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Using Stormwater Detention Ponds for Aquatic Science Instruction.
ERIC Educational Resources Information Center
Cahoon, Lawrence B.
Describes the use of recently constructed stormwater detention ponds to conduct a set of field and laboratory exercises in an undergraduate limnology course. Provides a number of logistical advantages that can benefit those teaching aquatic sciences. (JRH)
Stormwater Detention and Discharge from Aquaculture Ponds in Florida1
Watson, Craig A.
BUL334 Stormwater Detention and Discharge from Aquaculture Ponds in Florida1 A. G. Smajstrla, M. E Aquaculture Demonstration Farm, Program in Fisheries and Aquatic Sciences, School of Forest Resources and Conservation, Blountstown; J. E. Hill, assistant professor, Tropical Aquaculture Laboratory, Program
Implementation of reactive and predictive real-time control strategies to optimize dry stormwater detention ponds
NASA Astrophysics Data System (ADS)
Gaborit, Étienne; Anctil, François; Vanrolleghem, Peter A.; Pelletier, Genevičve
Dry detention ponds have been widely implemented in U.S.A (National Research Council, 1993) and Canada (Shammaa et al. 2002) to mitigate the impacts of urban runoff on receiving water bodies. The aim of such structures is to allow a temporary retention of the water during rainfall events, decreasing runoff velocities and volumes (by infiltration in the pond) as well as providing some water quality improvement from sedimentation. The management of dry detention ponds currently relies on static control through a fixed pre-designed limitation of their maximum outflow (Middleton and Barrett 2008), for example via a proper choice of their outlet pipe diameter. Because these ponds are designed for large storms, typically 1- or 2-hour duration rainfall events with return periods comprised between 5 and 100 years, one of their main drawbacks is that they generally offer almost no retention for smaller rainfall events (Middleton and Barrett 2008), which are by definition much more common. Real-Time Control (RTC) has a high potential for optimizing retention time (Marsalek 2005) because it allows adopting operating strategies that are flexible and hence more suitable to the prevailing fluctuating conditions than static control. For dry ponds, this would basically imply adapting the outlet opening percentage to maximize water retention time, while being able to open it completely for severe storms. This study developed several enhanced RTC scenarios of a dry detention pond located at the outlet of a small urban catchment near Québec City, Canada, following the previous work of Muschalla et al. (2009). The catchment's runoff quantity and TSS concentration were simulated by a SWMM5 model with an improved wash-off formulation. The control procedures rely on rainfall detection and measures of the pond's water height for the reactive schemes, and on rainfall forecasts in addition to these variables for the predictive schemes. The automatic reactive control schemes implemented here increased the pond's TSS (and associated pollution) removal efficiency from 46% (current state) to between 70 and 90%, depending on the pond's capacity considered. The RTC strategies allow simultaneously maximizing the detention time of water, while minimizing the hydraulic shocks induced to the receiving water bodies and preventing overflow. A constraint relative to a maximum time of 4 days with water accumulated in the pond was thus respected to avoid mosquito breeding issues. The predictive control schemes (taking rainfall forecasts into consideration) can further reinforce the safety of the management strategies, even if meteorological forecasts are, of course, not error-free. With RTC, the studied pond capacity could thus have been limited to 1250 m3 instead of the 4000 m3 capacity currently used under static control. References Marsalek, J. 2005. Evolution of urban drainage: from cloaca maxima to environmental sustainability. Paper presented at Acqua e Citta, I Convegno Nazionale di Idraulica Urbana, Cent. Stud. Idraul. Urbana, Sant'Agnello di Sorrento, Italy, 28- 30 Sept. Middleton, J.R. and Barrett, M.E. 2008. Water quality performance of a batch-type stormwater detention basin. Water Environment Research, 80 (2): 172-178. Doi: http://dx.doi.org/10.2175/106143007X220842 Muschalla, D., Pelletier, G., Berrouard, É., Carpenter, J.-F., Vallet, B., and Vanrolleghem, P.A. 2009. Ecohydraulic-driven real-time control of stormwater basins. In: Proceedings 8th International Conference on Urban Drainage Modelling (8UDM), Tokyo, Japan, September 7-11. National Research Council, 1993. Managing Wastewater in Coastal Urban Areas. Washington, DC: National Academy Press. Shammaa, Y., Zhu, D.Z., Gyürék, L.L., and Labatiuk C.W. 2002. Effectiveness of dry ponds for stormwater total suspended solids removal. Canadian Journal of Civil Engineering, 29 (2): 316-324 (9). Doi: 10.1139/l02-008
Effects of detention on water quality of two stormwater detention ponds receiving highway surface runoff in Jacksonville, Florida
Hampson, P.S.
Water and sediment samples were analyzed for major chemical constituents, nutrients, and heavy metals following ten storm events at two stormwater detention ponds that receive highway surface runoff in the Jacksonville, Florida, metropolitan area. The purpose of the sampling program was to detect changes in constituent concentration with time of detention within the pond system. Statistical inference of a relation with total rainfall was found in the initial concentrations of 11 constituents and with antecedent dry period for the initial concentrations of 3 constituents. Based on graphical examination and factor analysis , constituent behavior with time could be grouped into five relatively independent processes for one of the ponds. The processes were (1) interaction with shallow groundwater systems, (2) solubilization of bottom materials, (3) nutrient uptake, (4) seasonal changes in precipitation, and (5) sedimentation. Most of the observed water-quality changes in the ponds were virtually complete within 3 days following the storm event. (Author 's abstract)
Salinization alters ecosystem structure in urban stormwater detention ponds
Robin J. Van Meter; Christopher M. Swan; Joel W. Snodgrass
Stormwater ponds now comprise a significant portion of standing water in urban areas. These ponds act to sequester excess\\u000a run-off and pollutants, such as road salt deicers. While these man-made ponds are not intended to serve as freshwater ecosystems,\\u000a it is becoming clear that they do provide habitat for many organisms, but we know little of their ecosystem structure, function
Elimination and accumulation of polycyclic aromatic hydrocarbons in urban stormwater wet detention ponds.
Istenic, Darja; Arias, Carlos A; Matamoros, Víctor; Vollertsen, Jess; Brix, Hans
The concentrations of polycyclic aromatic hydrocarbons (PAHS) in water and sediments of seven wet detention ponds receiving urban stormwater were investigated. The ponds comprised traditional wet detention ponds with a permanent wet volume and a storage volume as well as ponds that were expanded with sand filters and other means to improve the removal of micropollutants. The concentrations of sigmaPAH in the sediments varied between 6 +/- 5 and 2,222 +/- 603 ng g(-1) dry weight (mean +/- standard deviation), and were highest in the ponds with lower pond volume per catchment area and did not clearly reflect different activities in the catchments. In general, the concentrations of PAHS in the sediments decreased from inlet to outlet, especially in the systems with good conditions for sedimentation such as systems with flow perpendicular sand dikes and extensive submerged vegetation. High molecular weight PAHs were predominant in the sediments indicating the pyrogenic origin of the PAHS. There was no correlation between PAH species concentrations in water or sediments and their hydrophobicity (log K(ow)). PAH concentrations in water fluctuated in response to intensity and frequency of rain events, whereas concentrations in the sediments integrated the pollutant load over time. Pond systems expanded with sand filters and other technologies to enhance removal of micropollutants consistently had concentrations of PAHS in the effluents below the detection level. PMID:22097066
Evaluation of the storm-water treatment facilities at the Lake Angel detention pond, Orange County, Florida. Final report, 2 Jan 90-1 Jul 91
M. Wanielista; J. Charba; J. Dietz; B. Russell
This is the final report on the use of Granulated Active Carbon (GAC) beds of Filtrasorb 400 in series to reduce the Trihalomethane Formation Potential (THMFP) concentrations at the Lake Angel detention pond, Orange County, Florida. The detention pond accepts runoff from an interstate highway and a commercial area. Breakthrough time was estimated from laboratory analyses and used to design
Hydrogeology and chemical quality of water and bottom sediment at three stormwater detention ponds, Pinellas County, Florida
Fernandez, Mario, Jr.; Hutchinson, C.B.
An investigation of three detention ponds in Pinellas County, Florida indicated little potential for chemical contamination of surficial-aquifer ground water; however, concentrations of contami- nants in some sediments are sufficient to indicate possible hazardous levels of bioconcentration in benthic organisms. The general direction of ground- water movement at three pond sites indicates that the ponds are ground-water discharge points. Shallow ground water tends to move laterally toward these ponds, which have surface outflow, instead of from the ponds into the aquifer. Surface-water and pond-sediment samples from a 1-year-old pond were collected and analyzed for inorganic constituents and organic compounds. The concentrations were either near or below analytical detection limits. Surface-water and pond-sediment samples from the other two ponds, 20- and 30-years old, respectively, also were analyzed for inorganic constituents and organic compounds. The water quality of these older ponds was not significantly different from that of the 1-year-old pond. However, bottom sediments in the 20- and 30-year-old ponds contained 16 and 23 organic compounds, respectively. None of the organic compounds were in sufficient concentrations to cause concern about their chronic effects on aquatic life. Concentrations of dichlordiphenyl-trichlorethane, dieldrin, and heptachlor were above the hazardous level with respect to bioconcentration in the food chain.
Development of baseline water quality stormwater detention pond model for Chesapeake Bay catchments
Musico, W.J.; Yoon, J.
An environmental impact assessment is required for every proposed development in the Commonwealth of Virginia to help identify areas of potential concerns. The purpose of the Chesapeake Bay Local Assistance Department (CBLAD), Guidance Calculation Procedures is to ensure that development of previously constructed areas do not further exacerbate current problems of stormwater-induced eutrophication and downstream flooding. The methodology is based on the post development conditions that will not generate greater peak flows and will result in a 10% overall reduction of total phosphorus. Currently, several well-known models can develop hydrographs and pollutographs that accurately model the real response of a given watershed to any given rainfall event. However, conventional method of achieving the desired peak flow reduction and pollutant removal is not a deterministic procedure, and is inherently a trail and error process. A method of quickly and accurately determining the required size of stormwater easements was developed to evaluate the effectiveness of alternative stormwater collection and treatment systems. In this method, predevelopment conditions were modeled first to estimate the peak flows and subsequent pollutants generation that can be used as a baseline for post development plan. Resulting stormwater easement estimates facilitate decision-making processes during the planning and development phase of a project. The design can be optimized for the minimum cost or the smallest-possible pond size required for peak flow reduction and detention time given the most basic data such as: inflow hydrograph and maximum allowable pond depth.
Patterson, Timothy
DISTRIBUTION OF THECAMOEBIANS (TESTATE AMOEBAE) IN SMALL LAKES AND PONDS, BARBADOS, WEST INDIES and ephemeral lakes and ponds on Barbados, West Indies, are characterized by low numbers of individuals and low
Hydrologic modeling of detention pond
Technology Transfer Automated Retrieval System (TEKTRAN)
Urban watersheds produce an instantaneous response to rainfall. That results in stormwater runoff in excess of the capacity of drainage systems. The excess stormwater must be managed to prevent flooding and erosion of streams. Management can be achieved with the help of structural stormwater Best...
Investigation of pond velocities using dye and small drogues: a case study of the Nelson City waste stabilisation pond.
Barter, P J
The city of Nelson, New Zealand, has a 27 hectare oxidation pond as its primary wastewater treatment facility. Recent changes in the configuration of the pond and installation of a mixer/aerator raised concerns that pond treatment rates and effluent quality may be affected by high internal pond velocities and short retention times. This paper presents the findings of an investigation into wastewater velocity and movement within the pond using qualitative dye dispersion and tracking of small-scale "holey-sock" drogues. Simultaneous deployment of drogues and dye allowed methods to be compared, since small-scale drogues have not commonly been used in wastewater ponds. Dye dispersion was assessed using low-level aerial photography from a tethered helium blimp to track short term movement and mixing, while a datalogger and fluorometer were used to measure pond retention time. Drogue movement was tracked in conjunction with the dye study from a small boat using hand-held GPS. The dye study found that: (i) the first portion of pond influent discharged from the pond after 37.5 hours, substantially quicker than the theoretical pond retention time of 27 days. However, the measured retention time was with a mixer in place and the theoretical time was without a mixer; (ii) the position of the paddle wheel mixer/aerator was not optimally placed for mixing the influent and a quiescent region existed adjacent to the influent point; and (iii) the low-level aerial photography was an effective method of evaluating larger pond systems. The "holey-sock" drogue studies showed that: (i) the drogues accurately followed the movement and velocity of dyed influent within the pond; (ii) wastewater velocity and movement was dominated by the paddle wheel mixer/aerator; and (iii) wind direction had a minor influence on wastewater velocity and movement in areas not directly affected by the paddle wheel mixer/aerator. The study demonstrated that the combined use of dye and drogues was a relatively low-cost and effective means of determining internal pond velocities and movement. Future studies using similar methods will be useful in helping validate computer-modelled movement and velocity. PMID:14510205
Production ecology of invertebrates in small experimental ponds
Cushman, R.M.; Franco, P.J.; Goyert, J.C.; Lesslie, P.A.
Production of invertebrates is estimated for a series of small experimental ponds in Tennessee. Annual dry weight production of predator insects is about 4.5 g/m/sup 2/ and of herbivore-detritivore insects about 3.8 g/m/sup 2/; insects whose trophic position could not be classified account for an annual dry weight production of about 0.3 g/m/sup 2/. Annual dry weight production of zooplankton is about 14.5 t/m/sup 2/, of annelids 25.4 g/m/sup 2/ and of snails 3.1 g/m/sup 2/. The data are consistent with published information that the predator insects probably depend on a variety of energy sources to support their estimated production rate.
Treated biosolids from small wastewater treatment plants in mid-western US are usually disposed off by land application. This practice allows for the recycling of the nutrients present in the biosolids for food and fiber production and can help re-vegetate sites destroyed by mini...
Methane production in sediments of small tundra ponds during winter
NASA Astrophysics Data System (ADS)
Macrae, M. L.; Fishback, L.; Bourbonniere, R. A.; Duguay, C. R.; Soliman, A. S.
Shallow tundra ponds in the Churchill region of the Hudson Bay Lowlands (HBL) store large quantities of organic material in the form of sediments. Organic sediments in ponds and wetlands have been identified as a source of atmospheric methane (CH4) during the summer season in many landscapes. However, less is known about CH4 production and emission during the winter months, following the formation of an ice layer on the water surface. Unfrozen sediments may continue to produce methane (CH4) during this time, which may become trapped in the ponds beneath the ice layer. This occurrence has been identified in some regions through the sampling and analysis of CH4 bubbles frozen in lake ice. The goal of this project is to examine the potential for the production and trapping of CH4 in ponds beneath the pond ice (water/ice and sediment profiles) in the Churchill region of the HBL. Thermistor and gas sampling arrays were installed in the water and sediments of two ponds. Gas samples were collected at 1-4 week intervals at the sediment-water interface and at 0-15cm and 20-35 cm depth. Results show that sediments are indeed thawed for 3-4 months of the winter season, and deeper sediments remain within the range of 0 to -5 C whereas shallow sediment temperatures ranged between 10 and -10 C over an annual cycle. Laboratory experiments showed that little difference in CH4 production was observed at sediment temperatures between -2 and 5 C, whereas production was very low at -10 C. No significant differences in CH4 production rates were observed for different sediment depths in the laboratory. Field data collected between August 2010 and June 2011 showed consistent accumulation of CH4 in sediments following the formation of an ice layer on pond surfaces. However, CH4 concentrations in gas samplers decreased in February through April after sediments were frozen, but began to increase again (May-June) as sediments thawed and began to warm. Future work will include the examination of gas fluxes from pond surfaces and mechanisms influencing variable CH4 concentrations in pond sediments.
Operation of a small-scale salt-gradient solar pond: Experimental results
Elhadidy, M.A.; Nimmo, B.G.; Zubair, S.
A small-scale sodium chloride salt gradient solar pond was operated outdoors in Dhahran over a period of nine months. Vertical temperature profiles in the pond and in the ground underneath the pond, density profiles and temperatures at fixed locations in the pond were measured. Variation of the bottom zone temperature with time over the operating period is presented as well as representative vertical pond temperature profiles taken in the morning and afternoon. From these profiles and additional temperature data taken from fixed locations in the bottom zone, some insight was gained regarding onset of bottom convection and the midday total energy collection. Evidence is shown which suggests that weak convective cells in the gradient zone will ''self-heal'' even when on the order of 5 cm in thickness.
Distribution of trematodes in snails in ponds at integrated small-scale aquaculture farms.
Boerlage, Annette S; Graat, Elisabeth A M; Verreth, Johan A; de Jong, Mart C M
In integrated small-scale aquaculture farming, animal and human excreta maybe used as fish feed and pond fertilizer, thereby enhancing transmission of fish-borne zoonotic trematodes (FZTs) from final hosts, like humans, pigs and chickens, to snails. Areas within a pond could vary in trematode egg-load due to the immediate bordering land, and this might provide implications for control of these trematodes or sampling in field studies measuring FZT prevalence in snails. We therefore estimated the effect of bordering land use on prevalence and FZT burden in snails in different areas within small-scale aquaculture ponds. Nine sampling areas within a pond were assigned in six ponds. For each sampling area, about 120 Melanoides tuberculata snails were collected. Based on land use bordering a sampling area, these were categorized in 5 risk-categories: low-risk (road, rice planted in pond, agriculture, or middle of pond), human access point to pond, livestock sty (pigs or poultry), both human access point and livestock sty, and water connection to canal. In total, 5392 snails were collected. Percentages of snails with parapleurolophocercous cercariae varied between 6% in areas categorized as low-risk and areas with livestock sty only to 15% in areas with both human access point and livestock sty; only this 15% was significantly different from the prevalence in the low-risk category. Percentages of snails with xiphidio cercariae did not differ between risk-categories and varied between 5% and 10%. Mean snail size was 15.2mm, and was significantly associated with both the probability of infection as well as parasite burden. Very small differences in parasite burden were found at different land use areas; the maximum difference was about 11 cercariae. This study demonstrated only small differences between areas surrounding a pond on risk of snails to be infected with fish-borne trematodes within different pond areas. In field studies on FZTs in M. tuberculata snails in ponds, sampling from ponds can therefore be done without considering areas within ponds. PMID:23200642
Performance of a small solar pond in the tropics
The performance of the 240 m² solar pond in Bangalore is discussed. The problems of erosion of gradient zone and formation of internal convective zones is highlighted. The technique of passive salt addition is shown to be a viable alternative for salt recycling. Different techniques of heat extraction are discussed and the use of an immersed copper heat exchanger is
Thermal behavior of a small salinity-gradient solar pond with wall shading effect
M. R. Jaefarzadeh
The thermal behavior of a small-scale salinity-gradient solar pond has been studied in this paper. The model of heat conduction equation for the non-convective zone has been solved numerically with the boundary conditions of the upper and lower convective zones. The variation of the solar radiation, during a year, and its attenuation in the depth of the pond has been
Modelling the long-term sediment trap efficiency of small ponds
NASA Astrophysics Data System (ADS)
Verstraeten, Gert; Poesen, Jean
A numerical model (sediment trap efficiency for small ponds - STEP) is developed to simulate sediment deposition in small ponds (i.e. <1 ha) and to calculate the sediment trap efficiency (STE). The algorithms are kept simple to allow the model to simulate larger time periods (i.e. several years). Eight runs with an experimental pond were executed to test the model. The STEP model produces reasonable predictions of STE as well as the shape and magnitude of the effluent sediment concentration graph. The model efficiency of STEP for the prediction of STE equals 0·38 and the root mean square error equals 4·7%. Similar models, such as DEPOSITS and CSTRS, were inefficient in predicting the experimental results. The STEP model was used to simulate the long-term (33 years) STE of small retention ponds in central Belgium using 10-min rainfall data. For a typical pond (1000 m2) with a catchment area of 25 ha, annual STE can vary from 58 to 100%, with a long-term STE of only 68%.
Characterizing seasonal markers using high-resolution water temperature data from small mountain ponds
NASA Astrophysics Data System (ADS)
Daly, J.; Engel, B.; Hansen, J.
Small mountain ponds in western Maine are near local topographic highs and are typically associated with distinctive ecological zones because of their elevation. Long-term historic records of seasonal markers such as ice-out for large, low elevation lakes in the region indicate that climate warming is affecting these large water bodies, but little data exist for the smaller, remote, higher elevation ponds. These ponds are typically 700 m elevation, have a surface area of about 4 hectares, and a maximum depth of 10 m. Because these ponds are associated with habitats restricted from migrating in response to climate change, characterizing and documenting the timing of seasonal markers such as ice-out and other events is important to assess whether these smaller ponds are following similar trends to the larger lakes, or if they might be more sensitive to climate forcing. High-resolution water temperature and light data collected at several depths by data loggers at study sites across the region since 2007 have been analyzed to characterize major seasonal markers that cannot be otherwise determined because of the remote character of the ponds. Ice-in and ice-out dates can be identified by characteristic signatures in the surface and bottom water temperatures; differences in the timing of the events among sites may be explained by elevation or basin aspect. Summer temperatures records also revealed multiple turnover events during some summer seasons, indicating that these ponds should be classified as discontinuous cold polymictic water bodies . These turnover events were nearly simultaneous at multiple study sites fifty kilometers apart, suggesting forcing by regional weather events. These high-resolution records permit long-term monitoring of sensitive, remote sites that will contribute to understanding the magnitude of the response to climate change in these small subalpine watersheds, as well as the spatial and temporal complexity of climate change in the northeastern 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
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.
Ecological Studies on the Planktonic Protozoa of a Small Artificial Pond1
A one-year survey was conducted on a small artificial pond to determine environmental relationships of planktonic protozoa to physical and inorganic chemical factors. Collections were made at 9:00 A. M., Eastern Standard Time, every other day. Plank- tonic samples were taken from the surface and bottom, and sunlight intensity and tempera- ture were measured. Chemical analyses included alkalinity, carbon dioxide,
Fertilizer solar ponds as a clean source of energy: Some observations from small scale experiments
S. H. Pawar; A. N. Chapgaon
Commercially available NH2CONH2 is used to establish a salinity gradient solar pond in a small 1 m2 outdoor tank. With a salinity difference of 35% between the upper and lower zone, a temperature difference of 23°C was obtained without any instabilities in the gradient zone. The difference in concentration of solution required to sustain a temperature difference of 40°C across
The nature of small-scale flooding, muddy floods and retention pond sedimentation in central Belgium
NASA Astrophysics Data System (ADS)
Verstraeten, Gert; Poesen, Jean
This study investigates the spatial variation of small-scale flooding and muddy floods in rural areas in a medium sized study area (5516 km 2) and the linkage with controlling factors. A questionnaire set up in central Belgium indicates that 43% of the municipalities have to deal from time to time with muddy floods generated from direct runoff from arable land and 36% with flooding of permanent streams. A strong relation exists between the nature of the problem and the site in relation to topography and landuse. Areas suffering from muddy floods have significantly steeper cultivated slopes compared to areas suffering only from small-scale flooding. The high spatial and temporal frequency of small-scale flooding and muddy floods results in emotional and significant economic damage to private households. As a control measure more than 100 retention ponds have been constructed with 50 more to be built in the near future. The mean cost for the construction of a retention pond amounts to 380,000 EURO. These retention ponds store large quantities of sediment from runoff events and must thus be dredged regularly with costs of the order of 1.5 million EURO yearly. The dredged sediment volumes can be used to assess and predict sediment yield for these drainage basins; values vary between 0.19 and 6 m 3 ha -1 year -1 for basins ranging from 25 to 5000 ha.
Replicating Detention Reform: Lessons from the Florida Detention Initiative. Pathways to Juvenile Detention Reform 12.
ERIC Educational Resources Information Center
Bishop, Donna M.; Griset, Pamala L.
This report describes lessons learned from the Broward Detention Initiative (BDI) in Broward County, Florida, a successful detention reform effort that led to attempts at replication. Chapter 1, "The Predecessor Program: The Broward Detention Initiative," explains key factors in BDI's success (e.g., the site was ready, problems were effectively…
Does biodiversity of macroinvertebrates and genome response of Chironomidae larvae (Diptera) reflect heavy metal pollution in a small pond?
Paraskeva Michailova; Elzbieta Warcha?owska-?liwa; Ewa Szarek-Gwiazda; Andrzej Kownacki
The investigation was carried out on a small pond situated on a recent mine spoil at Boles?aw in the Olkusz region with Zn–Pb\\u000a ore deposits. Water of the pond had pH 7.2–8.5 and low concentrations of heavy metals. Concentrations of Pb (487 ?g g???1) and Zn (1,991 ?g g???1) in the sediment were very high and potentially could lead to toxicological effects. In the pond,
Technical and economic aspects of small-scale solar-pond-powered seawater desalination systems
Tamás Szacsvay; Patrick Hofer-Noser; Mario Posnansky
The production of potable water from sea- or brackish water can be achieved using a solar pond as a heat source coupled to a desalination unit. This paper describes the self-regulating ATLANTIS "Autoflash" multistage desalination system coupled to a solar pond. The operating principles of the desalination unit as well as of the solar pond are reviewed. Performance and layout
Small Thaw Ponds: An Unaccounted Source of Methane in the Canadian High Arctic
Negandhi, Karita; Laurion, Isabelle; Whiticar, Michael J.; Galand, Pierre E.; Xu, Xiaomei; Lovejoy, Connie
Thawing permafrost in the Canadian Arctic tundra leads to peat erosion and slumping in narrow and shallow runnel ponds that surround more commonly studied polygonal ponds. Here we compared the methane production between runnel and polygonal ponds using stable isotope ratios, 14C signatures, and investigated potential methanogenic communities through high-throughput sequencing archaeal 16S rRNA genes. We found that runnel ponds had significantly higher methane and carbon dioxide emissions, produced from a slightly larger fraction of old carbon, compared to polygonal ponds. The methane stable isotopic signature indicated production through acetoclastic methanogenesis, but gene signatures from acetoclastic and hydrogenotrophic methanogenic Archaea were detected in both polygonal and runnel ponds. We conclude that runnel ponds represent a source of methane from potentially older C, and that they contain methanogenic communities able to use diverse sources of carbon, increasing the risk of augmented methane release under a warmer climate. PMID:24236014
Duckweed based wastewater stabilization ponds for wastewater treatment (a low cost technology for small urban areas in Zimbabwe)
NASA Astrophysics Data System (ADS)
Dalu, J. M.; Ndamba, J.
A three-year investigation into the potential use of duckweed based wastewater stabilizations ponds for wastewater treatment was carried out at two small urban areas in Zimbabwe. The study hoped to contribute towards improved environmental management through improving the quality of effluent being discharged into natural waterways. This was to be achieved through the development and facilitation of the use of duckweed based wastewater stabilizations ponds. The study was carried out at Nemanwa and Gutu Growth Points both with a total population of 23 000. The two centers, like more than 70% of Zimbabwe's small urban areas, relied on algae based ponds for domestic wastewater treatment. The final effluent is used to irrigate gum plantations before finding its way into the nearest streams. Baseline wastewater quality information was collected on a monthly basis for three months after which duckweed ( Lemna minor) was introduced into the maturation ponds to at least 50% pond surface cover. The influent and effluent was then monitored on a monthly basis for chemical, physical and bacteriological parameters as stipulated in the Zimbabwe Water (Waste and Effluent Disposal) regulations of 2000. After five months, the range of parameters tested for was narrowed to include only those that sometimes surpassed the limits. These included: phosphates, nitrates, pH, biological oxygen demand, iron, conductivity, chemical oxygen demand, turbidity, total dissolved solids and total suspended solids. Significant reductions to within permissible limits were obtained for most of the above-mentioned parameters except for phosphates, chemical and biological oxygen demand and turbidity. However, in these cases, more than 60% reductions were observed when the influent and effluent levels were compared. It is our belief that duckweed based waste stabilization ponds can now be used successfully for the treatment of domestic wastewater in small urban areas of Zimbabwe.
Using Digital Imagery from a Small Unmanned Aerial Vehicle (UAV) to Estimate Arctic Melt Pond Coverage on Sea Ice
B. L. Mulac; M. A. Tschudi; J. A. Maslanik; G. J. Holland
Photo mapping of melt pond coverage on sea ice was undertaken in the Arctic during the summer of 2004 using an Aerosonde. Aerosondes are small, long endurance UAV designed to undertake a wide range of operations in a highly flexible and inexpensive mode. The Aerosonde conducts a defined mission in a completely autonomous mode. All flights are under the command
Duckweed based wastewater stabilization ponds for wastewater treatment (a low cost technology for small urban areas in Zimbabwe)
J. M. Dalu; J. Ndamba
A three-year investigation into the potential use of duckweed based wastewater stabilizations ponds for wastewater treatment was carried out at two small urban areas in Zimbabwe. The study hoped to contribute towards improved environmental management through improving the quality of effluent being discharged into natural waterways. This was to be achieved through the development and facilitation of the use of
Don Quixote Pond: A Small Scale Model of Weathering and Salt Accumulation
NASA Technical Reports Server (NTRS)
Englert, P.; Bishop, J. L.; Patel, S. N.; Gibson, E. K.; Koeberl, C.
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.
Using Digital Imagery from a Small Unmanned Aerial Vehicle (UAV) to Estimate Arctic Melt Pond Coverage on Sea Ice
NASA Astrophysics Data System (ADS)
Mulac, B. L.; Tschudi, M. A.; Maslanik, J. A.; Holland, G. J.
Photo mapping of melt pond coverage on sea ice was undertaken in the Arctic during the summer of 2004 using an Aerosonde. Aerosondes are small, long endurance UAV designed to undertake a wide range of operations in a highly flexible and inexpensive mode. The Aerosonde conducts a defined mission in a completely autonomous mode. All flights are under the command of a ground controller who can change missions and respond to air traffic control requests, etc. An NSF-funded effort (Office of Polar Programs' Long Term Observations [LTO]) is now underway to deploy Aerosondes for routine mapping and atmospheric sounding missions in the Arctic. Aerosondes were deployed at Barrow, AK, during June, 2004 as part of the LTO effort. During this deployment, several flights were dedicated to examining the fractional coverage of melt ponds over sea ice in the Beaufort and Chukchi Seas, as part of a study funded by NASA. Melt ponds have been identified as a key feature in determining the amount of solar insulation absorbed by sea ice, and hence is a primary controller of the melt rate of the ice through the summer. Sea ice models have, to date, crudely parameterized ponds, due in part to a lack of large-scale observations of their temporal and spatial evolution. The NASA-funded study uses observations from the EOS sensor MODIS to estimate pond fraction over a large portion of the Beaufort and Chukchi, by examining several spectral (visible and near-infrared) MODIS bands and deducing melt pond coverage from the known spectral properties of ponds. The Aerosonde flights dedicated to the melt pond study were necessary to test the validity of the pond coverage estimated using the MODIS data. A downward-looking Olympus C-3030 digital camera was mounted within the Aerosonde to photograph the sea ice. The digital photos are analyzed to classify each photo according to the percentage cover of melt ponds, unponded ice, and open water. These estimates are compared to the values retrieved using MODIS for the same area of coverage. To enhance these comparisons, missions were flown with 10 km x 10 km grid patterns, with overlapping (along-track and cross-track) digital photos, which allow for comparison with 400 MODIS pixels (500 m resolution). Additional missions were designed to examine the evolution of pond coverage over sea ice off the coast of Point Barrow, Alaska. The sea ice in this area of interest was fast ice (i.e. not drifting ice) and served as an area where melt ponds can be observed during formation and their evolution through the summer. The Aerosonde team flew several flights paralleling Point Barrow and overlapping in a pattern that provided contiguous digital camera images of the fast ice from shore to a few km off the coast. These flights were repeated several times during June, providing imagery that will assist investigators in determining how pond fraction changes over this period. The technique and results of pond coverage estimation from airborne digital photography will be presented, as will comparisons to estimates retrieved using MODIS.
Detention and deception: limits of ethical acceptability in detention research.
Minas, I H
The core of Australia's response to asylum seekers who arrive in an unauthorised manner has been to detain them in immigration detention centres until they are judged to engage Australia's protection obligations or, if they do not, until they are returned to their country of origin. For a number of asylum seekers this has resulted in very prolonged detention. This policy has aroused a storm of controversy with very polarised positions being taken by participants in the debate. In particular, the claim has frequently been made (including by this author) that the circumstances and duration of immigration detention cause substantial harm to the mental health of a significant number of detained asylum seekers. A rational debate on the effects of detention has been hampered by the fact that the Australian government has not allowed researchers access to the detention centres in spite of persistent requests for access by professional bodies. This paper is written in response to the following questions posed by the Journal: Is there a case to be made for individuals agreeing to participate in research studies and for the wider population of current and future detainees to be involved in research without informing either the detention provider or the host nation? Is is legitimate for a researcher to engage in potentially deceptive actions in order to obtain access to such detention facilities to undertake research? What ethical framework should underpin such research? Although there is very little guidance in the literature on the ethical conduct of research in settings such as immigration detention centres, a consideration of the ethical implications of carrying out research in the manner raised by these questions leads this author to conclude that such research cannot be ethically justified. Governments must be persuaded to allow, and to provide substantial support for, ethically conducted research on all aspects of detention. There is also a need for the development of an explicit ethical framework for the conduct of research in settings characterised by a very problematic human rights context. PMID:15688513
Valley pond and ignimbrite veneer deposits in the small-volume phreatomagmatic 'Peperino Albano' basic ignimbrite, Lago Albano maar, Colli Albani volcano, Italy: influence of topography
G. Giordano; D De Rita; R. Cas; S. Rodani
The ca. 23-ka, small-volume, basic phreatomagmatic Peperino Albano ignimbrite, from the polygenetic Albano maar (Colli Albani volcano, central Italy) shows valley pond facies as well as veneer deposits along the maar rim and along topographic ridges. Valley pond facies is characterised mainly by massive structure and chaotic texture and can be up to 30 m thick. Veneer deposit facies is
28 CFR 541.22 - Administrative detention.
Code of Federal Regulations, 2010 CFR
...Is pending transfer; (5) Requests admission to administrative detention for the inmate's...protection, or staff determines that admission to or continuation in administrative...psychological assessment, including a personal interview, when administrative detention...
Restoration of floating mat bog vegetation after eutrophication damages by improving water quality in a small pond
Riyou TsujinoNoboru; Noboru Fujita; Masao Katayama; Daiju Kawase; Kiyoshi Matsui; Akihiro Seo; Tetsuya Shimamura; Yasuhiro Takemon; Nozomi Tsujimura; Takakazu Yumoto; Atushi Ushimaru
We studied vegetation changes in a small floating mat bog in Mizorogaike Pond (Kyoto, Japan), which had experienced a severe\\u000a decrease in the number and area of hummocks caused by nutrient loading in the 1960s and 1970s, to examine whether reducing\\u000a the extent of nutrient loading can restore degraded wetland vegetation. However, nutrient loading in the region has been minimized
Uncertainty in measuring runoff from small watersheds using instrumented outlet-pond
Technology Transfer Automated Retrieval System (TEKTRAN)
This study quantified the uncertainty associated with event runoff quantity monitored at watershed outlet ponds. Inflow and outflow depth data were collected from 2004 to 2011 at seven instrumented monitoring stations at the outlet of watersheds ranging in size from 35.2 to 159.5 ha on the USDA-ARS ...
Interactions between Larval White Crappie and Gizzard Shad: Quantifying Mechanisms in Small Ponds
Kevin L. Pope; Dennis R. Devries
To test potential competitive interactions between larvae of white crappie Pomoxis annularis and of gizzard shad Dorosoma cepedianum, we added adult gizzard shad to eight of twelve 0.1-ha ponds that had been stocked with adult white crappies. Larval white crappies and larval gizzard shad appeared within 1 week of one another and larval white crappie density did not differ between
Long?term changes in the structure of ciliate communities in a small isolated pond
Paolo Madoni; Franco Sartore
The ciliate community was studied for a one?year cycle in a shallow freshwater pond covered by a dense layer of floating macrophytes (Lemna minor) in northern Italy. In all, 38 ciliate species were found with segregation between aerobic (surface layer) and anaerobic (bottom) habitats. Some species, such as Spirostomum ambiguum, and 5. teres, were frequent in both sites and proved
Evaluation of Electrofishing and Fyke Netting for Collecting Black Carp in Small Ponds
Matthew C. Basler; Harold L. Schramm Jr
The introduced black carp Mylopharyngodon piceus has the potential of depredating many imperiled native mussel and snail populations in U.S. waterways. The purpose of this study was to evaluate methods for detecting and assessing the abundance of black carp in warmwater systems. We electrofished and fyke-netted 0.1- and 0.3-ha aquaculture ponds stocked with triploid black carp at densities of 39–373
Interactions between Larval White Crappie and Gizzard Shad: Quantifying Mechanisms in Small Ponds
To test potential competilive interactions between larvae of white crappie Pomoxis annularis and of gizzard shad Dorosoma cepedilJnum. we added adult gizzard shad to eight of twelve O.I-ha ponds that had been stocked with adult white crappies. Larval white crappies and larval gizzard shad appeared within I week of one another and larval white crappie density did not differ between
Effects of acidification on metal accumulation by aquatic plants and invertebrates. 2. Wetlands, ponds and small lakes
Albers, P.H.; Camardese, M.B.
High concentrations of trace metals in the water of low-pH lakes and streams could result in elevated amounts of metals within or adsorbed to aquatic plants and, possibly, invertebrates. Concentrations of Al, Cd, Ca, Cu, Fe, Pb, Mg, Mn, Hg, Ni, P, and Zn were compared in water, plants, and aquatic invertebrates of wetlands, ponds, and small lakes in Maryland and Maine. The accumulation of metals by aquatic plants and insects and the concentrations of metals in water were not greatly affected by pH. None of the metal concentrations significantly correlated with metals in insects. Plant metal concentrations poorly correlated with metal concentrations in water. Concentrations of metals exceeded acceptable dietary levels more frequently in plants than in invertebrates. Concerns about metal toxicity in birds that feed on invertebrates and plants from acidified waters seem to be unwarranted. Positive correlations among pH, Ca in water, Ca in insects, and Ca in plants imply that acidification can reduce the Ca content of aquatic biota. Aquatic insects were low in Ca, but crayfishes and snails, which are adversely affected by low pH, were very high. A concern for waterfowl is Ca deprivation from decreased Ca availability in low-pH wetlands, ponds, and small lakes.
Effects of acidification of metal accumulation by aquatic plants and invertebrates. 2. Wetlands, ponds and small lakes
Albers, P.H.; Camardese, M.B. (U.S. Fish and Wildlife Service, Laurel, MD (United States). Patuxent Wildlife Research Center)
Compared were concentrations of Al,Cd,Ca,Cu,Fe,Pb,Mg,Mn,Hg,Ni,P, and Zn in water, plants, and aquatic invertebrates of wetlands, ponds, and small lakes in Maryland and Maine. The accumulation of metals by aquatic plants and insects and the concentration of metals in water were not greatly affected by pH. None of the metal concentrations in water significantly correlated with metals in insects. Plant metal concentrations poorly correlated with metal concentrations in water. Concentrations of metals exceeded acceptable dietary levels more frequently in plants than in invertebrates. Concerns about metal toxicity in birds that feed on invertebrates and plants from acidified waters seems to be unwarranted. Positive correlations among pH, Ca in water, Ca in insects, and Ca in plants imply that acidification can reduce the Ca content of aquatic biota. Aquatic insects were low in Ca, but crayfishes and snails, which are adversely affected by low pH, were very high. A concern for waterfowl is Ca deprivation from decreased Ca availability in low-pH wetlands, ponds, and small lakes..
Instrumentation for a dry-pond detention study
Pope, L.M.; Jennings, M.E.; Thibodeaux, K.G.
A 12.3-acre, fully urbanized, residential land-use catchment was instrumented by the U. S. Geological Survey in Topeka, Kansas. Hydraulic instrumentation for flow measurement includes two types of flumes, a pipe-insert flume and a culvert-inlet (manhole) flume. Samples of rainfall and runoff for water-quality analyses were collected by automatic, 3-liter, 24-sample capacity water samples controlled by multichannel data loggers. Ancillary equipment included a raingage and wet/dry atmospheric-deposition sampler. Nineteen stormwater runoff events were monitored at the site using the instrumentation system. The system has a high reliability of data capture and permits an accurate determination of storm-water loads.
Agricultural ponds support amphibian populations
Knutson, M.G.; Richardson, W.B.; Reineke, D.M.; Gray, B.R.; Parmelee, J.R.; Weick, S.E.
In some agricultural regions, natural wetlands are scarce, and constructed agricultural ponds may represent important alternative breeding habitats for amphibians. Properly managed, these agricultural ponds may effectively increase the total amount of breeding habitat and help to sustain populations. We studied small, constructed agricultural ponds in southeastern Minnesota to assess their value as amphibian breeding sites. Our study examined habitat factors associated with amphibian reproduction at two spatial scales: the pond and the landscape surrounding the pond. We found that small agricultural ponds in southeastern Minnesota provided breeding habitat for at least 10 species of amphibians. Species richness and multispecies reproductive success were more closely associated with characteristics of the pond (water quality, vegetation, and predators) compared with characteristics of the surrounding landscape, but individual species were associated with both pond and landscape variables. Ponds surrounded by row crops had similar species richness and reproductive success compared with natural wetlands and ponds surrounded by nongrazed pasture. Ponds used for watering livestock had elevated concentrations of phosphorus, higher turbidity, and a trend toward reduced amphibian reproductive success. Species richness was highest in small ponds, ponds with lower total nitrogen concentrations, tiger salamanders (Ambystoma tigrinum) present, and lacking fish. Multispecies reproductive success was best in ponds with lower total nitrogen concentrations, less emergent vegetation, and lacking fish. Habitat factors associated with higher reproductive success varied among individual species. We conclude that small, constructed farm ponds, properly managed, may help sustain amphibian populations in landscapes where natural wetland habitat is rare. We recommend management actions such as limiting livestock access to the pond to improve water quality, reducing nitrogen input, and avoiding the introduction of fish.
Growth and reproduction of introduced goldfish Carassius auratus in small ponds of southeast England with and without native crucian carp Carassius carassius
Cucherousset, Julien
Growth and reproduction of introduced goldfish Carassius auratus in small ponds of southeast, Dorset, UK Summary The ornamental Asiatic species, goldfish Carassius auratus, was introduced to open at age), body condition and reproduction (fecundity, egg size, length and age at maturity) of goldfish
Life-cycles of some invertebrate taxa in a small pond together with changes in their numbers over a period of three years
Johnstone O. Young
1. \\u000a \\u000a Monthly quantitative samples of the invertebrate fauna (except Protozoa) in a small pond were taken over a period of three\\u000a years. During one year, insect emergence traps were in operation. Water temperatures were recorded during the investigation.\\u000a \\u000a \\u000a \\u000a \\u000a 2. \\u000a \\u000a The most abundant organisms in the pond were Phaenocora typhlops, Limnodrilus hoffmeisteri and Chaoborus crystallinus. Certain species of Micro-Crustacea and Chironomidae
Fertilizer solar pond: Observations from small-scale experiments with (NH{sub 4}){sub 2}SO{sub 4} as a candidate salt
Pawar, S.H. [Shivaji Univ., Kolhapur (India); Chapgaon, A.N. [D.Y. Patil Coll. of Engineering and Technology, Kolhapur (India). Mechanical Engineering Dept.
Commercially available fertilizer salt (NH{sub 4}){sub 2}SO{sub 4} is used to establish a salinity gradient in a small outdoor tank. The hydrodynamic and thermal behavior of the pond was compared with a pond containing NaCl. For temperature gradients between 40 and 100 K/m and salinity gradients between 200 and 600 kg/m{sup 4}, the data suggest that results for (NH{sub 4}){sub 2}SO{sub 4} are consistent with the Nielsen boundary criterion for NaCl.
H. Tabor
The history and current status of salt-gradient non-convecting solar ponds are presented. These ponds are large-area collectors, capable of providing low-cost thermal, mechanical, or electrical energy using low-temperature turbo-generators. The basic theory of salt-gradient solar ponds is sketched; the effects of wind, leakage, and fouling and their constraints on location selection for solar ponds are discussed. The methods of building
Jayadev, T.S.; Edesess, M.
This report first describes the different types of solar ponds including the nonconvecting salt gradient pond and various saltless pond designs. It then discusses the availability and cost of salts for salt gradient ponds, and compares the economics of salty and saltless ponds as a function of salt cost. A simple computational model is developed to approximate solar pond performance. This model is later used to size solar ponds for district heating and industrial process heat applications. For district heating, ponds are sized to provide space conditioning for a group of homes, in different regions of the United States. Size requirements is on the order of one acre for a group of 25 to 50 homes. An economic analysis is performed of solar ponds used in two industrial process heat applications. The analysis finds that solar ponds are competitive when conventional heat sources are priced at $5 per million Btu and expected to rise in price at a rate of 10% per year. The application of solar ponds to the generation of electricity is also discussed. Total solar pond potential for displacing conventional energy sources is estimated in the range of from one to six quadrillion Btu per year in the near and intermediate future.
Modelling the impact of retention-detention units on sewer surcharge and peak and annual runoff reduction.
Locatelli, Luca; Gabriel, Sřren; Mark, Ole; Mikkelsen, Peter Steen; Arnbjerg-Nielsen, Karsten; Taylor, Heidi; Bockhorn, Britta; Larsen, Hauge; Kjřlby, Morten Just; Blicher, Anne Steensen; Binning, Philip John
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 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 20-40% of a soakaway volume to detention would significantly increase peak runoff reduction with a small reduction in the annual runoff. PMID:25812100
21 CFR 800.55 - Administrative detention.
Code of Federal Regulations, 2010 CFR
...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL Administrative Practices and Procedures...This section sets forth the procedures for detention of medical devices intended for human use believed to be...
Effectiveness of a stormwater collection and detention system for reducing constituent loads from bridge runoff in Pinellas County, Florida
Stoker, Y.E.
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, orthophosphorus, phosphorus, total organic carbon, aluminum, arsenic, copper, and zinc in stormwater runoff generally were inversely related to runoff volume. The quality of outflow from the detention pond also varied during a storm event and with season. Maximum concentrations generally occurred near the beginning of a storm, and decreased as the storm continued. Maximum concentrations of many constituents occurred in June and July 1995. During the summer months, pH exceeded 9.0 while inorganic nitrogen concentrations were very low. These high pH values and low inorganic nitrogen concentrations are most likely associated with photosynthesis by algae or aquatic plants in the pond. Concentrations of nitrogen, phosphorus, and nickel in stormwater runoff were correlated with total organic carbon concentrations. Concentrations of chromium, copper, iron, nickel, lead, and zinc in stormwater runoff were correlated with aluminum concentrations. The source of these metals is probably the bridge materials and metallic debris from vehicles. The northern detention pond system of the Bayside Bridge effectively reduced concentrations of suspended solids, ammonia nitrogen, nitrite plus nitrate nitrogen, phosphorus, aluminum, cadmium, chromium, copper, iron, lead, nickel, and zinc in stormwater runoff before water discharged from the pond. However, concentrations of ammonia plus organic nitrogen, organic carbon, arsenic, and values for alkalinity, pH, and specific conductance generally were greater in outflow from the pond than in stormwater runoff from the bridge. Stormwater runoff and pond outflow for three storm events were evaluated to determine the effectiveness of the detention pond system in removing selected constituents from the stormwater runoff. Most constituents and constituent loads were reduced in the outflow from the pond. Suspended solids loads were reduced about 30 to 45 percent, inorganic nitrogen loads were reduced by about 60 to 90 percent, and loads of most trace elements
Transient thermal characteristics of a small, saltless solar pond with one semi-transparent air-filled surface insulation layer
Kamiuto, K.; Nagumo, Y.; Ebikai, I. (Oita Univ. (Japan))
An experimental outdoor saltless solar pond with a semi-transparent , air-filled, surface insulation layer was monitored for 10 months. The measured temperatures showed good agreement with calculated values from a previous theoretical model.
Volkov, G.K.; Lyagushin, S.F.; Polyakova, L.P.; Pryakhin, G.N.; Statsenko, I.N. [Dniepropetrovsk State Univ. (Ukraine). Research Inst. of Energetics
Power pond analogues using salt solutions as a main heat-carrier are well known in world practice. In such ponds higher layers heated by solar radiation come down the reservoir being replaced by cold layers, so thermal energy is stored. Kabakov and Yantovsky proposed to equip a solar pond with a magnetohydrodynamic generator for obtaining electric power simultaneously. The authors propose an absolutely new concept of a power pond where electric and thermal generating modules (ETGM`s) are a main carrier of both electric and thermal energy.
Psychiatric and Medical Health Care Policies in Juvenile Detention Facilities
ERIC Educational Resources Information Center
Pajer, Kathleen A.; Kelleher, Kelly; Gupta, Ravindra A.; Rolls, Jennifer; Gardner, William
A study aims to examine the existing health care policies in U.S. juvenile detention centres. The results conclude that juvenile detention facilities have many shortfalls in providing care for adolescents, particularly mental health care.
Big Fish in Small Ponds: Massive Stars in the Low-mass Clusters of M83
NASA Astrophysics Data System (ADS)
Andrews, J. E.; Calzetti, D.; Chandar, R.; Elmegreen, B. G.; Kennicutt, R. C.; Kim, Hwihyun; Krumholz, Mark R.; Lee, J. C.; McElwee, Sean; O'Connell, R. W.; Whitmore, B.
We have used multi-wavelength Hubble Space Telescope WFC3 data of the starbursting spiral galaxy M83 in order to measure variations in the upper end of the stellar initial mass function (uIMF) using the production rate of ionizing photons in unresolved clusters with ages <= 8 Myr. As in earlier papers on M51 and NGC 4214, the uIMF in M83 is consistent with a universal IMF, and stochastic sampling of the stellar populations in the lap103 M ? clusters are responsible for any deviations in this universality. The ensemble cluster population, as well as individual clusters, also imply that the most massive star in a cluster does not depend on the cluster mass. In fact, we have found that these small clusters seem to have an over-abundance of ionizing photons when compared to an expected universal or truncated IMF. This also suggests that the presence of massive stars in these clusters does not affect the star formation in a destructive way.
Solar pond fluid dynamics and heat transfer
Jones, G.F.
The primary objective of the solar pond research was to obtain an indepth understanding of solar pond fluid dynamics and heat transfer. The key product was the development of a validated one-dimensional computer model with the capability to accurately predict time-dependent solar pond temperature, salinities, and interface motions. Laboratory scale flow visualization experiments were conducted to better understand layer motion. Two laboratory small-scale ponds and a large-scale outdoor solar pond were designed and built to provide quantitative data. This data provided a basis for validating the model and enhancing the understanding of pond dynamic behavior.
Solar Pond Fluid Dynamics and Heat Transfer
NASA Technical Reports Server (NTRS)
Jones, G. F.
The primary objective of the solar pond research was to obtain an indepth understanding of solar pond fluid dynamics and heat transfer. The key product was the development of a validated one-dimensional computer model with the capability to accurately predict time-dependent solar pond temperature, salinities, and interface motions. Laboratory scale flow visualization experiments were conducted to better understand layer motion. Two laboratory small-scale ponds and a large-scale outdoor solar pond were designed and built to provide quantitative data. This data provided a basis for validating the model and enhancing the understanding of pond dynamic behavior.
NSDL National Science Digital Library
L.O. Cannon, et. al. (Utah State U.)
This Java applet provides opportunities for creative problem solving while encouraging young students to estimate length and angle measure. Using the Turtle Pond Applet, students enter a sequence of commands to help the turtle get to the pond. Children can write their own solutions using LOGO commands and input them into the computer. The turtle will then move and leave a trail or path according to the instructions given. (N.B. the applet is an upgrade of one that supported the Lesson "Get the Turtle to the Pond," cataloged separately.)
Crawford, Amanda
. These ponds also offer the ability to perform nutrient and chemical studies, behavioral and functional ecology experiments, and community ecological and evolutional studies of algae, aquatic vascular plants, invertebrate grazers and predators (snails...
Peace without Detente: Living with the Russians.
ERIC Educational Resources Information Center
Bresler, Robert J.
Since the early 1970s, Soviet positions have hardened and detente has failed. Despite this, the United States must seek arms control agreements with the Soviet Union to prevent nuclear war. Arms control proposals offered by the Reagan administration are reviewed. (IS)
After Guantanamo: War, Crime, and Detention
Madeline Morris; Frances A. Eberhard; Michael A. Watsula
Neither the law of war nor the criminal law, alone or in combination, provides an adequate legal structure for responding to the most serious threats posed by Al Qaeda and similar groups. After identifying the limits of the criminal law and the law of war for these purposes, this article outlines a comprehensive proposal for counterterrorism prosecution and detention policy.
ERIC Educational Resources Information Center
Rawitscher-Kunkel, Erika
A small pond in a schoolyard provided year-round biological activities for children. As seasons changed, concepts and life relations also changed. Besides microscopic organisms in water, children learned about microscopic algae, detritus, and food chains. Concepts of predator-prey relationships and of ecosystems were successfully developed. (PS)
Measuring infiltrability in an Australian dryland soil: inconsistent results from ponded cylinder infiltrometry and simulated rainfall over small plots.
NASA Astrophysics Data System (ADS)
Dunkerley, David
Dryland soils present challenges to the field measurement of infiltrability, which may include stoniness, brittle surface seals and crusts, high mechanical strength, tendency to slake rapidly, and changes in properties arising during desiccation and re-wetting. In a contour-aligned mosaic shrubland, soil infiltrabilities were measured on initially dry soils using simulated rainfall of moderate intensity (10 mm/h), on plots 0.5 x 0.5 m. Experiments were run until runoff had stabilised and infiltrability was then calculated as the difference between the equilibrium rainfall and runoff rates. The plots were allowed to dry, following which ponded cylinder infiltrometer tests were carried out within the boundaries of each plot. These used cylinders of 100 mm diameter and ponding depths of 10 mm. Cylinder tests suggested infiltrabilities averaging 11.5 mm/h (range 2.2 - 37.1 mm/h). In contrast, the rainfall simulation plots yielded a mean of 4.2 mm/h (range 2.74 - 7.63 mm/h). Across 14 plots, test results from the two methods were moderately well correlated (r2 = 0.7). Apart from differences in the areal scale of the tests (plot area was ~ 32 times cylinder area) and probably greater evaporative loss from splash droplets (plots), the major reason for the differing results appeared to be the absence of droplet impacts and seal formation in ponded tests. Though the ranking of sites in terms of infiltrability did not differ greatly with the method of measurement, the differing absolute values are important. Ponded tests suggest that little overland flow would arise in the local climate, whilst the plot results suggest that moderately frequent rainfall events would exceed soil infiltrability. The next phase of this work is to examine the significance of imposed rainfall rate and the temporal variability of rainfall on the apparent soil infiltrabilty, using data derived from local pluviograph records.
Composting process design criteria. II. Detention time
Haug, R.T.
Attention has always been directed to detention time as a criteria for design and operation of composting systems. Perhaps this is a logical outgrowth of work on liquid phase systems, where detention time is a fundamental parameter of design. Unlike liquid phase systems, however, the interpretation of detention time and actual values required for design have not been universally accepted in the case of composting. As a case in point, most compost systems incorporate facilities for curing the compost product. However, curing often is considered after the fact or as an add on with little relationship to the first stage, high-rate phase, whether reactor (in-vessel), static pile, or windrow. Design criteria for curing and the relationships between the first-stage, high-rate and second-stage, curing phases of a composting system have been unclear. In Part 2 of this paper, the concepts of hydraulic retention time (HRT) and solids residence time (SRT) are applied to the composting process. Definitions and design criteria for each are proposed. Based on these criteria, the first and second-stages can be designed and integrated into a complete composting system.
Hydrologic considerations associated with dredging spring ponds in Wisconsin
Rose, William J.
Spring ponds (small spring-fed bodies of water) are natural features of some glaciated areas. The purpose of this study was to determine the hydrology of three spring ponds in northeastern Wisconsin and the effects that dredging has had on the ponds. Sediments were dredged from Sunshine and Krause Ponds. Maxwell Pond, which was not dredged, was used as a hydrologic control. Sediment accumulation since glaciation caused a 2-fold reduction in the surface area of Sunshine Pond and a 4-fold reduction in the area of Krause Pond. Volume reduction caused by sediment accumulation was 9-fold in Sunshine Pond and 28-fold in Krause Pond. Dredging 4.2 acre-feet of sediment from Sunshine Pond caused a 41-percent increase in ground-water inflow. Dredging 4.0 acre-feet of sediments from Krause Pond caused only a 2-percent increase in ground-water inflow. (Woodard-USGS)
Bottom construction of ponds particularly solar ponds
Shacher, S.
A pond construction, especially useful for non-convective solar ponds, having a multi-layer bottom in order to minimize seepage of liquid through the pond bottom. Liquid which permeates the multi-layer construction is pumped back into the pond.
NASA Technical Reports Server (NTRS)
Miller, C. G.; Stephens, J. B. (inventors)
Shallow pools of liquid to collect low-temperature solar generated thermal energy are described. Narrow elongated trenches, grouped together over a wide area, are lined with a heat-absorbing black liner. The heat-absorbing liquid is kept separate from the thermal energy removing fluid by means such as clear polyethylene material. The covering for the pond may be a fluid or solid. If the covering is a fluid, fire fighting foam, continuously generated, or siloons are used to keep the surface covering clean and insulated. If the thermal energy removing fluid is a gas, a fluid insulation layer contained in a flat polyethlene tubing is used to cover the pond. The side of the tube directed towards the sun is treated to block out ultraviolet radiation and trap in infrared radiation.
The Restorative Justice Center: An Alternative to School Detention
ERIC Educational Resources Information Center
Ashworth, Julie; Van Bockern, Steve; Ailts, Julie; Donnelly, Jason; Erickson, Kelsey; Woltermann, Jenna
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…
27 CFR 26.194 - Detention of articles.
Code of Federal Regulations, 2011 CFR
...2011-04-01 false Detention of articles. 26.194 Section 26.194 Alcohol...THE TREASURY LIQUORS LIQUORS AND ARTICLES FROM PUERTO RICO AND THE VIRGIN ISLANDS...Puerto Rico § 26.194 Detention of articles. (a) Upon receiving a...
27 CFR 26.194 - Detention of articles.
Code of Federal Regulations, 2010 CFR
...2010-04-01 false Detention of articles. 26.194 Section 26.194 Alcohol...THE TREASURY LIQUORS LIQUORS AND ARTICLES FROM PUERTO RICO AND THE VIRGIN ISLANDS...Puerto Rico § 26.194 Detention of articles. (a) Upon receiving a...
Medical care for people under detention.
Ritom, M H
Human Rights traditionally refer to rights and freedom that are inherent to every human being. They are based on Human Rights Law and concern the respect for dignity and worth of a person. These rights are universal, inalienable, indivisible, inter-related and interdependent. Members of Societies are detained for varied reasons and are made up of different age groups and gender. The United Nations through its numerous agencies, associated Conventions, Treaties and Resolutions have laid down guidelines that govern the rights of those under detention. Article 5 of General Assembly Resolution 45/111 clearly stipulates that except for those limitations that are demonstrably necessitated by the fact of incarceration, all prisoners shall retain the human rights and fundamental freedom set out in the Universal Declaration of Human Rights. As such, the Medical and Health Care of People under Detention should not be any different from the other members of societies. The Right to Health and Medical Care is stipulated under various Articles contained in the UN Bill of Human Rights (UDHR, ICCPCR and ICESCR) as well as other Conventions, e.g. Convention against Torture (CAT), Convention on Rights of the Child (CRC) and Convention for the Extinction of all Forms of Discrimination against Women (CEDAW). The United Nations have also developed specific guidelines and instruments for Treatment of People under Detention. These include the General Assembly Resolution 45/111 December 1990 elucidating the Basic Principles for Treatment of Prisoners, ECOSOG resolution 663C and 2076 regarding the Standard Minimum Rules for the Treatment of Prisoners which covers rules pertaining to accommodation and Medical Services, General Assembly Resolution 37/194 on Principles of Medical Ethics relevant to the role of health personnel, particularly Physicians, in the Protection of Prisoners and Detainees against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment. PMID:14556353
Continued detention involvement and adolescent marijuana use trajectories.
Ewing, Sarah W Feldstein; Schmiege, Sarah J; Bryan, Angela D
Justice-involved youth have high rates of marijuana use. Less is known about what may drive these rates, particularly when justice-involved youth return to the community. One factor that has been implicated is continued detention involvement. Yet, it is unknown how this factor may influence marijuana use trajectories. Using longitudinal growth curve modeling, the researchers evaluated the association between continued detention involvement and marijuana use trajectories in two large, ethnically diverse samples of community-based, justice-involved youth. Across both samples, marijuana use decreased over time for youth with continued detention involvement but did not change for youth without continued detention involvement. These findings underscore the importance of attending to the influence of detention involvement in community-based, justice-involved adolescents' marijuana use trajectories. This study also highlights the importance of coordinating prevention/intervention programming for justice-involved youth once they are in the community. PMID:24272742
NASA Technical Reports Server (NTRS)
Lin, E. I.
Problems associated with heat storage in solar ponds eliminated by transparent insulating cover at surface of pond. Cover makes unnecessary salt gradient that suppresses natural convection within pond to promote thermal storage.
HIV and incarceration: prisons and detention
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. PMID:21595957
Wind effects on retention time in highway ponds.
Bentzen, T R; Larsen, T; Rasmussen, M R
The paper presents results from an experimental and numerical study of wind-induced flows and transportation patterns in highway wet detention ponds. The study presented here is part of a general investigation on road runoff and pollution in respect to wet detention ponds. The objective is to evaluate the quality of long term simulations based on historical rain series of the pollutant discharges from roads and highways. The idea of this paper is to evaluate the effects of wind on the retention time and compare the retention time for the situation of a spatial uniform wind shear stress with the situation of a "real" spatial non-uniform shear stress distribution on the surface of the pond. The result of this paper shows that wind plays a dominant role for the retention time and flow pattern. Furthermore, the results shows that the differences in retention time between the use of uniform and non-uniform wind field distributions are not significant to this study. PMID:18547921
NSDL National Science Digital Library
Lawrence Hall of Science
In this outdoor activity/field trip, learners locate and study plants and animals in several freshwater pond habitats. Learners take various samples from the pond, identify organisms using a pond guide, and collaborate to create a pond map. Includes background information, but it is recommended that learners do the activity What Lives Here?, also by OBIS, before this activity.
19 CFR 151.16 - Detention of merchandise.
Code of Federal Regulations, 2010 CFR
...Anticipated length of the detention; (4) Nature of the tests or inquiries to be conducted; and (5) Nature of any information which, if supplied...decision has not been reached for good cause, the court shall grant the...
25 CFR 11.1004 - Detention and shelter care.
Code of Federal Regulations, 2011 CFR
...COURTS OF INDIAN OFFENSES AND LAW AND ORDER CODE Juvenile Offender Procedure § 11.1004 Detention and shelter care. (a) A minor alleged to be a juvenile offender may be detained, pending a court hearing, in...
25 CFR 11.1004 - Detention and shelter care.
Code of Federal Regulations, 2010 CFR
...COURTS OF INDIAN OFFENSES AND LAW AND ORDER CODE Juvenile Offender Procedure § 11.1004 Detention and shelter care. (a) A minor alleged to be a juvenile offender may be detained, pending a court hearing, in...
25 CFR 11.1004 - Detention and shelter care.
Code of Federal Regulations, 2013 CFR
...COURTS OF INDIAN OFFENSES AND LAW AND ORDER CODE Juvenile Offender Procedure § 11.1004 Detention and shelter care. (a) A minor alleged to be a juvenile offender may be detained, pending a court hearing, in...
25 CFR 11.1004 - Detention and shelter care.
Code of Federal Regulations, 2014 CFR
...COURTS OF INDIAN OFFENSES AND LAW AND ORDER CODE Juvenile Offender Procedure § 11.1004 Detention and shelter care. (a) A minor alleged to be a juvenile offender may be detained, pending a court hearing, in...
25 CFR 11.1004 - Detention and shelter care.
Code of Federal Regulations, 2012 CFR
...COURTS OF INDIAN OFFENSES AND LAW AND ORDER CODE Juvenile Offender Procedure § 11.1004 Detention and shelter care. (a) A minor alleged to be a juvenile offender may be detained, pending a court hearing, in...
Treatability studies for waters in oil pond No. 1, oil pond No. 2, and the oil seep
J. M. Napier; C. W. Hancher; G. E. Harris; M. E. Johnson; B. C. Padgett
Laboratory and pilot plant studies have investigated treatment methods for water contained in 2 small ponds located at the Bear Creek burial grounds. The sediments in the bottom of the pond are contaminated with polychlorinated biphenyls (PCB) and plans to close out these ponds and remove the sediments have been prepared. These laboratory and pilot plant studies show that the
[Legal probation after deferred retrospective preventive detention: implications for the amended regulations on preventive detention].
Müller, J L; Stolpmann, G; Fromberger, P; Haase, K A; Jordan, K
The study examines the legal probation of offenders who are considered to be highly dangerous but due to the decision of the Federal High Court were not in retrospective preventive detention (§ 66b StGB). In view of the current discussion, in anticipation of a detailed presentation of the study results the relevant criteria "probation behavior", "personality characteristics" and "prognosis quality" are picked out. The results are evaluated with respect to knowledge of the restrictions conditioned by the study regarding the usefulness for the prognosis of reoffending. The results of this study suggest that it might be useful to describe psychological criteria for the not seriously reoffending group of probands. PMID:22588561
Demonstration of a solar gel pond. Final report
Wilkins, E.S.
The purpose of this work was to demonstrate the gel pond concept in a small pond, to document performance and to study various aspects of this new technology. The pond and the surrounding ground was instrumented with thermocouples, and meteorological parameters were monitored. Insofar as comparisons could be made, the gel pond was superior to a similar salt gradient pond. Surface heat losses were considerably less, and stability problems of course nonexistent. Existing models of stratified ponds were reviewed and both steady state and unsteady state model for the gel pond were constructed. Prediction of these models agreed well with actual experimental data from the gel pond. Possible use of phase change materials to enhance heat storage in the gel pond was investigated. Both calculation and laboratory experiments for selected materials were performed; it was concluded that the present cost of the best material does not justify their use at present. Physical properties of various gel material were measured (density, specific heat, thermal conductivity, life time, and optical transmissivity). In general the physical properties of gel were similar to that of water. Optical transmissivity was also monitored out doors in a pond. A restrictive cost-benefit analysis was conducted comparing the salt gradient and the gel pond in the same location for varying location, load, size. It is demonstrated that the gel pond energy cost is lower than that from salt gradient ponds.
42 CFR 70.6 - Apprehension and detention of persons with specific diseases.
Code of Federal Regulations, 2012 CFR
...and detention of persons with specific diseases. 70.6 Section 70.6 Public...and detention of persons with specific diseases. Regulations prescribed in this...transmission, and spread of the communicable diseases listed in an Executive Order...
42 CFR 70.6 - Apprehension and detention of persons with specific diseases.
Code of Federal Regulations, 2013 CFR
...and detention of persons with specific diseases. 70.6 Section 70.6 Public...and detention of persons with specific diseases. Regulations prescribed in this...transmission, and spread of the communicable diseases listed in an Executive Order...
42 CFR 70.6 - Apprehension and detention of persons with specific diseases.
Code of Federal Regulations, 2010 CFR
...and detention of persons with specific diseases. 70.6 Section 70.6 Public...and detention of persons with specific diseases. Regulations prescribed in this...transmission, and spread of the communicable diseases listed in an Executive Order...
42 CFR 70.6 - Apprehension and detention of persons with specific diseases.
Code of Federal Regulations, 2011 CFR
...and detention of persons with specific diseases. 70.6 Section 70.6 Public...and detention of persons with specific diseases. Regulations prescribed in this...transmission, and spread of the communicable diseases listed in an Executive Order...
42 CFR 70.6 - Apprehension and detention of persons with specific diseases.
Code of Federal Regulations, 2014 CFR
...and detention of persons with specific diseases. 70.6 Section 70.6 Public...and detention of persons with specific diseases. Regulations prescribed in this...transmission, and spread of the communicable diseases listed in an Executive Order...
48 CFR 3017.204-90 - Detention Facilities and Services (ICE).
Code of Federal Regulations, 2013 CFR
...2012-10-01 true Detention Facilities and Services (ICE). 3017.204-90 Section 3017.204-90 Federal... 3017.204-90 Detention Facilities and Services (ICE). The ICE Head of the Contracting Activity (HCA),...
48 CFR 3017.204-90 - Detention Facilities and Services (ICE).
Code of Federal Regulations, 2014 CFR
...2014-10-01 false Detention Facilities and Services (ICE). 3017.204-90 Section 3017.204-90 Federal... 3017.204-90 Detention Facilities and Services (ICE). The ICE Head of the Contracting Activity (HCA),...
48 CFR 3017.204-90 - Detention Facilities and Services (ICE).
Code of Federal Regulations, 2011 CFR
...2011-10-01 false Detention Facilities and Services (ICE). 3017.204-90 Section 3017.204-90 Federal... 3017.204-90 Detention Facilities and Services (ICE). The ICE Head of the Contracting Activity (HCA),...
48 CFR 3017.204-90 - Detention Facilities and Services (ICE).
Code of Federal Regulations, 2012 CFR
...2012-10-01 false Detention Facilities and Services (ICE). 3017.204-90 Section 3017.204-90 Federal... 3017.204-90 Detention Facilities and Services (ICE). The ICE Head of the Contracting Activity (HCA),...
NASA Technical Reports Server (NTRS)
Carpenter, S.
Flocculatory agents added to solar saltponds remove turbidity to increase solar-energy collection efficiency. Flocculating agent or bacteriocide used to remove micro-organisms sprayed onto pond from airplane and allowed to settle to bottom of pond.
NASA Technical Reports Server (NTRS)
French, R. L. (editor); Zangrando, F.; Johnson, D. H.; Jones, G. F.
The term solar pond is used to refer specifically to a salt-gradient solar pond. A technology assessment was done consisting of thermal performance; maintenance; applications; and economics. Research needs and recommendations were also included.
This pond liner replacement process will be used to replace 9 deteriorated clay pond liners with polyethylene liners that help hatchery employees at Garrison Dam National Fish Hatchery produce more fish at a larger size with less effort. Related to the R6PC ? Replace 9 Clay Pond Liners ?...
ERIC Educational Resources Information Center
O'Brien, W. J.
Presents the 1978 literature review of wastewater treatment. This review covers lagoons and oxidation ponds, and it includes some areas such as improving the effluents from ponds, stabilization ponds, aerated lagoons, and oxidation ditches. A list of 36 references is also presented. (HM)
Assessing Chemical Retention Process Controls in Ponds
NASA Astrophysics Data System (ADS)
Torgersen, T.; Branco, B.; John, B.
Small ponds are a ubiquitous component of the landscape and have earned a reputation as effective chemical retention devices. The most common characterization of pond chemical retention is the retention coefficient, Ri= ([Ci]inflow-[Ci] outflow)/[Ci]inflow. However, this parameter varies widely in one pond with time and among ponds. We have re-evaluated literature reported (Borden et al., 1998) monthly average retention coefficients for two ponds in North Carolina. Employing a simple first order model that includes water residence time, the first order process responsible for species removal have been separated from the water residence time over which it acts. Assuming the rate constant for species removal is constant within the pond (arguable at least), the annual average rate constant for species removal is generated. Using the annual mean rate constant for species removal and monthly water residence times results in a significantly enhanced predictive capability for Davis Pond during most months of the year. Predictive ability remains poor in Davis Pond during winter/unstratified periods when internal loading of P and N results in low to negative chemical retention. Predictive ability for Piedmont Pond (which has numerous negative chemical retention periods) is improved but not to the same extent as Davis Pond. In Davis Pond, the rate constant for sediment removal (each month) is faster than the rate constant for water and explains the good predictability for sediment retention. However, the removal rate constant for P and N is slower than the removal rate constant for sediment (longer water column residence time for P,N than for sediment). Thus sedimentation is not an overall control on nutrient retention. Additionally, the removal rate constant for P is slower than for TOC (TOC is not the dominate removal process for P) and N is removed slower than P (different in pond controls). For Piedmont Pond, sediment removal rate constants are slower than the removal rate constant for water indicating significant sediment resuspension episodes. It appears that these sediment resuspension events are aperiodic and control the loading and the chemical retention capability of Piedmont Pond for N,P,TOC. These calculated rate constants reflect the differing internal loading processes for each component and suggest means and mechanisms for the use of ponds in water quality management.
The School Principal and the Use of Detention, Suspension and Expulsion as Disciplinary Measures.
ERIC Educational Resources Information Center
Carter, David G.
In discussing school discipline, the place to begin is by considering whether detention, suspension, and expulsion help students and resolve discipline problems. Detention seems to be most effective when the student is detained on the same day and as close as possible to the time the offense occurs, but too often detention is used merely as a…
Analysis of the reduction of detent force in a permanent magnet linear synchronous motor
T. Yoshimura; H. J. Kim; M. Watada; S. Torii; D. Ebihara
The problem in improving the positioning precision of a permanent magnet linear synchronous motor (LSM) is the large detent force caused by the permanent magnet. The detent force is thought to arise from the difference of the position of a permanent magnet end and a tooth position. If one detent force is independent from the other, we can reduce the
Appropriate medical care for persons in detention.
Idris, I
The people who are in detention are screened by the Medical Officer of the Prison and if they are found to be unwell, these prisoners will be accommodated in the sickbay and medical treatment will be provided. If their sickness needs further investigations and management, they will be sent to the Government Hospital. If the prisoners are found to have infectious or contagious diseases, steps will be taken to prevent the spread of these diseases to other prisoners in the prison. Prisoners are given time to exercise to maintain good health and their clothing are regularly washed to make sure that they will not contract skin diseases, e.g. scabies, ringworm, etc. The Prison Department since 1989 has increasing numbers of HIV positive prisoners. The Department complies with this problem by sending staff for courses, lectures and seminars so that they will be able to handle these prisoners more efficiently in the prison. When these HIV/AIDS prisoners' condition turns bad, they are usually transferred to a Government Hospital. Another of the Prison Department's prominent medical problem among the prisoners is drug addiction. Staff trained with skill and techniques are counselors for the drug related prisoners. Realizing and in anticipation that the sickbays in the prisons are going to be full of HIV/AIDS prisoners and drug related prisoners, special attention will be given to more allocation to upgrade the sickbays in the prison. White attires will be provided to the sick prisoners in the sickbays so that they will look neat and clean. More doctors, medical assistants and nurses will be employed so that appropriate medical care or rather more appropriate medical care can be provided to the sick prisoners in the prisons. The Prison Department is in the process of privatizing medical care for prisoners in the prison and the Department is also trying to convert some prisons to be medical prisons so that adequate medical care can be given to the sick prisoners. PMID:14556359
NSDL National Science Digital Library
ExplorA-Pond is an online opportunity for collaborative science among classrooms from around the world. Classrooms that register with the site can adopt a local pond and submit the results of one or more of the Pond Activities/ Lesson Plans. Regardless of whether your classroom chooses to register, the activities and lesson plans designed for K-6th graders provide a hands-on approach to science and math lessons. A virtual pond option is even provided in the event that it is impractical for classrooms to visit and survey a real local pond.
Marlatt, W.P.; Murray, K.A.; Squier, S.E.
This report provides a single-source document useful to architects, engineers, builders, and homeowners that addresses numerous aspects of roof pond design, construction, and performance. An introduction to the roof pond passive solar space heating and cooling concept is provided, including basic methods of operation and system configurations adaptable to different climates. A brief history of the development of the roof pond concept is presented, and several existing roof pond buildings located throughout the United States are described. The regional applicability of roof ponds in both heating and cooling service; design considerations relating to architecture, heating and cooling aspects, and structural requirements; and current heat transfer relations important in roof pond design are examined. A chapter on roof pond system materials and components is included. It contains tables of material properties; descriptions of available and installed components; installation, operation, and maintenance concerns; and a compilation of operating experience to date. The results of actual performance testing of several instrumented roof pond buildings are presented, and in certain cases, these results are compared with roof pond performance simulation results. A life-cycle cost study of two roof pond homes is developed, and the results are compared with the life-cycle costs of two similar conventional residences. This document has application to many related roof pond concepts, such as the Cool Pool and Energy Roof. An extensive bibliography is provided.
Secure preventive detention in Germany: incapacitation or treatment intervention?
Drenkhahn, Kirstin
Secure preventive detention of dangerous offenders has been a major source of debate in German law and practice. Unlike the other two custodial measures of correction and security in the Penal Code (confinement in a psychiatric hospital and in a detoxification clinic), it has served mainly as incapacitation. Judgments by the German Federal Constitutional Court and the European Court of Human Rights challenged this traditional concept of secure preventive detention, which led to a redefinition of the measure. It is now conceived as an offending behavior treatment measure in a secure environment. This article reports on the background of this development and analyzes its implications. PMID:23682027
Perceptions about substance use among male adolescents in juvenile detention.
Anderson, N L
Although adolescents in juvenile detention represent a vulnerable population who are exposed to situations that foster risk-taking behaviors, few studies have been conducted with detained adolescents to determine their perceptions regarding substance use. Ethnographic interviews and observations were conducted with 20 male adolescents who resided in a large metropolitan area juvenile detention facility, to discover their substance use beliefs and the decisions they make to continue or discontinue substance use or abuse. The participants described how they initiated substance use and said that they had rarely made active decisions about substance use until they were detained. They explained the decisions they made, while they were in detention, to stop or cut down their substance use after release. They talked about the problems they anticipated when they returned home and how they hoped to balance their resolutions with their reputations and obligations. Time-out in juvenile detention may offer nurses the opportunity to capitalize on the potential readiness of detained adolescents to make resolution decisions regarding risky behaviors. Findings from a similar study conducted with 20 detained adolescent women were reported elsewhere. PMID:11512185
Jail Pedagogy: Liberatory Education inside a California Juvenile Detention Facility
ERIC Educational Resources Information Center
Flores, Jerry
Approximately 2 million juveniles are arrested each year. Half are sentenced to serve terms of incarceration. Although many scholars have written about teaching in detention facilities, few directly address how prisoners are being taught. This research explores the experiences, teaching philosophy, and practices of correctional educators. To learn…
The Cottage Farm Detention and Chlorination Station was placed in operation by the Metropolitan District Commission on April 29, 1971. The station, located in Cambridge, Massachusetts, diverts and treats combined sewage flows from the Charles River Valley sewer system (15,600 acr...
Psychiatric Disorders of Youth in Detention. Juvenile Justice Bulletin
ERIC Educational Resources Information Center
Teplin, Linda A.; Abram, Karen M.; McClelland, Gary M.; Mericle, Amy A.; Dulcan, Mina K.; Washburn, Jason J.
This bulletin examines the prevalence of alcohol, drug, and mental disorders among youth at the Cook County (Illinois) Juvenile Temporary Detention Center, by gender, race/ethnicity, and age. Drawing on research conducted by the Northwestern Juvenile Project, this bulletin finds that nearly two-thirds of males and three-quarters of females studied…
Vocational Training in Juvenile Detention: A Call for Action
ERIC Educational Resources Information Center
Ameen, Edward J.; Lee, Debbiesiu L.
Given high recidivism rates and the vulnerability of detained youth, the authors posit that juvenile detention centers may be most efficacious by serving as both place and process to create career opportunity through vocational training. The authors review the psychosocial factors contributing to delinquency and the primary theories of…
Conditions of Confinement: Juvenile Detention and Corrections Facilities. Research Summary.
ERIC Educational Resources Information Center
Parent, Dale G.; And Others
The most comprehensive nationwide research ever conducted on the juvenile detention and corrections field was a study by the Office of Juvenile Justice and Delinquency Prevention (OJJDP) assessing conditions of confinement for juveniles and determining the extent to which those conditions conform to recognized national professional standards. The…
Hull, J.R.
The physics of the solar pond and the results to date from an experimental solar pond are discussed. The pond is located at Living History Farms near Des Moines, Iowa. A mathematical model and a computer simulation of the pond are presented. The theory of convective stability in the solar pond salt gradient is briefly discussed. (BCS)
Solar ponds: a selected bibliography
Not Available
This bibliography contains citations on: regular solar ponds; shallow solar ponds; and patents. Certain references are specifically recommended. The data bases searched for the bibliography are listed. (LEW)
.............................................. 9 4 Stomach contents of adult yellow perch from Abbey Pond during 1970, expressed as percent number per stomach and percent volume per stomach (in parentheses) ...................20 5 Stomach contents of adult yellow perch from Abbey Pond during 1971, expressed as percent number per stomach and percent
NSDL National Science Digital Library
N/A N/A (None; )
Koi fish are somewhat related to goldfish. You can think of them as very large goldfish. Koi fish are usually kept in large ponds. Goldfish are often kept as pets in fish bowls or ponds. They are domesticated animals from a carp species and are not often found in the wild.
Detention, the War on Terror, and the Federal Courts
Judith Resnik
Between 2004 and 2009, the United States Supreme Court relied numerous times on habeas corpus to protect the rights of citizens and of aliens detained after 9\\/11. Various claims could be marshaled to bracket the 9\\/11 decisions—as "war" cases; "Guantanamo" cases; "torture" cases; aberrational responses to documented procedural unfairness; unusual instances of federal pretrial detention; and either as extraordinary judicial
Functional Impairment in Youth Three Years after Detention
Abram, Karen M.; Choe, Jeanne Y.; Washburn, Jason J.; Romero, Erin G.; Teplin, Linda A.
Purpose This article examines functional impairment across global and specific dimensions among youth 3 years after their detention. Methods Functional impairment was assessed using the Child and Adolescent Functional Assessment Scale (CAFAS) in a large, stratified, random sample of formerly detained youth (N = 1653). Results More than one-fifth of the sample were scored as having marked impairment that required, at minimum, "multiple sources of care" (CAFAS Total Score of 100 or higher); 7.0% required "intensive intervention" (CAFAS Total Score ?140). Most of the sample had impairment; only 7.5% of the sample had "no noteworthy impairment" (CAFAS Total Score ?10). Significantly more males were impaired than females. Among males living in the community at follow-up, African Americans and Hispanics were more likely to be impaired than non-Hispanic whites. In comparison to males living in the community, males who were incarcerated at follow-up were significantly more likely to have impaired thinking and impaired functioning at their place of residence but less likely to have substance use problems. Conclusions Three years after detention, most youth struggle in one or more life domains; more than one in five have marked impairment in functioning. These findings underscore the ongoing costs, to both youth and society, of our failure to provide effective rehabilitation to youth after detention. PMID:19465316
Hiergesell, R.A.; Dixon, K.L.
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.
Nickerson, J.A.
An improved solar pond apparatus is described which comprises a solar pond means having a substantially flat, extended surface with upwardly directed sides thereof to retain the liquid while the liquid is exposed to the sun absorbing solar radiation and a flooding valve means connected to the solar pond means and moveable between an open position and a closed position to provide the liquid from the source and flood the liquid upon the substantially flat, extended surface of the solar pond means. Means are provided to control the depth of the solar absorbtive liquid and flooding valve control means are connected to the flooding valve means and to the means to control the depth of the solar absorbtive liquid which activates the flooding valve means to the open position when the means to control the depth of the solar absorbtive liquid determines the liquid in the solar pond means and which activates the flooding valve means to the closed position when the means to control the depth of the solar absorbtive liquid determines the second level of liquid in the solar pond means. First liquid conduit means are connected to the source of the flooding valve means and drainage valve means are connected to the solar pond means and are moveable between an open position and a closed position to drain the liquid from the solar pond means. A first sensor means is attached to the solar pond means and arranged to sense a predetermined temperature and drainage valve control means are connected to the drainage valve and to the first sensor means which actives the drainage valve means to the open position when the first sensor means senses the predetermined temperature. Storage means are connected on one end to the drainage valve means to receive the liquid at the predetermined temperature therefrom, and on the other end to an outlet means. Second liquid conduit means connect the drainage valve means to the storage means.
A. Rabil; C. E. Nielsen
The absorption of solar radiation by the artificially salinized water in solar heat-storage ponds is considered, and equations are derived for the resulting temperature range of the pond during year-round operation. It is concluded that solar ponds can supply adequate heating, even in regions near the arctic circle. In midlatitudes the pond should be roughly comparable in surface area and
ERIC Educational Resources Information Center
Raun, Chester E.; Metz, William C.
An activity utilizing a bucket of pond water for study of microorganisms as presented to elementary school preservice and inservice teachers, and subsequently to their pupils, is described. Procedures for collecting, studying, tabulating data and extended activities are presented. (EB)
Pumping performance of a slow-rotating paddlewheel for split-ponds
Technology Transfer Automated Retrieval System (TEKTRAN)
Commercial catfish farmers are intensifying production by retrofitting ponds with variations of the partitioned aquaculture system. The split-pond system is the most common variation used commercially. The split-pond consists of a small fish-holding basin connected to a waste treatment lagoon by two...
Aquatic Habitats: Exploring Desktop Ponds. Teacher's Guide.
ERIC Educational Resources Information Center
Barrett, Katharine; Willard, Carolyn
This book, for grades 2-6, is designed to provide students with a highly motivating and unique opportunity to investigate an aquatic habitat. Students set up, observe, study, and reflect upon their own "desktop ponds." Accessible plants and small animals used in these activities include Elodea, Tubifex worms, snails, mosquito larvae, and fish.…
21 CFR 1.392 - Who receives a copy of the detention order?
Code of Federal Regulations, 2014 CFR
...must provide a copy of the detention order to the owner of the article of food if the owner's identity can be determined readily. (b) If FDA issues a detention order for an article of food located in a vehicle or other carrier used to...
21 CFR 1.392 - Who receives a copy of the detention order?
Code of Federal Regulations, 2011 CFR
...must provide a copy of the detention order to the owner of the article of food if the owner's identity can be determined readily. (b) If FDA issues a detention order for an article of food located in a vehicle or other carrier used to...
21 CFR 1.392 - Who receives a copy of the detention order?
Code of Federal Regulations, 2010 CFR
...must provide a copy of the detention order to the owner of the article of food if the owner's identity can be determined readily. (b) If FDA issues a detention order for an article of food located in a vehicle or other carrier used to...
21 CFR 1.392 - Who receives a copy of the detention order?
Code of Federal Regulations, 2012 CFR
...must provide a copy of the detention order to the owner of the article of food if the owner's identity can be determined readily. (b) If FDA issues a detention order for an article of food located in a vehicle or other carrier used to...
21 CFR 1.392 - Who receives a copy of the detention order?
Code of Federal Regulations, 2013 CFR
...must provide a copy of the detention order to the owner of the article of food if the owner's identity can be determined readily. (b) If FDA issues a detention order for an article of food located in a vehicle or other carrier used to...
Developing and Implementing a Stress Management Program for Special Educators in a Juvenile Detention Center.
ERIC Educational Resources Information Center
Francis, Joan R.
This paper describes a practicum designed to increase the stress management skills of 10 special educators working in a juvenile detention center. Teachers at the juvenile detention center were taking an inordinate amount of sick leave and engaging in behaviors that were counter-productive to their delivery of educational services to detained…
Multimetric Evaluation of Detention Basin Retrofit to Reduce Hydrologic Alteration of Urbanization and Restore Stream Stability
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...
69 FR 31660 - Administrative Detention of Food for Human or Animal Consumption Under the Public Health Security...
Federal Register 2010, 2011, 2012, 2013, 2014
...serious adverse health consequences or death...of administrative detention, FDA may consider...serious adverse health consequences'' because an illustrative list from FDA will...or unnecessary) detentions do not occur. A few...of serious adverse health consequences should...group of people, detention would not be the...
Falling head ponded infiltration in the nonlinear limit
NASA Astrophysics Data System (ADS)
Triadis, D.
The Green and Ampt infiltration solution represents only an extreme example of behavior within a larger class of very nonlinear, delta function diffusivity soils. The mathematical analysis of these soils is greatly simplified by the existence of a sharp wetting front below the soil surface. Solutions for more realistic delta function soil models have recently been presented for infiltration under surface saturation without ponding. After general formulation of the problem, solutions for a full suite of delta function soils are derived for ponded surface water depleted by infiltration. Exact expressions for the cumulative infiltration as a function of time, or the drainage time as a function of the initial ponded depth may take implicit or parametric forms, and are supplemented by simple asymptotic expressions valid for small times, and small and large initial ponded depths. As with surface saturation without ponding, the Green-Ampt model overestimates the effect of the soil hydraulic conductivity. At the opposing extreme, a low-conductivity model is identified that also takes a very simple mathematical form and appears to be more accurate than the Green-Ampt model for larger ponded depths. Between these two, the nonlinear limit of Gardner's soil is recommended as a physically valid first approximation. Relative discrepancies between different soil models are observed to reach a maximum for intermediate values of the dimensionless initial ponded depth, and in general are smaller than for surface saturation without ponding.
Salt-gradient Solar Ponds: Summary of US Department of Energy Sponsored Research
NASA Technical Reports Server (NTRS)
French, R. L.; Johnson, D. H.; Jones, G. F.; Zangrando, F.
The solar pond research program conducted by the United States Department of Energy was discontinued after 1983. This document summarizes the results of the program, reviews the state of the art, and identifies the remaining outstanding issues. Solar ponds is a generic term but, in the context of this report, the term solar pond refers specifically to saltgradient solar pond. Several small research solar ponds have been built and successfully tested. Procedures for filling the pond, maintaining the gradient, adjusting the zone boundaries, and extracting heat were developed. Theories and models were developed and verified. The major remaining unknowns or issues involve the physical behavior of large ponds; i.e., wind mixing of the surface, lateral range or reach of horizontally injected fluids, ground thermal losses, and gradient zone boundary erosion caused by pumping fluid for heat extraction. These issues cannot be scaled and must be studied in a large outdoor solar pond.
NASA Technical Reports Server (NTRS)
Lin, E. I. H. (inventor)
A solar pond adapted for efficiently trapping and storing radiant solar energy without the use of a salt concentration gradient in the pond is disclosed. A body of water which may be fresh, saline, relatively clear or turbid, is substantially covered by a plurality of floating honeycomb panels. The honeycomb panels are made of a material such as glass which is pervious to short wave solar radiation but impervious to infrared radiation. Each honeycomb panel includes a multitude of honeycomb cells. The honeycomb panels are divided into the elongated honeycomb cells by a multitude of intermediate plates disposed between a bottom plate and top plate of the panel. The solar pond is well suited for providing hot water of approximately 85 to 90 C temperature for direct heating applications, and for electrical power generation.
A Tree plantation and Native Woods in Maryland. The trees between the pond and the field are trees along a running creek. The pond had mixed vegetation (native and nonnative) restored along its edge as a runoff buffer....
Suicidal Ideation and Behaviors Among Youth in Juvenile Detention
Abram, Karen M.; Choe, Jeanne Y.; Washburn, Jason J.; Teplin, Linda A.; King, Devon C.; Dulcan, Mina K.
Objective To examine suicidal ideation, suicide attempts, lethality of suicide attempts, and the relationship between psychiatric disorder and recent attempts in newly detained juveniles. Methods The sample included 1829 juveniles, aged 10 to 18 years, sampled after intake to a detention center in Chicago, IL. Interviewers administered the Diagnostic Interview Schedule for Children (DISC) to assess for thoughts of death, suicidal ideation, suicide plans, lifetime suicide attempts, number of attempts, age at first attempt, attempts within the last 6 months, method of suicide attempts, and psychiatric disorder. Results More than one-third of juvenile detainees and nearly half of females had felt hopeless or thought about death in the 6 months prior to detention. Approximately 1 of 10 (10.3%, CI: 7.7% – 12.8%) juvenile detainees had thought about committing suicide in the past 6 months, and 1 of 10 (11.0%, CI: 8.3% – 13.7%) had ever attempted suicide. Recent suicide attempts were most prevalent in females and youth with major depression and generalized anxiety disorder. Conclusions Fewer than half of detainees with recent thoughts of suicide had told anyone about their ideation. Identifying youth at risk for suicide -- especially those suffering from depressive and anxiety disorders -- is a crucial step to preventing suicide. PMID:18216737
Gradient-zone erosion in seawater solar ponds
Shi, J.; Hart, R.A.; Kleis, S.J.; Bannerot, R.B. [Univ. of Houston, TX (United States). Dept. of Mechanical Engineering
An experimental program has been conducted to examine the feasibility of using seawater solar ponds in mariculture operations along the Texas gulf coast to protect fish crops from the potentially lethal, cold temperatures experienced in outdoor ponds. Seawater solar ponds in the form of floating thermal refuge areas are proposed as a method for reducing the loss of heat from small sections of a pond. Gradient zone erosion under various ambient and operating conditions is examined. Comparisons with previous laboratory studies show a much lower entrainment rate in the natural environment. For conditions which are typical of those encountered in mariculture pond operation, the entrainment rate was found to depend only weakly on the Richardson number. For these conditions, a simple (linear) correlation of entrainment rate with wind speed was developed.
Pond Construction: Some Practical Considerations
Liskiewicz, Maciej
soil removal. In most instances, the maxi mum height of a dam should be 20 to 25 feet. Dams higher than was shown for con struction safety in building farm pond dams. Now, however, many states are routinely checking pond dams, and condemning those which are unsafe. Condemned ponds must be drained and repaired
B. S. Sherman; J. Imberger
Solar ponds hold the promise of providing an alternative to diesel generation of electricity at remote locations in Australia where fuel costs are high. However, to reliably generate electricity with a solar pond requires high temperatures to be maintained throughout the year; this goal had eluded the Alice Springs solar pond prior to 1989 because of double-diffusive convection within the
H. Tabor
A salt gradient is imposed on a black-bottomed pond about 1 m deep; this creates a density gradient (positive measured downwards) which suppresses convection when the pond is heated from the bottom by absorbed solar radiation. Between 15 and 25% of the incident radiation, depending upon pond cleanliness, reaches the bottom and can be decanted by stratified hydrodynamic flow of
Observational bias and the apparent distribution of ponds on Eros
NASA Astrophysics Data System (ADS)
Roberts, James H.; Barnouin, Olivier S.; Kahn, Eliezer G.; Prockter, Louise M.
Over 300 "ponds" have been identified on 433 Eros: smooth deposits that sharply embay the bounding depressions in which they lie. The known ponds are largely concentrated near the equator at the ends of the long axis of the asteroid. Here, we examine the pixel scale of images available at the pond locations, and compare the observed distribution of ponds on Eros to that of the image pixel scale. We find that the majority (60%) of ponds are found in the regions covered by images with pixel scales less than 2 m/px, a total of only 13% of the surface area. The correlation between pond density and image pixel scale suggests a significant observational bias in the identification of small ponds. These findings suggest that the distribution of ponds on Eros may not be as clear-cut as previously reported, and that it may be best not to use this distribution to assess existing models regarding their formation of these landforms.
Active thermal storage using the ground underlying a solar pond
Lowrey, O.P. III
An apparatus is presented for actively using the ground underlying a solar pond for storage of heat accumulated in the pond. Heated water will be injected down shallow wells and percolated through the soil. Recovery of heat will usually just reverse this injection. With this invention both major components will perform better than they would alone. Solar ponds will now have huge, cheap, thermal storage without requiring extra brine. In addition, the ground will be insulated by the overlying solar pond so heat losses will be low and heat recovery efficiency quite high. Embodiments of the basic strategy-thermal storage in permeable material insulated by the overlying solar pond-can be economically adapted to a wide variety of solar pond applications and locations. For example, where impermeable rock underlies a pond site a pond should be designed with a very deep, lined bottom zone filled with gravel. A small amount of brine will fill and circulate through the voids in this gravel. This embodiment also gives the large insulated thermal storage desired.
Urban flood management: on the optimal design of off-line detention basins
NASA Astrophysics Data System (ADS)
Segni Abawallo, S.; Brandimarte, L.; Maglionico, M.
A detention basin is a structural measure used to manage floods by temporarily storing a fraction of the incoming water volume into selected areas. The design of the inlet and outlet structures is crucial for the optimal efficiency of the detention system. This research work investigates the sensitivity of flood attenuation, by means of an off-line detention basin, to the design characteristics of the inlet structures. The response of the attenuation efficiency is studied by varying the design characteristics of the different inlet components: elevation and length of the lateral weir and elevation, location and type of inline structure. The response of the detention basin to the different inlet layouts is evaluated by means of three performance criteria, two at the detention basin section and one at a downstream control section. Laboratory data available for the detention basin under implementation on the Navile channel (Italy) were used to calibrate a 1D numerical model in steady state conditions. The calibrated model was then used in simulating different inlet alternatives in unsteady state to determine the most influencing layout characteristics on attenuation. The results of this study can provide general guidelines for the design of the inlet structure of detention basins having similar structural components.
Partitioned pond aquaculture systems
Technology Transfer Automated Retrieval System (TEKTRAN)
World aquaculture is dominated by the use of simple earthen ponds in which suitable water quality is maintained by photosynthetic processes. Relying upon sunlight to maintain water quality offers the lowest cost and most sustainable approach to fish or shellfish production, which explains the popula...
OJJDP Journal of Juvenile Justice Preventive Detention and Out-of-Home Placement
Van Stryland, Eric
the role of legal and extralegal factors in the confinement decision (e.g., Cauffman et al., 2007), prior of their parents or held in preventive detention for the remainder of the court proceedings. Research has found that the
21 CFR 1.393 - What information must FDA include in the detention order?
Code of Federal Regulations, 2010 CFR
...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL GENERAL ENFORCEMENT...Administrative Detention of Food for Human or Animal Consumption How Does...serious adverse health consequences or death to humans or animals. (b) The...
21 CFR 1.378 - What criteria does FDA use to order a detention?
Code of Federal Regulations, 2010 CFR
...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL GENERAL ENFORCEMENT...Administrative Detention of Food for Human or Animal Consumption General Provisions...serious adverse health consequences or death to humans or...
21 CFR 1.378 - What criteria does FDA use to order a detention?
Code of Federal Regulations, 2011 CFR
...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL GENERAL ENFORCEMENT...Administrative Detention of Food for Human or Animal Consumption General Provisions...serious adverse health consequences or death to humans or...
21 CFR 1.393 - What information must FDA include in the detention order?
Code of Federal Regulations, 2011 CFR
...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL GENERAL ENFORCEMENT...Administrative Detention of Food for Human or Animal Consumption How Does...serious adverse health consequences or death to humans or animals. (b) The...
8 CFR 1241.14 - Continued detention of removable aliens on account of special circumstances.
Code of Federal Regulations, 2014 CFR
8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Continued detention of removable aliens on account of special circumstances. 1241.14 Section 1241.14 Aliens and Nationality EXECUTIVE OFFICE FOR...
8 CFR 1241.14 - Continued detention of removable aliens on account of special circumstances.
Code of Federal Regulations, 2011 CFR
8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Continued detention of removable aliens on account of special circumstances. 1241.14 Section 1241.14 Aliens and Nationality EXECUTIVE OFFICE FOR...
8 CFR 1241.14 - Continued detention of removable aliens on account of special circumstances.
Code of Federal Regulations, 2013 CFR
8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Continued detention of removable aliens on account of special circumstances. 1241.14 Section 1241.14 Aliens and Nationality EXECUTIVE OFFICE FOR...
8 CFR 1241.14 - Continued detention of removable aliens on account of special circumstances.
Code of Federal Regulations, 2012 CFR
8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Continued detention of removable aliens on account of special circumstances. 1241.14 Section 1241.14 Aliens and Nationality EXECUTIVE OFFICE FOR...
Mental Health Screenings in Juvenile Detention Centers: Predictors of Mental Health Service Utilization and Recidivism
Zhou, Yaoqi
meet criteria for mental illness. Unfortunately, the juvenile justice system does not consistently: Juveniles with mental illness problems are not getting the treatment services they need. FurthermoreMental Health Screenings in Juvenile Detention Centers: Predictors of Mental Health Service
International relations, covert action and secret detention: The perceptual theory of legitimacy and government decision making
Cox, Owen
either be sent to the United States detention center at Guantanamo Bay or they can be subjected to ?extraordinary rendition,? a process where they are turned over to a foreign nation to be interrogated. I suggest that the public would not support... sending detainees from democracies to Guantanamo Bay for ?enhanced interrogation.? For these detainees the United States government will be motivated to hide their interrogation and 30 detention by having them extraordinarily rendered. Our...
Pond leaks are a very common pond management problem in Pennsylvania. Some leaks may be barely
Boyer, Elizabeth W.
occur around the pond banks or on the pond dam as a result of tree roots or muskrat holes. These leaks can be prevented by removing trees from the pond dam and by discouraging muskrats. In older ponds
Awakening Seed Pond Water ChemistryAwakening Seed Pond Water Chemistry Our Question: Is our pond polluted?Our Question: Is our pond polluted?
Hall, Sharon J.
Awakening Seed Pond Water ChemistryAwakening Seed Pond Water Chemistry Our Question: Is our pond polluted?Our Question: Is our pond polluted? Our InvestigationOur Investigation We discussed what kinds of pollutants we should look for. We narrowed down the aspects of pond chemistry that we would investigate
Thermal Image of Pu'u '? '? Pond
This thermal image shows the lava pond within Pu`u `? `? crater. The view is towards the southeast. The pond is fed from two upwelling sources, one on the south margin of the pond and one on the north margin....
Heat extraction from salt-gradient solar pond
Kinose, K.
Heat extraction is done by recycling pond water. Hot water stored in the lower region (convective storage zone) of a salt-gradient solar pond is pumped from the end of the pond, passed though a heat exchanger, and returned to the other end of the pond. By the water circulation, a horizontal flow takes place in the convective storage zone. It is necessary that the velocity of the flow should be small enough to prevent the disturbance of the concentration gradient in the upper region (non-convective zone). The extent of the disturbance is estimated by analyzing a problem of the stratified flow in hydraulics. The variation of the storage temperature owing to the heat extraction is estimated by a simulation method. The comparison of an experimental result on heat extraction with the calculated values supports the availability of the analyses.
NSDL National Science Digital Library
Trees and Ponds is a collection of activities to be implemented with middle school youth in out-of-school environments. The website provides a rationale and goal of the activities, curriculum activities and resources such as relevant digital photos. Available for free as downloadable PDFs, these activities provide a structure for youth in out-of-school programs to carry out long-term observations of natural objects. This project uses a qualitative approach, where changes over time are studied, recorded (by youth through writing, drawing, and digital photography), and discussed.
NSDL National Science Digital Library
Donald L Hutson (Frank Brattin Middle School)
This activity allows students to apply their knowledge of the scientific method to solve a problem. Students are challenged to make pond water safe for human consumption while learning about what effects the growth of microorganisms. This inquiry activity was developed by a K-12 science teacher in the American Physiological SocietyÂ?s 1998 Frontiers in Physiology Program. The NSES Standards addressed by this activity are current as of the year of development. For more information on the Frontiers in Physiology Program, please visit www.frontiersinphys.org.
Anderson, A. L.
Solar ponds can provide low cost solar energy collection as well as low temperature heat storage. Currently there are two types of solar ponds in an advanced state of development in the U.S. Each system uses a different collection and energy storage...
The Absent Interpreter in Administrative Detention Center Medical Units.
Rondeau-Lutz, Murielle; Weber, Jean-Christophe
The particular situation of the French administrative detention center (ADC) medical units appears to be an exemplary case to study the difficulties facing medical practice. Indeed, the starting point of our inquiry was an amazing observation that needed to be addressed and understood: why are professional interpreters so seldom requested in ADC medical units, where one would expect that they would be "naturally" present? Aiming to fully explore the meanings of the "absent interpreter", this article takes into account the possible meanings of this situation: the recourse to professional interpreters in France is far from expected given cumulative evidence of its benefits; perceptions of illegal immigrants and medical habitus itself may both hamper the use of a third party; the ADCs are a very stressful place for healthcare professionals, with conflicting missions, political issues enmeshed with medical goals, and heavy affective burden that may lead to self-protection. Silencing voices of suffering others might be seen as the hidden indecent truth of the "absent interpreter". These reflections open a window to a larger issue with regard to the full range of medicine: what are the place, the role and the function of patient's words and narratives in contemporary medicine? The highly invested somatic perspective and its political corollary giving primacy to bare life harbor potential risks of obscuring speeches and undervaluing narratives. PMID:25189317
Sherman, B.S.; Imberger, J. (Univ. of Western Australia, Nedlands (Australia))
Solar ponds hold the promise of providing an alternative to diesel generation of electricity at remote locations in Australia where fuel costs are high. However, to reliably generate electricity with a solar pond requires high temperatures to be maintained throughout the year; this goal had eluded the Alice Springs solar pond prior to 1989 because of double-diffusive convection within the gradient zone. This paper presents control strategies designed to provide successful high temperature operation of a solar pond year-round. The strategies, which consist mainly of manipulating upper surface layer salinity and extracting heat from the storage zone are well suited to automation. They were tested at the Alice Springs solar pond during the summer of 1989 and maintained temperatures in excess of 85{degree}C for several months without any gradient stability problems.
A goal of the Urban Watershed Management Branch of USEPA's NRMRL, Edison, NJ is to develop and demonstrate technologies and methods to manage the ecological risks posed by stormwate runoff from highly developed watersheds. This study, in particular, uses extant data and controlle...
Experimental study of the salt gradient solar pond stability
Karim, Choubani; Slim, Zitouni; Kais, Charfi; Jomaa, Safi Mohamed [Ecole National d'Ingenieurs de Tunis, Unite de Recherche Mecanique-Energetique, 1002 El Belvedere, BP 37 (Tunisia); Akbarzadeh, Aliakbar [Energy CARE Group, Department of Mechanical and Manufacturing Engineering, RMIT University, P.O. Box 71, Bundoora 3083, Melbourne (Australia)
Many natural systems such as oceans, lakes, etc.., are influenced by the effect of double-diffusive convection. This phenomenon, which is a combination of heat and mass transfer, can destroy the stability of system-flows. In the case of solar ponds the middle layer, that is linearly stratified, acts as a thermal and mass insulator for the lower layer. This middle layer, called the Non-Convective Zone (NCZ), needs special care to avoid convection and to maintain its stability. In fact, due to an excess of heat stored, a thermal gradient occurs within the NCZ. A convective movement appears at the bottom of the stratified-layers and then grows to a double-diffusive convection movement. This movement transforms the stratified-layers into a well mixed layer, reducing the storage capacity of the pond. Laboratory small-scale pond and middle-scale outdoor solar ponds were designed and built to provide both quantitative data and to study the dynamic processes in solar ponds, including the behavior of the gradient zone. Particle Image Velocimetry (PIV) visualization-experiments carried out in the mechanical and energetic laboratory in the engineering school of Tunisia and experiments in the field showed that the instability of solar ponds could be limited by using porous media placed in the lower layer of the stratification. (author)
NSDL National Science Digital Library
The Hilton Pond Center for Piedmont Natural History is a nonprofit education and research organization based in York, South Carolina whose mission is to "conserve plants, animals, birds, and other natural components of the Piedmont Region of the eastern United States through observation, scientific study, and education for students of all ages." This colorful site provides a range of information on all sorts of nature topics and consists of sections like plant inventory, animal inventory, and ecological investigations. It also contains a link to the Operation RubyThroat: The Hummingbird Project Web site, which is a cross-disciplinary project in which participants in the US, Canada, Mexico, and Central America collaborate to study behavior and distribution of the Ruby-throated Hummingbird (Archilochus colubris). Both sites are excellent resources for science teachers, students, parents, bird lovers, and conservationists interested in Piedmont natural history.
NASA Astrophysics Data System (ADS)
Parlange, J.; Barry, D. A.; Steenhuis, T. S.
Our understanding of infiltration and ponding relies heavily on Buckingham's concepts and Green and Ampt(GA) results. At a higher level of approximation the need for a discontinuous profile and a constant diffusivity which is fundamental in GA,can be relaxed.For instance the more physical conductivity suggested by Wilford Gardner represents a great improvement to GA assumptions.At this level approximate results like the time compression analysis (TCA) are readily derived,showing the need for yet a higher level of approximation. This 3rd level is obtained following the approach of Heaslet and Alksne and extending it to include gravity and arbitrary diffusivities.At this level the accuracy of approximate results like TCA,can be estimated.
63 FR 27441 - Procedures for the Detention and Release of Criminal Aliens by the Immigration and Naturalization...
Federal Register 2010, 2011, 2012, 2013, 2014
...Naturalization Service and for Custody Redeterminations by...regulatory framework for the detention of criminal aliens pursuant...the Transition Period Custody Rules (TPCR) set forth in the Illegal Immigration Reform and...425 I Street NW., Room 6100, Washington...the Service lacks the detention space and...
68 FR 25242 - Administrative Detention of Food for Human or Animal Consumption Under the Public Health Security...
Federal Register 2010, 2011, 2012, 2013, 2014
...information to quantify the health benefits of substituting administrative detention for the other enforcement...might undertake, but merely illustrate the public health costs of foodborne disasters...disrupt the food supply and sicken many U.S. citizens would...resulting from administrative detention is unknown. [[Page...
Contesting Institutional Discourse to Create New Possibilities for Understanding Lived Experience: Life-Stories of Young Women in Detention, Rehabilitation, and Education
ERIC Educational Resources Information Center
Sharma, Suniti
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…
Contesting institutional discourse to create new possibilities for understanding lived experience: life?stories of young women in detention, rehabilitation, and education
Suniti Sharma
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 comprises their autobiographies, official documents of their
Detention times of microswimmers close to surfaces: Influence of hydrodynamic interactions and noise
Konstantin Schaar; Andreas Zöttl; Holger Stark
After colliding with a surface, microswimmers reside there during the detention time. They accumulate and may form complex structures such as biofilms. We introduce a general framework to calculate the distribution of detention times using the method of first-passage times and study how motional noise and hydrodynamic interactions influence the escape from a surface. We compare generic swimmer models to the simple active Brownian particle. While the respective detention times of source dipoles are reduced and of pullers are increased, spanning several orders of magnitudes, pushers show both trends. We apply our results to the more realistic squirmer model, for which we use lubrication theory, and validate them by simulations with multi-particle collision dynamics.
Throwing Away the Key: The Ethics of Risk Assessment for Preventive Detention Schemes
McSherry, B.
Preventive detention schemes that aim to protect the community from certain 'dangerous' individuals have long existed. While risk assessment is now pervasive in the management and treatment of many individuals, it raises particular issues when a person's liberty is at stake on the basis of what that person might do. This R.G. Myers Memorial Lecture addresses the ethical issues raised by mental health practitioners providing risk assessments for legislative schemes that involve the deprivation of liberty. It will focus in particular on Australian post-sentence preventive detention schemes for sex offenders that have been held by the United Nations Human Rights Committee to breach fundamental human rights. However, the ethical issues discussed also have repercussions for civil commitment laws that enable the detention of those with severe mental or intellectual impairments. PMID:25431531
Predictors of detention among juveniles referred for a court clinic forensic evaluation.
Tolou-Shams, Marina; Rizzo, Christie J; Conrad, Selby M; Johnson, Sarah; Oliveira, Cassandra; Brown, Larry K
Juvenile offenders have disproportionately high rates of psychiatric and substance use disorders relative to their nonoffending counterparts. Less is known about the impact of psychiatric and substance use disorders on repeat juvenile justice involvement among juveniles specifically referred for forensic mental health evaluations. We describe the demographic, psychiatric, and legal history background of 404 juveniles who underwent a court clinic forensic mental health evaluation, and we examine the association between these factors and detention rates of 20 percent over a 12-month post-evaluation period. After accounting for known predictors of reoffending, such as prior offense history and externalizing disorders, dual diagnosis (i.e., co-occurring psychiatric and substance use disorders) remained a salient predictor of future detention. Consistent with prior literature on juvenile offending, substance use may greatly enhance the likelihood of subsequent detention. PMID:24618520
The psychosocial impact of detention and deportation on U.S. migrant children and families.
Brabeck, Kalina M; Lykes, M Brinton; Hunter, Cristina
Approximately 4.5 million U.S. citizen children live in mixed-status families, in which at least 1 family member is an unauthorized migrant and therefore vulnerable to detention and deportation from the United States (Passel & Cohn, 2011). This article critically examines the current state of the literature on the psychosocial consequences of detention and deportation for unauthorized migrants, mixed-status families, and their U.S.-born children. In particular, drawing on social and psychological theory and research, we (a) review the impact of parents' unauthorized status on children; (b) summarize the literature on the impact of detention processes on psychosocial well-being; (c) describe the dilemma faced by a mixed-status family when a parent faces deportation; (d) examine the current social scientific literature on how parental deportation impacts children and their families; and (e) summarize several policy recommendations for protecting children and families. PMID:25110972
Northern Seasonal Woodland Ponds: Distribution, Biota, and Ecological Linkages with the Surrounding Forest
NASA Astrophysics Data System (ADS)
Batzer, D.; Palik, B.
Seasonal woodland ponds are important landscape features across much of eastern and central North America. Learning more about the ecology of these habitats is a pressing need in the US because federal protections are being reduced. Further, the fates of these habitats are not being monitored because most are too small for inclusion in the National Wetland Inventory. In our northern Minnesota study area, the distribution of seasonal woodland ponds is strongly influenced by glacial landform, with most ponds being associated with ground or end moraines. The habitats support an abundance of plants, invertebrates, and amphibians; these organisms are well adapted for the variable environments existing in ponds and they posses a durability that makes them resistant to most natural variation in conditions. Because of the small size of seasonal woodland ponds, input of plant litter and migration of invertebrates from the surrounding forest into ponds is an important ecological link. However, because ponds support an autochthonous growth of wetland trees, the relationship between ponds and the forest differs from that between streams and forests. Like eastern streams, logging of forests around ponds is a concern, but impacts of peripheral logging on theses wetlands appear less dramatic than for streams.
We will briefly summarize selected EPA research in Rhode Island's salt ponds from 2000 through 2003. In one project, during the summer of 2000, we used a 1.75 m2 drop sampler to quantify populations of juvenile flatfishes and other small nekton in Ninigret Pond. Mean abundance ...
Pond Characteristics and Occupancy by Red-Necked Phalaropes in the Mackenzie Delta, Northwest Territories, Canada
Red-necked phalaropes (Phalaropus lobatus) breed in Arctic and Subarctic lowlands throughout the circumpolar region. They are highly reliant on shallow freshwater ponds for social interaction, copulation, and foraging for small aquatic invertebrates. Threats related to warmer continental temperatures could lead to encroachment of shrub vegetation and premature drying of wetlands that serve as breeding habitat. We documented patterns of pond
Community-level impacts induced by introduced largemouth bass and bluegill in farm ponds in Japan
Yasunori Maezono; Tadashi Miyashita
Largemouth bass Micropterus salmoides and bluegill Lepomis macrochirus have been introduced into many countries and have become cosmopolitan exotic species. However, only a few studies show their impact on introduced communities. To investigate their impact, we performed natural snapshot experiments in 15 farm ponds in Saitama prefecture, eastern Japan. We selected 10 and 5 small ponds in similar environmental conditions,
Migratory Waterfowl at Coulson Pond
Migratory waterfowl congregate at Coulson Pond in Blackwater National Wildlife Refuge. Blackwater serves as an important habitat for these waterfowl, and was established in 1933 as a waterfowl sanctuary for birds migrating along the Atlantic Flyway....
NSDL National Science Digital Library
The representation depicts the food-based interconnections of selected organisms in a pond. Through the interactive interface, users can read about changes to organism populations as one species increases or decreases in number.
Par Pond vegetation status 1996
Mackey, H.E. Jr.; Riley, R.S.
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.
Biogeochemical ecology of aquaculture ponds
Weisburd, R.S.J.
Two methods to determine rates of organic matter production and consumption were applied in shrimp aquaculture ponds. Several questions were posed: can net rates of organic matter production and consumption be determined accurately through application of dissolved inorganic carbon (DIC) mass balance in a pond with high advective through-put Are organically loaded aquaculture ponds autotrophic How do rates of organic production vary temporally Are there diurnal changes in respiration rates Four marine ponds in Hawaii have been evaluated for a 53 day period through the use of geochemical mass balances. All fluxes of DIC into and out of the ponds were considered. DIC was calculated from hourly pH measurements and weekly alkalinity measurements. Average uptake of DIC from the pond water, equivalent to net community production, revealed net autotrophy in all cases. Hourly and longer period variations in organic matter production rates were examined. The daily cycle dominated the variation in rates of net community production. Maximal rates of net community production were maintained for four to six hours starting in mid-morning. Respiration rates decreased rapidly during the night in two of the ponds and remained essentially constant in the others. A similar pattern of decreasing respiration at night was seen in freshwater shrimp ponds which were studied with incubations. A new method involving isotope dilution of {sup 14}C-labeled DIC was used to measure respiration rates in light and dark bottles. This method is an inexpensive and convenient procedure which should also be useful in other environments. The incubations demonstrated that plankton respiration rates peak at or soon after solar noon and vary over the course of the day by about a factor of two.
Stable Stratification for Solar Ponds
NASA Technical Reports Server (NTRS)
Mehta, G. D.
Stable density gradient forms in pond saturated with disodium phosphate (DSP). Volume of DSP saturated water tends to develop temperature and density layers. Since tests indicate thermal and density gradients remain in equilibrium at heat removal rates of 60 percent or more of heat input rate, pond containing DSP would be suitable for collecting solar energy and transferring it to heat exchanger for practical use.
NASA Technical Reports Server (NTRS)
French, R. L.; Meitlis, I.
The feasibility of constructing salt gradient solar ponds within the Salton Sea is being studied. These ponds would serve a dual purpose: (1) become a depository for unwanted salt and (2) supply thermal energy for driving turbine electric power systems. Under present circumstances, the rise in salinity is expected to eliminate fish life and create other unfavorable conditions. The proposed concept would have a power generation potential of 600 MWe.
Heat transfer through a solar pond nonconvective zone of recycled glass
Ketchum, D. E.
The heat transfer through a recycled glass/water porous medium is examined experimentally to determine the medium's effectiveness as a nonconvective zone in a solar pond. Temperature distributions within clear bottle or broken glass/water mediums are studied with heated from above, and heated from below orientations. A small solar pond of glass bottles as well as a numerical simulation of a glass sphere solar pond are also investigated. Results of the experimental study show that convection was not suppressed by using bottles during bottom heating and indicate that stagnation will only occur with very small glass fragments. The computer simulation further indicated that even with perfect transmittance through the medium, pond efficiency will be far less than for a salt gradient pond. The small pond tests show no temperature gradient (indicating little stagnation), show little radiation transmittance through the medium (less than 10% for a .4 meter pond), and confirm the conclusion that a glass bottle or broken glass/water medium is unsuitable as a solar pond nonconvective zone.
High rates of methane emissions from south taiga wetland ponds.
NASA Astrophysics Data System (ADS)
Glagolev, M.; Kleptsova, I.; Maksyutov, S.
Since wetland ponds are often assumed to be insignificant sources of methane, there is a limited data about its fluxes. In this study, we found surprisingly high rates of methane emission at several shallow ponds in the south taiga zone of West Siberia. Wetland ponds within the Great Vasyugan Mire ridge-hollow-pool patterned bog system were investigated. 22 and 24 flux measurements from ponds and surrounded mires, respectively, were simultaneously made by a static chamber method in July, 2011. In contrast to previous measurements, fluxes were measured using the small boat with floated chamber to avoid disturbance to the water volume. Since the ebullition is most important emission pathway, minimization of physical disturbance provoking gas bubbling significantly increases the data accuracy. Air temperature varied from 15 to 22° C during the measurements, and pH at different pond depths - from 4.4 to 5. As it was found, background emission from surrounding ridges and hollows was 1.7/2.6/3.3 mgC·m-2·h1 (1st/2nd/3rd quartiles). These rates are in a perfect correspondence with the typical methane emission fluxes from other south taiga bogs. Methane emission from wetland ponds turned out to be by order of magnitude higher (9.3/11.3/15.6 mgC·m-2·h1). Comparing to other measurements in West Siberia, many times higher emissions (70.9/111.6/152.3 mgC·m-2·h1) were found in forest-steppe and subtaiga fen ponds. On the contrary, West Siberian tundra lakes emit methane insignificantly, with the flux rate close to surrounding wetlands (about 0.2-0.3 mgC·m-2·h1). Apparently, there is a naturally determined distribution of ponds with different flux rates over different West Siberia climate-vegetation zones. Further investigations aiming at revelation of the zones with different fluxes would be helpful for total flux revision purposes. With respect to other studies, high emission rates were already detected, for instance, in Baltic ponds (Dzyuban, 2002) and U.K. lakes (Casper et al., 2000). Annual CH4 emission from West Siberia south taiga ponds with area of 0.6·106 Mha was estimated to be 0.26 MtCH4·yr-1.
The origin and fate of arsenic in coalbed natural gas-produced water ponds.
Sowder, J T; Kelleners, T J; Reddy, K J
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. PMID:21043266
Solar pond\\/fuel assisted water desalination plant
S. E. Aly; S. Arabia
This article presents a thermodynamic analysis for a proposed hybrid system suitable for producing power or fresh water for small communities. The system includes a power generation loop and a desalination loop. These loops can work separately to produce power or combined to produce fresh water. The power loop comprises a solar pond, flashing chamber, vapour compressor VCI, steam superheater,
Towards the design of low maintenance salinity gradient solar ponds
M. R. Jaefarzadeh; A. Akbarzadeh
Applications of simple methods to reduce the maintenance of a small solar pond are discussed in this paper. It was found that floating rings along with continuous surface flushing could effectively control and maintain a relatively thin upper convective layer. A novel system of salt replenishment (a salt charger) is introduced. It is shown that the application of the proposed
Biomanipulation: A Classic Example in a Shallow Eutrophic Pond
Matthew F. Albright; Willard N. Harman; Wesley T. Tibbits; Michael S. Gray; David M. Warner; Rebecca J. Hamway
Moe Pond, Otsego County, New York, is an artificial impoundment created by the damming of a natural wetland in 1939. It was dominated by blue-green algal blooms between at least 1970–1998. During that time a few scattered clones of sedges (Cyperaceae) along the shoreline were the only vascular plants present. The zooplankton community was dominated by small individuals, primarily rotifers,
"It is a thin line to walk on": Challenges of staff working at Swedish immigration detention centres
Puthoopparambil, Soorej J.; Ahlberg, Beth M.; Bjerneld, Magdalena
Detention of irregular migrants awaiting deportation is widely practiced in many countries and has been shown to have profound negative impact on health and well-being of detainees. Detention staff, an integral part of the detention environment, affect and are affected by detainees' health and well-being. The objective of the study was to explore experiences of staff working at Swedish immigration detention centres. Fifteen semi-structured interviews were conducted with staff in three Swedish detention centres and were analysed using thematic analysis. The results indicate that the main challenge for the staff was to manage the emotional dilemma entailed in working as migration officers and simultaneously fellow human beings whose task was to implement deportation decisions while being expected to provide humane service to detainees. They tried to manage their dilemma by balancing the two roles, but still found it challenging. Among the staff, there was a high perception of fear of physical threat from detainees that made detention a stressful environment. Limited interaction between the staff and detainees was a reason for this. There is thus a need to support detention staff to improve their interaction with detainees in order to decrease their fear, manage their emotional dilemma, and provide better service to detainees. It is important to address staff challenges in order to ensure better health and well-being for both staff and detainees. PMID:25833827
Artistry in Lockdown: Transformative Music Experiences for Students in Juvenile Detention
ERIC Educational Resources Information Center
Marcum, Travis
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,…
78 FR 7994 - Criteria Used To Order Administrative Detention of Food for Human or Animal Consumption
Federal Register 2010, 2011, 2012, 2013, 2014
...of Food for Human or Animal Consumption'' that...detention of human or animal food as required by the...Food Safety and Applied Nutrition, Food and Drug Administration...adversely affects human or animal health and that FDA would...Food Safety and Applied Nutrition (CFSAN) or the...
Study on GIS-based flood risk map for flood detention area
Zhongmin Liang; Jun Wang; Ye Shi; Zhongbo Yu
Flood Risk Map is one of the important non-engineering measures for flood control and disaster reduction. On the basis of the flood risk analysis, and with the powerful spatial analysis and display functions of Arc GIS, the Flood Risk Map in flood detention area can be drawn automatically through the redevelopment of Arc GIS by Arc Engine. Firstly, a new
Academic Potential among African American Adolescents in Juvenile Detention Centers: Implications for Reentry to School
ERIC Educational Resources Information Center
Toldson, Ivory A.; Woodson, Kamilah M.; Braithwaite, Ronald; Holliday, Rhonda C.; De La Rosa, Mario
The study explores Black adolescent detainees' academic potential and motivation to return to school, to inform best practices and policies for juvenile reentry to educational settings. Adolescent detainees (N = 1,576) who were recruited from 1 male and 1 female youth detention facility, responded to surveys that assessed postdetention educational…
Girls in DetentionThe Results of Focus Group Discussion Interviews and Official Records Review
Suman Kakar; Marie-Luise Friedemann; Linda Peck
This study examined the risk factors related to delinquency in an effort to describe the problem of rising female juvenile delinquency. It also examined the context of family environments in which female juvenile delinquents live. Using a triangulated methods approach, the data collected via focus group discussions with 30 female residents in a Regional Detention Center and 100 official intake
Adele Thomas
The second state of emergency declared in South Africa in 1985 resulted in the enactment of legislation which superseded legislation designed to protect the rights and secure the well-being of children in the country. Detention without trial has, for many years, been a permanent feature of the legal system in South Africa. However, during the period 1985 to 1989 thousands
Effects of Stormwater Infiltration on Quality of Groundwater Beneath Retention and Detention Basins
Use of stormwater retention and detention basins has become a popular method for managing urban and suburban stormwater runoff. Infiltration of stormwater through these basins may increase the risk to ground-water quality, especially in areas where the soil is sandy and the wate...
Rap, Recidivism and the Creative Self: A Popular Music Programme for Young Offenders in Detention
ERIC Educational Resources Information Center
Baker, Sarah; Homan, Shane
Popular music is increasingly being viewed by local, state and national governments as a useful form of creative activity for at-risk youth both within and outside young offender institutions. This paper examines a music programme operating for a group of predominantly black youth within one North American detention centre, and considers the range…
Reducing Unnecessary Delay: Innovations in Case Processing. Pathways to Juvenile Detention Reform 5.
ERIC Educational Resources Information Center
Henry, D. Alan
This report discusses how to reduce unnecessary delay in the juvenile justice system, presenting data from the Juvenile Detention Alternatives Initiative (JDAI). Chapter 1, "Why Focus on Unnecessary Delay?" explains the negative effects of unnecessary delays. Chapter 2, "Guiding Principles," examines principles inherent in all case processing…
High Rates of Police Detention Among Recently Released HIV-infected Prisoners in Ukraine: Implications for Health Outcomes
Izenberg, Jacob M.; Bachireddy, Chethan; Soule, Michael; Kiryazova, Tetiana; Dvoryak, Sergey; Altice, Frederick L.
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
Solar pond power plant feasibility study for Davis, California
NASA Technical Reports Server (NTRS)
Wu, Y. C.; Singer, M. J.; Marsh, H. E.; Harris, J.; Walton, A. L.
The feasibility of constructing a solar pond power plant at Davis, California was studied. Site visits, weather data compilation, soil and water analyses, conceptual system design and analyses, a material and equipment market survey, conceptual site layout, and a preliminary cost estimate were studied. It was concluded that a solar pond power plant is technically feasible, but economically unattractive. The relatively small scale of the proposed plant and the high cost of importing salt resulted in a disproportionately high capital investment with respect to the annual energy production capacity of the plant. Cycle optimization and increased plant size would increase the economical attractiveness of the proposed concept.
Gradient zone boundary control in salt gradient solar ponds
Hull, John R. (Downers Grove, IL)
A method and apparatus for suppressing zone boundary migration in a salt gradient solar pond includes extending perforated membranes across the pond at the boundaries, between the convective and non-convective zones, the perforations being small enough in size to prevent individual turbulence disturbances from penetrating the hole, but being large enough to allow easy molecular diffusion of salt thereby preventing the formation of convective zones in the gradient layer. The total area of the perforations is a sizable fraction of the membrane area to allow sufficient salt diffusion while preventing turbulent entrainment into the gradient zone.
Saturated solar ponds: 2. Parametric studies
Subhakar, D.; Murthy, S.S. (Indian Institute of Technology, Madras (India))
The effects of following parameters on the performance of saturated solar ponds are studied: thickness of upper convective zone, nonconvective zone, and lower convective zone; starting time of the pond; water table depth below the pond; ground thermal conductivity; transmissivity of salt solution; incident radiation; ambient air temperature, humidity, and velocity; thermophysical properties of salt solution; pond bottom reflectivity; convection, evaporation, radiation, and ground heat losses; temperature and rate of heat removal; type of salt. Magnesium chloride and potassium nitrate salt ponds located at Madras (India) are considered for the parametric study. A comparison is also made with an unsaturated solar pond.
The limnology, primary production, and fish production in a tropical pond
The productivity of a small tropical temple pond was studied by the light-and-dark bottle method and by following the natural changes in carbon dioxicle and oxygen. Pro- duction varied from 6.0 g C\\/m\\
216-B-3 expansion ponds closure plan
Not Available
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.
Treatability studies for waters in oil pond No. 1, oil pond No. 2, and the oil seep
Napier, J.M.; Hancher, C.W.; Harris, G.E.; Johnson, M.E.; Padgett, B.C.
Laboratory and pilot plant studies have investigated treatment methods for water contained in 2 small ponds located at the Bear Creek burial grounds. The sediments in the bottom of the pond are contaminated with polychlorinated biphenyls (PCB) and plans to close out these ponds and remove the sediments have been prepared. These laboratory and pilot plant studies show that the water in the ponds contained no significant amounts of metals and only trace quantities of organics. The amount of PCB in the water was near the detection level. The biological quality of the water before treatment was excellent. Unit operations examined in these studies included filtration, air stripping and carbon filtration. Air stripping removed all of the trace amounts of volatile organics and carbon filtration removed all of the detectable quantities of other organics except for the low amounts of total organic carbon. Based on these tests it has been recommended that the water in the ponds be filtered and released without additional treatment through a permitted discharge point. Water from any oil seep is recommended to be collected and treated using filtration, air stripping and carbon filtration. Any water released from this process should meet the permitted discharge quality plus meet a biological test specified by the permitting agency. 2 figs., 16 tabs.
Management of an ornamental pond as a conservation site for a threatened native fish species, crucian carp Carassius carassius
G. H. Copp; S. Warrington; K. J. Wesley
\\u000a Ornamental ponds are important sites for conserving threatened native fish species (e.g. crucian carp Carassius carassius L.), but pond management plans rarely include considerations of native fishes. We developed and implemented a management\\u000a plan for a small (0.8 h), ornamental estate pond in Hertfordshire (England) using historical information (aquatic plant and\\u000a animal surveys) and a 9-year data set on climatic variables
Management of an ornamental pond as a conservation site for a threatened native fish species, crucian carp Carassius carassius
G. H. Copp; S. Warrington; K. J. Wesley
Ornamental ponds are important sites for conserving threatened native fish species (e.g. crucian carp Carassius carassius L.), but pond management plans rarely include considerations of native fishes. We developed and implemented a management\\u000a plan for a small (0.8 h), ornamental estate pond in Hertfordshire (England) using historical information (aquatic plant and\\u000a animal surveys) and a 9-year data set on climatic variables
Simulated pond-aquifer interactions under natural and stressed conditions near Snake Pond, Cape Cod, Massachusetts
Walter, Donald A.; Masterson, John P.; LeBlanc, Denis R.
A numerical model was used to simulate pond-aquifer interactions under natural and stressed conditions near Snake Pond, Cape Cod, Massachusetts. Simulation results show that pond-bottom hydraulic conductivity, which represents the degree of hydraulic connection between the pond and the aquifer, is an important control on these interactions. As this parameter was incrementally increased from 10 to 350 feet per day, the rate of ground-water inflow into the pond under natural conditions increased by about 250 percent, the associated residence times of water in the pond decreased by about 50 percent, and ground-water inflow to the pond shifted closer to the pond shore. Most ground-water inflow (90 to 98 percent) was in the upper model layer, which corresponded to shallow, near-shore areas of the pond, over the entire range of pond-bottom hydraulic conductivity. Ground-water flow paths into the pond became more vertical, the contributing area to the pond became larger, and the pond captured water from greater depths in the aquifer as the hydraulic conductivity of the pond bottom was increased. The pond level, however, remained nearly constant, and regional ground-water levels and gradients differed little over the range of pond-bottom hydraulic conductivity, indicating that calibrated models with similar head solutions can have different pond-aquifer interaction characteristics. Hydrologic stresses caused by a simulated plume-containment system that specifies the extraction and injection of large volumes of ground water near the pond increased the pond level by about 0.4 foot and ground-water inflow rates into the pond by about 25 percent. Several factors related to the operation of the simulated containment system are affected by the hydraulic conductivity of the pond bottom. With increasing pond-bottom hydraulic conductivity, the amount of injected water that flows into Snake Pond increased and the amount of water recirculated between extraction and injection wells decreased. Comparison of simulations in which pond-bottom hydraulic conductivity was varied throughout the pond and simulations in which hydraulic conductivity was varied only in areas corresponding to shallow, near-shore areas of the pond indicate that the simulated hydraulic conductivity of the pond bottom in deeper parts of the pond had little effect on pond-aquifer interactions under both natural and stressed conditions.
ARTIFICIAL FERTILIZATION OF LAKES AND PONDS A Review of the Literature SPECIAL SCIENTIFIC REPORT., John L. Farley, Director ARTIFICIAL FERTILIZATION OF LAKES AND PONDS A Review of the Literature By John fertilization. ......... 2 Physical considerations ................... 2 Biological considerations
Code of Federal Regulations, 2014 CFR
... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.600 Lagoon Pond. The draw of the Lagoon Pond Bridge, mile 0.0 in Tisbury, Massachusetts, shall operate as follows: (a) The draw...
Code of Federal Regulations, 2013 CFR
... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.600 Lagoon Pond. The draw of the Lagoon Pond Bridge, mile 0.0 in Tisbury, Massachusetts, shall operate as follows: (a) The draw...
Code of Federal Regulations, 2011 CFR
... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.600 Lagoon Pond. The draw of the Lagoon Pond Bridge, mile 0.0 in Tisbury, Massachusetts, shall operate as follows: (a) The draw...
Code of Federal Regulations, 2010 CFR
... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.600 Lagoon Pond. The draw of the Lagoon Pond Bridge, mile 0.0 in Tisbury, Massachusetts, shall operate as follows: (a) The draw...
Code of Federal Regulations, 2012 CFR
... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.600 Lagoon Pond. The draw of the Lagoon Pond Bridge, mile 0.0 in Tisbury, Massachusetts, shall operate as follows: (a) The draw...
Prospects and scopes of solar pond: A detailed review
V. Velmurugan; K. Srithar
Solar pond is an artificially constructed pond in which significant temperature rises are caused to occur in the lower regions by preventing convection. To prevent convection, salt water is used in the pond. Those ponds are called "salt gradient solar pond". In the last 15 years, many salt gradient solar ponds varying in size from a few hundred to a
8 CFR 241.4 - Continued detention of inadmissible, criminal, and other aliens beyond the removal period.
Code of Federal Regulations, 2013 CFR
8 Aliens and Nationality 1 2013-01-01 2013-01-01...Continued detention of inadmissible, criminal, and other aliens beyond the removal period. 241.4 Section 241.4 Aliens and Nationality DEPARTMENT OF HOMELAND...
8 CFR 241.4 - Continued detention of inadmissible, criminal, and other aliens beyond the removal period.
Code of Federal Regulations, 2012 CFR
8 Aliens and Nationality 1 2012-01-01 2012-01-01...Continued detention of inadmissible, criminal, and other aliens beyond the removal period. 241.4 Section 241.4 Aliens and Nationality DEPARTMENT OF HOMELAND...
8 CFR 241.4 - Continued detention of inadmissible, criminal, and other aliens beyond the removal period.
Code of Federal Regulations, 2014 CFR
8 Aliens and Nationality 1 2014-01-01 2014-01-01...Continued detention of inadmissible, criminal, and other aliens beyond the removal period. 241.4 Section 241.4 Aliens and Nationality DEPARTMENT OF HOMELAND...
8 CFR 241.4 - Continued detention of inadmissible, criminal, and other aliens beyond the removal period.
Code of Federal Regulations, 2011 CFR
8 Aliens and Nationality 1 2011-01-01 2011-01-01...Continued detention of inadmissible, criminal, and other aliens beyond the removal period. 241.4 Section 241.4 Aliens and Nationality DEPARTMENT OF HOMELAND...
8 CFR 241.4 - Continued detention of inadmissible, criminal, and other aliens beyond the removal period.
Code of Federal Regulations, 2010 CFR
8 Aliens and Nationality 1 2010-01-01 2010-01-01...Continued detention of inadmissible, criminal, and other aliens beyond the removal period. 241.4 Section 241.4 Aliens and Nationality DEPARTMENT OF HOMELAND...
76 FR 66073 - Guidance for Industry on What You Need to Know About Administrative Detention of Foods; Availability
Federal Register 2010, 2011, 2012, 2013, 2014
...administrative detention of food for human or animal consumption under the Federal Food...Center for Food Safety and Applied Nutrition, Food and Drug Administration...provide individuals in the human and animal food industries with an...
Stabilization Pond Operation and Maintenance Manual.
ERIC Educational Resources Information Center
Sexauer, Willard N.; Karn, Roger V.
This manual provides the waste stabilization pond operator with the basics necessary for the treatment of wastewater in stabilization ponds. The material is organized as a comprehensive guide that follows the normal operation and maintenance procedures from the time the wastewater enters the left station until it leaves the pond. A comprehensive…
Distance Education of Pennsylvania Pond Owners.
ERIC Educational Resources Information Center
Schmidt, Katherine L.; Swistock, Bryan R.; Sharpe, William E.
Evaluations by 175 of 557 Pennsylvania pond owners who attended an Extension program via satellite revealed that most were interested in aesthetic/recreational pond use and pond management. They wanted more in-depth information over a shorter time frame. Only 10% did not favor satellite delivery. Shorter, more focused satellite programs and…
Western Pond Turtle Recovery Columbia Gorge
Western Pond Turtle Recovery in the Columbia Gorge Project ID 200102700 Submitted by: 4 March 2009 species of concern Western Pond Turtle Washington Status #12;Columbia Mainstem Goals · Maintain;Western Pond Turtle Recovery Current Efforts · Head Start · Population Reintroduction · Predator Control
A parametric study on solar ponds
Y. F. Wang; A. Akbarzadeh
A linear relation between the efficiency of solar ponds and the temperature difference between the pond bottom and the ambient divided by the average insolation is presented. The relation, which has been developed based on a steady state analysis, provides valuable information on the relative importance of the parameters involved in the operation of solar ponds. It is found that
Solar pond conception — experimental and theoretical studies
Hüseyin Kurt; Fethi Halici; A. Korhan Binark
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
Par Pond Fish, Water, and Sediment Chemistry
Paller, M.H. [Westinghouse Savannah River Company, AIKEN, SC (United States); Wike, L.D.
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.
Spatial variability of methane ebullition from permafrost thaw ponds in a subarctic mire
NASA Astrophysics Data System (ADS)
Lang, A.; Varner, R. K.; Osman, M.; Burke, S. A.; Wik, M.; Crill, P. M.
Methane (CH4) has an important role in the energy budget of the atmosphere. Warming due to radiative forcing by this and other greenhouse gases is amplified at high latitudes. Rising soil and air temperatures in these regions lead to permafrost thaw and the potential release of large amounts of CH4 and CO2 to the atmosphere. Where permafrost thaw is occurring, a changing landscape may lead to new CH4 sources. Small ponds are key features of these landscapes. Forming in depressions of previously frozen ground, thaw ponds may release large quantities of CH4 through ebullition (bubbling), yet little has been done to assess their potential contribution to carbon emissions from ecosystems with thawing permafrost. We have made summer measurements of CH4 ebullition from thaw ponds located within the Stordalen Mire, a subarctic permafrost complex in northern Sweden. Our findings suggest that small water bodies can be a substantial local CH4 source. Ebullition occurred episodically and varied spatially, both within and among the ponds. Over a three-week period in July 2013, average bubble CH4 concentration varied from 2 ppm to 1.6% and total bubble flux from 0 to 5456 mg CH4 m-2 d-1. Fluxes were highest from deeper ponds while shallower, and presumably younger, ponds produced significantly less gas with a much lower CH4 concentration. Temperatures and physical characterization of the ponds suggest that substrate type may be as important as heat in influencing the rate of ebullitive flux. Although spatial and temporal variability make CH4 flux from thaw ponds difficult to quantify, these findings suggest that continued warming may drive a positive feedback for CH4 emission and permafrost degradation in the Arctic. Future data on thaw pond cover across Stordalen Mire will allow us to better understand the changing contribution of these ponds to the local total CH4 emission.
Science and the common good: indefinite, non-reviewable mandatory detention of asylum seekers and the research imperative.
Steel, Zachary; Silove, Derrick
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. PMID:15688517
NSDL National Science Digital Library
Biologists are working to restore the San Francisco Bay Area salt ponds to healthy wetlands for wildlife in one of the largest restoration projects on the West Coast. In this video from QUEST produced by KQED, students learn why wetlands are important to wildlife.
Electric Trees and Pond Creatures.
ERIC Educational Resources Information Center
Weaver, Helen; Hounshell, Paul B.
Two learning activities are presented to develop observation and classification skills at the elementary level. The first is an electric box that associates tree names with leaf and bark specimens, and the second is a pond water observation and slide preparation activity. (BB)
ERIC Educational Resources Information Center
Sterling, Donna R.; Hargrove, Dori L.
With crosscutting concepts such as stability and change in the "Next Generation Science Standards," this article was written for those who have wondered how to teach these concepts in a way that is relevant to students. In this investigation, students ask the question, "Why is the pond dirty?" As students investigate the health…
An evaluation of the gel pond performance
Wilkins, E.; El-Genk, M.; El-Husseini, K.; Thakur, D.
The gel pond concept replaces the stratified non-convective zone of the traditional salt gradient pond by a transparent layer of viscous or near-solid polymer gel. As part of the continuing development of this technology, the effect of gel thickness upon the performance of the gel solar pond is being studied. A simplified steady state model describing the physics of the pond has been constructed and tested. Preliminary comparison between the surface heat losses from the gel pond and a nearby salt gradient pond have been made. The measured values of insolation were used in the model to compute the temperature profiles in the gel layer, and in the non-convective layer of the salt gradient pond. The model was used to calculate collection, retention, and effective retention efficiencies for the gel pond for different gel thicknesses and estimate the surface heat losses for both the gel pond and the salt gradient pond. The calculated temperature profiles, for both the gel layer and the non-convective layer in the two ponds compared well with experimental data. It was found that a minimum gel thickness of 0.15 m was adequate on the basis of the effective retention efficiency. The surface heat losses from the 0.25 m gel pond were approximately half those from the salt gradient pond with 1 m stratified zone under the same conditions. Based on the preliminary work, the gel pond concept appears to be superior to the classic salt gradient pond, for solar collection and storage.
NSDL National Science Digital Library
The phenomenon is competition for water among organisms along a river during the dry season in Kruger National Park in South Africa. Narrated video footage shows how a number of African animals share a small watering hole and acquire water necessary for survival while avoiding predation.
Salt gradient solar pond development. Final report
Nielsen, C.E.
A research solar pond was constructed. From the operation of this pond and the continuing operation of the Farm Science review pond completed in 1975 important new information on pond performance and operating procedures has been obtained. Work discussed here includes design and construction of the research pond, measurement of energy balance and efficiency, measurements of salinity profiles and their use in determining salt transport rate, study of surface zone growth and the processes responsible for it, study of the processes involved in the interface between convective and gradient zones, tests of heat extraction systems, and measurement and control of water quality.
Administrative detention of drugs intended for human or animal use. Final rule.
The Food and Drug Administration (FDA or the Agency) is implementing administrative detention authority with respect to drugs intended for human or animal use as authorized by amendments made to the Federal Food, Drug, and Cosmetic Act (the FD&C Act) by the Food and Drug Administration Safety and Innovation Act (FDASIA). FDA's administrative detention authority with respect to drugs allows FDA to better protect the integrity of the drug supply chain. Specifically, FDA is able to administratively detain drugs encountered during an inspection that an authorized FDA representative conducting an inspection has reason to believe are adulterated or misbranded. This authority is intended to protect the public by preventing distribution or subsequent use of drugs encountered during inspections that are believed to be adulterated or misbranded, until FDA has had time to consider what action it should take concerning the drugs, and to initiate legal action, if appropriate. PMID:24873018
Academic potential among African American adolescents in juvenile detention centers: Implications for reentry to school
Toldson, Ivory A.; Woodson, Kamilah M.; Braithwaite, Ronald; Holliday, Rhonda C.
The study explores Black adolescent detainees academic potential and motivation to return to school to inform best practices and policies for juvenile reentry to educational settings. Adolescent detainees (N = 1,576) who were recruited from one male and one female youth detention facility, responded to surveys that assessed post-detention educational plans, as well as social and emotional characteristics, and criminal history. Multivariate analysis techniques were used to compare factors across race and gender, and plot linear relationships between key indicators of academic potential with associate factors. Findings revealed that youth were more likely to evince academic potential when they had a healthy level of self-esteem, adequate future goal orientation, positive mood, family and community involvement, fewer traumatic events, and less delinquent activity. PMID:21654936
Modeling of solar pond thermal performance
Hull, J.R.
The utility of solar ponds depends on the amount of thermal energy that the pond can deliver and the cost of constructing and maintaining the pond. Proper engineering of a solar pond requires that the size of the pond be carefully chosen to match the intended load. The thermal performance of a solar pond depends on how much incident solar radiation is collected, how much heat is lost through the gradient zone, how much heat is lost to the ground, the total storage capacity, and the effectiveness of the heat extraction system. The thermal behavior is relatively well understood because it depends basically on heat conduction, and it is much more advanced than the understanding of solar pond hydrodynamic behavior. Several of the different design methods available to predict thermal performance are discussed in this paper.
Flood detention area modelling based on nationwide topographic data: ALS-DTMs vs. conventional DTMs
NASA Astrophysics Data System (ADS)
Vesakoski, Jenni-Mari; Alho, Petteri; Hyyppä, Juha; Holopainen, Markus; Flener, Claude; Hyyppä, Hannu
Topographic depressions have an important role in hydrology. These effects on hydrological processes are caused by changes in the water balance and runoff response of a watershed. Nevertheless, research has focused in detail neither on the effects of acquisition and processing methods nor on the effects of resolution of nationwide grid digital terrain models (DTMs) on topographic depressions. Recently, many countries have conducted nationwide ALS (Airborne laser scanning) surveys for DTM purposes. Thus, detailed comparison between nationwide ALS-DTMs with different grid sizes and DTMs that represent more conventional acquisition methods, such as photogrammetric methods, is needed for different study fields. In here, the objective is to delineate the difference of depression variables between nationwide DTMs with different acquisition methods, processing methods and grid sizes. Our depression detection is based on nationwide 25x25 m and 10x10 m DTMs and 2x2 m ALS-DTM produced by NLS of Finland. ALS-DTM2 was resampled to 10x10 and 25x25 m DTMs. Thus, it was possible to compare DTMs that represent the same grid size but different acquisition and processing methods. The variables considered are the mean depth of the depression, the number of its pixels, and its area and volume. Shallow and single-pixel depressions and the impact of mean filtering on ALS-DTM were also examined. Quantitative methods and error models were applied. According to our study, the depression variables were dependent on the scale, area and acquisition method. When the depths of depression pixels were compared with the most accurate DTM based on accurate VRNS-GNSS (Virtual Reference Stations, Global Navigation Satellite Systems) field survey data, the maximum errors created the largest differences between DTMs and hence represented the amount of the depth error. The mean filtering of ALS-DTM2 focuses on the small and shallow depressions, and is thus suitable for using in flood risk management. According to our results, the decision about the suitability of the available DTMs for a specific purpose is good to make on the demands of the problem settings. In studies with a relatively low demand for accuracy, awareness of the error, its level and effects on analyses in general is sufficient. In more accurate studies, the awareness of the varying spatial accuracy and the knowledge about certain typical characteristics of available DTMs to represent a studied terrain variables is essential. On the whole, the ability of a DTM to accurately represent depressions varied uniquely according to each depression, although DTMs also displayed certain typical characteristics. Thus, a DTM's higher resolution is no guarantee of a more accurate representation of topography in flood detention studies.
Visual evoked potentials in relation to factors of imprisonment in detention camps
A. Vrca; V. Bozikov; Z. Brzovi?; R. Fuchs; M. Malinar
Visual evoked potentials (VEPs) of the pattern shift reversal type were determined in a representative group of 57 prisoners of war (POWs) released in 1992 from detention camps in former Yugoslavia. The parameters were correlated with the conditions in four camps (1–4). All subjects were male, with a mean age of 34.75 years (SD ± 8.92), average length of imprisonment
Reaffirming Rights: Human Rights Protections of Migrants, Asylum Seekers, and Refugees in Immigration Detention
Eleanor Acer; Jake Goodman
The International Migrants Bill of Rights (IMBR) addresses migrants' rights in a variety of contexts, and this paper looks closely at some of the most crucial rights that apply to migrants, refugees, and asylum seekers who are held in immigration detention.\\u000aMigrants, refugees and asylum seekers are entitled to a broad range of rights protections. These protections are spelled out
Design comparison of experimental storm water detention systems treating concentrated road runoff.
Nanbakhsh, Hassan; Kazemi-Yazdi, Sara; Scholz, Miklas
The aim was to assess the treatment efficiencies of experimental storm water detention (extended storage) systems based on the Atlantis Water Management Limited detention cells receiving concentrated runoff that has been primarily treated by filtration with different inert aggregates. Randomly collected gully pot liquor was used in stead of road runoff. To test for a 'worst case scenario', the experimental system received higher volumes and pollutant concentrations in comparison to real detention systems under real (frequently longer but diluted) runoff events. Gravel (6 and 20 mm), sand (1.5 mm), Ecosoil (inert 2 mm aggregate provided by Atlantis Water Management Limited), block paving and turf were tested in terms of their influence on the water quality. Concentrations of five-day at 20 degrees C ATU biochemical oxygen demand (BOD) in contrast to suspended solids (SS) were frequently reduced to below international secondary wastewater treatment standards. The denitrification process was not completed. This resulted in higher outflow than inflow nitrate-nitrogen concentrations. An analysis of variance indicated that some systems were similar in terms of most of their treatment performance variables including BOD and SS. It follows that there is no advantage in using additional aggregates with high adsorption capacities in the primary treatment stage. PMID:17156823
Pond 2: Life in a Drop of Pond Water
NSDL National Science Digital Library
Science Netlinks
This Science NetLinks lesson is the second in a two-part series on microorganisms. It is designed to follow the first lesson, but it can also stand alone. In this lesson, students observe microscopic organisms found in pond water using a hand lens, 30x magnification, and 100x magnification. Then students participate in discussions about how single-celled living things might satisfy their needs for food, water, and air.
The Kingston Pond: A Case Study of Stormwater Pond Upgrading
E D Watt; Jiri Marsalek; Bruce Anderson
The results of a decade of interdisciplinary research and our relations with stakeholders at the Kingston Pond stormwater\\u000a management facility provide an excellent background for recommending retrofits that are likely to be effective in removing\\u000a the priority pollutants of today. However, there are two challenges to implementation. First, the community, as represented\\u000a by it elected officials and public employees, may
Design, construction, and initial operation of the Los Alamos National Laboratory salt-gradient solar pond
Jones, G.F.; Meyer, K.A.; Hedstrom, J.C.; Dreicer, J.S.; Grimmer, D.P.
A 232 m/sup 2/ solar pond was constructed at Los Alamos National Laboratory for the purpose of studying pond hydrodynamics on a large scale and to complement the flow visualization and one-dimensional pond simulator experiments that are ongoing at the Laboratory. Design methods and construction techniques, some of which are unique to this pond, are described in detail. The pond was excavated from a soft volcanic rock known as tuff; such rock forms a large fraction of the Los Alamos area surface geology. Because tuff has a small thermal conductivity, little insulation was required to reduce perimeter energy losses. In addition, the strength of tuff permitted the pond to be built with vertical side walls; this design eliminated local side wall convection in the gradient zone that is possible with sloping side walls. Instrumentation in the pond consists of traversing and fixed rakes of thermometers and salinity probes, an underwater pyranometer, and a weather station. The traversing rake is a wheeled trolley driven vertically on a rectangular rail. Installed on the trolley are coplanar platinum RTDs, a point conductivity probe, and an induction salinometer. The stationary rake supports 28 thermocouples and 28 sample-fluid withdrawal taps located every 10 cm. About 127 T of sodium chloride has been introduced and is nearly dissolved. A 120-cm-thick salinity gradient was established and the pond is heating. Preliminary results indicate a lower-convective-zone heating rate of 1.2/sup 0/C/day during the pond's first month of operation. Recommendations on pond design, construction, and instrumentation are presented.
Orientation and migration distances of a pond-breeding salamander (Notophthalmus perstriatus, Salamandridae)
Johnson, S.A.
Habitat loss and modification have played a significant role in the decline of amphibian populations and species. Loss of wetlands, which are used as breeding sites for many amphibians, has contributed to the decline. The protection of small, isolated wetlands and core areas of associated uplands is one way in which population declines in certain species can be slowed or prevented. Nevertheless, migration distances of individuals of most amphibian species from their breeding sites are unknown. Using drift fences and pitfall traps, I studied migration distance and orientation of striped newts (Notophthalmus perstriatus) at a breeding pond in northern Florida, USA. Newts entered (immigration) and exited (emigration) the pond basin in a nonrandom fashion but no obvious effects of upland habitat were apparent. Patterns of emigration and immigration differed significantly between sexes, life-history stages, and migration events. Individuals tended to exit and enter the pond basin within the same quadrant, sometimes leaving and returning at the same point. Newts moved hundreds of meters into the sandhill uplands surrounding the pond. I found an inverse relationship between the proportion of newts migrating and distance from the pond. Nonetheless, I estimated that at least 16% of individuals breeding at the pond migrated in excess of 500 m from the pond. Thus, a core of protected upland with a radius of approximately 800 m from the pond would be needed to preserve the area used by the vast majority of individuals that breed at the pond. These data underscore the need to study upland habitat requirements for amphibians; findings for one taxon (e.g. ambystomatids) may not be applicable to others (e.g., salamandrids). Without such data, designating terrestrial core habitat to conserve aquatic-breeding amphibians will be difficult or impossible. However, without better protection of small, isolated wetlands, arguments to preserve surrounding uplands are irrelevant.
Research solar pond: Design and instrumentation
Pytlinski, J.T.; Lopez, A.M.; Straub, M.
Since the discovery of natural solar ponds, interest in the practical use of pond phenomena has led to the construction of a variety of research and application ponds throughout the world, and to a general understanding of the physical and engineering problems related to their use. The purpose of this study was to establish the design and construction parameters for a research pond of 39 m/sup 2/ (415 ft/sup 2/) area as a preliminary step before the building and operating of a 0.5 acre (21,780 ft/sup 2/) pond by the Center for Energy and Environment Research of the University of Puerto Rico. Commercially available swimming pool structures were used as the base for designing the saltgradient pond and the evaporative pond coupled to it. The physical parameters of pond operation were calculated by using the methodology described by M. Edesess et al. The basic emphasis in this work, however, was on the instrumentation package and the data acquisition system. The primary goal was automatic or semiautomatic pond operation and specifically the maintenance of the salinity gradient. This means automatic acquisition of data such as temperature, salinity and insolation within the pond, and measurement of temperature, isolation and wind velocity outside the pond. In addition to the above, measurements of soil temperature and thermal conductivity around the pond were included in the overall instrumentation package. The automatically collected data is processed and used for decision making by the microprocessor that controls and maintains the pond operation. The problem is technically similar to the one encountered when designing and putting together an instrumentation package for solar heating or cooling.
NSDL National Science Digital Library
Melissa Salpietra
This animated slideshow introduces biodiesel as a fuel alternative. With concern about the use of petroleum-based fuels at an all-time high, biodiesel is experiencing a popularity surge. And algaeâotherwise known to some as pond scumâ are grabbing headlines as the next potential biodiesel superstar. But how and why do algae make oil? And why do they make so much of it? In this audio slide show, U.C. Berkeley's Kris Niyogi describes the process and its potential.
Some aspects of ice phenology on ponds in central Alaska, USA
Martin O. Jeffries; Kim Morris
Ice phenology (freeze-up, break-up and duration) was monitored for five seasons between autumn 2001 and spring 2006 at 11 small, shallow ponds in the boreal forest of central Alaska, USA. The sequence in which freeze-up (FU; day of 100% ice cover) and break-up (BU; day of zero ice cover) occurred at the 11 ponds showed moderately high to very high
Rotifers from five high arctic ponds (Cape Herschel, Ellesmere Island, N.W.T.)
Thomas Nogrady; John P. Smol
Five small ponds on Cape Herschel, Ellesmere Island, N.W.T. (latitude 78° 37? N; 74° 42? W) were investigated, and their rotifer fauna discussed. Although the number of individuals is very low, the rotifer assemblage is remarkably rich (33 species), especially considering the harsh environmental conditions, and the short ice-free period of only six weeks. The shallow ponds are all alkaline,
Heat extraction from salinity-gradient solar ponds using heat pipe heat exchangers
Sura Tundee; Pradit Terdtoon; Phrut Sakulchangsatjatai; Randeep Singh; Aliakbar Akbarzadeh
This paper presents the results of experimental and theoretical analysis on the heat extraction process from solar pond by using the heat pipe heat exchanger. In order to conduct research work, a small scale experimental solar pond with an area of 7.0m2 and a depth of 1.5m was built at Khon Kaen in North-Eastern Thailand (16°27?N102°E). Heat was successfully extracted
Effects of pond draining on biodiversity and water quality of farm ponds.
Usio, Nisikawa; Imada, Miho; Nakagawa, Megumi; Akasaka, Munemitsu; Takamura, Noriko
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. PMID:23869702
Protecting and Restoring Ponds Following a Wildfire Quick facts....
Protecting and Restoring Ponds Following a Wildfire Quick facts.... Ponds and streams following wildfire. Flame retardants used in wildfire control can affect pond water quality. If ponds have following wildfire. Property owners in burned areas need to protect their ponds and streams from further
Spectral calculation of thermal performance of solar pond and comparison of the results with the experiments
Li, X.Y.; Kanayama, Kimio; Baba, Hiromu
This paper deals with the method and the result of the spectroscopic calculation on the heat balance of a salt-gradient solar pond under the conditions of spectral solar radiation. Furthermore, the reflection of the rays incident upon the surface of the pond water, the refraction of the rays within the salt water layer and the diffusion of the salt in the pond water are considered. On the other hand, in order to make clear the mechanism of heat collection and heat storage of a solar pond, the authors conducted the indoor experiment and numerical analysis on a small scale model of salt-gradient solar pond with 2 m{sup 2} surface area and 1.6 m depth, under incident ray from a Xe-lamp solar simulator. According to above experimental analysis, the authors made a simulation model of thermal performance for a solar pond and calculated the heat balance in it. They found that the simulation calculations correspond well to the experimental result, so that their thermal simulation model might be correct. Furthermore, the authors also did the thermal calculation by changing the incident ray from Xe-lamp into natural ray, and found that the temperature distributions were notably different due to spectral characteristics of the incident ray. Therefore, the spectroscopic consideration for thermal performance of any solar pond is necessary to obtain a correct solution under the spectral incidence of special distributions.
Parametric study of salt gradient solar ponds
Beniwal, R.S.; Saxena, N.S.; Bhandari, R.C.
A mathematical model for efficiency of a salt gradient solar pond is described. Heat losses from the bottom of the pond have been calculated, and the results for the effective thermal conductivity with the thicknesses of various insulating materials have been presented. The effect of the ground thermal resistance on the efficiency of the pond for different values of ..delta..T/S/sup 0/ are also shown.
Saturated solar ponds: 3. Experimental verification
Subhakar, D.; Murthy, S.S. (Indian Institute of Technology, Madras (India))
An experimental saturated solar pond is constructed using magnesium chloride salt. The temperature and concentration gradients are developed by heating the pond from the bottom and adding finely powdered salt from the top. The development of a temperature profile in the pond exposed to direct sunlight and its daily variation are studied. The predictions of the temperature profiles, using the authors' mathematical model, match the experiments better than the concentration profiles.
Pond age and riparian zone proximity influence anuran occupancy of urban retention ponds
Devynn A. Birx-Raybuck; Steven J. Price; Michael E. Dorcas
Urbanization is widespread throughout the United States and negatively affects many wildlife populations. However, certain\\u000a urban features, such as retention ponds, may provide habitat for some species, such as amphibians. This study examines the\\u000a influence of riparian zone proximity and pond age on retention pond occupancy by anurans. We identified and estimated the\\u000a age of 25 retention ponds near Charlotte,
Review of SERI Solar Pond Work
NASA Technical Reports Server (NTRS)
Zangrando, F.; Johnson, D. H.
Development of models of pond thermal performance; analysis of solar pond use for building space heat and hot water production; use of low-temperature pond-produced heat for industrial processes, desalination, and electricity production; development of direct-contact heat exchanger to reduce conversion equipment cost; determination of effects of extracted heat and mass from the storage layer on pond performance; and investigation of factors which determine gradient layer stability and the stability of this interface between this level and the upper and lower convecting layers were described.
Combined solar collector and storage pond
Spitzer, H.J.
The deep storage pond may comprise a flexible plastic bag or a rigid plastic compartment supported by a containment structure which may comprise insulating and supporting walls underground with an open top. The solar energy collector may comprise a smaller absorber bag or compartment of the same material which can be mounted atop the storage pond. Black-dyed water is used as the absorbing and storage medium and when the absorber bag temperature reaches an optimum value the contents thereof are transferred to the storage pond and subsequently replaced by cooler water from the bottom of the storage pond. The absorber means may be remotely located from the storage means.
Review of SERI solar pond work
Zangrando, F.; Johnson, D.H.
Development of models of pond thermal performance analysis of solar pond use for building space heat and hot water production, use of low-temperature pond-produced heat for industrial processes, desalination, and electricity production, development of direct-contact heat exchanger to reduce conversion equipment cost, determination of effects of extracted heat and mass from the storage layer on pond performance, and investigation of factors which determine gradient layer stability and the stability of this interface between this level and the upper and lower convecting layers were described.
Maintenance strategy for a salt gradient solar pond coupled with an evaporation pond
K. R. Agha; S. M. Abughres; A. M. Ramadan
In a previous study, the authors presented a simple mathematical model for predicting the ratio of the evaporation pond area to that of a salt gradient solar pond area. The evaporation pond idea provides a very attractive method of salt recycling by evaporation, especially in areas of high evaporation and low rates of rain as it is the case for
An Assessment of the Florida Department of Health and Rehabilitative Services Detention Risk Assessment Instrument on Youths Screened and Processed at the Hillsborough County Juvenile Assessment Center
Richard Dembo; Glenn Turner; Camille Chin Sue; James Schmeidler; Polly Borden; Darrell Manning
Screening data, including information obtained from the Florida Department of Health and Rehabilitative Services Detention Risk Assessment Instrument and the Problem Oriented Screening Instrument for Teenagers developed by NIDA, on arrested youths processed at the Hillsborough County, Florida Juvenile Assessment Center (JAC) in November 1993 are analyzed. The results provide support for the effectiveness of the Detention Risk Assessment Instrument
Developing Learning Identities in and through Music: A Case Study of the Outcomes of a Music Programme in an Australian Juvenile Detention Centre
ERIC Educational Resources Information Center
Barrett, Margaret S.; Baker, Jane S.
The last decades have witnessed significant growth in music programmes targeted at various populations in detention, including those in male and female prisons and juvenile detention centres. The aspirations of such programmes have included a concern to improve detainees' mental and physical health and well-being, develop pro-social behaviours…
Controlling Those Kids: Social Control and the Use of Pretrial Detention among Youth in the United States of America--National Implications
ERIC Educational Resources Information Center
Webb, Patrick; Kritsonis, William Allan
This analysis will identify the theoretical basis associated with the use of pretrial detention among youth in the United Sates. This article is designed to offer a comprehensive description of the use of pre-trial detention of youth. In addition, a theoretical discussion of this "crime-control" measure is identified. Policy implications are…
Computational fluid dynamics modelling of flow and particulate contaminants sedimentation in an urban stormwater detention and settling basin.
Yan, Hexiang; Lipeme Kouyi, Gislain; Gonzalez-Merchan, Carolina; Becouze-Lareure, Céline; Sebastian, Christel; Barraud, Sylvie; Bertrand-Krajewski, Jean-Luc
Sedimentation is a common but complex phenomenon in the urban drainage system. The settling mechanisms involved in detention basins are still not well understood. The lack of knowledge on sediment transport and settling processes in actual detention basins is still an obstacle to the optimization of the design and the management of the stormwater detention basins. In order to well understand the sedimentation processes, in this paper, a new boundary condition as an attempt to represent the sedimentation processes based on particle tracking approach is presented. The proposed boundary condition is based on the assumption that the flow turbulent kinetic energy near the bottom plays an important role on the sedimentation processes. The simulated results show that the proposed boundary condition appears as a potential capability to identify the preferential sediment zones and to predict the trapping efficiency of the basin during storm events. PMID:24390197
Throwing Away the Key: The Ethics of Risk Assessment for Preventive Detention Schemes: R.G. Myers Memorial Lecture 2013.
McSherry, B
Preventive detention schemes that aim to protect the community from certain 'dangerous' individuals have long existed. While risk assessment is now pervasive in the management and treatment of many individuals, it raises particular issues when a person's liberty is at stake on the basis of what that person might do. This R.G. Myers Memorial Lecture addresses the ethical issues raised by mental health practitioners providing risk assessments for legislative schemes that involve the deprivation of liberty. It will focus in particular on Australian post-sentence preventive detention schemes for sex offenders that have been held by the United Nations Human Rights Committee to breach fundamental human rights. However, the ethical issues discussed also have repercussions for civil commitment laws that enable the detention of those with severe mental or intellectual impairments. PMID:25431531
Beyond best management practices: pelagic biogeochemical dynamics in urban stormwater ponds.
Williams, Clayton J; Frost, Paul C; Xenopoulos, Marguerite A
Urban stormwater ponds are considered to be a best management practice for flood control and the protection of downstream aquatic ecosystems from excess suspended solids and other contaminants. Following this, urban ponds are assumed to operate as unreactive settling basins, whereby their overall effectiveness in water treatment is strictly controlled by physical processes. However, pelagic microbial biogeochemical dynamics could be significant contributors to nutrient and carbon cycling in these small, constructed aquatic systems. In the present study, we examined pelagic biogeochemical dynamics in 26 stormwater ponds located in southern Ontario, Canada, during late summer. Initially, we tested to see if total suspended solids (TSS) concentration, which provides a measure of catchment disturbance, landscape stability, and pond performance, could be used as an indirect predictor of plankton stocks in stormwater ponds. Structural equation modeling (SEM) using TSS as a surrogate for external loading suggested that TSS was an imperfect predictor. TSS masked plankton-nutrient relationships and appeared to reflect autochthonous production moreso than external forces. When TSS was excluded, the SEM model explained a large amount of the variation in dissolved organic matter (DOM) characteristics (55-75%) but a small amount of the variation in plankton stocks (3-38%). Plankton stocks were correlated positively with particulate nutrients and extracellular enzyme activities, suggesting rapid recycling of the fixed nutrient and carbon pool with consequential effects on DOM. DOM characteristics across the ponds were mainly of autochthonous origin. Humic matter from the watershed formed a larger part of the DOM pool only in ponds with low productivity and low dissolved organic carbon concentrations. Our results suggest that in these small, high nutrient systems internal processes might outweigh the impact of the landscape on carbon cycles. Hence, the overall benefit that constructed ponds serve to protect downstream environments must be weighed with the biogeochemical processes that take place within the water body, which could offset pond water quality gains by supporting intense microbial metabolism. Finally, TSS did not provide a useful indication of stormwater pond biogeochemistry and was biased by autochthonous production, which could lead to erroneous TSS-based management conclusions regarding pond performance. PMID:24147410
Assessing optical earth observation systems for mapping and monitoring temporary ponds in arid areas
NASA Astrophysics Data System (ADS)
Soti, Valérie; Tran, Annelise; Bailly, Jean-Stéphane; Puech, Christian; Seen, Danny Lo; Bégué, Agnes
Remote sensing methods for locating and monitoring temporary ponds over large areas in arid lands were tested on a study site in Northern Senegal. Three main results are presented, validated with field data and intended to highlight different spectral, spatial and temporal characteristics of the methods: (1) Among several water indices tested, two Middle Infrared-based indices (MNDWI—Modified Normalized Difference Water Index and NDWI 1—Normalized Difference Water Index) are found to be most efficient; (2) an objective method is given prescribing the necessary sensor spatial resolution in terms of minimal detected pond area; and (3) the potential of multi-temporal MODIS imagery for tracking the filling phases of small ponds is illustrated. These results should assist in epidemiological studies of vector-borne diseases that develop around these ponds, but also more generally for land and water management and preservation of threatened ecosystems in arid areas.
Suicidal Behaviors among Adolescents in Juvenile Detention: Role of Adverse Life Experiences
Bhatta, Madhav P.; Jefferis, Eric; Kavadas, Angela; Alemagno, Sonia A.; Shaffer-King, Peggy
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. PMID:24586756
Texas Catfish Production in Ponds
Masser, Michael P.; Woods, Peter; Clary, Gregory M.
at temperatures as low as 60 degrees F. All regions of Texas are suitable for commercial cat- fish production. Northeast Texas has about 200 days per year when water temperature is above 60 degrees F, while South Texas may have more than 320 days. Other factors... moving for pond construction until the first fish sale or positive cash flow. Sensitivity Analysis of Price and Production Factors As with any business, managers should pay close attention to fluctuations in the factors that signifi- cantly affect...
Detention of British citizens as hostages in the Gulf--health, psychological, and family consequences.
Easton, J A; Turner, S W
OBJECTIVE--To describe the physical, psychological, and family consequences of the detention of British subjects as hostages in Kuwait or Iraq, or both, after the invasion of Kuwait on 2 August 1990 and to investigate the relation between types of trauma experienced and these reactions. DESIGN--Postal questionnaire. SUBJECTS--381 respondents. RESULTS--Many health, social, and psychological sequelae were identified. Problems with present finance, accommodation, and work are important causes of distress. Many hostages coped well and gained self esteem. CONCLUSIONS--A minority of respondents require further support and treatment. Expatriates in risk areas should retain assets in their home country. PMID:1747642
Prey selection under laboratory conditions by pond-bred Trematocranus placodon (Regan, 1922), a molluscivorous cichlid from Lake Mala?i
Alexander S. Kefi; Henry Madsen; Jeremy S. Likongwe; Wilson Jere; Jay R. Stauffer Jr
Trematocranus placodon, a predator of freshwater snails in Lake Mala?i, has been recommended for the control of schistosome intermediate hosts in aquaculture ponds. Fish from Lake Mala?i were introduced into a pond close to Lilongwe and we attempted to elucidate whether pond-raised F1 retain their ability to consume snails. In laboratory experiments, small fish (70–80?mm total length) preyed only on
An in-field evaluation of the effectiveness of sediment ponds in reducing suspended solids in the runoff from surface mining activities was performed. Nine selected sedimentation ponds in the three eastern coal-mining States of Pennsylvania, West Virginia, and Kentucky were sampl...
Chemical and biological processes of evaporation ponds
Technology Transfer Automated Retrieval System (TEKTRAN)
Agricultural evaporation ponds are designed to impound and dissipate saline agricultural drainage water in areas with no opportunities for offsite disposal in the San Joaquin Valley of California. This paper reviews and summarizes research findings on the pond chemistry. Drainage waters in these pon...
100-D Ponds closure plan. Revision 1
Petersen, S.W.
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.
Par Pond vegetation status Summer 1995 -- Summary
Mackey, H.E. Jr.; Riley, R.S.
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.
SURVEY OF FISHING IN 1000 PONDS in 1959 HUG ^^^ri^L UNITED STATES DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE SERVICE BUREAU OF SPORT FISHERIES AND WILDLIFE Circular 86 #12;Cover. --Fishing in a pond, Secretary FISH AND WILDLIFE SERVICE, Arnle J. Suomela, Coimnissioner BUREAU OF SPORT FISHERIES AND WILDLIFE
Maintenance of Stormwater Wetlands and Wet Ponds
Hunt, William F.
. · Remove vegetation along the dam face. · Remove invasive plant species. · Mow the perimeter of wet ponds that includes many plant and animal species. It will also do an excellent job of removing pollution from, such as an aquatic shelf (or wetland bench) and a forebay. An aquatic shelf is a shallow-water zone of a pond
NSDL National Science Digital Library
NCTM Illuminations
The online applet provides for creative problem solving while encouraging young students to estimate length. Using the Turtle Pond Applet, students will direct the turtle to the pond by choosing a sequence of commands. Then the student will select play and watch the turtle move along the path as directed by the commands.
The role of microorganisms in aquaculture ponds
David J. W. Moriarty
Microorganisms have major roles in pond culture, particularly with respect to productivity, nutrient cycling, the nutrition of the cultured animals, water quality, disease control and environmental impact of the effluent. Management of the activities of microorganisms in food webs and nutrient cycling in ponds is necessary for optimising production, but the objectives will differ with the type of aquaculture, the
Sydney Tar Ponds Remediation: Experience to China
ERIC Educational Resources Information Center
Liu, Fan; Bryson, Ken A.
The infamous "Sydney Tar Ponds" are well known as one of the largest toxic waste sites of Canada, due to almost 100 years of steelmaking in Sydney, a once beautiful and peaceful city located on the east side of Cape Breton Island, Nova Scotia. This article begins with a contextual overview of the Tar Ponds issue including a brief introduction and…
Zooplankton succession in fingerling production ponds
Technology Transfer Automated Retrieval System (TEKTRAN)
Many pond cultured species require a range of zooplankton species for consumption before they can be weaned onto manufactured feed. The widest variety of plankton species develops when empty ponds are filled and fertilized. Use of organic and inorganic fertilizers facilitates the development of ba...
Studies on membrane viscosity stabilized solar pond
M. Taga; T. Matsumoto; T. Ochi
In this nonsalt type of solar pond, the nonconvecting layer is composed of a viscous polymer solution partitioned by a number of transparent films. An advantage of partitioning is that a thinner polymer solution can be used and that the light transmittance increases. Results of experimental and theoretical investigations on the performance of this solar pond are summarized as follows:
Saturated solar ponds: 1. Simulation procedure
D. Subhakar; S. S. Murthy
The mass and energy balances on the upper convective zone, nonconvective zone, and lower convective zone of a saturated solar pond are written to yield a set of nonlinear partial differential equations. These are solved numerically to predict the thermal performance of the pond over a long period of time for various initial and boundary conditions. This model considers external
Operation of a commercial solar gel pond
Wilkens, E. (Univ. of New Mexico, Albuquerque (United States))
The solar gel pond is an innovative concept which overcomes many of the shortcomings of the conventional salt-gradient solar pond. In this paper, the design, construction and start-up details of a commercial scale pond (400 m{sup 2}), built for a publishing company in Albuquerque, New Mexico will be presented. A pond with trapezoidal cross section was designed so that shadowing could be minimized and also the ratio of surface area to the volume of the storage zone could be maximized. The publishing company required a minimum of 1 GJ/day (1MBTU/day). Generally it has been noted that in ponds with large volume a lesser percentage of retained energy is lost as edge losses. Based on the above considerations a pond size of 400 m{sup 2} and 5 m deep with a gel thickness of 60 cm and a mass flow rate (for the heat extraction loop) of 1 {times} 10{sup {minus}4} to 1 {times} 10{sup {minus}3} kg/m{sup 2} {center dot} sec was determined to be the optimum size for the publishing company's needs. Two to seven percent salt water was used mainly to keep the gel bags floating on the surface. Tedlar bags were used to contain the gel. During the first year of operation, while the pond was still heating up, the pond obtained a temperature of 60C and the gel showed no signs of degradation.
The Pond Community. Primary Level. Teacher's Manual.
ERIC Educational Resources Information Center
Conner, Shirley
This teacher's guide includes four lessons dealing with animals and plants associated with ponds. Species discussed are selected because of their unusual means of adaptation to the pond environment. Each lesson includes suggestions on introducing the unit, discussion suggestions, blackboard activities, and activities with pictures and a magnetic…
We used a 1.75 m2 drop ring sampler in June and July of 2000 to quantify populations of juvenile flatfishes and other small nekton in Ninigret Pond, Rhode Island. The drop sampler was deployed in approximately 1 m of water from a boom mounted on the bow of a small boat. Abundance...
The use of local indicators of spatial association to improve LiDAR-derived predictions of potential amphibian breeding ponds
Julian, J.T.; Young, J.A.; Jones, J.W.; Snyder, C.D.; Wright, C.W.
We examined whether spatially explicit information improved models that use LiDAR return signal intensity to discriminate in-pond habitat from terrestrial habitat at 24 amphibian breeding ponds. The addition of Local Indicators of Spatial Association (LISA) to LiDAR return intensity data significantly improved predictive models at all ponds, reduced residual error by as much as 74%, and appeared to improve models by reducing classification errors associated with types of in-pond vegetation. We conclude that LISA statistics can help maximize the information content that can be extracted from time resolved LiDAR return data in models that predict the occurrence of small, seasonal ponds. ?? Springer-Verlag 2008.
Space Shuttle Orbiter Atlantis Liquid Oxygen Prevalve Detent Roller Cracking Investigation
NASA Technical Reports Server (NTRS)
Holleman, Elizabeth; Eddleman, David; Richard, James; Jacobs, Rebecca
During routine inspections of the Space Shuttle's Main Propulsion System (MPS) Liquid Oxygen (LO2) pre-valve, the mechanism provided to maintain the valve in the open position was found cracked. The mechanism is a Vespel roller held against the valve visor by a stack of Belleville springs. The roller has been found cracked 3 times. All three instances were in the same valve in the same location. There are 6 pre-valves on each orbiter, and only one has exhibited this problem. Every-flight inspections were instituted and the rollers were found to be cracked after only one flight. Engineers at Marshall Space Flight Center, Johnson Space Center and Kennedy Space Center worked together to determine a solution. There were several possible contributors to the failure: a mis-aligned visor, an out of specification edge with a sharp radius, an out of specification tolerance stack up of a Belleville spring stack that caused un-predicted loads on the Vespel SP-21 roller, and a dimple machined into the side of the roller to indicate LO2 compatibility that created a stress riser. The detent assembly was removed and replaced with parts that were on the low-side of the tolerance stack up to eliminate the potential for high loads on the detent roller. After one flight, the roller was inspected and showed fewer signs of wear and no cracks.
Fitness for detention in police custody: a practical proposal for improving the format of medical opinion.
Chariot, Patrick; Briffa, Hugo; Lepresle, Aude; Lefčvre, Thomas; Boraud, Cyril
Health issues among arrestees are a worldwide concern for which only local policies have been established. Physicians attending detainees in police custody are expected to decide whether the detainee's health status is compatible with detention in a police station and make any useful observations. A high degree of heterogeneity in the information collected by the physician and transmitted to the police has been observed. We analyzed the content and limitations of available documents and developed a model that could serve as a guide for any attending physician. The document presented here has been used in France on over 50,000 occasions since June 2010. We developed a two-page template consisting of (1) a standard medical certificate to be sent to the authority who requested the doctor's attendance and (2) a confidential medical record, not sent to the requesting authority. We evaluated perceived health by the three global health indicators of the Minimum European Health Module and used DSM IV criteria for the evaluation of addictive disorders. In the case of recent traumatic injuries, the certificate has also included the collection of data on traumatic injuries and the contexts of their occurrence. The proposed certificate achieved several goals, by protecting the interests of the person examined, in case of poor conditions of arrest or detention, protecting doctors in cases of legal proceedings, and allowing epidemiological data to be collected. The certificate may also contribute to an international awareness of medical care for detainees in police custody. PMID:24237804
Effects of fish on mercury contamination of macroinvertebrate communities of Grassland ponds.
Henderson, Byron L; Chumchal, Matthew M; Drenner, Ray W; Deng, Yanci; Diaz, Peter; Nowlin, Weston H
Mercury is an environmental contaminant that negatively affects the health of vertebrate consumers such as fish, birds, and mammals. Although aquatic macroinvertebrates are a key link in the trophic transfer of Hg to vertebrate consumers, Hg contamination in macroinvertebrate communities has not been well studied. The purpose of the present study was to examine how Hg in macroinvertebrate communities is affected by the presence of fish. We sampled macroinvertebrates from five ponds with fish and five ponds without fish, at the Lyndon B. Johnson National Grassland in north Texas, USA. Ponds without fish contained a higher biomass of macroinvertebrates and taxa with higher concentrations of Hg, which led to a higher Hg pool in the macroinvertebrate community. A total of 73% of the macroinvertebrate biomass from ponds without fish was composed of taxa with the potential to emerge and transport Hg out of ponds into terrestrial food webs. The results of the present study suggest that small ponds, the numerically dominant aquatic ecosystems in the United States, may be more at risk for containing organisms with elevated Hg concentrations than has been appreciated. PMID:22278821
Ecology of tundra ponds of the Arctic Coastal Plain: a community profile
Hobbie, J.E.
The Arctic Coastal Plain is a flat or gently rolling area of tundra which covers the entire coastal region of northern Alaska. This profile synthesizes data on the ecology of the thousands of small shallow ponds that form an important wetland community on the tundra. These polygonal ponds are formed by the freezing, thawing, and cracking of the perma-frost. Nutrient concentrations and rates of supply to the water column are controlled by interactions with the iron-rich peat sediments. Iron concentrations control phosphorus concentrations and these in turn control the growth of algae. Two fringing emergent vascular plants, Carex and Arctophila, are often the most important primary producers in the ponds. Most algae and higher plant biomass is decomposed by microbes in a detrital food web concentrated in the pond sediments. Chironomid larvae, oligochaete worms and other insects are the dominant benthic animals. Because the ponds freeze to the bottom each winter they contain no fish; however, the community is important for many species of migratory waterfowl and shorebirds that use the ponds for feeding and breeding. Activities associated with oil production, including spills, roads, and off-road vehicles, are the major issues facing managers of this wetland community. 63 references.
Evapotranspiration from Wetland Pond Complexes in the Western Boreal Forest, Alberta, Canada
NASA Astrophysics Data System (ADS)
Petrone, R. M.; Silins, U.; Devito, K. J.
Wetlands on the Canadian Western Boreal Plain account for as much as 50 % of the landscape and provide one of the most important waterfowl habitats in North America as well as representing a significant regional water resource and carbon pool. In this sub-humid region potential evapotranspiration (PET) exceeds precipitation in most years and consequently these wetland complexes are very vulnerable to any climate change that may alter patterns of precipitation and evapotranspiration. The permanence of these wetland and pond systems depends on the underlying glacial deposits, topography and evapotranspiration. Flow within these wetland pond catchments is from the pond to the hillslope for most of the time and small changes in precipitation can result in a dramatic change in runoff. Increased climatic variability (natural or anthropogenic) will likely influence the duration of drought cycles. However, whether or not, or for how long these ponds may dry completely remains unknown. Thus, it is essential to understand the ecological and physiographic factors within these complexes that control evapotranspiration, and how these are influenced by large scale climate and climate cycles. This paper investigates not only open water evaporation from the ponds, but also the role of ET from the surrounding riparian peatlands, and illustrates how the evaporative regimes from these units and their linkages with the ponds are significant to the permanence of these water bodies.
Stable density stratification solar pond
NASA Technical Reports Server (NTRS)
Lansing, F. L. (inventor)
A stable density-stratification solar pond for use in the collection and storage of solar thermal energy including a container having a first section characterized by an internal wall of a substantially cylindrical configuration and a second section having an internal wall of a substantially truncated conical configuration surmounting the first section in coaxial alignment therewith, the second section of said container being characterized by a base of a diameter substantially equal to the diameter of the first section and a truncated apex defining a solar energy acceptance opening is discussed. A body of immiscible liquids is disposed within the container and comprises a lower portion substantially filling the first section of the container and an upper portion substantially filling the second section of the container, said lower portion being an aqueous based liquid of a darker color than the upper portion and of a greater density. A protective cover plate is removably provided for covering the acceptance opening.
The Mental and Physical Health Difficulties of Children Held within a British Immigration Detention Center: A Pilot Study
ERIC Educational Resources Information Center
Lorek, Ann; Ehntholt, Kimberly; Nesbitt, Anne; Wey, Emmanuel; Githinji, Chipo; Rossor, Eve; Wickramasinghe, Rush
Objective: The present study aimed to assess the mental and physical health of children held within a British immigration detention center. Method: A total of 24 detained children (aged 3 months to 17 years) were assessed with their parents or carer after being referred by a registered legal charity. Thirteen were seen by a pediatrician alone, 4…
Assessing the Sensitivity and Specificity of the MAYSI-2 for Detecting Trauma among Youth in Juvenile Detention
ERIC Educational Resources Information Center
Kerig, Patricia K.; Moeddel, Melissa Arnzen; Becker, Stephen P.
This study investigated the sensitivity and specificity of the most widely used mental health screening instrument in juvenile detention, the Massachusetts Youth Screening Instrument (MAYSI-2), for detecting trauma and symptoms of posttraumatic stress disorder (PTSD) among detained youth. The MAYSI-2 scales measuring Substance Use,…
A systematic review of ethnic variations in hospital admission and compulsory detention in first-episode psychosis
Mann, Farhana; Fisher, Helen L.
Background Marked ethnic variations in incidence, pathways to care and outcomes have been demonstrated in psychosis. Less research has focused specifically on first-episode psychosis (FEP), particularly adverse contacts such as compulsory detention and hospitalization. This is despite international initiatives to promote equity of care and active early intervention. Aim Systematically review current evidence for ethnic variations in rates of compulsory admission and hospitalization in FEP. Methods Relevant articles published before December 2012 were identified from PubMed, PSYCInfo, and CINAHL together with manual searching of reference lists. Studies providing quantitative data on compulsory detention rates and/or hospitalization, comparing ethnic groups in FEP, were included and quality rated by independent raters. Results All included studies (n?=?7) provided data on compulsory detention while fewer (n?=?3) focused on admission rates. Three studies reported increased detention in Black and minority ethnic groups, while one reported more hospitalization in White patients. Only two studies covered early intervention services (EIS). Conclusions There is a paucity of high quality, well powered studies addressing this important issue, especially in EIS settings. In order to best inform and evaluate fast-developing services, it will be essential to combine large methodologically robust studies with qualitative analysis of patient, carer, and staff experiences. PMID:25054369
Heat rejection and energy extraction within solar ponds
Jaluria, Y.
A study of the heat transfer and fluid flow processes governing heat rejection to the surface layer and energy extraction from the storage zone has been carried out. The literature available on this and other related problems was studied in detail to determine the nature of the recirculating flows that arise and the effect they might have on the stability of the gradient layer. Simplified analytical models were considered to determine the governing parameters and their effect on the performance and efficiency of the solar pond. Estimates of the surface temperature rise and the increase in evaporation caused by heat rejection were made. Two flow configurations, end-to-end and top-to-bottom, were considered for every extraction and the spread of the flow in the storage zone was studied. It was found that the limited penetration of the top-to-bottom configuration restricts its satisfactory operation to small ponds. The experimental modeling of the flows under study was considered in terms of the governing parameters and it was found that the top-to-bottom configuration cannot be uniquely modeled. The choice of these parameters for a full-size pond is also discussed.
Photosynthesis and fish production in culture ponds
Szyper, J.P.
The widely-cultured Nile tilapia, Oreochromis niloticus, has been the major species used in standardized experiments by the Pond Dynamics/Aquaculture Collaborative Research Support Program (PD/ACRSP). Yields of Nile Tilapia from fertilized, unfed ponds have served as a bioassay for effectiveness of pond management protocols developed during worldwide tropical experiments. Yield rates near 10 T/ha/y can be achieved without feed inputs in ponds which maintain high standing stocks of phytoplankton and exhibit high rates near 10 T/ha/y can be achieved without feed inputs in ponds which maintain high standing stocks of phytoplankton and exhibit high rates of primary production. Fish production is related to daytime net photosynthetic production, but it is not clear whether production of food materials or oxygen is the more direct influence. Excessively high standing stocks of phytoplankton are not the best net producers, and increase and risk of nighttime oxygen depletion. Fish readily grow to individual sizes of 200-300 g/fish in fertilized ponds, which is sufficient market size in many locations. Supplemental feeding of caged or free-ranging fish greatly accelerates growth beyond 300 g and potentiates high areal yields; the PD/A CRSP has also developed efficient feeding regimes and shown that supplemental feeding need not begin before fish reach 200 g weight. High standing stocks of phytoplankton and high photosynthetic rates in eutrophic ponds make study of photosynthesis possible without radioisotopes. Such ponds also exhibit complete extinction of incident solar radiation within shallow depths, and vertical temperature structure resembling that of deeper bodies of water. These characteristics make ponds useful as microcosms for study of some aspects of photosynthesis in natural waters.
100-D Ponds groundwater quality assessment
Hartman, M.J.
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.
Potential Ecological Effects of Contaminants in the Exposed Par Pond Sediments
Paller, M.H. [Westinghouse Savannah River Company, AIKEN, SC (United States); Wike, L.D.
Sediment and small mammal samples were collected from the exposed sediments of Par Pond in early 1995, shortly before the reservoir was refilled after a 4-year drawdown. Sampling was confined to elevations between 58 and 61 meters (190 and 200 feet) above mean sea level, which includes the sediments likely to be exposed if the Par Pond water level is permitted to fluctuate naturally. Both soil and small mammal samples were analyzed for a number of radionuclides and metals. Some of the soil samples were also analyzed for organic contaminants. The objective of the study was to determine if contaminant levels in the Par Pond sediments were high enough to cause deleterious ecological effects.
Prevalence and Persistence of Psychiatric Disorders in Youth After Detention: A Prospective Longitudinal Study
Teplin, Linda A.; Welty, Leah J.; Abram, Karen M.; Washburn, Jason J.; Dulcan, Mina K.
Context Psychiatric disorders are prevalent among incarcerated juveniles. Most juveniles eventually return to their communities, where they become the responsibility of the community mental health system. Yet, no large-scale study has examined psychiatric disorders after youth leave detention. Objective To examine changes in prevalence and persistence of disorders during the 5 years after detention, focusing on sex and racial/ethnic differences. Design Prospective longitudinal study with up to 5 interviews (N = 1829). To ensure representation of key demographic subgroups, the randomly selected sample was stratified by sex, race/ethnicity (African American, non-Hispanic white, and Hispanic), age, and legal status (juvenile or adult court). Setting The Northwestern Juvenile Project, sampling youth from the Cook County Juvenile Temporary Detention Center, Chicago, Illinois. Participants Detained youth, 10 to 18 years at baseline interview. Main Outcome Measures At baseline, the Diagnostic Interview Schedule for Children Version 2.3. At follow-ups, the Diagnostic Interview Schedule for Children, Version IV (Child and Young Adult versions) and the Diagnostic Interview Schedule, Version IV (substance use disorders and antisocial personality disorder). Results Five years after baseline, more than 45% of males and nearly 30% of females had one or more psychiatric disorders with associated impairment. Substance use disorders were the most common disorders; males, however, had higher rates over time (5 years after baseline, adjusted odds ratio [AOR], 2.61; 95% CI, 1.96–3.47). Non-Hispanic whites and Hispanics also had higher rates of substance use disorders compared with African Americans (respectively, AOR, 1.96, 95% CI, 1.54–2.49; AOR, 1.59, 95% CI, 1.24–2.03). Females had higher rates of major depression over time (AOR, 1.59, 95% CI, 1.22–2.08). Conclusions Although prevalence rates of most psychiatric disorders declined over time, a substantial proportion of delinquent youth continue to have disorders. There were notable sex and racial/ethnic differences in the prevalence and persistence of disorders. PMID:23026953
Simulation of a solar pond with a stratified storage zone
Newell, T.A.
Numerical simulation results are presented which compare performances between a conventional solar pond and a proposed solar pond configuration. The proposed pond maintains a stratified storage zone below the lower convecting zone of a pond. Addition of a stratified storage zone is shown to have two general results. First, ground losses are minimized, and second, higher process temperature levels can be accommodated. Additionally, the proposed configuration may result in a reduction of pond investment cost.
The manual provides a concise overview of wastewater stabilization pond systems through discussion of factors affecting treatment, process design principles and applications, aspects of physical design and construction, suspended solids removal alternatives, and cost and energy r...
Ecologic simulation of warm water aquaculture ponds
Piedrahitu, R.H.; Brune, D.E.; Orlob, G.T.; Tchobanoglous, G.
A generalized ecologic model of a fertilized warm-water aquaculture pond is under development. The model is intended to represent the pond ecosystem and its response to external stimuli. The major physical, chemical and biological processes and parameters are included in the model. A total of 19 state variables are included in the model (dissolved oxygen, alkalinity, pH, ammonia, phytoplankton, etc.). The model is formulated as a system of mass balance equations. The equations include stimulatory and inhibitory effects of environmental parameters on processes taking place in the pond. The equations may be solved for the entire growth period and diurnal as well as seasonal fluctuations may be identified. The ultimate objective of the model is to predict the fish biomass that can be produced in a pond under a given set of environmental conditions.
Determining the Population Size of Pond Phytoplankton.
ERIC Educational Resources Information Center
Hummer, Paul J.
Discusses methods for determining the population size of pond phytoplankton, including water sampling techniques, laboratory analysis of samples, and additional studies worthy of investigation in class or as individual projects. (CS)
ERIC Educational Resources Information Center
American School and University, 1980
The latest development in solar energy is a four-acre pond planned for Clark College in Vancouver (Washington). Filled with brine, it will serve both as collector and heat storage tank for the entire campus. (Author)
Wintertime Emissions from Produced Water Ponds
NASA Astrophysics Data System (ADS)
Evans, J.; Lyman, S.; Mansfield, M. L.
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 surfaces. These compounds are highly reactive and, because of their relatively high water solubility, tend to concentrate in produced water. The average methanol emission rate from unfrozen pond surfaces was more than 100 mg m-2 h-1. Methanol, used as an antifreeze and anti-scaler in the oil and gas industry, is abundant during winter inversions in the Uintah Basin and may also be a significant precursor to ozone production. Total VOC and methanol emissions from produced water ponds during winter were estimated to be 178 and 83 tons month-1, respectively, for the entire Uintah Basin.
NSDL National Science Digital Library
If you want to add a touch of elegance to your chaconne, gavotte, or just a plain old ditty, LilyPond 2.11 is an application worth taking an interest in. Visitors can use the application to typeset popular music, or also have the program convert existing music notation into a format that is both crisp and elegant. The LilyPond site contains an introduction, a FAQ section, and a few testimonials. This version is compatible with all operating systems.
Radioecological implications of the Par Pond drawdown
Hickey, H. [Westinghouse Savannah River Co., Aiken, SC (United States); Whicker, F.W. [Savannah River Ecology Lab., Aiken, SC (United States)
The drawdown of the Par Pond reservoir created dramatic alterations in this formerly stable lentic ecosystem. In addition, the radiation environment at Par Pond has changed significantly because of the exposure of Cesium 137-contaminated sediments and the appearance of new transport pathways to the terrestrial environment. In response to this situation, SREL was asked to study the radioecological implications of the reservoir drawdown. This report contains the objectives, methods, and results of the SREL study.
Material Selection Considerations for Solar Ponds
NASA Technical Reports Server (NTRS)
Sastri, S.; Vaidyanathan, T. K.; Marsh, H. E.; French, R. L.
Among the various candidate materials tested, stainless steel shows the best potential for applications as heat exchanger components in solar ponds. Even stainless steel may lead to pitting type of corrosion. Weight loss measurements are probably unsatisfactory for corrosion evaluation in solar pond situations. Also included are the results from the potentiodynamic anodic polarization analysis, corrosion rate calculation via corrosion behavior diagrams, and immersion weight loss measurements.
Hydrogeologic maps of proposed flood detention area, Green Swamp area, Florida
Rutledge, A.T.; Grubb, Hayes F.
Information about the hydrogeology of that part of the Green Swamp area which has been designated by Southwest Florida Water Management District as the Flood Detention Area is given on seven maps. The maps show (1) core-hole numbers, (2) sand thickness, (3) clay thickness, (4) clay vertical hydraulic conductivity, (5) clay leakance, (6) depth to Floridan aquifer, and (7) altitude of top of Floridan aquifer. The data were obtained from 85 core holes drilled in 1977 and from 24 core hole drilled previously. The 127 square-mile study area is part of the headwaters of the Withlacooche River and the Little Wthlacoochee River. The data will be useful in future water-resources planning and in a concurrent interpretive study of the Green Swamp area. (Woodard-USGS)
Energy program of requirements for a new detention center -- Energy design criteria for prisons
Tseng, P.C.; Stanton-Hoyle, D. [Montgomery County Government, Rockville, MD (United States). Capitol Projects Management Division; Krout, R. [HEC Inc., Arlington, VA (United States)
Correctional facilities are typically ``energy hogs.`` Prison facilities normally have the highest energy costs and are the most energy-intensive building type for local and state jurisdictions. The 24-hour operation and continuous, year-round use of these facilities means very high maintenance and operating costs. To minimize future utility costs, an integrated energy planning approach for a new detention facility is highly desirable at the earliest stages of programming. When energy-efficiency criteria are integrated early in a planning and design process, significant energy and operating cost savings can be achieved with little or no additional construction costs. A planning document in the form of an energy program of requirements (EPOR) can be incorporated into the solicitation of design proposals and can be very effective in ensuring energy-efficient design for a new facility.
Studies on membrane viscosity stabilized solar pond
Taga, M. (Kinki Univ., Osaka (Japan)); Matsumoto, T.; Ochi, T. (Osaka Prefectural College of Technology (Japan))
In this nonsalt type of solar pond, the nonconvecting layer is composed of a viscous polymer solution partitioned by a number of transparent films. An advantage of partitioning is that a thinner polymer solution can be used and that the light transmittance increases. Results of experimental and theoretical investigations on the performance of this solar pond are summarized as follows: (1) ionized polyacrylamide solution was chosen as the thickener based on tests about solubility, viscosity, light transmittance and stability; (2) the critical temperature difference for the onset of convection in the polymer layer ({Delta}T/L){sub cr} ({degree}C/m) was given by the following formula based on the measurements in various thicknesses of the polymer layers (L) (m) and various concentrations ({zeta}) (%), ({Delta}T/L){sub cr} = (55 {minus} 185 lnL)exp(4.66 L{sup 0.505} ln{zeta}); (3) an outdoor model pond, 200 {times} 150 cm surface and 100 cm depth, was constructed in Osaka. Four types of model ponds were tested, and the availability of membrane type with partition films was confirmed; (4) the theoretical temperature rise of the pond using a one-dimensional model was calculated by solving the equations of the heat balance in the pond. As a result, the optimum values of thickness of polymer layer and number of films was determined.
Analysis of seepage from a pond
NASA Astrophysics Data System (ADS)
Mishra, Govinda C.; Saha, Amitava; Kansal, Mitthan L.; Gupta, Ravi P.
A semi-analytical solution has been derived for predicting the time of emptying a pond due to seepage. The time for the seeping water to reach the water table since the pond was initially filled has been calculated applying the Green-Ampt infiltration theory. The recharge rate after the wetting front joins the water table has been computed using a non-linear relationship between seepage head and recharge rate proposed by earlier investigators. The maximum rise in the water table beneath the center of the pond consequent to the time-varying recharge is calculated applying kernel coefficients obtained from solution of the linearized Boussinesq equation. It was observed that a pond with 50-m initial diameter at the water surface and 3-m maximum depth of water is dry after 168 days, where the subsoil is sandy clay. If the subsoil happens to be clay, the depth of water in the pond at the end of 9 months, i.e., after completion of the non-monsoon period, is 0.62 m. The maximum mound heights beneath the pond for constant recharge rate and uniform recharging area calculated from the present solution compare well with existing numerical as well as analytical solutions.
Experimental and numerical analysis of sodium-carbonate salt gradient solar-pond performance under simulated solar-radiation
Hüseyin Kurt; Mehmet Ozkaymak; A. Korhan Binark
The objective of this study is to investigate experimentally and theoretically whether sodium carbonate (Na2CO3) salt is suitable for establishing a salinity gradient in a salt-gradient solar-pond (SGSP). For this purpose, a small-scale prismatic solar-pond was constructed. Experiments were conducted in the laboratory under the incident radiation from two halogen-lamps acting as a solar simulator. Furthermore, a one-dimensional transient mathematical
A case study of enteric virus removal and insights into the associated risk of water reuse for two wastewater treatment pond systems in Bolivia.
Symonds, E M; Verbyla, M E; Lukasik, J O; Kafle, R C; Breitbart, M; Mihelcic, J R
Wastewater treatment ponds (WTP) are one of the most widespread treatment technologies in the world; however, the mechanisms and extent of enteric virus removal in these systems are poorly understood. Two WTP systems in Bolivia, with similar overall hydraulic retention times but different first stages of treatment, were analyzed for enteric virus removal. One system consisted of a facultative pond followed by two maturation ponds (three-pond system) and the other consisted of an upflow anaerobic sludge blanket (UASB) reactor followed by two maturation (polishing) ponds (UASB-pond system). Quantitative polymerase chain reaction with reverse transcription (RT-qPCR) was used to measure concentrations of norovirus, rotavirus, and pepper mild mottle virus, while cell culture methods were used to measure concentrations of culturable enteroviruses (EV). Limited virus removal was observed with RT-qPCR in either system; however, the three-pond system removed culturable EV with greater efficiency than the UASB-pond system. The majority of viruses were not associated with particles and only a small proportion was associated with particles larger than 180 ?m; thus, it is unlikely that sedimentation is a major mechanism of virus removal. High concentrations of viruses were associated with particles between 0.45 and 180 ?m in the UASB reactor effluent, but not in the facultative pond effluent. The association of viruses with this size class of particles may explain why only minimal virus removal was observed in the UASB-pond system. Quantitative microbial risk assessment of the treated effluent for reuse for restricted irrigation indicated that the three-pond system effluent requires an additional 1- to 2-log10 reduction of viruses to achieve the WHO health target of <10(-4) disability-adjusted life years (DALYs) lost per person per year; however, the UASB-pond system effluent may require an additional 2.5- to 4.5-log10 reduction of viruses. PMID:25129566
Investigation of salt stratified solar pond operational characteristics
NASA Astrophysics Data System (ADS)
Newell, T. A.
Operational characteristics and economic feasibility of the salt stratified solar pond are examined. A one dimensional transient numerical model is developed which offers flexibility for pond property specifications, thermal energy performance prediction, and thermal energy extraction uses. Stability of the gradient zone of a salt stratified pond is one of the most important areas of pond operational feasibility. A criterion for the operational state of a solar pond which constrains the allowable salinity and temperature profiles is developed and extended for use as a design tool for solar ponds. The decanting method of thermal energy extraction is most feasible for large scale ponds. A two dimensional numerical fluid dynamics program has been developed for this purpose and examines the effect of inlet and outlet jet placement in the storage zone of a pond. A simple laboratory experiment for qualitative investigations of solar pond phenomena is described.
Technology Transfer Automated Retrieval System (TEKTRAN)
Phytoplankton are the primary producers and consumers of dissolved oxygen in earthen channel catfish (Ictalurus punctatus) production ponds. In a pond with a dense plankton bloom, dissolved oxygen (DO) concentration can become supersaturated during daylight hours and fall to 10% of saturation or les...
Technology Transfer Automated Retrieval System (TEKTRAN)
Long-term temporal succession changes in nutrients, phytoplankton and zooplankton have not been previously investigated in aquaculture ponds. This study analyzed relationships of pond age with nutrients, zooplankton and phytoplankton populations, and incidence of off-flavor occurrence. Nutrient le...
Design methodology for a salt gradient solar pond coupled with an evaporation pond
K. R. Agha; S. M. Abughres; A. M. Ramadan
This paper presents the results of a simple mathematical model for predicting the ratio of the evaporation pond (EP) area to that of a Salt Gradient Solar Pond (SGSP) area. The EP idea provides a very attractive method of salt recycling by evaporation, especially in areas of high rates of evaporation and low rates of rain as it is the
Rapid Sand Filtration for Best Practical Treatment of Domestic Wastewater Stabilization Pond Effluent
ERIC Educational Resources Information Center
Boatright, D. T.; Lawrence, C. H.
The technical and economic feasibility of constructing and operating a rapid sand filtration sewage treatment system as an adjunct to a waste water stabilization pond is investigated. The study concludes that such units are within the technical and economic constraints of a small community and comply with the EPA criteria. (BT)
Invasion by the tufted duck Aythya fuligula into a pond area: implications of diffuse competition
Roland Brandl; Klaus Schmidtke
During the 20th century the Tufted Duck (Aythya fuligula) showed an expansion of its distribution to the west in Europe. We present data for a small fish pond system in northern Bavaria indicating that the Tufted Duck is not fully integrated in the already established communities. The possible mechanism producing this effect seems to be "diffuse competition" by a set
Degradation, Fate and Bioavailability of Sulfamethazine in Pond Water and Sediment
Technology Transfer Automated Retrieval System (TEKTRAN)
Antibiotics from animal agriculture are found in surface waters and stream sediments. We investigated the degradation and fate of sulfamethazine in small pond water and sediment microcosms. Sulfamethazine [14C-phenyl] was added to the water phase directly, or in a dilute swine manure solution that s...
Sport fishery potential of power plant cooling ponds: Final report
Heidinger, R.C.; Lewis, W.M.
This research was undertaken to determine if cooling ponds could serve as habitat for several coolwater fish species and also to evaluate the potential use of cooling ponds as nursery areas for receiving waters. The work was conducted on two cooling ponds in northern Illinois. Walleye (Stizostedion vitreum), muskellunge (Esox masquinongy), striped bass (Morone saxatilis) fingerlings, and adult threadfin shad (Dorosoma petenense) were stocked into both cooling ponds. The hybrids between the striped bass and white bass (M. chrysops) had been previously stocked into Collins Pond. Smallmouth bass (Micropterus dolomieui) fingerlings and larval striped bass and walleye were stocked in Dresden Pond. Several sampling techniques including seining, electrofishing, and rotenoning were used to monitor growth and survival of stocked species. In addition, escapement of stocked and indigenous species was monitored at the Dresden Pond spillway. Walleye, muskellunge, striped bass and hybrid striped bass exhibited excellent growth in Collins Pond as did smallmouth bass in Dresden Pond. One of the primary differences between an open system (such as Dresden Pond) and a closed system (such as Collins Pond) is the potential that the open system has to serve as a fish nursery area for receiving waters. The stocking of ''coolwater'' species in a closed type system such as Collins Pond is an effective way to control and maintain selected sport species. Dresden Pond was not open to public fishing during this study, but Collins Pond developed an excellent sport fishery as a result of these stockings.
Pond Dynamics and the Health of the Aquatic Residents The water quality is constantly changing in a pond. The animals, such as fish, living in the pond are
in a pond. The animals, such as fish, living in the pond are able to acclimate to some of these changes be monitored in order to maintain the health of the aquatic animals living in a pond include measurement, the oxygen levels decline because photosynthesis has stopped. Since plant and animal respiration occurs
Impact of beaver ponds on river discharge and sediment deposition along the Chevral River, Ardennes, Belgium
NASA Astrophysics Data System (ADS)
Nyssen, Jan; Frankl, Amaury; Pontzeele, Jolien; De Visscher, Maarten; Billi, Paolo
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 mł 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.
Gradient zone-boundary control in salt-gradient solar ponds
Hull, J.R.
A method and apparatus for suppressing zone boundary migration in a salt gradient solar pond includes extending perforated membranes across the pond at the boundaries, between the convective and non-convective zones, the perforations being small enough in size to prevent individual turbulence disturbances from penetrating the hole, but being large enough to allow easy molecular diffusion of salt thereby preventing the formation of convective zones in the gradient layer. The total area of the perforations is a sizeable fraction of the membrane area to allow sufficient salt diffusion while preventing turbulent entrainment into the gradient zone.
A review of the salt-gradient solar pond technology
NASA Technical Reports Server (NTRS)
Lin, E. I. H.
The state of the salt-gradient solar pond technology is reviewed. Highlights of findings and experiences from existing ponds to data are presented, and the behavior, energy yield, operational features, and economics of solar ponds are examined. It is concluded that salt-gradient solar ponds represent a technically feasible, environmentally benign, and economically attractive energy producing alternative. In order to bring this emerging technology to maturity, however, much research and development effort remains to be undertaken. Specific R&D areas requiring the attention and action of technical workers and decision-makers are discussed, both from the perspectives of smaller, thermally-oriented ponds and larger, electricity generating ponds.
Metal Cycling in Polymictic Suburban Retention Ponds
NASA Astrophysics Data System (ADS)
Segal, C. A.; Bushey, J. T.; Torgersen, T.
Stratified conditions in lakes have been demonstrated to enhance metal species mobilization as well as the potential for mercury methylation. However, few studies have been conducted in shallow engineered systems. Although each system is relatively small in area, the overall number of such engineered systems is large (and increasing) and warrants consideration within overall landscape nutrient cycling. Previous research has documented strong diel stratification cycles and the frequent development of anoxia within the bottom waters of such polymictic systems compared with larger, dimictic lakes. We examined the impact of polymixis and the shorter hydraulic residence time on the bioavailability and the downstream transport of Hg species and other trace metals. Filtered and unfiltered lake water samples were collected at 15 and 50 cm above the sediment as well as the surface of the 1-m deep Mirror Lake retention pond on the University of Connecticut Storrs campus. Additional samples were collected from the lake outlet under baseflow and elevated discharge conditions, including the capture of initial mobilization during precipitation events. Samples were analyzed for Hg speciation as well as dissolved organic carbon (DOC), total suspended solids, cations (including Cu, Zn and Pb) and anions. We measured stage height at the lake outlet to calculate flux. Lake total Hg (THg) concentrations were generally less than 4 ng/L with the majority in the particulate phase. Outlet THg increased to 32 ng/L and dissolved THg increased to 1.2 ng/L during high flow events likely due to enhanced mobilization of particulates from the sediment and runoff from impervious surfaces, respectively. In contrast, DOC concentrations decreased as runoff contributions increased and were not correlated with dissolved THg. In addition, THg concentrations increased following copper algaecide applications, possibly due to re- suspension in the water column of biotic material.
Sunlight, season, snowmelt, storm, and source affect E. coli populations in an artificially ponded stream.
Whitman, Richard L; Przybyla-Kelly, Katarzyna; Shively, Dawn A; Nevers, Meredith B; Byappanahalli, Muruleedhara N
Reducing fecal indicator bacteria, such as Escherichia coli (E. coli), in streams is important for many downstream areas. E. coli concentrations within streams may be reduced by intervening ponds or wetlands through a number of physical and biological means. A section of Dunes Creek, a small coastal stream of southern Lake Michigan, was impounded and studied for 30 months from pre-through post-construction of the experimental pond. E. coli reduction became more predictable and effective with pond age. E. coli followed the hydrograph and increased several-fold during both rainfall and snowmelt events. Seasonally, the pond was more effective at reducing E. coli during summer than winter. Late summer, non-solar reduction or inactivation of E. coli in the pond was estimated at 72% and solar inactivation at 26%. E. coli DNA fingerprinting demonstrated that the winter population was genetically more homogeneous than the summer population. Detection of FRNA coliphages suggests that there was fecal contamination during heavy rain events. An understanding of how environmental factors interact with E. coli populations is important for assessing anticipated contaminant loading and the reduction of indicator bacteria in downstream reaches. PMID:18031792
Anaerobic pond treatment of wastewater containing sulphate.
Rajbhandari, B K; Annachhatre, A P
Anaerobic ponds are usually used for treatment of industrial and agricultural wastes which contain high organic matter and sulphate. Competition for substrate between sulphate reducing bacteria and methane producing archaea, and the inhibitory effects of sulphide produced from microbial sulphate reduction reported in the literature varied considerably. In this research, a laboratory scale column-in-series anaerobic pond reactor, consisting of five cylindrical columns of acrylic tubes, was operated to evaluate the effect of COD and sulphate ratio on pond performance treating wastewater containing high organic matter and sulphate from a tapioca starch industry. The result depicted that no adverse effect of COD:SO4 ratios between 5 and 20 on overall COD removal performance of anaerobic pond operated with organic loading rate (OLR) of 150 to 600 g COD/m3d. Sulphate reducing bacteria could out-compete methane producing archaea for the same substrate at COD:SO4 ratio equal to or lower than 5 and OLR greater than 300 g COD/m3d. Sulphide inhibition was not observed on overall performance of pond up to an influent sulphate concentration of 650 mg/L. PMID:17591216
Site-Specific Research Conducted in Support of the Salton Sea Solar Pond Project - FY 1982 Report
NASA Technical Reports Server (NTRS)
French, R. L.; Marsh, H. E.; Roschke, E. J.; Wu, Y. C.
The design and operation of a salt-gradient solar pond power plant at the Salton Sea presents problems not encountered at small research ponds that were built in the United States. The specific characteristics of the Salton Sea site and the desire to construct the pond using the local clay as a sealant represent major deviations from previous solar pond experience. The site-specific research in support of the plant design is described. The research activity included validation of the spectrophotometric light transmission measurement technique, a search for options for clarifying the turbid and colored water of the Salton Sea, development of water clarification specifications in terms common to industry practice, quantification of gas production from microbiological reactions in the ground, a determination of the combined effects of temperature and salinity on the permeation of the local clays, and a preliminary evaluation of material corrosion.
Effects of urbanization on three ponds in Middleton, Wisconsin
House, Leo B.
A digital hydrologic model was used to simulate the effects of future residential development on pond inflow volumes and resulting water levels of three ponds in Middleton, Wisconsin. The model computed the daily water budget and the resulting water level for each pond. The results of the model calibration are presented in the report, along with the existing watershed hydrologic conditions and runoff volumes for the 1982 study period. Data was collected during 1982 to claibrate the model; the data included pond stage, ground-water levels, precipitation and other meteorological characteristics. In addition, water-quality samples were collected at each pond to characterize the water quality. Simulation of pond levels with the 1982 rainfall and fully developed watersheds did not result in stages greater than those observed in 1982. Simulation of pond levels with rainfall having a 20-year recurrence interval (1978) and hypothetical, fully developed watersheds resulted in maximum pond stages above those observed in 1982. Peak stage of Tiedeman 's Pond would increase by 2.77 feet, Stricker 's Pond by 3.91 feet, and Esser 's Pond by 1.44 feet. Simulation of pond levels with an estimated 100-year rainfall and hyopthetical, fully developed watersheds would result in peak stage increases of 5.30, 5.32, and 1.97 feet above the peak 1982 observed stages for Tiedeman's, Stricker's, and Esser 's Ponds, respectively. (USGS)
Development of a solar gel pond. Final report
Wilkins, E.S.
This work concentrated on developing a detailed design and cost estimate for a pilot scale gel pond, as a step towards the final scale up to a commercial size pond. The existing demonstration pond has been used to generate data to aid the design of the semi-pilot scale pond. The design has been carried out specifically to the requirements of the Albuquerque Journal and the results show that a pond area of 400m/sup 2/ and depth of 4.0m would be appropriate for their requirements. As a design tool for future requirements of any pond size, a computer code was developed by modifying existing models to suit the gel pond configuration. This code contains adequate information to predict the pond temperatures and heat loads throughout the year and thereby design a gel pond for any requirement. An economic analysis of 400m/sup 2/, 4m deep gel pond has also been performed. This analysis shows that the gel pond is superior for investment as calculated by rate of return and pay back period in comparison to the salt gradient pond and the flat plate collectors. A study of heat pipes has also been included in this work to demonstrate the mutual compatibility of heat pipes and the gel pond as an energy saving system.
Stabilising solar ponds by utilising porous materials
NASA Astrophysics Data System (ADS)
Hill, A. A.; Carr, M.
The linear instability of a solar pond containing porous material in the lower convective zone (LCZ) is investigated. It is found that, in general, for physically realistic values, solar ponds that contain porous material are more stable than ones that do not. Interestingly, it is found that the percentage of porous material contained in the LCZ does not stabilise the system in a linear fashion and, in particular, approximately 60% of porous material in the LCZ appears to optimise the maximum temperature that can be stored in the LCZ provided the proportion of heat flux extracted at the base of the pond, f, is held fixed at a physically realistic value of f=0.5. When f is varied it is found that there is a critical value of f = 0.6 below which inclusion of porous material stabilises the system but above which it does not.
33 CFR 117.598 - Eel Pond Channel.
Code of Federal Regulations, 2012 CFR
...DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.598 Eel Pond Channel. The following requirements...Pond (Water Street) drawbridge at mile 0.0 at Falmouth, Massachusetts. (a) The draw shall open at all times as...
33 CFR 117.598 - Eel Pond Channel.
Code of Federal Regulations, 2011 CFR
...DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.598 Eel Pond Channel. The following requirements...Pond (Water Street) drawbridge at mile 0.0 at Falmouth, Massachusetts. (a) The draw shall open at all times as...
33 CFR 117.598 - Eel Pond Channel.
Code of Federal Regulations, 2010 CFR
...DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.598 Eel Pond Channel. The following requirements...Pond (Water Street) drawbridge at mile 0.0 at Falmouth, Massachusetts. (a) The draw shall open at all times as...
33 CFR 117.598 - Eel Pond Channel.
Code of Federal Regulations, 2013 CFR
...DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.598 Eel Pond Channel. The following requirements...Pond (Water Street) drawbridge at mile 0.0 at Falmouth, Massachusetts. (a) The draw shall open at all times as...
33 CFR 117.598 - Eel Pond Channel.
Code of Federal Regulations, 2014 CFR
...DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.598 Eel Pond Channel. The following requirements...Pond (Water Street) drawbridge at mile 0.0 at Falmouth, Massachusetts. (a) The draw shall open at all times as...
Paris-Sud XI, Université de
of the 1st pond will be spread each day on four Sludge Dewatering Reed Bed Filters(SDRBF). The beginning sandfilters,pilots, rain water, sludge dewatering reed bedsfilters,waste stabilisation ponds, wastewater
Salt-gradient solar pond for heating a farm residence
Sidles, P.H.; Kratz, R.A.
A salt-gradient solar pond, designed to provide heat and domestic hot water for a farm residence, has been constructed at an agricultural museum near Des Moines, Iowa. This pond has been operational for about two years. The farm residence is under construction. Maintenance problems and costs for the solar pond have been minimal and it appears that salt-gradient solar ponds can, under favorable conditions, compete with other energy resources for wide-scale application. Construction and operation of the pond is described, with emphasis on the required scope of pond maintenance. A particular problem with wind-induced pond instabilities is described. Data are presented which illustrate the annual sinusoidal temperature variations predicted for solar pond behavior.
Measurement of solar radiation transmission in solar ponds
Enshayan, K.
Knowledge of the nature of solar radiation transmission into the pond is essential to improve performance and operation of solar ponds. While several analytical descriptions of solar radiation penetration in solar ponds exist, there are very few studies of the subject that include in-pond measurement of solar irradiance to verify the analytical predictions. The overall goal of this research was to measure the fate of the incident solar radiation as it penetrated a solar pond. Thermal and optical corrections as well as procedures for successful in-pond measurements were developed. Detailed pictures of the underwater radiative budget of several solar ponds were determined. The effects of pond water clarity on radiation transmission were investigated.
Carbon, nitrogen, and phosphorus budget in scampi (Macrobrachium rosenbergii) culture ponds.
Sahu, Bharat Chandra; Adhikari, Subhendu; Mahapatra, Abhijit S; Dey, Lambodar
Experiments were conducted for the study of nutrient budget in ten farmer's ponds (0.2-0.5 ha) in Orissa, India with a mean water depth of 1.0-1.2 m. Scampi (Macrobrachium rosenbergii) were stocked in these ponds at stocking density of 3.75-5.0/m(2). The average initial body weight of scampi was 0.02 mg. The culture period was for 4 months. Feed was the main input. Total feed applied to these ponds ranged from 945 to 2261 kg pond/cycle (crop). The feed conversion ratio varied 1.65 to 1.78. In addition to feed, rice straw, urea, and single super phosphate were applied to these ponds in small amounts for plankton production. At harvest time, the average weight of scampi varied from 60-90 g. The budget showed that feed was the major input of nitrogen (N), phosphorus (P), and carbon in these ponds. The inorganic fertilizer (urea and single super phosphate), organic fertilizer (rice straw and yeast extract), and inlet water, either from the initial fills or from rainwater, were the source of all other N, P, and organic carbon (OC) to these ponds. Total N applied to these ponds through all these inputs ranged from 44.45 to 103.98 kg N per crop, 12.23 to 28.79 kg P per crop, and from 381.54 to 905.22 kg OC per crop, respectively. Among all the inputs, feed alone accounted for 95.34 % N, 97.98 % P, and 94.27 % OC, respectively. Recovery of 16.34 to 38.66 kg N (average 29.27 kg), 1.28 to 3.02 kg P (average 2.29 kg), and 63.21 to 149.51 kg OC (average 113.20 kg), respectively, by the scampi harvest were observed in these ponds. Thus, harvest of scampi accounted for recovery of 35.18 to 39.01 (average 36.85%) of added N, 10.09 to 10.97 (average 10.44%) of added P, and 7.57 to 17.12 (average 16.34%) of added OC, respectively. PMID:23832231
Sealing Ponds and Lakes with Bentonite
Lesikar, Bruce J.
and vegetation from the bottom of the pond. For best results, have the soil just moist enough to be plowed or disked easily. Plow or disk the pond bottom and drag the surface until it is smooth. This preparation makes the top 4 to 6 inches of soil uniform so...-resistant layer that forms reduces the seepage from these areas. Figure 4 shows one way of apply- ing bentonite in this manner. igure 4. Sprinkle method. The sprinkle method is less effective than other methods. Accurate, uniform placement of ben- tonite...
Alabama's Hatter's Pond called a classic field
McCaslin, J.C.
Delineation of the combination (structural-stratigraphic) hydrocarbon traps in southern Alabama's Hatter's Pond field demands a thorough understanding of the facies distribution, diagenesis, and structural relations of the area. The field's trapping mechanism is highly complex. In addition to the salt movement associated with normal faulting, the porosity distribution - and hence reservoir development - is facies-selective and is significantly altered by the field's diagenetic changes. Hatter's Pond is one of the most important fields in the Smackover and Norphlet producing areas. The Jurassic section of southwest Alabama probably holds most of that state's oil and gas.
Direct Experimental Assessment of Microbial Activity in North Pond Sediments
T. G. Ferdelman; A. Picard; M. Morando; W. Ziebis
North Pond, an isolated sediment pond located at 22°45'N on the western flank of the Mid-Atlantic Ridge, offered the opportunity to study microbial activities in deeply-buried low-activity sediments. About 8 x 15 km in size with sediment maximum thickness of about 300 m, North Pond is completely surrounded by exposed 7 Ma old basement. North Pond lies above the carbonate
Desalination coupled with salinity-gradient solar ponds
Huanmin Lu; John C. Walton; Andrew H. P. Swift
Thermal desalination by salinity-gradient solar ponds (SGSP) is one of the most promising solar desalination technologies. Solar ponds combine solar energy collection with long-term storage and can provide reliable thermal energy at temperature ranges from 50 to 90°C. Solar-pond-powered desalination has been studied since 1987 at the El Paso Solar Pond Project, El Paso, Texas. From 1987 to 1992, the
Desalination coupled with salinity-gradient solar ponds
Huanmin Lu; John C. Walton; Andrew H. P. Swift
Thermal desalination by salinity-gradient solar ponds (SGSP) is one of the most promising solar desalination technologies. Solar ponds combine solar energy collection with long-term storage and can provide reliable thermal energy at temperature ranges from 50 to 90°C. Solar-pond-powered desalination has been studied since 1987 at the E1 Paso Solar Pond Project, El Paso, Texas. From 1987 to 1992, the
Practical operation and maintenance of a solar pond for greenhouse heating
R. P. Fynn; T. H. Short; S. A. Shah
Construction started on a Solar Pond in 1975. Problems with pond leaks and eventual liner failure resulted in a redesign and rebuilding of the pond in 1977. Since then the pond has been operated continuously and used to heat an adjacent greenhouse. Procedures for the pond gradient establishment and maintenance, pond clarity and equipment maintenance have been developed. Methods of
Water quality, phytoplankton and zooplankton of Par Pond and Pond B. Volume 2. Phytoplankton. Final report, January 1984-June 1985
Chimney, M.J.; Cody, W.R.; Starkel, W.M.
This document reports on the Par Pond and Pond B phytoplankton community. The objectives of this study were to (1) characterize the biological communities and environmental conditions in Par Pond and Pond B; (2) assess the impact and significance of entrainment losses of plankton at the Par Pond pumphouse; (3) assess the impact of heated discharge on the biotic communities throughout the reservoir; and (4) help determine if Par Pond maintains an indigenous balanced biological community as defined in state and federal regulations. A total of 368 phytoplankton taxa, representing all the major taxonomic groups characteristic of North American freshwaters, were identified from Par Pond and Pond B during this study (73 Bacillariophyta, 166 Chlorophyta, 30 Chrysophyta, 5 Cryptophyta, 47 Cyanophyta, 18 Euglenophyta, 11 phytoflaggelates and 18 Pyrrophyta).
The refreezing of melt ponds on Arctic sea ice
NASA Astrophysics Data System (ADS)
Flocco, Daniela; Feltham, Daniel L.; Bailey, Eleanor; Schroeder, David
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%.
Does size matter? The relationship between pond area and biodiversity
Beat Oertli; Dominique Auderset Joye; Emmanuel Castella; Raphaëlle Juge; Diana Cambin; Jean-Bernard Lachavanne
Larger areas support more species. To test the application of this biogeographic principle to ponds, we consider the relationship between size and diversity for 80 ponds in Switzerland, using richness (number of species) and conservation value (score for all species present, according to their degree of rarity) of aquatic plants, molluscs (Gastropoda, Sphaeriidae), Coleoptera, Odonata (adults) and Amphibia. Pond size
Transformation of chloramphenicol and oxytetracycline in aquaculture pond sediments
Transformation processes of two antibiotics, chloramphenicol (CM) and oxytetracycline (OTC), in aquaculture pond sediments collected from a freshwater eel pond and a marine shrimp pond were investigated. The sorption rates of CM in the freshwater and marine sediment slurries (10%, wt\\/vol) were 4% and 2%, respectively. In contrast, the sorption rates of OTC in the freshwater and marine sediment slurries
HABITAT RELATIONSHIPS OF WATERFOWL BROODS ON SOUTH DAKOTA STOCK PONDS GENB D. MAcK. AND LESTER D HABITAT RELATIONSHIPS OF WATERFOWL BROODS ON SOUTH DAKOTA STOCK PONDSl Over 88,000 stock watering ponds natural waterways; many of these ponds are of considerable value to waterfowl production (Bue et aI. 1952
Post-Emergence Behavior of Hatchling Western Pond Turtles
Rosenberg, Daniel K.
Post-Emergence Behavior of Hatchling Western Pond Turtles www.oregonwildlife.org #12;2 Post-Emergence Behavior of Hatchling Western Pond Turtles Final Report August 2010 Daniel K. Rosenberg Oregon Wildlife: Rosenberg, D. K. and R. Swift. 2010. Post-emergence behavior of hatchling western pond turtles. Oregon
A simple method to establish salt gradient solar ponds
F. Zangrando
A technique is presented for establishing a salinity gradient for salt gradient solar ponds. The procedure consists of partially filling the pond with high salinity brine; fresh water is then pumped through a diffuser which is immersed in the upper portion of the existing solution. The technique does not require additional storage tanks and may be applicable to ponds of
Optimization of solar pond electrical power generation system
R. A. Haj Khalil; B. A. Jubran; N. M. Faqir
This paper investigates the potential of using a solar pond for the generation of electricity in Jordan. A solar pond power plant model is presented to simulate and optimize such a system under the Jordanian climatic conditions. A Rankine cycle analysis is carried out using an environmentally friendly working fluid, Refrigerant 134a.It was found that using a solar pond for
First-year sea ice melt pond fraction estimation from dual-polarisation C-band SAR - Part 1: In situ observations
NASA Astrophysics Data System (ADS)
Scharien, R. K.; Landy, J.; Barber, D. G.
Understanding the evolution of melt ponds on Arctic sea ice is important for climate model parameterisations, weather forecast models and process studies involving mass, energy and biogeochemical exchanges across the ocean-sea ice-atmosphere interface. A field campaign was conducted in a region of level first-year sea ice (FYI) in the central Canadian Arctic Archipelago (CAA), during the summer of 2012, to examine the potential for estimating melt pond fraction (fp) from satellite synthetic aperture radar (SAR). In this study, 5.5 GHz (C-band) dual co- (HH + VV - horizontal transmit and horizontal receive + vertical transmit and vertical receive) and cross-polarisation (HV + HH - horizontal transmit and vertical receive + horizontal transmit and horizontal receive) radar scatterometer measurements of melt-pond-covered FYI are combined with ice and pond properties to analyse the effects of in situ physical and morphological changes on backscatter parameters. Surface roughness statistics of ice and ponds are characterised and compared to the validity domains of the Bragg and integral equation model (IEM) scattering models. Experimental and model results are used to outline the potential and limitations of the co-polarisation ratio (VV / HH) for retrieving melt pond information, including fp, at large incidence angles (?35°). Despite high variability in cross-polarisation ratio (HV / HH) magnitudes, increases at small incidence angles (<30°) are attributed to the formation of ice lids on ponds. Implications of the results for pond information retrievals from satellite C-, L- and P-band SARs are discussed.
Vegetation establishment and evolution in four ponds that received sewage and wastewater in a portion of the Olezoa wetland complex, Yaounde, Cameroon, central Africa
Atekwana, E.A. (Western Michigan Univ., Kalamazoo, MI (United States). Dept. of Geology); Agendia, P.L. (Univ. of Yaounde (Cameroon). Dept. of Plant Biology)
A study of the spatial and temporal changes in the pattern and distribution of tropical wetland vegetation in four ponds that received sewage and wastewater discharge, was undertaken for a small wetland ecosystem in the Olezoa drainage basin in Yaounde, Cameroon. More than 25 years of nutrient loading has led to the eutrophication and subsequent establishment of wetland vegetation in these ponds. Estimated free water surface areas of the ponds in 1964, 1976, and 1986 and 1992 determined from digitized aerial photographs and field measurements suggests a decline of 70 to 100% in the pond surface areas due to invasion and colonization by plants. The rate of pond surface decline and vegetation development is correlated with the construction of sewage plants and the discharge of untreated sewage and wastewater into the ponds. The main wetland plants that are established in the ponds consist of aquatic species Nymphae lotus, Enhydra fluctuants, Pistia stratiotes, Commelina sp., Ipomea aquatica and terrestrial species Echinochloa sp., Thalia welwitschii, Polygonum senegalense, Leersia haxandra and Cyperus papyrus. The pattern of wetland plant succession that resulted within each pond is correlated to the timing, duration and magnitude of sewage and wastewater discharge into the wetland complex.
Accumulated sediments in a detention basin: chemical and microbial hazard assessment linked to hydrological processes.
Sébastian, C; Barraud, S; Ribun, S; Zoropogui, A; Blaha, D; Becouze-Lareure, C; Kouyi, G Lipeme; Cournoyer, B
Accumulated sediments in a 32,000-m(3) detention basin linked to a separate stormwater system were characterized in order to infer their health hazards. A sampling scheme of 15 points was defined according to the hydrological behaviour of the basin. Physical parameters (particle size and volatile organic matter content) were in the range of those previously reported for stormwater sediments. Chemical analyses on hydrocarbons, PAHs, PCBs and heavy metals showed high pollutant concentrations. Microbiological analyses of these points highlighted the presence of faecal indicator bacteria (Escherichia coli and intestinal enterococci) and actinomycetes of the genus Nocardia. These are indicative of the presence of human pathogens. E. coli and enterococcal numbers in the sediments were higher at the proximity of the low-flow gutter receiving waters from the catchment. These bacteria appeared to persist over time among urban sediments. Samples highly contaminated by hydrocarbons were also shown to be heavily contaminated by these bacteria. These results demonstrated for the first time the presence of Nocardial actinomycetes in such an urban context with concentrations as high as 11,400 cfu g(-1). PMID:24337992
Benefits of Selected Physical Exercise Programs in Detention: A Randomized Controlled Study
Battaglia, Claudia; di Cagno, Alessandra; Fiorilli, Giovanni; Giombini, Arrigo; Fagnani, Federica; Borrione, Paolo; Marchetti, Marco; Pigozzi, Fabio
The aim of the study was to determine which kind of physical activity could be useful to inmate populations to improve their health status and fitness levels. A repeated measure design was used to evaluate the effects of two different training protocols on subjects in a state of detention, tested pre- and post-experimental protocol.Seventy-five male subjects were enrolled in the studyand randomly allocated to three groups: the cardiovascular plus resistance training protocol group (CRT) (n = 25; mean age 30.9 ± 8.9 years),the high-intensity strength training protocol group (HIST) (n = 25; mean age 33.9 ± 6.8 years), and a control group (C) (n = 25; mean age 32.9 ± 8.9 years) receiving no treatment. All subjects underwent a clinical assessmentandfitness tests. MANOVA revealed significant multivariate effects on group (p < 0.01) and group-training interaction (p < 0.05). CRT protocol resulted the most effective protocol to reach the best outcome in fitness tests. Both CRT and HIST protocols produced significant gains in the functional capacity (cardio-respiratory capacity and cardiovascular disease risk decrease) of incarcerated males. The significant gains obtained in functional capacity reflect the great potential of supervised exercise interventions for improving the health status of incarcerated people. PMID:24185842
An Analysis of Alternatives to New York City's Current Marijuana Arrest and Detention Policy
Johnson, Bruce D.; Golub, Andrew; Dunlap, Eloise; Sifaneck, Stephen J.
During the 1990s, the New York Police Department (NYPD) instituted a policy of arresting and detaining people for minor offenses that occur in public as part of their quality-of-life (hereafter QOL) policing initiative. The number of NYPD arrests for smoking marijuana in public view (MPV) increased from 3,000 in 1994 to over 50,000 in 2000, and have been about 30,000 in the mid 2000s. Most of these arrestees (84%) have been minority; blacks have been 2.7 more likely and Hispanics 1.8 times more likely to be detained than whites for an MPV arrest. Minorities have been most likely to receive more severe dispositions, even controlling for demographics and prior arrest histories. This paper examines the pros and cons of the current policy; this is compared with possible alternatives including the following: arrest and issue a desk appearance ticket (DAT); issue a non-criminal citation (violation); street warnings; and tolerate public marijuana smoking. The authors recommend that the NYPD change to issuing DATs on a routine basis. Drug policy reformers might wish to further pursue changing statutes regarding smoking marijuana in public view into a violation (noncriminal) or encourage the wider use of street warnings. Any of these policy changes would help reduce the disproportionate burden on minorities associated with the current arrest and detention policy. These policies could help maintain civic norms against smoking marijuana in public. PMID:18726007
The expected psychiatric impact of detention in Guantanamo Bay, Cuba, and related considerations.
Brenner, Grant Hilary
What are the likely mental and related physical health consequences of prolonged exposure to common stressors to detainees at Guantanamo Bay, Cuba? Significant distress leads to high rates of psychiatric disorders, medical problems, and functional impairments. The consequences are severe, physically and psychologically, affecting the individual, his or her family, and the culture at large. Damaging conditions endured by detainees are multiple and severe and are reviewed here in detail. The author identifies parallels between Guantanamo detainees and similarly mistreated populations (e.g., prisoners of war, asylum seekers, prisoners) to draw inferences from existing research regarding likely outcomes for Guantanamo detainees. Protective factors normally present are systematically disrupted at Guantanamo. Overall, it is likely that detainees and their families are experiencing significant mental and physical health problems as a result of overlapping severe and chronic stressors related to detention and that this will worsen over time, particularly in the absence of appropriate assessment and treatment. The author addresses political and ethical factors, as well as basic implications for assessment, treatment, and advocacy, although these are not the focus of the article. Researchers and clinicians will face challenges in providing care for this population and understanding the long-term effects of such mistreatment. Sources reviewed are current up to September 2009. PMID:20938870
Relationship Between Woody Plant Colonization and Typha L. Encroachment in Stormwater Detention Basins
NASA Astrophysics Data System (ADS)
Plumb, Priscilla Bocskor; Day, Susan D.; Wynn-Thompson, Theresa M.; Seiler, John R.
We studied stormwater detention basins where woody vegetation removal was suspended for 2 years in Virginia, USA to determine if woody vegetation can control Typha populations and how early woody plant succession interacts with Typha, other herbaceous vegetation, and site factors. Distribution and composition of woody vegetation, Typha and non- Typha herbaceous vegetation biomass, and site factors were assessed at 100 plots in four basins ranging in age from 7 to 17 years. A greenhouse study examined the interaction of shade and soil moisture on Typha biomass and persistence. Principal component analysis identified an environmental gradient associated with greater water table depths and decreased elevation that favored Typha but negatively influenced woody vegetation. Elevation was correlated with litter layer distribution, suggesting that initial topography influences subsequent environmental characteristics and thus plant communities. Soil organic matter at 0-10 cm ranged from 5.4 to 12.7 %. Woody plants present were native species with the exception of Ailanthus altissima and Pyrus calleryana. In the greenhouse, shade and reduced soil moisture decreased Typha biomass and rhizome length. The shade effect was strongest in flooded plants and the soil moisture effect was strongest for plants in full sun. Typha in dry soil and heavy shade had 95 % less total biomass and 83 % smaller rhizomes than Typha in flooded soil and full sun, but even moderate soil moisture reductions decreased above- and below-ground biomass by 63 and 56 %, respectively. Suspending maintenance allows restoration of woody vegetation dominated by native species and may suppress Typha invasion.
Impact of storm water on groundwater quality below retention/detention basins.
Zubair, Arif; Hussain, Asif; Farooq, Mohammed A; Abbasi, Haq Nawaz
Groundwater from 33 monitoring of peripheral wells of Karachi, Pakistan were evaluated in terms of pre- and post-monsoon seasons to find out the impact of storm water infiltration, as storm water infiltration by retention basin receives urban runoff water from the nearby areas. This may increase the risk of groundwater contamination for heavy metals, where the soil is sandy and water table is shallow. Concentration of dissolved oxygen is significantly low in groundwater beneath detention basin during pre-monsoon season, which effected the concentration of zinc and iron. The models of trace metals shown in basin groundwater reflect the land use served by the basins, while it differed from background concentration as storm water releases high concentration of certain trace metals such as copper and cadmium. Recharge by storm water infiltration decreases the concentration and detection frequency of iron, lead, and zinc in background groundwater; however, the study does not point a considerable risk for groundwater contamination due to storm water infiltration. PMID:19241126
Diversity and spatiotemporal distribution of larval odonate assemblages in temperate neotropical farm ponds.
Pires, Mateus Marques; Kotzian, Carla Bender; Spies, Marcia Regina
Farm ponds help maintain diversity in altered landscapes. However, studies on the features that drive this type of property in the Neotropics are still lacking, especially for the insect fauna. We analyzed the spatial and temporal distribution of odonate larval assemblages in farm ponds. Odonates were sampled monthly at four farm ponds from March 2008 to February 2009 in a temperate montane region of southern Brazil. A small number of genera were frequent and accounted for most of the dominant fauna. The dominant genera composition differed among ponds. Local spatial drivers such as area, hydroperiod, and margin vegetation structure likely explain these results more than spatial predictors due to the small size of the study area. Circular analysis detected seasonal effect on assemblage abundance but not on richness. Seasonality in abundance was related to the life cycles of a few dominant genera. This result was explained by temperature and not rainfall due to the temperate climate of the region studied. The persistence of dominant genera and the sparse occurrence of many taxa over time probably led to a lack in a seasonal pattern in assemblage richness. PMID:25527585
Experimental pond studies were used to demonstrate a means of assessing the accuracy of laboratory and in situ bioassays predicting the effects of chemical stress on phytoplankton. A short-term batch bioassay using changing carbon uptake in photosynthesis predicted an immediate (...
Building a Pond on the School Grounds.
ERIC Educational Resources Information Center
Pope, Jonathan
Describes the efforts of two teachers to construct a pond and woods on school grounds. The teachers used specialized student teams for working on a wetland study and the building project. An advisory committee including teachers, the principal, and the custodian worked through maintenance issues. Relates teaching surprises associated with the…
Ecology of Great Salt Pond, Block Island
Great Salt Pond is an island of estuarine water on Block Island, which sits in the middle of the Northwest Atlantic Continental Shelf. When the last continental glaciers retreated, they left a high spot on a terminal moraine. The rising sea from melting glaciers formed two island...
The USEPA's Urban Stormwater Management Branch has monitored stormwater drainage and best management practices (BMP) as part of its research program. One BMP being monitored, a wetland/retention pond, is in the Richmond Creek (RC) watershed in the New York City Department of Envi...
Plankton Management for Channel Catfish Nursery Ponds
Technology Transfer Automated Retrieval System (TEKTRAN)
We conducted a series of studies examining the fertilization practices used for channel catfish nursery ponds. The best fertilization protocol would be one that uses low-cost fertilizers, quickly establishes a desirable phytoplankton bloom, and produces the greatest number of large zooplankton. In...
Natural brine solar pond: an experimental study
M Hassairi; M. J Safi; S Chibani
The South East of Tunisia is a sunny region. This area contains many mineral reserves of natural brine, which currently are not well exploited. These reserves are estimated to several millions of cubic metres. The abundance of solar energy and salt has led us to test the collection and storage of solar energy by a salt gradient solar pond. A
Saturated solar ponds: 1. Simulation procedure
Subhakar, D.; Murthy, S.S. (Indian Inst. of Technology, Madras (India))
The mass and energy balances on the upper convective zone, nonconvective zone, and lower convective zone of a saturated solar pond are written to yield a set of nonlinear partial differential equations. These are solved numerically to predict the thermal performance of the pond over a long period of time for various initial and boundary conditions. This model considers external parameters such as hourly variation of incident solar radiation, ambient temperature, air velocity, and relative humidity. Temperature and concentration dependence of density, thermal conductivity, specific heat, and mass diffusivity are taken into account. Heat transfer modes considered between the upper convective zone and the ambient are convection, evaporation, and radiation. Ground heat losses from the lower convective zone are also considered. This model is used to study the development of temperature and concentration profiles inside a saturated solar pond. This model can also be used to predict the long-term performance of a saturated solar pond for various heat extraction temperatures and rates. 30 refs., 4 figs.
Absorption of solar radiation in ponds
R. Viskanta; J. S. Toor
Analysis is presented to predict the local rate of solar energy absorption in a pond using the radiative transfer theory. The physical model considers absorption and scattering by the water and internal reflection of radiation from the air-water interface as well as the bottom. A forward scattering approximation and a discrete-coordinate approximation of the radiative transfer equation are discussed. Numerical
Shallow solar pond energy conversion system
W. C. Dickinson; A. F. Clark; J. A. Day; L. F. Wouters
The concept of a shallow solar pond energy conversion system is presented as an effective way to produce large-scale electric power from solar energy. Water is used both for heat collection and heat storage. Inexpensive layers of weatherable transparent plastic over the water suppress heat loss to the environment. The hot water is stored in an insulated reservoir at night.
Solar pond with honeycomb surface insulation system
M. Arulanantham; P. Avanti; N. D. Kaushika
A solar pond consisting of transparent compound honeycomb encapsulated with Teflon film and glass plates at the bottom and top surface respectively, floating on the body of a hot water reservoir is considered and analysed for the heat transfer processes in the system. A mathematical model is developed where the energy balance equation of the convective water is formulated by
Solar Pond Research at Argonne National Laboratory
NASA Technical Reports Server (NTRS)
Hull, J. R.
Focus is on applications that utilize the seasonal heat-storage capability of the solar pond for low-temperature thermal processes, however the results of the research are directly applicable to electricity-generating and other applications. Important technical results are summarized.
A pilot rapid infiltration wastewater treatment system consisting of three 0.07 hectare basins was operated for four seasons at Brookings, South Dakota. The objectives of the study were to demonstrate that rapid infiltration land treatment could upgrade stabilization pond effluen...
Enhancing nitrification at low temperature with zeolite in a mining operations retention pond.
Miazga-Rodriguez, Misha; Han, Sukkyun; Yakiwchuk, Brian; Wei, Kai; English, Colleen; Bourn, Steven; Bohnert, Seth; Stein, Lisa Y
Ammonium nitrate explosives are used in mining operations at Diavik Diamond Mines Inc. in the Northwest Territories, Canada. Residual nitrogen is washed into the mine pit and piped to a nearby retention pond where its removal is accomplished by microbial activity prior to a final water treatment step and release into the sub-Arctic lake, Lac de Gras. Microbial removal of ammonium in the retention pond is rapid during the brief ice-free summer, but often slows under ice cover that persists up to 9?months of the year. The aluminosilicate mineral zeolite was tested as an additive to retention pond water to increase rates of ammonium removal at 4°C. Water samples were collected across the length of the retention pond monthly over a year. The structure of the microbial community (bacteria, archaea, and eukarya), as determined by denaturing gradient gel electrophoresis of PCR-amplified small subunit ribosomal RNA genes, was more stable during cold months than during July-September, when there was a marked phytoplankton bloom. Of the ammonia-oxidizing community, only bacterial amoA genes were consistently detected. Zeolite (10?g) was added to retention pond water (100?mL) amended with 5?mM ammonium and incubated at 12°C to encourage development of a nitrifying biofilm. The biofilm community was composed of different amoA phylotypes from those identified in gene clone libraries of native water samples. Zeolite biofilm was added to fresh water samples collected at different times of the year, resulting in a significant increase in laboratory measurements of potential nitrification activity at 4°C. A significant positive correlation between the amount of zeolite biofilm and potential nitrification activity was observed; rates were unaffected in incubations containing 1-20?mM ammonium. Addition of zeolite to retention ponds in cold environments could effectively increase nitrification rates year-round by concentrating active nitrifying biomass. PMID:22866052
Enhancing Nitrification at Low Temperature with Zeolite in a Mining Operations Retention Pond
Miazga-Rodriguez, Misha; Han, Sukkyun; Yakiwchuk, Brian; Wei, Kai; English, Colleen; Bourn, Steven; Bohnert, Seth; Stein, Lisa Y.
Ammonium nitrate explosives are used in mining operations at Diavik Diamond Mines Inc. in the Northwest Territories, Canada. Residual nitrogen is washed into the mine pit and piped to a nearby retention pond where its removal is accomplished by microbial activity prior to a final water treatment step and release into the sub-Arctic lake, Lac de Gras. Microbial removal of ammonium in the retention pond is rapid during the brief ice-free summer, but often slows under ice cover that persists up to 9?months of the year. The aluminosilicate mineral zeolite was tested as an additive to retention pond water to increase rates of ammonium removal at 4°C. Water samples were collected across the length of the retention pond monthly over a year. The structure of the microbial community (bacteria, archaea, and eukarya), as determined by denaturing gradient gel electrophoresis of PCR-amplified small subunit ribosomal RNA genes, was more stable during cold months than during July–September, when there was a marked phytoplankton bloom. Of the ammonia-oxidizing community, only bacterial amoA genes were consistently detected. Zeolite (10?g) was added to retention pond water (100?mL) amended with 5?mM ammonium and incubated at 12°C to encourage development of a nitrifying biofilm. The biofilm community was composed of different amoA phylotypes from those identified in gene clone libraries of native water samples. Zeolite biofilm was added to fresh water samples collected at different times of the year, resulting in a significant increase in laboratory measurements of potential nitrification activity at 4°C. A significant positive correlation between the amount of zeolite biofilm and potential nitrification activity was observed; rates were unaffected in incubations containing 1–20?mM ammonium. Addition of zeolite to retention ponds in cold environments could effectively increase nitrification rates year-round by concentrating active nitrifying biomass. PMID:22866052
Response of small New England ponds to historic land use
Donna R. Francis; David R. Foster
This palaeolimnological study addresses whether the timing, magnitude and nature of lake-ecosystem changes closely track changes in land-use intensity and forest cover in the watershed, and the extent to which lakes retuni to pre-disturbance states following the substantial long-term declinie in human activity that is typical for much of the rural eastern United States. Land-use intensity in the watersheds increased
NSDL National Science Digital Library
Katie Hale (California State University, Fullerton; Student, Biological Sciences)
These fish died because of excessive pollution in the lake. The pollution is the result of runoff and chemical pollution dumped directly into the water. Acid rain can also cause fish and other organisms to die is small bodies of water because it raises water temperatures and makes the water more acidic.
Practical operation and maintenance of a solar pond for greenhouse heating
Fynn, R.P.; Short, T.H.; Shah, S.A.
Construction started on a Solar Pond in 1975. Problems with pond leaks and eventual liner failure resulted in a redesign and rebuilding of the pond in 1977. Since then the pond has been operated continuously and used to heat an adjacent greenhouse. Procedures for the pond gradient establishment and maintenance, pond clarity and equipment maintenance have been developed. Methods of heat extraction have been studied and one has been exensively utilized. Pond instrumentation has been refined and is shown to be a useful part of pond maintenance. Studies have been made of the parameters involved in pond design and some suggestions are made as to how to improve solar pond performance.
Combining mariculture and seawater-based solar ponds
Lowrey, P.; Ford, R.; Collando, F.; Morgan, J.; Frusti, E. (San Diego State Univ., CA (USA). Dept. of Mechanical Engineering)
Solar ponds have been thoroughly studied as a means to produce electricity or heat, but there may be comparable potential to use solar ponds to produce optimized environments for the cultivation of some aquaculture crops. For this, conventional brine-based solar ponds could be used. This strategy would probably be most suitable at desert sites where concentrated brine was abundant, pond liners might not be needed, and the crop produced could be shipped to market. Generally, a heat exchanger would be required to transfer heat from the solar pond into the culture ponds. Culture ponds could therefore use either fresh or marine water. In contrast, this paper explores seawater-based solar ponds. These are solar ponds which use seawater in the bottom storage zone and fresh water in the upper convective zone. Because the required temperature elevations for mariculture are only about 10{degrees}C, seawater-based solar ponds are conceivable. Seawater-based ponds should be very inexpensive because, by the shore, salt costs would be negligible and a liner might be unnecessary.
Effect of soil conditions on solar pond performance
Leboeuf, C.M.; Johnson, D.H.
A recent effort to design a one-acre solar pond at the US Air Force Academy brought up several research issues pertaining to solar pond performance prediction. This report addresses those issues. Interactions of the pond with the soil below it have historically been estimated using very simplistic techniques that tend to ignore soil composition, moisture content, and the coupled heat and moisture transport phenomena. This study examines the models of soil thermal conductivity and heat and mass transport in soils under imposed temperature gradients to assess the potential applicability of these models to solar pond modeling. In addition, a computer simulation code is developed that incorporates the soil thermal conductivity model. Using the code, a parametric analysis was performed illustrating the impact of this property on pond behavior and the importance of experimental model verification for the range of soil temperatures experienced in solar ponds. Implications of the combined heat and moisture movement theory on solar pond performance are presented.
Purification and production of inorganic fertilizers in solar ponds
Doria, J.; de Andres, M.C.; Armenta, C. (Universidad Complutense, Madrid (Spain))
The separation of sodium nitrate from caliche and potassium chloride from silvinita, and the obtention of potassium nitrate from double decomposition of sodium nitrate and potassium chloride in aqueous solution, using the differential solubility method, has been treated. The necessary energy for solving salts and heating solutions can be provided by the sun if solar ponds - of caliche, silvinita or a mixture of both ores - are built. It has been found that this solar pond application is feasible, and the cycling pond efficiency could be improved beyond the typical 20% at low operating temperatures. The amount of nitrate or chloride obtained per liter of solution depends on the temperature at the bottom of the pond, the ambient temperature and, especially, on their difference. Finally, pond stability is improved to the higher solubility of the salts used, and the pond of silvinita could be stable even if evolving to a saturation operational pond.
Remaining Sites Verification Package for the 100-F-33, 146-F Aquatic Biology Fish Ponds, Waste Site Reclassification Form 2006-021
L. M. Dittmer
The 100-F-33, 146-F Aquatice Biology Fish Ponds waste site was an area with six small rectangular ponds and one large circular pond used to conduct tests on fish using various mixtures of river and reactor effluent water. The current site conditions achieve the remedial action objectives specified in the Remaining Sites ROD. The results of verification and applicable confirmatory sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.
Visual evoked potentials in relation to factors of imprisonment in detention camps.
Vrca, A; Bozikov, V; Brzovi?, Z; Fuchs, R; Malinar, M
Visual evoked potentials (VEPs) of the pattern shift reversal type were determined in a representative group of 57 prisoners of war (POWs) released in 1992 from detention camps in former Yugoslavia. The parameters were correlated with the conditions in four camps (1-4). All subjects were male, with a mean age of 34.75 years (SD +/- 8.92), average length of imprisonment 192.7 days (SD +/- 77.6), mean loss of body mass during imprisonment 19.32% (SD +/- 9.54), and the average number of reported blows to the head and neck was 25.7 (SD +/- 20.3). VEPs were determined on average 290.5 days after the last craniocerebral trauma caused by blows to the head and neck (SD +/- 152.0) i.e., on average 218.5 days after release from the camp (SD +/- 164.3). Although all the 57 POWs reported being maltreated to a certain extent, 14 reported being subjected to particularly brutal forms of torture, 5 had been held in solitary confinement and 25 had lost consciousness at least once. Solitary confinement and loss of consciousness had the most significant effect on VEPs, and the altered VEP parameters correlated significantly with the craniocerebral trauma experienced, loss of body mass and the length of time since the last craniocerebral trauma until examination, and from release until examination. However, the length of imprisonment and treatment in the camps did not have a significant effect on VEP parameters. The study confirmed that under such conditions the age of the subject is a risk factor. The results of this study also confirmed that prisoners in one camp had been subjected to the worst maltreatment. PMID:8956983
Relationship between woody plant colonization and Typha L. encroachment in stormwater detention basins.
Plumb, Priscilla Bocskor; Day, Susan D; Wynn-Thompson, Theresa M; Seiler, John R
We studied stormwater detention basins where woody vegetation removal was suspended for 2 years in Virginia, USA to determine if woody vegetation can control Typha populations and how early woody plant succession interacts with Typha, other herbaceous vegetation, and site factors. Distribution and composition of woody vegetation, Typha and non-Typha herbaceous vegetation biomass, and site factors were assessed at 100 plots in four basins ranging in age from 7 to 17 years. A greenhouse study examined the interaction of shade and soil moisture on Typha biomass and persistence. Principal component analysis identified an environmental gradient associated with greater water table depths and decreased elevation that favored Typha but negatively influenced woody vegetation. Elevation was correlated with litter layer distribution, suggesting that initial topography influences subsequent environmental characteristics and thus plant communities. Soil organic matter at 0-10 cm ranged from 5.4 to 12.7%. Woody plants present were native species with the exception of Ailanthus altissima and Pyrus calleryana. In the greenhouse, shade and reduced soil moisture decreased Typha biomass and rhizome length. The shade effect was strongest in flooded plants and the soil moisture effect was strongest for plants in full sun. Typha in dry soil and heavy shade had 95% less total biomass and 83% smaller rhizomes than Typha in flooded soil and full sun, but even moderate soil moisture reductions decreased above- and below-ground biomass by 63 and 56%, respectively. Suspending maintenance allows restoration of woody vegetation dominated by native species and may suppress Typha invasion. PMID:23925899
Preliminary measurement-based estimates of PAH emissions from oil sands tailings ponds
NASA Astrophysics Data System (ADS)
Galarneau, Elisabeth; Hollebone, Bruce P.; Yang, Zeyu; Schuster, Jasmin
Tailings ponds in the oil sands region (OSR) of western Canada are suspected sources of polycyclic aromatic hydrocarbons (PAHs) to the atmosphere. In the absence of detailed characterization or direct flux measurements, we present preliminary measurement-based estimates of the emissions of thirteen priority PAHs from the ponds. Using air concentrations measured under the Joint Canada-Alberta Oil Sands Monitoring Plan and water concentrations from a small sampling campaign in 2013, the total flux of 13 US EPA priority PAHs (fluorene to benzo[ghi]perylene) was estimated to be upward from water to air and to total 1069 kg y-1 for the region as a whole. By comparison, the most recent air emissions reported to Canada's National Pollutant Release Inventory (NPRI) from oil sands facilities totalled 231 kg y-1. Exchange fluxes for the three remaining priority PAHs (naphthalene, acenaphthylene and acenaphthene) could not be quantified but evidence suggests that they are also upward from water to air. These results indicate that tailings ponds may be an important PAH source to the atmosphere that is missing from current inventories in the OSR. Uncertainty and sensitivity analyses lend confidence to the estimated direction of air-water exchange being upward from water to air. However, more detailed characterization of ponds at other facilities and direct flux measurements are needed to confirm the quantitative results presented herein.
Water quality and restoration in a coastal subdivision stormwater pond.
Serrano, Lorimar; DeLorenzo, Marie E
Stormwater ponds are commonly used in residential and commercial areas to control flooding. The accumulation of urban contaminants in stormwater ponds can lead to a number of water quality problems including high nutrient, chemical contaminant, and bacterial levels. This study examined the interaction between land use and coastal pond water quality in a South Carolina residential subdivision pond. Eutrophic levels of chlorophyll and phosphorus were present in all seasons. Harmful cyanobacterial blooms were prevalent during the summer months. Microcystin toxin and fecal coliform bacteria levels were measured that exceeded health and safety standards. Low concentrations of herbicides (atrazine and 2,4-D) were also detected during summer months. Drainage from the stormwater pond may transport contaminants into the adjacent tidal creek and estuary. A survey of residents within the pond's watershed indicated poor pet waste management and frequent use of fertilizers and pesticides as possible contamination sources. Educational and outreach activities were provided to community members to create an awareness of the water quality conditions in the pond. Pond management strategies were then recommended, and selected mitigation actions were implemented. Water quality problems identified in this study have been observed in other coastal stormwater ponds of varying size and salinity, leading this project to serve as a potential model for coastal stormwater pond management. PMID:17368919
Beaver ponds increase methylmercury concentrations in Canadian shield streams along vegetation and pond-age gradients.
Roy, Virginie; Amyot, Marc; Carignan, Richard
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 (< 10 years old) and those located in coniferous watersheds had the highest MeHg concentrations (range, 0.10-4.53 ng L(-1)) and greatest methylation efficiencies (% THg as MeHg; range, 10-74%). High heterotrophic activity likely occurred in the 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. PMID:19731651
Predicting diffusion in aquifers beneath saline ponds
NASA Astrophysics Data System (ADS)
Verrall, D. P.; Read, W. W.
SummaryThis paper examines the contribution of diffusion to salt contamination of groundwater from leaky saline ponds. A hybrid analytical solution for diffusion from a region of constant concentration is developed using the series solutions method. This is used to predict when and where diffusion becomes the dominant transport process over advection (using existing knowledge of the advection process). A simple method is established to find when contamination will occur at any point in the aquifer, given knowledge of its physical parameters.
Cibola High Levee Pond annual report 2004
Mueller, Gordon A.; Carpenter, Jeanette; Marsh, Paul C.
This represents the fourth and last annual report of a five year study investigating the early life ecology of the bonytail and razorback sucker at Cibola High Levee Pond. The work in 2004 included: telemetry studies, collection of physical water quality measurements, zooplankton samples, netting fish, the collection of scale samples for aging, predator/prey tank tests and a preliminary analysis of the data base.
Performance investigation of a solar pond
Mehmet Karakilcik; Ibrahim Dincer; Marc A. Rosen
This work consists of both experimental and theoretical parts. In the experimental part, an insulated solar pond with a surface area of 4m2 and a depth of 1.5m was built at Cukurova University in Adana, Turkey to conduct performance experiments. The system was filled with salty water of various densities to form three salty water zones (upper convective, non-convective and
New approaches for Artemia pond culture.
Van Hoa, Nguyen; Le Tran, Huu; Hong Van, Nguyen Thi; Sorgeloos, P; Van Stappen, G
A project for intensive culture of Artemia in Vinhchau solar saltwork was funded by Soctrang Authority. The aim of this project is to increase the average cyst yield of 50kg.ha-1.crop, and to build up a stable culture technique with a better yield for local farmers. Multiple laboratory experiments were set up with inert food including fermented rice bran, tiger shrimp feed (PL15), as well as their combination with live algae (Chaetoceros). Results showed that, under laboratory conditions, fermented rice bran and tiger shrimp feed can be used as supplemental food sources. The shrimp feed alone or in combination with algae always gave better cyst production compared to the others, but should not account for more than 50% of the diet. In the field trials, aeration of Artemia ponds also increased cyst yields (from 195.8+/-44.2 to 207+/-46.1kg.ha-1.crop with 6 and 12 aeration a day, respectively) compared to ponds with no aeration (88.2+/-27.5kg.ha-1.crop), however the returns on investment (ROI=2.73-2.71 with aera tion vs. 2.24 without) are not significantly different. Utilization of fermented rice bran (20kg.ha-1.day) and shrimp feed (6kg.ha-1.day) as a supplementary feed during pond production in combination with greenwater supplies (10% of pond volume daily) resulted in higher yields (96.0+/-15.9 and 157.2+/-15.0kg.ha-1.crop, respectively) than traditional culture; Shrimp feed as a supplemental feed supported the cyst yield but their negative effect was at a high cost vs. traditional culture and use of fermented rice bran. Based on the cyst yield and ROI, fermented rice bran should be a promising item for poor farmers. PMID:25141701
Dispersion of plutonium from contaminated pond sediments
Rees, T.F.; Cleveland, J.M.; Carl, Gottschall W.
Sediment-water distributions of plutonium as a function of pH and contact time are investigated in a holding pond at the Rocky Flats plant of the Department of Energy. Although plutonium has been shown to sorb from natural waters onto sediments, the results of this study indicate that under the proper conditions it can be redispersed at pH 9 and above. Concentrations greater than 900 pCi Pu/L result after 34 h contact at pH 11 or 12 and the distribution coefficient, defined as the ratio of concentration in the sediment to that in the liquid, decreases from 1.1 ?? 105 at pH 7 to 1.2 ?? 103 at pH 11. The plutonium is probably dispersed as discrete colloids or as hydrolytic species adsorbed onto colloidal sediment particles whose average size decreases with increasing pH above pH 9. About 5% of the total plutonium is dispersed at pH 12, and the dispersion seems to readsorb on the sediment with time. Consequently, migration of plutonium from the pond should be slow, and it would be difficult to remove this element completely from pond sediment by leaching with high pH solutions. ?? 1978 American Chemical Society.
Environmental Problems Associated with Decommissioning of Chernobyl Power Plant Cooling Pond
NASA Astrophysics Data System (ADS)
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.
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 - 11.4 µGy/hr; birds - 6.3 µGy/hr; mammals - 15.1 µGy/hr; reptilians - 10.3 µGy/hr, with the recommended maximum allowable limit of 40 µGy/hr. The conservative risk coefficient ranged from 0.51 for birds to 1.82 for amphibians. In spite of a high contamination level of the shoreline areas, the current total doses received by the animals do not reach the recommended maximum allowable doses. However, drainage of the ChNPP Cooling Pond is likely to increase the dose rates as follows: amphibians - 94.5, birds - 95.2, mammals - 284.0, reptilians - 847.0 µGy/hr, which will significantly exceed the maximum allowable values. These predictions are conservative and prior to making the final decision on the fate of the ChNPP Cooling Pond, a detailed radio-ecological assessment of its drainage will have to be performed.
Windpowered irrigation system for small farm applications
England, B.
The overall purpose of the project was to conserve water on a small-scale truck patch vegetable gardening operation. The main thrust centered on improving water usage in the already-existing windmill/storage tank/house/farm pond setup. Most of the funds were spent on a trickle (drip) irrigation system linked into the existing wetup. Other areas improved were the farm pond itself, backup pumping for windmill and farm pond, and greywater reclamation. In spite of problems which had to be restudied and corrected, the project was an overall success both in terms of results and budget.
Spatiotemporal Distribution of Marine Magnetotactic Bacteria in a Seasonally Stratified Coastal Salt Pond
S. L. Simmons; S. M. Sievert; R. B. Frankel; D. A. Bazylinski; K. J. Edwards
The occurrence and distribution of magnetotactic bacteria (MB) were studied as a function of the physical and chemical conditions in meromictic Salt Pond, Falmouth, Mass., throughout summer 2002. Three dominant MB morphotypes were observed to occur within the chemocline. Small microaerophilic magnetite-producing cocci were present at the top of the chemocline, while a greigite-producing packet-forming bacterium occurred at the base
Polyculture of indigenous marine fishes stocked with penaeid shrimp in thermally enriched brackish water ponds
Rossberg, Karen Sue
and light manipulations supplemented with hormone injections (Hoff et al. 1972) . 6) They are not piscivorous except as very small fish. Successful polycultures have been accomplished with 10 striped mullet, spotted seatrout, CV no a ci on nehru cas...POLYCULTURE OF INDIGENOU MARINE FISHES STOCKED WITH PENAEID SHRIMP Ii~J THERMALLY ENRICHED BRACKISH RATER PONDS A Thesis by KAREN SUE ROSSBERG Submitted by the Graduate College of Texas A&M University in partial ulfillment of the requirement...
Using full-scale duckweed ponds as the finish stage for swine waste treatment with a focus on organic matter degradation.
Mohedano, R A; Costa, R H R; Hofmann, S M; Belli Filho, P
The rapid increase in the number of swine has caused pronounced environmental impacts worldwide, especially on water resources. As an aggregate, smallholdings have an important role in South American pork production, contributing to the net diffusion of pollution. Thus, duckweed ponds have been successfully used for swine waste polishing, mainly for nutrient removal. Few studies have been carried out to assess organic matter degradation in duckweed ponds. Hence, the present study evaluated the efficiency of two full-scale duckweed ponds for organic matter reduction of swine waste on small pig farms. Duckweed ponds, in series, received the effluent after an anaerobic biodigester and storage pond, with a flow rate of 1 m(3) day(-1). After 1 year of monitoring, an improvement in effluent quality was observed, with a reduction in biochemical oxygen demand (BOD) and total chemical oxygen demand (tCOD), respectively, of 94.8 and 96.7%, operating at a loading rate of approximately 27 kgBOD ha(-1) day(-1) and 131 kgCOD ha(-1) day(-1). Algae inhibition due to duckweed coverage was strongly observed in the pond effluent, where chlorophyll a and turbidity remained below 25 ?g L(-1) and 10 NTU. Using the study conditions described herein, duckweed ponds were shown to be a suitable technology for swine waste treatment, contributing to the environmental sustainability of rural areas. PMID:24845333
Geosynthetics in a salinity-gradient solar pond environment
Lichwardt, M.A.; Comer, A.I.
This paper describes the latest in salinity-gradient solar pond lining systems. The high-temperature, high-salinity environment unique to a salinity-gradient solar pond resulted in failure of the geomembrane liner at the El Paso Solar Pond Test Facility after only eight years of operation. Research involved in pond reconstruction led to the selection of a lining system consisting of a flexible polypropylene (PP) geomembrane for the sidewalls and a specially formulated geosynthetic clay liner (GCL) on the bottom of the pond. The two liners have been installed and a comprehensive test program is being conducted to measure their performance. The environment encountered in a salinity-gradient solar pond will be discussed as well as material selection criteria and the design of the two liners. Preliminary results of the GCL performance monitoring will also be presented.
Flax Pond ecosystem study: exchanges of carbon in water between a salt marsh and Long Island Sound
G. M. Woodwell; D. E. Whitney; C. A. S. Hall; R. A. Houghton
Flax Pond, a tidal marsh on the north shore of Long Island, New York, was used to examine the exchanges of carbon in its various forms between a salt marsh and the coastal waters. The marsh removed fine particulate carbon from the tidal water throughout the year; it tended to be a small source of C as total COâ and
The Impact of Colonization History and Fish Predation on Larval Odonates (Odonata: Anisoptera) in a Central New Jersey Farm Pond
John Nemjo
Larval odonates were manipulated in a small farm pond in central New Jersey to study the effects of colonization history and fish predation on species composition. Species exhibited a wide range of breeding phenologies. Temporal separation may have an affect on the larval assemblage by reducing interactions between species. Abundances of metamorphs were negatively correlated with species-specific final instar body
Flood water storage as a resource for agriculture and groundwater recharge: the empting of artificial leaking ponds
M. D'Oria; M. Tanda; A. Zanini
The large industrialization, intensive agriculture and the increasing population is giving rise to a lack of water resources. There is the need of capturing runoff for storing the water and using it during dry periods, but people now opposes to the realization of new dams. In Italy Public Authorities are showing a great interest in using ponds or small lakes
Implementation outcomes of Multidimensional Family Therapy-Detention to Community: a reintegration program for drug-using juvenile detainees.
Liddle, Howard A; Dakof, Gayle A; Henderson, Craig; Rowe, Cindy
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. PMID:20427547
Anxiety, depression, impulsivity and substance misuse in violent and non-violent adolescent boys in detention in China.
Zhou, Jiansong; Witt, Katrina; Zhang, Yingdong; Chen, Chen; Qiu, Changjian; Cao, Liping; Wang, Xiaoping
The present investigation aims to identify the factors which differentiate violent from non-violent juvenile offenders, with a particular emphasis on the association between internalizing psychiatric morbidity (i.e. anxiety and depression), impulsivity, substance misuse, and violence. A total of 323 incarcerated male juvenile offenders from one of three Youth Detention Centers (YDCs) in China were recruited between August 2007 and November 2008. Interviews were conducted by trained psychiatrists using the Barratt Impulsivity Scale (BIS-11), the Screen for Child Anxiety Related Emotional Disorders (SCARED), and the Birleson Depression Self-Rating Scale (DSRS) to assess impulsivity, anxiety and depression, respectively. The Schedule for Affective Disorder and Schizophrenia for School-Age Children Present and Lifetime (K-SADS-PL) was also used to assess psychiatric diagnoses. Violent offenders had significantly higher BIS-11 total scores, and attention and nonplanning subscale scores (p<0.05). In the multiple logistic regression model, substance use disorders (SUD) and BIS-11 total scores independently predicted violence. Prison-based treatment services designed to reduce impulsivity and substance misuse in juvenile detention facilities should be prioritized. PMID:24612970
Movement of heavy metals below sewage disposal ponds
L. J. Lund; A. L. Page; C. O. Nelson
Coarse-textured soils below sludge and effluent disposal ponds at two sewage treatment plants were studied. The concentrations of Zn, Cd, Cu, Cr, and Ni in the soils at various depths were determined to investigate the downward movement of these heavy metals below the two types of disposal ponds. Concentrations of acid-extractable metals (4N HNOâ) were greater under disposal ponds than
A gradient maintenance technique for seawater solar ponds
Kleis, S.J.; Li, H.; Shi, J. [Univ. of Houston, TX (United States). Dept. of Mechanical Engineering
Seawater solar ponds are being evaluated as a means of reducing heat losses from thermal refuge areas in outdoor mariculture ponds during cold weather. The thermal refuge areas are intended to provide a reliable means of protecting fish crops from lethal cold water temperatures in the winter months. A continuous filling technique is demonstrated for use in gradient zone maintenance of the seawater solar ponds. The technique allows indefinite operation of the refuge areas with a minimal amount of fresh water.
Environmental influences on fish assemblages in irrigation ponds
Yoshito Mitsuo; Hiroshi Tsunoda; Akira Takiguchi; Yutaro Senga
Ponds are common features of the landscape and are considered important for freshwater biodiversity conservation. Although\\u000a fish have a significant impact on the lentic ecosystems, the environmental factors that regulate fish assemblages in human-created\\u000a water bodies, such as irrigation ponds, remain unclear. We evaluated the relationship between environmental factors and the\\u000a fish assemblage structure in 31 ponds located in northern
Computer simulation model of salt-gradient solar ponds
Panahi, Z.
The mass and energy transfer processes of salt-gradient solar pond were developed into a finite element of computer model. The system represented by the model can be: (1) a non-convective salt-gradient solar pond for which the energy transfer takes place by conduction through the brine and the round beneath the pond; (2) a stratified three-zone solar pond consisting of upper and lower convective zones and a non-convective gradient zone in between. The temperature of the upper and lower convective zones are predicted in terms of the net energy input to the zones. The energy fluxes at the pond surface include: reflected and absorbed solar radiation, evaporation energy loss, net long wave radiation loss to the atmosphere, advected energy of precipitation and inflow water, and convective heat loss at the surface. The model predicts the time dependent concentration, density, and temperature gradients in the pond. The program can operate with any time step of less than or equal to 24 hours, using either average daily or variables (with the time step) values of air temperature (calculated in the model using average, maximum and minimum values) and solar radiation data. The different cases that have been studied using the model are (1) the performance of a non-insulated salt-gradient solar pond with seepage of the brine and energy exchange through the ground below the pond; (2) the performance of an insulated salt-gradient solar pond with seepage of the brine and energy exchange through the ground below the pond; (2) the performance of an insulated salt-gradient and stratified three-zone solar pond. For stratified ponds comparisons on performance are made by changing the thickness of: (1) the upper convective zone, (2) the non-convective gradient zone, and (3) the lower convective (storage) zone.
Performance of a portable mini solar-pond
M. A. Tahat; Z. H. Kodah; S. D. Probert; H. Al-Tahaineh
For the present experiments, such a pond was located at JUST, i.e. at 32°N latitude. Its walls were inclined at 45° to the horizontal. The pond was built of galvanized steel (1.44 mm thick) with a circular surface area and total depth of 1 m2 and 500 mm, respectively. The effects of the solar-pond's depth and its water's salinity on
7. William E. Barrett, Photographer, August 1975. LOG PONDS LOOKING ...
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
7. William E. Barrett, Photographer, August 1975. LOG PONDS LOOKING WEST FROM POWERHOUSE ROOF. TRANSFORMER SHED IN FOREGROUND. - Meadow River Lumber Company, Highway 60, Rainelle, Greenbrier County, WV
Minimizing contamination hazards to waterbirds using agricultural drainage evaporation ponds
NASA Astrophysics Data System (ADS)
Bradford, David F.; Smith, Lynda A.; Drezner, Deborah S.; Shoemaker, J. David
In much of the San Joaquin Valley, California, USA, inadequate drainage of applied irrigation water and accumulating salts in the soil have necessitated the installation of subsurface tile drainage systems to preserve crop productivity. At present, these subsurface drainage waters are disposed of by means of evaporation ponds or discharges into the San Joaquin River. Unfortunately, most of these agricultural drainage waters contain high concentrations of salts and naturally occurring trace elements, such as selenium, and recent evidence indicates that substantial numbers of waterbirds are exposed to contamination by selenium in the evaporation ponds. In order to avoid, minimize, or mitigate the adverse impacts on wildlife using the ponds, alternative pond management methods must be identified and evaluated for implementation. A number of methods have the potential to be cost-effective in significantly reducing the contamination hazard to birds using agricultural evaporation ponds. Twenty general methods were evaluated in this study, and four methods are recommended for implementation: remove levee vegetation, remove windbreaks, deepen the ponds, and haze birds. A number of other methods are recommended for further consideration because they appear to have good prospects for reducing the contamination hazard: steepen interior levee slopes, apply herbicides and insecticides, place netting on pond shorelines, and provide freshwater habitat adjacent to evaporation ponds. It may be necessary to use a combination of methods to effectively control selenium contamination of aquatic birds because it is unlikely that a single affordable pond management method will be able to entirely eliminate the contamination hazard.
A model of the refreezing of melt ponds
NASA Astrophysics Data System (ADS)
Flocco, D.; Feltham, D. L.; Schroeder, D.
Melt ponds form on Arctic sea ice during the melting season and their presence affects the heat and mass balance of the ice cover. Towards the end of the melt season melt ponds cover up to 50% of the sea ice area decreasing the value of the surface albedo by up to 20%. The dramatic impact of melt ponds on the albedo feedback mechanism for sea ice melt has been demonstrated in previous studies. Here, we focus on the refreezing of melt ponds. As the ponds freeze from above, they gradually release latent heat that inhibits basal ice growth. The refreezing process can take up to three months. Within the ASBO (Arctic Synoptic Basin-wide Observations) project we have developed a model of refreezing melt ponds that uses mushy layer theory to describe the sea ice and takes account of the presence of salt in the refreezing melt pond. We use this model to investigate the rate at which melt ponds refreeze, releasing latent heat, and their impact on sea ice growth. Model results are compared with in situ data collected by Ice Mass Balance buoys in the Arctic. Furthermore we will give an estimate of the impact of the melt pond presence on sea ice growth in the Arctic basin.
Convecting solar pond experiments. Progress report for FY 1980
Leboeuf, C.M.
The primary objective of this work is to determine the thermal, optical, and mechanical performance of several low-cost glazing and insulating materials in conjunction with a freshwater (convecting) solar pond. The effect of implementing a pond filtration system will also be examined. Progress is reported. Although actual pond performance data is not yet being collected, much progress has been made on this task during FY 1980. Several glazing materials were analyzed in various configurations and material properties of optical transmissivity and thermal conductivity were measured. In addition, the pond test facility was designed, constructed, and is nearly ready for testing the first surface treatment.
78 FR 15017 - Guidance for Industry: What You Need To Know About Administrative Detention of Foods; Small...
Federal Register 2010, 2011, 2012, 2013, 2014
...Food Safety and Applied Nutrition, Food and Drug Administration...Paint Branch Pkwy., College Park, MD 20740. Send...Food Safety and Applied Nutrition, Food and Drug Administration...Paint Branch Pkwy., College Park, MD 20740,...
Conceptual design of a downward-convecting solar pond filled with a water-saturated, porous medium
Hadim, A. (Stevens Inst. of Tech., Hoboken, NJ (United States). Dept. of Mechanical Engineering); Burmeister, L.C. (Kansas Univ., Lawrence, KS (United States). Dept. of Mechanical Engineering)
Previous results from a stability analysis of natural convection in a water-saturated porous medium with externally imposed downward flow of the fluid and distributed internal heat generation are used in this study for a preliminary design of a saltless solar pond. The pond is filled with a water-saturated porous medium to inhibit natural convection. This paper reports on downward flow of water which is steadily imposed to allow the absorbed solar radiation, dependent upon the extinction coefficient of the water-saturated porous medium, to be carried down to the bottom of the solar pond from whence warm water is conveyed to the point of use. The downward velocities used have small magnitudes to allow useful bottom temperatures to be obtained. A steady-state analytical study was performed to determine the maximum temperature that can be obtained at the bottom of the saltless solar pond which resulted in a relationship involving the internal and external Rayleigh numbers, extinction coefficient, and Peclet number of the imposed downward flow. Results from this analytical study are combined with results from the stability analysis in a design procedure. This procedure is used to design a saltless solar pond of the concept described above for several cases.
Constructed Wetlands and Waste Stabilization Ponds for municipal wastewater treatment in France: comparison of
Paris-Sud XI, Université de
13 Constructed Wetlands and Waste Stabilization Ponds for municipal wastewater treatment in France In France, vertical flow constructed wetlands and waste stabilisation ponds are both extensive treatment Vertical Flow Constructed Wetlands, Waste Stabilization Ponds, operation and maintenance, sludge management
Salt-Pond Box Model (SPOOM) and Its Application to the Napa-Sonoma Salt Ponds, San Francisco Bay, California
Lionberger, Megan L.; Schoellhamer, David H.; Buchanan, Paul A.; Meyer, Scott
A box model to simulate water volume and salinity of a salt pond has been developed by the U.S. Geological Survey to obtain water and salinity budgets. The model, SPOOM, uses the principle of conservation of mass to calculate daily pond volume and salinity and includes a salt crystallization and dissolution algorithm. Model inputs include precipitation, evaporation, infiltration, and water transfers. Salinity and water-surface-elevation data were collected monthly in the Napa-Sonoma Salt-Pond Complex from February 1999 through September 2001 and were used to calibrate and validate the model. The months when water transfers occurred were known but the magnitudes were unknown, so the magnitudes of water transfers were adjusted in the model to calibrate simulated pond volumes to measured pond volumes for three ponds. Modeled salinity was then compared with measured salinity, which remained a free parameter, in order to validate the model. Comparison showed good correlation between modeled and measured salinity. Deviations can be attributed to lack of water-transfer information. Water and salinity budgets obtained through modeling will be used to help interpret ecological data from the ponds. This model has been formulated to be applicable to the Napa-Sonoma salt ponds, but can be applied to other salt ponds.
Oxygen and nitrogen dynamics in split ponds vs. conventional catfish production ponds
Technology Transfer Automated Retrieval System (TEKTRAN)
The Split Pond aquaculture system (SP) has captured the attention of catfish producers across the southern U.S. The SP represents a lower cost adaptation of Clemson University's Partitioned Aquaculture System (PAS). The original PAS design relied on slowly rotating paddlewheels to move water throu...
Smooth pond-like deposits on asteroid 4 Vesta: First results from the Dawn mission.
NASA Astrophysics Data System (ADS)
Hiesinger, H.; Ruesch, O.; Jaumann, R.; Nathues, A.; Raymond, C. A.; Russell, C. T.
The Dawn spacecraft arrived at Vesta on July 16, 2011 to study the asteroid with a Framing Camera (FC), a Visible & Infrared Spectrometer (VIR), and a Gamma Ray and Neutron Detector (GRaND) [1]. Dawn provides the first high-resolution data from its survey orbit, high-altitude mapping orbit (HAMO), and low-altitude mapping orbit (LAMO). FC data revealed smooth pond-like deposits of ambiguous origin, similar to deposits on other asteroids, including Eros and Itokawa [2,3]. Several scenarios for the origin of these deposits can be tested with Dawn data, including volcanism, impact sedimentation, impact melt deposition, dust levitation and transport, seismic shaking, or landslides. We measured 83 small (~7 km2 average size) smooth deposits distributed across the surface of Vesta. Most ponds on Vesta occur on the floors of impact craters and in irregular depressions. We did not observe inflow of material into the depressions. Most of these deposits have well-defined geological contacts, indicating that they are younger than the surrounding terrain. However, lunar impact melt pools that formed contemporaneously with surrounding ejecta blankets show similar stratigraphic relationships. Sometimes the albedo of these ponds is lower than the surrounding terrain, in other cases the ponds are indistinguishable from the adjacent terrain. The ponds preferentially occur in a band between -10 and 30 degrees latitude with fewer ponds north of ~30 degrees and even fewer ponds in the southern hemisphere, i.e., the Rheasilvia region. The largest cluster of ponds occurs in the vicinity of the Marcia impact crater, which is part of the so-called snowman craters. Similar, but smaller (<230 m diameter) smooth ponds were also reported from the surface of asteroid Eros [2]. Robinson et al. [2] found that most smooth ponds on Eros occur in equatorial regions and concluded that the most likely process for their formation is electrostatic levitation and redistribution of the finest regolith components (<100 µm). Sierks et al. [4] argued that along the terminator, particularly strong electric fields can develop between the sun-lit and shaded areas, e.g., within craters, resulting in particle motion from sun-lit to dark regions. Dust levitation and transport was also discussed for asteroid 25143 Itokawa [3]. [1] Russell et al., (2007), Earth Moon Planets, 101; [2] Robinson et al., (2002), Met. Planet. Sci., 37; [3] Yano et al., (2006), Science, 312; [4] Sierks et al., (2011), Space Sci. Rev., doi:10.1007/s11214-011-9745-4. This research has been supported by the German Space Agency (DLR) and NASA. We would like to thank the Dawn Operations Team for their success-ful planning and acquisition of high-quality Vesta data.
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
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.
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.
Hilton Pond Center for Piedmont Natural History
NSDL National Science Digital Library
The Hilton Pond Center for Piedmont Natural History is a nonprofit research organization dedicated to the study of the plants, animals, and environments of the Piedmont physiographic province, in particular the banding of birds. Site materials include general information and photographs of the flora and fauna found in habitats of the Piedmont Region of the eastern United States. There are descriptions of the center's research projects, especially bird banding; educational opportunities such as field trips, workshops, and presentations; links to the center's publications; and featured weekly articles and announcements on birds, native cultures, and other topics related to the Piedmont province.
Biological productivity in small impoundments
Technology Transfer Automated Retrieval System (TEKTRAN)
Most ponds and small impoundments are built or used with a principal use in mind. That use may be recreational fishing, commercial aquaculture, waterfowl hunting, potable water storage, irrigation water supply, livestock watering, stormwater retention, landscaping, swimming, or others. In practice, ...
Correlation between snails and fish in fish ponds of World Fish Center (ICLARM) with special reference to snail vectors of schistosomiasis and fascioliasis.
Ismail, Nahed M M; El Gamal, Abd El Rahman A
The abundance of snail species in earthen fish ponds, irrigation and drainage canals at World Fish Center (ICLARM) in descending order was Bellamya unicolor (50.89%) > Physa acuta (18.94%) > Cleopatra bulimoides (7.6%) > Lanistes carinatus (6.73%) > Bulinus truncatus (5.19%) > Melanoides tuberculata (4.83%) > Lymnaea natalensis (3.14%) > Gabbiella senaariensis (0.9%) > Biomphalaria alexandrina (0.55%) > Lym naea truncatula (0.4%) > Planorbis planorbis and Succinea cleopatra (0.33%) > Ferrissia isseli (0.18%). Dead snails constituted about 5.19% of all the collected specimens. There were dramatic decrease in the total number of pulmonates in fish ponds which contained only Tilapia sp., and a very small number of cat fish, whereas the numbers of prosobranchia snails were much higher in these ponds. In fish ponds which accommodated a variety of fish species, the most dominant snail was B. unicolor followed by L. carinatus. However, pulmonate snails were absent in these ponds. B. truncatus was the only snail species found in concrete tank which contained only young tilapias with a very small size (5-8 cm in standard length). In irrigation canals, the number of snails and diversity was much higher than those in fish ponds. Out of 191 snails collected from inlet irrigation canal, 71 were dead, but in the outside irrigation canals, seven out of 564 snails were dead. P. acuta was absent in all examined fish ponds, but it was alive and in a high number (497 snails) in the outside irrigation canals. The number of snails collected from Bahnasawy drain was remarkably low (128 snails), however the diversity of snails was much higher compared to those in fish ponds and irrigation canals. Snail populations were stable with constant recruitment of young to adult snails for all the studied species. PMID:14964656
Box Model of a Series of Salt Ponds, as Applied to the Alviso Salt Pond Complex, South San Francisco Bay, California
Lionberger, Megan A.; Schoellhamer, David H.; Shellenbarger, Gregory G.; Orlando, James L.; Ganju, Neil K.
This report documents the development and application of a box model to simulate water level, salinity, and temperature of the Alviso Salt Pond Complex in South San Francisco Bay. These ponds were purchased for restoration in 2003 and currently are managed by the U.S. Fish and Wildlife Service to maintain existing wildlife habitat and prevent a build up of salt during the development of a long-term restoration plan. The model was developed for the purpose of aiding pond managers during the current interim management period to achieve these goals. A previously developed box model of a salt pond, SPOOM, which calculates daily pond volume and salinity, was reconfigured to simulate multiple connected ponds and a temperature subroutine was added. The updated model simulates rainfall, evaporation, water flowing between the ponds and the adjacent tidal slough network, and water flowing from one pond to the next by gravity and pumps. Theoretical and measured relations between discharge and corresponding differences in water level are used to simulate most flows between ponds and between ponds and sloughs. The principle of conservation of mass is used to calculate daily pond volume and salinity. The model configuration includes management actions specified in the Interim Stewardship Plan for the ponds. The temperature subroutine calculates hourly net heat transfer to or from a pond resulting in a rise or drop in pond temperature and daily average, minimum, and maximum pond temperatures are recorded. Simulated temperature was compared with hourly measured data from pond 3 of the Napa?Sonoma Salt Pond Complex and monthly measured data from pond A14 of the Alviso Salt-Pond Complex. Comparison showed good agreement of measured and simulated pond temperature on the daily and monthly time scales.
Disposal of hypergolic propellants, phase 6 task 4. Disposal pond products
NASA Technical Reports Server (NTRS)
Cohenour, B. C.; Wiederhold, C. N.
Waste monomethyl hydrazine scrubber liquor, consisting of aqueous solutions containing small amounts of CH4, Cl2, CH3Cl, CH2Cl2, and CHCl3 as well as large amounts of CH3OH is scheduled to be dumped in stabilization ponds along with nitrate and nitrite salt solutions obtained as waste liquors from the N2O4 scrubbers. The wastes are investigated as to the hazardous materials generated by such combinations of items as described as well as the finite lifetime of such materials in the stabilization ponds. The gas liquid chromatograph was used in the investigation. A series of experiments designed to convert nitrate and nitrite salts to the environmentally innocuous N2O and N2 using solar energy is reported. Results indicate that this solar conversion is feasible.
Luther, Douglas S.
BIOGEOCHEMICAL ECOLOGY OF AQUACULTURE PONDS A DISSERTATION SUBMITIED TO THE GRADUATE DIVISION production and consumption were applied in shrimp aquaculture ponds which served as convenient model systems
Surface Sediments in Precooler Ponds 2, 4, and 5: March 2000
Dunn, D.L.
Pond 2, Pond 4, and Pond 5 are inactive reactor cooling impoundments built in 1961 on the R-Reactor Effluent System in the east-central portion of the Department of Energy's Savannah River Site in Aiken, South Carolina. These precooler ponds are part of the Par Pond cooling water system and are considered part of the Par Pond operable unit. The intent was not to characterize the ponds, but to identify the maximum levels of contamination that could be exposed if the ponds are drained to remove the danger of dam failure.
Solar pond performance comparisons between mixed and stratified storage zone concepts
Newell, T.A.; Witte, M.J.
Numerical simulation results are presented for a solar pond utilizing a stratified storage zone. Stratification of a solar pond's storage zone can increase solar pond performance due to higher temperatures available for process use and lower temperatures at pond bottom which result in lower ground losses. The present study investigates sensitivity in solar pond performance with seasonal variation of process load demand. For the pond configuration and process conditions modeled, storage zone stratification increased pond performance 30 to 45 percent relative to a conventional pond with mixed storage zone.
Design, construction, and initial operation of the ANL research salt-gradient solar pond
Cha, Y.S.; Sha, W.T.; Hull, J.R.
The design consideration of a 1/4 acre research salt-gradient solar pond is described. Experience learned during the construction of the solar pond is presented. Initial operation of the pond indicates that the construction of the pond is sound and no leakage has occurred. The pond began to warm up during March of 1981. The maximum pond temperature reached 63/sup 0/C at the end of July and it is still rising. All signs indicate that the operation of the well instrumented pond will be a success and the performance of the pond will be as expected, if not better.
Amphibian Oasis: Designing and Building a Schoolyard Pond.
ERIC Educational Resources Information Center
Gosselin, Heather; Johnson, Bob
Building a pond in a schoolyard is a rewarding way to help boost local populations of amphibians, to increase the natural value of school grounds, and to serve as a locale for observing the life cycles of plants, invertebrates, and amphibians. This article outlines important considerations in designing and building a pond from siting through…
Gauging the Health of New England's Lakes and Ponds
The New England Lakes and Ponds Project provides a consistent and first time comprehensive assessment of the ecological and water quality condition of lakes and ponds across the New England region. The project is being conducted by EPA along with the New England Interstate Water...
The Performance of Two Phase Flow Systems in Pond Aeration
Fahri OZKAN; Ahmet BAYLAR; Mehmet TUGAL
Aeration is the process by which the area of contact between water and air is increased, either by natural methods or by mechanical devices. Proper aeration can make considerable improvements in a pond ecosystem. This paper investigates pond aeration by two phase flow systems such as high head gated conduit flow systems and two phase pipe flow systems using venturi
Coleman Revisited: School Segregation, Peers, and Frog Ponds
ERIC Educational Resources Information Center
Goldsmith, Pat Rubio
Students from minority segregated schools tend to achieve and attain less than similar students from White segregated schools. This study examines whether peer effects can explain this relationship using normative models and frog-pond models. Normative models (where peers become alike) suggest that minority schoolmates are a liability. Frog-pond…
Par Pond vegetation status summer 1995 - July survey descriptive summary
H. E. Jr. Mackey; R. S. Riley
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 (61 meters) above mean sea level, and continued with this July survey. Aquatic plant communities, similar to the pre-drawdown Par Pond communities, are becoming reestablished. Beds of maidencane (Panicum hemitomon), lotus (Nelumbo lutea), water lily
of the various State fish commissions which were created in the seventies, and in many States the effort was made for the construction of a system of ponds to be devoted to bassculture. 229 #12;230 BULLETIN OF THE UNITED STATES FISHXÂŻ] THEPROPAGATIONOF BLACK BASS IN PONDS. BY WILLIAM F. PAGE, Superintendent U.S. Fish Commission
HOLDING PONDS FOR ADULT SALMON Marine Biological Laboratory
, Secretary Fish and Wildlife Service, Arnie J. Suomela, Commissioner Bureau of Sport Fisheries and Wildlife and downstream trapping facilities are installed in the holding ponds to capture the sexually mature adults on the upstream migration and held either in the stream or improvised ponds until sexually mature without
An investigation into the performance of 'Phase Isolation' as a means of upgrading facultative lagoons was conducted at Clinton, Mississippi, using 2 facultative lagoons arranged in series followed by 2 isolation ponds used alternately for final polishing. The isolation ponds wer...
ORIGINAL PAPER Humanwildlife conflicts at pond fisheries in eastern Poland
Paris-Sud XI, Université de
ORIGINAL PAPER Humanwildlife conflicts at pond fisheries in eastern Poland: perceptions- tions of inflicted damage, and use of preventive measures at pond fisheries was conducted in 2003. Considering the wide range of species interacting with fisheries, adoption of more flexible policies
Ronquist, Fredrik
ATOLL RESEARCH BULLETIN NO. 476 DIVERSITY OF SPONGE FAUNA IN MANGROVE PONDS, PELICAN CAYS, BELIZE;DIVERSITY OF SPONGE FAUNA IN MANGROVE PONDS, PELICAN CAYS, BELIZE KLAUS RUTZLER,' MARIA CRISTINA DIAZ; ROB W. M. VAN SOEST: SVEN ZEA,4KATHLEEN P. SMITH,' BELINDA ALVAREZ,' and JANIE WULFF6 ABSTRACT Mangrove
Mangroves and brackishwater pond culture in the Philippines
J. Honculada Primavera
Around 50% of mangrove loss in the Philippines can be traced to brackishwater pond construction. The decrease in mangroves from 450 000 ha in 1920 to 132 500 ha in 1990 has been accompanied by expansion of culture ponds to 223 000 ha in 1990. The history of fishpond development in the country includes a government-sponsored fishpond boom in the
Modeling and simulation of solar pond floor heating system
M. T. Alkhalaileh; K. a. Atieh; N. G. Nasser; B. a. Jubran
This paper presents the development of modeling, simulation and analysis of a solar pond floor heating system. The developed computer simulation has been used to study the potential of using such a system under climatic conditions in Jordan. It was found that the solar pond heating system could meet most of the winter season in Jordan with Solar fraction in
Convective layers generated by side walls in solar ponds
A. Akbarzadeh; P. Manins
In this article, the results of series of demonstrative laboratory experiments simulating the possible instabilities in density-gradient solar ponds that can be induced by absorption of sunlight on the sun-facing wall are reported. It was observed that under simulated solar pond conditions, convective layers with thickness between 10 and 20 mm can be generated. The fronts of these layers advance
Solar-Pond Resources in the United States
NASA Technical Reports Server (NTRS)
Hurick, M. G.
Report describes survey of U.S. salt and brine deposits providing essential information for developers considering use of solar ponds for heat and electricity production. Sites classified as areas of ponds about 1 km2, or larger, accommodated in which salt, clay, and water are available.
A critical review of shrimp pond culture in the Philippines
J. Honculada Primavera
The paper reviews and evaluates shrimp pond culture in the Philippines and its ecological and socioeconomic effects. The intertwined histories of the country's mangrove forests and culture ponds are treated in depth; brackishwater aquaculture and the different shrimp culture systems are described. Intensive farming is discussed in terms of feed and water requirements, chemical inputs and waste production, and the
Delayed feeding of channel catfish fry stocked in ponds
Technology Transfer Automated Retrieval System (TEKTRAN)
We compared production variables between channel catfish, Ictalurus punctatus, nursery ponds fed according to industry standards, that is feeding immediately at stocking, to an alternative practice of delaying feeding for 6 wk after stocking in an effort to utilize natural pond productivity and redu...
2101-M Pond hydrogeologic characterization report
Chamness, M.A.; Luttrell, S.P.; Bates, D.J.; Martin, W.J.
This report documents information collected by the Pacific Northwest Laboratory {sup (a)} at the request of Westinghouse Hanford Company. Presented in this report is the interpretation of the hydrogeologic environment at the 2101-M Pond, located in the 200-East Area of the Hanford Site. This information and its accompanying interpretation were derived from sampling and testing activities associated with the installation of four ground-water monitoring wells, in addition to data gathered from several previously existing wells. The new monitoring wells were installed as part of a groundwater monitoring program initiated in 1988. The four new monitoring wells were installed around the 2101-M Pond between May 23 and August 27, 1988. Geologic sampling, aquifer testing, and initial ground-water sampling were performed during the installation of these wells. Laboratory analyses of the sediment samples for particle size, calcium carbonate content, and selected natural and contaminant constituents were performed. A full year of quarterly ground-water sampling and the first statistical analysis of background and downgradient data have also been performed. 112 refs., 49 figs., 18 tabs.
Fate of permethrin in model outdoor ponds
Rawn, G.P.; Webster, G.R.; Muir, D.C.
In 1979 and 1980, outdoor artificial ponds were treated with /sup 14/C-permethrin (labelled at either the cyclopropyl or methylene position) at 0.028 kg/ha (15 ug/L). Uptake of permethrin by duckweed and hydrosoil was monitored by direct combustion, TLC-autoradiography, HPLC, and liquid scintillation counting. Rapid loss of permethrin from the water coincided with the detection of five degradation products in the water at concentrations below 2.0 ug/L. The products were cis- and trans-cyclopropyl acid, phenoxybenzoic acid, and phenoxybenzyl alcohol, and an unknown non-cleaved product of permethrin. Permethrin was readily sorbed by duckweed but was not persistent. Permethrin residues in the hydrosoil, which was the major sink for permethrin added to the ponds, were persistent and were detected at 420 days post-treatment. Cis-permethrin was more persistent in the hydrosoil than the trans-permethrin. The results indicated that permethrin in water was short-lived at an application rate of 15 ug/L because of the rapid degradation of permethrin in the water and sorption of permethrin by the hydrosoil and vegetation. However, at one year post-treatment, permethrin residues were still detected in the hydrosoil at 1.0 ug/kg.
Fine-scale spatial patterns in bacterial community composition and function within freshwater ponds.
Lear, Gavin; Bellamy, Julia; Case, Bradley S; Lee, Jack E; Buckley, Hannah L
The extent to which non-host-associated bacterial communities exhibit small-scale biogeographic patterns in their distribution remains unclear. Our investigation of biogeography in bacterial community composition and function compared samples collected across a smaller spatial scale than most previous studies conducted in freshwater. Using a grid-based sampling design, we abstracted 100+ samples located between 3.5 and 60?m apart within each of three alpine ponds. For every sample, variability in bacterial community composition was monitored using a DNA-fingerprinting methodology (automated ribosomal intergenic spacer analysis) whereas differences in bacterial community function (that is, carbon substrate utilisation patterns) were recorded from Biolog Ecoplates. The exact spatial position and dominant physicochemical conditions (for example, pH and temperature) were simultaneously recorded for each sample location. We assessed spatial differences in bacterial community composition and function within each pond and found that, on average, community composition or function differed significantly when comparing samples located >20?m apart within any pond. Variance partitioning revealed that purely spatial variation accounted for more of the observed variability in both bacterial community composition and function (range: 24-38% and 17-39%) than the combination of purely environmental variation and spatially structured environmental variation (range: 17-32% and 15-20%). Clear spatial patterns in bacterial community composition, but not function were observed within ponds. We therefore suggest that some of the observed variation in bacterial community composition is functionally 'redundant'. We confirm that distinct bacterial communities are present across unexpectedly small spatial scales suggesting that populations separated by distances of >20?m may be dispersal limited, even within the highly continuous environment of lentic water. PMID:24577354
Salton Sea Project, Phase 1. [solar pond power plant
NASA Technical Reports Server (NTRS)
Peelgren, M. L.
A feasibility study was made for a salt gradient solar pond power plant in or near the Salton Sea of California. The conclusions support continuance 5-MWe proof-of-concept experiment, and ultimate construction by an electric utility company of a 600-MWe plant. The Solar Pond concept would be an environmental benefit to the Salton Sea by reversing the increasing salinity trend. The greatest cost drivers are the lake dike construction and pond sealing. Problems to be resolved include method of brine production from Salton Sea water for the first unit (which requires evaporation pond area and time), the high turbidity and color content of the Salton Sea water (which requires pretreatment), and other questions related to pond permeability, bio-activity and soil/brine chemical reactions. All technical and environmental problems appear solvable and/or manageable if care is taken in mitigating impacts.
Crossing the final ecological threshold in high Arctic ponds
Smol, John P.; Douglas, Marianne S. V.
A characteristic feature of most Arctic regions is the many shallow ponds that dot the landscape. These surface waters are often hotspots of biodiversity and production for microorganisms, plants, and animals in this otherwise extreme terrestrial environment. However, shallow ponds are also especially susceptible to the effects of climatic changes because of their relatively low water volumes and high surface area to depth ratios. Here, we describe our findings that some high Arctic ponds, which paleolimnological data indicate have been permanent water bodies for millennia, are now completely drying during the polar summer. By comparing recent pond water specific conductance values to similar measurements made in the 1980s, we link the disappearance of the ponds to increased evaporation/precipitation ratios, probably associated with climatic warming. The final ecological threshold for these aquatic ecosystems has now been crossed: complete desiccation. PMID:17606917
Solar ponds in alkaline lake and oil well regions
Lodhi, M.A.K. [Texas Tech Univ., Lubbock, TX (United States). Dept. of Physics
Solar ponds are probably the simplest technology available for useful conversion of solar energy. The basic technology is proven. Solar ponds have been shown to be technically feasible and economically viable for many applications particularly for thermal use. The electrical conversion and use of solar energy via solar ponds is still questionable in general for economic viability. By putting the untapped sources together in the South Plains region it looks promising economically both for thermal and electrical conversions and applications. There are a number of alkaline lake basins randomly scattered in the South Plains region of the USA. In that area there are thousands of crude oil producing wells which produce brine in abundance. Selection of suitable alkaline lake basins as a solar pond site and as depository sites of brine from oil wells and using of this brine and salty water from alkaline lakes makes the solar pond economically viable for both thermal and electrical demands in the area.
Factors Influencing Fecal Contamination in Pond of Bangladesh
NASA Astrophysics Data System (ADS)
Knappett, P. S.; Escamilla, V.; Layton, A.; McKay, L. D.; Emch, M.; Mailloux, B. J.; Williams, D. E.; Huq, M. R.; Alam, M.; Farhana, L.; Ferguson, A. S.; Sayler, G. S.; Ahmed, K.; Serre, M. L.; Akita, Y.; Yunus, M.; van Geen, A.
Occurrence of diarrheal disease in villages in rural Bangladesh remains relatively common, even though many households have switched to tubewell water for drinking and cooking. One factor contributing to this may be exposure to fecal contamination in ponds, which are often used for bathing and fishing. The objective of this study is to determine the dominant sources of fecal pollution in typical ponds and to explore the relationship between local population, latrine density, latrine quality and concentrations of fecal bacteria and pathogens in pond water. Forty-three ponds were sampled and analyzed for E. coli using culture-based methods and for E. coli, Bacteroides and adenovirus using quantitative PCR. Population and sanitation infrastructure were surveyed and compared to levels of pond fecal contamination. Molecular fecal source tracking using Bacteroides, determined that humans were the dominant source of fecal contamination in 79% of the ponds. Ponds directly receiving latrine effluent had the highest concentrations of fecal indicator bacteria. Concentrations of fecal indicator bacteria correlated with population surveyed within a distance of 30-70 m (p<0.01) and total latrines surveyed within 50-70 m (p<0.05). Unsanitary latrines with visible effluent within the pond drainage basin were also significantly correlated to fecal indicator concentrations (p<0.05). The vast majority of the surveyed ponds contained unsafe levels of fecal contamination primarily due to unsanitary latrines, and to lesser extent to sanitary latrines and cattle. Since the majority of fecal pollution is from humans, use of pond water could help explain the persistence of diarrheal disease in rural Bangladesh.
Eutrophic urban ponds suffer from cyanobacterial blooms: Dutch examples.
Waajen, Guido W A M; Faassen, Elisabeth J; Lürling, Miquel
Ponds play an important role in urban areas. However, cyanobacterial blooms counteract the societal need for a good water quality and pose serious health risks for citizens and pets. To provide insight into the extent and possible causes of cyanobacterial problems in urban ponds, we conducted a survey on cyanobacterial blooms and studied three ponds in detail. Among 3,500 urban ponds in the urbanized Dutch province of North Brabant, 125 showed cyanobacterial blooms in the period 2009-2012. This covered 79% of all locations registered for cyanobacterial blooms, despite the fact that urban ponds comprise only 11% of the area of surface water in North Brabant. Dominant bloom-forming genera in urban ponds were Microcystis, Anabaena and Planktothrix. In the three ponds selected for further study, the microcystin concentration of the water peaked at 77 ?g l(-1) and in scums at 64,000 ?g l(-1), which is considered highly toxic. Microcystin-RR and microcystin-LR were the most prevalent variants in these waters and in scums. Cyanobacterial chlorophyll-a peaked in August with concentrations up to 962 ?g l(-1) outside of scums. The ponds were highly eutrophic with mean total phosphorus concentrations between 0.16 and 0.44 mg l(-1), and the sediments were rich in potential releasable phosphorus. High fish stocks dominated by carp lead to bioturbation, which also favours blooms. As urban ponds in North Brabant, and likely in other regions, regularly suffer from cyanobacterial blooms and citizens may easily have contact with the water and may ingest cyanobacterial material during recreational activities, particularly swimming, control of health risk is of importance. Monitoring of cyanobacteria and cyanobacterial toxins in urban ponds is a first step to control health risks. Mitigation strategies should focus on external sources of eutrophication and consider the effect of sediment P release and bioturbation by fish. PMID:24798921
Impact of permafrost thaw on Arctic tundra pond geochemistry
NASA Astrophysics Data System (ADS)
Reyes, F.; Lougheed, V.
Increasing evidence indicates the arctic tundra is changing physically, biologically, and chemically due to climate warming. With a warmer climate, permafrost is expected to thaw and influence the chemistry of arctic aquatic ecosystems. However, knowledge is limited on how geochemistry of arctic tundra pond ecosystems will respond. By re-sampling historical IBP ponds in Barrow, AK first sampled in the 1970s, previous studies have shown an increase in water temperature, nutrients and algal biomass through time. Results from this study indicate an increase of Ca, Mg, and Na in the water column, and a decrease in pH relative to the 1970s, suggesting an increased rate and magnitude of carbonate and Mg release. Seasonal trends were also examined to understand what processes, such as mineral weathering, peat decomposition and evaporation, were currently most influential in determining pond geochemistry. An increase in Ca/Na molar ratios, and carbonate and magnesium concentrations indicates that these tundra ponds are experiencing greater carbonate weathering compared to the 1970s and the rate of carbonate weathering increases in ponds as the summer progresses. However, increasing dissolved organic carbon (DOC) concentrations originating from peat decomposition are likely neutralizing additional inputs of carbonate, causing pond pH to decrease and exacerbating mineral weathering. A strong positive relationship between element concentrations and active layer pond thaw depth suggests that the origin of these additional solutes is likely from permafrost thaw. Active layer thaw depth has increased substantially over the past 40 years in the IBP ponds. Chloride/Bromide molar ratios and Deuterium/ 18-Oxygen isotope ratios will be used to determine the degree of evaporation occurring in tundra ponds. Ultimately, this study provides evidence for how geochemistry can identify the sources of chemical inputs to Arctic ponds affected by climate change and permafrost thaw.
Diverting victims of commercial sexual exploitation from juvenile detention: development of the InterCSECt screening protocol.
Salisbury, Emily J; Dabney, Jonathan D; Russell, Kelli
Identifying victims of commercial sexual exploitation in the juvenile justice system is a challenging complexity requiring concerted organizational commitment. Using a three-tiered, trauma-informed screening process, a 3˝-month pilot intervention was implemented in Clark County Juvenile Court (Washington) to identify victims in an effort to connect them to community youth advocates and sexual assault resources. A total of 535 boys and girls ages 9 to 19 were screened during intake; 47 of these youth reported risk factors associated with commercial sexual exploitation of children (CSEC) and were subsequently referred to community advocates. Six youth (all girls) were confirmed CSEC victims and were successfully diverted from juvenile detention. Study results suggest that despite the lack of reliable data surrounding the prevalence of CSEC, juvenile justice agencies need to become educated on the risk factors to triage victims to services. PMID:25038222
Fuel Pond Sludge - Lessons Learned from Initial De-sludging of Sellafield's Pile Fuel Storage Pond - 12066
Carlisle, Derek; Adamson, Kate [Sellafield Ltd, Sellafield, Cumbria (United Kingdom)
The Pile Fuel Storage Pond (PFSP) at Sellafield was built and commissioned between the late 1940's and early 1950's as a storage and cooling facility for irradiated fuel and isotopes from the two Windscale Pile reactors. The pond was linked via submerged water ducts to each reactor, where fuel and isotopes were discharged into skips for transfer along the duct to the pond. In the pond the fuel was cooled then de-canned underwater prior to export for reprocessing. The plant operated successfully until it was taken out of operation in 1962 when the First Magnox Fuel Storage Pond took over fuel storage and de-canning operations on the site. The pond was then used for storage of miscellaneous Intermediate Level Waste (ILW) and fuel from the UK's Nuclear Programme for which no defined disposal route was available. By the mid 1970's the import of waste ceased and the plant, with its inventory, was placed into a passive care and maintenance regime. By the mid 1990s, driven by the age of the facility and concern over the potential challenge to dispose of the various wastes and fuels being stored, the plant operator initiated a programme of work to remediate the facility. This programme is split into a number of key phases targeted at sustained reduction in the hazard associated with the pond, these include: - Pond Preparation: Before any remediation work could start the condition of the pond had to be transformed from a passive store to a plant capable of complex retrieval operations. This work included plant and equipment upgrades, removal of redundant structures and the provision of a effluent treatment plant for removing particulate and dissolved activity from the pond water. - Canned Fuel Retrieval: Removal of canned fuel, including oxide and carbide fuels, is the highest priority within the programme. Handling and export equipment required to remove the canned fuel from the pond has been provided and treatment routes developed utilising existing site facilities to allow the fuel to be reprocessed or conditioned for long term storage. - Sludge Retrieval: In excess of 300 m{sup 3} of sludge has accumulated in the pond over many years and is made up of debris arising from fuel and metallic corrosion, wind blown debris and bio-organic materials. The Sludge Retrieval Project has provided the equipment necessary to retrieve the sludge, including skip washer and tipper machines for clearing sludge from the pond skips, equipment for clearing sludge from the pond floor and bays, along with an 'in pond' corral for interim storage of retrieved sludge. Two further projects are providing new plant processing routes, which will initially store and eventually passivate the sludge. - Metal Fuel Retrieval: Metal Fuel from early Windscale Pile operations and various other sources is stored within the pond; the fuel varies considerably in both form and condition. A retrieval project is planned which will provide fuel handling, conditioning, sentencing and export equipment required to remove the metal fuel from the pond for export to on site facilities for interim storage and disposal. - Solid Waste Retrieval: A final retrieval project will provide methods for handling, retrieval, packaging and export of the remaining solid Intermediate Level Waste within the pond. This includes residual metal fuel pieces, fuel cladding (Magnox, aluminium and zircaloy), isotope cartridges, reactor furniture, and miscellaneous activated and contaminated items. Each of the waste streams requires conditioning to allow it to be and disposed of via one of the site treatment plants. - Pond Dewatering and Dismantling: Delivery of the above projects will allow operations to progressively remove the radiological inventory, thereby reducing the hazard/risk posed by the plant. This will then allow subsequent dewatering of the pond and dismantling of the structure. (authors)
Par Pond phytoplankton in association with refilling of the pond: Final Report for sampling from February 1995 -- September 1996
Wilde, E.W.; Johnson, M.A.; Cody, W.C.
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.
Results of submerged sediment core sampling and analysis on Par Pond, Pond C, and L Lake: July 1995
Koch, J.W. II; Martin, F.D.; Friday, G.P.
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.
Western Pond Turtle Head-starting and Reintroduction, 2005-2006 Annual Report.
Van Leuven, Susan; Allen, Harriet; Slavens, Kate (Washington Department of Fish and Wildlife, Wildlife Management Program, Olympia, WA)
This report covers the results of the western pond turtle head-starting and reintroduction project for the period of October 2005-September 2006. Wild hatchling western pond turtles from the Columbia River Gorge were reared at the Woodland Park and Oregon zoos in 2005 and 2006 as part of the recovery effort for this Washington State endangered species. The objective of the program is to reduce losses to introduced predators like bullfrogs and largemouth bass by raising the hatchlings to a size where they are too large to be eaten by most of these predators. Twenty-six turtles were placed at the Woodland Park Zoo and 62 at the Oregon Zoo in fall 2005. These turtles joined two that were held back from release in summer 2005 due to their small size. All 90 juvenile turtles were released at three sites in the Columbia Gorge in 2006. Twenty-eight juvenile turtles were released at the Klickitat ponds, 22 at the Klickitat lake, 21 at the Skamania site, and 19 at Pierce National Wildlife Refuge (NWR). This brought the total number of head-start turtles released since 1991 to 944; 285 for the Klickitat ponds, 158 for the Klickitat lake, 227 for the Skamania pond complex, and 274 at Pierce NWR. In 2006, 20 females from the Klickitat population were equipped with transmitters and monitored for nesting activity. Fifteen nests were located and protected; these produced 55 hatchlings. The hatchlings were collected in September and transported to the Oregon and Woodland Park zoos for rearing in the head-start program. One wild hatchling captured in spring 2006 was placed in the head-start program to attain more growth in captivity. During the 2006 field season trapping effort, 414 western pond turtles were captured in the Columbia Gorge, including 374 previously head-started turtles. These recaptures, together with confirmed nesting by head-start females and visual resightings, indicate the program is succeeding in boosting juvenile recruitment to increase the populations. Records were also collected on 179 individual painted turtles captured in 2006 during trapping efforts at Pierce NWR, to gather baseline information on this native population.
CO2 dynamics of tundra ponds in the low-Arctic, Northwest Territories, Canada
NASA Astrophysics Data System (ADS)
Buell, Mary-Claire
Extensive research has gone into measuring changes to the carbon storage capacity of Arctic terrestrial environments as well as large water bodies in order to determine a carbon budget for many regions across the Arctic. Inland Arctic waters such as small lakes and ponds are often excluded from these carbon budgets, however a handful of studies have demonstrated that they can often be significant sources of carbon to the atmosphere. This study investigated the CO2 cycling of tundra ponds in the Daring Lake area, Northwest Territories, Canada (64°52'N, 111°35'W), to determine the role ponds have in the local carbon cycle. Floating chambers, nondispersive infrared (NDIR) sensors and headspace samples were used to estimate carbon fluxes from four selected local ponds. Multiple environmental, chemical and meteorological parameters were also monitored for the duration of the study, which took place during the snow free season of 2013. Average CO2 emissions for the two-month growing season ranged from approximately -0.0035 g CO2-C m-2 d -1 to 0.12 g CO2-C m-2 d-1. The losses of CO2 from the water bodies in the Daring Lake area were approximately 2-7% of the CO2 uptake over vegetated terrestrial tundra during the same two-month period. Results from this study indicated that the production of CO2 in tundra ponds was positively influenced by both increases in air temperature, and the delivery of carbon from their catchments. The relationship found between temperature and carbon emissions suggests that warming Arctic temperatures have the potential to increase carbon emissions from ponds in the future. The findings in this study did not include ebullition gas emissions nor plant mediated transport, therefore these findings are likely underestimates of the total carbon emissions from water bodies in the Daring Lake area. This study emphasizes the need for more research on inland waters in order to improve our understanding of the total impact these waters may have on the Arctic's atmospheric CO2 concentrations now and in the future.
Heavy metal composition in stormwater and retention in ponds dependent on pond age, design and catchment type.
Egemose, Sara; Sřnderup, Melanie J; Grudinina, Anna; Hansen, Anders S; Flindt, Mogens R
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. The concentrations varied considerably depending on the catchment type, with the highest concentrations coming from industrial areas and the lowest from uncultivated and rural areas. Ponds can effectively remove heavy metals in particulate forms through sedimentation processes, but the dissolved forms are more 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 such as pH, oxygen and organic matter. Input of metals to the ponds was reflected in the sediment content, but not significantly for all heavy metals probably due to low or varying retention caused by mineralization and re-suspension. The heavy metal concentration in the outlets was reduced to non-toxic levels, except for Cu and Cr at a few study sites. PMID:25262998
Solar pond research at the Los Alamos National Laboratory
Jones, G.F.; Meyer, K.A.; Hedstrom, J.C.; Grimmer, D.P.
A description of solar pond research at Los Alamos National Laboratory is presented. The main issues in the theory of solar ponds are discussed. Among these are the interfacial-boundary-layer model, models for interface motion and pond performance, heat extraction, and ground heat loss. The core of the research effort at Los Alamos was the development of a one-dimensional computer program to accurately predict dynamic performance of a solar pond. The computer model and the experiments that were designed and performed to validate it are described. The experiments include two laboratory tanks wherein temperature, salinity, and flow visualization data were obtained and a 232 m/sup 2/ outdoor solar pond. Results from preliminary validation show good agreement between the pond's predicted dynamic behavior and that which actually occurred in the experiments. More validation using data from full-sized solar ponds is needed. A new correlation for the ratio of interfacial salt-flux to heat-flux is proposed which agrees well with our data. Recommendations for future research are given.
Renewable energy for the aeration of wastewater ponds.
Hobus, I; Hegemann, W
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 < 1.5 m) corresponding to a high oxygen production of algae. For the layout of the individual components: 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. PMID:14510232
CO2 Efflux from Shrimp Ponds in Indonesia
Sidik, Frida; Lovelock, Catherine E.
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. PMID:23755306
Heat transfer from a solar pond through saturated groundwater flow
Dadkhah, A.
Heat losses from a salt gradient solar pond through saturated groundwater flow was studied by developing a finite difference computer model. The first part of the model calculates the rate of the seepage from the solar pond and measures the velocity components for the nodes of the hydraulic flownet created by the seepage flow. The second part of the model solves the time dependent two dimensional energy equation to predict the time dependent temperature distribution under a solar pond and estimates the amount of the at loss by conduction and the mass flow. The model can be applied to unlined solar pond where the heat loss is by conduction as well as convection (mass flow). It also may be applied to a lined solar pond where the heat loss by convection is neglected. Sensitivity analysis for the model was done by studying the rate of the heat loss, applying (1) different solar pond lower zone temperatures, (2) different hydraulic conductivities, (3) different groundwater velocities, and (4) different sizes of the solar pond.
Heat extraction from the ANL research salt gradient solar pond
Hull, J.R.; Scranton, A.B.; Mehta, J.M.; Cho, S.H.; Kasza, K.E.
This report documents the design considerations and test results of two heat extraction systems for the ANL Research Salt Gradient Solar Pond (RSGSP). Since operation began in November 1980, the RSGSP has been used to study a wide variety of solar pond phenomena, and the behavior of the RSGSP without heat extraction has been well characterized. Heat extraction equipment was installed in the spring of 1984, with heat extraction experiments conducted the following summer and fall and in the fall of 1985. The experiments simulated the use of the solar pond for grain drying. Two methods of heat extraction are compared. For both methods the heat exchangers are sized for 30 kW, with a peak load capability of 60 kW. In the first method, ethylene glycol solution is circulated through a plastic-tube heat exchanger submerged in the pond to a liquid-to-air fin-tube heat exchanger external to the pond. In the second method, hot brine is withdrawn from the bottom of the pond, circulated through a brine-to-air heat exchanger, and the cooled brine is returned to the bottom of the pond. The brine-to-air heat exchanger is constructed from copper-nickel to minimize corrosion. The effects of both heat extraction methods on the stability of the salt gradient are investigated.
Farfan, E.
Decommissioning of nuclear power plants and other nuclear fuel cycle facilities has been an imperative issue lately. There exist significant experience and generally accepted recommendations on remediation of lands with residual radioactive contamination; however, there are hardly any such recommendations on remediation of cooling ponds that, in most cases, are fairly large water reservoirs. The literature only describes remediation of minor reservoirs containing radioactive silt (a complete closure followed by preservation) or small water reservoirs resulting in reestablishing natural water flows. Problems associated with remediation of river reservoirs resulting in flooding of vast agricultural areas also have been described. In addition, the severity of environmental and economic problems related to the remedial activities is shown to exceed any potential benefits of these activities. One of the large, highly contaminated water reservoirs that require either remediation or closure is Karachay Lake near the MAYAK Production Association in the Chelyabinsk Region of Russia where liquid radioactive waste had been deep well injected for a long period of time. Backfilling of Karachay Lake is currently in progress. It should be noted that secondary environmental problems associated with its closure are considered to be of less importance since sustaining Karachay Lake would have presented a much higher radiological risk. Another well-known highly contaminated water reservoir is the Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond, decommissioning of which is planned for the near future. This study summarizes the environmental problems associated with the ChNPP Cooling Pond decommissioning.
Environmental Problems Associated With Decommissioning The Chernobyl Nuclear Power Plant Cooling Pond
Farfan, E. B.; Jannik, G. T.; Marra, J. C.; Oskolkov, B. Ya.; Bondarkov, M. D.; Gaschak, S. P.; Maksymenko, A. M.; Maksymenko, V. M.; Martynenko, V. I.
Decommissioning of nuclear power plants and other nuclear fuel cycle facilities has been an imperative issue lately. There exist significant experience and generally accepted recommendations on remediation of lands with residual radioactive contamination; however, there are hardly any such recommendations on remediation of cooling ponds that, in most cases, are fairly large water reservoirs. The literature only describes remediation of minor reservoirs containing radioactive silt (a complete closure followed by preservation) or small water reservoirs resulting in reestablishing natural water flows. Problems associated with remediation of river reservoirs resulting in flooding of vast agricultural areas also have been described. In addition, the severity of environmental and economic problems related to the remedial activities is shown to exceed any potential benefits of these activities. One of the large, highly contaminated water reservoirs that require either remediation or closure is Karachay Lake near the MAYAK Production Association in the Chelyabinsk Region of Russia where liquid radioactive waste had been deep well injected for a long period of time. Backfilling of Karachay Lake is currently in progress. It should be noted that secondary environmental problems associated with its closure are considered to be of less importance since sustaining Karachay Lake would have presented a much higher radiological risk. Another well-known highly contaminated water reservoir is the Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond, decommissioning of which is planned for the near future. This study summarizes the environmental problems associated with the ChNPP Cooling Pond decommissioning.
Development of Floating Wave Barriers for Cost Effective Protection of Irrigation and Catfish Pond Levees
NASA Astrophysics Data System (ADS)
Ozeren, Y.; Wren, D. G.; Alonso, C. V.
Earth levees for catfish ponds and irrigation water storage experience significant embankment erosion due to wind generated waves. Large seasonal fluctuations in water level make vegetative bank protection impractical, and other stabilization methods such as the use of old tires or riprap are not acceptable due to ecological and economic concerns. The goal of the present work is to define configurations and construction techniques for inexpensive floating breakwaters made of polyethylene irrigation tubing. Based on wave characteristics measured in an irrigation pond near Lonoke, Arkansas, a laboratory scale wave generating flume was designed, constructed, and used to test multiple wave barrier configurations for regular waves in deep and transitional water depths. Wave transmission characteristics were investigated for the following breakwater arrangements: (1) fully restrained, (2) vertically restrained with a single mooring line, (3) horizontally restrained with a rigid arm hinged at one end, and (4) horizontally restrained with piles at both sides of the breakwater. The test results show that cylindrical pipes can be used effectively as floating breakwaters and that wave transmission characteristics strongly depend on the draft of the breakwater and the mooring configuration. The use of multiple small cylinders instead of a single large one can reduce cost while maintaining the same level of wave attenuation. The wave characteristics measured in the field and the results of laboratory testing resulted in a final design that is to be tested at the prototype scale in an irrigation pond.
Aerobic bacterial microbiota isolated from the cloaca of the European pond turtle (Emys orbicularis) in Poland.
Nowakiewicz, Aneta; Zió?kowska, Gra?yna; Zi?ba, Przemys?aw; Dziedzic, Barbara Majer; Gnat, Sebastian; Wójcik, Mariusz; Dziedzic, Roman; Kostruba, Anna
We conducted a comparative analysis of the aerobic cloacal bacteria of European pond turtles (Emys orbicularis) living in their natural environment and juvenile turtles reared under controlled conditions in a breeding center. We included 130 turtles in the study. The aerobic bacteria isolated from the cloaca of the juvenile turtles were less diverse and more prevalent than the bacteria isolated from free-living adults. We isolated 17 bacterial species from juvenile captive turtles, among which the dominant species were Cellulomonas flavigena (77/96), Enterococcus faecalis (96/96), Escherichia coli (58/96), and Proteus mirabilis (41/96). From the adult, free-living turtles, we isolated 36 bacterial species, some of which are a potential threat to public health (e.g., Salmonella enterica serovars Newport, Daytona, and Braenderup; Listeria monocytogenes; Yersinia enterocolitica; Yersinia ruckeri; Klebsiella pneumoniae; Vibrio fluvialis; and Serratia marcescens), and pathogens that are etiologic agents of diseases of ectothermic animals (e.g., Aeromonas sobria, Aeromonas caviae, Hafnia alvei, Edwardsiella tarda, and Citrobacter braakii; the last two species were isolated from both groups of animals). The cloacal bacterial biota of the European pond turtle was characterized by numerous species of bacteria, and its composition varied with turtle age and environmental conditions. The small number of isolated bacteria that are potential human pathogens may indicate that the European pond turtle is of relatively minor importance as a threat to public health. PMID:25380369
The onset of thermohaline convection in the advanced solar pond (ASP)
Bemporad, G.A.; Rubin, H. (Technion-Israel Inst. of Technology, Haifa (Israel))
This manuscript concerns the onset of thermohaline convection in a solar pond subject to field conditions as well as a small scale laboratory test section simulating the solar pond performance. The onset of thermohaline convection is analyzed in this study by means of a linear stability analysis in which the flow field perturbations are expended in sets of complete orthonormal functions satisfying the boundary conditions of the flow field. The linear stability analysis is first performed with regard to an advanced solar pond (ASP) subject to field conditions in which thermohaline convection develops in planes perpendicular to the unperturbed flow velocity vector. In the laboratory simulator of the ASP the width and depth are of the same order of magnitude. In this case it is found that the side walls delay the onset of convection in planes perpendicular to the unperturbed flow velocity vector. The presence of the side walls may cause the planes parallel to the flow velocity to be the most susceptible to the development on all three spatial variables, are predicted. They may develop in planes parallel or perpendicular to the unperturbed velocity vector according to the value of the Reynolds number of the unperturbed flow and the ratio between the width and depth of the ASP simulator.
Groundwater impact assessment report for the 100-D Ponds
Alexander, D.J.
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.
Interactions between snow and melt ponds in sea ice models
NASA Astrophysics Data System (ADS)
Lecomte, Olivier; Fichefet, Thierry; Flocco, Daniela; Schroeder, David; Vancoppenolle, Martin
Snow cover on sea ice at the end of the winter persists into the early part of the sea ice melt season, and the spatial distribution of snow affects the surface topography, the distribution of initial melt pond formation and its subsequent evolution. After the initial formation of melt ponds, the low albedo of the ponds compared to snow or bare ice causes the ponds to preferentially absorb solar radiation and therefore further affects surface ice melt. A physically based melt pond model was coupled to the thermodynamic-dynamic Louvain-la-Neuve Sea-Ice Model (LIM, version 3), which recently includes a representation of snow properties and processes. In the new snow scheme, snow is represented in multiple layers with varying thermo-physical properties, and simple parameterizations for blowing snow and fresh water refreezing into the snow were implemented. Several simulations were performed using the combined snow and melt pond configuration to study the impacts of the processes described above on the Arctic sea ice melt pond fractions. Preliminary results lead to two expected but uncorroborated model behaviors. In the simulations, blowing snow tends to decrease the average snow depth on sea ice due to losses into leads, thus allowing wider but shallower ponds on multiyear ice, while no significant effect is noticeable on first-year ice. Similarly, the refreezing of water in the snow curtails the amount of meltwater available to feed melt ponds on thick ice categories, where some snow may persist through the melt season, but has a limited or no impact on thin ice where snow melts away rapidly.
Vegetation effects on floating treatment wetland nutrient removal and harvesting strategies in urban stormwater ponds.
Wang, Chih-Yu; Sample, David J; Bell, Cameron
Floating treatment wetlands (FTWs) consist of emergent macrophytes that are placed on a floating mat in a pond for water treatment and aesthetic purposes. FTWs may have unique advantages with respect to treating urban runoff within existing retention ponds for excess nutrients. However, research is lacking in providing guidance on performance of specific species for treating urban runoff, and on timing of harvest. Harvesting is needed to remove nutrients permanently from the retention pond. We investigated vegetation effects on FTWs on nitrogen (N) and phosphorus (P) removal performance and storage in above-ground FTW macrophyte tissues. The study evaluated pickerelweed (PW, Pontederia cordata L.) and softstem bulrush (SB, Schoenoplectus tabernaemontani) over time in microcosms flushed with water obtained from a nearby urban retention pond in northern Virginia near Washington, DC. While the literature exhibits a wide range of experimental sizes, using the term mesocosm, we have chosen the term microcosm to reflect the small size of our vessel; and do not include effects of sediment. The experiment demonstrated PW outperformed SB for P and N removal. Based upon analysis of the accumulated nutrient removal over time, a harvest of the whole PW and SB plants in September or October is recommended. However, when harvesting only the aerial parts, we recommend harvesting above-ground PW tissues in July or August to maximize nutrient removal. This is because PW translocates most of its nutrients to below-ground storage organs in the fall, resulting in less nutrient mass in the above-ground tissue compared to the case in the summer (vegetative stage). Further research is suggested to investigate whether vegetation can be overly damaged from multiple harvests on an annual basis in temperate regions. PMID:25214393
Changing the Rules on Fuel Export at Sellafield's First Fuel Storage Pond - 12065
Carlisle, Derek [Sellafield Ltd, Sellafield, Cumbria (United Kingdom)
The Pile Fuel Storage Pond (PFSP) was built in 1949/50 to receive, store and de-can fuel and isotopes from the Windscale Piles. Following closure of the Piles in 1957, plant operations were scaled down until fuel processing eventually ceased in 1962. The facility has held an inventory of metal fuel both from the Piles and from other programmes since that time. The pond is currently undergoing remediation and removal of the fuel is a key step in that process, unfortunately the fuel export infrastructure on the plant is no longer functional and due to the size and limited lifting capability, the plant is not compatible with today's large volume heavy export flasks. The baseline scheme for the plant is to package fuel into a small capacity flask and transfer it to another facility for treatment and repackaging into a flask compatible with other facilities on site. Due to programme priorities the repackaging facility is not available to do this work for several years causing a delay to the work. In an effort accelerate the programme the Metal Fuel Pilot Project (MFPP) was initiated to challenge the norms for fuel transfer and develop a new methodology for transferring the fuel. In developing a transfer scheme the team had to overcome challenges associated with unknown fuel condition, transfers outside of bulk containment, pyro-phoricity and oxidisation hazards as well as developing remote control and recovery systems for equipment not designed for this purpose. A combination of novel engineering and enhanced operational controls were developed which resulted in the successful export of the first fuel to leave the Pile Fuel Storage Pond in over 40 years. The learning from the pilot project is now being considered by the main project team to see how the new methodology can be applied to the full inventory of the pond. (author)
Heat extraction from salinity-gradient solar ponds using heat pipe heat exchangers
Tundee, Sura; Terdtoon, Pradit; Sakulchangsatjatai, Phrut [Department of Mechanical Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200 (Thailand); Singh, Randeep; Akbarzadeh, Aliakbar [Energy Conservation and Renewable Energy Group, School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Bundoora East Campus, Bundoora, Victoria 3083 (Australia)
This paper presents the results of experimental and theoretical analysis on the heat extraction process from solar pond by using the heat pipe heat exchanger. In order to conduct research work, a small scale experimental solar pond with an area of 7.0 m{sup 2} and a depth of 1.5 m was built at Khon Kaen in North-Eastern Thailand (16 27'N102 E). Heat was successfully extracted from the lower convective zone (LCZ) of the solar pond by using a heat pipe heat exchanger made from 60 copper tubes with 21 mm inside diameter and 22 mm outside diameter. The length of the evaporator and condenser section was 800 mm and 200 mm respectively. R134a was used as the heat transfer fluid in the experiment. The theoretical model was formulated for the solar pond heat extraction on the basis of the energy conservation equations and by using the solar radiation data for the above location. Numerical methods were used to solve the modeling equations. In the analysis, the performance of heat exchanger is investigated by varying the velocity of inlet air used to extract heat from the condenser end of the heat pipe heat exchanger (HPHE). Air velocity was found to have a significant influence on the effectiveness of heat pipe heat exchanger. In the present investigation, there was an increase in effectiveness by 43% as the air velocity was decreased from 5 m/s to 1 m/s. The results obtained from the theoretical model showed good agreement with the experimental data. (author)
Predation and the distribution and abundance of a pulmonate pond snail
Kenneth M. Brown; Dennis R. DeVries
The abundances of a freshwater pulmonate snail, Lymnaea elodes were studied in a temporary pond and a permanent, more productive pond in northeastern Indiana, USA. When snails from both populations were reared in each of the ponds in containers excluding predators, snails grew to be 1.3 to 2 times as large in the more productive pond, and laid 9 times
Construction and operation activities at the University of Illinois salt gradient solar pond
T. A. Newell; R. G. Cowie; J. M. Upper; M. K. Smith; G. L. Cler
The construction and operational activities at the University of Illinois (U.I.) salt gradient solar pond facility are described. Several discussions are given on major topics related to solar ponds. The discussions also contain cost information where available or relevant. Overall, the U.I. solar pond has demonstrated that solar ponds for low grade heating applications, such as space heating and grain
A model of melt pond evolution on sea ice P. D. Taylor and D. L. Feltham
Feltham, Daniel
short-wave radiation. The difference in solar energy ab- sorption between pond-covered and bare sea iceA model of melt pond evolution on sea ice P. D. Taylor and D. L. Feltham Centre for Polar-dimensional, thermodynamic, and radiative model of a melt pond on sea ice is presented that explicitly treats the melt pond
Theoretical and experimental comparison of conventional and advanced solar pond performance
Y. Keren; H. Rubin; J. Atkinson; M. Priven; G. A. Bemporad
Numerical and physical experiments were carried out to compare the performance of two solar pond systems: (a) a conventional salt gradient solar pond (CSP) and (b) a salt gradient pond operated as an [open quotes]advanced solar pond[close quotes] (ASP). The main differences in the ASP, as originally proposed by Osdor, are an increase in overall salinity and the introduction of
Evaluation of the Rulison drilling effluent pond as trout habitat
The Rulison Site is located in Section 25, township 7 South, Range 95 West, Garfield County, Colorado. The site is approximately 19 kilometers (km) (12 miles [mi]) southwest of Rifle Colorado, and approximately 65 km (40 mi) northeast of Grand Junction, Colorado. Project Ruhson was an experiment conducted jointly by the U.S. Atomic Energy Commission and Austral Oil Company to test the feasibility of using a nuclear device to increase natural gas production in low permeability geological formations. The experiment was conducted on September 10, 1969, and consisted of detonating a 43-kiloton nuclear device at a depth of 2,568 meters (m) (8,426 feet [ft]) below the ground surface (DOE, 1994). The Rulison Drilling Effluent Pond (called `the pond`) is an engineered structure covering approximately 0.2 hectare (0.5 acre), which was excavated and used to store drilling fluids during drilling of the device emplacement well. The drilling fluids consisted of bentonitic drilling mud with additives such as diesel fuel and chrome lignosulfonate. Most of the drilling muds were removed from the pond when the site was decommissioned in 1976, and the pond was subsequently stocked with rainbow trout by the land owner and used as a fishing pond. In 1994 and 1995, the U.S. Department of Energy (DOE) conducted sampling of the pond to evaluate residual contamination from the drilling fluids. Based on the results of this sampling, the DOE conducted a voluntary cleanup action in order to reduce the levels of total petroleum hydrocarbons and chromium in pond sediments. The cleanup was conducted between August and mid-November of 1995. At the end of cleanup activities, the pond was lined with a clay geofabric and left dry. The geofabric was covered with sod to protect it. The pond has since been refilled by snowmelt and inflow from a spring. Prior to remediation, the pond apparently had sufficient water quality and food resources to support stocked rainbow trout. The purpose of this investigation was to evaluate the present ecological status of the pond and to determine if post-remediation water quality and food resources are adequate to support stocked rainbow trout. Sampling of the pond was conducted by IT Corporation (IT) on September 10, 1996.
Limnological database for Par Pond: 1959 to 1980
Tilly, L.J.
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.
Dual Wall Angles Would Enhance Performance Of A Solar Pond
NASA Technical Reports Server (NTRS)
Noever, David A.
Proposed dual-angle design for Sun-facing wall of solar pond enhances solar-energy-storage performance of pond; increase in performance over that of similar pond with conventional (single-angle) wall estimated to be 25 percent. Design compromises between maximizing heating and minimizing convection. Top part of Sun-facing wall optimized for top colder layer of water, less tendency toward convective mixing. Bottom part of wall optimized for bottom, warmer layer of water, greater tendency towards convection. Optimization involves consideration of both anticipated temperature-vs.-depth profile (affects tendency toward convection) and latitude (affects angle of incidence of solar radiation and rate of heating).
Ponded Impact Melt Dynamics and its Effects on Pond Surface Morphology - Insights from King Crater
NASA Astrophysics Data System (ADS)
Ashley, J. W.; DiCarlo, N.; Enns, A. C.; Hawke, B. R.; Hiesinger, H.; Robinson, M. S.; Sato, H.; Speyerer, E.; van der Bogert, C.; Wagner, R.; Young, K. E.; LROC Science Team
King crater is a 77-km diameter impact feature located at 5.0°N and 120.5°E on the lunar farside. Previous work delimited King crater with an asymmetric distribution of ejecta that includes a large impact melt pond (~385 square kilometer surface area), located in nearby Al-Tusi crater. The pond provides an opportunity to study the behavior of a large impact melt deposit. The Lunar Reconnaissance Orbiter Camera (LROC) Wide Angle Camera (WAC) and Narrow Angle Cameras (NAC) [1] imaged King crater from a nominal 50 km altitude at pixel scales of 100 meters and up to 0.5 meters, respectively providing the means to create geologic maps for the region. Digital terrain/elevation models (DTMs) were derived [2] from both WAC and NAC images for the area, and supplemented the mapping effort. The high-resolution (50 cm/p) NAC images show fine details within the Al-Tusi melt pond that raise questions about melt pond dynamics and evolution. These include both positive- and negative-relief features, anomalous crater morphologies, and flow features that show variable degrees of melt viscosity. WAC DTM processing reveals a horizontal and relatively flat (at the 20 m contour interval) pond, demonstrating that an equipotential surface was achieved during initial melt accumulation. The NAC DTM shows kilometer-scale zones of topographic down-warping within the 20 m contour interval. The perimeters of these depressed areas show moderate to high spatial correlation with the occurrence of negative relief features (~10 to 100 m in length). Such sagging may have occurred as the result of contraction and/or compaction within the melt both during and following cooling, with the negative relief features resulting from consequent structural failure and separation of the thickening surface crust. The variability in the degree of contraction/compaction may be explained by the presence of underlying hummocky ejecta deposits (which probably also explains the positive relief features) emplaced by the King impact within Al-Tusi crater prior to melt accumulation. Crater counts on the extended ejecta blanket [e.g., 3] show that King crater is likely to be ~ 1 Ga in age.
Geohydrology and limnology of Walden Pond, Concord, Massachusetts
Colman, John A.; Friesz, Paul J.
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 nitrogen inputs (858 kilograms per year) were dominated (30 percent) by plume water from the septic leach field and, possibly, by swimmers (34 percent). Phosphorus inputs (32 kilograms per year) were dominated by atmospheric dry deposition, background ground water, and estimated swimmer inputs. Swimmer inputs may represent more than 50 percent of the phosphorus load during the summer. The septic-system plume did not contribute phosphorus, but increased the nitrogen to phosphorus ratio for inputs from 41 to 59, on an atom-to-atom basis. The ratio of nitrogen to phosphorus in input loads and within the lake indicated algal growth would be strongly phosphorus limited. Nitrogen supply in excess of plant requirements may mitigate against nitrogen fixing organisms including undesirable blooms of cyanobacteria. Based on areal nutrient loading, Walden Pond is a mesotrophic lake. Hypolimnetic oxygen demand of Walden Pond has increased since a profile was measured in 1939. Currently (1999), the entire hypolimnion of Walden Pond becomes devoid of dissolved oxygen before fall turnover in late November; whereas historical data indicated dissolved oxygen likely remained in the hypolimnion during 1939. The complete depletion of dissolved oxygen likely causes release of phosphorus from the sediments. Walden Pond contains a large population of the deep-growing benthic macro alga Nitella, which has been hypothesized to promote water clarity in other clear-water lakes by sequestering nutrients and keeping large areas of the sediment surface oxygenated. Loss of Nitella populations in other lakes has correlated with a decline in water quality. Although the Nitella standing crop is large in Walden Pond, Nitella still appears to be controlled by nutrient availability. Decreasing phosphorus inputs to Walden Pond, by amounts under anthropogenic control would likely contribute to the stability of the Nitella population in the metalimnion, may reverse oxygen depletion in the hypolimnion, and decreas
Chemistry of runoff and shallow ground water at the Cattlemans Detention basin site, South Lake Tahoe, California, August 2000-November 2001
Prudic, David E.; Sager, Sienna J.; Wood, James L.; Henkelman, Katherine K.; Caskey, Rachel M.
A study at the Cattlemans detention basin site began in November 2000. The site is adjacent to Cold Creek in South Lake Tahoe, California. The purpose of the study is to evaluate the effects of the detention basin on ground-water discharge and changes in nutrient loads to Cold Creek, a tributary to Trout Creek and Lake Tahoe. The study is being done in cooperation with the Tahoe Engineering Division of the El Dorado County Department of Transportation. This report summarizes data collected prior to and during construction of the detention basin and includes: (1) nutrient and total suspended solid concentrations of urban runoff; (2) distribution of unconsolidated deposits; (3) direction of ground-water flow; and (4) chemistry of shallow ground water and Cold Creek. Unconsolidated deposits in the area of the detention basin were categorized into three classes: fill material consisting of a red-brown loamy sand with some gravel and an occasional cobble that was placed on top of the meadow; meadow deposits consisting of gray silt and sand with stringers of coarse sand and fine gravel; and a deeper brown to yellow-brown sand and gravel with lenses of silt and sand. Prior to construction of the detention basin, ground water flowed west-northwest across the area of the detention basin toward Cold Creek. The direction of ground-water flow did not change during construction of the detention basin. Median concentrations of dissolved iron and chloride were 500 and 30 times higher, respectively, in ground water from the meadow deposits than dissolved concentrations in Cold Creek. Median concentration of sulfate in ground water from the meadow deposits was 0.4 milligrams per liter and dissolved oxygen was below the detection level of 0.3 milligrams per liter. The relatively high concentrations of iron and the lack of sulfate in the shallow ground water likely are caused by chemical reactions and biological microbial oxidation of organic matter in the unconsolidated deposits that result in little to no dissolved oxygen in the ground water. The higher chloride concentrations in ground water compared with Cold Creek likely are caused from the application of salt on Pioneer Trail and streets in Montgomery Estates subdivision during the winter. Runoff from these roads contributes to the recharge of the shallow ground water. The range of dissolved constituents generally was greater in the meadow deposits than in the deeper sand and gravel. Ammonia plus organic nitrogen were the dominant forms of dissolved nitrogen and concentrations ranged from 0.04 to 18 milligrams per liter as nitrogen. Highest concentration was beneath the middle of the detention basin. Nitrate plus nitrite concentrations were low (<0.33 milligrams per liter as nitrogen) throughout the area and dissolved phosphorus concentrations ranged from 0.001 to 0.34 milligrams per liter. Nitrogen and dissolved organic carbon showed no consistent pattern in the direction of ground-water flow, which suggests that, similar to iron and sulfate, local variations in the chemical and biological reactions within the meadow deposits controlled the variation in nitrogen concentrations. The gradual increase in dissolved phosphorus along the direction of ground-water flow suggest that phosphorus may be slowly dissolving into ground water. Dissolved phosphorus was consistently low in July, which may be the result of greater microbial activity in the unconsolidated deposits or from uptake by roots during the summer.