

Mikkelsen, Peter Steen; Vezzaro, Luca; Birch, Heidi

2012-01-01

runoff and treatment systems under sparse data conditions. The framework was applied to an industrial/residential area in the outskirts of Copenhagen (Denmark), where stormwater is discharged in a separate channel system discharging to a wet detention pond. Analysis of economic activities and GIS data...... on land usage allowed characterizing the catchment and identifying the major potential sources of stormwater MP. Monitoring of the pond inlet and outlet, as well as sediment analyses, allowed assessing the current situation and highlighted potential risks for the downstream surface water environment...

Follow-up study of female delinquent adolescents in a detention centre: effectiveness of psychiatric intervention as a mental health service.

Science.gov (United States)

Ariga, Michio; Uehara, Toru; Takeuchi, Kazuo; Ishige, Yoko; Nakano, Reiko; Mikuni, Masahiko

2010-01-01

of previous studies suggest that many female offenders have co-morbid psychiatric disorders, which require mental health services. However, few longitudinal studies examined subjects during incarceration or detention. This study compares depressive symptoms, abnormal eating behaviour and impulsivity before release from a detention centre and after incarceration, thereby indicating the effectiveness of psychiatric intervention in a Japanese detention centre. Of 64 young women, 36 were followed up. Self-report measures were used to assess depression, eating behaviour and impulsivity after incarceration and one month before release. s: Of the 36 participants, nine were diagnosed using the MINI-kids as needing mental health services. Those who received psychiatric intervention were diagnosed as having major depression and/or post-traumatic stress disorder. Significant main effects of intervention and effects of time were shown in the DSD. The EAT-26 score demonstrated the significance of the effects of time and interaction. In the BIS-11 scores, neither intervention nor time showed significant effects. Results of this study showed that the time course and psychiatric intervention contributed to recovery of depression and therapeutic intervention. The time course might reduce eating problems. Psychiatric intervention might be necessary for female juvenile detainees, which presents an important issue for future studies.

Development of shrimp in small ponds

Directory of Open Access Journals (Sweden)

Armando Adolfo Ortega Salas

2014-06-01

Full Text Available Development of white shrimp Litopenaeus vannamei in small ponds ( 6 m3 in fresh water (2-3‰ and seawater; ponds 3.66 x 1.65 x 1.0 m; availability of fresh water, sea water, aeration and drainage. Two cycles of three months each were made. The postlarvae were acclimated to seawater fresh water in four days. Four hundred postlarvas/m3 were seeded in freshwater pond and 500 in the pool of seawater. First, a culture of Daphnia magna in the freshwater pond, also appeared chyronomid larvae; Artemia cysts were seeded in sea water as a dietary supplement. The shrimp were fed Camaronina (25% protein at libitum, daily; is offered on a tray of food; the temperature ranged between 27 and 30° C, oxygen 4.26 ± 1.43 mg / L , pH between 7 and 8 . Detritus siphoned every third day. Water changes between 10 and 20% are often performed. The feed conversion rate (FCR was 1:1.3 . The shrimp were measured in length and weight to calculate weekly growth by Bertalanffy model. Survival in the first cycle was 95.8 , and 97.9% for the second cycle. In seawater parameters of the population of the first cycle were k = 0.0301, L ∞ = 322.16 and t0 = -0.8852, the second cycle of k = 0.0203, L ∞ = 294.42 and t0 = -5.3771. The biomass of 27 kg was obtained for the first cycle and 16 kg for the second cycle. Freshwater population parameters of the first cycle were k = 0.0957, L ∞ = 146.98 and t0 = - 0.93; in the second cycle of k = 0.0172 , L ∞ = 367.82 and t0 = - 4.60. The biomass of 26 kg was obtained for the first cycle and 16 kg for the second cycle. The results indicate a rapid growth during the first 10 weeks. In small ponds can be handled well aseptic conditions without disease problems, good crop was obtained.

Capturing temporal and spatial variability in the chemistry of shallow permafrost ponds

Science.gov (United States)

Morison, Matthew Q.; Macrae, Merrin L.; Petrone, Richard M.; Fishback, LeeAnn

2017-12-01

Across the circumpolar north, the fate of small freshwater ponds and lakes (mediated by processes within ponds. This work demonstrates the importance of understanding hydrologically driven chemodynamics in permafrost ponds on multiple scales (seasonal and event scale).

Energy resources of the west tailings pond, Airline-Sponsler Mine, Greene County, Indiana

Energy Technology Data Exchange (ETDEWEB)

Eggert, D.L.; Miller, L.V.; Irwin, P.N.

1980-12-01

The west tailings pond at the Airline-Sponsler Mine is a manmade prograding fan-delta system in which wastes from preparing coal are deposited in expected sequences. The tailings pond, originally a surface-mine final-cut and haulage road, is about 10,000 feet long, 200 to 300 feet wide, and 25 to 60 feet deep. The Indiana Geological Survey drilled eight auger holes at the pond. The first hole was 50 feet from the entry point, the second hole was 200 feet from the first, and the remaining six holes were 700 feet apart. At each hole samples were taken on 5-foot intervals, and a composite sample of each hole was also prepared. Coarse coal, dense rock fragments, and sulfide minerals settle first and are followed by medium to fine coal and clay and very fine coal. At the entry point ash is high (65.4 percent), sulfur is high (12 percent), calorific value is low (3220 Btu), and particle size is large. At the distal end ash is low near the surface but increases near the base (15.5 to 59.3 percent), sulfur is high near the surface but decreases near the base (2.6 to 1.0 percent), calorific value is high near the surface but decreases near the base (12,000 to 5250 Btu), and particle size is large near the surface but decreases near the base. Washability determinations indicate that some tailings located distally to the entry point might be reclaimed as a fuel with little further preparation and those located proximally could be upgraded by further preparation.

Heat transfer in melt ponds with convection and radiative heating: observationally-inspired modelling

Science.gov (United States)

Wells, A.; Langton, T.; Rees Jones, D. W.; Moon, W.; Kim, J. H.; Wilkinson, J.

2016-12-01

Melt ponds have key impacts on the evolution of Arctic sea ice and summer ice melt. Small changes to the energy budget can have significant consequences, with a net heat-flux perturbation of only a few Watts per square metre sufficient to explain the thinning of sea ice over recent decades. Whilst parameterisations of melt-pond thermodynamics often assume that pond temperatures remain close to the freezing point, recent in-situ observations show more complex thermal structure with significant diurnal and synoptic variability. We here consider the energy budget of melt ponds and explore the role of internal convective heat transfer in determining the thermal structure within the pond in relatively calm conditions with low winds. We quantify the energy fluxes and temperature variability using two-dimensional direct numerical simulations of convective turbulence within a melt pond, driven by internal radiative heating and surface fluxes. Our results show that the convective flow dynamics are modulated by changes to the incoming radiative flux and sensible heat flux at the pond surface. The evolving pond surface temperature controls the outgoing longwave emissions from the pond. Hence the convective flow modifies the net energy balance of a melt pond, modulating the relative fractions of the incoming heat flux that is re-emitted to the atmosphere or transferred downward into the sea ice to drive melt.

The effect of beaver ponds on water quality in rural coastal plain streams

Science.gov (United States)

Bason, Christopher W.; Kroes, Daniel; Brinson, Mark M.

2017-01-01

We compared water-quality effects of 13 beaver ponds on adjacent free-flowing control reaches in the Coastal Plain of rural North Carolina. We measured concentrations of nitrate, ammonium, soluble reactive phosphorus (SRP), and suspended sediment (SS) upstream and downstream of paired ponds and control reaches. Nitrate and SS concentrations decreased, ammonium concentrations increased, and SRP concentrations were unaffected downstream of the ponds and relative to the control reaches. The pond effect on nitrate concentration was a reduction of 112 ± 55 μg-N/L (19%) compared to a control-reach—influenced reduction of 28 ± 17 μg-N/L. The pond effect on ammonium concentration was an increase of 9.47 ± 10.9 μg-N/L (59%) compared to the control-reach—influenced reduction of 1.49 ± 1.37 μg-N/L. The pond effect on SS concentration was a decrease of 3.41 ± 1.68 mg/L (40%) compared to a control-reach—influenced increase of 0.56 ± 0.27 mg/L. Ponds on lower-order streams reduced nitrate concentrations by greater amounts compared to those in higher-order streams. Older ponds reduced SS concentrations by greater amounts compared to younger ponds. The findings of this study indicate that beaver ponds provide water-quality benefits to rural Coastal Plain streams by reducing concentrations of nitrate and suspended sediment.

Inventory of vegetation and benthos in newly laid and natural ponds in Forsmark 2012

International Nuclear Information System (INIS)

Qvarfordt, Susanne; Wallin, Anders; Borgiel, Micke

2013-01-01

SKB plans to build a repository for the spent nuclear fuel. The repository is planned to be built in Forsmark and constitutes installations above and below ground. The building and operation of the construction will involve activities that might affect the nature in the area. The impact means, among other things, that a small water body, which today is a reproduction site for the red listed pool frog (Rana lessonae), will disappear. The lost locality for the pool frog has been compensated by creating four new ponds in the Forsmark area. This study is part of the follow-up of these new habitats. The aim is to describe the plant and animal communities in the ponds, and follow the succession, i.e. the development of the habitats. The study also includes two natural ponds that will serve as reference objects. The survey of vegetation and invertebrate fauna in the ponds was conducted in October 2012. The results show that the new ponds had low coverage of submersed vegetation and the species composition in the plant communities differed between the ponds. The reference ponds also had different plant communities, both in terms of species composition and coverage. This indicates that the species composition of the plant communities in the new ponds will likely depend on physical factors specific to the respective pond, but that higher vegetation coverage can be expected over time in all new ponds. The reference ponds had similar animal communities that differed from the animal communities in the new ponds. The similar species composition in the reference ponds, despite the variety of plant communities, suggests that similar animal communities are likely to develop in the new ponds, even if the plant communities continues to be different. Water chemical sampling has also been conducted in the ponds during 2012. A comparison of the inorganic environment (with regard to analysed ions) showed that the reference ponds had relatively similar ion compositions with little

Insight into the risk of replenishing urban landscape ponds with reclaimed wastewater.

Science.gov (United States)

Chen, Rong; Ao, Dong; Ji, Jiayuan; Wang, Xiaochang C; Li, Yu-You; Huang, Yue; Xue, Tao; Guo, Hongbing; Wang, Nan; Zhang, Lu

2017-02-15

Increasing use of reclaimed wastewater (RW) for replenishing urban landscape ponds has aroused public concern about the water quality. Three ponds replenished with RW in three cities in China were chosen to investigate 22 indexes of water quality in five categories. This was achieved by comparing three pairs of ponds in the three different cities, where one pond in each pair was replenished with RW and the other with surface water (SW). The nutrients condition, heavy metal concentration and ecotoxicity did not differ significantly between RW- and SW-replenished ponds. By contrast, significant differences were observed in algal growth and pathogen risk. RW ponds presented a Cyanophyta-Chlorophyta-Bacillariophyta type with high algal diversity while SW ponds presented a Cyanophyta type with low diversity. Regrowth of bacterial pathogens and especially survival of viral pathogens in RW, was the main driver behind the higher risk for RW ponds compared with SW ones. The duration of RW replenishment was proved to have a marked impact on the algal growth and pathogen risk. With continued RW replenishment, non-dominant algal species subjected to decrease while dominant species were enhanced resulting in the biomass increasing but diversity declining, and the risk posed by viral pathogens might become greater. Copyright © 2016 Elsevier B.V. All rights reserved.

Preventive Detention in the War on Terror: A Plan for a More Moderate and Sustainable Solution

Science.gov (United States)

2008-12-01

claimed by the U.S. government are in any sense normal, even for a situation of national crisis.”538 Malaysia and Singapore have preventive detention...Representatives) could, while we still have the leisure , turn their considerable talents to deliberating how to fix a strained and mismatched legal system, before

216-U-10 Pond and 216-Z-19 Ditch characterization studies

Energy Technology Data Exchange (ETDEWEB)

Last, G.V.; Duncan, D.W.; Graham, M.J.; Hall, M.D.; Hall, V.W.; Landeen, D.S.; Leitz, J.G.; Mitchell, R.M.

1994-02-01

The chemical, reprocessing of spent nuclear fuels at the US Department of Energy`s Hanford Site has generated large volumes of radioactive liquid effluents. The majority of these effluents have been used strictly for cooling or other supportive functions and have been discharged to ditches and ponds. The 216-U-10 Pond and 216-Z-19 Ditch are two such disposal facilities. These facilities are components of an integrated system of ditches, ponds, and overflow facilities collectively referred to as the U-Pond disposal system. The U-Pond system has been used since 1943 and has received a large variety of radioisotopes from several sources. This study covered tho major aspects of the environment, including wind resuspension, biological uptake and transport, geologic distribution in surface and subsurface sediments, and ground-water impacts. The long-term use of U-Pond and the Z-19 Ditch has resulted in the localized accumulation of transuranic and fission product inventories as a result of sorption and filtration of particulates onto the uppermost sediments.

Concentrated Brine Treatment using New Energy in Coal Mine Evaporation Ponds

Science.gov (United States)

Li, Ting; Li, Jingfeng

2017-12-01

Recently, more and more coal mine water is being advanced treated and reused in China. The concentrated brine that results from advanced treatment methods can only be evaporated in an evaporation pond. Because of limited treatment capabilities and winter freezing, evaporation ponds often overflow, causing environment contamination. In this paper, based on analysis of brine water quality and economic-technical feasibility, we present a suitable treatment method for brine in evaporation ponds as electrodialysis using solar energy. In addition, we propose a new system to treat brine in coal mine evaporation ponds, which is powered by solar and wind. The operating efficiency of this treatment system proposed in this paper can meet the concentrated brine treatment demands in most coal mines in western mining areas of China and it places the photovoltaic power generation plates on the surface of the evaporation pond on a fixed floating island, which reduces any risk associated with land acquisition. This system can enhance brine treatment efficiency, requires a reduced evaporation pond area, increases the utilization of coal mine water, and minimizes the risk of environment contamination.

216-U-10 Pond and 216-Z-19 Ditch characterization studies

International Nuclear Information System (INIS)

Last, G.V.; Duncan, D.W.; Graham, M.J.; Hall, M.D.; Hall, V.W.; Landeen, D.S.; Leitz, J.G.; Mitchell, R.M.

1994-02-01

The chemical, reprocessing of spent nuclear fuels at the US Department of Energy's Hanford Site has generated large volumes of radioactive liquid effluents. The majority of these effluents have been used strictly for cooling or other supportive functions and have been discharged to ditches and ponds. The 216-U-10 Pond and 216-Z-19 Ditch are two such disposal facilities. These facilities are components of an integrated system of ditches, ponds, and overflow facilities collectively referred to as the U-Pond disposal system. The U-Pond system has been used since 1943 and has received a large variety of radioisotopes from several sources. This study covered tho major aspects of the environment, including wind resuspension, biological uptake and transport, geologic distribution in surface and subsurface sediments, and ground-water impacts. The long-term use of U-Pond and the Z-19 Ditch has resulted in the localized accumulation of transuranic and fission product inventories as a result of sorption and filtration of particulates onto the uppermost sediments

Preface: conservation of european ponds-current knowledge and future needs

OpenAIRE

Miracle, Rosa; Oertli, Beat; Céréghino, Régis; Hull, Andrew P.

2010-01-01

Ponds are common elements of the landscape with an important role in the global processes of biosphere and biodiversity preservation. Recent research indicates that ecological characteristics of ponds are different from other inland water systems, but scientific knowledge is still insufficient and poor compared to lakes and rivers. Therefore, whilst indicators and conservation tools have been developed for most aquatic systems, there is also a gap between existing basic information on pond ec...

A comparison between evaporation ponds and evaporation surfaces as a source of the concentrated salt brine for salt gradient maintenance at Tajoura solar pond

International Nuclear Information System (INIS)

Ramadan, Abdulghani M.; Agha, Khairy R.; Abughres, M.

2012-01-01

One of the main problems that negatively affect the operation of salt gradient solar ponds and influence its thermal stability is the maintenance of salt gradient profile. Evaporation pond (EP) is designed to generate the salt which lost upward salt diffusion from the lower convective zone (LCZ) of the solar pond. Another attractive method is the evaporation surface facility (ES). Regions with moderate to high precipitation favor Evaporation Surface over Evaporation Ponds. Dry climates will generally favor Evaporation Ponds for the brine re-concentration. In previous studies [1-3], the authors have shown that the (EP) of Tajoura's Experimental Solar Pond (TESP) is under sized and can provide only about 30% of the salt required by a Salt Gradient Solar Pond (SGSP). The anticipated size of (EP) was estimated and presented in those studies under different design conditions, including Summer, Autumn and Spring designs, while the winter design was excluded due to the low rates of net evaporation during the winter season. In addition, the results presented were predicted for the first three years of operation. The daily variations of brine concentration in the (EP) of (TESP) and those based on different designs were predicted and discussed under different scenarios. The quantities of brine provided by the evaporation pond and that required by SGSP were predicted for both cases of surface water flushing (fresh water and sea-water) under the different design conditions as shown in Table 1. This paper investigates the differences between (EP) and (ES) both as a source for salt brine generation by evaporation. The effect of (EP) depth on the area ratio and daily variations of salt concentrations for three years of operation is shown. Results show that evaporation can be a reasonable method for salt brine generation. Reducing the depth of (EP) improves the capability of (EP) for brine re-concentration. It also increases the (EP) surface area for the same quantity of

Biological removal of algae in an integrated pond system

CSIR Research Space (South Africa)

Meiring, PGJ

1995-01-01

Full Text Available A system of oxidation ponds in series with a biological trickling filter is described. It was known that this arrangement was incapable of reducing effectively the levels of algae present in the pond liquid even though nitrification was effected...

Thaw pond dynamics and carbon emissions in a Siberian lowland tundra landscape

Science.gov (United States)

van Huissteden, Ko; Heijmans, Monique; Dean, Josh; Meisel, Ove; Goovaerts, Arne; Parmentier, Frans-Jan; Schaepman-Strub, Gabriela; Belelli Marchesini, Luca; Kononov, Alexander; Maximov, Trofim; Borges, Alberto; Bouillon, Steven

2017-04-01

Arctic climate change induces drastic changes in permafrost surface wetness. As a result of thawing ground ice bodies, ice wedge troughs and thaw ponds are formed. Alternatively, ongoing thaw may enhance drainage as a result of increased interconnectedness of thawing ice wedge troughs, as inferred from a model study (Liljedahl et al., 2016, Nature Geoscience, DOI: 10.1038/NGEO2674). However, a recent review highlighted the limited predictability of consequences of thawing permafrost on hydrology (Walvoord and Kurylyk, 2016, Vadose Zone J., DOI:10.2136/vzj2016.01.0010). Overall, these changes in tundra wetness modify carbon cycling in the Arctic and in particular the emissions of CO2 and CH4 to the atmosphere, providing a possibly positive feedback on climate change. Here we present the results of a combined remote sensing, geomorphological, vegetation and biogechemical study of thaw ponds in Arctic Siberian tundra, at Kytalyk research station near Chokurdakh, Indigirka lowlands. The station is located in an area dominated by Pleistocene ice-rich 'yedoma' sediments and drained thaw lake bottoms of Holocene age. The development of three types of ponds in the Kytalyk area (polygon centre ponds, ice wedge troughs and thaw ponds) has been traced with high resolution satellite and aerial imagery. The remote sensing data show net areal expansion of all types of ponds. Next to formation of new ponds, local vegetation change from dry vegetation types to wet, sedge-dominated vegetation is common. Thawing ice wedges and thaw ponds show an increase in area and number at most studied locations. In particular the area of polygon centre ponds increased strongly between 2010 and 2015, but this is highly sensitive to antecedent precipitation conditions. Despite a nearly 60% increase of the area of thawing ice wedge troughs, there is no evidence of decreasing water surfaces by increasing drainage through connected ice wedge troughs. The number of thaw ponds shows an equilibrium

PRACTICAL SOLUTIONS FOR ECOLOGICAL RECONSTRUCTION OF GERAI POND

Directory of Open Access Journals (Sweden)

Alexandru Dimache

2012-06-01

Full Text Available Gerai Pond is one of the last natural wetlands along the Danube, being connected to natural flooding regime of the Danube and is situated at the confluence of the Danube River, between Gârcov and Islaz localities, in Olt County. Aquatic vegetation characteristic is a favorable habitat for two species of conservation concern that nest along the Danube: red duck and pygmy cormorant. During 1961-1970, Gerai Pond has changed radically due to impoundment and draining under the program of drainage and flood meadow regulate of the Danube. These works of land reclamation for decreasing surface lakes and wetlands and water stagnation period, had reduced the breeding areas of the two species mentioned above. Ecological reconstruction of Gerai Pond project was conducted by Technical University of Civil Engineering of Bucharest in collaboration with E.P.A. Olt and W.W.F.-Romania. The project was based on a hydrological study (which included a component related to flooding for the area analyzed, study in which were highlighted the areas which have water access to and from the Pond, surfaces and volumes of water corresponding to different rates, the optimal level of water for restoration of the nesting area. Based on this study were identified the areas of artificial feed-water discharge to and from the Danube. This paper presents the possible solutions for ecological reconstruction of Gerai Pond, identified in the project.

Preliminary study on the coconut crab (Birgus latro rearing in captive pond

Directory of Open Access Journals (Sweden)

. Sulistiono

2009-01-01

Full Text Available Preliminary study on the coconut crab (Birgus latro rearing was employed in captive pond at Citarate village, Lebak Regency (Banten from May to December 2008.  The rearing activity was done in captive pond sized 5x5x1.3 m3 divided into 22 smaller ponds sized 1x1x1.3 m3 with a hiding hole (constructed by pile stones, supported by two small ponds sized 30x40x40 cm3 for sea and fresh water stocks, respectively.  The coconut crab (N=22 individuals at cement pond I and N=18 individuals at cement pond II were reared in each small ponds (density: 1 individual/pond, feed by a piece of coconut (20-50 gram per individual in each cement pond.  The coconut and the water (sea and fresh water were replaced for 2-3 times per week. Result of the study showed that survival rate was around 82% (ponds I and 83% (ponds II, and mortality was around 18% (ponds I and 18% (ponds II. The coconut crab growth at captive ponds I and II were around 17.5 and 52 gram per month, respectively. Key words:  Preliminary study, rearing, coconut crab (Birgus latro   ABSTRAK Uji coba pemeliharaan kepiting kelapa (Birgus latro dilakukan di kolam penangkaran di Desa Citarate, Kabupaten Lebak (Banten pada Bulan Mei sampai Desember 2008.  Kegiatan pemeliharaan dilakukan pada bak semen berukuran 5x5x1.3 m2 yang terbagi menjadi 22 bak semen lebih kecil yang berukuran 1x1x1.3 m3 dilengkapi dengan tempat persembunyian (berupa tumpukan batu, serta bak kecil sebagai tempat penampungan air laut dan tawar masing-masing berukuran 30x40x40 cm3. Kepiting kelapa (N=22 ekor pada kolam I dan N=18 pada kolam II dimasukkan ke dalam setiap kolam (kepadatan 1 individu/kolam, dan diberikan pakan utama berupa potongan kelapa ukuran sekitar 20-50 gram per individu per kolam.  Penggantian kelapa dan air (tawar dan laut dilakukan 2-3 kali per minggu. Hasil uji coba pemeliharaan kepiting kelapa menunjukkan bahwa tingkat sintasan (survival rate di kolam peliharaan berkisar 82 (Kolam I dan 83% (Kolam II

Preparation of coal slurries deposited in ground settling ponds

Directory of Open Access Journals (Sweden)

Wiesław Blaschke

2005-11-01

Full Text Available As a result of the hard coal washing process, considerable quantities of coal slimes are generated. They belong to grain size classes below 1, 0 mm (with the majority of grains below 0,035 mm and are often sold in order to prepare blends for the power generation. It is assessed that in Poland about 11 mln tons of such slimes were deposited. The slimes of a low ash content can be exploited and sold. The slime of high ash content must be washed. In Poland there is one coal preparation plant for slurries. The article describes the technology and presents the results of a simplified economic analysis of exploitation of the slurries and their washing.

Visibility from roads predict the distribution of invasive fishes in agricultural ponds.

Science.gov (United States)

Kizuka, Toshikazu; Akasaka, Munemitsu; Kadoya, Taku; Takamura, Noriko

2014-01-01

Propagule pressure and habitat characteristics are important factors used to predict the distribution of invasive alien species. For species exhibiting strong propagule pressure because of human-mediated introduction of species, indicators of introduction potential must represent the behavioral characteristics of humans. This study examined 64 agricultural ponds to assess the visibility of ponds from surrounding roads and its value as a surrogate of propagule pressure to explain the presence and absence of two invasive fish species. A three-dimensional viewshed analysis using a geographic information system quantified the visual exposure of respective ponds to humans. Binary classification trees were developed as a function of their visibility from roads, as well as five environmental factors: river density, connectivity with upstream dam reservoirs, pond area, chlorophyll a concentration, and pond drainage. Traditional indicators of human-mediated introduction (road density and proportion of urban land-use area) were alternatively included for comparison instead of visual exposure. The presence of Bluegill (Lepomis macrochirus) was predicted by the ponds' higher visibility from roads and pond connection with upstream dam reservoirs. Results suggest that fish stocking into ponds and their dispersal from upstream sources facilitated species establishment. Largemouth bass (Micropterus salmoides) distribution was constrained by chlorophyll a concentration, suggesting their lower adaptability to various environments than that of Bluegill. Based on misclassifications from classification trees for Bluegill, pond visual exposure to roads showed greater predictive capability than traditional indicators of human-mediated introduction. Pond visibility is an effective predictor of invasive species distribution. Its wider use might improve management and mitigate further invasion. The visual exposure of recipient ecosystems to humans is important for many invasive species that

Par Pond vegetation status Summer 1995 -- October survey descriptive summary

International Nuclear Information System (INIS)

Mackey, H.E. Jr.; Riley, R.S.

1995-11-01

The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the emergent shoreline aquatic plant communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level and continued with this late October survey. Communities similar to the pre-drawdown Par Pond aquatic plant communities are becoming re-established; especially, beds of maiden cane, lotus, waterlily, and watershield are now extensive and well established. Cattail occurrence continues to increase, but large beds common to Par Pond prior to the drawdown have not formed. Future surveys throughout 1996 and 1997, along with the continued evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned

Par Pond vegetation status Summer 1995 -- September survey descriptive summary

International Nuclear Information System (INIS)

Mackey, H.E. Jr.; Riley, R.S.

1995-09-01

The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the emergent shoreline aquatic plant communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level and continued with this mid-September survey. Communities similar to the pre-drawdown Par Pond aquatic plant communities are becoming re-established; especially, beds of maidencane, lotus, waterlily, and watershield are now extensive and well established. Cattail occurrence continues to increase, but large beds common to Par Pond prior to the drawdown have not formed. Future surveys during the late growing seasons of 1995, and throughout 1996 and 1997, along with the evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned

Efficacy of an HIV/STI sexual risk-reduction intervention for African American adolescent girls in juvenile detention centers: a randomized controlled trial.

Science.gov (United States)

DiClemente, Ralph J; Davis, Teaniese L; Swartzendruber, Andrea; Fasula, Amy M; Boyce, Lorin; Gelaude, Deborah; Gray, Simone C; Hardin, James; Rose, Eve; Carry, Monique; Sales, Jessica M; Brown, Jennifer L; Staples-Horne, Michelle

2014-01-01

Few HIV/STI interventions exist for African American adolescent girls in juvenile detention. The objective was to evaluate the efficacy of an intervention to reduce incident STIs, improve HIV-preventive behaviors, and enhance psychosocial outcomes. We conducted a randomized controlled trial among African American adolescent girls (13-17 years, N = 188) in juvenile detention from March 2011 to May 2012. Assessments occurred at baseline and 3- and 6-months post-randomization and included: audio computer-assisted self-interview, condom skills assessment, and self-collected vaginal swab to detect Chlamydia and gonorrhea. The Imara intervention included three individual-level sessions and four phone sessions; expedited partner therapy was offered to STI-positive adolescents. The comparison group received the usual care provided by the detention center: STI testing, treatment, and counseling. At the 6-month assessment (3-months post-intervention), Imara participants reported higher condom use self-efficacy (p incident Chlamydia or gonorrhea infections, condom use, or number of vaginal sex partners. Imara for detained African American adolescent girls can improve condom use skills and psychosocial outcomes; however, a critical need for interventions to reduce sexual risk remains.

Review and evaluation of information on the thermal performance of ultimate heat sinks: spray ponds and cooling ponds

International Nuclear Information System (INIS)

Drake, R.L.

1975-09-01

A report is presented which identifies and evaluates available information and data useful in validating and improving existing models for the thermal performance of ultimate heat sinks. Included are discussions of the thermal elements of cooling ponds and spray ponds, the available information and data pertinent to the problem, and the requirements and needs for further research and performance data. An outline is presented of the necessary elements required for a performance test of an ultimate heat sink before the system is thermally approved. (auth)

Implementation outcomes of Multidimensional Family Therapy-Detention to Community: a reintegration program for drug-using juvenile detainees.

Science.gov (United States)

Liddle, Howard A; Dakof, Gayle A; Henderson, Craig; Rowe, Cindy

2011-06-01

Responding to urgent calls for effective interventions to address young offenders' multiple and interconnected problems, a new variant of an existing empirically-validated intervention for drug-using adolescents, Multidimensional Family Therapy (MDFT)-Detention to Community (DTC) was tested in a two-site controlled trial. This article (a) outlines the rationale and protocol basics of the MDFT-DTC intervention, a program for substance-using juvenile offenders that links justice and substance abuse treatment systems to facilitate adolescents' post-detention community reintegration; (b) presents implementation outcomes, including fidelity, treatment engagement and retention rates, amount of services received, treatment satisfaction, and substance abuse-juvenile justice system collaboration outcomes; and (c) details the implementation and sustainability challenges in a cross-system (substance abuse treatment and juvenile justice) adolescent intervention. Findings support the effectiveness of the MDFT-DTC intervention, and the need to develop a full implementation model in which transfer and dissemination issues could be explored more fully, and tested experimentally.

Self-represented witnessing: the use of social media by asylum seekers in Australia's offshore immigration detention centres.

Science.gov (United States)

Rae, Maria; Holman, Rosa; Nethery, Amy

2018-05-01

The act of witnessing connects audiences with distant suffering. But what happens when bearing witness becomes severely restricted? External parties, including the mainstream news media, are constrained from accessing Australia's offshore immigration detention centres. The effect is that people seeking asylum are hidden from the public and excluded from national debates. Some detainees have adopted social media as a platform to communicate their stories of flight, and their experiences of immigration detention, to a wider audience. This article examines the ways in which social media, and particularly Facebook, has facilitated what we call self-represented witnessing. We analyse two public Facebook pages to assess how detainees use such social media networks to document their experiences, and we observe the interaction between detainees, other social media users and mainstream media. Significantly, these social media networks enable detained asylum seekers to conduct an unmediated form of self-represented witnessing that exposes human rights abuses and documents justice claims.

Ash dust co-centration in the vicinity of the ash disposal site depending on the size of the pond (“Water Mirror”

Directory of Open Access Journals (Sweden)

Zoran Gršić

2010-09-01

Full Text Available Thermal power plants Nikola Tesla “A” and “B” are large sources of ash from their ashes/slag deposit sites. Total sizes of ashes/slag depots are 600ha and 382ha, with active cassettes having dimensions ∼200 ha and ∼130 ha. The active cassettes of the disposal sites are covered by rather large waste ponds, the sizes of vary depending on the working condition of a sluice system and on meteorological conditions. Modeling of ash lifting was attempted using results from the dust lifting research. The relation between sizes of ponds and air dust concentration in the vicinity of ash disposal sites was analyzed. As expected, greater sizes of dried disposal site surfaces in combination with stronger winds gave greater dust emission and greater air dust concentration.

Seismic Characterization of the Terrebonne Mini-basin, a Hydrate Rich Depositional System in the Gulf of Mexico

Science.gov (United States)

Dafov, L. N.; Eze, P. C.; Haines, S. S.; Graham, S. A.; McHargue, T.; Hosford Scheirer, A.

2017-12-01

Natural gas bearing hydrates are a focus of research as a potential source of energy and carbon storage because they occur globally in permafrost regions and marine sediment along every continent. This study focuses on the structural and stratigraphic architecture of the Terrebonne mini-basin, northwest Walker Ridge, Gulf of Mexico, to characterize the depositional architecture and to describe possible migration pathways for petroleum. Questions addressed include: a) continuity of sand layers b) effects of faulting and c) ponding versus fill and spill. To address these questions, seven of forty-two high resolution USGS 2D seismic lines were interpreted and then verified with WesternGeco 3D seismic data, yielding three qualitative models for the depositional environment of hydrate-bearing sand intervals. Deeper hydrate-bearing sand reservoirs were deposited as sheet-like turbidite lobes. Two shallower hydrate-bearing intervals display two possible depositional systems which form reservoirs- 1) sandy to muddy channel sealed laterally by muddy levees with associated sandy crevasse splays, and 2) ponded sandy lobes cut by channels filled with sand lags and mud. Additional observations in the 2D seismic include mass transport deposits and possible contourites. Salt movement facilitated mini-basin formation which was then ponded by sediment and followed by episodes of fill-and-spill and erosion. These seismic interpretations indicate periodic salt uplift. Overturn of salt along the northwestern edge of the basin resulted in thrust faults. The faults and erosional surfaces act as seals to reservoirs. The greatest volume of sandy reservoir potential occurs in sheet-like turbidite lobes with high lateral continuity, which facilitates updip migration of deep-sourced thermogenic gas along bedding surfaces. Channel levees serve as lateral seals to gas hydrate reservoirs, whereas faults, erosional surfaces, and shales provide vertical seals. Characterization of the Terrebonne

Groundwater monitoring plan for the Hanford Site 216-B-3 pond RCRA facility

International Nuclear Information System (INIS)

Barnett, D.B.; Chou, C.J.

1998-06-01

The 216-B-3 pond system was a series of ponds for disposal of liquid effluent from past Hanford production facilities. In operation since 1945, the B Pond system has been a RCRA facility since 1986, with Resource Conservation and Recovery Act (RCRA) interim-status groundwater monitoring in place since 1988. In 1994, discharges were diverted from the main pond, where the greatest potential for contamination was thought to reside, to the 3C expansion pond. In 1997, all discharges to the pond system were discontinued. In 1990, the B Pond system was elevated from detection groundwater monitoring to an assessment-level status because total organic halogens and total organic carbon were found to exceed critical means in two wells. Subsequent groundwater quality assessment failed to find any specific hazardous waste contaminant that could have accounted for the exceedances, which were largely isolated in occurrence. Thus, it was recommended that the facility be returned to detection-level monitoring

Supraglacial Ponds Regulate Runoff From Himalayan Debris-Covered Glaciers

Science.gov (United States)

Irvine-Fynn, Tristram D. L.; Porter, Philip R.; Rowan, Ann V.; Quincey, Duncan J.; Gibson, Morgan J.; Bridge, Jonathan W.; Watson, C. Scott; Hubbard, Alun; Glasser, Neil F.

2017-12-01

Meltwater and runoff from glaciers in High Mountain Asia is a vital freshwater resource for one-fifth of the Earth's population. Between 13% and 36% of the region's glacierized areas exhibit surface debris cover and associated supraglacial ponds whose hydrological buffering roles remain unconstrained. We present a high-resolution meltwater hydrograph from the extensively debris-covered Khumbu Glacier, Nepal, spanning a 7 month period in 2014. Supraglacial ponds and accompanying debris cover modulate proglacial discharge by acting as transient and evolving reservoirs. Diurnally, the supraglacial pond system may store >23% of observed mean daily discharge, with mean recession constants ranging from 31 to 108 h. Given projections of increased debris cover and supraglacial pond extent across High Mountain Asia, we conclude that runoff regimes may become progressively buffered by the presence of supraglacial reservoirs. Incorporation of these processes is critical to improve predictions of the region's freshwater resource availability and cascading environmental effects downstream.

Biological export of radioactive materials from a leaching pond in SE Idaho

International Nuclear Information System (INIS)

Millard, Jere B.

1978-01-01

A radioecological investigation was conducted to quantify biological export of radioactive materials from a test reactor area leaching pond located on the Idaho National Engineering Laboratory site in southeast Idaho. An estimated 42,000 Ci have been discharged to the pond since 1952. Approximately 35 gamma emitting radionuclides are detectable in unfiltered water. Biomass estimates and mean radionuclide concentrations were determined for major pond compartments. A radionuclide inventory of the pond ecosystem was constructed listing totals for radioactivity present in each compartment. Mean concentrations of predominant radionuclides and population census data were used to estimate biologically exported materials. Particular attention was paid to migrant waterfowl, a resident population of barn swallows (Hirundo rustica), and nesting shore birds. Whole body gamma spectra indicated 15 or more detectable fission and activation products associated with swallows and shore birds, and 20 or more for waterfowl. Concentration factors relative to filtered pond water were also calculated. Finally, biologically exported radioactive materials were compared with total amounts present in the pond. (author)

Remediation of an oily leachate pond in Estonia.

Science.gov (United States)

Kriipsalu, Mait; Marques, Marcia; Hogland, William

2005-12-01

Until recent years, waste oil and oil-contaminated waters commonly ended up in landfills. At some dump sites, ponds of oily liquids and leachate were formed. To remediate such ponds, an interdisciplinary approach is now required, keeping costs at an affordable level, particularly in countries with changing economies. From 1974 to 1993, liquid oily wastes taken to the Laguja landfill, in Estonia, were disposed of in a pond with a surface area of 9800 m2. It was estimated that the pond contained 4500-6000 m3 of oily water and 3500 m3 of oil-containing bottom sediments. This study aimed at developing an environmentally sound and cost-effective method for remediation of the oily liquids, leachate and contaminated underlying sediment material, to meet the existing legal demands. It was concluded that treatment of contaminated water is well established and the procedures carried out to meet the regulatory demands achieved satisfactory results. However, regarding treatment of sediments it was concluded that legal and technological aspects, as well as monitoring procedures are not fully established and are usually underestimated. Laboratory investigations can provide valuable information in decision-making, and contribute to effective full-scale remediation planning.

Modeling the summertime evolution of sea-ice melt ponds

DEFF Research Database (Denmark)

Lüthje, Mikael; Feltham, D.L.; Taylor, P.D.

2006-01-01

We present a mathematical model describing the summer melting of sea ice. We simulate the evolution of melt ponds and determine area coverage and total surface ablation. The model predictions are tested for sensitivity to the melt rate of unponded ice, enhanced melt rate beneath the melt ponds...

Mercury in the atmosphere, snow and melt water ponds in the North Atlantic Ocean during Arctic summer.

Science.gov (United States)

Aspmo, Katrine; Temme, Christian; Berg, Torunn; Ferrari, Christophe; Gauchard, L Pierre-Alexis; Fain, Xavier; Wibetoe, Grethe

2006-07-01

Atmospheric mercury speciation measurements were performed during a 10 week Arctic summer expedition in the North Atlantic Ocean onboard the German research vessel RV Polarstern between June 15 and August 29, 2004. This expedition covered large areas of the North Atlantic and Arctic Oceans between latitudes 54 degrees N and 85 degrees N and longitudes 16 degrees W and 16 degrees E. Gaseous elemental mercury (GEM), reactive gaseous mercury (RGM) and mercury associated with particles (Hg-P) were measured during this study. In addition, total mercury in surface snow and meltwater ponds located on sea ice floes was measured. GEM showed a homogeneous distribution over the open North Atlantic Ocean (median 1.53 +/- 0.12 ng/m3), which is in contrast to the higher concentrations of GEM observed over sea ice (median 1.82 +/- 0.24 ng/m3). It is hypothesized that this results from either (re-) emission of mercury contained in snow and ice surfaces that was previously deposited during atmospheric mercury depletion events (AMDE) in the spring or evasion from the ocean due to increased reduction potential at high latitudes during Arctic summer. Measured concentrations of total mercury in surface snow and meltwater ponds were low (all samples RGM and Hg-P without a significant diurnal variability. These results indicate that the production and deposition of these reactive mercury species do not significantly contribute to the atmospheric mercury cycle in the North Atlantic Ocean during the Arctic summer.

Don Quixote Pond: A Small Scale Model of Weathering and Salt Accumulation

Science.gov (United States)

Englert, P.; Bishop, J. L.; Patel, S. N.; Gibson, E. K.; Koeberl, C.

2015-01-01

The formation of Don Quixote Pond in the North Fork of Wright Valley, Antarctica, is a model for unique terrestrial calcium, chlorine, and sulfate weathering, accumulation, and distribution processes. The formation of Don Quixote Pond by simple shallow and deep groundwater contrasts more complex models for Don Juan Pond in the South Fork of Wright Valley. Our study intends to understand the formation of Don Quixote Pond as unique terrestrial processes and as a model for Ca, C1, and S weathering and distribution on Mars.

Feeding selectivity of wild and pond-cultured Nile tilapia ...

African Journals Online (AJOL)

A comparison of feeding selectivity of wild and pond-cultured Nile tilapia Oreochromis niloticus was conducted in 2008. Water and fish samples were collected in Shirati Bay, Lake Victoria, and from fish ponds in Tarime district using a La Motte water sampler and seine nets, respectively. Cyanophytes were abundant and ...

Balancing the Ecological Function of Residential Stormwater Ponds with Homeowner Landscaping Practices

Science.gov (United States)

Monaghan, Paul; Hu, Shangchun; Hansen, Gail; Ott, Emily; Nealis, Charles; Morera, Maria

2016-11-01

Stormwater ponds are installed in urban developments to provide the ecosystem services of flood control and water treatment. In coastal areas, these ponds are connected to watersheds that can drain directly into protected estuaries, making their design, function, and maintenance critical to environmental protection. However, stormwater ponds in residential areas are increasingly managed as aesthetic amenities that add value to real estate rather than as engineered devices with special maintenance requirements. To help extend the life of neighborhood stormwater systems and improve ecosystem services, homeowners should follow best management practices for nutrient management and add shoreline plantings and non-invasive, beneficial aquatic plants to their ponds. This study used focus group and survey research to document the knowledge, behaviors, and attitudes of homeowners living near stormwater ponds in a master-planned community in Florida. The study was designed to use a social marketing research approach to promote Extension best practices. Findings indicate that many residents were aware of the functional components of stormwater systems and respondents' receptivity to best management practices was mediated by age, their attitudes about water quality and whether their home was adjacent to a pond. These findings can be used to target Extension audiences and improve adoption of stormwater pond best management practices for increased protection of water quality.

Par Pond vegetation status Summer 1995 -- June survey descriptive summary

International Nuclear Information System (INIS)

Mackey, H.E. Jr.; Riley, R.S.

1995-06-01

The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the shoreline aquatic plant communities in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level, indicated that much of the original plant communities and the intermediate shoreline communities present on the exposed sediments have been lost. The extensive old-field and emergent marsh communities that were present on the exposed shoreline during the drawdown have been flooded and much of the pre-drawdown Par Pond aquatic plant communities have not had sufficient time for re-establishment. The shoreline does, however, have extensive beds of maidencane which extend from the shoreline margin to areas as deep as 2 and perhaps 3 meters. Scattered individual plants of lotus and watershield are common and may indicate likely directions of future wetland development in Par Pond. In addition, within isolated coves, which apparently received ground water seepage and/or stream surface flows during the period of the Par Pond draw down, extensive beds of waterlilies and spike rush are common. Invasion of willow and red maple occurred along the lake shoreline as well. Although not absent from this survey, evidence of the extensive redevelopment of the large cattail and eel grass beds was not observed in this first survey of Par Pond. Future surveys during the growing seasons of 1995, 1996, and 1997 along with the evaluation of satellite date to map the areal extent of the macrophyte beds of Par Pond are planned

Influences of radiation on carp from farm ponds in Fukushima

International Nuclear Information System (INIS)

Suzuki, Yuzuru

2015-01-01

A massive release of artificial radionuclides from the Fukushima Dai-ichi Nuclear Power Plant caused radioactive contamination of farms as well as of aquatic products. Carp in small ponds in the highly radiocontaminated area of Iitate Village, Fukushima Prefecture, have been confined to the ponds since the accident, and it is thought that the carp may have suffered health issues as a result. Therefore, I investigated the health condition of the carp in order to elucidate the effects of radiation. Blood neutrophil, monocyte and lymphocyte counts in the carp from three ponds in Fukushima were lower than those in carp from a non-polluted pond in Tochigi Prefecture. Histological observations indicated abnormal hyperplasia of macrophages in the spleen, kidney, liver and pancreas of carp in Fukushima. Although there are likely to have been deleterious effects on carp health due to the radiation in Fukushima, this has not yet been confirmed because only one control pond was available for comparison, and I was not able to find any symptoms in the carp that correlated with internal cesium concentration. Further research is now being conducted to investigate the effects of radiation on carp

Metal removal from tailings ponds water using indigenous micro-algae

Energy Technology Data Exchange (ETDEWEB)

Mahdavi, H.; Ulrich, A.; Liu, Y. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering

2010-07-01

Each barrel of oil produced by oil sands produce 1.25 m{sup 3} of tailings. The tailings are collected in ponds located at mining sites. The tailing pond water (TPW) must be reclaimed and released into the environment. This PowerPoint presentation discussed a method of removing metals from tailings pond water that used indigenous micro-algae. The in situ experimental method used Parachlorella kessliri to treat 2 ponds. The TPW was enriched with low and high concentrations of nutrients. Dry cell biomass analyses were then conducted, and the pH of the resulting samples was compared. Inductively coupled plasma mass spectrometry analysis methods were used to determine the initial metal concentrations in the raw TPWs. The study showed that the micro-algae remove significantly more metals when high levels of nutrients are used. tabs., figs.

Nutrient availability limits biological production in Arctic sea ice melt ponds

DEFF Research Database (Denmark)

Sørensen, Heidi Louise; Thamdrup, Bo; Jeppesen, Erik

2017-01-01

nutrient limitation in melt ponds. We also document that the addition of nutrients, although at relative high concentrations, can stimulate biological productivity at several trophic levels. Given the projected increase in first-year ice, increased melt pond coverage during the Arctic spring and potential......Every spring and summer melt ponds form at the surface of polar sea ice and become habitats where biological production may take place. Previous studies report a large variability in the productivity, but the causes are unknown. We investigated if nutrients limit the productivity in these first...... additional nutrient supply from, e.g. terrestrial sources imply that biological activity of melt ponds may become increasingly important for the sympagic carbon cycling in the future Arctic....

Patterns of Assemblage Structure Indicate a Broader Conservation Potential of Focal Amphibians for Pond Management.

Directory of Open Access Journals (Sweden)

Elin Soomets

Full Text Available Small freshwater ponds host diverse and vulnerable biotic assemblages but relatively few conspicuous, specially protected taxa. In Europe, the amphibians Triturus cristatus and Pelobates fuscus are among a few species whose populations have been successfully restored using pond restoration and management activities at the landscape scale. In this study, we explored whether the ponds constructed for those two target species have wider conservation significance, particularly for other species of conservation concern. We recorded the occurrence of amphibians and selected aquatic macro-invertebrates (dragonflies; damselflies; diving beetles; water scavenger beetles in 66 ponds specially constructed for amphibians (up to 8 years post construction and, for comparison, in 100 man-made ponds (created by local people for cattle or garden watering, peat excavation, etc. and 65 natural ponds in Estonia. We analysed nestedness of the species assemblages and its dependence on the environment, and described the co-occurrence patterns between the target amphibians and other aquatic species. The assemblages in all ponds were significantly nested, but the environmental determinants of nestedness and co-occurrence of particular species differed among pond types. Constructed ponds were most species-rich irrespective of the presence of the target species; however, T. cristatus was frequent in those ponds and rare elsewhere, and it showed nested patterns in every type of pond. We thus conclude that pond construction for the protected amphibians can serve broader habitat conservation aims in the short term. However, the heterogeneity and inconsistent presence of species of conservation concern observed in other types of ponds implies that long-term perspectives on pond management require more explicit consideration of different habitat and biodiversity values. We also highlight nestedness analysis as a tool that can be used for the practical task of selecting focal

A Summary of Best Management Practices for Nonpoint Source Pollution

Science.gov (United States)

1992-08-01

and concrete block material, and structures and systems for soil stabilization including erosion checks, revetments , retaining structures, and...industrial storage areas, and coal/ slag piles. Rural NPS pollution includes runoff from Some of the above sources plus runoff from agriculture...water quality. The effectiveness of detention ponds is reduced, however, when maintenance is neglected. Common problems include blocked outlets

Perched Lava Pond Complex on South Rift of Axial Volcano Revealed in AUV Mapping

Science.gov (United States)

Paduan, J. B.; Clague, D. A.; Caress, D. W.; Thomas, H. J.

2013-12-01

An extraordinary lava pond complex is located on Axial Volcano's distal south rift. It was discovered in EM300 multibeam bathymetry collected in 1998, and explored and sampled with ROVs Tiburon in 2005 and Doc Ricketts in 2013. It was surveyed with the MBARI Mapping AUV D. Allan B. in 2011, in a complicated mission first flying above the levees at constant depth, then skimming ~5 m over the levees at a different constant depth to survey the floors, then twice switching to constant altitude mode to map outside the ponds. The AUV navigation was adjusted using the MB-System tool mbnavadjust so that bathymetric features match in overlapping and crossing swaths. The ~1-m resolution AUV bathymetry reveals extremely rough terrain, where low-resolution EM300 data had averaged acoustic returns and obscured details of walls, floors, a breach and surrounding flows, and gives context to the ROV observations and samples. The 6 x 1.5 km pond complex has 4 large and several smaller drained ponds with rims 67 to 106 m above the floors. The combined volume before draining was 0.56 km3. The ponds overflowed to build lobate-flow levees with elongate pillows draping outer flanks, then drained, leaving lava veneer on vertical inner walls. Levee rim depths vary by only 10 m and are deeper around the southern ponds. Deep collapse-pits in the levees suggest porosity of pond walls. The eastern levee of the northeastern pond breached, draining the interconnected ponds, and fed thick, rapidly-emplaced, sheet-flows along the complex's east side. These flows travelled at least 5.5 km down-rift and have 19-33 m deep drained ponds. They extended up-rift as well, forming a 10 x 2.5 km ponded flow with level 'bathtub rings' as high as 35 m above the floor marking that flow's high-stand. Despite the breach, at least 0.066 km3 of the molten interior of the large ponds also drained back down the eruptive fissures, as the pond floors are deeper than the sill and sea floor outside the complex. Tumulus

Homestead fish pond and the environment in Nigeria

OpenAIRE

Okaeme, A.N.

1999-01-01

Homestead fish culture is a recent innovation for mass production of fish at backyard in Nigeria. The processes of pond construction often have resulted in soil disturbances, vegetation losses, and creation of new aquatic environment. The paper discusses homestead ponds in Nigeria, their potential impact on the environment which includes erosion, over flooding, pest and disease, accident risk, undesired fossil fuel production, vegetation destruction and fish genetic conservation, strategies f...

HRE-Pond Cryogenic Barrier Technology Demonstration: Pre- and Post-Barrier Hydrologic Assessment

International Nuclear Information System (INIS)

Moline, G.R.

1999-01-01

The Homogeneous Reactor Experiment (HRE) Pond is the site of a former impoundment for radioactive wastes on the Oak Ridge Reservation (ORR) in east Tennessee. The pond received radioactive wastes from 1957 to 1962, and was subsequently drained, filled with soil, and covered with an asphalt cap. The site is bordered to the east and south by an unnamed stream that contains significant concentrations of radioactive contaminants, primarily 90 Sr. Because of the proximity of the stream to the HRE disposal site and the probable flow of groundwater from the site to the stream, it was hypothesized that the HRE Pond has been a source of contamination to the creek. The HRE-Pond was chosen as the site of a cryogenic barrier demonstration to evaluate this technology as a means for rapid, temporary isolation of contaminants in the type of subsurface environment that exists on the ORR. The cryogenic barrier is created by the circulation of liquid CO 2 through a system of thermoprobes installed in boreholes which are backfilled with sand. The probes cool the subsurface, creating a vertical ice wall by freezing adjacent groundwater, effectively surrounding the pond on four sides. The purpose of this investigation was to evaluate the hydrologic conditions within and around the pond prior to, during, and after the cryogenic barrier emplacement. The objectives were (1) to provide a hydrologic baseline for post-banner performance assessment, (2) to confirm that the pond is hydraulically connected to the surrounding sediments, (3) to determine the likely contaminant exit pathways from the pond, and (4) to measure changes in hydrologic conditions after barrier emplacement in order to assess the barrier performance. Because relatively little information about the subsurface hydrology and the actual configuration of the pond existed, data from multiple sources was required to reconstruct this complex system

A new approach to the modeling of ultimate heat sink cooling ponds

International Nuclear Information System (INIS)

Policastro, A.J.; Wastag, M.; Paul, J.; Carhart, R.A.

1996-01-01

Ultimate heat sink (UHS) cooling pond thermal performance is analyzed by a new method in which zero, one, and three-dimensional models are used in combination. A typical UHS pond has an irregular shape covering 20 hectares at an average depth of 4 m with a heavy thermal load of 40 MWt (megawatts thermal) per hectare. The resulting flow field can be one, two or three dimensional. A three-dimensional numerical model (Paul 1983) is modified and used to determine the effective dimensionality of the pond under accident conditions. The model's surface heat transfer formulas and its predictions of thermal hydraulics are verified using laboratory and field data. The Paul model shows that, unlike normal cooling ponds, a typical UHS pond is vertically-mixed with only a longitudinal temperature variation. Buoyancy-driven circulations, strong discharge-to-intake flow, and rapid surface heat removal break down the usual vertical stratification. Predictions of the one-dimensional MITEMP model are shown to agree with Paul model predictions for a typical UHS pond at the Catawba Nuclear Power Plant

Comparison of phytoplankton communities in catfish split-pond aquaculture systems with conventional ponds

Science.gov (United States)

There has been a growing interest and use of variations of partitioned aquaculture systems (PAS) in recent years by the southeastern United States of America farmed catfish industry. Split-pond systems, one type of PAS, are designed to better manage fish waste byproducts (e.g., ammonia) and dissolv...

A holistic water depth simulation model for small ponds

Science.gov (United States)

Ali, Shakir; Ghosh, Narayan C.; Mishra, P. K.; Singh, R. K.

2015-10-01

Estimation of time varying water depth and time to empty of a pond is prerequisite for comprehensive and coordinated planning of water resource for its effective utilization. A holistic water depth simulation (HWDS) and time to empty (TE) model for small, shallow ephemeral ponds have been derived by employing the generalized model based on the Green-Ampt equation in the basic water balance equation. The HWDS model includes time varying rainfall, runoff, surface water evaporation, outflow and advancement of wetting front length as external inputs. The TE model includes two external inputs; surface water evaporation and advancement of wetting front length. Both the models also consider saturated hydraulic conductivity and fillable porosity of the pond's bed material as their parameters. The solution of the HWDS model involved numerical iteration in successive time intervals. The HWDS model has successfully evaluated with 3 years of field data from two small ponds located within a watershed in a semi-arid region in western India. The HWDS model simulated time varying water depth in the ponds with high accuracy as shown by correlation coefficient (R2 ⩾ 0.9765), index of agreement (d ⩾ 0.9878), root mean square errors (RMSE ⩽ 0.20 m) and percent bias (PB ⩽ 6.23%) for the pooled data sets of the measured and simulated water depth. The statistical F and t-tests also confirmed the reliability of the HWDS model at probability level, p ⩽ 0.0001. The response of the TE model showed its ability to estimate the time to empty the ponds. An additional field calibration and validation of the HWDS and TE models with observed field data in varied hydro-climatic conditions could be conducted to increase the applicability and credibility of the models.

Fertilization of Earth Ponds. II: Effects on Plankton Communities ...

African Journals Online (AJOL)

A study of the effects of slurry inorganic and organic of fertilizers on the production of phyto-and zooplankton in earth ponds was conducted in Central Scotland, U.K. over a period of one year. For the inorganic fertilization, replicate ponds were treated with low and high phosphorus (LP, HP), high phosphorus and nitrogen ...

Stochastic dynamics of melt ponds and sea ice-albedo climate feedback

Science.gov (United States)

Sudakov, Ivan

Evolution of melt ponds on the Arctic sea surface is a complicated stochastic process. We suggest a low-order model with ice-albedo feedback which describes stochastic dynamics of melt ponds geometrical characteristics. The model is a stochastic dynamical system model of energy balance in the climate system. We describe the equilibria in this model. We conclude the transition in fractal dimension of melt ponds affects the shape of the sea ice albedo curve.

Effects of marsh pond terracing on coastal wintering waterbirds before and after Hurricane Rita.

Science.gov (United States)

O'Connell, Jessica L; Nyman, John A

2011-11-01

From February to March 2005-2006, we surveyed wintering waterbirds to test effects of terracing on coastal pond use before and after Hurricane Rita. Marsh terracing is intended to slow coastal marsh loss in the Chenier Plain by slowing marsh erosion and encouraging vegetation expansion. Terraces also increase marsh edge in ponds, possibly benefiting waterbirds. We monitored paired terraced and unterraced ponds in three sites within southwestern Louisiana's Chenier Plain. Waterbirds were 75% more numerous in terraced than unterraced ponds. Waterbird richness was similar among ponds when corrected for number of individuals, suggesting terracing increased bird density but did not provide habitat unique from unterraced ponds. Birds were 93% more numerous following Hurricane Rita, mostly due to an influx of migrating waterfowl. Year round residents were similar in number before and after Hurricane Rita. Resident richness did not differ among years after correcting for number of observed individuals. Wading and dabbling foragers were more abundant in terraced ponds and these two guilds represented 74% of birds observed. We detected no difference among ponds for other guilds, i.e., probing, aerial, and diving foragers. Increasing proportion of mash edge increased bird density disproportionately: On average ponds with 10% edge had 6 birds observed and ponds with 30% edge had 16 birds observed. Terraces increased habitat interspersion and were an effective tool for increasing numbers of wintering waterfowl and wading birds. The extent to which terraces were sustainable following hurricane forces is unknown.

Effects of Marsh Pond Terracing on Coastal Wintering Waterbirds Before and After Hurricane Rita

Science.gov (United States)

O'Connell, Jessica L.; Nyman, John A.

2011-11-01

From February to March 2005-2006, we surveyed wintering waterbirds to test effects of terracing on coastal pond use before and after Hurricane Rita. Marsh terracing is intended to slow coastal marsh loss in the Chenier Plain by slowing marsh erosion and encouraging vegetation expansion. Terraces also increase marsh edge in ponds, possibly benefiting waterbirds. We monitored paired terraced and unterraced ponds in three sites within southwestern Louisiana's Chenier Plain. Waterbirds were 75% more numerous in terraced than unterraced ponds. Waterbird richness was similar among ponds when corrected for number of individuals, suggesting terracing increased bird density but did not provide habitat unique from unterraced ponds. Birds were 93% more numerous following Hurricane Rita, mostly due to an influx of migrating waterfowl. Year round residents were similar in number before and after Hurricane Rita. Resident richness did not differ among years after correcting for number of observed individuals. Wading and dabbling foragers were more abundant in terraced ponds and these two guilds represented 74% of birds observed. We detected no difference among ponds for other guilds, i.e., probing, aerial, and diving foragers. Increasing proportion of mash edge increased bird density disproportionately: On average ponds with 10% edge had 6 birds observed and ponds with 30% edge had 16 birds observed. Terraces increased habitat interspersion and were an effective tool for increasing numbers of wintering waterfowl and wading birds. The extent to which terraces were sustainable following hurricane forces is unknown.

No guts, no gains! The relation between living group climate and social development of juvenile delinquents in detention

NARCIS (Netherlands)

Heynen, E.J.E.

2016-01-01

One of the main goals of imprisonment of juvenile offenders is treatment and rehabilitation into the social world. Youth detention is living with strict rules and regulations and can negatively affect juvenile’s behavior. Today, there is abundant knowledge on the effects of individual treatment of

A highly sensitive underwater video system for use in turbid aquaculture ponds.

Science.gov (United States)

Hung, Chin-Chang; Tsao, Shih-Chieh; Huang, Kuo-Hao; Jang, Jia-Pu; Chang, Hsu-Kuang; Dobbs, Fred C

2016-08-24

The turbid, low-light waters characteristic of aquaculture ponds have made it difficult or impossible for previous video cameras to provide clear imagery of the ponds' benthic habitat. We developed a highly sensitive, underwater video system (UVS) for this particular application and tested it in shrimp ponds having turbidities typical of those in southern Taiwan. The system's high-quality video stream and images, together with its camera capacity (up to nine cameras), permit in situ observations of shrimp feeding behavior, shrimp size and internal anatomy, and organic matter residues on pond sediments. The UVS can operate continuously and be focused remotely, a convenience to shrimp farmers. The observations possible with the UVS provide aquaculturists with information critical to provision of feed with minimal waste; determining whether the accumulation of organic-matter residues dictates exchange of pond water; and management decisions concerning shrimp health.

Assessing metal pollution in ponds constructed for controlling runoff from reclaimed coal mines.

Science.gov (United States)

Miguel-Chinchilla, Leticia; González, Eduardo; Comín, Francisco A

2014-08-01

Constructing ponds to protect downstream ecosystems is a common practice in opencast coal mine reclamation. As these ponds remain integrated in the landscape, it is important to evaluate the extent of the effect of mine pollution on these ecosystems. However, this point has not been sufficiently addressed in the literature. The main objective of this work was to explore the metal pollution in man-made ponds constructed for runoff control in reclaimed opencast coal mines over time. To do so, we evaluated the concentration of ten heavy metals in the water, sediment, and Typha sp. in 16 runoff ponds ranging from 1 to 19 years old that were constructed in reclaimed opencast coal mines of northeastern Spain. To evaluate degree of mining pollution, we compared these data to those from a pit lake created in a local unreclaimed mine and to local streams as an unpolluted reference, as well as comparing toxicity levels in aquatic organisms. The runoff ponds showed toxic concentrations of Al, Cu, and Ni in the water and As and Ni in the sediment, which were maintained over time. Metal concentrations in runoff ponds were higher than in local streams, and macrophytes showed high metal concentrations. Nevertheless, metal concentrations in water and sediment in runoff ponds were lower than those in the pit lake. This study highlights the importance of mining reclamation to preserve the health of aquatic ecosystems and suggests the existence of chronic metal toxicity in the ponds, potentially jeopardizing pond ecological functions and services.

Seasonal dynamics of fish assemblage in a pond canal

Czech Academy of Sciences Publication Activity Database

Musil, J.; Adámek, Zdeněk; Baranyi, Ch.

2007-01-01

Roč. 15, č. 3-4 (2007), s. 217-226 ISSN 0967-6120. [New Challenges in Pond Aquaculture. České Budějovice, 26.04.2005-28.04.2005] Institutional research plan: CEZ:AV0Z60930519 Keywords : fish assemblage * pond canal * species richness * seasonal dynamics * alien species Subject RIV: GL - Fishing Impact factor: 0.828, year: 2007

DNR 100K Lakes - Fishing in the Neighborhood (FiN) Ponds

Data.gov (United States)

Minnesota Department of Natural Resources — This layer represents ponds included in DNR's Fishing in the Neighborhood (FiN) program. This program establishes local ponds to provide urban fishing opportunities...

Radionuclides behaviour in the silts-water system of a cooling pond

International Nuclear Information System (INIS)

Ol'khovik, Yu.A.; Kostyuchenko, N.G.; Koromyslichenko, T.I.

1989-01-01

As a result of the Chernobyl' accident a considerable amount of radioisotopes (1-5x10 5 Ci) concentrated in a cooling pond. A year later the accident a level of water contamination decreased by 2 orders, whereas the radionuclide distribution changed perceptibly. Processes of water self-decontamination in the cooling pond were considered. A forecast of water radiactivity level in the cooling pond in the summer of 1988 was made. 3 refs.; 1 refs.; 2 tabs

Revegetation of flue gas desulfurization sludge pond disposal sites

International Nuclear Information System (INIS)

Artiola, J.F.

1994-12-01

A comprehensive search of published literature was conducted to summarize research undertaken to date on revegetation of flue gas desulfurization (FGD) waste disposal ponds. A review of the physical and chemical properties of FGD sludges and wastes with similar characteristics is also included in order to determine the advantages and limitations of FGD sludge for plant growth. No specific guidelines have been developed for the revegetation of FGD sludge disposal sites. Survey studies showed that the wide-ranging composition of FGD wastes was determined primarily by the sulfur dioxide and other flue gas scrubbing processes used at powerplants. Sulfate rich (>90%CaSO 4 ) FGD sludges are physically and chemically more stable, and thus more amenable to revegetation. Because of lack of macronutrients and extremely limited microbial activity, FBD sludge ponds presented a poor plant growth environment without amendment. Studies showed the natural process of inoculation of the FGD sludge with soil microbes that promote plant growth be can after disposal but proceeded slowly. Revegetation studies reviewed showed that FGD sludges amended with soils supported a wider variety of plant species better and longer than abandoned FGD ponds. Two major types of plants have been successful in revegetation of FGD waste ponds and similar wastes: salt-tolerant plants and aquatic plants. A comprehensive list of plant species with potential for regetation of FGD sludge disposal pond sites is presented along with successful revegetation techniques

A temperature rise equation for predicting environmental impact and performance of cooling ponds

Energy Technology Data Exchange (ETDEWEB)

Serag-Eldin, M.A. [American Univ. in Cairo, Cairo (Egypt). Dept. of Mechanical Engineering

2009-07-01

Cooling ponds are used to cool the condenser water used in large central air-conditioning systems. However, larger cooling loads can often increase pond surface evaporation rates. A temperature-rise energy equation was developed to predict temperature rises in cooling ponds subjected to heating loads. The equation was designed to reduce the need for detailed meteorological data as well as to determine the required surface area and depth of the pond for any given design criteria. Energy equations in the presence and absence of cooling loads were subtracted from each other to determine increases in pond temperature resulting from the cooling load. The energy equations include solar radiation, radiation exchange with sky and surroundings, heat convection from the surface, evaporative cooling, heat conducted to the walls, and rate of change of water temperature. Results of the study suggested that the environmental impact and performance of the cooling pond is a function of temperature only. It was concluded that with the aid of the calculated flow field and temperature distribution, the method can be used to position sprays in order to produce near-uniform pond temperatures. 10 refs., 12 figs.

PONDS AND CLIMATE, THE GEOGRAPHICAL ASCENDANCY RELATIONSHIP (“LA BRENNE” CASE STUDY, FRANCE

Directory of Open Access Journals (Sweden)

Laurent TOUCHART

2012-03-01

Full Text Available Ponds and climate, the geographical ascendancy relationship (“La Brenne” case study, France. The climate influences markedly the volume of water ponds and lakes. However, the role and the influence of "small" water areas, and areas of ponds on the local climate remain poorly understood. Scientific studies for the Great Lakes have been made. Moreover, scientific studies on «small» water areas and areas of ponds do not exist until today. A first approach to study the area of ponds of “La Brenne” (Central Region, France was performed. The monthly climate data from some meteorological stations, with the reference station of “Issoudun”, located away from areas of ponds, were the basis of our analysis. The study focuses on the most representative climatic parameters. These are the temperature, precipitation and relative humidity. This first approach is used to distinguish and clarify the most important cases and relevant parameters in order to achieve a typology of criteria. Our results will be used for further study and quantify the real influence of "small" water areas and areas of ponds on the elements of the local climate.

Regional applicability and potential of salt-gradient solar ponds in the United States. Volume 2: Detailed report

Science.gov (United States)

Lin, E. I. H.

1982-03-01

A comprehensive assessment of the regional applicability and potential of salt-gradient solar ponds in the United States is provided. The assessment is focused on the general characteristics of twelve defined geographic regions. Natural resources essential to solar ponds are surveyed. Meteorological and hydrogeological conditions affecting pond performance are examined. Potentially favorable pond sites are identified. Regional thermal and electrical energy output from solar ponds is calculated. Selected pond design cases are studied. Five major potential market sectors are evaluated in terms of technical and energy-consumption characteristics, and solar-pond applicability and potential. Relevant pond system data and financial factors are analyzed. Solar-pond energy costs are compared with conventional energy costs. The assessment concludes that, excepting Alaska, ponds are applicable in all regions for at least two market sectors. Total solar pond energy supply potential in the five market sectors examined is estimated to be 8.94 quads/yr by the year 2000, approximately 7.2% of the projected total national energy demand.

Geo-engineering experiments in two urban ponds to control eutrophication

NARCIS (Netherlands)

Waaijen, G.; Oosterhout, J.F.X.; Douglas, G.C.; Lurling, M.F.L.L.W.

2016-01-01

Many urban ponds experience detrimental algal blooms as the result of eutrophication. During a two year field experiment, the efficacy of five in situ treatments to mitigate eutrophication effects in urban ponds was studied. The treatments targeted the sediment phosphorus release and were intended

Transferring prisoners within the EU framework: its cosmopolitan reflections and existing European detention norms

OpenAIRE

Deruiter, Rebecca

2015-01-01

A perverse side-effect of our interconnected world is that also crime crosses more and more borders. As a result, judicial cooperation in criminal matters is crucial before and after a criminal sentence. The increased global connectivity also gave rise to new paradigms in social sciences. As such, the paradigm of cosmopolitanism has been researched extensively in social sciences but has been largely neglected in criminology. By analyzing case law, European detention norms and EU legal instrum...

Invertebrate communities of Arctic tundra ponds as related to proximity to drill site reserve pits

International Nuclear Information System (INIS)

Byron, E.; Williams, N.; Hoffman, R.; Elder, B.

1994-01-01

Aquatic invertebrate communities were assessed for diversity and abundance in North Slope tundra ponds of Prudhoe Bay, Alaska during the summer of 1992 as part of an evaluation of potential effects of exposure to petroleum drill site reserve pits (previously used for storing drill site wastes). The invertebrate communities of these shallow, tundra ponds provide abundant food for migratory, aquatic birds that use this area during the summer breeding season. The study was designed to compare abundance and diversity estimates of invertebrates in ponds surrounding the drill sites that differed in distance (and presumed exposure) to drill site reserve pits. The pits, themselves, were not sampled as part of this study. Invertebrate abundance and diversity estimates, assessed as standard biological criteria, were evaluated relative to water chemistry of the ponds, distance to the gravel pads or reserve pits, and pond morphometry. The results indicated the importance of pond morphometry in determining the structure of the invertebrate community. Shallow, exposed ponds tended to be dominated by different invertebrate communities than deeper, narrow ponds at the margins of frost polygons. In contrast, pond chemistry and relative exposure to drill sites were not predictive of invertebrate abundance or diversity

Diffusion of single oxidation pond

Directory of Open Access Journals (Sweden)

Song Ruo-Yuan

2016-01-01

Full Text Available The hydraulic characteristic of an oxidation pond was studied by the tracer experiment, and an empirical formula of Peclet number was obtained, which can be well applied to the model of plug flow reactor with longitudinal diffusion.

Sub-tropical coastal lagoon salinization associated to shrimp ponds effluents

Science.gov (United States)

Cardoso-Mohedano, José-Gilberto; Lima-Rego, Joao; Sanchez-Cabeza, Joan-Albert; Ruiz-Fernández, Ana-Carolina; Canales-Delgadillo, Julio; Sánchez-Flores, Eric-Ivan; Páez-Osuna, Federico

2018-04-01

Anthropogenic salinization impacts the health of aquatic and terrestrial ecosystems worldwide. In tropical and subtropical areas, shrimp farm aquaculture uses water from adjacent ecosystems to fill the culture ponds, where enhanced evaporation cause salinization of discharged water. In this study, we studied water salinity before and after shrimp farm harvest and implemented a three-dimensional hydrodynamic model to assess the impact on a subtropical coastal lagoon that receives water releases from shrimp ponds. The shrimp pond discharge significantly increased the salinity of receiving waters, at least 3 psu over the local variation. In the worst-case salinization scenario, when harvest occurs after a long dry season, salinity could increase by up to 6 psu. The induced salinization due to shrimp pond effluents remained up to 2 tidal cycles after harvest, and could affect biota. The methodology and results of this study can be used to assess the impacts of shrimp aquaculture worldwide.

Ecological behavior of plutonium and americium in a freshwater pond

International Nuclear Information System (INIS)

Emery, R.M.; Klopfer, D.C.; Garland, T.R.; Weimer, W.C.

1975-03-01

A Pu processing waste pond on the Hanford Reservation has been studied since mid-1973 to characterize the pond's limnology and determine the ecological behavior in this ecosystem. About 8.1 kg of Pu was reported to have been discharged into waste trenches leading to the pond. Mean ratios of isotopes in the sediments are 0.85 for 238 Pu to 239 240 Pu, 0.61 for 241 Am to 238 Pu, and 0.49 for 241 Am to 239 240 Pu. Levels of Pu and Am in the interstitial water range from 0.5 to 13 pCi/g (dry wt. of sediment). For 238 Pu in pond water the mean concentration is 0.007 pCi/l, for 239 240 Pu it is 0.002 pCi/l, and for 241 Am it is 1.08 pCi/l. The remaining biota had Pu and Am levels which were generally well below those of the sediments. (U.S.)

On the risks from sediment and overlying water by replenishing urban landscape ponds with reclaimed wastewater.

Science.gov (United States)

Ao, Dong; Chen, Rong; Wang, Xiaochang C; Liu, Yanzheng; Dzakpasu, Mawuli; Zhang, Lu; Huang, Yue; Xue, Tao; Wang, Nan

2018-05-01

The extensive use of reclaimed wastewater (RW) as a source of urban landscape pond replenishment, stimulated by the lack of surface water (SW) resources, has raised public concern. Greater attention should be paid to pond sediments, which act as 'sinks' and 'sources' of contaminants to the overlying pond water. Three ponds replenished with RW (RW ponds) in three Chinese cities were chosen to investigate 22 indices of sediment quality in four categories: eutrophication, heavy metal, ecotoxicity and pathogens risk. RW ponds were compared with other ponds of similar characteristics in the same cities that were replenished with SW (SW ponds). Our results show a strong impact of RW to the eutrophication and pathogenic risks, which are represented by organic matter, water content, total nitrogen, total phosphorus and phosphorus fractions, and pathogens. In particular, total phosphorus concentrations in the RW pond sediments were, on average, 50% higher than those of SW ponds. Moreover, the content of phosphorus, extracted by bicarbonate/dithionite (normally represented by BD-P) and NaOH (NaOH-P), were 2.0- and 2.83-times higher in RW ponds, respectively. For pathogens, the concentrations of norovirus and rotavirus in RW pond sediments were, on average, 0.52 and 0.30- log times those of SW ponds. The duration of RW replenishment was proved to have a marked impact on the eutrophication and pathogens risks from sediments. The continued use of RW for replenishment increases the eutrophication risk, and the pathogens risk, especially by viral pathogens, becomes greater. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of a bentonite/soil mixture as a barrier for uranium ponds

International Nuclear Information System (INIS)

Osmanlioglu, A.E.

2002-01-01

Uranium mill tailings need safe management as they contain long-lived uranium and its daughters. Chemical treatment applied on these tailings to neutralize the acid solution and to stabilize the remaining radioactive elements. Then they are stored in ponds. These ponds are used for the accumulation of the solids and evaporation of the liquids. Sometimes the liquid returned to the plant for reuse. These applications are used to isolate the tailings from the environment. The purpose of this laboratory test is; initially to determine the effectiveness of bentonite/soil mixture as a barrier for uranium ponds. In this study, two experimental ponds equipped; with different two barriers in laboratory. Dimension of this container is; 120 cm in length, 100 cm in width and 100cm in depth. Sampling pipes were placed at different places of the container. First pond includes ordinary soil; second pond includes soil/bentonite mixture. Uranium mill tailing ponds were placed at the surfaces of these two systems. Uranium solution was prepared by using natural uranium ore. The solution was put into these ponds. These test carried out more than for 10 months. Passed solution was collected by sampling pipes and recorded. Amounts of passed solution were determined according to the location of discharge pipes. At the last stage of these tests, sampling from the different parts o the system has been carried out by small holes, which were opened from the surface by special sampling device. By this way, migration information about the upper parts of the sampling pipes has been received. Behaviour of uranium radionuclides and the effectiveness of the bentonite/soil mixture were experimentally determined. Bentonite/soil mixture layer has better ability to restrain the migration of uranium radionuclides. The performance of the ponds at the natural soil can be improved simply by mixing with bentonite during construction. Bentonite/soil mixture includes 5% bentonite, 95% ordinary soil in weight

Retrieval of sea ice thickness during Arctic summer using melt pond color

Science.gov (United States)

Istomina, L.; Nicolaus, M.; Heygster, G.

2016-12-01

The thickness of sea ice is an important climatic variable. Together with the ice concentration, it defines the total sea ice volume, is linked within the climatic feedback mechanisms and affects the Arctic energy balance greatly. During Arctic summer, the sea ice cover changes rapidly, which includes the presence of melt ponds, as well as reduction of ice albedo and ice thickness. Currently available remote sensing retrievals of sea ice thickness utilize data from altimeter, microwave, thermal infrared sensors and their combinations. All of these methods are compromised in summer in the presence of melt. This only leaves in situ and airborne sea ice thickness data available in summer. At the same time, data of greater coverage is needed for assimilation in global circulation models and correct estimation of ice mass balance.This study presents a new approach to estimate sea ice thickness in summer in the presence of melt ponds. Analysis of field data obtained during the RV "Polarstern" cruise ARK27/3 (August - October 2012) has shown a clear connection of ice thickness under melt ponds to their measured spectral albedo and to melt pond color in the hue-saturation-luminance color space from field photographs. An empirical function is derived from the HSL values and applied to aerial imagery obtained during various airborne campaigns. Comparison to in situ ice thickness shows a good correspondence to the ice thickness value retrieved in the melt ponds. A similar retrieval is developed for satellite spectral bands using the connection of the measured pond spectral albedo to the ice thickness within the melt ponds. Correction of the retrieved ice thickness in ponds to derive total thickness of sea ice is discussed. Case studies and application to very high resolution optical data are presented, as well as a concept to transfer the method to satellite data of lower spatial resolution where melt ponds become subpixel features.

Comet Pond II: Synergistic Intersection of Concentrated Extraterrestrial Materials and Planetary Environments to Form Procreative Darwinian Ponds.

Science.gov (United States)

Clark, Benton C; Kolb, Vera M

2018-05-11

In the “comet pond” model, a rare combination of circumstances enables the entry and landing of pristine organic material onto a planetary surface with the creation of a pond by a soft impact and melting of entrained ices. Formation of the constituents of the comet in the cold interstellar medium and our circumstellar disk results in multiple constituents at disequilibrium which undergo rapid chemical reactions in the warmer, liquid environment. The planetary surface also provides minerals and atmospheric gases which chemically interact with the pond’s organic- and trace-element-rich constituents. Pond physical morphology and the heterogeneities imposed by gravitational forces (bottom sludge; surface scum) and weather result in a highly heterogeneous variety of macro- and microenvironments. Wet/dry, freeze/thaw, and natural chromatography processes further promote certain reaction sequences. Evaporation concentrates organics less volatile than water. Freezing concentrates all soluble organics into a residual liquid phase, including CH₃OH, HCN, etc. The pond’s evolutionary processes culminate in the creation of a Macrobiont with the metabolically equivalent capabilities of energy transduction and replication of RNA (or its progenitor informational macromolecule), from which smaller organisms can emerge. Planet-wide dispersal of microorganisms is achieved through wind transport, groundwater, and/or spillover from the pond into surface hydrologic networks.

Comet Pond II: Synergistic Intersection of Concentrated Extraterrestrial Materials and Planetary Environments to Form Procreative Darwinian Ponds

Directory of Open Access Journals (Sweden)

Benton C. Clark

2018-05-01

Full Text Available In the “comet pond” model, a rare combination of circumstances enables the entry and landing of pristine organic material onto a planetary surface with the creation of a pond by a soft impact and melting of entrained ices. Formation of the constituents of the comet in the cold interstellar medium and our circumstellar disk results in multiple constituents at disequilibrium which undergo rapid chemical reactions in the warmer, liquid environment. The planetary surface also provides minerals and atmospheric gases which chemically interact with the pond’s organic- and trace-element-rich constituents. Pond physical morphology and the heterogeneities imposed by gravitational forces (bottom sludge; surface scum and weather result in a highly heterogeneous variety of macro- and microenvironments. Wet/dry, freeze/thaw, and natural chromatography processes further promote certain reaction sequences. Evaporation concentrates organics less volatile than water. Freezing concentrates all soluble organics into a residual liquid phase, including CH3OH, HCN, etc. The pond’s evolutionary processes culminate in the creation of a Macrobiont with the metabolically equivalent capabilities of energy transduction and replication of RNA (or its progenitor informational macromolecule, from which smaller organisms can emerge. Planet-wide dispersal of microorganisms is achieved through wind transport, groundwater, and/or spillover from the pond into surface hydrologic networks.

Economic Evaluation and Overall Assessment of Water Harvesting Ponds based on Scorecard System: A Case Study

Science.gov (United States)

Dabral, P. P.; Kumar, Santosh; Kiku, Karmchand

2017-12-01

In the present study, an attempt has been made to carry out an economic analysis of three (03) water harvesting ponds situated in the district of Lakhimpur (Assam), India. Economic analysis was carried out using three important economic criteria, namely Benefit Cost Ratio (BCR), Net Present Worth (NPW) and the Internal Rate of Returns (IRR). Ponds of the study area were compared with adopting score card system. All the water harvesting ponds were found economically viable as the BCR was more than unity at 12% discount rate. Net present worth was the highest for the water harvesting pond of Radhapukheri Fish Seed Farm, Department of Fisheries, Govt. of Assam, Narayanpur and the least for water harvesting pond of St. Xavier's School, Harmoti. The IRR was found to be the highest (60%) for water harvesting ponds of St. Xavier's School, Harmoti followed by water harvesting pond of a farmer of Narayanpur (48%) and water harvesting pond of Radhapukheri Fish Seed Farm (19.2%).Water harvesting pond of Radhapukheri Fish Seed Farm, Narayanpur scored the highest score (84 marks) followed by water harvesting pond of a farmer of Narayanpur (80 marks) and St. Xavier's school, Harmoti (61 marks).

Restoration of a shady urban pond - The pros and cons.

Science.gov (United States)

Jurczak, Tomasz; Wojtal-Frankiewicz, Adrianna; Kaczkowski, Zbigniew; Oleksińska, Zuzanna; Bednarek, Agnieszka; Zalewski, Maciej

2018-07-01

The Bzura-7 pond (Łódź, Poland) is a typical shallow and shady urban reservoir situated on the Bzura River that is exposed to pollutants introduced mainly by internal loads and the supply from the catchment. In 2010-2012, the following characteristics were observed in the pond: a high allochthonous input of organic matter, high concentration of ammonium, low concentration of dissolved oxygen and low diversity of zooplankton, dominated mainly by Daphnia spp. From January to June 2013, restoration measures were performed, including sediment removal, increasing light access to the pond and construction of a sequential sedimentation-biofiltration system (SSBS). The aim of the present study was to investigate how the water quality in the Bzura-7 pond was affected by the restoration process, which included reducing pollutant inflows and enhancing habitat potential, thus increasing the diversity of this ecosystem. Restoration efforts improved the chemical and physical parameters of the water. The oxygen concentration increased, and the concentrations of TN and ammonium significantly decreased. Despite the increase in pond lighting, the growth of cyanobacteria was limited. However, we observed increased abundance of green algae and diatoms but less than adequate changes in the zooplankton community structures. Although we observed a significant increase in the zooplankton species richness after restoration, this increase was related to the small-bodied groups of zooplankton, rotifers and bosminiids, characteristic of eutrophic ecosystems. In addition, a planktivorous fish - sunbleak (Leucaspius delineatus) - was identified as an unintended side effect of the restoration effort. Further conservation efforts in the Bzura-7 pond and monitoring of results are still needed. Copyright © 2018 Elsevier Ltd. All rights reserved.

A simple model for the evolution of melt pond coverage on permeable Arctic sea ice

Science.gov (United States)

Popović, Predrag; Abbot, Dorian

2017-05-01

As the melt season progresses, sea ice in the Arctic often becomes permeable enough to allow for nearly complete drainage of meltwater that has collected on the ice surface. Melt ponds that remain after drainage are hydraulically connected to the ocean and correspond to regions of sea ice whose surface is below sea level. We present a simple model for the evolution of melt pond coverage on such permeable sea ice floes in which we allow for spatially varying ice melt rates and assume the whole floe is in hydrostatic balance. The model is represented by two simple ordinary differential equations, where the rate of change of pond coverage depends on the pond coverage. All the physical parameters of the system are summarized by four strengths that control the relative importance of the terms in the equations. The model both fits observations and allows us to understand the behavior of melt ponds in a way that is often not possible with more complex models. Examples of insights we can gain from the model are that (1) the pond growth rate is more sensitive to changes in bare sea ice albedo than changes in pond albedo, (2) ponds grow slower on smoother ice, and (3) ponds respond strongest to freeboard sinking on first-year ice and sidewall melting on multiyear ice. We also show that under a global warming scenario, pond coverage would increase, decreasing the overall ice albedo and leading to ice thinning that is likely comparable to thinning due to direct forcing. Since melt pond coverage is one of the key parameters controlling the albedo of sea ice, understanding the mechanisms that control the distribution of pond coverage will help improve large-scale model parameterizations and sea ice forecasts in a warming climate.

Impact of pond aquaculture effluents on seagrass performance in NE Hainan, tropical China

International Nuclear Information System (INIS)

Herbeck, Lucia S.; Sollich, Miriam; Unger, Daniela; Holmer, Marianne; Jennerjahn, Tim C.

2014-01-01

Highlights: • Seagrass performance in relation to large-scale pond aquaculture was assessed. • Effluent-affected seagrass meadows have a low biodiversity, shoot density and biomass. • Shading by epiphytes and sulphide poisoning are major decline mechanisms of seagrasses. • Distance to effluent source and pond agglomeration size are major determinants of seagrass degradation. - Abstract: The impact of pond aquaculture effluents on the distribution and performance of seagrasses was examined in NE Hainan, tropical China. Samples were taken along transects in three back-reef areas with different extent of aquaculture production in their hinterland. High δ 15 N in seagrass leaves and epiphytes (6–9‰) similar to values in pond effluents documented aquaculture as dominant nitrogen source in the back-reefs with decreasing impact with distance from shore. Seagrass species abundance, shoot density and biomass were lower and concentrations of nutrients, chlorophyll and suspended matter were higher at nearshore sites with high and moderate pond abundance than at the control site. High epiphyte loads and low δ 34 S in seagrass leaves suggest temporal shading and sulphide poisoning of the nearshore seagrasses. Observed gradients in environmental parameters and seagrass performance indicate that the distance from the pond outlets and size of the adjacent pond agglomeration are major determinants of seagrass degradation

Phytoremediation to remove nutrients and improve eutrophic stormwaters using water lettuce (Pistia stratiotes L.).

Science.gov (United States)

Lu, Qin; He, Zhenli L; Graetz, Donald A; Stoffella, Peter J; Yang, Xiaoe

2010-01-01

Water quality impairment by nutrient enrichment from agricultural activities has been a concern worldwide. Phytoremediation technology using aquatic plants in constructed wetlands and stormwater detention ponds is increasingly applied to remediate eutrophic waters. The objectives of this study were to evaluate the effectiveness and potential of water lettuce (Pistia stratiotes L.) in removing nutrients including nitrogen (N) and phosphorus (P) from stormwater in the constructed water detention systems before it is discharged into the St. Lucie Estuary, an important surface water system in Florida, using phytoremediation technologies. In this study, water lettuce (P. stratiotes) was planted in the treatment plots of two stormwater detention ponds (East and West Ponds) in 2005-2007 and water samples from both treatment and control plots were weekly collected and analyzed for water quality properties including pH, electrical conductivity, turbidity, suspended solids, and nutrients (N and P). Optimum plant density was maintained and plant samples were collected monthly and analyzed for nutrient contents. Water quality in both ponds was improved, as evidenced by decreases in water turbidity, suspended solids, and nutrient concentrations. Water turbidity was decreased by more than 60%. Inorganic N (NH(4) (+) and NO(3) (-)) concentrations in treatment plots were more than 50% lower than those in control plots (without plant). Reductions in both PO(4) (3-) and total P were approximately 14-31%, as compared to the control plots. Water lettuce contained average N and P concentrations of 17 and 3.0 g kg(-1), respectively, and removed 190-329 kg N ha(-1) and 25-34 kg P ha(-1) annually. Many aquatic plants have been used to remove nutrients from eutrophic waters but water lettuce proved superior to most other plants in nutrient removal efficiency, owing to its rapid growth and high biomass yield potential. However, the growth and nutrient removal potential are affected by many

Aquaplaning : Development of a Risk Pond Model from Road Surface Measurements

OpenAIRE

Nygårdhs, Sara

2003-01-01

Aquaplaning accidents are relatively rare, but could have fatal effects. The task of this master’s thesis is to use data from the Laser Road Surface Tester to detect road sections with risk of aquaplaning. A three-dimensional model based on data from road surface measurements is created using MATLAB (version 6.1). From this general geometrical model of the road, a pond model is produced from which the theoretical risk ponds are detected. A risk pond indication table is fur-ther created. The...

Microcosm investigations of stormwater pond sediment toxicity to embryonic and larval amphibians: Variation in sensitivity among species

Energy Technology Data Exchange (ETDEWEB)

Snodgrass, Joel W. [Department of Biological Sciences, Towson University, 8000 York Road, Towson, MD 21252 (United States)], E-mail: jsnodgrass@towson.edu; Casey, Ryan E. [Department of Chemistry, Towson University, 8000 York Road, Towson, MD 21252 (United States); Joseph, Debra; Simon, Judith A. [Department of Biological Sciences, Towson University, 8000 York Road, Towson, MD 21252 (United States)

2008-07-15

Stormwater ponds have become common features of modern development and often represent significant amounts of open space in urbanized areas. Although stormwater ponds may provide habitat for wildlife, factors responsible for producing variation in wildlife use of ponds have received limited attention. To investigate the role of variation in species tolerances of pollutants in structuring pond-breeding amphibian assemblages, we exposed species tolerant (Bufo americanus) and not tolerant (Rana sylvatica) of urbanization to pond sediments in laboratory microcosms. Pond microcosms had elevated sediment metal levels and chloride water concentrations. Among R. sylvatica embryos, exposure to pond sediments resulted in 100% mortality. In contrast, B. americanus embryos and larvae experienced only sublethal effects (i.e., reduced size at metamorphosis) due to pond sediment exposure. Our results suggest variation in pollutant tolerance among early developmental stages of amphibians may act in concert with terrestrial habitat availability to structure amphibian assemblages associated with stormwater ponds. - Variation among species in sensitivity to pollutants can influence stormwater pond amphibian assemblages.

Dissolved Oxygen Availability on Traditional Pond Using Silvofishery Pattern in Mahakam Delta

Directory of Open Access Journals (Sweden)

Ismail Fahmy Almadi

2013-06-01

Full Text Available The development of aquaculture system should meet the community’s basic need economically by taking into account the carrying capacity and environmental sustainability. The development of the environmentally friendly system such as silvofishery is being promoted by government however its yield has not reached the target yet. Dissolved oxygen availability is an important indicator which determines the success of the aquaculture system. The objective of the research was to determine dissolved oxygen availability on traditional pond systems using silvofishery pattern. Time series data collection was conducted once in 14 days with 2 measuring times; in the morning (06.00 am and in the evening (06.00 pm for 112 days. The research was conducted at four different silvofishery pond patterns, Pond Pattern 1 (0% mangrove canopy covered, Pond Pattern 2 (35% mangrove canopy covered, Pond Pattern 3 (67% mangrove canopy covered, and Pond Pattern 4 (75% mangrove canopy covered. Measurement was observed openly in the pond (in situ with parameters: dissolved oxygen, temperature, Water pH, Salinity, Transparency, Wind Speed, and Depth of Water Table, while chlorofil-a was ex-situ measured. The result from each parameter was compared to optimum concentration rate for shrimp growth. From the experiment, Pond Pattern 1 showed the most satisfaction results. Its dissolved oxygen availability during the research was ≥ 4 mg/L which was 5.88 mg/L ±0.48 mg/L in the evening (06.00 pm and 4.33 mg/L ±1.24 mg/L in the morning (06.00 am. It was also supported by optimum condition of other parameters such as temperature, Water pH, Salinity, Wind Speed, and Depth of Water Table. However, it was not supported by fertility and transparency of water. Thus, the traditional pattern of conservation still needs additional technology to maintain adequate dissolved oxygen availability for optimum shrimp growth.

Report on the methylmercury situation in Par Pond. Final report

International Nuclear Information System (INIS)

Schindler, J.E.; Williams, D.J.; Alberts, J.J.

1975-06-01

Studies are reported on the methylation and accumulation of mercury in fish populations of the pond. Results showed that the majority of the mercury in the fish muscles was in the methyl mercury form. Very low concentrations of mercury were found in the pond sediments. Physiological methylation of the mercury could not be demonstrated by in vivo or in vitro techniques. Organic ligand methylation and reduction of the mercury was shown to be a possible mechanism to account for both the mercury distribution in the pond and the concentrations of methylmercury in the fish. Recommendations are made for remedial treatments to eliminate the mercury problem. (HLW)

Thermal behavior of laboratory models of honeycomb-covered solar ponds

Science.gov (United States)

Lin, E. I. H.

1983-01-01

Laboratory experiments were conducted to provide insight into the technical feasibility of honeycomb-covered solar ponds. Cooling tests using honeycomb panels of various materials and geometries showed that a 5.7-cm-thick one-tier panel insulated as effectively as a 10-cm fiberglass slab. Heating tests demonstrated that a model pond covered with a polycarbonate panel boiled upon 16 hours of continuous exposure to a 150-W spotlight. Analysis of the experimental data indicates positively that honeycomb-covered solar ponds can be expected to perform satisfactorily, and that larger-scale outdoor tests should be conducted to provide a more realistic assessment and a more refined performance estimate.

A survey for the presence of microcystins in aquaculture ponds in ...

African Journals Online (AJOL)

PRECIOUS

2009-11-16

Nov 16, 2009 ... form of blue green algae in an aquaculture pond, they. *Corresponding author. ... passing through the food chain. Fish and other ... Some of these aqua- culture ponds supply their products (harvested fish) directly to spe-.

Two-Phase Flow Modeling of Solid Dissolution in Liquid for Nutrient Mixing Improvement in Algal Raceway Ponds

Directory of Open Access Journals (Sweden)

Haider Ali

2018-04-01

Full Text Available Achieving optimal nutrient concentrations is essential to increasing the biomass productivity of algal raceway ponds. Nutrient mixing or distribution in raceway ponds is significantly affected by hydrodynamic and geometric properties. The nutrient mixing in algal raceway ponds under the influence of hydrodynamic and geometric properties of ponds is yet to be explored. Such a study is required to ensure optimal nutrient concentrations in algal raceway ponds. A novel computational fluid dynamics (CFD model based on the Euler–Euler numerical scheme was developed to investigate nutrient mixing in raceway ponds under the effects of hydrodynamic and geometric properties. Nutrient mixing was investigated by estimating the dissolution of nutrients in raceway pond water. Experimental and CFD results were compared and verified using solid–liquid mass transfer coefficient and nutrient concentrations. Solid–liquid mass transfer coefficient, solid holdup, and nutrient concentrations in algal pond were estimated with the effects of pond aspect ratios, water depths, paddle wheel speeds, and particle sizes of nutrients. From the results, it was found that the proposed CFD model effectively simulated nutrient mixing in raceway ponds. Nutrient mixing increased in narrow and shallow raceway ponds due to effective solid–liquid mass transfer. High paddle wheel speeds increased the dissolution rate of nutrients in raceway ponds.

Monitoring and Modelling of Salinity Behaviour in Drinking Water Ponds in Southern Bangladesh

Science.gov (United States)

Hoque, M. A.; Williams, A.; Mathewson, E.; Rahman, A. K. M. M.; Ahmed, K. M.; Scheelbeek, P. F. D.; Vineis, P.; Butler, A. P.

2015-12-01

Drinking water in southern Bangladesh is provided by a variety of sources including constructed storage ponds, seasonal rainwater and, ubiquitously saline, shallow groundwater. The ponds, the communal reservoirs for harvested rainwater, also tend to be saline, some as high as 2 g/l. Drinking water salinity has several health impacts including high blood pressure associated major risk factor for several cardio-vascular diseases. Two representative drinking water ponds in Dacope Upazila of Khulna District in southwest Bangladesh were monitored over two years for rainfall, evaporation, pond and groundwater level, abstraction, and solute concentration, to better understand the controls on drinking water salinity. Water level monitoring at both ponds shows groundwater levels predominantly below the pond level throughout the year implying a downward gradient. The grain size analysis of the underlying sediments gives an estimated hydraulic conductivity of 3E-8 m/s allowing limited seepage loss. Water balance modelling indicates that the seepage has a relatively minor effect on the pond level and that the bulk of the losses come from the combination of evaporation and abstraction particularly in dry season when precipitation, the only inflow to the pond, is close to zero. Seasonal variation in salinity (electrical conductivities, EC, ranged between 1500 to 3000 μS/cm) has been observed, and are primarily due to dilution from rainfall and concentration from evaporation, except on one occasion when EC reached 16,000 μS/cm due to a breach in the pond levee. This event was analogous to the episodic inundation that occurs from tropical cyclone storm surges and appears to indicate that such events are important for explaining the widespread salinisation of surface water and shallow groundwater bodies in coastal areas. A variety of adaptations (either from practical protection measures) or novel alternative drinking sources (such as aquifer storage and recovery) can be applied

Stability considerations and a double-diffusive convection model for solar ponds

Energy Technology Data Exchange (ETDEWEB)

Lin, E.I.H.; Sha, W.T.; Soo, S.L.

1979-04-01

A brief survey is made on the basic principles, current designs and economic advantages of salinity-gradient solar ponds as solar collectors and reservoirs. Solar ponds are well-suited for various AIPH (agricultural and industrial process heat) applications, and as annual storage devices for space heating and cooling. The benefit of an efficient pond is demonstrated via a preliminary economic analysis which suggests the idea of energy farming as a profitable alternative for land usage in the face of rising fuel cost. The economy and reliability of solar-pond operation depend crucially on the stability of the nonconvective gradient zone against disturbances such as generated by a severe weather condition. Attention is focused on the subject of stability, and pertinent existing results are summarized and discussed. Details of the derivation of three-dimensional stability criteria for thermohaline convection with linear gradients are presented. Ten key questions pertaining to stability are posed, whose answers must be sought through extensive analytical and numerical studies. Possible methods of approach toward enhancing solar-pond stability are also discussed. For the numerical studies of pond behavior and stability characteristics, a double-diffusive convection model is proposed. The model can be constructed by extending the three-dimensional thermohydrodynamic computer code COMMIX-SA, following the necessary steps outlined; computational plans are described. Similarities exist between the halothermocline and the thermocline storage systems, and an extended COMMIX-SA will be a valuable tool for the investigation of both.

Experimental and comparative study of the effect of paraffin oil and covering for solar ponds without saline water

Energy Technology Data Exchange (ETDEWEB)

Spyridonos, A V; Anagnostatos, G S; Novakovic, M M

1989-01-01

The effect of a superficial layer of paraffin or a plastic covering on the thermal storage efficiency of three kinds of non-saline solar pond has been investigated. Four small scale ponds were used for experimental measurements. These were: (1) a reference pond; (2) a pond divided horizontally into compartments separated by plastic sheets; (3) a pond with a superficial layer of paraffin and (4) a pond filled with hollow plastic cubes. Comparisons were made between these four ponds with and without plastic coverings, and with a layer of paraffin in addition on ponds 2 and 4. The rise in mean temperature of each pond during a number of heating cycles has been studied. A difference in mean temperature of the order of 10 to 20/sup 0/C was observed in each case between the beginning and end of the heating period and the temperature at the bottom of the pond after heating was in the range 30 to 50/sup 0/C. The results for these experimental ponds may be of use in the choice of full-size shallow ponds and may also give important indications for ponds of much greater depth.

Liner used in tailings ponds

International Nuclear Information System (INIS)

Dinchak, W.G.

1984-01-01

A composite liner has been developed for use in hazardous waste impoundments and in tailings ponds where uranium is involved. The liner offers a high degree of reliability against seepage, is durable, and provides a firm working surface. The advantages of the liner are discussed

Beaver Ponds: Resurgent Nitrogen Sinks for Rural Watersheds in the Northeastern United States.

Science.gov (United States)

Lazar, Julia G; Addy, Kelly; Gold, Arthur J; Groffman, Peter M; McKinney, Richard A; Kellogg, Dorothy Q

2015-09-01

Beaver-created ponds and dams, on the rise in the northeastern United States, reshape headwater stream networks from extensive, free-flowing reaches to complexes of ponds, wetlands, and connecting streams. We examined seasonal and annual rates of nitrate transformations in three beaver ponds in Rhode Island under enriched nitrate-nitrogen (N) conditions through the use of N mass balance techniques on soil core mesocosm incubations. We recovered approximately 93% of the nitrate N from our mesocosm incubations. Of the added nitrate N, 22 to 39% was transformed during the course of the incubation. Denitrification had the highest rates of transformation (97-236 mg N m d), followed by assimilation into the organic soil N pool (41-93 mg N m d) and ammonium generation (11-14 mg N m d). Our denitrification rates exceeded those in several studies of freshwater ponds and wetlands; however, rates in those ecosystems may have been limited by low concentrations of nitrate. Assuming a density of 0.7 beaver ponds km of catchment area, we estimated that in nitrate-enriched watersheds, beaver pond denitrification can remove approximately 50 to 450 kg nitrate N km catchment area. In rural watersheds of southern New England with high N loading (i.e., 1000 kg km), denitrification from beaver ponds may remove 5 to 45% of watershed nitrate N loading. Beaver ponds represent a relatively new and substantial sink for watershed N if current beaver populations persist. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Arthropod fauna of the University of Nigeria, Nsukka, Sewage pond ...

African Journals Online (AJOL)

A survey of arthropod fauna of the University of Nigeria Nsukka sewage pond was carried out within May and June 2011. The aim was to determine the various arthropod species and its abundance in the sewage pond. The analysis was carried out by two methods, physico-chemical analysis and arthropod faunal studies.

Effects of riparian buffers on hydrology of northern seasonal ponds

Science.gov (United States)

Randall K. Kolka; Brian J. Palik; Daniel P. Tersteeg; James C. Bell

2011-01-01

Although seasonal ponds are common in northern, glaciated, forested landscapes, forest management guidelines are generally lacking for these systems. The objective of this study was to determine the effect of riparian buffer type on seasonal pond hydrology following harvest of the adjacent upland forest. A replicated block design consisting of four buffer treatments...

Palaeoecology of Holocene peat deposits from Nordvestø, north-west Greenland

DEFF Research Database (Denmark)

Bennike, Ole; Goodsite, Michael Evan; Heinemeier, Jan

2008-01-01

Two extensive peat deposits on Nordvestø, between Greenland and Canada, were examined for macroscopic remains of plants and animals. One of the peat deposits accumulated during the period from c. 7,100 to 5,100 cal. years BP. This peat is guanogenic and completely dominated by the coprophilous...... bryophyte Aplodon wormskioldii, and also contains frequent remains of feathers. The peat formed close to a large former sea bird colony, probably a puffin (Fratercula arctica) colony. Puffins are now rare in the region, but the population may have been larger during the mid Holocene, when the sea was ice......-free for a longer period than at present. The other peat deposit is dated to c. 9,300-7,400 cal. years BP, it is minerogenic and the macrofossils reflect deposition in a shallow, richly vegetated pond. This peat formed during warmer summers than at present....

Interactions of an insecticide with competition and pond drying in amphibian communities

Science.gov (United States)

Boone, M.D.; Semlitsch, R.D.

2002-01-01

Amphibian populations are often imbedded in agricultural landscapes. Therefore the potential for contamination of their habitat is considerable. Our study examined the effects of an insecticide (carbaryl, a neurotoxin), on larval amphibian communities experiencing natural stresses of competition for resources, predation, and pond drying. In a set of experimental ponds, tadpoles of three anuran species (southern leopard frog [Rana sphenocephala], plains leopard frog [R. blairi], and the Woodhouse's toad [Bufo woodhousii]) were added to 1000-L ponds containing leaf litter, plankton, two newts (Notophthalmus viridescens), and four overwintered green frog (R. clamitans) tadpoles. We manipulated the overall tadpole density (low or high), pond hydroperiod (constant or drying), and chemical exposure (0, 3.5, 5.0, or 7.0 mg/L carbaryl) of the ponds. We measured mass, time, and survival to metamorphosis to determine treatment effects. Carbaryl positively affected Woodhouse's toad survival, although it had a negligible effect on both leopard frog species. Tadpole density interacted with the chemical treatment: Proportionately more Woodhouse's toads survived to metamorphosis in high-density environments than in low-density or control environments. Greater survival may be an indirect effect of increased algal food resources from carbaryl exposure. Most newts lost mass over the course of the experiment, although ponds with drying hydroperiods and high anuran density were the least favorable environments. Overwintered green frogs exposed to carbaryl had longer larval periods on average than did green frogs in control ponds. Our study demonstrated that even sublethal, short-lived contaminants can alter natural communities in ways that cannot be predicted from simple, one-factor studies.

Passive flow heat exchanger simulation for power generation from solar pond using thermoelectric generators

Science.gov (United States)

Baharin, Nuraida'Aadilia; Arzami, Amir Afiq; Singh, Baljit; Remeli, Muhammad Fairuz; Tan, Lippong; Oberoi, Amandeep

2017-04-01

In this study, a thermoelectric generator heat exchanger system was designed and simulated for electricity generation from solar pond. A thermoelectric generator heat exchanger was studied by using Computational Fluid Dynamics to simulate flow and heat transfer. A thermoelectric generator heat exchanger designed for passive in-pond flow used in solar pond for electrical power generation. A simple analysis simulation was developed to obtain the amount of electricity generated at different conditions for hot temperatures of a solar pond at different flow rates. Results indicated that the system is capable of producing electricity. This study and design provides an alternative way to generate electricity from solar pond in tropical countries like Malaysia for possible renewable energy applications.

Food inputs, water quality and nutrient accumulation in integrated pond systems: A multivariate approach

NARCIS (Netherlands)

Nhan, D.K.; Milstein, A.; Verdegem, M.C.J.; Verreth, J.A.J.

2006-01-01

A participatory on-farm study was conducted to explore the effects of food input patterns on water quality and sediment nutrient accumulation in ponds, and to identify different types of integrated pond systems. Ten integrated agriculture-aquaculture (IAA) farms, in which ponds associate with fruit

Sedimentology of a surficial uranium deposit on North Flodelle Creek, Stevens County, Washington

International Nuclear Information System (INIS)

Macke, D.L.; Johnson, S.Y.; Otton, J.K.

1985-01-01

Surficial accumulations of uranium (up to 0.2 wt. % U/sub 3/O/sub 8/, dry basis) are currently forming in organic-rich, poorly drained sediments deposited in fluvial-lacustrine environments. Known occurrences are in northeastern Washington, northern Idaho, the Sierra Nevada, the Colorado Front Range, New Hampshire, and several areas in Canada. The first accumulation of this type to be mined is in postglacial sediments of a 10-acre boggy meadow along North Flodelle Creek in Stevens County, Washington. The meadow is flanked by hills of fine- to medium-grained two-mica quartz monzonite that are mantled by glacial drift of late Wisconsin age (about 18,000 to 11,500 yr B.P.). Relatively thick, hummocky deposits of this same glacial drift impede drainage at the lower end of the meadow. Following ice retreat, glacial sediments on the meadow floor were reworked by fluvial processes, and patches of organic-rich sediment may have formed in ice-melt depressions. About 6700 yr B.P., a blanket of Mazama ash from the Crater Lake eruption was deposited in the meadow. Shortly thereafter, a beaver dam across the lower end of the meadow further restricted drainage, and peat and organic mud accumulated in the pond behind the dam. The dam is preserved in the stratigraphic record as a sheet-like body of woody peat (with beaver-gnawed sticks) about 100m wide and 60 cm thick. After the gradual influx of sand and coarse silt had filled the pond, and the beavers had abandoned the site, fluvial deposition was reestablished

Resource-Saving Cleaning Technologies for Power Plant Waste-Water Cooling Ponds

Directory of Open Access Journals (Sweden)

Zakonnova Lyudmila

2017-01-01

Full Text Available One of the frequently encountered problems of power plant small cooling ponds is rapid eutrophication and related intensified development of phytoplankton (“hyperflow” and overgrowing of ponds by higher aquatic vegetation. As a result of hyper-flowering, an enormous amount of detritus settles on the condenser tubes, reducing the efficiency of the power plant operation. The development of higher aquatic vegetation contributes to the appearing of the shoals. As a result the volume, area and other characteristics of the cooling ponds are getting changed. The article describes the environmental problems of small manmade ponds of power plants and coal mines in mining regions. Two approaches to the problem of eutrophication are considered: technological and ecological. The negative effects of herbicides application to aquatic organisms are experimentally proved. An ecological approach to solving the problem by fish-land reclamation method is shown.

An Expert-Based Assessment Model for Evaluating Habitat Suitability of Pond-Breeding Amphibians

Directory of Open Access Journals (Sweden)

Shin-Ruoh Juang

2017-02-01

Full Text Available Farm ponds are important habitats for amphibians, birds, and other wildlife. In Taiwan, artificial ponds were originally created on farmlands for irrigation purposes and the needs of the domestic water supply. Although pond creation is a typical farming practice, it also provides habitats for pond-breeding amphibians. Thus, it is essential to understand the current status of habitats and their vulnerability regarding urgent conservation needs for target species. Günther’s frog (Hylarana guentheri, a pond-breeding amphibian, has a high sensitivity towards surrounding environmental changes, and can be used as an indicator species to assess habitat suitability. The purpose of this study is to establish a systematic framework to assess the habitat suitability of pond-breeding amphibians by using Günther’s frog as a pilot-study species. First, we collected frog survey data from Chiayi, Taiwan, from winter 2013 to spring 2015, and investigated the present status of the environmental conditions around the ponds. Next, expert questionnaires and the fuzzy Delphi method were applied to establish the hierarchical evaluation criteria regarding the habitat suitability assessment. Four indicators: the aquatic environments of farm ponds; the terrestrial environments around ponds; landscape connectivity; and the conservation perceptions of the residents, were determined as first-layer factors in the assessment criteria, while ten other indicators were defined as second-layer factors. Based on the established assessment criteria, we performed in situ habitat suitability evaluations on 69 selected sites and surveyed the perceptions of the residents using questionnaires. Results revealed that 19% of locations were rich in frog species with a high habitat suitability. However, 67% of locations showed signs of habitat degradation, which may imply a higher need in practicing habitat improvement or restoration. The Kappa value was 0.6061, which indicated a high

Storage ponds for fuel elements of nuclear reactors

International Nuclear Information System (INIS)

Kumpf, H.

1981-01-01

Heat exchangers are inserted in storage ponds for fuel elements of nuclear reactors, so that the heat to be removed is given up to an external coolant, without any radio-activity being emitted. The heat exchanger is a hollow body, which is connected to an air cooler, which works with a cooling circuit with natural circulation. A cooling pipe is enclosed in the hollow body, which forms a cooling circuit with forced flow with an open pond. One therefore obtains two successive separating walls for the external coolant. (orig.) [de

Comparative productivity of distillation and reverse osmosis desalination using energy from solar ponds

Energy Technology Data Exchange (ETDEWEB)

Tleimat, B.W.; Howe, E.D.

1982-11-01

This paper presents comparative analyses of two methods for producing desalted water using the heat collected by a solar pond - the first by distillation, and the second by reverse osmosis. The distillation scheme uses a multiple-effect distiller supplied with steam generated in a flash boiler using heat from a solar pond. Solar pond water passes through a heat exchanger in the water system ahead of the flash boiler. The second scheme uses a similar arrangement to generate hydrocarbon vapor which drives a Rankine cycle engine. This engine produces mechanical/ electrical power for the RO plant. The analyses use two pond water temperatures -82.2/sup 0/C (180/sup 0/F) and 71.1/sup 0/C (160/sup 0/F) -- which seem to cover the range expected from salt-gradient ponds. In each case, the pond water temperature drops by 5.56/sup 0/C (10/sup 0/F) while passing through the vapor generator system. Results of these analyses show that, based on the assumptions made, desalted water could be produced by distillation at productivity rates much greater than those estimated for the RO plant.

Comparative productivity of distillation and reverse osmosis desalination using energy from solar ponds

Energy Technology Data Exchange (ETDEWEB)

Tleimat, B.W.; Howe, E.D.

1982-11-01

This paper presents comparative analyses of two methods for producing desalted water using the heat collected by a solar pond - the first by distillation, and the second by reverse osmosis. The distillation scheme uses a multiple-effect distiller supplied with steam generated in a flash boiler using heat from a solar pond. Solar pond water passes through a heat exchanger in the water system ahead of the flash boiler. The second scheme uses a similar arrangement to generate hydrocarbon vapor which drives a Rankine cycle engine. This engine produces mechanical/ electrical power for the RO plant. The analyses use two pond water temperatures 82.2/sup 0/C (180/sup 0/F) and 71.1/sup 0/C (160/sup 0/F) - which seem to cover the range expected from salt-gradient ponds. In each case, the pond water temperature drops by 5.56/sup 0/C (10/sup 0/F) while passing through the vapor generator system. Results of these analyses show that, based on the assumptions made, desalted water could be produced by distillation at productivity rates much greater than those estimated for the RO plant.

Gaming under pre-trial detention: At-risk youth and their digital leisure practices during remand

OpenAIRE

Nielsen, Rune Kristian; Witkowski, Emma

2013-01-01

This paper looks at the practices of young men engaging with digital leisure activities within the physical, social, and psychological setting of a Danish Juvenile Detention Center. The study of young men's digital play prevails in game studies, yet the experiences and lifestyles captured in over a decade of research on youth gaming practices are far from representative of the diversity of gamer lives. In view of this disparity, this exploration renders visible gaming practices from other kin...

Snow Dunes: A Controlling Factor of Melt Pond Distribution on Arctic Sea Ice

Science.gov (United States)

Petrich, Chris; Eicken, Hajo; Polashenski, Christopher M.; Sturm, Matthew; Harbeck, Jeremy P.; Perovich, Donald K.; Finnegan, David C.

2012-01-01

The location of snow dunes over the course of the ice-growth season 2007/08 was mapped on level landfast first-year sea ice near Barrow, Alaska. Landfast ice formed in mid-December and exhibited essentially homogeneous snow depths of 4-6 cm in mid-January; by early February distinct snow dunes were observed. Despite additional snowfall and wind redistribution throughout the season, the location of the dunes was fixed by March, and these locations were highly correlated with the distribution of meltwater ponds at the beginning of June. Our observations, including ground-based light detection and ranging system (lidar) measurements, show that melt ponds initially form in the interstices between snow dunes, and that the outline of the melt ponds is controlled by snow depth contours. The resulting preferential surface ablation of ponded ice creates the surface topography that later determines the melt pond evolution.

Determination of Summertime VOC Emission Rates from Produced Water Ponds in the Uintah Basin

Science.gov (United States)

Martin, R. S.; Woods, C.; Lyman, S.

2013-12-01

The observance of excess ozone concentrations in Utah's Uintah Basin over past several years has prompted several investigations into the extent and causes of the elevated ozone. Among these is the assessment of potential emissions of reactive VOCs. Evaporation ponds, used a remediation technique for treatment of contaminated production and other waters, are one potential source of significant VOC emissions and is estimated that there are around 160 such ponds within the Uintah Basin's oil and gas production areas. In June 2012 VOC emission rates for several reactive VOCs were derived for an evaporation facility consisting of a small inlet pond (≈0.03 acres) and two larger, serial ponds (≈4.3 acres each). The emission rates were determined over three sampling periods using an inverse modeling approach. Under this methodology, ambient VOC concentrations are determined at several downwind locations through whole-air collection into SUMMA canisters, followed by GC/MS quantification and compared with predicted concentrations using an EPA-approved dispersion model, AERMOD. The presumed emission rates used within the model were then adjusted until the modeled concentrations approach the observed concentrations. The derived emission rates for the individual VOCs were on the order of 10-3 g/s/m2 from the inlet pond and 10-6 g/s/m2 from the larger ponds. The emissions from the 1st pond in series after the inlet pond were about 3-4x the emissions from the 2nd pond. These combined emission rates are about an order of magnitude those reported for a single study in Colorado (Thoma, 2009). It should be noted, however, that the variability about each of the VOC emission rates was significant (often ×100% at the 95% confidence interval). Extrapolating these emission rates to the estimated total areas of all the evaporation ponds within Basin resulted in calculated Basin-wide VOC emissions 292,835 tons/yr. However, Bar-Ilan et al. (2009) estimated 2012 VOC oil and gas related

Valuating Ecosystem Services of Urban Ponds - case study from Bangladesh

Science.gov (United States)

Carle, Nina

2016-04-01

A climate risk assessment for the city of Barisal was carried out by a consultancy firm, financed by KfW Development Bank of Germany. Due to high dependencies on natural capital of people in developing countries they are facing high vulnerability when it comes to changes of the asset category 'natural capital' (here: urban ponds), whether due to the exposition on climate (change) related impacts, implemented measures or land use change. With a closer view on the city's assets, the question remained open to the author 1) Under current conditions, what is the demand for ecosystem services (ES) 2) What is the value of the benefits and the how much is the contribution to the city's welfare? 3) What are the future changes in the demand for ES? And what are the future changes on the supply side (pressures and threats to the ecosystem)? Methodology: The City of Barisal in Bangladesh has a calculated number of around 10.000 urban rain-fed ponds,representing 6.5% of the city area, which represents a huge natural water supply and gives the city its characteristic face. In August 2015 a user survey was conducted in the city of Barisal, in every ward (administrative unit), to determine the demand for ecosystem services related to urban ponds, evaluating over 600 ponds. The findings will present the huge variation of provisioning ecosystem services and an important regulating service, related to economic and domestic use, in a spatial resolution. It will be shown, how the importance of ES changes, by changing the unit of analysis (families or ponds or the city) and the importance for the livelihood of pond owners and users. A relationship between pond area(m2) and number of users was detected, also the role of compensation payments for the pond owners by the users. It will be shown how natural capital, privately and publicly owned,contributes in an important way in buffering unequal distribution of societies resources in the short- and long-run. However society's demand for ES

Shrinking ponds in subarctic Alaska based on 1950-2002 remotely sensed images

Science.gov (United States)

Riordan, B.; Verbyla, D.; McGuire, A.D.

2006-01-01

Over the past 50 years, Alaska has experienced a warming climate with longer growing seasons, increased potential evapotranspiration, and permafrost warming. Research from the Seward Peninsula and Kenai Peninsula has demonstrated a substantial landscape-level trend in the reduction of surface water and number of closed-basin ponds. We investigated whether this drying trend occurred at nine other regions throughout Alaska. One study region was from the Arctic Coastal Plain where depp permafrost occurs continuously across the landscape. The other eight study regions were from the boreal forest regions where discontinuous permafrost occurs. Mean annual precipitation across the study regions ranged from 100 to over 700 min yr-1. We used remotely sensed imagery from the 1950s to 2002 to inventory over 10,000 closed-basin ponds from at least three periods from this time span. We found a reduction in the area and number of shallow, closed-basin ponds for all boreal regions. In contrast, the Arctic Coastal Plain region had negligible change in the area of closed-basin ponds. Since the 1950s, surface water area of closed-basin ponds included in this analysis decreased by 31 to 4 percent, and the total number of closed-basin ponds surveyed within each study region decreased from 54 to 5 percent. There was a significant increasing trend in annual mean temperature and potential evapotranspiration since the 1950s for all study regions. There was no significant trend in annual precipitation during the same period. The regional trend of shrinking ponds may be due to increased drainage as permafrost warms, or increased evapotranspiration during a warmer and extended growing season. Copyright 2006 by the American Geophysical Union.

INCREASING FISH PRODUCTIVITY OF POND ECOSYSTEMS BY FERTILIZING THEM WITH DISTILLER'S GRAINS

Directory of Open Access Journals (Sweden)

N. Tson’

2015-03-01

Full Text Available Purpose. To study fish culture parameters of young-of-the-year carp in the conditions of industrial fish-growing ponds when applying experimental repeated fertilization with distiller’s grain. Methodology. The study was conducted in industrial fish-growing ponds. The wastes of alcohol industry – the distiller’s grain as organic fertilizer was gradually introduced into ponds at following amounts: first application – 1,0 t/ha, second application in 10 days – 0,5 t/ha, third application in 12 days – 0,5 t/ha. The control ponds were fertilized with humus (2 t/ha. Young-of-the-year carp (Cyprinus carpio were grown in monoculture at stocking density of 30 000 fish/ha. In addition, 100 kg/ha of lime were applied during the culture season in the experiment and control. Fertilization with humus and application of lime in ponds, hydrochemical studies, sampling and processing of hydrobiological samples, fish culturing and statistical studies were carried out according to standard methods. Findings. Gradual fertilizing with distiller’s grain (to the total 2 t/ha gave the possibility to create favorable hydrochemical and hydrobiological regimes. An average daily growth in the experimental fish groups of 0,44 ± 0,09 g/day that was similar to in the control (0,45 ± 0,11 g/day with positive significant correlation between them (r = 0,97; p <0,001 was achieved. The performed measures gave a possibility to obtain fish productivity in the experimental variant 10.7% more than in the control. An economic effect of 14.3% cost reduction for fertilizing ponds was achieved. Originality. For the first time we presented the results of fish culture and biological parameters of young-of-the-year carp in industrial ponds when applying 3-time fertilization with distiller’s grain. Practical Value. The obtained results are the basis for the broad use of non-traditional organic fertilizer – distiller’s grain in industrial ponds, when growing young

Solar pond for heating anaerobic digesters

International Nuclear Information System (INIS)

Song Kehui; Li Shensheng

1991-10-01

A theoretical analysis and numerical results calculated for solar pond heating anaerobic digesters in Beijing area in China are presented. The effect of temperature rise is evident and rather steady. 3 refs, 1 fig., 1 tab

Comparison of different water pollution control methods in decreaseing sediment load from peat mining areas

Energy Technology Data Exchange (ETDEWEB)

Kloeve, B.

1997-11-01

Different water treatment alternatives used to reduce sediment from peat mines were compared with a mathematical model. The simulation tested the benefit of different alternatives to reduce sediment transport during a simulated storm. Traditional structures such as bed ditch pipe barriers, sedimentation ponds were compared against new alternatives such as artificial floodplains, and peak runoff control structures. The results of simulations show that detention of peak discharge is the most efficient way to reduce sediment transport. When runoff peaks are reduced traditional sedimentation ponds seem to have a smaller effect on sediment transport; increased settling is achieved by using shallow settling basins such as artificial floodplains. (orig.) 21 refs.

Comparison of different water pollution control methods in decreaseing sediment load from peat mining areas

International Nuclear Information System (INIS)

Kloeve, B.

1997-01-01

Different water treatment alternatives used to reduce sediment from peat mines were compared with a mathematical model. The simulation tested the benefit of different alternatives to reduce sediment transport during a simulated storm. Traditional structures such as bed ditch pipe barriers, sedimentation ponds were compared against new alternatives such as artificial floodplains, and peak runoff control structures. The results of simulations show that detention of peak discharge is the most efficient way to reduce sediment transport. When runoff peaks are reduced traditional sedimentation ponds seem to have a smaller effect on sediment transport; increased settling is achieved by using shallow settling basins such as artificial floodplains. (orig.) 21 refs

Evaluation of Universitas Indonesia’s Recharge Pond Performance and Potential Utilization for Raw Water Source

Directory of Open Access Journals (Sweden)

Nyoman Suwartha

2012-05-01

Full Text Available The UI recharge pond has been constructed 5 years ago. However, monitoring and evaluation activities on its performances are very lack. Aims of this study are to understand the recharge rate, and to evaluate existing quantity and water quality of the pond during dry and rainy season. Measurement of water depth, rainfall intensity, and evaporation is conducted to determine water availability, recharge rate, and water balance of the recharge pond. Amount of surface water is collected from recharge pond and river at three sampling point to determine existing water quality of the pond. The results showed that recharge rate of the pond between dry season (3.2 mm/day and wet season (6.1 mm/day are considered as insignificant different. The water balance of the recharge pond shows an excessive rate. Various physics and chemical parameters (turbidity, color, TDS, pH, and  Cl are found to have concentration lower than the water quality standard. The results suggest that the pond surface water is remain suitable to be recharged into aquifer zone so that sustaining ground water conservation campaign, and it is potential to be utilized as an additional  raw water source for domestic water demand of UI Campus Depok.

Avian communities in baylands and artificial salt evaporation ponds of the San Francisco Bay estuary

Science.gov (United States)

Takekawa, John Y.; Lu, C.T.; Pratt, R.T.

2001-01-01

San Francisco Bay wetlands, seasonal and tidal marshes between the historic low and high tide lines, are now highly fragmented because of development during the past 150 years. Artificial salt pond systems in the Bay are hypersaline and typically support simple assemblages of algae and invertebrates. In order to establish the value of salt ponds for migratory waterbirds, we used datasets to conduct a meta-analysis of avian communities in the baylands and salt ponds of San Pablo Bay. Fifty-three species of waterbirds in the salt ponds represented six foraging guilds: surface feeders, shallow probers, deep probers, dabblers, diving benthivores and piscivores. The total number of species and the Shannon-Weiner diversity index was higher in baylands than in salt ponds during all four seasons. However, overall bird density (number/ha) was higher in salt ponds compared with baylands in the winter and spring, primarily because of large concentrations of benthivores. Cessation of salt production in 1993 and subsequent reduction in water depth resulted in a decline of some diving duck populations that used the salt ponds.

Effects of season on ecological processes in extensive earthen tilapia ponds in Southeastern Brazil.

Science.gov (United States)

Favaro, E G P; Sipaúba-Tavares, L H; Milstein, A

2015-11-01

In Southeastern Brazil tilapia culture is conducted in extensive and semi-intensive flow-through earthen ponds, being water availability and flow management different in the rainy and dry seasons. In this region lettuce wastes are a potential cheap input for tilapia culture. This study examined the ecological processes developing during the rainy and dry seasons in three extensive flow-through earthen tilapia ponds fertilized with lettuce wastes. Water quality, plankton and sediment parameters were sampled monthly during a year. Factor analysis was used to identify the ecological processes occurring within the ponds and to construct a conceptual graphic model of the pond ecosystem functioning during the rainy and dry seasons. Processes related to nitrogen cycling presented differences between both seasons while processes related to phosphorus cycling did not. Ecological differences among ponds were due to effects of wind protection by surrounding vegetation, organic loading entering, tilapia density and its grazing pressure on zooplankton. Differences in tilapia growth among ponds were related to stocking density and ecological process affecting tilapia food availability and intraspecific competition. Lettuce wastes addition into the ponds did not produce negative effects, thus this practice may be considered a disposal option and a low-cost input source for tilapia, at least at the amounts applied in this study.

Basal-topographic control of stationary ponds on a continuously moving landslide

Science.gov (United States)

Coe, J.A.; McKenna, J.P.; Godt, J.W.; Baum, R.L.

2009-01-01

The Slumgullion landslide in the San Juan Mountains of southwestern Colorado has been moving for at least the last few hundred years and has multiple ponds on its surface. We have studied eight ponds during 30 trips to the landslide between July 1998 and July 2007. During each trip, we have made observations on the variability in pond locations and water levels, taken ground-based photographs to document pond water with respect to moving landslide material and vegetation, conducted Global Positioning System surveys of the elevations of water levels and mapped pond sediments on the landslide surface. Additionally, we have used stereo aerial photographs taken in October 1939, October 1940 and July 2000 to measure topographic profiles of the eight pond locations, as well as a longitudinal profile along the approximate centerline of the landslide, to examine topographic changes over a 60- to 61-year period of time. Results from field observations, analyses of photographs, mapping and measurements indicate that all pond locations have remained spatially stationary for 60-300 years while landslide material moves through these locations. Water levels during the observation period were sensitive to changes in the local, spring-fed, stream network, and to periodic filling of pond locations by sediment from floods, hyperconcentrated flows, mud flows and debris flows. For pond locations to remain stationary, the locations must mimic depressions along the basal surface of the landslide. The existence of such depressions indicates that the topography of the basal landslide surface is irregular. These results suggest that, for translational landslides that have moved distances larger than the dimensions of the largest basal topographic irregularities (about 200 m at Slumgullion), landslide surface morphology can be used as a guide to the morphology of the basal slip surface. Because basal slip surface morphology can affect landslide stability, kinematic models and stability

Study for reclamation of land occupied by solar evaporation pond at UCIL, Bhopal, India.

Science.gov (United States)

George, K V; Patil, M R; Swaminathan, R

2001-12-01

Solar Evaporation Ponds (SEP) were used by Union Carbide India Limited (UCIL), Bhopal for storage of wastewater containing high concentrations of inorganic chemicals especially chlorides. Area occupied by the SEPs had to be recovered due to closure of the plant. A prerequisite to the reclamation of the SEP area is a study of adjoining soil and groundwater, which may be contaminated due to possible leakage in the pond. Surface soil, subsurface soil and groundwater samples were collected and analysed. The electrical conductivity method was employed inside the pond to test for leak in the geo-membrane liner. This was further confirmed by physically checking the liners. Based on the wet period, total rainfall and evaporation rate of the region, drying of remaining wastewater by spreading in dry ponds followed by pond dismantling was scheduled.

EXPERIMENTAL INVESTIGATION OF HEAT STORAGE CHARACTERISTIC OF UREA AND BORAX SALT GRADIENT SOLAR PONDS

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Hüseyin KURT

2006-03-01

Full Text Available Salt gradient solar ponds are simple and low cost solar energy system for collecting and storing solar energy. In this study, heat storage characteristic of urea and borax solutions in the solar pond were examined experimentally. Establishing density gradients in different concentration, variations in the temperature and density profiles were observed in four different experiments. Maximum storage temperatures were measured as 28ºC and 36 ºC for the ponds with urea and borax solution, respectively. The temperature difference between the bottom and the surface of the pond were measured as 13 ºC for urea and 17 ºC for borax- solutions. According to these results, heat storage characteristic of the solar pond with borax solution was found to be better than urea solution.

Ponded infiltration tests at the Box Canyon site: data report and preliminary analysis

International Nuclear Information System (INIS)

Cook, Paul; Faybishenko, Boris; Freifeld, Barry; Jacobsen, Janet; Lee, Ki Ha; Salve, Rohit; Zawislanski, Peter

1998-01-01

We discuss the design and present the main results of a two-week ponded infiltration test conducted in 1996 at the Box Canyon site near the Idaho National Engineering and Environmental Laboratory. To investigate liquid flow and chemical transport in fractured basalt, the following types of instruments were installed in boreholes: tensiometers, suction lysimeters, thermistors, time domain reflectrometry probes, and electrical resisitivity probes. These probes were installed using an innovative technology of borehole instrumentation and completion using polyurethane foam injection. The probes were attached to plastic packers that were inflated using the polyurethane foam, and then the space between packers was back-filled with the foam in order to ensure the isolation of the instruments at different depths. Polyurethane foam showed great promise in enabling rapid, cost-effective installation of sensors and probes in fractured rock. A ponded infiltration test was conducted from 8/27/96 to 9/9/96, by maintaining water to an average depth of 23 cm in a rectangular infiltration pond. Within the 7 x 8 m pond, nine local infiltrometers (0.25 m diameter) were-installed to determine local values of the water flux. A slug of conservative tracer (KM) was added to the pond on 9/2/96, yielding a tracer concentration in the pond of approximately 3 g/L. The water supply to the pond was halted for two days so that the tracer concentration in the pond water would remain essentially constant. Thereafter, the water supply was re-established to maintain a constant water level. Installation procedures and measurement results for each type of probe are presented, along with a description of the data acquisition system. The attachments include a description of the calibration and testing of instrumentation. The data files can be found at the FTP site zenitMnel/ or the Web site http://www- esd.lbl.gov/ERT/inel/inel.htrnl

SEARCH AND DETENTION OF THE MILITARY PERSONNEL WHO HAS AVOIDED THE MILITARY SERVICE: SOURCES, REALITIES, IMPROVEMENT PROSPECTS

OpenAIRE

Natalia V. V.

2014-01-01

The article is devoted to the topical issues of the search and detention of the military personnel who has avoided the military service. On the basis of official information, the author gave a short historical digression, the analysis of a current state of the problem of evasion of the military personnel from military service is carried out and possible ways of its solutions are proposed

Influence of inlet water on the biotic and abiotic variables in a fish pond

Directory of Open Access Journals (Sweden)

L. H. Sipaúba-Tavares

Full Text Available Abstract The effects of treated and untreated water inlets with macrophytes on the improvement of water quality and zooplankton community were evaluated in a fish pond with continuous water flow. Water and zooplankton samples were retrieved at four sites during nine months. There were differences (p<0.01 between inlet water from fish pond and inlet water from canal with macrophytes, featuring higher concentrations of nutrient load, mainly TAN and TP in the former. The inlet water from fish pond contained a higher number of abundant species (9 species, whilst the water supply from the canal with macrophytes had a greater richness (31 species of zooplankton species. Results showed that inlet water without macrophytes directly affected the characteristics of the water column and the dominance of zooplankton species such as Thermocyclops decipiens, and greater abundance of Rotifera species. Since aquatic plants in the inlet water of fish pond analyzed showed lower allochthonous material loads from the previous fish pond, the management adopted with macrophytes may be applied to avoid eutrophication risks, common in farm ponds.

Data analysis protocol for using resistivity array as an early-warning wastewater pond leak detector

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Typically, holding ponds are used to control runoff from concentrated animal feeding operations. The integrity of these holding ponds has come under increased scrutiny since subsurface leakage has the potential to affect soil and groundwater quality. Traditionally, ponds are monitored by installin...

Road Salts as Environmental Constraints in Urban Pond Food Webs

Science.gov (United States)

Van Meter, Robin J.; Swan, Christopher M.

2014-01-01