MALLARD REPRODUCTIVE TESTING IN A POND ENVIRONMENT: A PRELIMINARY STUDY

Science.gov (United States)

A 2-year preliminary study was conducted on mallard ducks to determine the feasibility of using outdoor pond enclosures for reproductive studies and to evaluate the effects of the insecticide chlorpyrifos on mallard reproduction. No significant reproductive effects were observed ...

Microcosm 2.011

CERN Multimedia

CERN Bulletin

2011-01-01

Microcosm, CERN's first exhibition centre, will soon be upgraded. While keeping its present character and many of its nice features, the use of new cutting-edge exhibition technologies together with an area for student experiments and physics demonstrations will make version 2.011 even more attractive to the general public and school classes.   Layout of the new Microcosm 2.011 exhibition. New Year, and a new look for Microcosm! CERN's popular exhibition centre will undergo a transformation that will see, among other things, the installation of a new area dedicated to modern physics experiments for school groups. “Microcosm will keep its main features and character,” says Rolf Landua, Head of the Education Group, which is in charge of the project. “While some parts will be replaced by more modern exhibition technologies and contemporary scenography, others will be moved to allow a better visitor flow and make room for the brand-new school lab and public demonstration...

Microcosm reloaded!

CERN Multimedia

Stefania Pandolfi

2015-01-01

On 20 July, Microcosm reopened its doors to the public. CERN’s guides are already leading many enthusiastic visitors through the new attractions of the popular exhibition. More areas will reopen progressively over the coming weeks before the official inauguration this autumn.   A group of visitors is guided through the new Microcosm exhibit. After six months of extensive refurbishment work, Microcosm is back and open for public visits. As some installations are not yet up and running, CERN’s guides are there to provide visitors with additional explanations. “The two groups I guided were amazed to see real detector components before their eyes, laid out in inviting and informative displays,” says Achintya Rao, member of the CMS collaboration and a CERN guide. “The life-sized CMS mock-up and the CCC panorama are excellent locations to have in-depth conversations with enthusiastic visitors and give them a glimpse into everyday life at CERN.&...

Influence of the seasonal variation of environmental conditions on biogas upgrading in an outdoors pilot scale high rate algal pond.

Science.gov (United States)

Marín, David; Posadas, Esther; Cano, Patricia; Pérez, Víctor; Lebrero, Raquel; Muñoz, Raúl

2018-05-01

The influence of the daily and seasonal variations of environmental conditions on the quality of the upgraded biogas was evaluated in an outdoors pilot scale high rate algal pond (HRAP) interconnected to an external absorption column (AC) via a conical settler. The high alkalinity in the cultivation broth resulted in a constant biomethane composition during the day regardless of the monitored month, while the high algal-bacterial activity during spring and summer boosted a superior biomethane quality. CO 2 concentrations in the upgraded biogas ranged from 0.1% in May to 11.6% in December, while a complete H 2 S removal was always achieved regardless of the month. A limited N 2 and O 2 stripping from the scrubbing cultivation broth was recorded in the upgraded biogas at a recycling liquid/biogas ratio in the AC of 1. Finally, CH 4 concentration in the upgraded biogas ranged from 85.6% in December to 99.6% in August. Copyright © 2018 Elsevier Ltd. All rights reserved.

Atrazine remediation in wetland microcosms.

Science.gov (United States)

Runes, H B; Bottomley, P J; Lerch, R N; Jenkins, J J

2001-05-01

Laboratory wetland microcosms were used to study treatment of atrazine in irrigation runoff by a field-scale-constructed wetland under controlled conditions. Three experiments, in which 1 ppm atrazine was added to the water column of three wetland, one soil control, and one water control microcosm, were conducted. Atrazine dissipation from the water column and degradate formation (deethylatrazine [DEA]; deisopropylatrazine [DIA]; and hydroxyatrazine [HA]) were monitored. Atrazine dissipation from the water column of wetland microcosms was biphasic. Less than 12% of the atrazine applied to wetland microcosms remained in the water column on day 56. Atrazine degradates were observed in water and sediment, with HA the predominant degradate. Analysis of day 56 sediment samples indicated that a significant portion of the initial application was detected as the parent compound and HA. Most probable number (MPN) assays demonstrated that atrazine degrader populations were small in wetland sediment. Wetland microcosms were able to reduce atrazine concentration in the water column via sorption and degradation. Based on results from this study, it is hypothesized that plant uptake contributed to atrazine dissipation from the water column.

Effect of thiram and of a hydrocarbon mixture on freshwater macroinvertebrate communities in outdoor stream and pond mesocosms: I. Study design, chemicals fate and structural responses.

Science.gov (United States)

Bayona, Yannick; Roucaute, Marc; Cailleaud, Kevin; Lagadic, Laurent; Bassères, Anne; Caquet, Thierry

2015-11-01

Higher-tier ecological risk assessment (ERA) in mesocosms is commonly performed in lotic or lentic experimental systems. These systems differ in their physico-chemical and hydrological properties, leading to differences in chemical fate, community characteristics and potential recovery. This raises the issue of the relevance and sensitivity of community-level endpoints in different types of mesocosms. In this study, macroinvertebrate abundance and biomass estimates were used to assess the effects of a dithiocarbamate fungicide, thiram (35 and 170 µg l(-1)), and a petroleum middle distillate (PMD; 0.01, 0.4, 2 and 20 mg l(-1)) in outdoor stream and pond mesocosms. Streams were continuously treated during 3 weeks followed by a 2-month long post-treatment period. Ponds were treated weekly for 4 weeks, followed by a 10-month long post-treatment period. Taxonomic structure of macroinvertebrate communities was characterized using the α, β and γ components of taxa richness, Shannon and Gini-Simpson indices. Computations were based either on abundance or biomass data. Results clearly highlighted that the effects of chemicals depended on the exposure regime (for thiram) and type of system (for the PMD). Causes of the differences between streams and ponds in the magnitude and nature of effects include differential sensitivity of taxa dwelling in lentic and lotic systems and the influence of hydrology (e.g., drift from upstream) and mesocosm connectivity on recovery dynamics. This study also showed complementarities in the use of both types of mesocosms to improve the characterization of chemical effects on communities in ERA.

A New Exhibition in Microcosm

CERN Document Server

2000-01-01

Sebastien Pelletier explains states of matter to an enthusiastic group of youngsters during the opening of a new exhibition in Microcosm last week. The Fun with Physics workshop will be offered to all 13-14 year olds in school groups visiting CERN this year. The new Microcosm contents have been developed in collaboration with the local teaching community, and cover particles and the forces that act between them.

Aromatic hydrocarbon degradation in hydrogen peroxide- and nitrate-amended microcosms

International Nuclear Information System (INIS)

Christian, B.J.; Pugh, L.B.; Clarke, B.H.

1995-01-01

Fifty microcosms were constructed using aquifer materials from a former coal gasification site and divided into four groups: poisoned control, nutrient-free control, hydrogen peroxide-amended, and nitrate-amended microcosms. Each microcosm contained site soil and groundwater in a 1.2-L glass media bottle. When depleted, hydrogen peroxide and sodium nitrate were injected into the microcosms. Microcosms were periodically sacrificed for analysis of polycyclic aromatic hydrocarbons (PAHs); monocyclic aromatic hydrocarbons (benzene, toluene, ethylbenzene, and xylenes [BTEX]); total petroleum hydrocarbons (TPH); and heterotrophic plate counts (HPCs). BTEX and two- and three-ringed PAHs were degraded in microcosms receiving electron-acceptor additions compared to poisoned controls. Four-, five-, and six-ringed PAHs were not significantly degraded during this study. Except in poisoned controls, significant amounts of dissolved oxygen (DO) or nitrate were utilized, and microbial populations increased by 3 to 5 orders of magnitude compared to site soils used to assemble the microcosms (i.e., baseline samples)

Neonicotinoids thiamethoxam and clothianidin adversely affect the colonisation of invertebrate populations in aquatic microcosms.

Science.gov (United States)

Basley, Kate; Goulson, Dave

2018-04-01

Surface waters are sometimes contaminated with neonicotinoids: a widespread, persistent, systemic class of insecticide with leaching potential. Previous ecotoxicological investigations of this chemical class in aquatic ecosystems have largely focused on the impacts of the neonicotinoid imidacloprid; few empirical, manipulative studies have investigated the effect on invertebrate abundances of two other neonicotinoids which are now more widely used: clothianidin and thiamethoxam. In this study, we employ a simple microcosm semi-field design, incorporating a one-off contamination event, to investigate the effect of these pesticides at field-realistic levels (ranging from 0 to 15 ppb) on invertebrate colonisation and survival in small ephemeral ponds. In line with previous research on neonicotinoid impacts on aquatic invertebrates, significant negative effects of both neonicotinoids were found. There were clear differences between the two chemicals, with thiamethoxam generally producing stronger negative effects than clothianidin. Populations of Chironomids (Diptera) and Ostracoda were negatively affected by both chemicals, while Culicidae appeared to be unaffected by clothianidin at the doses used. Our data demonstrate that field-realistic concentrations of neonicotinoids are likely to reduce populations of invertebrates found in ephemeral ponds, which may have knock on effects up the food chain. We highlight the importance of developing pesticide monitoring schemes for European surface waters.

Environmental assessment of surfactant using aquatic microcosm system; Konuma no suiken seitaikei ni oyobosu kaimen kasseizai no microcosm system wo mochiita hyoka

Energy Technology Data Exchange (ETDEWEB)

Takamatsu, Y.; Matsumura, M. [University of Tsukuba, Tsukuba (Japan); Inamori, Y. [National Institute for Environmental Studies, Tsukuba (Japan); Sudo, R. [Tohoku University, Sendai (Japan). Faculty of Engineering

1995-10-10

Microcosm system was applied to assess effect of surfactants on aquatic ecosystem. Surfactants such as LAS and Soap were added to an aquatic flask-size microcosm consisting of four species of bacteria as decomposer, one species of ciliate protozoa (Cyclidium glaucoma), two rotifers (Philodina sp. and Lepadella sp.) and one aquatic oligochaete (Aeolosoma hemprichi) as predator, and a green alga (Chlorella sp.) and a filamentous blue-green alga (Tolypothrix sp.) as producer. In the system, NOEC (no observed effect concentration) of LAS was below 1.5mg{center_dot}l{sup -1}, whereas soap was below 30mg{center_dot}l{sup -1}. Microcosm test is a pertinent tool to assess the effect of surfactant on ecosystem because microcosm test makes it possible to evaluate the effect of surfactant from a viewpoint of the interaction of microorganisms, material cycle and energy flow. With these respects, microcosm test is useful environmental assessment method which can reflect aquatic ecosystem. 10 refs., 6 figs., 1 tab.

Microcosm 2015: showcasing real objects, real people and real discoveries

CERN Multimedia

CERN Bulletin

2014-01-01

Every year since its inauguration in 1994, the well-loved Microcosm exhibition has played host to tens of thousands of students, tourists and VIPs alike. But the ever-changing CERN landscape warranted a new look for the exhibition, which was last updated in 2003. On 8 December, Microcosm will close for refurbishment, making way for a new, interactive exhibition space to be opened summer 2015.   In the Accelerator zone, Microcosm visitors will don the helmet of an LHC operator. Social media tools will be integrated into the exhibit, allowing visitors to share their "beam" with friends at home. (Conceptual art for the new Microcosm exhibition.) While the Globe of Science and Innovation provides a spectacular introduction to CERN's key messages, Microcosm has always employed a more didactic approach. The new Microcosm will continue this complementary approach, whilst also immersing visitors into the day-to-day life of CERN people. "We want to highlight the ama...

Behind the scenes at Microcosm

CERN Document Server

Emma Sanders

2015-01-01

Works advance at Microcosm in preparation for a progressive opening of the new exhibitions from mid-July onwards.   Construction of the section on the LHC experiments (mid-June 2015).   The Microcosm exhibition space is undergoing a total revamp and will feature many new objects. Old favourites, such as the LHC tunnel model and the Linac module, will be brought up to date with more modern exhibition techniques. Another main thrust of the new exhibitions will be the focus on the people that make CERN work. This is both to show the huge diversity of expertise needed at CERN and also to help students envisage where a career in physics or engineering might take them. With the project getting the go-ahead last autumn and the closure of the Globe for building works starting from May this year, the new Microcosm exhibition areas will open progressively as and when installations are completed to ensure that summer visitors who haven’t booked a guided tour will have something to ...

Characterization of Amoeboaphelidium protococcarum, an Algal Parasite New to the Cryptomycota Isolated from an Outdoor Algal Pond Used for the Production of Biofuel

Science.gov (United States)

Letcher, Peter M.; Lopez, Salvador; Schmieder, Robert; Lee, Philip A.; Behnke, Craig; Powell, Martha J.; McBride, Robert C.

2013-01-01

Mass culture of algae for the production of biofuels is a developing technology designed to offset the depletion of fossil fuel reserves. However, large scale culture of algae in open ponds can be challenging because of incidences of infestation with algal parasites. Without knowledge of the identity of the specific parasite and how to control these pests, algal-based biofuel production will be limited. We have characterized a eukaryotic parasite of Scenedesmus dimorphus growing in outdoor ponds used for biofuel production. We demonstrated that as the genomic DNA of parasite FD01 increases, the concentration of S. dimorphus cells decreases; consequently, this is a highly destructive pathogen. Techniques for culture of the parasite and host were developed, and the endoparasite was identified as the Aphelidea, Amoeboaphelidium protococcarum. Phylogenetic analysis of ribosomal sequences revealed that parasite FD01 placed within the recently described Cryptomycota, a poorly known phylum based on two species of Rozella and environmental samples. Transmission electron microscopy demonstrated that aplanospores of the parasite produced filose pseudopodia, which contained fine fibers the diameter of actin microfilaments. Multiple lipid globules clustered and were associated with microbodies, mitochondria and a membrane cisternae, an arrangement characteristic of the microbody-lipid globule complex of chytrid zoospores. After encystment and attachment to the host cells, the parasite injected its protoplast into the host between the host cell wall and plasma membrane. At maturity the unwalled parasite occupied the entire host cell. After cleavage of the protoplast into aplanospores, a vacuole and lipids remained in the host cell. Amoeboaphelidium protococcarum isolate FD01 is characteristic of the original description of this species and is different from strain X-5 recently characterized. Our results help put a face on the Cryptomycota, revealing that the phylum is more

Corexit 9500 microcosm data

Data.gov (United States)

U.S. Environmental Protection Agency — Relative abundance of bacterial groups in the microcosms. This dataset is associated with the following publication: Techtman, S., M. Zhuang, P. Campo-Moreno, E....

Bioindication in natural-like aquatic ecosystems: endocrine disruptors in outdoor microcosms. Status-report

Energy Technology Data Exchange (ETDEWEB)

Schramm, K.W.; Severin, G.F.

2002-07-01

Over the past few decades scientists have shown that the hormone system of a wide range of organisms can be affected by numerous environmental chemicals. Society strongly demands studies about the fate and effects of such endocrine disruptors on the aquatic environment. It has been scientifically accepted that risk assessment studies done in aquatic microcosms can be used to extrapolate the potential impact of the tested compound on natural ecosystems. Realistic exposure situations were simulated and screening methods as well as analytical methods with high accuracy were applied on water and sediment. For the comprehensive risk assessment as many trophic levels as possible have to be investigated. Changes in the population dynamics and the community structure serve as ecotoxicological endpoints. Modelling the concentrations of the chemicals in the different aquatic compartments complements and confirms the analytical diagnostics. A directed design of the analytical procedures according to amount of sample and limits of determination becomes possible. Bridging acute and chronic time scales in effect diagnostics the 'area under the curve' - approach has been followed in combination with multivariate statistics. Haber's rule have been applied to the results about complex effect- and exposure-conditions. In some cases the interpretation of results becomes more easy and clear by this approach. (orig.)

Effects of the pyrethroid insecticide gamma-cyhalothrin on aquatic invertebrates in laboratory and outdoor microcosm tests

NARCIS (Netherlands)

Wijngaarden, van R.P.A.; Barber, I.; Brock, T.C.M.

2009-01-01

The sensitivity of a range of freshwater lentic invertebrates to gamma-cyhalothrin (GCH), a single enantiomer of the synthetic pyrethroid lambda-cyhalothrin, was assessed in single species laboratory tests and an outdoor multi-species ecosystem test. The most sensitive species in the laboratory

MICROCOSM - INSTALLATION OF THE LHC MODEL

CERN Multimedia

2002-01-01

This week, installation of a 6m long section of the LHC starts in Microcosm. This full-scale model is the first part of a new exhibition highlighting the technological challenges and the exciting physics of the LHC era. Many people at CERN have helped with the preparations for the model and the Microcosm team would like to thank all those involved. An inauguration for the press will take place at the start of the next school term.

Semicontinuous microcosm study of aerobic cometabolism of trichloroethylene using toluene

Energy Technology Data Exchange (ETDEWEB)

Han, Y.L. [Department of Mineral and Petroleum Engineering, National Cheng Kung University, 1 University Avenue, Tainan 701, Taiwan (China); Kuo, M.C. Tom [Department of Mineral and Petroleum Engineering, National Cheng Kung University, 1 University Avenue, Tainan 701, Taiwan (China)], E-mail: mctkuobe@mail.ncku.edu.tw; Tseng, I.C. [Department of Life Sciences, National Cheng Kung University, 1 University Avenue, Tainan 701, Taiwan (China); Lu, C.J. [Department of Environmental Engineering, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 402, Taiwan (China)

2007-09-30

A semicontinuous slurry-microcosm method was applied to mimic trichloroethylene (TCE) cometabolic biodegradation field results at the Que-Jen in-situ pilot study. The microcosm study confirmed the process of aerobic cometabolism of TCE using toluene as the primary substrate. Based on the nucleotide sequence of 16S rRNA genes, the toluene-oxidizing bacteria in microcosms were identified, i.e. Ralstonia sp. P-10 and Pseudomonasputida. The first-order constant of TCE-degradation rate was 0.5 day{sup -1} for both Ralstonia sp. P-10 and P.putida. The TCE cometabolic-biodegradation efficiency measured from the slurry microcosms was 46%, which appeared pessimistic compared to over 90% observed from the in-situ pilot study. The difference in the TCE cometabolic-biodegradation efficiency was likely due to the reactor configurations and the effective time duration of toluene presence in laboratory microcosms (1 days) versus in-situ pilot study (3 days). The results of microcosm experiments using different toluene-injection schedules supported the hypothesis. With a given amount of toluene injection, it is recommended to maximize the effective time duration of toluene presence in reactor design for TCE cometabolic degradation.

Semicontinuous microcosm study of aerobic cometabolism of trichloroethylene using toluene

International Nuclear Information System (INIS)

Han, Y.L.; Kuo, M.C. Tom; Tseng, I.C.; Lu, C.J.

2007-01-01

A semicontinuous slurry-microcosm method was applied to mimic trichloroethylene (TCE) cometabolic biodegradation field results at the Que-Jen in-situ pilot study. The microcosm study confirmed the process of aerobic cometabolism of TCE using toluene as the primary substrate. Based on the nucleotide sequence of 16S rRNA genes, the toluene-oxidizing bacteria in microcosms were identified, i.e. Ralstonia sp. P-10 and Pseudomonasputida. The first-order constant of TCE-degradation rate was 0.5 day -1 for both Ralstonia sp. P-10 and P.putida. The TCE cometabolic-biodegradation efficiency measured from the slurry microcosms was 46%, which appeared pessimistic compared to over 90% observed from the in-situ pilot study. The difference in the TCE cometabolic-biodegradation efficiency was likely due to the reactor configurations and the effective time duration of toluene presence in laboratory microcosms (1 days) versus in-situ pilot study (3 days). The results of microcosm experiments using different toluene-injection schedules supported the hypothesis. With a given amount of toluene injection, it is recommended to maximize the effective time duration of toluene presence in reactor design for TCE cometabolic degradation

Radioactivity Risk Assessment of Radon and Gamma Dose at One Uranium Tailings Pond in China

Science.gov (United States)

Lou, Yalong; Liu, Yong; Peng, Guowen; Zhao, Guodong; Zhang, Yan; Yang, Zhu

2018-01-01

A year-long monitoring of gamma radiation effective dose rate and radon concentration had been done in the reservoir area of one uranium tailings pond in Hunan province (The monitoring area included indoor and outdoor area of residential buildings and workshops, tailings dam slope). Afterwards, the annual effective radiation dose of the people in that radiation environment had been calculated based on the results of monitoring, as well as a radiation risk assessment. According to the assessment, gamma radiation effective dose rate and radon concentration in the monitoring area were low, and the annual effective radiation dose was far below the international standard (30mSv), which showed that the radiation would not put the people’s health at risk. However, the annual effective radiation dose of gamma was far above that of radon in the area of uranium tailings pond; therefore, it’s advisable to take quarantine measures in in the area of uranium tailings pond to keep the surrounding residents away from unnecessary ionizing radiation.

Outdoor Growth Characterization of an Unknown Microalga Screened from Contaminated Chlorella Culture

Directory of Open Access Journals (Sweden)

Shuhao Huo

2017-01-01

Full Text Available Outdoor microalgae cultivation process is threatened by many issues, such as pest pollution and complex, changeable weather. Therefore, it is difficult to have identical growth rate for the microalgae cells and to keep their continuous growth. Outdoor cultivation requires the algae strains not only to have a strong ability to accumulate oil, but also to adapt to the complicated external environment. Using 18S rRNA technology, one wild strain Scenedesmus sp. FS was isolated and identified from the culture of Chlorella zofingiensis. Upon contamination by Scenedesmus sp., the species could quickly replace Chlorella zofingiensis G1 and occupy ecological niche in the outdoor column photobioreactors. The results indicated that Scenedesmus sp. FS showed high alkali resistance. It also showed that even under the condition of a low inoculum rate (OD680, 0.08, Scenedesmus sp. FS could still grow in the outdoor raceway pond under a high alkaline environment. Even under unoptimized conditions, the oil content of Scenedesmus sp. FS could reach more than 22% and C16–C18 content could reach up to 79.68%, showing that this species has the potential for the biodiesel production in the near future.

Novel Safranin-Tinted Candida rugosa Lipase Nanoconjugates Reagent for Visualizing Latent Fingerprints on Stainless Steel Knives Immersed in a Natural Outdoor Pond

Directory of Open Access Journals (Sweden)

Aida Rasyidah Azman

2018-05-01

Full Text Available Waterways are popular locations for the disposition of criminal evidence because the recovery of latent fingerprints from such evidence is difficult. Currently, small particle reagent is a method often used to visualize latent fingerprints containing carcinogenic and hazardous compounds. This study proposes an eco-friendly, safranin-tinted Candida rugosa lipase (triacylglycerol ester hydrolysis EC 3.1.1.3 with functionalized carbon nanotubes (CRL-MWCNTS/GA/SAF as an alternative reagent to the small particle reagent. The CRL-MWCNTS/GA/SAF reagent was compared with the small particle reagent to visualize groomed, full fingerprints deposited on stainless steel knives which were immersed in a natural outdoor pond for 30 days. The quality of visualized fingerprints using the new reagent was similar (modified-Centre for Applied Science and Technology grade: 4; p > 0.05 to small particle reagent, even after 15 days of immersion. Despite the slight decrease in quality of visualized fingerprints using the CRL-MWCNTS/GA/SAF on the last three immersion periods, the fingerprints remained forensically identifiable (modified-Centre for Applied Science and Technology grade: 3. The possible chemical interactions that enabled successful visualization is also discussed. Thus, this novel reagent may provide a relatively greener alternative for the visualization of latent fingerprints on immersed non-porous objects.

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...

Influence of tubificid worms on nutrient fluxes across water-sediment interface in fish farm settling ponds

Directory of Open Access Journals (Sweden)

Puigagut J.

2014-04-01

Full Text Available The influence of tubificid worms on nutrient translocation from water to fish farm sediments accumulating in settling ponds was addressed under laboratory conditions. Small microcosms of 0.5 L were filled up with 35 g of sludge from a fish farm settling pond and 0.15 L of filtered settling pond water. The experimental set up consisted of one control line (no worms added, a second experimental line with 1 mg of tubificid worms·g-1 fresh sediment (550 individuals·m-2 and a third experimental line with 40 mg of tubificid worms·g-1 fresh sediment (22 000 individuals·m-2. Nutrients translocation was determined by monitoring overlaying water concentration of ammonia, nitrate and phosphate for ten days. Results showed that abundances of 550 individuals·m-2 had no significant influence on the fluxes of nutrients here considered. However, the influence of higher abundances of tubificids (22 000 individuals·m-2 was of significant extent on the translocation of nitrate and phosphate. Accordingly, bioturbation of tubificids caused 55% lower nitrate uptake by the sediment when compared to control conditions. Phosphorus released by the sediments of the control condition was ca. 90% higher than that recorded under abundances of tubificids (22 000 individuals·m-2. Results obtained allowed us to estimate that fish farm settling ponds highly colonized by tubificid worms (22 000 individuals·m-2 may contribute to decrease phosphorus discharge (in terms of soluble phosphorus in ca. 5 g of P·ton-1 of fish produced.

Closure of Microcosm for refurbishment

CERN Multimedia

2014-01-01

Since 1994, the Microcosm exhibition has given the opportunity to visitors of all ages and backgrounds to have a first glimpse into the secrets of physics.   To ensure that Microcosm can continue fulfilling its educational aims at the same level of quality for many years to come, it is closing for renovation work on 8 December 2014 and is expected to reopen during Summer 2015. During the closure, the “Fun with Physics” workshop will not take place, but the Universe of Particles exhibition in the Globe and the Passport to the Big Bang circuit will remain accessible to the public, free of charge and with no need to book in advance.  Guided tours of CERN are also available (advance booking required via this page).

Characterization of Amoeboaphelidium protococcarum, an algal parasite new to the cryptomycota isolated from an outdoor algal pond used for the production of biofuel.

Directory of Open Access Journals (Sweden)

Peter M Letcher

Full Text Available Mass culture of algae for the production of biofuels is a developing technology designed to offset the depletion of fossil fuel reserves. However, large scale culture of algae in open ponds can be challenging because of incidences of infestation with algal parasites. Without knowledge of the identity of the specific parasite and how to control these pests, algal-based biofuel production will be limited. We have characterized a eukaryotic parasite of Scenedesmus dimorphus growing in outdoor ponds used for biofuel production. We demonstrated that as the genomic DNA of parasite FD01 increases, the concentration of S. dimorphus cells decreases; consequently, this is a highly destructive pathogen. Techniques for culture of the parasite and host were developed, and the endoparasite was identified as the Aphelidea, Amoeboaphelidium protococcarum. Phylogenetic analysis of ribosomal sequences revealed that parasite FD01 placed within the recently described Cryptomycota, a poorly known phylum based on two species of Rozella and environmental samples. Transmission electron microscopy demonstrated that aplanospores of the parasite produced filose pseudopodia, which contained fine fibers the diameter of actin microfilaments. Multiple lipid globules clustered and were associated with microbodies, mitochondria and a membrane cisternae, an arrangement characteristic of the microbody-lipid globule complex of chytrid zoospores. After encystment and attachment to the host cells, the parasite injected its protoplast into the host between the host cell wall and plasma membrane. At maturity the unwalled parasite occupied the entire host cell. After cleavage of the protoplast into aplanospores, a vacuole and lipids remained in the host cell. Amoeboaphelidium protococcarum isolate FD01 is characteristic of the original description of this species and is different from strain X-5 recently characterized. Our results help put a face on the Cryptomycota, revealing that the

Microbial community analysis of switchgrass planted and unplanted soil microcosms displaying PCB dechlorination.

Science.gov (United States)

Liang, Yi; Meggo, Richard; Hu, Dingfei; Schnoor, Jerald L; Mattes, Timothy E

2015-08-01

Polychlorinated biphenyls (PCBs) pose potential risks to human and environmental health because they are carcinogenic, persistent, and bioaccumulative. In this study, we investigated bacterial communities in soil microcosms spiked with PCB 52, 77, and 153. Switchgrass (Panicum virgatum) was employed to improve overall PCB removal, and redox cycling (i.e., sequential periods of flooding followed by periods of no flooding) was performed in an effort to promote PCB dechlorination. Lesser chlorinated PCB transformation products were detected in all microcosms, indicating the occurrence of PCB dechlorination. Terminal restriction fragment length polymorphism (T-RFLP) and clone library analysis showed that PCB spiking, switchgrass planting, and redox cycling affected the microbial community structure. Putative organohalide-respiring Chloroflexi populations, which were not found in unflooded microcosms, were enriched after 2 weeks of flooding in the redox-cycled microcosms. Sequences classified as Geobacter sp. were detected in all microcosms and were most abundant in the switchgrass-planted microcosm spiked with PCB congeners. The presence of possible organohalide-respiring bacteria in these soil microcosms suggests that they play a role in PCB dechlorination therein.

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.

Ecological effects assessment of anionic surfactant on aquatic ecosystem using microcosm system; Microcosm wo mochiita in ion kaimen kasseizai no suiken seitaikei ni oyobosu eikyo hyoka

Energy Technology Data Exchange (ETDEWEB)

Takamatsu, Y. [University of Tsukuba, Tsukuba (Japan); Inamori, Y. [National Institute for Environmental Studies, Tsukuba (Japan); Sudo, R. [Tohoku University, Sendai (Japan). Faculty of Engineering; Kurihara, Y. [Ou Univ., Fukushima (Japan). Faculty of Engineering; Matsumura, M. [University of Tsukuba, Tsukuba (Japan). Institute of Applied Biochemical

1997-11-10

Microcosm system was applied to assess effect of anionic surfactant (LAS) on aquatic ecosystem. Anionic surfactant such as LAS was added to an flask microcosm consisting of four species of bacteria as decomposer, one species of ciliate protozoa (Cyclidium glaucoma), two rotifers (Philodina sp. and Lepadella sp.) and one aquatic oligochaete (Aeolosoma hemprichi) as predator, and a green alga (Chlorella sp.) and a filamentous blue-green alga (Tolypothrix sp.) as producer, comparing with that of an natural lake model ecosystem derived from natural lake water. In the flask microcosm system and the natural lake model ecosystem, biodegradation rates of LAS were almost same and NOECs (no observed effect concentration) of LAS were also below 1.5 mg{center_dot} l{sup -1}. It was found that flask microcosm test could provide precise ecological effect assessment of LAS on number of microorganisms because the system showed higher reproducibility and stability than natural take model ecosystem. It was suggested that flask microcosm test was useful ecological effect assessment method which can reflect natural aquatic ecosystem. 10 refs., 4 figs., 2 tabs.

Iron released from ilmenite mineral sustains a phytoplankton community in microcosms

Digital Repository Service at National Institute of Oceanography (India)

Fernandes, C.E.G.; Velip, D.; Mourya, B.S.; Shaikh, S.; Das, A.; LokaBharathi, P.A.

Natural biotic communities from Kalbadevi Bay were monitored in microcosms (1-l glass flasks) to test the hypothesis that iron released from ilmenite through microbial action contributes to proliferation of phytoplankton. Microcosms containing...

Come and play with HEAL in Microcosm!

CERN Multimedia

Stefania Pandolfi

2016-01-01

A new interactive game in Microcosm informs about hadron therapy – come and test it!   HEAL is a new interactive game currently under evaluation at Microcosm to inform visitors about hadron therapy, one aspect of the CERN-related contributions to the medical field. Microcosm is continuously evolving and new content is installed regularly. One of the most recent exhibits is called HEAL - an interactive game with the aim of informing visitors about the hadron therapy to treat cancer. It has been developed by Jenny Rompa, a PhD student at CERN, within the activities of MediaLab.  The application is controlled through body movements and the player is asked to set the right energy and the right angle of the hadron beam to make the (brain) cancer disappear. As part of her doctoral thesis, Jenny also built a questionnaire to hand out to visitors in order to examine their user experience. The goal of the study is to evaluate the effectiveness of using inter...

Evaluation of indigenous microalgal isolate Chlorella sp. FC2 IITG as a cell factory for biodiesel production and scale up in outdoor conditions.

Science.gov (United States)

Muthuraj, Muthusivaramapandian; Kumar, Vikram; Palabhanvi, Basavaraj; Das, Debasish

2014-03-01

The present study reports evaluation of an indigenous microalgal isolate Chlorella sp. FC2 IITG as a potential candidate for biodiesel production. Characterization of the strain was performed under photoautotrophic, heterotrophic, and mixotrophic cultivation conditions. Further, an open-pond cultivation of the strain under outdoor conditions was demonstrated to evaluate growth performance and lipid productivity under fluctuating environmental parameters and in the presence of potential contaminants. The key findings were: (1) the difference in cultivation conditions resulted in significant variation in the biomass productivity (73-114 mg l⁻¹ day⁻¹) and total lipid productivity (35.02-50.42 mg l⁻¹ day⁻¹) of the strain; (2) nitrate and phosphate starvation were found to be the triggers for lipid accumulation in the cell mass; (3) open-pond cultivation of the strain under outdoor conditions resulted in biomass productivity of 44 mg l⁻¹ day⁻¹ and total lipid productivity of 10.7 mg l⁻¹ day⁻¹; (4) a maximum detectable bacterial contamination of 7 % of the total number of cells was recorded in an open-pond system; and (5) fatty acid profiling revealed abundance of palmitic acid (C16:0), oleic acid (C18:1) and linoleic acid (C18:2), which are considered to be the key elements for suitable quality biodiesel.

The effects of H2SO4 and (NH42SO4 treatments on the chemistry of soil drainage water and pine seedlings in forest soil microcosms

Directory of Open Access Journals (Sweden)

M. I. Stutter

2004-01-01

Full Text Available An experiment comparing effects of sulphuric acid and reduced N deposition on soil water quality and on chemical and physical growth indicators for forest ecosystems is described. Six H2SO4 and (NH42SO4 treatment loads, from 0 – 44 and 0 – 25 kmolc ha-1 yr-1, respectively, were applied to outdoor microcosms of Pinus sylvestris seedlings in 3 acid to intermediate upland soils (calc-silicate, quartzite and granite for 2 years. Different soil types responded similarly to H2SO4 loads, resulting in decreased leachate pH, but differently to reduced N inputs. In microcosms of calc-silicate soil, nitrification of NH4 resulted in lower pH and higher cation leaching than in acid treatments. By contrast, in quartzite and granite soils, (NH42SO4 promoted direct cation leaching, although leachate pH increased. The results highlighted the importance of soil composition on the nature of the cations leached, the SO4 adsorption capacities and microbial N transformations. Greater seedling growth on calc-silicate soils under both treatment types was related to sustained nutrient availability. Reductions in foliar P and Mg with higher N treatments were observed for seedlings in the calc-silicate soil. There were few treatment effects on quartzite and granite microcosm tree seedlings since P limitation precluded seedling growth responses to treatments. Hence, any benefits of N deposition to seedlings on quartzite and granite soils appeared limited by availability of co-nutrients, exacerbated by rapid depletion of soil exchangeable base cations. Keywords: acidification, manipulation, nitrogen, ammonium, deposition, soil, drainage, pine, microcosms, forest

Nutrient cycling Microbial Ecosystems: Assembly, Function and Targeted Design

Science.gov (United States)

2017-05-05

Replicate microcosms created from freshwater pond sediment and water , supplemented by cellulose and sulfate.  Figure 2. Analytical predictions of a ‘2...used as food by other populations [14,15]. On the experimental side, we have used laboratory microcosms, made from pond sediment and water ...different chemical transformations, converting potentially harmful chemicals via a series of intermediates, to harmless waste products. This shuttling of

Thermal modeling and parametric studies of a greenhouse fish pond in the Central Himalayan Region

International Nuclear Information System (INIS)

Sarkar, Bikash; Tiwari, G.N.

2006-01-01

This study describes the thermal modeling and its validation of greenhouse fish pond systems. Numerical computations have been performed for a typical day in the month of June, 2005, for the climatic condition of Champawat in the Central Himalayan Region. The energy balance equations have been written considering the effects of conduction, convection, radiation, evaporation and ventilation. The governing equations are numerically solved with Matlab 7.0 software to predict the water temperature. A parametric study has also been performed to find the effects of various parameters, namely the number of air changes per hour, the transmissivity (τ) and the isothermal mass and height of the greenhouse. It is observed that there is no significant effect in the parametric studies on water temperature due to the larger isothermal mass. The model has been validated with experimental data. On an average, the even span passive greenhouse fish pond can increase the inside temperature 4.14 deg. C higher than the temperature of an outdoor pond. Statistical analysis shows that the predicted and experimental values of water temperature exhibited fair agreement with a coefficient of correlation r = 0.90 and root mean square percent deviation e = 1.67%

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.

Photowalk Exhibition opens at Microcosm

CERN Document Server

Katarina Anthony

2011-01-01

The winning photographs from the 2010 Global Particle Physics Photowalk competition will go on display at Microcosm from 11 February to 2 April. The exhibition is part of a global photography event taking place over three continents, with Photowalk exhibitions opening simultaneously at Fermilab in the US, KEK in Japan and here at CERN.   DESY wire chamber - First place people's choice; second place global jury competition. Photographer: Hans-Peter Hildebrandt  If you were one of the 1,300 photography lovers who voted in last year’s Photowalk competition, this exhibition is your chance to see the winning entries in print. The exhibition will take place in the downstairs gallery of Microcosm, overlooking the garden. 15 photographs will be on display, with each of the laboratories that participated in Photowalk represented by their 3 winning entries. Among them will be the “people’s choice” sunburst photo of a particle detector at DESY (Photo 1), and...

Productivity and biochemical composition of Phaeodactylum tricornutum (Bacillariophyceae) cultures grown outdoors in tubular photobioreactors and open ponds

Czech Academy of Sciences Publication Activity Database

Benavides, A. M. S.; Torzillo, G.; Kopecký, Jiří; Masojídek, Jiří

2013-01-01

Roč. 54, JUL 2013 (2013), s. 115-122 ISSN 0961-9534 R&D Projects: GA MŠk(CZ) ED2.1.00/03.0110 Institutional support: RVO:61388971 Keywords : Lipid * Open ponds * Phaeodactylum tricornutum Subject RIV: EE - Microbiology, Virology Impact factor: 3.411, year: 2013

Fate of neptunium in an anaerobic, methanogenic microcosm

International Nuclear Information System (INIS)

Banaszak, J.E.; Webb, S.M.; Rittmann, B.E.; Gaillard, J.F.; Reed, D.T.

1999-01-01

Neptunium is found predominantly as Np(IV) in reducing environments, but as Np(V) in aerobic environments. Currently, it is not known how the interplay between biotic and abiotic processes affects Np redox speciation in the environment. To evaluate the effect of anaerobic microbial activity on the fate of Np in natural systems, Np(V) was added to a microcosm inoculated with anaerobic sediments from a metal-contaminated freshwater lake. The consortium included metal-reducing, sulfate-reducing, and methanogenic microorganisms, and acetate was supplied as the only exogenous substrate. Addition of more than 10 -5 M Np did not inhibit methane production. Total Np solubility in the active microcosm, as well as in sterilized control samples, decreased by nearly two orders of magnitude. A combination of analytical techniques, including VIS-NIR absorption spectroscopy and XANES, identified Np(IV) as the oxidation state associated with the sediments. The similar results from the active microcosm and the abiotic controls suggest that microbially produced Mn(II/III) and Fe(II) may serve as electron donors for Np reduction

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.

Microcosm: s'instruire en s'amusant

CERN Multimedia

2003-01-01

Since the 5th May, on the first Monday of each month, CERN Microcosm invites you to its "Lundis Découverte" presentations. Each presentation has a theme connected to the science and technology used at CERN (0.5 page)

Status of outdoor radioactive contamination at the Hanford Site

International Nuclear Information System (INIS)

McKinney, S.M.; Markes, B.M.

1994-12-01

This document summarizes the status of outdoor radioactive contamination near Hanford Site facilities and disposal sites. It defines the nature and areal extend of the radioactively contaminated areas and describes the historical, ongoing, and planned radiological monitoring and control activities. Radioactive waste has been disposed of to the soil column since shortly after the reactors and production facilities began operating. Radioactive liquid wastes were placed directly into the ground via liquid discharges to cribs, ponds, ditches, and reverse wells. Solid wastes were placed in trenches, burial vaults, and caissons. Although the Hanford Site covers 1,450 km 2 , the radioactively contaminated area is only about 36 km 2 or 2.5% of the original site. Over time, contamination has migrated from some of the waste management sites through various vectors (e.g., burrowing animals, deep-rooted vegetation, erosion, containment system failure) or has been deposited to the surface soil via spills and unplanned releases (e.g., line leaks/breaks, tank leaks, and stack discharges) and created areas of outdoor radioactivity both on and below the surface. Currently 26 km 2 are posted as surface contamination and 10 km 2 are posted as underground contamination

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

Naturally-Derived Microcosms for Estimating Stress Effects in Aquatic Ecosystems

Science.gov (United States)

1991-05-31

Respiration; RAIII: Protozoans: Lub 06 Biomonitoring; Enzyme; Ecotoxicology : Microcoasm; Artificial L aa Substrates 19. ABSTRACT (Continue on tverie...and macrophytes for 5 weeks and found that CV’s for most microcosm measures were 10 to 30% and that CV’s decreased as microcosms matured. Brockway et...212 Contract DAMD17-88-C-8068 convey ecotoxicological meaning and provide investigators with resolving power for finding differences. At the present

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

Long-term effects of ozone on CO2 exchange in peatland microcosms

DEFF Research Database (Denmark)

Haapala, JK; Mörsky, SK; Rinnan, Riikka

2011-01-01

Effects of elevated tropospheric ozone concentration on the CO2 exchange of peatland microcosms and the photosynthetic capacity of the dominating sedge, Eriophorum vaginatum, were studied in a four-year open-field experiment. The net ecosystem CO2 exchange and the dark respiration rate of the mic......Effects of elevated tropospheric ozone concentration on the CO2 exchange of peatland microcosms and the photosynthetic capacity of the dominating sedge, Eriophorum vaginatum, were studied in a four-year open-field experiment. The net ecosystem CO2 exchange and the dark respiration rate...... exchange of the peatland microcosms....

Some Outdoor Educators' Experiences of Outdoor Education

Science.gov (United States)

Gunn, Terry

2006-01-01

The phenomenological study presented in this paper attempts to determine, from outdoor educators, what it meant for them to be teaching outdoor education in Victorian secondary schools during 2004. In 1999, Lugg and Martin surveyed Victorian secondary schools to determine the types of outdoor education programs being run, the objectives of those…

A DNA Origami Mechanical Device for the Regulation of Microcosmic Structural Rigidity.

Science.gov (United States)

Wan, Neng; Hong, Zhouping; Wang, Huading; Fu, Xin; Zhang, Ziyue; Li, Chao; Xia, Han; Fang, Yan; Li, Maoteng; Zhan, Yi; Yang, Xiangliang

2017-11-01

DNA origami makes it feasible to fabricate a tremendous number of DNA nanostructures with various geometries, dimensions, and functionalities. Moreover, an increasing amount of research on DNA nanostructures is focused on biological and biomedical applications. Here, the reversible regulation of microcosmic structural rigidity is accomplished using a DNA origami device in vitro. The designed DNA origami monomer is composed of an internal central axis and an external sliding tube. Due to the external tube sliding, the device transforms between flexible and rigid states. By transporting the device into the liposome, the conformational change of the origami device induces a structural change in the liposome. The results obtained demonstrate that the programmed DNA origami device can be applied to regulate the microcosmic structural rigidity of liposomes. Because microcosmic structural rigidity is important to cell proliferation and function, the results obtained potentially provide a foundation for the regulation of cell microcosmic structural rigidity using DNA nanostructures. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An analysis of how to improve production of copepods as live feed from tropical Taiwanese outdoor aquaculture ponds

DEFF Research Database (Denmark)

Blanda, Elisa; Drillet, Guillaume; Huang, Cheng-Chien

2017-01-01

. Lastly, this study shows evidence on the yearlong availability of copepods to the pond managers, which, based on standing stock and secondary productivity, easily could improve and intensify their harvest effort. Nauplii could be harvested all year long and adult copepods and copepodites could also...

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...

Impact of imidaclorprid on live-cycle development of Coccinella septempunctata in laborratory microcosms

NARCIS (Netherlands)

Caihong, Yu; Ronghua, Lin; Maoran, Fu; Yanming, Zhou; Brock, T.C.M.

2014-01-01

Long-term effects of a single application of imidacloprid on ladybird beetle, Coccinella septempunctata L., were studied in indoor laboratory microcosms, starting with the 2nd instar larvae of C. septempunctata but covering the full life cycle. The microcosms comprised enclosures containing a pot

Outdoor recreation-related outdoor education: scope of the research (1995-2010) 2

OpenAIRE

Lynch, Philippa

2012-01-01

Article made available with the permission of the New Zealand Journal of Outdoor Education. This is part two of an article on the scope of the New Zealand outdoor recreation-related outdoor education research published from January 1995 to June 2010. It draws on the literature covered the 2010 Sport and Recreation New Zealand-funded Outdoor Recreation Research Stocktake, which included outdoor education material. This part covers resources for outdoor recreation-related outdoor education, ...

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.

Tetracyclines and tetracycline resistance in agricultural soils: microcosm and field studies.

OpenAIRE

Schmitt, Heike; Stoob, Krispin; Hamscher, Gerd; Smit, Eric; Seinen, Willem

2006-01-01

The influence of the use of antibiotics on the prevalence of resistance genes in the environment is still poorly understood. We studied the diversity of tetracycline and sulfonamide resistance genes as influenced by fertilization with pig manure in soil microcosms and at two field locations. Manure contained a high diversity of resistance genes, regardless of whether it stemmed from a farm operation with low or regular use of antibiotics. In the microcosm soils, the influence of fertilization...

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...

Nutrient Limitation in Surface Waters of the Oligotrophic Eastern Mediterranean Sea: an Enrichment Microcosm Experiment

KAUST Repository

Tsiola, A.; Pitta, P.; Fodelianakis, Stylianos; Pete, R.; Magiopoulos, I.; Mara, P.; Psarra, S.; Tanaka, T.; Mostajir, B.

2015-01-01

groups of the prokaryotic and eukaryotic (pico-, nano-, and micro-) plankton using a microcosm experiment during stratified water column conditions in the Cretan Sea (Eastern Mediterranean). Microcosms were enriched with N and P (either solely

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.

Petroleum Oxidation in Marine Microcosms by Natural Microbial Assemblages

Science.gov (United States)

Wardlaw, G. D.; Reddy, C. M.; Nelson, R. K.; Ehrhardt, C. J.; Valentine, D. L.

2006-12-01

Millions of gallons of petroleum are emitted into marine environments each year and the oxidation of this oil by microbes is an important mechanism for mediating toxicity. In terms of quantity, petroleum is the most abundant organic pollutant impacting marine environments today. Recent advances in chromatography have led to the development of comprehensive two-dimensional gas chromatography (GC &GC). The acronym, GC GC, is used because orthogonal gas chromatographic separations are achieved in both analytical dimensions by using stationary phases with varying partitioning abilities and selectivity. This novel method has greatly expanded the analytical window of petroleum hydrocarbons and was used to track the loss of petroleum hydrocarbons in aerobic marine microcosm experiments. Sediment microcosms were composed of seawater and sediment collected from the Coal Oil Point (COP) seep field off the coast of Santa Barbara, CA. Oil collected directly from the reservoir underlying the seep field was added to each microcosm, and samples were incubated for one year. Net metabolism was tracked by quantifying oxygen consumption and carbon dioxide production. The loss of petroleum components was tracked with GC GC, whereas the bacterial and archaeal community structures were tracked using T-RFLP. Results of these incubation studies will be presented.

An automated image analysis system to measure and count organisms in laboratory microcosms.

Directory of Open Access Journals (Sweden)

François Mallard

Full Text Available 1. Because of recent technological improvements in the way computer and digital camera perform, the potential use of imaging for contributing to the study of communities, populations or individuals in laboratory microcosms has risen enormously. However its limited use is due to difficulties in the automation of image analysis. 2. We present an accurate and flexible method of image analysis for detecting, counting and measuring moving particles on a fixed but heterogeneous substrate. This method has been specifically designed to follow individuals, or entire populations, in experimental laboratory microcosms. It can be used in other applications. 3. The method consists in comparing multiple pictures of the same experimental microcosm in order to generate an image of the fixed background. This background is then used to extract, measure and count the moving organisms, leaving out the fixed background and the motionless or dead individuals. 4. We provide different examples (springtails, ants, nematodes, daphnia to show that this non intrusive method is efficient at detecting organisms under a wide variety of conditions even on faintly contrasted and heterogeneous substrates. 5. The repeatability and reliability of this method has been assessed using experimental populations of the Collembola Folsomia candida. 6. We present an ImageJ plugin to automate the analysis of digital pictures of laboratory microcosms. The plugin automates the successive steps of the analysis and recursively analyses multiple sets of images, rapidly producing measurements from a large number of replicated microcosms.

Ecological effects of ionizing radiation and other toxic agents on the aquatic microcosm

International Nuclear Information System (INIS)

Fuma, Shoichi; Ishii, Nobuyoshi; Tanaka, Nobuyuki; Takeda, Hiroshi; Miyamoto, Kiriko; Yanagisawa, Kei; Kawabata, Zen'ichiro

2004-01-01

The purpose of this study was comparative evaluation of effects of ionizing radiation and other various toxic agents on aquatic microbial communities. For this purpose, the authors investigated effects of γ-rays, ultraviolet (UV) radiation, acidification, aluminum, manganese, nickel, copper and gadolinium on the microcosm, i.e., the experimental model ecosystem consisting of populations of the flagellate alga Euglena gracilis as a producer, the ciliate protozoan Tetrahymena thermophila as a consumer and the bacterium Eseherichia coli as a decomposer. Effects of toxic agents in the microcosm were not only direct effects but also community-level effects due to interactions among the constituting species or between organisms and toxic agents. In general, the degrees of effects observed in the microcosm could be categorized as follows: no effects; recognizable effects, i.e., decrease or increase in the cell densities of at least one species; severe effects, i.e., extinction of one or two species; and destructive effects, i.e., extinction of all species. These results were analyzed by the ecological effect index (EEI), in which differences in the cell densities between exposed and control microcosm were represented by the Euclidean distance function. A 50% effect doses for the microcosm (ED M50 ), at which the EEI became 50%, were evaluated to be 530 Gy for γ-rays, 2100 J m -2 for UV, 4100 μM for manganese, 45 μM for nickel, 110 μM for copper and 250 μM for gadolinium. (author)

A plasma ball in the Microcosm museum

CERN Multimedia

Maximilien Brice

2005-01-01

Plasma balls, like the one shown here, are displayed in the Microcosm exhibition where families can visit to learn more about the experiments carried out in a research institute like CERN. Hands-on activities allow visitors to get a step closer to the research activities carried out at CERN.

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

MICROCOSM AND IN-SITU FIELD STUDIES OF ENHANCED BIOTRANSFORMATION OF TRICHLOROETHYLENE BY PHENOL-UTILIZING MICROORGANISMS

Science.gov (United States)

The ability of different aerobic groundwater microorganisms to cometabolically degrade trichloroethylene (TCE), 1,2-cis-dichloroethylene (c-DCE), and 1,2-trans-dichloroethylene (t-DCE) was evaluated both in groundwater-fed microcosms and in situ in a shallow aquifer. Microcosms a...

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

Comparing the impacts of sediment-bound bifenthrin on aquatic macroinvertebrates in laboratory bioassays and field microcosms.

Science.gov (United States)

Boyle, Rhianna L; Hoak, Molly N; Pettigrove, Vincent J; Hoffmann, Ary A; Long, Sara M

2016-11-01

We conducted two laboratory bioassays and two field microcosm exposures with bifenthrin (a synthetic pyrethroid) in order to evaluate the capacity of single-species laboratory bioassays to predict lethal and sublethal impacts on aquatic invertebrates in microcosms. For the laboratory species, Chironomus tepperi, larval survival was reduced by 24% at 53.66µg/g OC, while adult emergence was reduced at concentrations of 33.33µg/g OC and higher, with a 61% decrease at 77.78µg/g OC and no emergence at 126.67µg/g OC. The abundance of several other microcosm taxa was reduced in the microcosms at a similar concentration range (33.33µg/g OC and above), however there was no impact on the abundance of the congeneric species, Chironomus oppositus. The differences in impacts between test systems were potentially due to both differing species sensitivity and the interaction of ambient temperature with bifenthrin toxicity. Bifenthrin also was associated with early emergence of Chironomus sp. in both test systems, at concentrations of 10µg/g OC and higher (laboratory) and 43.90µg/g OC (microcosm), and with a significant decrease in the proportion of C. oppositus males in a microcosm. These findings indicate that while laboratory bioassays accurately predict many impacts in the field, there are some limitations to the predictive capacity of these tests. Copyright © 2016 Elsevier Inc. All rights reserved.

Biodegradation of polycyclic aromatic hydrocarbons (PAH) from crude oil in sandy-beach microcosms

International Nuclear Information System (INIS)

Lepo, J.E.; Cripe, C.R.

2000-01-01

Experiments were conducted using triplicate microcosm chambers for each treatment of a simulated oil spill on a beach. The treatments were sterile control, 10 ppm of a rhamnolipid biosurfactant added to the seawater and bi-weekly inoculation of the microcosms with two marine bacteria that produce biosurfactants but degrade only n-alkanes. The results showed that raw seawater cycled through the microcosms over a 30-day period led to a substantial depletion of fluorene, phenanthrene, and other polyaromatic hydrocarbons (PAH). It was not possible to detect PAH in pooled test system effluents. The oiled-beach microcosms were run with sterile synthetic seawater to differentiate between wash out and degradation. Depletion of n-alkanes was noticed in the systems inoculated with the alkane-degrading microbes and virtually all the aromatic analytes were recoverable from the oiled sand. The other two treatments permitted the recovery of all the analytes (PAH or alkanes). Under aerobic conditions, the biodegradation by microorganisms indigenous to natural seawater supported that lower molecular weight PAH were substantially depleted, but not the n-alkanes under similar conditions. 16 refs., 4 tabs., 1 fig

Outdoor recreation-related outdoor education: scope of the research (1995-2010) I

OpenAIRE

Lynch, Philippa

2012-01-01

Article made available with the permission of the New Zealand Journal of Outdoor Education. This article reports on the scope of the New Zealand outdoor recreationrelated outdoor education research literature published from January 1995 to June 2010. It draws on the literature covered by the 2010 Sport and Recreation New Zealand-funded Outdoor Recreation Research Stocktake, which included outdoor education material. This article is divided into two parts, both published in this issue of th...

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

Influence of erythromycin A on the microbial populations in aquaculture sediment microcosms

International Nuclear Information System (INIS)

Kim, Yong-Hak; Cerniglia, Carl E.

2005-01-01

Degradation of erythromycin A was studied using two sediment samples obtained from the salmon and trout hatchery sites at Hupp Springs (HS) and Goldendale (GD), Washington, United States. The former site had been treated for 3 years with erythromycin-medicated feed prior to the experiments, and the latter site had not been treated with any antibiotic for at least 6 years. The two sediment microcosms treated with either N-[methyl- 14 C]erythromycin A or [1,3,5,7,9,11,13- 14 C]erythromycin A showed S-curves for erythromycin A mineralization with a prolonged lag time of 120 days, except for GD microcosms treated with [1,3,5,7,9,11,13- 14 C]erythromycin A. We proposed a simplified logistic model to interpret the mineralization curves under the assumption of the low densities of initial populations metabolizing erythromycin A. The model was helpful for knowing the biological potential for erythromycin A degradation in sediments. Although erythromycin A added to the two sediment microcosms did not significantly alter the numbers of total viable aerobic bacteria or erythromycin-resistant bacteria, it affected the bacterial composition. The influence on the bacterial composition appeared to be greater in GD microcosms without pre-exposure to antibiotics. PCR-RFLP and DNA sequence analyses of the 16S ribosomal RNA gene and the erythromycin esterase (ere) gene revealed that ereA type 2 (ereA2) was present in potentially erythromycin-degrading Pseudomonas spp. strains GD100, GD200, HS100, HS200 and HS300, isolated from erythromycin-treated and non-treated GD and HS microcosms. Erythromycin A appeared to influence the development and proliferation of strain GD200, possibly via the lateral gene transfer of ereA2

Influence of erythromycin A on the microbial populations in aquaculture sediment microcosms

Energy Technology Data Exchange (ETDEWEB)

Kim, Yong-Hak [Division of Microbiology, National Center for Toxicological Research, US Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079 (United States)]. E-mail: yhkim660628@hotmail.com; Cerniglia, Carl E. [Division of Microbiology, National Center for Toxicological Research, US Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079 (United States)]. E-mail: ccerniglia@nctr.fda.gov

2005-07-01

Degradation of erythromycin A was studied using two sediment samples obtained from the salmon and trout hatchery sites at Hupp Springs (HS) and Goldendale (GD), Washington, United States. The former site had been treated for 3 years with erythromycin-medicated feed prior to the experiments, and the latter site had not been treated with any antibiotic for at least 6 years. The two sediment microcosms treated with either N-[methyl-{sup 14}C]erythromycin A or [1,3,5,7,9,11,13-{sup 14}C]erythromycin A showed S-curves for erythromycin A mineralization with a prolonged lag time of 120 days, except for GD microcosms treated with [1,3,5,7,9,11,13-{sup 14}C]erythromycin A. We proposed a simplified logistic model to interpret the mineralization curves under the assumption of the low densities of initial populations metabolizing erythromycin A. The model was helpful for knowing the biological potential for erythromycin A degradation in sediments. Although erythromycin A added to the two sediment microcosms did not significantly alter the numbers of total viable aerobic bacteria or erythromycin-resistant bacteria, it affected the bacterial composition. The influence on the bacterial composition appeared to be greater in GD microcosms without pre-exposure to antibiotics. PCR-RFLP and DNA sequence analyses of the 16S ribosomal RNA gene and the erythromycin esterase (ere) gene revealed that ereA type 2 (ereA2) was present in potentially erythromycin-degrading Pseudomonas spp. strains GD100, GD200, HS100, HS200 and HS300, isolated from erythromycin-treated and non-treated GD and HS microcosms. Erythromycin A appeared to influence the development and proliferation of strain GD200, possibly via the lateral gene transfer of ereA2.

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

Persistence of selected ammonium- and phosphonium-based ionic liquids in urban park soil microcosms

DEFF Research Database (Denmark)

Sydow, Mateusz; Szczepaniak, Zuzanna; Framski, Grzegorz

2015-01-01

Knowledge about biodegradability of ionic liquids (ILs) in terrestrial systems is limited. Here, using urban park soil microcosms spiked with either ammonium- or phosphonium-based ILs [didecyldimethylammonium 3-amino-1,2,4-triazolate, benzalkonium 3-amino-1,2,4-triazolate, trihexyl(tetradecyl)pho......Knowledge about biodegradability of ionic liquids (ILs) in terrestrial systems is limited. Here, using urban park soil microcosms spiked with either ammonium- or phosphonium-based ILs [didecyldimethylammonium 3-amino-1,2,4-triazolate, benzalkonium 3-amino-1,2,4-triazolate, trihexyl......(tetradecyl)phosphonium chloride, or trihexyl(tetradecyl)phosphonium 1,2,4-triazolate], we studied their (i) 300-day primary biodegradation, and (ii) influence on CO2 evolution from the microcosms. The primary biodegradation ranged from 21 to 33% of total compound in the dissolved phase. The evolution of CO2 from spiked...... microcosms was either lower or within the range of background soil respiration, indicating no or small mineralization of the parent compounds and/or their metabolites, and their negligible or small toxicity to soil microorganisms. Our results suggest the potential for persistence of the four studied ILs...

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 effects of a pesticide mixture on aquatic ecosystems differing in trophic status: responses of the macrophyte Myriophyllum spicatum and the periphytic algal community

NARCIS (Netherlands)

Wendt-Rasch, L.; Brink, van den P.J.; Crum, S.J.H.; Woin, P.

2004-01-01

The effects of a pesticide mixture (asulam, fluazinam, lambda-cyhalothrin, and metamitron) on aquatic ecosystems were investigated in 20 outdoor aquatic microcosms. Ten of the microcosms simulated mesotrophic aquatic ecosystems dominated by submerged macrophytes (Elodea). The others simulated

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).

Culture modes and financial evaluation of two oleaginous microalgae for biodiesel production in desert area with open raceway pond.

Science.gov (United States)

He, Qiaoning; Yang, Haijian; Hu, Chunxiang

2016-10-01

Cultivation modes of autotrophic microalgae for biodiesel production utilizing open raceway pond were analyzed in this study. Five before screened good microalgae were tested their lipid productivity and biodiesel quality again in outdoor 1000L ORP. Then, Chlorella sp. L1 and Monoraphidium dybowskii Y2 were selected due to their stronger environmental adaptability, higher lipid productivity and better biodiesel properties. Further scale up cultivation for two species with batch and semi-continuous culture was conducted. In 40,000L ORP, higher lipid productivity (5.15 versus 4.06gm(-2)d(-1) for Chlorella sp. L1, 5.35 versus 3.00gm(-2)d(-1) for M. dybowskii Y2) was achieved in semi-continuous mode. Moreover, the financial costs of 14.18$gal(-1) and 13.31$gal(-1) for crude biodiesel in two microalgae with semi-continuous mode were more economically feasible for commercial production on large scale outdoors. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

Roy, Virginie; Amyot, Marc; Carignan, Richard

2009-08-01

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

Frozen ponds

DEFF Research Database (Denmark)

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

2015-01-01

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

Inhibition of bacterial ammonia oxidation by organohydrazines in soil microcosms

Directory of Open Access Journals (Sweden)

Yucheng eWu

2012-01-01

Full Text Available Hydroxylamine oxidation by hydroxylamine oxidoreductase (HAO is a key step for energy-yielding in support of the growth of ammonia-oxidizing bacteria (AOB. Organohydrazines have been shown to inactivate HAO from Nitrosomonas europaea, and may serve as selective inhibitors to differentiate bacterial from archaeal ammonia oxidation due to the absence of bacterial HAO gene homologue in known ammonia-oxidizing archaea (AOA. In this study, the effects of three organohydrazines on activity, abundance and composition of AOB and AOA were evaluated in soil microcosms. The results indicate that phenylhydrazine and methylhydrazine at the concentration of 100 mol per gram dry weight soil completely suppressed the activity of soil nitrification. DGGE fingerprinting and sequencing analysis of bacterial ammonia monooxygenase subunit A gene (amoA clearly demonstrated that nitrification activity change is well paralleled with the growth of Nitrosomonas europaea-like AOB in soil microcosms. No significant correlation between AOA community structure and nitrification activity was observed among all treatments during the incubation period, although incomplete inhibition of nitrification activity occurred in 2-hydroxyethylhydrazine-amended soil microcosms. These findings show that the HAO-targeted organohydrazines can effectively inhibit bacterial nitrification in soil, and the mechanism of organohydrazine affecting AOA remains unclear.

Azolla-anabaena-bacteria system as a natural microcosm

Science.gov (United States)

Carrapico, Francisco J.

2002-02-01

Azolla is an aquatic fern that contains a permanent endosymbiotic prokaryotic community (cyanobacteria and bacteria) inside of the cavity in the leaf dorsal lobe of the pteridophyte. This is a unique situation and can be seen as a microcosm inside of an organism and also can be considered a good example of a living model for biological and environmental studies. These symbionts are specific of this symbiosis and lives immobilized in a mucilaginous fibrillar network, which fills part of the cavity. The symbionts works as immobilized organisms in a natural system that can be used as a model for biotechnological research and in biologically based life support systems. The nature and the complexity of this system is simultaneously a reference and a challenge for the research in the communication between the two levels of nature organization (microcosm and mesocosm), and can also be used as a reference for the design of new environmental engineered symbiotic systems that include man as a prelude to life in space.

Microcosm: Mysteries of the Universe and of computing

CERN Multimedia

2003-01-01

In the first week of December, two new exhibitions open in Microcosm: "Mysteries of the Universe" and "Computing@CERN". Ever wondered why the Universe is habitable? How many dimensions there are? Or indeed, where matter comes from? In Microcosm's new "Mysteries of the Universe" exhibition 20 CERN researchers reveal the question that intrigues them the most and why they find the search for answers so fascinating. The exhibition consists of 20 stories, told by the researchers themselves in one of 4 languages (English, French, German or Italian). Through their tales, the visitor can discover the essence of CERN - a curiosity to understand the mechanisms of a universe full of surprises, where many fundamental questions remain unresolved. With their diverse nationalities and experience, the participants reveal not only the variety of physics research underway at CERN, but also the experiments yet to come and indeed an element of the international collaboration so essential to the laboratory. In the words of on...

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.)

Fear of moving outdoors and development of outdoor walking difficulty in older people

DEFF Research Database (Denmark)

Rantakokko, Merja; Mänty, Minna; Iwarsson, Susanne

2009-01-01

To study which individual characteristics and environmental factors correlate with fear of moving outdoors and whether fear of moving outdoors predicts development of mobility limitation.......To study which individual characteristics and environmental factors correlate with fear of moving outdoors and whether fear of moving outdoors predicts development of mobility limitation....

Outdoor thermal comfort.

Science.gov (United States)

Nikolopoulou, Marialena

2011-06-01

A review of the various approaches in understanding outdoor thermal comfort is presented. The emphasis on field surveys from around the world, particularly across Europe, enables us to understand thermal perception and evaluate outdoor thermal comfort conditions. The consistent low correlations between objective microclimatic variables, subjective thermal sensation and comfort outdoors, internationally, suggest that thermophysiology alone does not adequate describe these relationships. Focusing on the concept of adaptation, it tries to explain how this influences outdoor comfort, enabling us to inhabit and get satisfaction from outdoor spaces throughout the year. Beyond acclimatization and behavioral adaptation, through adjustments in clothing and changes to the metabolic heat, psychological adaptation plays a critical role to ensure thermal comfort and satisfaction with the outdoor environment. Such parameters include recent experiences and expectations; personal choice and perceived control, more important than whether that control is actually exercised; and the need for positive environmental stimulation suggesting that thermal neutrality is not a pre-requisite for thermal comfort. Ultimately, enhancing environmental diversity can influence thermal perception and experience of open spaces.

Linking variations in sea spray aerosol particle hygroscopicity to composition during two microcosm experiments

Directory of Open Access Journals (Sweden)

S. D. Forestieri

2016-07-01

Full Text Available The extent to which water uptake influences the light scattering ability of marine sea spray aerosol (SSA particles depends critically on SSA chemical composition. The organic fraction of SSA can increase during phytoplankton blooms, decreasing the salt content and therefore the hygroscopicity of the particles. In this study, subsaturated hygroscopic growth factors at 85 % relative humidity (GF(85 % of predominately submicron SSA particles were quantified during two induced phytoplankton blooms in marine aerosol reference tanks (MARTs. One MART was illuminated with fluorescent lights and the other was illuminated with sunlight, referred to as the "indoor" and "outdoor" MARTs, respectively. Optically weighted GF(85 % values for SSA particles were derived from measurements of light scattering and particle size distributions. The mean optically weighted SSA diameters were 530 and 570 nm for the indoor and outdoor MARTs, respectively. The GF(85 % measurements were made concurrently with online particle composition measurements, including bulk composition (using an Aerodyne high-resolution aerosol mass spectrometer and single particle (using an aerosol time-of-flight mass spectrometer measurement, and a variety of water-composition measurements. During both microcosm experiments, the observed optically weighted GF(85 % values were depressed substantially relative to pure inorganic sea salt by 5 to 15 %. There was also a time lag between GF(85 % depression and the peak chlorophyll a (Chl a concentrations by either 1 (indoor MART or 3-to-6 (outdoor MART days. The fraction of organic matter in the SSA particles generally increased after the Chl a peaked, also with a time lag, and ranged from about 0.25 to 0.5 by volume. The observed depression in the GF(85 % values (relative to pure sea salt is consistent with the large observed volume fractions of non-refractory organic matter (NR-OM comprising the SSA. The GF(85 % values

Ecological effects of various toxic agents on the aquatic microcosm in comparison with acute ionizing radiation

International Nuclear Information System (INIS)

Fuma, S.; Ishii, N.; Takeda, H.; Miyamoto, K.; Yanagisawa, K.; Ichimasa, Y.; Saito, M.; Kawabata, Z.; Polikarpov, G.G.

2003-01-01

The purpose of this study was an evaluation of the effect levels of various toxic agents compared with acute doses of ionizing radiation for the experimental model ecosystem, i.e., microcosm mimicking aquatic microbial communities. For this purpose, the authors used the microcosm consisting of populations of the flagellate alga Euglena gracilis as a producer, the ciliate protozoan Tetrahymena thermophila as a consumer and the bacterium Escherichia coli as a decomposer. Effects of aluminum and copper on the microcosm were investigated in this study, while effects of γ-rays, ultraviolet radiation, acidification, manganese, nickel and gadolinium were reported in previous studies. The microcosm could detect not only the direct effects of these agents but also the community-level effects due to the interspecies interactions or the interactions between organisms and toxic agents. The authors evaluated doses or concentrations of each toxic agent which had the following effects on the microcosm: (1) no effects; (2) recognizable effects, i.e., decrease or increase in the cell densities of at least one species; (3) severe effects, i.e., extinction of one or two species; and (4) destructive effects, i.e., extinction of all species. The resulting effects data will contribute to an ecological risk assessment of the toxic agents compared with acute doses of ionizing radiation

Diurnal Thermal Behavior of Pavements, Vegetation, and Water Pond in a Hot-Humid City

Directory of Open Access Journals (Sweden)

Xiaoshan Yang

2015-12-01

Full Text Available This study investigated the diurnal thermal behavior of several urban surfaces and landscape components, including pavements, vegetation, and a water pond. The field experiment was conducted in a university campus of Guangzhou, South China, which is characterized by a hot and humid summer. The temperature of ground surface and grass leaves and the air temperature and humidity from 0.1 to 1.5 m heights were measured for a period of 24 h under hot summer conditions. The results showed that the concrete and granite slab pavements elevated the temperature of the air above them throughout the day. In contrast, the trees and the pond lowered the air temperature near ground during the daytime but produced a slight warming effect during the nighttime. The influence of vegetation on air temperature and humidity is affected by the configurations of greenery. Compared to the open lawn, the grass shaded by trees was more effective in cooling and the mixture of shrub and grass created a stronger cooling effect during the nighttime. The knowledge of thermal behavior of various urban surfaces and landscape components is an important tool for planners and designers. If utilized properly, it can lead to climatic rehabilitation in urban areas and an improvement of the outdoor thermal environment.

Effects of the antibiotic enrofloxacin on the ecology of tropical eutrophic freshwater microcosms.

Science.gov (United States)

Rico, Andreu; Dimitrov, Mauricio R; Van Wijngaarden, René P A; Satapornvanit, Kriengkrai; Smidt, Hauke; Van den Brink, Paul J

2014-02-01

The main objective of the present study was to assess the ecological impacts of the fluoroquinolone antibiotic enrofloxacin on the structure and functioning of tropical freshwater ecosystems. Enrofloxacin was applied at a concentration of 1, 10, 100 and 1,000 μg/L for 7 consecutive days in 600-L outdoor microcosms in Thailand. The ecosystem-level effects of enrofloxacin were monitored on five structural (macroinvertebrates, zooplankton, phytoplankton, periphyton and bacteria) and two functional (organic matter decomposition and nitrogen cycling) endpoint groups for 4 weeks after the last antibiotic application. Enrofloxacin was found to dissipate relatively fast from the water column (half-dissipation time: 11.7h), and about 11% of the applied dose was transformed into its main by-product ciprofloxacin after 24h. Consistent treatment-related effects on the invertebrate and primary producer communities and on organic matter decomposition could not be demonstrated. Enrofloxacin significantly affected the structure of leaf-associated bacterial communities at the highest treatment level, and reduced the abundance of ammonia-oxidizing bacteria and ammonia-oxidizing archaea in the sediments, with calculated NOECs of 10 and enrofloxacin are not likely to result in direct or indirect toxic effects on the invertebrate and primary producer communities, nor on important microbially mediated functions such as nitrification. Copyright © 2014 Elsevier B.V. All rights reserved.

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.

Effects of microcosm scaling and food resources on growth and survival of larval Culex pipiens

Directory of Open Access Journals (Sweden)

Paradise Christopher J

2001-08-01

Full Text Available Abstract Background We used a simple experimental design to test for the effects of microcosm scaling on the growth and survival of the mosquito, Culex pipiens. Microcosm and mesocosm studies are commonly used in ecology, and there is often an assumption that scaling doesn't affect experimental outcomes. The assumption is implicit in the design; choice of mesocosms may be arbitrary or based on convenience or cost. We tested the hypothesis that scale would influence larvae due to depth and surface area effects. Larvae were predicted to perform poorly in microcosms that were both deep and had small openings, due to buildup of waste products, less exchange with the environment, and increased competition. To determine if the choice of scale affected responses to other factors, we independently varied leaf litter quantity, whose effects on mosquitoes are well known. Results We found adverse effects of both a lower wall surface area and lower horizontal surface area, but microcosm scale interacted with resources such that C. pipiens is affected by habitat size only when food resources are scarce. At low resource levels mosquitoes were fewer, but larger, in microcosms with smaller horizontal surface area and greater depth than in microcosms with greater horizontal surface area and shallower depth. Microcosms with more vertical surface area/volume often produced larger mosquitoes; more food may have been available since mosquitoes browse on walls and other substrates for food. Conclusions The interaction between habitat size and food abundance is consequential to aquatic animals, and choice of scale in experiments may affect results. Varying surface area and depth causes the scale effect, with small horizontal surface area and large depth decreasing matter exchange with the surrounding environment. In addition, fewer resources leads to less leaf surface area, and the effects of varying surface area will be greater under conditions of limiting resources

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

Effects of acute {gamma}-irradiation on community structure of the aquatic microbial microcosm

Energy Technology Data Exchange (ETDEWEB)

Fuma, Shoichi, E-mail: fuma@nirs.go.j [Environmental Radiation Effects Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Ishii, Nobuyoshi; Takeda, Hiroshi [Environmental Radiation Effects Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Doi, Kazutaka; Kawaguchi, Isao [Regulatory Sciences Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Shikano, Shuichi [Center for Northeast Asian Studies, Tohoku University, 41 Kawauchi, Aoba-ku, Sendai, Miyagi 980-8576 (Japan); Tanaka, Nobuyuki [Marine Environment Section, Water and Soil Environment Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan); Inamori, Yuhei [Faculty of Symbiotic Systems Science, Fukushima University, 1 Kanayagawa, Fukushima 960-1296 (Japan)

2010-11-15

To characterise indirect effects of ionising radiation on aquatic microbial communities, effects of acute {gamma}-irradiation were investigated in a microcosm consisting of populations of green algae (Chlorella sp. and Scenedesmus sp.) and a blue-green alga (Tolypothrix sp.) as producer; a ciliate protozoan (Cyclidium glaucoma), rotifers (Lecane sp. and Philodina sp.) and an oligochaete (Aeolosoma hemprichi) as consumer; and more than four species of bacteria as decomposers. Population changes in the constituent organisms were observed over 160 days after irradiation. Prokaryotic community structure was also examined by denaturing gradient gel electrophoresis (DGGE) of 16S rDNA. Principle response curve analysis revealed that the populations of the microcosm as a whole were not significantly affected at 100 Gy while they were adversely affected at 500-5000 Gy in a dose-dependent manner. However, some effects on each population, including each bacterial population detected by DGGE, did not depend on radiation doses, and some populations in the irradiated microcosm were larger than those of the control. These unexpected results are regarded as indirect effects through interspecies interactions, and possible mechanisms are proposed originating from population changes in other organisms co-existing in the microcosm. For example, some indirect effects on consumers and decomposers likely arose from interspecies competition within each trophic level. It is also likely that prey-predator relationships between producers and consumers caused some indirect effects on producers.

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

Transfers and transformations of zinc in flow-through wetland microcosms.

Science.gov (United States)

Gillespie, W B; Hawkins, W B; Rodgers, J H; Cano, M L; Dorn, P B

1999-06-01

Two microcosm-scale wetlands (570-liter containers) were integratively designed and constructed to investigate transfers and transformations of zinc associated with an aqueous matrix, and to provide future design parameters for pilot-scale constructed wetlands. The fundamental design of these wetland microcosms was based on biogeochemical principles regulating fate and transformations of zinc (pH, redox, etc.). Each wetland consisted of a 45-cm hydrosoil depth inundated with 25 cm of water, and planted with Scirpus californicus. Zinc ( approximately 2 mg/liter) as ZnCl2 was amended to each wetland for 62 days. Individual wetland hydraulic retention times (HRT) were approximately 24 h. Total recoverable zinc was measured daily in microcosm inflow and outflows, and zinc concentrations in hydrosoil and S. californicus tissue were measured pre- and post-treatment. Ceriodaphnia dubia and Pimephales promelas7-day aqueous toxicity tests were performed on wetland inflows and outflows, and Hyalella azteca whole sediment toxicity tests (10-day) were performed pre- and post-treatment. Approximately 75% of total recoverable zinc was transferred from the water column. Toxicity decreased from inflow to outflow based on 7-day C. dubia tests, and survival of H. azteca in hydrosoil was >80%. Data illustrate the ability of integratively designed wetlands to transfer and sequester zinc from the water column while concomitantly decreasing associated toxicity. Copyright 1999 Academic Press.

Environmental effect and fate of selected phenols in aquatic ecosystems using microcosm approaches

International Nuclear Information System (INIS)

Portier, R.J.; Chen, H.M.; Meyers, S.P.

1983-01-01

Microbiological studies, together with physicochemical analyses of selected industrial source phenols of environmental significance, were conducted in continuous flow and carbon metabolism microcosms to determine the behavior of these priority pollutants in soil and sediment-water systems typical of coastal wetlands. Phenols used included 4- nitrophenol, 2,4,6-trichlorophenol, 2-chlorophenol, and phenol. The organophosphate, 14 C-UL-Methyl Parathion, was used as a benchmark toxicant control while 14 C-Ring-Phenol was employed for all phenolic compound additions. Microbial diversity, ATP, and specific enzyme systems (i.e., phosphatase, dehydrogenase) were continuously monitored along with 14 CO 2 expiration and 14 C assimilation by the cellular component. Residual analysis of all microcosm tests employed procedures using combined gas chromatography/high-performance liquid chromatography. Statistical analyses were conducted of variations of testing criteria, along with a ranking profile of relative biotransformation and biodegradation potential. Data presented confirm the validity of microcosm approaches and related correlation analysis in toxic substance fate investigations. 17 references, 6 figures, 1 table

Lakes and rivers as microcosms, version 2.0

Directory of Open Access Journals (Sweden)

David G. Jenkins

2013-08-01

Full Text Available Limnology has been greatly influenced by The Lake as a Microcosm (Forbes, 1887, which described a holistic focus on the internal machinations of singular, island-like aquatic ecosystems. I consider three persistent influences of The Lake as a Microcosm: as an organizing paradigm for the teaching of limnology relative to its practice; the idea that inland waters are like islands, and the replicability of types of inland waters. Based on inspection of recent peer-reviewed literature and 32 limnology texts, we teach limnology according to Forbes but do not practice it in that holistic context. Instead, we practice limnology as aquatic ecology. Based on novel analyses of species-area relationships for 275 inland waters and 392 islands, inland waters are more like continental habitat patches than islands; the island metaphor is poetic but not accurate. Based on a quantitative review of beta diversity (40 data sets representing 10,576 inland waters and 26 data sets representing 1529 terrestrial sites, aquatic systems are no more replicable than are terrestrial systems; a typological approach to limnology is no more justified than it is in terrestrial systems. I conclude that a former distinction between limnology and aquatic ecology no longer applies, and that we should define limnology as the ecology of inland waters. Also, we should not consider lakes and rivers as islands that represent other systems of the same type, but should consider them as open, interactive habitat patches that vary according to their geology and biogeography. I suggest modern limnology operates according to 3 paradigms, which combine to form 3 broad limnological disciplines and establish a basis for a plural, interactive view of lakes and rivers as microcosms. This model of modern limnology may help better connect it to ecology and biogeography and help limnology be even more relevant to science and society.

Survival study of enterotoxigenic Escherichia colistrain in seawater and wastewater microcosms.

Science.gov (United States)

Boukef Ben Omrane, I; El Bour, M; Mejri, S; Mraouna, R; Got, P; Troussellier, M; Boudabous, A

2011-01-01

In order to survey osmotic and oligotrophic stress consequence on pathogenic enterobacteria discharged in marine areas, we examined enterotoxigenic Escherichia coli (ETEC) and a reference (Ecoli O126:B16) strains during their survival (47 days) in wastewater microcosms, submerged in natural seawater and maintained in laboratory conditions. The results revealed that the survival time for the two strains was prolonged when bacterial cells were previously incubated in wastewater, with less cellular membrane damage. In addition, the wild clinical E. coli strain showed a better survival capacity than the reference E. coli strain one. For both, we noted some modifications in biochemical profiles relatively to the initial state, notably when they were previously incubated in wastewater microcosm.

Effects of Lactobacillus rhamnosus GG on saliva-derived microcosms

NARCIS (Netherlands)

Pham, L.C.; Hoogenkamp, M.A.; Exterkate, R.A.M.; Terefework, Z.; de Soet, J.J.; ten Cate, J.M.; Crielaard, W.; Zaura, E.

2011-01-01

Objective The probiotic strain Lactobacillus rhamnosus GG (LGG) is shown to hamper the presence of mutans streptococci in saliva and may have positive effects on oral health. We investigated the effects of LGG on the cariogenic potential and microbial composition of saliva-derived microcosms. Design

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

Outdoor Classrooms

Science.gov (United States)

Mayes, Valynda

2010-01-01

An outdoor classroom is the ideal vehicle for community involvement: Parents, native plant societies, 4-H, garden clubs, and master naturalists are all resources waiting to be tapped, as are local businesses offering support. If you enlist your community in the development and maintenance of your outdoor classroom, the entire community will…

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)

This summer, go behind-the-scenes of CERN in photos in the Microcosm

CERN Multimedia

2016-01-01

Find out the best photos of the 2015 CERN Photowalk competition in the Microcosm.   Photo: Olivier Miche. The best photos taken at the 2015 CERN Photowalk competition are now exhibited in the Microcosm, for the whole summer period. Through this photographic exhibition, the visitors will be taken behind-the scenes of CERN, through the main workshop, the ISOLDE facility and the future accelerator Linac 4. They will also take a glimpse of the life on the CERN campus.

Walden Pond, Massachusetts: Environmental Setting and Current Investigations

Science.gov (United States)

Colman, John A.; Waldron, Marcus C.

1998-01-01

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

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

International Nuclear Information System (INIS)

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

1996-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-12-31

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

The refreezing of melt ponds on Arctic sea ice

Science.gov (United States)

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

2015-02-01

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

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…

Evaluation of terrestrial microcosms for detection, fate, and survival analysis of genetically engineered microorganisms and their recombinant genetic material

Energy Technology Data Exchange (ETDEWEB)

Fredrickson, J.K.; Seidler, R.J.

1989-02-01

The research included in this document represents the current scientific information available regarding the applicability of terrestrial microcosms and related methodologies for evaluating detection methods and the fate and survival of microorganisms in the environment. The three terrestrial microcosms described in this document were used to evaluate the survival and fate of recombinant bacteria in soils and in association with plant surfaces and insects and their transport through soil with percolating water and root systems, and to test new methods and procedures to improve detection and enumeration of bacteria in soil. Simple (potting soil composed of peat mix and perlite, lacking environmental control and monitoring) and complex microcosms (agricultural soil with partial control and monitoring of environmental conditions) were demonstrated to be useful tools for preliminary assessments of microbial viability in terrestrial ecosystems. These studies evaluated the survival patterns of Enterobacter cloacae (pBR322) in soil and on plant surfaces and the ingestion of this same microorganism by cutworms and survival in the foregut and frass. The Versacore microcosm design was used to monitor the fate and competitiveness of genetically engineered bacteria in soil. Both selective media and gene probes were used successfully to follow the fate of two recombinant Pseudomonas sp. introduced into Versacore microcosms. Intact soil-core microcosms were employed to evaluate the fate and transport of genetically altered Azospirillum sp. and Pseudomonas sp. in soil and the plant rhizosphere. The usefulness of these various microcosms as a tool for risk assessment is underscored by the ease in obtaining soil from a proposed field release site to evaluate subsequent GEM fate and survival.

Pond of Illusion: Interacting through Mixed Reality

DEFF Research Database (Denmark)

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

2013-01-01

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

The color of melt ponds on Arctic sea ice

Science.gov (United States)

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

2018-04-01

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

Examining Water Quality Variations of Tidal Pond System

Science.gov (United States)

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

2014-12-01

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

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

Science.gov (United States)

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

2016-01-01

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

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.

Fear of moving outdoors and development of outdoor walking difficulty in older people.

Science.gov (United States)

Rantakokko, Merja; Mänty, Minna; Iwarsson, Susanne; Törmäkangas, Timo; Leinonen, Raija; Heikkinen, Eino; Rantanen, Taina

2009-04-01

To study which individual characteristics and environmental factors correlate with fear of moving outdoors and whether fear of moving outdoors predicts development of mobility limitation. Observational prospective cohort study and cross-sectional analyses. Community and research center. Seven hundred twenty-seven community-living people aged 75 to 81 were interviewed at baseline, of whom 314 took part in a 3.5-year follow-up. Fear of moving outdoors and its potential individual and environmental correlates were assessed at baseline. Perceived difficulties in walking 0.5 km and 2 km were assessed twice a year over a 3.5-year period. At baseline, 65% of the women and 29% of the men reported fear of moving outdoors. Poor socioeconomic status; musculoskeletal diseases; slow walking speed; and the presence of poor street conditions, hills in the nearby environment, and noisy traffic correlated with fear of moving outdoors. At the first 6-month follow-up, participants with fear of moving outdoors had more than four times the adjusted risk (odds ratio (OR)=4.6, 95% confidence interval (CI)=1.92-11.00) of developing difficulties in walking 0.5 km and a three times greater adjusted risk (OR=3.10, 95% CI=1.49-6.46) for developing difficulty in walking 2 km compared with those without fear. The difference in the prevalence of walking difficulties remained statistically significant over the 3.5-year follow-up (P=.02 and P=.009, respectively). Fear of moving outdoors is common in older adults and increases the risk of developing self-reported difficulties in walking 0.5 km and 2 km. Knowledge about individual and environmental factors underlying fear of moving outdoors and finding ways to alleviate fear of moving outdoors are important for community planning and prevention of disability.

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

Evaluation of terrestrial microcosms for assessing the fate and effects of genetically engineered microorganisms on ecological processes

Energy Technology Data Exchange (ETDEWEB)

Fredrickson, J.K.; Bentjen, S.A.; Bolton, H. Jr.; Li, S.W.; Ligotke, M.W.; McFadden, K.M.; Van Voris, P.

1989-04-01

This project evaluates and modifies the existing US Environmental Protection Agency's Office of Pesticides and Toxic Substances (EPA/OPTS) terrestrial microcosm test system and test protocols such that they can be used to determine the environmental fate and ecological hazards of genetically engineered microorganisms (GEMs). The intact soil-core microcosm represents terrestrial ecosystems, and when coupled with appropriate test protocols, such microcosms may be appropriate to define and limit risks associated with the intentional release of GEMs. The terrestrial microcosm test system was used to investigate the survival and transport of two model GEMs (Azospirillum lipoferum and Pseudomonas sp. Tn5 mutants) to various trophic levels and niches and through intact soil cores. Subsequent effects on nutrient cycling and displacement of indigenous microorganisms were evaluated. The model organisms were a diazotrophic root-colonizing bacterium (A. lipoferum) and a wheat root growth-inhibiting rhizobacterium (Pseudomonas sp.). The transposable element Tn5 was used as a genetic marker for both microorganisms in two separate experiments. The organisms were subjected to transposon mutagenesis using a broad host-range-mobilizable suicide plasmid. The transposon Tn5 conferred levels of kanamycin resistance up to 500 ..mu..g/ml (Pseudomonas sp.), which allowed for selection of the bacteria from environmental samples. The presence of Tn5 DNA in the genome of the model GEMs also allowed the use of Tn5 gene probes to confirm and enumerate the microorganisms in different samples from the microcosms. Two types of root growth-inhibiting Pseudomonas sp. Tn5 mutants were obtained and used in microcosm studies: those that lacked the ability to inhibit either wheat root growth or the growth of other microorganisms in vitro (tox/sup /minus//) and those which retained these properties (tox/sup +/). 53 refs., 7 figs., 6 tabs.

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

Chromium Resistant Bacteria: Impact on Plant Growth in Soil Microcosm

Directory of Open Access Journals (Sweden)

Sayel Hanane

2014-07-01

Full Text Available Three chromium resistant bacterial strains, Pseudomonas fluorescens PF28, Enterobacter amnigenus EA31 and Enterococcus gallinarum S34 isolated from tannery waste contaminated soil were used in this study. All strains could resist a high concentration of K2Cr2O7 that is up to 300 mg/L. The effect of these strains on clover plants (Trifolium campestre in the presence of two chromium salts CrCl3 and K2Cr2O7 was studied in soil microcosm. Application of chromium salts adversely affected seed germination, root and shoot length. Bacterial inoculation improved the growth parameters under chromate stress when compared with non inoculated respective controls. There was observed more than 50% reduction of Cr(VI in inoculated soil microcosms, as compared to the uninoculated soil under the same conditions. The results obtained in this study are significant for the bioremediation of chromate pollution.

Biodegradation of weathered polystyrene films in seawater microcosms

OpenAIRE

Syranidou, Evdokia; Karkanorachaki, Katerina; Amorotti, Filippo; Franchini, Martina; Repouskou, Eftychia; Kaliva, Maria; Vamvakaki, Maria; Kolvenbach, Boris; Fava, Fabio; Corvini, Philippe F.-X.; Kalogerakis, Nicolas

2017-01-01

A microcosm experiment was conducted at two phases in order to investigate the ability of indigenous consortia alone or bioaugmented to degrade weathered polystyrene (PS) films under simulated marine conditions. Viable populations were developed on PS surfaces in a time dependent way towards convergent biofilm communities, enriched with hydrocarbon and xenobiotics degradation genes. Members of Alphaproteobacteria and Gammaproteobacteria were highly enriched in the acclimated plastic associate...

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

Comparison of an assay for Dehalococcoides DNA and a microcosm study in predicting reductive dechlorination of chlorinated ethenes in the field

International Nuclear Information System (INIS)

Lu Xiaoxia; Wilson, John T.; Kampbell, Donald H.

2009-01-01

The study aims to compare the detection of 16S rRNA gene of Dehalococcoides species and the microcosm study for biotransformation in predicting reductive dechlorination of chlorinated ethenes in ground water at hazardous waste sites. A total of 72 ground water samples were collected from 12 PCE or TCE contaminated sites in the United States. The samples were analyzed and used to construct microcosms in the laboratory. The results showed that the presence of Dehalococcoides DNA was well associated with dechlorination to ethene in the field. Nearly half of the wells where Dehalococcoides DNA was detected had ethene as a dechlorination end product. In comparison, for ground water samples of 16 wells where ethene was detected, ethene was produced in 11 of the corresponding microcosms. For most microcosms, during two years of incubation, dechlorination was less extensive than that observed in the field. - Positive results of the assay for Dehalococcoides DNA and the microcosm study may suggest that reductive dechlorination is occurring in the field

Valuing Multiple Benefits, and the Public Perception of SUDS Ponds

Directory of Open Access Journals (Sweden)

Joy Jarvie

2017-02-01

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

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

Science.gov (United States)

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

2018-01-01

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

Impact of triphenyltin acetate in microcosms simulating floodplain lakes. II. Comparison of species sensitivity distributions between laboratory and semi-field.

Science.gov (United States)

Roessink, I; Belgers, J D M; Crum, S J H; van den Brink, P J; Brock, T C M

2006-07-01

The study objectives were to shed light on the types of freshwater organism that are sensitive to triphenyltin acetate (TPT) and to compare the laboratory and microcosm sensitivities of the invertebrate community. The responses of a wide array of freshwater taxa (including invertebrates, phytoplankton and macrophytes) from acute laboratory Single Species Tests (SST) were compared with the concentration-response relationships of aquatic populations in two types of freshwater microcosms. Representatives of several taxonomic groups of invertebrates, and several phytoplankton and vascular plant species proved to be sensitive to TPT, illustrating its diverse modes of toxic action. Statistically calculated ecological risk thresholds (HC5 values) based on 96 h laboratory EC50 values for invertebrates were 1.3 microg/l, while these values on the basis of microcosm-Species Sensitivity Distributions (SSD) for invertebrates in sampling weeks 2-8 after TPT treatment ranged from 0.2 to 0.6 microg/l based on nominal peak concentrations. Responses observed in the microcosms did not differ between system types and sampling dates, indicating that ecological threshold levels are not affected by different community structures including taxa sensitive to TPT. The laboratory-derived invertebrate SSD curve was less sensitive than the curves from the microcosms. Possible explanations for the more sensitive field response are delayed effects and/or additional chronic exposure via the food chain in the microcosms.

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.

Turismo Activo y Outdoor Training: Metodología. (Adventure Sport Tourism and Outdoor Training: Methodology.

Directory of Open Access Journals (Sweden)

Vicente Gómez Encinas

2008-10-01

Full Text Available ResumenUno de los aspectos más atractivos que tiene el outdoor training es su supuesta capacidad para conseguir que los aprendizajes obtenidos a través de sus actividades sean transferidos a otros ámbitos de la vida personal y profesional de sus participantes. En este sentido, la clave está en la metodología empleada. Este artículo profundiza en las fases que estructuran el proceso formativo del outdoor training describiendo: 1 las bases folosóficas que lo apoyan y que están expresadas en la teoría de la “educación a través de la experiencia” y 2 las diferentes fases que estructuran el proceso de formación de un outdoor, haciendo una descripción en profundidad de cada una de ellas: a Pre-Outdoor (Análisis y valoración de las necesidades, diseño de la actividad y reunión previa a la actividad, b Outdoor, c Post-outdoor (Reflexión y transferencia, y d Seguimiento posterior.AbstractOne of the most attractive aspects that has the outdoor training is their supposed capacity to get that the learnings obtained through their activities are transferred to other environments of the personal life and their participants' professional. In this sense, the key is in the used methodology. This article deepens in the phases that structure the formative process of the outdoor training describing: 1 the philosophy´s bases that support this process and that are expressed in the theory of experiential education, and 2 the different phases that structure the process of formation of an outdoor, making a description in depth of each one of them: to Pre-Outdoor (Analysis and valuation of the necessities, design of the activity and previous meeting to the activity, b Outdoor, c Post-outdoor (Reflection and transfer, and d Later Pursuit.

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

Chlordecone fate and mineralisation in a tropical soil (andosol) microcosm under aerobic conditions

Energy Technology Data Exchange (ETDEWEB)

Fernández-Bayo, Jesus D., E-mail: fernanje@supagro.inra.fr [IRD, UMR LISAH Bât 24, 2 Place Viala, 34060 Montpellier cedex 1 (France); INRA, UMR LISAH Bât 24, 2 Place Viala, 34060 Montpellier cedex 1 (France); Saison, Carine [IRD, UMR LISAH Bât 24, 2 Place Viala, 34060 Montpellier cedex 1 (France); Voltz, Marc [INRA, UMR LISAH Bât 24, 2 Place Viala, 34060 Montpellier cedex 1 (France); Disko, Ulrich; Hofmann, Diana; Berns, Anne E. [Forschungszentrum Jülich GmbH, IBG 3, 52425 Jülich (Germany)

2013-10-01

Chlordecone is a persistent organochlorine insecticide that, even decades after its ban, poses a threat to the environment and human health. Nevertheless, its environmental fate in soils has scarcely been investigated, and elementary data on its degradation and behaviour in soil are lacking. The mineralisation and sorption of chlordecone and the formation of possible metabolites were evaluated in a tropical agricultural andosol. Soil microcosms with two different soil horizons (S-A and S-B) were incubated for 215 days with {sup 14}C-chlordecone. At five different times (1, 33, 88, 150 and 215 days) the extractability of {sup 14}C-chlordecone was analysed. Mineralisation was monitored using {sup 14}CO{sub 2} traps of NaOH. The appearance of metabolites was studied using thin layer and gas chromatography techniques. At the end of the experiment, the water soluble {sup 14}C-activity was 2% of the remaining {sup 14}C-chlordecone for S-A and 8% for S-B. Only 12% of the remaining activity was non extractable and more than 80% remained extractable with organic solvents. For the first time to our knowledge, a significant mineralisation of chlordecone was measured in a microcosm under aerobic conditions (4.9% for S-A and 3.2% for S-B of the initial {sup 14}C-activity). The drastically lower emission of {sup 14}CO{sub 2} in sterilised microcosms indicated the biological origin of chlordecone mineralisation in the non-sterilised microcosms. No metabolites could be detected in the soil extracts. The mineralisation rate of chlordecone decreased by one order of magnitude throughout the incubation period. Thus, the chlordecone content in the soil remained large. This study confirms the existence of chlordecone degrading organisms in a tropical andosol. The reasons why their activity is restricted should be elucidated to allow the development of bioremediation approaches. Possible reasons are a heterogeneous distribution a chlordecone between sub-compartments with different

Chlordecone fate and mineralisation in a tropical soil (andosol) microcosm under aerobic conditions

International Nuclear Information System (INIS)

Fernández-Bayo, Jesus D.; Saison, Carine; Voltz, Marc; Disko, Ulrich; Hofmann, Diana; Berns, Anne E.

2013-01-01

Chlordecone is a persistent organochlorine insecticide that, even decades after its ban, poses a threat to the environment and human health. Nevertheless, its environmental fate in soils has scarcely been investigated, and elementary data on its degradation and behaviour in soil are lacking. The mineralisation and sorption of chlordecone and the formation of possible metabolites were evaluated in a tropical agricultural andosol. Soil microcosms with two different soil horizons (S-A and S-B) were incubated for 215 days with 14 C-chlordecone. At five different times (1, 33, 88, 150 and 215 days) the extractability of 14 C-chlordecone was analysed. Mineralisation was monitored using 14 CO 2 traps of NaOH. The appearance of metabolites was studied using thin layer and gas chromatography techniques. At the end of the experiment, the water soluble 14 C-activity was 2% of the remaining 14 C-chlordecone for S-A and 8% for S-B. Only 12% of the remaining activity was non extractable and more than 80% remained extractable with organic solvents. For the first time to our knowledge, a significant mineralisation of chlordecone was measured in a microcosm under aerobic conditions (4.9% for S-A and 3.2% for S-B of the initial 14 C-activity). The drastically lower emission of 14 CO 2 in sterilised microcosms indicated the biological origin of chlordecone mineralisation in the non-sterilised microcosms. No metabolites could be detected in the soil extracts. The mineralisation rate of chlordecone decreased by one order of magnitude throughout the incubation period. Thus, the chlordecone content in the soil remained large. This study confirms the existence of chlordecone degrading organisms in a tropical andosol. The reasons why their activity is restricted should be elucidated to allow the development of bioremediation approaches. Possible reasons are a heterogeneous distribution a chlordecone between sub-compartments with different microbial activities or a degradation of

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.

Transition in the fractal geometry of Arctic melt ponds

Directory of Open Access Journals (Sweden)

C. Hohenegger

2012-10-01

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

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

International Nuclear Information System (INIS)

Kelty, G.G.

1993-01-01

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

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...

9 CFR 3.27 - Facilities, outdoor.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Facilities, outdoor. 3.27 Section 3.27... Pigs and Hamsters Facilities and Operating Standards § 3.27 Facilities, outdoor. (a) Hamsters shall not be housed in outdoor facilities. (b) Guinea pigs shall not be housed in outdoor facilities unless...

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.

Influence of sediment on the fate and toxicity of a polyethoxylated tallowamine surfactant system (MON 0818) in aquatic microcosms

Science.gov (United States)

Wang, N.; Besser, J.M.; Buckler, D.R.; Honegger, J.L.; Ingersoll, C.G.; Johnson, B. Thomas; Kurtzweil, M.L.; MacGregor, J.; McKee, M.J.

2005-01-01

The fate and toxicity of a polyethoxylated tallowamine (POEA) surfactant system, MON 0818, was evaluated in water–sediment microcosms during a 4-d laboratory study. A surfactant solution of 8 mg l−1 nominal concentration was added to each of nine 72-l aquaria with or without a 3-cm layer of one of two natural sediments (total organic carbon (TOC) 1.5% or 3.0%). Control well water was added to each of nine additional 72-l aquaria with or without sediment. Water samples were collected from the microcosms after 2, 6, 24, 48, 72, and 96 h of aging to conduct 48-h toxicity tests with Daphnia magna and to determine surfactant concentrations. Elevated mortality of D. magna (43–83%) was observed in overlying water sampled from water-only microcosms throughout the 96-h aging period, whereas elevated mortality (23–97%) was only observed in overlying water sampled from water–sediment microcosms during the first 24 h of aging. Measured concentrations of MON 0818 in water-only microcosms remained relatively constant (4–6 mg l−1) during the 96-h period, whereas the concentrations in overlying water from microcosms containing either of the two types of sediment dissipated rapidly, with half-lives of 13 h in the 3.0% TOC sediment and 18 h in the 1.5% TOC sediment. Both toxicity and the concentration of MON 0818 in overlying water decreased more rapidly in microcosms containing sediment with the higher percent TOC and clay and with a higher microbial biomass. Mortality of D. magna was significantly correlated with surfactant concentrations in the overlying water. These results indicate that the toxicity of the POEA surfactant in water rapidly declines in the presence of sediment due to a reduction in the surfactant concentration in the overlying water above the sediment.

Outdoor recreational use of the Salton Sea with reference to potential impacts of geothermal development

Energy Technology Data Exchange (ETDEWEB)

Twiss, R.; Sidener, J.; Bingham, G.; Burke, J.E.

1978-04-01

The objectives of this study were to describe the types, levels, and locations of outdoor recreation uses in the Salton Sea area, the number and principal activities of visitors, and to estimate the consequences upon outdoor recreation of geothermal development and other activities that might affect the Salton Sea. It is concluded that since the Salton Sea is considered legally to be a sump for agricultural, municipal, and presumably geothermal waste waters, recreational use of the Sea for fishing and boating (from present marinas) will undoubtedly continue to decline, unless there is a major policy change. Use of the shoreline for camping, the surrounding roads and lands for scenic viewing, ORV events, and retirement or recreation communities will not decline, and will probably increase, assuming control of hydrogen sulfide odors. Two ways in which the fishing and present boating facilities could be returned to a wholly usable steady state are discussed. One is by construction of a diked evaporation pond system at the south end of the Sea. This would allow a means of control over both water level and salinity. Another means, less costly but more difficult to effectively control, would be to budget geothermal plant use of, and disposal of wastes in, Salton Sea water. (JGB)

Outdoor Education and Science Achievement

Science.gov (United States)

Rios, José M.; Brewer, Jessica

2014-01-01

Elementary students have limited opportunities to learn science in an outdoor setting at school. Some suggest this is partially due to a lack of teacher efficacy teaching in an outdoor setting. Yet the research literature indicates that outdoor learning experiences develop positive environmental attitudes and can positively affect science…

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

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

Directory of Open Access Journals (Sweden)

James W. LaBaugh

2018-06-01

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

Molecular analysis of microbial community structures in pristine and contaminated aquifers--Field and laboratory microcosm experiments

Science.gov (United States)

Shi, Y.; Zwolinski, M.D.; Schreiber, M.E.; Bahr, J.M.; Sewell, G.W.; Hickey, W.J.

1999-01-01

Molecular Analysis of Microbial Community Structures in Pristine and Contaminated Aquifers: Field and Laboratory Microcosm Experimentsvar callbackToken='531E8ACDB6C8511'; var subCode='asmjournal_sub'; var OAS_sitepage = 'aem.asm.org'; This study used phylogenetic probes in hybridization analysis to (i) determine in situ microbial community structures in regions of a shallow sand aquifer that were oxygen depleted and fuel contaminated (FC) or aerobic and noncontaminated (NC) and (ii) examine alterations in microbial community structures resulting from exposure to toluene and/or electron acceptor supplementation (nitrate). The latter objective was addressed by using the NC and FC aquifer materials for anaerobic microcosm studies in which phylogenetic probe analysis was complemented by microbial activity assays. Domain probe analysis of the aquifer samples showed that the communities were predominantlyBacteria; Eucarya and Archaea were not detectable. At the phylum and subclass levels, the FC and NC aquifer material had similar relative abundance distributions of 43 to 65% β- and γ-Proteobacteria (B+G), 31 to 35% α-Proteobacteria (ALF), 15 to 18% sulfate-reducing bacteria, and 5 to 10% high G+C gram positive bacteria. Compared to that of the NC region, the community structure of the FC material differed mainly in an increased abundance of B+G relative to that of ALF. The microcosm communities were like those of the field samples in that they were predominantly Bacteria (83 to 101%) and lacked detectable Archaea but differed in that a small fraction (2 to 8%) of Eucarya was detected regardless of the treatment applied. The latter result was hypothesized to reflect enrichment of anaerobic protozoa. Addition of nitrate and/or toluene stimulated microbial activity in the microcosms, but only supplementation of toluene alone significantly altered community structures. For the NC material, the dominant subclass shifted from B+G to ALF, while in the FC microcosms 55 to 65

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.

Short-term emissions of ammonia and carbon dioxide from cattle urine contaminated tropical grassland microcosm.

Science.gov (United States)

Majumdar, Deepanjan; Patel, Manoj; Drabar, Reena; Vyas, Manish

2006-11-01

The study was designed to understand the emissions of ammonia (NH(3)) and carbon dioxide (CO(2)) from a single cattle urination event on a tropical grassland and underline the significance of the emissions in the context of huge animal population grazing on large pasture areas in some countries. Emissions of ammonia (NH(3)) and carbon dioxide (CO(2)) were monitored for three weeks from a tropical grassland (dominated by Cynodon dactylon Pers.) microcosm contaminated with cow and buffalo urine. The grassland microcosms were treated with urine (50 and 100 ml of each) only once and irrigated with water once every week. Ammonia was sampled by an automatic sampling system comprising of a vacuum pump, three-way stopcocks and rubber tubing and an impinger containing suitable absorbing solution (H(2)SO(4)), connected to the tubing suitably. The sampled gas, after sucked by the vacuum pump and absorbed in H(2)SO(4), was allowed to enter the closed microcosm again maintaining internal pressure of the microcosm. Carbon dioxide was sampled by absorption in an alkali (NaOH) trap inside the microcosm. Both NH(3) and CO(2) emissions were highly variable temporally and there was no continuous increasing or decreasing emission trend with time. Respectively, 45 and 46% of total NH(3)-N were emitted within first 48 h from 50 and 100 ml cow urine application while the corresponding values for buffalo urine were 34 and 32%. Total NH(3)-N emissions, integrated for sampling days (i.e. 1, 2, 3, 4, 6, 15, 18 and 21st) were 11 and 6% in cow and 8 and 5% in buffalo urine, of the total-N added through 50 and 100 ml urine samples. Carbon dioxide emissions were standardized at 25 degrees C by using a suitable formula which were lower than actual emissions at actual soil temperature (> 25 degrees C). Carbon dioxide emission rates were classified on the basis of soil repiratory classification and classes ranged from moderately low soil activity up to unusually high soil activity, the latter

Outdoorsman: Outdoor Cooking.

Science.gov (United States)

Alberta Dept. of Agriculture, Edmonton.

This Outdoor Cookery manual provides information and instruction on the basic outdoor skills of building suitable cooking fires, handling fires safely, and storing food. The necessity of having the right kind of fire is stressed (high flames for boiling, low for stewing, and coals for frying and broiling). Tips on gauging temperature, what types…

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%.

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

Outdoor smoking behaviour and support for outdoor smoking restrictions before and after France's national smoking ban.

Science.gov (United States)

Kennedy, Ryan David; Behm, Ilan; Craig, Lorraine; Thompson, Mary E; Fong, Geoffrey T; Guignard, Romain; Beck, Francois

2012-02-01

On January 1, 2008, the French government implemented a national ban on indoor smoking in hospitality venues. Survey results indicate the indoor ban has been successful at dramatically reducing indoor smoking; however, there are reports of an increased number of outdoor hospitality spaces (patios) where smoking can take place. This study sought to understand if the indoor ban simply moved smoking to the outdoors, and to assess levels of support for smoking restrictions in outdoor hospitality settings after the smoke-free law. Telephone interviews were conducted among 1067 adult smokers before and after the 2008 indoor ban as part of the International Tobacco Control (ITC) France Survey. Among other topics, this survey measures how the smoking ban has influenced smoking behaviour relevant to outdoor sections of hospitality venues. In addition, 414 non-smoking adults and 164 respondents who had quit smoking between waves were also asked about support for outdoor smoking restrictions. Reported smoking outdoors at cafés/pubs/bars increased from 33.6% of smokers at Wave 1 to 75.9% at Wave 2. At restaurants, smoking outdoors increased from 28.9% to 59.0%. There was also an increase in reported non-smoking for both visits to cafés/pubs/bars, and restaurants from 13.4% to 24.7%, and 30.4% to 40.8% respectively. The majority of smokers (74.5%), non-smokers (89.4%) and quitters (74.0%) support a partial or complete ban on smoking in outdoor areas of restaurants. The indoor smoking ban moved smoking to outdoor spaces; however, the ban is also associated with increased non-smoking behaviour. The majority of respondents support outdoor smoking restrictions in patio environments.

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...

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.

The Contribution of Outdoor Recreation and Outdoor Education to the Economy of Scotland: Case Studies and Preliminary Findings.

Science.gov (United States)

Higgins, Peter

2000-01-01

Outdoor recreation and education contribute substantially to the Scottish economy. Outdoor recreation generates considerable tourism income, much of it in rural areas, and also extends the traditional tourist season. Outdoor education centers are significant employers in certain rural areas. In addition, "therapeutic" outdoor programs…

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.

Evaluated fate and effects of atrazine and lambda-cyhalothrin in vegetated and unvegetated microcosms.

Science.gov (United States)

Bouldin, J L; Farris, J L; Moore, M T; Smith, S; Stephens, W W; Cooper, C M

2005-10-01

Contaminants such as nutrients, metals, and pesticides can interact with constructed wetlands and existing drainage ditches used as agricultural best-management practices. Our research has shown that the presence of macrophytes and a hydrologic regime aid in the transfer and transformation of pesticides associated with agricultural runoff. This study consisted of application of both atrazine (triazine herbicide) and lambda-cyhalothrin (pyrethroid insecticide) to vegetated and unvegetated microcosms in order to measure the fate and effects of pesticides applied at suggested field application rates. Exposures focused on monocultures of Ludwigia peploides (water primrose) and Juncus effusus (soft rush). Pesticide sorption was evident through concentrations of atrazine and lambda-cyhalothrin in plant tissue as high as 2461.4 and 86.50 microg/kg, respectively. Toxicity was measured in water from unvegetated microcosms for 28 days and in Chironomus tentans (midge larvae) exposed to sediment collected from 3 h to 56 days in microcosms receiving the pesticide combination. The comparative survival of test organisms in this study suggests that effective mitigation of pesticides from runoff can depend on the macrophyte contact and vegetative attributes associated with ditches. (c) 2005 Wiley Periodicals, Inc.

Predicting outdoor sound

CERN Document Server

Attenborough, Keith; Horoshenkov, Kirill

2014-01-01

1. Introduction  2. The Propagation of Sound Near Ground Surfaces in a Homogeneous Medium  3. Predicting the Acoustical Properties of Outdoor Ground Surfaces  4. Measurements of the Acoustical Properties of Ground Surfaces and Comparisons with Models  5. Predicting Effects of Source Characteristics on Outdoor Sound  6. Predictions, Approximations and Empirical Results for Ground Effect Excluding Meteorological Effects  7. Influence of Source Motion on Ground Effect and Diffraction  8. Predicting Effects of Mixed Impedance Ground  9. Predicting the Performance of Outdoor Noise Barriers  10. Predicting Effects of Vegetation, Trees and Turbulence  11. Analytical Approximations including Ground Effect, Refraction and Turbulence  12. Prediction Schemes  13. Predicting Sound in an Urban Environment.

The effects of short term exposure to Bass Strait crude oil and Corexit 8667 on benthic community metabolism in Posidonia australis Hook. f. dominated microcosms

Energy Technology Data Exchange (ETDEWEB)

Hatcher, A.I.; Larkum, A.W.D.

1982-03-01

Microcosms consisting of a sublittoral seagrass meadow from Botany Bay, N.S.W. were maintained in aquaria in a controlled environment room from March to August 1979. Oxygen production and consumption in the microcosms and leaf turnover of the seagrass, Posidonia australis Hook.f. were measured before, during and after a 7-day treatment in June with Bass Strait crude oil and the dispersant Corexit 8667. Four microcosms received oil and two of these received dispersant. The leaf turnover of P. australis was not significantly affected by the addition of oil and dispersant. Photosynthetic oxygen production decreased and respiration increased in the microcosms during treatment. In August, 40 days after treatment, oxygen production rates and P/R ratios in the oil-treated microcosms were higher than rates measured before treatment. The oil-and-dispersant-treated microcosms did not show this trend. The results of this study indicate that a more severe stress is placed on the P. australis dominated benthic community by oil and dispersant than by oil alone.

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.

Tetracyclines and tetracycline resistance in agricultural soils: microcosm and field studies.

NARCIS (Netherlands)

Schmitt, Heike; Stoob, Krispin; Hamscher, Gerd; Smit, Eric; Seinen, Willem

2006-01-01

The influence of the use of antibiotics on the prevalence of resistance genes in the environment is still poorly understood. We studied the diversity of tetracycline and sulfonamide resistance genes as influenced by fertilization with pig manure in soil microcosms and at two field locations. Manure

A lake as a microcosm: reflections on developments in aquatic ecology

DEFF Research Database (Denmark)

Hansson, Lars-Anders; Brodersen, Jakob; Chapman, Ben B.

2013-01-01

and still is, specially since it touches upon almost all aspects of the lake ecosystem, from individual behaviour to food web interactions and environmental issues. Therefore, there is no doubt that even if 125 years have passed, Forbes’ paper still is a source of inspiration and deserves to be read. Hence......In the present study, we aim at relating Forbes’ remarkable paper on ‘‘The lake as a microcosm’’, published 125 years ago, to the present status of knowledge in our own research group. Hence, we relate the observations Forbes made to our own microcosm, Lake Krankesjo¨n in southern Sweden, that has...... that lakes are more isolated than many other biomes, but have, indeed, many extensions, for example, input from the catchment, fishing and fish migration. We also conclude that irrespective of whether lakes should be viewed as microcosms or not, the paper by Forbes has been exceptionally influential...

Formal education in outdoor studies: introduction

OpenAIRE

Prince, Heather

2015-01-01

Regional cultural perspectives involve outdoor studies in different ways in formal curricula. This section focuses on Western Europe, particularly the UK and Scandinavia, although also has a more international reach in Backman’s consideration of the training of teachers and in place-responsive teaching as described by Mannion and Lynch. ‘Outdoor studies’ is not seen in curricula per se but under various more specialised aspects such as outdoor play, outdoor learning, environmental education, ...

The Cost of Becoming an Outdoor Instructor.

Science.gov (United States)

Cashel, Chris

This article describes instructor criteria in three outdoor organizations: Outward Bound (OB), the National Outdoor Leadership School (NOLS), and the Wilderness Education Association (WEA). Common requirements for outdoor leadership programs are outdoor experience and skills, advanced first aid, CPR, and a minimum age requirement. Traditionally…

Thermal evolutions of two kinds of melt pond with different salinity

Science.gov (United States)

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

2016-04-01

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

Enhancing Ecoefficiency in Shrimp Farming through Interconnected Ponds

Directory of Open Access Journals (Sweden)

Ramón Héctor Barraza-Guardado

2015-01-01

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

First description of underwater acoustic diversity in three temperate ponds

Directory of Open Access Journals (Sweden)

Camille Desjonquères

2015-11-01

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

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

Science.gov (United States)

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

2017-08-01

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

Curriculum Development in Outdoor Education: Tasmanian Teachers' Perspectives on the New Pre-Tertiary Outdoor Leadership Course

Science.gov (United States)

Dyment, Janet; Morse, Marcus; Shaw, Simon; Smith, Heidi

2014-01-01

The paper examines how outdoor education teachers in Tasmania, Australia have implemented and perceive a new pre-tertiary Outdoor Leadership curriculum document. It draws on an analysis of in-depth semi-structured interviews with 11 outdoor education teachers. The results revealed that teachers were generally welcoming of the new higher-order…

Molecular Analysis of Microbial Community Structures in Pristine and Contaminated Aquifers: Field and Laboratory Microcosm Experiments

Science.gov (United States)

Shi, Y.; Zwolinski, M. D.; Schreiber, M. E.; Bahr, J. M.; Sewell, G. W.; Hickey, W. J.

1999-01-01

This study used phylogenetic probes in hybridization analysis to (i) determine in situ microbial community structures in regions of a shallow sand aquifer that were oxygen depleted and fuel contaminated (FC) or aerobic and noncontaminated (NC) and (ii) examine alterations in microbial community structures resulting from exposure to toluene and/or electron acceptor supplementation (nitrate). The latter objective was addressed by using the NC and FC aquifer materials for anaerobic microcosm studies in which phylogenetic probe analysis was complemented by microbial activity assays. Domain probe analysis of the aquifer samples showed that the communities were predominantly Bacteria; Eucarya and Archaea were not detectable. At the phylum and subclass levels, the FC and NC aquifer material had similar relative abundance distributions of 43 to 65% β- and γ-Proteobacteria (B+G), 31 to 35% α-Proteobacteria (ALF), 15 to 18% sulfate-reducing bacteria, and 5 to 10% high G+C gram positive bacteria. Compared to that of the NC region, the community structure of the FC material differed mainly in an increased abundance of B+G relative to that of ALF. The microcosm communities were like those of the field samples in that they were predominantly Bacteria (83 to 101%) and lacked detectable Archaea but differed in that a small fraction (2 to 8%) of Eucarya was detected regardless of the treatment applied. The latter result was hypothesized to reflect enrichment of anaerobic protozoa. Addition of nitrate and/or toluene stimulated microbial activity in the microcosms, but only supplementation of toluene alone significantly altered community structures. For the NC material, the dominant subclass shifted from B+G to ALF, while in the FC microcosms 55 to 65% of the Bacteria community was no longer identifiable by the phylum or subclass probes used. The latter result suggested that toluene exposure fostered the proliferation of phylotype(s) that were otherwise minor constituents of the

Special Education: A Microcosm of Bureaucracy. Part Two: The Elements of the System

Science.gov (United States)

Clark, Ann D.

1971-01-01

Delineates a case study of special education that provides a unique microcosm of the emergence of an educational subsystem with inherent and forceful bureaucratic controls that were present from its inception. (Author)

Outdoor schools: Limits and dilemmas

Directory of Open Access Journals (Sweden)

Irena Smetáčková

2011-12-01

Full Text Available Outdoor school is a stable element of Czech educational system. However,many changes have occurred during the last twenty years in the purposes of outdoorschools and in their organization. The article presents various school statistics andresults of research which included questionnaire survey in elementary schools in Pragueand a case study of two classes. The study found that the outdoor school programmesare getting shorter, budgets for outdoor schools are reduced, and prices of outdoorschool programmes for parents are increasing. Because of high prices, almost 20 % ofpupils cannot attend outdoor schools. Nevertheless, according to teachers, pupils andparents, the main purpose of outdoor school programmes is to create a better socialclimate in peer groups. Because of high rates of absence, this goal is partly invalid.Another purpose should be that teachers and children get to know each other better.This goal is invalid as well because many schools hire commercial agencies which limitsthe time that pupils and teachers spend together.

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

Definition: Conservation Education, Environmental Education, Outdoor Education.

Science.gov (United States)

1970

Conservation education, outdoor education, and environmental education all have as a common goal the understanding and appreciation of the natural world. Outdoor education is a method of teaching wherein established disciplines, topics, and concepts which can best be taught outdoors are taught outdoors. Conservation education is the study of man's…

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....

Definitions of Outdoor Recreation and Other Associated Terminology.

Science.gov (United States)

Phipps, Maurice L.

This document defines terms related to outdoor recreation: (1) outdoor recreation includes activities that occur outdoors in an urban and man-made environment as well as those activities traditionally associated with the natural environment; (2) outdoor education is education in, about, and for the outdoors; (3) environmental education is an…

A microcosm for the breeding of plants under controlled conditions

International Nuclear Information System (INIS)

D'Aquino, Luigi; Maglione, Maria Grazia; Minarini, Carla; Pandolfi Giuseppe; Lanza, Bruno; Atrigna, Mauro; De Filippo, Giovanni; Giannotta, Giovanni; Pedicini Antonio; Aprano Salvatore

2015-01-01

In order to enhance studies of the effects of multiple stress on plant physiology laboratory scale, in collaboration with FOS Srl and Sesmat Srl and the project application for organic PON02 0 0556 3 420580 «SMARTAGS-SMARt TAGS 'was conceived, designed and built a 'microcosm for the breeding of plants under biotic and abiotic stress conditioning '. [it

Outdoor Leadership Skills: A Program Perspective

Science.gov (United States)

Shooter, Wynn; Sibthorp, Jim; Paisley, Karen

2009-01-01

Successful hiring, training, and pairing or grouping of staff requires administrators to consider the relationship between their programs' goals and the specific outdoor leadership skills of individual leaders. Authors have divided outdoor leadership skills into a three-category structure, and models of outdoor leadership have focused on skills…

Artificial soil microcosms: a tool for studying microbial autecology under controlled conditions.

Science.gov (United States)

Ellis, Richard J

2004-02-01

A novel artificial microcosm containing all the essential chemical components of soil, but with reduced heterogeneity and biological complexity, has been developed. Its utility for supporting realistic microbial populations was demonstrated and an example of how competing bacteria can be studied is illustrated.

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.

The Dirt on Outdoor Classrooms.

Science.gov (United States)

Rich, Steve

2000-01-01

Explains the planning procedure for outdoor classrooms and introduces an integrated unit on monarch butterflies called the Monarch Watch program. Makes recommendations to solve financial problems of outdoor classrooms. (YDS)

A review of virus removal in wastewater treatment pond systems.

Science.gov (United States)

Verbyla, Matthew E; Mihelcic, James R

2015-03-15

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

9 CFR 3.52 - Facilities, outdoor.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Facilities, outdoor. 3.52 Section 3.52 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL... outdoors when the atmospheric temperature falls below 40 °F. (d) Protection from predators. Outdoor housing...

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

Directory of Open Access Journals (Sweden)

Natali Ortiz Perea

2017-05-01

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

Abundance and activity of oil-degrading and indigenous bacteria in sediment microcosms

International Nuclear Information System (INIS)

Araujo, R.; Molina, M.; Bachoon, D.

1995-01-01

The responses of bacterial community composition and degradation crude oil to applications of bioremediation products and plant detrital material were investigated in wetlands microcosms. The microcosms were constructed of sieved sediments and operated as tidal marshes. Products included nutrients, organisms, surfactants and combinations thereof; dried ground Spartina was the source of detrital material. Plate count and most probable-number techniques were used to enumerate microbial populations and GC/MS analysis of indicator petroleum hydrocarbons was used to assess oil degradation. Microbial communities were characterized by whole-genome hybridization and specific probes for bacterial groups, including Pseudomonas, Streptomycetes, Vibrio, and sulfate-reducing bacteria. Although the total microbial numbers were similar in all bioremediation treatments, the numbers of oil degraders increased two to three log units in the fertilizer and microbial-degrader-enriched treatments. Oil-degraders comprised the largest fraction of the total population in the treatment amended with microbial degraders, apparently at the expense of indigenous bacteria, as indicated by specific probes. Oil-degraders were also detected in the subsurface in all treatments except the controls. The extent of oil degradation was not consistent with bacterial numbers; only nutrient additions resulted in significantly enhanced degradation of oil. After 1 month of microcosm operation, oil-degraders had increased at least two orders of magnitude in sediment surface layers when oil was added alone or with Spartina detritus, although total bacterial numbers and the number of oil-degraders decreased to near initial levels by 2 months. The peak coincides with bacterial utilization of the alkane fraction of petroleum hydrocarbons

Bioremediation of 1,2-dichloroethane contaminated groundwater: Microcosm and microbial diversity studies

International Nuclear Information System (INIS)

Wang, S.Y.; Kuo, Y.C.; Huang, Y.Z.; Huang, C.W.; Kao, C.M.

2015-01-01

In this study, the effectiveness of bioremediating 1,2-dichloroethane (DCA)-contaminated groundwater under different oxidation–reduction processes was evaluated. Microcosms were constructed using indigenous bacteria and activated sludge as the inocula and cane molasses and a slow polycolloid-releasing substrate (SPRS) as the primary substrates. Complete DCA removal was obtained within 30 days under aerobic and reductive dechlorinating conditions. In anaerobic microcosms with sludge and substrate addition, chloroethane, vinyl chloride, and ethene were produced. The microbial communities and DCA-degrading bacteria in microcosms were characterized by 16S rRNA-based denatured-gradient-gel electrophoresis profiling and nucleotide sequence analyses. Real-time polymerase chain reaction was applied to evaluate the variations in Dehalococcoides spp. and Desulfitobacterium spp. Increase in Desulfitobacterium spp. indicates that the growth of Desulfitobacterium might be induced by DCA. Results indicate that DCA could be used as the primary substrate under aerobic conditions. The increased ethene concentrations imply that dihaloelimination was the dominate mechanism for DCA biodegradation. - Highlights: • DCA can be used as the primary substrate and degraded by the indigenous microbial consortia. • Reductive dechlorination of DCA can be enhanced by the supplement of substrates and sludge. • Dihaloelimination is the dominant mechanism for DCA dechlorination and ethene is the end product. • SPRS can serve as the primary substrate and creates anaerobic conditions for DCA dechlorination. • Reductive dechlorination is a feasible option for DCA-contaminated groundwater remediation. - DCA can serve as the primary substrate and degraded by indigenous bacteria aerobically. Dihaloelimination is the dominant mechanism and ethene is the end product via dechlorination

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. 

Influence of Coal Ash Leachates and Emergent Macrophytes on Water Quality in Wetland Microcosms

Data.gov (United States)

U.S. Environmental Protection Agency — Influence of Coal Ash Leachates and Emergent Macrophytes on Water Quality in Wetland Microcosms. This dataset is associated with the following publication: Olson,...

Continuous Hydrologic and Water Quality Monitoring of Vernal Ponds.

Science.gov (United States)

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

2017-11-13

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

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

Science.gov (United States)

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

2017-09-01

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

FROM PONDS TO MAN-MADE SEAS IN RUSSIA

Directory of Open Access Journals (Sweden)

Sergey Gorshkov

2013-01-01

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

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

Science.gov (United States)

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

2010-07-01

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

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

International Nuclear Information System (INIS)

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

2015-01-01

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

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

Science.gov (United States)

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

2017-08-01

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

Factors Influencing TCE Anaerobic Dechlorination Investigated via Simulations of Microcosm Experiments

Science.gov (United States)

Mao, X.; Harkness, M.; Lee, M. D.; Mack, E. E.; Dworatzek, S.; Acheson, C.; McCarty, P.; Barry, D. A.; Gerhard, J. I.

2006-12-01

SABRE (Source Area BioREmediation) is a public-private consortium whose charter is to determine if enhanced anaerobic bioremediation can result in effective and quantifiable treatment of chlorinated solvent DNAPL source areas. The focus of this 4-year, $5.7 million research project is a field site in the United Kingdom containing a TCE DNAPL source area. In preparation, a microcosm study was performed to determine the optimal combination of factors to support reductive dechlorination of TCE in site soil and groundwater. The study consisted of 168 bottles distributed between four laboratories (Dupont, GE, SiREM, and Terra Systems) and tested the impact of six carbon substrates (lactate, acetate, methanol, SRS (soybean oil), hexanol, butyl acetate), bioaugmentation with KB-1 bacterial culture, three TCE levels (100 mg/L, 400 mg/L, and 800 mg/L) and two sulphate levels (200 mg/L, >500 mg/L) on TCE dechlorination. This research presents a numerical model designed to simulate the main processes occurring in the microcosms, including substrate fermentation, sequential dechlorination, toxic inhibition, and the influence of sulphate concentration. In calibrating the model to over 60 of the microcosm experiments, lumped parameters were employed to quantify the effect of key factors on the conversion rate of each chlorinated ethene in the TCE degradation sequence. Results quantify the benefit (i.e., increased stepwise dechlorination rate) due to both bioaugmentation and the presence of higher sulphate concentrations. Competitive inhibition is found to increase in significance as TCE concentrations increase; however, inclusion of Haldane inhibition is not supported. Over a wide range of experimental conditions and dechlorination steps, SRS appears to induce relatively little hydrogen limitation, thereby facilitating relatively quick conversion of TCE to ethene. In general, hydrogen limitation is found to increase with increasing TCE concentration and with bioaugmentation, and

Mercury decreases culturability of Pseudomonas frederiksbergensis JAJ 28 in soil microcosms

DEFF Research Database (Denmark)

Johnsen, Kaare; Ekelund, Flemming; Binnerup, Svend J.

2003-01-01

Mercury is a biologically potent heavy metal, which has been found to change the diversity of culturable bacteria. Therefore, we investigated whether Hg kills bacteria in soil or reduces culturability. Soil microcosms were inoculated with Pseudomonas frederiksbergensis JAJ 28 and were sampled...... into account when studying the effects of heavy metals on bacterial diversity....

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

International Nuclear Information System (INIS)

Halverson, N.V.

1999-01-01

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

Seasonality of dipteran-mediated methylmercury flux from ponds.

Science.gov (United States)

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

2018-03-12

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

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

Science.gov (United States)

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

2018-01-01

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

Monthly and diurnal variations of limnological conditions of two ponds

Directory of Open Access Journals (Sweden)

AKM Fazlur Rahaman

2017-06-01

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

A mathematical procedure to estimate solar absorptance of shallow water ponds

International Nuclear Information System (INIS)

Wu Hongbo; Tang Runsheng; Li Zhimin; Zhong Hao

2009-01-01

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

Let's Walk Outdoors! Self-Paced Walking Outdoors Improves Future Intention to Exercise in Women With Obesity.

Science.gov (United States)

Krinski, Kleverton; Machado, Daniel G S; Lirani, Luciana S; DaSilva, Sergio G; Costa, Eduardo C; Hardcastle, Sarah J; Elsangedy, Hassan M

2017-04-01

In order to examine whether environmental settings influence psychological and physiological responses of women with obesity during self-paced walking, 38 women performed two exercise sessions (treadmill and outdoors) for 30 min, where oxygen uptake, heart rate, ratings of perceived exertion, affect, attentional focus, enjoyment, and future intentions to walk were analyzed. Physiological responses were similar during both sessions. However, during outdoor exercise, participants displayed higher externally focused attention, positive affect, and lower ratings of perceived exertion, followed by greater enjoyment and future intention to participate in outdoor walking. The more externally focused attention predicted greater future intentions to participate in walking. Therefore, women with obesity self-selected an appropriate exercise intensity to improve fitness and health in both environmental settings. Also, self-paced outdoor walking presented improved psychological responses. Health care professionals should consider promoting outdoor forms of exercise to maximize psychological benefits and promote long-term adherence to a physically active lifestyle.

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.)

Vernalophrys algivore gen. nov., sp. nov. (Rhizaria: Cercozoa: Vampyrellida), a New Algal Predator Isolated from Outdoor Mass Culture of Scenedesmus dimorphus.

Science.gov (United States)

Gong, Yingchun; Patterson, David J; Li, Yunguang; Hu, Zixuan; Sommerfeld, Milton; Chen, Yongsheng; Hu, Qiang

2015-06-15

Microbial contamination is the main cause of loss of biomass yield in microalgal cultures, especially under outdoor environmental conditions. Little is known about the identities of microbial contaminants in outdoor mass algal cultures. In this study, a new genus and species of vampyrellid amoeba, Vernalophrys algivore, is described from cultures of Scenedesmus dimorphus in open raceway ponds and outdoor flat-panel photobioreactors. This vampyrellid amoeba was a significant grazer of Scenedesmus and was frequently associated with a very rapid decline in algal numbers. We report on the morphology, subcellular structure, feeding behavior, molecular phylogeny, and life cycle. The new amoeba resembles Leptophrys in the shape of trophozoites and pseudopodia and in the mechanism of feeding (mainly by engulfment). It possesses two distinctive regions in helix E10_1 (nucleotides 117 to 119, CAA) and E23_1 (nucleotides 522 and 523, AG) of the 18S rRNA gene. It did not form a monophyletic group with Leptophrys in molecular phylogenetic trees. We establish a new genus, Vernalophrys, with the type species Vernalophrys algivore. The occurrence, impact of the amoeba on mass culture of S. dimorphus, and means to reduce vampyrellid amoeba contamination in Scenedesmus cultures are addressed. The information obtained from this study will be useful for developing an early warning system and control measures for preventing or treating this contaminant in microalgal mass cultures. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

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

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

The effects of high-tannin leaf litter from transgenic poplars on microbial communities in microcosm soils.

Directory of Open Access Journals (Sweden)

Richard S. Winder

2013-09-01

Full Text Available The impacts of leaf litter from genetically-modified hybrid poplar accumulating high levels of condensed tannins (proanthocyanidins were examined in soil microcosms consisting of moss growing on sieved soil. Moss preferentially proliferated in microcosms with lower tannin content; DGGE detected increased fungal diversity in microcosms with low-tannin litter. The proportion of cloned rDNA sequences from Actinobacteria decreased with litter addition while Bacteroidetes, Chloroflexi, Cyanobacteria, and α-Proteobacteria significantly increased. β–Proteobacteria were proportionally more numerous at high tannin levels. Tannins had no significant impact on overall diversity of bacterial communities analyzed with various estimators. There was an increased proportion of N-fixing bacteria corresponding to the addition of litter with low tannin levels. The addition of litter increased the proportion of Ascomycota/Basidiomycota. Dothideomycetes, Pucciniomycetes, and Tremellomycetes also increased and Agaricomycetes decreased. Agaricomycetes and Sordariomycetes were significantly more abundant in controls, whereas Pucciniomycetes increased in soil with litter from transformed trees (P = 0.051. Richness estimators and diversity indices revealed no significant difference in the composition of fungal communities; PCoA partitioned the fungal communities into three groups: (i those with higher amounts of added tannin from both transformed and untransformed treatments, (ii those corresponding to soils without litter, and (iii those corresponding to microcosms with litter added from trees transformed only with a β-glucuronidase (GUS control vector. While the litter from transformed poplars had significant effects on soil microbe communities, the observed impacts reflected known impacts on soil processes associated with tannins, and were similar to changes that would be expected from natural variation in tannin levels.

The effects of high-tannin leaf litter from transgenic poplars on microbial communities in microcosm soils.

Science.gov (United States)

Winder, Richard S; Lamarche, Josyanne; Constabel, C Peter; Hamelin, Richard C

2013-01-01

The impacts of leaf litter from genetically modified hybrid poplar accumulating high levels of condensed tannins (proanthocyanidins) were examined in soil microcosms consisting of moss growing on sieved soil. Moss preferentially proliferated in microcosms with lower tannin content; DGGE (denaturing gradient gel electrophoresis) detected increased fungal diversity in microcosms with low-tannin litter. The proportion of cloned rDNA sequences from Actinobacteria decreased with litter addition while Bacteroidetes, Chloroflexi, Cyanobacteria, and α-Proteobacteria significantly increased. β-Proteobacteria were proportionally more numerous at high-tannin levels. Tannins had no significant impact on overall diversity of bacterial communities analyzed with various estimators. There was an increased proportion of N-fixing bacteria corresponding to the addition of litter with low-tannin levels. The addition of litter increased the proportion of Ascomycota/Basidiomycota. Dothideomycetes, Pucciniomycetes, and Tremellomycetes also increased and Agaricomycetes decreased. Agaricomycetes and Sordariomycetes were significantly more abundant in controls, whereas Pucciniomycetes increased in soil with litter from transformed trees (P = 0.051). Richness estimators and diversity indices revealed no significant difference in the composition of fungal communities; PCoA (principal coordinate analyses) partitioned the fungal communities into three groups: (i) those with higher amounts of added tannin from both transformed and untransformed treatments, (ii) those corresponding to soils without litter, and (iii) those corresponding to microcosms with litter added from trees transformed only with a β-glucuronidase control vector. While the litter from transformed poplars had significant effects on soil microbe communities, the observed impacts reflected known impacts on soil processes associated with tannins, and were similar to changes that would be expected from natural variation in

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

Directory of Open Access Journals (Sweden)

Mehmet ÖZKAYMAK

2004-01-01

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

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

Directory of Open Access Journals (Sweden)

Queiroz Julio Ferraz de

2004-01-01

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

Treatment of pond sludge at the Rocky Flats Plant

International Nuclear Information System (INIS)

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

1992-01-01

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

Microbial degradation of street dust polycyclic aromatic hydrocarbons in microcosms simulating diffuse pollution of urban soil

DEFF Research Database (Denmark)

Johnsen, Anders R; de Lipthay, Julia R; Sørensen, Søren J

2006-01-01

Diffuse pollution with polycyclic aromatic hydrocarbons (PAHs) of topsoil in urban regions has caused increasing concerns in recent years. We simulated diffuse pollution of soil in microcosms by spiking sandy topsoil (A-horizon) and coarse, mineral subsoil (C-horizon) with street dust (PM63...... for the persistence and low bioaccessibility of 5- and 6-ring PAHs in diffusely polluted soil.......) isolated from municipal street sweepings from central Copenhagen. The microbial communities adapted to PAH degradation in microcosms spiked with street dust in both A-horizon and C-horizon soils, in spite of low PAH-concentrations. The increased potential for PAH degradation was demonstrated on several...

A combined microcosm and mesocosm approach to examine factors affecting survival and mortality of Pseudomonas fluorescens Ag1 in seawater

DEFF Research Database (Denmark)

Ahl, Thomas; Christoffersen, K.; Riemann, B.

1995-01-01

.5‰). In microcosms with 0.2 µm-filtered seawater, addition of a carbon + nitrogen + phosphorus nutrient mixture was needed to induce proliferation of Ag1. In nutrient-amended microcosms the Ag1 population maintained viability, as determined by the direct viable counts method, at a level close to 100%. In natural...

Interconnected ponds operation for flood hazard distribution

Science.gov (United States)

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

2016-05-01

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

Validation Hydrodynamic Models of Three Topological Models of Secondary Facultative Ponds

OpenAIRE

Aponte-Reyes Alxander

2014-01-01

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

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

Science.gov (United States)

Walter, Donald A.; Masterson, John P.

2011-01-01

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

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

Directory of Open Access Journals (Sweden)

Т. Hryhorenko

2017-09-01

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

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)

Reducing indoor residential exposures to outdoor pollutants

Energy Technology Data Exchange (ETDEWEB)

Sherman, Max H.; Matson, Nance E.

2003-07-01

The basic strategy for providing indoor air quality in residences is to dilute indoor sources with outdoor air. This strategy assumes that the outdoor air does not have pollutants at harmful levels or that the outdoor air is, at least, less polluted than the indoor air. When this is not the case, different strategies need to be employed to ensure adequate air quality in the indoor environment. These strategies include ventilation systems, filtration and other measures. These strategies can be used for several types of outdoor pollution, including smog, particulates and toxic air pollutants. This report reviews the impacts that typical outdoor air pollutants can have on the indoor environment and provides design and operational guidance for mitigating them. Poor quality air cannot be used for diluting indoor contaminants, but more generally it can become an indoor contaminant itself. This paper discusses strategies that use the building as protection against potentially hazardous outdoor pollutants, including widespread pollutants, accidental events, and potential attacks.

OUTDOOR EDUCATION AND GEOGRAPHICAL EDUCATION

Directory of Open Access Journals (Sweden)

ANDREA GUARAN

2016-01-01

Full Text Available This paper focuses on the reflection on the relationship between values and methodological principles of Outdoor Education and spatial and geographical education perspectives, especially in pre-school and primary school, which relates to the age between 3 and 10 years. Outdoor Education is an educational practice that is already rooted in the philosophical thought of the 16th and the 17th centuries, from John Locke to Jean-Jacques Rousseau, and in the pedagogical thought, in particular Friedrich Fröbel, and it has now a quite stable tradition in Northern Europe countries. In Italy, however, there are still few experiences and they usually do not have a systematic and structural modality, but rather a temporarily and experimentally outdoor organization. In the first part, this paper focuses on the reasons that justify a particular attention to educational paths that favour outdoors activities, providing also a definition of outdoor education and highlighting its values. It is also essential to understand that educational programs in open spaces, such as a forest or simply the schoolyard, surely offers the possibility to learn geographical situations. Therefore, the question that arises is how to finalize the best stimulus that the spatial location guarantees for the acquisition of knowledge, skills and abilities about space and geography.

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.

Impact of triphenyltin acetate in microcosms simulating floodplain lakes; II comparison of species sensitivity distributions between laboratory and semi-field

OpenAIRE

Roessink, I.; Belgers, J.D.M.; Crum, S.J.H.; Brink, van den, P.J.; Brock, T.C.M.

2006-01-01

The study objectives were to shed light on the types of freshwater organism that are sensitive to triphenyltin acetate (TPT) and to compare the laboratory and microcosm sensitivities of the invertebrate community. The responses of a wide array of freshwater taxa (including invertebrates, phytoplankton and macrophytes) from acute laboratory Single Species Tests (SST) were compared with the concentration¿response relationships of aquatic populations in two types of freshwater microcosms. Repres...

Benchmarking Outdoor Expeditionary Program Risk Management Strategies

Science.gov (United States)

Meerts-Brandsma, Lisa; Furman, Nate; Sibthorp, Jim

2017-01-01

In 2003, the University of Utah and the National Outdoor Leadership School (NOLS) completed a study that developed a risk management taxonomy in the outdoor adventure industry and assessed how different outdoor expeditionary programs (OEPs) managed risk (Szolosi, Sibthorp, Paisley, & Gookin, 2003). By unifying the language around risk, the…

Hinterbrand Lodge Outdoor Education Center. Program Information.

Science.gov (United States)

Dependents Schools (DOD), Washington, DC. European Area.

Describing Department of Defense Dependents Schools Europe (DODDSEUR) use of Hinterbrand Lodge Outdoor Education Center, this document is directed to sponsors wishing to take groups to Hinterbrand for one or more of the five program options (outdoor education week, teacher weekend, school-designed outdoor education program, administrative faculty…

Heat recovery from ground below the solar pond

NARCIS (Netherlands)

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

2017-01-01

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

Mathematical modeling of dissolved oxygen in fish ponds ...

African Journals Online (AJOL)

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

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

International Nuclear Information System (INIS)

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

1984-01-01

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

THERMAL AND OXYGEN CONDITIONS IN CARP PONDS DURING THE SUMMER PERIOD

Directory of Open Access Journals (Sweden)

Magdalena Wiśnios

2015-11-01

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

Effects of lambda-cyhalothrin in two ditch microcosm systems of different trophic status

NARCIS (Netherlands)

Roessink, I.; Arts, G.H.P.; Belgers, J.D.M.; Bransen, F.F.J.; Maund, S.J.; Brock, T.C.M.

2005-01-01

The fate and effects of the pyrethroid insecticide lambda-cyhalothrin were compared in mesotrophic (macrophyte-dominated) and eutrophic (phytoplankton-dominated) ditch microcosms (0.5 m3). Lambda-cyhalothrin was applied three times at one-week intervals at concentrations of 10, 25, 50, 100, and 250

A Phenomenology of Outdoor Education Leader Experiences

Science.gov (United States)

Field, Stephanie C.; Lauzon, Lara L.; Meldrum, John T.

2016-01-01

Limited qualitative research exists on the experiences of outdoor education leaders. The purpose of this phenomenological study was to explore the job-related experiences of outdoor education leaders within and outside the workplace. Five participants who had experience as outdoor education leaders completed in-depth, one-on-one interviews about…

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…

Outdoor Education: Definition and Philosophy.

Science.gov (United States)

Ford, Phyllis

Because outdoor education programs occur in every geographic location, are sponsored by all levels of educational institutions, state and local government agencies, and private entrepreneurs, and have no nationally standardized curriculum or measures of competency or knowledge, outdoor education may best be defines as "education in, about, and for…

Sea Ice Melt Pond Data from the Canadian Arctic

Data.gov (United States)

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

Ecological behavior of plutonium and americium in a freshwater pond

International Nuclear Information System (INIS)

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

1976-01-01

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

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

Science.gov (United States)

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

2018-06-01

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

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

International Nuclear Information System (INIS)

Bozkurt, Ismail; Karakilcik, Mehmet

2015-01-01

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

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

Science.gov (United States)

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

2017-02-01

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

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

Dental plaque microcosm biofilm behavior on calcium phosphate nanocomposite with quaternary ammonium.

Science.gov (United States)

Cheng, Lei; Weir, Michael D; Zhang, Ke; Wu, Eric J; Xu, Sarah M; Zhou, Xuedong; Xu, Hockin H K

2012-08-01

Half of dental restorations fail in 10 years, with secondary caries as the main reason. Calcium phosphate composites could remineralize tooth lesions. The objectives of this study were to: (1) impart antibacterial activity to a composite with nanoparticles of amorphous calcium phosphate (NACP); and (2) investigate the effect of quaternary ammonium dimethacrylate (QADM) on mechanical and dental plaque microcosm biofilm properties for the first time. The NACP and glass particles were filled into a dental resin that contained bis(2-methacryloyloxy-ethyl) dimethyl-ammonium bromide, the QADM. NACP nanocomposites containing 0%, 7%, 14%, and 17.5% of QADM by mass, respectively, were photo-cured. A commercial composite with no antibacterial activity was used as control. Mechanical properties were measured in three-point flexure. A human saliva microcosm model was used to grow biofilms on composites. Live/dead assay, metabolic activity, colony-forming unit (CFU) counts, and lactic acid production of biofilms on the composites were measured. Increasing QADM mass fraction monotonically reduced the biofilm viability, CFU and lactic acid. Biofilms on NACP nanocomposite with 17.5% QADM had metabolic activity that was 30% that on a commercial composite control (pbacterial cells with normal short-rod shapes, while some cells on NACP-QADM nanocomposites disintegrated into pieces. Adding QADM to NACP did not decrease the composite strength and elastic modulus, which matched (p>0.1) those of a commercial composite without Ca-PO(4) or antibacterial activity. A dental plaque microcosm model was used to evaluate the novel NACP-QADM nanocomposite. The nanocomposite greatly reduced the biofilm viability, metabolic activity and lactic acid, while its mechanical properties matched those of a commercial composite. NACP-QADM nanocomposite with calcium phosphate fillers, good mechanical properties and a strong antibacterial activity may have potential for anti-biofilm and anti

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

International Nuclear Information System (INIS)

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

2014-01-01

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

Evaluation of relocation of unionid mussels into artificial ponds

Science.gov (United States)

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

2001-01-01

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

Fate of Pyrethroids in Farmland Ponds

DEFF Research Database (Denmark)

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

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

Thermal performance measurements on ultimate heat sinks--cooling ponds

International Nuclear Information System (INIS)

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

1977-12-01

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

Position Statement on Active Outdoor Play.

Science.gov (United States)

Tremblay, Mark S; Gray, Casey; Babcock, Shawna; Barnes, Joel; Bradstreet, Christa Costas; Carr, Dawn; Chabot, Guylaine; Choquette, Louise; Chorney, David; Collyer, Cam; Herrington, Susan; Janson, Katherine; Janssen, Ian; Larouche, Richard; Pickett, William; Power, Marlene; Sandseter, Ellen Beate Hansen; Simon, Brenda; Brussoni, Mariana

2015-06-08

A diverse, cross-sectorial group of partners, stakeholders and researchers, collaborated to develop an evidence-informed Position Statement on active outdoor play for children aged 3-12 years. The Position Statement was created in response to practitioner, academic, legal, insurance and public debate, dialogue and disagreement on the relative benefits and harms of active (including risky) outdoor play. The Position Statement development process was informed by two systematic reviews, a critical appraisal of the current literature and existing position statements, engagement of research experts (N=9) and cross-sectorial individuals/organizations (N=17), and an extensive stakeholder consultation process (N=1908). More than 95% of the stakeholders consulted strongly agreed or somewhat agreed with the Position Statement; 14/17 participating individuals/organizations endorsed it; and over 1000 additional individuals and organizations requested their name be listed as a supporter. The final Position Statement on Active Outdoor Play states: "Access to active play in nature and outdoors--with its risks--is essential for healthy child development. We recommend increasing children's opportunities for self-directed play outdoors in all settings--at home, at school, in child care, the community and nature." The full Position Statement provides context for the statement, evidence supporting it, and a series of recommendations to increase active outdoor play opportunities to promote healthy child development.

Quantitative survival of Leptospira interrogans in soil and water microcosms.

Science.gov (United States)

Casanovas-Massana, Arnau; Pedra, Gabriel Ghizzi; Wunder, Elsio A; Diggle, Peter J; Begon, Mike; Ko, Albert I

2018-04-27

Leptospira interrogans is the etiological agent of leptospirosis, a globally distributed zoonotic disease. Human infection usually occurs through skin exposure with water and soil contaminated with the urine of chronically infected animals. In this study, we aimed to quantitatively characterize the survival of Leptospira interrogans serovar Copenhageni in environmental matrices. We constructed laboratory microcosms to simulate natural conditions and determined the persistence of DNA markers in soil, mud, spring water and sewage using a qPCR and a PMA-qPCR assay. We found that L. interrogans does not survive at high concentrations in the tested matrices. No net growth was detected in any of the experimental conditions and in all cases the concentration of the DNA markers targeted decreased from the beginning of the experiment following an exponential decay with a decreasing decay rate over time. After 12 and 21 days of incubation the spiked concentration of 10 6 L. interrogans cells/mL or g decreased to approximately 100 cells/mL or g in soil and spring water microcosms, respectively. Furthermore, culturable L. interrogans persisted at concentrations under the limit of detection by PMA-qPCR or qPCR for at least 16 days in soil and 28 days in spring water. Altogether our findings suggest that the environment is not a multiplication reservoir, but a temporary carrier of the L. interrogans Copenhageni, although the observed prolonged persistence at low concentrations may still enable the transmission of the disease. IMPORTANCE Leptospirosis is a zoonotic disease caused by spirochetes of the genus Leptospira that primarily affects impoverished populations worldwide. Although leptospirosis is transmitted by contact with water and soil, little is known about the ability of the pathogen to survive in the environment. In this study, we quantitatively characterized the survival of L. interrogans in environmental microcosms and found that although it cannot multiply in water

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.

Outdoor Acoustics as a General Discipline

DEFF Research Database (Denmark)

Rasmussen, Karsten Bo

1999-01-01

A tutorial paper exploring the characteristics of sound outdoors. Outdoor acoustics is contrasted to room acoustics. A number of important aspects of outdoor acoustics are exemplified and theoretical approaches are outlined. These are influence of ground impedance, influence of weather, screening...... to the application in question. In this way results providing a certain level of accuracy are obtained using methods which are balanced with the accuracy of the input data. Advanced measurement techniques are looked into and suggestions for future research are made...

Group Cooperation in Outdoor Education

Science.gov (United States)

Matthews, Bruce E.

1978-01-01

Utilizing the Beatles' Yellow Submarine fantasy (e.g., the Blue Meanies), this outdoor education program is designed for sixth graders and special education students. Activities developed at the Cortland Resident Outdoor Education Camp include a series of group stress/challenge activities to be accomplished by everyone in the group, as a group.…

Disturbance promotes non-indigenous bacterial invasion in soil microcosms

DEFF Research Database (Denmark)

Liu, Manqiang; Strandmark, Lisa Bjørnlund; Rønn, Regin

2012-01-01

Invasion-biology is largely based on non-experimental observation of larger organisms. Here, we apply an experimental approach to the subject. By using microbial-based microcosm-experiments, invasion-biology can be placed on firmer experimental, and hence, less anecdotal ground. A better...... understanding of the mechanisms that govern invasion-success of bacteria in soil communities will provide knowledge on the factors that hinder successful establishment of bacteria artificially inoculated into soil, e.g. for remediation purposes. Further, it will yield valuable information on general principles...... of invasion biology in other domains of life....

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.

Effects of substrate type and arsenic dosage level on arsenic behavior in grassland microcosms. Part I. Preliminary results on 74As transport

International Nuclear Information System (INIS)

Draggan, S.

1977-01-01

Microcosm design is an important factor in interpreting results obtained from studies of the environmental effects, mobility and persistence of contaminants. The behavior of pentavalent arsenic and a radioarsenic tracer was studied in three substrate types exposed to differing levels of stable As dosage. Soil cores excised intact from a natural grassland ecosystem were considered to most reliably represent the natural system under study since they retained the soil structure, and closely simulated the abiotic and biotic complexity, of the grassland ecosystem. The behavior of 74 As in the components of intact soil core microcosms differed appreciably from that observed for the other microcosm types where soil underwent manipulation. These differences were explained primarily on the basis of differences in soil structure

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

Energy Technology Data Exchange (ETDEWEB)

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

1994-02-01

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

Concentrated Brine Treatment using New Energy in Coal Mine Evaporation Ponds

Science.gov (United States)

Li, Ting; Li, Jingfeng

2017-12-01

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

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

International Nuclear Information System (INIS)

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

1994-02-01

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

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

OpenAIRE

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

2010-01-01

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

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Biological removal of algae in an integrated pond system

CSIR Research Space (South Africa)

Meiring, PGJ

1995-01-01

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

Towards Consensus on the Nature of Outdoor Education. Editorial.

Science.gov (United States)

Higgins, Peter; Loynes, Chris

1997-01-01

At a European conference in Finland, various outdoor education organizations drafted a statement of intent for the newly created European Institute for Outdoor Adventure Education. Their common view of outdoor education is that it strives to stimulate personal and social development experientially through some experience of the outdoors. Discusses…

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)

Split-second recognition: what makes outdoor advertising work?

NARCIS (Netherlands)

van Meurs, A.; Aristoff, M.

2009-01-01

CBS Outdoor used a tachistoscope to determine how long it takes to recognize the brand/product advertised in 187 outdoor posters in the Netherlands. Additionally, CBS Outdoor measured the creative appeal of these advertisements. Using 80 content and format variables, an explanatory model was

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...

Science museum staff taking part in the ECSITE 2018 conference visit Microcosm

CERN Multimedia

AUTHOR|(CDS)2070299; Ordan, Julien Marius

2018-01-01

Science museum staff taking part in the ECSITE 2018 conference visit Microcosm with Marta Bajko and Dwayne Spiteri guiding. https://cern.service-now.com/nav_to.do?uri=u_request_fulfillment.do%3Fsys_id=ae774fec4fa653401bb8c0501310c748%26sysparm_stack=u_request_fulfillment_list.do%3Fsysparm_query=active=true

Systems identification: a theoretical method applied to tracer kinetics in aquatic microcosms

International Nuclear Information System (INIS)

Halfon, E.; Georgia Univ., Athens

1974-01-01

A mathematical model of radionuclide kinetics in a laboratory microcosm was built and the transfer parameters estimated by multiple regression and system identification techniques. Insight into the functioning of the system was obtained from analysis of the model. Methods employed have allowed movements of radioisotopes not directly observable in the experimental systems to be distinguished. Results are generalized to whole ecosystems

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.

Fate of the pyrethroid insecticide deltamethrin in small ponds: a mass balance study

International Nuclear Information System (INIS)

Muir, D.C.G.; Rawn, G.P.; Grift, N.P.

1985-01-01

The fate and distribution of 14 C-radiolabeled deltamethrin (1(R)[la(S),3a]-cyano-(3-phenoxyphenyl)methyl 3-(2,2-dibromoethenyl)-2,2-dimethylcyclopropanecarboxylate) were monitored for 306 days, following a single application at 10 g/ha to two small outdoor ponds (17 m 2 surface area). Initial concentrations of the insecticide in filtered water ranged from 1.28 to 2.50 μg/L. Deltamethrin ([ 14 C]cyclopropyl acid or benzyl alcohol labeled) rapidly partitioned into suspended solids, plants, sediment, and air, with a half-life of 2-4 h in water. Duckweed (Lemna sp.) and a submerged pondweed (Potamogeton berchtoldi) accumulated deltamethrin concentrations ranging from 253 to 1021 ng/g, respectively, at 24 h posttreatment. Sediments were the major sink for radioactivity at 306 days posttreatment, and intact deltamethrin was present at concentrations ranging from 3 to 5 ng/g. Deltamethrin levels in air above the water ranged from 10-100 ng/m 3 during a 48-h monitoring period following application. Fathead minnows (Pimephales promelas) accumulated levels of extractable radioactivity 248-907-fold higher than concentrations in water 24 h posttreatment, but no fish mortality was observed

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.

Parents' Perceptions of Preschool Activities: Exploring Outdoor Play

Science.gov (United States)

Jayasuriya, Avanthi; Williams, Marcia; Edwards, Todd; Tandon, Pooja

2016-01-01

Research Findings: Outdoor play is important for children's health and development, yet many preschool-age children in child care settings do not receive the recommended 60 min/day of outdoor play. Child care providers have previously described parent-related barriers to increasing outdoor playtime, including parents not providing appropriate…

Impact of protists on a hydrocarbon-degrading bacterial community from deep-sea Gulf of Mexico sediments: A microcosm study

Science.gov (United States)

Beaudoin, David J.; Carmichael, Catherine A.; Nelson, Robert K.; Reddy, Christopher M.; Teske, Andreas P.; Edgcomb, Virginia P.

2016-07-01

In spite of significant advancements towards understanding the dynamics of petroleum hydrocarbon degrading microbial consortia, the impacts (direct or indirect via grazing activities) of bacterivorous protists remain largely unknown. Microcosm experiments were used to examine whether protistan grazing affects the petroleum hydrocarbon degradation capacity of a deep-sea sediment microbial community from an active Gulf of Mexico cold seep. Differences in n-alkane content between native sediment microcosms and those treated with inhibitors of eukaryotes were assessed by comprehensive two-dimensional gas chromatography following 30-90 day incubations and analysis of shifts in microbial community composition using small subunit ribosomal RNA gene clone libraries. More biodegradation was observed in microcosms supplemented with eukaryotic inhibitors. SSU rRNA gene clone libraries from oil-amended treatments revealed an increase in the number of proteobacterial clones (particularly γ-proteobacteria) after spiking sediments with diesel oil. Bacterial community composition shifted, and degradation rates increased, in treatments where protists were inhibited, suggesting protists affect the hydrocarbon degrading capacity of microbial communities in sediments collected at this Gulf of Mexico site.

Seeking Resilience and Sustainability: Outdoor Education in Singapore

Science.gov (United States)

Martin, Peter; Ho, Susanna

2009-01-01

Outdoor education is not a universal value. Rather, outdoor education's contributions need to be grounded in time, place and culture. In this paper we describe the historical and cultural milieu that has enabled the emergence of outdoor education in Singapore and report on exploratory survey research into Singaporean teachers' conceptions of…

Physical Education & Outdoor Education: Complementary but Discrete Disciplines

Science.gov (United States)

Martin, Peter; McCullagh, John

2011-01-01

The Australian Council for Health, Physical Education and Recreation (ACHPER) includes Outdoor Education (OE) as a component of Physical Education (PE). Yet Outdoor Education is clearly thought of by many as a discrete discipline separate from Physical Education. Outdoor Education has a body of knowledge that differs from that of Physical…

Federal outdoor recreation trends: effects on economic opportunities

Science.gov (United States)

Eric White; J.M. Bowker; Ashley E. Askew; Linda L. Langner; J. Ross Arnold; Donald B.K. English

2016-01-01

Outdoor recreation is a central way that people interact with the natural environment. Federal land agencies are key providers of settings, facilities, and landscapes for recreation. Outdoor recreation is also an important driver of economic activity in rural communities near recreation destinations and across the United States. Future participation in outdoor...

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 ...

Microcosm. The world of the smallest particles; Mikrokosmos. Die Welt der kleinsten Teilchen

Energy Technology Data Exchange (ETDEWEB)

Fritzsch, Harald

2012-07-01

In order to understand, why all, what us surrounds, exists, -men, animals, plants, planets, the universe-, we must draw our eyes from the gigantic to the tiny. From the universe to the atom. From the macrocosm to the microcosm. There the physicists search for the formula, which can explain the structure of the world.

Outdoor radon variation in Romania

International Nuclear Information System (INIS)

Simion, Elena; Simion, Florin

2008-01-01

Full text: The results of a long-term survey (1992 - 2006) of the variations of outdoor radon concentrations in semi-natural location from Romania are reported in the present paper. Measurements, covering between two and four sessions of the day (morning, afternoon, evening and night), were performed on a daily bases by 37 Environmental Radioactivity Monitoring Stations from National Environmental Radioactivity Survey Network. The method used was based on indirect determination of outdoor radon from aerosol samples collected on glass micro-fibre filters by drawing the air through the filters. The sampling was performed in a fixed place at a height of 2 m above the ground surface. Total beta counting of aerosol samples collected was performed immediately and after 20 hours. Values recorded during the years of continuous measurement indicated the presence of several patterns in the long-term variation of outdoor radon concentration: diurnal, seasonal and annual variation. For diurnal variation, outdoor radon concentration shows a maximum values in the night (early hours) and minimum values by day (in the afternoon). On average, this maximum is a factor of 2 higher than the minimum. Late autumn - beginning of winter maximum and an early spring minimum are characteristic for seasonal patterns. In the long term a seasonal pattern was observed for diurnal variation, with an average diurnal maximum to minimum ratio of 1.33 in winter compared with 3.0 in the summer months. The variations of outdoor radon levels showed little correlation with the uranium concentration of the ground and were attributed to changes in soil moisture content. In dry seasons, because of the low precipitation, the soil was drying out in the summer allowing fractures to develop and radon to migrate easily through the ground. Depending on micro-climatic and geological conditions, outdoor radon average concentrations in different regions of Romania are from 1200 mBq/mc to 13065 mBq/mc. The smallest

Effects of acute gamma-irradiation on the aquatic microbial microcosm in comparison with chemicals

Energy Technology Data Exchange (ETDEWEB)

Fuma, Shoichi, E-mail: fuma@nirs.go.j [Environmental Radiation Effects Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Ishii, Nobuyoshi; Takeda, Hiroshi; Miyamoto, Kiriko; Yanagisawa, Kei [Environmental Radiation Effects Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Doi, Kazutaka; Kawaguchi, Isao [Regulatory Sciences Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Tanaka, Nobuyuki [Environmental Chemistry Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan); Inamori, Yuhei [Faculty of Symbiotic Systems Science, Fukushima University, 1 Kanayagawa, Fukushima 960-1296 (Japan); Polikarpov, Gennady G. [The A.O. Kovalevsky Institute of Biology of Southern Seas, Sevastopol 99011 (Ukraine)

2009-12-15

Effects of acute gamma-irradiation were investigated in the aquatic microcosm consisting of green algae (Chlorella sp. and Scenedesmus sp.) and a blue-green alga (Tolypothrix sp.) as producers; an oligochaete (Aeolosoma hemprichi), rotifers (Lecane sp. and Philodina sp.) and a ciliate protozoan (Cyclidium glaucoma) as consumers; and more than four species of bacteria as decomposers. At 100 Gy, populations were not affected in any taxa. At 500-5000 Gy, one or three taxa died out and populations of two or three taxa decreased over time, while that of Tolypothrix sp. increased. This Tolypothrix sp. increase was likely an indirect effect due to interspecies interactions. The principal response curve analysis revealed that the main trend of the effects was a dose-dependent population decrease. For a better understanding of radiation risks in aquatic microbial communities, effect doses of gamma-rays compared with copper, herbicides and detergents were evaluated using the radiochemoecological conceptual model and the effect index for microcosm.

Effects of acute γ-irradiation on the aquatic microbial microcosm in comparison with chemicals

International Nuclear Information System (INIS)

Fuma, Shoichi; Ishii, Nobuyoshi; Takeda, Hiroshi; Miyamoto, Kiriko; Yanagisawa, Kei; Doi, Kazutaka; Kawaguchi, Isao; Tanaka, Nobuyuki; Inamori, Yuhei; Polikarpov, Gennady G.

2009-01-01

Effects of acute γ-irradiation were investigated in the aquatic microcosm consisting of green algae (Chlorella sp. and Scenedesmus sp.) and a blue-green alga (Tolypothrix sp.) as producers; an oligochaete (Aeolosoma hemprichi), rotifers (Lecane sp. and Philodina sp.) and a ciliate protozoan (Cyclidium glaucoma) as consumers; and more than four species of bacteria as decomposers. At 100 Gy, populations were not affected in any taxa. At 500-5000 Gy, one or three taxa died out and populations of two or three taxa decreased over time, while that of Tolypothrix sp. increased. This Tolypothrix sp. increase was likely an indirect effect due to interspecies interactions. The principal response curve analysis revealed that the main trend of the effects was a dose-dependent population decrease. For a better understanding of radiation risks in aquatic microbial communities, effect doses of γ-rays compared with copper, herbicides and detergents were evaluated using the radiochemoecological conceptual model and the effect index for microcosm.

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

Outdoor recreation and ethnicity

DEFF Research Database (Denmark)

Gentin, Sandra

recreation, activities, and preferred outdoor recreation areas) between the minority and majority populations and related these differences to the ethnic minorities’ cultural background. The second paper presents the empirical work of this thesis, which is based on a survey of adolescents’ outdoor recreation....... In the UK the focus on underrepresented groups seems closely related to the focus on equality for access, while specific focus on access for ethnic minorities is not addressed in the forest and nature legislation and the national forest programs in Denmark, Germany and the Netherlands. Paper 4 proposes...

Indoor versus outdoor time in preschoolers at child care.

Science.gov (United States)

Tandon, Pooja S; Saelens, Brian E; Zhou, Chuan; Kerr, Jacqueline; Christakis, Dimitri A

2013-01-01

Being outdoors may have health benefits including being more physically active. Understanding the relationship between outdoor time and health is hampered by the difficulty of measuring outdoor time. To examine the accuracy and validity of light-sensor and GPS methods for quantifying outdoor time among those aged 3-5 years at child care. A total of 45 children (mean age 4.5 years, 64% boys) from five child care centers wore portable accelerometers with built-in light sensors and a separate GPS device around their waists during child care, providing 80,648 episodes (15 seconds each) for analysis. Direct observation (gold standard) of children being outdoors versus indoors was conducted for 2 days at each center. GPS signal-to-noise ratios, processed through the Personal Activity and Location Measurement System were used to define indoor versus outdoor locations. Receiver operating characteristic (ROC) analyses were used to determine thresholds for defining being indoors versus outdoors. Data were collected in Fall 2011, analyzed in 2012. Mean observed outdoor time was 63 [±44; range: 18-152] minutes/day. Mean light-sensor levels were significantly higher outdoors. The area under the ROC curve for location based on light sensor for all weather conditions was 0.82 (range: 0.70 on partly cloudy days to 0.97 on sunny days); for GPS, it was 0.89. The light sensor had a sensitivity of 74% and specificity of 86%. GPS had a sensitivity of 82% and specificity of 88%. A light sensor and a GPS device both distinguish indoor from outdoor time for preschoolers with moderate to high levels of accuracy. These devices can increase the feasibility and lower the cost of measuring outdoor time in studies of preschool children. Copyright © 2013 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

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

The influence of outdoor thermal environment on young Japanese females

DEFF Research Database (Denmark)

Sakoi, Tomonori; Ishii, Jin; Kondo, Emi

2014-01-01

The influence of short wave solar radiation appears to be strong outdoors in summer, and the influence of airflow appears to be strong outdoors in winter. The purpose of this paper was to clarify the influence of the outdoor environment on young Japanese females. This research shows the relations......The influence of short wave solar radiation appears to be strong outdoors in summer, and the influence of airflow appears to be strong outdoors in winter. The purpose of this paper was to clarify the influence of the outdoor environment on young Japanese females. This research shows...

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...

Outdoor air dominates burden of disease from indoor exposures

DEFF Research Database (Denmark)

Hänninen, O.; Asikainen, A.; Carrer, P.

2014-01-01

Both indoor and outdoor sources of air pollution have significant public health impacts in Europe. Based on quantitative modelling of the burden of disease the outdoor sources dominate the impacts by a clear margin.......Both indoor and outdoor sources of air pollution have significant public health impacts in Europe. Based on quantitative modelling of the burden of disease the outdoor sources dominate the impacts by a clear margin....

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.

Studies on the restoration succession of PFU microbial communities in a pilot-scale microcosm.

Science.gov (United States)

Jiang, Jian-Guo; Shen, Yun-Fen

2007-06-01

In order to imitate the restoration succession process of natural water ecosystem, a laboratory microcosm system of constant-flow-restoration was designed and established. A eutrophycation lake, Lake Donghu, was selected as the subject investigated. Six sampling stations were set on the lake, among which the water of station IV was natural clean water, and others were polluted with different degrees. Polyurethane foam unit microbial communities, which had colonized in the stations for a month, were collected from these stations and placed in their respective microcosms, using clean water of station IV to gradually replace the water of these microcosms. In this process, the healthy community in clean water continuously replaced the damaged communities in polluted water, the restoration succession of the damaged communities was characterized by weekly determination of several functional and structural community parameters, including species number (S), diversity index (DI), community pollution value (CPV), heterotrophy index (HI), and similarity coefficient. Cluster analysis based on similarity coefficient was used to compare the succession discrepancies of these microbial communities from different stations. The ecological succession of microbial communities during restoration was investigated by the variable patterns of these parameters, and based on which, the restoration standards of these polluted stations were suggested in an ecological sense. That was, while being restored, the water of station 0 (supereutrophycation) should be substituted with natural clean water by 95%; station I (eutrophycation), more than 90%; station II (eutrophycation), more than 85%; station III (eutrophycation), about 85%; station V (mesoeutrophycation), less than 50%. The effects of the structural and functional parameters in monitoring and assessing ecological restoration are analyzed and compared.

Fostering Trust in Outdoor Leaders: The Role of Personal Attributes

Science.gov (United States)

Shooter, Wynn; Paisley, Karen; Sibthorp, Jim

2012-01-01

This study examined trust development between participants of outdoor education programs and outdoor leaders. Participants were college students enrolled in outdoor education courses. Using a factorial survey design, the technical ability, interpersonal ability, benevolence, integrity, and gender of an outdoor leader was displayed randomly in a…

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.

Mobile Phones and Outdoor Advertising: Measurable Advertising

OpenAIRE

Quercia, Daniele; Di Lorenzo, Giusy; Calabrese, Francesco; Ratti, Carlo

2011-01-01

Television and newspapers sit at the top of many agency marketing plans, while outdoor advertising stays at the bottom. The reason for this is that it’s difficult to account for who views a billboard, so there is no way of consistently determining the effectiveness of outdoor advertising. As a result, agencies do not consider the medium and allocate their money elsewhere. To change this situation, one needs to create new credible audience measurements for the outdoor marketing industry. He...

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.

Position Statement on Active Outdoor Play

Science.gov (United States)

Tremblay, Mark S.; Gray, Casey; Babcock, Shawna; Barnes, Joel; Costas Bradstreet, Christa; Carr, Dawn; Chabot, Guylaine; Choquette, Louise; Chorney, David; Collyer, Cam; Herrington, Susan; Janson, Katherine; Janssen, Ian; Larouche, Richard; Pickett, William; Power, Marlene; Sandseter, Ellen Beate Hansen; Simon, Brenda; Brussoni, Mariana

2015-01-01

A diverse, cross-sectorial group of partners, stakeholders and researchers, collaborated to develop an evidence-informed Position Statement on active outdoor play for children aged 3–12 years. The Position Statement was created in response to practitioner, academic, legal, insurance and public debate, dialogue and disagreement on the relative benefits and harms of active (including risky) outdoor play. The Position Statement development process was informed by two systematic reviews, a critical appraisal of the current literature and existing position statements, engagement of research experts (N = 9) and cross-sectorial individuals/organizations (N = 17), and an extensive stakeholder consultation process (N = 1908). More than 95% of the stakeholders consulted strongly agreed or somewhat agreed with the Position Statement; 14/17 participating individuals/organizations endorsed it; and over 1000 additional individuals and organizations requested their name be listed as a supporter. The final Position Statement on Active Outdoor Play states: “Access to active play in nature and outdoors—with its risks— is essential for healthy child development. We recommend increasing children’s opportunities for self-directed play outdoors in all settings—at home, at school, in child care, the community and nature.” The full Position Statement provides context for the statement, evidence supporting it, and a series of recommendations to increase active outdoor play opportunities to promote healthy child development. PMID:26062040

Position Statement on Active Outdoor Play

Directory of Open Access Journals (Sweden)

Mark S. Tremblay

2015-06-01

Full Text Available A diverse, cross-sectorial group of partners, stakeholders and researchers, collaborated to develop an evidence-informed Position Statement on active outdoor play for children aged 3–12 years. The Position Statement was created in response to practitioner, academic, legal, insurance and public debate, dialogue and disagreement on the relative benefits and harms of active (including risky outdoor play. The Position Statement development process was informed by two systematic reviews, a critical appraisal of the current literature and existing position statements, engagement of research experts (N = 9 and cross-sectorial individuals/organizations (N = 17, and an extensive stakeholder consultation process (N = 1908. More than 95% of the stakeholders consulted strongly agreed or somewhat agreed with the Position Statement; 14/17 participating individuals/organizations endorsed it; and over 1000 additional individuals and organizations requested their name be listed as a supporter. The final Position Statement on Active Outdoor Play states: “Access to active play in nature and outdoors—with its risks— is essential for healthy child development. We recommend increasing children’s opportunities for self-directed play outdoors in all settings—at home, at school, in child care, the community and nature.” The full Position Statement provides context for the statement, evidence supporting it, and a series of recommendations to increase active outdoor play opportunities to promote healthy child development.

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...

Ecological effects of Spring and late Summer applications of Lambda-Cyhalothrin on freshwater microcosms

NARCIS (Netherlands)

Wijngaarden, van R.P.A.; Brock, T.C.M.; Brink, van den P.J.; Gylstra, R.; Maund, S.J.

2006-01-01

The aim of the study was to compare the effects of the pyrethroid insecticide lambda-cyhalothrin (treated at 10, 25, 50, 100, 250 ng active ingredient a.i./L) on a drainage ditch ecosystem in spring and late summer. Microcosms (water volume approximately 430 L) were established using enclosures in a

Planning School Grounds for Outdoor Learning

Science.gov (United States)

Wagner, Cheryl; Gordon, Douglas

2010-01-01

This publication covers the planning and design of school grounds for outdoor learning in new and existing K-12 facilities. Curriculum development as well as athletic field planning and maintenance are not covered although some references on these topics are provided. It discusses the different types of outdoor learning environments that can be…

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

Safety assessment of outdoor live fire range

Energy Technology Data Exchange (ETDEWEB)

NONE

1989-05-01

The following Safety Assessment (SA) pertains to the outdoor live fire range facility (LFR). The purpose of this facility is to supplement the indoor LFR. In particular it provides capacity for exercises that would be inappropriate on the indoor range. This SA examines the risks that are attendant to the training on the outdoor LFR. The outdoor LFR used by EG&G Mound is privately owned. It is identified as the Miami Valley Shooting Grounds. Mondays are leased for the exclusive use of EG&G Mound.

United States of America: outdoor recreation.

Science.gov (United States)

H.Ken Cordell; G.Theodore Green; V.R. Leeworthy; R. Stephens; M.J. Fly; Carter J. Betz

2005-01-01

the first nationwide survey of outdoor recreation in the USA was conducted in 1960 for the outdoor recreation resources review commission (ORRC, 1962; Cordell et al., 1996). since that time, seven additional national surveys have been conducted, in 1965, 1970, 1972, 1977, 1983, 1995, and 2000/01 - summary details are presented in Table 16.1.

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

Glyceria maxima as new test species for the EU risk assessment for herbicides: a microcosm study.

Science.gov (United States)

Mohr, S; Schott, J; Hoenemann, L; Feibicke, M

2015-03-01

In its recent guidance document on tiered risk assessment for plant protection products for aquatic organisms, the European Food Safety Authority (EFSA) proposed to use Glyceria maxima as monocotyledonous grass species for the testing of special herbicide groups. However, published toxicity data for this species is very limited and there is no test guideline for Glyceria sp. For this reason a microcosm study was conducted in order to gain experience on the degree of sensitivity of G. maxima to the herbicidal substances clodinafop-propargyl (grass herbicide) and fluroxypyr (auxin) in comparison to the already established test organism water milfoil Myriophyllum spicatum and the duckweed species Landoltia punctata. Five concentrations without replicates were tested for each test substance using 10 microcosms and three microcosms served as controls. The experiment was run for 8 weeks. Morphological endpoints were used to determine growth and EC50 values. The results show that M. spicatum was most sensitive to fluroxypyr (37 days EC50 for roots: 62 µg/L) and G. maxima most sensitive to clodinafop-propargyl (22 days EC50 for total shoot length: 48 µg/L) whereas the duckweed species was considerable less sensitive. Hence, G. maxima turns out to be a good candidate for testing grass specific herbicides, supporting its inclusion as an additional macrophyte test for the risk assessment of herbicides as proposed by the EFSA.

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.

Outdoor skaber særlig professionel identitet

DEFF Research Database (Denmark)

Kjeldsen, Lis Reinholdt; Lybæk-Hansen, Esper

2015-01-01

På pædagoguddannelsen i Horsens tilbydes årligt en toning af pædagoguddannelsen i Outdoor - en beskrivelse......På pædagoguddannelsen i Horsens tilbydes årligt en toning af pædagoguddannelsen i Outdoor - en beskrivelse...

In- and outdoor reproduction of first generation common sole Solea solea under a natural photothermal regime: Temporal progression of sexual maturation assessed by monitoring plasma steroids and gonadotropin mRNA expression.

Science.gov (United States)

Palstra, A P; Blok, M C; Kals, J; Blom, E; Tuinhof-Koelma, N; Dirks, R P; Forlenza, M; Blonk, R J W

2015-09-15

Reproduction of many temperate fishes is seasonal and maturation and spawning of gametes are under photothermal control. Reproductive success of first generation (G1) common sole Solea solea in captivity has been low. In this study, the sexual maturation status has been assessed during the prespawning months in G1 sole that were housed (a) outdoor under the natural photoperiod and temperature, or (b) indoor under artificial photothermal induction. Maturation was assessed in male and female G1 broodstock in November as controls, after which the remaining population was divided over two outdoor flow-through tanks placed in a pond and two indoor recirculating aquaculture system (RAS) tanks. Subsequently, maturation status (gonadosomatic index GSI and plasma levels of testosterone T and 17β-estradiol E2) was assessed in one tank for each condition in January, February and during spawning in early April, while fish in the other tank were not disturbed in achieving reproductive success. Quantitative real-time PCR was performed to determine species-specific gonadotropin mRNA expression in females. Successful G1 spawning and egg fertilisation occurred in all experimental tanks. Gonadal development was similar under both conditions. Higher E2 and T levels were found in indoor housed females. Gonadotropin expression revealed similar profiles between outdoor and indoor housed females. G1 sole could be reproduced in the outdoor tanks under the natural photoperiod and in the indoor tanks under artificial simulation of this regime that includes a potentially crucial chilling period of 2-3 months at 5-7 °C. Copyright © 2015 Elsevier Inc. All rights reserved.

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.

Sub-tropical coastal lagoon salinization associated to shrimp ponds effluents

Science.gov (United States)

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

2018-04-01

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

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.

Outdoor recreation in forest policy and legislation

DEFF Research Database (Denmark)

Mann, Carsten; Pouta, Eija; Gentin, Sandra

2010-01-01

in the field of outdoor recreation, and reveal similarities, differences, gaps and future needs. Among the main findings is a contradiction between the expressed political importance of outdoor recreation at the national level, and the absence of binding commitments for action. The majority of the countries...... surveyed recognise and express outdoor recreation in some form of political and/or legislative way. However, recreation monitoring or measurements are rarely mentioned in relevant policies or acts at the national, regional or local level, perhaps due to a l ack of political will or resources. The analysis...

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.

People participation in natural outdoors recreation activities and its ...

African Journals Online (AJOL)

... of the visitors believe natural outdoor recreation in the south-west of the country ... These identified benefits of Natural Outdoors Recreational in the course of the ... promotion, employment, urban aesthetic, healthy livings and improve tourism ... outdoor recreation centres to augment medical service in improving life span ...

Pengaruh Outdoor Learning Terhadap Kemampuan Berpikir Kritis Matematis Siswa

Directory of Open Access Journals (Sweden)

Prima Cristi Crismono

2017-12-01

Full Text Available Tujuan penelitian ini untuk mengetahui pengaruh Outdoor Learning terhadap kemampuan berpikir kritis matematis siswa. Hipotesis pada penelitian ini adalah Outdoor Learning berpengaruh dalam meningkatkan kemampuan berpikir kritis matematis siswa. Mengacu pada teori perkembangan kognitifnya penggunaan Outdoor Learning dengan memanfaatkan lingkungan sekitar pada media pembelajaran dan semua aktifitas belajar yang dilakukan oleh siswa di bawah pengawasan dan bimbingan guru. Penggunaan sumber belajar yang bersifat kontektual mampu mengembangkan kemampuan berpikir kritis matematis siswa. Data penelitian dapat diperoleh dengan menggunakan tes yang terdiri dari seperangkat soal uraian untuk mengukur dan mengetahui  kemampuan  awal  matematika  berupa  kemampuan  berpikir  kritis siswa. Hasil analisis pengaruh penerapan metode Outdoor Learning terhadap kemampuan berpikir kritis matematis siswa yang telah dilakukan diketahui bahwa terdapat pengaruh positif penerapan metode Outdoor Learning terhadap kemampuan berpikir kritis matematis siswa. Kesimpulan dari peneitian ini adalah metode Outdoor learning berpengaruh terhadap kemampuan berpikir kritis matematis siswa.

Outdoor recreation

Science.gov (United States)

J. M. Bowker; Ashley Askew; H. Ken Cordell; John C. Bergstrom

2013-01-01

Key FindingsBy 2060, the number of southern adults participating in each of 10 different popular outdoor recreation activities is projected to increase. Depending on future demographic, economic, land use, and population changes, the activity demonstrating the least growth in participants is hunting (8–25 percent). The activity projected to...

Thermal Perception in the Mediterranean Area: Comparing the Mediterranean Outdoor Comfort Index (MOCI to Other Outdoor Thermal Comfort Indices

Directory of Open Access Journals (Sweden)

Iacopo Golasi

2016-07-01

Full Text Available Outdoor thermal comfort is an essential factor of people’s everyday life and deeply affects the habitability of outdoor spaces. However the indices used for its evaluation were usually developed for indoor environments assuming still air conditions and absence of solar radiation and were only later adapted to outdoor spaces. For this reason, in a previous study the Mediterranean Outdoor Comfort Index (MOCI was developed, which is an empirical index able to estimate the thermal perception of people living in the Mediterranean area. In this study it was compared numerically (by using the data obtained through a field survey with other selected thermal indices. This comparison, performed in terms of Spearman’s rho correlation coefficient, association Gamma, percentage of correct predictions and cross-tabulation analysis, led to identify the MOCI as the most suitable index to examine outdoor thermal comfort in the interested area. As a matter of fact it showed a total percentage of correct predictions of 35.5%. Good performances were reported even in thermophysiological indices as the Physiological Equivalent Temperature (PET and Predicted Mean Vote (PMV. Moreover it was revealed that adaptation and acclimatization phenomena tend to have a certain influence as well.

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.

Determination of Science Teachers' Opinions about Outdoor Education

Science.gov (United States)

Kubat, Ulas

2017-01-01

The aim of this research is to discover what science teachers' opinions about outdoor education learning environments are. Outdoor education learning environments contribute to problem-solving, critical and creative thinking skills of students. For this reason, outdoor education learning environments are very important for students to learn by…

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.

Metamorphosis of two amphibian species after chronic cadmium exposure in outdoor aquatic mesocosms

Science.gov (United States)

James, S.M.; Little, E.E.; Semlitsch, R.D.

2005-01-01

Amphibian larvae at contaminated sites may experience an alteration of metamorphic traits and survival compared to amphibians in uncontaminated conditions. Effects of chronic cadmium (Cd) exposure on the metamorphosis of American toads (Bufo americanus) and southern leopard frogs (Rana sphenocephala) were determined. The two species were reared separately from shortly after hatching through metamorphosis in outdoor mesocosms (1,325-L polyethylene cattle tanks) that simulated natural ponds and enhanced environmental realism relative to the laboratory. Both species exhibited a decrease in survival with increasing initial nominal aqueous Cd concentration. Cadmium treatment did not influence mass at metamorphosis for either species when survival was included as a covariate, but increased the age at metamorphosis for the American toads. The whole body Cd content of metamorphs increased with aqueous Cd treatment level for both species, and the American toads tended to possess more elevated residues. Cadmium quickly partitioned out of the water column and accumulated in and altered the abundance of the tadpoles' diet. Cadmium-contaminated sites may produce fewer metamorphs, and those that survive will metamorphose later and contain Cd. Interspecific differences in the response variables illustrate the importance of testing multiple species when assessing risk.

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...

Impacts of earthworm, .i.Pheretima (Amynthas) cornosa./i. on nutrient loss from soil in microcosm experiment

Czech Academy of Sciences Publication Activity Database

Kaneda, Satoshi; Nakajima, M.; Murakami, T.; Urashima, Y.

2008-01-01

Roč. 10, - (2008) ISSN 1029-7006. [EGU General Assembly 2008. 13.04.2008-18.04.2008, Vienna] Institutional research plan: CEZ:AV0Z60660521 Keywords : Pheretima (Amynthas) cornosa * nutrient loss from soil * microcosm experiment Subject RIV: EH - Ecology, Behaviour

Prescribing Outdoor Physical Activity to Children: Health Care Providers’ Perspectives

Science.gov (United States)

Christiana, Richard W.; James, J. Joy; Battista, Rebecca A.

2017-01-01

Little evidence exists on health care provider (HCP) prescriptions for children’s outdoor physical activity (PA). Semistructured interviews were conducted with 15 children’s HCPs to explore perspectives on outdoor PA prescription programs for children and barriers to implementation. Thematic analytic techniques were used to analyze the data. Most participants reported an awareness of health benefits to children being in the outdoors. Ten themes emerged from the data related to 3 thematic categories: (1) current strategies that HCPs are using to promote PA among children, (2) barriers that HCPs see to prescribing outdoor PA, and (3) potential strategies for promoting outdoor PA among children. Assessment of the local outdoor PA environment and resource development must be done prior to a prescription program. HCPs should be skilled in conducting conversations and setting goals related to outdoor PA tailored to the patient. Developing a system for follow-up with patients on established goals should also be included. PMID:29152542

Prescribing Outdoor Physical Activity to Children: Health Care Providers' Perspectives.

Science.gov (United States)

Christiana, Richard W; James, J Joy; Battista, Rebecca A

2017-01-01

Little evidence exists on health care provider (HCP) prescriptions for children's outdoor physical activity (PA). Semistructured interviews were conducted with 15 children's HCPs to explore perspectives on outdoor PA prescription programs for children and barriers to implementation. Thematic analytic techniques were used to analyze the data. Most participants reported an awareness of health benefits to children being in the outdoors. Ten themes emerged from the data related to 3 thematic categories: (1) current strategies that HCPs are using to promote PA among children, (2) barriers that HCPs see to prescribing outdoor PA, and (3) potential strategies for promoting outdoor PA among children. Assessment of the local outdoor PA environment and resource development must be done prior to a prescription program. HCPs should be skilled in conducting conversations and setting goals related to outdoor PA tailored to the patient. Developing a system for follow-up with patients on established goals should also be included.

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.

Education in and for the Outdoors. Report of the National Conference on Outdoor Education (Kellogg Gull Lake Biological Station, Hickory Corners, Michigan, May 2-4, 1962).

Science.gov (United States)

American Association for Health, Physical Education, and Recreation, Washington, DC.

The two board aspects of outdoor education considered in this document are education in the outdoors, using the natural environment as a laboratory for learning, and education for the outdoors, with a focus on teaching skills and appreciations for outdoor recreation. Conference procedures, keynote addresses, current practices, contributions to…

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)

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-.

Effect of zinc-enriched natural sediments, in isolated and microcosm models, on three species of benthic invertebrates

International Nuclear Information System (INIS)

Galar Martinez, Marcela; Martinez-Tabche, Laura; Sanchez-Hidalgo, Eugenia; Lopez Lopez, Eugenia

2006-01-01

Availability of toxic in aquatic bodies is limited by the physicochemical characteristics of sediments and water, as well as by the interactions between the different xenobiotics and inhabits species. The aim of this work was to relate the effect produced by zinc (Zn) spiked in sediments of the Ignacio Ramirez dam (PIR), in isolated and microcosm models, on ATP concentration of three benthic organisms with the metal biodisponibility. The selected species were a crustacean, an annelid and a mollusk: Hyalella azteca (Amphipoda: Hyalellidae), Limnodrilus hoffmeisteri (Oligochaeta: Tubificidae) and Stagnicola attenuata (Basommatophora: Lymnaeidae), species that are found at high proportions in the reservoir and use different spaces in the benthos. Samples of sediments and organisms were collected from the PIR during the dry season (February of 1999). Metal concentration (Zn, Fe, Cu and Ni), pH, texture, particle size, total nitrogen and organic matter were determined in sediments. Sublethal studies were carried out using two types of static systems (isolated and in microcosm organisms). Both models contained PIR sediments enriched with Zn (nominal concentration of 0.8129 mg/kg) and synthetic water in a proportion of 1:4. The test organisms were added to the systems once the equilibrium was reached (2 hr) considering the biomass quantity with respect to volume (1.0 g of organism by each 100 ml of water:sediment). After 0, 12, 24, 36, 48 and 72 hr of exposure, samples of sediment and hydrobionts were taken, and Zn content was quantified by atomic absorption. ATP concentration was also determined in organisms. The effect produced by natural sediments spiked with Zn is increased by the presence of more than one specie in the system (microcosm). With respect to Zn levels, two of the organisms (L. hoffmeisteri y S. attenuata) tend to lose this metal in isolated and microcosm models, probably as a regulation strategy in its accumulation, as well as Fe presence in the

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.

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

Science.gov (United States)

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

2015-12-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1979-04-01

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

Degradation of 1,1,2,2-tetrachloroethane and accumulation of vinyl chloride in wetland sediment microcosms and in situ porewater: biogeochemical controls and associations with microbial communities

Science.gov (United States)

Lorah, Michelle M.; Voytek, Mary A.

2004-05-01

The biodegradation pathways of 1,1,2,2-tetrachloroethane (TeCA) and 1,1,2-trichloroethane (112TCA) and the associated microbial communities in anaerobic wetland sediments were evaluated using concurrent geochemical and genetic analyses over time in laboratory microcosm experiments. Experimental results were compared to in situ porewater data in the wetland to better understand the factors controlling daughter product distributions in a chlorinated solvent plume discharging to a freshwater tidal wetland at Aberdeen Proving Ground, Maryland. Microcosms constructed with wetland sediment from two sites showed little difference in the initial degradation steps of TeCA, which included simultaneous hydrogenolysis to 112TCA and dichloroelimination to 1,2-dichloroethene (12DCE). The microcosms from the two sites showed a substantial difference, however, in the relative dominance of subsequent dichloroelimination of 112TCA. A greater dominance of 112TCA dichloroelimination in microcosms constructed with sediment that was initially iron-reducing and subsequently simultaneously iron-reducing and methanogenic caused approximately twice as much vinyl chloride (VC) production as microcosms constructed with sediment that was methanogenic only throughout the incubation. The microcosms with higher VC production also showed substantially more rapid VC degradation. Field measurements of redox-sensitive constituents, TeCA, and its anaerobic degradation products along flowpaths in the wetland porewater also showed greater production and degradation of VC with concurrent methanogenesis and iron reduction. Molecular fingerprinting indicated that bacterial species [represented by a peak at a fragment size of 198 base pairs (bp) by MnlI digest] are associated with VC production from 112TCA dichloroelimination, whereas methanogens (190 and 307 bp) from the Methanococcales or Methanobacteriales family are associated with VC production from 12DCE hydrogenolysis. Acetate-utilizing methanogens

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.

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

Energy Technology Data Exchange (ETDEWEB)

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

1989-01-01

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

Liner used in tailings ponds

International Nuclear Information System (INIS)

Dinchak, W.G.

1984-01-01

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

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

Science.gov (United States)

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

2015-09-01

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

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

African Journals Online (AJOL)

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

Effects of riparian buffers on hydrology of northern seasonal ponds

Science.gov (United States)

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

2011-01-01

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

[Exploration of microcosmic Chinese medicine used by western medicine].

Science.gov (United States)

Zheng, Zhi-jing

2015-02-01

"Microcosmic syndrome", "treatment based on syndrome differentiation", and "combination of disease identification and syndrome differentiation" generally refer to a mode: following the syndrome if with no disease identified, following the disease if with no syndrome type differentiated. For example, Chinese medical treatment of hypertension, high blood lipids, increased transaminase, and so on candirectly use Chinese recipes, but no longer with syndrome differentiation. Clinical application of Chinese patent medicine can also obtain favorable clinical. Western doctors need not follow syndrome differentiation. The invention of artemisinin was screened from more than 40 000 kinds of compounds and herbs, but with no reference of any traditional Chinese medical theory. A lot of folk remedy and empirical recipes have obtained effective efficacy but unnecessarily with profound Chinese medical theories. Various evidences showed that disease can also be cured without syndrome differentiation. I held that it might be associated with the same mechanism of Chinese medicine and Western medicine. Any disease can be cured or alleviated by Chinese medicine is a result from its modern pharmacological effect, which is achieved by improving etiologies, and pathogeneses. I was inspired by whether we can directly use traditional Chinese medicine with modern pharmacological effects to treat symptomatic disease. So I raised an idea of microcosmic Chinese medicine used by Western medicine, i.e., we find and use Chinese herbs with relatively effective modern pharmacological effect to treat diseases targeting at patients' clinical symptoms and signs, as well as various positive laboratory results (collectively called as microscopic dialectical indicators). More Western doctors would use it to treat disease due to omission of complicated and mysterious syndrome differentiation. This will promote extensive application and expansion of Chi- nese medicine and pharmacy, enlarge the team of

Aquatic risk assessment of a realistic exposure to pesticides used in bulb crops: a microcosm study

NARCIS (Netherlands)

Wijngaarden, van R.P.A.; Cuppen, J.G.M.; Arts, G.H.P.; Crum, S.J.H.; Hoorn, van den M.W.; Brink, van den P.J.; Brock, T.C.M.

2004-01-01

The fungicide fluazinam, the insecticide lambda-cyhalothrin, and the herbicides asulam and metamitron were applied to indoor freshwater microcosms (water volume approximately 0.6 m3). The treatment regime was based on a realistic application scenario in tulip cultivation. Concentrations of each

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.

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.

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

Science.gov (United States)

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

2017-04-01

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

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

NARCIS (Netherlands)

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

2006-01-01

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

Lyme Disease: A Challenge for Outdoor Educators.

Science.gov (United States)

Whitcombe, Mark

1989-01-01

Describes signs and symptoms of Lyme disease; life cycle and feeding habits of the deer tick (Ixodes dammini), which transmits the spirochete bacterium; tick control measures; outdoor precautions; and veterinary considerations. Discusses the disease's potential impact on outdoor education, and suggests a reasoned, nonhysterical approach. Contains…

The little book of maths outdoors

CERN Document Server

Gould, Terry

2013-01-01

This is a unique book that supports the current thinking behind outdoor learning. It features over 40 ideas for outdoor activities that support mathematics in the early years and the specific areas of learning in the revised EYFS. All the ideas are tried and tested by Terry and this book will prove to be popular in the early years and well into Key stage 1.

Risk Management and Litigation Avoidance in Outdoor Recreation Programming.

Science.gov (United States)

Hanna, Glenda

This paper reviews aspects of Canadian and U.S. law related to liability and negligence of outdoor programs and suggests strategies for risk management. To prove negligence, an individual injured in an outdoor program must prove that the outdoor leader had a duty of care to the participant, standards of care were breached, actual injury was…

Investigation of Mountaineering and Outdoor Sports Clubs with Activity Areas

Directory of Open Access Journals (Sweden)

Burak GÜRER

2016-12-01

Full Text Available Current study aims to identify activity areas of mountaineering and outdoor sports clubs in Turkey that organize activities regularly. Universe of the study was composed of mountaineering and outdoor sports clubs that were active between the dates of 11 March 2012 and 5 January 2013. This study and the sample included 49 active outdoor sports clubs that could be reached in the region. Data were collected via surveys. Obtained data were analyzed and interpreted with the help of statistical package program (SPSS 16.0. Frequencies and percentage distributions were provided. Criteria for the provision of outdoor sports activities in clubs include requests from members and geographical conditions of the area. It is observed that those clubs provide outdoor walks approximately for 21-40 members. There are clubs without trainers. Clubs provide mountaineering and rock climbing activities the most. Aegean and Marmara Regions are more active compared to other regions. In general, most of the clubs are active in areas such as mountaineering, rock climbing and outdoor walks. It is suggested that local administrations and federations support outdoor sports clubs

Evaluation of ethyl tert-butyl ether biodegradation in a contaminated aquifer by compound-specific isotope analysis and in situ microcosms

Energy Technology Data Exchange (ETDEWEB)

Bombach, Petra, E-mail: petra.bombach@ufz.de [UFZ – Helmholtz Centre for Environmental Research, Department of Isotope Biogeochemistry, Permoserstrasse 15, D-04318 Leipzig (Germany); Isodetect GmbH Leipzig, Deutscher Platz 5b, D-04103 Leipzig (Germany); Nägele, Norbert [Kuvier the Biotech Company S.L., Ctra. N-I, p.k. 234–P.E. INBISA 23" a, E-09001 Burgos (Spain); Rosell, Mònica [UFZ – Helmholtz Centre for Environmental Research, Department of Isotope Biogeochemistry, Permoserstrasse 15, D-04318 Leipzig (Germany); Grup de Mineralogia Aplicada i Medi Ambient, Departament de Cristallografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona (UB), C/Martí i Franquès s/n, 08028 Barcelona (Spain); Richnow, Hans H. [UFZ – Helmholtz Centre for Environmental Research, Department of Isotope Biogeochemistry, Permoserstrasse 15, D-04318 Leipzig (Germany); Fischer, Anko [Isodetect GmbH Leipzig, Deutscher Platz 5b, D-04103 Leipzig (Germany)

2015-04-09

Highlights: • In situ biodegradation of ETBE was investigated in a fuel contaminated aquifer. • Degradation was studied by CSIA and in situ microcosms in combination with TLFA-SIP. • ETBE was degraded when ETBE was the main groundwater contaminant. • ETBE was also degraded in the presence of BTEX and MTBE. • Hydrochemical analysis indicated aerobic and anaerobic ETBE biodegradation. - Abstract: Ethyl tert-butyl ether (ETBE) is an upcoming groundwater pollutant in Europe whose environmental fate has been less investigated, thus far. In the present study, we investigated the in situ biodegradation of ETBE in a fuel-contaminated aquifer using compound-specific stable isotope analysis (CSIA), and in situ microcosms in combination with total lipid fatty acid (TLFA)-stable isotope probing (SIP). In a first field investigation, CSIA revealed insignificant carbon isotope fractionation, but low hydrogen isotope fractionation of up to +14‰ along the prevailing anoxic ETBE plume suggesting biodegradation of ETBE. Ten months later, oxygen injection was conducted to enhance the biodegradation of petroleum hydrocarbons (PH) at the field site. Within the framework of this remediation measure, in situ microcosms loaded with [{sup 13}C{sub 6}]-ETBE (BACTRAP{sup ®}s) were exposed for 119 days in selected groundwater wells to assess the biodegradation of ETBE by TLFA-SIP under the following conditions: (i) ETBE as main contaminant; (ii) ETBE as main contaminant subjected to oxygen injection; (iii) ETBE plus other PH; (iv) ETBE plus other PH subjected to oxygen injection. Under all conditions investigated, significant {sup 13}C-incorporation into microbial total lipid fatty acids extracted from the in situ microcosms was found, providing clear evidence of ETBE biodegradation.

Evaluation of ethyl tert-butyl ether biodegradation in a contaminated aquifer by compound-specific isotope analysis and in situ microcosms

International Nuclear Information System (INIS)

Bombach, Petra; a, E-09001 Burgos (Spain))" data-affiliation=" (Kuvier the Biotech Company S.L., Ctra. N-I, p.k. 234–P.E. INBISA 23a, E-09001 Burgos (Spain))" >Nägele, Norbert; Rosell, Mònica; Richnow, Hans H.; Fischer, Anko

2015-01-01

Highlights: • In situ biodegradation of ETBE was investigated in a fuel contaminated aquifer. • Degradation was studied by CSIA and in situ microcosms in combination with TLFA-SIP. • ETBE was degraded when ETBE was the main groundwater contaminant. • ETBE was also degraded in the presence of BTEX and MTBE. • Hydrochemical analysis indicated aerobic and anaerobic ETBE biodegradation. - Abstract: Ethyl tert-butyl ether (ETBE) is an upcoming groundwater pollutant in Europe whose environmental fate has been less investigated, thus far. In the present study, we investigated the in situ biodegradation of ETBE in a fuel-contaminated aquifer using compound-specific stable isotope analysis (CSIA), and in situ microcosms in combination with total lipid fatty acid (TLFA)-stable isotope probing (SIP). In a first field investigation, CSIA revealed insignificant carbon isotope fractionation, but low hydrogen isotope fractionation of up to +14‰ along the prevailing anoxic ETBE plume suggesting biodegradation of ETBE. Ten months later, oxygen injection was conducted to enhance the biodegradation of petroleum hydrocarbons (PH) at the field site. Within the framework of this remediation measure, in situ microcosms loaded with [ 13 C 6 ]-ETBE (BACTRAP ® s) were exposed for 119 days in selected groundwater wells to assess the biodegradation of ETBE by TLFA-SIP under the following conditions: (i) ETBE as main contaminant; (ii) ETBE as main contaminant subjected to oxygen injection; (iii) ETBE plus other PH; (iv) ETBE plus other PH subjected to oxygen injection. Under all conditions investigated, significant 13 C-incorporation into microbial total lipid fatty acids extracted from the in situ microcosms was found, providing clear evidence of ETBE biodegradation

Effects of imidacloprid on the ecology of sub-tropical freshwater microcosms.

Science.gov (United States)

Sumon, Kizar Ahmed; Ritika, Afifat Khanam; Peeters, Edwin T H M; Rashid, Harunur; Bosma, Roel H; Rahman, Md Shahidur; Fatema, Mst Kaniz; Van den Brink, Paul J

2018-05-01

The neonicotinoid insecticide imidacloprid is used in Bangladesh for a variety of crop protection purposes. Imidacloprid may contaminate aquatic ecosystems via spray drift, surface runoff and ground water leaching. The present study aimed at assessing the fate and effects of imidacloprid on structural (phytoplankton, zooplankton, macroinvertebrates and periphyton) and functional (organic matter decomposition) endpoints of freshwater, sub-tropical ecosystems in Bangladesh. Imidacloprid was applied weekly to 16 freshwater microcosms (PVC tanks containing 400 L de-chlorinated tap water) at nominal concentrations of 0, 30, 300, 3000 ng/L over a period of 4 weeks. Results indicated that imidacloprid concentrations from the microcosm water column declined rapidly. Univariate and multivariate analysis showed significant effects of imidacloprid on the zooplankton and macroinvertebrate community, some individual phytoplankton taxa, and water quality variables (i.e. DO, alkalinity, ammonia and nitrate), with Cloeon sp., Diaptomus sp. and Keratella sp. being the most affected species, i.e. showing lower abundance values in all treatments compared to the control. The observed high sensitivity of Cloeon sp. and Diaptomus sp. was confirmed by the results of single species tests. No significant effects were observed on the species composition of the phytoplankton, periphyton biomass and organic matter decomposition for any of the sampling days. Our study indicates that (sub-)tropical aquatic ecosystems can be much more sensitive to imidacloprid compared to temperate ones. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Interactions among buffelgrass, phenanthrene and phenanthrene-degrading bacteria in gnotobiotic microcosms.

Science.gov (United States)

Robert, Francoise M; Sun, Wenhao H; Toma, Marisa; Jones, Ryan K; Tang, Chung-Shih

2008-07-15

An experiment was undertaken in gnotobiotic microcosms to determine the role of buffelgrass (Cenchrus ciliaris) and a phenanthrene-degrading bacterium (strain PM600) in the degradation of phenanthrene. The Gram-negative bacterium was identified as a Sphingomonas sp. by 16S rRNA gene sequence analysis and as S. paucimobilis by biochemical tests (API 20 NE strips). Its yellow pigment corresponded to nostoxanthin and its cellular fatty acids were typical of the genus Sphingomonas. Moreover, it was devoid of lipopolysaccharides. Strain PM600 was tested for growth on mineral medium supplemented with No. 2 diesel, hexadecane, mineral oil, pristane, phenanthrene, and pyrene as single carbon sources. It was capable of utilizing phenanthrene only. In the gnotobiotic microcosms silica sand was either or not supplemented with 150 mg of phenanthrene kg(-1) sand, inoculated with strain PM600, and planted to sterile young seedlings of buffelgrass. After 28 days, 67% of the reduction of the phenanthrene concentration was assigned to degradation by the bacterium and ca. 20% to abiotic factors. No statistically significant effect of the young buffelgrass was found. In the absence of phenanthrene, the bacterial population significantly increased in the rhizosphere of buffelgrass. However, in the presence of buffelgrass and phenanthrene, the bacterial population preferentially responded to phenanthrene. The growth of buffelgrass was severely curtailed by phenanthrene in the absence of the bacterium. However, strain PM600 effectively protected buffelgrass against the phytotoxicity of phenanthrene.

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.

77 FR 33597 - Great Outdoors Month, 2012

Science.gov (United States)

2012-06-07

... Outdoors Month, 2012 By the President of the United States of America A Proclamation America's natural... launch the America's Great Outdoors Initiative. Building on input from tens of thousands of people across... engine of growth. As part of our National Travel and Tourism Strategy, my Administration is working to...

Monitoring Outdoor Alcohol Advertising in Developing Countries ...

African Journals Online (AJOL)

Analyses on the placement, channels, size and content of outdoor alcohol advertising practices (N=807) in relation to existing regulations are given. For example, in Gambia, the country with the most stringent alcohol marketing regulations of all countries studied, outdoor alcohol advertisements are on average smaller and ...

Realistic Real-Time Outdoor Rendering in Augmented Reality

Science.gov (United States)

Kolivand, Hoshang; Sunar, Mohd Shahrizal

2014-01-01

Realistic rendering techniques of outdoor Augmented Reality (AR) has been an attractive topic since the last two decades considering the sizeable amount of publications in computer graphics. Realistic virtual objects in outdoor rendering AR systems require sophisticated effects such as: shadows, daylight and interactions between sky colours and virtual as well as real objects. A few realistic rendering techniques have been designed to overcome this obstacle, most of which are related to non real-time rendering. However, the problem still remains, especially in outdoor rendering. This paper proposed a much newer, unique technique to achieve realistic real-time outdoor rendering, while taking into account the interaction between sky colours and objects in AR systems with respect to shadows in any specific location, date and time. This approach involves three main phases, which cover different outdoor AR rendering requirements. Firstly, sky colour was generated with respect to the position of the sun. Second step involves the shadow generation algorithm, Z-Partitioning: Gaussian and Fog Shadow Maps (Z-GaF Shadow Maps). Lastly, a technique to integrate sky colours and shadows through its effects on virtual objects in the AR system, is introduced. The experimental results reveal that the proposed technique has significantly improved the realism of real-time outdoor AR rendering, thus solving the problem of realistic AR systems. PMID:25268480

Realistic real-time outdoor rendering in augmented reality.

Directory of Open Access Journals (Sweden)

Hoshang Kolivand

Full Text Available Realistic rendering techniques of outdoor Augmented Reality (AR has been an attractive topic since the last two decades considering the sizeable amount of publications in computer graphics. Realistic virtual objects in outdoor rendering AR systems require sophisticated effects such as: shadows, daylight and interactions between sky colours and virtual as well as real objects. A few realistic rendering techniques have been designed to overcome this obstacle, most of which are related to non real-time rendering. However, the problem still remains, especially in outdoor rendering. This paper proposed a much newer, unique technique to achieve realistic real-time outdoor rendering, while taking into account the interaction between sky colours and objects in AR systems with respect to shadows in any specific location, date and time. This approach involves three main phases, which cover different outdoor AR rendering requirements. Firstly, sky colour was generated with respect to the position of the sun. Second step involves the shadow generation algorithm, Z-Partitioning: Gaussian and Fog Shadow Maps (Z-GaF Shadow Maps. Lastly, a technique to integrate sky colours and shadows through its effects on virtual objects in the AR system, is introduced. The experimental results reveal that the proposed technique has significantly improved the realism of real-time outdoor AR rendering, thus solving the problem of realistic AR systems.

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

The Outdoor Classroom: School Camping as Education in NSW 1890-1960s