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

Christmas in England

Institute of Scientific and Technical Information of China (English)

孟伟根

1991-01-01

In England,Christmas is the most important of all the ’Bank Holidays’ in the year.Two important things,apart from itsreligious significance,help to set this holiday apart fromall others:the custom of giving gifts and the habit ofspending it with family. In the present highly commercialised age we arereminded of Christmas many weeks before the event.In

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.

The sweet Christmas rash (case series)

DEFF Research Database (Denmark)

Gyldenløve, Mette; Nepper-Christensen, Steen; Thyssen, Jacob P

2013-01-01

Christmas tree hypersensitivity is a rare condition, which has so far obtained scarce attention in the medical literature. We present two clinical cases of hypersensitivity associated with Christmas tree exposure, a 51-year-old woman with allergic contact dermatitis and a 41-year-old man...... with allergic rhinitis. The female patient had a positive patch test reaction to colophony, and the male patient had a positive skin prick test reaction to alternaria mould. Both were successfully advised to avoid prolonged exposure to Christmas trees and buy artificial trees for Christmas....

Christmas, consumption and materialism: discourse analysis of children’s Christmas letters

Directory of Open Access Journals (Sweden)

Georgiana Luna Batinga

2017-10-01

Full Text Available Purpose – This article reports the results of an empirical research that sought to understand the many meanings referring to Christmas that appear in letters written by children and sent to Santa Claus. It is based on the idea that, by means of a playful activity such as writing Christmas letters, children would be able to bring up a variety of issues referring to their daily lives. Design/methodology/approach – This research, which is of interpretative nature, made use of elements belonging to discourse analysis. Discourse analysis is a theoretical and methodological field linked to Linguistics, which studies language in movement, producing meaning since it is a social practice. Findings – The results point to discursive marks that suggest traces of materialism and secularism in the narratives and stories created by children concerning Christmas. Moreover, Santa Claus is directly associated with the date and stands out as an emblematic figure in children’s imagination. Originality/value – Reporting Christmas imagery and the creation of its meanings by children can help unveil essential issues, or at least point out “clues” referring to the degree of symbolism that is present in the various social and cultural manifestations of contemporary society

Geology and porphyry copper-type alteration-mineralization of igneous rocks at the Christmas Mine, Gila County, Arizona

Science.gov (United States)

Koski, Randolph A.

1979-01-01

igneous rocks is progressively more alkaline and silicic from basalt to granodiorite. Early (Stage I) chalcopyrite-bornite (-molybdenite) mineralization and genetically related K-silicate alteration are centered on the Christmas stock. K-silicate alteration is manifested by pervasive hornblende-destructive biotitization in the stock, biotitization of basaltic volcanic wall rocks, and a continuous stockwork of K-feldspar veinlets and quartz-K-feldspar veins in the stock and quartz-sulfide veins in volcanic rocks. Younger (Stage II) pyrite-chalcopyrite mineralization and quartz-sericite-chlorite alteration occur in a zone overlapping with but largely peripheral to the zone of Stage I stockwork veins. Within the Christmas intrusive complex, K-silicate-altered rocks in the central stock are flanked east and west by zones of fracture-controlled quartz-sericite alteration and strong pyritization. In volcanic rocks quartz-chlorite-pyrite-chalcopyrite veins are superimposed on earlier biotitization and crosscut Stage I quartz-sulfide veins. Beyond the zones of quartz-sericite alteration, biotite rhyodacite porphyry dikes contain the propylitic alteration assemblage epidote-chlorite-albite-sphene. Chemical analyses indicate the following changes during pervasive alteration of igneous rocks: (1) addition of Si, K, H, S, and Cu, and loss of Fe 3+ and Ca during intense biotitization of basalt; (2) loss of Na and Ca, increase of Fe3+/Fe2+, and strong H-metasomatism during sericitization of quartz diorite; and (3) increase in Ca, Na, and Fe3+/Fe2+, and loss of K during intense propylitization of biotite rhyodacite porphyry dikes. Thorough biotitization of biotite granodiorite porphyry in the Christmas stock was largely an isochemical process. Fluid-inclusion petrography reveals that Stage I veins are characterized by low to moderate populations of moderate-salinity and gas-rich inclusions, and sparse but ubiquitous halite-bearing inclusions. Moderate-salinity an

Evidence of a Christmas spirit network in the brain

DEFF Research Database (Denmark)

Hougaard, Anders; Lindberg, Ulrich; Arngrim, Nanna

2015-01-01

OBJECTIVE: To detect and localise the Christmas spirit in the human brain. DESIGN: Single blinded, cross cultural group study with functional magnetic resonance imaging (fMRI). SETTING: Functional imaging unit and department of clinical physiology, nuclear medicine and PET in Denmark. PARTICIPANTS......: 10 healthy people from the Copenhagen area who routinely celebrate Christmas and 10 healthy people living in the same area who have no Christmas traditions. MAIN OUTCOME MEASURES: Brain activation unique to the group with Christmas traditions during visual stimulation with images with a Christmas......, differences between the two groups were calculated to determine Christmas specific brain activation. RESULTS: Significant clusters of increased BOLD activation in the sensory motor cortex, the premotor and primary motor cortex, and the parietal lobule (inferior and superior) were found in scans of people who...

Alternative Fuels Data Center: Biodiesel Truck Transports Capitol Christmas

Science.gov (United States)

Tree Biodiesel Truck Transports Capitol Christmas Tree to someone by E-mail Share Alternative Fuels Data Center: Biodiesel Truck Transports Capitol Christmas Tree on Facebook Tweet about Alternative Fuels Data Center: Biodiesel Truck Transports Capitol Christmas Tree on Twitter Bookmark Alternative

Factors that influence Christmas tree sales

Science.gov (United States)

Thomas H. Pendleton; Lawrence D. Garrett

1970-01-01

An analysis of the metropolitan Christmas tree market in Winston-Salem, N. C., shows that to sell more trees, Christmas tree retailers should locate their lots on heavily traveled streets in business areas, have adequate parking facilities, advertise, and have attractive displays of trees. Retailers who follow these practices can expect to receive higher prices for...

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.

Christmas feast in Prévessin

CERN Multimedia

2000-01-01

Restaurant No3 was invaded by a happy bunch of Santa Clauses last Wednesday. It has become a tradition for the restaurant staff to dress up to serve a real Christmas feast. In the menu : Foie gras des Landes, scallops, salmon tartar and of course the traditional Christmas turkey. And a special extra - an aperitif graciously offered by the restaurant. Places were laid for 450 people for this exceptional lunch.

Chemical composition and nutritional value of boiled Christmas ...

African Journals Online (AJOL)

A study was conducted to determine the chemical composition and the nutritive value of boiled Christmas bush (Alchornea cordifolia) for starter broiler chickens. Dried Christmas bush fruits (Capsules + seed) were boiled for 30 minutes, sundried and ground into meal. The meal was analyzed for proximate composition and ...

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

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

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

Pilot-scale continuous recycling of growth medium for the mass culture of a halotolerant Tetraselmis sp. in raceway ponds under increasing salinity: a novel protocol for commercial microalgal biomass production.

Science.gov (United States)

Fon Sing, S; Isdepsky, A; Borowitzka, M A; Lewis, D M

2014-06-01

The opportunity to recycle microalgal culture medium for further cultivation is often hampered by salinity increases from evaporation and fouling by dissolved and particulate matter. In this study, the impact of culture re-use after electro-flocculation of seawater-based medium on growth and biomass productivity of the halotolerant green algal strain Tetraselmis sp., MUR 233, was investigated in pilot-scale open raceway ponds over 5months. Despite a salinity increase from 5.5% to 12% (w/v) NaCl, Tetraselmis MUR 233 grown on naturally DOC-enriched recycled medium produced 48-160% more ash free dry weight (AFDW) biomass daily per unit pond area than when grown on non-recycled medium. A peak productivity of 37.5±3.1gAFDWm(-2)d(-1) was reached in the recycled medium upon transition from ∼14% to ∼7% NaCl. The combination of high biomass-yielding mixotrophic growth under high salinity has been proven to be a successful sustainable cultivation strategy. Copyright © 2014 Elsevier Ltd. All rights reserved.

Submarine groundwater discharge to a small estuary estimated from radon and salinity measurements and a box model

Directory of Open Access Journals (Sweden)

J. Crusius

2005-01-01

Full Text Available Submarine groundwater discharge was quantified by a variety of methods for a 4-day period during the early summer of 2004, in Salt Pond, adjacent to Nauset Marsh, on Cape Cod, USA. Discharge estimates based on radon and salinity took advantage of the presence of the narrow channel connecting Salt Pond to Nauset Marsh, which allowed constructing whole-pond mass balances as water flowed in and out due to tidal fluctuations. The data suggest that less than one quarter of the discharge in the vicinity of Salt Pond happened within the pond itself, while three quarters or more of the discharge occurred immediately seaward of the pond, either in the channel or in adjacent regions of Nauset Marsh. Much of this discharge, which maintains high radon activities and low salinity, is carried into the pond during each incoming tide. A box model was used as an aid to understand both the rates and the locations of discharge in the vicinity of Salt Pond. The model achieves a reasonable fit to both the salinity and radon data assuming submarine groundwater discharge is fresh and that most of it occurs either in the channel or in adjacent regions of Nauset Marsh. Salinity and radon data, together with seepage meter results, do not rule out discharge of saline groundwater, but suggest either that the saline discharge is at most comparable in volume to the fresh discharge or that it is depleted in radon. The estimated rate of fresh groundwater discharge in the vicinity of Salt Pond is 3000-7000 m3 d-1. This groundwater flux estimated from the radon and salinity data is comparable to a value of 3200-4500 m3 d-1 predicted by a recent hydrologic model (Masterson, 2004; Colman and Masterson, 2004, although the model predicts this rate of discharge to the pond whereas our data suggest most of the groundwater bypasses the pond prior to discharge. Additional work is needed to determine if the measured rate of discharge is representative of the long-term average, and to

A very LIGO Christmas

Science.gov (United States)

Kijbunchoo, Nutsinee

2017-12-01

In this exclusive comic drawn by physicist Nutsinee Kijbunchoo, the LIGO Collaboration gets a surprise visit and an unexpected gravitational-wave signal. We invite you to fill in the blank speech bubble in the last frame. Merry Christmas!

Hydrologic aspects of marsh ponds during winter on the Gulf Coast Chenier Plain, USA: Effects of structural marsh management

Science.gov (United States)

Bolduc, F.; Afton, A.D.

2004-01-01

The hydrology of marsh ponds influences aquatic invertebrate and waterbird communities. Hydrologic variables in marsh ponds of the Gulf Coast Chenier Plain are potentially affected by structural marsh management (SMM: levees, water control structures and impoundments) that has been implemented since the 1950s. Assuming that SMM restricts tidal flows and drainage of rainwater, we predicted that SMM would increase water depth, and concomitantly decrease salinity and transparency in impounded marsh ponds. We also predicted that SMM would increase seasonal variability in water depth in impounded marsh ponds because of the potential incapacity of water control structures to cope with large flooding events. In addition, we predicted that SMM would decrease spatial variability in water depth. Finally, we predicted that ponds of impounded freshwater (IF), oligohaline (IO), and mesohaline (IM) marshes would be similar in water depth, temperature, dissolved oxygen (O2), and transparency. Using a priori multivariate analysis of variance (MANOVA) contrast, we tested these predictions by comparing hydrologic variables within ponds of impounded and unimpounded marshes during winters 1997-1998 to 1999-2000 on Rockefeller State Wildlife Refuge, near Grand Chenier, Louisiana. Specifically, we compared hydrologic variables (1) between IM and unimpounded mesohaline marsh ponds (UM); and (2) among IF, IO, and IM marshes ponds. As predicted, water depth was higher and salinity and O2 were lower in IM than in UM marsh ponds. However, temperature and transparency did not differ between IM and UM marsh ponds. Water depth varied more among months in IM marsh ponds than within those of UM marshes, and variances among and within ponds were lower in IM than UM marshes. Finally, all hydrologic variables, except salinity, were similar among IF, IO, and IM marsh ponds. Hydrologic changes within marsh ponds due to SMM should (1) promote benthic invertebrate taxa that tolerate low levels of O2 and

Christmas in Mexico.

Science.gov (United States)

Kern County Superintendent of Schools, Bakersfield, CA.

The Christmas season in Mexico starts on December 16 with "las posadas," a series of religious processions in which families or neighbors reenact Joseph's search for shelter for Mary en route to Bethlehem. Those representing pilgrims travel from home to home until they are finally accepted by those representing innkeepers at a home with…

Danish TV Christmas calendars: Folklore, myth and cultural history

DEFF Research Database (Denmark)

Agger, Gunhild

2013-01-01

in which this traditional genre has succeeded in renewing itself. The so-called Pyrus series, TV 2’s Christmas calendars during the mid-1990s, exhibited folklore, myth and cultural history in a combination of entertainment and information. They were succeeded by calendars such as Jul i Valhal......This article aims at characterizing the Danish Christmas calendar as a TV institution and a meeting place for the traditions of the almanac, folklore and the history of culture. Against the background of a brief outline of the history of Danish Christmas calendars, the article explores ways...

Restaurants closed over Christmas

CERN Multimedia

2011-01-01

The restaurants will be closed during the Christmas holiday period : please note that all three CERN Restaurants will be closed from 5 p.m. on Wednesday, 21 December until Wednesday, 4 January inclusive. The Restaurants will reopen on Thursday, 5 January 2012.

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.

Bah humbug: Unexpected Christmas cards and the reciprocity norm.

Science.gov (United States)

Meier, Brian P

2016-01-01

The reciprocity norm refers to the expectation that people will help those who helped them. A well-known study revealed that the norm is strong with Christmas cards, with 20% of people reciprocating a Christmas card received from a stranger. I attempted to conceptually replicate and extend this effect. In Study 1, 755 participants received a Christmas card supposedly from a more- versus less-similar stranger. The reciprocation rate was unexpectedly low (2%), which did not allow for a test of a similarity effect. Two potential reasons for this low rate were examined in Study 2 in which 494 participants reported their likelihood of reciprocating a Christmas card from a stranger as well as their felt suspicions/threat about the card and their frequency of e-mail use. Reciprocation likelihood was negatively correlated with perceived threat/suspicion and e-mail use. It appears that reciprocating a gift from a stranger in offline settings may be less likely than expected.

Drought-induced recharge promotes long-term storage of porewater salinity beneath a prairie wetland

Science.gov (United States)

Levy, Zeno F.; Rosenberry, Donald O.; Moucha, Robert; Mushet, David M.; Goldhaber, Martin B.; LaBaugh, James W.; Fiorentino, Anthony J.; Siegel, Donald I.

2018-02-01

Subsurface storage of sulfate salts allows closed-basin wetlands in the semiarid Prairie Pothole Region (PPR) of North America to maintain moderate surface water salinity (total dissolved solids [TDS] from 1 to 10 g L-1), which provides critical habitat for communities of aquatic biota. However, it is unclear how the salinity of wetland ponds will respond to a recent shift in mid-continental climate to wetter conditions. To understand better the mechanisms that control surface-subsurface salinity exchanges during regional dry-wet climate cycles, we made a detailed geoelectrical study of a closed-basin prairie wetland (P1 in the Cottonwood Lake Study Area, North Dakota) that is currently experiencing record wet conditions. We found saline lenses of sulfate-rich porewater (TDS > 10 g L-1) contained in fine-grained wetland sediments 2-4 m beneath the bathymetric low of the wetland and within the currently ponded area along the shoreline of a prior pond stand (c. 1983). During the most recent drought (1988-1993), the wetland switched from a groundwater discharge to recharge function, allowing salts dissolved in surface runoff to move into wetland sediments beneath the bathymetric low of the basin. However, groundwater levels during this time did not decline to the elevation of the saline lenses, suggesting these features formed during more extended paleo-droughts and are stable in the subsurface on at least centennial timescales. We hypothesize a "drought-induced recharge" mechanism that allows wetland ponds to maintain moderate salinity under semiarid climate. Discharge of drought-derived saline groundwater has the potential to increase the salinity of wetland ponds during wet climate.

75 FR 68529 - Proposed Christmas Tree Promotion, Research, and Information Order; Referendum Procedures

Science.gov (United States)

2010-11-08

... and procedure, Advertising, Consumer information, Marketing agreements, Christmas trees, Promotion...-0008-PR] RIN 0581-AD00 Proposed Christmas Tree Promotion, Research, and Information Order; Referendum... or continuation of the proposed Christmas Promotion, Research, and Information Order (Proposed Order...

Mystery photos: Christmas edition

CERN Multimedia

Alex Brown, Jens Vigen, Rosaria Marraffino

2014-01-01

Paraphrasing George R.R. Martin's novel Game of Thrones’ most famous quote: “Christmas is coming”. According to tradition, we’ve themed our last issue of the year to share the spirit of the festivities with our readers. We’ve collected some pictures of snowy scenes and Christmas parties at CERN from our archives.   Identifying pictures and albums in the CERN photo archive continues apace and we still need your help. However, in keeping with the holiday spirit, we’ve set you some Christmassy challenges. Were you at any of the events shown below, or do you recognise anyone in the pictures? Get in touch by email: photo.archive@cern.ch or use the “suggest a caption” link on each picture’s page. So far, more than 33,000 pictures have been uploaded, with nearly 1,000 old album records inspected and about 150 new ones created. We’ve had contact from an ever-increasing number of reti...

Sacred and profane view of Christmas in advertising

OpenAIRE

Mădălina MORARU (BUGA)

2013-01-01

This article investigates the way seasonal advertising campaigns convey the paradoxical relationship between sacred and profane views of Christmas. The following research reveals the differences between commercialized and religious Christmas celebrations by analyzing the advertisements running on the Romanian market between November 15th and December 25th, 2012. The present study focuses on the following topics: the values promoted by both local and international brands, the sacred mindset ve...

Salinization and arsenic contamination of surface water in southwest Bangladesh.

Science.gov (United States)

Ayers, John C; George, Gregory; Fry, David; Benneyworth, Laura; Wilson, Carol; Auerbach, Leslie; Roy, Kushal; Karim, Md Rezaul; Akter, Farjana; Goodbred, Steven

2017-09-11

To identify the causes of salinization and arsenic contamination of surface water on an embanked island (i.e., polder) in the tidal delta plain of SW Bangladesh we collected and analyzed water samples in the dry (May) and wet (October) seasons in 2012-2013. Samples were collected from rice paddies (wet season), saltwater ponds used for brine shrimp aquaculture (dry season), freshwater ponds and tidal channels (both wet and dry season), and rainwater collectors. Continuous measurements of salinity from March 2012 to February 2013 show that tidal channel water increases from ~0.15 ppt in the wet season up to ~20 ppt in the dry season. On the polder, surface water exceeds the World Health Organization drinking water guideline of 10 μg As/L in 78% of shrimp ponds and 27% of rice paddies, raising concerns that produced shrimp and rice could have unsafe levels of As. Drinking water sources also often have unsafe As levels, with 83% of tubewell and 43% of freshwater pond samples having >10 μg As/L. Water compositions and field observations are consistent with shrimp pond water being sourced from tidal channels during the dry season, rather than the locally saline groundwater from tubewells. Irrigation water for rice paddies is also obtained from the tidal channels, but during the wet season when surface waters are fresh. Salts become concentrated in irrigation water through evaporation, with average salinity increasing from 0.43 ppt in the tidal channel source to 0.91 ppt in the rice paddies. Our observations suggest that the practice of seasonally alternating rice and shrimp farming in a field has a negligible effect on rice paddy water salinity. Also, shrimp ponds do not significantly affect the salinity of adjacent surface water bodies or subjacent groundwater because impermeable shallow surface deposits of silt and clay mostly isolate surface water bodies from each other and from the shallow groundwater aquifer. Bivariate plots of conservative element

Christmas Sale on 11 and 12 December

CERN Multimedia

DSU Unit

2008-01-01

CERN Shop Are you short of ideas for Christmas presents? If so, come and have a look at the stall the CERN shop will be setting up outside Restaurant No. 1 in the Main Building on the Meyrin site on Thursday 11 and Friday 12 December from 10.30 a.m. to 4.30 p.m. Various new items will be on sale, including a new LHC booklet for the general public. In the style of a travel log, it recounts the fabulous voyage of a proton inside the accelerator. The text is complemented by eye-catching photos and illustrations and is available in English or French. The 2009 calendar, based on the same theme, will also be on sale at 10 CHF. Special reductions will be available on certain items. So come and stock up on your Christmas presents at the CERN shop. Bookshop If you are looking for an idea for your Christmas gifts, the Bookshop of the Central Library offers you a wide choice of titles in Physics, ...

The Stuff of Christmas Homemaking: Transforming the House and Church on Christmas Eve in the Bay of Kotor, Montenegro

Directory of Open Access Journals (Sweden)

Vesna Vučinić-Nešković

2016-03-01

Full Text Available The domestic burning of Yule logs on Christmas Eve is an archaic tradition characteristic of the Christian population in the central Balkans. In the fifty years following World War Two, the socialist state suppressed these and other popular religious practices. However, ethnographic research in Serbia and Montenegro in the late 1980s showed that many village households, nevertheless, preserved their traditional Christmas rituals at home, in contrast to the larger towns, in which they were practically eradicated. Even in the micro-regions, such as the Bay of Kotor, there were observable differences between more secluded rural communities, in which the open hearth is still the ritual center of the house (on which the Yule logs are burned as many as seven times during the Christmas season, and the towns in which only a few households continued with the rite (burning small logs in the wood-stove. In the early 1990s, however, a revival of domestic religious celebrations as well as their extension into the public realm has occurred. This study shows how on Christmas Eve, houses and churchyards (as well as townsquares are being transformed into sacred places. By analyzing the temporal and spatial aspects of this ritual event, the roles that the key actors play, the actions they undertake and artifacts they use, I attempt to demonstrate how the space of everyday life is transformed into a sacred home. In the end, the meanings and functions of homemaking are discussed in a way that confronts the classic distinction between private and public ritual environs.

CERN Shop - Christmas Sale on 13 and 14 December

CERN Multimedia

2006-01-01

Looking for Christmas present ideas? As every year, we will be running a CERN Shop Stand in the Main Building, ground floor, on Wednesday 13 and on Thursday 14 December from 10.30 to 16.00. Some new articles will be on sale and special reductions are given for some articles. Come and visit the CERN Shop Stand and find your Christmas presents. DSU-CO group

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.

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%.

CHRISTMAS AND EASTER THEMES IN THE LITERARY HERITAGE OF YURIY MIROLYUBOV

Directory of Open Access Journals (Sweden)

Sergey F. Dmitrenko

2015-11-01

Full Text Available A  Russian emigrant writer Yuri Mirolyubov (1892—1970 wrote a  lot about Slavic antiquities. His name is associated with the origin of a  legendary “The book of Veles”  (Velesova kniga. This article studies his literary works in a historical and literary context, thematically associated with Christmas and Easter. The son of a priest, Mirolyubov was able to create original Christmas and Easter tales. As a priest’s son Mirolyubov managed to create indigenous Christmas and Easter stories. He brought back an already existing genre tradition of Christmas and Easter literature to its folklore origins, freed it from absolutely literary accretions and narrative stereotypes. Yuri Mirolyubov strived to put the Christmas and Easter stories beyond moral (much less entertaining literature, put them in the mainstream of a  folk, “Russian epic” (Ivan Shmelyov. That was a defi nition given by an author Ivan Shmelyov to his writing “The Lord’s summer”  (Leto Gospodne, who also updated the Canon of Russian calendar (Christmas and Easter literature in his own way. In fictional prose Yuri Mirolyubov acted as a scientist-ethnographer, a  sensitive receptionist of  everyday phenomena and psychological states. But in the works defi ned as scientific, he became a true artist, who felt free to deal with the most complicated and poorly studied material, however, existing in the depths of people’s consciousness.

29 CFR 778.212 - Gifts, Christmas and special occasion bonuses.

Science.gov (United States)

2010-07-01

... 29 Labor 3 2010-07-01 2010-07-01 false Gifts, Christmas and special occasion bonuses. 778.212... COMPENSATION Payments That May Be Excluded From the âRegular Rateâ Bonuses § 778.212 Gifts, Christmas and... “regular rate” shall not be deemed to include “sums paid as gifts; payments in the nature of gifts made at...

A silicon tracker for Christmas

CERN Multimedia

2008-01-01

The CMS experiment installed the world’s largest silicon tracker just before Christmas. Marcello Mannelli: physicist and deputy CMS project leader, and Alan Honma, physicist, compare two generations of tracker: OPAL for the LEP (at the front) and CMS for the LHC (behind). There is quite a difference between 1m2 and 205m2.. CMS received an early Christmas present on 18 December when the silicon tracker was installed in the heart of the CMS magnet. The CMS tracker team couldn’t have hoped for a better present. Carefully wrapped in shiny plastic, the world’s largest silicon tracker arrived at Cessy ready for installation inside the CMS magnet on 18 December. This rounded off the year for CMS with a major event, the crowning touch to ten years of work on the project by over five hundred scientists and engineers. "Building a scientific instrument of this size and complexity is a huge technical a...

Suggestions for Christmas gifts.

CERN Document Server

Connie Potter; Markus Nordberg

Have you been working long hours lately? Stuck in meetings too long to make it in time before the shops close? No need to worry. The ATLAS secretariat has plenty of items that will make great Christmas gifts for friends and family. Here are some of the items in stock. Note that you can negotiate a good price for bulk order. ATLAS caps (new item), 12 chf ATLAS t-shirts designed by Alan Alda, 20 chf ATLAS fleece jackets in several sizes and colors, 30 chf grey or dark blue in men's sizes pale blue for women's sizes (limited quantity) red for children (limited quantity) ATLAS puzzles with 500 pieces made by the Ravensburger company 15 chf for 1 box (price is less when purchasing more boxes) 50 chf for 5 boxes or more can also be purchased in boxes of 24, ready to ship to your institute ATLAS 3-D viewers, 5 chf ATLAS DVD, 5 chf CERN playing cards, 2 chf Make sure to get several boxes of the ATLAS puzzle for Christmas gifts. Offer hours of entertainement to friends and family! We tak...

Holocene closure of Lib Pond, Marshall Islands.

Directory of Open Access Journals (Sweden)

Conor L Myhrvold

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

Holocene closure of Lib Pond, Marshall Islands.

Science.gov (United States)

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

2014-01-01

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

29 CFR 780.216 - Nursery activities generally and Christmas tree production.

Science.gov (United States)

2010-07-01

... 29 Labor 3 2010-07-01 2010-07-01 false Nursery activities generally and Christmas tree production... Nursery activities generally and Christmas tree production. (a) The employees of a nursery who are engaged... horticultural commodities such as the following are employed in agriculture: (1) Planting seedlings in a nursery...

Dissolved Oxygen Availability on Traditional Pond Using Silvofishery Pattern in Mahakam Delta

Directory of Open Access Journals (Sweden)

Ismail Fahmy Almadi

2013-06-01

Full Text Available The development of aquaculture system should meet the community’s basic need economically by taking into account the carrying capacity and environmental sustainability. The development of the environmentally friendly system such as silvofishery is being promoted by government however its yield has not reached the target yet. Dissolved oxygen availability is an important indicator which determines the success of the aquaculture system. The objective of the research was to determine dissolved oxygen availability on traditional pond systems using silvofishery pattern. Time series data collection was conducted once in 14 days with 2 measuring times; in the morning (06.00 am and in the evening (06.00 pm for 112 days. The research was conducted at four different silvofishery pond patterns, Pond Pattern 1 (0% mangrove canopy covered, Pond Pattern 2 (35% mangrove canopy covered, Pond Pattern 3 (67% mangrove canopy covered, and Pond Pattern 4 (75% mangrove canopy covered. Measurement was observed openly in the pond (in situ with parameters: dissolved oxygen, temperature, Water pH, Salinity, Transparency, Wind Speed, and Depth of Water Table, while chlorofil-a was ex-situ measured. The result from each parameter was compared to optimum concentration rate for shrimp growth. From the experiment, Pond Pattern 1 showed the most satisfaction results. Its dissolved oxygen availability during the research was ≥ 4 mg/L which was 5.88 mg/L ±0.48 mg/L in the evening (06.00 pm and 4.33 mg/L ±1.24 mg/L in the morning (06.00 am. It was also supported by optimum condition of other parameters such as temperature, Water pH, Salinity, Wind Speed, and Depth of Water Table. However, it was not supported by fertility and transparency of water. Thus, the traditional pattern of conservation still needs additional technology to maintain adequate dissolved oxygen availability for optimum shrimp growth.

Green Christmas kasvas suureks / Aarne Mäe

Index Scriptorium Estoniae

Mäe, Aarne, 1967-

2004-01-01

Suurbritannia rockansambli Paradise Lost' kontsertidest 18. dets. Rakvere spordihallis ja Riias Kipsala hallis, rockfestivali Green Christmas korraldamisest Gunnar Viese ja Oleg Knjazevi ühisfirma Baltic East Machine poolt

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.

Taxonomic uncertainty and the loss of biodiversity on Christmas Island, Indian Ocean.

Science.gov (United States)

Eldridge, Mark D B; Meek, Paul D; Johnson, Rebecca N

2014-04-01

The taxonomic uniqueness of island populations is often uncertain which hinders effective prioritization for conservation. The Christmas Island shrew (Crocidura attenuata trichura) is the only member of the highly speciose eutherian family Soricidae recorded from Australia. It is currently classified as a subspecies of the Asian gray or long-tailed shrew (C. attenuata), although it was originally described as a subspecies of the southeast Asian white-toothed shrew (C. fuliginosa). The Christmas Island shrew is currently listed as endangered and has not been recorded in the wild since 1984-1985, when 2 specimens were collected after an 80-year absence. We aimed to obtain DNA sequence data for cytochrome b (cytb) from Christmas Island shrew museum specimens to determine their taxonomic affinities and to confirm the identity of the 1980s specimens. The Cytb sequences from 5, 1898 specimens and a 1985 specimen were identical. In addition, the Christmas Island shrew cytb sequence was divergent at the species level from all available Crocidura cytb sequences. Rather than a population of a widespread species, current evidence suggests the Christmas Island shrew is a critically endangered endemic species, C. trichura, and a high priority for conservation. As the decisions typically required to save declining species can be delayed or deferred if the taxonomic status of the population in question is uncertain, it is hoped that the history of the Christmas Island shrew will encourage the clarification of taxonomy to be seen as an important first step in initiating informed and effective conservation action. © 2013 Society for Conservation Biology.

Analysis of Market Factors Associatedwith Sales of Cut Natural Christmas Trees

Science.gov (United States)

Lawrence D. Garrett

1977-01-01

A study of the market performance of natural Christmas tree retailers in Winston-Salem, North Carolins, revealed that success was strongly related to location in active retail shopping areas. Christmas tree retailers in shopping centers or areas high in retail sales sold more trees, received a higher average price, and had fewer trees left unsold than retailers in...

CERN Shop - Christmas Sale on 12 and 13 December

CERN Document Server

2007-01-01

Looking for Christmas present ideas? As every year, we will be running a CERN Shop stand in the Main Building, ground floor, on Wednesday 12 and Thursday 13 December from 10.30 to 16.30. Some new items will be on sale, such as cool fridge magnets and fleeces. The 2008 CERN calendar will be also available at the price of 10 CHF. Some items will have special reductions. Come and visit the CERN Shop stand and find your Christmas presents. DSU-CO group

Gastrointestinal parasites of feral cats from Christmas Island.

Science.gov (United States)

Adams, P J; Elliot, A D; Algar, D; Brazell, R I

2008-01-01

To investigate the gastrointestinal parasites present in feral cats on Christmas Island, with particular interest in the protozoan parasite Toxoplasma gondii. Faecal and serum samples were collected from 28 and 25 cats respectively that were trapped as part of an ongoing eradication program being run on Christmas Island by the Department of Environment and Conservation. Faecal samples were screened microscopically for helminth and protozoan parasites. Serum samples were screened for antibodies to T gondii using a commercial indirect immunofluorescence assay (IFA) and a latex agglutination test (LAT). The most common helminth parasites detected were Toxocara cati (present in 15 of 28 faecal samples), Strongyloides sp (13/28), Aelurostrongylus abstrusus, (7/28), an unidentified capillarid (6/28) and Ancylostoma sp (4/28). Based on serology, T gondii was the most common parasite detected (protozoan or otherwise) with antibodies detected in 24 serum samples by IFA and 23 serum samples by LAT. Cats on Christmas Island harbour many of the helminth and protozoan parasites reported from feral cats elsewhere in Australia. The high seroprevalence of T gondii in these cats indicates a high level of exposure to the parasite in this environment.

What proof is in your Christmas pudding? Is caring under the influence possible?

Science.gov (United States)

Brieger, Daniel G; Amir, Amaleena B; Punch, Gratian J; Lim, Christopher S H; Toh, James

2014-12-11

To determine the ethanol concentration of commonly available Christmas puddings, and to extrapolate the blood alcohol content (BAC) of typical health care professionals after Christmas lunch at the hospital. We conducted fractional distillation of Christmas puddings and analysed the distillate for ethanol content. We then applied standard pharmacological and physiological assumptions to assess predicted BAC in typical male and female health care professionals at our hospital. Ethanol concentration of each pudding; estimated BAC of health care professionals after ingestion and at the end of a 30-minute lunch break. The concentration of ethanol in common Christmas puddings ranged from 0.260 to 1.685 g per 125 mg slice. The concentration of ethanol per pudding was not greater than the stipulated specifications on the packaging, where shown. After pudding ingestion, the theoretical BAC of a typical 70 kg male and 60 kg female health care professional ranged from 0.001 to 0.004 g/dL and from 0.001 to 0.006 g/dL, respectively. Neither male nor female staff had a predicted BAC > 0.000 g/dL by the end of the lunch break. Christmas puddings contain ethanol that does not all evaporate during the cooking process. However, the rise in BAC after ingestion of a typical slice of Christmas pudding was negligible and unlikely to affect work performance or safety or impair a health care worker's ability to make complex decisions.

Predicting salt advection in groundwater from saline aquaculture ponds

Science.gov (United States)

Verrall, D. P.; Read, W. W.; Narayan, K. A.

2009-01-01

SummaryThis paper predicts saltwater advection in groundwater from leaky aquaculture ponds. A closed form solution for the potential function, stream function and velocity field is derived via the series solutions method. Numerically integrating along different streamlines gives the location (or advection front) of saltwater throughout the domain for any predefined upper time limit. Extending this process produces a function which predicts advection front location against time. The models considered in this paper are easily modified given knowledge of the required physical parameters.

CERN Shop - Christmas Sale on 15 and 16 December 2005

CERN Multimedia

DSU-CO Group

2005-01-01

Looking for Christmas present ideas? As every year, we will be running a CERN Shop Stand in the Main Building, ground floor, on Thursday 15 and on Friday 16 December from 10.30 to 16.00. Some new articles will be on sale and special reductions are given for articles such as 50th Anniversary T-shirts (15,-), all silk ties (30,-) and 50th Anniversary watches (35,-). Come and visit the CERN Shop Stand and find your Christmas presents. DSU-CO group

Immediate allergic and nonallergic reactions to Christmas and Easter cacti

DEFF Research Database (Denmark)

Andersen, F; Bindslev-Jensen, C; Stahl Skov, P

1999-01-01

BACKGROUND: Occupational exposure to Christmas cacti has been reported as a cause of type I allergy. Therefore, the prevalence of immediate-type mucosal and skin reactions related to cactus exposure was studied in 103 employees in a cactus nursery. METHODS: The study was based on a questionnaire ...... and mucosal symptoms. CONCLUSIONS: Christmas and Easter cacti seemed to be able to induce contact urticaria and rhinoconjunctivitis on both an immunologic and a nonimmunologic basis. Personal atopy was associated with positive reactions to cacti....

STUDY ON IMPACT OF SALINE WATER INUNDATION ON FRESHWATER AQUACULTURE IN SUNDARBAN USING RISK ANALYSIS TOOLS

Directory of Open Access Journals (Sweden)

B.K Chand

2012-11-01

Full Text Available The impact of saline water inundation on freshwater aquaculture was evaluated through risk assessment tools. Fishponds in low-lying areas of Sagar and Basanti block are prone to saline water flooding. Respondents of Sagar block considered events like cyclone and coastal flooding as extreme risk; erratic monsoon, storm surge and land erosion as high risk; temperature rise, sea level rise, hot & extended summer and precipitation as medium risk. Likewise, in Basanti block the respondents rated cyclone as extreme risk; erratic monsoon, storm surge as high risk; temperature rise, hot & extended summer, land erosion, and precipitation as medium risk; coastal flooding and sea level rise as low risk. Fish farmers of Sagar block classified the consequences of saline water flooding like breach of pond embankment and mass mortality of fishes as extreme risk; escape of existing fish stock and diseases as high risk; entry of unwanted species, retardation of growth and deterioration of water quality as medium risk; and damage of pond environment as low risk. Farmers of Basanti block categorised breach of pond dyke, mass mortality of fishes and entry of unwanted species as extreme risk; escape of fish and diseases as high risk; retardation of growth as medium risk; deterioration of water quality and damage of pond environment as low risk. To reduce the threats against saline water ingression, farmers are taking some coping measures like increase in pond dyke height; repair and strengthening of dyke; plantation on dyke; dewatering and addition of fresh water; application of chemicals/ lime/ dung; addition of tree branches in pond for hide outs etc.

Generosity and Hospitality in Christmas Story

NARCIS (Netherlands)

Laine, T.

2013-01-01

This short subject discusses what might be understood as Santa Claus’ essence, which is the logic of and limits to his overarching generosity, as depicted in the film Christmas Story (Wuolijoki, 2007). The plot centres on the orphan Nikolas, who grew up to be Santa Claus. Young Nikolas moves to a

Studies on the environmental conditions of tidal ponds in the Ramanthuruth Island (Cochin)

Digital Repository Service at National Institute of Oceanography (India)

Sankaranarayanan, V.N.; Kumaran, S.; Balasubramanian, T.; Stephen, R.; Panampunnayil, S.U.

Environmental characteristics of certain enclosures and tidal ponds in Ramanthuruth Island, Kerala, India where prawns grow in abundance were studied. Various parameters such as temperature, salinity, pH, Eh, dissolved oxygen, nutrients, chlorophyll...

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.

Tolerance to road salt deicers in chronically exposed urban pond communities

Science.gov (United States)

Freshwater salinization is a concern in urban aquatic ecosystems that receive road salt runoff from vast expanses of impervious surface cover. Our study was designed to evaluate the effects of chloride contamination on urban stormwater pond food webs and to assess the tolerance o...

CERN Shop - Christmas Sale in Bldg. 33

CERN Multimedia

PH Department

2010-01-01

Looking for Christmas present ideas? The CERN Shop will give CERN card holders a special reduction of 10 % on all CERN Shop articles from Monday 13.12.2010 to Saturday 18.12.2010. Come and visit the CERN Shop in the Reception Building 33.

Leptospira Species in Feral Cats and Black Rats from Western Australia and Christmas Island.

Science.gov (United States)

Dybing, Narelle A; Jacobson, Caroline; Irwin, Peter; Algar, David; Adams, Peter J

2017-05-01

Leptospirosis is a neglected, re-emerging bacterial disease with both zoonotic and conservation implications. Rats and livestock are considered the usual sources of human infection, but all mammalian species are capable of carrying Leptospira spp. and transmitting pathogenic leptospires in their urine, and uncertainty remains about the ecology and transmission dynamics of Leptospira in different regions. In light of a recent case of human leptospirosis on tropical Christmas Island, this study aimed to investigate the role of introduced animals (feral cats and black rats) as carriers of pathogenic Leptospira spp. on Christmas Island and to compare this with two different climatic regions of Western Australia (one island and one mainland). Kidney samples were collected from black rats (n = 68) and feral cats (n = 59) from Christmas Island, as well as feral cats from Dirk Hartog Island (n = 23) and southwest Western Australia (n = 59). Molecular (PCR) screening detected pathogenic leptospires in 42.4% (95% confidence interval 29.6-55.9) of cats and 2.9% (0.4-10.2) of rats from Christmas Island. Sequencing of cat- and rat-positive samples from Christmas Island showed 100% similarity for Leptospira interrogans. Pathogenic leptospires were not detected in cats from Dirk Hartog Island or southwest Western Australia. These findings were consistent with previous reports of higher Leptospira spp. prevalence in tropical regions compared with arid and temperate regions. Despite the abundance of black rats on Christmas Island, feral cats appear to be the more important reservoir species for the persistence of pathogenic L. interrogans on the island. This research highlights the importance of disease surveillance and feral animal management to effectively control potential disease transmission.

Structure of an urban Christmas tree market

Science.gov (United States)

Thomas H. Pendleton; Lawrence D. Garrett; Lawrence D. Garrett

1973-01-01

The retail Christmas tree market in Winston-Salem, N.C., was studied 3 years. Types of retailers and their sales are described. Best sales were made by dealers who had lots on heavily traveled streets in business districts, had ample parking facilities, advertised, and displayed their trees well.

CERN Shop - Christmas Sale in Bldg. 33

CERN Multimedia

PH Department

Looking for Christmas present ideas? The CERN Shop will give the CERN card holders a special reduction of 10 % on all CERN Shop articles from Friday 11.12.2009 to Thursday 17.12.2009. Come to visit the CERN Shop at the Reception, Building 33. PH-EDU-PO

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.

THE TRANSFORMATION OF THE GENRE OF THE CHRISTMAS STORY IN MODERN LITERATURE (D. BYKOV, L. PETRUSHEVSKAYA

Directory of Open Access Journals (Sweden)

Yulia Yur'evna Danilenko

2014-11-01

Full Text Available Article is devoted to the study of the transformation of the genre of the Christmas story in modern literature. Th e article analyzes the infl uence of the classic Christmas story by Hans Christian Andersen Th e Little Match Girl on the structure of modern texts of mass and elite literature. (D. Bykov Th e Little Match Girl gives a light, L. Petrushevskaya Black Coat. Th e subject of the study is a strategy of rethinking, recoding the source of the original content in the fabric of a new product. Th e structural and semiotic analysis of the texts revealed some tricks to updates-the-genre: fi lling-up with the new semantics, complicating a genre model of a Christmas story. Analysis showed that referring to the genre of a Christmas story, modern authors have diff erent purposes, using diff erent artistic strategies and methods. Some of them tend to reproduce the canon, appealing to the reader's memory (D. Bykov. Others develop the genre of a Christmas story, enriching it with new structural elements, interlacing it with other genres (L. Petrushevskaya.

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 ...

Women's club - Christmas Sale - Solidarité Femmes

CERN Document Server

CERN Women's club

2010-01-01

Thursday, 25 November from 9am to 3pm Main Building 60, Ground floor All proceeds from the sale will be given to the charity Solidarité Femmes Numerous items for sale: Christmas wreaths, Cakes and Biscuits, Coffee, Preserves, Paintings, Books, Embroidery, Patchwork, Painting on porcelain... Tombola! Win a patchwork quilt, handmade by CWC members. All are welcome!

Road Salts as Environmental Constraints in Urban Pond Food Webs

Science.gov (United States)

Van Meter, Robin J.; Swan, Christopher M.

2014-01-01

Freshwater salinization is an emerging environmental filter in urban aquatic ecosystems that receive chloride road salt runoff from vast expanses of impervious surface cover. Our study was designed to evaluate the effects of chloride contamination on urban stormwater pond food webs through changes in zooplankton community composition as well as density and biomass of primary producers and consumers. From May – July 2009, we employed a 2×2×2 full-factorial design to manipulate chloride concentration (low = 177 mg L−1 Cl−/high = 1067 mg L−1 Cl−), gray treefrog (Hyla versicolor) tadpoles (presence/absence) and source of stormwater pond algae and zooplankton inoculum (low conductance/high conductance urban ponds) in 40, 600-L mesocosms. Road salt did serve as a constraint on zooplankton community structure, driving community divergence between the low and high chloride treatments. Phytoplankton biomass (chlorophyll [a] µg L−1) in the mesocosms was significantly greater for the high conductance inoculum (Psalts among algal resources and zooplankton taxa, and further suggest that road salts can act as a significant environmental constraint on urban stormwater pond communities. PMID:24587259

Christmas and Easter Art Programs in Elementary School.

Science.gov (United States)

Duncum, Paul

2000-01-01

Describes art programs that were given at several elementary Australian schools focusing on Christmas and Easter. Explains that the programs are based on the accounts of the birth and death of Jesus given in the Bible. States that the programs integrate studio art, art criticism, and art history. (CMK)

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.

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.

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.

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

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...

A Hydrodynamic Study of Davis Pond, Near New Orleans, LA

Science.gov (United States)

2008-08-01

District 2004). This project will make the Barataria estuary a more prolific producer of oysters, shrimp, crab , and fish, as well as a major habitat...yards 0.9144 meters ERDC/CHL TR-08-11 1 1 Introduction The Davis Pond freshwater diversion project is a salinity -control structure located in St...Mathematical model of estuarial sediment transport. Technical Report D-77-12. Vicksburg, MS: U.S. Army Engineer Waterways Experiment Station

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.

78 FR 71493 - Special Local Regulation; Lake Havasu City Christmas Boat Parade of Lights; Colorado River; Lake...

Science.gov (United States)

2013-11-29

...-AA00 Special Local Regulation; Lake Havasu City Christmas Boat Parade of Lights; Colorado River; Lake... temporarily modifying the dates for the special local regulation in support of the Lake Havasu City Christmas Boat Parade of Lights on the Colorado River. This modification is necessary to reflect the actual dates...

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.

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)

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

Larval tolerance to salinity in three species of Australian anuran: an indication of saline specialisation in Litoria aurea.

Directory of Open Access Journals (Sweden)

Brian D Kearney

Full Text Available Recent anthropogenic influences on freshwater habitats are forcing anuran populations to rapidly adapt to high magnitude changes in environmental conditions or face local extinction. We examined the effects of ecologically relevant elevated salinity levels on larval growth, metamorphosis and survival of three species of Australian anuran; the spotted marsh frog (Limnodynastes tasmaniensis, the painted burrowing frog (Neobatrachus sudelli and the green and golden bell frog (Litoria aurea, in order to better understand the responses of these animals to environmental change. Elevated salinity (16% seawater negatively impacted on the survival of L. tasmaniensis (35% survival and N sudelli (0% survival, while reduced salinity had a negative impact on L. aurea. (16% seawater: 85% survival; 0.4% seawater: 35% survival. L. aurea tadpoles survived in salinities much higher than previously reported for this species, indicating the potential for inter-populations differences in salinity tolerance. In L. tasmaniensis and L. aurea, development to metamorphosis was fastest in low and high salinity treatments suggesting it is advantageous for tadpoles to invest energy in development in both highly favourable and developmentally challenging environments. We propose that this response might either maximise potential lifetime fecundity when tadpoles experience favourable environments, or, facilitate a more rapid escape from pond environments where there is a reduced probability of survival.

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.

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.

Developing Models to Forcast Sales of Natural Christmas Trees

Science.gov (United States)

Lawrence D. Garrett; Thomas H. Pendleton

1977-01-01

A study of practices for marketing Christmas trees in Winston-Salem, North Carolina, and Denver, Colorado, revealed that such factors as retail lot competition, tree price, consumer traffic, and consumer income were very important in determining a particular retailer's sales. Analyses of 4 years of market data were used in developing regression models for...

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)

Father Christmas came to CERN on Saturday, 2 December!

CERN Document Server

Staff Association

2017-01-01

Every year, ever since its creation, the Staff Association has organised the CERN Children’s Christmas Party, bringing together 5- to 7-year-old children of employed members of the personnel. The success of the party continues to motivate the organizers of the Staff Association. This year, the party took place on Saturday, 2 December, and no less than 240 children were welcomed in two sessions, at 13.30 and at 15.30. The children attended a show with music, tales and a speaking puppet: “Zéphirine et les légendes de Noël”. After the show, they enjoyed a snack in Restaurant 1. We would like to thank Novae for their valuable help and generous contribution. Then, Father Christmas himself came to give the children their presents. The Staff Association would also like to warmly thank him for taking the time to bring happiness and joy to little ones and big ones alike during the busy season! We would also like to thank all the parents for their valuable c...

Fuss over function: In case you missed the annual IP-World Christmas party

DEFF Research Database (Denmark)

Elsmore, Matthew James

2016-01-01

have tried to weave a familiar legal discussion into a festive setting. Hence, I stage an office IP party and place it (and the legal discussion) loosely in the ‘happiest’ of settings, Denmark, and at Christmas time (well, just after). A promising start, perhaps. What emerges is a look at the main...... ahead in bright mood to how the future might pan out (as I try to do at this time of year). It might be that this essay can be compared to Christmas: festive and fun at the surface, with a sober side beneath all the decoration. This essay’s content and style comprises an informal, non-technical, tongue...

Christmas Messages by heads of state Multimodality and media adaptations

NARCIS (Netherlands)

Sauer, C.L.A.; Fetzer, A.; Lauerbach, G.E.

2007-01-01

This chapter investigates the multimodal quality of Christmas Messages by European heads of state on TV from a functional-pragmatic and semiotic angle. It defines them as dealing with multiple types of materialities from different modes and sub-modes. Section 1 develops the central concept of

CERN Shop Christmas Sale

CERN Multimedia

Visits & Exhibition Service/ETT-VE

2001-01-01

11-13.12.2001 Looking for Christmas present ideas? Come to the Reception Shop Special Stand in Meyrin, Main Building, ground floor, from Tuesday 11 to Thursday 13 December from 10.30 to 16.00. CERN Calendar 10.- CERN Sweat-shirts(M, L, XL) 30.- CERN T-shirt (M, L, XL) 20.- New CERN silk tie (2 colours) 35.- Fancy silk tie (blue, bordeau) 25.- Silk scarf (light blue, red, yellow) 35.- Swiss army knife with CERN logo 25.- CERN watch 25.- CERN baseball cap 15.- CERN briefcase 15.- Book 'Antimatter' (English) 35.- Book 'How the web was born' (English) 25.- The Search for Infinity (French, Italian, English, German) 40.-   If you miss this special occasion, the articles are also available at the Reception Shop in Building 33 from Monday to Saturday between 08.30 and 17.30 hrs.

Impacts of Climatic Hazards on the Small Wetland Ecosystems (ponds: Evidence from Some Selected Areas of Coastal Bangladesh

Directory of Open Access Journals (Sweden)

Lucy Faulkner

2013-04-01

Full Text Available Most climate related hazards in Bangladesh are linked to water. The climate vulnerable poor—the poorest and most marginalized communities living in remote villages along Bangladesh’s coastal zone that are vulnerable to climate change impacts and who possess low adaptive capacity are most affected by lack of access to safe water sources. Many climate vulnerable poor households depend on small isolated wetlands (ponds for daily drinking water needs and other domestic requirements, including cooking, bathing and washing. Similarly, the livelihoods of many of these households also depend on access to ponds due to activities of small-scale irrigation for rice farming, vegetable farming and home gardening. This is particularly true for those poorest and most marginalized communities living in Satkhira, one of the most vulnerable coastal districts in south-west Bangladesh. These households rely on pond water for vegetable farming and home gardening, especially during winter months. However, these pond water sources are highly vulnerable to climate change induced hazards, including flooding, drought, salinity intrusion, cyclone and storm surges, erratic rainfall patterns and variations in temperature. Cyclone Sidr and Cyclone Aila, which hit Bangladesh in 2007 and 2009 respectively, led to a significant number of such ponds being inundated with saline water. This impacted upon and resulted in wide scale implications for climate vulnerable poor households, including reduced availability of safe drinking water, and safe water for health and hygiene practices and livelihood activities. Those households living in remote areas and who are most affected by these climate impacts are dependent on water being supplied through aid, as well as travelling long distances to collect safe water for drinking purposes.

Christmas in Physics Land

Science.gov (United States)

1999-01-01

A short story of everyday folk for the Yuletide season It was a beautiful scene. Children were sledging, or at least adults were sledging whilst the children waited for a go. Snow flakes were falling gently to the ground. The physicist was extremely content. All the snow flakes had a perfectly symmetric hexagonal crystal structure; the sledges were all reaching the bottom of the slope at just the correct velocity, neglecting heat loss due to friction. A skater went past. The physicist smiled. The change in melting point under the blades was just as it should have been, and angular momentum was completely conserved in the pirouette. A snowball hit the physicist squarely in the face, probably thrown by a geographer. But even this made the physicist laugh, as the trajectory was perfect, as long as you accounted for the changing mass. How different to last year when the physicist had spent Christmas in the real world. How glad he was that he had come to Physics Land for the festive season where everything was just as it ought to be. Someone in the crowd barged into him, but it didn't matter, he was a boson, so they just ignored each other. How horrid it had been last Christmas.... As a young man carrying a light ladder went past, whistling merrily and enjoying the experience of the Doppler effect, the physicist leant back against the perfectly smooth wall, revelling in the joy of resolving his forces on the rough ground... and began to think dark thoughts about the previous year. You see the problem with the real world was that it didn't understand physicists at all. Probably the worst place of all for a physicist was at a party. So often things would go wrong and he would leave early in disgrace. How well he remembered the evening when he had been curious whether it was a pnp or npn type semiconductor controlling the disco lights. It had taken barely three hours to reassemble the lights, and indeed improve on the flashing sequence by altering the reverse bias voltage

A working Christmas

CERN Multimedia

2005-01-01

The repair of faulty elements in the cryogenic distribution line is making great progress in building 927 at CERN. While many of us were relaxing over the two-week Christmas break, the team repairing elements of the LHC cryogenic distribution line - or QRL - continued working, keeping the repair schedule on course for completion by the end of March. Pipe elements with faulty sliding tables are being repaired by the ICS consortium, in charge of installing the cryo-magnets in their cryostats. This team began repairs at the beginning of November, fixing 10 elements a week (See Bulletin 42/2004 from 11 October 2004). However, during the five-week winter shutdown of the magnet test facility they are being assisted by 20 personnel who normally work on magnet testing. With the extra help a repair rate of five pipe elements a day has been reached - 25 elements a week - thanks to the remarkable effort of the ICS personnel led by Patrick Voisin, the DBS personnel assuring the transport and handling of the elements, an...

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.

Selected species and amendments for revegetating saline flue gas desulfurization sludge: greenhouse study

Energy Technology Data Exchange (ETDEWEB)

Salo, L.F.; Artiola, J.F.; Goodrich-Mahoney, J.W. [University of Arizona, Tuscon, AZ (United States). Dept. of Soil, Water and Environmental Science

1997-07-01

Codisposing low-volume wastes from electrical generating stations with flue gas desulfurization (FGD) scrubber sludge simplifies waste disposal but produces a saline waste that presents unique challenges to revegetation. This greenhouse study identified plants and amendments for revegetating a saline FGD sludge disposal pond in eastern Arizona. Survival and growth of 16 sown accessions plus two vegetatively propagated accessions of inland saltgrass were investigated in saline FGD sludge. Amendments used included two soils from the disposal site, Claysprings gravelly clay and Sheppard sand, composted steer manure, and N-P-K fertilizers. Sols and manure were added at 2:1 sludge/amendment (v/v). Plants were irrigated with a 1:1 mixture of disposal pond water and untreated well water. One accession of inland saltgrass, two cultivars of tall wheatgrass, Altai wildrye tall fescue and alkali sacaton show promise for revegetating saline FGD sludge disposal sites. Survival rates were the same in unamended sludge and in sludge amended with the clay soil or with N-P-K fertilizer. Plant dry matter produced was the same in unamended sludge and in sludge amended with either of the soils or with N-P-K. Although survival rates were significantly lower with manure than with any other amendment, growth was significantly greater by all measurements, due to the high fertility of this treatment. 34 refs., 5 tabs.

Long-Term Soil Productivity in Christmas Tree Farms of Oregon and Washington: A Comparative Analysis between First- and Multi-Rotation Plantations

Directory of Open Access Journals (Sweden)

Jeff Hatten

2014-10-01

Full Text Available Christmas tree production removes organic matter and associated nutrients from a site and can change soil physical properties, reduce mycorrhizal populations, and result in pesticide over-use/accumulation. These impacts have been implicated in potential field productivity declines. Assessing Christmas tree productivity is complicated by genetics, management, and market forces. We approached the perceived or possible productivity decline by examining soil properties on 22 pairs of sites. Each pair was comprised of an early rotation and late rotation plot with 1 and 3 or more rotations of Christmas trees, respectively. All sites were located on commercial Christmas tree plantations from the major production areas in Washington and Oregon. Chemical properties assessed to 45cm included pH, total C and N, and extractable P, K, Ca, and Mg. Soil physical properties assessed included aggregate stability and soil resistance. In general, we found little impact on soil resources that would impact long term production of Christmas trees. These impacts may have been mitigated by farmers following extension service recommendations. Nitrogen, K, and Ca appeared to be primarily affected by harvesting, but replacement by fertilizer application was probably adequate.

The Christmas Season as a Risk Factor for Chronic Obstructive Pulmonary Disease Exacerbations

Directory of Open Access Journals (Sweden)

Neil W Johnston

2010-01-01

Full Text Available BACKGROUND: Epidemics of hospitalization for chronic obstructive pulmonary disease (COPD occur annually during the Christmas holidays, and COPD exacerbations commonly coincide with respiratory viral infections.

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.

CERN SHOP CHRISTMAS SALE

CERN Multimedia

Visits & Exhibition Service

2000-01-01

Looking for Christmas present ideas? Come to the Reception Shop Special Stand in Meyrin, Main Building, ground floor, from Tuesday 12 to Thursday 14 December from 10.00 to 16.00.   Sweat-shirt col zippé, grey, blue, black (M, L, XL) 30.- Sweat-shirt col polo, grey, collar blue (M, L, XL) 30.- T-shirt, black, (M, L, XL) 15.- WWW T-shirt, white, bordeau (M, L, XL) 15.- CERN silk tie (3 colours) 33.- Fancy silk tie (blue, bordeau 25.- Silk scarf (blue, red, yellow) 35.- Swiss army knife with CERN logo 25.- New model of CERN watch 25.- New CERN baseball cap 10.- Antimatter (English/anglais) 30.- The Search for Infinity (French, Italian, English,) 35.- Auf der Suche nach dem Unendlichen 45.- If you miss this special occasion, the articles are also available at the Reception Shop in Building 33 from Monday to Saturday between 08.30 and 17.30 hrs (Shop will be closed at 12.00 on 22.12.).

Teaching child growth and development: the Christmas shoebox.

Science.gov (United States)

Epp, Sheila M; McAulay, Judy E

2008-01-01

Teaching growth and development to nursing students can be dry, uninteresting, and labor-intensive. Engaging students in learning this material was the challenge of a short, 4-week pediatric experience. Students use growth and development knowledge to select toys and activities that fit in a shoebox and explain to their classmates the rationale for their selection. The Christmas shoebox activity increases their ability to transfer knowledge to both the examination questions and the clinical setting and provides a charitable service to the community.

The effect of Christmas joy on the mood among medical doctors - a randomized, blinded intervention study

DEFF Research Database (Denmark)

Ilkjær, Christine; Møller, Marianne Birkebæk; Lauridsen, Mette H

2016-01-01

Abstract INTRODUCTION: Each December Santa's elves spread Christmas joy (JN). Laughter and humour may influence health and stress level. No other study has investigated the effect of JN on the good spirit (DGH) among healthcare professionals. MATERIAL AND METHODS: We performed a single-centre bli......Abstract INTRODUCTION: Each December Santa's elves spread Christmas joy (JN). Laughter and humour may influence health and stress level. No other study has investigated the effect of JN on the good spirit (DGH) among healthcare professionals. MATERIAL AND METHODS: We performed a single...

Isolation and characterization of halophilic bacteria and archaea from salt ponds in Hangu Saltworks, Tianjin, China

Science.gov (United States)

Deng, Yuangao; Xu, Gaochao; Sui, Liying

2015-07-01

A total of 26 isolates were obtained from solar salt ponds of different salinities (100, 150, 200, and 250) in Hangu Saltworks Co. Ltd., Tianjin, China. Phylogenetic analysis of 16S rRNA gene sequences indicated that five bacteria genera Halomonas, Salinicoccus, Oceanobacillus, Gracibacillus, and Salimicrobium and one archaea genera Halorubrum were present. The genus Halomonas was predominant with eight strains distributed in a salinity range of 100-200, followed by Halorubrum with six strains in salinity 250. Based on the genus and original sampling salinity, eight bacterial and two archaeal isolates were selected for further morphological, physiological, and biochemical characterization. All of the bacterial strains were moderately halophilic with the optimal salinity for growth being either 50 or 100, while two archaeal strains were extremely halophilic with an optimal growth salinity of 200. Additionally, we put forth strain SM.200-5 as a new candidate Salimicrobium species based on the phylogenic analysis of the 16S rRNA gene sequence and its biochemical characteristics when compared with known related species.

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.

Re-modeling Chara action potential: II. The action potential form under salinity stress

Directory of Open Access Journals (Sweden)

Mary Jane Beilby

2017-04-01

Full Text Available In part I we established Thiel-Beilby model of the Chara action potential (AP. In part II the AP is investigated in detail at the time of saline stress. Even very short exposure of salt-sensitive Chara cells to artificial pond water with 50 mM NaCl (Saline APW modified the AP threshold and drastically altered the AP form. Detailed modeling of 14 saline APs from 3 cells established that both the Ca2+ pump and the Ca2+ channels on internal stores seem to be affected, with the changes sometimes cancelling and sometimes re-enforcing each other, leading to APs with long durations and very complex forms. The exposure to salinity offers further insights into AP mechanism and suggests future experiments. The prolonged APs lead to greater loss of chloride and potassium ions, compounding the effects of saline stress.

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

The thematic framework of Christmas orations by Venclović

Directory of Open Access Journals (Sweden)

Anđelković Maja M.

2013-01-01

Full Text Available The paper examines Christmas orations delivered by Gavrilo Stefanović Venclović to Komoran congregation from 1739 to 1743, the records of which are to be found in the anthology of orations, entitled Slova izbrana (1743. Particular attention has been paid to the thematic framework and to defining thematic layers, but in their correlation. In addition to that, the integral part of the analysis is identifying the Church Fathers' notional concepts as patterns to orations by Venclović.

Ecotoxicology of organisms adapted to life in temporary freshwater ponds in arid and semi-arid regions.

Science.gov (United States)

Lahr, J

1997-01-01

Hot arid and semi-arid zones are characterized by an abundance of temporary ponds. Most of these depend on rain for their existence. These habitats are distinguished by fluctuating and unpredictable changes in their hydrological regime and of physical and chemical conditions.They contain a uniquely-adapted fauna that copes in different ways with changing and often extreme temperatures, oxygen levels, pH, salinity and turbidity. A classification is presented of the most distinctive adaptations,the various tactics that organisms apply to survive dry periods. The main strategies are dormancy (escape in time) and dispersal (escape in space). These adaptations may affect the impact of toxicants on individuals, populations and communities of temporary ponds. The physiological adaptations of species found in temporary ponds are likely to alter the sensitivity to pollutants of characteristic species. Results from laboratory experiments,for example, suggest that fairy shrimp (Branchiopoda, Anostraca) may react differently to heavy metals and pesticides as the standard test species Daphnia. Life history strategies influence recovery rates of populations after exposure to acutely toxic substances such as pesticides. It is also suggested that slow growth and decreased reproductive capacity of organisms caused by toxicants may, in ephemeral ponds, result in the failure of annual recruitment. Whether assemblages of organisms in temporary ponds are generally more vulnerable or more resilient than those in permanent waters or temperate regions could not be determined conclusively with the limited data available. Ecological concepts for studying the habitat and the development of risk assessment methods for temporary ponds are briefly discussed.

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...

Ethno linguistic material regarding Christmas rituals among the Serbs in Bela Krajina

Directory of Open Access Journals (Sweden)

Petrović Tanja

2002-01-01

Full Text Available The paper aims at presenting the current ethno linguistic situation in four Orthodox Serbian villages in the Bela Krajina region of Slovenia. Ethno linguistic material collected in these villages enables the synchronic state of traditional culture to be established. Special attention is payed to the way the interviewees describe Christmas rituals and interpret and evaluate then-present state; apart from description of Christmas interviewees' statements (here named ethno linguistic texts also carry precious information about attitudes of carriers of a certain culture towards its values, and indicate in- and out-group relations, establishing oppositions such as then vs. now, me vs. them, us vs. them. These subjective comments provided by the interviewees help obtain a complete, multilevel picture of a traditional culture, with all interactions that characterize it, both within the ethno linguistic community and in relation to other communities. It is especially important that these interactions be taken into account for isolated ethnic and linguistic groups such as the Orthodox Serbs in Bela Krajina.

216-B-3 expansion ponds closure plan

International Nuclear Information System (INIS)

1994-10-01

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

216-B-3 expansion ponds closure plan

Energy Technology Data Exchange (ETDEWEB)

1994-10-01

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

The effect of hydrogen peroxide on N/P ratio and phytoplankton diversity in Vannamei shrimp (litopeneus vanname) ponds in Banyuwangi, East Java

Science.gov (United States)

Daruti, D. N.; Rozi; Rahayu, K.

2018-04-01

Abundance of plankton in a waters is influenced by environmental parameters and physiological characteristics. Complex factors support phytoplankton growth. They are light intensity, dissolved oxygen, temperature stratification, salinity and availability of nitrogen and phosphorus. Nitrogen is an important element in the formation of chlorophyll, protoplasm, protein and nucleic acids. Observation of the three ponds in North Banyuwangi (Wongsorejo, Bangsring and Bulusan) and three ponds area of South Banyuwangi (Bomo, Jatisari and Badean). The observed parameters were NH4, NO2, NO3, PO4. Hidrogen peroxide effectively improve water quality, however it has a different effect in each different area.

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...

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).

A GIS cost model to assess the availability of freshwater, seawater, and saline groundwater for algal biofuel production in the United States.

Science.gov (United States)

Venteris, Erik R; Skaggs, Richard L; Coleman, Andre M; Wigmosta, Mark S

2013-05-07

A key advantage of using microalgae for biofuel production is the ability of some algal strains to thrive in waters unsuitable for conventional crop irrigation such as saline groundwater or seawater. Nonetheless, the availability of sustainable water supplies will provide significant challenges for scale-up and development of algal biofuels. We conduct a partial techno-economic assessment based on the availability of freshwater, saline groundwater, and seawater for use in open pond algae cultivation systems. We explore water issues through GIS-based models of algae biofuel production, freshwater supply (constrained to less than 5% of mean annual flow per watershed) and costs, and cost-distance models for supplying seawater and saline groundwater. We estimate that, combined, these resources can support 9.46 × 10(7) m(3) yr(-1) (25 billion gallons yr(-1)) of renewable biodiesel production in the coterminous United States. Achievement of larger targets requires the utilization of less water efficient sites and relatively expensive saline waters. Despite the addition of freshwater supply constraints and saline water resources, the geographic conclusions are similar to our previous results. Freshwater availability and saline water delivery costs are most favorable for the coast of the Gulf of Mexico and Florida peninsula, where evaporation relative to precipitation is moderate. As a whole, the barren and scrub lands of the southwestern U.S. have limited freshwater supplies, and large net evaporation rates greatly increase the cost of saline alternatives due to the added makeup water required to maintain pond salinity. However, this and similar analyses are particularly sensitive to knowledge gaps in algae growth/lipid production performance and the proportion of freshwater resources available, key topics for future investigation.

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

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

Science.gov (United States)

Clarke, John S.; Rumman, Malek Abu

2005-01-01

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

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...

South Bay Salt Pond Tidal Marsh Restoration at Pond A17 Project

Science.gov (United States)

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

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

Science.gov (United States)

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

2011-09-01

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

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

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

Science.gov (United States)

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

2018-01-01

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

2101-M pond closure plan

International Nuclear Information System (INIS)

1993-06-01

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

Par Pond vegetation status 1996

International Nuclear Information System (INIS)

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

1996-12-01

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

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

Analysis of the Discourse of Power in Etel Adnan's Play "Like a Christmas Tree"

Science.gov (United States)

Alashqar, Hossam Mahmoud

2015-01-01

This paper seeks to investigate the sources of power in the discourse of an Arab-American writer, Etel Adnan's one act play, "Like a Christmas Tree." The play represents a heated argument between two figures who stand for two different ideologies and who fall within the frame of "binary opposition," transcultural…

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

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).

News from the library: CERN Bookshop christmas sales

CERN Multimedia

CERN Library

2010-01-01

If you are looking for an idea for your Christmas gifts, the Bookshop of the Central Library offers you a wide choice of titles in Physics, Mathematics and Computing.   It will have a stall in the Ground Floor of the Main Building (Bldg 500) from 7 to 8 December 2010. You are welcome to come, browse and buy books at very interesting prices! The title list of the Bookshop is available here. This Bookshop is located in the Central Library, Building 52 1-052 and is open on weekdays from 8.30 a.m. to 7.00 p.m. It can be contacted by e-mail at bookshop@cern.ch. CERN Users can buy books and CDs at discount prices.

Stability of tailings ponds in the mining district of Mazarron (SE Spain): potential risks for the Moreras Rambla; Estudio de estabilidad en depositos de lodos del Distrito Minero de Mazarron (SE Espana): Riesgos potenciales sobre la Rambla de Las Moreras

Energy Technology Data Exchange (ETDEWEB)

Acosta, J. A.; Martinez-Martinez, S.; Martinez-Pagan, P.; Zornoza, R.; Carmona, D. M.; Faz, A.

2011-07-01

We have used geochemical, geophysical and geotechnical techniques to identify and quantify the environmental risks of the San Cristobal and Las Moreras tailing ponds, which have been left since the closing down of Pb-Zn mining activities in a semi-arid Mediterranean area. The results show that the tailings ponds present a potential risk to nearby ecosystems because of their high acidity, high salinity and high concentrations of metals, especially Pb and Zn contain. If the pond dams were to fail or if erosion carried dry sludge to the surrounding areas, the result would be pollution, acidification, salinization, compaction and nutrient depletion of the soil, thus reducing the biodiversity of the area. Geoelectrical tomography has shown the depth of the deposits, their volume and the geomorphology of the basement. The profiles reveal that in none of the pseudo-sections are there any regions betraying cracks that might affect the stability of the structures. In fact, geotechnical studies indicate that on a large scale both ponds are stable. Nevertheless, if we contemplate circular rupture and seismic action in the San Cristobal pond, the safety factor values become critical. It is recommended, therefore, that periodic inspections should be carried out to assess moisture, upsurges and settlements in the dam. To reduce erosion of the surface sludge in the tailing ponds we suggest the application of alkaline and organic remediation so as to improve their geochemical characteristics and encourage the establishment of natural vegetation. (Author) 48 refs.

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.

Relationship between white spot syndrome virus (WSSV) loads and characterizations of water quality in Litopenaeus vannamei culture ponds during the tropical storm.

Science.gov (United States)

Zhang, J S; Li, Z J; Wen, G L; Wang, Y L; Luo, L; Zhang, H J; Dong, H B

2016-01-01

An in-situ experiment was conducted to investigate the effect of tropical storm on the white spot syndrome virus (WSSV) loads in Litopenaeus vannamei rearing ponds. White spot syndrome virus loads, heterotrophic bacteria, Vibrio and water quality (including temperature, dissolved oxygen (DO), salinity, pH, NH 4 -N, and NO 2 -N) were continually monitored through one tropical storm. The WSSV loads decreased when tropical storm made landfall, and substantially increased when typhoon passed. The variation of WSSV loads was correlated with DO, temperature, heterotrophic bacteria count, and ammonia-N concentrations. These results suggested that maintaining high level DO and promoting heterotrophic bacteria growth in the shrimp ponds might prevent the diseases' outbreak after the landfall of tropical storm.

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...

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.)

Characterization of soil salinization in typical estuarine area of the Jiaozhou Bay, China

Science.gov (United States)

Li, Qifei; Xi, Min; Wang, Qinggai; Kong, Fanlong; Li, Yue

2018-02-01

In this study, the characteristics of soil salinization and the effects of main land use/land cover and other factors in typical estuarine area of the Jiaozhou Bay are investigated. Soil samples were collected in the parallel coastal zone, vertical coastal zone and longitudinal profile depth in the area to determine the soil salt content. The correlation analysis and principal component analysis are used to address the general characteristics of soil salinization in the study area. In the horizontal direction, there are moderate salinization, severe salinization and saline soil state. The farther from the sea (within 1.1 km), the lower the soil salinization degree. In the direction of longitudinal profile depth, there are severe salinization and saline soil state, and the soil salt content is accumulated in the surface and bottom. The Na+ and Cl- are the dominant cation and anion, respectively, the distributions of which are consistent with that of salt content. All the salinization indexes, except for soil pH, are of moderate/strong variability. The invasion of Spartina alterniflora results in the increase of soil salt content and salinization degree, the effects of which are mainly determined by the physiological characteristics and the growth years. The degree of soil salinization increased significantly in the aquaculture ponds, which is mainly caused by the use of chemicals. The correlation between soil salt content and Na+, Cl- is particularly significant. From the results of principal component analysis, Na+, Cl-, Ca2+, Mg2+ and SO42- could be used as main diagnostic factors for salinization in typical estuarine area of the Jiaozhou Bay. The effects of NaCl and sulfate on salt content further affect the degree of salinization in the estuarine area.

Lessons from history: asylum patients' Christmas experience.

Science.gov (United States)

Carpenter, Diane

This article outlines the asylum building programme of the mid-to-late nineteenth century and focuses on case studies of the two Hampshire asylums built during this period, the subject of the author's doctoral thesis. It demonstrates the plight of 'pauper lunatic' before asylum reform and contrasts this with the improved quality of life provided by the Hampshire County Lunatic Asylum and the Borough of Portsmouth Lunatic Asylum respectively. Asylum care during this period followed the moral treatment regime which became the Victorian blueprint for mental health, components of which are illustrated. Criticism of this regime is addressed briefly and arguments are made against anachronistic analysis. Comparison with contemporary in-patient care and treatment is made concluding with a call to reconsider some of the better aspects of earlier care delivery. The particular experience of patients in Hampshire asylums at Christmas is used to exemplify the points raised.

Abundance and composition of benthic fauna in Penaeus monodon Fabricius culture pond on the west coast of Malaysia peninsular

OpenAIRE

Abu Hena, M.K.; Hishamuddin, O.; Misri, K.

2006-01-01

This paper reports a study on the benthic faunal abundance and diversity of tiger shrimp P. monodon culture ponds in Perak, west coast of Malaysia Peninsular. Sampling was carried out at three weeks interval throughout the 116 days culture period. In addition, water temperature, dissolved oxygen, salinity, transparency, pH and organic matter of soil were also measured. Results showed that the major groups of macro-benthos comprised of gastropod, foraminifera, polychaetes, bivalve and insects;...

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.

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

International Nuclear Information System (INIS)

Hadlock, R.K.

1976-12-01

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

100-D Ponds closure plan. Revision 1

International Nuclear Information System (INIS)

Petersen, S.W.

1997-09-01

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

Comparison of prokaryotic community structure from Mediterranean and Atlantic saltern concentrator ponds by a metagenomic approach

Directory of Open Access Journals (Sweden)

Ana Beatriz eFernández

2014-05-01

Full Text Available We analyzed the prokaryotic community structure of a saltern pond with 21 % total salts located in Isla Cristina, Huelva, Southwest Spain, close to the Atlantic ocean coast. For this purpose, we constructed a metagenome (designated as IC21 obtained by pyrosequencing consisting of 486 Mb with an average read length of 397 bp and compared it with other metagenomic datasets obtained from ponds with 19, 33 and 37 % total salts acquired from Santa Pola marine saltern, located in Alicante, East Spain, on the Mediterranean coast. Although the salinity in IC21 is closer to the pond with 19 % total salts from Santa Pola saltern (designated as SS19, IC21 is more similar at higher taxonomic levels to the pond with 33 % total salts from Santa Pola saltern (designated as SS33, since both are predominated by the phylum Euryarchaeota. However, there are significant differences at lower taxonomic levels where most sequences were related to the genus Halorubrum in IC21 and to Haloquadratum in SS33. Within the Bacteroidetes, the genus Psychroflexus is the most abundant in IC21 while Salinibacter dominates in SS33. Sequences related to bacteriorhodopsins and halorhodopsins correlate with the abundance of Haloquadratum in Santa Pola SS19 to SS33 and of Halorubrum in Isla Cristina IC21 dataset, respectively. Differences in composition might be attributed to local ecological conditions since IC21 showed a decrease in the number of sequences related to the synthesis of compatible solutes and in the utilization of phosphonate.

Abundance patterns of macrofauna and infauna in nursery habitats of Christmas Bay, Texas: July 1984 through June 1985.

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Between July 1984 and June 1985, monthly samples were collected from marsh, seagrass, and nonvegetated habitats in Christmas Bay and West Bay in the Galveston Bay...

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)

Par Pond vegetation status Summer 1995 -- Summary

International Nuclear Information System (INIS)

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

1996-01-01

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

Technical manual for calculating cooling pond performance

International Nuclear Information System (INIS)

Krstulovich, S.F.

1988-01-01

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

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

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)

Influence of seasonal variations in sea level on the salinity regime of a coastal groundwater-fed wetland.

Science.gov (United States)

Wood, Cameron; Harrington, Glenn A

2015-01-01

Seasonal variations in sea level are often neglected in studies of coastal aquifers; however, they may have important controls on processes such as submarine groundwater discharge, sea water intrusion, and groundwater discharge to coastal springs and wetlands. We investigated seasonal variations in salinity in a groundwater-fed coastal wetland (the RAMSAR listed Piccaninnie Ponds in South Australia) and found that salinity peaked during winter, coincident with seasonal sea level peaks. Closer examination of salinity variations revealed a relationship between changes in sea level and changes in salinity, indicating that sea level-driven movement of the fresh water-sea water interface influences the salinity of discharging groundwater in the wetland. Moreover, the seasonal control of sea level on wetland salinity seems to override the influence of seasonal recharge. A two-dimensional variable density model helped validate this conceptual model of coastal groundwater discharge by showing that fluctuations in groundwater salinity in a coastal aquifer can be driven by a seasonal coastal boundary condition in spite of seasonal recharge/discharge dynamics. Because seasonal variations in sea level and coastal wetlands are ubiquitous throughout the world, these findings have important implications for monitoring and management of coastal groundwater-dependent ecosystems. © 2014, National Ground Water Association.

The Crisis at Christmas Dental Service: a review of an annual volunteer-led dental service for homeless and vulnerably housed people in London.

Science.gov (United States)

Doughty, J; Stagnell, S; Shah, N; Vasey, A; Gillard, C

2018-01-01

Background The UK charity Crisis originated in 1967 as a response to the increasing numbers of homeless people in London, and the first Crisis at Christmas event for rough sleepers was established in 1971. Since then, Crisis has provided numerous services over the Christmas period to the most vulnerable members of society. One of these is the Crisis at Christmas Dental Service (CCDS) which provides emergency and routine dental care from 23-29 of December each year. The charity is entirely dependent on voluntary staffing and industry donations including materials and facilities. This paper aims to assess the impact of the service over the last six years of clinical activity from 2011-2016.Method Anonymised data were collected from the annual CCDS delivered over the last six consecutive years. Services included: dental consultations; oral hygiene instruction; scale and polishes; permanent fillings; extractions; and fluoride varnish applications. In addition, anonymised patient feedback was collected after each dental attendance.Results On average, 80-85% of the patients were male and the majority were between 21 and 60 years of age. The most common nationality was British (46%). Over the six-year data collection period intervention treatments (restorations and extractions) remained fairly consistent, while the number of fluoride varnish applications and oral hygiene instruction have increased. The majority of patients reported positive satisfaction with their treatment and would have recommended the service to others. Approximately 75% of patients did not regularly attend a dentist outside of Crisis and a similar proportion were given information on where to access year round dental services for homeless people in London. The majority of dental volunteers felt that they enjoyed the experience and would consider volunteering again for Crisis in the future.Conclusion The Crisis at Christmas Dental Service has emerged as a valuable asset to the portfolio of resources

Investigation of a possible 18th century Dutch shipwreck on Christmas Island or the Cocos (Keeling) Islands

NARCIS (Netherlands)

Ariese, C.E.

2011-01-01

The existence of an unidentified 18th century Dutch shipwreck emerges periodically in books, letters and conversations about Christmas Island and the Cocos (Keeling) Islands. An investigation of these sources indicated that different ships may be responsible for these rumours, but it is equally

Eating Christmas Cookies, Whole-wheat Bread and Frozen Chicken in the Kindergarten: Doing Pedagogy by Other Means

NARCIS (Netherlands)

Kontopodis, M.

2013-01-01

The study presented here explores eating as a pedagogical practice by paying attention to arrangements of things such as Christmas cookies, whole-wheat and white bread, frozen chicken, plates, chairs, tables, and freezers. Through a series of ethnographic research examples from German and Brazilian

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

Antioxidant responses in Mesopodopsis zeylanica at varying salinity to detect mercury influence in culture ponds

Digital Repository Service at National Institute of Oceanography (India)

Verlecar, X.N.; Das, P.B.; Jena, K.; Maharana, D.; Desai, S.R.

addition. CAT increased significantly from 5 to 15 psu before Hg influence, and GST increased after addition of the metal. However, a reduction in both these enzymes is evident at higher salinities (25 psu) with or without Hg. The energy cost involved...

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

International Nuclear Information System (INIS)

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

1996-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-12-31

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

CO₂ efflux from shrimp ponds in Indonesia.

Science.gov (United States)

Sidik, Frida; Lovelock, Catherine E

2013-01-01

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

CO₂ efflux from shrimp ponds in Indonesia.

Directory of Open Access Journals (Sweden)

Frida Sidik

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

The Pond Is Our Laboratory

Science.gov (United States)

Marchewka, Barbara Turco

1978-01-01

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

Pond of Illusion: Interacting through Mixed Reality

DEFF Research Database (Denmark)

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

2013-01-01

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

The color of melt ponds on Arctic sea ice

Science.gov (United States)

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

2018-04-01

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

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

News from the Library: CERN Bookshop Christmas sales

CERN Multimedia

CERN Library

2012-01-01

If you are looking for an idea for your Christmas gifts, CERN's Central Library Bookshop offers a wide choice of titles in physics, mathematics, computing and popular science.   The Bookshop will have a stand on the Ground Floor of the Main Building (Building 500) from 4 to 5 December 2012. You are welcome to come by, and browse and buy books at very competitive prices! The title list of the Bookshop is available here. This Bookshop is located in the Central Library, Building 52 1-052, and is open on weekdays from 8.30 a.m. to 7.00 p.m. You can contact the Bookshop by e-mail. Accepted forms of payment in the Bookshop are: cash, credit card and budget code. You can also purchase books using your budget code via the CERN Stores: "Catalogue - CERN Stores" > "BOOKS - PUBLICATIONS" (category 90).

CERN Shop - Christmas Sale 15-17.12.2003

CERN Multimedia

2003-01-01

Looking for Christmas present ideas? Come to the Reception Shop Special Stand: in Meyrin, Main Building, ground floor, from Monday 15 to Wednesday 17 December from 10:30 to 16:00 hrs. CERN Sweat-shirts (M, L, XL) 30.- CERN T-shirt, (M, L, XL) 20.- CERN silk tie (2 colours) 35.- Fancy silk tie (blue, bordeau) 20.- Silk scarf (light blue, red, yellow) 35.- Swiss army knife with CERN logo 25.- Swiss Duo Pack with CERN logo 30.- CERN/Atlas watch 40.- CERN baseball cap 15.- CERN briefcase 15,- Mouse mat 10,- CERN Calendar 5,- Books: - "Antimatter" (English) 35.- - "How the web was born" (English, Italian) 30,- - "The Search for Infinity" (French, Italian, English, German) 40.- - "World of Particles/le monde de particules" 6,- - "Facts and Mysteries" (English) 28,- - "Nucleus" (English) 50,- If you miss this special occasion, the articles are also available at the Reception Shop in Buildin...

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.

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

International Nuclear Information System (INIS)

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

1996-06-01

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

Par Pond Fish, Water, and Sediment Chemistry

International Nuclear Information System (INIS)

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

1996-06-01

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

Par Pond Fish, Water, and Sediment Chemistry

Energy Technology Data Exchange (ETDEWEB)

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

1996-06-01

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

100-D Ponds groundwater quality assessment

International Nuclear Information System (INIS)

Hartman, M.J.

1996-01-01

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

ANL-W 779 pond seepage test

International Nuclear Information System (INIS)

Braun, D.R.

1992-11-01

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

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

International Nuclear Information System (INIS)

Hobbs, B.J.

1996-06-01

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

Mechanisms for parasites removal in a waste stabilisation pond.

Science.gov (United States)

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

2011-04-01

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

Greenhouse Gas Exchange in Small Arctic Thaw Ponds

Science.gov (United States)

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

2014-12-01

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

Valuing Multiple Benefits, and the Public Perception of SUDS Ponds

Directory of Open Access Journals (Sweden)

Joy Jarvie

2017-02-01

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

Microbial activities and communities in oil sands tailings ponds

Energy Technology Data Exchange (ETDEWEB)

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

2011-07-01

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

Musculoskeletal disorder survey for pond workers

Science.gov (United States)

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

2018-04-01

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

Salinization and Saline Environments

Science.gov (United States)

Vengosh, A.

2003-12-01

One of the most conspicuous phenomena of water-quality degradation, particularly in arid and semi-arid zones, is salinization of water and soil resources. Salinization is a long-term phenomenon, and during the last century many aquifers and river basins have become unsuitable for human consumption owing to high levels of salinity. Future exploitation of thousands of wells in the Middle East and in many other water-scarce regions in the world depends, to a large extent, on the degree and rate of salinization. Moreover, every year a large fraction of agricultural land is salinized and becomes unusable.Salinization is a global environmental phenomenon that affects many different aspects of our life (Williams, 2001a, b): changing the chemical composition of natural water resources (lakes, rivers, and groundwater), degrading the quality of water supply to the domestic and agriculture sectors, contribution to loss of biodiversity, taxonomic replacement by halotolerant species ( Williams, 2001a, b), loss of fertile soil, collapse of agricultural and fishery industries, changing of local climatic conditions, and creating severe health problems (e.g., the Aral Basin). The damage due to salinity in the Colorado River Basin alone, for example, ranges between 500 and 750 million per year and could exceed 1 billion per year if the salinity in the Imperial Dam increases from 700 mg L-1 to 900 mg L-1 (Bureau of Reclamation, 2003, USA). In Australia, accelerating soil salinization has become a massive environmental and economic disaster. Western Australia is "losing an area equal to one football oval an hour" due to spreading salinity ( Murphy, 1999). The annual cost for dryland salinity in Australia is estimated as AU700 million for lost land and AU$130 million for lost production ( Williams et al., 2002). In short, the salinization process has become pervasive.Salinity in water is usually defined by the chloride content (mg L-1) or total dissolved solids content (TDS, mg L-1or g

Origin of seamount volcanism in northeast Indian Ocean with emphasis on Christmas Island

Science.gov (United States)

Taneja, R.; O'Neill, C.; Rushmer, T. A.; Jourdan, F.; Blichert-Toft, J.; Turner, S.; Lackie, M. A.

2012-12-01

The Northeast Indian Ocean has been a central point of research in the recent past due to its intraplate geophysical and geochemical characteristics. It is dominated by sub-aerial volcanic islands and submerged guyots and two islands, namely, Cocos (Keeling) Island and Christmas Island. Christmas Island, the focus of this study, consists of limestone and mafic intraplate volcanics. The origin of most of the features in northeast Indian Ocean is not fully understood. Christmas Island has experienced multiple stages of intraplate volcanic activity as previously established by 40Ar/39Ar radioisotopic analyses of basalts from the island (Hoernl et al., 2011). Here, we present new 40Ar/39Ar ages where the rock samples from Waterfall Spring (WS), Ethel Beach (EB) & Dolly Beach (DB) on the east coast of the island yielded plateau and mini-plateau ages of 37.75±0.77 Ma, 37.10±0.66 Ma and 43.37±0.45 Ma respectively, whereas a sample from Flying Fish Cove (FFC) in the north of the island yielded a minimum age of 38.6±0.5 Ma. All these units are part of the Lower Volcanics Series. The samples from the west coast (Winifred Beach, WB) are younger with an age of 4.32 ± 0.17 Ma, and are part of the Upper Volcanic Series. This confirms two stages of volcanism at the island with a gap of around 38 Ma. The 40Ar/39Ar radioisotopic ages were overlayed on Gplates and seismic tomography models to determine its paleo motion. The present position of the island is 10.5°S, 105.5°E. During Eocene its reconstructed position was 30°S latitude. Seismic tomography models have highlighted a low velocity zone beneath the island during Eocene. Geochemically, the two volcanic suites (Upper & Lower) are mostly similar in their major and trace element composition. The majority of localities (WS, EB, and WB) are basanites; where as that from Dolly Beach is basaltic. The Dale's (west coast), are trachyte and appear evolved with high SiO2. They also have low Ba and Sr ~25ppm, whereas those from

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

International Nuclear Information System (INIS)

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

2014-01-01

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

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

International Nuclear Information System (INIS)

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

2001-01-01

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

UHS, Ultimate Heat Sink Cooling Pond Analysis

International Nuclear Information System (INIS)

Codell, R.; Nuttle, W.K.

1998-01-01

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

Flocculation of retention pond water

International Nuclear Information System (INIS)

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

1982-05-01

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

PERFORMANCES OF TIGER SHRIMP CULTURE IN ENVIRONMENTALLY FRIENDLY PONDS

Directory of Open Access Journals (Sweden)

Taufik Ahmad

2016-10-01

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

News from the Library: CERN Bookshop Christmas sales

CERN Multimedia

CERN Library

2011-01-01

If you are looking for an idea for your Christmas gifts, the Bookshop of the Central Library offers you a wide choice of titles in physics, mathematics, computing and popular science.   The Bookshop will have a stand on the Ground Floor of the Main Building (Bldg 500) from 12 to 13 December 2011. You are welcome to come, browse and buy books at very interesting prices! The title list of the Bookshop is available here. This Bookshop is located in the Central Library, Building 52 1-052, and is open on weekdays from 8.30 a.m. to 7.00 p.m. You can contact the Bookshop by e-mail at bookshop@cern.ch. Accepted forms of payment in the Bookshop are: cash, credit card and budget code. You can also purchase books using your budget code via the CERN Stores: http://edh.cern.ch > "Catalogue - CERN Stores" > "BOOKS - PUBLICATIONS" (category 90).

CERN SHOP - CHRISTMAS SALE - 11-12.12.2002

CERN Multimedia

Visits & Exhibition Service

2002-01-01

Looking for Christmas present ideas? Come to the Reception Shop Special Stand in Meyrin, Main Building, ground floor, from Wednesday 11 to Thursday 12 December from 10.30 to 16.00. CERN Sweat-shirts(M, L, XL) 30.- CERN T-shirt,(M, L, XL) 20.- New CERN silk tie (2 colours) 35.- Blue silk tie 15.- Fancy silk tie (blue, bordeau) 20.- Silk scarf (light blue, red, yellow) 35.- Swiss army knife with CERN logo 25.- Swiss Duo Pack with CERN logo 30.- CERN watch 20.- CERN baseball cap 15.- CERN briefcase 15.- Book 'Antimatter' (English) 35.- Book 'Particle Odyssey' (English) 60.- Book 'How the web was born' (English, Italian) 30.- The Search for Infinity (French, Italian, English, German)  40.- If you miss this special occasion, the articles are also available at the Reception Shop in Building 33 from Monday to Saturday between 08.30 and 17.00 hrs. Visits & Exhibition Service/ETT-VE

CERN Shop: Christmas Sale, 10 & 16.12.2004

CERN Multimedia

2004-01-01

Looking for Christmas present ideas? Come to the Reception Shop Special Stand in Meyrin, Main Building, ground floor, on Friday 10 and/or on Thursday 16 December from 10:30 to 16:00. CERN 50th Anniversary sweat-shirt (grey in M, L, XL) 30.- CERN 50th Anniversary T-shirt, (S, M, L, XL) 20.- CERN 50th Anniversary silk tie (2 colours) 30.- Einstein silk tie (blue, grey) 45.- Silk scarf 40.- Swiss army knife with CERN logo 25.- Swiss Duo-Pack with CERN logo 30.- CERN 50th Anniversary watch (2 models) 40.- CERN pens (2 models) 5.- Small Open Day souvenirs (a few different items) 2.- CERN 50th Anniversary Book (English & French) 70.- "Prestigious Discoveries" at CERN (English/anglais) 32.- "Particle Odyssey" soft cover (English/anglais) 35.- If you miss this special occasion, the articles are also available at the Reception Shop in Building 33 from Monday to Saturday between 08:30 and 17:00 hrs. Education and Communica...

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.

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.

Christmas Island lagoonal lakes, models for the deposition of carbonate–evaporite–organic laminated sediments

OpenAIRE

Trichet , Jean; Défarge , Christian; Tribble , J.; Tribble , G.W.; Sansone , F.J.

2001-01-01

The atoll of Christmas Island (now known as Kiritimati) in the Kiribati Republic (Central Pacific) lies at about 2°N in the intertropical convergence zone. Much of the surface area of the atoll (ca. 360 km2) is occupied by numerous lakes in which carbonate, evaporite (calcium sulfate, halite) and organic layers are deposited. Observations suggest that deposition of these different laminae is controlled by climatic and biologic factors. It is thought that periodic climatic variations, such as ...

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

International Nuclear Information System (INIS)

Kelty, G.G.

1993-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-09-01

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

The western pond turtle: Habitat and history. Final report

International Nuclear Information System (INIS)

Holland, D.C.

1994-08-01

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

Bioaccumulation of heavy metals in two wet retention ponds

DEFF Research Database (Denmark)

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

2016-01-01

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

Should Ramadan be prescribed after Christmas? Obesity in the healthcare profession and the health benefits of fasting.

Science.gov (United States)

Hankir, Ahmed; Hankir, Mohammed; Zaman, Rashid

2014-01-15

Obesity is an important risk factor for cardiovascular morbidity and mortality. In the UK, one in four people are considered overweight or obese and that number is expected to rise to one in three by 2020. Employees of the National Health Service (NHS) are no exception with up to half of healthcare workers considered overweight or obese. Religious periods such as Christmas and Ramadan are associated with weight changes. Weight gain has been reported during the Christmas period albeit not as much as was traditionally believed according to the results of recent research. Conversely, weight loss has been reported in Muslims who fast during the Islamic month of Ramadan; however, this amount tends to be modest and weight gradually returns to pre-Ramadan status according to a meta-analysis of the literature. We report a case of an NHS healthcare worker - which is the first of its kind that illustrates the role that fasting and other factors have played a role in causing dramatic oscillations in his weight.

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.

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

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

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.

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

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%.

Sentiment and Vision in Charles Dickens's A Christmas Carol and The Cricket on the Hearth

Directory of Open Access Journals (Sweden)

Heather Tilley

2007-04-01

Full Text Available This essay explores the ways in which sentimentality is manifested through the visible, and through associative functions of the eye, in two of Dickens's Christmas books of the 1840s. I situate the relationship between vision and sentiment within discourses from eighteenth-century moral philosophy, as Adam Smith's figure of the “Impartial Spectator” (of central importance to the development of ideas around sympathy is constructed mainly through the visual. I focus on two of the Christmas Books as they offer an interesting local study to test these ideas, coming at a critical juncture within the development of Dickens's own writing style, and also at an important historical moment within an investigation into Victorian sentimentality. Within Dickens's writing, sentimentality is typically associated with the exaggerated emotional portrayal of pathetic scenes (particularly the deaths of children, designed to elicit emotional responses from the reader. However, behind the hyperbole rests a concern with the self's need to take social, ethical and moral care of others, and the role of literature and art in tutoring the reader's emotional response, with the eye playing a crucial role in this act. I further explore the way in which Dickens's interest in blindness both reinforces, and points to certain disturbances, in his sentimental vision.

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%.

WWER-type NPP spray ponds screen

International Nuclear Information System (INIS)

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

2003-01-01

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

The evaporation from ponds in the French Midwest

Directory of Open Access Journals (Sweden)

Mohammad AL DOMANY

2013-12-01

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

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.

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...

Effects of pond salinization on survival rate of amphibian hosts infected with the chytrid fungus.

Science.gov (United States)

Stockwell, Michelle Pirrie; Storrie, Lachlan James; Pollard, Carla Jean; Clulow, John; Mahony, Michael Joseph

2015-04-01

The chytrid fungus Batrachochytrium dendrobatidis has been implicated in the decline and extinction of amphibian populations worldwide, but management options are limited. Recent studies show that sodium chloride (NaCl) has fungicidal properties that reduce the mortality rates of infected hosts in captivity. We investigated whether similar results can be obtained by adding salt to water bodies in the field. We increased the salinity of 8 water bodies to 2 or 4 ppt and left an additional 4 water bodies with close to 0 ppt and monitored salinity for 18 months. Captively bred tadpoles of green and golden bell frog (Litoria aurea) were released into each water body and their development, levels of B. dendrobatidis infection, and survival were monitored at 1, 4, and 12 months. The effect of salt on the abundance of nontarget organisms was also investigated in before and after style analyses. Salinities remained constant over time with little intervention. Hosts in water bodies with 4 ppt salt had a significantly lower prevalence of chytrid infection and higher survival, following metamorphosis, than hosts in 0 ppt salt. Tadpoles in the 4 ppt group were smaller in length after 1 month in the release site than those in the 0 and 2 ppt groups, but after metamorphosis body size in all water bodies was similar . In water bodies with 4 ppt salt, the abundance of dwarf tree frogs (Litoria fallax), dragonfly larvae, and damselfly larvae was lower than in water bodies with 0 and 2 ppt salt, which could have knock-on effects for community structure. Based on our results, salt may be an effective field-based B. dendrobatidis mitigation tool for lentic amphibians that could contribute to the conservation of numerous susceptible species. However, as in all conservation efforts, these benefits need to be weighed against negative effects on both target and nontarget organisms. © 2014 Society for Conservation Biology.

Simple Rules Govern the Patterns of Arctic Sea Ice Melt Ponds

Science.gov (United States)

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

2018-04-01

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

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

Science.gov (United States)

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

2018-04-06

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

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.

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.

MORFOMETRI ROTIFER Brachionus rotundiformis STRAIN SS ASAL TAMBAK MINANGA DAN TAMBAK WATULINEY SULAWESI UTARA YANG DIKULTUR PADA SALINITAS YANG BERBEDA

Directory of Open Access Journals (Sweden)

Inneke Fenny Melke Rumengan

2016-11-01

The rotifers Brachionus rotundiformis were found predominantly in Minanga and Watuliney brackishwater ponds in North Sulawesi. The two ponds are located 7 km apart at south-eastern coast of North Sulawesi facing to Maluku Sea. Morphometry of the two groups may associate with the original salinities of the ponds, 25—33 and 0—3 ppt in Minanga and Watuliney ponds, respectively. The rotifers were cultured at different salinities in laboratory in order to observe the plasticity of their size. Rotifers from Minanga ponds were gradually adapted by lowering salinities from 30 ppt to 25, 20 until 5 ppt. In contrast, Rotifers from Watuliney ponds were adapted gradually by increasing salinities from 5 ppt to 10, 15, 20, 25, and 30 ppt. In each treatment, 5 first laid eggs were put into each test tube containing Nannochloropsi oculata (3x106 cells/mL at 25°C, and after 7 days, the rotifer population remarkably increased due to parthenogenetic reproduction, and then body size of 30 egg-carrying rotifers of each treatment were measured under microscope. Body size of rotifers from Minanga ponds in all treatment was lower than that of rotifers from Watuliney ponds. Statistically, morphometry of the two groups was significantly different. However, there was a tendency for that lorica length of rotifers from Watuliney ponds to increase as the salinity increase, while rotifers from Minanga  ponds did not significantly changed in their sizes as the salinity changed.

Water logging and salinity control for environmentally sustainable crop production

International Nuclear Information System (INIS)

Chaudhry, M.R.; Bhutta, M.N.

2005-01-01

Irrigation supplies at proper time and adequate quantities are imperative for potential agricultural production under arid and semi-arid climatic conditions. To achieve this goal one of the largest integrated irrigation network was established. Without adequate drainage it resulted in the problems of water logging and salinity. To control these problems a big programme of Salinity Control and Reclamation projects (SCARPs) was initiated during 1960 and 82 such SCARPs have been completed and 9 were in progress up to June, 2002 covering an area of 18.6 ma (7.5 mh) at a cost of Rs.93 billions. Under these projects 12746 tube wells in fresh, 3572 in saline groundwater and 13726 km surface and 12612 km tile pipes covering 6391.7 ha, 160 km interceptor drains have been constructed an area of 0.998 ma (GCA). In addition to this some other measures like on farm water management, canal command project, canal lining, construction of evaporation ponds, establishment of research Inst./Organizations were also taken. Many drainage plans like Master Plan (1963), Northern Regional Plan (1967), Water Sector Investment Plan Study (1990), Right Bank Master Plan (1992), Drainage Sector Environmental Assessment (1993) and National Drainage Programme (1995) were prepared and implemented. The cost of the, phase-I of the National Drainage Programme was 785 million US$. The main activities undertaken were remodeling/extension of existing surface and new drains; rehabilitation/replacement of saline ground water (SGW) tube wells; construction of interceptor drains, reclamation of waterlogged areas through biological drainage and transfer of fresh ground water tube wells to the farmers. The data indicate that all the measures taken have played a significant role in reducing the water logging, salinity/sodicity and have increased the crop production and consequently improved the socio-economic conditions of the peoples especially the farming community. The environment in these areas was also

Christmas Valley Renewable Energy Assessment

Energy Technology Data Exchange (ETDEWEB)

Del Mar, Robert [Oregon Department of Energy, Salem, OR (United States)

2017-05-22

In partnership with the Oregon Military Department, the Department of Energy used the award to assess and evaluate renewable resources in a 2,622-acre location in Lake County, central Oregon, leading to future development of up to 200 MW of solar electricity. In partnership with the Oregon Military Department, the Department of Energy used the award to assess and evaluate renewable resources in a 2,622-acre location in Lake County, central Oregon, leading to future development of up to 200 MW of solar electricity. The Oregon Military Department (Military) acquired a large parcel of land located in south central Oregon. The land was previously owned by the US Air Force and developed for an Over-the-Horizon Backscatter Radar Transmitter Facility, located about 10 miles east of the town of Christmas Valley. The Military is investigating a number of uses for the site, including Research and Development (R&D) laboratory, emergency response, military operations, developing renewable energy and related educational programs. One of the key potential uses would be for a large scale solar photovoltaic power plant. This is an attractive use because the site has excellent solar exposure; an existing strong electrical interconnection to the power grid; and a secure location at a moderate cost per acre. The project objectives include: 1. Site evaluation 2. Research and Development (R&D) facility analysis 3. Utility interconnection studies and agreements 4. Additional on-site renewable energy resources analysis 5. Community education, outreach and mitigation 6. Renewable energy and emergency readiness training program for veterans

Did Winston Churchill suffer a myocardial infarction in the White House at Christmas 1941?

Science.gov (United States)

Vale, J Allister; Scadding, John W

2017-12-01

While staying in the White House over Christmas 1941, Churchill developed chest pain on trying to open a window in his bedroom. Sir Charles Wilson, his personal physician, diagnosed a 'heart attack' (myocardial infarction). Wilson, for political and personal reasons, decided not to inform his patient of the diagnosis or obtain assistance from US medical colleagues. On Churchill's return to London, Wilson sought a second opinion from Dr John Parkinson who did not support the diagnosis of coronary thrombosis (myocardial infarction) and reassured Churchill accordingly.

National Audubon society's technology initiatives for bird conservation: a summary of application development for the Christmas bird count

Science.gov (United States)

Kathy Dale

2005-01-01

Since 1998, Audubon's Christmas Bird Count (CBC) has been supported by an Internet-based data entry application that was initially designed to accommodate the traditional paper-based methods of this long-running bird monitoring program. The first efforts to computerize the data and the entry procedures have informed a planned strategy to revise the current...

Endogenous Auxin Profile in the Christmas Rose (Helleborus niger L.) Flower and Fruit: Free and Amide Conjugated IAA

Czech Academy of Sciences Publication Activity Database

Brcko, A.; Pěnčík, Aleš; Magnus, V.; Prebeg, T.; Mlinaric, S.; Antunovic, J.; Lepeduš, H.; Cesar, V.; Strnad, Miroslav; Rolčík, Jakub; Salopek-Sondi, B.

2012-01-01

Roč. 31, č. 1 (2012), s. 63-78 ISSN 0721-7595 R&D Projects: GA AV ČR KAN200380801 Keywords : Auxin * Indole-3-acetic acid * Amide conjugates * Christmas rose * Helleborus niger L. * Flower and fruit development * Perianth greening * Peduncle elongation * Vascular system Subject RIV: EF - Botanics Impact factor: 1.990, year: 2012

Enhancing Ecoefficiency in Shrimp Farming through Interconnected Ponds

Directory of Open Access Journals (Sweden)

Ramón Héctor Barraza-Guardado

2015-01-01

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

First description of underwater acoustic diversity in three temperate ponds

Directory of Open Access Journals (Sweden)

Camille Desjonquères

2015-11-01

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

Evaluation of Rhizophora Mucronata Growth at first-year Mangrove Restoration at Abandoned Ponds, Langkat, North Sumatra

Science.gov (United States)

Basyuni, M.; Telaumbanua, TFC; Wati, R.; Sulistyono, N.; Putri, LAP

2018-03-01

Degraded mangrove areas can be restored and rehabilitated. In Indonesia, one of the main recommended of mangrove species for restoration of degraded was Rhizophora mucronata. The purpose of the study was to evaluate R. mucronata growth at first-year mangrove restoration at abandoned shrimp ponds, Pulau Sembilan village, Langkat, North Sumatera, Indonesia. The recovery area divided into three zones based on the salinity concentration, landward, middle, and seaward zones. The evaluation parameters of mangrove reforestation consist of seedling diameter and height, leaves number, and seedling growth rate. Results showed that 3 of 4 evaluation parameters of R. mucronata growth belong to landward zone, namely seedlings diameter, the number of leaves, and percentage of growth. By contrast, height R. mucronata seedlings dominated in the middle area. The study also found that the proper zone for mangrove restoration with R. mucronata was in the landward with 96% growth rate and 30 part per thousand salinity concentration. The present study, therefore, suggested that the recommended species for the degraded area was the prerequisite for successful mangrove restoration.

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

Science.gov (United States)

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

2017-08-01

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

Groundwater impact assessment report for the 100-D Ponds

International Nuclear Information System (INIS)

Alexander, D.J.

1993-07-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1993-06-01

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

Investigation of turbidity effect on exergetic performance of solar ponds

International Nuclear Information System (INIS)

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

2014-01-01

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

Organic matter decomposition in simulated aquaculture ponds

NARCIS (Netherlands)

Torres Beristain, B.

2005-01-01

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

Simple intervention to reduce mosquito breeding in waste stabilisation ponds

DEFF Research Database (Denmark)

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

2007-01-01

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

Groundwater fluxes in a shallow seasonal wetland pond: The effect of bathymetric uncertainty on predicted water and solute balances

Science.gov (United States)

Trigg, Mark A.; Cook, Peter G.; Brunner, Philip

2014-09-01

The successful management of groundwater dependent shallow seasonal wetlands requires a sound understanding of groundwater fluxes. However, such fluxes are hard to quantify. Water volume and solute mass balance models can be used in order to derive an estimate of groundwater fluxes within such systems. This approach is particularly attractive, as it can be undertaken using measurable environmental variables, such as; rainfall, evaporation, pond level and salinity. Groundwater fluxes estimated from such an approach are subject to uncertainty in the measured variables as well as in the process representation and in parameters within the model. However, the shallow nature of seasonal wetland ponds means water volume and surface area can change rapidly and non-linearly with depth, requiring an accurate representation of the wetland pond bathymetry. Unfortunately, detailed bathymetry is rarely available and simplifying assumptions regarding the bathymetry have to be made. However, the implications of these assumptions are typically not quantified. We systematically quantify the uncertainty implications for eight different representations of wetland bathymetry for a shallow seasonal wetland pond in South Australia. The predictive uncertainty estimation methods provided in the Model-Independent Parameter Estimation and Uncertainty Analysis software (PEST) are used to quantify the effect of bathymetric uncertainty on the modelled fluxes. We demonstrate that bathymetry can be successfully represented within the model in a simple parametric form using a cubic Bézier curve, allowing an assessment of bathymetric uncertainty due to measurement error and survey detail on the derived groundwater fluxes compared with the fixed bathymetry models. Findings show that different bathymetry conceptualisations can result in very different mass balance components and hence process conceptualisations, despite equally good fits to observed data, potentially leading to poor management

Arctic sea ice melt pond fractal dimension - explained

Science.gov (United States)

Popovic, Predrag

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

A review of virus removal in wastewater treatment pond systems.

Science.gov (United States)

Verbyla, Matthew E; Mihelcic, James R

2015-03-15

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

Can terraced pond wetland systems improve urban watershed water quality?

Science.gov (United States)

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

2017-12-01

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

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...

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.

Pond dyes are Culex mosquito oviposition attractants

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Natali Ortiz Perea

2017-05-01

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

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

Science.gov (United States)

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

2014-01-01

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

Antibiotic resistance patterns in fecal bacteria isolated from Christmas shearwater (Puffinus nativitatis) and masked booby (Sula dactylatra) at remote Easter Island.

Science.gov (United States)

Ardiles-Villegas, Karen; González-Acuña, Daniel; Waldenström, Jonas; Olsen, Björn; Hernández, Jorge

2011-09-01

Antibiotic use and its implications have been discussed extensively in the past decades. This situation has global consequences when antibiotic resistance becomes widespread in the intestinal bacterial flora of stationary and migratory birds. This study investigated the incidence of fecal bacteria and general antibiotic resistance, with special focus on extended spectrum beta-lactamase (ESBL) isolates, in two species of seabirds at remote Easter Island. We identified 11 species of bacteria from masked booby (Sula dactylatra) and Christmas shearwater (Puffinus nativitatis); five species of gram-negative bacilli, four species of Streptococcus (Enterococcus), and 2 species of Staphylococcus. In addition, 6 types of bacteria were determined barely to the genus level. General antibiotic susceptibility was measured in the 30 isolated Enterobacteriaceae to 11 antibiotics used in human and veterinary medicine. The 10 isolates that showed a phenotypic ESBL profile were verified by clavulanic acid inhibition in double mixture discs with cefpodoxime, and two ESBL strains were found, one strain in masked booby and one strain in Christmas shearwater. The two bacteria harboring the ESBL type were identified as Serratia odorifera biotype 1, which has zoonotic importance. Despite minimal human presence in the masked booby and Christmas shearwater habitats, and the extreme geographic isolation of Easter Island, we found several multiresistant bacteria and even two isolates with ESBL phenotypes. The finding of ESBLs has animal and public health significance and is of potential concern, especially because the investigation was limited in size and indicated that antibiotic-resistant bacteria now are distributed globally.

Continuous Hydrologic and Water Quality Monitoring of Vernal Ponds.

Science.gov (United States)

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

2017-11-13

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

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

Science.gov (United States)

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

2017-09-01

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

FROM PONDS TO MAN-MADE SEAS IN RUSSIA

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Sergey Gorshkov

2013-01-01

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

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

Science.gov (United States)

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

2010-07-01

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

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

International Nuclear Information System (INIS)

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

2015-01-01

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

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

Science.gov (United States)

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

2017-08-01

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

Algal massive growth in relation to water quality and salinity at Damietta, north of Egypt

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Mohamed Ali Ibraheem Deyab

2015-02-01

Full Text Available Objective: To relate the proliferation and dominance of certain algal species at the Damietta and its relation to water quality. Methods: Water and algal biomass were bimonthly sampled from five selected sites at Damietta Province, Egypt during 2012. Algae were identified and quantified. Waters, algae and sediment were analyzed. Results: The physicochemical properties of water showed limited seasonal but substantial local variation. The high levels of nitrogen and phosphorus and turbidity of water pointed to marked eutrophication, which could enhance massive algal growth. The temporal fluctuation in temperature, exposure to industrial and domestic sewage and salinity results in succession between blooming algal species. Spirulina platensis and Chlorella vulgaris alternated in a moderately saline water and Oscillatoria agardhii and Mougeotia scalaris in a fresh water body during summer and winter respectively. Likewise, Microcystis aureginosa and Ulva lactuca alternated in a moderately saline site during autumn and summer respectively. Cladophora albida dominated a fish pond of brackish water and Dunaliella salina dominated the most saline water over the whole period of study. Conclusions: Growth of the predominant algal species is correlated to water quality. These species are of considerable nutritive value, with moderate contents of protein, carbohydrate, macronutrients and micronutrients, which evaluates them for usage as food (green and macroalgae, fodder or bio-fertilizer (cyanophytes.

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

International Nuclear Information System (INIS)

Halverson, N.V.

1999-01-01

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

Seasonality of dipteran-mediated methylmercury flux from ponds.

Science.gov (United States)

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

2018-03-12

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

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

Science.gov (United States)

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

2018-01-01

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

Monthly and diurnal variations of limnological conditions of two ponds

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AKM Fazlur Rahaman

2017-06-01

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

A mathematical procedure to estimate solar absorptance of shallow water ponds

International Nuclear Information System (INIS)

Wu Hongbo; Tang Runsheng; Li Zhimin; Zhong Hao

2009-01-01

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

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

International Nuclear Information System (INIS)

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

1975-06-01

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

Distribution of transuranic elements in a freshwater pond ecosystem

International Nuclear Information System (INIS)

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

1975-05-01

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

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

Science.gov (United States)

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

2017-12-01

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

Distribution of transuranic elements in a freshwater pond ecosystem

International Nuclear Information System (INIS)

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

1976-01-01

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

Impact of highly saline wetland ecosystem on floral diversity of the Cholistan desert

International Nuclear Information System (INIS)

Gill, A.H.; Ahmad, K.S.; Habib, S.; Ahmad, S.A.; Nawaz, T.; Ahmad, F.

2012-01-01

The impact of highly saline wetland ecosystem created under Salinity Control and Reclamation Project (SCARP) on floral diversity was investigated in the arid environments of Cholistan Desert. Species richness, diversity indices and evenness indices were worked out to look at the distance at which the salt water has altered the native vegetation. Four sites including SCARP ponds of different ages (S1, S2, S3 and S4), and a reference site (SR) were selected for vegetation studies and data were recorded by 1 x 1 m quadrats, which were laid on permanent transect lines. Salt water showed great influence on ecological parameters of the native vegetation up to 40 m. Multivariate (cluster) analysis showed close clustering of highly salt tolerant species, Aeluropus lagopoides, Tamarix dioica and Suaeda fruticosa in one group, and relatively less tolerant Crotalaria burhia, Cyperus conglomeratus, Indigofera argentea, Haloxylon salicornicum, Haloxylon stocksii, Neurada procumbens and Salsola baryosma in second group. Moderately salt tolerant Aristida adscensionis, Lasiurus scindicus and Sporobolus iocladus were clustered in a separate group. (author)

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)

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

International Nuclear Information System (INIS)

Smith, D.L.

1985-01-01

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

Polycyclic aromatic hydrocarbon contamination in stormwater detention pond sediments in coastal South Carolina.

Science.gov (United States)

Weinstein, John E; Crawford, Kevin D; Garner, Thomas R

2010-03-01

The purpose of this study was to characterize the polycyclic aromatic hydrocarbon (PAH) contamination in the sediments of stormwater detention ponds in coastal South Carolina. Levels of the sum of PAH analytes were significantly higher in the sediments of commercial ponds compared to that of reference, golf course, low-density residential, and high-density residential ponds. Isomer ratio analysis suggested that the predominant source of PAHs were pyrogenic; however, many ponds had a PAH signature consistent with mixed uncombusted and combusted PAH sources. PAH levels in these sediments could be modeled using both pond drainage area and pond surface area. These results demonstrate that the sediment from most commercial ponds, and a few residential and golf course ponds, were moderately contaminated with PAHs. PAH levels in these contaminated ponds exceeded between 42% and 75% of the ecological screening values for individual PAH analytes established by US EPA Region IV, suggesting that they may pose a toxicological risk to wildlife.

Limnological database for Par Pond: 1959 to 1980

International Nuclear Information System (INIS)

Tilly, L.J.

1981-03-01

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

EXPERIMENTAL INVESTIGATION OF SOLAR POND PERFORMANCE IN KARABUK ENVIRONMENT

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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.

Prediction of local effects of proposed cooling ponds

International Nuclear Information System (INIS)

Hicks, B.B.

1978-01-01

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

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

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Queiroz Julio Ferraz de

2004-01-01

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

Treatment of pond sludge at the Rocky Flats Plant

International Nuclear Information System (INIS)

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

1992-01-01

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

Emergent multisystemic Enterococcus infection threatens endangered Christmas Island reptile populations.

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Karrie Rose

Full Text Available Multisystemic infections with a morphologically unusual bacterium were first observed in captive critically endangered Lister's geckos (Lepidodactylus listeri on Christmas Island in October 2014. Since then the infection was identified in another captive critically endangered lizard species, the blue-tailed skink (Cryptoblepharus egeriae and two species of invasive geckos; the four clawed gecko (Gehyra mutilata and Asian house gecko (Hemidactylus frenatus, in a wide geographic range across the east side of the island. The Gram and periodic acid-Schiff positive cocci to diplococci have a propensity to form chains surrounded by a matrix, which ultrastructurally appears to be formed by fibrillar capsular projections. The bacterium was associated with severe and extensive replacement of tissues, but minimal host inflammatory response. Attempts to grow the organism in culture and in embryonated eggs were unsuccessful. Molecular characterisation of the organism placed it as a novel member of the genus Enterococcus. Disease Risk Analyses including this organism should now be factored into conservation management actions and island biosecurity.

Interconnected ponds operation for flood hazard distribution

Science.gov (United States)

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

2016-05-01

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

Validation Hydrodynamic Models of Three Topological Models of Secondary Facultative Ponds

OpenAIRE

Aponte-Reyes Alxander

2014-01-01

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

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

Science.gov (United States)

Walter, Donald A.; Masterson, John P.

2011-01-01

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

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

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Т. Hryhorenko

2017-09-01

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

Modeling a ponded infiltration experiment at Yucca Mountain, NV

International Nuclear Information System (INIS)

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

1994-01-01

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

Sediment remediation of the Hespeler Mill Pond, Cambridge, Ontario

Energy Technology Data Exchange (ETDEWEB)

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

2002-06-15

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

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

Science.gov (United States)

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

2017-08-01

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

Heat recovery from ground below the solar pond

NARCIS (Netherlands)

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

2017-01-01

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

Mathematical modeling of dissolved oxygen in fish ponds ...

African Journals Online (AJOL)

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

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

International Nuclear Information System (INIS)

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

1984-01-01

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

THERMAL AND OXYGEN CONDITIONS IN CARP PONDS DURING THE SUMMER PERIOD

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Magdalena Wiśnios

2015-11-01

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

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

Science.gov (United States)

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

2017-10-01

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

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

Science.gov (United States)

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

2010-01-01

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

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

African Journals Online (AJOL)

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

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

Science.gov (United States)

Moye, Johnny J.

2011-01-01

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

Sea Ice Melt Pond Data from the Canadian Arctic

Data.gov (United States)

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

Ecological behavior of plutonium and americium in a freshwater pond

International Nuclear Information System (INIS)

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

1976-01-01

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

Fatty acids from high rate algal pond's microalgal biomass and osmotic stress effects.

Science.gov (United States)

Drira, Neila; Dhouibi, Nedra; Hammami, Saoussen; Piras, Alessandra; Rosa, Antonella; Porcedda, Silvia; Dhaouadi, Hatem

2017-11-01

The extraction of oil from a wild microalgae biomass collected from a domestic wastewater treatment facility's high rate algal pond (HRAP) was investigated. An experiment plan was used to determine the most efficient extraction method, the optimal temperature, time and solvent system based on total lipids yield. Microwave-assisted extraction was the most efficient method whether in n-hexane or in a mixture of chloroform/methanol compared to Soxhlet, homogenization, and ultrasounds assisted extractions. This same wild biomass was cultivated in a photobioreactor (PBR) and the effect of osmotic stress was studied. The lipids extraction yield after 3days of stress increased by more than four folds without any significant loss of biomass, however, the quality of extracted total lipids in terms of saturated, monounsaturated and polyunsaturated fatty acids was not affected by salinity change in the culture medium. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

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

2018-06-01

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

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

International Nuclear Information System (INIS)

Bozkurt, Ismail; Karakilcik, Mehmet

2015-01-01

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

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

Science.gov (United States)

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

2017-02-01

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

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

International Nuclear Information System (INIS)

Price, J.B.

1980-01-01

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

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

Directory of Open Access Journals (Sweden)

Evan S. Miles

2017-09-01

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

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

International Nuclear Information System (INIS)

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

2014-01-01

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

Evaluation of relocation of unionid mussels into artificial ponds

Science.gov (United States)

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

2001-01-01

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

Fate of Pyrethroids in Farmland Ponds

DEFF Research Database (Denmark)

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

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

Fate of high loads of ammonia in a pond and wetland downstream from a hazardous waste disposal site.

Science.gov (United States)

Cutrofello, Michele; Durant, John L

2007-07-01

Halls Brook (eastern Massachusetts, USA) is a significant source of total dissolved ammonia (sum of NH(3) and NH(4)(+); (NH(3))(T)) to the Aberjona River, a water body listed for NH(3) impairment on the Clean Water Act section 303(d) list. We hypothesized (1) that (NH(3))(T) in Halls Brook derived from a hazardous waste site via groundwater discharging to a two-basin pond that feeds the brook; and (2) that transport of (NH(3))(T) to the Aberjona River was controlled by lacustrine and wetland processes. To test these hypotheses we measured (NH(3))(T) levels in the brook, the pond, and a wetlands directly downstream of the pond during both dry and wet weather over a ten month period. In addition, we analyzed sediment cores and nitrogen isotopes, and performed mass balance calculations. Groundwater discharge from beneath the hazardous waste site was the major source of (NH(3))(T) (20-67 kg d(-1)) and salinity to the north basin of the pond. The salty bottom waters of the north basin were anoxic on all sampling dates, and exhibited relatively stable (NH(3))(T) concentrations between 200 and 600 mg Nl(-1). These levels were >100-times higher than typical background levels, and 8-24-times above the acute effects level for (NH(3))(T) toxicity. Bottom waters from the north basin continuously spill over into the south basin contributing approximately 50% of the (NH(3))(T) load entering this basin. The remainder comes from Halls Brook, which receives (NH(3))(T) loadings from as yet unknown sources upstream. During storm events up to 50% of the mass of (NH(3))(T) was flushed from the south basin and into the wetlands. The wetlands acted as a (NH(3))(T) sink in dry weather in the growing season and a discharge-dependent (NH(3))(T) source to the Aberjona River during rainstorms.

Thermal performance measurements on ultimate heat sinks--cooling ponds

International Nuclear Information System (INIS)

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

1977-12-01

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

Development of shrimp in small ponds

Directory of Open Access Journals (Sweden)

Armando Adolfo Ortega Salas

2014-06-01

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

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

Science.gov (United States)

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

2017-12-01

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

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

Science.gov (United States)

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

2016-12-01

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

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

Science.gov (United States)

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

2017-01-01

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

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

International Nuclear Information System (INIS)

Qvarfordt, Susanne; Wallin, Anders; Borgiel, Micke

2013-01-01

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

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

Science.gov (United States)

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

2017-02-15

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1994-02-01

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

Concentrated Brine Treatment using New Energy in Coal Mine Evaporation Ponds

Science.gov (United States)

Li, Ting; Li, Jingfeng

2017-12-01

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

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

International Nuclear Information System (INIS)

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

1994-02-01

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

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

OpenAIRE

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

2010-01-01

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

Biological removal of algae in an integrated pond system

CSIR Research Space (South Africa)

Meiring, PGJ

1995-01-01

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

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

Science.gov (United States)

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

2017-04-01

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

PRACTICAL SOLUTIONS FOR ECOLOGICAL RECONSTRUCTION OF GERAI POND

Directory of Open Access Journals (Sweden)

Alexandru Dimache

2012-06-01

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

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

Directory of Open Access Journals (Sweden)

. Sulistiono

2009-01-01

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

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

Science.gov (United States)

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

2014-01-01

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

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...

Bioaccumulation of heavy metals in fauna from wet detention ponds for stormwater runoff

DEFF Research Database (Denmark)

Stephansen, Diana; Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild

2012-01-01

Stormwater detention ponds remove pollutants e.g. heavy metals and nutrients from stormwater runoff. These pollutants accumulate in the pond sediment and thereby become available for bioaccumulation in fauna living in the ponds. In this study the bioaccumulation was investigated by fauna samples...... from 5 wet detention ponds for analyses of heavy metal contents. Five rural shallow lakes were included in the study to survey the natural occurrence of heavy metals in water-dwelling fauna. Heavy metal concentrations in water-dwelling fauna were generally found higher in wet detention ponds compared...

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

International Nuclear Information System (INIS)

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

1995-11-01

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

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

International Nuclear Information System (INIS)

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

1995-09-01

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

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

International Nuclear Information System (INIS)

Drake, R.L.

1975-09-01

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

Comparative Genomics of the Baltic Sea Toxic Cyanobacteria Nodularia spumigena UHCC 0039 and Its Response to Varying Salinity.

Science.gov (United States)

Teikari, Jonna E; Hou, Shengwei; Wahlsten, Matti; Hess, Wolfgang R; Sivonen, Kaarina

2018-01-01

Salinity is an important abiotic factor controlling the distribution and abundance of Nodularia spumigena , the dominating diazotrophic and toxic phototroph, in the brackish water cyanobacterial blooms of the Baltic Sea. To expand the available genomic information for brackish water cyanobacteria, we sequenced the isolate Nodularia spumigena UHCC 0039 using an Illumina-SMRT hybrid sequencing approach, revealing a chromosome of 5,294,286 base pairs (bp) and a single plasmid of 92,326 bp. Comparative genomics in Nostocales showed pronounced genetic similarity among Nodularia spumigena strains evidencing their short evolutionary history. The studied Baltic Sea strains share similar sets of CRISPR-Cas cassettes and a higher number of insertion sequence (IS) elements compared to Nodularia spumigena CENA596 isolated from a shrimp production pond in Brazil. Nodularia spumigena UHCC 0039 proliferated similarly at three tested salinities, whereas the lack of salt inhibited its growth and triggered transcriptome remodeling, including the up-regulation of five sigma factors and the down-regulation of two other sigma factors, one of which is specific for strain UHCC 0039. Down-regulated genes additionally included a large genetic region for the synthesis of two yet unidentified natural products. Our results indicate a remarkable plasticity of the Nodularia salinity acclimation, and thus salinity strongly impacts the intensity and distribution of cyanobacterial blooms in the Baltic Sea.

Comparative Genomics of the Baltic Sea Toxic Cyanobacteria Nodularia spumigena UHCC 0039 and Its Response to Varying Salinity

Directory of Open Access Journals (Sweden)

Jonna E. Teikari

2018-03-01

Full Text Available Salinity is an important abiotic factor controlling the distribution and abundance of Nodularia spumigena, the dominating diazotrophic and toxic phototroph, in the brackish water cyanobacterial blooms of the Baltic Sea. To expand the available genomic information for brackish water cyanobacteria, we sequenced the isolate Nodularia spumigena UHCC 0039 using an Illumina-SMRT hybrid sequencing approach, revealing a chromosome of 5,294,286 base pairs (bp and a single plasmid of 92,326 bp. Comparative genomics in Nostocales showed pronounced genetic similarity among Nodularia spumigena strains evidencing their short evolutionary history. The studied Baltic Sea strains share similar sets of CRISPR-Cas cassettes and a higher number of insertion sequence (IS elements compared to Nodularia spumigena CENA596 isolated from a shrimp production pond in Brazil. Nodularia spumigena UHCC 0039 proliferated similarly at three tested salinities, whereas the lack of salt inhibited its growth and triggered transcriptome remodeling, including the up-regulation of five sigma factors and the down-regulation of two other sigma factors, one of which is specific for strain UHCC 0039. Down-regulated genes additionally included a large genetic region for the synthesis of two yet unidentified natural products. Our results indicate a remarkable plasticity of the Nodularia salinity acclimation, and thus salinity strongly impacts the intensity and distribution of cyanobacterial blooms in the Baltic Sea.

Climate-simulated raceway pond culturing: quantifying the maximum achievable annual biomass productivity of Chlorella sorokiniana in the contiguous USA

Energy Technology Data Exchange (ETDEWEB)

Huesemann, M.; Chavis, A.; Edmundson, S.; Rye, D.; Hobbs, S.; Sun, N.; Wigmosta, M.

2017-09-13

Chlorella sorokiniana (DOE 1412) emerged as one of the most promising microalgae strains from the NAABB consortium project, with a remarkable doubling time under optimal conditions of 2.57 hr-1. However, its maximum achievable annual biomass productivity in outdoor ponds in the contiguous United States remained unknown. In order to address this knowledge gap, this alga was cultured in indoor LED-lighted and temperature-controlled raceways in nutrient replete freshwater (BG-11) medium at pH 7 under conditions simulating the daily sunlight intensity and water temperature fluctuations during three seasons in Southern Florida, an optimal outdoor pond culture location for this organism identified by biomass growth modeling. Prior strain characterization indicated that the average maximum specific growth rate (µmax) at 36 ºC declined continuously with pH, with µmax corresponding to 5.92, 5.83, 4.89, and 4.21 day-1 at pH 6, 7, 8, and 9, respectively. In addition, the maximum specific growth rate declined nearly linearly with increasing salinity until no growth was observed above 35 g/L NaCl. In the climate-simulated culturing studies, the volumetric ash-free dry weight-based biomass productivities during the linear growth phase were 57, 69, and 97 mg/L-day for 30-year average light and temperature simulations for January (winter), March (spring), and July (summer), respectively, which corresponds to average areal productivities of 11.6, 14.1, and 19.9 g/m2-day at a constant pond depth of 20.5 cm. The photosynthetic efficiencies (PAR) in the three climate-simulated pond culturing experiments ranged from 4.1 to 5.1%. The annual biomass productivity was estimated as ca. 15 g/m2-day, nearly double the U.S. Department of Energy (DOE) 2015 State of Technology annual cultivation productivity of 8.5 g/m2-day, but this is still significantly below the projected 2022 target of ca. 25 g/m2-day (U.S. DOE, 2016) for economic microalgal biofuel production, indicating the need for

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...

Water cycle and salinity dynamics in the mangrove forests of Europa and Juan de Nova Islands, southwest Indian Ocean.

Science.gov (United States)

Lambs, Luc; Mangion, Perrine; Mougin, Eric; Fromard, François

2016-01-30

The functioning of mangrove forests found on small coralline islands is characterized by limited freshwater inputs. Here, we present data on the water cycling of such systems located on Europa and Juan de Nova Islands, Mozambique Channel. In order to better understand the water cycle and mangrove growth conditions, we have analysed the hydrological and salinity dynamics of the systems by gauge pressure and isotopic tracing (δ18O and δ2H values). Both islands have important seawater intrusion as measured by the water level change and the high salinities in the karstic ponds. Europa Island displays higher salinity stress, with its inner lagoon, but presents a pluri-specific mangrove species formation ranging from shrub to forest stands. No freshwater signal could be detected around the mangrove trees. On Juan de Nova Island, the presence of sand and detrital sediment allows the storage of some amount of rainfall to form a brackish groundwater. The mangrove surface area is very limited with only small mono-specific stands being present in karstic depression. On the drier Europa Island, the salinity of all the water points is equal to or higher than that of the seawater, and on Juan de Nova the groundwater salinity is lower (5 to 20 PSU). This preliminary study shows that the karstic pothole mangroves exist due to the sea connection through the fractured coral and the high tidal dynamics.

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

International Nuclear Information System (INIS)

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

1998-06-01

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

Supraglacial Ponds Regulate Runoff From Himalayan Debris-Covered Glaciers

Science.gov (United States)

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

2017-12-01

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

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

International Nuclear Information System (INIS)

Millard, Jere B.

1978-01-01

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

Remediation of an oily leachate pond in Estonia.

Science.gov (United States)

Kriipsalu, Mait; Marques, Marcia; Hogland, William

2005-12-01

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

Modeling the summertime evolution of sea-ice melt ponds

DEFF Research Database (Denmark)

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

2006-01-01

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

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

Science.gov (United States)

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

2015-01-01

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

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

African Journals Online (AJOL)

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

The integrated impacts of natural processes and human activities on groundwater salinization in the coastal aquifers of Beihai, southern China

Science.gov (United States)

Li, Qinghua; Zhang, Yanpeng; Chen, Wen; Yu, Shaowen

2018-03-01

Salinization in coastal aquifers is usually related to both seawater intrusion and water-rock interaction. The results of chemical and isotopic methods were combined to identify the origin and processes of groundwater salinization in Daguansha area of Beihai, southern China. The concentrations of the major ions that dominate in seawater (Cl-, Na+, Ca2+, Mg2+ and SO4 2- ), as well as the isotopic content and ratios (2H, 18O, 87Sr/86Sr and 13C), suggest that the salinization occurring in the aquifer of the coastal plain is related to seawater and that the prevailing hydrochemical processes are evaporation, mixing, dissolution and ion exchange. For the unconfined aquifer, groundwater salinization has occurred in an area that is significantly influenced by land-based sea farming. The integrated impacts of seawater intrusion from the Beibuwan Gulf and infiltration of seawater from the culture ponds are identified in the shallowest confined aquifer (I) in the middle of the area (site BBW2). Leakage from this polluted confined aquifer causes the salinization of groundwater in the underlying confined aquifer (II). At the coastal monitoring site (BBW3), confined aquifer I and lower confined aquifer II are heavily contaminated by seawater intrusion. The weak connectivity between the upper aquifers, and the seaward movement of freshwater, prevents saltwater from encroaching the deepest confined aquifer (III). A conceptual model is presented. Above all, understanding of the origin and processes of groundwater salinization will provide essential information for the planning and sustainable management of groundwater resources in this region.

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

Science.gov (United States)

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

2016-11-01

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

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

International Nuclear Information System (INIS)

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

1995-06-01

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

Influences of radiation on carp from farm ponds in Fukushima

International Nuclear Information System (INIS)

Suzuki, Yuzuru

2015-01-01

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

Metal removal from tailings ponds water using indigenous micro-algae

Energy Technology Data Exchange (ETDEWEB)

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

2010-07-01

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

Nutrient availability limits biological production in Arctic sea ice melt ponds

DEFF Research Database (Denmark)

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

2017-01-01

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

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

Directory of Open Access Journals (Sweden)

Elin Soomets

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

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

Science.gov (United States)

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

2013-12-01

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

Homestead fish pond and the environment in Nigeria

OpenAIRE

Okaeme, A.N.

1999-01-01

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

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

International Nuclear Information System (INIS)

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

1993-09-01

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

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

International Nuclear Information System (INIS)

Moline, G.R.

1999-01-01

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

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

International Nuclear Information System (INIS)

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

1996-01-01

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

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

Science.gov (United States)

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

A holistic water depth simulation model for small ponds

Science.gov (United States)

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

2015-10-01

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

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

African Journals Online (AJOL)

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

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

Science.gov (United States)

Sudakov, Ivan

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

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

Science.gov (United States)

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

2005-12-01

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

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

Science.gov (United States)

O'Connell, Jessica L; Nyman, John A

2011-11-01

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

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

Science.gov (United States)

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

2011-11-01

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

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

Science.gov (United States)

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

2006-05-01

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

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

Science.gov (United States)

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

2016-08-24

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

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

Science.gov (United States)

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

2014-08-01

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

Seasonal dynamics of fish assemblage in a pond canal

Czech Academy of Sciences Publication Activity Database

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

2007-01-01

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

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

Data.gov (United States)

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

Primary Nutritional Content of Bio-Flocs Cultured with Different Organic Carbon Sources and Salinity

Directory of Open Access Journals (Sweden)

JULIE EKASARI

2010-09-01

Full Text Available Application of bio-flocs technology (BFT in aquaculture offers a solution to avoid environmental impact of high nutrient discharges and to reduce the use of artificial feed. In BFT, excess of nutrients in aquaculture systems are converted into microbial biomass, which can be consumed by the cultured animals as a food source. In this experiment, upconcentrated pond water obtained from the drum filter of a freshwater tilapia farm was used for bio-flocs reactors. Two carbon sources, sugar and glycerol, were used as the first variable, and two different levels of salinity, 0 and 30 ppt, were used as the second variable. Bio-flocs with glycerol as a carbon source had higher total n-6 PUFAs (19.1 ± 2.1 and 22.3 ± 8.6 mg/g DW at 0 and 30 ppt, respectively than that of glucose (4.0 ± 0.1 and 12.6 ± 2.5 mg/g DW at 0 and 30 ppt. However, there was no effect of carbon source or salinity on crude protein, lipid, and total n-3 PUFAs contents of the bio-flocs.

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

International Nuclear Information System (INIS)

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

1989-01-01

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

Revegetation of flue gas desulfurization sludge pond disposal sites

International Nuclear Information System (INIS)

Artiola, J.F.

1994-12-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-07-01

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

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

Directory of Open Access Journals (Sweden)

Laurent TOUCHART

2012-03-01

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

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

Science.gov (United States)

Lin, E. I. H.

1982-03-01

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

Geo-engineering experiments in two urban ponds to control eutrophication

NARCIS (Netherlands)

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

2016-01-01

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

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

Directory of Open Access Journals (Sweden)

Chun-Hsien Lai

2018-04-01

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

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

International Nuclear Information System (INIS)

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

1994-01-01

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

Diffusion of single oxidation pond

Directory of Open Access Journals (Sweden)

Song Ruo-Yuan

2016-01-01

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

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.

Removal of Heavy Metals and PAH in Highway Detention Ponds

DEFF Research Database (Denmark)

Bentzen, Thomas Ruby; Larsen, Torben; Thorndahl, Søren Liedtke

2005-01-01

, which has been designed according to standard design criteria for several decades. The study will focus on heavy metals (Cd, Cr, Cu, Pb and Zn) and polyaromatic hydrocarbons (PAH). The long-term simulation of input of flow and pollution to the ponds will be a hind cast based on time series of historical......The paper presents some of the first results from a study of the removal of pollutants in highway detention ponds in Denmark. The objective of the study is to set up a procedure for long-term modelling of discharges of pollutants to the environment from the many Danish highway detention ponds...... rainfalls. The modelling will take place in a special version of the MIKE URBAN. The modelling is calibrated and validated on measurements from selected highway catchments. The removal of pollutants in the ponds is studied by local measurements in combination with CFD modelling using the MIKE 21 and MIKE 3...

Ecological behavior of plutonium and americium in a freshwater pond

International Nuclear Information System (INIS)

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

1975-03-01

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

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

Science.gov (United States)

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

2018-05-01

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

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

International Nuclear Information System (INIS)

Osmanlioglu, A.E.

2002-01-01

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

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

Science.gov (United States)

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

2016-12-01

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

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

Science.gov (United States)

Clark, Benton C; Kolb, Vera M

2018-05-11

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

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

Directory of Open Access Journals (Sweden)

Benton C. Clark

2018-05-01

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

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

Science.gov (United States)

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

2017-12-01

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

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

Science.gov (United States)

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

2018-07-01

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

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

Science.gov (United States)

Popović, Predrag; Abbot, Dorian

2017-05-01

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

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

International Nuclear Information System (INIS)

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

2014-01-01

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

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

OpenAIRE

Nygårdhs, Sara

2003-01-01

Aquaplaning accidents are relatively rare, but could have fatal effects. The task of this master’s thesis is to use data from the Laser Road Surface Tester to detect road sections with risk of aquaplaning. A three-dimensional model based on data from road surface measurements is created using MATLAB (version 6.1). From this general geometrical model of the road, a pond model is produced from which the theoretical risk ponds are detected. A risk pond indication table is fur-ther created. The...

Microcosm investigations of stormwater pond sediment toxicity to embryonic and larval amphibians: Variation in sensitivity among species

Energy Technology Data Exchange (ETDEWEB)

Snodgrass, Joel W. [Department of Biological Sciences, Towson University, 8000 York Road, Towson, MD 21252 (United States)], E-mail: jsnodgrass@towson.edu; Casey, Ryan E. [Department of Chemistry, Towson University, 8000 York Road, Towson, MD 21252 (United States); Joseph, Debra; Simon, Judith A. [Department of Biological Sciences, Towson University, 8000 York Road, Towson, MD 21252 (United States)

2008-07-15

Stormwater ponds have become common features of modern development and often represent significant amounts of open space in urbanized areas. Although stormwater ponds may provide habitat for wildlife, factors responsible for producing variation in wildlife use of ponds have received limited attention. To investigate the role of variation in species tolerances of pollutants in structuring pond-breeding amphibian assemblages, we exposed species tolerant (Bufo americanus) and not tolerant (Rana sylvatica) of urbanization to pond sediments in laboratory microcosms. Pond microcosms had elevated sediment metal levels and chloride water concentrations. Among R. sylvatica embryos, exposure to pond sediments resulted in 100% mortality. In contrast, B. americanus embryos and larvae experienced only sublethal effects (i.e., reduced size at metamorphosis) due to pond sediment exposure. Our results suggest variation in pollutant tolerance among early developmental stages of amphibians may act in concert with terrestrial habitat availability to structure amphibian assemblages associated with stormwater ponds. - Variation among species in sensitivity to pollutants can influence stormwater pond amphibian assemblages.

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

Report on the methylmercury situation in Par Pond. Final report

International Nuclear Information System (INIS)

Schindler, J.E.; Williams, D.J.; Alberts, J.J.

1975-06-01

Studies are reported on the methylation and accumulation of mercury in fish populations of the pond. Results showed that the majority of the mercury in the fish muscles was in the methyl mercury form. Very low concentrations of mercury were found in the pond sediments. Physiological methylation of the mercury could not be demonstrated by in vivo or in vitro techniques. Organic ligand methylation and reduction of the mercury was shown to be a possible mechanism to account for both the mercury distribution in the pond and the concentrations of methylmercury in the fish. Recommendations are made for remedial treatments to eliminate the mercury problem. (HLW)

Thermal behavior of laboratory models of honeycomb-covered solar ponds

Science.gov (United States)

Lin, E. I. H.

1983-01-01

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

A survey for the presence of microcystins in aquaculture ponds in ...

African Journals Online (AJOL)

PRECIOUS

2009-11-16

Nov 16, 2009 ... form of blue green algae in an aquaculture pond, they. *Corresponding author. ... passing through the food chain. Fish and other ... Some of these aqua- culture ponds supply their products (harvested fish) directly to spe-.

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

Two-Phase Flow Modeling of Solid Dissolution in Liquid for Nutrient Mixing Improvement in Algal Raceway Ponds

Directory of Open Access Journals (Sweden)

Haider Ali

2018-04-01

Full Text Available Achieving optimal nutrient concentrations is essential to increasing the biomass productivity of algal raceway ponds. Nutrient mixing or distribution in raceway ponds is significantly affected by hydrodynamic and geometric properties. The nutrient mixing in algal raceway ponds under the influence of hydrodynamic and geometric properties of ponds is yet to be explored. Such a study is required to ensure optimal nutrient concentrations in algal raceway ponds. A novel computational fluid dynamics (CFD model based on the Euler–Euler numerical scheme was developed to investigate nutrient mixing in raceway ponds under the effects of hydrodynamic and geometric properties. Nutrient mixing was investigated by estimating the dissolution of nutrients in raceway pond water. Experimental and CFD results were compared and verified using solid–liquid mass transfer coefficient and nutrient concentrations. Solid–liquid mass transfer coefficient, solid holdup, and nutrient concentrations in algal pond were estimated with the effects of pond aspect ratios, water depths, paddle wheel speeds, and particle sizes of nutrients. From the results, it was found that the proposed CFD model effectively simulated nutrient mixing in raceway ponds. Nutrient mixing increased in narrow and shallow raceway ponds due to effective solid–liquid mass transfer. High paddle wheel speeds increased the dissolution rate of nutrients in raceway ponds.

Seal Formation Mechanism Beneath Animal Waste Holding Ponds

Science.gov (United States)

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

2005-12-01

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

Liner used in tailings ponds

International Nuclear Information System (INIS)

Dinchak, W.G.

1984-01-01

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

Beaver Ponds: Resurgent Nitrogen Sinks for Rural Watersheds in the Northeastern United States.

Science.gov (United States)

Lazar, Julia G; Addy, Kelly; Gold, Arthur J; Groffman, Peter M; McKinney, Richard A; Kellogg, Dorothy Q

2015-09-01

Beaver-created ponds and dams, on the rise in the northeastern United States, reshape headwater stream networks from extensive, free-flowing reaches to complexes of ponds, wetlands, and connecting streams. We examined seasonal and annual rates of nitrate transformations in three beaver ponds in Rhode Island under enriched nitrate-nitrogen (N) conditions through the use of N mass balance techniques on soil core mesocosm incubations. We recovered approximately 93% of the nitrate N from our mesocosm incubations. Of the added nitrate N, 22 to 39% was transformed during the course of the incubation. Denitrification had the highest rates of transformation (97-236 mg N m d), followed by assimilation into the organic soil N pool (41-93 mg N m d) and ammonium generation (11-14 mg N m d). Our denitrification rates exceeded those in several studies of freshwater ponds and wetlands; however, rates in those ecosystems may have been limited by low concentrations of nitrate. Assuming a density of 0.7 beaver ponds km of catchment area, we estimated that in nitrate-enriched watersheds, beaver pond denitrification can remove approximately 50 to 450 kg nitrate N km catchment area. In rural watersheds of southern New England with high N loading (i.e., 1000 kg km), denitrification from beaver ponds may remove 5 to 45% of watershed nitrate N loading. Beaver ponds represent a relatively new and substantial sink for watershed N if current beaver populations persist. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Arthropod fauna of the University of Nigeria, Nsukka, Sewage pond ...

African Journals Online (AJOL)

A survey of arthropod fauna of the University of Nigeria Nsukka sewage pond was carried out within May and June 2011. The aim was to determine the various arthropod species and its abundance in the sewage pond. The analysis was carried out by two methods, physico-chemical analysis and arthropod faunal studies.

Effects of riparian buffers on hydrology of northern seasonal ponds

Science.gov (United States)

Randall K. Kolka; Brian J. Palik; Daniel P. Tersteeg; James C. Bell

2011-01-01

Although seasonal ponds are common in northern, glaciated, forested landscapes, forest management guidelines are generally lacking for these systems. The objective of this study was to determine the effect of riparian buffer type on seasonal pond hydrology following harvest of the adjacent upland forest. A replicated block design consisting of four buffer treatments...

Interactions of an insecticide with competition and pond drying in amphibian communities

Science.gov (United States)

Boone, M.D.; Semlitsch, R.D.

2002-01-01

Amphibian populations are often imbedded in agricultural landscapes. Therefore the potential for contamination of their habitat is considerable. Our study examined the effects of an insecticide (carbaryl, a neurotoxin), on larval amphibian communities experiencing natural stresses of competition for resources, predation, and pond drying. In a set of experimental ponds, tadpoles of three anuran species (southern leopard frog [Rana sphenocephala], plains leopard frog [R. blairi], and the Woodhouse's toad [Bufo woodhousii]) were added to 1000-L ponds containing leaf litter, plankton, two newts (Notophthalmus viridescens), and four overwintered green frog (R. clamitans) tadpoles. We manipulated the overall tadpole density (low or high), pond hydroperiod (constant or drying), and chemical exposure (0, 3.5, 5.0, or 7.0 mg/L carbaryl) of the ponds. We measured mass, time, and survival to metamorphosis to determine treatment effects. Carbaryl positively affected Woodhouse's toad survival, although it had a negligible effect on both leopard frog species. Tadpole density interacted with the chemical treatment: Proportionately more Woodhouse's toads survived to metamorphosis in high-density environments than in low-density or control environments. Greater survival may be an indirect effect of increased algal food resources from carbaryl exposure. Most newts lost mass over the course of the experiment, although ponds with drying hydroperiods and high anuran density were the least favorable environments. Overwintered green frogs exposed to carbaryl had longer larval periods on average than did green frogs in control ponds. Our study demonstrated that even sublethal, short-lived contaminants can alter natural communities in ways that cannot be predicted from simple, one-factor studies.

Do laboratory salinity tolerances of freshwater animals correspond with their field salinity?

Energy Technology Data Exchange (ETDEWEB)

Kefford, Ben J.; Papas, Phil J.; Metzeling, Leon; Nugegoda, Dayanthi

2004-06-01

The degree to which laboratory derived measures of salinity tolerance reflect the field distributions of freshwater biota is uncertain. In this paper we compare laboratory-derived acute salinity tolerance (LC{sub 50} values) of freshwater macroinvertebrates (range 5.5-76 mS/cm) and fish (range 2.7-82 mS/cm) from southeastern Australia with the salinity from which they have been collected in the field. Only 4% of the macroinvertebrates were collected at salinity levels substantially higher than their 72-h LC{sub 50} obtained from directly transferring animals from low salinity water to the water they were tested (direct transfer LC{sub 50}). This LC{sub 50} value was correlated with the maximum salinity at which a species had been collected. For common macroinvertebrates, the maximum field salinity was approximated by the direct transfer 72-h LC{sub 50}. For adult freshwater fish, 21% of species were collected at salinities substantially greater than their acute direct transfer LC{sub 50} and there was a weak relationship between these two variables. Although there was a weak correlation between the direct transfer LC{sub 50} of early life stages of freshwater fish and the maximum field salinity, 58% of the field distribution were in higher than their LC{sub 50} values. In contrast, LC{sub 50} determined from experiments that acclimated adult fish to higher salinity (slow acclimation) provided a better indication of the field distribution: with only one fish species (7%) being in conflict with their maximum field salinity and a strong positive relationship between these variables. This study shows that laboratory measures of acute salinity tolerance can reflect the maximum salinity that macroinvertebrate and fish species inhabit and are consistent with some anecdotal observations from other studies. - Acute laboratory salinity tolerances relate to maximum salinity where organisms occur in nature.

Do laboratory salinity tolerances of freshwater animals correspond with their field salinity?

International Nuclear Information System (INIS)

Kefford, Ben J.; Papas, Phil J.; Metzeling, Leon; Nugegoda, Dayanthi

2004-01-01

The degree to which laboratory derived measures of salinity tolerance reflect the field distributions of freshwater biota is uncertain. In this paper we compare laboratory-derived acute salinity tolerance (LC 50 values) of freshwater macroinvertebrates (range 5.5-76 mS/cm) and fish (range 2.7-82 mS/cm) from southeastern Australia with the salinity from which they have been collected in the field. Only 4% of the macroinvertebrates were collected at salinity levels substantially higher than their 72-h LC 50 obtained from directly transferring animals from low salinity water to the water they were tested (direct transfer LC 50 ). This LC 50 value was correlated with the maximum salinity at which a species had been collected. For common macroinvertebrates, the maximum field salinity was approximated by the direct transfer 72-h LC 50 . For adult freshwater fish, 21% of species were collected at salinities substantially greater than their acute direct transfer LC 50 and there was a weak relationship between these two variables. Although there was a weak correlation between the direct transfer LC 50 of early life stages of freshwater fish and the maximum field salinity, 58% of the field distribution were in higher than their LC 50 values. In contrast, LC 50 determined from experiments that acclimated adult fish to higher salinity (slow acclimation) provided a better indication of the field distribution: with only one fish species (7%) being in conflict with their maximum field salinity and a strong positive relationship between these variables. This study shows that laboratory measures of acute salinity tolerance can reflect the maximum salinity that macroinvertebrate and fish species inhabit and are consistent with some anecdotal observations from other studies. - Acute laboratory salinity tolerances relate to maximum salinity where organisms occur in nature

Estudo da ação do moluscocida (Bayluscide-SRB da Dynatech R/D Company em lagos do nordeste brasileiro - Sergipe, Brasil Study on the action of molluscicide (Bayluscide-SRB of Dynatech R/D company in ponds in northeast Brazil - Sergipe State

Directory of Open Access Journals (Sweden)

Edivaldo Rosas

1987-01-01

Full Text Available To study the action of molluscicide nine ponds were selected: 3 of them lying in Maruim municipality, 29 km far from north Aracaju, the State capital, and 6 ponds in Itabaianinha municipality, 118 km far from south Aracaju. This study was carried out for 16 months. Environmental parameters observed were those thought to have any influence on the planorbids and/or the molluscicide: water temperature, transparence, salinity, pH, dissolved oxygen, CO2, and the nutrients-phosphorus, nitrogen, potassium and calcium. Plancton microorganisms were also considered to observe Bayluscide action on them. SRB was used in a concentration of 6.25 kg per 1.000 [cubic metres] water, to achieve 1.0 ppm Bayluscide concentration according to the producer's instruction in Massachussett-USA.

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.

The integrated impacts of natural processes and human activities on the origin and processes of groundwater salinization in the coastal aquifers of Beihai, Southern China

Science.gov (United States)

Li, Q.; Zhan, Y., , Dr; Chen, W. Ms; Yu, S., , Dr

2017-12-01

Salinization in coastal aquifers usually is the results of contamination related to both seawater intrusion and water-rock interaction. The chemical and isotopic methods were combined to identify the origin and processes of groundwater salinization in Daguansha area of Beihai. The concentrations of the major ions that dominate in sea water (Cl-, Na+, Ca2+, Mg2+ and SO2- 4), as well as the isotopic ratios (2H, 18O, 87Sr/86Sr and 13C) suggest that the salinization occurring in the aquifer water of the coastal plain is related to seawater and the prevailing hydrochemical processes are evaporation, mixing, dissolution and ion exchange. For the unconfined aquifer, groundwater salinization occurred in parts of the area, which is significantly influenced by the land-based sea farming. The integrated impacts of seawater intrusion from the Beibuwan Gulf and infiltration of seawater from the culture ponds is identified in the confined aquifer I at site BBW2. In consequence, the leakage from this polluted aquifer causes the salinization of groundwater in the confined aquifer II. At site BBW3, the confined aquifer I and lower confined aquifer II are remarkably contaminated by seawater intrusion. The weak connectivity with upper aquifers and seaward movement of freshwater prevents saltwater from encroaching the confined aquifer III. Above all, understanding of the origin and processes of groundwater salinization will provide essential information for sustainable planning and management of groundwater resources in this region.

Food inputs, water quality and nutrient accumulation in integrated pond systems: A multivariate approach

NARCIS (Netherlands)

Nhan, D.K.; Milstein, A.; Verdegem, M.C.J.; Verreth, J.A.J.

2006-01-01

A participatory on-farm study was conducted to explore the effects of food input patterns on water quality and sediment nutrient accumulation in ponds, and to identify different types of integrated pond systems. Ten integrated agriculture-aquaculture (IAA) farms, in which ponds associate with fruit

Resource-Saving Cleaning Technologies for Power Plant Waste-Water Cooling Ponds

Directory of Open Access Journals (Sweden)

Zakonnova Lyudmila

2017-01-01

Full Text Available One of the frequently encountered problems of power plant small cooling ponds is rapid eutrophication and related intensified development of phytoplankton (“hyperflow” and overgrowing of ponds by higher aquatic vegetation. As a result of hyper-flowering, an enormous amount of detritus settles on the condenser tubes, reducing the efficiency of the power plant operation. The development of higher aquatic vegetation contributes to the appearing of the shoals. As a result the volume, area and other characteristics of the cooling ponds are getting changed. The article describes the environmental problems of small manmade ponds of power plants and coal mines in mining regions. Two approaches to the problem of eutrophication are considered: technological and ecological. The negative effects of herbicides application to aquatic organisms are experimentally proved. An ecological approach to solving the problem by fish-land reclamation method is shown.

An Expert-Based Assessment Model for Evaluating Habitat Suitability of Pond-Breeding Amphibians

Directory of Open Access Journals (Sweden)

Shin-Ruoh Juang

2017-02-01

Full Text Available Farm ponds are important habitats for amphibians, birds, and other wildlife. In Taiwan, artificial ponds were originally created on farmlands for irrigation purposes and the needs of the domestic water supply. Although pond creation is a typical farming practice, it also provides habitats for pond-breeding amphibians. Thus, it is essential to understand the current status of habitats and their vulnerability regarding urgent conservation needs for target species. Günther’s frog (Hylarana guentheri, a pond-breeding amphibian, has a high sensitivity towards surrounding environmental changes, and can be used as an indicator species to assess habitat suitability. The purpose of this study is to establish a systematic framework to assess the habitat suitability of pond-breeding amphibians by using Günther’s frog as a pilot-study species. First, we collected frog survey data from Chiayi, Taiwan, from winter 2013 to spring 2015, and investigated the present status of the environmental conditions around the ponds. Next, expert questionnaires and the fuzzy Delphi method were applied to establish the hierarchical evaluation criteria regarding the habitat suitability assessment. Four indicators: the aquatic environments of farm ponds; the terrestrial environments around ponds; landscape connectivity; and the conservation perceptions of the residents, were determined as first-layer factors in the assessment criteria, while ten other indicators were defined as second-layer factors. Based on the established assessment criteria, we performed in situ habitat suitability evaluations on 69 selected sites and surveyed the perceptions of the residents using questionnaires. Results revealed that 19% of locations were rich in frog species with a high habitat suitability. However, 67% of locations showed signs of habitat degradation, which may imply a higher need in practicing habitat improvement or restoration. The Kappa value was 0.6061, which indicated a high

Salty or Sweet: Exploring the Challenges of Groundwater Salinization Within a Sustainability Framework

Science.gov (United States)

Basu, N. B.; Van Meter, K. J.; Tate, E.

2012-12-01

In semi-arid to arid landscapes under intensive irrigation, groundwater salinization can be a persistent and critical problem, leading to reduced agricultural productivity, limited access to fresh drinking water, and ultimately desertification. It is estimated that in India alone, problems of salinity are now affecting over 6 million hectares of agricultural land. In villages of the Mewat district of Haryana in Northern India, subsistence-level farming is the primary source of income, and farming families live under serious threat from increasing salinity levels, both in terms of crop production and adequate supplies of drinking water. The Institute for Rural Research and Development (IRRAD), a non-governmental organization (NGO) working in Mewat, has taken an innovative approach in this area to problems of groundwater salinization, using check dams and rainwater harvesting ponds to recharge aquifers in the freshwater zones of upstream hill areas, and to create freshwater pockets within the saline groundwater zones of down-gradient areas. Initial, pilot-scale efforts have led to apparent success in raising groundwater levels in freshwater zones and changing the dynamics of encroaching groundwater salinity, but the expansion of such efforts to larger-scale restoration is constrained by the availability of adequate resources. Under such resource constraints, which are typical of international development work, it becomes critical to utilize a decision-analysis framework to quantify both the immediate and long-term effectiveness and sustainability of interventions by NGOs such as IRRAD. In the present study, we have developed such a framework, linking the climate-hydrological dynamics of monsoon driven systems with village-scale socio-economic attributes to evaluate the sustainability of current restoration efforts and to prioritize future areas for intervention. We utilize a multi-dimensional metric that takes into account both physical factors related to water

Storage ponds for fuel elements of nuclear reactors

International Nuclear Information System (INIS)

Kumpf, H.

1981-01-01

Heat exchangers are inserted in storage ponds for fuel elements of nuclear reactors, so that the heat to be removed is given up to an external coolant, without any radio-activity being emitted. The heat exchanger is a hollow body, which is connected to an air cooler, which works with a cooling circuit with natural circulation. A cooling pipe is enclosed in the hollow body, which forms a cooling circuit with forced flow with an open pond. One therefore obtains two successive separating walls for the external coolant. (orig.) [de

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

Energy Technology Data Exchange (ETDEWEB)

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

1982-11-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1982-11-01

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

Snow Dunes: A Controlling Factor of Melt Pond Distribution on Arctic Sea Ice

Science.gov (United States)

Petrich, Chris; Eicken, Hajo; Polashenski, Christopher M.; Sturm, Matthew; Harbeck, Jeremy P.; Perovich, Donald K.; Finnegan, David C.

2012-01-01

The location of snow dunes over the course of the ice-growth season 2007/08 was mapped on level landfast first-year sea ice near Barrow, Alaska. Landfast ice formed in mid-December and exhibited essentially homogeneous snow depths of 4-6 cm in mid-January; by early February distinct snow dunes were observed. Despite additional snowfall and wind redistribution throughout the season, the location of the dunes was fixed by March, and these locations were highly correlated with the distribution of meltwater ponds at the beginning of June. Our observations, including ground-based light detection and ranging system (lidar) measurements, show that melt ponds initially form in the interstices between snow dunes, and that the outline of the melt ponds is controlled by snow depth contours. The resulting preferential surface ablation of ponded ice creates the surface topography that later determines the melt pond evolution.

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

Science.gov (United States)

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

2013-12-01

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

Valuating Ecosystem Services of Urban Ponds - case study from Bangladesh

Science.gov (United States)

Carle, Nina

2016-04-01

A climate risk assessment for the city of Barisal was carried out by a consultancy firm, financed by KfW Development Bank of Germany. Due to high dependencies on natural capital of people in developing countries they are facing high vulnerability when it comes to changes of the asset category 'natural capital' (here: urban ponds), whether due to the exposition on climate (change) related impacts, implemented measures or land use change. With a closer view on the city's assets, the question remained open to the author 1) Under current conditions, what is the demand for ecosystem services (ES) 2) What is the value of the benefits and the how much is the contribution to the city's welfare? 3) What are the future changes in the demand for ES? And what are the future changes on the supply side (pressures and threats to the ecosystem)? Methodology: The City of Barisal in Bangladesh has a calculated number of around 10.000 urban rain-fed ponds,representing 6.5% of the city area, which represents a huge natural water supply and gives the city its characteristic face. In August 2015 a user survey was conducted in the city of Barisal, in every ward (administrative unit), to determine the demand for ecosystem services related to urban ponds, evaluating over 600 ponds. The findings will present the huge variation of provisioning ecosystem services and an important regulating service, related to economic and domestic use, in a spatial resolution. It will be shown, how the importance of ES changes, by changing the unit of analysis (families or ponds or the city) and the importance for the livelihood of pond owners and users. A relationship between pond area(m2) and number of users was detected, also the role of compensation payments for the pond owners by the users. It will be shown how natural capital, privately and publicly owned,contributes in an important way in buffering unequal distribution of societies resources in the short- and long-run. However society's demand for ES

Shrinking ponds in subarctic Alaska based on 1950-2002 remotely sensed images

Science.gov (United States)

Riordan, B.; Verbyla, D.; McGuire, A.D.

2006-01-01

Over the past 50 years, Alaska has experienced a warming climate with longer growing seasons, increased potential evapotranspiration, and permafrost warming. Research from the Seward Peninsula and Kenai Peninsula has demonstrated a substantial landscape-level trend in the reduction of surface water and number of closed-basin ponds. We investigated whether this drying trend occurred at nine other regions throughout Alaska. One study region was from the Arctic Coastal Plain where depp permafrost occurs continuously across the landscape. The other eight study regions were from the boreal forest regions where discontinuous permafrost occurs. Mean annual precipitation across the study regions ranged from 100 to over 700 min yr-1. We used remotely sensed imagery from the 1950s to 2002 to inventory over 10,000 closed-basin ponds from at least three periods from this time span. We found a reduction in the area and number of shallow, closed-basin ponds for all boreal regions. In contrast, the Arctic Coastal Plain region had negligible change in the area of closed-basin ponds. Since the 1950s, surface water area of closed-basin ponds included in this analysis decreased by 31 to 4 percent, and the total number of closed-basin ponds surveyed within each study region decreased from 54 to 5 percent. There was a significant increasing trend in annual mean temperature and potential evapotranspiration since the 1950s for all study regions. There was no significant trend in annual precipitation during the same period. The regional trend of shrinking ponds may be due to increased drainage as permafrost warms, or increased evapotranspiration during a warmer and extended growing season. Copyright 2006 by the American Geophysical Union.

Performance and Modelling of a Highway Wet Detention Pond Designed for Cold Climate

DEFF Research Database (Denmark)

Vollertsen, Jes; Åstebøl, Svein Ole; Coward, Jan Emil

2009-01-01

A wet detention pond in Norway has been monitored for 12 months. The pond receives runoff from a highway with a traffic load of 42,000 average daily traffic. Hydraulic conditions in terms of inflow, outflow, and pond water level were recorded every minute. Water quality was monitored by volume pr...

INCREASING FISH PRODUCTIVITY OF POND ECOSYSTEMS BY FERTILIZING THEM WITH DISTILLER'S GRAINS

Directory of Open Access Journals (Sweden)

N. Tson’

2015-03-01

Full Text Available Purpose. To study fish culture parameters of young-of-the-year carp in the conditions of industrial fish-growing ponds when applying experimental repeated fertilization with distiller’s grain. Methodology. The study was conducted in industrial fish-growing ponds. The wastes of alcohol industry – the distiller’s grain as organic fertilizer was gradually introduced into ponds at following amounts: first application – 1,0 t/ha, second application in 10 days – 0,5 t/ha, third application in 12 days – 0,5 t/ha. The control ponds were fertilized with humus (2 t/ha. Young-of-the-year carp (Cyprinus carpio were grown in monoculture at stocking density of 30 000 fish/ha. In addition, 100 kg/ha of lime were applied during the culture season in the experiment and control. Fertilization with humus and application of lime in ponds, hydrochemical studies, sampling and processing of hydrobiological samples, fish culturing and statistical studies were carried out according to standard methods. Findings. Gradual fertilizing with distiller’s grain (to the total 2 t/ha gave the possibility to create favorable hydrochemical and hydrobiological regimes. An average daily growth in the experimental fish groups of 0,44 ± 0,09 g/day that was similar to in the control (0,45 ± 0,11 g/day with positive significant correlation between them (r = 0,97; p <0,001 was achieved. The performed measures gave a possibility to obtain fish productivity in the experimental variant 10.7% more than in the control. An economic effect of 14.3% cost reduction for fertilizing ponds was achieved. Originality. For the first time we presented the results of fish culture and biological parameters of young-of-the-year carp in industrial ponds when applying 3-time fertilization with distiller’s grain. Practical Value. The obtained results are the basis for the broad use of non-traditional organic fertilizer – distiller’s grain in industrial ponds, when growing young

Solar pond for heating anaerobic digesters

International Nuclear Information System (INIS)

Song Kehui; Li Shensheng

1991-10-01

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

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

Directory of Open Access Journals (Sweden)

Nyoman Suwartha

2012-05-01

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

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

Science.gov (United States)

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

2001-01-01

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

Effects of season on ecological processes in extensive earthen tilapia ponds in Southeastern Brazil.

Science.gov (United States)

Favaro, E G P; Sipaúba-Tavares, L H; Milstein, A

2015-11-01

In Southeastern Brazil tilapia culture is conducted in extensive and semi-intensive flow-through earthen ponds, being water availability and flow management different in the rainy and dry seasons. In this region lettuce wastes are a potential cheap input for tilapia culture. This study examined the ecological processes developing during the rainy and dry seasons in three extensive flow-through earthen tilapia ponds fertilized with lettuce wastes. Water quality, plankton and sediment parameters were sampled monthly during a year. Factor analysis was used to identify the ecological processes occurring within the ponds and to construct a conceptual graphic model of the pond ecosystem functioning during the rainy and dry seasons. Processes related to nitrogen cycling presented differences between both seasons while processes related to phosphorus cycling did not. Ecological differences among ponds were due to effects of wind protection by surrounding vegetation, organic loading entering, tilapia density and its grazing pressure on zooplankton. Differences in tilapia growth among ponds were related to stocking density and ecological process affecting tilapia food availability and intraspecific competition. Lettuce wastes addition into the ponds did not produce negative effects, thus this practice may be considered a disposal option and a low-cost input source for tilapia, at least at the amounts applied in this study.

Basal-topographic control of stationary ponds on a continuously moving landslide

Science.gov (United States)

Coe, J.A.; McKenna, J.P.; Godt, J.W.; Baum, R.L.

2009-01-01

The Slumgullion landslide in the San Juan Mountains of southwestern Colorado has been moving for at least the last few hundred years and has multiple ponds on its surface. We have studied eight ponds during 30 trips to the landslide between July 1998 and July 2007. During each trip, we have made observations on the variability in pond locations and water levels, taken ground-based photographs to document pond water with respect to moving landslide material and vegetation, conducted Global Positioning System surveys of the elevations of water levels and mapped pond sediments on the landslide surface. Additionally, we have used stereo aerial photographs taken in October 1939, October 1940 and July 2000 to measure topographic profiles of the eight pond locations, as well as a longitudinal profile along the approximate centerline of the landslide, to examine topographic changes over a 60- to 61-year period of time. Results from field observations, analyses of photographs, mapping and measurements indicate that all pond locations have remained spatially stationary for 60-300 years while landslide material moves through these locations. Water levels during the observation period were sensitive to changes in the local, spring-fed, stream network, and to periodic filling of pond locations by sediment from floods, hyperconcentrated flows, mud flows and debris flows. For pond locations to remain stationary, the locations must mimic depressions along the basal surface of the landslide. The existence of such depressions indicates that the topography of the basal landslide surface is irregular. These results suggest that, for translational landslides that have moved distances larger than the dimensions of the largest basal topographic irregularities (about 200 m at Slumgullion), landslide surface morphology can be used as a guide to the morphology of the basal slip surface. Because basal slip surface morphology can affect landslide stability, kinematic models and stability

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

Science.gov (United States)

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

2001-12-01

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

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

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.

Ponded infiltration tests at the Box Canyon site: data report and preliminary analysis

International Nuclear Information System (INIS)

Cook, Paul; Faybishenko, Boris; Freifeld, Barry; Jacobsen, Janet; Lee, Ki Ha; Salve, Rohit; Zawislanski, Peter

1998-01-01

We discuss the design and present the main results of a two-week ponded infiltration test conducted in 1996 at the Box Canyon site near the Idaho National Engineering and Environmental Laboratory. To investigate liquid flow and chemical transport in fractured basalt, the following types of instruments were installed in boreholes: tensiometers, suction lysimeters, thermistors, time domain reflectrometry probes, and electrical resisitivity probes. These probes were installed using an innovative technology of borehole instrumentation and completion using polyurethane foam injection. The probes were attached to plastic packers that were inflated using the polyurethane foam, and then the space between packers was back-filled with the foam in order to ensure the isolation of the instruments at different depths. Polyurethane foam showed great promise in enabling rapid, cost-effective installation of sensors and probes in fractured rock. A ponded infiltration test was conducted from 8/27/96 to 9/9/96, by maintaining water to an average depth of 23 cm in a rectangular infiltration pond. Within the 7 x 8 m pond, nine local infiltrometers (0.25 m diameter) were-installed to determine local values of the water flux. A slug of conservative tracer (KM) was added to the pond on 9/2/96, yielding a tracer concentration in the pond of approximately 3 g/L. The water supply to the pond was halted for two days so that the tracer concentration in the pond water would remain essentially constant. Thereafter, the water supply was re-established to maintain a constant water level. Installation procedures and measurement results for each type of probe are presented, along with a description of the data acquisition system. The attachments include a description of the calibration and testing of instrumentation. The data files can be found at the FTP site zenitMnel/ or the Web site http://www- esd.lbl.gov/ERT/inel/inel.htrnl

Absolute Salinity, ''Density Salinity'' and the Reference-Composition Salinity Scale: present and future use in the seawater standard TEOS-10

Science.gov (United States)

Wright, D. G.; Pawlowicz, R.; McDougall, T. J.; Feistel, R.; Marion, G. M.

2011-01-01

Salinity plays a key role in the determination of the thermodynamic properties of seawater and the new TEOS-101 standard provides a consistent and effective approach to dealing with relationships between salinity and these thermodynamic properties. However, there are a number of practical issues that arise in the application of TEOS-10, both in terms of accuracy and scope, including its use in the reduction of field data and in numerical models. First, in the TEOS-10 formulation for IAPSO Standard Seawater, the Gibbs function takes the Reference Salinity as its salinity argument, denoted SR, which provides a measure of the mass fraction of dissolved material in solution based on the Reference Composition approximation for Standard Seawater. We discuss uncertainties in both the Reference Composition and the Reference-Composition Salinity Scale on which Reference Salinity is reported. The Reference Composition provides a much-needed fixed benchmark but modified reference states will inevitably be required to improve the representation of Standard Seawater for some studies. However, the Reference-Composition Salinity Scale should remain unaltered to provide a stable representation of salinity for use with the TEOS-10 Gibbs function and in climate change detection studies. Second, when composition anomalies are present in seawater, no single salinity variable can fully represent the influence of dissolved material on the thermodynamic properties of seawater. We consider three distinct representations of salinity that have been used in previous studies and discuss the connections and distinctions between them. One of these variables provides the most accurate representation of density possible as well as improvements over Reference Salinity for the determination of other thermodynamic properties. It is referred to as "Density Salinity" and is represented by the symbol SAdens; it stands out as the most appropriate representation of salinity for use in dynamical physical

Absolute Salinity, "Density Salinity" and the Reference-Composition Salinity Scale: present and future use in the seawater standard TEOS-10

Science.gov (United States)

Wright, D. G.; Pawlowicz, R.; McDougall, T. J.; Feistel, R.; Marion, G. M.

2010-08-01

Salinity plays a key role in the determination of the thermodynamic properties of seawater and the new TEOS-101 standard provides a consistent and effective approach to dealing with relationships between salinity and these thermodynamic properties. However, there are a number of practical issues that arise in the application of TEOS-10, both in terms of accuracy and scope, including its use in the reduction of field data and in numerical models. First, in the TEOS-10 formulation for IAPSO Standard Seawater, the Gibbs function takes the Reference Salinity as its salinity argument, denoted SR, which provides a measure of the mass fraction of dissolved material in solution based on the Reference Composition approximation for Standard Seawater. We discuss uncertainties in both the Reference Composition and the Reference-Composition Salinity Scale on which Reference Salinity is reported. The Reference Composition provides a much-needed fixed benchmark but modified reference states will inevitably be required to improve the representation of Standard Seawater for some studies. The Reference-Composition Salinity Scale should remain unaltered to provide a stable representation of salinity for use with the TEOS-10 Gibbs function and in climate change detection studies. Second, when composition anomalies are present in seawater, no single salinity variable can fully represent the influence of dissolved material on the thermodynamic properties of seawater. We consider three distinct representations of salinity that have been used in previous studies and discuss the connections and distinctions between them. One of these variables provides the most accurate representation of density possible as well as improvements over Reference Salinity for the determination of other thermodynamic properties. It is referred to as "Density Salinity" and is represented by the symbol SAdens; it stands out as the most appropriate representation of salinity for use in dynamical physical

A preliminary observation on the pond culture of European eel, Anguilla anguilla (Linnaeus, 1758) in Egypt: recommendations for future studies.

Science.gov (United States)

El-Shebly, Abdalla A; El-kady, Mohamed A H; Hossain, M Yeamin

2007-04-01

An experiment was conducted to assess the potential of the European eel, Anguilla anguilla for earthen pond aquaculture without supplementary feeding at Lake Manzala, Egypt. Juvenile A. anguilla of mean length 11.7 cm and 2.4 g weight were stocked in earthen ponds measuring 3 feddans (about 12,600 m2) and 1 m deep. Stocking was done in May 2003 at a rate of 5000 fish feddan(-1) in a polyculture system including tilapia and mullets and fed mainly on natural occurring prey (natural spawned tilapia) and small shrimp. The eels were culture for a period of 2 years, May 2003 to April 2005. Sampling for growth and survival were evaluated yearly. At the end of the culture period, the gross weight of the harvested eels was measured and the net pond production calculated by the difference between weight stocked and weight harvested. Temperature varied from 11.5 to 28.2 degrees C and 12.2 to 29.3 degrees C; P(H), 7.3 to 8.9 and 7.5 to 8.8; Dissolved Oxygen (DO), 5.2 to 9.8 mg L(-1) and 4.1 to 8.3 mg L(-1); and Salinity, 2.5 to 5.5 psu and 3.0 to 6.8 psu for first year and second year, respectively. At the end of the culture period, A. anguilla attained average weight of 121.4 g fish(-1) at the end of the first year and a weight range of 152.5 to 430 g fish(-1) with an average of 280.36 g fish(-1) at the end of the second year. Survival rate ranged from 91% during the first year to 100% during the second year. Net eel production was 540.18 kg feddan(-1) at the end of the first year and 723.36 kg feddan(-1) at the end of the second year. Daily increments in weight per fish were 0.33 and 0.44 for first and second year, respectively. This experiment demonstrated the possibility of cultivation of eels as well as the higher growth rate in earthen ponds. The aquaculture strategy of eel with high stocking densities through low cost artificial feeds are recommended in future studies.

Influence of inlet water on the biotic and abiotic variables in a fish pond

Directory of Open Access Journals (Sweden)

L. H. Sipaúba-Tavares

Full Text Available Abstract The effects of treated and untreated water inlets with macrophytes on the improvement of water quality and zooplankton community were evaluated in a fish pond with continuous water flow. Water and zooplankton samples were retrieved at four sites during nine months. There were differences (p<0.01 between inlet water from fish pond and inlet water from canal with macrophytes, featuring higher concentrations of nutrient load, mainly TAN and TP in the former. The inlet water from fish pond contained a higher number of abundant species (9 species, whilst the water supply from the canal with macrophytes had a greater richness (31 species of zooplankton species. Results showed that inlet water without macrophytes directly affected the characteristics of the water column and the dominance of zooplankton species such as Thermocyclops decipiens, and greater abundance of Rotifera species. Since aquatic plants in the inlet water of fish pond analyzed showed lower allochthonous material loads from the previous fish pond, the management adopted with macrophytes may be applied to avoid eutrophication risks, common in farm ponds.

Data analysis protocol for using resistivity array as an early-warning wastewater pond leak detector

Science.gov (United States)

Typically, holding ponds are used to control runoff from concentrated animal feeding operations. The integrity of these holding ponds has come under increased scrutiny since subsurface leakage has the potential to affect soil and groundwater quality. Traditionally, ponds are monitored by installin...

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

Science.gov (United States)

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

2016-10-01

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

Groundwater modeling for the long-term safety assessment of uranium tailings ponds

International Nuclear Information System (INIS)

Nair, R.N.

2010-01-01

Uranium tailings ponds contain naturally occurring long lived radionuclides such as 238 U, 234 U, 230 Th and 226 Ra as sources which are the parents of a very long radionuclide decay chain. Uranium tailings ponds by the virtue of the longevity of its contents may pose as a long-term radiological hazard if not designed and monitored properly. The principal radiation risks from uranium tailings are gamma radiation: windblown radioactive dust dispersion; and radon gas and its progenies. Uranium tailings ponds are also a major source of surface and groundwater contamination due to leaching of radioactive and other toxic elements. In many countries, the tailings ponds are designed to control the radiological hazards for up to 1000 years, to the extent achievable, and in any case for at least 200 years. Stringent regulations stipulations exist worldwide for the safe design, operation and closure of uranium tailings ponds. The long- term radiological impact assessment of uranium tailings ponds, hence, is an extremely important exercise in uranium mining industry. The simulations conducted for uranium over a period of 1000 years indicate that contaminant fronts from the source with a paste permeability of 1x10 -4 m/day would migrate a probable distance of less than 50 m. The maximum computed distance for this case is less than 300 m. Indian studies show that the total annual effective dose to members of the public at 1.0 km from the centre of the tailings pond is trivial up to a period of 4000 y. The estimated dose is 0.01 mSv/y after 10,000 years and it is 10 times lower than 0.1 mSv/y, which is considered as a safe dose limit for drinking water pathway. (author)

Cadmium tolerance and antibiotic resistance in Escherichia coli isolated from waste stabilization ponds.

Science.gov (United States)

Patra, Sova; Das, T K; Avila, C; Cabello, V; Castillo, F; Sarkar, D; Lahiri, Susmita; Jana, B B

2012-04-01

The incidence pattern of cadmium tolerance and antibiotics resistance by Escherichia coli was examined periodically from the samples of water, sludge and intestine of fish raised in waste stabilization ponds in a sewage treatment plant. Samples of water and sludge were collected from all the selected ponds and were monitored for total counts of fecal coliform (FC), total coliform (TC) and the population of Escherichia coli, which was also obtained from the intestine of fishes. Total counts of both FC and TC as well as counts of E. coli were markedly reduced from the facultative pond to the last maturation pond. Tolerance limit to cadmium by E. coli tended to decline as the distance of the sewage effluent from the source increased; the effective lethal concentration of cadmium ranged from 0.1 mM in split chamber to 0.05 mM in first maturation pond. E. coli isolated from water, sludge and fish gut were sensitive to seven out of ten antibiotics tested. It appears that holistic functions mediated through the mutualistic growth of micro algae and heterotrophic bacteria in the waste stabilization ponds were responsible for the promotion of water quality and significant reduction of coliform along the sewage effluent gradient.

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

Decommissioning of the SPERT-III large leach pond at the Idaho National Engineering Laboratory. Final report

International Nuclear Information System (INIS)

Bradford, J.D.

1984-04-01

This report describes the decontamination and decommissioning of the SPERT-III large leach pond. Prior to decontamination and decommissioning the pond basin was enclosed by a mesh and barbed wire fence. An 8-in. carbon steel discharge pipe ran from the SPERT-III reactor building to the pond basin. The outlet of the discharge pipe rested on a concrete apron in the pond basin. The soil in the pond basin contained low-level radioactive contamination. The fence and apron were removed, radiologically surveyed, found to be uncontaminated, and sent to the sanitary landfill for disposal. The discharge pipe was left buried in place. The pond basin was backfilled with radiologically clean soil to reduce the surface activity to background. The area was then seeded with crested wheatgrass. A permanent marker was erected at the center of the pond basin to indicate the presence of subsurface radioactive contamination and the location of the buried discharge pipe. 5 references, 32 figures, 2 tables

Assessment of water quality around Jaduguda uranium tailings ponds

International Nuclear Information System (INIS)

Mohanty, A.K.; Gurunadha Rao, V.V.S.; Ramesh, G.; Surinaidu, L.; Thama Rao, G.; Dhakate, R.; Sarangi, A.K.; Nair, R.N.

2010-01-01

The environmental impacts of uranium mining and milling activities are of great concern in many countries for the last three decades. These impacts range from the creation of massive stockpiles of radioactive and toxic waste rock and sand-like tailings to serious contamination of surface and groundwater with radioactive and toxic pollutants, and releases of conventional, toxic and radioactive air pollutants. Uranium mining is also associated with high concentrations of highly toxic heavy metals, which are a major source of surface and groundwater contamination. Depending upon the hydraulic properties of the fractures involved, contaminated ground water may be transported many miles from its point of origin before feeding into an aquifer. Tailings pond may contaminate the groundwater regime by continuous seepage and leaching of radionuclides and other toxic metals due to interaction of rain water through the tailings ponds. The uranium milling and tailings pond operations were started at Jaduguda since 1968. A comprehensive geological and geophysical investigation has been carried out in the Jaduguda watershed covering the tailings ponds to understand the geohydrological characteristics of the region. High resolution electrical resistivity tomography (ERT) surveys have been carried out to delineate the aquifer geometry. Water quality analyses were carried out in three seasons covering from premonsoon to postmonsoon period during 2008-2009. Uranium concentrations have been observed in the dug wells, surface water and monitoring wells

Inorganic carbon dynamics of melt pond-covered first year sea ice in the Canadian Arctic

DEFF Research Database (Denmark)

Geilfus, Nicolas-Xavier; Galley, R.J.; Crabeck, O.

2014-01-01

Melt pond formation is a common feature of the spring and summer Arctic sea ice. However, the role of the melt ponds formation and the impact of the sea ice melt on both the direction and size of CO2 flux between air and sea is still unknown. Here we describe the CO2-carbonate chemistry of melting...... a strong decrease of the total alkalinity (TA), total dissolved inorganic carbon (TCO2) and partial pressure of CO2 (pCO2) within the bulk sea ice and the brine. Later on, melt pond formation affects both the bulk sea ice and the brine system. As melt ponds are formed from melted snow the in situ melt pond...

How to maximally support local and regional biodiversity in applied conservation? Insights from pond management.

Science.gov (United States)

Lemmens, Pieter; Mergeay, Joachim; De Bie, Tom; Van Wichelen, Jeroen; De Meester, Luc; Declerck, Steven A J

2013-01-01

Biodiversity and nature values in anthropogenic landscapes often depend on land use practices and management. Evaluations of the association between management and biodiversity remain, however, comparatively scarce, especially in aquatic systems. Furthermore, studies also tend to focus on a limited set of organism groups at the local scale, whereas a multi-group approach at the landscape scale is to be preferred. This study aims to investigate the effect of pond management on the diversity of multiple aquatic organism groups (e.g. phytoplankton, zooplankton, several groups of macro-invertebrates, submerged and emergent macrophytes) at local and regional spatial scales. For this purpose, we performed a field study of 39 shallow man-made ponds representing five different management types. Our results indicate that fish stock management and periodic pond drainage are crucial drivers of pond biodiversity. Furthermore, this study provides insight in how the management of eutrophied ponds can contribute to aquatic biodiversity. A combination of regular draining of ponds with efforts to keep ponds free of fish seems to be highly beneficial for the biodiversity of many groups of aquatic organisms at local and regional scales. Regular draining combined with a stocking of fish at low biomass is also preferable to infrequent draining and lack of fish stock control. These insights are essential for the development of conservation programs that aim long-term maintenance of regional biodiversity in pond areas across Europe.

Geo-engineering experiments in two urban ponds to control eutrophication.

Science.gov (United States)

Waajen, Guido; van Oosterhout, Frank; Douglas, Grant; Lürling, Miquel

2016-06-15

Many urban ponds experience detrimental algal blooms as the result of eutrophication. During a two year field experiment, the efficacy of five in situ treatments to mitigate eutrophication effects in urban ponds was studied. The treatments targeted the sediment phosphorus release and were intended to switch the ponds from a turbid phytoplankton-dominated state to a clear-water state with a low phytoplankton biomass. Two eutrophic urban ponds were each divided into six compartments (300-400 m(2); 210-700 m(3)). In each pond the following treatments were tested: dredging in combination with biomanipulation (involving fish biomass control and the introduction of macrophytes) with and without the addition of the flocculant polyaluminiumchloride, interception and reduction of sediment phosphorus release with lanthanum-modified bentonite (Phoslock(®)) in combination with biomanipulation with and without polyaluminiumchloride; biomanipulation alone; and a control. Trial results support the hypothesis that the combination of biomanipulation and measures targeting the sediment phosphorus release can be effective in reducing the phytoplankton biomass and establishing and maintaining a clear-water state, provided the external phosphorus loading is limited. During the experimental period dredging combined with biomanipulation showed mean chlorophyll-a concentrations of 5.3 and 6.2 μg L(-1), compared to 268.9 and 52.4 μg L(-1) in the control compartments. Lanthanum-modified bentonite can be an effective alternative to dredging and in combination with biomanipulation it showed mean chlorophyll-a concentrations of 5.9 and 7.6 μg L(-1). Biomanipulation alone did not establish a clear-water state or only during a limited period. As the two experimental sites differed in their reaction to the treatments, it is important to choose the most promising treatment depending on site specific characteristics. In recovering the water quality status of urban ponds, continuing

The impact of melt ponds on summertime microwave brightness temperatures and sea-ice concentrations

DEFF Research Database (Denmark)

Kern, Stefan; Rösel, Anja; Pedersen, Leif Toudal

2016-01-01

% sea-ice concentration. None of the algorithms investigated performs best based on our investigation of data from summer 2009. We suggest that those algorithms which are more sensitive to melt ponds could be optimized more easily because the influence of unknown snow and sea-ice surface property...... of eight sea-ice concentration retrieval algorithms to melt ponds by comparing sea-ice concentration with the melt-pond fraction. We derive gridded daily sea-ice concentrations from microwave brightness temperatures of summer 2009. We derive the daily fraction of melt ponds, open water between ice floes......, and the ice-surface fraction from contemporary Moderate Resolution Spectroradiometer (MODIS) reflectance data. We only use grid cells where the MODIS sea ice concentration, which is the melt-pond fraction plus the ice-surface fraction, exceeds 90 %. For one group of algorithms, e.g., Bristol and Comiso...

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.

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