WorldWideScience

Sample records for solar evaporation ponds

  1. Dewatering and RCRA partial closure action on solar evaporation ponds, Rocky Flats Plant, Golden, Colorado

    International Nuclear Information System (INIS)

    1991-06-01

    The Department of Energy (DOE) has prepared an Environmental Assessment (DOE/EA-0487) on its proposal to partially close five solar evaporation ponds at the Rocky Flats Plant (RFP) pursuant to the requirements of the Resource Conservation and Recovery Act (RCRA). This proposal would be known as a RCRA partial closure and would be accomplished by dewatering the ponds, where necessary, and converting any remaining sludge or evaporator concentrate to a solid wasteform (pondcrete and saltcrete). The pond sites would be stabilized to prevent erosion or other disturbance to the soil and to prevent infiltration of rain or snowmelt. The solid wasteform would be transported offsite for disposal. The five solar ponds (designated 207-A, 207-B (north, center, and south), and 207-C), are the only solar evaporation ponds that exist at the RFP. A finding of no significant impact is included

  2. Environmental sampling program for a solar evaporation pond for liquid radioactive wastes

    International Nuclear Information System (INIS)

    Romero, R.; Gunderson, T.C.; Talley, A.D.

    1980-04-01

    Los Alamos Scientific Laboratory (LASL) is evaluating solar evaporation as a method for disposal of liquid radioactive wastes. This report describes a sampling program designed to monitor possible escape of radioactivity to the environment from a solar evaporation pond prototype constructed at LASL. Background radioactivity levels at the pond site were determined from soil and vegetation analyses before construction. When the pond is operative, the sampling program will qualitatively and quantitatively detect the transport of radioactivity to the soil, air, and vegetation in the vicinity. Possible correlation of meteorological data with sampling results is being investigated and measures to control export of radioactivity by biological vectors are being assessed

  3. Study for reclamation of land occupied by solar evaporation pond at UCIL, Bhopal, India.

    Science.gov (United States)

    George, K V; Patil, M R; Swaminathan, R

    2001-12-01

    Solar Evaporation Ponds (SEP) were used by Union Carbide India Limited (UCIL), Bhopal for storage of wastewater containing high concentrations of inorganic chemicals especially chlorides. Area occupied by the SEPs had to be recovered due to closure of the plant. A prerequisite to the reclamation of the SEP area is a study of adjoining soil and groundwater, which may be contaminated due to possible leakage in the pond. Surface soil, subsurface soil and groundwater samples were collected and analysed. The electrical conductivity method was employed inside the pond to test for leak in the geo-membrane liner. This was further confirmed by physically checking the liners. Based on the wet period, total rainfall and evaporation rate of the region, drying of remaining wastewater by spreading in dry ponds followed by pond dismantling was scheduled.

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  5. Rocky Flats Solar Evaporation Ponds RCRA hybrid-closure case study

    International Nuclear Information System (INIS)

    Ogg, R.T.; Everett, L.G.; Cullen, S.J.

    1994-01-01

    The Solar Evaporation Ponds (SEP)/Operable Unit 4 (OU 4), located at the Rocky Flats Plant (RFP) sixteen miles northwest of Denver, Colorado, is currently undergoing remediation/Resource Conservation and Recovery Act (RCRA) closure in accordance with the Rocky Flats Interagency Agreement (IAG) signed by the US Department of Energy (DOE), US Environmental Protection Agency (EPA) and Colorado Department of Health (CDH) on January 22, 1991. Based on the ''Phase 1'' (source and soils) RCRA Facility Investigation/Remedial Investigation (RFM data and interpretations), the DOE and EG and G Rocky Flats, Inc. (EG and G) have selected a permanent surface engineered/isolation barrier as the technological option for remediation of the SEP. The DOE and EG and G will utilize all natural materials to create an ''impermeable'' barrier/structure to isolate the waste being left in place from impacting human health and the environment for a minimum of 1,000 years. Their rationale for utilizing natural materials is two fold; (1) optimize long term performance of the barrier and; (2) design a structure which will be near maintenance free (passive remediation) for 1,000 years. The DOE and EG and G have taken a proactive approach in providing post closure performance assessment for this RCRA closure action. An integrated monitoring system has been designed which will include monitoring the engineered barrier, vadose zone and ground water systems. Rocky Flats will integrate instrumentation into the permanent engineered barrier which will provide early warning of potential liquid migration through the barrier and into the waste zone

  6. Microbiology of solar salt ponds

    Science.gov (United States)

    Javor, B.

    1985-01-01

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

  7. Long-term cover design for low-level radioactive and hazardous waste sites as applied to the Rocky Flats Environmental Technology Site solar evaporation ponds

    International Nuclear Information System (INIS)

    Stenseng, S.E.; Nixon, P.A.

    1996-01-01

    The US Department of Energy (DOE) operated five lined solar evaporation ponds (SEPs) at the Rocky Flats Environmental Technology Site (RFETS) in Jefferson County, Colorado from 1953 until 1986. The SEPs were used primarily to store and evaporate low-level radioactive and hazardous process wastes. Operation of the SEPs has resulted in contamination of the surrounding soils, and may also provide a source of groundwater contamination. The DOE proposes to close the SEPs by consolidating the contaminated material beneath an engineered cover. The primary objective of the closure of such hazardous and radioactive sites is to limit the exposure of the general public to the contaminants for time periods ranging from 100 to 10,000 years. The goal of the SEPs engineered cover is to isolate hazardous and low-level radioactive soils for a minimum of 1,000 years. Since there is currently no existing regulatory design guidance for a 1,000-year engineered cover, the proposed design of the SEPs engineered cover is based on research and testing that has been conducted for many years at various DOE facilities in the US. This paper discusses the main design theories of the proposed engineered cover for the closure of the SEPs, and how the research and test results of these other programs have been used to arrive at the final cover configuration, the material selections, the component layering, layer thicknesses, and the balance and interaction between components to establish an overall effective cover system

  8. Naphtha evaporation from oil sands tailings ponds

    Energy Technology Data Exchange (ETDEWEB)

    Kasperski, K.; Munoz, V.; Mikula, R. [Natural Resources Canada, Devon, AB (Canada). CANMET Western Research Centre

    2010-07-01

    The environmental impacts of volatile organic compounds (VOCs) from oil sands tailings ponds must be considered when evaluating new oil sands mining and extraction operations. Studies have suggested that only 40 percent of the solvent sent to tailings ponds is available to the environment, while the rest is irreversibly trapped. The recovery of hydrocarbons from oil sands froth process water is low. This PowerPoint presentation discussed a method of distinguishing between water and hydrocarbons at low temperatures. Samples were heated to 246 degrees C at 15 degrees C and held for 10 minutes. Heating was then resumed at 750 degrees C and held for 10 minutes in a pyrolysis phase, then cooled and reheated with an oxygen addition. The method demonstrated that the diluent distribution between the solids and water phases is misinterpreted as diluent that will evaporate, and diluent that will not evaporate. The study concluded by suggesting that the definition of recoverable and unrecoverable hydrocarbon should be re-termed as easily recoverable, and difficult to recover. tabs., figs.

  9. Concentrated Brine Treatment using New Energy in Coal Mine Evaporation Ponds

    Science.gov (United States)

    Li, Ting; Li, Jingfeng

    2017-12-01

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

  10. The evaporation from ponds in the French Midwest

    Directory of Open Access Journals (Sweden)

    Mohammad AL DOMANY

    2013-12-01

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

  11. Solar pond conception - experimental and theoretical studies

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-07-01

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

  12. Solar pond for heating anaerobic digesters

    International Nuclear Information System (INIS)

    Song Kehui; Li Shensheng

    1991-10-01

    A theoretical analysis and numerical results calculated for solar pond heating anaerobic digesters in Beijing area in China are presented. The effect of temperature rise is evident and rather steady. 3 refs, 1 fig., 1 tab

  13. Identification and characterization of bacteria in a selenium-contaminated hypersaline evaporation pond.

    Science.gov (United States)

    de Souza, M P; Amini, A; Dojka, M A; Pickering, I J; Dawson, S C; Pace, N R; Terry , N

    2001-09-01

    Solar evaporation ponds are commonly used to reduce the volume of seleniferous agricultural drainage water in the San Joaquin Valley, Calif. These hypersaline ponds pose an environmental health hazard because they are heavily contaminated with selenium (Se), mainly in the form of selenate. Se in the ponds may be removed by microbial Se volatilization, a bioremediation process whereby toxic, bioavailable selenate is converted to relatively nontoxic dimethylselenide gas. In order to identify microbes that may be used for Se bioremediation, a 16S ribosomal DNA phylogenetic analysis of an aerobic hypersaline pond in the San Joaquin Valley showed that a previously unaffiliated group of uncultured bacteria (belonging to the order Cytophagales) was dominant, followed by a group of cultured gamma-Proteobacteria which was closely related to Halomonas species. Se K-edge X-ray absorption spectroscopy of selenate-treated bacterial isolates showed that they accumulated a mixture of predominantly selenate and a selenomethionine-like species, consistent with the idea that selenate was assimilated via the S assimilation pathway. One of these bacterial isolates (Halomonas-like strain MPD-51) was the best candidate for the bioremediation of hypersaline evaporation ponds contaminated with high Se concentrations because it tolerated 2 M selenate and 32.5% NaCl, grew rapidly in media containing selenate, and accumulated and volatilized Se at high rates (1.65 microg of Se g of protein(-1) x h(-1)), compared to other cultured bacterial isolates.

  14. Solar pond design for Arabian Gulf conditions

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-01-01

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

  15. Environmental Projects. Volume 8: Modifications of wastewater evaporation ponds

    Science.gov (United States)

    1989-01-01

    The Goldstone Deep Space Communications Complex (GDSCC), located in the Mojave Desert about 45 miles north of Barstow, California, and about 160 miles northeast of Pasadena, is part of NASA's Deep Space Network, one of the world's largest and most sensitive scientific telecommunications and radio navigation networks. The Goldstone Complex is managed, technically directed, and operated for NASA by the Jet Propulsion Laboratory (JPL) of the California Institute of Technology in Pasadena, California. Activities at the GDSCC are carried out in support of seven parabolic dish antennas. These activities may give rise to environmental hazards: use of hazardous chemicals, asbestos, and underground storage tanks as well as the generation of hazardous wastes and the disposal of wastewater. Federal, state, and local laws governing the management of hazardous substances, asbestos, underground storage tanks and wastewater disposal have become so complex there is a need to devise specific programs to comply with the many regulations that implement these laws. In support of the national goal of the preservation of the environment and the protection of human health and safety, NASA, JPL, and the GDSCC have adopted a position that their operating installations shall maintain a high level of compliance with these laws. One of the environmental problems at the GDSCC involved four active, operational, wastewater evaporation ponds designed to receive and evaporate sewage effluent from upstream septic tank systems. One pair of active wastewater evaporation ponds is located at Echo Site, while another operational pair is at Mars Site.

  16. Advancement in solar evaporation techniques for volume reduction of chemical effluents

    Energy Technology Data Exchange (ETDEWEB)

    Parakasamurthy, K S [Nuclear Fuel Complex, Hyderabad (India); Pande, D P [Process Engineering and Systems Development Division, Bhabha Atomic Research Centre, Mumbai (India)

    1994-06-01

    A typical example of advancement of a unit operation for the given requirement is described. The solar evaporation ponds (SEP) have technical and economic advantages compared to other evaporation methods for concentrating chemical effluents. The operation of SEP is strongly dependent on the environmental and site conditions. Tropical conditions with high solar incidence, good wind speed along with hot and dry weather provide suitable climate for efficient operation of solar evaporation ponds. The particular site selected for the ponds at Nuclear Fuel Complex (NFC) has a rocky terrain with murrum over sheet with very low water table and small velocity of groundwater. During the past twenty five years extensive theoretical and experimental investigations have been carried out for advancement of solar evaporation technique. (author). 7 refs.

  17. Advancement in solar evaporation techniques for volume reduction of chemical effluents

    International Nuclear Information System (INIS)

    Parakasamurthy, K.S.; Pande, D.P.

    1994-01-01

    A typical example of advancement of a unit operation for the given requirement is described. The solar evaporation ponds (SEP) have technical and economic advantages compared to other evaporation methods for concentrating chemical effluents. The operation of SEP is strongly dependent on the environmental and site conditions. Tropical conditions with high solar incidence, good wind speed along with hot and dry weather provide suitable climate for efficient operation of solar evaporation ponds. The particular site selected for the ponds at Nuclear Fuel Complex (NFC) has a rocky terrain with murrum over sheet with very low water table and small velocity of groundwater. During the past twenty five years extensive theoretical and experimental investigations have been carried out for advancement of solar evaporation technique. (author)

  18. Feeding ecology of waterfowl wintering on evaporation ponds in California

    Science.gov (United States)

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

    1991-01-01

    We examined the feeding ecology of Northern Pintails (Anas acuta), Northern Shovelers (A. clypeata), and Ruddy Ducks (Oxyura jamaicensis) wintering on drainwater evaporation ponds in California from 1982 through 1984. Pintails primarily consumed midges (Chironomidae) (39.3%) and widegeongrass (Ruppia maritima) nutlets (34.6%). Shovelers and Ruddy Ducks consumed 92.5% and 90.1% animal matter, respectively. Water boatmen (Corixidae) (51.6%), rotifers (Rotatoria) (20.4%), and copepods (Copepoda) (15.2%) were the most important Shoveler foods, and midges (49.7%) and water boatmen (36.0%) were the most important foods of Ruddy Ducks. All three species were opportunistic foragers, shifting their diets seasonally to the most abundant foods given their behavioral and morphological attributes.

  19. Investigation of turbidity effect on exergetic performance of solar ponds

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  20. Discussion on the source survey method in a natural evaporation pond

    International Nuclear Information System (INIS)

    Dai Xiaoshu; Fan Chengrong; Fu Yunshan

    2014-01-01

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

  1. Carbonate deposition on tail feathers of ruddy ducks using evaporation ponds

    Science.gov (United States)

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

    1989-01-01

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

  2. Heat recovery from ground below the solar pond

    NARCIS (Netherlands)

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

    2017-01-01

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

  3. Fate of Potential Contaminants Due to Disposal of Olive Mill Wastewaters in Unprotected Evaporation Ponds.

    Science.gov (United States)

    Kavvadias, V; Elaiopoulos, K; Theocharopoulos, Sid; Soupios, P

    2017-03-01

    The disposal of olive mill wastewaters (OMW) in shallow and unprotected evaporation ponds is a common, low-cost management practice, followed in Mediterranean countries. So far, the fate of potential soil pollutants in areas located near evaporation ponds is not adequately documented. This study investigates the extent in which the long-term disposal of OMW in evaporation ponds can affect the soil properties of the area located outside the evaporation pond and assesses the fate of the pollution loads of OMW. Four soil profiles situated outside and around the down slope side of the disposal area were excavated. The results showed considerable changes in concentration of soil phenols at the down-site soil profiles, due to the subsurface transport of the OMW. In addition, excessive concentrations of NH 4 + , PO 4 3- and phenols were recorded in liquid samples taken from inside at the bottom of the soil profiles. It is concluded that unprotected evaporation ponds located in light texture soils pose a serious threat to favour soil and water pollution.

  4. Evaluation of remedial alternatives for the Solar Ponds Plume, Rocky Flats Environmental Technology Site

    International Nuclear Information System (INIS)

    Hranac, K.C.

    1998-01-01

    This paper describes the process used to select a remedial alternative for handling contaminated groundwater emanating from the Solar Evaporation Ponds (Solar Ponds) at the Rocky Flats Environmental Technology Site (RFETS) and prevent it from reaching the nearest surface water body, North Walnut Creek. Preliminary results of field investigations conducted to provide additional information for the alternatives analysis are also presented. The contaminated groundwater is referred to as the Solar Ponds Plume (SPP). The primary contaminants in the SPP are nitrate and uranium; however, some metals exceed the site action levels at several locations and volatile organic compounds, originating from other sources, also have been detected. Currently the SPP, local surface water runoff, and infiltrated precipitation are collected by a trench system located downgradient of the Solar Ponds and pumped to three storage tanks. The water (two to three million gallons annually) is then pumped to an on-site treatment plant for evaporation at an approximate cost of $7.57 per liter

  5. EXPERIMENTAL INVESTIGATION OF SOLAR POND PERFORMANCE IN KARABUK ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Mehmet ÖZKAYMAK

    2004-01-01

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

  6. Assesing the effect of an olive mill wastewater evaporation pond in Sousse, Tunisia

    Science.gov (United States)

    S'habou, Rakia; Zairi, Moncef; Kallel, Amjed; Aydi, Abdelwaheb; Ben Dhia, Hamed

    2009-08-01

    Olive oil is a typical and valuable agro-industrial product in Mediterranean countries. In Tunisia, olive mill wastewaters (OMW) reach an amount of about 1,000,000 t year-1 and constitute a serious organic pollution risk because of the high chemical oxygen demand values and the presence of phytotoxic and antibacterial polyphenols. OMW have been generally stored in pond sites to be eliminated by natural evaporation or valorised by spreading on cultivated soils or by composting. Many researches on the interactions of OMW with soils at laboratory scale (columns) have been reported, but less attention have been paid to the effect of OMW on soils at field scale. The aim of this work is to investigate an area used for >15 years as an uncontrolled OMW pond site. The transformations of soil properties and groundwater occurring during OMW storage were characterised by the pH, phenolic contents, electrical conductivity (EC), moisture content and organic contents. The soil samples were taken from two borings and compared to those of a control one located near the pond site. Groundwater samples were taken on the accessible and nearest water wells to the evaporation ponds. The permeable silty and sandy layers in the site support the infiltration of OMW near the evaporation ponds. This infiltration has reached a depth of 6 m at a distance of almost 50 m laterally. The results show that the OMW infiltration in the subsoil has affected the pH, EC, organic content, phenolic compounds and the moisture.

  7. Performance of constructed evaporation ponds for disposal of smelter waste water: a case study at Portland Aluminum, Victoria, Australia.

    Science.gov (United States)

    Salzman, S A; Allinson, G; Stagnitti, F; Coates, M; Hill, R J

    2001-06-01

    The construction of evaporative ponds and wetlands for the disposal of waste water high in ionic concentrations is a waste disposal strategy currently considered by many industries. However, the design, construction and management of these ponds and wetlands are not straightforward as complex chemical interactions result in both spatial and temporal changes in water quality. The effects of evaporation and drainage on the water quality in two constructed ponds, an adjacent man-made wetland and local groundwater at Portland Aluminium were investigated. The minimum volume of water entering the ponds during the study period was 0.96 +/- 0.16 ML per month. The predicted theoretical evaporative capacity of the two ponds was calculated to be 0.30 +/- 0.07 ML per month. More water enters the ponds than it is theoretically possible to evaporate under the ambient weather conditions at Portland, yet the ponds do not overflow, suggesting percolation through the pond lining. No spatial differences in solute concentrations (fluoride, sulphate, bicarbonate, carbonate, sodium, potassium, calcium, and magnesium ions) were found within the waters of either pond, although temporal differences were apparent. The results support the conclusion that the ponds are not impermeable, and that much of the waste water entering the ponds is being lost through seepage. The impacts on local groundwater chemistry of this seepage are addressed. Significant correlations exist between solute presence within and between the ponds. wetland and groundwater. Fluoride and sulphate concentrations were significantly higher in pond waters throughout the duration of the experiment. Pond sediments revealed a high degree of spatial and temporal heterogeneity in the concentration of all monitored ions resulting from the chemical heterogeneity of the material making up the pond linings. Adsorption isotherms for fluoride indicate that the adsorption capacity of the pond linings remains high for this ion

  8. Observations of the transmittance in two solar ponds

    Energy Technology Data Exchange (ETDEWEB)

    Almanza, R.; Bryant, M.C.

    1983-11-01

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

  9. Quality monitoring of salt produced in Indonesia through seawater evaporation on HDPE geomembrane lined ponds

    Science.gov (United States)

    Jumaeri; Sulistyaningsih, T.; Alighiri, D.

    2018-03-01

    Salt is one of the primary ingredients that humans always need for various purposes, both for consumption and industry. The need for high-quality salt continues to increase, as long as industry growth. It must improve product quality through the development of salt production process technology. In this research, the quality monitoring of salt produced in Indonesia by evaporation of seawater on ponds lined using high-density polyethylene (HDPE) geomembrane has been studied. The manufacturing of salt carried out through the gradual precipitation principle on prepared ponds. HDPE geomembrane is used to coat evaporation ponds with viscosity 12-22°Be and crystallization ponds with a viscosity of 23°Be. The monitoring of the product is carried out in the particular periods during the salt production period. The result of control shows that the quality of salt produced in HDPE geomembrane coated salt ponds has an average NaCl content of 95.75%, so it has fulfilled with Indonesia National Standard (SNI), that is NaCl> 94.70%. The production of salt with HDPE geomembrane can improve the quality of salt product from NaCl 85.4% (conventional system) to 95.75%.

  10. Heating an aquaculture pond with a solar pool blanket

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-01-01

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

  11. Remote sensing of the biological dynamics of large-scale salt evaporation ponds

    Science.gov (United States)

    Richardson, Laurie L.; Bachoon, Dave; Ingram-Willey, Vebbra; Chow, Colin C.; Weinstock, Kenneth

    1992-01-01

    Optical properties of salt evaporation ponds associated with Exportadora de Sal, a salt production company in Baja California Sur, Mexico, were analyzed using a combination of spectroradiometer and extracted pigment data, and Landsat-5 Thematic Mapper imagery. The optical characteristics of each pond are determined by the biota, which consists of dense populations of algae and photosynthetic bacteria containing a wide variety of photosynthetic and photoprotective pigments. Analysis has shown that spectral and image data can differentiate between taxonomic groups of the microbiota, detect changes in population distributions, and reveal large-scale seasonal dynamics.

  12. Stabilization of mixed waste - Rocky Flats solar ponds

    International Nuclear Information System (INIS)

    Bittner, T.A.; Mathew, S.A.; Henderson, W.C.

    1993-01-01

    Among the wastes that require disposal as part of the Department of Energy's (DOE's) Environmental Restoration Program are large amounts of contaminated sludge and inorganic wastes. Halliburton NUS Corporation was awarded a contract by EG ampersand G Rocky Flats in March 1991 to stabilize mixed waste sludge contained in five solar evaporator ponds and to reprocess billets of solidified waste called Pondcrete and Saltcrete at DOE's Rocky Flats Plant. The scope of the project consists of waste characterization and treatability studies for process development, followed by design, construction and operation of various process trains to remediate different waste forms ranging from solid Pondcrete/Saltcrete blocks to aqueous brine solutions. One of the significant advances made was the development of a durable and certifiable stabilization formulation capable of treating concentrated nitrate solution wastes. The project uses high-volume grout mixing and pumping technologies with process control techniques that accommodate the heterogeneity of the wastes. To comply with all relevant environmental regulations and to provide a safe working atmosphere for plant personnel, Halliburton NUS designed process trains such that all emissions were eliminated during the remediation process. Personnel protection equipment requirements have been downgraded due to safeguards incorporated in the design. The technical and regulatory issues that were encountered would be typical of stabilization efforts underway at other DOE sites. Thus the lessons learned and concepts developed can be expected to have widespread application

  13. Study on radionuclides transport from natural evaporating ponds to the atmosphere

    International Nuclear Information System (INIS)

    Liu Keqiang; Zou Changgui

    1997-08-01

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

  14. Volatilization of selenium from agricultural evaporation pond sediments.

    Science.gov (United States)

    Karlson, U; Frankenberger, W T

    1990-03-01

    Microbial volatilization of Se was evaluated as a means of detoxifying Se-contaminated sediments. Sediment samples containing 60.7 (Kesterson Reservoir) and 9.0 mg Se kg-1 (Peck ponds) were incubated for 273 days in closed systems located in the greenhouse. Volatile Se was collected from a continuous air-exchange stream using activated carbon. Various economical and readily available organic and inorganic amendments were tested for their capacity to enhance the microbial process, including Citrus (orange) peel, Vitis (grape) pomace, feedlot manure, barley straw, chitin, pectin, ZnSO4, (NH4)2SO4, and an inoculum of Acremonium falciforme (an active Se methylating fungus). With the Kesterson sediment, the highest Se removal (44.0%) resulted from the combined application of citrus peel and ZnSO4, followed by citrus peal alone (39.6%), and citrus peel combined with ZnSO4, (NH4)2SO4 and A. falciforme (30.1%). Manure (19.5%), pectin (16.4%), chitin (9.8%) and straw plus N (8.8%) had less pronounced effects. Without the amendments, cumulative Se volatilization was 6.1% of the initial inventory. Grape pomace (3.0%) inhibited the process. With the Peck sediment, the highest amount of Se removed was observed with chitin (28.6%), manure (28.5%), and citrus peel alone (27.3%). Without amendments, 14.0% of the native Se was volatilized in 273 days. Cumulative Se volatilization was 24.7% with citrus plus Zn and N, 17.2% with citrus plus Zn, and 18.8% with citrus plus Zn, N and A. falciforme. Pectin (15.2%), straw plus N (16.4%), and grape pomace (7.3%) were among the less effective amendments for the Peck sediment. The differences in the effectiveness of each treatment between the two seleniferous soils may be a result of the residual N content of the sediments. With the Kesterson sediment, which was high in organic C and N, added N inhibited volatilization of Se, while with Peck sediments (low in organic C and N) N-rich materials tended to accelerate Se volatilization

  15. Long-term surveillance of sulfate-reducing bacteria in highly saline industrial wastewater evaporation ponds.

    Science.gov (United States)

    Ben-Dov, Eitan; Kushmaro, Ariel; Brenner, Asher

    2009-02-18

    Abundance and seasonal dynamics of sulfate-reducing bacteria (SRB), in general, and of extreme halophilic SRB (belonging to Desulfocella halophila) in particular, were examined in highly saline industrial wastewater evaporation ponds over a forty one month period. Industrial wastewater was sampled and the presence of SRB was determined by quantitative real-time PCR (qPCR) with a set of primers designed to amplify the dissimilatory sulfite reductase (dsrA) gene. SRB displayed higher abundance during the summer (10(6)-10(8) targets ml(-1)) and lower abundance from the autumn-spring (10(3)-10(5) targets ml(-1)). However, addition of concentrated dissolved organic matter into the evaporation ponds during winter immediately resulted in a proliferation of SRB, despite the lower wastewater temperature (12-14 degrees C). These results indicate that the qPCR approach can be used for rapid measurement of SRB to provide valuable information about the abundance of SRB in harsh environments, such as highly saline industrial wastewaters. Low level of H2S has been maintained over five years, which indicates a possible inhibition of SRB activity, following artificial salination (approximately 16% w/v of NaCl) of wastewater evaporation ponds, despite SRB reproduction being detected by qPCR.

  16. Nabarlek evaporation and storage ponds: possible role of biological activity in the escape of toxic substances to the general environment

    International Nuclear Information System (INIS)

    Martinick, W.

    1982-01-01

    An investigation was undertaken to determine whether or not game birds might become contaminated with radionuclides while visiting the evaporating ponds at the Nabarlek uranium mine. The level of biological community development in the ponds and water bird activity were low. It is concluded that at present escape of radionuclides or toxic elements from the ponds as a result of biological activity is not a problem

  17. Greenhouse heating with a fresh water floating collector solar pond

    International Nuclear Information System (INIS)

    Arbel, A.; Sokolov, M.

    1991-01-01

    The fresh water floating collector solar pond was investigated both experimentally and theoretically in a previous work, and it is now matched, by simulation, with the heat load requirements of a greenhouse. Results of the simulation indicate that such a pond is a potential energy source for greenhouse heating. This is especially true when the material properties are such that solar absorption and storage are enhanced. This paper reports that to demonstrate this point, three sets of collectors constructed with materials of different physical (radiation) properties were tested. One set is constructed of common materials which are readily available and are normally used as covers for greenhouses. The second set made of improved materials which are also available but have a smaller long-wave transmittance. The last set made of ideal material which additionally possesses selective radiation absorption properties. Collectors made of ideal materials make a superior solar pond; thus, manufacturing films with improved properties should become a worthwhile challenge for the agricultural polyethylene-films industry. Preliminary economic studies indicate that even with the low oil (<$20/Bbl) prices which exist between 1986-1989, the fresh water floating collectors solar pond provides an economically attractive alternative to the conventional oil-burning heating system. This is especially true in mild climate areas and when the large initial investment is justified by long-term greenhouse utilization planning

  18. Disposal of olive oil mill wastes in evaporation ponds: effects on soil properties.

    Science.gov (United States)

    Kavvadias, V; Doula, M K; Komnitsas, K; Liakopoulou, N

    2010-10-15

    The most common practice followed in the Med countries for the management of olive oil mill wastes (OMW) involves disposal in evaporation ponds or direct disposal on soil. So far there is lack of reliable information regarding the long-term effects of OMW application on soils. This study assesses the effects of OMW disposal in evaporation ponds on underlying soil properties in the wider disposal site as well as the impacts of untreated OMW application on agricultural soils. In case of active disposal sites, the carbonate content in most soils was decreased, whereas soil EC, as well as Cl(-), SO(4)(2-), PO(4)(3-), NH(4)(+) and particularly K(+) concentrations were substantially increased. Soil pH was only marginally affected. Phenol, total N, available P and PO(4)(3-) concentrations were considerably higher in the upper soil layers in areas adjacent to the ponds. Available B as well as DTPA extractable Cu, Mn, Zn and Fe increased substantially. Most surface soil parameters exhibited increased values at the inactive site 6 years after mill closure and cease of OMW disposal activities but differences were diminished in deeper layers. It is therefore concluded that long-term uncontrolled disposal of raw OMW on soils may affect soil properties and subsequently enhance the risk for groundwater contamination. 2010 Elsevier B.V. All rights reserved.

  19. A Two-Dimensional Numerical Study of Hydrodynamic, Heat and Mass Transfer and Stability in a Salt Gradient Solar Pond

    Directory of Open Access Journals (Sweden)

    Ali Ben Moussa

    2012-10-01

    Full Text Available In this work, the problem of hydrodynamic, heat and mass transfer and stability in a salt gradient solar pond has been numerically studied by means of computational fluid dynamics in transient regime. The body of the simulated pond is an enclosure of height H and length L wherein an artificial salinity gradient is created in order to suppress convective motions induced by solar radiation absorption and to stabilize the solar pond during the period of operation. Here we show the distribution of velocity, temperature and salt concentration fields during energy collection and storage in a solar pond filled with water and constituted by three different salinity zones. The bottom of the pond is blackened and the free-surface is subjected to heat losses by convection, evaporation and radiation while the vertical walls are adiabatic and impermeable. The governing equations of continuity, momentum, thermal energy and mass transfer are discretized by finite–volume method in transient regime. Velocity vector fields show the presence of thin convective cells in the upper convective zone (UCZ and large convective cells in the lower convective zone (LCZ. This study shows the importance of buoyancy ratio in the decrease of temperature in the UCZ and in the preservation of high temperature in the LCZ. It shows also the importance of the thickness of Non-Convective Zone (NCZ in the reduction of the upwards heat losses.

  20. The use of some geochemical methods in evaporation pond reclamation assessments

    International Nuclear Information System (INIS)

    Thimm, H. F.; Siebert, L. D.

    1998-01-01

    Certain geochemical techniques, such as complete inorganic identification, rare earth fingerprints, and the use of chondrite plots that may be used over and above CCME (Canadian Council of Ministers of the Environment) standards in the reclamation of evaporation ponds, are described. These techniques permit the separation of contaminant elements that occur naturally beyond provincial or CCME standards. They also permit conclusions to be drawn about soil stratification around the lagoons. The methods are less costly yet more effective than conventional assessment methods. Use of these techniques is illustrated with an example from an Alberta gas plant. 7 refs., 6 tabs., 5 figs

  1. On the addition of heat to solar pond from external sources

    NARCIS (Netherlands)

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

    2017-01-01

    This brief note addresses the method of adding heat to a solar pond from an external source which is used to enhance the performance of a solar pond. Heat energy collected by Evacuated Tube Solar Collectors (ETSC) is transferred by circulating fluid from the Lower Convective Zone (LCZ) of a solar

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

    International Nuclear Information System (INIS)

    Bozkurt, Ismail; Karakilcik, Mehmet

    2015-01-01

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

  3. Odorous compounds treatment of winery and distillery effluents during natural evaporation in ponds.

    Science.gov (United States)

    Bories, A; Sire, Y; Colin, T

    2005-01-01

    During treatment of winery and distillery wastewater by natural evaporation in ponds, formation of malodorous compounds induces harmful olfactory effects. In this work, we studied the origin of malodorous compounds and methods to prevent and treat odours. The formation of volatile fatty acids (VFA) from pure substrates (glycerol, lactic and tartaric acids, ethanol) and complex media (winery and distillery wastewater) was studied. Various anaerobic bacteria ferment the glycerol and produce butyric or propionic acid. Valeric and caproic acids were observed at lower concentrations than butyric and propionic acids, but their malodorous intensities were higher. Microflora produce butyric, valeric, caproic, heptanoic and octanoic acids from ethanol, the main component of winery wastewater. When nitrate (an electron acceptor) is added, catabolism leads to an anaerobic respiration phenomenon (denitrification). The organic compounds are oxidised to CO2 and the nitrate is reduced to N2 (odourless compounds), without VFA formation. The preventive treatment of odours by nitrate addition was tested on an industrial scale in winery and distillery ponds. Furthermore, the study took the effect of nitrate on VFA degradation into consideration. The results make it possible to consider using nitrate for the curative treatment of pond odours.

  4. The identification and characterization of osmotolerant yeast isolates from chemical wastewater evaporation ponds.

    Science.gov (United States)

    Lahav, R; Fareleira, P; Nejidat, A; Abeliovich, A

    2002-04-01

    Ramat Hovav is a major chemical industrial park manufacturing pharmaceuticals, pesticides, and various aliphatic and aromatic halogens. All wastewater streams are collected in large evaporation ponds. Salinity in the evaporation ponds fluctuates between 3% (w/v) and saturation and pH values range between 2.0 and 10.0. We looked for microorganisms surviving in these extreme environmental conditions and found that 2 yeast strains dominate this biotope. 18S rDNA sequence analysis identified the isolates as Pichia guilliermondii and Rhodotorula mucilaginosa. Both isolates grew in NaCl concentrations ranging up to 3.5 M and 2.5 M, respectively, and at a pH range of 2-10. There was a distinct difference between the Rhodotorula and Pichia strains and S. cerevisiae RS16 that served as a control strain with respect to accumulation of osmoregulators and internal ion concentrations when exposed to osmotic stress. The Pichia and Rhodotorula strains maintained high glycerol concentration also in media low in NaCl. Utilization of various carbon sources was examined. Using a tetrazolium-based assay we show that the Rhodotorula and Pichia strains are capable of utilizing a wide range of different carbon sources including anthracene, phenanthrene, and other cyclic aromatic hydrocarbons.

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

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  6. A mathematical procedure to estimate solar absorptance of shallow water ponds

    International Nuclear Information System (INIS)

    Wu Hongbo; Tang Runsheng; Li Zhimin; Zhong Hao

    2009-01-01

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

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  8. Renewable water: Direct contact membrane distillation coupled with solar ponds

    International Nuclear Information System (INIS)

    Suárez, Francisco; Ruskowitz, Jeffrey A.; Tyler, Scott W.; Childress, Amy E.

    2015-01-01

    Highlights: • Experimental investigation of direct contact membrane distillation driven by solar ponds. • The DCMD/SGSP system treats ∼6 times the water flow treated by an AGMD/SGSP system. • Half of the energy extracted from the SGSP was used to transport water across the membrane. • Reducing heat losses through the DCMD/SGSP system would yield higher water fluxes. - Abstract: Desalination powered by renewable energy sources is an attractive solution to address the worldwide water-shortage problem without contributing significant to greenhouse gas emissions. A promising system for renewable energy desalination is the utilization of low-temperature direct contact membrane distillation (DCMD) driven by a thermal solar energy system, such as a salt-gradient solar pond (SGSP). This investigation presents the first experimental study of fresh water production in a coupled DCMD/SGSP system. The objectives of this work are to determine the experimental fresh water production rates and the energetic requirements of the different components of the system. From the laboratory results, it was found that the coupled DCMD/SGSP system treats approximately six times the water flow treated by a similar system that consisted of an air–gap membrane distillation unit driven by an SGSP. In terms of the energetic requirements, approximately 70% of the heat extracted from the SGSP was utilized to drive thermal desalination and the rest was lost in different locations of the system. In the membrane module, only half of the useful heat was actually used to transport water across the membrane and the remainder was lost by conduction in the membrane. It was also found that by reducing heat losses throughout the system would yield higher water fluxes, pointing out the need to improve the efficiency throughout the DCMD/SGSP coupled system. Therefore, further investigation of membrane properties, insulation of the system, or optimal design of the solar pond must be addressed in

  9. Lanthanide behavior in hypersaline evaporation ponds at Guerrero Negro, Baja California, Mexico - an environment with halophiles

    Science.gov (United States)

    Choumiline, K.; López-Cortés, A.; Grajeda-Muñoz, M.; Shumilin, E.; Sapozhnikov, D.

    2013-12-01

    Lanthanides are known, in some cases, to be sensitive to changes in water column or sediment chemistry, a fact that allows them to be used as environmental fingerprints. Nevertheless, the behavior of these elements in hypersaline environments is insufficiently understood, especially in those colonized by bacteria, archaea and eukarya halophiles. Extreme environments like the mentioned exist in the artificially-controlled ponds of the 'Exportadora de Sal' salt-producing enterprise located in Guerrero Negro (Baja California, Mexico). Sediment cores from various ponds were collected, subsampled and measured by ICP-MS and INAA. This allowed differencing the behavior of lanthanides and trace elements under a water column salinity gradient along the evaporation sequence of ponds. Sediment profiles (30 mm long), obtained in Pond 5, dominated by Ca and Mg precipitation and at the same time rich in organic matter due to bacterial mat presence, showed highs and lows of the shale-normalized patterns along different in-core depths. Two groups of elements could be distinguished with similar trends: set A (La, Ce, Pr and Nd) and set B (Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu). The first 'group A' had two prominent peaks at 15 mm and around 22 mm, whereas the 'group B' showed only slight increase at 15 mm and none at 22 mm. Microscopic analyses of prokaryotic cells of a stratified mat in Pond 5 (collected in 2004) showed filamentous bacteria and cyanobacteria with a cell abundance and morphotype richness maxima of prokaryotic cells in a chemocline from 3 mm to 7 mm depth which co-exists nine morphotypes of aerobic and anaerobic prokaryotes Microcoleus chthonoplastes, Leptolyngbya, Cyanothece, Geitlerinema, Spirulina, Chloroflexus, Beggiatoa, Chromatium and Thioploca. Below the 7 mm depth, oxygenic photosynthesis depletes and sulfur reducing compounds increase. The highs of the shale-normalized lanthanide contents of the 'group A' (at 15 mm depth) seem to correlate with the

  10. Evolution of trimethylarsine by a Penicillium sp. isolated from agricultural evaporation pond water.

    Science.gov (United States)

    Huysmans, K D; Frankenberger, W T

    1991-06-01

    Arsenicals are used in agriculture as pesticides and defoliants. In the Central Valley of California, arsenic is present in soil at naturally high concentrations, being derived from marine sedimentary parent material of the Coastal Range. Due to intense agricultural irrigation, soluble arsenic is leached from the soil and accumulates in evaporation ponds where it may pose an environmental threat to the waterfowl and wildlife. A Penicillium sp. isolated from evaporation pond water was found to be capable of methylating and subsequently volatilizing organic arsenic. The major focus of this study was to characterize the environmental conditions, including culture media, arsenic substrates, pH, temperature, and the presence of phosphates, carbohydrates and amino acids on the methylation of arsenic. Trimethylarsine was monitored by gas chromatography (GC)-flame ionization detection and identified by GC-mass spectrometry. The conditions or additions for optimum trimethylarsine production were: a minimal medium in which 100 mgl-1 methylarsonic acid served as the arsenic source, pH 5-6, temperature of incubation 20 degrees C, and phosphate concentration of 0.1-50 mM (KH2PO4). The addition of carbohydrates and sugar acids to the minimal medium suppressed trimethylarsine production. The amino acids phenylalanine, isoleucine, and glutamine promoted trimethylarsine production with an enhancement ranging from 10.2- to 11.6-fold over the control without amino acid supplementation. The information obtained from this study may be useful in developing a bioremediation approach in trapping the arsenic gas evolved from soil or water as a mitigation alternative in the cleanup of arsenic contamination.

  11. Changes in microbial diversity in industrial wastewater evaporation ponds following artificial salination.

    Science.gov (United States)

    Ben-Dov, Eitan; Shapiro, Orr H; Gruber, Ronen; Brenner, Asher; Kushmaro, Ariel

    2008-11-01

    The salinity of industrial wastewater evaporation ponds was artificially increased from 3-7% to 12-16% (w/v), in an attempt to reduce the activity of sulfate-reducing bacteria (SRB) and subsequent emission of H2S. To investigate the changes in bacterial diversity in general, and SRB in particular, following this salination, two sets of universal primers targeting the 16S rRNA gene and the functional apsA [adenosine-5'-phosphosulfate (APS) reductase alpha-subunit] gene of SRB were used. Phylogenetic analysis indicated that Proteobacteria was the most dominant phylum both before and after salination (with 52% and 68%, respectively), whereas Firmicutes was the second most dominant phylum before (39%) and after (19%) salination. Sequences belonging to Bacteroidetes, Spirochaetes and Actinobacteria were also found. Several groups of SRB from Proteobacteria and Firmicutes were also found to inhabit this saline environment. Comparison of bacterial diversity before and after salination of the ponds revealed both a shift in community composition and an increase in microbial diversity following salination. The share of SRB in the 16S rRNA gene was reduced following salination, consistent with the reduction of H2S emissions. However, the community composition, as shown by apsA gene analysis, was not markedly affected.

  12. Performance of solar still with a concave wick evaporation surface

    Energy Technology Data Exchange (ETDEWEB)

    Kabeel, A.E. [Mechanical Power Department, Faculty of Engineering, Tanta University (Egypt)

    2009-10-15

    Surfaces used for evaporation and condensation phenomenon play important roles in the performance of basin type solar still. In the present study, a concave wick surface was used for evaporation, whereas four sides of a pyramid shaped still were used for condensation. Use of jute wick increased the amount of absorbed solar radiation and enhanced the evaporation surface area. A concave shaped wick surface increases the evaporation area due to the capillary effect. Results show that average distillate productivity in day time was 4.1 l/m{sup 2} and a maximum instantaneous system efficiency of 45% and average daily efficiency of 30% were recorded. The maximum hourly yield was 0.5 l/h. m{sup 2} after solar noon. An estimated cost of 1l of distillate was 0.065 $ for the presented solar still. (author)

  13. Performance of solar still with a concave wick evaporation surface

    International Nuclear Information System (INIS)

    Kabeel, A.E.

    2009-01-01

    Surfaces used for evaporation and condensation phenomenon play important roles in the performance of basin type solar still. In the present study, a concave wick surface was used for evaporation, whereas four sides of a pyramid shaped still were used for condensation. Use of jute wick increased the amount of absorbed solar radiation and enhanced the evaporation surface area. A concave shaped wick surface increases the evaporation area due to the capillary effect. Results show that average distillate productivity in day time was 4.1 l/m 2 and a maximum instantaneous system efficiency of 45% and average daily efficiency of 30% were recorded. The maximum hourly yield was 0.5 l/h. m 2 after solar noon. An estimated cost of 1 l of distillate was 0.065 $ for the presented solar still.

  14. Trophic structure and avian communities across a salinity gradient in evaporation ponds of the San Francisco Bay estuary

    Science.gov (United States)

    Takekawa, John Y.; Miles, A.K.; Schoellhamer, D.H.; Athearn, N.D.; Saiki, M.K.; Duffy, W.D.; Kleinschmidt, S.; Shellenbarger, G.G.; Jannusch, C.A.

    2006-01-01

    Commercial salt evaporation ponds comprise a large proportion of baylands adjacent to the San Francisco Bay, a highly urbanized estuary. In the past two centuries, more than 79% of the historic tidal wetlands in this estuary have been lost. Resource management agencies have acquired more than 10 000 ha of commercial salt ponds with plans to undertake one of the largest wetland restoration projects in North America. However, these plans have created debate about the ecological importance of salt ponds for migratory bird communities in western North America. Salt ponds are unique mesohaline (5–18 g l−1) to hyperhaline (> 40 g l−1) wetlands, but little is known of their ecological structure or value. Thus, we studied decommissioned salt ponds in the North Bay of the San Francisco Bay estuary from January 1999 through November 2001. We measured water quality parameters (salinity, DO, pH, temperature), nutrient concentrations, primary productivity, zooplankton, macroinvertebrates, fish, and birds across a range of salinities from 24 to 264 g l−1. Our studies documented how unique limnological characteristics of salt ponds were related to nutrient levels, primary productivity rates, invertebrate biomass and taxa richness, prey fish, and avian predator numbers. Salt ponds were shown to have unique trophic and physical attributes that supported large numbers of migratory birds. Therefore, managers should carefully weigh the benefits of increasing habitat for native tidal marsh species with the costs of losing these unique hypersaline systems.

  15. An experimental and theoretical investigation of novel configurations of solar ponds for use in Iraq.

    OpenAIRE

    Sayer, Asaad Hameed

    2017-01-01

    Solar energy is likely to be the energy of the future; solar ponds, especially salinity gradient solar ponds (SGSPs), facilitate simple and cost-effective thermal energy storage. Research on maximising their potential is of particular relevance to developing countries, which often have an abundance of solar energy and a critical need for increased power supplies. For this research, a theoretical model for heat transfer in a SGSP was developed to study the energy balance in the three separate ...

  16. EXPERIMENTAL INVESTIGATION OF HEAT STORAGE CHARACTERISTIC OF UREA AND BORAX SALT GRADIENT SOLAR PONDS

    Directory of Open Access Journals (Sweden)

    Hüseyin KURT

    2006-03-01

    Full Text Available Salt gradient solar ponds are simple and low cost solar energy system for collecting and storing solar energy. In this study, heat storage characteristic of urea and borax solutions in the solar pond were examined experimentally. Establishing density gradients in different concentration, variations in the temperature and density profiles were observed in four different experiments. Maximum storage temperatures were measured as 28ºC and 36 ºC for the ponds with urea and borax solution, respectively. The temperature difference between the bottom and the surface of the pond were measured as 13 ºC for urea and 17 ºC for borax- solutions. According to these results, heat storage characteristic of the solar pond with borax solution was found to be better than urea solution.

  17. Olive mill wastewater evaporation management using PCA method Case study of natural degradation in stabilization ponds (Sfax, Tunisia).

    Science.gov (United States)

    Jarboui, Raja; Sellami, Fatma; Azri, Chafai; Gharsallah, Néji; Ammar, Emna

    2010-04-15

    Olive mill wastewater (OMW) evaporation ponds management was investigated in five serial evaporation open-air multiponds of 50 ha located in Sfax (Tunisia). Physico-chemical parameters and microbial flora evolution were considered. Empirical models describing the OMW characteristic changes with the operation time were established and Principal Component Analysis (PCA) described the correlation between physico-chemical and biological parameters. COD, BOD, total solids, polyphenols and electrical conductivity exhibited first-order models. Four groups exhibited high correlations. The first included temperature, density, COD, TSS, TS, BOD, VS, TOC, TKN, polyphenols and minerals. The second group was made up of yeasts and moulds. The third group was established with phenolic compounds, total sugars, fats, total phosphorous, NH(4)(+) and pH. The fourth group was constituted by exclusively aerobic bacteria. Bacterial-growth toxic effect was exhibited by high organic load, ash content and polyphenols, whereas moulds and yeasts were more adapted to OMW. During the storage, all the third group parameter values decreased and were inversely related to the others. In the last pond, COD, BOD, TS and TSS rates were reduced by 40%, 50%, 50% and 75% respectively. The evaporation and the biological activity were the main processes acting, predicting the OMW behavior during evaporation in air-open ponds. 2009 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2016-01-01

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

  19. Avian response to early tidal salt marsh restoration at former commercial salt evaporation ponds in San Francisco Bay, California, USA

    Science.gov (United States)

    Athearn, Nicole D.; Takekawa, John Y.; Shinn, Joel

    2009-01-01

    Restoration of former commercial salt evaporation ponds in the San Francisco Bay estuary is intended to reverse a severe decline (>79%) in tidal salt marshes. San Francisco Bay is a critical migratory stopover site and wintering area for shorebirds and waterfowl, and salt ponds are important high tide roosting and foraging areas. Conservation of past bird abundance is a stated goal of area restoration projects, and early adaptive management will be critical for achieving this objective. However, initial avian response at sites restored to tidal flow may not be indicative of long-term results. For example, winter shorebirds at a 529 ha pond breached in 2002 showed a marked increase in shorebird abundance following breaching. Shorebirds comprised 1% of area totals during 1999-2002 and increased to 46% during 2003-2008. These changes accompanied increased tidal range and sedimentation, but minimal vegetation establishment. Conversely, a fully vegetated, restored 216 ha pond in the same system consistently supported less than 2% of all waterbirds in the region. Early restoration may temporarily increase habitat, but managed ponds will be needed for long-term waterbird abundance within a restored pond-marsh system.

  20. Performance study of a laboratory model shallow solar pond with and without single transparent glass cover for solar thermal energy conversion applications.

    Science.gov (United States)

    Ganesh, S; Arumugam, S

    2016-12-01

    The thermal performance of a shallow solar pond with and without the single transparent glass cover has been investigated experimentally. This experiment has been performed during the summer season of 2014 under the operational condition for five different storage volumes of water upto a maximum of 10liter. The pond performance is investigated in terms of the rate of energy collected and its collection efficiency. A Low Density Polyethylene (LDPE) black sheet liner of 200μm thickness was laid on all the interior sides of the pond for solar energy absorption. A clear transparent PVC plastic sheet of 150μm thickness was laid over the water surface as evaporation suppressing membrane. Calibrated Copper constantan thermocouples were used to measure the temperatures of the system. A highest temperature of 81.5°C has been achieved for the stored volume of 2liter of water, when the pond was used with a single transparent glass cover of 5mm thickness. When the shallow solar pond was used without the transparent glass cover the system attained a maximum temperature of 62°C for the same stored volume of 2liter. A comparison between the two conditions of with and without the transparent glass cover, on the thermal performance of the SSP has been reported. A shallow solar pond system of the present type could be used us a source of warm water, of desired temperature, below 10°C which are required for the domestic and industrial utilities. The global warming is increased day by day; inorder to reduce global warming a typical method of small scale shallow solar pond has been used to absorb the radiation from the sun to convert it to useful heat energy by the source of water. The SSP is an eco friendly way to generate energy without polluting our environment and in an environment safety manner. Based on environmental safety this study has experimentally investigated the thermal performance of the shallow solar pond. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Performance investigation of a salt gradient solar pond coupled with desalination facility near the Dead Sea

    International Nuclear Information System (INIS)

    Saleh, A.; Qudeiri, J.A.; Al-Nimr, M.A.

    2011-01-01

    Solar ponds provide the most convenient and least expensive option for heat storage for daily and seasonal cycles. This is particularly important for a desalination facility, if steady and constant water production is required. If, in addition to high storage capacity, other favorable conditions exist, the salt gradient solar ponds (SGSPs) are expected to be able to carry the entire load of a large-scale flash desalination plants without dependence upon supplementary sources. This paper presents a performance investigation of a SGSP coupled with desalination plant under Jordanian climatic conditions. This is particularly convenient in the Dead Sea region characterized by high solar radiation intensities, high ambient temperature most of the year, and by the availability of high concentration brine. It was found that a 3000 m 2 solar pond installed near the Dead Sea is able to provide an annual average production rate of 4.3 L min -1 distilled water compared with 3.3 L min -1 that would be produced by El Paso solar pond, which has the same surface area. Based on this study, solar ponds appear to be a feasible and an appropriate technology for water desalination near the Dead Sea in Jordan. -- Research highlights: → A performance investigation of a solar pond coupled with desalination plant. → Dead Sea area is characterized by availability of high solar radiation and brine. → The Dead Sea solar pond can provide production rate of 4.3 L min -1 . → El Paso solar pond has production rate of 3.32 L min -1 . The improvement is about 30%. → The solar pond with desalination investigated showed to be a feasible technology.

  2. CFD Analysis of Evaporation-Condensation Phenomenon In an Evaporation Chamber of Natural Vacuum Solar Desalination

    Science.gov (United States)

    Ambarita, H.; Ronowikarto, A. D.; Siregar, R. E. T.; Setyawan, E. Y.

    2018-01-01

    Desalination technologies is one of solutions for water scarcity. With using renewable energy, like solar energy, wind energy, and geothermal energy, expected will reduce the energy demand. This required study on the modeling and transport parameters determination of natural vacuum solar desalination by using computational fluid dynamics (CFD) method to simulate the model. A three-dimensional case, two-phase model was developed for evaporation-condensation phenomenon in natural vacuum solar desalination. The CFD simulation results were compared with the avalaible experimental data. The simulation results shows inthat there is a phenomenon of evaporation-condensation in an evaporation chamber. From the simulation, the fresh water productivity is 2.21 litre, and from the experimental is 2.1 litre. This study shows there’s an error of magnitude 0.4%. The CFD results also show that, vacuum pressure will degrade the saturation temperature of sea water.

  3. Passive flow heat exchanger simulation for power generation from solar pond using thermoelectric generators

    Science.gov (United States)

    Baharin, Nuraida'Aadilia; Arzami, Amir Afiq; Singh, Baljit; Remeli, Muhammad Fairuz; Tan, Lippong; Oberoi, Amandeep

    2017-04-01

    In this study, a thermoelectric generator heat exchanger system was designed and simulated for electricity generation from solar pond. A thermoelectric generator heat exchanger was studied by using Computational Fluid Dynamics to simulate flow and heat transfer. A thermoelectric generator heat exchanger designed for passive in-pond flow used in solar pond for electrical power generation. A simple analysis simulation was developed to obtain the amount of electricity generated at different conditions for hot temperatures of a solar pond at different flow rates. Results indicated that the system is capable of producing electricity. This study and design provides an alternative way to generate electricity from solar pond in tropical countries like Malaysia for possible renewable energy applications.

  4. Bacillus isabeliae sp. nov., a halophilic bacterium isolated from a sea salt evaporation pond.

    Science.gov (United States)

    Albuquerque, Luciana; Tiago, Igor; Taborda, Marco; Nobre, M Fernanda; Veríssimo, António; da Costa, Milton S

    2008-01-01

    A low-G+C, Gram-positive isolate, designated strain CVS-8(T), was isolated from a sea salt evaporation pond on the Island of Sal in the Cape Verde Archipelago. This organism was found to be a catalase- and oxidase-positive, non-motile, spore-forming, aerobic, curved rod-shaped organism with an optimum growth temperature of about 35-37 degrees C and an optimum pH between 7.5 and 8.0. Optimal growth occurred in media containing 4-6% (w/v) NaCl and no growth occurred in medium without NaCl. The cell-wall peptidoglycan was of the A1gamma type with meso-diaminopimelic acid, the major respiratory quinone was MK-7, the major fatty acids were iso-15:0, 16:0, anteiso-15:0 and iso-16:0 and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified aminoglycophospholipid. The G+C content of the DNA was 37.9 mol%. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain CVS-8(T) represented a novel species of the genus Bacillus, the highest levels of sequence similarity (mean pairwise similarity values of approximately 97.5 %) being found with respect to the type strains of Bacillus shackletonii and Bacillus acidicola. On the basis of the phylogenetic, physiological and biochemical data, strain CVS-8(T) represents a novel species of the genus Bacillus, for which the name Bacillus isabeliae sp. nov. is proposed. The type strain is CVS-8(T) (=LMG 22838(T)=CIP 108578(T)).

  5. Microporous Cokes Formed in Zeolite Catalysts Enable Efficient Solar Evaporation

    KAUST Repository

    Wang, Jianjian

    2017-03-13

    Cokes are inevitably generated during zeolite-catalyzed reactions as deleterious side products that deactivate the catalyst. In this study, we in-situ converted cokes into carbons within the confined microporous zeolite structures and evaluated their performances as absorbing materials for solar-driven water evaporation. With a properly chosen zeolite, the cokederived carbons possessed ordered interconnected pores and tunable compositions. We found that the porous structure and the oxygen content in as-prepared carbons had important influences on their energy conversion efficiencies. Among various investigated carbon materials, the carbon derived from the methanol-to-olefins reaction over zeolite Beta gave the highest conversion efficiency of 72% under simulated sunlight with equivalent solar intensity of 2 suns. This study not only demonstrates the great potential of traditionally useless cokes for solar thermal applications but also provides new insights into the design of carbon-based absorbing materials for efficient solar evaporation.

  6. Solar Pond Potential as A New Renewable Energy in South Sulawesi

    Science.gov (United States)

    Fadliah Baso, Nur; Chaerah Gunadin, Indar; Yusran

    2018-03-01

    Renewable energy sources need to be developed to maintain the electric energy availability by utilizing oceanic energy, namely solar pond energy. This energy is highly influenced by several factors including salinity, air temperature and solar radiation. This study was focused on finding the potential of solar pond in South Sulawesi, a region with fairly high solar radiation and abundant salt water raw materials availability. The method used in this study was analyzing the values from the mathematic models of daily horizontal solar radiation, air temperature, wind speed, relative humidity and atmospheric pressure for the last 22 years which were finalized using MATLAB. The findings of this study will show the areas with good potentials to apply solar pond in South Sulawesi that can be utilized in various fields including power generator, industrial heating process, desalination and heating for biomass conversion.

  7. Use of clays as liners in solar ponds

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Gerardo [Facultad de Ingenieria, Universidad Anahuac Mexico Norte, Huixquilucan, Edo. de Mexico 52786 (Mexico); Almanza, Rafael [Instituto de Ingenieria, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, Mexico D.F. 04510 (Mexico)

    2009-06-15

    An alternative to synthetic materials for use in solar pond liners is to select clayey soils as hydraulic barriers. This option reduces the cost of construction and the risk of contamination of subsoil and groundwater by hot brines. This paper deals with the physical, chemical and hydraulic properties of different soils tested mainly as compacted clay liners. The underdeveloped nations have the option to use this type of liner, but before doing so several tests are recommended, including those for soil and water composition, permeability, plasticity and X-ray diffraction analysis. In this investigation the following samples are analyzed: native clayey soils with illite, montmorillonite and halloysite, treated and non-treated bentonites in powder and granulated form, a mixture of zeolite and sodium bentonite, and industrial minerals composed largely of halloysite, kaolinite and attapulgite selected clays. Neutral salt aqueous solutions (NaCl and KCl) at different concentrations and under temperature gradients were used for compatibility testing conducted on these specimens. Experiment setup and particular testing procedures are also discussed. (author)

  8. ANALYSIS AND MODELING OF SOLAR EVAPORATOR-COLLECTOR

    Directory of Open Access Journals (Sweden)

    Zakaria Mohd. Amin

    2015-11-01

    Full Text Available Solar energy is considered a sustainable resource that poses little to no harmful effects on the environment. The performance of a solar system depends to a great extent on the collector used for the conversion of solar radiant energy to thermal energy. A solar evaporator-collector (SEC is basically an unglazed flat plate collector where refrigerants, such as R134a is used as the working fluid. As the operating temperature of the SEC is very low, it utilizes both solar irradiation and ambient energy leading to a much higher efficiency than the conventional collectors. This capability of SECs to utilize ambient energy also enables the system to operate at night. This type of collector can be locally made and is relatively much cheaper than the conventional collector.   At the National University of Singapore, the evaporator-collector was integrated to a heat pump and the performance was investigated for several thermal applications: (i water heating, (ii drying and (iii desalination. A 2-dimensional transient mathematical model of this system was developed and validated by experimental data. The present study provides a comprehensive study of performance. KEYWORDS: heat pump; evaporator-collector.

  9. Avian communities in baylands and artificial salt evaporation ponds of the San Francisco Bay estuary

    Science.gov (United States)

    Takekawa, John Y.; Lu, C.T.; Pratt, R.T.

    2001-01-01

    San Francisco Bay wetlands, seasonal and tidal marshes between the historic low and high tide lines, are now highly fragmented because of development during the past 150 years. Artificial salt pond systems in the Bay are hypersaline and typically support simple assemblages of algae and invertebrates. In order to establish the value of salt ponds for migratory waterbirds, we used datasets to conduct a meta-analysis of avian communities in the baylands and salt ponds of San Pablo Bay. Fifty-three species of waterbirds in the salt ponds represented six foraging guilds: surface feeders, shallow probers, deep probers, dabblers, diving benthivores and piscivores. The total number of species and the Shannon-Weiner diversity index was higher in baylands than in salt ponds during all four seasons. However, overall bird density (number/ha) was higher in salt ponds compared with baylands in the winter and spring, primarily because of large concentrations of benthivores. Cessation of salt production in 1993 and subsequent reduction in water depth resulted in a decline of some diving duck populations that used the salt ponds.

  10. Stability considerations and a double-diffusive convection model for solar ponds

    Energy Technology Data Exchange (ETDEWEB)

    Lin, E.I.H.; Sha, W.T.; Soo, S.L.

    1979-04-01

    A brief survey is made on the basic principles, current designs and economic advantages of salinity-gradient solar ponds as solar collectors and reservoirs. Solar ponds are well-suited for various AIPH (agricultural and industrial process heat) applications, and as annual storage devices for space heating and cooling. The benefit of an efficient pond is demonstrated via a preliminary economic analysis which suggests the idea of energy farming as a profitable alternative for land usage in the face of rising fuel cost. The economy and reliability of solar-pond operation depend crucially on the stability of the nonconvective gradient zone against disturbances such as generated by a severe weather condition. Attention is focused on the subject of stability, and pertinent existing results are summarized and discussed. Details of the derivation of three-dimensional stability criteria for thermohaline convection with linear gradients are presented. Ten key questions pertaining to stability are posed, whose answers must be sought through extensive analytical and numerical studies. Possible methods of approach toward enhancing solar-pond stability are also discussed. For the numerical studies of pond behavior and stability characteristics, a double-diffusive convection model is proposed. The model can be constructed by extending the three-dimensional thermohydrodynamic computer code COMMIX-SA, following the necessary steps outlined; computational plans are described. Similarities exist between the halothermocline and the thermocline storage systems, and an extended COMMIX-SA will be a valuable tool for the investigation of both.

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

    Science.gov (United States)

    Lin, E. I. H.

    1982-03-01

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

  12. Thermal Desalination using MEMS and Salinity-Gradient Solar Pond Technology

    Science.gov (United States)

    Lu, H.; Walton, J. C.; Hein, H.

    2002-08-01

    MEMS (multi-effect, multi-stage) flash desalination (distillation) driven by thermal energy derived from a salinity-gradient solar pond is investigated in this study for the purpose of improving the thermodynamic efficiency and economics of this technology. Three major tasks are performed: (1) a MEMS unit is tested under various operating conditions at the El Paso Solar Pond site; (2) the operation and maintenance procedures of the salinity-gradient solar pond coupled with the MEMS operation is studied; and (3) previous test data on a 24-stage, falling-film flash distillation unit (known as the Spinflash) is analyzed and compared with the performance of the MEMS unit. The data and information obtained from this investigation is applicable to a variety of thermal desalination processes using other solar options and/or waste heat.

  13. Solar pond-based rural development programme for selected coastal regions - A concept

    Digital Repository Service at National Institute of Oceanography (India)

    Gopinathan, C.K.

    is expected to aid speedy development of selected coastal areas. The programme involves design and construction of a solar pond in which brine in the lower layer is heated to 85 degrees C by solar radiation and is used as the heat source for a closed cycle...

  14. Application of RESRAD Model to Assess Radiation Doses due to TENORM Accumulation in Evaporation Pond during Petroleum Production

    International Nuclear Information System (INIS)

    Othman, M.H.; Hassan, H.B.

    2013-01-01

    TE- Naturally Occurring Radioactive Materials (TE- NORM) is the potential radiation source in the petroleum industry which needs to be identified and controlled to maintain safe working conditions and protection of the environment. In this study radioactive contamination of produced water by NORM has been modeled by using RESRAD (version 6.5) computer code to evaluate potential radiological doses and health risks to workers at several oil field locations. The presence of NORM in produced water unlikely to cause external exposures which may be exceeded dose limits for workers. In this assessment the exposure source parameters were adjusted a period of 100 years and area of evaporation pond was 1300 m 2 and 10 m depth. The predicted maximum total effective doses equivalent received by workers from produced water in evaporation pond are (1.5×10 -5 mSv/yr) and for soil (categories I, II and III) are (0.732, 0.244 and 0.150 mSv/yr). Also its annual total cancer risk for produced water is (1.25×10 -9 ) and for soil (categories I, II and III) are (6.0×x10 -5 , 2.0 x10 -5 , 1.25 x10 -5 ) respectively.

  15. Cuinse2 Thin Film For Solar Cell By Flash Evaporation

    OpenAIRE

    A.H. Soepardjo

    2009-01-01

    Deposition of thin films for material solar cell CuInSe2 are relatively simple. In this research mainly focused on the use of flash evaporation method, and the material created can then be characterized by optical and electrical properties. The optical characterization is done by X-ray Diffraction (XRD), Energy Dispersive Spectroscopy (EDS), and transmission and reflection by UV-VIS spectrophotometry. Electrical characterization is done by utilizing the Hall effect equipment. From these chara...

  16. Water-quality and sediment-chemistry data of drain water and evaporation ponds from Tulare Lake Drainage District, Kings County, California March 1985 to March 1986

    Science.gov (United States)

    Fujii, Roger

    1988-01-01

    Trace element and major ion concentrations were measured in water samples collected monthly between March 1985 and March 1986 at the MD-1 pumping station at the Tulare Lake Drainage District evaporation ponds, Kings County, California. Samples were analyzed for selected pesticides several times during the year. Salinity, as measured by specific conductance, ranged from 11,500 to 37,600 microsiemens/centimeter; total recoverable boron ranged from 4,000 to 16,000 micrg/L; and total recoverable molybdenum ranged from 630 to 2,600 microg/L. Median concentrations of total arsenic and total selenium were 97 and 2 microg/L. Atrazine, prometone, propazine, and simazine were the only pesticides detected in water samples collected at the MD-1 pumping station. Major ions, trace elements, and selected pesticides also were analyzed in water and bottom-sediment samples from five of the southern evaporation ponds at Tulare Lake Drainage District. Water enters the ponds from the MD-1 pumping station at pond 1 and flows through the system terminating at pond 10. The water samples increased in specific conductance (21,700 to 90,200 microsiemens/centimeter) and concentrations of total arsenic (110 to 420 microg/L), total recoverable boron (12,000 to 80,000 microg/L) and total recoverable molybdenum (1,200 to 5,500 microg/L) going from pond 1 to pond 10, respectively. Pesticides were not detected in water from any of the ponds sampled. Median concentrations of total arsenic and total selenium in the bottom sediments were 4.0 and 0.9 microg/g, respectively. The only pesticides detected in bottom sediment samples from the evaporation ponds were DDD and DDE, with maximum concentration of 0.8 microg/kilogram. (Author 's abstract)

  17. Comparative productivity of distillation and reverse osmosis desalination using energy from solar ponds

    Energy Technology Data Exchange (ETDEWEB)

    Tleimat, B.W.; Howe, E.D.

    1982-11-01

    This paper presents comparative analyses of two methods for producing desalted water using the heat collected by a solar pond - the first by distillation, and the second by reverse osmosis. The distillation scheme uses a multiple-effect distiller supplied with steam generated in a flash boiler using heat from a solar pond. Solar pond water passes through a heat exchanger in the water system ahead of the flash boiler. The second scheme uses a similar arrangement to generate hydrocarbon vapor which drives a Rankine cycle engine. This engine produces mechanical/ electrical power for the RO plant. The analyses use two pond water temperatures -82.2/sup 0/C (180/sup 0/F) and 71.1/sup 0/C (160/sup 0/F) -- which seem to cover the range expected from salt-gradient ponds. In each case, the pond water temperature drops by 5.56/sup 0/C (10/sup 0/F) while passing through the vapor generator system. Results of these analyses show that, based on the assumptions made, desalted water could be produced by distillation at productivity rates much greater than those estimated for the RO plant.

  18. Comparative productivity of distillation and reverse osmosis desalination using energy from solar ponds

    Energy Technology Data Exchange (ETDEWEB)

    Tleimat, B.W.; Howe, E.D.

    1982-11-01

    This paper presents comparative analyses of two methods for producing desalted water using the heat collected by a solar pond - the first by distillation, and the second by reverse osmosis. The distillation scheme uses a multiple-effect distiller supplied with steam generated in a flash boiler using heat from a solar pond. Solar pond water passes through a heat exchanger in the water system ahead of the flash boiler. The second scheme uses a similar arrangement to generate hydrocarbon vapor which drives a Rankine cycle engine. This engine produces mechanical/ electrical power for the RO plant. The analyses use two pond water temperatures 82.2/sup 0/C (180/sup 0/F) and 71.1/sup 0/C (160/sup 0/F) - which seem to cover the range expected from salt-gradient ponds. In each case, the pond water temperature drops by 5.56/sup 0/C (10/sup 0/F) while passing through the vapor generator system. Results of these analyses show that, based on the assumptions made, desalted water could be produced by distillation at productivity rates much greater than those estimated for the RO plant.

  19. Olive mill wastewater disposal in evaporation ponds in Sfax (Tunisia): moisture content effect on microbiological and physical chemical parameters.

    Science.gov (United States)

    Jarboui, Raja; Hadrich, Bilel; Gharsallah, Néji; Ammar, Emna

    2009-11-01

    The study of the isotherms desorption of olive mill wastewater (OMW) was investigated to describe its water activity under different saturated environments. The microbial biodegradation of OMW during its storage in 5 evaporation ponds located in Agareb (Sfax-Tunisia) was carried out during the oil-harvesting year held 105 days in 2004. Gravimetric static method using saturated salt solutions was used and OMW as placed at 30 degrees C and under different water activities ranging from 0.11 to 0.90. Eight models were taken from the literature to describe experimental desorption isotherms. During storage, the evolution of physico-chemical parameters including pH, temperature, evaporation, humidity, total phosphorus, chemical oxygen demand (COD), biological oxygen demand (BOD) and phenols and three microbiological flora (aerobic mesophilic bacteria, yeasts and moulds) were considered. At 30 degrees C, when relative humidity increased in the experimented ponds of 69, 84 and 90%, the evaporation speed decreased from 1.24 x 10(-5) to 5 x 10(-6) cm(3) s(-1), from 6 x 10(-5) to 7 x 10(-6) cm(3) s(-1) and from 5 x 10(-6) to 1.1 x 10(-7) cm(3) s(-1) respectively. The desorption isotherm exhibited a sigmoidal curve corresponding to type II, typical of many organic material. The GAB and Peleg models gave the best fit for describing the relationship between the equilibrium moisture content and water activity in OMW (R (2) = 0.998). During the storage period, the analysis showed an increase of all the physico-chemical parameters studied, except phenols and total phosphorus concentrations. The microbiological study showed the predominance of yeasts and moulds and the decrease of bacteria population after 75 days reflecting both effect of recalcitrant compounds and the water activity on microbial growth.

  20. Thermal performance of a single-basin solar still integrated with a shallow solar pond

    International Nuclear Information System (INIS)

    El-Sebaii, A.A.; Ramadan, M.R.I.; Aboul-Enein, S.; Salem, N.

    2008-01-01

    In an attempt to improve the daily productivity of the single effect solar stills, a single-slope single-basin solar still integrated with a shallow solar pond (SSP) was studied to perform solar distillation at a relatively high temperature. The energy balance equations of various elements of the considered system were formulated and solved analytically. Suitable computer programs were prepared for optimizing and predicting the thermal performance of the considered system. Numerical calculations were carried out on typical summer and winter days in Tanta (latitude 30 deg. 47'N) for different thicknesses and mass flow rates of the flowing water to study the effect of these parameters on the daily productivity and efficiency of the system. To validate the proposed theoretical model, comparisons between calculated and measured results were carried out. Good agreement has been achieved. The year-round performances of the still with and without the SSP were also investigated. The optimum values of the flowing water thickness and the mass flow rate for this typical configuration of the SSP-active solar still were obtained as 0.03 m and 0.0009 kg/s. The annual average values of the daily productivity P-bar d and efficiency η-bar d of the still with the SSP were found to be higher than those obtained without the SSP by 52.36% and 43.80%, respectively

  1. Thermal performance of a single-basin solar still integrated with a shallow solar pond

    Energy Technology Data Exchange (ETDEWEB)

    El-Sebaii, A.A.; Ramadan, M.R.I.; Aboul-Enein, S.; Salem, N. [Department of Physics, Faculty of Science, Tanta University, Tanta (Egypt)

    2008-10-15

    In an attempt to improve the daily productivity of the single effect solar stills, a single-slope single-basin solar still integrated with a shallow solar pond (SSP) was studied to perform solar distillation at a relatively high temperature. The energy balance equations of various elements of the considered system were formulated and solved analytically. Suitable computer programs were prepared for optimizing and predicting the thermal performance of the considered system. Numerical calculations were carried out on typical summer and winter days in Tanta (latitude 30 47'N) for different thicknesses and mass flow rates of the flowing water to study the effect of these parameters on the daily productivity and efficiency of the system. To validate the proposed theoretical model, comparisons between calculated and measured results were carried out. Good agreement has been achieved. The year-round performances of the still with and without the SSP were also investigated. The optimum values of the flowing water thickness and the mass flow rate for this typical configuration of the SSP-active solar still were obtained as 0.03 m and 0.0009 kg/s. The annual average values of the daily productivity anti P{sub d} and efficiency anti {eta}{sub d} of the still with the SSP were found to be higher than those obtained without the SSP by 52.36% and 43.80%, respectively. (author)

  2. Experimental and numerical analysis of sodium-carbonate salt gradient solar-pond performance under simulated solar-radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kurt, Hueseyin; Ozkaymak, Mehmet [Zonguldak Karaelmas University, Technical Education Faculty, 78200 Karabuk (Turkey); Binark, A. Korhan [Marmara University, Technical Education Faculty, 34722 Kuyubasi-Istanbul (Turkey)

    2006-04-01

    The objective of this study is to investigate experimentally and theoretically whether sodium carbonate (Na{sub 2}CO{sub 3}) 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 model that describes the heat and mass transfer behaviour of the SGSP was developed. The differential equations obtained were solved numerically using a finite-difference method. It was found from the experiments that the density gradient, achieved using sodium carbonate salt, can suppress convection from the bottom to the surface of the pond. (author)

  3. Experimental and numerical analysis of sodium-carbonate salt gradient solar-pond performance under simulated solar-radiation

    International Nuclear Information System (INIS)

    Kurt, Hueseyin; Ozkaymak, Mehmet; Binark, A. Korhan

    2006-01-01

    The objective of this study is to investigate experimentally and theoretically whether sodium carbonate (Na 2 CO 3 ) 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 model that describes the heat and mass transfer behaviour of the SGSP was developed. The differential equations obtained were solved numerically using a finite-difference method. It was found from the experiments that the density gradient, achieved using sodium carbonate salt, can suppress convection from the bottom to the surface of the pond

  4. Cuinse2 Thin Film For Solar Cell By Flash Evaporation

    Directory of Open Access Journals (Sweden)

    A.H. Soepardjo

    2009-11-01

    Full Text Available Deposition of thin films for material solar cell CuInSe2 are relatively simple. In this research mainly focused on the use of flash evaporation method, and the material created can then be characterized by optical and electrical properties. The optical characterization is done by X-ray Diffraction (XRD, Energy Dispersive Spectroscopy (EDS, and transmission and reflection by UV-VIS spectrophotometry. Electrical characterization is done by utilizing the Hall effect equipment. From these characterization, the atomic structure, absorption coefficient, energy gap, material type, composition of each elements and the mobility of CuInSe2 can be measured and determined. During process evaporation were carried out at substrate temperatures the range between 20ºC-415ºC.

  5. A First Approach to Natural Thermoventilation of Residential Buildings through Ventilation Chimneys Supplied by Solar Ponds

    Directory of Open Access Journals (Sweden)

    Ferdinando Salata

    2015-07-01

    Full Text Available The exploitation of natural ventilation is a good solution to improve buildings from an energetic point of view and to fulfill the requirements demanded by the thermohygrometric comfort and the air quality in enclosed spaces. Some past researches demonstrated how some devices, useful to this purpose, follow the principles of solar chimneys and are able to move air masses while exploiting the Archimedes thrust. The natural ventilation must be supplied by a flow moving upward, generated by a heat source performing at temperatures slightly higher than the one present in the environment. To have a minimum energetic effect, the heat can be extracted from solar ponds; solar ponds are able to collect and store solar energy in the geographical regions characterized by sufficient values of solar radiation. Thus it is possible, in summer, to provoke a nocturnal natural ventilation useful for the air change in indoor spaces (in those climatic areas where, during the night, there is a temperature gradient.

  6. Chemistry of uranium in evaporation pond sediment in the San Joaquin Valley, California, USA, using x-ray fluorescence and XANES techniques

    International Nuclear Information System (INIS)

    Duff, M.C.; Amrhein, C.; Bertsch, P.M.; Hunter, D.B.

    1997-01-01

    Evaporation ponds in the San Joaquin Valley (SJV), CA, used for the disposal of irrigation drainage waters, contain elevated levels of uranium. The ponds are filled periodically and support algae which upon evaporation become incorporated in the sediments as layers of decaying organic matter. This rich source of organic matter promotes reducing conditions in the sediments. Our research was conducted to characterize oxidation/reduction reactions that affect soluble and sediment U(IV)/U(VI) concentrations in the SJV ponds. Studies were done to (1) determine soluble U(Vl)/U(IV) in waters in contact with a pond sediment subjected to changes in redox status, (2) observe U solid oxidation state as a reducing pond sediment underwent (in vitro) oxidation, and (3) determine U solid oxidation state with respect to depth in pond surface sediment layers. Low pressure ion-exchange chromatography with an eluent of 0.125 M H 2 C 2 O 4 /0.25 M HNO 3 was used for the separation of U(IV) and U(VI) oxidation states in the drainage waters. Soluble U(VI) and U(IV) coexisted in sediment suspensions exposed to changes in redox potential (Eh) (-260 mV to +330 mV), and U(VI) was highly soluble in the oxidized, surface pond sediments. X-ray near edge absorption spectroscopy (XANES) showed that the U solid phases were 25% U(IV) and 75% U(VI) and probably a mixed solid [U 3 O 8(s) ] in highly reducing pond sediments. Sediment U(IV) increased slightly with depth in the surface pond sediment layers suggesting a gradual reduction of U(VI) to U(IV) with time. Under oxidized conditions, this mixed oxidation-state solid was highly soluble. 59 refs., 6 figs., 1 tab

  7. Olive mill wastewater sludge from evaporation ponds: evolution of physico-chemical parameters during storage and composting process.

    Science.gov (United States)

    Abid, N; Aloui, F; Dhouib, A; Sayadi, S

    2006-02-01

    The evolution of analytical parameters of olive mill waste water sludge stored in evaporation ponds was investigated after one year and two years of storage. It was observed that some of the phenolic monomer compounds resisted removal and the fraction of water soluble phenols was only slightly polymerised. Co-composting of the sludge was carried out with yard trimming as bulking agent ratio and poultry manure to balance the C/N. Three turned piles with three proportions of 35%, 65% and 80% of olive mill waste water sludge were prepared. Co-composting of the sludge was possible in all the cases. Best results were obtained, however, at a proportion of 35% which permitted a shorter composting time, a higher degree of nitrification and a higher rate of total phenols decreasing. A high polymerisation of the fraction of water soluble phenols was observed at the end of composting in all the piles.

  8. Experimental and comparative study of the effect of paraffin oil and covering for solar ponds without saline water

    Energy Technology Data Exchange (ETDEWEB)

    Spyridonos, A V; Anagnostatos, G S; Novakovic, M M

    1989-01-01

    The effect of a superficial layer of paraffin or a plastic covering on the thermal storage efficiency of three kinds of non-saline solar pond has been investigated. Four small scale ponds were used for experimental measurements. These were: (1) a reference pond; (2) a pond divided horizontally into compartments separated by plastic sheets; (3) a pond with a superficial layer of paraffin and (4) a pond filled with hollow plastic cubes. Comparisons were made between these four ponds with and without plastic coverings, and with a layer of paraffin in addition on ponds 2 and 4. The rise in mean temperature of each pond during a number of heating cycles has been studied. A difference in mean temperature of the order of 10 to 20/sup 0/C was observed in each case between the beginning and end of the heating period and the temperature at the bottom of the pond after heating was in the range 30 to 50/sup 0/C. The results for these experimental ponds may be of use in the choice of full-size shallow ponds and may also give important indications for ponds of much greater depth.

  9. Thermal behavior of laboratory models of honeycomb-covered solar ponds

    Science.gov (United States)

    Lin, E. I. H.

    1983-01-01

    Laboratory experiments were conducted to provide insight into the technical feasibility of honeycomb-covered solar ponds. Cooling tests using honeycomb panels of various materials and geometries showed that a 5.7-cm-thick one-tier panel insulated as effectively as a 10-cm fiberglass slab. Heating tests demonstrated that a model pond covered with a polycarbonate panel boiled upon 16 hours of continuous exposure to a 150-W spotlight. Analysis of the experimental data indicates positively that honeycomb-covered solar ponds can be expected to perform satisfactorily, and that larger-scale outdoor tests should be conducted to provide a more realistic assessment and a more refined performance estimate.

  10. Convective instability of sludge storage under evaporation and solar radiation

    Science.gov (United States)

    Tsiberkin, Kirill; Tatyana, Lyubimova

    2014-05-01

    The sludge storages are an important part of production cycle at salt manufacturing, water supply, etc. A quality of water in the storage depends on mixing of pure water and settled sediment. One of the leading factors is thermal convection. There are two main mechanisms of the layer instability exist. First, it is instability of water due to evaporation from the free surface [1]. It cools the water from upside, increases the particles concentration and leads to the instability in the near-surface layer. Second, the sediment absorbs a solar radiation and heats the liquid from below making it unstable in the near-bottom area. We assume the initial state is the mechanical equilibrium. The water and sediment particles are motionless, the sediment forms a uniform sludge layer of thickness z0, there are no evaporation and heating by solar energy, and the temperature has a linear profile is determined by fixed upper and bottom temperatures of the layer. Taking into account the evaporation and solar radiation absorption, we obtain a non-stationary solution for the temperature using Fourier series method. The local temperature gradients increases rapidly with time, and local Rayleigh number can be estimated by thermal conduction length Lt: Raloc(z,t) = gβ(δT(z,t)/δz)L4t-/νΞ , Lt ~ √Ξt, (1) where g is gravity acceleration, β, ν and Ξ are thermal volume expansion coefficient, kinematic viscosity and thermal conductivity of the liquid, respectively. Raloc* reaches the critical value at finite time t* and water motion begins. The maximal power of solar radiation in visible band equals 230 Wt/m2 at the latitude of "Uralkalii" salt manufacturer (Berezniki, Perm Region, Russian Federation). We neglect IR and UV radiation because of its huge absorption by water [2]. The evaporation speed is found using results for shallow water reservoir [3] and meteorological data for Berezniki [4]. We get the t*~ 6 · 102 s (10 min) for the layer of 1 m depth and t*~ 2 · 103 s (40

  11. Solar Irradiance and Pan Evaporation Estimation from Meteorological Satellite Data

    Directory of Open Access Journals (Sweden)

    Ming-Ren Syu

    2016-04-01

    Full Text Available Knowledge about spatial and temporal variations in surface global solar radiation (GSR and evaporative water loss from the ground are important issues to many researches and applications. In this study empirical relationships suitable for Taiwan were established for GSR retrieval from geostationary satellite images using the Heliosat method for the period from 2011 - 2013. The derived GSR data has been used to generate consecutive maps of 10-day averaged pan evaporation (Epan as the basis to produce regional ET estimation using a strategy that does not require remote sensed land surface temperatures (LST. The retrieved daily GSR and the derived 10-day averaged Epan were validated against pyranometer and class-A pan measurements at selected Central Weather Bureau (CWB stations spread across various climatic regions in Taiwan. Compared with the CWB observed data the overall relative mean bias deviations (MBD% and root mean square differences (RMSD% in daily solar irradiance retrieval were about 5 and 15%, respectively. Seasonally, the largest MBD% and RMSD% of retrieved daily solar irradiance occur in spring (9.5 and 21.3% on average, while the least MBD% (-0.3% on average and RMSD% (9.7% on average occur in autumn and winter, respectively. For 10-day averaged Epan estimation, the mean MBD% and RMSD% for stations located in the coastal plain areas were 0.1 and 16.9%, respectively. However, in mountainous areas the mean MBD% and RMSD% increased to 30.2 and 34.5%, respectively. This overestimation was due mainly to the large differences in surrounding micro-environments between the mountainous and plain areas.

  12. Treatment of pond sludge at the Rocky Flats Plant

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  13. Time-dependent evolution of olive mill wastewater sludge organic and inorganic components and resident microbiota in multi-pond evaporation system.

    Science.gov (United States)

    Jarboui, Raja; Chtourou, Mohamed; Azri, Chafai; Gharsallah, Néji; Ammar, Emna

    2010-08-01

    The physico-chemical and microbiological characterizations of olive mill wastewater sludge (OMWS) were investigated in five OMW evaporation ponds of the open-pond system in Sfax (Tunisia), during the olive oil production period in 2004. Time-dependent changes in both physico-chemical parameters and the microbiota were investigated. Mathematical models and principal component analysis (PCA) were used to establish the correlations between the studied parameters. During the effluent time-dependent changes in the ponds, the result of OMWS analysis showed an increase of sludge index (SI), ash content, total solids (TS), volatile solids (VS), ethyl acetate extractive (EAE) and total phosphorus (Total P), as well as microbial flora especially the yeasts and moulds. The SI, TS, VS and Total P changes with time fit a simple linear equation, while EAE, phenols and NH(4)(+) fit a second-degree polynomial model. The PCA analysis exhibited three correlated groups. The first group included temperature, ash content, evaporation, SI, TS, VS, Total P, EAE, yeasts and moulds. The second group was made by bacteria and moisture; and the third group by NH(4)(+), oil and phenol. Such modelling might be of help in the prediction of OMW changes in natural evaporation ponds. (c) 2010 Elsevier Ltd. All rights reserved.

  14. Evaporators

    DEFF Research Database (Denmark)

    Knudsen, Hans Jørgen Høgaard

    1996-01-01

    Type of evaporators. Regulation. Thermal dimensioning. Determination of pressure loss and heat transfer coefficients.......Type of evaporators. Regulation. Thermal dimensioning. Determination of pressure loss and heat transfer coefficients....

  15. Thermal performance of shallow solar pond under open cycle continuous flow heating mode for heat extraction

    Energy Technology Data Exchange (ETDEWEB)

    El-Sebaii, A.A. [Department of Physics, Faculty of Science, Tanta University, Tanta 31527 (Egypt)]. E-mail: aasebaii@yahoo.com; Aboul-Enein, S. [Department of Physics, Faculty of Science, Tanta University, Tanta 31527 (Egypt); Ramadan, M.R.I. [Department of Physics, Faculty of Science, Tanta University, Tanta 31527 (Egypt); Khallaf, A.M. [Department of Physics, Faculty of Science, Tanta University, Tanta 31527 (Egypt)

    2006-05-15

    The thermal performance of a shallow solar pond (SSP) under an open cycle continuous flow heating mode for heat extraction has been investigated. A serpentine heat exchanger (HE), either welded to the absorber plate or immersed in the pond water, has been used for extracting the heat. Suitable computer programs have been developed based on analytical solutions of the energy balance equations for the various elements of the SSP in the presence of the HE. Numerical calculations have been performed to study the effect of different operational and configurational parameters on the pond performance. In order to improve the pond performance, optimization of the various dimensions of the pond with the HE has been performed. The effects of the design parameters of the HE's tube, i.e. length L{sub he}, diameter D and mass flow rate m-bar {sub f} of the fluid flowing through the HE, on the pond performance have been investigated. The outlet temperature of the HE's fluid T{sub fo} is found to increase with increase of the HE length L{sub he}, and it decreases with increase of the mass flow rate of the HE's fluid m-bar {sub f} up to typical values for these parameters. Typical values for L{sub he} and m-bar {sub f} are found to be 4m and 0.004kg/s beyond which the change in T{sub fo} becomes insignificant. Experiments have been performed for the pond under different operational conditions with a HE welded to the absorber plate. To validate the proposed mathematical models, comparisons between experimental and theoretical results have been performed. Good agreement has been achieved.

  16. Evaporation

    International Nuclear Information System (INIS)

    Delaney, B.T.; Turner, R.J.

    1989-01-01

    Evaporation has long been used as a unit operation in the manufacture of various products in the chemical-process industries. In addition, it is currently being used for the treatment of hazardous wastes such as radioactive liquids and sludges, metal-plating wastes, and other organic and inorganic wastes. Design choice is dependent on the liquid to be evaporated. The three most common types of evaporation equipment are the rising-film, falling-film, and forced-circulation evaporators. The first two rely on boiling heat transfer and the latter relies on flash vaporization. Heat exchangers, flash tanks, and ejectors are common auxiliary equipment items incorporated with evaporator bodies to complete an evaporator system. Properties of the liquid to be evaporated are critical in final selection of an appropriate evaporator system. Since operating costs are a significant factor in overall cost, heat-transfer characteristics and energy requirements are important considerations. Properties of liquids which are critical to the determination of final design include: heat capacity, heat of vaporization, density, thermal conductivity, boiling point rise, and heat-transfer coefficient. Evaporation is an expensive technology, both in terms of capital costs and operating costs. Additionally, mechanical evaporation produces a condensate and a bottoms stream, one or both of which may require further processing or disposal. 3 figs

  17. Evaporation Ponds or Recharge Structures ? the Role of Check Dams in Arkavathy River Basin, India

    Science.gov (United States)

    Jeremiah, K.; Srinivasan, V.; R, A.

    2014-12-01

    "Watershed development" has been the dominant paradigm for water management in India for the last two decades. Current spending on watershed development programmes rivals spending on large dams. In practice, watershed development involves a range of soil and water conservation measures including building check dams, gully plugs, contour bunds etc. Despite their dominance in water management paradigms, relatively little empirical data exists on these structures. Importantly, even though the benefits of individual watershed structures are recognized, the cumulative impact of building hundreds of such structures on hydrologic partitioning of a watershed remains unknown. We investigated the role of check dams in two small milli-watersheds in the Arkavathy River basin in South India. We conducted a comprehensive census of all check dams in the two milli-watersheds with a total area of 26 sq km. 40 check dams (representing a density of 1.35/sq km of watershed area) were geotagged, photographed, measured and their condition was recorded. We then selected twelve check dams and monitored the water stored using capacitance sensors. We also set up Automatic Weather Stations in each watershed. Inflows, evaporation and infiltration were calculated at each site to evaluate how check dams alter hydrologic partitioning in the watershed as a whole.

  18. Power generation enhancement in a salinity-gradient solar pond power plant using thermoelectric generator

    International Nuclear Information System (INIS)

    Ziapour, Behrooz M.; Saadat, Mohammad; Palideh, Vahid; Afzal, Sadegh

    2017-01-01

    Highlights: • Thermoelectric generator was used and simulated within a salinity-gradient solar pond power plant. • Results showed that the thermoelectric generator can be able to enhance the power plant efficiency. • Results showed that the presented models can be able to produce generation even in the cold months. • The optimum size of area of solar pond based on its effect on efficiency is 50,000 m 2 . - Abstract: Salinity-gradient solar pond (SGSP) has been a reliable supply of heat source for power generation when it has been integrated with low temperature thermodynamics cycles like organic Rankine cycle (ORC). Also, thermoelectric generator (TEG) plays a critical role in the production of electricity from renewable energy sources. This paper investigates the potential of thermoelectric generator as a power generation system using heat from SGSP. In this work, thermoelectric generator was used instead of condenser of ORC with the purpose of improving the performance of system. Two new models of SGSP have been presented as: (1) SGSP using TEG in condenser of ORC without heat exchanger and (2) SGSP using TEG in condenser of ORC with heat exchanger. These proposed systems was evaluated through computer simulations. The ambient conditions were collected from beach of Urmia lake in IRAN. Simulation results indicated that, for identical conditions, the model 1 has higher performance than other model 2. For models 1 and 2 in T LCZ = 90 °C, the overall thermal efficiency of the solar pond power plant, were obtained 0.21% and 0.2% more than ORC without TEG, respectively.

  19. Solar-thermal-energy collection/storage-pond system

    Science.gov (United States)

    Blahnik, D.E.

    1982-03-25

    A solar thermal energy collection and storage system is disclosed. Water is contained, and the water surface is exposed directly to the sun. The central part of an impermeable membrane is positioned below the water's surface and above its bottom with a first side of the membrane pointing generally upward in its central portion. The perimeter part of the membrane is placed to create a watertight boundary separating the water into a first volume which is directly exposable to the sun and which touches the membranes first side, and a second volumn which touches the membranes second side. A salt is dissolved in the first water volume.

  20. Research and Development of Solar Evaporation on Low Level Radioactive Liquid Waste

    Directory of Open Access Journals (Sweden)

    ZHANG Hua

    2016-02-01

    Full Text Available Solar evaporation, which can save energy and obtain the higher decontamination factor, the larger treatment capability with the simpler designed and easy operation, was one of the general methods to treat low level radioactive liquid waste. However, the use of solar evaporation was limited because the facilities had to occupy the larger area and require sunshine for the longer duration, etc. Several cases form USA, Australian, India and South Korea were presented on R&D of solar evaporation to treat low level radioactive liquid waste.

  1. Salirhabdus euzebyi gen. nov., sp. nov., a Gram-positive, halotolerant bacterium isolated from a sea salt evaporation pond.

    Science.gov (United States)

    Albuquerque, Luciana; Tiago, Igor; Rainey, Fred A; Taborda, Marco; Nobre, M Fernanda; Veríssimo, António; da Costa, Milton S

    2007-07-01

    A low-G+C, Gram-positive bacterium, designated CVS-14(T), was recovered from a sea salt evaporation pond on the island of Sal in the Cape Verde Archipelago. This organism was catalase- and oxidase-positive. Cells were motile, spore-forming aerobic rods, with an optimum growth temperature of about 35-40 degrees C and optimum pH between 7.0 and 8.5. Optimal growth occurred in media containing 4-6 % (w/v) NaCl, although the organism was able to grow in medium without added NaCl and in medium containing 16 % NaCl. The cell-wall peptidoglycan was of A1 gamma type and the major respiratory quinone was menaquinone 7 (MK-7). Major fatty acids were iso-15 : 0, anteiso-15 : 0, iso-17 : 0 and anteiso-17 : 0. The DNA G+C content was 37.0 mol%. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain CVS-14(T) formed a distinct new branch within the radiation of the moderately halophilic bacilli group, forming a separate lineage from species of the genera Salinibacillus, Paucisalibacillus, Oceanobacillus, Lentibacillus and Virgibacillus. Strain CVS-14(T) showed 16S rRNA gene pairwise similarity values of approximately 95 % with species of the genus Salinibacillus. On the basis of morphological, physiological, chemotaxonomic and phylogenetic characteristics, strain CVS-14(T) is considered to represent a novel species in a new genus, for which the name Salirhabdus euzebyi gen. nov., sp. nov. is proposed. The type strain is CVS-14(T) (=LMG 22839(T)=CIP 108577(T)).

  2. Combined effect of bottom reflectivity and water turbidity on steady state thermal efficiency of salt gradient solar pond

    International Nuclear Information System (INIS)

    Husain, M.; Patil, P.S.; Patil, S.R.; Samdarshi, S.K.

    2004-01-01

    In salt gradient solar ponds, the clarity of water and absorptivity of the bottom are important concerns. However, both are practically difficult to maintain beyond a certain limit. The reflectivity of the bottom causes the loss of a fraction of the incident radiation flux, resulting in lower absorption of flux in the pond. Turbidity hinders the propagation of radiation. Thereby it decreases the flux reaching the storage zone. Both these factors lower the efficiency of the pond significantly. However, the same turbidity also prevents the loss of radiation reflected from the bottom. Hence, the combined effect is compensatory to some extent. The present work is an analysis of the combined effect of the bottom's reflectivity and water turbidity on the steady state efficiency of solar ponds. It is found that in the case of a reflective bottom, turbidity, within certain limits, improves the efficiency of pond. This is apparently contradictory to the conventional beliefs about the pond. Nevertheless, this conclusion is of practical importance for design and maintenance of solar ponds

  3. Numerical Study on Radiation Effects to Evaporator in Natural Vacuum Solar Desalination System

    Science.gov (United States)

    Siregar, R. E. T.; Ronowikarto, A. D.; Setyawan, E. Y.; Ambarita, H.

    2018-01-01

    The need for clean water is increasing day by day due to the increasing factor of living standard of mankind, hence designed natural vacuum solar desalination. The natural vacuum Solar desalination is studied experimentally. A small-scale natural vacuum desalination study consists of evaporator and condenser as the main components designed and manufactured. To transfer heat from the solar collector into the evaporator, the fluid transfer system uses a pump powered by a solar cell. Thus, solar collectors are called hybrid solar collectors. The main purpose of this exposure is to know the characteristics of the radiation effects on incoming energy on the evaporator during the process. This system is tested by exposing the unit to the solar radiation in the 4th floor building in Medan. The experiment was conducted from 8.00 to 16.00 local time. The results show that natural vacuum solar desalination with hybrid solar collectors can be operated perfectly. If the received radiation is high, then the incoming energy received by the evaporator will also be high. From measurements with HOBO microstation, obtained the highest radiation 695.6 W/m2, and the calculation result of incoming energy received evaporator obtained highest result 1807.293 W.

  4. Different methods for modeling absorption heat transformer powered by solar pond

    International Nuclear Information System (INIS)

    Sencan, Arzu; Kizilkan, Onder; Bezir, Nalan C.; Kalogirou, Soteris A.

    2007-01-01

    Solar ponds are a type of solar collector used for storing solar energy at temperature below 90 o C. Absorption heat transformers (AHTs) are devices used to increase the temperature of moderately warm fluid to a more useful temperature level. In this study, a theoretical modelling of an absorption heat transformer for the temperature range obtained from an experimental solar pond with dimensions 3.5 x 3.5 x 2 m is presented. The working fluid pair in the absorption heat transformer is aqueous ternary hydroxide fluid consisting of sodium, potassium and caesium hydroxides in the proportions 40:36:24 (NaOH:KOH:CsOH). Different methods such as linear regression (LR), pace regression (PR), sequential minimal optimization (SMO), M5 model tree, M5' rules, decision table and back propagation neural network (BPNN) are used for modelling the absorption heat transformer. The best results were obtained by the back propagation neural network model. A new formulation based on the BPNN is presented to determine the flow ratio (FR) and the coefficient of performance (COP) of the absorption heat transformer. The BPNN procedure is more accurate and requires significantly less computation time than the other methods

  5. Natural heat storage in a brine-filled solar pond in the Tully Valley of central New York

    Science.gov (United States)

    Hayhurst, Brett; Kappel, William M.

    2014-01-01

    The Tully Valley, located in southern Onondaga County, New York, has a long history of unusual natural hydrogeologic phenomena including mudboils (Kappel, 2009), landslides (Tamulonis and others, 2009; Pair and others, 2000), landsurface subsidence (Hackett and others, 2009; Kappel, 2009), and a brine-filled sinkhole or “Solar pond” (fig. 1), which is documented in this report. A solar pond is a pool of salty water (brine) which stores the sun’s energy in the form of heat. The saltwater naturally forms distinct layers with increasing density between transitional zones (haloclines) of rapidly changing specific conductance with depth. In a typical solar pond, the top layer has a low salt content and is often times referred to as the upper convective zone (Lu and others, 2002). The bottom layer is a concentrated brine that is either convective or temperature stratified dependent on the surrounding environment. Solar insolation is absorbed and stored in the lower, denser brine while the overlying halocline acts as an insulating layer and prevents heat from moving upwards from the lower zone (Lu and others, 2002). In the case of the Tully Valley solar pond, water within the pond can be over 90 degrees Fahrenheit (°F) in late summer and early fall. The purpose of this report is to summarize observations at the Tully Valley brine-filled sinkhole and provide supplemental climate data which might affect the pond salinity gradients insolation (solar energy).

  6. Development of a small-scale solar pond technology testbed for education purposes

    International Nuclear Information System (INIS)

    Rahmat, I.; Shazi, M.; Farizal, M.; Nor Azli; Fakhruldin M Hashim

    2006-01-01

    The search for clean energy sources that do not pollute have led researchers to test their ideas on a multitude of possible technology avenues. A number of these solutions rely on the sun. however, the initial financial investment required is great. These solutions, such as solar water heaters, depend on an insulated water tank to store the captured energy. A more effective device could be used to both capture and store copious amounts of sunlight energy, allowing almost continuous use even at night. Solar ponds show great promise in fulfilling this requirement. The one currently in operation at Universiti Teknologi PETRONAS is of the non-convecting type. It uses concentrated brine in the depths of the pond to capture solar energy. The energy is then trapped by the presence of a non-saline top layer, which insulates from convection heat losses. This phenomenon manifests itself as a rise in temperature of the brine. In this manner, thermal energy is contained in the pond, which can serve as the heat source for any appropriate power cycle or used for heating purposes. To make the technology feasible for education purposes it is imperative that its cost is lowered. The system is not dug out of the ground but uses a commercial bathtub to simulate the body of water. This method also greatly simplifies fabrication and maintenance. With this rudimentary setup, the highest temperature reached so far is 54 o C, achieved in a water depth of only 0.28 m. The next step is to increase the water depth, search for the most cost-effective side insulation and continue research into the appropriate energy extraction system to match the output and size of the solar pond. The main intent of this project is to educate students on this concept and develop it into an effective technology demonstrator. By keeping the cost low it can be turned into a viable secondary school Living Skills project to educate them on the potential of solar energy and the existence of alternative solutions in

  7. Site-Specific Research Conducted in Support of the Salton Sea Solar Pond Project - FY 1982 Report

    Science.gov (United States)

    French, R. L.; Marsh, H. E.; Roschke, E. J.; Wu, Y. C.

    1984-01-01

    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.

  8. A study of the natural biodegradation of two-phase olive mill solid waste during its storage in an evaporation pond.

    Science.gov (United States)

    Borja, R; Sánchez, E; Raposo, F; Rincón, B; Jiménez, A M; Martín, A

    2006-01-01

    A study of the natural biodegradation of two-phase olive mill solid waste (OMSW) during its storage in an evaporation pond was carried out. This system is traditionally used as the final disposal of this waste or constitutes a previous stage before being processed by cogeneration or anaerobic digestion processes. A laboratory-scale pond with a total volume of 520 l was used. The experiment was carried out between December 2002 and August 2003 covering a total period of 269 days. During the experiment, the variations of temperature (outside and inside the pond), the effective volume of the OMSW in the pond, moisture content, total solids (TS), volatile solids (VS), the total chemical oxygen demand (TCOD), total volatile acids (TVA), pH and cumulative methane production as a function of the operation time were evaluated. The experimental results obtained showed that the characteristics of the two-phase OMSW in the pond were dependent on the time of operation and temperature. During the experiment, three periods were clearly observed and differentiated: (a) An initial period with a rapid reduction of moisture content and effective volume, with an increase of TS, VS and TCOD removals, a decrease of pH and an increase of TVA and methane production until day 21. (b) A second period of slow decrease of moisture content and effective volume, due to the decrease of the ambient temperature. This period took place between day 21 and days 120-150 of assay, and it was characterised by a slight change in the OMSW properties. (c) A third period where the characteristics of the waste in the pond changed considerably due to the increase of the temperature outside the pond. The methane gas production also showed an increase due to the increase of methanogenic activity with the increase of temperature. An empirical model to describe the changes of two-phase OMSW characteristics and methane production with the operation time was developed. The proposed model, based on the use of

  9. Solar and Net Radiation for Estimating Potential Evaporation from Three Vegetation Canopies

    Science.gov (United States)

    D.M. Amatya; R.W. Skaggs; G.W. Cheschier; G.P. Fernandez

    2000-01-01

    Solar and net radiation data are frequent/y used in estimating potential evaporation (PE) from various vegetative surfaces needed for water balance and hydrologic modeling studies. Weather parameters such as air temperature, relative humidity, wind speed, solar radiation, and net radiation have been continuously monitored using automated sensors to estimate PE for...

  10. Solar Pond devices: free energy or bioreactors for Artemia biomass production?

    Science.gov (United States)

    Gouveia, Luisa; Sousa, João; Marques, Ana; Tavares, Célia; Giestas, Margarida

    2009-08-01

    The recent exponential growth in industrial aquaculture has led to a huge increase in Artemia biomass production in order to meet increased fish production needs. The present study explores the potential use of salt gradient solar ponds (SGSPs) for production of Artemia nauplii. An SGSP is a basin of water where solar energy is trapped and collected via an artificially imposed gradient. Three zones can be identified in an SGSP: upper and lower zones, which are both convective, and a middle zone, which is intended to be non-convective. The latter acts as a transparent insulation layer and allows for storage of solar energy at the bottom, where it is available for use. The combination of salt, temperature and high transparency could make SGSPs promising bioreactors for the production of Artemia nauplii. Using particle image velocymetry (PIV) and Shadowgraph visualisation techniques, the behaviour of Artemia nauplii under critical cultivation parameters (namely, salinity, temperature and light) was monitored to determine movement velocity, and how movement of Artemia affects the salt gradient. It was observed that Artemia nauplii constantly follow light, irrespective of adverse salinity and/or temperature conditions. However, despite the substantial displacement of Artemia following the light source, the salt gradient is not disrupted. The suitability of SGSPs as bioreactors for Artemia biomass production was then tested. The results were disappointing, probably due to the lack of sufficient O(2) for Artemia survival and growth. Follow-up trials were conducted aimed at using the SGSP as a green and economically attractive energy source to induce faster hatching of cysts and improved Artemia nauplii growth. The results of these trials, and a case study of Artemia nauplii production using an SGSP, are presented. The authors constructed a Solar Pond device, which they suggest as a novel way of supplying thermal energy for Artemia biomass production in an aquaculture

  11. A THEORETICAL AND NUMERICAL STUDY OF THERMOSOLUTAL CONVECTION: STABILITY OF A SALINITY GRADIENT SOLAR POND

    Directory of Open Access Journals (Sweden)

    Djamel Kalache

    2011-01-01

    Full Text Available A theoretical and numerical study of the effect of thermodiffusion on the stability of a gradient layer is presented. It intends to clarify the mechanisms of fluid dynamics and the processes which occur in a salinity gradient solar pond. A mathematical modelling is developed to describe the thermodiffusion contribution on the solar pond where thermal, radiative, and massive fluxes are coupled in the double diffusion. More realistic boundary conditions for temperature and concentration profiles are used. Our results are compared with those obtained experimentally by authors without extracting the heat flux from the storage zone. We have considered the stability analysis of the equilibrium solution. We assumed that the perturbation of quantities such as velocity, temperature, and concentration are infinitesimal. Linearized equations satisfying appropriate prescribed boundary conditions are then obtained and expanded into polynomials form. The Galerkin method along with a symbolic algebra code (Maple are used to solve these equations. The effect of the separation coefficient y is analyzed in the positive and negative case. We have also numerically compared the critical Rayleigh numbers for the onset of convection with those obtained by the linear stability analysis for Le = 100, µa = 0.8, and f = 0.5.

  12. Achievement report for fiscal 1999 on project for supporting the formation of energy/environmental technology verification project. International joint verification research project (Study on an optimum heat and electricity supply system using a solar pond); 1999 nendo solar pond ni okeru saiteki netsuden kyokyu system no kenkyu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This report covers the outcome of survey and research jointly conducted by a Russian research organization and a Japanese committee of experts. Concerning the present trend and the future outlook of the solar pond technology across the world, feasibility studies of Australia, America, Malaysia, Italy, etc., are presented. It is reported that a solar pond may be able to compete with other profitable power generation systems in terms of cost if advantageous siting conditions are available; that solar ponds are already in presence in Israel, America, Australia, India, etc.; but that none of them is commercially active on a large scale. In the evaluation of solar pond feasibility, various findings are obtained on solar pond performance characteristics through the examination of solar pond operating data supplied from the University of Texas, America. The findings are used in the evaluation of the siting cost in case one is to be installed in Russia and Japan. (NEDO)

  13. Performance of evaporator-collector and air collector in solar assisted heat pump dryer

    International Nuclear Information System (INIS)

    Hawlader, M.N.A.; Rahman, S.M.A.; Jahangeer, K.A.

    2008-01-01

    A solar assisted heat pump dryer has been designed, fabricated and tested. This paper presents the performance of the evaporator-collector and the air collector when operated under the same meteorological conditions. ASHRAE standard procedure for collector testing has been followed. The evaporator-collector of the heat pump is acting directly as the solar collector, and the temperature of the refrigerant at the inlet to the evaporator-collector always remained below the ambient temperature. Because of the rejection of sensible and latent heats of air at the dehumidifier, the temperature at the inlet to the air collector is lower than that of the ambient air. Hence, the thermal efficiency of the air collector also increases due to a reduction of losses from the collector. The efficiencies of the evaporator-collector and the air collector were found to vary between 0.8-0.86 and 0.7-0.75, respectively, when operated under the meteorological conditions of Singapore

  14. Enhanced solar evaporation of water from porous media, through capillary mediated forces and surface treatment

    International Nuclear Information System (INIS)

    Canbazoglu, F. M.; Fan, B.; Kargar, A.; Vemuri, K.; Bandaru, P. R.

    2016-01-01

    The relative influence of the capillary, Marangoni, and hydrophobic forces in mediating the evaporation of water from carbon foam based porous media, in response to incident solar radiation, are investigated. It is indicated that inducing hydrophilic interactions on the surface, through nitric acid treatment of the foams, has a similar effect to reduced pore diameter and the ensuing capillary forces. The efficiency of water evaporation may be parameterized through the Capillary number (Ca), with a lower Ca being preferred. The proposed study is of much relevance to efficient solar energy utilization.

  15. Egg production and hatching success of Paracartia grani (Copepoda, Calanoida, Acartiidae) in two hypersaline ponds of a Tunisian Solar Saltern

    Science.gov (United States)

    Annabi-Trabelsi, Neila; Rebai, Rayda Kobbi; Ali, Mohammad; Subrahmanyam, M. N. V.; Belmonte, Genuario; Ayadi, Habib

    2018-04-01

    Reproductive traits of Paracartia grani [percentage of spawning females, egg production rate (EPR), and hatching success (HS)] were investigated for the first time at high salinities (39-121 psu) to examine the impact of such a particular situation. The study was done in two hypersaline ponds [A1 (39-46 psu) and C31 (70-121 psu)] in Sfax Solar Saltern, central-eastern coast of Tunisia. These ponds also differed in terms of the composition and concentrations of nutritional parameters. The EPR differed significantly between the ponds (ANOVA, F = 29.45, p eggs female- 1 day- 1 (7 December 2009) and 14 ± 1 eggs female- 1 day- 1 (19 January 2010) with an average of 13.3 ± 0.44 eggs female- 1 day- 1. HS after 48 h of incubation were significantly higher than those after 24 h. The mean values of HS after 48 h were 42.72 ± 2.58% at pond A1 and 41.67 ± 3.92% at pond C31. The two peaks of HS (after 48 h) were observed at 15 °C in pond A1 (21 December 2009, 45.18% nauplii eggs- 1) and in C31 (4 January 2010, 48.78%) at the same temperature. This study confirms that a broad salinity tolerance allows P. grani to settle itself in environments, which are normally hostile to the development of other Acartiidae.

  16. Field screening sampling and analysis strategy and methodology for the 183-H Solar Evaporation Basins: Phase 2, Soils

    International Nuclear Information System (INIS)

    Antipas, A.; Hopkins, A.M.; Wasemiller, M.A.; McCain, R.G.

    1996-01-01

    This document provides a sampling/analytical strategy and methodology for Resource Conservation and Recovery Act (RCRA) closure of the 183-H Solar Evaporation Basins within the boundaries and requirements identified in the initial Phase II Sampling and Analysis Plan for RCRA Closure of the 183-H Solar Evaporation Basins

  17. Table Salt from Seawater (Solar Evaporation). What We Take from Our Environment. Science and Technology Education in Philippine Society.

    Science.gov (United States)

    Philippines Univ., Quezon City. Science Education Center.

    This module discusses methods of obtaining table salt from seawater. Topic areas considered include: (1) obtaining salt by solar evaporation of seawater in holes; (2) obtaining salt by boiling seawater in pots; (3) how table salt is obtained from seawater in the Philippines; and (4) methods of making salt by solar evaporation of seawater in the…

  18. Genotoxic Assessment of Some Inorganic Compounds in Desert Pupfish (Cyprinodon macularius) in the Evaporation Pond from a Geothermal Plant.

    Science.gov (United States)

    Flores-Galván, Miguel; Arellano-García, Evarista; Ruiz-Campos, Gorgonio; Daesslé, Luis Walter

    2017-08-01

    The frequency of micro nucleated erythrocytes in peripheral blood of the desert pupfish (Cyprinodon macularius) from a geothermal effluent pond is determined and compared to organisms kept in an aquarium. The frequency of micronucleated erythrocytes found in pupfish from the geothermal pond is 2.75 (±2.09) and only 0.44 (±0.52) in captivity organisms. Dissolved As in the ponds doubles the 340 µg L -1 US-EPA acute quality criteria for aquatic life and Hg equals the 1.77 µg L -1 chronic criteria. The organisms with high MNE also have significantly high Se, As and Hg concentrations in muscle and liver. Compared to international maximum allowable limits for fish consumption, there is 81× enrichment for Se, 6× for As and 5× for Hg. Although Se is not significantly enriched in water, it is likely that its bioaccumulation occurs via feeding of detritus. The desert pupfish has a significant resistance to extreme metal accumulations and to recover under unpolluted conditions.

  19. On the evaporation of solar dark matter: spin-independent effective operators

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Zheng-Liang [Institute of High Energy Physics, Chinese Academy of Sciences,19B Yuquan Road, Beijing, 100049 (China); Wu, Yue-Liang; Yang, Zi-Qing; Zhou, Yu-Feng [Kavli Institute for Theoretical Physics China,CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics,Chinese Academy of Sciences, Zhong Guan Cun Street 55#, Beijing, 100190 (China)

    2016-09-13

    As a part of the effort to investigate the implications of dark matter (DM)-nucleon effective interactions on the solar DM detection, in this paper we focus on the evaporation of the solar DM for a set of the DM-nucleon spin-independent (SI) effective operators. In order to put the evaluation of the evaporation rate on a more reliable ground, we calculate the non-thermal distribution of the solar DM using the Monte Carlo methods, rather than adopting the Maxwellian approximation. We then specify relevant signal parameter spaces for the solar DM detection for various SI effective operators. Based on the analysis, we determine the minimum DM masses for which the DM-nucleon coupling strengths can be probed from the solar neutrino observations. As an interesting application, our investigation also shows that evaporation effect can not be neglectd in a recent proposal aiming to solve the solar abundance problem by invoking the momentum-dependent asymmetric DM in the Sun.

  20. On the evaporation of solar dark matter: spin-independent effective operators

    International Nuclear Information System (INIS)

    Liang, Zheng-Liang; Wu, Yue-Liang; Yang, Zi-Qing; Zhou, Yu-Feng

    2016-01-01

    As a part of the effort to investigate the implications of dark matter (DM)-nucleon effective interactions on the solar DM detection, in this paper we focus on the evaporation of the solar DM for a set of the DM-nucleon spin-independent (SI) effective operators. In order to put the evaluation of the evaporation rate on a more reliable ground, we calculate the non-thermal distribution of the solar DM using the Monte Carlo methods, rather than adopting the Maxwellian approximation. We then specify relevant signal parameter spaces for the solar DM detection for various SI effective operators. Based on the analysis, we determine the minimum DM masses for which the DM-nucleon coupling strengths can be probed from the solar neutrino observations. As an interesting application, our investigation also shows that evaporation effect can not be neglectd in a recent proposal aiming to solve the solar abundance problem by invoking the momentum-dependent asymmetric DM in the Sun.

  1. Explosive Chromospheric Evaporation Driven by Nonthermal Electrons around One Footpoint of a Solar Flare Loop

    Energy Technology Data Exchange (ETDEWEB)

    Li, D.; Ning, Z. J.; Huang, Y.; Zhang, Q. M., E-mail: lidong@pmo.ac.cn [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, CAS, Nanjing 210008 (China)

    2017-05-20

    We explore the temporal relationship between microwave/hard X-ray (HXR) emission and Doppler velocity during the impulsive phase of a solar flare on 2014 October 27 (SOL2014-10-27) that displays a pulse on the light curves in the microwave (34 GHz) and HXR (25–50 keV) bands before the flare maximum. Imaging observation shows that this pulse mainly comes from one footpoint of a solar flare loop. The slit of the Interface Region Imaging Spectrograph ( IRIS ) stays at this footpoint during this solar flare. The Doppler velocities of Fe xxi 1354.09 Å and Si iv 1402.77 Å are extracted from the Gaussian fitting method. We find that the hot line of Fe xxi 1354.09 Å (log T ∼ 7.05) in the corona exhibits blueshift, while the cool line of Si iv 1402.77 Å (log T ∼ 4.8) in the transition region exhibits redshift, indicating explosive chromospheric evaporation. Evaporative upflows along the flare loop are also observed in the AIA 131 Å image. To our knowledge, this is the first report of chromospheric evaporation evidence from both spectral and imaging observations in the same flare. Both microwave and HXR pulses are well correlated with the Doppler velocities, suggesting that the chromospheric evaporation is driven by nonthermal electrons around this footpoint of a solar flare loop.

  2. Thermally evaporated Ag nanoparticle films for plasmonic enhancement in organic solar cells: effects of particle geometry

    NARCIS (Netherlands)

    Haidari, G.; Hajimahmoodzadeh, M.; Fallah, H.R.; Peukert, A.; Chanaewa, A.; von Hauff, E.L.

    2015-01-01

    We report on the simple fabrication of Ag NP films via thermal evaporation and subsequent annealing. The NPs are formed on indium tin oxide electrodes, coated with PEDOT:PSS and implemented into PCPDTBT:PC70BM solar cells. Scanning electron microscopy and atomic force microscopy are used to

  3. Interim status of closure/post-closure plan for 183-H solar evaporation basins

    International Nuclear Information System (INIS)

    1988-03-01

    This report describes a plan for decommissioning several solar evaporation basins on the Hanford reservation. The document describes procedures for sampling during decommissioning and a plan for certification of the resulting completed landfill. Additional plans deal with the training, security of the site, and post-closure monitoring

  4. The impact of surface chemistry on the performance of localized solar-driven evaporation system.

    Science.gov (United States)

    Yu, Shengtao; Zhang, Yao; Duan, Haoze; Liu, Yanming; Quan, Xiaojun; Tao, Peng; Shang, Wen; Wu, Jianbo; Song, Chengyi; Deng, Tao

    2015-09-04

    This report investigates the influence of surface chemistry (or wettability) on the evaporation performance of free-standing double-layered thin film on the surface of water. Such newly developed evaporation system is composed of top plasmonic light-to-heat conversion layer and bottom porous supporting layer. Under solar light illumination, the induced plasmonic heat will be localized within the film. By modulating the wettability of such evaporation system through the control of surface chemistry, the evaporation rates are differentiated between hydrophilized and hydrophobized anodic aluminum oxide membrane-based double layered thin films. Additionally, this work demonstrated that the evaporation rate mainly depends on the wettability of bottom supporting layer rather than that of top light-to-heat conversion layer. The findings in this study not only elucidate the role of surface chemistry of each layer of such double-layered evaporation system, but also provide additional design guidelines for such localized evaporation system in applications including desalination, distillation and power generation.

  5. In-line high-rate evaporation of aluminum for the metallization of silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mader, Christoph Paul

    2012-07-11

    This work focuses on the in-line high-rate evaporation of aluminum for contacting rear sides of silicon solar cells. The substrate temperature during the deposition process, the wafer bow after deposition, and the electrical properties of evaporated contacts are investigated. Furthermore, this work demonstrates for the first time the formation of aluminum-doped silicon regions by the in-line high-rate evaporation of aluminum without any further temperature treatment. The temperature of silicon wafers during in-line high-rate evaporation of aluminum is investigated in this work. The temperatures are found to depend on the wafer thickness W, the aluminum layer thickness d, and on the wafer emissivity {epsilon}. Two-dimensional finite-element simulations reproduce the measured peak temperatures with an accuracy of 97%. This work also investigates the wafer bow after in-line high-rate evaporation and shows that the elastic theory overestimates the wafer bow of planar Si wafers. The lower bow is explained with plastic deformation in the Al layer. Due to the plastic deformation only the first 79 K in temperature decrease result in a bow formation. Furthermore the electrical properties of evaporated point contacts are examined in this work. Parameterizations for the measured saturation currents of contacted p-type Si wafers and of contacted boron-diffused p{sup +}-type layers are presented. The contact resistivity of the deposited Al layers to silicon for various deposition processes and silicon surface concentrations are presented and the activation energy of the contact formation is determined. The measured saturation current densities and contact resistivities of the evaporated contacts are used in one-dimensional numerical Simulations and the impact on energy conversion efficiency of replacing a screen-printed rear side by an evaporated rear side is presented. For the first time the formation of aluminum-doped p{sup +}-type (Al-p{sup +}) silicon regions by the in

  6. A rational approach for evaluation and screening of treatment and disposal options for the solar pond sludges at Rocky Flats

    International Nuclear Information System (INIS)

    Dickerson, K.S.

    1995-01-01

    This document consists of information about the treatment options for the sludge that is located in the evaporation ponds at the Rocky Flats Plant. The sludges are mixed low-level radioactive wastes whose composition and character were variable. Sludges similar to these are typically treated prior to ultimate disposal. Disposal of treated sludges includes both on-site and off-site options. The rational approach described in this paper is useful for technology evaluation and screening because it provides a format for developing objectives, listing alternatives, and weighing the alternatives against the objectives and against each other

  7. A rational approach for evaluation and screening of treatment and disposal options for the solar pond sludges at Rocky Flats

    Energy Technology Data Exchange (ETDEWEB)

    Dickerson, K.S.

    1995-12-31

    This document consists of information about the treatment options for the sludge that is located in the evaporation ponds at the Rocky Flats Plant. The sludges are mixed low-level radioactive wastes whose composition and character were variable. Sludges similar to these are typically treated prior to ultimate disposal. Disposal of treated sludges includes both on-site and off-site options. The rational approach described in this paper is useful for technology evaluation and screening because it provides a format for developing objectives, listing alternatives, and weighing the alternatives against the objectives and against each other.

  8. RELATIONSHIP BETWEEN CHROMOSPHERIC EVAPORATION AND MAGNETIC FIELD TOPOLOGY IN AN M-CLASS SOLAR FLARE

    Energy Technology Data Exchange (ETDEWEB)

    Sadykov, Viacheslav M; Kosovichev, Alexander G [Department of Physics, New Jersey Institute of Technology, Newark, NJ 07102 (United States); Sharykin, Ivan N; Zimovets, Ivan V [Space Research Institute (IKI) of Russian Academy of Sciences, Moscow 117997 (Russian Federation); Dominguez, Santiago Vargas [Universidad Nacional de Colombia, Sede Bogotá, Observatorio Astronómico, Carrera 45 # 26-85, Bogotá (Colombia)

    2016-09-01

    Chromospheric evaporation is observed as Doppler blueshift during solar flares. It plays a key role in the dynamics and energetics of solar flares; however, its mechanism is still unknown. In this paper, we present a detailed analysis of spatially resolved multi-wavelength observations of chromospheric evaporation during an M 1.0-class solar flare (SOL2014-06-12T21:12) using data from NASA’s Interface Region Imaging Spectrograph and HMI/ SDO (the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory), and high-resolution observations from VIS/NST (the Visible Imaging Spectrometer at the New Solar Telescope). The results show that the averaged over the flare region Fe xxi blueshift of the hot (10{sup 7} K) evaporating plasma is delayed relative to the C ii redshift of the relatively cold (10{sup 4} K) chromospheric plasma by about one minute. The spatial distribution of the delays is not uniform across the region and can be as long as two minutes in several zones. Using vector magnetograms from HMI, we reconstruct the magnetic field topology and the quasi-separatrix layer, and find that the blueshift delay regions as well as the H α flare ribbons are connected to the region of the magnetic polarity inversion line (PIL) and an expanding flux rope via a system of low-lying loop arcades with a height of ≲4.5 Mm. As a result, the chromospheric evaporation may be driven by the energy release in the vicinity of PIL, and has the observed properties due to a local magnetic field topology.

  9. A theoretical study of a direct contact membrane distillation system coupled to a salt-gradient solar pond for terminal lakes reclamation.

    Science.gov (United States)

    Suárez, Francisco; Tyler, Scott W; Childress, Amy E

    2010-08-01

    Terminal lakes are water bodies that are located in closed watersheds with the only output of water occurring through evaporation or infiltration. The majority of these lakes, which are commonly located in the desert and influenced by human activities, are increasing in salinity. Treatment options are limited, due to energy costs, and many of these lakes provide an excellent opportunity to test solar-powered desalination systems. This paper theoretically investigates utilization of direct contact membrane distillation (DCMD) coupled to a salt-gradient solar pond (SGSP) for sustainable freshwater production at terminal lakes. A model for heat and mass transport in the DCMD module and a thermal model for an SGSP were developed and coupled to evaluate the feasibility of freshwater production. The construction of an SGSP outside and inside of a terminal lake was studied. As results showed that freshwater flows are on the same order of magnitude as evaporation, these systems will only be successful if the SGSP is constructed inside the terminal lake so that there is little or no net increase in surface area. For the study site of this investigation, water production on the order of 2.7 x 10(-3) m(3) d(-1) per m(2) of SGSP is possible. The major advantages of this system are that renewable thermal energy is used so that little electrical energy is required, the coupled system requires low maintenance, and the terminal lake provides a source of salts to create the stratification in the SGSP. (c) 2010 Elsevier Ltd. All rights reserved.

  10. Layered tin monoselenide as advanced photothermal conversion materials for efficient solar energy-driven water evaporation.

    Science.gov (United States)

    Yao, Jiandong; Zheng, Zhaoqiang; Yang, Guowei

    2018-02-08

    Solar energy-driven water evaporation lays a solid foundation for important photothermal applications such as sterilization, seawater desalination, and electricity generation. Due to the strong light-matter coupling, broad absorption wavelength range, and prominent quantum confinement effect, layered tin monoselenide (SnSe) holds a great potential to effectively harness solar irradiation and convert it to heat energy. In this study, SnSe is successfully deposited on a centimeter-scale nickel foam using a facile one-step pulsed-laser deposition approach. Importantly, the maximum evaporation rate of SnSe-coated nickel foam (SnSe@NF) reaches 0.85 kg m -2 h -1 , which is even 21% larger than that obtained with the commercial super blue coating (0.7 kg m -2 h -1 ) under the same condition. A systematic analysis reveals that its good photothermal conversion capability is attributed to the synergetic effect of multi-scattering-induced light trapping and the optimal trade-off between light absorption and phonon emission. Finally, the SnSe@NF device is further used for seawater evaporation, demonstrating a comparable evaporation rate (0.8 kg m -2 h -1 ) to that of fresh water and good stability over many cycles of usage. In summary, the current contribution depicts a facile one-step scenario for the economical and efficient solar-enabled SnSe@NF evaporation devices. More importantly, an in-depth analysis of the photothermal conversion mechanism underneath the layered materials depicts a fundamental paradigm for the design and application of photothermal devices based on them in the future.

  11. Effect of solution processed and thermally evaporated interlayers on the performance of backgrated polymer solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Jayawardena, K.D.G.I.; Amarasinghe, K.M.P.; Nismy, N.A. [Advanced Technology Institute, Department of Electronic Engineering, University of Surrey, Guildford GU2 7XH (United Kingdom); Mills, C.A. [Advanced Technology Institute, Department of Electronic Engineering, University of Surrey, Guildford GU2 7XH (United Kingdom); Advanced Coatings Group, Surface Engineering Department, Tata Steel Research Development and Technology, Swinden Technology Centre, Rotherham, S60 3AR (United Kingdom); Silva, S.R.P., E-mail: s.silva@surrey.ac.uk [Advanced Technology Institute, Department of Electronic Engineering, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2015-09-30

    Polymer solar cells are fast gaining momentum as a potential solution towards low cost sustainable energy generation. However, the performance of architectures is known to be limited by the thin film nature of the active layer which, although required due to low charge carrier mobilities, limits the optical coupling to the active layer. The formation of periodic backgratings has been proposed as a solution to this problem. Here, we investigate the effect of solution processed and thermally evaporated interlayers on the performance of backgrated polymer solar cells. Analysis of device performance under standard conditions indicates higher power conversion efficiencies with the incorporation of the evaporated interlayer (5.7%) over a sol–gel processed interlayer (4.9%). This is driven by a more conformal coating as evidenced through two orders of magnitude higher electron mobilities (10{sup −5} versus 10{sup −7} cm{sup 2} V{sup −1} s{sup −1}) as well as the balanced electron and hole transport observed for the former architecture. It is believed that these results will catalyse further development of such device engineering concepts for improved optical coupling in thin film photovoltaics. - Highlights: • Effect of interlayers on backgrated photovoltaic devices is tested. • Evaporated interlayers lead to better device performance. • Better charge extraction is observed for evaporated interlayers.

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

    Science.gov (United States)

    Robertson Handford, C.

    1990-08-01

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

  13. Superior stability for perovskite solar cells with 20% efficiency using vacuum co-evaporation.

    Science.gov (United States)

    Zhu, Xuejie; Yang, Dong; Yang, Ruixia; Yang, Bin; Yang, Zhou; Ren, Xiaodong; Zhang, Jian; Niu, Jinzhi; Feng, Jiangshan; Liu, Shengzhong Frank

    2017-08-31

    Chemical composition and film quality are two key figures of merit for large-area high-efficiency perovskite solar cells. To date, all studies on mixed perovskites have used solution-processing, which results in imperfect surface coverage and pin-holes generated during solvent evaporation, execrably influencing the stability and efficiency of perovskite solar cells. Herein, we report our development using a vacuum co-evaporation deposition method to fabricate pin-hole-free cesium (Cs)-substituted perovskite films with complete surface coverage. Apart from the simplified procedure, the present method also promises tunable band gap, reduced trap-state density and longer carrier lifetime, leading to solar cell efficiency as high as 20.13%, which is among the highest reported for planar perovskite solar cells. The splendid performance is attributed to superior merits of the Cs-substituted perovskite film including tunable band gap, reduced trap-state density and longer carrier lifetime. Moreover, the Cs-substituted perovskite device without encapsulation exhibits significantly higher stability in ambient air compared with the single-component counterpart. When the Cs-substituted perovskite solar cells are stored in dark for one year, the PCE remains at 19.25%, degrading only 4.37% of the initial efficiency. The excellent stability originates from reduced lattice constant and relaxed strain in perovskite lattice by incorporating Cs cations into the crystal lattice, as demonstrated by the positive peak shifts and reduced peak width in X-ray diffraction analysis.

  14. 1996 Phase 2 soil sampling at the 183-H Solar Evaporation Basin site

    International Nuclear Information System (INIS)

    Kramer, C.D.

    1996-10-01

    This report consolidates 1996 soil sampling data collected from the 183-H Solar Evaporation Basin Site. This report is intended to be a data reference and does not make comparisons or conclusions regarding specific regulatory criteria. Chemical and radiological data were collected to support cleanup activities at the Hanford Site; soil sampling occurred beneath and next to the former basin structures. The 183-H Solar Evaporation Basins, which consisted of four adjoining concrete basins, were located in the 100 Area of the Hanford Site, north of the retired 105-H Reactor. Originally, the basins were built as part of the 100-H water treatment structures. The four basins were inactive from the mid-1960's until 1973 when radioactive and dangerous (mixed) waste from the 300 Area Fuel Fabrication Facility was shipped to the basins for storage and treatment. The basins were used for solar evaporation of the waste. The last shipment of waste to the 183-H Basins took place in November 1985. Decontamination of the cement structure took place in 1995. The structure has subsequently been dismantled and disposed. Chapters 2.0 through 4.0 present summary information about sampling (1) beneath the loading ramp and berm piles, (2) in shallow soils beneath the former basin floor, and (3) deep vadose soils. Detailed data are provided in the appendices

  15. Solar chimney integrated with passive evaporative cooler applied on glazing surfaces

    International Nuclear Information System (INIS)

    Al Touma, Albert; Ghali, Kamel; Ghaddar, Nesreen; Ismail, Nagham

    2016-01-01

    This study investigates the performance of a hybrid system applied on glazing surfaces for reducing the space cooling load and radiation asymmetry. The proposed system combines the principles of passive evaporative cooling with the natural buoyant flow in solar chimneys to entrain outdoor air and attenuate the window surface temperature. A predictive heat and mass transport model combining the evaporative cooler, glazing section, solar chimney and an office space is developed to study the system performance in harshly hot climates. The developed model was validated through experiments conducted in a twin climatic chamber for given ambient temperature, humidity, and solar radiation conditions. Good agreement was found between the measured and the predicted window temperatures and space loads at maximum discrepancy lower than 4.3%. The proposed system is applied to a typical office space to analyze its effectiveness in reducing the window temperature, the space load and radiation asymmetry, while maintaining the indoor comfort conditions. Results have shown that the system is reduced the space load by −19.8% and attenuated the radiation asymmetry significantly for office spaces having window-to-wall ratio of 40% in climate of Riyadh, KSA. The system performance diminished when applied in locations suffering from humid weather climates. - Highlights: • A passive evaporative-cooled solar chimney system is introduced to decrease window temperature. • A mathematical model is developed of the system to predict induce air flow and window surface temperature. • The model is validated with experiments in twin room climatic chamber and using artificial solar lamps. • The system reduces window maximum temperature by 5 °C in the hot dry climate of Riyadh, KSA. • It reduced the space load by 19.4% for office spaces at window-to-wall ratio of 40% in Riyadh, KSA.

  16. 3D-Printed, All-in-One Evaporator for High-Efficiency Solar Steam Generation under 1 Sun Illumination.

    Science.gov (United States)

    Li, Yiju; Gao, Tingting; Yang, Zhi; Chen, Chaoji; Luo, Wei; Song, Jianwei; Hitz, Emily; Jia, Chao; Zhou, Yubing; Liu, Boyang; Yang, Bao; Hu, Liangbing

    2017-07-01

    Using solar energy to generate steam is a clean and sustainable approach to addressing the issue of water shortage. The current challenge for solar steam generation is to develop easy-to-manufacture and scalable methods which can convert solar irradiation into exploitable thermal energy with high efficiency. Although various material and structure designs have been reported, high efficiency in solar steam generation usually can be achieved only at concentrated solar illumination. For the first time, 3D printing to construct an all-in-one evaporator with a concave structure for high-efficiency solar steam generation under 1 sun illumination is used. The solar-steam-generation device has a high porosity (97.3%) and efficient broadband solar absorption (>97%). The 3D-printed porous evaporator with intrinsic low thermal conductivity enables heat localization and effectively alleviates thermal dissipation to the bulk water. As a result, the 3D-printed evaporator has a high solar steam efficiency of 85.6% under 1 sun illumination (1 kW m -2 ), which is among the best compared with other reported evaporators. The all-in-one structure design using the advanced 3D printing fabrication technique offers a new approach to solar energy harvesting for high-efficiency steam generation. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Different parameter and technique affecting the rate of evaporation on active solar still -a review

    Science.gov (United States)

    A, Muthu Manokar; D, Prince Winston; A. E, Kabeel; Sathyamurthy, Ravishankar; T, Arunkumar

    2018-03-01

    Water is one of the essential sources for the endurance of human on the earth. As earth having only a small amount of water resources for consumption purpose people in rural and urban areas are getting affected by consuming dirty water that leads to water-borne diseases. Even though ground water is available in small quantity, it has to be treated properly before its use for internal consumption. Brackish water contains dissolve and undissolved contents, and hence it is not suitable for the household purpose. Nowadays, distillation process is done by using passive and active solar stills. The major problem in using passive solar still is meeting higher demand for fresh water. The fresh water production from passive solar still is critically low to meet the demand. To improve the productivity of conventional solar still, input feed water is preheated by integrating the solar still to different collector panels. In this review article, the different parameters that affect the rate of evaporation in an active solar still and the different methods incorporated has been presented. In addition to active distillation system, forced convection technique can be incorporated to increase the yield of fresh water by decreasing the temperature of cover. Furthermore, it is identified that the yield of fresh water from the active desalination system can be improved by sensible and latent heat energy storage. This review will motivate the researchers to decide appropriate active solar still technology for promoting development.

  18. Unit-Specific Contingency Plan for the 183-H Solar Evaporation Basins

    International Nuclear Information System (INIS)

    Edens, V.G.

    1998-04-01

    This document is a supplement to DOE/RL-93-75, 'Hanford Contingency Plan.' It provides the unit-specific information needed to fully comply with the Washington Administrative Code. General emergency and response information is contained in the Hanford Facility Contingency Plan and is not repeated in this supplement. The 183-H Solar Evaporation Basins were four concrete internal surfaces, which contained radiologically and hazardous contaminated waste. The 183-H Basin area is a final status treatment, storage, and disposal unit undergoing Resource Conservation and Recovery Act modified post- closure care

  19. Efficient Solar-Thermal Energy Harvest Driven by Interfacial Plasmonic Heating-Assisted Evaporation.

    Science.gov (United States)

    Chang, Chao; Yang, Chao; Liu, Yanming; Tao, Peng; Song, Chengyi; Shang, Wen; Wu, Jianbo; Deng, Tao

    2016-09-07

    The plasmonic heating effect of noble nanoparticles has recently received tremendous attention for various important applications. Herein, we report the utilization of interfacial plasmonic heating-assisted evaporation for efficient and facile solar-thermal energy harvest. An airlaid paper-supported gold nanoparticle thin film was placed at the thermal energy conversion region within a sealed chamber to convert solar energy into thermal energy. The generated thermal energy instantly vaporizes the water underneath into hot vapors that quickly diffuse to the thermal energy release region of the chamber to condense into liquids and release the collected thermal energy. The condensed water automatically flows back to the thermal energy conversion region under the capillary force from the hydrophilic copper mesh. Such an approach simultaneously realizes efficient solar-to-thermal energy conversion and rapid transportation of converted thermal energy to target application terminals. Compared to conventional external photothermal conversion design, the solar-thermal harvesting device driven by the internal plasmonic heating effect has reduced the overall thermal resistance by more than 50% and has demonstrated more than 25% improvement of solar water heating efficiency.

  20. A simple model of chromospheric evaporation and condensation driven conductively in a solar flare

    Energy Technology Data Exchange (ETDEWEB)

    Longcope, D. W. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States)

    2014-11-01

    Magnetic energy released in the corona by solar flares reaches the chromosphere where it drives characteristic upflows and downflows known as evaporation and condensation. These flows are studied here for the case where energy is transported to the chromosphere by thermal conduction. An analytic model is used to develop relations by which the density and velocity of each flow can be predicted from coronal parameters including the flare's energy flux F. These relations are explored and refined using a series of numerical investigations in which the transition region (TR) is represented by a simplified density jump. The maximum evaporation velocity, for example, is well approximated by v{sub e} ≅ 0.38(F/ρ{sub co,} {sub 0}){sup 1/3}, where ρ{sub co,} {sub 0} is the mass density of the pre-flare corona. This and the other relations are found to fit simulations using more realistic models of the TR both performed in this work, and taken from a variety of previously published investigations. These relations offer a novel and efficient means of simulating coronal reconnection without neglecting entirely the effects of evaporation.

  1. Effect of solar radiation on the lipid characterization of biomass cultivated in high-rate algal ponds using domestic sewage.

    Science.gov (United States)

    Assemany, Paula Peixoto; Calijuri, Maria Lúcia; Santiago, Anibal da Fonseca; do Couto, Eduardo de Aguiar; Leite, Mauricio de Oliveira; Sierra, Jose Jovanny Bermudez

    2014-01-01

    The objective of this paper is to compare the lipid content and composition ofbiomass produced by a consortium of microalgae and bacteria, cultivated under different solar radiation intensities and tropical conditions in pilot-scale high-rate ponds (HRPs) using domestic sewage as culture medium. The treatment system consisted of an upflow anaerobic sludge blanket reactor followed by UV disinfection and six HRPs covered with shading screens that blocked 9%, 18%, 30%, 60% and 80% of the solar radiation. The total lipid content does not vary significantly among the units, showing a medium value of 9.5%. The results show that blocking over 30% of the solar radiation has a negative effect on the lipid productivity. The units with no shading and with 30% and 60% of solar radiation blocking have statistically significant lipid productivities, varying from 0.92 to 0.96 gm(-2) day(-1). Besides radiation, other variables such as volatile suspended solids and chlorophyll-a are able to explain the lipid accumulation. The lipid profile has a predominance of C16, C18:1 and C18:3 acids. The unsaturation of fatty acids increases with the reduction in solar radiation. On the other hand, the effect of polyunsaturation is not observed, which is probably due to the presence of a complex and diverse biomass.

  2. Evaporation of Arabian light crude oil spilled on sea and on beach sands : influence of solar radiation and wind velocity

    International Nuclear Information System (INIS)

    Bergueiro, J.R.; Marti, A.; Fuertes, A.; Moreno, S.; Guijarro, S.

    1998-01-01

    The evaporation of crude oil resulting from a spill on sea water was studied to develop a simulation model. Evaporation takes place within a complex process of mass and energy transfer. The effects of physical and chemical variables (such as wind velocity and direct and diffused solar radiation) and the environmental conditions of the spillage were also considered. Arabian crude oil was used in the simulation model for crude oil spillage on sea water. An equation for the evaporation process was used to correlate the evaporated fraction of oil as a function of time. The area of spreading was determined as a function of the dominant stage at each moment of spreading. The evaporation of spilled crude oil on beach sand consisting of three different particle sizes was also studied and used for a simulation model for crude oil spillage on a polluted beach. 7 refs., 6 tabs., 10 figs

  3. Feasibility of a solar-assisted winter air-conditioning system using evaporative air-coolers

    Energy Technology Data Exchange (ETDEWEB)

    El-Awad, Mohamed M. [Mechanical Engineering Department, the University of Khartoum, P.O. Box 321 Khartoum (Sudan)

    2011-07-01

    The paper presents a winter air-conditioning system which is suitable for regions with mildly cold but dry winters. The system modifies the evaporative air-cooler that is commonly used for summer air-conditioning in such regions by adding a heating process after the humidification process. The paper describes a theoretical model that is used to estimate the system's water and energy consumption. It is shown that a 150-LPD solar heater is adequate for air-conditioning a 500 ft3/min (14.4 m3/min) air flow rate for four hours of operation. The maximum air-flow rate that can be heated by a single solar water-heater for four hours of operation is about 900-cfm, unless a solar water heater large than a 250-LPD heater is used. For the 500 ft3/min air flow rate the paper shows that the 150, 200, 250 and 300 LPD solar water-heaters can provide air-conditioning for 4, 6, 8 and 10 hours, respectively, while consuming less energy than the equivalent refrigerated-type air-conditioner.

  4. Efficient steam generation by inexpensive narrow gap evaporation device for solar applications.

    Science.gov (United States)

    Morciano, Matteo; Fasano, Matteo; Salomov, Uktam; Ventola, Luigi; Chiavazzo, Eliodoro; Asinari, Pietro

    2017-09-20

    Technologies for solar steam generation with high performance can help solving critical societal issues such as water desalination or sterilization, especially in developing countries. Very recently, we have witnessed a rapidly growing interest in the scientific community proposing sunlight absorbers for direct conversion of liquid water into steam. While those solutions can possibly be of interest from the perspective of the involved novel materials, in this study we intend to demonstrate that efficient steam generation by solar source is mainly due to a combination of efficient solar absorption, capillary water feeding and narrow gap evaporation process, which can also be achieved through common materials. To this end, we report both numerical and experimental evidence that advanced nano-structured materials are not strictly necessary for performing sunlight driven water-to-vapor conversion at high efficiency (i.e. ≥85%) and relatively low optical concentration (≈10 suns). Coherently with the principles of frugal innovation, those results unveil that solar steam generation for desalination or sterilization purposes may be efficiently obtained by a clever selection and assembly of widespread and inexpensive materials.

  5. Rational design of a bi-layered reduced graphene oxide film on polystyrene foam for solar-driven interfacial water evaporation

    KAUST Repository

    Shi, Le; Wang, Yuchao; Zhang, Lianbin; Wang, Peng

    2016-01-01

    Solar-driven water evaporation has been emerging as a highly efficient way for utilizing solar energy for clean water production and wastewater treatment. Here we rationally designed and fabricated a bi-layered photothermal membrane with a porous

  6. Bifunctional Au@TiO_2 core–shell nanoparticle films for clean water generation by photocatalysis and solar evaporation

    International Nuclear Information System (INIS)

    Huang, Jian; He, Yurong; Wang, Li; Huang, Yimin; Jiang, Baocheng

    2017-01-01

    Highlights: • Au@TiO_2 core-shell nanoparticles were prepared in this study. • Bifunctional films for photocatalysis and solar evaporation were designed. • The evaporation and photodegradation with core-shell structures were investigated. - Abstract: With water scarcity becoming an increasingly critical issue for modern society, solar seawater desalination represents a promising approach to mitigating water shortage. In addition, solar seawater desalination shows great potential for mitigating the energy crisis due to its high photo-thermal conversion efficiency. However, the increasing contamination of seawater makes it difficult to generate clean water through simple desalination processes. In this work, clean water is generated by a newly designed bifunctional Au@TiO_2 core-shell nanoparticle film with a high photo-thermal conversion efficiency that is capable of photocatalysis and solar evaporation for seawater desalination. Bifunctional films of Au@TiO_2 core-shell nanoparticles with good stability were prepared. It was found that the formation of the core-shell structures played a key role in promoting the photo-thermal conversion efficiency and the evaporation of seawater, while the photocatalytic function demonstrated herein could contribute to the purification of polluted seawater. Furthermore, the film structure can serve to concentrate the NPs for the photo-reaction, as well as heat for water evaporation, improving both the photo-reaction efficiency and photo-thermal conversion efficiency. This efficient approach to solar seawater desalination, which combines evaporation with the photodegradation of pollutants, could help to address the dual issues of water scarcity and water pollution.

  7. Unit-specific contingency plan for the 183-H solar evaporation basins. Revision 1

    International Nuclear Information System (INIS)

    Zoric, J.P.

    1996-03-01

    This document is a supplement to the Hanford Facility Contingency Plan. It provides the unit-specific information needed to fully comply with the Washington Administrative Code, Chapter 173-303, ''Dangerous Waste Regulations,'' for contingency plans. General emergency and response information is contained in the Hanford Facility Contingency Plan and is not repeated in this supplement. The 183-H solar evaporation basins are four concrete internal surfaces which contained radiologically- and hazardous-contaminated waste. The 183-H basins are currently empty, inactive and designated as a Resource Conservation and Recovery Act interim-status treatment, storage, and disposal unit undergoing closure. There is no dangerous waste management actively occurring. There is very little likelihood of any incidents that would present hazards to public health or the environment occurring at the 183-H basins

  8. Unit-specific contingency plan for the 183-H Solar Evaporation Basins. Revision 2

    International Nuclear Information System (INIS)

    Zoric, J.P.

    1997-01-01

    This document is a supplement to the Hanford Facility Contingency Plan. It provides the unit-specific information needed to fully comply with the Washington Administrative Code, Chapter 173-303, ''Dangerous Waste Regulations,'' for contingency plans. General emergency and response information is contained in the Hanford Facility Contingency Plan and is not repeated in this supplement. The 183-H Solar Evaporation Basins are four concrete internal surfaces which contained radiologically- and hazardous-contaminated waste. The 183-H basins are currently empty, inactive and designated as a Resource Conservation and Recovery Act interim-status treatment, storage, and disposal unit undergoing closure. There is no dangerous waste management actively occurring. There is very little likelihood of any incidents that would present hazards to public health or the environment occurring at the 183-H basins

  9. Solar thermal evaporation of human urine for nitrogen and phosphorus recovery in Vietnam

    International Nuclear Information System (INIS)

    Antonini, Samantha; Nguyen, Phong Thanh; Arnold, Ute; Eichert, Thomas; Clemens, Joachim

    2012-01-01

    A No Mix sanitation system was installed in a dormitory at the University of Can Tho in Vietnam, with the objective of recycling nutrients from source separated urine. This paper presents a pilot scale evaporation technology, and investigates the feasibility of recovering nitrogen and phosphorus from human urine by solar still for use as fertilizer. After 26 days of sun exposure, 360 g of solid fertilizer material was recovered from 50 L undiluted urine. This urine-derived fertilizer was mainly composed of sodium chloride, and had phosphorus and nitrogen contents of almost 2%. When tested with maize and ryegrass, the urine fertilizer led to biomass yields and phosphorus and nitrogen uptakes comparable to those induced by a commercial mineral fertilizer. Urine acidification with sulfuric or phosphoric acid prior treatment reduced nitrogen losses, improved the nutrient content of the generated fertilizers, and induced higher biomass yields and nitrogen and phosphorus uptakes than the commercial mineral fertilizer. However, acidification is not recommended in developing countries due to additional costs and handling risks. The fate of micropollutants and the possibility of separating sodium chloride from other beneficial nutrients require further investigation. - Highlights: ► 360 g of fertilizer was derived from 50 L urine by solar evaporative distillation. ► The fertilizer contained 90% sodium chloride, 3% sulfur, 2% nitrogen, 2% phosphorus. ► It induced biomass yields comparable to those produced by a commercial fertilizer. ► Urine acidification improved the nutrient content of the generated fertilizers. ► Acidification is not recommended for use in developing countries (costs, safety).

  10. Development of a hybrid sputtering/evaporation process for Cu(In,Ga)Se{sub 2} thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Acciarri, M.; Binetti, S.; Le Donne, A.; Lorenzi, B.; Caccamo, L.; Miglio, L. [Dipartimento di Scienza dei Materiali e Solar Energy Research Center MIB-SOLAR, Universita di Milano Bicocca, Milan (Italy); Moneta, R.; Marchionna, S.; Meschia, M. [Voltasolar s.r.l, Turate (Italy)

    2011-08-15

    In this paper we report a new method for Cu(In,Ga)Se{sub 2} deposition for solar cell application. Differently from the common co-evaporation process, an alterative approach for thin film Cu(In,Ga)Se{sub 2} has been tested: the sputtering deposition of metal elements combined with the selenium evaporation. We have studied the relationships between the growth parameters of our hybrid sputtering/evaporation method and the chemical-physical properties of the CIGS films. The cells are completed with a CdS buffer layer deposited by chemical bath deposition and ZnO + ITO deposited by RF sputtering. Test solar cells of 0.5 cm{sup 2} have shown an efficiency of 10% and 2.5% on glass and stainless steel substrate respectively. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Electron Beam Evaporated TiO2 Layer for High Efficiency Planar Perovskite Solar Cells on Flexible Polyethylene Terephthalate Substrates

    KAUST Repository

    Qiu, Weiming; Paetzold, Ulrich W; Gehlhaar, Robert; Smirnov, Vladimir; Boyen, Hans-Gerd; Tait, Jeffrey Gerhart; Conings, Bert; Zhang, Weimin; Nielsen, Christian; McCulloch, Iain; Froyen, Ludo; Heremans, Paul; Cheyns, David

    2015-01-01

    The TiO2 layer made by electron beam (e-beam) induced evaporation is demonstrated as electron transport layer (ETL) in high efficiency planar junction perovskite solar cells. The temperature of the substrate and the thickness of the TiO2 layer can

  12. Calculation of heat balance considering the reflection, refraction of incident ray and salt diffusion on solar pad; Hikari no hansha kussetsu oyobi shio no kakusan wo koryoshita solar pond no netsukeisan

    Energy Technology Data Exchange (ETDEWEB)

    Kanayama, K; Li, X; Baba, H; Endo, N [Kitami Institute of Technology, (Japan)

    1997-11-25

    In calculating heat balance of solar pond, calculation was made considering things except quality of the incident ray and physical properties of pond water which were conventionally considered. The real optical path length was determined from the reflection ratio of ray on the water surface based on the refraction ratio of pond water and the locus of water transmitted ray in order to calculate a total transmission rate. The rate of absorption of monochromatic lights composing of solar light in their going through the media is different by wavelength, and therefore, calculation was made in each monochromatic light. As to four kinds of salt water solution, NaCl, KCl, MgCl2 and CaCl2, these phenomena seen in solar pond are taken in, and a total transmission rate based on reality can be calculated by the wavelength integration method. Moreover, in the salt gradient layer, there are gradients in both concentration and temperature, and thermal physical values of each layer change. Accordingly, mass transfer and thermal transfer by both gradients were considered at the same time. An analytic solution was introduced which analyzes salt diffusion in the temperature field in the gradient layer and determines the concentration distribution. By these, concentration and physical values of each layer were calculated according to phenomena, and thermal balance of each layer of the solar pond was able to be accurately calculated. 6 refs., 5 figs., 2 tabs.

  13. Comparison of the Al back contact deposited by sputtering, e-beam, or thermal evaporation for inverted perovskite solar cells

    Science.gov (United States)

    Wahl, Tina; Hanisch, Jonas; Ahlswede, Erik

    2018-04-01

    In this work, we present inverted perovskite solar cells with Al top electrodes, which were deposited by three different methods. Besides the widely used thermal evaporation of Al, we also used the industrially important high deposition rate processes sputtering and electron beam evaporation for aluminium electrodes and examined the influence of the deposition method on the solar cell performance. The current-voltage characteristics of as grown solar cells with sputtered and e-beam Al electrode show an s-shape due to damage done to the organic electronic transport layers (ETL) during Al deposition. It can be cured by a short annealing step at a moderate temperature so that fill factors  >60% and power conversion efficiencies of almost 12% with negligible hysteresis can be achieved. While solar cells with thermally evaporated Al electrode do not show an s-shape, they also exhibit a clear improvement after a short annealing step. In addition, we varied the thickness of the ETL consisting of a double layer ([6,6]-Phenyl-C61-butyric acid methyl ester and bathocuproine) and investigated the influence on the solar cell parameters for the three different Al deposition methods, which showed distinct dependencies on ETL thickness.

  14. Thermally evaporated thin films of SnS for application in solar cell devices

    International Nuclear Information System (INIS)

    Miles, Robert W.; Ogah, Ogah E.; Zoppi, Guillaume; Forbes, Ian

    2009-01-01

    SnS (tin sulphide) is of interest for use as an absorber layer and the wider energy bandgap phases e.g. SnS 2 , Sn 2 S 3 and Sn/S/O alloys of interest as Cd-free buffer layers for use in thin film solar cells. In this work thin films of tin sulphide have been thermally evaporated onto glass and SnO 2 :coated glass substrates with the aim of optimising the properties of the material for use in photovoltaic solar cell device structures. In particular the effects of source temperature, substrate temperature, deposition rate and film thickness on the chemical and physical properties of the layers were investigated. Energy dispersive X-ray analysis was used to determine the film composition, X-ray diffraction to determine the phases present and structure of each phase, transmittance and reflectance versus wavelength measurements to determine the energy bandgap and scanning electron microscopy to observe the surface topology and topography and the properties correlated to the deposition parameters. Using the optimised conditions it is possible to produce thin films of tin sulphide that are pinhole free, conformal to the substrate and that consist of densely packed columnar grains. The composition, phases present and the optical properties of the layers deposited were found to be highly sensitive to the deposition conditions. Energy bandgaps in the range 1.55 eV-1.7 eV were obtained for a film thickness of 0.8 μm, and increasing the film thickness to > 1 μm resulted in a reduction of the energy bandgap to less than 1.55 eV. The applicability of using these films in photovoltaic solar cell device structures is also discussed.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  16. Self-floating carbon nanotube membrane on macroporous silica substrate for highly efficient solar-driven interfacial water evaporation

    KAUST Repository

    Wang, Yuchao

    2016-01-22

    Given the emerging energy and water challenges facing the mankind, solar-driven water evaporation has been gaining renewed research attention from both academia and industry as an energy efficient means of wastewater treatment and clean water production. In this project, a bi-layered material, consisting of a top self-floating hydrophobic CNT membrane and a bottom hydrophilic macroporous silica substrate, was rationally designed and fabricated for highly energy-efficient solar driven water evaporation based on the concept of interfacial heating. The top thin CNT membrane with excellent light adsorption capability, acted as photothermal component, which harvested and converted almost the entire incident light to heat for exclusively heating of interfacial water. On the other hand, the macroporous silica substrate provided multi-functions toward further improvement of operation stability and water evaporation performance of the material, including water pumping, mechanical support and heat barriers. The silica substrate was conducive in forming the rough surface structures of the CNT top layers during vacuum filtration and thus indirectly contributed to high light adsorption by the top CNT layers. With optimized thicknesses of the CNT top layer and silica substrate, a solar thermal conversion efficiency of 82 % was achieved in this study. The bi-layered material also showed great performance toward water evaporation from seawater and contaminated water, realizing the separation of water from pollutants, and indicating its application versatility.

  17. Self-floating carbon nanotube membrane on macroporous silica substrate for highly efficient solar-driven interfacial water evaporation

    KAUST Repository

    Wang, Yuchao; Zhang, Lianbin; Wang, Peng

    2016-01-01

    Given the emerging energy and water challenges facing the mankind, solar-driven water evaporation has been gaining renewed research attention from both academia and industry as an energy efficient means of wastewater treatment and clean water production. In this project, a bi-layered material, consisting of a top self-floating hydrophobic CNT membrane and a bottom hydrophilic macroporous silica substrate, was rationally designed and fabricated for highly energy-efficient solar driven water evaporation based on the concept of interfacial heating. The top thin CNT membrane with excellent light adsorption capability, acted as photothermal component, which harvested and converted almost the entire incident light to heat for exclusively heating of interfacial water. On the other hand, the macroporous silica substrate provided multi-functions toward further improvement of operation stability and water evaporation performance of the material, including water pumping, mechanical support and heat barriers. The silica substrate was conducive in forming the rough surface structures of the CNT top layers during vacuum filtration and thus indirectly contributed to high light adsorption by the top CNT layers. With optimized thicknesses of the CNT top layer and silica substrate, a solar thermal conversion efficiency of 82 % was achieved in this study. The bi-layered material also showed great performance toward water evaporation from seawater and contaminated water, realizing the separation of water from pollutants, and indicating its application versatility.

  18. Enhancement in microstructural and optoelectrical properties of thermally evaporated CdTe films for solar cells

    Science.gov (United States)

    Chander, Subhash; Dhaka, M. S.

    2018-03-01

    The optimization of microstructural and optoelectrical properties of a thin layer is an important step prior device fabrication process, so an enhancement in these properties of thermally evaporated CdTe thin films is reported in this communication. The films having thickness 450 nm and 850 nm were deposited on thoroughly cleaned glass and indium tin oxide (ITO) substrates followed by annealing at 450 °C in air atmosphere. These films were characterized for microstructural and optoelectrical properties employing X-ray diffraction, scanning electron microscopy coupled with energy-dispersive spectroscopy, UV-Vis spectrophotometer and source meter. The films found to be have zinc-blende cubic structure with preferred reflection (111) while the crystallographic parameters and direct energy band gap are strongly influenced by the film thickness. The surface morphology studies show that the films are uniform, smooth, homogeneous and nearly dense-packed as well as free from voids and pitfalls as where elemental analysis revealed the presence of Cd and Te element in the deposited films. The electrical analysis showed linear behavior of current with voltage while conductivity is decreased for higher thickness. The results show that the microstructural and optoelectrical properties of CdTe thin layer could be enhanced by varying thickness and films having higher thickness might be processed as promising absorber thin layer to the CdTe-based solar cells.

  19. Systems and methods for solar cells with CIS and CIGS films made by reacting evaporated copper chlorides with selenium

    Science.gov (United States)

    Albin, David S.; Noufi, Rommel

    2015-06-09

    Systems and methods for solar cells with CIS and CIGS films made by reacting evaporated copper chlorides with selenium are provided. In one embodiment, a method for fabricating a thin film device comprises: providing a semiconductor film comprising indium (In) and selenium (Se) upon a substrate; heating the substrate and the semiconductor film to a desired temperature; and performing a mass transport through vapor transport of a copper chloride vapor and se vapor to the semiconductor film within a reaction chamber.

  20. Composition changes of phototrophic microbial communities along the salinity gradient in the solar saltern evaporation ponds of Eilat, Israel

    Czech Academy of Sciences Publication Activity Database

    Řeháková, Klára; Zapomělová, Eliška; Prášil, Ondřej; Veselá, J.; Medová, Hana; Oren, A.

    2009-01-01

    Roč. 636, č. 1 (2009), s. 77-88 ISSN 0018-8158 R&D Projects: GA ČR GA206/06/0462; GA AV ČR KJB600960703; GA AV ČR 1QS600170504; GA AV ČR 1QS500200570 Institutional research plan: CEZ:AV0Z60050516; CEZ:AV0Z60170517; CEZ:AV0Z50200510 Keywords : phototrophic microbial community * salterns * species composition Subject RIV: EF - Botanics Impact factor: 1.754, year: 2009

  1. Prospects of e-beam evaporated molybdenum oxide as a hole transport layer for perovskite solar cells

    Science.gov (United States)

    Ali, F.; Khoshsirat, N.; Duffin, J. L.; Wang, H.; Ostrikov, K.; Bell, J. M.; Tesfamichael, T.

    2017-09-01

    Perovskite solar cells have emerged as one of the most efficient and low cost technologies for delivering of solar electricity due to their exceptional optical and electrical properties. Commercialization of the perovskite solar cells is, however, limited because of the higher cost and environmentally sensitive organic hole transport materials such as spiro-OMETAD and PEDOT:PSS. In this study, an empirical simulation was performed using the Solar Cell Capacitance Simulator software to explore the MoOx thin film as an alternative hole transport material for perovskite solar cells. In the simulation, properties of MoOx thin films deposited by the electron beam evaporation technique from high purity (99.99%) MoO3 pellets at different substrate temperatures (room temperature, 100 °C and 200 °C) were used as input parameters. The films were highly transparent (>80%) and have low surface roughness (≤2 nm) with bandgap energy ranging between 3.75 eV and 3.45 eV. Device simulation has shown that the MoOx deposited at room temperature can work in both the regular and inverted structures of the perovskite solar cell with a promising efficiency of 18.25%. Manufacturing of the full device is planned in order to utilize the MoOx as an alternative hole transport material for improved performance, good stability, and low cost of the perovskite solar cell.

  2. An economic optimization of evaporator and air collector area in a solar assisted heat pump drying system

    International Nuclear Information System (INIS)

    Rahman, S.M.A.; Saidur, R.; Hawlader, M.N.A.

    2013-01-01

    Highlights: • The optimum combination will provide around 89% of the total load. • The system has a savings during the life cycle with least payback period of 4.37 year. • The optimal system is insensitive to the variation in fuel inflation and discount rate. - Abstract: This paper presents an economic optimization of evaporator and air collector area of a solar assisted heat pump drying system. Economic viability of solar heating systems is usually made by comparing the cost flows recurring throughout the lifetime of the solar and conventional alternative systems. Therefore, identification of optimum variables by using a simulation program and an economic analysis based on payback period of the system are presented in this paper. FORTRAN language is used to run the simulation. Effect of load and different economic variables on payback period is also investigated. Economic analysis reveals that system has sufficient amount of savings during the life cycle with a minimum payback period of about 4 years

  3. Floatable, Self-Cleaning, and Carbon-Black-Based Superhydrophobic Gauze for the Solar Evaporation Enhancement at the Air-Water Interface.

    Science.gov (United States)

    Liu, Yiming; Chen, Jingwei; Guo, Dawei; Cao, Moyuan; Jiang, Lei

    2015-06-24

    Efficient solar evaporation plays an indispensable role in nature as well as the industry process. However, the traditional evaporation process depends on the total temperature increase of bulk water. Recently, localized heating at the air-water interface has been demonstrated as a potential strategy for the improvement of solar evaporation. Here, we show that the carbon-black-based superhydrophobic gauze was able to float on the surface of water and selectively heat the surface water under irradiation, resulting in an enhanced evaporation rate. The fabrication process of the superhydrophobic black gauze was low-cost, scalable, and easy-to-prepare. Control experiments were conducted under different light intensities, and the results proved that the floating black gauze achieved an evaporation rate 2-3 times higher than that of the traditional process. A higher temperature of the surface water was observed in the floating gauze group, revealing a main reason for the evaporation enhancement. Furthermore, the self-cleaning ability of the superhydrophobic black gauze enabled a convenient recycling and reusing process toward practical application. The present material may open a new avenue for application of the superhydrophobic substrate and meet extensive requirements in the fields related to solar evaporation.

  4. Electron Beam Evaporated TiO2 Layer for High Efficiency Planar Perovskite Solar Cells on Flexible Polyethylene Terephthalate Substrates

    KAUST Repository

    Qiu, Weiming

    2015-09-30

    The TiO2 layer made by electron beam (e-beam) induced evaporation is demonstrated as electron transport layer (ETL) in high efficiency planar junction perovskite solar cells. The temperature of the substrate and the thickness of the TiO2 layer can be easily controlled with this e-beam induced evaporation method, which enables the usage of different types of substrates. Here, Perovskite solar cells based on CH3NH3PbI3-xClx achieve power conversion efficiencies of 14.6% on glass and 13.5% on flexible plastic substrates. The relationship between the TiO2 layer thickness and the perovskite morphology is studied with scanning electron microscope (SEM), atomic force microscope (AFM), and X-ray photoelectron spectroscopy (XPS). Our results indicate that pinholes in thin TiO2 layer lead to pinholes in the perovskite layer. By optimizing the TiO2 thickness, perovskite layers with substantially increased surface coverage and reduced pinhole areas are fabricated, increasing overall device performance.

  5. Analytical Investigation of the Heat-Transfer Limits of a Novel Solar Loop-Heat Pipe Employing a Mini-Channel Evaporator

    Directory of Open Access Journals (Sweden)

    Thierno M. O. Diallo

    2018-01-01

    Full Text Available This paper presents an analytical investigation of heat-transfer limits of a novel solar loop-heat pipe developed for space heating and domestic hot water use. In the loop-heat pipe, the condensate liquid returns to the evaporator via small specially designed holes, using a mini-channel evaporator. The study considered the commonly known heat-transfer limits of loop-heat pipes, namely, the viscous, sonic, entrainment, boiling and heat-transfer limits due to the two-phase pressure drop in the loop. The analysis considered the main factors that affect the limits in the mini-channel evaporator: the operating temperature, mini-channel aspect ratio, evaporator length, evaporator inclination angle, evaporator-to-condenser height difference and the dimension of the holes. It was found that the entrainment is the main governing limit of the system operation. With the specified loop design and operational conditions, the solar loop-heat pipe can achieve a heat-transport capacity of 725 W. The analytical model presented in this study can be used to optimise the heat-transfer capacity of the novel solar loop-heat pipe.

  6. Response surface methodology modeling to improve degradation of Chlorpyrifos in agriculture runoff using TiO2 solar photocatalytic in a raceway pond reactor.

    Science.gov (United States)

    Amiri, Hoda; Nabizadeh, Ramin; Silva Martinez, Susana; Jamaleddin Shahtaheri, Seyed; Yaghmaeian, Kamyar; Badiei, Alireza; Nazmara, Shahrokh; Naddafi, Kazem

    2018-01-01

    This paper deals with the use of a raceway pond reactor (RPR) as an alternative photoreactor for solar photocatalytic applications. Raceway pond reactors are common low-cost reactors which can treat large volumes of water. The experiments were carried out with TiO 2 in the agriculture effluent spiked with Chlorpyrifos (CPF) at circumneutral pH. The Response Surface Methodology (RSM) was used to find the optimum process parameters to maximize CPF oxidation from the mathematical model equations developed in this study using R software. By ANOVA, p-value of lack of fit > 0.05 indicated that, the equation was well-fitted. The theoretical efficiency of CPF removal, under the optimum oxidation conditions with UV solar energy of around 697 ± 5.33 lux, was 84.01%, which is in close agreement with the mean experimental value (80 ± 1.42%) confirming that the response model was suitable for the optimization. As far as the authors know, this is the first study of CPF removal using RPR in agriculture runoff at circumneutral pH. Copyright © 2017. Published by Elsevier Inc.

  7. Electrical properties and surface morphology of electron beam evaporated p-type silicon thin films on polyethylene terephthalate for solar cells applications

    Science.gov (United States)

    Ang, P. C.; Ibrahim, K.; Pakhuruddin, M. Z.

    2015-04-01

    One way to realize low-cost thin film silicon (Si) solar cells fabrication is by depositing the films with high-deposition rate and manufacturing-compatible electron beam (e-beam) evaporation onto inexpensive foreign substrates such as glass or plastic. Most of the ongoing research is reported on e-beam evaporation of Si films on glass substrates to make polycrystalline solar cells but works combining both e-beam evaporation and plastic substrates are still scarce in the literature. This paper studies electrical properties and surface morphology of 1 µm electron beam evaporated Al-doped p-type silicon thin films on textured polyethylene terephthalate (PET) substrate for application as an absorber layer in solar cells. In this work, Si thin films with different doping concentrations (including an undoped reference) are prepared by e-beam evaporation. Energy dispersion X-ray (EDX) showed that the Si films are uniformly doped by Al dopant atoms. With increased Al/Si ratio, doping concentration increased while both resistivity and carrier mobility of the films showed opposite relationships. Root mean square (RMS) surface roughness increased. Overall, the Al-doped Si film with Al/Si ratio of 2% (doping concentration = 1.57×1016 atoms/cm3) has been found to provide the optimum properties of a p-type absorber layer for fabrication of thin film Si solar cells on PET substrate.

  8. Electrical properties and surface morphology of electron beam evaporated p-type silicon thin films on polyethylene terephthalate for solar cells applications

    Energy Technology Data Exchange (ETDEWEB)

    Ang, P. C.; Ibrahim, K.; Pakhuruddin, M. Z. [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, Minden 11800 Penang (Malaysia)

    2015-04-24

    One way to realize low-cost thin film silicon (Si) solar cells fabrication is by depositing the films with high-deposition rate and manufacturing-compatible electron beam (e-beam) evaporation onto inexpensive foreign substrates such as glass or plastic. Most of the ongoing research is reported on e-beam evaporation of Si films on glass substrates to make polycrystalline solar cells but works combining both e-beam evaporation and plastic substrates are still scarce in the literature. This paper studies electrical properties and surface morphology of 1 µm electron beam evaporated Al-doped p-type silicon thin films on textured polyethylene terephthalate (PET) substrate for application as an absorber layer in solar cells. In this work, Si thin films with different doping concentrations (including an undoped reference) are prepared by e-beam evaporation. Energy dispersion X-ray (EDX) showed that the Si films are uniformly doped by Al dopant atoms. With increased Al/Si ratio, doping concentration increased while both resistivity and carrier mobility of the films showed opposite relationships. Root mean square (RMS) surface roughness increased. Overall, the Al-doped Si film with Al/Si ratio of 2% (doping concentration = 1.57×10{sup 16} atoms/cm{sup 3}) has been found to provide the optimum properties of a p-type absorber layer for fabrication of thin film Si solar cells on PET substrate.

  9. Description of Idiomarina insulisalsae sp. nov., isolated from the soil of a sea salt evaporation pond, proposal to transfer the species of the genus Pseudidiomarina to the genus Idiomarina and emended description of the genus Idiomarina.

    Science.gov (United States)

    Taborda, Marco; Antunes, André; Tiago, Igor; Veríssimo, António; Nobre, M Fernanda; da Costa, Milton S

    2009-09-01

    A halophilic, aerobic Gram-negative bacterium, designated strain CVS-6(T), was isolated from a sea salt evaporation pond on the Island of Sal in the Cape Verde Archipelago. Phylogenetic analysis of the 16S rRNA gene sequence revealed a clear affiliation of the organism with members of the family Idiomarinaceae. Sequence similarities between CVS-6(T) and the type strains of the species of the genera Pseudidiomarina and Idiomarina ranged from 93.7% to 96.9%. The major isoprenoid quinone was ubiquinone 8 (Q-8). The major cellular fatty acids were 15:0 iso (21.8%), 17:0 iso (12.5%), 17:1 iso omega9c (10.7%), and 16:1 omega7c (10.6%). The DNA G+C content was 51.6 mol%. The species represented by strain CVS-6(T) could be distinguished from the species of the genera Pseudidiomarina and Idiomarina; however, it was not possible to distinguish both genera from each other using the phenotypic or chemotaxonomic characteristics examined. Consequently, we propose that the species classified in the genus Pseudidiomarina should be transferred to the genus Idiomarina. We also propose that, on the basis of physiological and biochemical characteristics, strain CVS-6(T) (=LMG 23123=CIP 108836) represents a new species which we name Idiomarina insulisalsae.

  10. Spatial modeling of limnological parameters in a solar saltwork of northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Diógenes Félix da Silva Costa

    2015-03-01

    Full Text Available AimIn this research, we aimed to model limnological parameters in the Salina Unidos (Macau-Brazil using GIS technology. We hypothesized that in solar saltworks, the geochemical characteristics of the brines (i.e. the strong solution of salts vary considerably through the salt ponds circuit, in which drastic changes can damage the entire salt production.MethodsGeochemical parameters were monitored in seven sampling points distributed along the salt ponds circuit, during a complete cycle of salt production, i.e., from January to December 2007. The open source software Spring 5.1.6 was used to build, store, analyze and model the spatial distribution of the parameters.ResultsWe identified a spatial gradient of the salinity and temperature, with values increasing from evaporation ponds to concentration ponds, showing a relationship with the salt production. The parameters, depth, dissolved oxygen concentrations and total dissolved reactive phosphorus showed a decrease from the evaporation ponds towards the concentration ponds. Among the dissolved inorganic nitrogen forms analyzed (NH3-, NO2- and NO3-, nitrate was the predominant, namely in the concentration ponds, where it reached the highest concentrations. The concentration of chlorophyll awas higher in the initial and intermediate evaporation ponds, showing a distinct dynamics of in relation to other environmental variables.ConclusionsThe increased concentration of the analyzed limnological parameters, from the evaporation ponds towards the concentration ponds, evidenced a heterogeneous distribution varying significantly with season. The geochemical spatialization of brine, as illustrated by GIS approach, is very important for the conservation of these environments because this spatial heterogeneity can provide a high diversity of habitat types. This spatial analysis proved to be a practical tool for an adequate management of solar saltworks considering the environmental (ecosystem and the socio

  11. Biological activity during co-composting of sludge issued from the OMW evaporation ponds with poultry manure-Physico-chemical characterization of the processed organic matter.

    Science.gov (United States)

    Hachicha, Salma; Sellami, Fatma; Cegarra, Juan; Hachicha, Ridha; Drira, Noureddine; Medhioub, Khaled; Ammar, Emna

    2009-02-15

    Olive mill sludge (OMS), a by-product resulting from natural evaporation of olive oil processing effluent, poses a major environmental threat. A current cost-effective practice of OMS management is composting. A mixture of OMS (60%) with poultry manure (PM) was successfully composted for 210 days. During the process, effluents of olive oil mill and confectionary were used to keep moisture at optimal level (40-60%). Biological indicators reflecting stability of the compost (microbial biota respiration and enumeration, and germination index) were analysed for the assessment of the product quality. The composted mixture showed a high microbial activity with a succession of microbial populations depending on the temperature reached during the biodegradation. The pathogen content from PM decreased with composting as did phytotoxic compounds. Phenols and lipids were reduced, respectively, by 40% and 84% while germination index increased with composting progress. Fourier transform infrared (FTIR) spectroscopic analysis revealed that the final compost improved the aromatic content compared to the starting materials, with a decrease in aliphatic groups and a reduction in the easily assimilated components by the microflora acting during the biological process. The final compost was characterized by relatively high organic matter content (26.21%), a low C/N ratio (16.21), an alkaline pH (8.32), a relatively high electrical conductivity (9.21mS/cm) and a high level of nutrients. The germination index for Lepidium sativum L. was 87.71% after 210 days of composting, showing that the final compost was not phytotoxic.

  12. SLIPPING MAGNETIC RECONNECTION, CHROMOSPHERIC EVAPORATION, IMPLOSION, AND PRECURSORS IN THE 2014 SEPTEMBER 10 X1.6-CLASS SOLAR FLARE

    Energy Technology Data Exchange (ETDEWEB)

    Dudík, Jaroslav; Karlický, Marian; Dzifčáková, Elena [Astronomical Institute of the Czech Academy of Sciences, Fričova 298, 251 65 Ondřejov (Czech Republic); Polito, Vanessa; Mulay, Sargam M.; Zanna, Giulio Del; Mason, Helen E. [Department of Applied Mathematics and Theoretical Physics, CMS, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Janvier, Miho [Institut d’Astrophysique Spatiale, Centre Universitaire d’Orsay, Bt 120121, F-91405 Orsay Cedex (France); Aulanier, Guillaume; Schmieder, Brigitte, E-mail: dudik@asu.cas.cz [LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universits, UPMC Univ. Paris 06, Univ. Paris-Diderot, Sorbonne Paris Cit, 5 place Jules Janssen, F-92195 Meudon (France)

    2016-05-20

    We investigate the occurrence of slipping magnetic reconnection, chromospheric evaporation, and coronal loop dynamics in the 2014 September 10 X-class flare. Slipping reconnection is found to be present throughout the flare from its early phase. Flare loops are seen to slip in opposite directions toward both ends of the ribbons. Velocities of 20–40 km s{sup −1} are found within time windows where the slipping is well resolved. The warm coronal loops exhibit expanding and contracting motions that are interpreted as displacements due to the growing flux rope that subsequently erupts. This flux rope existed and erupted before the onset of apparent coronal implosion. This indicates that the energy release proceeds by slipping reconnection and not via coronal implosion. The slipping reconnection leads to changes in the geometry of the observed structures at the Interface Region Imaging Spectrograph slit position, from flare loop top to the footpoints in the ribbons. This results in variations of the observed velocities of chromospheric evaporation in the early flare phase. Finally, it is found that the precursor signatures, including localized EUV brightenings as well as nonthermal X-ray emission, are signatures of the flare itself, progressing from the early phase toward the impulsive phase, with the tether-cutting being provided by the slipping reconnection. The dynamics of both the flare and outlying coronal loops is found to be consistent with the predictions of the standard solar flare model in three dimensions.

  13. Radiant heat transfer during the natural evaporation from free surfaces exposed to solar radiation; Transferencia de calor radiante durante a evaporacao natural em superficies livres expostas a radiacao solar

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, C O.M. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia; Hackenberg, C M [Universidade Federal do Rio de Janeiro, RJ (Brazil). Escola de Quimica

    1985-12-31

    In this work a conductive-convective-radiant model which includes phase change behavior, is developed in order to determine the rate of evaporation from free surface exposed to solar radiation and consequently the most important parameters, and their effects, on the design of salt solutions concentrating natural evaporation reservoirs may be analysed. The numerical solutions of the resulting of system of equations are shown to represent very well the experimental results measured on evaporation chambers specially built for daily operations. The thermal effect of spectrally selective surfaces as coating agents for the reservoir is also analysed. (author). 11 refs., 8 figs

  14. DESIGN, DEVELOPMENT AND TESTING OF MULTIEFFECT DISTILLER/EVAPORATOR USING SCHEFFLER SOLAR CONCENTRATORS

    Directory of Open Access Journals (Sweden)

    AJAY CHANDAK

    2009-09-01

    Full Text Available Authors designed and experimented with multistage evaporation system for production of distilled water. Two Scheffler concentrators of 16 sqm each were used for generating steam in the first stage at 8 bar pressure and the pressure is gradually brought down to 1 bar, in four stage distillation unit. Total yield obtained in the project was 2.3 times that of single stage distillation. Temperature drop in every subsequent stage was designed to 25 degree centigrade. Heat of condensation in the last stage and also sensible heat of the condensate in all the stages were used for preheating of water in the next batch. The system has great potential in food processing industry for applications of juice thickening, sauces, jams, salt concentrating systems and distilled water applications, desalination etc. Results of the project are very encouraging for commercial scale application.

  15. SiO2 Antireflection Coatings Fabricated by Electron-Beam Evaporation for Black Monocrystalline Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    Minghua Li

    2014-01-01

    Full Text Available In this work we prepared double-layer antireflection coatings (DARC by using the SiO2/SiNx:H heterostructure design. SiO2 thin films were deposited by electron-beam evaporation on the conventional solar cell with SiNx:H single-layer antireflection coatings (SARC, while to avoid the coverage of SiO2 on the front side busbars, a steel mask was utilized as the shelter. The thickness of the SiNx:H as bottom layer was fixed at 80 nm, and the varied thicknesses of the SiO2 as top layer were 105 nm and 122 nm. The results show that the SiO2/SiNx:H DARC have a much lower reflectance and higher external quantum efficiency (EQE in short wavelengths compared with the SiNx:H SARC. A higher energy conversion efficiency of 17.80% was obtained for solar cells with SiO2 (105 nm/SiNx:H (80 nm DARC, an absolute conversion efficiency increase of 0.32% compared with the conventional single SiNx:H-coated cells.

  16. Frozen ponds

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  17. Thermal and chemical evolution in the early Solar System as recorded by FUN CAIs: Part II - Laboratory evaporation of potential CMS-1 precursor material

    Science.gov (United States)

    Mendybaev, Ruslan A.; Williams, Curtis D.; Spicuzza, Michael J.; Richter, Frank M.; Valley, John W.; Fedkin, Alexei V.; Wadhwa, Meenakshi

    2017-03-01

    We present the results of laboratory experiments in which a forsterite-rich melt estimated to be a potential precursor of Allende CMS-1 FUN CAI was evaporated into vacuum for different lengths of time at 1900 °C. The evaporation of this melt resulted in residues that define trajectories in chemical as well as magnesium, silicon and oxygen isotopic composition space and come very close to the measured properties of CMS-1. The isotopic composition of the evaporation residues was also used to determine the kinetic isotopic fractionation factors [α2,1 (vapor-melt) defined as the ratio of isotopes 2 and 1 of a given element in the evaporating gas divided by their ratio in the evaporating source] for evaporation of magnesium (α25,24 for 25Mg/24Mg), silicon (α29,28 for 29Si/28Si) and oxygen (α18,16 for 18O/16O) from the forsterite-rich melt at 1900 °C. The values of α25,24 = 0.98383 ± 0.00033 and α29,28 = 0.99010 ± 0.00038 are essentially independent of change in the melt composition as evaporation proceeds. In contrast, α18,16 changes from 0.9815 ± 0.0016 to ∼0.9911 when the residual melt composition changes from forsteritic to melilitic. Using the determined values of α25,24 and α29,28 and present-day bulk chemical composition of the CMS-1, the composition of the precursor of the inclusion was estimated to be close to the clinopyroxene + spinel + forsterite assemblage condensed from a solar composition gas. The correspondence between the chemical composition and isotopic fractionation of experimental evaporation residues and the present-day bulk chemical and isotopic compositions of CMS-1 is evidence that evaporation played a major role in the chemical evolution of CMS-1.

  18. Enhanced Charge Extraction of Li-Doped TiO2 for Efficient Thermal-Evaporated Sb2S3 Thin Film Solar Cells

    Directory of Open Access Journals (Sweden)

    Chunfeng Lan

    2018-02-01

    Full Text Available We provided a new method to improve the efficiency of Sb2S3 thin film solar cells. The TiO2 electron transport layers were doped by lithium to improve their charge extraction properties for the thermal-evaporated Sb2S3 solar cells. The Mott-Schottky curves suggested a change of energy band and faster charge transport in the Li-doped TiO2 films. Compared with the undoped TiO2, Li-doped mesoporous TiO2 dramatically improved the photo-voltaic performance of the thermal-evaporated Sb2S3 thin film solar cells, with the average power conversion efficiency (PCE increasing from 1.79% to 4.03%, as well as the improved open-voltage (Voc, short-circuit current (Jsc and fill factors. The best device based on Li-doped TiO2 achieved a power conversion efficiency up to 4.42% as well as a Voc of 0.645 V, which are the highest values among the reported thermal-evaporated Sb2S3 solar cells. This study showed that Li-doping on TiO2 can effectively enhance the charge extraction properties of electron transport layers, offering a new strategy to improve the efficiency of Sb2S3-based solar cells.

  19. Enhanced Charge Extraction of Li-Doped TiO2 for Efficient Thermal-Evaporated Sb2S3 Thin Film Solar Cells

    Science.gov (United States)

    Lan, Chunfeng; Luo, Jingting; Lan, Huabin; Fan, Bo; Peng, Huanxin; Zhao, Jun; Sun, Huibin; Zheng, Zhuanghao; Liang, Guangxing; Fan, Ping

    2018-01-01

    We provided a new method to improve the efficiency of Sb2S3 thin film solar cells. The TiO2 electron transport layers were doped by lithium to improve their charge extraction properties for the thermal-evaporated Sb2S3 solar cells. The Mott-Schottky curves suggested a change of energy band and faster charge transport in the Li-doped TiO2 films. Compared with the undoped TiO2, Li-doped mesoporous TiO2 dramatically improved the photo-voltaic performance of the thermal-evaporated Sb2S3 thin film solar cells, with the average power conversion efficiency (PCE) increasing from 1.79% to 4.03%, as well as the improved open-voltage (Voc), short-circuit current (Jsc) and fill factors. The best device based on Li-doped TiO2 achieved a power conversion efficiency up to 4.42% as well as a Voc of 0.645 V, which are the highest values among the reported thermal-evaporated Sb2S3 solar cells. This study showed that Li-doping on TiO2 can effectively enhance the charge extraction properties of electron transport layers, offering a new strategy to improve the efficiency of Sb2S3-based solar cells. PMID:29495612

  20. Enhanced Charge Extraction of Li-Doped TiO₂ for Efficient Thermal-Evaporated Sb₂S₃ Thin Film Solar Cells.

    Science.gov (United States)

    Lan, Chunfeng; Luo, Jingting; Lan, Huabin; Fan, Bo; Peng, Huanxin; Zhao, Jun; Sun, Huibin; Zheng, Zhuanghao; Liang, Guangxing; Fan, Ping

    2018-02-28

    We provided a new method to improve the efficiency of Sb₂S₃ thin film solar cells. The TiO₂ electron transport layers were doped by lithium to improve their charge extraction properties for the thermal-evaporated Sb₂S₃ solar cells. The Mott-Schottky curves suggested a change of energy band and faster charge transport in the Li-doped TiO₂ films. Compared with the undoped TiO₂, Li-doped mesoporous TiO₂ dramatically improved the photo-voltaic performance of the thermal-evaporated Sb₂S₃ thin film solar cells, with the average power conversion efficiency ( PCE ) increasing from 1.79% to 4.03%, as well as the improved open-voltage ( V oc ), short-circuit current ( J sc ) and fill factors. The best device based on Li-doped TiO₂ achieved a power conversion efficiency up to 4.42% as well as a V oc of 0.645 V, which are the highest values among the reported thermal-evaporated Sb₂S₃ solar cells. This study showed that Li-doping on TiO₂ can effectively enhance the charge extraction properties of electron transport layers, offering a new strategy to improve the efficiency of Sb₂S₃-based solar cells.

  1. Spectroscopic Observations of Magnetic Reconnection and Chromospheric Evaporation in an X-shaped Solar Flare

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y.; Gan, W. Q. [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Kelly, M.; Qiu, J. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Ding, M. D. [School of Astronomy and Space Science, Nanjing University, Nanjing 210023 (China); Zhu, X. S. [CAS Key Laboratory of Solar Activity, National Astronomical Observatories, Beijing 100012 (China)

    2017-10-20

    We present observations of distinct UV spectral properties at different locations during an atypical X-shaped flare (SOL2014-11-09T15:32) observed by the Interface Region Imaging Spectrograph ( IRIS ). In this flare, four chromospheric ribbons appear and converge at an X-point where a separator is anchored. Above the X-point, two sets of non-coplanar coronal loops approach laterally and reconnect at the separator. The IRIS slit was located close to the X-point, cutting across some of the flare ribbons and loops. Near the location of the separator, the Si iv 1402.77 Å line exhibits significantly broadened line wings extending to 200 km s{sup −1} with an unshifted line core. These spectral features suggest the presence of bidirectional flows possibly related to the separator reconnection. While at the flare ribbons, the hot Fe xxi 1354.08 Å line shows blueshifts and the cool Si iv 1402.77 Å, C ii 1335.71 Å, and Mg ii 2803.52 Å lines show evident redshifts up to a velocity of 80 km s{sup −1}, which are consistent with the scenario of chromospheric evaporation/condensation.

  2. Evidence for explosive chromospheric evaporation in a solar flare observed with SMM

    Science.gov (United States)

    Zarro, D. M.; Saba, J. L. R.; Strong, K. T.; Canfield, R. C.; Metcalf, T.

    1986-01-01

    SMM soft X-ray data and Sacramento Peak Observatory H-alpha observations are combined in a study of the impulsive phase of a solar flare. A blue asymmetry, indicative of upflow motions, was observed in the coronal Ca XIX line during the soft X-ray rise phase. H-alpha redshifts, indicative of downward motions, were observed simultaneously in bright flare kernels during the period of hard X-ray emission. It is shown that, to within observational errors, the impulsive phase momentum transported by the upflowing soft X-ray plasma is equivalent to that of the downward moving chromospheric material.

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

    Science.gov (United States)

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

    2014-01-01

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

  4. A new hybrid ocean thermal energy conversion–Offshore solar pond (OTEC–OSP) design: a cost optimization approach

    NARCIS (Netherlands)

    Straatman, P.J.T.; van Sark, W.G.J.H.M.

    2008-01-01

    Solar thermal electricity (STE) generation offers an excellent opportunity to supply electricity with a non-CO2 emitting technology. However, present costs hamper widespread deployment and therefore research and development efforts are concentrated on accelerated cost reductions and efficiency

  5. Deposition of organic dyes for dye-sensitized solar cell by using matrix-assisted pulsed laser evaporation

    Directory of Open Access Journals (Sweden)

    Chih-Ping Yen

    2016-08-01

    Full Text Available The deposition of various distinct organic dyes, including ruthenium complex N3, melanin nanoparticle (MNP, and porphyrin-based donor-π-acceptor dye YD2-o-C8, by using matrix-assisted pulsed laser evaporation (MAPLE for application to dye-sensitized solar cell (DSSC is investigated systematically. It is found that the two covalently-bonded organic molecules, i.e., MNP and YD2-o-C8, can be transferred from the frozen target to the substrate with maintained molecular integrity. In contrast, N3 disintegrates in the process, presumably due to the lower bonding strength of metal complex compared to covalent bond. With the method, DSSC using YD2-o-C8 is fabricated, and an energy conversion efficiency of 1.47% is attained. The issue of the low penetration depth of dyes deposited by MAPLE and the possible resolution to it are studied. This work demonstrates that MAPLE could be an alternative way for deposition of organic dyes for DSSC.

  6. Deposition of organic dyes for dye-sensitized solar cell by using matrix-assisted pulsed laser evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Yen, Chih-Ping [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Yu, Pin-Feng [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Department of Physics, National Chung Cheng University, Chiayi 621, Taiwan (China); Wang, Jyhpyng [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Department of Physics, National Central University, Taoyuan 320, Taiwan (China); Lin, Jiunn-Yuan [Department of Physics, National Chung Cheng University, Chiayi 621, Taiwan (China); Chen, Yen-Mu [SuperbIN Co., Ltd., Taipei 114, Taiwan (China); Chen, Szu-yuan, E-mail: sychen@ltl.iams.sinica.edu.tw [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Department of Physics, National Central University, Taoyuan 320, Taiwan (China)

    2016-08-15

    The deposition of various distinct organic dyes, including ruthenium complex N3, melanin nanoparticle (MNP), and porphyrin-based donor-π-acceptor dye YD2-o-C8, by using matrix-assisted pulsed laser evaporation (MAPLE) for application to dye-sensitized solar cell (DSSC) is investigated systematically. It is found that the two covalently-bonded organic molecules, i.e., MNP and YD2-o-C8, can be transferred from the frozen target to the substrate with maintained molecular integrity. In contrast, N3 disintegrates in the process, presumably due to the lower bonding strength of metal complex compared to covalent bond. With the method, DSSC using YD2-o-C8 is fabricated, and an energy conversion efficiency of 1.47% is attained. The issue of the low penetration depth of dyes deposited by MAPLE and the possible resolution to it are studied. This work demonstrates that MAPLE could be an alternative way for deposition of organic dyes for DSSC.

  7. Rational design of a bi-layered reduced graphene oxide film on polystyrene foam for solar-driven interfacial water evaporation

    KAUST Repository

    Shi, Le

    2016-12-20

    Solar-driven water evaporation has been emerging as a highly efficient way for utilizing solar energy for clean water production and wastewater treatment. Here we rationally designed and fabricated a bi-layered photothermal membrane with a porous film of reduced graphene oxide (rGO) on the top and polystyrene (PS) foam at the bottom. The top porous rGO layer acts as a light absorber to harvest and convert light efficiently to thermal energy and the bottom PS layer, which purposefully disintegrates water transport channels, acts as an excellent thermal barrier to minimize heat transfer to the nonevaporative bulk water. The optimized bi-layered membrane was able to produce water evaporation rate as high as 1.31 kg m−2 h−1 with light to evaporation conversion efficiency as high as 83%, which makes it a promising photothermal material in the literature. Furthermore, the experiments and theoretical simulation were both conducted to examine the relationship between the overall energy efficiency and the depth of the photothermal material underwater and the experimental and simulations results coincided with each other. Therefore, this work provides systematic evidence in support of the concept of the interfacial heating and shines important light on practical applications of solar-driven processes for clean water production.

  8. Approximate computation of hydrothermal conditions of nuclear reactor spray ponds

    International Nuclear Information System (INIS)

    Yarkho, A.A.; Borshchev, V.A.

    1990-01-01

    An algorithm is presented for determining the evaporation numbers of nuclear reactor spray ponds which provide necessary reactor cooling during its normal operation under given meteorological conditions with account of restrictions on the cooled water temperature at the reactor entrance

  9. Biogeochemical ecology of aquaculture ponds

    International Nuclear Information System (INIS)

    Weisburd, R.S.J.

    1988-01-01

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

  10. Wintertime Emissions from Produced Water Ponds

    Science.gov (United States)

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

    2013-12-01

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

  11. UHS, Ultimate Heat Sink Cooling Pond Analysis

    International Nuclear Information System (INIS)

    Codell, R.; Nuttle, W.K.

    1998-01-01

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

  12. Waste Stabilisation Ponds

    OpenAIRE

    Von Sperling, Marcos

    2007-01-01

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

  13. Radiological dose assessment for the decontaminated concrete removed from 183-H solar evaporation basins at the Hanford site, Richland, Washington

    International Nuclear Information System (INIS)

    Kamboj, S.; Faillace, E.; Yu, C.

    1997-01-01

    Potential maximum radiation dose rates over a 1,000-year time horizon were calculated for exposure to the decontaminated concrete removed from the 183-H Solar Evaporation Basins at the Hanford Site, Richland, Washington. The RESRAD computer code, Version 5.62, which implements the methodology described in the US Department of Energy's manual for developing residual radioactive material guidelines, was used in this evaluation. Currently, the concrete is not being used. Four potential exposure scenarios were developed for the land area where the decontaminated concrete will be stored. In Scenario A industrial use of the land is assumed; in Scenario B recreational use of the land is assumed; in Scenario C residential use of the land is assumed; and in Scenario D (a plausible but unlikely land-use scenario), the presence of a subsistence farmer in the immediate vicinity of the land is assumed. For Scenarios A and B, water used for drinking is assumed to be surface water from the Columbia River; for Scenarios C and D, groundwater drawn from a well located at the downgradient edge of the storage area is the only source of water for drinking, irrigation, and raising livestock. Conservative parameters values were used to estimate the radiation doses. The results of the evaluation indicate that the US Department of Energy's dose limit of 100 mrem/yr would not be exceeded for any of the scenarios analyzed. The potential maximum dose rates for Scenarios A, B, C, and D are 0.75, 0.022, 29, 29 mrem/yr, respectively. An uncertainty analysis was performed to determine which parameters have the greatest impact on the estimated doses. The doses in Scenarios C and D were found to be very sensitive to the magnitude of the irrigation rate

  14. RESULTS OF GROUNDWATER MONITORING FOR THE 183-H SOLAR EVAPORATION BASINS AND 300 AREA PROCESS TRENCHES JANUARY - JUNE 2008

    International Nuclear Information System (INIS)

    Hartman, M.J.

    2008-01-01

    This is one of a series of reports on Resource Conservation and Recovery Act of 1976 (RCRA) monitoring at the 183-H solar evaporation basins and the 300 Area process trenches. It fulfills the requirement of Washington Administrative Code (WAC) 173-303-645(11)(g), 'Release from Regulated Units', to report twice each year on the effectiveness of the corrective action program. This report covers the period from January through June 2008. The current objective of corrective action monitoring the 183-H basins is simply to track trends. Although there is short-term variability in contaminant concentrations, trends over the past 10 years are downward. The current Hanford Facility RCRA Permit (Dangerous Waste Portion of the Resource Conservation and Recovery Act Permit for the Treatment, Storage, and Disposal of Dangerous Waste (Permit No. WA 7890008967)) and monitoring plan remain adequate for the objective of tracking trends. The objective of groundwater monitoring at the 300 Area process trenches is to demonstrate the effectiveness of the corrective action program by examining the trend of the constituents of interest to confirm that they are attenuating naturally. The overall concentration of uranium in network wells remained above the 30 (micro)g/L drinking water standard in the three downgradient wells screened at the water table. Fluctuations of uranium concentration are caused by changes in river stage. The concentration of cis-1,2-dichloroethene remained above the 70 (micro)g/L drinking water standard in one well (399-1-16B). Concentrations are relatively steady at this well and are not affected by river stage. Trichloroethene and tetrachloroethene concentrations were below detection limits in all wells during the reporting period

  15. Streamer Evaporation

    Science.gov (United States)

    Suess, Steven T.; Wang, A. H.; Wu, Shi T.; Nerney, S.

    1998-01-01

    Evaporation is the consequence of slow plasma heating near the tops of streamers where the plasma is only weakly contained by the magnetic field. The form it takes is the slow opening of field lines at the top of the streamer and transient formation of new solar wind. It was discovered in polytropic model calculations, where due to the absence of other energy loss mechanisms in magnetostatic streamers, its ultimate endpoint is the complete evaporation of the streamer. This takes, for plausible heating rates, weeks to months in these models. Of course streamers do not behave this way, for more than one reason. One is that there are losses due to thermal conduction to the base of the streamer and radiation from the transition region. Another is that streamer heating must have a characteristic time constant and depend on the ambient physical conditions. We use our global Magnetohydrodynamics (MHD) model with thermal conduction to examine a few examples of the effect of changing the heating scale height and of making ad hoc choices for how the heating depends on ambient conditions. At the same time, we apply and extend the analytic model of streamers, which showed that streamers will be unable to contain plasma for temperatures near the cusp greater than about 2xl0(exp 6) K. Slow solar wind is observed to come from streamers through transient releases. A scenario for this that is consistent with the above physical process is that heating increases the near-cusp temperature until field lines there are forced open. The subsequent evacuation of the flux tubes by the newly forming slow wind decreases the temperature and heating until the flux tubes are able to reclose. Then, over a longer time scale, heating begins to again refill the flux tubes with plasma and increase the temperature until the cycle repeats itself. The calculations we report here are first steps towards quantitative evaluation of this scenario.

  16. Preparation of Cu{sub 2}ZnSnSe{sub 4} solar cells by low-temperature co-evaporation and following selenization

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Chao, E-mail: chao.gao@kit.edu; Hetterich, Michael [Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe (Germany); Schnabel, Thomas; Abzieher, Tobias; Ahlswede, Erik [Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg (ZSW), 70565 Stuttgart (Germany); Powalla, Michael [Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg (ZSW), 70565 Stuttgart (Germany); Light Technology Institute (LTI), Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe (Germany)

    2016-01-04

    Cu{sub 2}ZnSnSe{sub 4} (CZTSe) thin films are prepared by a two-step method which involves co-evaporation of Cu, Zn, Sn, and Se on molybdenum-coated soda-lime glass at low substrate temperature and a following selenization. Solar cells with efficiencies of up to 6.5% can be achieved. The influence of the selenium deposition rates during co-evaporation and the nitrogen pressure during selenization on the properties of the CZTSe films are investigated. It is found that these two parameters can significantly affect the morphology and crystallinity of the CZTSe films. The possible reasons for the experimental results are discussed.

  17. Estimate potential evaporation and solar radiation in the Yaqui valley, Sonora, Mexico, using data from satellite; Estimacion de evaporacion y radiacion solar en el valle del Yaqui, Sonora, usando datos de satelite

    Energy Technology Data Exchange (ETDEWEB)

    J Watts, Christopher; Rodriguez, Julio Cesar [Instituto del Medio Ambiente y el Desarrollo sustentable del estado de Sonora (Mexico); Garatuza Payan, Jaime [Instituto Tecnologico de Sonora (Mexico); Henk de Bruin [Universidad Agricola de Wageningen (Netherlands); Stewart, John [Universidad de Southampton (United Kingdom)

    1999-12-01

    The data from tow automatic weather stations in the Yaqui valley were used to estimate potential evaporation using the Makkink formula, based on observed incoming solar radiation and climatological values of air temperature. The usefulness of this formula was assessed by comparison with the Penman-Monteith, Penman and Priestley-Taylor formula and measurements of net radiation. A methodology was presented for estimating incoming solar radiation using visible band data from the GOES satellite. Comparisons against ground-based measurements from two pyranometers installed in the Yaqui valley gave good results, particularly in months with low cloud cover. Images for August 1993 were used to produce a map of the spatial distribution of potential evaporation. [Spanish] Para calcular la evaporacion potencial en el valle del Yaqui, usando la formula de Makkink, se utilizaron datos de dos estaciones meteorologicas automaticas. La mencionada formula se basa en la radiacion solar incidente observada y en ciertos valores climatologicos de temperatura del aire. Se evaluo la utilidad de esta formula, comparandola con las de Penman-Monteith, Pennan y Priestley-Taylor, asi como con mediciones de radiacion neta. Se desarrollo una metodologia para estimar la radiacion solar incidente usando la banda visible del satelite GOES. Se hizo una comparacion con mediciones de dos piranometros instalados en el valla del Yaqui, obteniendose buenos resultados, principalmente en meses con poca nubosidad. Se utilizaron imagenes de agosto de 1993 para producir un mapa de la distribucion espacial de la evaporacion potencial.

  18. Effect of Annealing Temperature on CuInSe2/ZnS Thin-Film Solar Cells Fabricated by Using Electron Beam Evaporation

    Directory of Open Access Journals (Sweden)

    H. Abdullah

    2013-01-01

    Full Text Available CuInSe2 (CIS thin films are successfully prepared by electron beam evaporation. Pure Cu, In, and Se powders were mixed and ground in a grinder and made into a pellet. The pallets were deposited via electron beam evaporation on FTO substrates and were varied by varying the annealing temperatures, at room temperature, 250°C, 300°C, and 350°C. Samples were analysed by X-ray diffractometry (XRD for crystallinity and field-emission scanning electron microscopy (FESEM for grain size and thickness. I-V measurements were used to measure the efficiency of the CuInSe2/ZnS solar cells. XRD results show that the crystallinity of the films improved as the temperature was increased. The temperature dependence of crystallinity indicates polycrystalline behaviour in the CuInSe2 films with (1 1 1, (2 2 0/(2 0 4, and (3 1 2/(1 1 6 planes at 27°, 45°, and 53°, respectively. FESEM images show the homogeneity of the CuInSe2 formed. I-V measurements indicated that higher annealing temperatures increase the efficiency of CuInSe2 solar cells from approximately 0.99% for the as-deposited films to 1.12% for the annealed films. Hence, we can conclude that the overall cell performance is strongly dependent on the annealing temperature.

  19. Lake or Pond WBID

    Data.gov (United States)

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

  20. Engineering evaluation/cost analysis for disposal of structural concrete and soil from the 183-H Solar Evaporation Basin

    International Nuclear Information System (INIS)

    Badden, J.W.; Miller, L.R.

    1996-08-01

    This engineering evaluation/cost analysis is intended to aid the US Department of Energy, Richland Operations Office in selecting a preferred response action alternative for removing contaminated structural concrete and soils stockpiled next to the 183-H evaporation basin, which was conducted under the Resource Conservation and Recovery Act of 1976. This EE/CA evaluates possible alternative response actions and documents the decision making process

  1. Technical manual for calculating cooling pond performance

    International Nuclear Information System (INIS)

    Krstulovich, S.F.

    1988-01-01

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

  2. Standing crops and ecology of aquatic invertebrates in agricultural drainwater ponds in California

    Science.gov (United States)

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

    1991-01-01

    We examined standing crops and ecology of aquatic invertebrates in agricultural drainwater evaporation ponds in California from October 1982 to March 1983 and September 1983 to March 1984. Evaporation ponds supported low diversities but high standing crops of aquatic invertebrates. A water boatman (Trichocorixa reticulata) and a midge (Tanypus grodhausi) were the most abundant invertebrates, constituting 44.9% and 51.4% of total macroinvertebrate biomass. Regression models indicated that of 6 environmental variables measured, only electrical conductivity (EC) and Julian date affected biomass and density of water boatmen. EC was the only significant correlate of midge biomass in evaporation ponds.

  3. Parametric Analysis of Design Parameter Effects on the Performance of a Solar Desiccant Evaporative Cooling System in Brisbane, Australia

    Directory of Open Access Journals (Sweden)

    Yunlong Ma

    2017-06-01

    Full Text Available Solar desiccant cooling is widely considered as an attractive replacement for conventional vapor compression air conditioning systems because of its environmental friendliness and energy efficiency advantages. The system performance of solar desiccant cooling strongly depends on the input parameters associated with the system components, such as the solar collector, storage tank and backup heater, etc. In order to understand the implications of different design parameters on the system performance, this study has conducted a parametric analysis on the solar collector area, storage tank volume, and backup heater capacity of a solid solar desiccant cooling system for an office building in Brisbane, Australia climate. In addition, a parametric analysis on the outdoor air humidity ratio control set-point which triggers the operation of the desiccant wheel has also been investigated. The simulation results have shown that either increasing the storage tank volume or increasing solar collector area would result in both increased solar fraction (SF and system coefficient of performance (COP, while at the same time reduce the backup heater energy consumption. However, the storage tank volume is more sensitive to the system performance than the collector area. From the economic aspect, a storage capacity of 30 m3/576 m2 has the lowest life cycle cost (LCC of $405,954 for the solar subsystem. In addition, 100 kW backup heater capacity is preferable for the satisfaction of the design regeneration heating coil hot water inlet temperature set-point with relatively low backup heater energy consumption. Moreover, an outdoor air humidity ratio control set-point of 0.008 kgWater/kgDryAir is more reasonable, as it could both guarantee the indoor design conditions and achieve low backup heater energy consumption.

  4. Differential in-depth characterization of co-evaporated Cu(In,Ga)Se{sub 2} thin films for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Klinkert, Torben; Jubault, Marie; Donsanti, Frédérique; Lincot, Daniel; Guillemoles, Jean-François

    2014-05-02

    In this paper we report an alternative approach to perform in-depth characterisation of Cu(In,Ga)Se{sub 2} (CIGS) absorber layers. While usually groups stop their co-evaporation process at different points and analyse the precursor or intermediate phases, we perform in-depth analysis on the finished absorber layer as it will be used in the solar cell. A co-evaporated CIGS layer was cut to several samples, which then were chemically etched to different thicknesses. Compared to sputtering ablation techniques, this avoids the selective abrasion of atoms with different binding energies. The samples were analysed by Raman spectroscopy and X-ray diffraction. In-depth information is obtained by differentiating the signals of samples with different thicknesses after etching and a first order correction for absorption losses was executed. The Ga/(Ga + In) ratio extracted from X-ray diffraction measurements is in good agreement with the double gradient observed by glow discharge optical emission spectroscopy. A slight variation might indicate residual stress in the CIGS layer. A preferred (112) orientation across the whole film together with changing (220), (116) and (312) orientation preferences is reported and explained on the basis of the CIGS crystal structure. Raman signals attributed to ordered vacancy compounds are found throughout the whole sample thickness and not only close to the surface, as often reported in the literature. - Highlights: • Co-evaporated CIGS with double Ga gradient was chemically etched to different thicknesses. • X-ray diffractograms were differentiated to gain in-depth information. • (116)-oriented grains are found to tend to grow on (312)-oriented grains. • Change of preferred orientation was linked to crystal structure at grain boundaries. • Ga gradient from Vegard's law of XRD peaks is in agreement with GDOES measurement.

  5. Flash evaporator

    OpenAIRE

    1997-01-01

    A device and method for flash evaporating a reagent includes an evaporation chamber that houses a dome on which evaporation occurs. The dome is solid and of high thermal conductivity and mass, and may be heated to a temperature sufficient to vaporize a specific reagent. The reagent is supplied from an external source to the dome through a nozzle, and may be supplied as a continuous stream, as a shower, and as discrete drops. A carrier gas may be introduced into the evaporation chamber and cre...

  6. 75 FR 81307 - Notice of Availability of Record of Decision for the Tonopah Solar Energy, LLC, Crescent Dunes...

    Science.gov (United States)

    2010-12-27

    ... generator, water treatment facilities and evaporation ponds, evaporative cooling tower and air cooled condenser (combined to form a hybrid-cooling system), electrical equipment and buildings, heliostat assembly...

  7. Stability enhancement of P3HT:PCBM polymer solar cells using thermally evaporated MoO3 anode buffer layer

    Science.gov (United States)

    Ameen, M. Yoosuf; Shamjid, P.; Abhijith, T.; Radhakrishnan, Thulasi; Reddy, V. S.

    2018-02-01

    Polymer solar cells have been fabricated with thermally evaporated MoO3 as anode buffer layer (ABL). The stability of MoO3 and PEDOT:PSS based devices was examined under different test conditions. The MoO3 based device exhibited a slightly better efficiency and significantly higher stability compared to PEDOT:PSS based device. At a relative humidity of 45% the unencapsulated PEDOT:PSS based device degraded completely within 96 h. On the other hand, MoO3 based device retained more than 60% of its initial efficiency after 96 h. The reason behind stability enhancement was investigated by measuring time-evolution of reflectance and hole-current. Experimental results revealed that the stability enhancement for MoO3 based device originates from the reduction in degradation of anode/active layer interface.

  8. Improving Efficiency of Evaporated Cu2ZnSnS4 Thin Film Solar Cells by a Thin Ag Intermediate Layer between Absorber and Back Contact

    Directory of Open Access Journals (Sweden)

    Hongtao Cui

    2015-01-01

    Full Text Available A 20 nm Ag coating on Mo back contact was adopted to improve the back contact of evaporated Cu2ZnSnS4 (CZTS solar cells. The Ag layer helped reduce the thickness of MoS2 which improves fill factor (FF significantly; additionally, it reduced secondary phases ZnS and SnS2−x, which may help carrier transport; it was also involved in the doping of the absorber layer, which compensated the intrinsic p-type doping and therefore drags down the doping level. The doping involvement may enlarge the depletion region and improve lifetime of the absorber, which led to enhancing open circuit voltage (VOC, short circuit current density (JSC, and efficiency significantly. However, it degrades the crystallinity of the material slightly.

  9. The color of melt ponds on Arctic sea ice

    Science.gov (United States)

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

    2018-04-01

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

  10. Comparative study on systems of residual water treatment in the process industry by evaporation, using fossils fuels or solar energy; Estudio comparativo sobre sistemas de tratamiento de aguas residuales de la industria de procesamiento por evaporacion, utilizando combustibles fosiles o energia solar

    Energy Technology Data Exchange (ETDEWEB)

    Landgrave Romero, Julio; Canseco Contreras, Jose [Facultad de Quimica, UNAM (Mexico)

    1996-07-01

    The residual water treatment of the process industry, nowadays is an imminent necessity in our country. In the present study two different forms are considered to concentrate residual waters: multiple effect evaporation and solar evaporation. The use of solar evaporation lagoons is a good possibility to conserving energy by means of the diminution of fossil fuel consumption. The design basis of the evaporation systems via multiple effect, as well as solar evaporation, the results of the respective sizing and the estimation of the corresponding costs are presented. A practical case is described on the cooking of cotton linters (flock) [Spanish] El tratamiento de aguas residuales de la industria de proceso, hoy en dia es una necesidad inminente en nuestro pais. En el presente trabajo se consideran dos formas distintas para concentrar las aguas residuales: evaporacion de multiple efecto y evaporacion solar. El empleo de lagunas de evaporacion solar es una buena posibilidad para conseguir el ahorro de energia mediante disminucion del consumo de combustibles fosiles. Se presentan las bases de diseno de los sistemas de evaporacion via multiple efecto, asi como solar, los resultados del dimensionamiento respectivo y la estimacion de los costos correspondientes. Se describe un caso practico sobre el cocido de linters de algodon (borra)

  11. Simulation Analysis of the Four Configurations of Solar Desiccant Cooling System Using Evaporative Cooling in Tropical Weather in Malaysia

    Directory of Open Access Journals (Sweden)

    M. M. S. Dezfouli

    2014-01-01

    Full Text Available A high demand for air conditioning systems exists in hot and humid regions because of the warm climate during the year. The high energy consumption of conventional air conditioning system is the reason for our investigation of the solar desiccant cooling system as an energy-efficient cooling system. Four model configurations were considered to determine the best configuration of a solar desiccant cooling system: one-stage ventilation, one-stage recirculation, two-stage ventilation, and two-stage recirculation. These models were stimulated for 8,760 hr of operation under hot and humid weather in Malaysia. Several parameters (i.e., coefficient of performance or COP, room temperature and humidity ratio, and the solar fraction of each system were evaluated by detecting the temperature and humidity ratio of the different points of each configuration by TRNSYS simulation. The latent and sensible loads of the test room were 0.875 kW and 2.625 kW, respectively. By investigating the simulation results of the four systems, the ventilation modes were found to be higher than the recirculation modes in the one- and two-stage solar desiccant cooling systems. The isothermal dehumidification COP of the two-stage ventilation was higher than that of the two-stage recirculation. Hence, the two-stage ventilation mode desiccant cooling system in a hot and humid area has higher efficiency than the other configurations.

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

    Science.gov (United States)

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

    2015-12-01

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

  13. Optical and Morphological Studies of Thermally Evaporated PTCDI-C8 Thin Films for Organic Solar Cell Applications

    Directory of Open Access Journals (Sweden)

    Ronak Rahimi

    2013-01-01

    Full Text Available PTCDI-C8 due to its relatively high photosensitivity and high electron mobility has attracted much attention in organic semiconductor devices. In this work, thin films of PTCDI-C8 with different thicknesses were deposited on silicon substrates with native silicon dioxide using a vacuum thermal evaporator. Several material characterization techniques have been utilized to evaluate the structure, morphology, and optical properties of these films. Their optical constants (refractive index and extinction coefficient have been extracted from the spectroscopic ellipsometry (SE. X-ray reflectivity (XRR and atomic force microscopy (AFM were employed to determine the morphology and structure as well as the thickness and roughness of the PTCDI-C8 thin films. These films revealed a high degree of structural ordering within the layers. All the experimental measurements were performed under ambient conditions. PTCDI-C8 films have shown to endure ambient condition which allows pots-deposition characterization.

  14. Sequence crystallization during isotherm evaporation of southern ...

    African Journals Online (AJOL)

    Southern Algerian's natural brine sampled from chott Baghdad may be a source of mineral salts with a high economic value. These salts are recoverable by simple solar evaporation. Indeed, during isothermal solar evaporation, it is possible to recover mineral salts and to determine the precipitation sequences of different ...

  15. Evaluation of Universitas Indonesia’s Recharge Pond Performance and Potential Utilization for Raw Water Source

    OpenAIRE

    Nyoman Suwartha; Resky Pramadin

    2012-01-01

    The UI recharge pond has been constructed 5 years ago. However, monitoring and evaluation activities on its performances are very lack. Aims of this study are to understand the recharge rate, and to evaluate existing quantity and water quality of the pond during dry and rainy season. Measurement of water depth, rainfall intensity, and evaporation is conducted to determine water availability, recharge rate, and water balance of the recharge pond. Amount of surface water is collected from recha...

  16. Growth and Characterization of the Evaporated Quaternary Absorber Cu2FeSnS4 for Solar Cell Applications

    Science.gov (United States)

    Oueslati, Hiba; Ben Rabeh, Mohamed; Kanzari, Mounir

    2018-03-01

    Cu2FeSnS4 (CFTS) was synthesized by direct fusion of high-purity elemental copper, iron, tin and sulfur. CFTS thin films were deposited on glass substrates heated by single source vacuum thermal evaporation, after which the obtained samples were annealed under a sulfur atmosphere in a sealed quartz tube at 400°C for 1 h in order to optimize the CFTS stannite phase. The substrate temperature was varied from room temperature to 200°C. The formation of a stannite structure with (112), (200) and (004) planes in the powder and thin films was confirmed using x-ray diffraction measurements and the crystallites were found to have a preferred orientation along the (112) direction. Optical measurements analysis showed that after the sulfurization process the layers have a relatively high absorption coefficient close to 105 cm-1 in the visible spectrum. The films show a direct optical band gap in the range 1.30-1.63 eV for substrate temperature varied from room temperature to 200°C. All samples revealed p-type conductivity as determined by the hot probe method.

  17. Field evaporation test of uranium tailings solution

    International Nuclear Information System (INIS)

    Chandler, B.L.; Shepard, T.A.; Stewart, T.A.

    1985-01-01

    A field experiment was performed to observe the effect on evaporation rate of a uranium tailings impoundment pond water as salt concentration of the water increased. The duration of the experiment was long enough to cause maximum salt concentration of the water to be attained. The solution used in the experiment was tailings pond water from an inactive uranium tailings disposal site in the initial stages of reclamation. The solution was not neutralized. The initial pH was about 1.0 decreasing to a salt gel at the end of the test. The results of the field experiment show a gradual and slight decrease in evaporation efficiency. This resulted as salt concentrations increased and verified the practical effectiveness of evaporation as a water removal method. In addition, the physical and chemical nature of the residual salts suggest that no long-term stability problem would likely result due to their presence in the impoundment during or after reclamation

  18. QUASI-PERIODIC FLUCTUATIONS AND CHROMOSPHERIC EVAPORATION IN A SOLAR FLARE RIBBON OBSERVED BY HINODE /EIS, IRIS , AND RHESSI

    Energy Technology Data Exchange (ETDEWEB)

    Brosius, Jeffrey W.; Inglis, Andrew R. [Catholic University of America at NASA Goddard Space Flight Center, Solar Physics Laboratory, Code 671, Greenbelt, MD 20771 (United States); Daw, Adrian N., E-mail: Jeffrey.W.Brosius@nasa.gov [NASA Goddard Space Flight Center, Solar Physics Laboratory, Code 671, Greenbelt, MD 20771 (United States)

    2016-10-20

    The Hinode /Extreme-ultraviolet Imaging Spectrometer (EIS) obtained rapid cadence (11.2 s) EUV stare spectra of an M7.3 flare ribbon in AR 12036 on 2014 April 18. Quasi-periodic ( P ≈ 75.6 ± 9.2 s) intensity fluctuations occurred in emission lines of O iv, Mg vi, Mg vii, Si vii, Fe xiv, and Fe xvi during the flare's impulsive rise, and ended when the maximum intensity in Fe xxiii was reached. The profiles of the O iv–Fe xvi lines reveal that they were all redshifted during most of the interval of quasi-periodic intensity fluctuations, while the Fe xxiii profile revealed multiple components including one or two highly blueshifted ones. This indicates that the flare underwent explosive chromospheric evaporation during its impulsive rise. Fluctuations in the relative Doppler velocities were seen, but their amplitudes were too subtle to extract significant quasi-periodicities. RHESSI detected 25–100 keV hard-X-ray sources in the ribbon near the EIS slit's pointing position during the peaks in the EIS intensity fluctuations. The observations are consistent with a series of energy injections into the chromosphere by nonthermal particle beams. Electron densities derived with Fe xiv (4.6 × 10{sup 10} cm{sup −3}) and Mg vii (7.8 × 10{sup 9} cm{sup −3}) average line intensity ratios during the interval of quasi-periodic intensity fluctuations, combined with the radiative loss function of an optically thin plasma, yield radiative cooling times of 32 s at 2.0 × 10{sup 6} K, and 46 s at 6.3 × 10{sup 5} K (about half the quasi-period); assuming Fe xiv's density for Fe xxiii yields a radiative cooling time of 10{sup 3} s (13 times the quasi-period) at 1.4 × 10{sup 7} K.

  19. Cu deficiency in multi-stage co-evaporated Cu(In,Ga)Se{sub 2} for solar cells applications: Microstructure and Ga in-depth alloying

    Energy Technology Data Exchange (ETDEWEB)

    Caballero, R., E-mail: raquel.caballero@helmholtz-berlin.de [Helmholtz Zentrum Berlin fuer Materialien und Energie, Hahn-Meitner Platz 1, 14109 Berlin (Germany); Izquierdo-Roca, V. [M-2E/XaRMAE/IN2UB, Departament d' Electronica, Universitat de Barcelona, C. Marti i Franques 1, 08028 Barcelona (Spain); Fontane, X. [IREC, Catalonia Institute for Energy Research, C. Joseph Pla 2 B2, 08019 Barcelona (Spain); Kaufmann, C.A. [Helmholtz Zentrum Berlin fuer Materialien und Energie, Hahn-Meitner Platz 1, 14109 Berlin (Germany); Alvarez-Garcia, J. [Centre de Recerca i Investigacio de Catalunya (CRIC), Trav. de Gracia 108, 08012 Barcelona (Spain); Eicke, A. [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung, Industriestrasse 6, 70565 Stuttgart (Germany); Calvo-Barrio, L. [Lab. Analisis de Superficies, SCT, Universitat de Barcelona, Lluis Sole i Sabaris 1-3, 08028 Barcelona (Spain); Perez-Rodriguez, A. [M-2E/XaRMAE/IN2UB, Departament d' Electronica, Universitat de Barcelona, C. Marti i Franques 1, 08028 Barcelona (Spain)] [IREC, Catalonia Institute for Energy Research, C. Joseph Pla 2 B2, 08019 Barcelona (Spain); Schock, H.W. [Helmholtz Zentrum Berlin fuer Materialien und Energie, Hahn-Meitner Platz 1, 14109 Berlin (Germany); Morante, J.R. [M-2E/XaRMAE/IN2UB, Departament d' Electronica, Universitat de Barcelona, C. Marti i Franques 1, 08028 Barcelona (Spain)] [IREC, Catalonia Institute for Energy Research, C. Joseph Pla 2 B2, 08019 Barcelona (Spain)

    2010-05-15

    The objective of this work is to study the influence of the maximum Cu content during the deposition of Cu(In,Ga)Se{sub 2} (CIGSe) by multi-stage co-evaporation on the phases present in the final film, the film structure and the electrical properties of resulting solar cell devices. The variation of the composition is controlled by the Cu content in stage 2 of the deposition process. The different phases are identified by Raman spectroscopy. The in-depth Ga gradient distribution is investigated by in-depth resolved Raman scattering and secondary neutral mass spectroscopy. The morphology of the devices is studied by scanning electron microscopy. Efficiencies of 9.2% are obtained for ordered-vacancy-compound-based cells with a Cu/(In + Ga) ratio = 0.35, showing the system's flexibility. This work supports the current growth model: a small amount of Cu excess during the absorber process is required to obtain a quality microstructure and high performance devices.

  20. Controlled Crystal Grain Growth in Mixed Cation-Halide Perovskite by Evaporated Solvent Vapor Recycling Method for High Efficiency Solar Cells.

    Science.gov (United States)

    Numata, Youhei; Kogo, Atsushi; Udagawa, Yosuke; Kunugita, Hideyuki; Ema, Kazuhiro; Sanehira, Yoshitaka; Miyasaka, Tsutomu

    2017-06-07

    We developed a new and simple solvent vapor-assisted thermal annealing (VA) procedure which can reduce grain boundaries in a perovskite film for fabricating highly efficient perovskite solar cells (PSCs). By recycling of solvent molecules evaporated from an as-prepared perovskite film as a VA vapor source, named the pot-roast VA (PR-VA) method, finely controlled and reproducible device fabrication was achieved for formamidinium (FA) and methylammonium (MA) mixed cation-halide perovskite (FAPbI 3 ) 0.85 (MAPbBr 3 ) 0.15 . The mixed perovskite was crystallized on a low-temperature prepared brookite TiO 2 mesoporous scaffold. When exposed to very dilute solvent vapor, small grains in the perovskite film gradually unified into large grains, resulting in grain boundaries which were highly reduced and improvement of photovoltaic performance in PSC. PR-VA-treated large grain perovskite absorbers exhibited stable photocurrent-voltage performance with high fill factor and suppressed hysteresis, achieving the best conversion efficiency of 18.5% for a 5 × 5 mm 2 device and 15.2% for a 1.0 × 1.0 cm 2 device.

  1. Par Pond water balance

    International Nuclear Information System (INIS)

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

    1996-06-01

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

  2. Evaporator bulb

    International Nuclear Information System (INIS)

    Stoll, W.

    1977-01-01

    In order to prevent the hazard of a possible excursion in an evaporator bulb for radioactive liquids there is provided in the bottom of the vessel a recess filled with a neutron-absorbing and moderating material. The bottom drain pipe is coming out sideways and connected with a heated pipe feeding above into the vessel tangentially. (TK) [de

  3. Evaporating firewalls

    Science.gov (United States)

    Van Raamsdonk, Mark

    2014-11-01

    In this note, we begin by presenting an argument suggesting that large AdS black holes dual to typical high-energy pure states of a single holographic CFT must have some structure at the horizon, i.e. a fuzzball/firewall, unless the procedure to probe physics behind the horizon is state-dependent. By weakly coupling the CFT to an auxiliary system, such a black hole can be made to evaporate. In a case where the auxiliary system is a second identical CFT, it is possible (for specific initial states) that the system evolves to precisely the thermofield double state as the original black hole evaporates. In this case, the dual geometry should include the "late-time" part of the eternal AdS black hole spacetime which includes smooth spacetime behind the horizon of the original black hole. Thus, if a firewall is present initially, it evaporates. This provides a specific realization of the recent ideas of Maldacena and Susskind that the existence of smooth spacetime behind the horizon of an evaporating black hole can be enabled by maximal entanglement with a Hawking radiation system (in our case the second CFT) rather than prevented by it. For initial states which are not finely-tuned to produce the thermofield double state, the question of whether a late-time infalling observer experiences a firewall translates to a question about the gravity dual of a typical high-energy state of a two-CFT system.

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

    Science.gov (United States)

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

    2017-12-01

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

  5. Liquid evaporation process and evaporator

    International Nuclear Information System (INIS)

    Bergey, Claude; Ravenel, Jacques.

    1975-01-01

    The process described enables a liquid to be evaporated rapidly without any projection. A jet of hot gas is applied to the liquid, the power and angle of the jet being chosen so as to spin the liquid. It is particularly used in the case of radioactive products [fr

  6. Crop maize evapotranspiration; 2: ratios between the evapotranspiration to class A pan evaporation, to the reference evapotranspiration and to global solar radiation, at three sowing dates

    International Nuclear Information System (INIS)

    Matzenauer, R.; Bergamashi, H.; Berlato, M.A.

    1998-01-01

    Water availability is the most limiting factor for growth and grain yield of maize in the State of Rio Grande do Sul, Brazil, reducing frequently this production. Therefore, studies involving the determination of the water requirements are important for irrigation management to minimize the water availability problem. The main objective of this study was to calculate ratios between the maize crop evapotranspiration (ETm) to the class A pan evaporation (Eo), to the reference evapotranspiration (ETo) and to global solar radiation (Rs), in order to obtain ralations between ETm/Eo, ETm/ETo and ETm/Rs, at different crop stages for three different sowing dates. Field experiments were carried out at the Experimental Station of Taquari/RS, 29°48’ of south latitude, 51°49’of west longitude, and 76m of altitude, from 1976/77 to 1988/89. ETm was measured using drainage lysimeters (Thornthwaite-Mather type). The average ratio between ETm and Eo for whole crop cycle (from sowing to physiological maturity) was 0.66, 0.72, and 0.68, respectively, in crops sown on September, October, and November. The average ratio between ETm and ETo for whole crop cycle was 0.74, 0.81, and 0.8, in crops sown on September, October, and November, while the average ratio between ETm and Rs was 0.45, 0.51, and 0.49 for the same sowing dates. The higher average values of crop coefficients occured from tasseling to the milk grain stage, when ETm/Eo was 0.81, 0.92, and 0.81; ETm/ETo was 0.97, 1.05, and 0.96, whereas ETm/Rs was 0.6, 0.68, and 0.6 for crops sown on September, October, and November, respectively [pt

  7. CHANGES OF WATER BALANCE COMPONENTS OF MIDFOREST POND IN A HYDROLOGICAL YEARS OF A DIFFERENT METEOROLOGICAL CONDITION COURSE

    Directory of Open Access Journals (Sweden)

    Mariusz Korytowski

    2014-10-01

    years. Evaporation from pond surface which was from 408 mm (2009/2010 to 835 mm (2002/2003 was the dominant factor of outgoing part of water balance. Outflow from the pond to neighboring areas had significant participation – about 44% of precipitation, in water balance in wet 2009/2010 hydrological year.

  8. Intrinsic Evaporative Cooling by Hygroscopic Earth Materials

    Directory of Open Access Journals (Sweden)

    Alexandra R. Rempel

    2016-08-01

    Full Text Available The phase change of water from liquid to vapor is one of the most energy-intensive physical processes in nature, giving it immense potential for cooling. Diverse evaporative cooling strategies have resulted worldwide, including roof ponds and sprinklers, courtyard fountains, wind catchers with qanats, irrigated green roofs, and fan-assisted evaporative coolers. These methods all require water in bulk liquid form. The evaporation of moisture that has been sorbed from the atmosphere by hygroscopic materials is equally energy-intensive, however, yet has not been examined for its cooling potential. In arid and semi-arid climates, hygroscopic earth buildings occur widely and are known to maintain comfortable indoor temperatures, but evaporation of moisture from their walls and roofs has been regarded as unimportant since water scarcity limits irrigation and rainfall; instead, their cool interiors are attributed to well-established mass effects in delaying the transmission of sensible gains. Here, we investigate the cooling accomplished by daily cycles of moisture sorption and evaporation which, requiring only ambient humidity, we designate as “intrinsic” evaporative cooling. Connecting recent soil science to heat and moisture transport studies in building materials, we use soils, adobe, cob, unfired earth bricks, rammed earth, and limestone to reveal the effects of numerous parameters (temperature and relative humidity, material orientation, thickness, moisture retention properties, vapor diffusion resistance, and liquid transport properties on the magnitude of intrinsic evaporative cooling and the stabilization of indoor relative humidity. We further synthesize these effects into concrete design guidance. Together, these results show that earth buildings in diverse climates have significant potential to cool themselves evaporatively through sorption of moisture from humid night air and evaporation during the following day’s heat. This finding

  9. Cooling pond fog studies

    International Nuclear Information System (INIS)

    Hicks, B.B.

    1978-01-01

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

  10. Structural analysis of co-evaporated In{sub 2}S{sub 3} and In{sub 2}S{sub 3}:V for solar cell absorber applications

    Energy Technology Data Exchange (ETDEWEB)

    Waegele, Leonard A.; Rata, Diana; Scheer, Roland [Institute of Physics, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 3, 06120 Halle (Saale) (Germany); Gurieva, Galina [Department Structure and Dynamics of Energy Materials, Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, 14109 Berlin (Germany)

    2017-06-15

    In this study we use co-evaporation to grow In{sub 2}S{sub 3} thin films on glass substrates and X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) to analyse the structural properties of annealed In{sub 2}S{sub 3} and V-doped In{sub 2}S{sub 3} for intermediate band solar cell application. We find co-evaporated In{sub 2}S{sub 3} to be polycrystalline on float glass and with improved crystallinity after annealing in S-atmosphere. We confirm that excessive incorporation of vanadium into the host structure is possible without formation of secondary crystalline phases. The analysis indicates a reduced crystalline quality after V doping. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

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

    Science.gov (United States)

    Walter, Donald A.; Masterson, John P.

    2011-01-01

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

  12. Renewable energy for the aeration of wastewater ponds.

    Science.gov (United States)

    Hobus, I; Hegemann, W

    2003-01-01

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

  13. REGIONAL DRAINWATER MANAGEMENT: SOURCE CONTROL, AGROFORESTRY, AND EVAPORATION PONDS

    OpenAIRE

    Posnikoff, Judith F.; Knapp, Keith C.

    1996-01-01

    Source control is one way to address salinity and drainage problems in irrigated agriculture, and reuse of drainage flows on salt-tolerant crops or trees in agroforestry production is another. A regional model of agricultural production with drainwater reuse and disposal is developed. Deep percolation flows are controlled through choice of crop areas, irrigation systems, and applied-water quantities. Crop drainwater may by reused in agroforestry production, and residual emissions are disposed...

  14. Transport of radioactive droplet moisture from a source in a nuclear power plant spray pond

    International Nuclear Information System (INIS)

    Elokhin, A.P.

    1995-01-01

    In addition to a change in the microclimate in the region surrounding a nuclear power plant resulting from the emission of vapor form a cooling tower, evaporation of water from the water surface of a cooling pond or a spray pond, in the latter case direct radioactive contamination of the underlying surface around the nuclear power plant can also occur due to discharge of process water (radioactive) into the pond and its transport in the air over a certain distance in the form of droplet moisture. A typical example may be the situation at the Zaporozhe nuclear power plant in 1986 when accidental discharge of process water into the cooling pond occurred. Below we present a solution for the problem of transport of droplet moisture taking into account its evaporation, which may be used to estimate the scale of radioactive contamination of the locality

  15. A holistic water depth simulation model for small ponds

    Science.gov (United States)

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

    2015-10-01

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

  16. Prepared thin laminae of CuInS{sub 2} by means of evaporation in flow modulated for its application like absorbents in solar cells; Laminas delgadas de CuInS{sub 2} preparadas mediante evaporacion en flujo modulado para su aplicacion como absorbentes en celulas solares

    Energy Technology Data Exchange (ETDEWEB)

    Bollero, A.; Trigo, J. F.; Herrero, J.; Gutierrez, M. T.

    2008-07-01

    The Department of energy of CIEMAT focuses one of its research lines on the preparation of CuInS{sub 2} films to be used as absorber in solar cells. this work shows the influence of the different process parameters (deposition sequence, modulation of the evaporation flux of the constituent elements,...) on the morphology and the optical properties of the final films. A simplified evaporation procedure has allowed the preparation of CuInS{sub 2} films with a low Cu content. this avoids the necessity of applying subsequent toxic treatment for removal of the CuS phase prior to implementation of the film as absorber in the solar cell device. (Author)

  17. A Robust CuCr2O4/SiO2 Composite Photothermal Material with Underwater Black Property and Extremely High Thermal Stability for Solar-Driven Water Evaporation

    KAUST Repository

    Shi, Yusuf

    2017-12-27

    The design and fabrication of efficient photothermal materials is the key issue in solar-driven water evaporation. In this work, a robust CuCr2O4/SiO2 composite membrane with outstanding solar-driven water evaporation performance (1.32 kg m−2 h−1) under one sun irradiation is rationally designed and synthesized by using quartz glass fibrous membrane as supporting matrix and stable CuCr2O4 particles as the active light absorber. Instead of coating a separate layer on top of the support, the CuCr2O4 particles are evenly distributed inside the matrix, which endows the membrane with great mechanical strength and excellent wear and abrasion resistance. The highly porous composite survives 6 atm pressure and retains its performance even after 75% of the membrane is removed by sandpaper. This work also looks into a generally overlooked aspect of wet versus dry state of photothermal material and its implications. Interestingly, the composite possesses a gray color with a high reflectance in dry state but turns into deep black with a low reflectance in wet state due to the decreased subsurface scattering and strong NIR light absorbance of water in wet state. This composite material also possesses excellent thermal stability and thermal shock resistance, making it able to be easily recovered by calcination in air or direct burning in fire for contaminants removal. The results demonstrate that this composite is a competitive photothermal material for practical solar distillation and indicate that the optical properties of material in wet state are more relevant to photothermal material screening and optimization for solar distillation.

  18. Geohydrology and limnology of Walden Pond, Concord, Massachusetts

    Science.gov (United States)

    Colman, John A.; Friesz, Paul J.

    2001-01-01

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

  19. Monitoring and Modelling of Salinity Behaviour in Drinking Water Ponds in Southern Bangladesh

    Science.gov (United States)

    Hoque, M. A.; Williams, A.; Mathewson, E.; Rahman, A. K. M. M.; Ahmed, K. M.; Scheelbeek, P. F. D.; Vineis, P.; Butler, A. P.

    2015-12-01

    Drinking water in southern Bangladesh is provided by a variety of sources including constructed storage ponds, seasonal rainwater and, ubiquitously saline, shallow groundwater. The ponds, the communal reservoirs for harvested rainwater, also tend to be saline, some as high as 2 g/l. Drinking water salinity has several health impacts including high blood pressure associated major risk factor for several cardio-vascular diseases. Two representative drinking water ponds in Dacope Upazila of Khulna District in southwest Bangladesh were monitored over two years for rainfall, evaporation, pond and groundwater level, abstraction, and solute concentration, to better understand the controls on drinking water salinity. Water level monitoring at both ponds shows groundwater levels predominantly below the pond level throughout the year implying a downward gradient. The grain size analysis of the underlying sediments gives an estimated hydraulic conductivity of 3E-8 m/s allowing limited seepage loss. Water balance modelling indicates that the seepage has a relatively minor effect on the pond level and that the bulk of the losses come from the combination of evaporation and abstraction particularly in dry season when precipitation, the only inflow to the pond, is close to zero. Seasonal variation in salinity (electrical conductivities, EC, ranged between 1500 to 3000 μS/cm) has been observed, and are primarily due to dilution from rainfall and concentration from evaporation, except on one occasion when EC reached 16,000 μS/cm due to a breach in the pond levee. This event was analogous to the episodic inundation that occurs from tropical cyclone storm surges and appears to indicate that such events are important for explaining the widespread salinisation of surface water and shallow groundwater bodies in coastal areas. A variety of adaptations (either from practical protection measures) or novel alternative drinking sources (such as aquifer storage and recovery) can be applied

  20. Solar India - 82: national solar energy convention

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    This document is the proceedings of the Solar India - 82 conference, which was held 17-19 December 1982. The papers are organized into functional groupings which include: (1) solar radiation, (2) flat plate solar collectors and solar water heaters, (3) solar concentrators, (4) solar air heaters and dryers, (5) solar ponds and energy storage, (6) solar cookers, (7) solar stills, (8) selective coatings, (9) photovoltaics, (10) space heating and cooling, (11) bio-energy, and (12) miscellaneous papers. The vast majority of the papers describe work carried out in India, the vast majority of the papers also contain relatively readable abstracts.

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

    Science.gov (United States)

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

    2014-01-01

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

  2. Trends and habitat associations of waterbirds using the South Bay Salt Pond Restoration Project, San Francisco Bay, California

    Science.gov (United States)

    De La Cruz, Susan E. W.; Smith, Lacy M.; Moskal, Stacy M.; Strong, Cheryl; Krause, John; Wang, Yiwei; Takekawa, John Y.

    2018-04-02

    Executive SummaryThe aim of the South Bay Salt Pond Restoration Project (hereinafter “Project”) is to restore 50–90 percent of former salt evaporation ponds to tidal marsh in San Francisco Bay (SFB). However, hundreds of thousands of waterbirds use these ponds over winter and during fall and spring migration. To ensure that existing waterbird populations are supported while tidal marsh is restored in the Project area, managers plan to enhance the habitat suitability of ponds by adding islands and berms to change pond topography, manipulating water salinity and depth, and selecting appropriate ponds to maintain for birds. To help inform these actions, we used 13 years of monthly (October–April) bird abundance data from Project ponds to (1) assess trends in waterbird abundance since the inception of the Project, and (2) evaluate which pond habitat characteristics were associated with highest abundances of different avian guilds and species. For comparison, we also evaluated waterbird abundance trends in active salt production ponds using 10 years of monthly survey data.We assessed bird guild and species abundance trends through time, and created separate trend curves for Project and salt production ponds using data from every pond that was counted in a year. We divided abundance data into three seasons—fall (October–November), winter (December–February), and spring (March–April). We used the resulting curves to assess which periods had the highest bird abundance and to identify increasing or decreasing trends for each guild and species.

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

    Science.gov (United States)

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

    2010-01-01

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

  4. 76 FR 52008 - Keālia Pond National Wildlife Refuge (NWR) and Kakahai'a NWR, Maui County, HI; Draft...

    Science.gov (United States)

    2011-08-19

    ... control the most aggressive invasive species. Reduce midge swarms, wind-blown dust, and foul-smelling... the main pond recedes due to evaporation, trade winds disperse dust from the pond to the south... well, installing a water pump and distribution line, and repairing the electric panel. This alternative...

  5. Mixed phase evaporation source

    International Nuclear Information System (INIS)

    1975-01-01

    Apparatus for reducing convection current heat loss in electron beam evaporator is described. A material to be evaporated (evaporant) is placed in the crucible of an electron beam evaporation source along with a porous mass formed of a powdered or finely divided solid to act as an impedance to convection currents. A feed system is employed to replenish the supply of evaporant as it is vaporized

  6. Evaluation of Universitas Indonesia’s Recharge Pond Performance and Potential Utilization for Raw Water Source

    Directory of Open Access Journals (Sweden)

    Nyoman Suwartha

    2012-05-01

    Full Text Available The UI recharge pond has been constructed 5 years ago. However, monitoring and evaluation activities on its performances are very lack. Aims of this study are to understand the recharge rate, and to evaluate existing quantity and water quality of the pond during dry and rainy season. Measurement of water depth, rainfall intensity, and evaporation is conducted to determine water availability, recharge rate, and water balance of the recharge pond. Amount of surface water is collected from recharge pond and river at three sampling point to determine existing water quality of the pond. The results showed that recharge rate of the pond between dry season (3.2 mm/day and wet season (6.1 mm/day are considered as insignificant different. The water balance of the recharge pond shows an excessive rate. Various physics and chemical parameters (turbidity, color, TDS, pH, and  Cl are found to have concentration lower than the water quality standard. The results suggest that the pond surface water is remain suitable to be recharged into aquifer zone so that sustaining ground water conservation campaign, and it is potential to be utilized as an additional  raw water source for domestic water demand of UI Campus Depok.

  7. The Pond Is Our Laboratory

    Science.gov (United States)

    Marchewka, Barbara Turco

    1978-01-01

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

  8. The Salt-Gradient Solar Pond.

    Science.gov (United States)

    1983-02-01

    X rGP)**2H1*(DEFH+X1 UP)(i... X CP( *(E-’PfH+XTGP]/lo) 10851) y 1000)i(IC tZE*X~GT*0.) 109001 11110 D( I )= (,,+* IELT *PtH1 ( 2) 2/ .o+4LX ) ( I.’(Q...2.*LLX**2)( I.-(0*DRbT)/(DELX 12100 _. D *42)) +PhI()+((* iELT )/(2.*(.ELA*42) ))PHI(T-1)+(EELT/2.. -1 2 3 0 9 ... . . .... ---(1 I

  9. Solar Spots - Activities to Introduce Solar Energy into the K-8 Curricula.

    Science.gov (United States)

    Longe, Karen M.; McClelland, Michael J.

    Following an introduction to solar technology which reviews solar heating and cooling, passive solar systems (direct gain systems, thermal storage walls, sun spaces, roof ponds, and convection loops), active solar systems, solar electricity (photovoltaic and solar thermal conversion systems), wind energy, and biomass, activities to introduce solar…

  10. Evaporator Cleaning Studies

    International Nuclear Information System (INIS)

    Wilmarth, W.R.

    1999-01-01

    Operation of the 242-16H High Level Waste Evaporator proves crucial to liquid waste management in the H-Area Tank Farm. Recent operational history of the Evaporator showed significant solid formation in secondary lines and in the evaporator pot. Additional samples remain necessary to ensure material identity in the evaporator pot. Analysis of these future samples will provide actinide partitioning information and dissolution characteristics of the solid material from the pot to ensure safe chemical cleaning

  11. Evaporation and Climate Change

    NARCIS (Netherlands)

    Brandsma, T.

    1993-01-01

    In this article the influence of climate change on evaporation is discussed. The emphasis is on open water evaporation. Three methods for calculating evaporation are compared considering only changes in temperature and factors directly dependent on temperature. The Penman-method is used to

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

    Science.gov (United States)

    Steckloff, Jordan; Soderblom, Jason M.

    2017-10-01

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

  13. Sub-tropical coastal lagoon salinization associated to shrimp ponds effluents

    Science.gov (United States)

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

    2018-04-01

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

  14. Diffusion of single oxidation pond

    Directory of Open Access Journals (Sweden)

    Song Ruo-Yuan

    2016-01-01

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

  15. Par Pond vegetation status 1996

    International Nuclear Information System (INIS)

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

    1996-12-01

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

  16. 2101-M pond closure plan

    International Nuclear Information System (INIS)

    1993-06-01

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

  17. Trends in evaporation of a large subtropical lake

    Science.gov (United States)

    Hu, Cheng; Wang, Yongwei; Wang, Wei; Liu, Shoudong; Piao, Meihua; Xiao, Wei; Lee, Xuhui

    2017-07-01

    How rising temperature and changing solar radiation affect evaporation of natural water bodies remains poor understood. In this study, evaporation from Lake Taihu, a large (area 2400 km2) freshwater lake in the Yangtze River Delta, China, was simulated by the CLM4-LISSS offline lake model and estimated with pan evaporation data. Both methods were calibrated against lake evaporation measured directly with eddy covariance in 2012. Results show a significant increasing trend of annual lake evaporation from 1979 to 2013, at a rate of 29.6 mm decade-1 according to the lake model and 25.4 mm decade-1 according to the pan method. The mean annual evaporation during this period shows good agreement between these two methods (977 mm according to the model and 1007 mm according to the pan method). A stepwise linear regression reveals that downward shortwave radiation was the most significant contributor to the modeled evaporation trend, while air temperature was the most significant contributor to the pan evaporation trend. Wind speed had little impact on the modeled lake evaporation but had a negative contribution to the pan evaporation trend offsetting some of the temperature effect. Reference evaporation was not a good proxy for the lake evaporation because it was on average 20.6 % too high and its increasing trend was too large (56.5 mm decade-1).

  18. A Closer Look on Spatiotemporal Variations of Dissolved Oxygen in Waste Stabilization Ponds Using Mixed Models

    Directory of Open Access Journals (Sweden)

    Long Ho

    2018-02-01

    Full Text Available Dissolved oxygen is an essential controlling factor in the performance of facultative and maturation ponds since both take many advantages of algal photosynthetic oxygenation. The rate of this photosynthesis strongly depends on the time during the day and the location in a pond system, whose roles have been overlooked in previous guidelines of pond operation and maintenance (O&M. To elucidate these influences, a linear mixed effect model (LMM was built on the data collected from three intensive sampling campaigns in a waste stabilization pond in Cuenca, Ecuador. Within two parallel lines of facultative and maturation ponds, nine locations were sampled at two depths in each pond. In general, the output of the mixed model indicated high spatial autocorrelations of data and wide spatiotemporal variations of the oxygen level among and within the ponds. Particularly, different ponds showed different patterns of oxygen dynamics, which were associated with many factors including flow behavior, sludge accumulation, algal distribution, influent fluctuation, and pond function. Moreover, a substantial temporal change in the oxygen level between day and night, from zero to above 20 mg O2·L−1, was observed. Algal photosynthetic activity appeared to be the main reason for these variations in the model, as it was facilitated by intensive solar radiation at high altitude. Since these diurnal and spatial patterns can supply a large amount of useful information on pond performance, insightful recommendations on dissolved oxygen (DO monitoring and regulations were delivered. More importantly, as a mixed model showed high predictive performance, i.e., high goodness-of-fit (R2 of 0.94, low values of mean absolute error, we recommended this advanced statistical technique as an effective tool for dealing with high autocorrelation of data in pond systems.

  19. Blogging from North Pond

    Science.gov (United States)

    Marziali, C. G.; Edwards, K. J.

    2009-12-01

    Sea going research expeditions provide an ideal opportunity for outreach through blogs: the finite duration limits the author's commitment; scientists are usually in a remote location with fewer distractions; and fieldwork is visual and interesting to describe. Over four weeks this winter, Katrina Edwards of USC authored a blog about her deep-sea drilling expedition to North Pond, a depression in the ocean crust in the mid-Atlantic. She emailed daily dispatches and photos to USC Media Relations, which maintained a (still accessible) blog. Written for the general public, the blog quickly attracted interest from lay readers as well as from media organizations. Scientific American carried the blog on its web site, and the National Science Foundation linked to it in its "Science 360" electronic news digest. The blog also led to a Q&A with Edwards in the widely-read "Behind the Scenes" feature of LiveScience. Interest from science bloggers and National Geographic towards the end suggests that the blog could have expanded its reach given more time: expeditions lasting between six weeks and three months, such as occur during ocean drilling expeditions, would appear to be ideal candidates for a blog. Most importantly, the blog educated readers about the importance to planetary life of what Edwards calls the "intraterrestrials": the countless microbes that inhabit the oceanic crust and influence major chemical and biological cycles. Considering that the subjects of the expedition were invisible critters in a pitch-dark place, the blog shows what can be accomplished by scientists and institutions committed to public outreach.

  20. Comparative study of structural and electro-optical properties of ZnO:Ga films grown by steered cathodic arc plasma evaporation and sputtering on plastic and their application on polymer-based organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Chih-Hao, E-mail: dataman888@hotmail.com [R& D Division, Walsin Technology Corporation, Kaohsiung, Taiwan (China); Hsiao, Yu-Jen [National Nano Device Laboratories, National Applied Research Laboratories, Tainan, Taiwan (China); Hwang, Weng-Sing [Department of Materials Science and Engineering, National Cheng Kung University, Tainan, Taiwan (China)

    2016-08-01

    Ga-doped ZnO (GZO) films with various thicknesses (105–490 nm) were deposited on PET substrates at a low temperature of 90 °C by a steered cathodic arc plasma evaporation (steered CAPE), and a GZO film with a thickness of 400 nm was deposited at 90 °C by a magnetron sputtering (MS) for comparison. The comparative analysis of the microstructure, residual stress, surface morphology, electrical and optical properties, chemical states, and doping efficiency of the films produced by the steered CAPE and MS processes was performed, and the effect of thickness on the CAPE-grown GZO films was investigated in detail. The results showed that the GZO films grown by steered CAPE exhibited higher crystallinity and lower internal stress than those deposited by MS. The transmittance and electrical properties were also enhanced for the steered CAPE-grown films. The figure of merit (Φ = T{sup 10}/R{sub s}, where T is the transmittance and R{sub s} is the sheet resistance in Ω/□). was used to evaluate the performance of the electro-optical properties. The GZO films with a thickness of 400 nm deposited by CAPE had the highest Φ value, 1.94 × 10{sup −2} Ω{sup −1}, a corresponding average visible transmittance of 88.8% and resistivity of 6.29 × 10{sup −4} Ω·cm. In contrast, the Φ value of MS-deposited GZO film with a thickness of 400 nm is only 1.1 × 10{sup −3} Ω{sup −1}. This can be attributed to the increase in crystalline size, [0001] preferred orientation, decrease in stacking faults density and Ar contamination in steered CAPE-grown films, leading to increases in the Hall mobility and carrier density. In addition, the power conversion efficiency (PCE) of organic solar cells was significantly improved by using the CAPE-grown GZO electrode, and the PCE values were 1.2% and 1.7% for the devices with MS-grown and CAPE-grown GZO electrodes, respectively. - Highlights: • ZnO:Ga (GZO) films were grown on PET by steered cathodic arc plasma evaporation (CAPE

  1. Determination of Summertime VOC Emission Rates from Produced Water Ponds in the Uintah Basin

    Science.gov (United States)

    Martin, R. S.; Woods, C.; Lyman, S.

    2013-12-01

    The observance of excess ozone concentrations in Utah's Uintah Basin over past several years has prompted several investigations into the extent and causes of the elevated ozone. Among these is the assessment of potential emissions of reactive VOCs. Evaporation ponds, used a remediation technique for treatment of contaminated production and other waters, are one potential source of significant VOC emissions and is estimated that there are around 160 such ponds within the Uintah Basin's oil and gas production areas. In June 2012 VOC emission rates for several reactive VOCs were derived for an evaporation facility consisting of a small inlet pond (≈0.03 acres) and two larger, serial ponds (≈4.3 acres each). The emission rates were determined over three sampling periods using an inverse modeling approach. Under this methodology, ambient VOC concentrations are determined at several downwind locations through whole-air collection into SUMMA canisters, followed by GC/MS quantification and compared with predicted concentrations using an EPA-approved dispersion model, AERMOD. The presumed emission rates used within the model were then adjusted until the modeled concentrations approach the observed concentrations. The derived emission rates for the individual VOCs were on the order of 10-3 g/s/m2 from the inlet pond and 10-6 g/s/m2 from the larger ponds. The emissions from the 1st pond in series after the inlet pond were about 3-4x the emissions from the 2nd pond. These combined emission rates are about an order of magnitude those reported for a single study in Colorado (Thoma, 2009). It should be noted, however, that the variability about each of the VOC emission rates was significant (often ×100% at the 95% confidence interval). Extrapolating these emission rates to the estimated total areas of all the evaporation ponds within Basin resulted in calculated Basin-wide VOC emissions 292,835 tons/yr. However, Bar-Ilan et al. (2009) estimated 2012 VOC oil and gas related

  2. Operation of roof pond systems, considering its advantages and disadvantages

    Energy Technology Data Exchange (ETDEWEB)

    Noohi, Samira; Rezaei, Davood [Faculty of engineering, Zanjan University (Iran, Islamic Republic of)], email: noohi.sam@gmail.com, email: d_rezaei@znu.ac.ir

    2011-07-01

    With the coming shortage of fossil fuels it is important to develop energy efficient buildings to reduce both energy consumption and pollution at the same time. The roof pond system is a passive solar system which gathers heat from the sun and can distribute it to the living space to cool it or heat it by changing the operating cycle. Although not recent, this method has not been widely implemented due to certain limitations and the aim of this paper is to assess the different advantages and disadvantages of this system over other passive solar heating systems. This study showed that a roof pond has a low impact on the building, provides controllable energy delivery and variations in indoor temperature are low; however it requires an active solar system as a backup and vegetation can limit sunlight penetration. This study highlighted that the efficiency of the roof system pond depends on climate conditions and that it is best suited to lower latitude and low humidity areas.

  3. Thermal evolutions of two kinds of melt pond with different salinity

    Science.gov (United States)

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

    2016-04-01

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

  4. Solar-Powered Desalination: A Modelling and Experimental Study

    Science.gov (United States)

    Leblanc, Jimmy; Andrews, John

    2007-10-01

    Water shortage is becoming one of the major problems worldwide. As such, desalination technologies have been implemented to meet growing demands for fresh water. Among the desalination technologies, thermal desalination, including multi stage flash (MSF) and multi effect evaporation (MEE), is the current leading desalination process. Reverse osmosis (RO) is also being increasingly used. Despite technological improvements, thermal desalination and reverse osmosis continue to be intensive fossil-fuel consumers and contribute to increased levels of greenhouse gases. As energy costs rise, thermal desalination by solar energy and/or low cost waste heat is likely to become increasingly attractive. As part of a project investigating the productive use of saline land and the development of sustainable desalination systems, the feasibility of producing potable water from seawater or brackish water using desalination systems powered by renewable energy in the form of low-temperature solar-thermal sources has been studied. A salinity-gradient solar pond and an evacuated tube solar collector system have been used as heat sources. Solar ponds combine solar energy collection with long-term storage and can provide reliable thermal energy at temperature ranges from 50 to 90 °C. A visual basic computer model of the different multi-stage flash desalination processes coupled with a salinity-gradient solar pond was developed to determine which process is preferable in regards to performance and greenhouse impact. The governing mathematical equations are derived from mass balances, heat energy balances, and heat transfer characteristics. Using the results from the modelling, a small-scale solar-powered desalination system, capable of producing up to 500 litres of fresh water per day, was designed and manufactured. This single-stage flash system consists of two main units: the heat supply and storage system and the flash desalination unit. Two different condenser heat exchanger

  5. Crystal Structure, Optical, and Electrical Properties of SnSe and SnS Semiconductor Thin Films Prepared by Vacuum Evaporation Techniques for Solar Cell Applications

    Science.gov (United States)

    Ariswan; Sutrisno, H.; Prasetyawati, R.

    2017-05-01

    Thin films of SnSe and SnS semiconductors had been prepared by vacuum evaporation techniques. All prepared samples were characterized on their structure, optical, and electrical properties in order to know their application in technology. The crystal structure of SnSe and SnS was determined by X-Ray Diffraction (XRD) instrument. The morphology and chemical composition were obtained by Scanning Electron Microscopy (SEM) coupled with Energy Dispersive of X-Ray Analysis (EDAX). The optical property such as band gap was determined by DR-UV-Vis (Diffuse Reflectance-Ultra Violet-Visible) spectroscopy, while the electrical properties were determined by measuring the conductivity by four probes method. The characterization results indicated that both SnSe and SnS thin films were polycrystalline. SnSe crystallized in an orthorhombic crystal system with the lattice parameters of a = 11.47 Å, b = 4.152 Å and c = 4.439 Å, while SnS had an orthorhombic crystal system with lattice parameters of a = 4.317 Å, b = 11.647 Å and c = 3.981 Å. Band gaps (Eg) of SnSe and SnS were 1.63 eV and 1.35 eV, respectively. Chemical compositions of both thin films were non-stoichiometric. Molar ratio of Sn : S was close to ideal which was 1 : 0.96, while molar ratio of Sn : S was 1 : 0.84. The surface morphology described the arrangement of the grains on the surface of the thin film with sizes ranging from 0.2 to 0.5 microns. Color similarity on the surface of the SEM images proved a homogenous thin layer.

  6. Microwave heating type evaporator

    International Nuclear Information System (INIS)

    Taura, Masazumi; Nishi, Akio; Morimoto, Takashi; Izumi, Jun; Tamura, Kazuo; Morooka, Akihiko.

    1987-01-01

    Purpose: To prevent evaporization stills against corrosion due to radioactive liquid wastes. Constitution: Microwaves are supplied from a microwave generator by way of a wave guide tube and through a microwave permeation window to the inside of an evaporatization still. A matching device is attached to the wave guide tube for transmitting the microwaves in order to match the impedance. When the microwaves are supplied to the inside of the evaporization still, radioactive liquid wastes supplied from a liquid feed port by way of a spray tower to the inside of the evaporization still is heated and evaporated by the induction heating of the microwaves. (Seki, T.)

  7. Spent-fuel pool thermal hydraulics: The evaporation question

    International Nuclear Information System (INIS)

    Yilmaz, T.P.; Lai, J.C.

    1996-01-01

    Many nuclear power plants are currently using dense fuel arrangements that increase the number of spent fuel elements stored in their spent-fuel pools (SFPs). The denser spent-fuel storage results in higher water temperatures, especially when certain event scenarios are analyzed. In some of these event scenarios, it is conservative to maximize the evaporation rate, while in other circumstances it is required to minimize the evaporation rates for conservatism. Evaporation is such a fundamental phenomenon that many branches of engineering developed various equations based on theory and experiments. The evaporation rates predicted by existing equations present a wide range of variation, especially at water temperatures >40 degrees C. Furthermore, a study on which equations provide the highest and lowest evaporation rates has not been done until now. This study explores the sensitivity of existing evaporation equations to various parameters and recommends the limiting evaporation equations for use in the solution of SFP thermal problems. Note that the results of this study may be applicable to a much wider range of applications from irrigation ponds, cooling lakes, and liquid-waste management to calculating adequate air exchange rate for swimming pools and health spas

  8. 216-B-3 expansion ponds closure plan

    Energy Technology Data Exchange (ETDEWEB)

    1994-10-01

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

  9. 216-B-3 expansion ponds closure plan

    International Nuclear Information System (INIS)

    1994-10-01

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

  10. Flocculation of retention pond water

    International Nuclear Information System (INIS)

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

    1982-05-01

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

  11. Isolation of hydrolase producing bacteria from Sua pan solar ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... sp. Sua-BAC020 were studied further. Isolate Sua-BAC005 affiliated with Bacillus amyloliquefaciens secreted ... halotolerant eubacteria from Sua pan evaporator ponds in ... PCR fragments were ligated into pGEM-T Easy.

  12. Potential for natural evaporation as a reliable renewable energy resource.

    Science.gov (United States)

    Cavusoglu, Ahmet-Hamdi; Chen, Xi; Gentine, Pierre; Sahin, Ozgur

    2017-09-26

    About 50% of the solar energy absorbed at the Earth's surface drives evaporation, fueling the water cycle that affects various renewable energy resources, such as wind and hydropower. Recent advances demonstrate our nascent ability to convert evaporation energy into work, yet there is little understanding about the potential of this resource. Here we study the energy available from natural evaporation to predict the potential of this ubiquitous resource. We find that natural evaporation from open water surfaces could provide power densities comparable to current wind and solar technologies while cutting evaporative water losses by nearly half. We estimate up to 325 GW of power is potentially available in the United States. Strikingly, water's large heat capacity is sufficient to control power output by storing excess energy when demand is low, thus reducing intermittency and improving reliability. Our findings motivate the improvement of materials and devices that convert energy from evaporation.The evaporation of water represents an alternative source of renewable energy. Building on previous models of evaporation, Cavusoglu et al. show that the power available from this natural resource is comparable to wind and solar power, yet it does not suffer as much from varying weather conditions.

  13. Habitat selection by Forster's Terns (Sterna forsteri) at multiple spatial scales in an urbanized estuary: The importance of salt ponds

    Science.gov (United States)

    Bluso-Demers, Jill; Ackerman, Joshua T.; Takekawa, John Y.; Peterson, Sarah

    2016-01-01

    The highly urbanized San Francisco Bay Estuary, California, USA, is currently undergoing large-scale habitat restoration, and several thousand hectares of former salt evaporation ponds are being converted to tidal marsh. To identify potential effects of this habitat restoration on breeding waterbirds, habitat selection of radiotagged Forster's Terns (Sterna forsteri) was examined at multiple spatial scales during the pre-breeding and breeding seasons of 2005 and 2006. At each spatial scale, habitat selection ratios were calculated by season, year, and sex. Forster's Terns selected salt pond habitats at most spatial scales and demonstrated the importance of salt ponds for foraging and roosting. Salinity influenced the types of salt pond habitats that were selected. Specifically, Forster's Terns strongly selected lower salinity salt ponds (0.5–30 g/L) and generally avoided higher salinity salt ponds (≥31 g/L). Forster's Terns typically used tidal marsh and managed marsh habitats in proportion to their availability, avoided upland and tidal flat habitats, and strongly avoided open bay habitats. Salt ponds provide important habitat for breeding waterbirds, and restoration efforts to convert former salt ponds to tidal marsh may reduce the availability of preferred breeding and foraging areas.

  14. Investigations on electron beam evaporated Cu(In{sub 0.85}Ga{sub 0.15})Se{sub 2} thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Venkatachalam, M.; Kannan, M.D.; Prasanna, S.; Jayakumar, S.; Balasundaraprabhu, R. [Thin Film Center, Department of Physics, PSG College of Technology, Coimbatore (India); Muthukumarasamy, N. [Department of Physics, Coimbatore Institute of Technology, Coimbatore (India); Saroja, M. [Department of Electronics, Erode Arts College, Erode (India)

    2009-09-15

    CIGS bulk with composition of CuIn{sub 0.85}Ga{sub 0.15}Se{sub 2} was synthesized by direct reaction of elemental copper, indium, gallium and selenium. CIGS thin films were then deposited onto well-cleaned glass substrates using the prepared bulk alloy by electron beam deposition method. The structural properties of the deposited films were studied using X-ray diffraction technique. The as-deposited CIGS films were found to be amorphous. On annealing, the films crystallized with a tetragonal chalcopyrite structure. An intermediate Cu-rich phase precipitated at 200 C and dissociated at higher annealing temperatures. Average grain size calculated from the XRD spectra indicated that the films had a nano-crystalline structure and was further corroborated by AFM analysis of the sample surface. The chemical constituents present in the deposited CIGS films were identified using energy dispersive X-ray analysis. CIGS based solar cells were then fabricated on molybdenum and ITO coated glass substrates and the efficiencies have been evaluated. (author)

  15. Performance potential of low-defect density silicon thin-film solar cells obtained by electron beam evaporation and laser crystallisation

    Directory of Open Access Journals (Sweden)

    Kim K. H.

    2013-01-01

    Full Text Available A few microns thick silicon films on glass coated with a dielectric intermediate layer can be crystallised by a single pass of a line-focused diode laser beam. Under favorable process conditions relatively large linear grains with low defect density are formed. Most grain boundaries are defect-free low-energy twin-boundaries. Boron-doped laser crystallised films are processed into solar cells by diffusing an emitter from a phosphorous spin-on-dopant source, measuring up to 539 mV open-circuit voltage prior to metallisation. After applying a point-contact metallisation the best cell achieves 7.8% energy conversion efficiency, open-circuit voltage of 526 mV and short-circuit current of 26 mA/cm2. The efficiency is significantly limited by a low fill-factor of 56% due to the simplified metallisation approach. The internal quantum efficiency of laser crystallised cells is consistent with low front surface recombination. By improving cell metallisation and enhancing light-trapping the efficiencies of above 13% can be achieved.

  16. Evaporation, Boiling and Bubbles

    Science.gov (United States)

    Goodwin, Alan

    2012-01-01

    Evaporation and boiling are both terms applied to the change of a liquid to the vapour/gaseous state. This article argues that it is the formation of bubbles of vapour within the liquid that most clearly differentiates boiling from evaporation although only a minority of chemistry textbooks seems to mention bubble formation in this context. The…

  17. A breeding site model for regional, dynamical malaria simulations evaluated using in situ temporary ponds observations

    Directory of Open Access Journals (Sweden)

    Ernest O. Asare

    2016-03-01

    Full Text Available Daily observations of potential mosquito developmental habitats in a suburb of Kumasi in central Ghana reveal a strong variability in their water persistence times, which ranged between 11 and 81 days. The persistence of the ponds was strongly tied with rainfall, location and size of the puddles. A simple power-law relationship is found to fit the relationship between the average pond depth and area well. A prognostic water balance model is derived that describes the temporal evolution of the pond area and depth, incorporating the power-law geometrical relation. Pond area increases in response to rainfall, while evaporation and infiltration act as sink terms. Based on a range of evaluation metrics, the prognostic model is judged to provide a good representation of the pond coverage evolution at most sites. Finally, we demonstrate that the prognostic equation can be generalised and equally applied to a grid-cell to derive a fractional pond coverage, and thus can be implemented in spatially distributed models for relevant vector- borne diseases such as malaria.

  18. A breeding site model for regional, dynamical malaria simulations evaluated using in situ temporary ponds observations.

    Science.gov (United States)

    Asare, Ernest O; Tompkins, Adrian M; Amekudzi, Leonard K; Ermert, Volker

    2016-03-31

    Daily observations of potential mosquito developmental habitats in a suburb of Kumasi in central Ghana reveal a strong variability in their water persistence times, which ranged between 11 and 81 days. The persistence of the ponds was strongly tied with rainfall, location and size of the puddles. A simple power-law relationship is found to fit the relationship between the average pond depth and area well. A prognostic water balance model is derived that describes the temporal evolution of the pond area and depth, incorporating the power-law geometrical relation. Pond area increases in response to rainfall, while evaporation and infiltration act as sink terms. Based on a range of evaluation metrics, the prognostic model is judged to provide a good representation of the pond coverage evolution at most sites. Finally, we demonstrate that the prognostic equation can be generalised and equally applied to a grid-cell to derive a fractional pond coverage, and thus can be implemented in spatially distributed models for relevant vector- borne diseases such as malaria.

  19. Olive mill wastewater stabilization in open-air ponds: impact on clay-sandy soil.

    Science.gov (United States)

    Jarboui, Raja; Sellami, Fatma; Kharroubi, Adel; Gharsallah, Néji; Ammar, Emna

    2008-11-01

    The aim of this work was to study the natural biodegradation of the stored olive mill wastewater (OMW) in ponds and the infiltration as well as the impact on soil of the effluent in the evaporation pond used for the storage over the past eight years. For this, two approaches were considered. First, a laboratory-scale column was used for the infiltration of OMW through soil (clay and sand) to predict the effect of the clayey soil in reducing OMW pollution. Second, the ponds including the effluent annually stored and having this clayey structure were investigated. At the laboratory-scale, a modification of OMW contents was noticed, with the elimination of 95% of total suspended solids (TSS), 60% of chemical oxygen demand (COD), 40% of total organic carbon (TOC), 50% of total P, 50% of phenols and 40% of minerals (K+, Mg++ and Na+). The experimented soil was able to restrain the considerable effects of OMW pollution. In the ponds, the granulometric characteristics, the physico-chemical and the biological parameters of the soil profile from the contaminated pond were compared to those of a control soil, located near the contaminated pond. Property modifications of the contaminated soil were noted, especially pH, electrical conductivity, COD and microflora. These changes can be explained by the infiltration of OMW constituents, which were noticed in the soil layers, especially phenolic compounds that have a negative effect on the ground water.

  20. Par Pond Fish, Water, and Sediment Chemistry

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-06-01

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

  1. Par Pond Fish, Water, and Sediment Chemistry

    International Nuclear Information System (INIS)

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

    1996-06-01

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

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

    Science.gov (United States)

    Clark, Benton C; Kolb, Vera M

    2018-05-11

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

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

    Directory of Open Access Journals (Sweden)

    Benton C. Clark

    2018-05-01

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

  4. Liner used in tailings ponds

    International Nuclear Information System (INIS)

    Dinchak, W.G.

    1984-01-01

    A composite liner has been developed for use in hazardous waste impoundments and in tailings ponds where uranium is involved. The liner offers a high degree of reliability against seepage, is durable, and provides a firm working surface. The advantages of the liner are discussed

  5. Water withdrawal for brackish and inland aquaculture, and options to produce more fish in ponds with present water use

    NARCIS (Netherlands)

    Verdegem, M.C.J.; Bosma, R.H.

    2009-01-01

    This paper reviews freshwater use in inland and coastal pond aquaculture, and focuses on options to increase productivity while reducing water use. Total freshwater use depends on system-associated and feed-associated water losses. System-associated water losses depend on total area, evaporation,

  6. Metagenomic Sequence of Prokaryotic Microbiota from an Intermediate-Salinity Pond of a Saltern in Isla Cristina, Spain

    OpenAIRE

    Fernández, Ana B.; León, María José; Vera, Blanca; Sánchez-Porro, Cristina; Ventosa, Antonio

    2014-01-01

    Marine salterns are artificial multipond systems designed for the commercial production of salt by evaporation of seawater. We report here the metagenomic sequence of the prokaryotic microbiota of a pond with intermediate salinity (21% total salts) of a saltern located in Isla Cristina, Huelva, southwest Spain.

  7. Metagenomic sequence of prokaryotic microbiota from an intermediate-salinity pond of a saltern in isla cristina, Spain.

    Science.gov (United States)

    Fernández, Ana B; León, María José; Vera, Blanca; Sánchez-Porro, Cristina; Ventosa, Antonio

    2014-02-13

    Marine salterns are artificial multipond systems designed for the commercial production of salt by evaporation of seawater. We report here the metagenomic sequence of the prokaryotic microbiota of a pond with intermediate salinity (21% total salts) of a saltern located in Isla Cristina, Huelva, southwest Spain.

  8. Vacuum evaporation of pure metals

    OpenAIRE

    Safarian, Jafar; Engh, Thorvald Abel

    2013-01-01

    Theories on the evaporation of pure substances are reviewed and applied to study vacuum evaporation of pure metals. It is shown that there is good agreement between different theories for weak evaporation, whereas there are differences under intensive evaporation conditions. For weak evaporation, the evaporation coefficient in Hertz-Knudsen equation is 1.66. Vapor velocity as a function of the pressure is calculated applying several theories. If a condensing surface is less than one collision...

  9. Evaporation in hydrology and meteorology

    OpenAIRE

    Brandsma, T.

    1990-01-01

    In this paper the role of evaporation in hydrology and meteorology is discussed, with the emphasis on hydrology. The basic theory of evaporation is given and methods to determine evaporation are presented. Some applications of evaporation studies in literature are given in order to illustrate the theory. Further, special conditions in evaporation are considered, followed by a fotmulation of the difficulties in determining evaporation, The last part of the paper gives a short discussion about ...

  10. Evaporation under vacuum condition

    International Nuclear Information System (INIS)

    Mizuta, Satoshi; Shibata, Yuki; Yuki, Kazuhisa; Hashizume, Hidetoshi; Toda, Saburo; Takase, Kazuyuki; Akimoto, Hajime

    2000-01-01

    In nuclear fusion reactor design, an event of water coolant ingress into its vacuum vessel is now being considered as one of the most probable accidents. In this report, the evaporation under vacuum condition is evaluated by using the evaporation model we have developed. The results show that shock-wave by the evaporation occurs whose behavior strongly depends on the initial conditions of vacuum. And in the case of lower initial pressure and temperature, the surface temp finally becomes higher than other conditions. (author)

  11. CAPSULE REPORT: EVAPORATION PROCESS

    Science.gov (United States)

    Evaporation has been an established technology in the metal finishing industry for many years. In this process, wastewaters containing reusable materials, such as copper, nickel, or chromium compounds are heated, producing a water vapor that is continuously removed and condensed....

  12. Spectroscopic characterization of uranium in evaporation basin sediments

    Science.gov (United States)

    Duff, M. C.; Morris, D. E.; Hunter, D. B.; Bertsch, P. M.

    2000-05-01

    Evaporation ponds in the San Joaquin Valley (SJV), CA, used for the containment of irrigation drainage waters contain elevated levels of uranium (U) resulting from the extensive leaching by carbonate-rich irrigation waters of the local agricultural soils that contain low levels of naturally-occurring U. The SJV ponds are subjected to changes in redox chemistry with cycles of drying and flooding. Our past studies have shown that U in the SJV Pond 14 surface sediments is present as mostly the oxidized and soluble form, U(VI). However, we were uncertain whether the U in the soil was only present as a U oxide of mixed stoichiometry, such as U 3O 8(s) (pitchblende) or other species. Here we present characterization information, which includes wet chemical and in situ spectroscopic techniques (X-ray absorption near-edge structure (XANES) and low temperature time-resolved luminescence spectroscopies) for samples from two SJV Pond sediments. Surface sediments from SJV Pond 16 were characterized for average oxidation state of U with XANES spectroscopy. The fraction of U(VI) to U(IV) in the Pond 16 sediments decreased with depth with U(IV) being the dominant oxidation state in the 5 cm to 15 cm depth. Two luminescent U(VI) species were identified in the surface sediments from Pond 14; a U(VI)-tricarbonate phase and another phase likely comprised of U(VI)-hydroxide or hydroxycarbonate. The luminescent U(VI) population in the Pond 16 sediments is dominated by species with comparable spectral characteristics to the U(VI)-hydroxide or hydroxycarbonate species found in the Pond 14 sediments. The luminescence spectroscopic results were complemented by wet chemical U leaching methods, which involved the use of carbonate and sulfuric acid solutions and oxidizing solutions of peroxide, hypochlorite and Mn(IV). Leaching was shown to decrease the total U concentration in the sediments in all cases. However, results from luminescence studies of the residual fraction in the leached

  13. Unintended consequences of management actions in salt pond restoration: cascading effects in trophic interactions.

    Directory of Open Access Journals (Sweden)

    John Y Takekawa

    Full Text Available Salt evaporation ponds have played an important role as habitat for migratory waterbirds across the world, however, efforts to restore and manage these habitats to maximize their conservation value has proven to be challenging. For example, salinity reduction has been a goal for restoring and managing former salt evaporation ponds to support waterbirds in the South Bay Salt Pond Restoration Project in San Francisco Bay, California, USA. Here, we describe a case study of unexpected consequences of a low-dissolved oxygen (DO event on trophic interactions in a salt pond system following management actions to reduce salinity concentrations. We document the ramifications of an anoxic event in water quality including salinity, DO, and temperature, and in the response of the biota including prey fish biomass, numerical response by California Gulls (Larus californicus, and chick survival of Forster's Tern (Sterna forsteri. Management actions intended to protect receiving waters resulted in decreased DO concentrations that collapsed to zero for ≥ 4 consecutive days, resulting in an extensive fish kill. DO depletion likely resulted from an algal bloom that arose following transition of the pond system from high to low salinity as respiration and decomposition outpaced photosynthetic production. We measured a ≥ 6-fold increase in biomass of fish dropped on the levee by foraging avian predators compared with weeks prior to and following the low-DO event. California Gulls rapidly responded to the availability of aerobically-stressed and vulnerable fish and increased in abundance by two orders of magnitude. Mark-recapture analysis of 254 Forster's Tern chicks indicated that their survival declined substantially following the increase in gull abundance. Thus, management actions to reduce salinity concentrations resulted in cascading effects in trophic interactions that serves as a cautionary tale illustrating the importance of understanding the interaction

  14. Unintended consequences of management actions in salt pond restoration: cascading effects in trophic interactions

    Science.gov (United States)

    Takekawa, John Y.; Ackerman, Joshua T.; Brand, Arriana; Graham, Tanya R.; Eagles-Smith, Collin A.; Herzog, Mark; Topping, Brent R.; Shellenbarger, Gregory; Kuwabara, James S.; Mruz, Eric; Piotter, Sara L.; Athearn, Nicole D.

    2015-01-01

    Salt evaporation ponds have played an important role as habitat for migratory waterbirds across the world, however, efforts to restore and manage these habitats to maximize their conservation value has proven to be challenging. For example, salinity reduction has been a goal for restoring and managing former salt evaporation ponds to support waterbirds in the South Bay Salt Pond Restoration Project in San Francisco Bay, California, USA. Here, we describe a case study of unexpected consequences of a low-dissolved oxygen (DO) event on trophic interactions in a salt pond system following management actions to reduce salinity concentrations. We document the ramifications of an anoxic event in water quality including salinity, DO, and temperature, and in the response of the biota including prey fish biomass, numerical response by California Gulls (Larus californicus), and chick survival of Forster's Tern (Sterna forsteri). Management actions intended to protect receiving waters resulted in decreased DO concentrations that collapsed to zero for ≥ 4 consecutive days, resulting in an extensive fish kill. DO depletion likely resulted from an algal bloom that arose following transition of the pond system from high to low salinity as respiration and decomposition outpaced photosynthetic production. We measured a ≥ 6-fold increase in biomass of fish dropped on the levee by foraging avian predators compared with weeks prior to and following the low-DO event. California Gulls rapidly responded to the availability of aerobically-stressed and vulnerable fish and increased in abundance by two orders of magnitude. Mark-recapture analysis of 254 Forster's Tern chicks indicated that their survival declined substantially following the increase in gull abundance. Thus, management actions to reduce salinity concentrations resulted in cascading effects in trophic interactions that serves as a cautionary tale illustrating the importance of understanding the interaction of water quality

  15. Unintended consequences of management actions in salt pond restoration: cascading effects in trophic interactions.

    Science.gov (United States)

    Takekawa, John Y; Ackerman, Joshua T; Brand, L Arriana; Graham, Tanya R; Eagles-Smith, Collin A; Herzog, Mark P; Topping, Brent R; Shellenbarger, Gregory G; Kuwabara, James S; Mruz, Eric; Piotter, Sara L; Athearn, Nicole D

    2015-01-01

    Salt evaporation ponds have played an important role as habitat for migratory waterbirds across the world, however, efforts to restore and manage these habitats to maximize their conservation value has proven to be challenging. For example, salinity reduction has been a goal for restoring and managing former salt evaporation ponds to support waterbirds in the South Bay Salt Pond Restoration Project in San Francisco Bay, California, USA. Here, we describe a case study of unexpected consequences of a low-dissolved oxygen (DO) event on trophic interactions in a salt pond system following management actions to reduce salinity concentrations. We document the ramifications of an anoxic event in water quality including salinity, DO, and temperature, and in the response of the biota including prey fish biomass, numerical response by California Gulls (Larus californicus), and chick survival of Forster's Tern (Sterna forsteri). Management actions intended to protect receiving waters resulted in decreased DO concentrations that collapsed to zero for ≥ 4 consecutive days, resulting in an extensive fish kill. DO depletion likely resulted from an algal bloom that arose following transition of the pond system from high to low salinity as respiration and decomposition outpaced photosynthetic production. We measured a ≥ 6-fold increase in biomass of fish dropped on the levee by foraging avian predators compared with weeks prior to and following the low-DO event. California Gulls rapidly responded to the availability of aerobically-stressed and vulnerable fish and increased in abundance by two orders of magnitude. Mark-recapture analysis of 254 Forster's Tern chicks indicated that their survival declined substantially following the increase in gull abundance. Thus, management actions to reduce salinity concentrations resulted in cascading effects in trophic interactions that serves as a cautionary tale illustrating the importance of understanding the interaction of water quality

  16. Boilers, evaporators, and condensers

    International Nuclear Information System (INIS)

    Kakac, S.

    1991-01-01

    This book reports on the boilers, evaporators and condensers that are used in power plants including nuclear power plants. Topics included are forced convection for single-phase side heat exchangers, heat exchanger fouling, industrial heat exchanger design, fossil-fuel-fired boilers, once through boilers, thermodynamic designs of fossil fuel-first boilers, evaporators and condensers in refrigeration and air conditioning systems (with respect to reducing CFC's) and nuclear steam generators

  17. 40 CFR 721.8675 - Halogenated pyridines.

    Science.gov (United States)

    2010-07-01

    ... treatment will occur, or treatment in a lined, self-contained solar evaporation pond where UV light will... tertiary waste treatment will occur, or treatment in a lined, self-contained solar evaporation pond where...

  18. Closure report for CAU 93: Area 6 steam cleaning effluent ponds, Nevada Test Site. Volume 2

    International Nuclear Information System (INIS)

    1997-11-01

    The Steam Cleaning Effluent Ponds (SCEP) waste unit is located in Area 6 at the Nevada Test Site. The SCEPs are evaporation basins formerly used for the disposal of untreated liquid effluent discharged from steam cleaning activities associated with Buildings 6-623 and 6-800. This report contains Appendix B which provides all of the laboratory summary data sheets for the Area 6 SCEPs closure activities

  19. Closure report for CAU 93: Area 6 steam cleaning effluent ponds, Nevada Test Site. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-01

    The Steam Cleaning Effluent Ponds (SCEP) waste unit is located in Area 6 at the Nevada Test Site. The SCEPs are evaporation basins formerly used for the disposal of untreated liquid effluent discharged from steam cleaning activities associated with Buildings 6-623 and 6-800. This report contains Appendix B which provides all of the laboratory summary data sheets for the Area 6 SCEPs closure activities.

  20. Wastewater reuse in central Asia: implications for the design of pond systems

    OpenAIRE

    Heaven, S.; Banks, C.J.; Pak, L.N.; Rspaev, M.K.

    2007-01-01

    The paper examines the potential of waste stabilisation ponds to provide water for reuse in extreme continental climates such as those of central Asia, where precipitation is low and summer evaporation rates are high. A simple model is used to predict water availability, BOD and faecal coliform removal for different configurations and operating regimes. The results show a significant proportion of flows could be saved for irrigation or river and aquifer replenishment: if current standard desi...

  1. Managed flood effects on beaver pond habitat in a desert riverine ecosystem, bill williams river, Arizona USA

    Science.gov (United States)

    Andersen, D.C.; Shafroth, P.B.; Pritekel, C.M.; O'Neill, M. W.

    2011-01-01

    The ecological effects of beaver in warm-desert streams are poorly documented, but potentially significant. For example, stream water and sediment budgets may be affected by increased evaporative losses and sediment retention in beaver ponds. We measured physical attributes of beaver pond and adjacent lotic habitats on a regulated Sonoran Desert stream, the Bill Williams River, after ???11 flood-free months in Spring 2007 and Spring 2008. Neither a predicted warming of surface water as it passed through a pond nor a reduction in dissolved oxygen in ponds was consistently observed, but bed sediment sorted to finest in ponds as expected. We observed a river segment-scale downstream rise in daily minimum stream temperature that may have been influenced by the series of ??100 beaver ponds present. Channel cross-sections surveyed before and after an experimental flood (peak flow 65 m3/s) showed net aggradation on nine of 13 cross-sections through ponds and three of seven through lotic reaches. Our results indicate that beaver affect riverine processes in warm deserts much as they do in other biomes. However, effects may be magnified in deserts through the potential for beaver to alter the stream thermal regime and water budget. ?? Society of Wetland Scientists 2011.

  2. The Ruminant and the Pond

    OpenAIRE

    Lajarin-Encina, Aitor

    2015-01-01

    The Ruminant and the Pond presents a group of paintings and a film that explore contemporary psycho-social conditions through fictional narratives. Paintings and film explore territories of thinking and emotion engaging the audience in subjective digressions related to ideas of artificiality, relativeness, absurdity, futility or alienation in relation to intersubjective reality perception, production and representation. At the same time the project delves in the specific relationship existin...

  3. Evaporation in hydrology and meteorology

    NARCIS (Netherlands)

    Brandsma, T.

    1990-01-01

    In this paper the role of evaporation in hydrology and meteorology is discussed, with the emphasis on hydrology. The basic theory of evaporation is given and methods to determine evaporation are presented. Some applications of evaporation studies in literature are given in order to illustrate the

  4. Evaluation of the correlations for predicting evaporative loss from water body

    International Nuclear Information System (INIS)

    Yilmaz, T.P.; Aybar, H.S.

    1999-01-01

    Water evaporation (evaporation from here on) is a natural phenomenon that is important for system design and system safety in many engineering branches. Indeed, evaporative heat and mass loss are observed and calculated in very diverse situations, such as irrigation plants, water purification plants, cooling ponds, lakes, dams, swimming pools, health spas, management of liquid wastes as in evaporation pools, and spent fuel pools in nuclear power plants. There are a number of correlations obtained from experimental studies that predict the evaporative heat and mass loss from a water body. This study aims to summarize and to compare the existing evaporation correlations to determine the upper and lower bounding correlations for use in various thermal-hydraulic analyses of systems. Currently and widely used, six correlations found in the literature have been selected and tested using the major parameters of evaporation such as water temperature, air relative humidity, air velocity, and temperature. The comparison test cases show that ASHRAE (1991) and Ryan et al. (1974) equations result in the highest evaporative loss, while the Brady et al. (1969) equation provides the lowest evaporative loss in most conditions. Engineering designers may sometimes need the upper bound value of evaporative loss or sometimes the lower bound value for a conservative calculation. The authors conclude that using a single equation does not provide the conservative calculation for every situation and show which correlation gives the lower or upper bound for different conditions

  5. Optimized evaporation technique for leachate treatment: Small scale implementation.

    Science.gov (United States)

    Benyoucef, Fatima; Makan, Abdelhadi; El Ghmari, Abderrahman; Ouatmane, Aziz

    2016-04-01

    This paper introduces an optimized evaporation technique for leachate treatment. For this purpose and in order to study the feasibility and measure the effectiveness of the forced evaporation, three cuboidal steel tubs were designed and implemented. The first control-tub was installed at the ground level to monitor natural evaporation. Similarly, the second and the third tub, models under investigation, were installed respectively at the ground level (equipped-tub 1) and out of the ground level (equipped-tub 2), and provided with special equipment to accelerate the evaporation process. The obtained results showed that the evaporation rate at the equipped-tubs was much accelerated with respect to the control-tub. It was accelerated five times in the winter period, where the evaporation rate was increased from a value of 0.37 mm/day to reach a value of 1.50 mm/day. In the summer period, the evaporation rate was accelerated more than three times and it increased from a value of 3.06 mm/day to reach a value of 10.25 mm/day. Overall, the optimized evaporation technique can be applied effectively either under electric or solar energy supply, and will accelerate the evaporation rate from three to five times whatever the season temperature. Copyright © 2016. Published by Elsevier Ltd.

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

    Science.gov (United States)

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

    2013-12-01

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

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

    Data.gov (United States)

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

  8. South Bay Salt Pond Tidal Marsh Restoration at Pond A17 Project

    Science.gov (United States)

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

  9. 40 CFR 721.8775 - Substituted pyridines.

    Science.gov (United States)

    2010-07-01

    ... tertiary waste treatment will occur, or treatment in a lined, self-contained solar evaporation pond where...-contained solar evaporation pond where UV light will degrade the substance, the number of kilograms per day... a lined, self-contained solar evaporation pond where UV light will degrade the substance, the number...

  10. Modeling black hole evaporation

    CERN Document Server

    Fabbri, Alessandro

    2005-01-01

    The scope of this book is two-fold: the first part gives a fully detailed and pedagogical presentation of the Hawking effect and its physical implications, and the second discusses the backreaction problem, especially in connection with exactly solvable semiclassical models that describe analytically the black hole evaporation process. The book aims to establish a link between the general relativistic viewpoint on black hole evaporation and the new CFT-type approaches to the subject. The detailed discussion on backreaction effects is also extremely valuable.

  11. Systematics of evaporation

    International Nuclear Information System (INIS)

    Klots, C.E.

    1991-01-01

    Beginning with rather basic principles, general relations are obtained for evaporative rate constants. These are established both as a function of energy and of temperature. In parallel with this, expressions are developed for the kinetic energy distribution of the separating species. Explicit evaluation of the rate constants in the case of 'chemical' evaporation from an entity containing n monomeric units yields as a typical result k(T)(s -1 )=3.10 13 n 2/3 exp[6/n 1/3 ]exp(-ΔE a (n)/k B T). Experimental evidence in support of this relation is cited. Applications to thermionic emission are also noted. (orig.)

  12. Proposed Casey's Pond Improvement Project, Fermi National Accelerator Laboratory

    International Nuclear Information System (INIS)

    1995-05-01

    The U.S. Department of Energy (DOE) has prepared an Environmental Assessment (EA), evaluating the impacts associated with the proposed Casey's Pond Improvement Project at the Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois. The improvement project would maximize the efficiency of the Fermilab Industrial Cooling Water (ICW) distribution system, which removes (via evaporation) the thermal load from experimental and other support equipment supporting the high energy physics program at Fermilab. The project would eliminate the risk of overheating during fixed target experiments, ensure that the Illinois Water Quality Standards are consistently achieved and provide needed additional water storage for fire protection. Based on the analysis in the EA, the DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an Environmental Impact Statement is not required

  13. Performance of evaporative condensers

    Energy Technology Data Exchange (ETDEWEB)

    Ettouney, Hisham M.; El-Dessouky, Hisham T.; Bouhamra, Walid; Al-Azmi, Bader

    2001-07-01

    Experimental investigation is conducted to study the performance of evaporative condensers/coolers. The analysis includes development of correlations for the external heat transfer coefficient and the system efficiency. The evaporative condenser includes two finned-tube heat exchangers. The system is designed to allow for operation of a single condenser, two condensers in parallel, and two condensers in series. The analysis is performed as a function of the water-to-air mass flow rate ratio (L/G) and the steam temperature. Also, comparison is made between the performance of the evaporative condenser and same device as an air-cooled condenser. Analysis of the collected data shows that the system efficiency increases at lower L/G ratios and higher steam temperatures. The system efficiency for various configurations for the evaporative condenser varies between 97% and 99%. Lower efficiencies are obtained for the air-cooled condenser, with values between 88% and 92%. The highest efficiency is found for the two condensers in series, followed by two condensers in parallel and then the single condenser. The parallel condenser configuration can handle a larger amount of inlet steam and can provide the required system efficiency and degree of subcooling. The correlation for the system efficiency gives a simple tool for preliminary system design. The correlation developed for the external heat transfer coefficient is found to be consistent with the available literature data. (Author)

  14. Forest evaporation models: Relationships between stand growth and evaporation

    CSIR Research Space (South Africa)

    Le Maitre, David C

    1997-06-01

    Full Text Available The relationships between forest stand structure, growth and evaporation were analysed to determine whether forest evaporation can be estimated from stand growth data. This approach permits rapid assessment of the potential impacts of afforestation...

  15. Solar engineering 1994

    International Nuclear Information System (INIS)

    Klett, D.E.; Hogan, R.E.; Tanaka, Tadayoshi

    1994-01-01

    This volume of 83 papers constitutes the Proceedings of the 1994 International Solar Energy Conference held March 27--30, 1994 in San Francisco, California. The Conference was jointly sponsored by the Solar Energy Division of the American Society of Mechanical Engineers, The Japan Society of Mechanical Engineers and the Japan Solar Energy Society. This is the fourth cooperation between ASME, JSME and JSES in cosponsoring the International Solar Energy Conference. The papers cover a wide range of solar technologies from low temperature solar ponds and desalinization to high temperature concentrators for space applications and central receivers for terrestrial power generation. Other topics covered include solar detoxification of hazardous waste, dish Stirling systems, solar cooling, photovoltaics, building energy analysis and conservation, simulation, and testing and measurement techniques. All papers were indexed separately for the data base

  16. 100-D Ponds closure plan. Revision 1

    International Nuclear Information System (INIS)

    Petersen, S.W.

    1997-09-01

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

  17. Aquatic studies of Gable Mountain Pond

    International Nuclear Information System (INIS)

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

    1974-12-01

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

  18. Par Pond vegetation status Summer 1995 -- Summary

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  19. Organic matter decomposition in simulated aquaculture ponds

    NARCIS (Netherlands)

    Torres Beristain, B.

    2005-01-01

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

  20. Pond of Illusion: Interacting through Mixed Reality

    DEFF Research Database (Denmark)

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

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Raymond D Semlitsch

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

  2. Convection-enhanced water evaporation

    OpenAIRE

    B. M. Weon; J. H. Je; C. Poulard

    2011-01-01

    Water vapor is lighter than air; this can enhance water evaporation by triggering vapor convection but there is little evidence. We directly visualize evaporation of nanoliter (2 to 700 nL) water droplets resting on silicon wafer in calm air using a high-resolution dual X-ray imaging method. Temporal evolutions of contact radius and contact angle reveal that evaporation rate linearly changes with surface area, indicating convective (instead of diffusive) evaporation in nanoliter water droplet...

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

    International Nuclear Information System (INIS)

    Osmanlioglu, A.E.

    2002-01-01

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

  4. Dietary flexibility in three representative waterbirds across salinity and depth gradients in salt ponds of San Francisco Bay

    Science.gov (United States)

    Takekawa, John Y.; Miles, A.K.; Tsao-Melcer, D. C.; Schoellhamer, D.H.; Fregien, S.; Athearn, N.D.

    2009-01-01

    Salt evaporation ponds have existed in San Francisco Bay, California, for more than a century. In the past decade, most of the salt ponds have been retired from production and purchased for resource conservation with a focus on tidal marsh restoration. However, large numbers of waterbirds are found in salt ponds, especially during migration and wintering periods. The value of these hypersaline wetlands for waterbirds is not well understood, including how different avian foraging guilds use invertebrate prey resources at different salinities and depths. The aim of this study was to investigate the dietary flexibility of waterbirds by examining the population number and diet of three feeding guilds across a salinity and depth gradient in former salt ponds of the Napa-Sonoma Marshes. Although total invertebrate biomass and species richness were greater in low than high salinity salt ponds, waterbirds fed in ponds that ranged from low (20 g l-1) to very high salinities (250 g l -1). American avocets (surface sweeper) foraged in shallow areas at pond edges and consumed a wide range of prey types (8) including seeds at low salinity, but preferred brine flies at mid salinity (40-80 g l-1). Western sandpipers (prober) focused on exposed edges and shoal habitats and consumed only a few prey types (2-4) at both low and mid salinities. Suitable depths for foraging were greatest for ruddy ducks (diving benthivore) that consumed a wide variety of invertebrate taxa (5) at low salinity, but focused on fewer prey (3) at mid salinity. We found few brine shrimp, common in higher salinity waters, in the digestive tracts of any of these species. Dietary flexibility allows different guilds to use ponds across a range of salinities, but their foraging extent is limited by available water depths. ?? 2009 USGS, US Government.

  5. CO₂ efflux from shrimp ponds in Indonesia.

    Science.gov (United States)

    Sidik, Frida; Lovelock, Catherine E

    2013-01-01

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

  6. CO₂ efflux from shrimp ponds in Indonesia.

    Directory of Open Access Journals (Sweden)

    Frida Sidik

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

  7. Waste Stabilization Ponds and Aerated Lagoons Performance in Removal of Wastewater Indicator Microorganisms

    Directory of Open Access Journals (Sweden)

    Seyed ali Ghasemi

    2013-08-01

    Full Text Available In this work, the performance of two treatment plants in the City of Mashhad, one with an aerated lagoons system and the other one with waste stabilization ponds system were evaluated in regard to their efficiency in reduction of pathogenic microorganisms. For this purpose, over a period of one year (with 15-days intervals, samples were taken from the influent and effluent (prior to disinfection unit of the above mentioned treatment plants. The samples then were analyzed for parameters such as temperature, pH, density of total coliforms (TC and fecal coliforms (FC, dissolved oxygen and total suspended solids concentration. The results indicated that the aerated lagoons system was much more efficient in removal of indicator bacteria than the waste stabilization ponds during autumn and winter periods. However during the summer months, the waste stabilization ponds showed a higher efficiency in this regard. In general, the waste stabilization ponds system reduced the density of TC and FC by 0.21-2.15 log10 and 0.20-2.33 log10, respectively. In contrast, the levels of reduction in aerated lagoons system were in the range of 0.29-2.03 log10 for TC and 0.42-2.40 log10 for FC. Results indicated that solar intensity, pH and dissolved oxygen concentration were found to be the most significant parameters that reduced the microorganisms population in waste stabilization ponds, While, in the aerated lagoons system, the dissolved oxygen concentration in aerated basin and solar intensity play the most important role. In general, without receiving an adequate disinfection, the effluent from waste stabilization ponds and aerated lagoons cannot provide the microbiological standards required for irrigation of agricultural crops.

  8. ANL-W 779 pond seepage test

    International Nuclear Information System (INIS)

    Braun, D.R.

    1992-11-01

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

  9. 100-D Ponds groundwater quality assessment

    International Nuclear Information System (INIS)

    Hartman, M.J.

    1996-01-01

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

  10. WWER-type NPP spray ponds screen

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  11. An automatic energy-saving and thermal monitoring/controlling system for a pond

    Directory of Open Access Journals (Sweden)

    Cheng Ching-Chien

    2017-01-01

    Full Text Available Because of low temperatures and oxygen in cold water, fish will die when cold currents arrive. This will cause tremendous loss of money. In order reduce the cooling of the pond, an automatic thermal detecting and cold-roofing system using a wind-proofing device, heaters, and thermal detectors is proposed. To reduce heat loss due to thermal convection above the pond surface, a motor-driven wind-proofing device automatically controlled by a PLC controller is adopted. Here, the wind-proofing device, thermal detectors, and heating system are connected to the PLC controller. The PLC will also be connected to the PC interface. The temperature thresholds used to trigger the heater and the wind proofing device can be set at the PC interface. Two options for manipulating the heating and the automatic heating can be selected. The related wind-proofing area and the number of heaters will be determined according to the current temperature. Moreover, the PLC can be wirelessly connected to the server PC in the control room. The pond keeper can monitor everything online and control the pond water's temperature. With this, the problem of fish dying in a cold wave can be solved. Consequently, to reduce the electrical exhaust when heating up the pond water, green energy, solar energy and wind energy, is used.

  12. Percolation blockage: A process that enables melt pond formation on first year Arctic sea ice

    Science.gov (United States)

    Polashenski, Chris; Golden, Kenneth M.; Perovich, Donald K.; Skyllingstad, Eric; Arnsten, Alexandra; Stwertka, Carolyn; Wright, Nicholas

    2017-01-01

    Melt pond formation atop Arctic sea ice is a primary control of shortwave energy balance in the Arctic Ocean. During late spring and summer, the ponds determine sea ice albedo and how much solar radiation is transmitted into the upper ocean through the sea ice. The initial formation of ponds requires that melt water be retained above sea level on the ice surface. Both theory and observations, however, show that first year sea ice is so highly porous prior to the formation of melt ponds that multiday retention of water above hydraulic equilibrium should not be possible. Here we present results of percolation experiments that identify and directly demonstrate a mechanism allowing melt pond formation. The infiltration of fresh water into the pore structure of sea ice is responsible for blocking percolation pathways with ice, sealing the ice against water percolation, and allowing water to pool above sea level. We demonstrate that this mechanism is dependent on fresh water availability, known to be predominantly from snowmelt, and ice temperature at melt onset. We argue that the blockage process has the potential to exert significant control over interannual variability in ice albedo. Finally, we suggest that incorporating the mechanism into models would enhance their physical realism. Full treatment would be complex. We provide a simple temperature threshold-based scheme that may be used to incorporate percolation blockage behavior into existing model frameworks.

  13. Modeling Nitrogen Decrease in Water Lettuce Ponds from Waste Stabilization Ponds

    Science.gov (United States)

    Putri, Gitta Agnes; Sunarsih

    2018-02-01

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

  14. Miniature electron bombardment evaporation source: evaporation rate measurement

    International Nuclear Information System (INIS)

    Nehasil, V.; Masek, K.; Matolin, V.; Moreau, O.

    1997-01-01

    Miniature electron beam evaporation sources which operate on the principle of vaporization of source material, in the form of a tip, by electron bombardment are produced by several companies specialized in UHV equipment. These sources are used primarily for materials that are normally difficult to deposit due to their high evaporation temperature. They are appropriate for special applications such as heteroepitaxial thin film growth requiring a very low and well controlled deposition rate. A simple and easily applicable method of evaporation rate control is proposed. The method is based on the measurement of ion current produced by electron bombardment of evaporated atoms. The absolute evaporation flux values were measured by means of the Bayard-Alpert ion gauge, which enabled the ion current vs evaporation flux calibration curves to be plotted. (author). 1 tab., 4 figs., 6 refs

  15. Disappearing Arctic tundra ponds: Fine-scale analysis of surface hydrology in drained thaw lake basins over a 65 year period (1948-2013)

    Science.gov (United States)

    Andresen, Christian G.; Lougheed, Vanessa L.

    2015-03-01

    Long-term fine-scale dynamics of surface hydrology in Arctic tundra ponds (less than 1 ha) are largely unknown; however, these small water bodies may contribute substantially to carbon fluxes, energy balance, and biodiversity in the Arctic system. Change in pond area and abundance across the upper Barrow Peninsula, Alaska, was assessed by comparing historic aerial imagery (1948) and modern submeter resolution satellite imagery (2002, 2008, and 2010). This was complemented by photogrammetric analysis of low-altitude kite-borne imagery in combination with field observations (2010-2013) of pond water and thaw depth transects in seven ponds of the International Biological Program historic research site. Over 2800 ponds in 22 drained thaw lake basins (DTLB) with different geological ages were analyzed. We observed a net decrease of 30.3% in area and 17.1% in number of ponds over the 62 year period. The inclusion of field observations of pond areas in 1972 from a historic research site confirms the linear downward trend in area. Pond area and number were dependent on the age of DTLB; however, changes through time were independent of DTLB age, with potential long-term implications for the hypothesized geomorphologic landscape succession of the thaw lake cycle. These losses were coincident with increases in air temperature, active layer, and density and cover of aquatic emergent plants in ponds. Increased evaporation due to warmer and longer summers, permafrost degradation, and transpiration from encroaching aquatic emergent macrophytes are likely the factors contributing to the decline in surface area and number of ponds.

  16. PFR evaporator leak

    International Nuclear Information System (INIS)

    Smedley, J.A.

    1975-01-01

    PFR has three heat removal circuits each one having an evaporator, superheater, reheater; all separate units. The status of the system was that circuit No 3 was steaming with 10 MW thermal nuclear power; No 1 circuit was filled with sodium but with the evaporator awaiting modification to cure gas entrainment problems already reported. The leak was in No 2 circuit and was located in the evaporator unit. The evaporator is rated at 120 M thermal at full power and as such is a large unit. The circuit was filled with both sodium and water for the first time three weeks before the conference so it was recent history being reported and therefore any figures quoted should be taken as indicative only. The history of the steam generator was that it was built at works to a very high standard and underwent all the usual tests of strength, inspection of welds and helium leak testing. The steam generator is of U tube design with a tube plate to which the boiler tubes are welded, with all the welds in one of two gas spaces. The inlet and outlet sides are separated by a baffle and the salient features are illustrated in the attached figure. The unit achieved a leak tightness better than the detection limit in the helium leak test at works. This limit was assessed as being less than an equivalent leak of 10 -6 g/s water under steam generator service conditions. However even though all the steam generator units passed this test at works a further test was carried out when the circuits had been completed. The test was carried out during commissioning after sodium filling and with the units hot. The method was to introduce a mixture of helium/ argon at 500 pounds/square inch into the water side of the steam generators and measure the helium concentration in the sodium side gas spaces of the circuit. The test lasted many days and under these conditions the sensitivity is such that a leak equivalent to somewhere between 10 -7 to 10 -6 g/s equivalent water leak could be detected, i

  17. PFR evaporator leak

    Energy Technology Data Exchange (ETDEWEB)

    Smedley, J A

    1975-07-01

    PFR has three heat removal circuits each one having an evaporator, superheater, reheater; all separate units. The status of the system was that circuit No 3 was steaming with 10 MW thermal nuclear power; No 1 circuit was filled with sodium but with the evaporator awaiting modification to cure gas entrainment problems already reported. The leak was in No 2 circuit and was located in the evaporator unit. The evaporator is rated at 120 M thermal at full power and as such is a large unit. The circuit was filled with both sodium and water for the first time three weeks before the conference so it was recent history being reported and therefore any figures quoted should be taken as indicative only. The history of the steam generator was that it was built at works to a very high standard and underwent all the usual tests of strength, inspection of welds and helium leak testing. The steam generator is of U tube design with a tube plate to which the boiler tubes are welded, with all the welds in one of two gas spaces. The inlet and outlet sides are separated by a baffle and the salient features are illustrated in the attached figure. The unit achieved a leak tightness better than the detection limit in the helium leak test at works. This limit was assessed as being less than an equivalent leak of 10{sup -6} g/s water under steam generator service conditions. However even though all the steam generator units passed this test at works a further test was carried out when the circuits had been completed. The test was carried out during commissioning after sodium filling and with the units hot. The method was to introduce a mixture of helium/ argon at 500 pounds/square inch into the water side of the steam generators and measure the helium concentration in the sodium side gas spaces of the circuit. The test lasted many days and under these conditions the sensitivity is such that a leak equivalent to somewhere between 10{sup -7} to 10{sup -6} g/s equivalent water leak could be

  18. Evaporation and Antievaporation Instabilities

    Directory of Open Access Journals (Sweden)

    Andrea Addazi

    2017-10-01

    Full Text Available We review (antievaporation phenomena within the context of quantum gravity and extended theories of gravity. The (antievaporation effect is an instability of the black hole horizon discovered in many different scenarios: quantum dilaton-gravity, f ( R -gravity, f ( T -gravity, string-inspired black holes, and brane-world cosmology. Evaporating and antievaporating black holes seem to have completely different thermodynamical features compared to standard semiclassical black holes. The purpose of this review is to provide an introduction to conceptual and technical aspects of (antievaporation effects, while discussing problems that are still open.

  19. South Bay Salt Pond Mercury Studies Project

    Science.gov (United States)

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

  20. Musculoskeletal disorder survey for pond workers

    Science.gov (United States)

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

    2018-04-01

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

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

    Science.gov (United States)

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

    2018-01-01

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

  2. 40 CFR 721.8700 - Halogenated alkyl pyridine.

    Science.gov (United States)

    2010-07-01

    ... tertiary waste treatment will occur, or treatment in a lined, self-contained solar evaporation pond where... evaporation pond where UV light will degrade the substance, the number of kilograms per day per site is...

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

    Science.gov (United States)

    Clarke, John S.; Painter, Jaime A.

    2010-01-01

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

  4. Evaporation of inclined water droplets

    Science.gov (United States)

    Kim, Jin Young; Hwang, In Gyu; Weon, Byung Mook

    2017-01-01

    When a drop is placed on a flat substrate tilted at an inclined angle, it can be deformed by gravity and its initial contact angle divides into front and rear contact angles by inclination. Here we study on evaporation dynamics of a pure water droplet on a flat solid substrate by controlling substrate inclination and measuring mass and volume changes of an evaporating droplet with time. We find that complete evaporation time of an inclined droplet becomes longer as gravitational influence by inclination becomes stronger. The gravity itself does not change the evaporation dynamics directly, whereas the gravity-induced droplet deformation increases the difference between front and rear angles, which quickens the onset of depinning and consequently reduces the contact radius. This result makes the evaporation rate of an inclined droplet to be slow. This finding would be important to improve understanding on evaporation dynamics of inclined droplets. PMID:28205642

  5. 242-A evaporator hazards assessment

    International Nuclear Information System (INIS)

    Johnson, T.L.

    1998-01-01

    This document establishes the technical basis in support of Emergency Planning activities for the 242-A Evaporator, on the Hanford Site. Through this document the technical basis for the development of facility specific Emergency Action Levels and the Emergency Planning Zone is demonstrated. The evaporator sues a conventional, forced-circulation, vacuum evaporation system to concentrate radioactive waste solutions. This concentration results in the reduction in waste volume and reduces the number of double-shelled tanks required to store the waste

  6. Assessment of groundwater pollution from the oxidation ponds in tenth of Ramadan city, using isotopic techniques and hydrogeological modelling

    International Nuclear Information System (INIS)

    Abd El-Samie, S.G.; Sadek, M.A.; Mahmoud, N.S.

    2002-01-01

    The tenth of ramadan city is an intensive industrial settement on the peripheries of cairo. All types of wastewater from industrial and domestic practices are discharged into three unlined oxidation ponds to eliminate pollutants. The present srudy has been conduted to assess the extent of seepage to groundwater from the ponds and how efficient they are for pollution reduction. The chemical composition is more developed in the groundwater of the miocene aquifer due to the less active recharge and the dominance of readily dissolved salts that interact with the inflow. The seepage from ismailia canal and the excess irrigation from agricultural lands and the infiltration from the oxidation ponds as well as the upleaked water represent the main sources of recharge in the quaternary aquifer. The chemical and isotopic composition of the water in the oxidation ponds is controlled by the nature of the drained water and the geochemical processes affecting the solute content. The isotopic enrichment differs for the three ponds being related to the evaporation intensity in each

  7. Closure report for CAU 93: Area 6 steam cleaning effluent ponds, Nevada Test Site. Volume 1

    International Nuclear Information System (INIS)

    1997-12-01

    The Steam Cleaning Effluent Ponds (SCEP) waste unit is located in Area 6 at the Nevada Test Site. The SCEPs are evaporation basins formerly used for the disposal of untreated liquid effluent discharged from steam cleaning activities associated with Buildings 6-623 and 6-800. This closure report documents the strategy and analytical results that support the clean closure or closure in place of each of the components within CAU 93. In addition, the report documents all deviations from the approved closure plan and provides rationale for all deviations

  8. Turkish Undergraduates' Misconceptions of Evaporation, Evaporation Rate, and Vapour Pressure

    Science.gov (United States)

    Canpolat, Nurtac

    2006-01-01

    This study focused on students' misconceptions related to evaporation, evaporation rate, and vapour pressure. Open-ended diagnostic questions were used with 107 undergraduates in the Primary Science Teacher Training Department in a state university in Turkey. In addition, 14 students from that sample were interviewed to clarify their written…

  9. Modelling radiative transfer through ponded first-year Arctic sea ice with a plane-parallel model

    Science.gov (United States)

    Taskjelle, Torbjørn; Hudson, Stephen R.; Granskog, Mats A.; Hamre, Børge

    2017-09-01

    Under-ice irradiance measurements were done on ponded first-year pack ice along three transects during the ICE12 expedition north of Svalbard. Bulk transmittances (400-900 nm) were found to be on average 0.15-0.20 under bare ice, and 0.39-0.46 under ponded ice. Radiative transfer modelling was done with a plane-parallel model. While simulated transmittances deviate significantly from measured transmittances close to the edge of ponds, spatially averaged bulk transmittances agree well. That is, transect-average bulk transmittances, calculated using typical simulated transmittances for ponded and bare ice weighted by the fractional coverage of the two surface types, are in good agreement with the measured values. Radiative heating rates calculated from model output indicates that about 20 % of the incident solar energy is absorbed in bare ice, and 50 % in ponded ice (35 % in pond itself, 15 % in the underlying ice). This large difference is due to the highly scattering surface scattering layer (SSL) increasing the albedo of the bare ice.

  10. Modelling radiative transfer through ponded first-year Arctic sea ice with a plane-parallel model

    Directory of Open Access Journals (Sweden)

    T. Taskjelle

    2017-09-01

    Full Text Available Under-ice irradiance measurements were done on ponded first-year pack ice along three transects during the ICE12 expedition north of Svalbard. Bulk transmittances (400–900 nm were found to be on average 0.15–0.20 under bare ice, and 0.39–0.46 under ponded ice. Radiative transfer modelling was done with a plane-parallel model. While simulated transmittances deviate significantly from measured transmittances close to the edge of ponds, spatially averaged bulk transmittances agree well. That is, transect-average bulk transmittances, calculated using typical simulated transmittances for ponded and bare ice weighted by the fractional coverage of the two surface types, are in good agreement with the measured values. Radiative heating rates calculated from model output indicates that about 20 % of the incident solar energy is absorbed in bare ice, and 50 % in ponded ice (35 % in pond itself, 15 % in the underlying ice. This large difference is due to the highly scattering surface scattering layer (SSL increasing the albedo of the bare ice.

  11. Models and observations of Arctic melt ponds

    Science.gov (United States)

    Golden, K. M.

    2016-12-01

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

  12. Solar thermal technology report, FY 1981. Volume 1: Executive summary

    Science.gov (United States)

    1982-01-01

    The activities of the Department of Energy's Solar Thermal Technology Program are discussed. Highlights of technical activities and brief descriptions of each technology are given. Solar thermal conversion concepts are discussed in detail, particularily concentrating collectors and salt-gradient solar ponds.

  13. Environmental Problems Associated with Decommissioning of Chernobyl Power Plant Cooling Pond

    Science.gov (United States)

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

    2009-12-01

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

  14. Solar air conditioning. Dresden colloquium; Solare Klimatisierung. Dresdner Kolloquium

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    Subjects: R + D activities in solar air conditioning; dessicative and evaporative cooling (DEC) - systems and components; Chances of solar air conditioning in Europe; Practical experience with solar-assisted air conditioning; Performance of a solar system at Lissabon; DEC system in the Alsenblock building, Berlin; Does solar air conditioning require specially designed buildings; Performance of solar heated adsorption refrigerators; Low-capacity absacity absorption systems for solar air conditioning. [German] Die Kolloquiumsschrift beinhaltet Unterlagen ueber die abgehandelten Themen. Sie lauten: F and E-Aktivitaeten im Bereich Solare Klimatisierung; SGK(DEC-Technik) - ausgefuehrte Anlagen und deren Komponenten; Chancen der solaren Klimatisierung in Europa; Erfahrungen mit der solarunterstuetzten Klimatisierung; Energieverbrauch und Regelung von SGK-Anlagen; Betriebserfahrungen einer Solaranlage in Lissabon; Realisierung der SGK im Alsenblock Berlin; Erfordert die solare Klimatisierung besondere Gebaeude?; Betriebserfahrungen mit solar beheizten Adsorptionskaeltemaschinen; Absorptionsanlagen kleiner Leistung fuer solare Klimatisierung. (orig.)

  15. Evaporative cooling: Effective latent heat of evaporation in relation to evaporation distance from the skin

    NARCIS (Netherlands)

    Havenith, G.; Bröde, P.; Hartog, E.A. den; Kuklane, K.; Holmer, I.; Rossi, R.M.; Richards, M.; Farnworth, B.; Wang, X.

    2013-01-01

    Calculation of evaporative heat loss is essential to heat balance calculations. Despite recognition that the value for latent heat of evaporation, used in these calculations, may not always reflect the real cooling benefit to the body, only limited quantitative data on this is available, which has

  16. Accumulation of Pollutants in Highway Detention Ponds

    DEFF Research Database (Denmark)

    Bentzen, Thomas Ruby

    single rain event. From the hindcast results it is possible to calculate mean water and pollutant loads. This method is commonly used in urban drainage systems for capacity analysis or for prediction of CSO's. The challenge is to develop a simplified and still accurate description of flow and transport......This PhD study deals with issues related to water and pollutant transport from highway surfaces caused by rain. It is essential in the study to apply methods and models in which improvements in relation to removal of pollutants can be identified and to be able to predict the yearly discharges....... Measurements of water and pollutant transport are carried out in different highway systems. A geometrically well-defined test pond is established, wherein the deposition of particulate matter can be measured. The result from the test pond is transferred to real detention ponds in which the three...

  17. Rapid Evaporation of microbubbles

    Science.gov (United States)

    Gautam, Jitendra; Esmaeeli, Asghar

    2008-11-01

    When a liquid is heated to a temperature far above its boiling point, it evaporates abruptly. Boiling of liquid at high temperatures can be explosive and destructive, and poses a potential hazard for a host of industrial processes. Explosive boiling may occur if a cold and volatile liquid is brought into contact with a hot and non-volatile liquid, or if a liquid is superheated or depressurized rapidly. Such possibilities are realized, for example, in the depressurization of low boiling point liquefied natural gas (LNG) in the pipelines or storage tanks as a result of a leak. While boiling of highly heated liquids can be destructive at macroscale, the (nearly) instantaneous pace of the process and the release of large amount of kinetic energy make the phenomena extremely attractive at microscale where it is possible to utilize the released energy to derive micromechanical systems. For instance, there is currently a growing interest in micro-explosion of liquid for generation of micro bubbles for actuation purposes. The aim of the current study is to gain a fundamental understanding of the subject using direct numerical simulations. In particular, we seek to investigate the boundary between stable and unstable nucleus growth in terms of the degree of liquid superheat and to compare the dynamics of unstable and stable growth.

  18. Fate of Pyrethroids in Farmland Ponds

    DEFF Research Database (Denmark)

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

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

  19. Pond dyes are Culex mosquito oviposition attractants

    Directory of Open Access Journals (Sweden)

    Natali Ortiz Perea

    2017-05-01

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

  20. Solar Thermal Utilization: Past, Present and Future

    Science.gov (United States)

    2010-09-01

    SO•C NON-FOCUSSING FLAT PLATE / (FPC) 100- 150•C For low temperature 50- 200•C COMPOUND applications PARABOLIC EVACUATED CONCENTRATOR ~ (ETC...2030 Ø 200GW BY 2050 Ø 20 MILLION SQ.METER SOLAR THERMAL COLLECTORS (20GW power) Ø 20 MILLION SOLAR LIGHTS LAUNCHING OF SOLAR INDIA SOLAR THERMAL...Temperature (20oC- 80oC) NALSUN ApplicationsThermal Conversion range SOLAR ENERGY COLLECTORS 40- GO•C UNGLAZED COLLECTORS 60- 90•C SOLAR POND 60

  1. Use of satellite data to estimate radiation and evaporation for northwest Mexico

    International Nuclear Information System (INIS)

    Stewart, J.B.; Watts, C.J.; Rodriguez, J.C.; Bruin, H.A.R. de; Berg, A.R. van den; Garatuza-Payán, J.

    1999-01-01

    Incoming solar radiation was estimated from visible band data obtained by the GOES satellite over northwest Mexico. Comparisons against ground-based measurements of incoming solar radiation showed good agreement, particularly in months with low cloud cover. The data from an automatic weather station installed within the Yaqui Valley Irrigation Scheme was used to estimate potential evaporation from a formula based on incoming solar radiation and climatological values of temperature. The success of this formula was assessed by comparison against potential evaporation estimated using the Penman and Penman–Monteith formulae and measurements of net radiation. (author)

  2. Hydrothermal waves in evaporating sessile drops

    OpenAIRE

    Brutin, D.; Rigollet, F.; Niliot, C. Le

    2009-01-01

    Drop evaporation is a simple phenomena but still unclear concerning the mechanisms of evaporation. A common agreement of the scientific community based on experimental and numerical work evidences that most of the evaporation occurs at the triple line. However, the rate of evaporation is still empirically predicted due to the lack of knowledge on the convection cells which develop inside the drop under evaporation. The evaporation of sessile drop is more complicated than it appears due to the...

  3. Developing Ecological Models on Carbon and Nitrogen in Secondary Facultative Ponds

    Directory of Open Access Journals (Sweden)

    Aponte-Reyes Alexander

    2014-07-01

    Full Text Available Ecological models formulated for TOC, CO2, NH4+, NO3- and NTK, based in literature reviewed and field work were obtained monitoring three facultative secondary stabilization ponds, FSSP, pilots: conventional pond, CP, baffled pond, BP, and baffled-meshed pond, BMP. Models were sensitive to flow inlet, solar radiation, pH and oxygen content; the sensitive parameters in Carbon Model were KCOT Ba, umax Ba, umax Al, K1OX, VAl, R1DCH4, YBh. The sensitive parameters in the Nitrogen model were KCOT Ba, umax Ba, umax Al, VAl, KOPH, KOPA, r4An. The test t–paired showed a good simulating of Carbon model refers to TOC in FSSP; on the other side, the Nitrogen model showed a good simulating of NH4+. Different topological models modify ecosystem ecology forcing different transformation pathways of Nitrogen; equal transformations of the Carbon BMP topology could be achieved using lower volumes, however, a calibration for a new model would be required. Carbon and Nitrogen models developed could be coupled to hydrodynamics models for better modeling of FSSP.

  4. Interfacial Instabilities in Evaporating Drops

    Science.gov (United States)

    Moffat, Ross; Sefiane, Khellil; Matar, Omar

    2007-11-01

    We study the effect of substrate thermal properties on the evaporation of sessile drops of various liquids. An infra-red imaging technique was used to record the interfacial temperature. This technique illustrates the non-uniformity in interfacial temperature distribution that characterises the evaporation process. Our results also demonstrate that the evaporation of methanol droplets is accompanied by the formation of wave-trains in the interfacial temperature field; similar patterns, however, were not observed in the case of water droplets. More complex patterns are observed for FC-72 refrigerant drops. The effect of substrate thermal conductivity on the structure of the complex pattern formation is also elucidated.

  5. Control of black hole evaporation?

    International Nuclear Information System (INIS)

    Ahn, Doyeol

    2007-01-01

    Contradiction between Hawking's semi-classical arguments and the string theory on the evaporation of a black hole has been one of the most intriguing problems in fundamental physics. A final-state boundary condition inside the black hole was proposed by Horowitz and Maldacena to resolve this contradiction. We point out that the original Hawking effect can also be regarded as a separate boundary condition at the event horizon for this scenario. Here, we found that the change of the Hawking boundary condition may affect the information transfer from the initial collapsing matter to the outgoing Hawking radiation during the evaporation process and as a result the evaporation process itself, significantly

  6. Sea Ice Melt Pond Data from the Canadian Arctic

    Data.gov (United States)

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

  7. Valuing Multiple Benefits, and the Public Perception of SUDS Ponds

    Directory of Open Access Journals (Sweden)

    Joy Jarvie

    2017-02-01

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

  8. Thermal modeling and parametric studies of a greenhouse fish pond in the Central Himalayan Region

    International Nuclear Information System (INIS)

    Sarkar, Bikash; Tiwari, G.N.

    2006-01-01

    This study describes the thermal modeling and its validation of greenhouse fish pond systems. Numerical computations have been performed for a typical day in the month of June, 2005, for the climatic condition of Champawat in the Central Himalayan Region. The energy balance equations have been written considering the effects of conduction, convection, radiation, evaporation and ventilation. The governing equations are numerically solved with Matlab 7.0 software to predict the water temperature. A parametric study has also been performed to find the effects of various parameters, namely the number of air changes per hour, the transmissivity (τ) and the isothermal mass and height of the greenhouse. It is observed that there is no significant effect in the parametric studies on water temperature due to the larger isothermal mass. The model has been validated with experimental data. On an average, the even span passive greenhouse fish pond can increase the inside temperature 4.14 deg. C higher than the temperature of an outdoor pond. Statistical analysis shows that the predicted and experimental values of water temperature exhibited fair agreement with a coefficient of correlation r = 0.90 and root mean square percent deviation e = 1.67%

  9. Introducing ultrasonic falling film evaporator for moderate temperature evaporation enhancement.

    Science.gov (United States)

    Dehbani, Maryam; Rahimi, Masoud

    2018-04-01

    In the present study, Ultrasonic Falling Film (USFF), as a novel technique has been proposed to increase the evaporation rate of moderate temperature liquid film. It is a proper method for some applications which cannot be performed at high temperature, such as foodstuff industry, due to their sensitivity to high temperatures. Evaporation rate of sodium chloride solution from an USFF on an inclined flat plate compared to that for Falling Film without ultrasonic irradiation (FF) at various temperatures was investigated. The results revealed that produced cavitation bubbles have different effects on evaporation rate at different temperatures. At lower temperatures, size fluctuation and collapse of bubbles and in consequence induced physical effects of cavitation bubbles resulted in more turbulency and evaporation rate enhancement. At higher temperatures, the behavior was different. Numerous created bubbles joined together and cover the plate surface, so not only decreased the ultrasound vibrations but also reduced the evaporation rate in comparison with FF. The highest evaporation rate enhancement of 353% was obtained at 40 °C at the lowest Reynolds number of 250. In addition, the results reveal that at temperature of 40 °C, USFF has the highest efficiency compared to FF. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. EVALUACIÓN DE ALTERNATIVAS PARA CLIMATIZACIÓN DE ESTANQUES CON ENERGÍA SOLAR PARA CULTIVO DE TILAPIA ROJA (Oreochromis sp), LOCALIZADOS EN LA ZONA FRÍA DEL VALLE DEL CAUCA, COLOMBIA EVALUATION OF ALTERNATIVES FOR AIR CONDITIONING OF PONDS WITH SOLAR ENERGY FOR CULTIVATION OF RED TILAPIA (Oreochromis sp), LOCATED IN THE COLD AREA OF THE CAUCA VALLEY, COLOMBIA

    OpenAIRE

    Francisco Javier Borja Gallardo; Luis Octavio González Salcedo; Victoria Eugenia Quintero de Vallejo

    2006-01-01

    La investigación fue desarrollada para que la tilapia roja (Oreochromis sp), especie de pez mÁs producida en Colombia, pueda ser explotada en lugares donde las condiciones óptimas para su normal desarrollo no son las adecuadas, como son las regiones altas con temperaturas por debajo de los 24 °C, aplicando metodologías relacionadas con el aprovechamiento de la energía solar. Las técnicas evaluadas fueron: climatización por medio de colectores solares, climatización por medio de manta térmica,...

  11. Dual manifold heat pipe evaporator

    Science.gov (United States)

    Adkins, D.R.; Rawlinson, K.S.

    1994-01-04

    An improved evaporator section is described for a dual manifold heat pipe. Both the upper and lower manifolds can have surfaces exposed to the heat source which evaporate the working fluid. The tubes in the tube bank between the manifolds have openings in their lower extensions into the lower manifold to provide for the transport of evaporated working fluid from the lower manifold into the tubes and from there on into the upper manifold and on to the condenser portion of the heat pipe. A wick structure lining the inner walls of the evaporator tubes extends into both the upper and lower manifolds. At least some of the tubes also have overflow tubes contained within them to carry condensed working fluid from the upper manifold to pass to the lower without spilling down the inside walls of the tubes. 1 figure.

  12. The evaporative vector: Homogeneous systems

    International Nuclear Information System (INIS)

    Klots, C.E.

    1987-05-01

    Molecular beams of van der Waals molecules are the subject of much current research. Among the methods used to form these beams, three-sputtering, laser ablation, and the sonic nozzle expansion of neat gases - yield what are now recognized to be ''warm clusters.'' They contain enough internal energy to undergo a number of first-order processes, in particular that of evaporation. Because of this evaporation and its attendant cooling, the properties of such clusters are time-dependent. The states of matter which can be arrived at via an evaporative vector on a typical laboratory time-scale are discussed. Topics include the (1) temperatures, (2) metastability, (3) phase transitions, (4) kinetic energies of fragmentation, and (5) the expression of magical properties, all for evaporating homogeneous clusters

  13. The refreezing of melt ponds on Arctic sea ice

    Science.gov (United States)

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

    2015-02-01

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

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  15. Examination of evaporative fraction diurnal behaviour using a soil-vegetation model coupled with a mixed-layer model

    Directory of Open Access Journals (Sweden)

    J.-P. Lhomme

    1999-01-01

    Full Text Available In many experimental conditions, the evaporative fraction, defined as the ratio between evaporation and available energy, has been found stable during daylight hours. This constancy is investigated over fully covering vegetation by means of a land surface scheme coupled with a mixed-layer model, which accounts for entrainment of overlying air. The evaporation rate follows the Penman-Monteith equation and the surface resistance is given by a Jarvis type parameterization involving solar radiation, saturation deficit and leaf water potential. The diurnal course of the evaporative fraction is examined, together with the influence of environmental factors (soil water availability, solar radiation input, wind velocity, saturation deficit above the well-mixed layer. In conditions of fair weather, the curves representing the diurnal course of the evaporative fraction have a typical concave-up shape. Around midday (solar time these curves appear as relatively constant, but always lower that the daytime mean value. Evaporative fraction decreases when soil water decreases or when solar energy increases. An increment of saturation deficit above the mixed-layer provokes only a slight increase of evaporative fraction, and wind velocity has almost no effect. The possibility of estimation daytime evaporation from daytime available energy multiplied by the evaporative fraction at a single time of the day is also investigated. It appears that it is possible to obtain fairly good estimates of daytime evaporation by choosing adequately the time of the measurement of the evaporative fraction. The central hours of the day, and preferably about 3 hr before or after noon, are the most appropriate to provide good estimates. The estimation appears also to be much better when soil water availability (or evaporation is high than when it is low.

  16. EVALUACIÓN DE ALTERNATIVAS PARA CLIMATIZACIÓN DE ESTANQUES CON ENERGÍA SOLAR PARA CULTIVO DE TILAPIA ROJA (Oreochromis sp, LOCALIZADOS EN LA ZONA FRÍA DEL VALLE DEL CAUCA, COLOMBIA EVALUATION OF ALTERNATIVES FOR AIR CONDITIONING OF PONDS WITH SOLAR ENERGY FOR CULTIVATION OF RED TILAPIA (Oreochromis sp, LOCATED IN THE COLD AREA OF THE CAUCA VALLEY, COLOMBIA

    Directory of Open Access Journals (Sweden)

    Francisco Javier Borja Gallardo

    2006-06-01

    Full Text Available La investigación fue desarrollada para que la tilapia roja (Oreochromis sp, especie de pez mÁs producida en Colombia, pueda ser explotada en lugares donde las condiciones óptimas para su normal desarrollo no son las adecuadas, como son las regiones altas con temperaturas por debajo de los 24 °C, aplicando metodologías relacionadas con el aprovechamiento de la energía solar. Las técnicas evaluadas fueron: climatización por medio de colectores solares, climatización por medio de manta térmica, climatización por medio de mangueras térmicas y climatización por medio de resistencias eléctricas. Se analizaron factores como funcionalidad, mantenimiento, limitaciones organizativas, espaciales, y costos.The research was developed so that the red tilapia (Oreochromis sp, fish species that more taken place in Colombia can be exploited in regions where the good conditions for its normal development are not the appropriate ones as in the high regions with temperatures below the 24 °C, applying methodologies related with the use of the solar energy. The evaluated methodologies were: air conditioning by means of solar collectors, air conditioning by means of thermal blanket, air conditioning by means of thermal hoses and air conditioning by means of electric resistances. Factors like functionality, maintenance, organizational and space limitations, and costs were analized.

  17. Assessing the long-term effects of the Sahel drought on ponds and semi-arid hydrology.

    Science.gov (United States)

    Gal, L.; Grippa, M.; Kergoat, L.; Hiernaux, P.; Peugeot, C.; Mougin, E.

    2015-12-01

    The Sahel underwent a severe rainfall deficit in the late 20th century, with extreme droughts in the early 70s and early 80s. This drought is the strongest multidecadal drought of the 20th century, globally. It has strongly impacted ecosystems, water availability, and populations. However, an increase of surface water has been observed during the same period: higher discharge of Sahelian rivers, and a general increase in pond's surface. This phenomenon, "less rain but more surface runoff", is referred to as the "Sahelian paradox". The causes of this paradox are still debated. The role of the significant increase in cropped areas, often cited for cultivated Sahel, does not hold for pastoral areas in central and northern Sahel. Degradation of vegetation as a result of the drought, soils erosion, may also play an important role. Most Sahelian watersheds are still poorly gauged or ungauged, which makes it difficult to quantify surface runoff and its determinants. A method is developed to estimate runoff over ungauged ponds watersheds. It is tested for the Agoufou pond in the Gourma region in Mali, where in situ data are available for 2007-2014. A 3D model is first developed to relate water volume to height surface. This model is combined with daily evaporation and precipitation, to estimate the water supply to the pond which is a proxy for runoff over the watershed. This model highlights a spectacular increase of the runoff coefficient over the last 60 years. The method is then applied to two ungauged Sahelian watersheds in Mauritania and Niger, where pond surfaces by remote sensing are the only information. The runoff coefficients also increased in the last 60 years over these watersheds. The runoff derived for the Agoufou pond is used to evaluate simulations with the KINEROS2 model. We discuss to what extent the changes in rain intensity, soil hydrological properties and land-use land cover are able to cause the observed change in runoff over the last 60 years.

  18. Characterisation of potential aquaculture pond effluents, and ...

    African Journals Online (AJOL)

    Conventional treatment of effluents from these small-scale, low-volume operations, which discharge relatively dilute effluents infrequently, might not be cost-effective. Keywords: aquaculture–environment interaction, earthen ponds, effluent characterisation, K-means clustering, t ilapia, water quality. African Journal of Aquatic ...

  19. Aquatic Habitats: Exploring Desktop Ponds. Teacher's Guide.

    Science.gov (United States)

    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.…

  20. Interconnected ponds operation for flood hazard distribution

    Science.gov (United States)

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

    2016-05-01

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

  1. Scenario evaluation of open pond microalgae production

    NARCIS (Netherlands)

    Slegers, P.M.; Lösing, M.B.; Wijffels, R.H.; Straten, van G.; Boxtel, van A.J.B.

    2013-01-01

    To evaluate microalgae production in large scale open ponds under different climatologic conditions, a model-based framework is used to study the effect of light conditions, water temperature and reactor design on trends in algae productivity. Scenario analyses have been done for two algae species

  2. Climatological effects on heliohydroelectric (HHE) power generation. [Based on evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Kettani, M A

    1973-12-01

    Large scale conversion of solar energy into electricity can be efficiently made by transforming first the solar energy into hydraulic energy by evaporation. This concept has been presented at the International Conference of 1971. Since then work has been done to correlate the power generated by an HHE plant to the climatological variables of a region. The effects of such variables as air temperature, relative humidity, station pressure, and wind speed on the generated power are discussed. The Dawhat Salwah area is being emphasized; however, the results could be generalized to other arid zones.

  3. DWPF Recycle Evaporator Simulant Tests

    International Nuclear Information System (INIS)

    Stone, M

    2005-01-01

    Testing was performed to determine the feasibility and processing characteristics of an evaporation process to reduce the volume of the recycle stream from the Defense Waste Processing Facility (DWPF). The concentrated recycle would be returned to DWPF while the overhead condensate would be transferred to the Effluent Treatment Plant. Various blends of evaporator feed were tested using simulants developed from characterization of actual recycle streams from DWPF and input from DWPF-Engineering. The simulated feed was evaporated in laboratory scale apparatus to target a 30X volume reduction. Condensate and concentrate samples from each run were analyzed and the process characteristics (foaming, scaling, etc) were visually monitored during each run. The following conclusions were made from the testing: Concentration of the ''typical'' recycle stream in DWPF by 30X was feasible. The addition of DWTT recycle streams to the typical recycle stream raises the solids content of the evaporator feed considerably and lowers the amount of concentration that can be achieved. Foaming was noted during all evaporation tests and must be addressed prior to operation of the full-scale evaporator. Tests were conducted that identified Dow Corning 2210 as an antifoam candidate that warrants further evaluation. The condensate has the potential to exceed the ETP WAC for mercury, silicon, and TOC. Controlling the amount of equipment decontamination recycle in the evaporator blend would help meet the TOC limits. The evaporator condensate will be saturated with mercury and elemental mercury will collect in the evaporator condensate collection vessel. No scaling on heating surfaces was noted during the tests, but splatter onto the walls of the evaporation vessels led to a buildup of solids. These solids were difficult to remove with 2M nitric acid. Precipitation of solids was not noted during the testing. Some of the aluminum present in the recycle streams was converted from gibbsite to

  4. Cloudy with a Chance of Ice: The Stratification of Titan's Vernal Ponds and Formation of Ethane Ice

    Science.gov (United States)

    Soderblom, J. M.; Steckloff, J. K.

    2017-12-01

    Cassini ISS observations revealed regions on Saturn's moon Titan that become significantly darker (lower albedo) following storm events [1]. These regions are observed to be topographically low [2], indicating that liquid (predominantly methane-ethane-nitrogen) is pooling on Titan after these storm events. These dark ponds, however, are then observed to significantly brighten (higher albedo relative to pre-storm albedo), before fading to their pre-storm albedos [2-3]. We interpret these data to indicate ethane ice formation, which cools from evaporation of methane. The formation of ethane ices results from a unique sequence of thermophysical and thermochemical phenomena. Initially, the methane in the mixture evaporates, cooling the pond. Nitrogen, dissolved primarily in the methane, exsolves, further cooling the liquid. However, because nitrogen is significantly more soluble in cooler methane-hydrocarbon mixtures, relatively more methane than nitrogen leaves the fluid, increasing the relative fraction of nitrogen. This increased nitrogen fraction increases the density of the liquid, as nitrogen is significantly denser than methane or ethane (pure ethane's density is intermediate to that of methane and nitrogen). At around 85 K the mixture is as dense as pure liquid ethane. Thus, further evaporative methane loss and cooling at the pond's surface leads to a chemical stratification, with an increasingly ethane rich epilimnion (surface layer) overlying a methane rich hypolimnion (subsurface layer). Further evaporation of methane from the ethane-rich epilimnion drives its temperature and composition toward the methane-ethane-nitrogen liquidus curve, causing pure ethane ice to precipitate out of solution and settle to the bottom of the pool. This settling would obscure the ethane ice from Cassini VIMS and ISS, which would instead continue to appear as a dark pond on the surface. As the ethane precipitates out completely, a binary methane-nitrogen liquid mixture remains

  5. Lake Nasser evaporation reduction study

    Directory of Open Access Journals (Sweden)

    Hala M.I. Ebaid

    2010-10-01

    Full Text Available This study aims to evaluate the reduction of evaporation of Lake Nasser’s water caused by disconnecting (fully or partially some of its secondary channels (khors. This evaluation integrates remote sensing, Geographic Information System (GIS techniques, aerodynamic principles, and Landsat7 ETM+ images. Three main procedures were carried out in this study; the first derived the surface temperature from Landsat thermal band; the second derived evaporation depth and approximate evaporation volume for the entire lake, and quantified evaporation loss to the secondary channels’ level over one month (March by applied aerodynamic principles on surface temperature of the raster data; the third procedure applied GIS suitability analysis to determine which of these secondary channels (khors should be disconnected. The results showed evaporation depth ranging from 2.73 mm/day at the middle of the lake to 9.58 mm/day at the edge. The evaporated water-loss value throughout the entire lake was about 0.86 billion m3/month (March. The analysis suggests that it is possible to save an approximate total evaporation volume loss of 19.7 million m3/month (March, and thus 2.4 billion m3/year, by disconnecting two khors with approximate construction heights of 8 m and 15 m. In conclusion, remote sensing and GIS are useful for applications in remote locations where field-based information is not readily available and thus recommended for decision makers remotely planning in water conservation and management.

  6. Patterns of microbial diversity along a salinity gradient in the Guerrero Negro solar saltern, Baja CA Sur, Mexico

    Directory of Open Access Journals (Sweden)

    Jesse G Dillon

    2013-12-01

    Full Text Available The goal of this study was to use environmental sequencing of 16S rRNA and bop genes to compare the diversity of planktonic bacteria and archaea across ponds with increasing salinity in the Exportadora de Sal (ESSA evaporative saltern in Guerrero Negro, Baja CA S., Mexico. We hypothesized that diverse communities of heterotrophic bacteria and archaea would be found in the ESSA ponds, but that bacterial diversity would decrease relative to archaea at the highest salinities. Archaeal 16S rRNA diversity was higher in Ponds 11 and 12 (370 & 380 g l-1 total salts respectively compared to Pond 9 (180 g l-1 total salts. Both Pond 11 and 12 communities had high representation (47 and 45% of clones respectively by Haloquadratum walsbyi-like (99% similarity lineages. The archaeal community in Pond 9 was dominated (79% by a single uncultured phylotype with 99% similarity to sequences recovered from the Sfax saltern in Tunisia. This pattern was mirrored in bop gene diversity with greater numbers of highly supported phylotypes including many Haloquadratum-like sequences from the two highest salinity ponds. In Pond 9, most bop sequences, were not closely related to sequences in databases. Bacterial 16S rRNA diversity was higher than archaeal in both Pond 9 and Pond 12 samples, but not Pond 11, where a non-Salinibacter lineage within the Bacteroidetes >98% similar to environmental clones recovered from Lake Tuz in Turkey and a saltern in Chula Vista, CA was most abundant (69% of community. This OTU was also the most abundant in Pond 12, but only represented 14% of clones in the more diverse pond. The most abundant OTU in Pond 9 (33% of community was 99% similar to an uncultured gammaproteobacterial clone from the Salton Sea. Results suggest that the communities of saltern bacteria and archaea vary even in ponds with similar salinity and further investigation into the ecology of diverse, uncultured halophile communities is warranted.

  7. Microbial activities and communities in oil sands tailings ponds

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-01

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

  8. Heavy metals, PAHs and toxicity in stormwater wet detention ponds

    DEFF Research Database (Denmark)

    Wium-Andersen, Tove; Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild

    2011-01-01

    Concentrations of 6 different heavy metals and total Polycyclic Aromatic Hydrocarbons (PAH) were determined in stormwater runoff and in the pond water of two Danish wet detention ponds. The pond water samples were analyzed for toxic effects, using the algae Selenastrum capricornutum as a test...... organism. Stormwater and pond water from a catchment with light industry showed high levels of heavy metals, especially zinc and copper. The pond water showed high toxic effects and copper were found to be the main toxicant. Additionally, a large part of the copper was suspected to be complex bound......, reducing the potential toxicity of the metal. Another catchment (residential) produced stormwater and pond water with moderate concentration of heavy metals. The pond water occasionally showed toxic effects but no correlation between heavy metals and toxicity was identified. PAHs concentrations were...

  9. Ponds' water balance and runoff of endorheic watersheds in the Sahel

    Science.gov (United States)

    Gal, Laetitia; Grippa, Manuela; Kergoat, Laurent; Hiernaux, Pierre; Mougin, Eric; Peugeot, Christophe

    2015-04-01

    The Sahel has been characterized by a severe rainfall deficit since the mid-twentieth century, with extreme droughts in the early seventies and again in the early eighties. These droughts have strongly impacted ecosystems, water availability, fodder resources, and populations living in these areas. However, an increase of surface runoff has been observed during the same period, such as higher "summer discharge" of Sahelian's rivers generating local floods, and a general increase in pond's surface in pastoral areas of central and northern Sahel. This behavior, less rain but more surface runoff is generally referred to as the "Sahelian paradox". Various hypotheses have been put forward to explain this paradoxical situation. The leading role of increase in cropped areas, often cited for cultivated Sahel, does not hold for pastoral areas in central and northern Sahel. Processes such as degradation of vegetation subsequent to the most severe drought events, soils erosion and runoff concentration on shallow soils, which generate most of the water ending up in ponds, seem to play an important role. This still needs to be fully understood and quantified. Our study focuses on a model-based approach to better understand the hydrological changes that affected the Agoufou watershed (Gourma, Mali), typical of the central, non-cultivated Sahel. Like most of the Sahelian basins, the Agoufou watershed is ungauged. Therefore we used indirect data to provide the information required to validate a rainfall-runoff model approach. The pond volume was calculated by combining in-situ water level measurements with pond's surface estimations derived by remote sensing. Using the pond's water balance equation, the variations of pond volume combined to estimates of open water bodies' evaporation and infiltration determined an estimation for the runoff supplying the pond. This estimation highlights a spectacular runoff increase over the last sixty years on the Agoufou watershed. The runoff

  10. The geochemistry of Don Juan Pond: Evidence for a deep groundwater flow system in Wright Valley, Antarctica

    Science.gov (United States)

    Toner, J. D.; Catling, D. C.; Sletten, R. S.

    2017-09-01

    Don Juan Pond (DJP), Antarctica, is one of the most unusual surface waters on Earth because of its CaCl2-rich composition. To investigate the evolution of pond waters during closed-basin evaporation and to understand the source of brines responsible for the chemistry of DJP, we apply a newly developed low-temperature aqueous model in the Na-K-Ca-Mg-Cl system to DJP. By modeling the closed-basin evaporation of DJP and comparing ionic ratios between DJP surface water, deep groundwater, shallow groundwater, and other surface chemistries in Wright Valley, we find that DJP is best explained by upwelling deep groundwater, as opposed to recent hypotheses proposing shallow groundwater sources. The early closed-basin evolution of brines in our model accurately predicts observed chemistries in DJP; however, late-stage closed-basin evaporation produces Mg-K-rich brines and salts that do not match the CaCl2-rich brine in DJP. Based on groundwater inflow rates to DJP, we estimate that even the most concentrated brines in DJP have undergone closed-basin evaporation for less than a year. To explain the observed lack of Mg2+ and K+ accumulation in DJP over time, and the surprisingly young age for the brines, we deduce that DJP is a localized upwelling from a regional groundwater flow-through system in which evaporated DJP brines are recycled back into the subsurface over yearly timescales. The existence of a regional groundwater flow system beneath DJP has implications for water and solute budgets in cold desert ecosystems, and may provide clues for the formation of groundwater and aqueous flows on Mars.

  11. The influence of fish ponds and salinization on groundwater quality in the multi-layer coastal aquifer system in Israel

    Science.gov (United States)

    Tal, A.; Weinstein, Y.; Yechieli, Y.; Borisover, M.

    2017-08-01

    This study focuses on the impact of surface reservoirs (fish ponds) on a multi aquifer coastal system, and the relation between the aquifer and the sea. The study was conducted in an Israeli Mediterranean coastal aquifer, which includes a sandy phreatic unit and two confined calcareous sandstone units. The geological description is based on 52 wells, from which 33 samples were collected for stable isotope analysis and 25 samples for organic and inorganic parameters. Hydraulic head and chemical measurements suggest that there is an hydraulic connection between the fish ponds above the aquifer and the phreatic unit, whereas the connection with the confined units is very limited. The phreatic unit is characterized by a low concentration of oxygen and high concentrations of ammonium and phosphate, while the confined units are characterized by higher oxygen and much lower ammonium and phosphate concentrations. Organic matter fluorescence was found to be a tool to distinguish the contribution of the pond waters, whereby a pond water signature (characterized by proteinaceous (tryptophan-like) and typical humic-matter fluorescence) was found in the phreatic aquifer. The phreatic unit is also isotopically enriched, similar to pond waters, with δ18O of -1‰ and δD of -4.6‰, indicating enhanced evaporation of the pond water before infiltration, whereas there is a depleted isotopic composition in the confined units (δ18O = -4.3‰, δD = -20.4‰), which are also OM-poor. The Phreeqc model was used for quantitative calculation of the effect of pond losses on the different units. The Dissolved Inorganic Nitrogen (DIN) in the upper unit increases downstream from the ponds toward the sea, probably due to organic matter degradation, suggesting contribution of DIN from shallow groundwater flow to the sea. 87Sr/86Sr and Mg/Ca in the brackish and saline groundwater of the lower confined units increase toward seawater value, suggesting that the salinization process in the region

  12. Produced water ponds are an important source of aromatics and alcohols in Rocky Mountain oil and gas basins

    Science.gov (United States)

    Lyman, S. N.

    2017-12-01

    Most of the water extracted with oil and natural gas (i.e., produced water) is disposed of by injection into the subsurface. In the arid western United States, however, a significant portion of produced water is discharged in ponds for evaporative disposal, and produced water is often stored in open ponds prior to subsurface injection. Even though they are common in the West (Utah's Uinta Basin has almost 200 ha), produced water ponds have been excluded from oil and gas emissions inventories because little information about their emission rates and speciation is available. We used flux chambers and inverse plume modeling to measure emissions of methane, C2-C11 hydrocarbons, light alcohols, carbonyls, and carbon dioxide from oil and gas produced water storage and disposal ponds in the Uinta Basin and the Upper Green River Basin, Wyoming, during 2013-2017. Methanol was the most abundant organic compound in produced water (91 ± 2% of the total volatile organic concentration; mean ± 95% confidence interval) but accounted for only 25 ± 30% of total organic compound emissions from produced water ponds. Non-methane hydrocarbons, especially C6-C9 alkanes and aromatics, accounted for the majority of emitted organics. We were able to predict emissions of individual compounds based on water concentrations, but only to within an order of magnitude. The speciation and magnitude of emissions varied strongly across facilities and was influenced by water age, the presence or absence of oil sheens, and with meteorological conditions (especially ice cover). Flux chamber measurements were lower than estimates from inverse modeling techniques.Based on our flux chamber measurements, we estimate that produced water ponds are responsible for between 3 and 9% of all non-methane organic compound emissions in the Uinta Basin (or as much as 18% if we rely on our inverse modeling results). Emissions from produced water ponds contain little methane and are more reactive (i.e., they have

  13. Open fibre reinforced plastic (FRP) flat plate collector (FPC) and spray network systems for augmenting the evaporation rate of tannery effluent (soak liquor)

    International Nuclear Information System (INIS)

    Srithar, K.; Mani, A.

    2007-01-01

    Presently, tanneries in Tamilnadu, India are required to segregate the effluent of soaking and pickling sections from other wastewater streams and send it to shallow solar pans for evaporation to avoid land pollution. A large area of solar pans is required for evaporating the water in the effluent at salt concentration in the range of 4-5%. An experimental study has been made by using fibre reinforced plastic flat plate collector (FRP-FPC) and spray system in a pilot plant with a capacity to handle 5000 l per day, which increases the evaporation rate. After increasing the salt concentration level to near saturation limit, the concentrated liquid was sent to conventional solar pans for its continued evaporation and recovery of salt. In this improved system, the rate of evaporation was found to be 30-40% more than that in the conventional solar pans. The performance is compared with the theoretically simulated performance. (author)

  14. Par Pond refill water quality sampling

    International Nuclear Information System (INIS)

    Koch, J.W. II; Martin, F.D.; Westbury, H.M.

    1996-08-01

    This study was designed to document anoxia and its cause in the event that the anoxia caused a fish kill. However, no fish kill was observed during this study, and dissolved oxygen and nutrient concentrations generally remained within the range expected for southeastern reservoirs. Par Pond water quality monitoring will continue during the second summer after refill as the aquatic macrophytes become reestablished and nutrients in the sediments are released to the water column

  15. Engineered design of SSC cooling ponds

    International Nuclear Information System (INIS)

    Bear, J.B.

    1993-05-01

    The cooling requirements of the SSC are significant and adequate cooling water systems to meet these requirements are critical to the project's successful operation. The use of adequately designed cooling ponds will provide reliable cooling for operation while also meeting environmental goals of the project to maintain streamflow and flood peaks to preconstruction levels as well as other streamflow and water quality requirements of the Texas Water Commission and the Environmental Protection Agency

  16. Holocene closure of Lib Pond, Marshall Islands.

    Directory of Open Access Journals (Sweden)

    Conor L Myhrvold

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

  17. Holocene closure of Lib Pond, Marshall Islands.

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2011-09-01

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

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

    Science.gov (United States)

    Roy, Virginie; Amyot, Marc; Carignan, Richard

    2009-08-01

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

  20. Mechanisms for parasites removal in a waste stabilisation pond.

    Science.gov (United States)

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

    2011-04-01

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

  1. Rapid surface-water volume estimations in beaver ponds

    Science.gov (United States)

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

    2017-02-01

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

  2. Development of shrimp in small ponds

    Directory of Open Access Journals (Sweden)

    Armando Adolfo Ortega Salas

    2014-06-01

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

  3. Assessment of groundwater pollution from ash ponds using stable and unstable isotopes around the Koradi and Khaperkheda thermal power plants (Maharashtra, India).

    Science.gov (United States)

    Voltaggio, M; Spadoni, M; Sacchi, E; Sanam, R; Pujari, P R; Labhasetwar, P K

    2015-06-15

    The impact on local water resources due to fly ash produced in the Koradi and Khaperkheda thermal power plants (district of Nagpur, Maharashtra - India) and disposed in large ponds at the surface was assessed through the study of environmental variation of ratios of stable and unstable isotopes. Analyses of oxygen and hydrogen isotopes suggest scarce interaction between the water temporarily stored in the ponds and the groundwater in the study area. Data also highlight that the high salinity of groundwater measured in the polluted wells is not due to evaporation, but to subsequent infiltration of stream waters draining from the ponds to the local aquifer. (87)Sr/(86)Sr values, when associated with Sr/Ca ratios, demonstrate the dominant role of waste waters coming from tens of brick kilns surrounding the pond sulfate pollution. Uranium isotopic analyses clearly show evidence of the interaction between groundwater and aquifer rocks, and confirm again the low influence of ash ponds. A new conceptual model based on the study of the isotopes of radium is also proposed and used to estimate residence times of groundwater in the area. This model highlights that high salinity cannot be in any case attributed to a prolonged water-rock interaction, but is due to the influence of untreated waste water of domestic or brick kiln origin on the shallow and vulnerable aquifers. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. The sustainability of LNG evaporation

    NARCIS (Netherlands)

    Stougie, L.; Van der Kooi, H.J.

    2011-01-01

    Numerous LNG (Liquefied Natural Gas) import terminals are under construction to fulfil the growing demand for energy carriers. After storage in tanks, the LNG needs to be heated and evaporated, also called ‘regasified’, to the natural gas needed in households and industry. Several options exist for

  5. Evaporation in relation to hydrology

    NARCIS (Netherlands)

    Wartena, L.; Keijman, J.Q.; Bruijn, H.A.R. de; Bakel, P.J.T. van; Stricker, J.N.M.; Velds, C.A.

    1981-01-01

    In meteorology some topics enjoy particular interest from other disciplines. The interest of hydrologists for the evaporation of water is a case in point, understandably and rightly so. In fact, over the last few decades, hydrology has clearly done more than using meteorological knowledge thus

  6. Micro-evaporation electrolyte concentrator

    NARCIS (Netherlands)

    Timmer, B.H.; van Delft, K.M.; Olthuis, Wouter; Bergveld, Piet; van den Berg, Albert

    2003-01-01

    The sensitivity of miniaturized chemical analysis systems depends most of the time on the obtainable detection limit. Concentrating the analyte prior to the detection system can enhance the detection limit. In this writing an analyte concentrator is presented that makes use of evaporation to

  7. Evaporation rate of nucleating clusters.

    Science.gov (United States)

    Zapadinsky, Evgeni

    2011-11-21

    The Becker-Döring kinetic scheme is the most frequently used approach to vapor liquid nucleation. In the present study it has been extended so that master equations for all cluster configurations are included into consideration. In the Becker-Döring kinetic scheme the nucleation rate is calculated through comparison of the balanced steady state and unbalanced steady state solutions of the set of kinetic equations. It is usually assumed that the balanced steady state produces equilibrium cluster distribution, and the evaporation rates are identical in the balanced and unbalanced steady state cases. In the present study we have shown that the evaporation rates are not identical in the equilibrium and unbalanced steady state cases. The evaporation rate depends on the number of clusters at the limit of the cluster definition. We have shown that the ratio of the number of n-clusters at the limit of the cluster definition to the total number of n-clusters is different in equilibrium and unbalanced steady state cases. This causes difference in evaporation rates for these cases and results in a correction factor to the nucleation rate. According to rough estimation it is 10(-1) by the order of magnitude and can be lower if carrier gas effectively equilibrates the clusters. The developed approach allows one to refine the correction factor with Monte Carlo and molecular dynamic simulations.

  8. Biological and physical modification of carbonate system parameters along the salinity gradient in shallow hypersaline solar salterns in Trapani, Italy

    Science.gov (United States)

    Isaji, Yuta; Kawahata, Hodaka; Kuroda, Junichiro; Yoshimura, Toshihiro; Ogawa, Nanako O.; Suzuki, Atsushi; Shibuya, Takazo; Jiménez-Espejo, Francisco J.; Lugli, Stefano; Santulli, Andrea; Manzi, Vinicio; Roveri, Marco; Ohkouchi, Naohiko

    2017-07-01

    We investigated changes in the chemical characteristics of evaporating seawater under the influence of microbial activity by conducting geochemical analyses of the brines and evaporite sediments collected from solar salterns in Trapani, Italy. The microbial activity had a substantial effect on the carbonate system parameters. Dissolved inorganic carbon (DIC) was substantially removed from the brine during the course of evaporation from the seawater to the point where calcium carbonate precipitates, with an accompanying decrease in its carbon isotopic composition (δ13CDIC) to as low as -10.6‰. Although the removal of DIC was due to calcium carbonate precipitation, photosynthesis, and the degassing of CO2(aq) induced by evaporation, the presence of 13C-depleted δ13CDIC in ponds where calcium carbonate precipitates can be attributed to the dissolution of atmospheric CO2 because of intensive CO2(aq) uptake by photosynthesis, and/or mineralization of organic matter by sulfate reduction. In contrast, δ13CDIC increased up to 7.2‰ in the salinity range where halite precipitates, which can be ascribed to the domination of the effect of degassing of CO2(aq) under conditions with reduced microbial activity. A gradual decrease in microbial activity was also reflected in compound-specific δ13C of photosynthetic pigments; isotopic fractionation associated with DIC assimilation increased linearly as the evaporation proceeded, indicating DIC-limited conditions within the microbial mats and gypsum crusts because of restricted DIC diffusion from the overlying brine and/or suppression of primary production at higher salinity.

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

    International Nuclear Information System (INIS)

    Hobbs, B.J.

    1996-06-01

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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  11. The western pond turtle: Habitat and history. Final report

    International Nuclear Information System (INIS)

    Holland, D.C.

    1994-08-01

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

  12. Bioaccumulation of heavy metals in two wet retention ponds

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  13. Relationship Between Accumulation and Influx of Pollutants in Highway Ponds

    DEFF Research Database (Denmark)

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

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

  14. Samples of Asteroid Surface Ponded Deposits in Chondritic Meteorites

    Science.gov (United States)

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

    2004-01-01

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

  15. Simple intervention to reduce mosquito breeding in waste stabilisation ponds

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  16. Transition in the fractal geometry of Arctic melt ponds

    Directory of Open Access Journals (Sweden)

    C. Hohenegger

    2012-10-01

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

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

    International Nuclear Information System (INIS)

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

    1975-06-01

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

  18. Quantifying Evaporation in a Permeable Pavement System

    Science.gov (United States)

    Studies quantifying evaporation from permeable pavement systems are limited to a few laboratory studies and one field application. This research quantifies evaporation for a larger-scale field application by measuring the water balance from lined permeable pavement sections. Th...

  19. Fundamentals of evaporation and condensation phenomena

    International Nuclear Information System (INIS)

    Munir, Z.A.

    1979-01-01

    Fundamental relationships governing evaporation and condensation processes are reviewed. The terrace-ledge-kink (TLK) model is discussed in terms of atomic steps comprising growth and evaporation of crystals. Recent results in the field are described

  20. Full-energy-chain analysis of greenhouse gas emissions for solar thermal electric power generation systems

    International Nuclear Information System (INIS)

    Norton, B.; Lawson, W.R.

    1997-01-01

    Technical attributes and environmental impacts of solar thermal options for centralized electricity generation are discussed. In particular, the full-energy-chain, including embodied energy and energy production, is considered in relation to greenhouse gas emission arising from solar thermal electricity generation. Central receiver, parabolic dish, parabolic trough and solar pond systems are considered. (author)

  1. Emerging investigator series: the rise of nano-enabled photothermal materials for water evaporation and clean water production by sunlight

    KAUST Repository

    Wang, Peng

    2018-01-01

    Solar driven water evaporation and distillation is an ancient technology, but has been rejuvenated by nano-enabled photothermal materials in the past 4 years. The nano-enabled state-of-the-art photothermal materials are able to harvest a full solar

  2. Evaporative lithographic patterning of binary colloidal films.

    Science.gov (United States)

    Harris, Daniel J; Conrad, Jacinta C; Lewis, Jennifer A

    2009-12-28

    Evaporative lithography offers a promising new route for patterning a broad array of soft materials. In this approach, a mask is placed above a drying film to create regions of free and hindered evaporation, which drive fluid convection and entrained particles to regions of highest evaporative flux. We show that binary colloidal films exhibit remarkable pattern formation when subjected to a periodic evaporative landscape during drying.

  3. Evaporative cooling in polymer electrolyte fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Shimotori, S; Sonai, A [Toshiba Corp. Tokyo (Japan)

    1996-06-05

    The concept of the evaporative cooling for the internally humidified PEFC was confirmed by the experiment. The evaporative cooling rates at the anode and the cathode were mastered under the various temperatures and air utilizations. At a high temperature the proportion of the evaporative cooling rate to the heat generation rate got higher, the possibility of the evaporative cooling was demonstrated. 2 refs., 7 figs., 1 tab.

  4. Evaporation of Lennard-Jones clusters

    International Nuclear Information System (INIS)

    Roman, C.E.; Garzon, I.L.

    1991-01-01

    Extensive molecular dynamics simulations have been done to study the evaporation of a 13-atom Lennard-Jones cluster. The survival probability and the evaporative lifetime are calculated as a function of the cluster total energy from a classical trajectory analysis. The results are interpreted in terms of the RRK theory of unimolecular dissociation. The calculation of the binding energy of the evaporated species from the evaporation rate and the average kinetic energy release is discussed. (orig.)

  5. Modelling of a cross flow evaporator for CSP application

    DEFF Research Database (Denmark)

    Sørensen, Kim; Franco, Alessandro; Pelagotti, Leonardo

    2016-01-01

    ) applications. Heat transfer and pressure drop prediction methods are an important tool for design and modelling of diabatic, two-phase, shell-side flow over a horizontal plain tubes bundle for a vertical up-flow evaporator. With the objective of developing a model for a specific type of cross flow evaporator...... the available correlations for the definition of two-phase flow heat transfer, void fraction and pressure drop in connection with the operation of steam generators, focuses attention on a comparison of the results obtained using several different models resulting by different combination of correlations......Heat exchangers consisting of bundles of horizontal plain tubes with boiling on the shell side are widely used in industrial and energy systems applications. A recent particular specific interest for the use of this special heat exchanger is in connection with Concentrated Solar Power (CSP...

  6. On the Increase in Evaporation, Climate Change Dissent

    Science.gov (United States)

    DeVore, M. E.

    2017-12-01

    To better understand the effects of global warming, I analyzed the Pan Evaporation Rate and Precipitation data in the Global Historical Climatology Dataset provided by NOAA. With this data, I show a clear increase in temperature resulting in an anomaly in the Pan Evaporation Rate that is then confirmed in the analysis of the precipitation dataset. In comparing the behavior of the data before 2005 to the data from 2005 and later, I will show a significant change that warrents greater investigation. In particular, I will show how the behavior of the NOAA data closely correlates with that of Solar Cycle 24, as opposed to other man-made causes as suggested by current theory. Due to the distinct nature and timing of the anomaly, this analysis of the NOAA data set provides a counter-argument to anthropogenic climate change.

  7. International experience in tailings pond remediation

    International Nuclear Information System (INIS)

    Robertson, A.MacG.

    2001-01-01

    Tailings pond remediation is required primarily on mine closure. While mining is an ancient industry, requirement for mine facility remediation is a comparatively new development. Requirement for remediation has come about partly as a result of mans awareness of the environmental impacts of mining and his desire to minimize this, partly, as a result of the ever-increasing scale and production rates of tailings generation and the resulting increased environmental impacts and safety risks. The paper starts with a review of the evolution of mans intolerance of environmental impacts from tailings production and the assignment of liability to remediate such impacts. Many of the tailings ponds currently undergoing remediation were designed and constructed using methods and technology that would be considered inappropriate for new impoundments being designed and developed today. The paper reviews the history of tailings impoundment design and construction practice and the resulting inherent deficiencies that must be remediated. Current practices and future trends in tailings pond remediation are reviewed. The evolution of regulatory requirements is not only in terms of technical and safety criteria, but also in terms of financial and political risk. Perhaps the most substantive driver of risk management is today the requirement for corporate governance at mining company board level and oversight of new project development in the underdeveloped countries by the large financial institutions responsible for funding projects. Embarrassment in the public eye and punishment in the stock markets for poor environmental and safety performance is driving the need for efficient and effective risk management of potential impacts and the remediation to avoid these. A basis for practical risk management is described. (orig.)

  8. International experience in tailings pond remediation

    Energy Technology Data Exchange (ETDEWEB)

    MacG. Robertson, A. [Robertson GeoConsultants Ltd., Vancouver (Canada)

    2001-07-01

    Tailings pond remediation is required primarily on mine closure. While mining is an ancient industry, requirement for mine facility remediation is a comparatively new development. Requirement for remediation has come about partly as a result of mans awareness of the environmental impacts of mining and his desire to minimize this, partly, as a result of the ever-increasing scale and production rates of tailings generation and the resulting increased environmental impacts and safety risks. The paper starts with a review of the evolution of mans intolerance of environmental impacts from tailings production and the assignment of liability to remediate such impacts. Many of the tailings ponds currently undergoing remediation were designed and constructed using methods and technology that would be considered inappropriate for new impoundments being designed and developed today. The paper reviews the history of tailings impoundment design and construction practice and the resulting inherent deficiencies that must be remediated. Current practices and future trends in tailings pond remediation are reviewed. The evolution of regulatory requirements is not only in terms of technical and safety criteria, but also in terms of financial and political risk. Perhaps the most substantive driver of risk management is today the requirement for corporate governance at mining company board level and oversight of new project development in the underdeveloped countries by the large financial institutions responsible for funding projects. Embarrassment in the public eye and punishment in the stock markets for poor environmental and safety performance is driving the need for efficient and effective risk management of potential impacts and the remediation to avoid these. A basis for practical risk management is described. (orig.)

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

    Science.gov (United States)

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

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

    International Nuclear Information System (INIS)

    Hadlock, R.K.

    1976-12-01

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

  11. Phyllosphere mycobiota on garden ponds plants

    Directory of Open Access Journals (Sweden)

    Maria Kowalik

    2013-12-01

    Full Text Available Investigations were conducted on calamus, common cattail, soft rush, yellow iris and white water lily plants in twenty ponds in Malopolska and Podkarpacie Regions. Mycobiota existing in the phyllosphere caused discolouring and necroses of leaves and shoots. 88 species of mycobiota were identified and isolated from the diseased tissues. Dominant were Alternaria alternata, Epicoccum nigrum and Isaria farinosa. Fungi of genera: Aspergillus, Botrytis, Chaetomium, Cladosporium, Fusarium, Ilyonectria, Mortierella, Mucor, Penicillium, Phialophora, Phoma, Pleustomophora, Sordaria, Trichoderma and Umbelopsis were also numerous. The monophagous and the polyphagous were identified.

  12. New models for droplet heating and evaporation

    KAUST Repository

    Sazhin, Sergei S.; Elwardani, Ahmed Elsaid; Gusev, Ivan G.; Xie, Jianfei; Shishkova, Irina N.; Cao, Bingyang; Snegirev, Alexander Yu.; Heikal, Morgan Raymond

    2013-01-01

    and evaporation, taking into account the effects of the moving boundary due to evaporation, hydrodynamic models of multi-component droplet heating and evaporation, taking and not taking into account the effects of the moving boundary, new kinetic models of mono

  13. Evaporation from a sphagnum moss surface

    Science.gov (United States)

    D.S. Nichols; J.M. Brown

    1980-01-01

    Peat cores, 45 cm in diameter, were collected from a sphagnum bog in northern Minnesota, and used to measure the effects of different temperatures and water levels on evaporation from a sphagnum moss surface in a growth chamber. Under all conditions, evaporation from the moss surface was greater than that from a free-water surface. Evaporation from the moss increased...

  14. Thermogravimetric analysis of fuel film evaporation

    Institute of Scientific and Technical Information of China (English)

    HU Zongjie; LI Liguang; YU Shui

    2006-01-01

    Thermogravimetric analysis (TGA) was compared with the petrochemical distillation measurement method to better understand the characteristics of fuel film evaporation at different wall tem- peratures. The film evaporation characteristics of 90# gasoline, 93# gasoline and 0# diesel with different initial thicknesses were investigated at different environmental fluxes and heating rates. The influences of heating rate, film thickness and environmental flux on fuel film evaporation for these fuels were found. The results showed that the environmental conditions in TGA were similar to those for fuel films in the internal combustion engines, so data from TGA were suitable for the analysis of fuel film evaporation. TGA could simulate the key influencing factors for fuel film evaporation and could investigate the basic quantificational effect of heating rate and film thickness. To get a rapid and sufficient fuel film evaporation, sufficiently high wall temperature is necessary. Evaporation time decreases at a high heating rate and thin film thickness, and intense gas flow is important to promoting fuel film evaporation. Data from TGA at a heating rate of 100℃/min are fit to analyze the diesel film evaporation during cold-start and warming-up. Due to the tense molecular interactions, the evaporation sequence could not be strictly divided according to the boiling points of each component for multicomponent dissolved mixture during the quick evaporation process, and the heavier components could vaporize before reaching their boiling points. The 0# diesel film would fully evaporate when the wall temperature is beyond 250℃.

  15. An evaporation driven pump for microfluidics applications

    NARCIS (Netherlands)

    Nie, C.; Mandamparambil, R.; Frijns, A.J.H.; den Toonder, J.M.J.; Tadrist, L.; Graur, I.

    2014-01-01

    We present an evaporation driven micro-pump for micro fluidic applications on a foil. In such a device, the evaporation rate is controlled by the geometry of the channel outlet and its temperature. The evaporation is also influenced by environmental parameters such as air humidity and temperature.

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

    International Nuclear Information System (INIS)

    Codell, R.

    1982-09-01

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

  17. Water Evaporation in Swimming Baths

    DEFF Research Database (Denmark)

    Hyldgård, Carl-Erik

    This paper is publishing measuring results from models and full-scale baths of the evaporation in swimming baths, both public baths and retraining baths. Moreover, the heat balance of the basin water is measured. In addition the full-scale measurements have given many experiences which are repres......This paper is publishing measuring results from models and full-scale baths of the evaporation in swimming baths, both public baths and retraining baths. Moreover, the heat balance of the basin water is measured. In addition the full-scale measurements have given many experiences which...... are represented in instructions for carrying out and running swimming baths. If you follow the instructions you can achieve less investments, less heat consumption and a better comfort to the bathers....

  18. Black hole evaporation: a paradigm

    International Nuclear Information System (INIS)

    Ashtekar, Abhay; Bojowald, Martin

    2005-01-01

    A paradigm describing black hole evaporation in non-perturbative quantum gravity is developed by combining two sets of detailed results: (i) resolution of the Schwarzschild singularity using quantum geometry methods and (ii) time evolution of black holes in the trapping and dynamical horizon frameworks. Quantum geometry effects introduce a major modification in the traditional spacetime diagram of black hole evaporation, providing a possible mechanism for recovery of information that is classically lost in the process of black hole formation. The paradigm is developed directly in the Lorentzian regime and necessary conditions for its viability are discussed. If these conditions are met, much of the tension between expectations based on spacetime geometry and structure of quantum theory would be resolved

  19. Duplex Tear Film Evaporation Analysis.

    Science.gov (United States)

    Stapf, M R; Braun, R J; King-Smith, P E

    2017-12-01

    Tear film thinning, hyperosmolarity, and breakup can cause irritation and damage to the human eye, and these form an area of active investigation for dry eye syndrome research. Recent research demonstrates that deficiencies in the lipid layer may cause locally increased evaporation, inducing conditions for breakup. In this paper, we explore the conditions for tear film breakup by considering a model for tear film dynamics with two mobile fluid layers, the aqueous and lipid layers. In addition, we include the effects of osmosis, evaporation as modified by the lipid, and the polar portion of the lipid layer. We solve the system numerically for reasonable parameter values and initial conditions and analyze how shifts in these cause changes to the system's dynamics.

  20. Solar Still Coupled With Solar Collector and Storage Tank

    OpenAIRE

    Rajesh, A. M.; Bharath, K. N.

    2010-01-01

    Acute shortage of good, clean drinking water is a major problem for most developing countries of the world. In most cases, ponds, streams, wells and rivers are often polluted that they are unsafe for direct use as drinking water >.Often water sources are brackish and or contain harmful bacteria. Therefore cannot be used for drinking .In addition there are many coastal locations where sea water is abundant but potable water is not available. Solar distillation is one of the important methods o...

  1. Dew Point Evaporative Comfort Cooling

    Science.gov (United States)

    2012-11-01

    Multiple DASs were installed at Fort Carson, and the data from all the sensors were stored and partially processed on Campbell Scientific Data Loggers. The...evaporative cooling technologies would be expected to easily overcome utility- scale water withdrawal rates. As an example, an evaluation of an...Ambient pressure Outdoor Setra 276 1% of full scale Pyranometer Horizontal Campbell Scientific CS300 5% of daily total The OAT measurement has an

  2. PERFORMANCES OF TIGER SHRIMP CULTURE IN ENVIRONMENTALLY FRIENDLY PONDS

    Directory of Open Access Journals (Sweden)

    Taufik Ahmad

    2016-10-01

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

  3. First description of underwater acoustic diversity in three temperate ponds

    Directory of Open Access Journals (Sweden)

    Camille Desjonquères

    2015-11-01

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

  4. Examining Water Quality Variations of Tidal Pond System

    Science.gov (United States)

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

    2014-12-01

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

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

    Science.gov (United States)

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

    2017-12-01

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

  6. Experimental results on evaporation waves

    Science.gov (United States)

    Grana Otero, Jose; Parra Fabian, Ignacio

    2010-11-01

    A liquid contained in a vertical glass tube is suddenly depressurized from a high initial pressure down to one for which the stable state is vapour, so vaporization sets off at the free surface. For large enough evaporation rates, the planar vapour-liquid interface is Darrieus-Landau unstable [1], leading to the interface surface rippling close to the instability threshold. Further increasing the initial to final pressure ratio brings about evaporation waves [2,3], in which a highly corrugated front propagates downwards into the liquid. A new experimental method is presented as well as some experimental results obtained by tracking the evolution of the front with a high speed camera. In addition, a number of new phenomena related to the dynamics of bubbles growth at the walls has been uncovered. In particular, a new mode of propagation of the evaporation front is found. In this mode the front originates from below the interface, so the propagation is upwards against gravity with a curved but smooth front.[4pt] [1] F. J. Higuera, Phys. Fluids, V. 30, 679 (1987).[0pt] [2] J.E.Shepherd and B.Sturtevant, J.Fluid Mech., V.121,379 (1982).[0pt] [3] P.Reinke and G.Yadigaroglu, Int.J.Multiph. Flow, V.27,1487 (2001).

  7. Improvements of evaporation drag model

    International Nuclear Information System (INIS)

    Li Xiaoyan; Yang Yanhua; Xu Jijun

    2004-01-01

    A special observable experiment facility has been established, and a series of experiments have been carried out on this facility by pouring one or several high-temperature particles into a water pool. The experiment has verified the evaporation drag model, which believe the non-symmetric profile of the local evaporation rate and the local density of the vapor would bring about a resultant force on the hot particle so as to resist its motion. However, in Yang's evaporation drag model, radiation heat transfer is taken as the only way to transfer heat from hot particle to the vapor-liquid interface and all of the radiation energy is deposited on the vapor-liquid interface, thus contributing to the vaporization rate and mass balance of the vapor film. So, the heat conduction and the heat convection are taken into account in improved model. At the same time, the improved model given by this paper presented calculations of the effect of hot particles temperature on the radiation absorption behavior of water

  8. Cooling clothing utilizing water evaporation

    DEFF Research Database (Denmark)

    Sakoi, Tomonori; Tominaga, Naoto; Melikov, Arsen Krikor

    2014-01-01

    . To prevent wet discomfort, the T-shirt was made of a polyester material having a water-repellent silicon coating on the inner surface. The chest, front upper arms, and nape of the neck were adopted as the cooling areas of the human body. We conducted human subject experiments in an office with air......We developed cooling clothing that utilizes water evaporation to cool the human body and has a mechanism to control the cooling intensity. Clean water was supplied to the outer surface of the T-shirt of the cooling clothing, and a small fan was used to enhance evaporation on this outer surface...... temperature ranging from 27.4 to 30.7 °C to establish a suitable water supply control method. A water supply control method that prevents water accumulation in the T-shirt and water dribbling was validated; this method is established based on the concept of the water evaporation capacity under the applied...

  9. Mini-review: high rate algal ponds, flexible systems for sustainable wastewater treatment.

    Science.gov (United States)

    Young, P; Taylor, M; Fallowfield, H J

    2017-06-01

    Over the last 20 years, there has been a growing requirement by governments around the world for organisations to adopt more sustainable practices. Wastewater treatment is no exception, with many currently used systems requiring large capital investment, land area and power consumption. High rate algal ponds offer a sustainable, efficient and lower cost option to the systems currently in use. They are shallow, mixed lagoon based systems, which aim to maximise wastewater treatment by creating optimal conditions for algal growth and oxygen production-the key processes which remove nitrogen and organic waste in HRAP systems. This design means they can treat wastewater to an acceptable quality within a fifth of time of other lagoon systems while using 50% less surface area. This smaller land requirement decreases both the construction costs and evaporative water losses, making larger volumes of treated water available for beneficial reuse. They are ideal for rural, peri-urban and remote communities as they require minimum power and little on-site management. This review will address the history of and current trends in high rate algal pond development and application; a comparison of their performance with other systems when treating various wastewaters; and discuss their potential for production of added-value products. Finally, the review will consider areas requiring further research.

  10. The evolution of 17O-excess in surface water of the arid environment during recharge and evaporation.

    Science.gov (United States)

    Surma, J; Assonov, S; Herwartz, D; Voigt, C; Staubwasser, M

    2018-03-21

    This study demonstrates the potential of triple O-isotopes to quantify evaporation with recharge on a salt lake from the Atacama Desert, Chile. An evaporative gradient was found in shallow ponds along a subsurface flow-path from a groundwater source. Total dissolved solids (TDS) increased by 177 g/l along with an increase in δ 18 O by 16.2‰ and in δD by 65‰. 17 O-excess decreased by 79 per meg, d-excess by 55‰. Relative humidity (h), evaporation over inflow (E/I), the isotopic composition of vapor ( * R V ) and of inflowing water ( * R WI ) determine the isotope distribution in 17 O-excess over δ 18 O along a well-defined evaporation curve as the classic Craig-Gordon model predicts. A complementary on-site simple (pan) evaporation experiment over a change in TDS, δ 18 O, and 17 O-excess by 392 g/l, 25.0‰, and -130 per meg, respectively, was used to determine the effects of sluggish brine evaporation and of wind turbulence. These effects translate to uncertainty in E/I rather than h. The local composition of * R V relative to * R WI pre-determines the general ability to resolve changes in h. The triple O-isotope system is useful for quantitative hydrological balancing of lakes and for paleo-humidity reconstruction, particularly if complemented by D/H analysis.

  11. Spray pond design for nuclear power plants

    International Nuclear Information System (INIS)

    Codell, R.B.; Asce, A.M.

    1986-01-01

    This paper presents a complex methodology for assessing the performance of spray ponds in ultimate heat sink service at nuclear power plants. A spray pond performance model, developed in the companion paper, is used in conjunction with on-site and off-site meteorological data to predict the highest temperature and greatest 30 day water loss which can reasonable be expected to occur during the lifetime of the plant. The performance model for heat and mass transfer is used to develop an efficient phenomenological model used to scan the long-term meteorological records. Refined estimates of temperature or water loss may then be based on more complicated models if necessary. Short-term onsite data are correlated to the long-term off-site data to formulate correction factors for the difference in location. Cumulative distribution functions for temperature and water loss are determined from the long-term meteorological records to predict the occurrence of these quantities which are less severe that the peak. The methodology is demonstrated using data and parameters from the Palo Verde nuclear plant as an example

  12. 2101-M Pond hydrogeologic characterization report

    Energy Technology Data Exchange (ETDEWEB)

    Chamness, M.A.; Luttrell, S.P.; Bates, D.J.; Martin, W.J.

    1990-09-01

    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.

  13. Heat and mass transfer analogies for evaporation models at high evaporation rate

    OpenAIRE

    Trontin , P.; Villedieu , P.

    2014-01-01

    International audience; In the framework of anti and deicing applications, heated liquid films can appear above the ice thickness, or directly above the wall. Then, evaporation plays a major role in the Messinger balance and evaporated mass has to be predicted accurately. Unfortunately, it appears that existing models under-estimate evaporation at high temperature. In this study, different evaporation models at high evaporation rates are studied. The different hypothesis on which these models...

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

    Science.gov (United States)

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

    2018-03-25

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

  15. Biological removal of algae in an integrated pond system

    CSIR Research Space (South Africa)

    Meiring, PGJ

    1995-01-01

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

  16. Modeling the summertime evolution of sea-ice melt ponds

    DEFF Research Database (Denmark)

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

    2006-01-01

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

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

    African Journals Online (AJOL)

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

  18. Arthropod fauna of the University of Nigeria, Nsukka, Sewage pond ...

    African Journals Online (AJOL)

    A survey of arthropod fauna of the University of Nigeria Nsukka sewage pond was carried out within May and June 2011. The aim was to determine the various arthropod species and its abundance in the sewage pond. The analysis was carried out by two methods, physico-chemical analysis and arthropod faunal studies.

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

    African Journals Online (AJOL)

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

  20. Effects of riparian buffers on hydrology of northern seasonal ponds

    Science.gov (United States)

    Randall K. Kolka; Brian J. Palik; Daniel P. Tersteeg; James C. Bell

    2011-01-01

    Although seasonal ponds are common in northern, glaciated, forested landscapes, forest management guidelines are generally lacking for these systems. The objective of this study was to determine the effect of riparian buffer type on seasonal pond hydrology following harvest of the adjacent upland forest. A replicated block design consisting of four buffer treatments...

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

    African Journals Online (AJOL)

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

  2. Mathematical modeling of dissolved oxygen in fish ponds ...

    African Journals Online (AJOL)

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

  3. Energy and water management in evaporative cooling systems in Saudi Arabia

    Energy Technology Data Exchange (ETDEWEB)

    Kassem, Abdel-wahab S. (Agricultural and Veterinary Training and Research Station, King Faisal University, Al-Hassa (Saudi Arabia))

    1994-11-01

    A mathematical model was developed to estimate water evaporation rate, airflow rate and cooling effect in an evaporative cooling system for farm structures. The model was only applied to evaporative cooling systems for greenhouses. The effect of ambient air temperature, solar radiation and system efficiency on water evaporation rate, airflow rate and the resulting cooling effect were studied. Generally, water flow rate and air flow rate are adjusted based on daily maximum temperature. However, a substantial saving in energy and water consumption in the cooling system would be achieved by regulating water flow rate and air flow rate to follow the diurnal variation on temperature. Improving the cooling efficiency and covering the roof of the greenhouse with an external shading would save an appreciable amount of energy and water consumption. The model could also be applied to other farm structures such as animal shelters

  4. Air Evaporation closed cycle water recovery technology - Advanced energy saving designs

    Science.gov (United States)

    Morasko, Gwyndolyn; Putnam, David F.; Bagdigian, Robert

    1986-01-01

    The Air Evaporation water recovery system is a visible candidate for Space Station application. A four-man Air Evaporation open cycle system has been successfully demonstrated for waste water recovery in manned chamber tests. The design improvements described in this paper greatly enhance the system operation and energy efficiency of the air evaporation process. A state-of-the-art wick feed design which results in reduced logistics requirements is presented. In addition, several design concepts that incorporate regenerative features to minimize the energy input to the system are discussed. These include a recuperative heat exchanger, a heat pump for energy transfer to the air heater, and solar collectors for evaporative heat. The addition of the energy recovery devices will result in an energy reduction of more than 80 percent over the systems used in earlier manned chamber tests.

  5. Walden Pond, Massachusetts: Environmental Setting and Current Investigations

    Science.gov (United States)

    Colman, John A.; Waldron, Marcus C.

    1998-01-01

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

  6. Does evaporation paradox exist in China?

    Directory of Open Access Journals (Sweden)

    Z. T. Cong

    2009-03-01

    Full Text Available One expected consequence of global warming is the increase in evaporation. However, lots of observations show that the rate of evaporation from open pans of water has been steadily decreasing all over the world in the past 50 years. The contrast between expectation and observation is called "evaporation paradox". Based on data from 317 weather stations in China from 1956 to 2005, the trends of pan evaporation and air temperature were obtained and evaporation paradox was analyzed. The conclusions include: (1 From 1956 to 2005, pan evaporation paradox existed in China as a whole while pan evaporation kept decreasing and air temperature became warmer and warmer, but it does not apply to Northeast and Southeast China; (2 From 1956 to 1985, pan evaporation paradox existed narrowly as a whole with unobvious climate warming trend, but it does not apply to Northeast China; (3 From 1986 to 2005, in the past 20 years, pan evaporation paradox did not exist for the whole period while pan evaporation kept increasing, although it existed in South China. Furthermore, the trend of other weather factors including sunshine duration, windspeed, humidity and vapor pressure deficit, and their relations with pan evaporation are discussed. As a result, it can be concluded that pan evaporation decreasing is caused by the decreasing in radiation and wind speed before 1985 and pan evaporation increasing is caused by the decreasing in vapor pressure deficit due to strong warming after 1986. With the Budyko curve, it can be concluded that the actual evaporation decreased in the former 30 years and increased in the latter 20 year for the whole China.

  7. Effectiveness of indirect evaporative cooling and thermal mass in a hot arid climate

    Energy Technology Data Exchange (ETDEWEB)

    Krueger, Eduardo [Programa de Pos-Graduacao em Tecnologia/Programa de Pos-Graduacao em Engenharia Civil, Departamento de Construcao Civil, Universidade Tecnologica Federal do Parana - UTFPR, Av. Sete de Setembro, 3165. Curitiba PR, CEP. 80230-901 (Brazil); Gonzalez Cruz, Eduardo [Instituto de Investigaciones de la Facultad de Arquitectura y Diseno (IFAD), Universidad del Zulia, Nucleo Tecnico de LUZ, Av. Goajira (16) con Calle 67, Maracaibo, CP 4011-A-526 (Venezuela); Givoni, Baruch [Department of Architecture, School of Arts and Architecture, UCLA, Los Angeles CA, USA, and Ben Gurion University (Israel)

    2010-06-15

    In this paper, we compare results of a long-term temperature monitoring in a building with high thermal mass to indoor temperature predictions of a second building that uses an indirect evaporative cooling system as a means of passive cooling (Vivienda Bioclimatica Prototipo -VBP-1), for the climatic conditions of Sde Boqer, Negev region of Israel (local latitude 30 52'N, longitude 34 46'E, approximately 480 m above sea level). The high-mass building was monitored from January through September 2006 and belongs to a student dormitory complex located at the Sde Boqer Campus of Ben-Gurion University. VBP-1 was designed and built in Maracaibo, Venezuela (latitude 10 34'N, longitude 71 44'W, elevation 66 m above sea level) and had its indoor air temperatures, below and above a shaded roof pond, as well as the pond temperature monitored from February to September 2006. Formulas were developed for the VBP-1, based on part of the whole monitoring period, which represent the measured daily indoor maximum, average and minimum temperatures. The formulas were then validated against measurements taken independently in different time periods. The developed formulas were here used for estimating the building's thermal and energy performance at the climate of Sde Boqer, allowing a comparison of two different strategies: indirect evaporative cooling and the use of thermal mass. (author)

  8. Vanishing Ponds and Regional Water Resources in Taoyuan, Taiwan

    Directory of Open Access Journals (Sweden)

    Yuei-An Liou

    2015-01-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

  10. Evaporative oxidation treatability test report

    International Nuclear Information System (INIS)

    1995-04-01

    In 1992, Congress passed the Federal Facilities Compliance Act that requires the U.S. Department of Energy (DOE) to treat and dispose of its mixed waste in accordance with the Resource Conservation and Recovery Act (RCRA) land disposal restrictions (LDRs). In response to the need for mixed-waste treatment capacity where available off-site commercial treatment facilities do not exist or cannot be used, the DOE Albuquerque Operations Office (DOE-AL) organized a Treatment Selection Team to match mixed wastes with treatment options and develop a strategy for treatment of its mixed wastes. DOE-AL manages operations at nine sites with mixed-waste inventories. The Treatment Selection Team determined a need to develop mobile treatment capacity to treat wastes at the sites where the wastes are generated. Treatment processes used for mixed waste not only must address the hazardous component (i.e., meet LDRs) but also must contain the radioactive component in a form that allows final disposal while protecting workers, the public, and the environment. On the basis of recommendations of the Treatment Selection Team, DOE-AL assigned projects to the sites to bring mixed-waste treatment capacity on-line. The three technologies assigned to the DOE Grand Junction Projects Office (GJPO) are evaporative oxidation, thermal desorption, and treated wastewater evaporation. Rust Geotech, the DOE-GJPO prime contractor, was assigned to design and fabricate mobile treatment units (MTUs) for these three technologies and to deliver the MTUs to selected DOE-AL sites. To conduct treatability tests at the GJPO, Rust leased a pilot-scale evaporative oxidation unit from the Clemson Technical Center (CTC), Anderson, South Carolina. The purpose of this report is to document the findings and results of tests performed using this equipment

  11. Mobile evaporator corrosion test results

    International Nuclear Information System (INIS)

    Rozeveld, A.; Chamberlain, D.B.

    1997-05-01

    Laboratory corrosion tests were conducted on eight candidates to select a durable and cost-effective alloy for use in mobile evaporators to process radioactive waste solutions. Based on an extensive literature survey of corrosion data, three stainless steel alloys (304L, 316L, AL-6XN), four nickel-based alloys (825, 625, 690, G-30), and titanium were selected for testing. The corrosion tests included vapor phase, liquid junction (interface), liquid immersion, and crevice corrosion tests on plain and welded samples of candidate materials. Tests were conducted at 80 degrees C for 45 days in two different test solutions: a nitric acid solution. to simulate evaporator conditions during the processing of the cesium ion-exchange eluant and a highly alkaline sodium hydroxide solution to simulate the composition of Tank 241-AW-101 during evaporation. All of the alloys exhibited excellent corrosion resistance in the alkaline test solution. Corrosion rates were very low and localized corrosion was not observed. Results from the nitric acid tests showed that only 316L stainless steel did not meet our performance criteria. The 316L welded interface and crevice specimens had rates of 22.2 mpy and 21.8 mpy, respectively, which exceeds the maximum corrosion rate of 20 mpy. The other welded samples had about the same corrosion resistance as the plain samples. None of the welded samples showed preferential weld or heat-affected zone (HAZ) attack. Vapor corrosion was negligible for all alloys. All of the alloys except 316L exhibited either open-quotes satisfactoryclose quotes (2-20 mpy) or open-quotes excellentclose quotes (<2 mpy) corrosion resistance as defined by National Association of Corrosion Engineers. However, many of the alloys experienced intergranular corrosion in the nitric acid test solution, which could indicate a susceptibility to stress corrosion cracking (SCC) in this environment

  12. Assessment of groundwater pollution from ash ponds using stable and unstable isotopes around the Koradi and Khaperkheda thermal power plants (Maharashtra, India)

    Energy Technology Data Exchange (ETDEWEB)

    Voltaggio, M.; Spadoni, M. [CNR — Istituto di Geologia Ambientale e Geoingegneria, Via Salaria km. 29.300, 00010 Montelibretti, Roma (Italy); Sacchi, E. [Dept. of Earth and Environmental Sciences, University of Pavia and CNR-IGG, Via Ferrata 1, 27100 Pavia (Italy); Sanam, R.; Pujari, P.R.; Labhasetwar, P.K. [CSIR-National Environmental Engineering Research Institute, Nehru Marg, Nagpur 440020 (India)

    2015-06-15

    The impact on local water resources due to fly ash produced in the Koradi and Khaperkheda thermal power plants (district of Nagpur, Maharashtra — India) and disposed in large ponds at the surface was assessed through the study of environmental variation of ratios of stable and unstable isotopes. Analyses of oxygen and hydrogen isotopes suggest scarce interaction between the water temporarily stored in the ponds and the groundwater in the study area. Data also highlight that the high salinity of groundwater measured in the polluted wells is not due to evaporation, but to subsequent infiltration of stream waters draining from the ponds to the local aquifer. {sup 87}Sr/{sup 86}Sr values, when associated with Sr/Ca ratios, demonstrate the dominant role of waste waters coming from tens of brick kilns surrounding the pond sulfate pollution. Uranium isotopic analyses clearly show evidence of the interaction between groundwater and aquifer rocks, and confirm again the low influence of ash ponds. A new conceptual model based on the study of the isotopes of radium is also proposed and used to estimate residence times of groundwater in the area. This model highlights that high salinity cannot be in any case attributed to a prolonged water–rock interaction, but is due to the influence of untreated waste water of domestic or brick kiln origin on the shallow and vulnerable aquifers. - Highlights: • Ash ponds have wide environmental and social impact in India. • Isotope ratios can be used as tracers for possible pollution of groundwater. • Isotopes of O, H, Sr, U and Ra have been used to investigate the area of Koradi. • Salinity of groundwater is not due to fly ash but linked to local brick kilns. • A model for the residence time of water based on Ra isotopes is described.

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

    International Nuclear Information System (INIS)

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

    1996-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

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

    International Nuclear Information System (INIS)

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

    1996-06-01

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

  16. Evaporation From Soil Containers With Irregular Shapes

    Science.gov (United States)

    Assouline, Shmuel; Narkis, Kfir

    2017-11-01

    Evaporation from bare soils under laboratory conditions is generally studied using containers of regular shapes where the vertical edges are parallel to the flow lines in the drying domain. The main objective of this study was to investigate the impact of irregular container shapes, for which the flow lines either converge or diverge toward the surface. Evaporation from initially saturated sand and sandy loam soils packed in cones and inverted cones was compared to evaporation from corresponding cylindrical columns. The initial evaporation rate was higher in the cones, and close to potential evaporation. At the end of the experiment, the cumulative evaporation depth in the sand cone was equal to that in the column but higher than in the inverted cone, while in the sandy loam, the order was cone > column > inverted cone. By comparison to the column, stage 1 evaporation was longer in the cones, and practically similar in the inverted cones. Stage 2 evaporation rate decreased with the increase of the evaporating surface area. These results were more pronounced in the sandy loam. For the sand column, the transition between stage 1 and stage 2 evaporation occurred when the depth of the saturation front was approximately equal to the characteristic length of the soil. However, for the cone and the inverted cone, it occurred for a shallower depth of the saturation front. It seems therefore that the concept of the characteristic length derived from the soil hydraulic properties is related to drying systems of regular shapes.

  17. Data validation report for the 100-D Ponds Operable Unit: 100-D ponds sampling

    International Nuclear Information System (INIS)

    Stankovich, M.T.

    1994-01-01

    Westinghouse-Hanford has requested that 100 percent of the Sample Delivery Groups be validated for the 100-D Ponds Operable Unit Sampling Investigation. Therefore the data from the chemical analysis of all 30 samples from this sampling event and their related quality assurance samples were reviewed and validated to verify that reported sample results were of sufficient quality to support decisions regarding remedial actions performed at this site

  18. Quantized evaporation from liquid helium

    Science.gov (United States)

    Baird, M. J.; Hope, F. R.; Wyatt, A. F. G.

    1983-07-01

    The atomic-level kinetics of evaporation from a liquid surface are investigated experimentally for the case of liquid He-4. A pulse of phonons was injected by a submerged thin-film heater into purified He-4 (cooled to less than about 0.1 K) and collimated into a beam directed at the liquid surface; the atoms liberated at the surface were detected by a bolometer. The energy of the incident phonon and the kinetic energy of the liberated atom were calculated by determining the group velocity (from the minimum time elapsed between the beginning of the heater pulse and the arrival of the leading edge of the signal) and combining it with neutron-measured excitation dispersion data. Measurements were also made with a mixture of He-3 and He-4. The results are shown to be in good agreement with theoretical predictions of the phonon-induced quantum evaporation of surface atoms: the energy of the phonon is divided between the kinetic energy of the liberated atom and the energy required to overcome the binding forces.

  19. Evaporator modeling - A hybrid approach

    International Nuclear Information System (INIS)

    Ding Xudong; Cai Wenjian; Jia Lei; Wen Changyun

    2009-01-01

    In this paper, a hybrid modeling approach is proposed to model two-phase flow evaporators. The main procedures for hybrid modeling includes: (1) Based on the energy and material balance, and thermodynamic principles to formulate the process fundamental governing equations; (2) Select input/output (I/O) variables responsible to the system performance which can be measured and controlled; (3) Represent those variables existing in the original equations but are not measurable as simple functions of selected I/Os or constants; (4) Obtaining a single equation which can correlate system inputs and outputs; and (5) Identify unknown parameters by linear or nonlinear least-squares methods. The method takes advantages of both physical and empirical modeling approaches and can accurately predict performance in wide operating range and in real-time, which can significantly reduce the computational burden and increase the prediction accuracy. The model is verified with the experimental data taken from a testing system. The testing results show that the proposed model can predict accurately the performance of the real-time operating evaporator with the maximum error of ±8%. The developed models will have wide applications in operational optimization, performance assessment, fault detection and diagnosis

  20. QUALITATIVE COMPOSITION OF PHYTOPLANKTONS IN DIFFERENTLY MANURED CARP PONDS

    Directory of Open Access Journals (Sweden)

    Ljubica Debeljak

    1997-04-01

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

  1. New models for droplet heating and evaporation

    KAUST Repository

    Sazhin, Sergei S.

    2013-02-01

    A brief summary of new models for droplet heating and evaporation, developed mainly at the Sir Harry Ricardo Laboratory of the University of Brighton during 2011-2012, is presented. These are hydrodynamic models for mono-component droplet heating and evaporation, taking into account the effects of the moving boundary due to evaporation, hydrodynamic models of multi-component droplet heating and evaporation, taking and not taking into account the effects of the moving boundary, new kinetic models of mono-component droplet heating and evaporation, and a model for mono-component droplet evaporation, based on molecular dynamics simulation. The results, predicted by the new models are compared with experimental data and the prehctions of the previously developed models where possible. © 2013 Asian Network for Scientific Information.

  2. Wetting and evaporation of binary mixture drops.

    Science.gov (United States)

    Sefiane, Khellil; David, Samuel; Shanahan, Martin E R

    2008-09-11

    Experimental results on the wetting behavior of water, methanol, and binary mixture sessile drops on a smooth, polymer-coated substrate are reported. The wetting behavior of evaporating water/methanol drops was also studied in a water-saturated environment. Drop parameters (contact angle, shape, and volume) were monitored in time. The effects of the initial relative concentrations on subsequent evaporation and wetting dynamics were investigated. Physical mechanisms responsible for the various types of wetting behavior during different stages are proposed and discussed. Competition between evaporation and hydrodynamic flow are evoked. Using an environment saturated with water vapor allowed further exploration of the controlling mechanisms and underlying processes. Wetting stages attributed to differential evaporation of methanol were identified. Methanol, the more volatile component, evaporates predominantly in the initial stage. The data, however, suggest that a small proportion of methanol remained in the drop after the first stage of evaporation. This residual methanol within the drop seems to influence subsequent wetting behavior strongly.

  3. Is evaporative colling important for shallow clouds?

    Science.gov (United States)

    Gentine, P.; Park, S. B.; Davini, P.; D'Andrea, F.

    2017-12-01

    We here investigate and test using large-eddy simulations the hypothesis that evaporative cooling might not be crucial for shallow clouds. Results from various Shallow convection and stratocumulus LES experiments show that the influence of evaporative cooling is secondary compared to turbulent mixing, which dominates the buoyancy reversal. In shallow cumulus subising shells are not due to evaporative cooling but rather reflect a vortical structure, with a postive buoyancy anomaly in the core due to condensation. Disabling evaporative cooling has negligible impact on this vortical structure and on buoyancy reversal. Similarly in non-precipitating stratocumuli evaporative cooling is negeligible copmared to other factors, especially turbulent mixing and pressure effects. These results emphasize that it may not be critical to icnlude evaporative cooling in parameterizations of shallow clouds and that it does not alter entrainment.

  4. Ecological behavior of plutonium and americium in a freshwater pond

    International Nuclear Information System (INIS)

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

    1976-01-01

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

  5. Monthly and diurnal variations of limnological conditions of two ponds

    Directory of Open Access Journals (Sweden)

    AKM Fazlur Rahaman

    2017-06-01

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

  6. Groundwater impact assessment report for the 100-D Ponds

    International Nuclear Information System (INIS)

    Alexander, D.J.

    1993-07-01

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

  7. Sessile Drop Evaporation and Leidenfrost Phenomenon

    OpenAIRE

    A. K. Mozumder; M. R. Ullah; A. Hossain; M. A. Islam

    2010-01-01

    Problem statement: Quenching and cooling are important process in manufacturing industry for controlling the mechanical properties of materials, where evaporation is a vital mode of heat transfer. Approach: This study experimentally investigated the evaporation of sessile drop for four different heated surfaces of Aluminum, Brass, Copper and Mild steel with a combination of four different liquids as Methanol, Ethanol, Water and NaCl solution. The time of evaporation for the droplet on the hot...

  8. A review of virus removal in wastewater treatment pond systems.

    Science.gov (United States)

    Verbyla, Matthew E; Mihelcic, James R

    2015-03-15

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

  9. FROM PONDS TO MAN-MADE SEAS IN RUSSIA

    Directory of Open Access Journals (Sweden)

    Sergey Gorshkov

    2013-01-01

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

  10. Report on the methylmercury situation in Par Pond. Final report

    International Nuclear Information System (INIS)

    Schindler, J.E.; Williams, D.J.; Alberts, J.J.

    1975-06-01

    Studies are reported on the methylation and accumulation of mercury in fish populations of the pond. Results showed that the majority of the mercury in the fish muscles was in the methyl mercury form. Very low concentrations of mercury were found in the pond sediments. Physiological methylation of the mercury could not be demonstrated by in vivo or in vitro techniques. Organic ligand methylation and reduction of the mercury was shown to be a possible mechanism to account for both the mercury distribution in the pond and the concentrations of methylmercury in the fish. Recommendations are made for remedial treatments to eliminate the mercury problem. (HLW)

  11. Limnological database for Par Pond: 1959 to 1980

    International Nuclear Information System (INIS)

    Tilly, L.J.

    1981-03-01

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

  12. Greenhouse Gas Exchange in Small Arctic Thaw Ponds

    Science.gov (United States)

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

    2014-12-01

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

  13. Portable brine evaporator unit, process, and system

    Science.gov (United States)

    Hart, Paul John; Miller, Bruce G.; Wincek, Ronald T.; Decker, Glenn E.; Johnson, David K.

    2009-04-07

    The present invention discloses a comprehensive, efficient, and cost effective portable evaporator unit, method, and system for the treatment of brine. The evaporator unit, method, and system require a pretreatment process that removes heavy metals, crude oil, and other contaminates in preparation for the evaporator unit. The pretreatment and the evaporator unit, method, and system process metals and brine at the site where they are generated (the well site). Thus, saving significant money to producers who can avoid present and future increases in transportation costs.

  14. Role of rainwater induced subsurface flow in water-level dynamics and thermoerosion of shallow thermokarst ponds on the Northeastern Qinghai-Tibet Plateau

    Science.gov (United States)

    Pan, X.; Yu, Q.; You, Y.

    2014-12-01

    Understanding hydrological and thermal regimes of thermokarst lakes is of great importance for predicting their responses to climate change. However, mechanism of water-level dynamics and associated thermal effects on thermoerosion of thermokarst lakes are still not well understood on the Qinghai-Tibet Plateau (QTP). In this study, we investigate two typical shallow thermokarst ponds (namely small lakes) in a warm permafrost region with thick active layer on the northeastern QTP through quantifying water budget. Results demonstrate that, rainfall induced subsurface lateral flow dominates pond water-level regime. Annual variation of pond water-level relies on areal water budget of surrounding active layer, particularly the high variable of precipitation. Besides, it is worth noting the extraordinary warming during the late ice-cover period, because marked air gap between upper ice-cover and underlying water, led by the upward thawing of thick ice-cover, might result in greenhouse-like condition due to the unique weather that strong solar radiation and little snowpack. This hydrological mechanism also exerts evident impacts on thermal regime and thermoerosion of the shallow thermokarst ponds, and they are closely related to retreat of thermokarst pondshore and underlying permafrost degradation. These findings imply a localized model addressing the unique hydrological and thermal regimes of thermokarst lakes would be essential to study the evolution of these shallow rainwater dominated thermokarst ponds on the QTP.

  15. Elimination and accumulation of polycyclic aromatic hydrocarbons (PAHs) in urban stormwater wet detention ponds

    DEFF Research Database (Denmark)

    Istenič, Daria; Arias, Carlos Alberto; Matamoros, Victor

    2011-01-01

    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...

  16. Entropy Budget for Hawking Evaporation

    Directory of Open Access Journals (Sweden)

    Ana Alonso-Serrano

    2017-07-01

    Full Text Available Blackbody radiation, emitted from a furnace and described by a Planck spectrum, contains (on average an entropy of 3 . 9 ± 2 . 5 bits per photon. Since normal physical burning is a unitary process, this amount of entropy is compensated by the same amount of “hidden information” in correlations between the photons. The importance of this result lies in the posterior extension of this argument to the Hawking radiation from black holes, demonstrating that the assumption of unitarity leads to a perfectly reasonable entropy/information budget for the evaporation process. In order to carry out this calculation, we adopt a variant of the “average subsystem” approach, but consider a tripartite pure system that includes the influence of the rest of the universe, and which allows “young” black holes to still have a non-zero entropy; which we identify with the standard Bekenstein entropy.

  17. Organic evaporator steam valve failure

    International Nuclear Information System (INIS)

    Jacobs, R.A.

    1992-01-01

    Defense Waste Processing Facility (DWPF) Technical has requested an analysis of the capacity of the Organic Evaporator (OE) condenser (OEC) be performed to determine its capability in the case where the OE steam flow control valve fails open. Calculations of the OE boilup and the OEC heat transfer coefficient indicate the OEC will have more than enough capacity to remove the heat at maximum OE boilup. In fact, the Salt Cell Vent Condenser (SCVC) should also have sufficient capacity to handle the maximum OE boilup. Therefore, it would require simultaneous loss of OEC and/or SCVC condensing capacity for the steam valve failure to cause high benzene in the Process Vessel Vent System (PVVS)

  18. Estimation of bare soil evaporation for different depths of water table in the wind-blown sand area of the Ordos Basin, China

    Science.gov (United States)

    Chen, Li; Wang, Wenke; Zhang, Zaiyong; Wang, Zhoufeng; Wang, Qiangmin; Zhao, Ming; Gong, Chengcheng

    2018-04-01

    Soil surface evaporation is a significant component of the hydrological cycle, occurring at the interface between the atmosphere and vadose zone, but it is affected by factors such as groundwater level, soil properties, solar radiation and others. In order to understand the soil evaporation characteristics in arid regions, a field experiment was conducted in the Ordos Basin, central China, and high accuracy sensors of soil moisture, moisture potential and temperature were installed in three field soil profiles with water-table depths (WTDs) of about 0.4, 1.4 and 2.2 m. Soil-surface-evaporation values were estimated by observed data combined with Darcy's law. Results showed that: (1) soil-surface-evaporation rate is linked to moisture content and it is also affected by air temperature. When there is sufficient moisture in the soil profile, soil evaporation increases with rising air temperature. For a WTD larger than the height of capillary rise, the soil evaporation is related to soil moisture content, and when air temperature is above 25 °C, the soil moisture content reduces quickly and the evaporation rate lowers; (2) phreatic water contributes to soil surface evaporation under conditions in which the WTD is within the capillary fringe. This indicates that phreatic water would not participate in soil evaporation for a WTD larger than the height of capillary rise. This finding developed further the understanding of phreatic evaporation, and this study provides valuable information on recognized soil evaporation processes in the arid environment.

  19. Bacterial flora of pond reared Penaeus indicus (Milne Edwards)

    Digital Repository Service at National Institute of Oceanography (India)

    Singh, I.S.B.; Lakshmanaperumalsamy, P.; Chandramohan, D.

    The population size, generic diversity and potential to produce hydrolytic enzymes of heterotrophic bacteria associated with pond reared Penaeus indicus was worked out following standard bacteriological procedures. Chitinoclastic vibrios were found...

  20. The Effects of Species Interaction and Pond Stocking Density on ...

    African Journals Online (AJOL)

    Burchell) and Heterobranchus bidorsalis (Geoffrey Saint-Hilaire) and pond stocking density on the culture of tilapia species which display different parental care strategies. In the presence of catfishes, the maternal mouth-brooder O. niloticus ...