1. WATER ENTERING CONFLUENCE POOL FROM BEAR CREEK AT LEFT, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. WATER ENTERING CONFLUENCE POOL FROM BEAR CREEK AT LEFT, AND FROM SANTA ANA RIVER THROUGH TUNNEL #0 AT RIGHT. VIEW TO NORTHEAST. - Santa Ana River Hydroelectric System, Bear Creek Diversion Dam & Confluence Pool, Redlands, San Bernardino County, CA

Muon reconstruction in the Daya Bay water pools

DOE PAGES

Hackenburg, R. W.

2017-08-12

Muon reconstruction in the Daya Bay water pools would serve to verify the simulated muon fluxes and offer the possibility of studying cosmic muons in general. This reconstruction is, however, complicated by many optical obstacles and the small coverage of photomultiplier tubes (PMTs) as compared to other large water Cherenkov detectors. The PMTs’ timing information is useful only in the case of direct, unreflected Cherenkov light. This requires PMTs to be added and removed as an hypothesized muon trajectory is iteratively improved, to account for the changing effects of obstacles and direction of light. Therefore, muon reconstruction in the Dayamore » Bay water pools does not lend itself to a general fitting procedure employing smoothly varying functions with continuous derivatives. Here, we describe an algorithm which overcomes these complications. It employs the method of Least Mean Squares to determine an hypothesized trajectory from the PMTs’ charge-weighted positions. This initially hypothesized trajectory is then iteratively refined using the PMTs’ timing information. Reconstructions with simulated data reproduce the simulated trajectory to within about 5° in direction and about 45 cm in position at the pool surface, with a bias that tends to pull tracks away from the vertical by about 3°.« less

Muon reconstruction in the Daya Bay water pools

NASA Astrophysics Data System (ADS)

Hackenburg, R. W.

2017-11-01

Muon reconstruction in the Daya Bay water pools would serve to verify the simulated muon fluxes and offer the possibility of studying cosmic muons in general. This reconstruction is, however, complicated by many optical obstacles and the small coverage of photomultiplier tubes (PMTs) as compared to other large water Cherenkov detectors. The PMTs' timing information is useful only in the case of direct, unreflected Cherenkov light. This requires PMTs to be added and removed as an hypothesized muon trajectory is iteratively improved, to account for the changing effects of obstacles and direction of light. Therefore, muon reconstruction in the Daya Bay water pools does not lend itself to a general fitting procedure employing smoothly varying functions with continuous derivatives. Here, an algorithm is described which overcomes these complications. It employs the method of Least Mean Squares to determine an hypothesized trajectory from the PMTs' charge-weighted positions. This initially hypothesized trajectory is then iteratively refined using the PMTs' timing information. Reconstructions with simulated data reproduce the simulated trajectory to within about 5°in direction and about 45 cm in position at the pool surface, with a bias that tends to pull tracks away from the vertical by about 3°.

Water ingestion during swimming activities in a pool: a pilot study.

PubMed

Dufour, Alfred P; Evans, Otis; Behymer, Thomas D; Cantú, Ricardo

2006-12-01

Chloroisocyanurates are commonly added to outdoor swimming pools to stabilize chlorine disinfectants. The chloroisocyanurates decompose slowly to release chlorine and cyanuric acid. Studies conducted to determine if the chloroisocyanurates might be toxic to swimmers showed that they were not and that ingested cyanuric acid passed through the body unmetabolized. This fact was used to determine the amount of water swallowed during swimming activity. Fifty-three recreational swimmers, using a community swimming pool disinfected with cyanuric acid stabilized chlorine, participated in the study. The participants did not swim on the day before or after the test swim. The swimmers were asked to actively swim for at least 45 minutes and to collect their urine for the next 24 hours. Cyanuric acid was measured in pool water using high performance liquid chromatography and porous graphitic carbon columns with UV detection. The urine sample assay required a clean-up procedure to remove urinary proteins and interfering substances. Results of the study indicate that non-adults ingest about twice as much water as adults during swimming activity. The average amount of water swallowed by non-adults and adults was 37 ml and 16 ml, respectively. The design for this study and the analytical methodology used to assay cyanuric acid in swimming pool water and human urine were effective for measuring the volume of water swallowed during swimming activity.

DROWNING IN DISINFECTION BY-PRODUCTS? SWIMMING POOL WATER QUALITY RECONSIDERED.

EPA Science Inventory

The development of treated water for swimming pools has made swimming a year ¬round activity, widely enjoyed for leisure as well as exercise. Swimming pools can be found in different kinds and sizes in public areas, hotels and spas, or at private homes. In Germany ~250-300 millio...

IDENTIFICATION OF DISINFECTION BY-PRODUCTS IN SWIMMING POOL WATER

EPA Science Inventory

In order to kill harmful pathogens, swimming pool water is treated with a disinfectant, such as chlorine or ozone. One of the most commonly used disinfectants is stabilized chlorine (typically trichloro-S-triazinetrione). Trichloro-S-triazinetrione reacts in water to form one m...

[Water birthing: retrospective review of 2625 water births. Contamination of birth pool water and risk of microbial cross-infection].

PubMed

Thöni, A; Mussner, K; Ploner, F

2010-06-01

The aim of this study was to document the practice of 2625 water births at Vipiteno over the period 1997-2009 and compare outcome and safety with normal vaginal delivery. The microbial load of the birth pool water was analyzed, and neonatal infection rates after water birth and after land delivery were compared. Methods. The variables analyzed in the 1152 primiparae were: length of labor; incidence of episiotomies and tears; arterial cord blood pH and base excess values; percentage of pH<7.10 and base excess values >/=12 mmol/L. In all 2625 water births, the variables were: analgesic requirements; shoulder dystocia/ neonatal complications; and deliveries after a previous caesarean section. Bacterial cultures of water samples obtained from the bath after filling (sample A) and after delivery (sample B) were analyzed in 300 cases. The pediatricians recorded signs of suspected neonatal infection after water birth and after conventional vaginal delivery. There was a marked reduction in labor duration in the primiparae who birthed in water; the episiotomy rate was 0.46%. Owing to the pain relieving effect of the warm birth pool water, pain relievers (opiates) were required in only 12.9% of water births. Arterial cord blood pH and base excess values were comparable in both groups. Shoulder dystocia/neonatal complications were managed in 4 water births; 105 women with a previous caesarean section had a water birth. In sample A, the isolated micro-organisms were Legionella spp. and Pseudomonas aeruginosa; in sample B, there was elevated colonization of birth pool water by total coliform bacilli and Escherichia coli. Despite microbial contamination of birth pool water during delivery, antibiotic prophylaxis, as indicated by clinical and laboratory suspicion of infection, was administered to only 0.98% of babies after water birth versus 1.64% of those after land delivery. Results suggest clear medical advantages of water birthing: significantly shorter labor duration among

The impact of urbanization on water and sediment chemistry of ephemeral forest pools

Treesearch

Robert T. Brooks; Suzanne D. Miller; John Newsted

2002-01-01

We compared the water and sediment composition of two ephemeral pools located in forested settings in a developed suburban area with two similar pools located in extensive forest in Massachusetts. We also compared the macroinvertebrate communities. The sediments of the forest pools were 100% organic material, while those of the urban pools were predominantly silt. The...

What’s in the Pool? A Comprehensive Identification of Disinfection By-Products and Assessment of Mutagenicity of Chlorinated and Brominated Swimming Pool Water

EPA Science Inventory

Swimming pool disinfectants and disinfection by-products (DBPs) have been linked to human health effects, including asthma and bladder cancer, but no studies have provided a comprehensive identification of DBPs in pool water and related those DBPs to the mutagenicity of pool wate...

Observations of cross-Saharan transport of water vapour via cycle of cold pools and moist convection

NASA Astrophysics Data System (ADS)

Trzeciak, Tomasz; Garcia-Carreras, Luis; Marsham, John H.

2017-04-01

Very limited observational data has previously limited our ability to study meteorological processes in the Sahara. The Sahara is a key component of the West African monsoon and the world's largest dust source, but its representation is a major uncertainty in global models. Past studies have shown that there is a persistent warm and dry model bias throughout the Sahara, and this has been attributed to the lack of convectively-generated cold pools in the model, which can ventilate the central Sahara from its margins. Here we present an observed case from June 2012 which explains how cold pools are able to transport water vapour across a large area of the Sahara over a period of several days. A daily cycle is found to occur, where deep convection in the evening generates moist cold pools that then feed the next day's convection; the new convection in turn generates new cold pools, providing a vertical recycling of moisture. Trajectories driven by analyses can capture the general direction of transport, but not its full extent, especially at night when cold pools are most active, highlighting the difficulties for models to capture these processes. These results show the importance of cold pools for moisture transport, dust and clouds in the region, and demonstrate the need to include these processes in models to improve the representation of the Saharan atmosphere.

Assessment of swimmer behaviors on pool water ingestion

EPA Science Inventory

Enteric pathogens in pool water can be unintentionally ingested during swimming, increasing the likelihood of acute gastrointestinal illness(AGI). AGI cases in outbreaks are more likely to submerge heads than non-cases, but an association is unknown since outbreak data are self-r...

Titanium distribution in swimming pool water is dominated by dissolved species.

PubMed

David Holbrook, R; Motabar, Donna; Quiñones, Oscar; Stanford, Benjamin; Vanderford, Brett; Moss, Donna

2013-10-01

The increased use of titanium dioxide nanoparticles (nano-TiO2) in consumer products such as sunscreen has raised concerns about their possible risk to human and environmental health. In this work, we report the occurrence, size fractionation and behavior of titanium (Ti) in a children's swimming pool. Size-fractionated samples were analyzed for Ti using ICP-MS. Total titanium concentrations ([Ti]) in the pool water ranged between 21 μg/L and 60 μg/L and increased throughout the 101-day sampling period while [Ti] in tap water remained relatively constant. The majority of [Ti] was found in the dissolved phase (<1 kDa), with only a minor fraction of total [Ti] being considered either particulate or microparticulate. Simple models suggest that evaporation may account for the observed variation in [Ti], while sunscreen may be a relevant source of particulate and microparticule Ti. Compared to diet, incidental ingestion of nano-Ti from swimming pool water is minimal. Published by Elsevier Ltd.

Elevated soil nitrogen pools after conversion of turfgrass to water-efficient residential landscapes

NASA Astrophysics Data System (ADS)

Heavenrich, Hannah; Hall, Sharon J.

2016-08-01

As a result of uncertain resource availability and growing populations, city managers are implementing conservation plans that aim to provide services for people while reducing household resource use. For example, in the US, municipalities are incentivizing homeowners to replace their water-intensive turfgrass lawns with water-efficient landscapes consisting of interspersed drought-tolerant shrubs and trees with rock or mulch groundcover (e.g. xeriscapes, rain gardens, water-wise landscapes). While these strategies are likely to reduce water demand, the consequences for other ecosystem services are unclear. Previous studies in controlled, experimental landscapes have shown that conversion from turfgrass to shrubs may lead to high rates of nutrient leaching from soils. However, little is known about the long-term biogeochemical consequences of this increasingly common land cover change across diverse homeowner management practices. We explored the fate of soil nitrogen (N) across a chronosequence of land cover change from turfgrass to water-efficient landscapes in privately owned yards in metropolitan Phoenix, Arizona, in the arid US Southwest. Soil nitrate ({{{{NO}}}3}--N) pools were four times larger in water-efficient landscapes (25 ± 4 kg {{{{NO}}}3}--N/ha 0-45 cm depth) compared to turfgrass lawns (6 ± 7 kg {{{{NO}}}3}--N/ha). Soil {{{{NO}}}3}--N also varied significantly with time since landscape conversion; the largest pools occurred at 9-13 years after turfgrass removal and declined to levels comparable to turfgrass thereafter. Variation in soil {{{{NO}}}3}--N with landscape age was strongly influenced by management practices related to soil water availability, including shrub cover, sub-surface plastic sheeting, and irrigation frequency. Our findings show that transitioning from turfgrass to water-efficient residential landscaping can lead to an accumulation of {{{{NO}}}3}--N that may be lost from the plant rooting zone over time following irrigation or

Bacterial community structure and dissolved organic matter in repeatedly flooded subsurface karst water pools.

PubMed

Shabarova, Tanja; Villiger, Jörg; Morenkov, Oleg; Niggemann, Jutta; Dittmar, Thorsten; Pernthaler, Jakob

2014-07-01

Bacterial diversity, community assembly, and the composition of the dissolved organic matter (DOM) were studied in three temporary subsurface karst pools with different flooding regimes. We tested the hypothesis that microorganisms introduced to the pools during floods faced environmental filtering toward a 'typical' karst water community, and we investigated whether DOM composition was related to floodings and the residence time of water in stagnant pools. As predicted, longer water residence consistently led to a decline of bacterial diversity. The microbial assemblages in the influx water harbored more 'exotic' lineages with large distances to known genotypes, yet these initial communities already appeared to be shaped by selective processes. β-Proteobacterial operational taxonomic units (OTUs) closely related to microbes from subsurface or surface aquatic environments were mainly responsible for the clustering of samples according to water residence time in the pools. By contrast, several Cytophagaceae and Flavobacteriaceae OTUs were related to different floodings, which were also the main determinants of DOM composition. A subset of compounds distinguishable by molecular mass and O/C content were characteristic for individual floods. Moreover, there was a transformation of DOM in stagnant pools toward smaller and more aromatic compounds, potentially also reflecting microbial utilization. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

9. Tower building. Hot water tap floor shown. Mixing vat ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. Tower building. Hot water tap floor shown. Mixing vat at center level. Juices mix and flow and left lower level. Copper kettles are down below view level. Looking toward front of building. - Tivoli-Union Brewery, 1320-1348 Tenth Street, Denver, Denver County, CO

Numerical simulation of ground-water flow in La Crosse County, Wisconsin, and into nearby pools of the Mississippi River

USGS Publications Warehouse

Hunt, Randall J.; Saad, David A.; Chapel, Dawn M.

2003-01-01

The models provide estimates of the locations and amount of ground-water flow into Pool 8 and the southern portion of Pool 7 of the Mississippi River. Ground-water discharges into all areas of the pools, except along the eastern shore in the vicinity of the city of La Crosse and immediately downgradient from lock and dam 7 and 8. Ground-water flow into the pools is generally greatest around the perimeter with decreasing amounts away from the perimeter. An area of relatively high ground-water discharge extends out towards the center of Pool 7 from the upper reaches of the pool and may

Pool Purification

NASA Technical Reports Server (NTRS)

1988-01-01

Caribbean Clear, Inc. used NASA's silver ion technology as a basis for its automatic pool purifier. System offers alternative approach to conventional purification chemicals. Caribbean Clear's principal markets are swimming pool owners who want to eliminate chlorine and bromine. Purifiers in Caribbean Clear System are same silver ions used in Apollo System to kill bacteria, plus copper ions to kill algae. They produce spa or pool water that exceeds EPA Standards for drinking water.

A simplified model to predict diurnal water temperature dynamics in a shallow tropical water pool.

PubMed

Paaijmans, Krijn P; Heusinkveld, Bert G; Jacobs, Adrie F G

2008-11-01

Water temperature is a critical regulator in the growth and development of malaria mosquito immatures, as they are poikilothermic. Measuring or estimating the diurnal temperature ranges to which these immatures are exposed is of the utmost importance, as these immatures will develop into adults that can transmit malaria. Recent attempts to predict the daily water temperature dynamics in mosquito breeding sites in Kenya have been successful. However, the developed model may be too complex, as the sophisticated equipment that was used for detailed meteorological observations is not widely distributed in Africa, making it difficult to predict the daily water temperature dynamics on a local scale. Therefore, we compared two energy budget models with earlier made observations of the daily water temperature dynamics in a small, shallow and clear water pool (diameter 0.96 m, depth 0.32 m) in Kenya. This paper describes (1) a complex 1-Dimensional model, and (2) a simplified second model, and (3) shows that both models mimic the water temperature dynamics in the water pool accurately. The latter model has the advantage that it only needs common weather data (air temperature, air humidity, wind speed and cloud cover) to estimate the diurnal temperature dynamics in breeding sites of African malaria mosquitoes.

Cross‐Saharan transport of water vapor via recycled cold pool outflows from moist convection

PubMed Central

Trzeciak, Tomasz M.; Garcia‐Carreras, Luis

2017-01-01

Abstract Very sparse data have previously limited observational studies of meteorological processes in the Sahara. We present an observed case of convectively driven water vapor transport crossing the Sahara over 2.5 days in June 2012, from the Sahel in the south to the Atlas in the north. A daily cycle is observed, with deep convection in the evening generating moist cold pools that fed the next day's convection; the convection then generated new cold pools, providing a vertical recycling of moisture. Trajectories driven by analyses were able to capture the direction of the transport but not its full extent, particularly at night when cold pools are most active, and analyses missed much of the water content of cold pools. The results highlight the importance of cold pools for moisture transport, dust and clouds, and demonstrate the need to include these processes in models in order to improve the representation of Saharan atmosphere. PMID:28344367

Perceived health problems in swimmers according to the chemical treatment of water in swimming pools.

PubMed

Fernández-Luna, Álvaro; Burillo, Pablo; Felipe, José Luis; del Corral, Julio; García-Unanue, Jorge; Gallardo, Leonor

2016-01-01

The objective of this study was to determine which chemical treatment used for disinfecting water in indoor swimming pools had the least impact on users' perceptions of health problems, and which generated the greatest satisfaction with the quality of the water. A survey on satisfaction and perceived health problems was given to 1001 users at 20 indoor swimming pools which used different water treatment methods [chlorine, bromine, ozone, ultraviolet lamps (UV) and salt electrolysis]. The findings suggest that there is a greater probability of perceived health problems, such as eye and skin irritation, respiratory problems and skin dryness, in swimming pools treated with chlorine than in swimming pools using other chemical treatment methods. Pools treated with bromine have similar, although slightly better, results. Other factors, such as age, gender, time of day of use (morning and afternoon) and type of user (competitive and recreational), can also affect the probability of suffering health problems. For all of the above, using combined treatment methods as ozone and UV, or salt electrolysis produces a lower probability of perceived health problems and greater satisfaction.

Mass effects meet species sorting: transformations of microbial assemblages in epiphreatic subsurface karst water pools.

PubMed

Shabarova, Tanja; Widmer, Franco; Pernthaler, Jakob

2013-09-01

We investigated the transformations of the microbial communities in epiphreatic karst cave pools with different flooding frequencies. Fingerprinting of 16S rRNA genes was combined with microscopic and sequence analysis to examine if source water would transport comparable microbial inocula into the pools at consecutive flood events, and to assess possible effects of residence time on the microbial assemblages during stagnant periods. Variability in the concentrations of dissolved organic carbon and conductivity indicated differences between floods and changes of pool water over time. High numbers of Betaproteobacteria affiliated with Methylophilaceae and Comamonadaceae were introduced into the pools during floodings. While the former persisted in the pools, the latter exhibited considerable microdiversification. These Betaproteobacteria might thus represent core microbial groups in karst water. A decrease in the estimated total diversity of the remaining bacterial taxa was apparent after a few weeks of residence: Some were favoured by stagnant conditions, whereas the majority was rapidly outcompeted. Thus, the microbial communities consisted of different components governed by complementary assembly mechanisms (dispersal versus environmental filtering) upon introduction into the pools. High overlap of temporary and persistent community members between samplings from two winters, moreover, reflected the seasonal recurrence of the studied microbial assemblages. © 2013 John Wiley & Sons Ltd and Society for Applied Microbiology.

From Source Water to Tap Water to Spa and Swimming Pool Water: Effects of Disinfectanta and Precursors and Implications for Exposure and Toxicity

EPA Science Inventory

Introduction The current study investigated the effect of different disinfection treatments on the disinfection by-products (DBPs) formed in finished drinking water vs. tap water vs. swimming pool water vs. spa waters. To this end, samples across the complete water pathway (untr...

Rapid general dental erosion by gas-chlorinated swimming pool water. Review of the literature and case report.

PubMed

Geurtsen, W

2000-12-01

Several reports indicate an increased prevalence of dental erosion among intensive swimmers due to low pH gas-chlorinated pool water. Contrary to other extrinsic factors which induce erosion located on the facial aspect, low pH pool water results in general dental erosion. Additionally, a case report is presented which describes the very rapid occurrence of excessive general dental erosion of a competitive swimmer due to gas-chlorinated pool water within 27 days. The observation of several authors as well as this case underscore the significance of a regular pH monitoring of chlorinated swimming pool water. The high incidence indicates that dental erosion due to frequent swimming is of considerable diagnostic and therapeutic significance. Furthermore, it is recommended to fluoridate the teeth of intensive swimmers regularly to prevent dental erosion.

Prevalence of dental erosion in adolescent competitive swimmers exposed to gas-chlorinated swimming pool water.

PubMed

Buczkowska-Radlińska, J; Łagocka, R; Kaczmarek, W; Górski, M; Nowicka, A

2013-03-01

The purpose of this study was to analyze the prevalence of dental erosion among competitive swimmers of the local swimming club in Szczecin, Poland, who train in closely monitored gas-chlorinated swimming pool water. The population for this survey consisted of a group of junior competitive swimmers who had been training for an average of 7 years, a group of senior competitive swimmers who had been training for an average of 10 years, and a group of recreational swimmers. All subjects underwent a clinical dental examination and responded to a questionnaire regarding aspects of dental erosion. In pool water samples, the concentration of calcium, magnesium, phosphate, sodium, and potassium ions and pH were determined. The degree of hydroxyapatite saturation was also calculated. Dental erosion was found in more than 26 % of the competitive swimmers and 10 % of the recreational swimmers. The lesions in competitive swimmers were on both the labial and palatal surfaces of the anterior teeth, whereas erosions in recreational swimmers developed exclusively on the palatal surfaces. Although the pH of the pool water was neutral, it was undersaturated with respect to hydroxyapatite. The factors that increase the risk of dental erosion include the duration of swimming and the amount of training. An increased risk of erosion may be related to undersaturation of pool water with hydroxyapatite components. To decrease the risk of erosion in competitive swimmers, the degree of dental hydroxyapatite saturation should be a controlled parameter in pool water.

Pore diffusion limits removal of monochloramine in treatment of swimming pool water using granular activated carbon.

PubMed

Skibinski, Bertram; Götze, Christoph; Worch, Eckhard; Uhl, Wolfgang

2018-04-01

Overall apparent reaction rates for the removal of monochloramine (MCA) in granular activated carbon (GAC) beds were determined using a fixed-bed reactor system and under conditions typical for swimming pool water treatment. Reaction rates dropped and quasi-stationary conditions were reached quickly. Diffusional mass transport in the pores was shown to be limiting the overall reaction rate. This was reflected consistently in the Thiele modulus, in the effect of temperature, pore size distribution and of grain size on the reaction rates. Pores <2.5 times the diameter of the monochloramine molecule were shown to be barely accessible for the monochloramine conversion reaction. GACs with a significant proportion of large mesopores were found to have the highest overall reactivity for monochloramine removal. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Recreational Water Cycle: From Source Water to Tap Water to Spa and Swimming Pool Water: Effects of Disinfectants and Precursors and Implications for Exposure and Toxicity

EPA Science Inventory

The current study investigates the effect of different disinfection treatments on the disinfection by-products (DBPs) formed in finished drinking water vs. tap water vs. swimming pool water vs. spa waters. To this end, complete water pathway samples (untreated source waters ->fi...

Temperature dependence of water diffusion pools in brain white matter.

PubMed

Dhital, Bibek; Labadie, Christian; Stallmach, Frank; Möller, Harald E; Turner, Robert

2016-02-15

Water diffusion in brain tissue can now be easily investigated using magnetic resonance (MR) techniques, providing unique insights into cellular level microstructure such as axonal orientation. The diffusive motion in white matter is known to be non-Gaussian, with increasing evidence for more than one water-containing tissue compartment. In this study, freshly excised porcine brain white matter was measured using a 125-MHz MR spectrometer (3T) equipped with gradient coils providing magnetic field gradients of up to 35,000 mT/m. The sample temperature was varied between -14 and +19 °C. The hypothesis tested was that white matter contains two slowly exchanging pools of water molecules with different diffusion properties. A Stejskal-Tanner diffusion sequence with very short gradient pulses and b-factors up to 18.8 ms/μm(2) was used. The dependence on b-factor of the attenuation due to diffusion was robustly fitted by a biexponential function, with comparable volume fractions for each component. The diffusion coefficient of each component follows Arrhenius behavior, with significantly different activation energies. The measured volume fractions are consistent with the existence of three water-containing compartments, the first comprising relatively free cytoplasmic and extracellular water molecules, the second of water molecules in glial processes, and the third comprising water molecules closely associated with membranes, as for example, in the myelin sheaths and elsewhere. The activation energy of the slow diffusion pool suggests proton hopping at the surface of membranes by a Grotthuss mechanism, mediated by hydrating water molecules. Copyright © 2015 Elsevier Inc. All rights reserved.

[Environmental surveillance of a sample of indoor swimming pools from Emilia Romagna region: microclimate characteristics and chemical parameters, particularly disinfection by products, in pool waters].

PubMed

Fantuzzi, G; Righi, E; Predieri, G; Giacobazzi, P; Mastroianni, K; Aggazzotti, G

2010-01-01

The aim of the present study was to investigate the environmental and healthy aspects from a representative sample of indoor swimming pools located in the Emilia Romagna region. During the sampling sessions, the occupational environment was evaluated in terms of microclimate parameters and thermal comfort/discomfort conditions. Moreover the chemical risk was assessed by analyzing from the pool water the presence of disinfection by-products (DBPs), such as: trihalomethanes (THMs), haloacetic acids (HAAs), chlorite, chlorate and bromate. The analytical results are in agreement with the Italian legislation (Accordo Stato-Regioni; 2003) even if in some of the sampled indoor swimming pools, the dosed combined chlorine levels, were greater than the Italian limit. With the regard to the microclimate conditions evaluation, the considered thermal indices, Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD%), described a satisfactory occupational environment. Among DBPs, the THMs mean levels (41.4 +/- 30.0 microg/l) resulted close to the values of the current Italian drinking water legislation, and seem to not represent an health issue. The pool waters chlorate levels (range: 5 - 19537 microg/l) need further investigations as recent epidemiological studies on drinking water hypothesized a potential genotoxicity effect of these compounds which are involved in cellular oxidative processes.

TOPEX/El Nino Watch - El Nino Warm Water Pool Decreasing, Jan, 08, 1998

NASA Technical Reports Server (NTRS)

1998-01-01

This image of the Pacific Ocean was produced using sea surface height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on Jan. 8, 1998, and sea surface height is an indicator of the heat content of the ocean. The volume of the warm water pool related to the El Nino has decreased by about 40 percent since its maximum in early November, but the area of the warm water pool is still about one and a half times the size of the continental United States. The volume measurements are computed as the sum of all the sea surface height changes as compared to normal ocean conditions. In addition, the maximum water temperature in the eastern tropical Pacific, as measured by the National Oceanic and Atmospheric Administration (NOAA), is still higher than normal. Until these high temperatures diminish, the El Nino warm water pool still has great potential to disrupt global weather because the high water temperatures directly influence the atmosphere. Oceanographers believe the recent decrease in the size of the warm water pool is a normal part of El Nino's natural rhythm. TOPEX/Poseidon has been tracking these fluctuations of the El Nino warm pool since it began in early 1997. These sea surface height measurements have provided scientists with their first detailed view of how El Nino's warm pool behaves because the TOPEX/Poseidon satellite measures the changing sea surface height with unprecedented precision. In this image, the white and red areas indicate unusual patterns of heat storage; in the white areas, the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal; in the red areas, it's about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions, while purple (the western Pacific) means at least 18 centimeters (7 inches) below normal sea level.

The El Nino phenomenon is thought to be triggered when the steady westward blowing trade winds

Photolytic removal of DBPs by medium pressure UV in swimming pool water.

PubMed

Hansen, Kamilla M S; Zortea, Raissa; Piketty, Aurelia; Vega, Sergio Rodriguez; Andersen, Henrik Rasmus

2013-01-15

Medium pressure UV is used for controlling the concentration of combined chlorine (chloramines) in many public swimming pools. Little is known about the fate of other disinfection by-products (DBPs) in UV treatment. Photolysis by medium pressure UV treatment was investigated for 12 DBPs reported to be found in swimming pool water: chloroform, bromodichloromethane, dibromochloromethane, bromoform, dichloroacetonitrile, bromochloroacetonitrile, dibromoacetronitrile, trichloroacetonitrile, trichloronitromethane, dichloropropanone, trichloropropanone, and chloral hydrate. First order photolysis constants ranged 26-fold from 0.020 min(-1) for chloroform to 0.523 min(-1) for trichloronitromethane. The rate constants generally increased with bromine substitution. Using the UV removal of combined chlorine as an actinometer, the rate constants were recalculated to actual treatment doses of UV applied in a swimming pool. In an investigated public pool the UV dose was equivalent to an applied electrical energy of 1.34 kWh m(-3) d(-1) and the UV dose required to removed 90% of trichloronitromethane was 0.4 kWh m(-3) d(-1), while 2.6 kWh m(-3) d(-1) was required for chloral hydrate and the bromine containing haloacetonitriles and trihalomethanes ranged from 0.6 to 3.1 kWh m(-3) d(-1). It was predicted thus that a beneficial side-effect of applying UV for removing combined chlorine from the pool water could be a significant removal of trichloronitromethane, chloral hydrate and the bromine containing haloacetonitriles and trihalomethanes. Copyright © 2012 Elsevier B.V. All rights reserved.

HPLC DETERMINATION OF CYANURIC ACID IN SWIMMING POOL WATERS USING PHENYL AND CONFIRMATORY POROUS GRAPHITIC CARBON COLUMNS

EPA Science Inventory

The chlorinated salts of cyanuric acid have found an important role in recreational swimming pool waters across the United States. Upon application to pool water, they can (1) release disinfectant chlorine or (2) stabilize the free available chlorine by acting as chlorine reserv...

Design of hydrotherapy exercise pools.

PubMed

Edlich, R F; Abidin, M R; Becker, D G; Pavlovich, L J; Dang, M T

1988-01-01

Several hydrotherapy pools have been designed specifically for a variety of aquatic exercise. Aqua-Ark positions the exerciser in the center of the pool for deep-water exercise. Aqua-Trex is a shallow underwater treadmill system for water walking or jogging. Swim-Ex generates an adjustable laminar flow that permits swimming without turning. Musculoskeletal conditioning can be accomplished in the above-ground Arjo shallow-water exercise pool. A hydrotherapy pool also can be custom designed for musculoskeletal conditioning in its shallow part and cardiovascular conditioning in a deeper portion of the pool. Regardless of the type of exercise, there is general agreement that the specific exercise conducted in water requires significantly more energy expenditure than when the same exercise is performed on land.

Seasonal dynamics of water and air chemistry in an indoor chlorinated swimming pool.

PubMed

Zare Afifi, Mehrnaz; Blatchley, Ernest R

2015-01-01

Although swimming is known to be beneficial in terms of cardiovascular health, as well as for some forms of rehabilitation, swimming is also known to present risks to human health, largely in the form of exposure to microbial pathogens and disinfection byproducts (DBPs). Relatively little information is available in the literature to characterize the seasonal dynamics of air and water chemistry in indoor chlorinated swimming pools. To address this issue, water samples were collected five days per week from an indoor chlorinated swimming pool facility at a high school during the academic year and once per week during summer over a fourteen-month period. The samples were analyzed for free and combined chlorine, urea, volatile DBPs, pH, temperature and total alkalinity. Membrane Introduction Mass Spectrometry (MIMS) was used to identify and measure the concentrations of eleven aqueous-phase volatile DBPs. Variability in the concentrations of these DBPs was observed. Factors that influenced variability included bather loading and mixing by swimmers. These compounds have the ability to adversely affect water and air quality and human health. A large fraction of the existing literature regarding swimming pool air quality has focused on trichloramine (NCl₃). For this work, gas-phase NCl₃ was analyzed by an air sparging-DPD/KI method. The results showed that gas-phase NCl₃ concentration is influenced by bather loading and liquid-phase NCl₃ concentration. Urea is the dominant organic-N compound in human urine and sweat, and is known to be an important precursor for producing NCl₃ in swimming pools. Results of daily measurements of urea indicated a link between bather load and urea concentration in the pool.

HYDROLOGY AND LANDSCAPE CONNECTIVITY OF VERNAL POOLS

EPA Science Inventory

Vernal pools are shaped by hydrologic processes which influence many aspects of pool function. The hydrologic budget of a pool can be summarized by a water balance equation that relates changes in the amount of water in the pool to precipitation, ground- and surface-water flows, ...

Secondary formation of disinfection by-products by UV treatment of swimming pool water.

PubMed

Spiliotopoulou, Aikaterini; Hansen, Kamilla M S; Andersen, Henrik R

2015-07-01

Formation of disinfection by-products (DBPs) during experimental UV treatment of pool water has previously been reported with little concurrence between laboratory studies, field studies and research groups. In the current study, changes in concentration of seven out of eleven investigated volatile DBPs were observed in experiments using medium pressure UV treatment, with and without chlorine and after post-UV chlorination. Results showed that post-UV chlorine consumption increased, dose-dependently, with UV treatment dose. A clear absence of trihalomethane formation by UV and UV with chlorine was observed, while small yet statistically significant increases in dichloroacetonitrile and dichloropropanone concentrations were detected. Results indicate that post-UV chlorination clearly induced secondary formation of several DBPs. However, the formation of total trihalomethanes was no greater than what could be replicated by performing the DBP formation assay with higher chlorine concentrations to simulate extended chlorination. Post-UV chlorination of water from a swimming pool that continuously uses UV treatment to control combined chlorine could not induce secondary formation for most DBPs. Concurrence for induction of trihalomethanes was identified between post-UV chlorination treatments and simulated extended chlorination time treatment. Trihalomethanes could not be induced by UV treatment of water from a continuously UV treated pool. This indicates that literature reports of experimentally induced trihalomethane formation by UV may be a result of kinetic increase in formation by UV. However, this does not imply that higher trihalomethane concentrations would occur in pools that apply continuous UV treatment. The bromine fraction of halogens in formed trihalomethanes increased with UV dose. This indicates that UV removes bromine atoms from larger molecules that participate in trihalomethane production during post-UV chlorination. Additionally, no significant

Occurrence of brominated disinfection byproducts in the air and water of chlorinated seawater swimming pools.

PubMed

Manasfi, Tarek; Temime-Roussel, Brice; Coulomb, Bruno; Vassalo, Laurent; Boudenne, Jean-Luc

2017-05-01

An undesirable consequence of disinfection is the formation of chemical contaminants known as disinfection byproducts (DBPs). Chronic exposure to DBPs has been linked to adverse health effects. The occurrence of DBPs in chlorinated pools filled with seawater (such as thalassotherapy pools and pools in spas) has received little attention so far. The present study evaluated the speciation and levels of disinfection byproducts in indoor swimming pools filled with seawater and treated with chlorine. Water and air samples were collected from three indoor swimming pools located in Southern France. Several classes of DBPs including trihalomethanes, haloacetic acids, haloacetonitriles, and trihaloacetaldehydes were analyzed in water. Halogenated volatile organic compounds were analyzed in air. Extractable organic halides (EOX) contents were determined using combustion/micro-coulometry system. The speciation of DBPs identified in the three pools was predominantly brominated. The mean (arithmetic) concentration of bromoform, dibromoacetic acid, tribromoacetic acid, dibromoacetonitrile and bromal hydrate in the three pools was 79.2, 72.9, 59.9, 26.9 and 10.0μg/L, respectively. By weight, HAAs represented the most abundant chemical class followed by THMs. In air, bromoform was the most abundant THM occurring at a mean concentration of 133.2μg/m 3 in the three pools. The mean EOX level was 706μgCl - /L for the three pools. In average, the quantified DBPs accounted for only 14% of EOX, thus 86% of EOX remained unknown. Further research is warranted to identify the unknown DBPs. Copyright © 2017 Elsevier GmbH. All rights reserved.

Life cycle environmental implications of residential swimming pools.

PubMed

Forrest, Nigel; Williams, Eric

2010-07-15

Ownership of private swimming pools in the U.S. grew 2 to 4% per annum from 1997 to 2007. The environmental implications of pool ownership are analyzed by hybrid life cycle assessment (LCA) for nine U.S. cities. An operational model is constructed estimating consumption of chemicals, water, and energy for a typical residential pool. The model incorporates geographical climatic variations and upstream water and energy use from electricity and water supply networks. Results vary considerably by city: a factor of 5-6 for both water and energy use. Water use is driven by aridness and length of the swimming season, while energy use is mainly driven by length of the swimming season. Water and energy impacts of pools are significant, particularly in arid climates. In Phoenix for example pools account for 22% and 13% of a household's electricity and water use, respectively. Measures to reduce water and energy use in pools such as optimizing the pump schedule and covering the pool in winter can realize greater savings than many common household efficiency improvements. Private versus community pools are also compared. Community pools in Phoenix use 60% less swimming pool water and energy per household than subdivisions without community pools.

Water and sediment quality of dry season pools in a dryland river system: the upper Leichhardt River, Queensland, Australia.

PubMed

Mackay, Alana K; Taylor, Mark P; Hudson-Edwards, Karen A

2011-07-01

This article presents the geochemical characteristics and physicochemical properties of water and sediment from twelve semi-permanent, dryland pools in the upper Leichhardt River catchment, north-west Queensland, Australia. The pools were examined to better understand the quality of sediments and temporary waters in a dryland system with a well-established metal contamination problem. Water and sediment sampling was conducted at the beginning of the hydroperiod in May and September 2007. Water samples were analyzed for major solute compositions (Ca, Na, K, Mg, Cl, SO(4), HCO(3)) and water-soluble (operationally defined as the <0.45 μm fraction) metals (Cd, Cu, Pb, Zn). Sediment samples were analyzed for total extractable and bioaccessible metals (As, Cd, Cu, Pb, Zn), elemental composition and grain morphology. At the time of sampling a number of pools contained water and sediment with elevated concentrations, compared to Australian regulatory guidelines, of Cu (maximum: water 28 μg L(-1); sediment 770 mg kg(-1)), Pb (maximum: water 3.4 μg L(-1); sediment 630 mg kg(-1)) and Zn (maximum: water 150 μg L(-1); sediment 780 mg kg(-1)). Concentrations of Cd and As in pools were relatively low and generally within Australian regulatory guideline values. Localized factors, such as the interaction of waters with anthropogenic contaminants from modern and historic mine wastes (i.e. residual smelter and slag materials), exert influence on the quality of pool waters. Although the pools of the upper Leichhardt River catchment are contaminated, they do not appear to be the primary repository of water and sediment associated metals when compared to materials in the remainder channel and floodplain. Nevertheless, a precautionary approach should be adopted to mitigating human exposure to contaminated environments, which might include the installation of appropriate warning signs by local health and environmental authorities.

ASCAN Ochoa floats in pool during Elgin AFB water survival training

NASA Technical Reports Server (NTRS)

1990-01-01

1990 Group 13 Astronaut Candidate (ASCAN) Ellen Ochoa, wearing helmet and flight suit, climbs into a single person life raft while floating in a pool at Elgin Air Force Base (AFB) in Pensacola, Florida, during water survival exercises. Ochoa's underarm flotation device holds her above the water as she pulls herself into the life raft. The training familiarized the candidates with survival techniques necessary in the event of a water landing. ASCANs participated in the exercises from 08-14-90 through 08-17-90.

[Surveillance of the sanitary conditions of a public swimming pool in the city of Palermo (Italy)].

PubMed

Maida, Carmelo Massimo; Di Benedetto, Maria Antonella; Firenze, Alberto; Calamusa, Giuseppe; Di Piazza, Florinda; Milici, Maria Eleonora; Romano, Nino

2008-01-01

In a previous study we evaluated the microbiological quality of water of seven pools in the city of Palermo through evaluation of bacterial indicators of faecal contamination and of protozoa (Giardia and Cryptosporidium). In this study we also searched for the presence of fungi in two swimming pools of a public swimming facility in the same city. Samples were collected from both pools, their filtration systems and floor surfaces of the facility. Chemical-physical and microbiological examination of water of the two pools have shown that quality of water depends on the concentration of residual free chlorine and on the number of bathers in the pool. The values of four microbiological parameters (bacterial load at 22 degrees C and 36 degrees C, presence of coagulase-negative Staphylococci and Pseudomonas spp.) increased with diminishing chlorine concentrations and with increasing number of pool users. Faecal bacteria, Giardia and Cryptosporidium were not found. On the other hand, various fungi were isolated from floor surfaces and pool water even in the presence of optimal chlorine concentrations. This study confirms the importance of regular maintenance of pool disinfection systems and suggests the need to search for other micro-organisms not included in the current legislation (Giardia, Cryptosporidium and fungi).

Chemistry of Hot Spring Pool Waters in Calamba and Los Banos and Potential Effect on the Water Quality of Laguna De Bay

NASA Astrophysics Data System (ADS)

Balangue, M. I. R. D.; Pena, M. A. Z.; Siringan, F. P.; Jago-on, K. A. B.; Lloren, R. B.; Taniguchi, M.

2014-12-01

Since the Spanish Period (1600s), natural hot spring waters have been harnessed for balneological purposes in the municipalities of Calamba and Los Banos, Laguna, south of Metro Manila. There are at more than a hundred hot spring resorts in Brgy. Pansol, Calamba and Tadlac, Los Banos. These two areas are found at the northern flanks of Mt. Makiling facing Laguna de Bay. This study aims to provide some insights on the physical and chemical characteristics of hot spring resorts and the possible impact on the lake water quality resulting from the disposal of used water. Initial ocular survey of the resorts showed that temperature of the pool water ranges from ambient (>300C) to as high as 500C with an average pool size of 80m3. Water samples were collected from a natural hot spring and pumped well in Los Banos and another pumped well in Pansol to determine the chemistry. The field pH ranges from 6.65 to 6.87 (Pansol springs). Cation analysis revealed that the thermal waters belonged to the Na-K-Cl-HCO3 type with some trace amount of heavy metals. Methods for waste water disposal are either by direct discharge down the drain of the pool or by discharge in the public road canal. Both methods will dump the waste water directly into Laguna de Bay. Taking in consideration the large volume of waste water used especially during the peak season, the effect on the lake water quality would be significant. It is therefore imperative for the environmental authorities in Laguna to regulate and monitor the chemistry of discharges from the pool to protect both the lake water as well as groundwater quality.

Direct observation of terahertz surface modes in nanometer-sized liquid water pools.

PubMed

Boyd, J E; Briskman, A; Colvin, V L; Mittleman, D M

2001-10-01

The far-infrared absorption spectrum of nanometer-sized water pools at the core of AOT micelles exhibits a pronounced resonance which is absent in bulk water. The amplitude and spectral position of this resonance are sensitive to the size of the confined water core. This resonance results from size-dependent modifications in the vibrational density of states, and thus has far-reaching implications for chemical processes which involve water sequestered within small cavities. These data represent the first study of the terahertz dielectric properties of confined liquids.

Pool boiling of water-Al2O3 and water-Cu nanofluids on horizontal smooth tubes

PubMed Central

2011-01-01

Experimental investigation of heat transfer during pool boiling of two nanofluids, i.e., water-Al2O3 and water-Cu has been carried out. Nanoparticles were tested at the concentration of 0.01%, 0.1%, and 1% by weight. The horizontal smooth copper and stainless steel tubes having 10 mm OD and 0.6 mm wall thickness formed test heater. The experiments have been performed to establish the influence of nanofluids concentration as well as tube surface material on heat transfer characteristics at atmospheric pressure. The results indicate that independent of concentration nanoparticle material (Al2O3 and Cu) has almost no influence on heat transfer coefficient while boiling of water-Al2O3 or water-Cu nanofluids on smooth copper tube. It seems that heater material did not affect the boiling heat transfer in 0.1 wt.% water-Cu nanofluid, nevertheless independent of concentration, distinctly higher heat transfer coefficient was recorded for stainless steel tube than for copper tube for the same heat flux density. PMID:21711741

Swimming Pool Water Treatment Chemicals and/or Processes. Standard No. 22.

ERIC Educational Resources Information Center

National Sanitation Foundation, Ann Arbor, MI.

Chemicals or processes used or intended for use, in the treatment of swimming pool water are covered. Minimum public health limits or acceptability in regard to toxicity, biocidal effectiveness, and chemical behavior and analysis are presented. The appendices give guidelines to the scientific and statistically sound evaluations to determine the…

Experimental study on pool boiling of distilled water and HFE7500 fluid under microgravity

NASA Astrophysics Data System (ADS)

Yang, Yan-jie; Chen, Xiao-qian; Huang, Yi-yong; Li, Guang-yu

2018-02-01

The experimental study on bubble behavior and heat transfer of pool boiling for distilled water and HFE7500 fluid under microgravity has been conducted by using drop tower in the National Microgravity Laboratory of China (NMLC). Two MCH ceramic plates of 20 mm(L) × 10 mm(W) × 1.2 mm(H) were used as the heaters. The nucleate boiling evolution under microgravity was observed during the experiment. It has been found that at the same heat flux, the bubbles of HFE7500 (which has smaller contact angle) grew faster and bigger, moved quickly on the heater surface, and were easier to merge into a central big bubble with other bubbles than that of distilled water. The whole process of bubbles coalescence from seven to one was recorded by using video camera. For distilled water (with bigger contact angle), the bubbles tended to keep at the nucleate location on heater surface, and the central big bubble evolved at its nucleate cite by absorbing smaller bubbles nearby. Compared with the bubbles under normal gravity, bubble radius of distilled water under microgravity was about 1.4 times bigger and of HFE7500 was about more than 6 times bigger till the end of experiment. At the beginning, pool boiling heat transfer of distilled water was advanced and then impeded under microgravity. As to HFE7500, the pool boiling impedes the heat transfer from heater to liquid under microgravity throughout the experiment.

Occurrence and Spatial and Temporal Variations of Disinfection By-Products in the Water and Air of Two Indoor Swimming Pools

PubMed Central

Catto, Cyril; Sabrina, Simard; Ginette, Charest-Tardif; Manuel, Rodriguez; Robert, Tardif

2012-01-01

In order to improve disinfection by-product (DBP) exposure assessment, this study was designed to document both water and air levels of these chemical contaminants in two indoor swimming pools and to analyze their within-day and day-to-day variations in both of them. Intensive sampling was carried out during two one-week campaigns to measure trihalomethanes (THMs) and chloramines (CAMs) in water and air, and haloacetic acids (HAAs) in water several times daily. Water samples were systematically collected at three locations in each pool and air samples were collected at various heights around the pool and in other rooms (e.g., changing room) in the buildings. In addition, the ability of various models to predict air concentrations from water was tested using this database. No clear trends, but actual variations of contamination levels, appeared for both water and air according to the sampling locations and times. Likewise, the available models resulted in realistic but imprecise estimates of air contamination levels from water. This study supports the recommendation that suitable minimal air and water sampling should be carried out in swimming pools to assess exposure to DBPs. PMID:23066383

Quantitative Measurement of Bromoform in Swimming Pool Water Using SPME with GC-MS. An Undergraduate Instrumental Analysis Experiment

NASA Astrophysics Data System (ADS)

Hardee, John R.; Long, John; Otts, Julie

2002-05-01

A senior-level undergraduate laboratory experiment that demonstrates the use of solid-phase microextraction (SPME) and capillary gas chromatography-mass spectrometry (GC-MS) was developed for the quantitative determination of bromoform in swimming pool water. Bromoform was extracted by SPME from the headspace of vials containing sodium chloride-saturated swimming pool water. Bromoform concentrations were determined from comparisons of peak areas on a student-generated calibration curve. Students compared results to OSHA water and air exposure limits for bromoform.

Disinfection by-products and microbial contamination in the treatment of pool water with granular activated carbon.

PubMed

Uhl, W; Hartmann, C

2005-01-01

For swimming pools, it is generally agreed that free chlorine levels have to be maintained to guarantee adequate disinfection. Recommended free chlorine levels can vary between 0.3 and 0.6 mg/L in Germany and up to 3 mg/L in other countries. Bathers introduce considerable amounts of organic matter, mainly in the form of such as urine and sweat, into the pool water. As a consequence, disinfection byproducts (DBPs) are formed. Regulations in Germany recommend levels of combined chlorine of less than 0.2 mg/L and levels of trihalomethanes (THMs) of less than 20 microg/L. Haloacetic acids (HAAs), haloacetonitriles (HANs), chloropicrin and chloral hydrate are also detected in considerable amounts. However, these compounds are not regulated yet. Swimming pool staff and swimmers, especially athletes, are primarily exposed to these byproducts by inhalation and/or dermal uptake. In Germany, new regulations for swimming pool water treatment generally require the use of activated carbon. In this project, three different types of granular activated carbon (GAC) (one standard GAC, two catalytic GACs) are compared for their long time behaviour in pool water treatment. In a pilot plant operated with real swimming pool water, production and removal of disinfection byproducts (THMs, HAAs, AOXs), of biodegradable substances (AOC), of bacteria (Pseudomonas aeruginosa, Legionella, coliforms, HPC) as well as the removal of chlorine and chloramines are monitored as function of GAC bed depth. Combined chlorine penetrates deeper in the filter bed than free chlorine does. However, both, free and combined chlorine removal efficiencies decrease over the time of filter operation. The decreases of removal efficiencies are also observed for parameters such as dissolved organic carbon, spectral absorption coefficient, adsorbable organic carbon and most of the disinfection byproducts. However, THMs, especially chloroform are produced in the filter bed. The GAC beds were contaminated microbially

10 CFR 36.33 - Irradiator pools.

Code of Federal Regulations, 2013 CFR

2013-01-01

... purification system designed to be capable of maintaining the water during normal operation at a conductivity..., irradiator pools must either: (1) Have a water-tight stainless steel liner or a liner metallurgically... water level that could allow water to drain out of the pool. Pipes that have intakes more than 0.5 meter...

10 CFR 36.33 - Irradiator pools.

Code of Federal Regulations, 2010 CFR

2010-01-01

... purification system designed to be capable of maintaining the water during normal operation at a conductivity..., irradiator pools must either: (1) Have a water-tight stainless steel liner or a liner metallurgically... water level that could allow water to drain out of the pool. Pipes that have intakes more than 0.5 meter...

10 CFR 36.33 - Irradiator pools.

Code of Federal Regulations, 2011 CFR

2011-01-01

... purification system designed to be capable of maintaining the water during normal operation at a conductivity..., irradiator pools must either: (1) Have a water-tight stainless steel liner or a liner metallurgically... water level that could allow water to drain out of the pool. Pipes that have intakes more than 0.5 meter...

10 CFR 36.33 - Irradiator pools.

Code of Federal Regulations, 2014 CFR

2014-01-01

... purification system designed to be capable of maintaining the water during normal operation at a conductivity..., irradiator pools must either: (1) Have a water-tight stainless steel liner or a liner metallurgically... water level that could allow water to drain out of the pool. Pipes that have intakes more than 0.5 meter...

10 CFR 36.33 - Irradiator pools.

Code of Federal Regulations, 2012 CFR

2012-01-01

... purification system designed to be capable of maintaining the water during normal operation at a conductivity..., irradiator pools must either: (1) Have a water-tight stainless steel liner or a liner metallurgically... water level that could allow water to drain out of the pool. Pipes that have intakes more than 0.5 meter...

Development of the laboratory prototype "CavyPool" for assessing treatments and materials for swimming pools.

PubMed

Valeriani, F; Gianfranceschi, G; Vitali, M; Protano, C; Romano Spica, V

2017-01-01

Hygiene and surveillance in swimming pools are established by WHO Guidelines and national laws. Progress in water management and pool construction is revolutionizing the field, introducing new materials, systems, disinfection procedures or monitoring markers. Innovation advances challenge the upgrading of safety and quality in pools and the appropriate implementation of guidelines. In order to provide a device for laboratory test, a prototype was realized and applied to study and compare swimming pool materials and treatments. A pool scale-model was engineered and evaluated by computational fluid dynamics algorithms. An automated real time monitoring assured steady state. Critical control points along the water circuit were made accessible to allow the placing of different biocides or water sampling. Simulations were safely performed in a standard hood. Materials for pool surfaces and pipelines were evaluated for biofilm formation under different disinfection conditions. Adherent microorganisms were assayed by mfDNA analysis using real time PCR. The prototype reached the steady state within 5-25 hours under different conditions, showing chemical, physical and fluid-dynamic stability. A method was optimized for testing materials showing their different response to biofilm induction. Several innovative PVC samples displayed highest resistance to bacterial adhesion. A device and method was developed for testing swimming pool hygienic parameters in laboratory. It allowed to test materials for pools hygiene and maintenance, including biofilm formation. It can be applied to simulate contaminations under different water treatments or disinfection strategies. It may support technical decisions and help policymakers in acquiring evidences for comparing or validating innovative solutions.

Re-defining and quantifying inorganic phosphate pools in the Soil and Water Assessment Tool

USDA-ARS?s Scientific Manuscript database

Abstract The Soil and Water Assessment Tool (SWAT), a large-scale hydrologic model, can be used to estimate the impact of land management practices on phosphate (P) loading in streams and water bodies. Three inorganic soil P pools (labile, active, and stable P) are currently defined in the SWAT mo...

What's in The Pool? A Comprehensive Identification Of Disinfection By-Products and Assessment of Mutagenicity of Chlorinated and Brominated Swimming Pool Water

EPA Science Inventory

Swimming pool disinfectants and disinfection by-products (DBPs) have been linked to human health effects, including asthma and bladder cancer, but no studies have provided a comprehensive identification of DBPs in the water and related that to mutagenicity. We performed a compreh...

Assessment of air and water contamination by disinfection by-products at 41 indoor swimming pools.

PubMed

Tardif, Robert; Catto, Cyril; Haddad, Sami; Simard, Sabrina; Rodriguez, Manuel

2016-07-01

This study was aimed at assessing the profiles (occurrence and speciation) of disinfection by-product (DBP) contamination in air and water of a group of 41 public indoor swimming pools in Québec (Canada). The contaminants measured in the water included the traditional DBPs [i.e., four trihalomethanes (THMs), six haloacetic acids (HAAs)] but also several emergent DBPs [i.e., halonitriles, halonitromethanes, haloketones and nitrosodimethylamine (NDMA)]. Those measured in the air comprised THMs and chloramines (CAMs). Overall, extremely variable DBP levels were found from one pool to another (both quantitatively and in terms of speciation). For instance, in water, among the four THMs, chloroform was usually the most abundant compound (37.9±25.7µg/L). Nevertheless, the sum of the three other brominated THMs represented more than 25% of total THMs at almost half the facilities visited (19 cases). In 13 of them, the levels of brominated THMs (66±24.2µg/L) even greatly outweighed the levels of chloroform (15.2±6.31µg/L). Much higher levels of HAAs (294.8±157.6µg/L) were observed, with a consistent preponderance of brominated HAAs in the swimming pools with more brominated THMs. NDMA levels which were measured in a subset of 8 pools ranged between 2.8ng/L and 105ng/L. With respect to air, chloroform was still the most abundant THM globally (119.4±74.2µg/m(3)) but significant levels of brominated THMs were also observed in various cases, particularly in the previously evoked group of 13 swimming pools with preponderant levels of brominated THMs in water. CAM levels (0.23±0.15mg/m(3)) varied highly, ranging from not detected to 0.56mg/m(3). Overall, the levels were generally relatively high compared to current guidelines or reference values from several countries, and they point to a relatively atypical presence of brominated compounds, and to significant levels of emergent DBPs for which health risk is less documented. Copyright © 2016 Elsevier Inc. All rights

Conditions inside Water Pooled in a Failed Nuclear Waste Container and its Effect on Radionuclide Release

NASA Astrophysics Data System (ADS)

Hamdan, L. K.; Walton, J. C.; Woocay, A.

2009-12-01

Nuclear power use is expected to expand in the future, as part of the global clean energy initiative, to meet the world’s surging energy demand, and attenuate greenhouse gas emissions, which are mainly caused by fossil fuels. As a result, it is estimated that hundreds of thousands of metric tons of spent nuclear fuel (SNF) will accumulate. SNF disposal has major environmental (radiation exposure) and security (nuclear proliferation) concerns. Storage in unsaturated zone geological repositories is a reasonable solution for dealing with SNF. One of the key factors that determine the performance of the geological repository is the release of radionuclides from the engineered barrier system. Over time, the nuclear waste containers are expected to fail gradually due to general and localized corrosions and eventually infiltrating water will have access to the nuclear waste. Once radionuclides are released, they will be transported by water, and make their way to the accessible environment. Physical and chemical disturbances in the environment over the container will lead to different corrosion rates, causing different times and locations of penetration. One possible scenario for waste packages failure is the bathtub model, where penetrations occur on the top of the waste package and water pools inside it. In this paper the bathtub-type failed waste container is considered. We shed some light on chemical and physical processes that take place in the pooled water inside a partially failed waste container (bathtub category), and the effects of these processes on radionuclide release. Our study considers two possibilities: temperature stratification of the pooled water versus mixing process. Our calculations show that temperature stratification of the pooled water is expected when the waste package is half (or less) filled with water. On the other hand, when the waste package is fully filled (or above half) there will be mixing in the upper part of water. The effect of

Local structuring factors of invertebrate communities in ephemeral freshwater rock pools and the influence of more permanent water bodies in the region

USGS Publications Warehouse

Jocque, M.; Graham, T.; Brendonck, L.

2007-01-01

We used three isolated clusters of small ephemeral rock pools on a sandstone flat in Utah to test the importance of local structuring processes on aquatic invertebrate communities. In the three clusters we characterized all ephemeral rock pools (total: 27) for their morphometry, and monitored their water quality, hydrology and community assemblage during a full hydrocycle. In each cluster we also sampled a set of more permanent interconnected freshwater systems positioned in a wash, draining the water from each cluster of rock pools. This design allowed additional testing for the potential role of more permanent water bodies in the region as source populations for the active dispersers and the effect on the community structure in the rock pools. Species richness and community composition in the rock pools correlated with level of permanence and the ammonia concentration. The length of the rock pool inundation cycle shaped community structure, most probably by inhibiting colonization by some taxa (e.g. tadpoles and insect larvae) through developmental constraints. The gradient in ammonia concentrations probably reflects differences in primary production. The more permanent water bodies in each wash differed both environmentally and in community composition from the connected set of rock pools. A limited set of active dispersers was observed in the rock pools. Our findings indicate that aquatic invertebrate communities in the ephemeral rock pools are mainly structured through habitat permanence, possibly linked with biotic interactions and primary production. ?? 2007 Springer Science+Business Media B.V.

21 CFR 1250.89 - Swimming pools.

Code of Federal Regulations, 2011 CFR

2011-04-01

... equipped so as to provide complete circulation, replacement, and filtration of the water in the pool every six hours or less. Suitable means of chlorination and, if necessary, other treatment of the water shall be provided to maintain the residual chlorine in the pool water at not less than 0.4 part per...

21 CFR 1250.89 - Swimming pools.

Code of Federal Regulations, 2010 CFR

2010-04-01

... equipped so as to provide complete circulation, replacement, and filtration of the water in the pool every six hours or less. Suitable means of chlorination and, if necessary, other treatment of the water shall be provided to maintain the residual chlorine in the pool water at not less than 0.4 part per...

Rainbow trout responses to water temperature and dissolved oxygen stress in two southern California stream pools

Treesearch

K.R. Matthews; N.H. Berg

1997-01-01

Habitat use by rainbow trout Oncorhynchus mykiss is described for a southern California stream where the summer water temperatures typically exceed the lethal limits for trout (>25) C). During August 1994, water temperature, dissolved oxygen (DO), and trout distribution were monitored in two adjacent pools in Sespe Creek, Ventura County, where summer water...

Model of large pool fires.

PubMed

Fay, J A

2006-08-21

A two zone entrainment model of pool fires is proposed to depict the fluid flow and flame properties of the fire. Consisting of combustion and plume zones, it provides a consistent scheme for developing non-dimensional scaling parameters for correlating and extrapolating pool fire visible flame length, flame tilt, surface emissive power, and fuel evaporation rate. The model is extended to include grey gas thermal radiation from soot particles in the flame zone, accounting for emission and absorption in both optically thin and thick regions. A model of convective heat transfer from the combustion zone to the liquid fuel pool, and from a water substrate to cryogenic fuel pools spreading on water, provides evaporation rates for both adiabatic and non-adiabatic fires. The model is tested against field measurements of large scale pool fires, principally of LNG, and is generally in agreement with experimental values of all variables.

Intertidal pool fish Girella laevifrons (Kyphosidae) shown strong physiological homeostasis but shy personality: The cost of living in hypercapnic habitats.

PubMed

Benítez, S; Duarte, C; Opitz, T; Lagos, N A; Pulgar, J M; Vargas, C A; Lardies, M A

2017-05-15

Tide pools habitats are naturally exposed to a high degree of environmental variability. The consequences of living in these extreme habitats are not well established. In particular, little it is known about of the effects of hypercanic seawater (i.e. high pCO 2 levels) on marine vertebrates such as intertidal pool fish. The aim of this study was to evaluate the effects of increased pCO 2 on the physiology and behavior in juveniles of the intertidal pool fish Girella laevifrons. Two nominal pCO 2 concentrations (400 and 1600μatm) were used. We found that exposure to hypercapnic conditions did not affect oxygen consumption and absorption efficiency. However, the lateralization and boldness behavior was significantly disrupted in high pCO 2 conditions. In general, a predator-risk cost of boldness is assumed, thus the increased occurrence of shy personality in juvenile fishes may result in a change in the balance of this biological interaction, with significant ecological consequences. Copyright © 2017 Elsevier Ltd. All rights reserved.

Spread of large LNG pools on the sea.

PubMed

Fay, J A

2007-02-20

A review of the standard model of LNG pool spreading on water, comparing it with the model and experiments on oil pool spread from which the LNG model is extrapolated, raises questions about the validity of the former as applied to spills from marine tankers. These questions arise from the difference in fluid density ratios, in the multi-dimensional flow at the pool edge, in the effects of LNG pool boiling at the LNG-water interface, and in the model and experimental initial conditions compared with the inflow conditions from a marine tanker spill. An alternate supercritical flow model is proposed that avoids these difficulties; it predicts significant increase in the maximum pool radius compared with the standard model and is partially corroborated by tests of LNG pool fires on water. Wind driven ocean wave interaction has little effect on either spread model.

Common Pool Water Markets and their Role in Facilitating Land Use Change in Drying Climates

NASA Astrophysics Data System (ADS)

Teasley, R. L.; Milke, M.; Raffensperger, J. F.; Zargar, M.

2010-12-01

Concern is growing worldwide that climate change will lead to drier climates in many regions and in turn diminish water resources. To protect these limited resources, users may need to shift water use to more economically productive areas. However, changing the land use associated with water permits can be quite difficult, because water is not easily traded. Water markets have been well researched as a method for trading water between users, but these markets can often be difficult and costly requiring one-to-one trades between buyers and sellers. In contrast to a one-to-one market, a common pool market can reduce the transaction costs associated with trading water. In this research, a common pool market is applied to an example groundwater system set up in GWM2000 with ten users and various environmental constraints. The users represent three types of the largest groundwater users in the Canterbury region of New Zealand: agricultural, dairy and livestock. The response matrix from GWM2000 is used to develop constraints in the market model along with user bids. Bids are calculated from economic and water use data for Canterbury, New Zealand. Varying spatial distributions of water users by type are evaluated for the effect on the market under drying conditions. These conditions are simulated from climate change scenarios produced by the National Institute of Water and Atmospheric Research in New Zealand. The results demonstrate potential land use changes falls under drying conditions. As water availability falls, the price for additional water increases, particularly near environmental constraints, driving the land and water towards more efficient uses.

Seasonal warming of the Middle Atlantic Bight Cold Pool

NASA Astrophysics Data System (ADS)

Lentz, S. J.

2017-02-01

The Cold Pool is a 20-60 m thick band of cold, near-bottom water that persists from spring to fall over the midshelf and outer shelf of the Middle Atlantic Bight (MAB) and Southern Flank of Georges Bank. The Cold Pool is remnant winter water bounded above by the seasonal thermocline and offshore by warmer slope water. Historical temperature profiles are used to characterize the average annual evolution and spatial structure of the Cold Pool. The Cold Pool gradually warms from spring to summer at a rate of order 1°C month-1. The warming rate is faster in shallower water where the Cold Pool is thinner, consistent with a vertical turbulent heat flux from the thermocline to the Cold Pool. The Cold Pool warming rate also varies along the shelf; it is larger over Georges Bank and smaller in the southern MAB. The mean turbulent diffusivities at the top of the Cold Pool, estimated from the spring to summer mean heat balance, are an order of magnitude larger over Georges Bank than in the southern MAB, consistent with much stronger tidal mixing over Georges Bank than in the southern MAB. The stronger tidal mixing causes the Cold Pool to warm more rapidly over Georges Bank and the eastern New England shelf than in the New York Bight or southern MAB. Consequently, the coldest Cold Pool water is located in the New York Bight from late spring to summer.

Swimming Pools. Managing School Facilities, Guide 2.

ERIC Educational Resources Information Center

Department for Education and Employment, London (England). Architects and Building Branch.

This guide for schools with swimming pools offers advice concerning appropriate training for pool managers, the importance of water quality and testing, safety in the handling of chemicals, maintenance and cleaning requirements, pool security, and health concerns. The guide covers both indoor and outdoor pools, explains some technical terms,…

Drowning in Disinfection Byproducts? Swimming Pool Water Quality

EPA Science Inventory

Disinfection is mandatory for swimming pools, because transmission of disease by bacteria, virus and protozoa is the most significant health issue. However another issue arises, and care should be taken to minimize the risks from disinfection by-products (DBPs). Public pools are ...

Concentrations of disinfection by-products in swimming pool following modifications of the water treatment process: An exploratory study.

PubMed

Tardif, Robert; Rodriguez, Manuel; Catto, Cyril; Charest-Tardif, Ginette; Simard, Sabrina

2017-08-01

The formation and concentration of disinfection by-products (DBPs) in pool water and the ambient air vary according to the type of water treatment process used. This exploratory study was aimed at investigating the short-term impact of modifications of the water treatment process on traditional DBP levels (e.g., trihalomethanes (THMs), chloramines) and emerging DBPs (e.g., Halonitromethanes, Haloketones, NDMA) in swimming pool water and/or air. A sampling program was carried to understand the impact of the following changes made successively to the standard water treatment process: activation of ultraviolet (UV) photoreactor, halt of air stripping with continuation of air extraction from the buffer tank, halt of air stripping and suppression of air extraction from the buffer tank, suppression of the polyaluminium silicate sulfate (PASS) coagulant. UV caused a high increase of Halonitromethanes (8.4 fold), Haloketones (2.1 fold), and THMs in the water (1.7 fold) and, of THMs in the air (1.6 fold) and contributed to reducing the level of chloramines in the air (1.6 fold) and NDMA in the water (2.1 fold). The results highlight the positive impact of air stripping in reducing volatile contaminants. The PASS did not change the presence of DBPs, except for the THMs, which decrease slightly with the use of this coagulant. This study shows that modifications affecting the water treatment process can rapidly produce important and variable impacts on DBP levels in water and air and suggests that implementation of any water treatment process to reduce DBP levels should take into account the specific context of each swimming pool. Copyright © 2017. Published by Elsevier B.V.

Mercury bioaccumulation in wood frogs developing in seasonal pools

USGS Publications Warehouse

Loftin, Cynthia S.; Calhoun, Aram J.K.; Nelson, Sarah J.; Elskus, Adria; Simon, Kevin S.

2012-01-01

Seasonal woodland pools contribute significant biomass to terrestrial ecosystems through production of pool-breeding amphibians. The movement of amphibian metamorphs potentially transports toxins bioaccumulated during larval development in the natal pool into the surrounding terrestrial environment. We documented total mercury (THg) in seasonal woodland pool water, sediment, litter, and Lithobates sylvaticus LeConte (Wood Frog) in Acadia National Park, ME. THg concentrations in pool water varied over the study season, increasing during April—June and remaining high in 2 of 4 pools upon October refill. Water in pools surrounded by softwoods had lower pH, greater dissolved organic carbon, and greater THg concentrations than pools surrounded by hardwoods, with seasonal patterns in sediment THg but not litter THg. THg increased rapidly from near or below detection in 1–2 week old embryos (<0.2 ng; 0–0.49 ppb wet weight) to 17.1–54.2 ppb in tadpoles within 6 weeks; 7.2–42.0% of THg was methyl Hg in tadpoles near metamorphosis. Metamorphs emigrating from seasonal pools may transfer mercury into terrestrial food webs.

H3-THYMIDINE DERIVATIVE POOLS IN RELATION TO MACRONUCLEAR DNA SYNTHESIS IN TETRAHYMENA PYRIFORMIS

PubMed Central

Stone, G. E.; Miller, O. L.; Prescott, D. M.

1965-01-01

The formation of a soluble H3-thymidine derivative pool has been examined in Tetrahymena pyriformis as a function of macronuclear DNA synthesis during the cell life cycle. An autoradiographic technique which allows the detection of water-soluble materials within a cell has shown that these cells do not take up and retain exogenous H3-thymidine during G1 or G2. Uptake of H3-thymidine is restricted to the S period of the cell cycle. Additional autoradiographic experiments show, however, that a soluble pool of H3-thymidine derivatives persists from the end of one DNA synthesis period to the beginning of the next synthesis period in the subsequent cell cycle. Since this persisting pool cannot be labeled with H3-thymidine, the pool does not turn over during non-S periods. PMID:19866660

Legionella species colonization of water distribution systems, pools and air conditioning systems in cruise ships and ferries

PubMed Central

Goutziana, Georgia; Mouchtouri, Varvara A; Karanika, Maria; Kavagias, Antonios; Stathakis, Nikolaos E; Gourgoulianis, Kostantinos; Kremastinou, Jenny; Hadjichristodoulou, Christos

2008-01-01

Background Legionnaires' disease continues to be a public health concern in passenger ships. This study was scheduled in order to investigate Legionella spp. colonization of water distribution systems (WDS), recreational pools, and air-conditioning systems on board ferries and cruise ships in an attempt to identify risk factors for Legionella spp. colonization associated with ship water systems and water characteristics. Methods Water systems of 21 ferries and 10 cruise ships including WDS, air conditioning systems and pools were investigated for the presence of Legionella spp. Results The 133 samples collected from the 10 cruise ships WDS, air conditioning systems and pools were negative for Legionella spp. Of the 21 ferries WDS examined, 14 (66.7%) were legionellae-positive. A total of 276 samples were collected from WDS and air conditioning systems. Legionella spp. was isolated from 37.8% of the hot water samples and 17.5% of the cold water samples. Of the total 96 positive isolates, 87 (90.6%) were L. pneumophila. Legionella spp. colonization was positively associated with ship age. The temperature of the hot water samples was negatively associated with colonization of L. pneumophila serogroup (sg) 1 and that of L. pneumophila sg 2 to 14. Increases in pH ≥7.8 and total plate count ≥400 CFU/L, correlated positively with the counts of L. pneumophila sg 2 to 14 and Legionella spp. respectively. Free chlorine of ≥0.2 mg/L inhibited colonization of Legionella spp. Conclusion WDS of ferries can be heavily colonized by Legionella spp. and may present a risk of Legionnaires' disease for passengers and crew members. Guidelines and advising of Legionnaires' disease prevention regarding ferries are needed, in particular for operators and crew members. PMID:19025638

Legionella species colonization of water distribution systems, pools and air conditioning systems in cruise ships and ferries.

PubMed

Goutziana, Georgia; Mouchtouri, Varvara A; Karanika, Maria; Kavagias, Antonios; Stathakis, Nikolaos E; Gourgoulianis, Kostantinos; Kremastinou, Jenny; Hadjichristodoulou, Christos

2008-11-24

Legionnaires' disease continues to be a public health concern in passenger ships. This study was scheduled in order to investigate Legionella spp. colonization of water distribution systems (WDS), recreational pools, and air-conditioning systems on board ferries and cruise ships in an attempt to identify risk factors for Legionella spp. colonization associated with ship water systems and water characteristics. Water systems of 21 ferries and 10 cruise ships including WDS, air conditioning systems and pools were investigated for the presence of Legionella spp. The 133 samples collected from the 10 cruise ships WDS, air conditioning systems and pools were negative for Legionella spp. Of the 21 ferries WDS examined, 14 (66.7%) were legionellae-positive. A total of 276 samples were collected from WDS and air conditioning systems. Legionella spp. was isolated from 37.8% of the hot water samples and 17.5% of the cold water samples. Of the total 96 positive isolates, 87 (90.6%) were L. pneumophila. Legionella spp. colonization was positively associated with ship age. The temperature of the hot water samples was negatively associated with colonization of L. pneumophila serogroup (sg) 1 and that of L. pneumophila sg 2 to 14. Increases in pH >/=7.8 and total plate count > or =400 CFU/L, correlated positively with the counts of L. pneumophila sg 2 to 14 and Legionella spp. respectively. Free chlorine of > or =0.2 mg/L inhibited colonization of Legionella spp. WDS of ferries can be heavily colonized by Legionella spp. and may present a risk of Legionnaires' disease for passengers and crew members. Guidelines and advising of Legionnaires' disease prevention regarding ferries are needed, in particular for operators and crew members.

Deepwater Horizon oil in Gulf of Mexico waters after 2 years: transformation into the dissolved organic matter pool.

PubMed

Bianchi, Thomas S; Osburn, Christopher; Shields, Michael R; Yvon-Lewis, Shari; Young, Jordan; Guo, Laodong; Zhou, Zhengzhen

2014-08-19

Recent work has shown the presence of anomalous dissolved organic matter (DOM), with high optical yields, in deep waters 15 months after the Deepwater Horizon (DWH) oil spill in the Gulf of Mexico (GOM). Here, we continue to use the fluorescence excitation-emission matrix (EEM) technique coupled with parallel factor analysis (PARAFAC) modeling, measurements of bulk organic carbon, dissolved inorganic carbon (DIC), oil indices, and other optical properties to examine the chemical evolution and transformation of oil components derived from the DWH in the water column of the GOM. Seawater samples were collected from the GOM during July 2012, 2 years after the oil spill. This study shows that, while dissolved organic carbon (DOC) values have decreased since just after the DWH spill, they remain higher at some stations than typical deep-water values for the GOM. Moreover, we continue to observe fluorescent DOM components in deep waters, similar to those of degraded oil observed in lab and field experiments, which suggest that oil-related fluorescence signatures, as part of the DOM pool, have persisted for 2 years in the deep waters. This supports the notion that some oil-derived chromophoric dissolved organic matter (CDOM) components could still be identified in deep waters after 2 years of degradation, which is further supported by the lower DIC and partial pressure of carbon dioxide (pCO2) associated with greater amounts of these oil-derived components in deep waters, assuming microbial activity on DOM in the current water masses is only the controlling factor of DIC and pCO2 concentrations.

Development of Ren Qiou fractured carbonate oil pools by water injection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Z.; Li, G.

1982-01-01

This work gives a brief description on the geologic characteristics of Ren Qiou oil field and its development. Different methods have been used in its reservoir engineering study such as outcrop investigation, fracture and crevice description in tunnels, observation on core samples and their statistical data, thin section observation, casting section, fluorescence section, scanning electron microscope, mercury injection and withdrawal, down-hole television, and geophysical well logging. Physical modeling, 3-dimensional numeric simulation and reservoir performance analysis, and production profiles by production logging in an open hole, have been used to study mechanics of displacing oil by water and the movement ofmore » oil and water in reservoir pools production technologies with double-porosity. Pressure maintenance by bottomwater injection to keep producing wells flowing, acidization with emulsifying acid to penetrate deeply into the reservoir formation, and water plugging with chemical agent, have been used to maintain a consistent annual recovery rate. 11 references.« less

An introduction to mid-Atlantic seasonal pools

USGS Publications Warehouse

Brown, L.J.; Jung, R.E.

2005-01-01

Seasonal pools, also known as vernal ponds, provide important ecological services to the mid-Atlantic region. This publication serves as an introduction to seasonal pool ecology and management; it also provides tools for exploring seasonal pools, including a full-color field guide to wildlife. Seasonal pools are defined as having four distinctive features: surface water isolation, periodic drying, small size and shallow depth, and support of a characteristic biological community. Seasonal pools experience regular drying that excludes populations of predatory fish. Thus, pools in the mid-Atlantic region provide critical breeding habitat for amphibian and invertebrate species (e.g., spotted salamander (Ambystoma maculatum), wood frog (Rana sylvatica), and fairy shrimp (Order Anostraca)) that would be at increased risk of predation in more permanent waters. The distinctive features of seasonal pools also make them vulnerable to human disturbance. In the mid-Atlantic region, land-use changes pose the greatest challenges to seasonal pool conservation. Seasonal pools are threatened by direct loss (e.g., filling or draining of the pool) as well as by destruction and fragmentation of adjoining terrestrial habitat. Many of the species that depend on seasonal pools for breeding spend the majority of their lives in the surrounding lands that extend a radius of 1000 feet or more from the pools; these vital habitats are being transected by roads and converted to other land uses. Other threats to seasonal pools include biological introductions and removals, mosquito control practices, amphibian diseases, atmospheric deposition, and climate change. The authors recommend a three-pronged strategy for seasonal pool conservation and management in the mid-Atlantic region: education and research, inventory and monitoring of seasonal pools, and landscape-level planning and management.

Regional variation in the biogeochemical and physical characteristics of natural peatland pools.

PubMed

Turner, T Edward; Billett, Michael F; Baird, Andy J; Chapman, Pippa J; Dinsmore, Kerry J; Holden, Joseph

2016-03-01

Natural open-water pools are a common feature of northern peatlands and are known to be an important source of atmospheric methane (CH4). Pool environmental variables, particularly water chemistry, vegetation community and physical characteristics, have the potential to exert strong controls on carbon cycling in pools. A total of 66 peatland pools were studied across three regions of the UK (northern Scotland, south-west Scotland, and Northern Ireland). We found that within-region variability of pool water chemistry was low; however, for many pool variables measured there were significant differences between regions. PCA analysis showed that pools in SW Scotland were strongly associated with greater vegetative cover and shallower water depth which is likely to increase dissolved organic carbon (DOC) mineralisation rates, whereas pools in N Scotland were more open and deeper. Pool water DOC, particulate organic carbon and dissolved CH4 concentrations were significantly different between regions. Pools in Northern Ireland had the highest concentrations of DOC (mean=14.5 mg L(-1)) and CH4 (mean=20.6 μg C L(-1)). Chloride and sulphate concentrations were significantly higher in the pools in N Scotland (mean values 26.3 and 2.40 mg L(-1), respectively) than elsewhere, due to a stronger marine influence. The ratio of UV absorbance at 465 nm to absorbance at 665 nm for pools in Northern Ireland indicated that DOC was sourced from poorly humified peat, potentially increasing the bioavailability and mineralisation of organic carbon in pools compared to the pools elsewhere. This study, which specifically aims to address a lack of basic biogeochemical knowledge about pool water chemistry, clearly shows that peatland pools are highly regionally variable. This is likely to be a reflection of significant regional-scale differences in peatland C cycling. Copyright © 2015 Elsevier B.V. All rights reserved.

A dual stable-isotope approach to analyse the linkages between tree water fluxes and soil water pools in a Mediterranean mountain catchment

NASA Astrophysics Data System (ADS)

Llorens, Pilar; Cayuela, Carles; Sánchez-Costa, Elisenda; Gallart, Francesc; Latron, Jérôme

2017-04-01

This work uses a dual isotope-based approach (18O, 2H) to examine the mixing of water in the soil and the linkages between tree water fluxes and soil water pools in a Mediterranean mountain catchment (Vallcebre Research Catchments, NE Spain, 42° 12'N, 1° 49'E). Since May 2015, water-isotopes have been monitored in rainfall, throughfall and stemflow below a Scots pine stand and in stream water at the Can Vila (0.56 km2) catchment outlet. Moreover, fortnightly (From May to December 2015) soil samples (10, 20, 30, 50 and 100 cm), xylem samples (3 Scots pines) and mobile soil water samples in low-suction lysimeters (20, 50 and 100 cm) and in a piezometer (150-300 cm deep) were collected at the same stand. Water from soil and xylem samples was extracted by cryogenic vacuum distillation and isotope analyses were obtained by infrared spectroscopy. All this information has been combined with continuous measurement of meteorological, soil moisture and water potential, piezometric levels and hydrological variables at the stand and catchment scales. Stable isotopes ratios of bound soil water fell below the local meteoric water line (LMWL), with more evaporative enrichment in the shallow horizons. On the contrary, mobile soil water (low suction lysimeters) and groundwater fell along the LMWL, well mixed with stream water. The differences observed between these two water pools remained similar during the whole study period. Stable isotopes ratios indicate that Scots pine trees use shallow bound soil water during the whole study period. No marked changes in depth of water uptake were observed, presumably due to the availability of water in the shallow horizons, even during the summer months.

Effects of exposure to water disinfection by-products in a swimming pool: A metabolome-wide association study.

PubMed

van Veldhoven, Karin; Keski-Rahkonen, Pekka; Barupal, Dinesh K; Villanueva, Cristina M; Font-Ribera, Laia; Scalbert, Augustin; Bodinier, Barbara; Grimalt, Joan O; Zwiener, Christian; Vlaanderen, Jelle; Portengen, Lützen; Vermeulen, Roel; Vineis, Paolo; Chadeau-Hyam, Marc; Kogevinas, Manolis

2018-02-01

Exposure to disinfection by-products (DBPs) in drinking water and chlorinated swimming pools are associated with adverse health outcomes, but biological mechanisms remain poorly understood. Evaluate short-term changes in metabolic profiles in response to DBP exposure while swimming in a chlorinated pool. The PISCINA-II study (EXPOsOMICS project) includes 60 volunteers swimming 40min in an indoor pool. Levels of most common DBPs were measured in water and in exhaled breath before and after swimming. Blood samples, collected before and 2h after swimming, were used for metabolic profiling by liquid-chromatography coupled to high-resolution mass-spectrometry. Metabolome-wide association between DBP exposures and each metabolic feature was evaluated using multivariate normal (MVN) models. Sensitivity analyses and compound annotation were conducted. Exposure levels of all DBPs in exhaled breath were higher after the experiment. A total of 6,471 metabolic features were detected and 293 features were associated with at least one DBP in exhaled breath following Bonferroni correction. A total of 333 metabolic features were associated to at least one DBP measured in water or urine. Uptake of DBPs and physical activity were strongly correlated and mutual adjustment reduced the number of statistically significant associations. From the 293 features, 20 could be identified corresponding to 13 metabolites including compounds in the tryptophan metabolism pathway. Our study identified numerous molecular changes following a swim in a chlorinated pool. While we could not explicitly evaluate which experiment-related factors induced these associations, molecular characterization highlighted metabolic features associated with exposure changes during swimming. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

MELCOR Model of the Spent Fuel Pool of Fukushima Dai-ichi Unit 4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carbajo, Juan J

2012-01-01

decay heat of the fuel in the pool was, at the time of the accident, 2.284 MWt, of which 1.872 MWt were from the 548 assemblies of the last core discharged and 0.412 MWt were from the older 783 assemblies. These decay heat values were calculated at Oak Ridge National Laboratory using the ORIGEN2.2 code (Ref. 2) - they agree with values reported elsewhere (Ref. 3). The pool dimensions are 9.9 m x 12.2 m x 11.8 m (height), and with the water level at 11.5 m, the pool volume is 1389 m3, of which only 1240 m3 is water, as some volume is taken by the fuel and by the fuel racks. The initial water temperature of the SFP4 was assumed to be 301 K. The fuel racks are made of an aluminum alloy but are modeled in MELCOR with stainless steel and B4C. MELCOR calculations were completed for different initial water levels: 11.5 m (pool almost full, water is only 0.3 m below the top rim), 4.4577 m (top of the racks), 4.2 m, and 4.026 m (top of the active fuel). A calculation was also completed for a rapid loss of water due to a leak at the bottom of the pool, with the fuel rapidly uncovered and oxidized in air. Results of these calculations are shown in the enclosed Table I. The calculation with the initial water level at 11.5 m (full pool) takes 11 days for the water to boil down to the top of the fuel racks, 11.5 days for the fuel to be uncovered, 14.65 days to generate 150 kg of hydrogen and 19 days for the pool to be completely dry. The calculation with the initial water level at 4.4577 m, takes 1.1 days to uncover the fuel and 4.17 days to generate 150 kg of hydrogen. The calculation with the initial water level at 4.02 m takes 3.63 days to generate 150 kg of hydrogen this is exactly the time when the actual explosion occurred in Unit 4. Finally, fuel oxidation in air after the pool drained the water in 20 minutes, generates only 10 kg of hydrogen this is because very little steam is available and Zircaloy (Zr) oxidation with the oxygen of the air does not generate hydrogen. MELCOR

Sidestream Elevated Pool Aeration, a Technology for Improving Water Quality in Urban Rivers

NASA Astrophysics Data System (ADS)

Motta, D.; Garcia, T.; Abad, J. D.; Bombardelli, F. A.; Waratuke, A.; Garcia, M. H.

2010-12-01

Dissolved Oxygen (DO) levels are frequently depleted in rivers located in urban areas, as in the case of the Matanza-Riachuelo River in Buenos Aires, Argentina. This stream receives both domestic and industrial loads which have received minor or no treatment before being discharged into the water body. Major sources of pollution include, but are not limited, to leather and meat packing industries. Additionally, deep slow moving water in the river is associated with limited reaeration and facilitates deposition of organic-rich sediment, therefore exacerbating the DO consumption through sediment oxygen demand. In this study we assessed the efficiency of Sidestream Elevated Pool Aeration (SEPA) stations as a technology for alleviating conditions characterized by severely low DO levels. A SEPA station takes water from the stream at low DO concentrations, through a screw pump; then, water is transported to an elevated pool from where it flows over a series of weirs for water reaeration; finally, the aerated water is discharged back into the river sufficiently downstream from the intake point. This system mimics a phenomenon that occurs in mountain streams, where water is purified by bubbling over rocks. The impact of the use of SEPA stations on the DO concentrations in the Matanza-Riachuelo River was evaluated at both local and reach scales: this was done by deploying and monitoring an in situ pilot SEPA station, and by performing numerical modeling for the evaluation of the hydrodynamics in the SEPA station and the water quality in the reach where SEPA stations are planned to be implemented. An efficiency of aeration of 99% was estimated from DO measurements in the pilot SEPA, showing the potential of this technology for DO recovery in urban streams. Three-dimensional hydrodynamic modeling, besides assisting in the design of the pilot SEPA, has allowed for designing a prototype SEPA to be built soon. Finally, one-dimensional water quality modeling has provided the

An infrared scattering by evaporating droplets at the initial stage of a pool fire suppression by water sprays

NASA Astrophysics Data System (ADS)

Dombrovsky, Leonid A.; Dembele, Siaka; Wen, Jennifer X.

2018-06-01

The computational analysis of downward motion and evaporation of water droplets used to suppress a typical transient pool fire shows local regions of a high volume fraction of relatively small droplets. These droplets are comparable in size with the infrared wavelength in the range of intense flame radiation. The estimated scattering of the radiation by these droplets is considerable throughout the entire spectrum except for a narrow region in the vicinity of the main absorption peak of water where the anomalous refraction takes place. The calculations of infrared radiation field in the model pool fire indicate the strong effect of scattering which can be observed experimentally to validate the fire computational model.

Thermally stratified pools and their use by steelhead in northern California streams

Treesearch

Jennifer L. Nielsen; Thomas E. Lisle; Vicki Ozaki

1994-01-01

Abstract - Thermal stratification occurred in pools of three rivers in northern California when inflow of cold water was sufficiently great or currents were sufficiently weak to prevent thorough mixing of water of contrasting temperatures. Surface water temperatures in such pools were commonly 3-9°C higher than those at the bottom. Cold water entered pools from...

The Chemistry of Swimming Pool Maintenance

ERIC Educational Resources Information Center

Salter, Carl; Langhus, David L.

2007-01-01

The study of chemistry involved in the maintenance of a swimming pool provides a lot of chemical education to the students, including the demonstration of the importance of pH in water chemistry. The various chemical aspects hidden in the maintenance of the pool are being described.

Swimming Pools. A Guide to Their Planning, Design and Operation.

ERIC Educational Resources Information Center

Gabrielsen, M. Alexander, Ed.

Information is presented regarding all phases of swimming pool development and operation from earliest planning considerations to final programing. This comprehensive book covers--(1) the steps involved in planning a pool, (2) designing the pool, (3) water circulation, filtration, and treatment, (4) community pools, school and agency pools, and…

Cool pool development. Quarterly technical report No. 2, June-December 1979

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crowther, K.

1980-01-05

The Cool Pool is a variation of the evaporating roof pond idea. The pool is isolated from the living space and the cooled pond water thermosiphons into the water columns located within the building. A computer model of the Cool Pool and the various heat and mass transfer mechanisms involved in the system are discussed. Theory will be compared to experimental data collected from a Cool Pool test building.

Cool pool development. Quarterly technical report No. 1, April-June 1979

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crowther, K.

1979-10-15

The Cool Pool is a passive cooling system consisting of a shaded, evaporating roof pond which thermosiphons cool water into water-filled, metal columns (culvert pipes) located within the building living space. The water in the roof pond is cooled by evaporation, convection and radiation. Because the water in the pool and downcomer is colder and denser than the water in the column a pressure difference is created and the cold water flows from the pool, through the downcomer and into the bottom of the column. The warm column water rises and flows through a connecting pipe into the pool. Itmore » is then cooled and the cycle repeats itself. The system requires no pumps. The water column absorbs heat from the building interior primarily by convection and radiation. Since the column is radiating at a significantly lower temperature than the interior walls it plays a double role in human comfort. Not only does it cool the air by convection but it provides a heat sink to which people can radiate. Since thermal radiation is important to the cooling of people, the cold water column contributes substantially to their feelings of comfort. Research on the Cool Pool system includes the following major tasks: control of biological organisms and debris in the roof pond and water cylinders; development of a heat exchanger; experimental investigation of the system's thermal performance; and development of a predictive computer simulation of the Cool Pool. Progress in these tasks is reported.« less

TOPEX/El Nino Watch - El Nino Warm Water Pool Returns to Near Normal State, Mar, 14, 1998

NASA Technical Reports Server (NTRS)

1998-01-01

This image of the Pacific Ocean was produced using sea surface height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on Mar. 14, 1998 and sea surface height is an indicator of the heat content of the ocean. The image shows that the sea surface height along the central equatorial Pacific has returned to a near normal state. Oceanographers indicate this is a classic pattern, typical of a mature El Nino condition. Remnants of the El Nino warm water pool, shown in red and white, are situated to the north and south of the equator. These sea surface height measurements have provided scientists with a detailed view of how the 1997-98 El Nino's warm pool behaves because the TOPEX/Poseidon satellite measures the changing sea surface height with unprecedented precision. In this image, the white and red areas indicate unusual patterns of heat storage; in the white areas, the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal; in the red areas, it's about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions, while purple (the western Pacific) means at least 18 centimeters (7 inches) below normal sea level. The El Nino phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white area) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. Using satellite imagery, buoy and ship data, and a forecasting model of the ocean-atmosphere system, the National Oceanic and Atmospheric Administration, (NOAA), has continued to issue an advisory indicating the so-called El Nino weather

Inventory of Anchialine Pools in Hawaii's National Parks

USGS Publications Warehouse

Foote, David

2005-01-01

BACKGROUND Anchialine (?near the sea?) pools are rare and localized brackish waters along coastal lava flows that exhibit tidal fluctuations without a surface connection with the ocean (Fig. 1). In Hawai`i, these pools were frequently excavated or otherwise modified by Hawaiians to serve as sources of drinking water, baths and fish ponds. National Parks in Hawai`i possess the full spectrum of pool types, from walled fish ponds to undisturbed pools in collapsed lava tubes, cracks and caves. Pools contain relatively rare and unique fauna threatened primarily by invasive species and habitat loss. In collaboration with the National Park Service?s Inventory and Monitoring Program, the U.S. Geological Survey?s Pacific Island Ecosystems Research Center undertook inventories of these unique ecosystems in two National Parks on the island of Hawai`i: Hawai`i Volcanoes National Park and Kaloko-Honokohau National Historical Park.

Progressive Increase in Disinfection Byproducts and Mutagenicity from Sourceto Tap to Swimming Pool and Spa Water: Implications for Public Health

EPA Science Inventory

Pools and spas are enjoyed throughout the world for exercise and relaxation. However, there are no previous studies on the mutagenicity of disinfected spa (hot tub) waters or comprehensive identification of disinfection byproducts (DBPs) formed in spas. Using 28 water samples f...

Institutional Boundaries and Common-Pool Resource Management: A Comparative Analysis of Water Management Programs in California

ERIC Educational Resources Information Center

Heikkila, Tanya

2004-01-01

Policymakers and academics often identify institutional boundaries as one of the factors that shape the capacity of jurisdictions to manage natural resources such as water, forests, and scenic lands. This article examines two key bodies of literature--common-pool resource management theory and local public economy theory--to explain how the…

Resuscitation with Pooled and Pathogen-Reduced Plasma Attenuates the Increase in Brain Water Content following Traumatic Brain Injury and Hemorrhagic Shock in Rats.

PubMed

Genét, Gustav Folmer; Bentzer, Peter; Ostrowski, Sisse Rye; Johansson, Pär Ingemar

2017-03-01

Traumatic brain injury and hemorrhagic shock is associated with blood-brain barrier (BBB) breakdown and edema formation. Recent animal studies have shown that fresh frozen plasma (FFP) resuscitation reduces brain swelling and improves endothelial function compared to isotonic NaCl (NS). The aim of this study was to investigate whether pooled and pathogen-reduced plasma (OctaplasLG ® [OCTA]; Octapharma, Stockholm, Sweden) was comparable to FFP with regard to effects on brain water content, BBB permeability, and plasma biomarkers of endothelial glycocalyx shedding and cell damage. After fluid percussion brain injury, hemorrhage (20 mL/kg), and 90-min shock, 48 male Sprague-Dawley rats were randomized to resuscitation with OCTA, FFP, or NS (n = 16/group). Brain water content (wet/dry weight) and BBB permeability (transfer constant for 51 Cr-EDTA) were measured at 24 h. Plasma osmolality, oncotic pressure, and biomarkers of systemic glycocalyx shedding (syndecan-1) and cell damage (histone-complexed DNA) were measured at 0 and 23 h. At 24 h, brain water content was 80.44 ± 0.39%, 80.82 ± 0.82%, and 81.15 ± 0.86% in the OCTA, FFP, and NS groups (lower in OCTA vs. NS; p = 0.026), with no difference in BBB permeability. Plasma osmolality and oncotic pressures were highest in FFP and OCTA resuscitated, and osmolality was further highest in OCTA versus FFP (p = 0.027). In addition, syndecan-1 was highest in FFP and OCTA resuscitated (p = 0.010). These results suggest that pooled solvent-detergent (SD)-treated plasma attenuates the post-traumatic increase in brain water content, and that this effect may, in part, be explained by a high crystalloid and colloid osmotic pressure in SD-treated plasma.

Microbiological Analysis in Three Diverse Natural Geothermal Bathing Pools in Iceland

PubMed Central

Thorolfsdottir, Berglind Osk Th.; Marteinsson, Viggo Thor

2013-01-01

Natural thermal bathing pools contain geothermal water that is very popular to bathe in but the water is not sterilized, irradiated or treated in any way. Increasing tourism in Iceland will lead to increasing numbers of bath guests, which can in turn affect the microbial flora in the pools and therefore user safety. Today, there is no legislation that applies to natural geothermal pools in Iceland, as the water is not used for consumption and the pools are not defined as public swimming pools. In this study, we conducted a microbiological analysis on three popular but different natural pools in Iceland, located at Lýsuhóll, Hveravellir and Landmannalaugar. Total bacterial counts were performed by flow cytometry, and with plate count at 22 °C, 37 °C and 50 °C. The presence of viable coliforms, Enterococcus spp. and pseudomonads were investigated by growth experiments on selective media. All samples were screened for noroviruses by real time PCR. The results indicate higher fecal contamination in the geothermal pools where the geothermal water flow was low and bathing guest count was high during the day. The number of cultivated Pseudomonas spp. was high (13,000–40,000 cfu/100 mL) in the natural pools, and several strains were isolated and classified as opportunistic pathogens. Norovirus was not detected in the three pools. DNA was extracted from one-liter samples in each pool and analyzed by partial 16S rRNA gene sequencing. Microbial diversity analysis revealed different microbial communities between the pools and they were primarily composed of alpha-, beta- and gammaproteobacteria. PMID:23493033

Blood-pool contrast agent for pre-clinical computed tomography

NASA Astrophysics Data System (ADS)

Cruje, Charmainne; Tse, Justin J.; Holdsworth, David W.; Gillies, Elizabeth R.; Drangova, Maria

2017-03-01

Advances in nanotechnology have led to the development of blood-pool contrast agents for micro-computed tomography (micro-CT). Although long-circulating nanoparticle-based agents exist for micro-CT, they are predominantly based on iodine, which has a low atomic number. Micro-CT contrast increases when using elements with higher atomic numbers (i.e. lanthanides), particularly at higher energies. The purpose of our work was to develop and evaluate a lanthanide-based blood-pool contrast agent that is suitable for in vivo micro-CT. We synthesized a contrast agent in the form of polymer-encapsulated Gd nanoparticles and evaluated its stability in vitro. The synthesized nanoparticles were shown to have an average diameter of 127 +/- 6 nm, with good size dispersity. Particle size distribution - evaluated by dynamic light scattering over the period of two days - demonstrated no change in size of the contrast agent in water and saline. Additionally, our contrast agent was stable in a mouse serum mimic for up to 30 minutes. CT images of the synthesized contrast agent (containing 27 mg/mL of Gd) demonstrated an attenuation of over 1000 Hounsfield Units. This approach to synthesizing a Gd-based blood-pool contrast agent promises to enhance the capabilities of micro-CT imaging.

Livestock Grazing as a Driver of Vernal Pool Ecohydrology

NASA Astrophysics Data System (ADS)

Michaels, J.; McCarten, N. F.

2017-12-01

Vernal pools are seasonal wetlands that host rare plant communities of high conservation priority. Plant community composition is largely driven by pool hydroperiod. A previous study found that vernal pools grazed by livestock had longer hydroperiods compared with pools excluded from grazing for 10 years, and suggests that livestock grazing can be used to protect plant diversity. It is important to assess whether observed differences are due to the grazing or due to water balance variables including upland discharge into or out of the pools since no a priori measurements were made of the hydrology prior to grazing. To address this question, in 2016 we compared 15 pools that have been grazed continuously and 15 pools that have been fenced off for over 40 years at a site in Sacramento County. We paired pools based on abiotic characteristics (size, shape, slope, soil type) to minimize natural variation. We sampled vegetation and water depth using Solinst level loggers. We found that plant diversity and average hydroperiod was significantly higher in the grazed pools. We are currently measuring groundwater connectivity and upland inputs in order to compare the relative strength of livestock grazing as a driver of hydroperiod to these other drivers.

The Value of Risk Pooling for Mitigating Water Utility Financial Risks Arising From Water Scarcity

NASA Astrophysics Data System (ADS)

Baum, R.; Characklis, G. W.; Hughes, J.; Eskaf, S.

2015-12-01

Water utilities across the United States face growing supply risks as demand growth and extreme weather events make water scarcity more common. As it has become more difficult and expensive to build new supply capacity to accommodate these events, many utility managers respond by either imposing conservation measures, which reduces revenues, or acquiring additional water from other sources, which increases costs. These actions lead to changing financial trends that are difficult to predict and that utilities are currently ill-equipped to manage. As a result, adaptation strategies and tools are being developed to reduce utility vulnerabilities, ensuring both financial stability and continued access to low cost financing, a critical consideration for a capital intensive industry. Previous work in this area has involved the development of utility specific financial hedging tools. However, the time and informational requirements associated with developing these individualized strategies may be a limiting factor for widespread implementation. The objective of this research is to develop more generalized hedging instruments that can be applied simultaneously to multiple utilities across the United States, thereby increasing the potential for widespread implementation. This work first analyzes the financial risks of water scarcity for a large set of water utilities across the country and then proposes a financial hedging solution to mitigate these risks through hydrologic index-based financial insurance. Results provide insights into the most effective indices, the potential for risk pooling to reduce insurance costs, and the performance of these contracts in managing utility financial risk arising from drought.

TOPEX/El Nino Watch - Warm Water Pool is Thinning, Feb, 5, 1998

NASA Technical Reports Server (NTRS)

1998-01-01

This image of the Pacific Ocean was produced using sea surface height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on Feb. 5, 1998 and sea surface height is an indicator of the heat content of the ocean. The area and volume of the El Nino warm water pool that is affecting global weather patterns remains extremely large, but the pool has thinned along the equator and near the coast of South America. This 'thinning' means that the warm water is not as deep as it was a few months ago. Oceanographers indicate this is a classic pattern, typical of a mature El Nino condition that they would expect to see during the ocean's gradual transition back to normal sea level. In this image, the white and red areas indicate unusual patterns of heat storage; in the white areas, the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal; in the red areas, it's about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions, while purple (the western Pacific) means at least 18 centimeters (7 inches) below normal sea level. The El Nino phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white area) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. Using satellite imagery, buoy and ship data, and a forecasting model of the ocean-atmosphere system, the National Oceanic and Atmospheric Administration, (NOAA), has continued to issue an advisory indicating the so-called El Nino weather conditions that have impacted much of the United States and the world are expected to remain through

A Three-Pool Model Dissecting Readily Releasable Pool Replenishment at the Calyx of Held

PubMed Central

Guo, Jun; Ge, Jian-long; Hao, Mei; Sun, Zhi-cheng; Wu, Xin-sheng; Zhu, Jian-bing; Wang, Wei; Yao, Pan-tong; Lin, Wei; Xue, Lei

2015-01-01

Although vesicle replenishment is critical in maintaining exo-endocytosis recycling, the underlying mechanisms are not well understood. Previous studies have shown that both rapid and slow endocytosis recycle into a very large recycling pool instead of within the readily releasable pool (RRP), and the time course of RRP replenishment is slowed down by more intense stimulation. This finding contradicts the calcium/calmodulin-dependence of RRP replenishment. Here we address this issue and report a three-pool model for RRP replenishment at a central synapse. Both rapid and slow endocytosis provide vesicles to a large reserve pool (RP) ~42.3 times the RRP size. When moving from the RP to the RRP, vesicles entered an intermediate pool (IP) ~2.7 times the RRP size with slow RP-IP kinetics and fast IP-RRP kinetics, which was responsible for the well-established slow and rapid components of RRP replenishment. Depletion of the IP caused the slower RRP replenishment observed after intense stimulation. These results establish, for the first time, a realistic cycling model with all parameters measured, revealing the contribution of each cycling step in synaptic transmission. The results call for modification of the current view of the vesicle recycling steps and their roles. PMID:25825223

Physical and chemical differences between natural and artificial pools in blanket peatlands

NASA Astrophysics Data System (ADS)

Turner, Ed; Baird, Andy; Billett, Mike; Chapman, Pippa; Dinsmore, Kerry; Holden, Joseph

2014-05-01

Natural pools are common features of many northern peatlands. Numerous artificial pools are being created behind dams installed during drain-blocking, a common peatland restoration technique, significantly increasing the area of open water. Natural pools are known to be major sources of GHGs (e.g. Hamilton et al. 1994), but the reasons they are such 'hotspots' is poorly understood. We hypothesize that pools act as 'biochemical reactors' of particulate and dissolved organic carbon (POC and DOC) transported from surrounding peat that is processed into a range of products including CH4 and CO2. Therefore, understanding the processes operating in both natural and artificial pool systems is fundamental to elucidating this hypothesis. Water levels and temperature have been continuously monitored at six natural and six artificial pools within the 'Flow Country' blanket peatland in northern Scotland since May 2013. Bi-weekly sampling of waters from pools, peat matrix through-flow (via piezometers) and surface flow has been conducted for analysis of DOC, POC, DIC, CH4diss and CO2diss, together with GHG flux measurements from pool surfaces and adjacent peat. We show that, to date, pool water levels rapidly respond to rainfall, although artificial pools appear to respond with greater magnitude. For example, over the course of same rainfall event (20-23 June 2013), natural and artificial pool levels increased between 5.3 and 9.8 cm, and 12.5 and 22.6 cm respectively. Temperature measured at c. 5 cm from the base of each pool shows distinct diurnal fluctuations, which are of greater magnitude in all but one of the natural pools compared to the artificial pools: over the same period (20-23 July 2013), the maximum diurnal variation at the artificial pool site was 5.1 °C compared to 9.2 °C within the natural pools. Vegetation cover is generally higher in artificial pools and may have a moderating effect on variations in pool temperature. Results of pool-water DOC analysis from

Prior Individual Training and Self-Organized Queuing during Group Emergency Escape of Mice from Water Pool

PubMed Central

Saloma, Caesar; Perez, Gay Jane; Gavile, Catherine Ann; Ick-Joson, Jacqueline Judith; Palmes-Saloma, Cynthia

2015-01-01

We study the impact of prior individual training during group emergency evacuation using mice that escape from an enclosed water pool to a dry platform via any of two possible exits. Experimenting with mice avoids serious ethical and legal issues that arise when dealing with unwitting human participants while minimizing concerns regarding the reliability of results obtained from simulated experiments using ‘actors’. First, mice were trained separately and their individual escape times measured over several trials. Mice learned quickly to swim towards an exit–they achieved their fastest escape times within the first four trials. The trained mice were then placed together in the pool and allowed to escape. No two mice were permitted in the pool beforehand and only one could pass through an exit opening at any given time. At first trial, groups of trained mice escaped seven and five times faster than their corresponding control groups of untrained mice at pool occupancy rate ρ of 11.9% and 4%, respectively. Faster evacuation happened because trained mice: (a) had better recognition of the available pool space and took shorter escape routes to an exit, (b) were less likely to form arches that blocked an exit opening, and (c) utilized the two exits efficiently without preference. Trained groups achieved continuous egress without an apparent leader-coordinator (self-organized queuing)—a collective behavior not experienced during individual training. Queuing was unobserved in untrained groups where mice were prone to wall seeking, aimless swimming and/or blind copying that produced circuitous escape routes, biased exit use and clogging. The experiments also reveal that faster and less costly group training at ρ = 4%, yielded an average individual escape time that is comparable with individualized training. However, group training in a more crowded pool (ρ = 11.9%) produced a longer average individual escape time. PMID:25693170

Pools for the Handicapped.

ERIC Educational Resources Information Center

American School and University, 1979

1979-01-01

Three institutions in Ohio now stress hydrotherapy and water recreation as important parts of individual educational programs for the handicapped. Specially designed and adapted pools provide freedom of movement and ego building as well as physical education and recreation. (Author)

Modeling of the Temperature Field Recovery in the Oil Pool

NASA Astrophysics Data System (ADS)

Khabibullin, I. L.; Davtetbaev, A. Ya.; Mar'in, D. F.; Khisamov, A. A.

2018-05-01

This paper considers the problem on mathematical modeling of the temperature field recovery in the oil pool upon termination of injection of water into the pool. The problem is broken down into two stages: injection of water and temperature and pressure recovery upon termination of injection. A review of the existing mathematical models is presented, analytical solutions for a number of cases have been constructed, and a comparison of the analytical solutions of different models has been made. In the general form, the expression has been obtained that permits determining the temperature change in the oil pool upon termination of injection of water (recovery of the temperature field).

Method development and validation for simultaneous determination of IEA-R1 reactor’s pool water uranium and silicon content by ICP OES

NASA Astrophysics Data System (ADS)

Ulrich, J. C.; Guilhen, S. N.; Cotrim, M. E. B.; Pires, M. A. F.

2018-03-01

IPEN’s research reactor, IEA-R1, an open pool type research reactor moderated and cooled by light water. High quality water is a key factor in preventing the corrosion of the spent fuel stored in the pool. Leaching of radionuclides from the corroded fuel cladding may be prevented by an efficient water treatment and purification system. However, as a safety management policy, IPEN has adopted a water chemistry control which periodically monitors the levels of uranium (U) and silicon (Si) in the pool’s reactor, since IEA-R1 employs U3Si2-Al dispersion fuel. An analytical method was developed and validated for the determination of uranium and silicon by ICP OES. This work describes the validation process, in a context of quality assurance, including the parameters selectivity, linearity, quantification limit, precision and recovery.

Progressive Increase in Disinfection By-products and Mutagenicity from Source to Tap to Swimming Pool and Spa Water: Impact of Human Use

EPA Science Inventory

Pools and spas are enjoyed throughout the world for exercise and relaxation. However, there are no previous studies on mutagenicity of disinfected spa (hot tub) waters or comprehensive identification of disinfection byproducts (DBPs) formed in spas. Using 28 water samples from ...

A swimming pool array for ultra high energy showers

NASA Astrophysics Data System (ADS)

Yodh, Gaurang B.; Shoup, Anthony; Barwick, Steve; Goodman, Jordan A.

1992-11-01

A very preliminary design concept for an array using water Cherenkov counters, built out of commercially available backyard swimming pools, to sample the electromagnetic and muonic components of ultra high energy showers at large lateral distances is presented. The expected performance of the pools is estimated using the observed lateral distributions by scintillator and water Cherenkov arrays at energies above 1019 eV and simulations.

Effects of Geographic Diversification on Risk Pooling to Mitigate Drought-Related Financial Losses for Water Utilities

NASA Astrophysics Data System (ADS)

Baum, Rachel; Characklis, Gregory W.; Serre, Marc L.

2018-04-01

As the costs and regulatory barriers to new water supply development continue to rise, drought management strategies have begun to rely more heavily on temporary conservation measures. While these measures are effective, they often lead to intermittent and unpredictable reductions in revenues that are financially disruptive to water utilities, raising concerns over lower credit ratings and higher rates of borrowing for this capital intensive sector. Consequently, there is growing interest in financial risk management strategies that reduce utility vulnerabilities. This research explores the development of financial index insurance designed to compensate a utility for drought-related losses. The focus is on analyzing candidate hydrologic indices that have the potential to be used by utilities across the US, increasing the potential for risk pooling, which would offer the possibility of both lower risk management costs and more widespread implementation. This work first analyzes drought-related financial risks for 315 publicly operated water utilities across the country and examines the effectiveness of financial contracts based on several indices both in terms of their correlation with utility revenues and their spatial autocorrelation across locations. Hydrologic-based index insurance contracts are then developed and tested over a 120 year period. Results indicate that risk pooling, even under conditions in which droughts are subject to some level of spatial autocorrelation, has the potential to significantly reduce the cost of managing financial risk.

Sediment transport through self-adjusting, bedrock-walled waterfall plunge pools

NASA Astrophysics Data System (ADS)

Scheingross, Joel S.; Lamb, Michael P.

2016-05-01

Many waterfalls have deep plunge pools that are often partially or fully filled with sediment. Sediment fill may control plunge-pool bedrock erosion rates, partially determine habitat availability for aquatic organisms, and affect sediment routing and debris flow initiation. Currently, there exists no mechanistic model to describe sediment transport through waterfall plunge pools. Here we develop an analytical model to predict steady-state plunge-pool depth and sediment-transport capacity by combining existing jet theory with sediment transport mechanics. Our model predicts plunge-pool sediment-transport capacity increases with increasing river discharge, flow velocity, and waterfall drop height and decreases with increasing plunge-pool depth, radius, and grain size. We tested the model using flume experiments under varying waterfall and plunge-pool geometries, flow hydraulics, and sediment size. The model and experiments show that through morphodynamic feedbacks, plunge pools aggrade to reach shallower equilibrium pool depths in response to increases in imposed sediment supply. Our theory for steady-state pool depth matches the experiments with an R2 value of 0.8, with discrepancies likely due to model simplifications of the hydraulics and sediment transport. Analysis of 75 waterfalls suggests that the water depths in natural plunge pools are strongly influenced by upstream sediment supply, and our model provides a mass-conserving framework to predict sediment and water storage in waterfall plunge pools for sediment routing, habitat assessment, and bedrock erosion modeling.

Environmental controls of C, N and P biogeochemistry in peatland pools.

PubMed

Arsenault, Julien; Talbot, Julie; Moore, Tim R

2018-08-01

Pools are common in northern peatlands but studies have seldom focused on their nutrient biogeochemistry, especially in relation to their morphological characteristics and through seasons. We determined the environmental characteristics controlling carbon (C), nitrogen (N) and phosphorus (P) biogeochemistry in pools and assessed their evolution over the course of the 2016 growing season in a subboreal ombrotrophic peatland of eastern Canada. We showed that water chemistry variations in 62 pools were significantly explained by depth (81.9%) and the surrounding vegetation type (14.8%), but not by pool area or shape. Shallow pools had larger dissolved organic carbon (DOC) and total nitrogen (TN) concentrations and lower pH than deep pools, while pools surrounded by coniferous trees had more recalcitrant DOC than pools where vegetation was dominated by mosses. The influence of depth on pool biogeochemistry was confirmed by the seasonal survey of pools of different sizes with 47.1% of the variation in pool water chemistry over time significantly explained. Of this, 67.3% was explained by the interaction between time and pool size and 32.7% by pool size alone. P concentrations were small in all pools all summer long and combined with high N:P ratios, are indicative of P-limitation. Our results show that pool biogeochemistry is influenced by internal processes and highlight the spatial and temporal heterogeneity of nutrient biogeochemistry in ombrotrophic peatlands. Copyright © 2018 Elsevier B.V. All rights reserved.

33 CFR 207.60 - Federal Dam, Hudson River, Troy, N.Y.; pool level.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Federal Dam, Hudson River, Troy, N.Y.; pool level. 207.60 Section 207.60 Navigation and Navigable Waters CORPS OF ENGINEERS..., N.Y.; pool level. (a) Whenever the elevation of the pool created by the Federal dam at Troy, N.Y...

Mixing effects on nitrogen and oxygen concentrations and the relationship to mean residence time in a hyporheic zone of a riffle-pool sequence

USGS Publications Warehouse

Naranjo, Ramon C.; Niswonger, Richard G.; Clinton Davis,

2015-01-01

Flow paths and residence times in the hyporheic zone are known to influence biogeochemical processes such as nitrification and denitrification. The exchange across the sediment-water interface may involve mixing of surface water and groundwater through complex hyporheic flow paths that contribute to highly variable biogeochemically active zones. Despite the recognition of these patterns in the literature, conceptualization and analysis of flow paths and nitrogen transformations beneath riffle-pool sequences often neglect to consider bed form driven exchange along the entire reach. In this study, the spatial and temporal distribution of dissolved oxygen (DO), nitrate (NO3-) and ammonium (NH4+) were monitored in the hyporheic zone beneath a riffle-pool sequence on a losing section of the Truckee River, NV. Spatially-varying hyporheic exchange and the occurrence of multi-scale hyporheic mixing cells are shown to influence concentrations of DO and NO3- and the mean residence time (MRT) of riffle and pool areas. Distinct patterns observed in piezometers are shown to be influenced by the first large flow event following a steady 8 month period of low flow conditions. Increases in surface water discharge resulted in reversed hydraulic gradients and production of nitrate through nitrification at small vertical spatial scales (0.10 to 0.25 m) beneath the sediment-water interface. In areas with high downward flow rates and low MRT, denitrification may be limited. The use of a longitudinal two-dimensional flow model helped identify important mechanisms such as multi-scale hyporheic mixing cells and spatially varying MRT, an important driver for nitrogen transformation in the riverbed. Our observations of DO and NO3- concentrations and model simulations highlight the role of multi-scale hyporheic mixing cells on MRT and nitrogen transformations in the hyporheic zone of riffle-pool sequences. This article is protected by copyright. All rights reserved.

Comprehensive Identification of Chemical DBPs from Chlorinated and Brominated Swimming Pools

EPA Science Inventory

Swimming pools have been recently recognized as important routes of exposure to potentially harmful chemicals. Previous epidemiologic research has shown increased incidence of asthma and other respiratory effects for people who have significant indoor swimming pool exposures, an...

How big is the influence of biogenic silicon pools on short-term changes in water-soluble silicon in soils? Implications from a study of a 10-year-old soil-plant system

NASA Astrophysics Data System (ADS)

Puppe, Daniel; Höhn, Axel; Kaczorek, Danuta; Wanner, Manfred; Wehrhan, Marc; Sommer, Michael

2017-11-01

The significance of biogenic silicon (BSi) pools as a key factor for the control of Si fluxes from terrestrial to aquatic ecosystems has been recognized for decades. However, while most research has been focused on phytogenic Si pools, knowledge of other BSi pools is still limited. We hypothesized that different BSi pools influence short-term changes in the water-soluble Si fraction in soils to different extents. To test our hypothesis we took plant (Calamagrostis epigejos, Phragmites australis) and soil samples in an artificial catchment in a post-mining landscape in the state of Brandenburg, Germany. We quantified phytogenic (phytoliths), protistic (diatom frustules and testate amoeba shells) and zoogenic (sponge spicules) Si pools as well as Tiron-extractable and water-soluble Si fractions in soils at the beginning (t0) and after 10 years (t10) of ecosystem development. As expected the results of Tiron extraction showed that there are no consistent changes in the amorphous Si pool at Chicken Creek (Hühnerwasser) as early as after 10 years. In contrast to t0 we found increased water-soluble Si and BSi pools at t10; thus we concluded that BSi pools are the main driver of short-term changes in water-soluble Si. However, because total BSi represents only small proportions of water-soluble Si at t0 (< 2 %) and t10 (2.8-4.3 %) we further concluded that smaller (< 5 µm) and/or fragile phytogenic Si structures have the biggest impact on short-term changes in water-soluble Si. In this context, extracted phytoliths (> 5 µm) only amounted to about 16 % of total Si contents of plant materials of C. epigejos and P. australis at t10; thus about 84 % of small-scale and/or fragile phytogenic Si is not quantified by the used phytolith extraction method. Analyses of small-scale and fragile phytogenic Si structures are urgently needed in future work as they seem to represent the biggest and most reactive Si pool in soils. Thus they are the most important drivers of Si cycling

Pool boiling of water on nano-structured micro wires at sub-atmospheric conditions

NASA Astrophysics Data System (ADS)

Arya, Mahendra; Khandekar, Sameer; Pratap, Dheeraj; Ramakrishna, S. Anantha

2016-09-01

Past decades have seen active research in enhancement of boiling heat transfer by surface modifications. Favorable surface modifications are expected to enhance boiling efficiency. Several interrelated mechanisms such as capillarity, surface energy alteration, wettability, cavity geometry, wetting transitions, geometrical features of surface morphology, etc., are responsible for change in the boiling behavior of modified surfaces. Not much work is available on pool boiling at low pressures on microscale/nanoscale geometries; low pressure boiling is attractive in many applications wherein low operating temperatures are desired for a particular working fluid. In this background, an experimental setup was designed and developed to investigate the pool boiling performance of water on (a) plain aluminum micro wire (99.999 % pure) and, (b) nano-porous alumina structured aluminum micro wire, both having diameter of 250 µm, under sub-atmospheric pressure. Nano-structuring on the plain wire surface was achieved via anodization. Two samples, A and B of anodized wires, differing by the degree of anodization were tested. The heater length scale (wire diameter) was much smaller than the capillary length scale. Pool boiling characteristics of water were investigated at three different sub-atmospheric pressures of 73, 123 and 199 mbar (corresponding to T sat = 40, 50 and 60 °C). First, the boiling characteristics of plain wire were measured. It was noticed that at sub-atmospheric pressures, boiling heat transfer performance for plain wire was quite low due to the increased bubble sizes and low nucleation site density. Subsequently, boiling performance of nano-structured wires (both Sample A and Sample B) was compared with plain wire and it was noted that boiling heat transfer for the former was considerably enhanced as compared to the plain wire. This enhancement is attributed to increased nucleation site density, change in wettability and possibly due to enhanced pore scale

Trihalomethanes in Lisbon indoor swimming pools: occurrence, determining factors, and health risk classification.

PubMed

Silva, Zelinda Isabel; Rebelo, Maria Helena; Silva, Manuela Manso; Alves, Ana Martins; Cabral, Maria da Conceição; Almeida, Ana Cristina; Aguiar, Fátima Rôxo; de Oliveira, Anabela Lopes; Nogueira, Ana Cruz; Pinhal, Hermínia Rodrigues; Aguiar, Pedro Manuel; Cardoso, Ana Sofia

2012-01-01

Characterization of water quality from indoor swimming pools, using chorine-based disinfection techniques, was performed during a 6-mo period to study the occurrence, distribution, and concentration factors of trihalomethanes (THM). Several parameters such as levels of water THM, water and air chloroform, water bromodichloromethane (BDCM), water dibromochloromethane (DBCM), water bromoform (BF), free residual chlorine (FrCl), pH, water and air temperature, and permanganate water oxidizability (PWO) were determined in each pool during that period. Chloroform (CF(W)) was the THM detected at higher concentrations in all pools, followed by BDCM, DBCM, and BF detected at 99, 34, and 6% of the samples, respectively. Water THM concentrations ranged from 10.1 to 155 μg/L, with 6.5% of the samples presenting values above 100 μg/L (parametric value established in Portuguese law DL 306/2007). In this study, air chloroform (CF(Air)) concentrations ranged from 45 to 373 μg/m³ with 24% of the samples presenting values above 136 μg/m³ (considered high exposure value). Several significant correlations were observed between total THM and other parameters, namely, CF(W), CF(Air), FrCl, water temperature (T(W)), and PWO. These correlations indicate that FrCl, T(W) and PWO are parameters that influence THM formation. The exposure criterion established for water THM enabled the inclusion of 67% of Lisbon pools in the high exposure group, which reinforces the need for an improvement in pool water quality.

Formation of trihalomethanes as disinfection byproducts in herbal spa pools.

PubMed

Fakour, Hoda; Lo, Shang-Lien

2018-04-09

Herbal spa treatments are favorite recreational activities throughout the world. The water in spas is often disinfected to control pathogenic microorganisms and guarantee hygiene. However, chlorinated water may cause the formation of disinfection byproducts (DBPs). Although there have been many studies on DBP formation in swimming pools, the role of organic matter derived from herbal medicines applied in herbal spa water has been largely neglected. Accordingly, the present study investigated the effect of herbal medicines on the formation of trihalomethanes (THMs) in simulated herbal spa water. Water samples were collected from a spa pool, and then, disinfection and herbal addition experiments were performed in a laboratory. The results showed that the organic molecules introduced by the herbal medicines are significant precursors to the formation of THMs in spa pool water. Since at least 50% of THMs were produced within the first six hours of the reaction time, the presence of herbal medicines in spa water could present a parallel route for THM exposure. Therefore, despite the undeniable benefits of herbal spas, the effect of applied herbs on DBP formation in chlorinated water should be considered to improve the water quality and health benefits of spa facilities.

The two water worlds hypothesis: Addressing multiple working hypotheses and proposing a way forward

USDA-ARS?s Scientific Manuscript database

Recent studies using water isotopes have shown that trees and streams appear to return distinct water pools to the hydrosphere. Cryogenically extracted plant and soil water isotopic signatures diverge from the Meteoric Water Lines (MWL), suggesting that plants would preferentially use bound soil wat...

Getting Pool Light Right.

ERIC Educational Resources Information Center

Hunsaker, Scot

1998-01-01

Examines the use of lighting, both artificial and natural, that can enhance the aesthetic quality and functionality of areas with indoor swimming pools. Discusses glare and shadow-reduction measures that aid competitive events, including lighting above and below water levels, and highlights lighting issues during televised events. Descriptions of…

A Survey of Enzymatic Activity in Commercially Available Pool and Spa Products

USDA-ARS?s Scientific Manuscript database

Many pool water treatment products currently available commercially claim that they work effectively by possessing enzyme activity (specifically lipase) that degrades common oil (lipid) contaminants found in pool water. Currently, there is no standard in measuring the enzymatic activity of these enz...

Decontamination of outdoor school swimming pools in Fukushima after the nuclear accident in March 2011.

PubMed

Saegusa, J; Kurikami, H; Yasuda, R; Kurihara, K; Arai, S; Kuroki, R; Matsuhashi, S; Ozawa, T; Goto, H; Takano, T; Mitamura, H; Nagano, T; Naganawa, H; Yoshida, Z; Funaki, H; Tokizawa, T; Nakayama, S

2013-03-01

Because of radioactive fallout resulting from the Fukushima Daiichi Nuclear Power Plant (NPP) accident, water discharge from many outdoor swimming pools in Fukushima was suspended out of concern that radiocesium in the pool water would flow into farmlands. The Japan Atomic Energy Agency has reviewed the existing flocculation method for decontaminating pool water and established a practical decontamination method by demonstrating the process at eight pools in Fukushima. In this method, zeolite powder and a flocculant are used for capturing radiocesium present in pool water. The supernatant is discharged if the radiocesium concentration is less than the targeted level. The radioactive residue is collected and stored in a temporary storage space. Radioactivity concentration in water is measured with a NaI(Tl) or Ge detector installed near the pool. The demonstration results showed that the pool water in which the radiocesium concentration was more than a few hundred Bq L was readily purified by the method, and the radiocesium concentration was reduced to less than 100 Bq L. The ambient dose rates around the temporary storage space were slightly elevated; however, the total increase was up to 30% of the background dose rates when the residue was shielded with sandbags.

Characterizing convective cold pools: Characterizing Convective Cold Pools

DOE PAGES

Drager, Aryeh J.; van den Heever, Susan C.

2017-05-09

Cold pools produced by convective storms play an important role in Earth's climate system. However, a common framework does not exist for objectively identifying convective cold pools in observations and models. The present study investigates convective cold pools within a simulation of tropical continental convection that uses a cloud-resolving model with a coupled land-surface model. Multiple variables are assessed for their potential in identifying convective cold pool boundaries, and a novel technique is developed and tested for identifying and tracking cold pools in numerical model simulations. This algorithm is based on surface rainfall rates and radial gradients in the densitymore » potential temperature field. The algorithm successfully identifies near-surface cold pool boundaries and is able to distinguish between connected cold pools. Once cold pools have been identified and tracked, composites of cold pool evolution are then constructed, and average cold pool properties are investigated. Wet patches are found to develop within the centers of cold pools where the ground has been soaked with rainwater. These wet patches help to maintain cool surface temperatures and reduce cold pool dissipation, which has implications for the development of subsequent convection.« less

Characterizing convective cold pools: Characterizing Convective Cold Pools

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drager, Aryeh J.; van den Heever, Susan C.

Cold pools produced by convective storms play an important role in Earth's climate system. However, a common framework does not exist for objectively identifying convective cold pools in observations and models. The present study investigates convective cold pools within a simulation of tropical continental convection that uses a cloud-resolving model with a coupled land-surface model. Multiple variables are assessed for their potential in identifying convective cold pool boundaries, and a novel technique is developed and tested for identifying and tracking cold pools in numerical model simulations. This algorithm is based on surface rainfall rates and radial gradients in the densitymore » potential temperature field. The algorithm successfully identifies near-surface cold pool boundaries and is able to distinguish between connected cold pools. Once cold pools have been identified and tracked, composites of cold pool evolution are then constructed, and average cold pool properties are investigated. Wet patches are found to develop within the centers of cold pools where the ground has been soaked with rainwater. These wet patches help to maintain cool surface temperatures and reduce cold pool dissipation, which has implications for the development of subsequent convection.« less

Declassification of radioactive water from a pool type reactor after nuclear facility dismantling

NASA Astrophysics Data System (ADS)

Arnal, J. M.; Sancho, M.; García-Fayos, B.; Verdú, G.; Serrano, C.; Ruiz-Martínez, J. T.

2017-09-01

This work is aimed to the treatment of the radioactive water from a dismantled nuclear facility with an experimental pool type reactor. The main objective of the treatment is to declassify the maximum volume of water and thus decrease the volume of radioactive liquid waste to be managed. In a preliminary stage, simulation of treatment by the combination of reverse osmosis (RO) and evaporation have been performed. Predicted results showed that the combination of membrane and evaporation technologies would result in a volume reduction factor higher than 600. The estimated time to complete the treatment was around 650 h (25-30 days). For different economical and organizational reasons which are explained in this paper, the final treatment of the real waste had to be reduced and only evaporation was applied. The volume reduction factor achieved in the real treatment was around 170, and the time spent for treatment was 194 days.

The Pool Is Not Just for Swimming

ERIC Educational Resources Information Center

Metzker, Andrea

2004-01-01

Participating in water fitness workouts is one way to benefit one's health at very little cost. If the pool at a school is used only for swimming, then the benefits of having one barely causes a ripple. When the properties of water and how humans react to water are understood and applied to water activity programs, health benefits and enjoyment…

13 CFR 120.611 - Pools backing Pool Certificates.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false Pools backing Pool Certificates. 120.611 Section 120.611 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS LOANS Secondary Market Certificates § 120.611 Pools backing Pool Certificates. (a) Pool characteristics. As set...

13 CFR 120.611 - Pools backing Pool Certificates.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Pools backing Pool Certificates. 120.611 Section 120.611 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS LOANS Secondary Market Certificates § 120.611 Pools backing Pool Certificates. (a) Pool characteristics. As set...

Using "residual depths" to monitor pool depths independently of discharge

Treesearch

Thomas E. Lisle

1987-01-01

As vital components of habitat for stream fishes, pools are often monitored to follow the effects of enhancement projects and natural stream processes. Variations of water depth with discharge, however, can complicate monitoring changes in the depth and volume of pools. To subtract the effect of discharge on depth in pools, residual depths can be measured. Residual...

Controls on Filling and Evacuation of Sediment in Waterfall Plunge Pools

NASA Astrophysics Data System (ADS)

Scheingross, J. S.; Lamb, M. P.

2014-12-01

Many waterfalls are characterized by the presence of deep plunge pools that experience periods of sediment fill and evacuation. These cycles of sediment fill are a first order control on the relative magnitude of lateral versus vertical erosion at the base of waterfalls, as vertical incision requires cover-free plunge pools to expose the bedrock floor, while lateral erosion can occur when pools are partially filled and plunge-pool walls are exposed. Currently, there exists no mechanistic model describing sediment transport through waterfall plunge pools, limiting our ability to predict waterfall retreat. To address this knowledge gap, we performed detailed laboratory experiments measuring plunge-pool sediment transport capacity (Qsc_pool) under varying waterfall and plunge-pool geometries, flow hydraulics, and sediment size. Our experimental plunge-pool sediment transport capacity measurements match well with a mechanistic model we developed which combines existing waterfall jet theory with a modified Rouse profile to predict sediment transport capacity as a function of water discharge and suspended sediment concentration at the plunge-pool lip. Comparing the transport capacity of plunge pools to lower gradient portions of rivers (Qsc_river) shows that, for transport limited conditions, plunge pools fill with sediment under modest water discharges when Qsc_river > Qsc_pool, and empty to bedrock under high discharges when Qsc_pool > Qsc_river. These results are consistent with field observations of sand-filled plunge pools with downstream boulder rims, implying filling and excavation of plunge pools over single-storm timescales. Thus, partial filling of waterfall plunge pools may provide a mechanism to promote lateral undercutting and retreat of waterfalls in homogeneous rock in which plunge-pool vertical incision occurs during brief large floods that expose bedrock, whereas lateral erosion may prevail during smaller events.

Laboratory investigation and simulation of breakthrough curves in karst conduits with pools

NASA Astrophysics Data System (ADS)

Zhao, Xiaoer; Chang, Yong; Wu, Jichun; Peng, Fu

2017-12-01

A series of laboratory experiments are performed under various hydrological conditions to analyze the effect of pools in pipes on breakthrough curves (BTCs). The BTCs are generated after instantaneous injections of NaCl tracer solution. In order to test the feasibility of reproducing the BTCs and obtain transport parameters, three modeling approaches have been applied: the equilibrium model, the linear graphical method and the two-region nonequilibrium model. The investigation results show that pools induce tailing of the BTCs, and the shapes of BTCs depend on pool geometries and hydrological conditions. The simulations reveal that the two-region nonequilibrium model yields the best fits to experimental BTCs because the model can describe the transient storage in pools by the partition coefficient and the mass transfer coefficient. The model parameters indicate that pools produce high dispersion. The increased tailing occurs mainly because the partition coefficient decreases, as the number of pools increases. When comparing the tracer BTCs obtained using the two types of pools with the same size, the more appreciable BTC tails that occur for symmetrical pools likely result mainly from the less intense exchange between the water in the pools and the water in the pipe, because the partition coefficients for the two types of pools are virtually identical. Dispersivity values decrease as flow rates increase; however, the trend in dispersion is not clear. The reduced tailing is attributed to a decrease in immobile water with increasing flow rate. It provides evidence for hydrodynamically controlled tailing effects.

Pool Boiling Experiment Has Five Successful Flights

NASA Technical Reports Server (NTRS)

Chiaramonte, Fran

1997-01-01

The Pool Boiling Experiment (PBE) is designed to improve understanding of the fundamental mechanisms that constitute nucleate pool boiling. Nucleate pool boiling is a process wherein a stagnant pool of liquid is in contact with a surface that can supply heat to the liquid. If the liquid absorbs enough heat, a vapor bubble can be formed. This process occurs when a pot of water boils. On Earth, gravity tends to remove the vapor bubble from the heating surface because it is dominated by buoyant convection. In the orbiting space shuttle, however, buoyant convection has much less of an effect because the forces of gravity are very small. The Pool Boiling Experiment was initiated to provide insight into this nucleate boiling process, which has many earthbound applications in steamgeneration power plants, petroleum plants, and other chemical plants. In addition, by using the test fluid R-113, the Pool Boiling Experiment can provide some basic understanding of the boiling behavior of cryogenic fluids without the large cost of an experiment using an actual cryogen.

Violations identified from routine swimming pool inspections--selected states and counties, United States, 2008.

PubMed

2010-05-21

Swimming is the third most popular U.S. sport or exercise activity, with approximately 314 million visits to recreational water venues, including treated venues (e.g., pools), each year. The most frequently reported type of recreational water illness (RWI) outbreak is gastroenteritis, the incidence of which is increasing. During 1997--2006, chlorine- and bromine-susceptible pathogens (e.g., Shigella and norovirus) caused 24 (23%) of 104 treated venue--associated RWI outbreaks of gastroenteritis, indicating lapses in proper operation of pools. Pool inspectors help minimize the risk for RWIs and injuries by enforcing regulations that govern public treated recreational water venues. To assess pool code compliance, CDC analyzed 2008 data from 121,020 routine pool inspections conducted by a convenience sample of 15 state and local agencies. Because pool codes and, therefore, inspection items differed across jurisdictions, reported denominators varied. Of 111,487 inspections, 13,532 (12.1%) resulted in immediate closure because of serious violations (e.g., lack of disinfectant in the water). Of 120,975 inspections, 12,917 (10.7%) identified disinfectant level violations. Although these results likely are not representative of all pools in the United States, they suggest the need for increased public health scrutiny and improved pool operation. The results also demonstrate that pool inspection data can be used as a potential source for surveillance to guide resource allocation and regulatory decision-making. Collecting pool inspection data in a standardized, electronic format can facilitate routine analysis to support efforts to reduce health and safety risks for swimmers.

A Survey of Precipitation-Induced Atmospheric Cold Pools over Oceans and Their Interactions with the Larger-Scale Environment

NASA Astrophysics Data System (ADS)

Zuidema, Paquita; Torri, Giuseppe; Muller, Caroline; Chandra, Arunchandra

2017-11-01

Pools of air cooled by partial rain evaporation span up to several hundreds of kilometers in nature and typically last less than 1 day, ultimately losing their identity to the large-scale flow. These fundamentally differ in character from the radiatively-driven dry pools defining convective aggregation. Advancement in remote sensing and in computer capabilities has promoted exploration of how precipitation-induced cold pool processes modify the convective spectrum and life cycle. This contribution surveys current understanding of such cold pools over the tropical and subtropical oceans. In shallow convection with low rain rates, the cold pools moisten, preserving the near-surface equivalent potential temperature or increasing it if the surface moisture fluxes cannot ventilate beyond the new surface layer; both conditions indicate downdraft origin air from within the boundary layer. When rain rates exceed ˜ 2 mm h^{-1}, convective-scale downdrafts can bring down drier air of lower equivalent potential temperature from above the boundary layer. The resulting density currents facilitate the lifting of locally thermodynamically favorable air and can impose an arc-shaped mesoscale cloud organization. This organization allows clouds capable of reaching 4-5 km within otherwise dry environments. These are more commonly observed in the northern hemisphere trade wind regime, where the flow to the intertropical convergence zone is unimpeded by the equator. Their near-surface air properties share much with those shown from cold pools sampled in the equatorial Indian Ocean. Cold pools are most effective at influencing the mesoscale organization when the atmosphere is moist in the lower free troposphere and dry above, suggesting an optimal range of water vapor paths. Outstanding questions on the relationship between cold pools, their accompanying moisture distribution and cloud cover are detailed further. Near-surface water vapor rings are documented in one model inside but

A Survey of Precipitation-Induced Atmospheric Cold Pools over Oceans and Their Interactions with the Larger-Scale Environment

NASA Astrophysics Data System (ADS)

Zuidema, Paquita; Torri, Giuseppe; Muller, Caroline; Chandra, Arunchandra

Pools of air cooled by partial rain evaporation span up to several hundreds of kilometers in nature and typically last less than 1 day, ultimately losing their identity to the large-scale flow. These fundamentally differ in character from the radiatively-driven dry pools defining convective aggregation. Advancement in remote sensing and in computer capabilities has promoted exploration of how precipitation-induced cold pool processes modify the convective spectrum and life cycle. This contribution surveys current understanding of such cold pools over the tropical and subtropical oceans. In shallow convection with low rain rates, the cold pools moisten, preserving the near-surface equivalent potential temperature or increasing it if the surface moisture fluxes cannot ventilate beyond the new surface layer; both conditions indicate downdraft origin air from within the boundary layer. When rain rates exceed 2 mm h-1, convective-scale downdrafts can bring down drier air of lower equivalent potential temperature from above the boundary layer. The resulting density currents facilitate the lifting of locally thermodynamically favorable air and can impose an arc-shaped mesoscale cloud organization. This organization allows clouds capable of reaching 4-5 km within otherwise dry environments. These are more commonly observed in the northern hemisphere trade wind regime, where the flow to the intertropical convergence zone is unimpeded by the equator. Their near-surface air properties share much with those shown from cold pools sampled in the equatorial Indian Ocean. Cold pools are most effective at influencing the mesoscale organization when the atmosphere is moist in the lower free troposphere and dry above, suggesting an optimal range of water vapor paths. Outstanding questions on the relationship between cold pools, their accompanying moisture distribution and cloud cover are detailed further. Near-surface water vapor rings are documented in one model inside but near the

Convective cooling in a pool-type research reactor

NASA Astrophysics Data System (ADS)

Sipaun, Susan; Usman, Shoaib

2016-01-01

A reactor produces heat arising from fission reactions in the nuclear core. In the Missouri University of Science and Technology research reactor (MSTR), this heat is removed by natural convection where the coolant/moderator is demineralised water. Heat energy is transferred from the core into the coolant, and the heated water eventually evaporates from the open pool surface. A secondary cooling system was installed to actively remove excess heat arising from prolonged reactor operations. The nuclear core consists of uranium silicide aluminium dispersion fuel (U3Si2Al) in the form of rectangular plates. Gaps between the plates allow coolant to pass through and carry away heat. A study was carried out to map out heat flow as well as to predict the system's performance via STAR-CCM+ simulation. The core was approximated as porous media with porosity of 0.7027. The reactor is rated 200kW and total heat density is approximately 1.07+E7 Wm-3. An MSTR model consisting of 20% of MSTR's nuclear core in a third of the reactor pool was developed. At 35% pump capacity, the simulation results for the MSTR model showed that water is drawn out of the pool at a rate 1.28 kg s-1 from the 4" pipe, and predicted pool surface temperature not exceeding 30°C.

Occurrence of Cryptosporidium and Giardia and the Relationship between Protozoa and Water Quality Indicators in Swimming Pools.

PubMed

Xiao, Shumin; Yin, Pengna; Zhang, Yan; Hu, Sike

2017-04-01

A total of 60 samples were collected from 35 swimming pools in Beijing, China, and the presence of Cryptosporidium and Giardia were investigated. The results showed that 16.7% and 15.0% of samples were positive for Cryptosporidium oocyst and Giardia cysts, respectively, with a mean concentration of 0.30 oocysts/10 L and 0.27 cysts/10 L. The oocysts and cysts were found to have higher rates of occurrence in August than in May. Genotyping confirmed the presence of Cryptosporidium hominis, C. parvum , and Giardia assemblages A and B, all of which were associated with human infections. The predominant species/assemblages were C. hominis and Giardia assemblage A. Analyses of the relationships between parasite oocysts/cysts, indicator bacteria, and physical-chemical parameters revealed that there was no correlation between 2 parasites and fecal bacterial indicators, whilst there was a significant correlation between protozoa and urea concentration, which indicates that urea concentration rather than fecal bacterial indicators might be an appropriate index for chlorine-resistant protozoa in swimming pools. This study provides useful information to improve the safety of swimming pool water and deduce the risk of protozoan infections.

WaterBotics: Pooling Students to STEM

NASA Astrophysics Data System (ADS)

Stambaugh, Beverly

2015-04-01

challenge that integrates learning from the prior challenges. The nature of these challenges allows for easy adaptation to various real-world scenarios for students to engage in, such as developing a submarine for ocean floor study or designing a vehicle to explore and mine the ocean for mineral resources. First-hand experience with WaterBotics curriculum has shown the increased engagement and excitement for STEM. Starting with a peanut butter and jelly sandwich leads to amazing discovery as students work through the engineering design process, sketching and building their LEGO robots and learning the steps to simple programs that allow their robotic creations to complete various tasks. With LEGOs being so easy to use, students can easily revise their design over and over again until it looks and works as it should. Once the students have the opportunity to test their design in the water for the first time, they are hooked. They can see that something they designed and built actually completes the task, even if it takes multiple tries, and they want to try the next challenge.

Physical and biogeochemical controls on polymictic behavior in Sierra Nevada stream pools

NASA Astrophysics Data System (ADS)

Lucas, R. G.; Conklin, M. H.; Tyler, S. W.; Suarez, F. I.; Moran, J. E.; Esser, B. K.

2011-12-01

We observed polymictic behavior in stream pools in a low gradient montane meadow in the southern Sierra Nevada mountains, California. Thermal stratification in stream pools has been observed in various environments; stratification generally persists where the buoyancy forces created by a variation in water density, as a function of water temperature, are able to overcome turbulent forces resulting from stream flow. Because the density gradient creates a relatively weak buoyancy force, low flow conditions are generally required in order to overcome the turbulent forces. In some studies, a cold water source in to the pool bottoms can help to increase the density gradient and perpetuate thermal stratification. Our study took place in Long Meadow, Sequoia National Park, California. Long Meadow lies in the Wolverton Creek watershed and is part of the Southern Sierra Critical Zone Observatory. The 1-4 m diameter and 1-2 m deep pools in our study stratified thermally during the day and mixed completely at night. The low gradient of the meadow provided low stream flows. Piezometers in the meadow indicated groundwater discharge into the meadow in the months during which stratification was observed. Radon 222 activity measured in the pools also indicated groundwater influx to the pool bottoms. We used Fluent, a computational fluid dynamics equation solver, to construct a model of one of the observed pools. Initially we attempted to model the physical mechanisms controlling thermal stratification in the pool including stream flow, groundwater discharge, solar radiation, wind speed, and air, stream and ground water temperatures. Ultimately we found the model best agreed with our observed pool temperatures when we considered the light attenuation coefficients as a function of the dissolve organic carbon (DOC) concentration. Elevated DOC concentrations are expected in low stream flow regimes associated with highly organic soils such as a montane meadow. DOC concentrations

Occurrence and formation of disinfection by-products in the swimming pool environment: A critical review.

PubMed

Carter, Rhys A A; Joll, Cynthia A

2017-08-01

Disinfection of water for human use is essential to protect against microbial disease; however, disinfection also leads to formation of disinfection by-products (DBPs), some of which are of health concern. From a chemical perspective, swimming pools are a complex matrix, with continual addition of a wide range of natural and anthropogenic chemicals via filling waters, disinfectant addition, pharmaceuticals and personal care products and human body excretions. Natural organic matter, trace amounts of DBPs and chlorine or chloramines may be introduced by the filling water, which is commonly disinfected distributed drinking water. Chlorine and/or bromine is continually introduced via the addition of chemical disinfectants to the pool. Human body excretions (sweat, urine and saliva) and pharmaceuticals and personal care products (sunscreens, cosmetics, hair products and lotions) are introduced by swimmers. High addition of disinfectant leads to a high formation of DBPs from reaction of some of the chemicals with the disinfectant. Swimming pool air is also of concern as volatile DBPs partition into the air above the pool. The presence of bromine leads to the formation of a wide range of bromo- and bromo/chloro-DBPs, and Br-DBPs are more toxic than their chlorinated analogues. This is particularly important for seawater-filled pools or pools using a bromine-based disinfectant. This review summarises chemical contaminants and DBPs in swimming pool waters, as well as in the air above pools. Factors that have been found to affect DBP formation in pools are discussed. The impact of the swimming pool environment on human health is reviewed. Copyright © 2017. Published by Elsevier B.V.

"Hot tub" Folliculitis from a nonchlorinated children's pool.

PubMed

Segna, Kara G; Koch, Laine H; Williams, Judith V

2011-01-01

Pseudomonas aeruginosa is common cause of folliculitis following contact with contaminated water. We report a case of pseudomonal folliculitis that occurred after swimming in a children's pool filled with water from a well. © 2011 Wiley Periodicals, Inc.

Test of precoat filtration technology for treatment of swimming pool water.

PubMed

Christensen, Morten Lykkegaard; Klausen, Morten Møller; Christensen, Peter Vittrup

2018-02-01

The technical performance of a precoat filter was compared with that of a traditional sand filter. Particle concentration and size distribution were measured before and after the filtration of swimming pool water. Both the sand and precoat filters could reduce the particle concentration in the effluent. However, higher particle removal efficiency was generally observed for the precoat filter, especially for particles smaller than 10 μm in diameter. Adding flocculant improved the removal efficiency of the sand filter, resulting in removal efficiencies comparable to those of the precoat filter. Three powders, i.e., two types of perlite (Harbolite ® and Aquatec perlite) and cellulose fibers (Arbocel ® ), were tested for the precoat filter, but no significant difference in particle removal efficiency was observed among them. The maximum efficiency was reached within 30-40 min of filtration. The energy required for the pumps increased by approximately 35% over a period of 14 days. The energy consumption could be reduced by replacing the powder on the filter cloth. The sand filter was backwashed once a week, while the powder on the precoat filter was replaced every two weeks. Under these conditions, it was possible to reduce the water used for cleaning by 88% if the precoat filter was used instead of the sand filter.

Swimming Pools.

ERIC Educational Resources Information Center

Ministry of Housing and Local Government, London (England).

Technical and engineering data are set forth on the design and construction of swimming pools. Consideration is given to site selection, pool construction, the comparative merits of combining open air and enclosed pools, and alternative uses of the pool. Guidelines are presented regarding--(1) pool size and use, (2) locker and changing rooms, (3)…

Environmental assessment, K Pool fish rearing, Hanford Site, Richland, Washington

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-12-01

The US Department of Energy (DOE) has a need to respond to a request to lease facilities at the Hanford Site 100-KE and 100-KW filter plant pools (K Pools) for fish rearing activities. These fish rearing activities would be: (1) business ventures with public and private funds and (2) long-term enhancement and supplementation programs for game fish populations in the Columbia River Basin. The proposed action is to enter into a use permit or lease agreement with the YIN or other parties who would rear fish in the 100-K Area Pools. The proposed action would include necessary piping, pump, andmore » electrical upgrades of the facility; cleaning and preparation of the pools; water withdrawal from the Columbia River, and any necessary water or wastewater treatment; and introduction, rearing and release of fish. Future commercial operations may be included.« less

Cardiorespiratory Responses to Pool Floor Walking in People Poststroke.

PubMed

Jeng, Brenda; Fujii, Takuto; Lim, Hyosok; Vrongistinos, Konstantinos; Jung, Taeyou

2018-03-01

To compare cardiorespiratory responses between pool floor walking and overground walking (OW) in people poststroke. Cross-sectional study. University-based therapeutic exercise facility. Participants (N=28) were comprised of 14 community-dwelling individuals poststroke (5.57±3.57y poststroke) and 14 age- and sex-matched healthy adults (mean age, 58.00±15.51y; male/female ratio, 9:5). Not applicable. A telemetric metabolic system was used to collect cardiorespiratory variables, including oxygen consumption (V˙o 2 ), energy expenditure (EE), and expired volume per unit time (V˙e), during 6-minute walking sessions in chest-depth water and on land at a matched speed, determined by average of maximum walking speed in water. Individuals poststroke elicited no significant differences in cardiorespiratory responses between pool floor walking and OW. However, healthy controls showed significant increases in mean V˙o 2 values by 94%, EE values by 109%, and V˙e values by 94% (all P<.05) during pool floor walking compared with OW. A 2×2 mixed model analysis of variance revealed a significant group × condition interaction in V˙o 2 , in which the control group increased V˙o 2 from OW to pool floor walking, whereas the stroke group did not. Our results indicate that people poststroke, unlike healthy adults, do not increase EE while walking in water compared with on land. Unlike stationary walking on an aquatic treadmill, forward locomotion during pool floor walking at faster speeds may have increased drag force, which requires greater EE from healthy adults. Without demanding excessive EE, walking in water may offer a naturally supportive environment for gait training in the early stages of rehabilitation. Copyright © 2017 American Congress of Rehabilitation Medicine. All rights reserved.

Convective cooling in a pool-type research reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sipaun, Susan, E-mail: susan@nm.gov.my; Usman, Shoaib, E-mail: usmans@mst.edu

2016-01-22

A reactor produces heat arising from fission reactions in the nuclear core. In the Missouri University of Science and Technology research reactor (MSTR), this heat is removed by natural convection where the coolant/moderator is demineralised water. Heat energy is transferred from the core into the coolant, and the heated water eventually evaporates from the open pool surface. A secondary cooling system was installed to actively remove excess heat arising from prolonged reactor operations. The nuclear core consists of uranium silicide aluminium dispersion fuel (U{sub 3}Si{sub 2}Al) in the form of rectangular plates. Gaps between the plates allow coolant to passmore » through and carry away heat. A study was carried out to map out heat flow as well as to predict the system’s performance via STAR-CCM+ simulation. The core was approximated as porous media with porosity of 0.7027. The reactor is rated 200kW and total heat density is approximately 1.07+E7 Wm{sup −3}. An MSTR model consisting of 20% of MSTR’s nuclear core in a third of the reactor pool was developed. At 35% pump capacity, the simulation results for the MSTR model showed that water is drawn out of the pool at a rate 1.28 kg s{sup −1} from the 4” pipe, and predicted pool surface temperature not exceeding 30°C.« less

Chemical Safety Alert: Safe Storage and Handling of Swimming Pool Chemicals

EPA Pesticide Factsheets

Hazards of pool water treatment and maintenance chemicals (e.g., chlorine), and the protective measures pool owners should take to prevent fires, toxic vapor releases, and injuries. Triggered by improper wetting, mixing, or self-reactivity over time.

Moral equality and success of common-pool water governance in Namibia.

PubMed

Schnegg, Michael; Bollig, Michael; Linke, Theresa

2016-09-01

In the course of decentralization, pastoral communities in Namibia have had to find new ways to share their most salient resource, water, and the costs involved in providing it. Using data from sixty communities, we examine (1) whether and to what extent different sharing rules emerge, (2) how variations can be explained, (3) how rules are perceived and influence success, and (4) what economic consequences they have. Our results reveal that either all members pay the same (numerical equality) or payment is according to usage (proportional equality). We find that although proportional equality provides more success, the rule can only pertain where the state maintains an active role. Simulations show that where it does not prevail, wealth inequality is likely to grow. These findings have political implications and suggest that, in the context of the widespread decentralization policies, the state should not withdraw if it aims to ensure the success of common-pool resource management and to fight poverty.

Insights into assessing water quality using taxonomic distinctness based on a small species pool of biofilm-dwelling ciliate fauna in coastal waters of the Yellow Sea, northern China.

PubMed

Zhang, Wei; Liu, Yuanyuan; Warren, Alan; Xu, Henglong

2014-12-15

The aim of this study is to determine the feasibility of using a small species pool from a raw dataset of biofilm-dwelling ciliates for bioassessment based on taxonomic diversity. Samples were collected monthly at four stations within a gradient of environmental stress in coastal waters of the Yellow Sea, northern China from August 2011 to July 2012. A 33-species subset was identified from the raw 137-species dataset using a multivariate method. The spatial patterns of this subset were significantly correlated with the changes in the nutrients and chemical oxygen demand. The taxonomic diversity indices were significantly correlated with nutrients. The pair-wise indices of average taxonomic distinctness (Δ(+)) and the taxonomic distinctness (Λ(+)) showed a clear departure from the expected taxonomic pattern. These findings suggest that this small ciliate assemblage might be used as an adequate species pool for discriminating water quality status based on taxonomic distinctness in marine ecosystems. Copyright © 2014 Elsevier Ltd. All rights reserved.

Fast determination of octinoxate and oxybenzone uv filters in swimming pool waters by gas chromatography/mass spectrometry after solid-phase microextraction.

PubMed

Yılmazcan, Ö; Kanakaki, C; Izgi, B; Rosenberg, E

2015-07-01

A fast gas chromatography/mass spectrometry method was developed and validated for the analysis of the potential endocrine disrupters octinoxate and oxybenzone in swimming pool water samples based on the solvent-free solid-phase microextraction technique. The low-pressure gas chromatography/mass spectrometry method used for the fast identification of UV filter substances was compared to a conventional method in terms of sensitivity and speed. The fast method proposed resulted in 2 min runs, leading to an eightfold decrease in the total analysis time and a sevenfold improvement in detection limits. The main parameters affecting the solid-phase microextraction process were also studied in detail and the optimized conditions were as follows: fiber coating, polyacrylate; extraction mode, direct immersion; extraction temperature, 25°C; sample volume, 5 mL; extraction time 45 min; pH 6.5. Under the optimized conditions, a linear response was obtained in the concentration range of 0.5-25 μg/L with correlation coefficients in the range 0.990-0.999. The limits of detection were 0.17-0.29 μg/L, and the recoveries were 80-83%. Combined method uncertainty was assessed and found to be less than 7% for both analytes for concentrations equal to or higher than 5 μg/L. Pool water samples were analyzed to demonstrate the applicability of the proposed method. Neither octinoxate nor oxybenzone were detected in the swimming pool water samples at concentrations above the respective limits of detection. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hydrology of the Floral City Pool of Tsala Apopka Lake, west-central Florida

USGS Publications Warehouse

Bradner, L.A.

1988-01-01

Tsala Apopka Lake, in west-central Florida, has an area of about 19,000 acres and is divided into three water-management pools, with the Floral City Pool, the most upgradient. The Floral City Pool, which has a surface area of approximately 4,750 acres, contains an extensive combination of lakes, wetlands, and connecting canals. The Pool receives inflow from the Withlacoochee River through two canals. Outflow is through one manmade canal and one natural slough. Canal flow is partially controlled by manmade structures. A cumulative deficit of 19.4 inches of rainfall from August 1984 through May 1985 reduced surface-water inflow to the Floral City Pool to about 0.5 cu ft/sec by May 1985. During May 1985, pool levels declined approximately 0.04 ft/day. By the end of May, there was no observable outflow. From June 1985 through September 1985, 39.8 inches of rainfall caused above-average inflow to the Floral City Pool and a pool-level increase of 6.2 ft. The inflow of 340 CFS nearly equaled the outflow of 338 CFS by the end of September. (USGS)

Software for the Design of Swimming Pool Dehumidifiers Units

NASA Astrophysics Data System (ADS)

Rubina, Aleš; Blasinski, Petr; Tesař, Zdeněk

2013-06-01

The article deals with the description and solution of physical phenomena taking place during evaporation of water. The topicality of the theme is given a number of built indoor swimming pool and wellness centers at present. In addressing HVAC systems serving these areas, it is necessary to know the various design parameters in the interior including the water temperature as the pool temperature and humidity. Following is a description of the calculation module, air handling units, including optimizing the settings of the physical changes in order to ensure the lowest energy consumption for air treatment and required maintaining internal microclimate parameters.

Late Miocene - Pliocene Evolution of the Pacific Warm Pool and Cold Tongue: Implications for El Niño

NASA Astrophysics Data System (ADS)

Zhang, Y.; Pagani, M.

2011-12-01

The Western Pacific Warm Pool of the tropical Pacific Ocean retains the largest and warmest sea surface water body on Earth, while the eastern equatorial Pacific is characterized by strong upwelling of cold, nutrient-rich deep waters, termed the Pacific cold tongue. Evolution of the Pacific warm pool and cold tongue are important because they control the circum-Pacific climate and impact the globe via El Niño - Southern Oscillation (ENSO) teleconnections. Sea surface temperature (SST) reconstructions using a single site from the warm pool (ODP 806) and two sites from the cold tongue (ODP 846, 847) suggest that the temperature of the warm pool was "stable" throughout the Plio-Pleistocene, whereas the cold tongue was much warmer in the Pliocene and subsequently cooled. The absence of an east-west Pacific temperature gradient during the early Pliocene is the basis for the "permanent El Niño" hypothesis. However, annually-resolved fossil coral and evaporite records found 3-7 years climate variability during the Pliocene warm period and late Miocene, challenging a "permanent" or invariant climate state. Here we present a multi-proxy (TEX86, UK37, Mg/Ca), multi-site reconstruction of the late Miocene - Pliocene (ca. 12 Ma - 3 Ma) SST in the Pacific warm pool (ODP 806, ODP 769 in the Sulu Sea, ODP 1143 in the South China Sea) and the cold tongue (ODP 850, 849, 846). Our results show that the cold tongue was even warmer in the late Miocene than the Pliocene, and that the warm pool cooled 2-3°C from the late Miocene into the Pliocene - in contrast to the invariant character previously assumed. Temperature comparison between different sites suggests that the warm pool may have expanded in size in the late Miocene. Although eastern and western ends of the tropical Pacific were warmer, a persistent, but low east-west temperature gradient (~3°C) is apparent. This agrees with recent studies which have shown ENSO-related frequency of climate change in the late Miocene and

Characteristics of pools used by adult summer steelhead oversummering in the New River, California

Treesearch

Rodney J. Nakamoto

1994-01-01

Abstract - I assessed characteristics of pools used by oversummering adults of summer steelhead Oncorhynchus mykiss between July and October 1991 in the New River, northwestern California. Most fish occupied channel confluence pools and other pools of moderate size (200-1,200 m 2); these pools had less than 35% substrate embeddedness and mean water depths of about 1.0...

The Body Mass Index of San Francisco Cold-water Swimmers: Comparisons to U.S. National and Local Populations, and Pool Swimmers

PubMed Central

CROW, BRENDAN T.; MATTHAY, ELLICOTT C.; SCHATZ, STEPHEN P.; DEBELISO, MARK D.; NUCKTON, THOMAS J.

2017-01-01

To determine if cold-water swimmers have substantial differences in BMI, which might have a protective effect against heat loss during swims in cold water without wetsuits, and to determine if obesity is more or less prevalent in cold-water swimmers, we compared the body mass index (BMI) values of 103 recreational open-water swimmers (mean age 54.3 ±10.8 years) to data from various population groups. Swimmers swam consistently throughout the winter months, in the San Francisco Bay (water temperature range: 9.6° C [49.3 ° F] to 12.6° C [54.7 ° F]), without wetsuits. After matching for age and sex, the average BMI of cold-water swimmers (25.9 kg/m2) was lower than the corresponding predicted U.S. average BMI (29.2 kg/m2; p<.001), the predicted California state average BMI (28.0 kg/m2; p<.001), and the predicted San Francisco city average BMI (26.6 kg/m2; p=.047). The average BMI value for cold-water swimmers (25.9 kg/m2) was not significantly different from values of North American masters pool swimmers (25.1 kg/m2; p=.15) or international masters pool swimmers (25.3 kg/m2; p=.16). 10.7% of cold-water swimmers were classified as obese (BMI > 30 kg/m2) vs. 35.7%, 25.8%, and 11.8% of the U.S., California, and San Francisco populations, respectively. The lower or similar BMI values of our swimmers suggest that successful recreational swimming in cold water is influenced by factors other than body habitus, such as acclimatization, heat production while swimming, and most importantly, limiting immersion time. The relatively low prevalence of obesity in our swimmers suggests that cold-water swimming could contribute to a healthy lifestyle. PMID:29399251

High-Viscosity Oil Filtration in the Pool Under Thermal Action

NASA Astrophysics Data System (ADS)

Shagapov, V. Sh.; Yumagulova, Yu. A.; Gizzatullina, A. A.

2018-05-01

We have developed a mathematical model and constructed numerical solutions of the problem of heating a high-viscosity oil pool through one horizontal well or a system of wells and have shown the possibility of their further operation until the limiting profitable discharge of oil is attained. The expenditure of heat in heating the oil pool, the evolution of discharge of oil, and the mass of extracted oil over the considered period have been considered.

Hydrologic effects of proposed changes in management practices, Winnebago Pool, Wisconsin

USGS Publications Warehouse

Krug, William R.

1981-01-01

In addition, the study illustrated that the discharge from the Winnebago pool could be managed to guarantee that the discharge in the Fox River downstream would not fall below a specified discharge up to 1,500 ft^/s. In most years this would have no effect on the stage of the pool. In a few years there would be a conflict between releasing water from the pool to maintain the desired discharge and maintaining water levels above the required minimum stage. The frequency of this possible conflict varies with the level of discharge desired in the Fox River from 1 year in 60 for a discharge of 1,100 ft^/s to about 1 year in 15 for a discharge of 1,500 ft^/s.

Source Water Identification and Chemical Typing for Nitrogen at the Kissimmee River, Pool C, Florida--Preliminary Assessment

USGS Publications Warehouse

,

2002-01-01

As part of the South Florida Water Management District's Ground Water-Surface Water Interactions Study, a project was undertaken to identify the ages and sources of water in the area of Pool C, Kissimmee River, Florida. Twenty-two water samples were collected along two transects: at a remnant river oxbows (Site D) and in the dredged part of the channel (Site C). The samples were analyzed for concentrations of fluoride and strontium, and for isotopes of oxygen, hydrogen, and nitrogen. Selected samples were analyzed for one or more additional isotopes (carbon-14, the ratio of strontium-87 to strontium-86, tritium, and tritium-helium-3). Delta nitrogen-15 values for nitrate at Site C can be explained by soil nitrogen and fertilizer sources; at Site D soil nitrogen accounts for most values, although animal wastes may explain higher values. Some of the isotopic data seem to be contradictory: carbon-14 data apparently indicate that shallow ground water is younger at Site D than at Site C, whereas strontium-87/86 ratios lead to the opposite conclusion. More detailed analysis of major ions and nutrients for all sampling points, along with flow measurements, could allow more definitive interpretation of isotope data and provide additional insight into mixing of ground water and surface water at the sites.

Investigation of Air Quality Problems in an Indoor Swimming Pool: A Case Study.

PubMed

Lévesque, Benoit; Vézina, Lorraine; Gauvin, Denis; Leroux, Patrice

2015-10-01

Trichloramine (NCl3) is the contaminant suspected the most to cause irritative respiratory symptoms among swimmers and swimming pool workers. Following complaints by employees working in an indoor swimming pool, this study set out to identify the determinants of NCl3 air concentrations in that particular swimming pool. To document NCl3 air levels, air samples (n = 26) were collected once or twice a day for 3 h, at least 3 days per week, between October and December 2011. Water samples were taken three times during air sampling to verify free chlorine, chloramines, alkalinity, conductivity, pH, water temperature, and turbidity. Water changes were also recorded, along with the number of bathers. Ventilation (outdoor air flow) was modified to verify the influence of this important variable. Data were evaluated by analysis of variance. Mean NCl3 air concentration was 0.38 mg m(-3). The best model explaining variations of NCl3 air levels (r2 = 0.83) included sampling period (P = 0.002, NCl3 was higher in the evening versus the morning), water changes (P = 0.02, NCl3 was lower with water changes between 60 and 90 min day(-1) versus <60 min day(-1)), and ventilation (P = 0.0002, NCl3 was lower with ≥2 air changes per hour (ACH) versus <1 ACH). Although based on only 26 air samples, our results indicate that ventilation is an important determinant of NCl3 air concentration in swimming pool air. There is limited information available on the air quality of indoor swimming pools and the relationship with ventilation. Efforts are needed to document the situation and to develop state-of-the-art facilities for ventilation of indoor swimming pools. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

13 CFR 120.1704 - Pool Loans eligible for Pooling.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., construction or renovation of an aquarium, zoo, golf course, or swimming pool; or (iv) To a business covered by... zoos—712130 (“Zoos and Botanical Gardens”). (b) SBA review of a Pool Loan prior to pool formation. SBA...

13 CFR 120.1704 - Pool Loans eligible for Pooling.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., construction or renovation of an aquarium, zoo, golf course, or swimming pool; or (iv) To a business covered by... zoos—712130 (“Zoos and Botanical Gardens”). (b) SBA review of a Pool Loan prior to pool formation. SBA...

13 CFR 120.1704 - Pool Loans eligible for Pooling.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., construction or renovation of an aquarium, zoo, golf course, or swimming pool; or (iv) To a business covered by... zoos—712130 (“Zoos and Botanical Gardens”). (b) SBA review of a Pool Loan prior to pool formation. SBA...

13 CFR 120.1704 - Pool Loans eligible for Pooling.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., construction or renovation of an aquarium, zoo, golf course, or swimming pool; or (iv) To a business covered by... zoos—712130 (“Zoos and Botanical Gardens”). (b) SBA review of a Pool Loan prior to pool formation. SBA...

13 CFR 120.1704 - Pool Loans eligible for Pooling.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., construction or renovation of an aquarium, zoo, golf course, or swimming pool; or (iv) To a business covered by... zoos—712130 (“Zoos and Botanical Gardens”). (b) SBA review of a Pool Loan prior to pool formation. SBA...

Coliphages and Gastrointestinal Illness in Recreational Waters: Pooled Analysis of Six Coastal Beach Cohorts.

PubMed

Benjamin-Chung, Jade; Arnold, Benjamin F; Wade, Timothy J; Schiff, Kenneth; Griffith, John F; Dufour, Alfred P; Weisberg, Stephen B; Colford, John M

2017-09-01

Coliphages have been proposed as indicators of fecal contamination in recreational waters because they better mimic the persistence of pathogenic viruses in the environment and wastewater treatment than fecal indicator bacteria. We estimated the association between coliphages and gastrointestinal illness and compared it with the association with culturable enterococci. We pooled data from six prospective cohort studies that enrolled coastal beachgoers in California, Alabama, and Rhode Island. Water samples were collected and gastrointestinal illness within 10 days of the beach visit was recorded. Samples were tested for enterococci and male-specific and somatic coliphages. We estimated cumulative incidence ratios (CIR) for the association between swimming in water with detectable coliphage and gastrointestinal illness when human fecal pollution was likely present, not likely present, and under all conditions combined. The reference group was unexposed swimmers. We defined continuous and threshold-based exposures (coliphage present/absent, enterococci >35 vs. ≤35 CFU/100 ml). Under all conditions combined, there was no association between gastrointestinal illness and swimming in water with detectable coliphage or enterococci. When human fecal pollution was likely present, coliphage and enterococci were associated with increased gastrointestinal illness, and there was an association between male-specific coliphage level and illness that was somewhat stronger than the association between enterococci and illness. There were no substantial differences between male-specific and somatic coliphage. Somatic coliphage and enterococci had similar associations with gastrointestinal illness; there was some evidence that male-specific coliphage had a stronger association with illness than enterococci in marine waters with human fecal contamination.

Reverse micelle-based water-soluble nanoparticles for simultaneous bioimaging and drug delivery.

PubMed

Chen, Ying; Liu, Yong; Yao, Yongchao; Zhang, Shiyong; Gu, Zhongwei

2017-04-11

With special confined water pools, reverse micelles (RMs) have shown potential for a wide range of applications. However, the inherent water-insolubility of RMs hinders their further application prospects, especially for applications related to biology. We recently reported the first successful transfer of RMs from organic media to an aqueous phase without changing the smart water pools by the hydrolysis of an arm-cleavable interfacial cross-linked reverse micelles. Herein, we employed another elaborate amphiphile 1 to construct new acrylamide-based cross-linked water-soluble nanoparticles (ACW-NPs) under much gentler conditions. The special property of the water pools of the ACW-NPs was confirmed by both the Förster resonance energy transfer (FRET) between 5-((2-aminoethyl)amino)naphthalene-1-sulfonic acid (1,5-EDANS) and benzoic acid, 4-[2-[4-(dimethylamino)phenyl]diazenyl] (DABCYL) and satisfactory colloidal stability in 10% fetal bovine serum. Importantly, featured by the gentle synthetic strategy, confined water pool, and carboxylic acid-functionalized surface, the new ACW-NPs are well suitable for biological applications. As an example, the fluorescent reagent 8-hydroxy-1,3,6-pyrenetrisulfonic acid trisodium salt (HPTS) was encapsulated in the core and simultaneously, the anticancer drug gemcitabine (Gem) was covalently conjugated onto the surface exterior. As expected, the resulting multifunctional ACW-NPs@HPTS@Gem exhibits a high imaging effect and anticancer activity for non-small lung cancer cells.

Dominant factors in controlling marine gas pools in South China

USGS Publications Warehouse

Xu, S.; Watney, W.L.

2007-01-01

In marine strata from Sinian to Middle Triassic in South China, there develop four sets of regional and six sets of local source rocks, and ten sets of reservoir rocks. The occurrence of four main formation periods in association with five main reconstruction periods, results in a secondary origin for the most marine gas pools in South China. To improve the understanding of marine gas pools in South China with severely deformed geological background, the dominant control factors are discussed in this paper. The fluid sources, including the gas cracked from crude oil, the gas dissolved in water, the gas of inorganic origin, hydrocarbons generated during the second phase, and the mixed pool fluid source, were the most significant control factors of the types and the development stage of pools. The period of the pool formation and the reconstruction controlled the pool evolution and the distribution on a regional scale. Owing to the multiple periods of the pool formation and the reconstruction, the distribution of marine gas pools was complex both in space and in time, and the gas in the pools is heterogeneous. Pool elements, such as preservation conditions, traps and migration paths, and reservoir rocks and facies, also served as important control factors to marine gas pools in South China. Especially, the preservation conditions played a key role in maintaining marine oil and gas accumulations on a regional or local scale. According to several dominant control factors of a pool, the pool-controlling model can be constructed. As an example, the pool-controlling model of Sinian gas pool in Weiyuan gas field in Sichuan basin was summed up. ?? Higher Education Press and Springer-Verlag 2007.

STS-35 MS Hoffman is suspended above pool during JSC water egress exercises

NASA Technical Reports Server (NTRS)

1990-01-01

STS-35 Mission Specialist (MS) Jeffrey A. Hoffman is suspended above pool during launch emergency egress procedures conducted in JSC's Weightless Environmental Training Facility Bldg 29. Hoffman, wearing a launch and entry suit (LES) and launch and entry helmet (LEH), adjusts flotation device (life jacket) as he is raised above the pool.

Cool Water Formation and Trout Habitat Use in a Deep Pool in the Sierra Nevada, California

Treesearch

KATHLEEN R. MATTHEWS; NEIL H. BERG; AZUMA DAVID L.

1994-01-01

We documented temperature stratification in a deep bedrock pool in the North Fork of the American River, described the diel movement of rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta. and determined whether these trout used cooler portions of the pool.From July 30 to October 10, 1992, the main study pool and an adjacent pool were stratified(temperature...

Experimental evaluation of a heat pump for the water-supply heating of a public swimming pool

NASA Astrophysics Data System (ADS)

López, R.; Vaca, M.; Terres, H.; Lizardi, A.; Morales, J.; Chávez, S.

2017-01-01

In this work the analysis of the thermodynamic behavior of heat pumps (HP) which supply the energy needed in the public pool at the Aquatic Center of Azcapotzalco was performed. There are 18 installed HP’s but only those needed to provide the energy required are alternately activated. The evaluation was conducted during May and June of 2015. We selected one of the HP to implement temperature and pressure gauges at the inlet and outlet of the compressor. The measurements were made every day at three times, 6:30, 13:00 and 18:00 hours. In a period of 24 hours, 1 000 L evaporated, there was no variation registered overnight, since the pool was covered with plastic to avoid loss of the fluid. The heat pump provided 150 kW to maintain the water temperature at the right level of operation, namely 28 °C. The coefficients of performance (COP) of the HP were 6.39 at 6:30, 7.42 at 13:00 and 7:32 at 18:00 hrs., values which are very close to the one provided by the manufacturer.

Addressing data privacy in matched studies via virtual pooling.

PubMed

Saha-Chaudhuri, P; Weinberg, C R

2017-09-07

Data confidentiality and shared use of research data are two desirable but sometimes conflicting goals in research with multi-center studies and distributed data. While ideal for straightforward analysis, confidentiality restrictions forbid creation of a single dataset that includes covariate information of all participants. Current approaches such as aggregate data sharing, distributed regression, meta-analysis and score-based methods can have important limitations. We propose a novel application of an existing epidemiologic tool, specimen pooling, to enable confidentiality-preserving analysis of data arising from a matched case-control, multi-center design. Instead of pooling specimens prior to assay, we apply the methodology to virtually pool (aggregate) covariates within nodes. Such virtual pooling retains most of the information used in an analysis with individual data and since individual participant data is not shared externally, within-node virtual pooling preserves data confidentiality. We show that aggregated covariate levels can be used in a conditional logistic regression model to estimate individual-level odds ratios of interest. The parameter estimates from the standard conditional logistic regression are compared to the estimates based on a conditional logistic regression model with aggregated data. The parameter estimates are shown to be similar to those without pooling and to have comparable standard errors and confidence interval coverage. Virtual data pooling can be used to maintain confidentiality of data from multi-center study and can be particularly useful in research with large-scale distributed data.

Interfacial heat transfer in multiphase molten pools with gas injection

NASA Astrophysics Data System (ADS)

Bilbao Y Leon, Rosa Marina

1998-12-01

In the very unlikely event of a severe reactor accident involving core meltdown and pressure vessel failure, it is vital to identify the circumstances that would allow the molten core material to cool down and resolidify, bringing core debris to a safe and stable state. In this type of accident, the molten material which escapes from the reactor pressure vessel will accumulate as a molten pool in the reactor cavity below. To achieve coolability of the corium in this configuration it has been proposed to flood the cavity with water from above forming a layered structure where upward heat loss from the molten pool to the water will cause the core material to quench and solidify. The effectiveness of this procedure depends largely on the rate of upward heat loss as well as on the formation and stability of an upper crust. In this situation the molten pool becomes a three phase mixture: the solid and liquid slurry formed by the molten pool cooled to a temperature below the temperature of liquidus, agitated by the gases formed in the concrete ablation process. The present work quantifies the partition of the heat losses upward and downward considering the influence of the solid fraction in the pool and the viscosity effects, and the rate of heat loss through a solid layer. To complete this task a intermediate scale experimental test section has been designed and built at the University of Wisconsin - Madison, in which simulant materials are used to model the process of heat and mass transfer which involves the molten pool, the solid layer atop and the coolant layer above. The design includes volumetric heating, gas injection from the bottom and solids within the pool. New experimental results showing the heat transfer behavior for pools with different viscosities and various solid fractions are presented. The current results indicate a power split which favors heat transfer upward to the coolant simulant above by a 2:1 or 3:1 ratio. In addition, the power split is

Measuring the fraction of pool volume filled with fine sediment

Treesearch

Sue Hilton; Thomas E. Lisle

1993-01-01

The fraction of pool volume filled with fine sediment (usually fine sand to medium gravel) can be a useful index of the sediment supply and substrate habitat of gravel-bed channels. It can be used to evaluate and monitor channel condition and to detect and evaluate sediment sources. This fraction (V*) is the ratio of fine-sediment volume to pool water volume plus fine-...

An evaluation of the relative quality of dike pools for benthic macroinvertebrates in the Lower Missouri River, USA

USGS Publications Warehouse

Poulton, B.C.; Allert, A.L.

2012-01-01

A habitat-based aquatic macroinvertebrate study was initiated in the Lower Missouri River to evaluate relative quality and biological condition of dike pool habitats. Water-quality and sediment-quality parameters and macroinvertebrate assemblage structure were measured from depositional substrates at 18 sites. Sediment porewater was analysed for ammonia, sulphide, pH and oxidation-reduction potential. Whole sediments were analysed for particle-size distribution, organic carbon and contaminants. Field water-quality parameters were measured at subsurface and at the sediment-water interface. Pool area adjacent and downstream from each dike was estimated from aerial photography. Macroinvertebrate biotic condition scores were determined by integrating the following indicator response metrics: % of Ephemeroptera (mayflies), % of Oligochaeta worms, Shannon Diversity Index and total taxa richness. Regression models were developed for predicting macroinvertebrate scores based on individual water-quality and sediment-quality variables and a water/sediment-quality score that integrated all variables. Macroinvertebrate scores generated significant determination coefficients with dike pool area (R2=0.56), oxidation–reduction potential (R2=0.81) and water/sediment-quality score (R2=0.71). Dissolved oxygen saturation, oxidation-reduction potential and total ammonia in sediment porewater were most important in explaining variation in macroinvertebrate scores. The best two-variable regression models included dike pool size + the water/sediment-quality score (R2=0.84) and dike pool size + oxidation-reduction potential (R2=0.93). Results indicate that dike pool size and chemistry of sediments and overlying water can be used to evaluate dike pool quality and identify environmental conditions necessary for optimizing diversity and productivity of important aquatic macroinvertebrates. A combination of these variables could be utilized for measuring the success of habitat enhancement

Genotoxic Effects in Swimmers Exposed to Disinfection By-products in Indoor Swimming Pool

EPA Science Inventory

BACKGROUND: Exposure to disinfection by-products (DBPs) in drinking water has been associated with cancer risk, and a recent study found an increased bladder cancer risk among subjects attending swimming pools. OBJECTIVES: To evaluate whether swimming in pools is associated with ...

Submersible purification system for radioactive water

DOEpatents

Abbott, Michael L.; Lewis, Donald R.

1989-01-01

A portable, submersible water purification system for use in a pool of water containing radioactive contamination includes a prefilter for filtering particulates from the water. A resin bed is then provided for removal of remaining dissolved, particulate, organic, and colloidal impurities from the prefiltered water. A sterilizer then sterilizes the water. The prefilter and resin bed are suitably contained and are submerged in the pool. The sterilizer is water tight and located at the surface of the pool. The water is circulated from the pool through the prefilter, resin bed, and sterilizer by suitable pump or the like. In the preferred embodiment, the resin bed is contained within a tank which stands on the bottom of the pool and to which a base mounting the prefilter and pump is attached. An inlet for the pump is provided adjacent the bottom of the pool, while the sterilizer and outlet for the system is located adjacent the top of the pool.

The Tropical Western Hemisphere Warm Pool

NASA Astrophysics Data System (ADS)

Wang, C.; Enfield, D. B.

2002-12-01

The paper describes and examines variability of the tropical Western Hemisphere warm pool (WHWP) of water warmer than 28.5oC. The WHWP is the second-largest tropical warm pool on Earth. Unlike the Eastern Hemisphere warm pool in the western Pacific, which straddles the equator, the WHWP is entirely north of the equator. At various stages of development the WHWP extends over parts of the eastern North Pacific, the Gulf of Mexico, the Caribbean, and the western tropical North Atlantic. It has a large seasonal cycle and its interannual fluctuations of area and intensity are significant. Surface heat fluxes warm the WHWP through the boreal spring to an annual maximum of SST and WHWP area in the late summer/early fall, associated with eastern North Pacific and Atlantic hurricane activities and rainfall from northern South America to the southern tier of the United States. Observations suggest that a positive ocean-atmosphere feedback operating through longwave radiation and associated cloudiness seems to operate in the WHWP. During winter preceding large warm pool, there is an alteration of the Walker and Hadley circulation cells that serves as a "tropospheric bridge" for transferring Pacific ENSO effects to the Atlantic sector and inducing initial warming of warm pool. Associated with the warm SST anomalies is a decrease in sea level pressure anomalies and an anomalous increase in atmospheric convection and cloudiness. The increase in convective activity and cloudiness results in less net longwave radiation loss from the sea surface, which then reinforces SST anomalies.

TOPEX/El Nino Watch - Warm Water Pool is Increasing, Nov. 10, 1997

NASA Technical Reports Server (NTRS)

1997-01-01

This image of the Pacific Ocean was produced using sea surface height measurements taken by the U.S./French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on Nov. 10, 1997. The volume of extra warm surface water (shown in white) in the core of the El Nino continues to increase, especially in the area between 15 degrees south latitude and 15 degrees north latitude in the eastern Pacific Ocean. The area of low sea level (shown in purple) has decreased somewhat from late October. The white and red areas indicate unusual patterns of heat storage; in the white areas, the sea surface is between 14 centimeters and 32 cm (6 inches to 13 inches) above normal; in the red areas, it is about 10 centimeters (4 inches) above normal. The surface area covered by the warm water mass is about one-and-one-half times the size of the continental United States. The added amount of oceanic warm water near the Americas, with a temperature between 21 to 30 degrees Celsius (70 to 85 degrees Fahrenheit), is about 30 times the volume of water in all the U.S. Great Lakes combined. The green areas indicate normal conditions, while purple (the western Pacific) means at least 18 centimeters (7 inches) below normal sea level.

The El Nino phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white areas) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. Using these global data, limited regional measurements from buoys and ships, and a forecasting model of the ocean-atmospheric system, the National Centers for Environmental Prediction (NCEP) of the National Oceanic and

Nucleate pool boiling heat transfer characteristics of TiO{sub 2}-water nanofluids at very low concentrations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suriyawong, Adirek; Wongwises, Somchai

2010-11-15

A study of nucleate pool boiling heat transfer of TiO{sub 2}-water nanofluids is experimentally conducted. Nanofluids with various concentrations of 0.00005, 0.0001, 0.0005, 0.005, and 0.01 vol.% are employed. Horizontal circular plates made from copper and aluminium with different roughness values of 0.2 and 4 {mu}m are used as heating surfaces. The experiments are performed to explore the effects of nanofluids concentration as well as heating surface material and roughness on nucleate pool boiling characteristics and the heat transfer coefficient under ambient pressure. The results show that based on the copper heated surface which is tested with a concentration ofmore » 0.0001 vol.%, higher nucleate pool boiling heat transfer coefficient is obtained when compared with the base fluid. A 15% increase is obtained for the surface roughness of 0.2 {mu}m and a 4% increase is obtained for roughness of 4 {mu}m. For concentrations higher than 0.0001 vol.%, however, the higher the concentration, the lower the heat transfer coefficient. In the case of aluminium heated surface, the corresponding heat transfer coefficients are larger than for the copper surface by around 30% with a roughness of 0.2 {mu}m and around 27% with a roughness of 4 {mu}m. Moreover, the results also indicate that the heat transfer coefficient obtained based on a roughness of 4 {mu}m is higher than that for a roughness of 0.2 {mu}m by around 12% for aluminium and by around 13% for copper. (author)« less

Depth-area-volume and hydroperiod relationships of ephemeral (vernal) forest pools in southern New England

Treesearch

Robert T. Brooks; Masaki Hayashi

2002-01-01

Ephemeral or "vernal" pools occur commonly throughout the forests of the northeastern United States and adjacent eastern Canada. These pools are critical breeding habitat for a number of amphibian species and support a diverse invertebrate community. The hydroperiod or duration of surface water of vernal pools affects faunal composition and reproduction. We...

Health Effects from Swimming Training in Chlorinated Pools and the Corresponding Metabolic Stress Pathways

PubMed Central

Li, Jiang-Hua; Wang, Zhi-Hui; Zhu, Xiao-Juan; Deng, Zhao-Hui; Cai, Can-Xin; Qiu, Li-Qiang; Chen, Wei; Lin, Ya-Jun

2015-01-01

Chlorination is the most popular method for disinfecting swimming pool water; however, although pathogens are being killed, many toxic compounds, called disinfection by-products (DBPs), are formed. Numerous epidemiological publications have associated the chlorination of pools with dysfunctions of the respiratory system and with some other diseases. However, the findings concerning these associations are not always consistent and have not been confirmed by toxicological studies. Therefore, the health effects from swimming in chlorinated pools and the corresponding stress reactions in organisms are unclear. In this study, we show that although the growth and behaviors of experimental rats were not affected, their health, training effects and metabolic profiles were significantly affected by a 12-week swimming training program in chlorinated water identical to that of public pools. Interestingly, the eyes and skin are the organs that are more directly affected than the lungs by the irritants in chlorinated water; instead of chlorination, training intensity, training frequency and choking on water may be the primary factors for lung damage induced by swimming. Among the five major organs (the heart, liver, spleen, lungs and kidneys), the liver is the most likely target of DBPs. Through metabolomics analysis, the corresponding metabolic stress pathways and a defensive system focusing on taurine were presented, based on which the corresponding countermeasures can be developed for swimming athletes and for others who spend a lot of time in chlorinated swimming pools. PMID:25742134

Colors of the Yellowstone thermal pools for teaching optics

NASA Astrophysics Data System (ADS)

Shaw, J. A.; Nugent, P. W.; Vollmer, M.

2015-10-01

Nature provides many beautiful optical phenomena that can be used to teach optical principles. Here we describe an interdisciplinary education project based on a simple computer model of the colors observed in the famous thermal pools of Yellowstone National Park in the northwestern United States. The primary wavelength-dependent parameters that determine the widely varying pool colors are the reflectance of the rocks or the microbial mats growing on the rocks beneath the water (the microbial mat color depends on water temperature) and optical absorption and scattering in the water. This paper introduces a teaching module based on a one-dimensional computer model that starts with measured reflectance spectra of the microbial mats and modifies the spectra with depth-dependent absorption and scattering in the water. This module is designed to be incorporated into a graduate course on remote sensing systems, in a section covering the propagation of light through air and water, although it could be adapted to a general university optics course. The module presents the basic 1-D radiative transfer equation relevant to this problem, and allows them to build their own simple model. Students can then simulate the colors that would be observed for different variations of the microbial mat reflectance spectrum, skylight spectrum, and water depth.

Observed Structure and Characteristics of Cold Pools over Tropical Oceans using Vector Wind Retrievals and WRF simulations

NASA Astrophysics Data System (ADS)

Garg, P.; Nesbitt, S. W.; Lang, T. J.; Chronis, T.; Thayer, J. D.; Hence, D. A.

2017-12-01

Cold pools generated in the wake of convective activity can enhance the surface sensible heat flux, latent heat flux, and also changes in evaporation out of, and fresh water flux into, the ocean. Recent studies have shown that over the open ocean, cold pool outflow boundaries and their intersections can organize and initiate a spectrum of deep convective clouds, which is a key driver of shallow and deep convection over conditionally-unstable tropical oceans. The primary goal of this study is to understand the structure and characteristics of cold pools over the tropical oceans using observations. With the idea that cold pools will have strong wind gradients at their boundaries, we use ASCAT vector wind retrievals. We identify regions of steep gradients in wind vectors as gradient features (GFs), akin to cold pools. Corresponding to these GFs, sensible and latent heat fluxes were calculated using the observed winds and background temperatures from MERRA-2 reanalysis. To evaluate the proposed technique, cold pools were observed using S-PolKa radar from the DYNAMO/AMIE field campaign in the Indian Ocean for the period of 1 October 2011 to 31 March 2012 and were compared with ASCAT GFs. To relate the thermodynamic and kinematic characteristics of observed and simulated cold pools, simulations were carried out on WRF on a 3-km domain explicitly. The areas of cold pools were identified in the models using virtual temperature (Tv), which is a direct measure of air density, while GFs were identified using model simulated winds. Quantitative measures indicate that GFs are highly correspondent with model-simulated cold pools. In global measurements of cold pools from 2007-2015, it is possible to examine the characteristics of GFs across all tropical ocean basins, and relate them to meteorological conditions, as well as the characteristics of the parent precipitation systems. Our results indicate that while there is a general relationship between the amount of precipitation

Formation of the southern Bay of Bengal cold pool

NASA Astrophysics Data System (ADS)

Das, Umasankar; Vinayachandran, P. N.; Behara, Ambica

2016-09-01

A pool of relatively cooler water, called here as the southern Bay of Bengal cold pool, exists around Sri Lanka and southern tip of India during the summer monsoon. This cold pool is enveloped by the larger Indian Ocean warm pool and is believed to affect the intraseasonal variations of summer monsoon rainfall. In this study, we have investigated the mechanisms responsible for the formation of the cold pool using a combination of both satellite data sets and a general circulation model of the Indian Ocean. Sea surface temperature (SST) within the cold pool, after the steady increase during the February-April period, decreases first during a pre-monsoon spell in April and then with the monsoon onset during May. The onset cooling is stronger (~1.8°C) than the pre-monsoon cooling (~0.8°C) and culminates in the formation of the cold pool. Analysis of the model temperature equation shows that SST decrease during both events is primarily due to a decrease in incoming solar radiation and an increase in latent heat loss. These changes in the net heat flux are brought about by the arrival of cloud bands above the cold pool during both periods. During the pre-monsoon period, a cloud band originates in the western equatorial Indian Ocean and subsequently arrives above the cold pool. Similarly, during the monsoon onset, a band of clouds originating in the eastern equatorial Indian Ocean comes over the cold pool region. A lead-lag correlation calculation between daily SST and rainfall anomalies suggest that cooling in SST occurs in response to rainfall events with a lag of 5 days. These sequence of events occur every year with certain amount of interannual variability.

"Ripples" in an Aluminum Pool?

NASA Astrophysics Data System (ADS)

Rohr, James; Wang, Si-Yin; Nesterenko, Vitali F.

2018-05-01

Our motivation for this article is for students to realize that opportunities for discovery are all around them. Discoveries that can still puzzle present day researchers. Here we explore an observation by a middle school student concerning the production of what appears to be water-like "ripples" produced in aluminum foil when placed between two colliding spheres. We both applaud and explore the student's reasoning that the ripples were formed in a melted aluminum pool.

Solar-heated municipal swimming pools, a case study: Dade County, Florida

NASA Astrophysics Data System (ADS)

Levin, M.

1981-09-01

The installation of a solar energy system to heat the water in the swimming pool in one of Dade County, Florida's major parks is described. The mechanics of solar heated swimming pools are explained. The solar heating system consists of 216 unglazed polypropylene tube collectors, a differential thermostat, and the distribution system. The systems performance and economics as well as future plants are discussed.

The statistical characteristics of rain-generated stalks on water surface

NASA Astrophysics Data System (ADS)

Liu, Xinan; Liu, Ren; Duncan, James H.

2017-11-01

Laboratory measurements of the stalks generated by the impact of raindrops are performed in a 1.22-m-by-1.22-m water pool with a water depth of 0.3 m. Simulated raindrops are generated by an array of 22-gauge hypodermic needles that are attached to the bottom of an open-surface rain tank. The raindrop diameter is about 2.6 mm and the height of the rain tank above the water surface of the pool is varied from 1 m to 4.5 m to provide different impact velocities. A number of parameters, including the diameter, height and initial upward velocity of the center jets (stalks) are measured with a cinematic laser-induced- fluorescence technique. It is found that the maximum potential energy of the stalk and the joint distribution of stalk height and diameter are strongly correlated to the impact velocities of raindrops. Comparisons between the rain experiments and single drop impacts on a quiescent water surface are also shown.

Strong influence of regional species pools on continent-wide structuring of local communities.

PubMed

Lessard, Jean-Philippe; Borregaard, Michael K; Fordyce, James A; Rahbek, Carsten; Weiser, Michael D; Dunn, Robert R; Sanders, Nathan J

2012-01-22

There is a long tradition in ecology of evaluating the relative contribution of the regional species pool and local interactions on the structure of local communities. Similarly, a growing number of studies assess the phylogenetic structure of communities, relative to that in the regional species pool, to examine the interplay between broad-scale evolutionary and fine-scale ecological processes. Finally, a renewed interest in the influence of species source pools on communities has shown that the definition of the source pool influences interpretations of patterns of community structure. We use a continent-wide dataset of local ant communities and implement ecologically explicit source pool definitions to examine the relative importance of regional species pools and local interactions for shaping community structure. Then we assess which factors underlie systematic variation in the structure of communities along climatic gradients. We find that the average phylogenetic relatedness of species in ant communities decreases from tropical to temperate regions, but the strength of this relationship depends on the level of ecological realism in the definition of source pools. We conclude that the evolution of climatic niches influences the phylogenetic structure of regional source pools and that the influence of regional source pools on local community structure is strong.

WATER INGESTION DURING SWIMMING ACTIVITIES IN A POOL: A PILOT STUDY

EPA Science Inventory

Chloroisocyanurates are commonly added to outdoor swimming pools to stabilize chlorine disinfectants. The chloroisocyanurates decompose slowly to release chlorine and cyanuric acid. Studies conducted to determine if the chloroisocyanurates might be toxic to swimmers showed that...

Convective Cold Pool Structure and Boundary Layer Recovery in DYNAMO

NASA Astrophysics Data System (ADS)

Savarin, A.; Chen, S. S.; Kerns, B. W.; Lee, C.; Jorgensen, D. P.

2012-12-01

One of the key factors controlling convective cloud systems in the Madden-Julian Oscillation (MJO) over the tropical Indian Ocean is the property of the atmospheric boundary layer. Convective downdrafts and precipitation from the cloud systems produce cold pools in the boundary layer, which can inhibit subsequent development of convection. The recovery time is the time it takes for the boundary layer to return to pre convective conditions. It may affect the variability of the convection on various time scales during the initiation of MJO. This study examines the convective cold pool structure and boundary layer recovery using the NOAA WP-3D aircraft observations, include the flight-level, Doppler radar, and GPS dropsonde data, collected during the Dynamics of MJO (DYNAMO) field campaign from November-December 2011. The depth and strength of convective cold pools are defined by the negative buoyancy, which can be computed from the dropsonde data. Convective downdraft can be affected by environmental water vapor due to entrainment. Mid-level dry air observed during the convectively suppressed phase of MJO seems to enhance convective downdraft, making the cold pools stronger and deeper. Recovery of the cold pools in the boundary layer is determined by the strength and depth of the cold pools and also the air-sea heat and moisture fluxes. Given that the water vapor and surface winds are distinct for the convectively active and suppressed phases of MJO over the Indian Ocean, the aircraft data are stratified by the two different large-scale regimes of MJO. Preliminary results show that the strength and depth of the cold pools are inversely correlated with the surrounding mid-level moisture. During the convectively suppressed phase, the recovery time is ~5-20 hours in relative weak wind condition with small air-sea fluxes. The recovery time is generally less than 6 hours during the active phase of MJO with moist mid-levels and stronger surface wind and air-sea fluxes.

Exciting Pools

ERIC Educational Resources Information Center

Wright, Bradford L.

1975-01-01

Advocates the creation of swimming pool oscillations as part of a general investigation of mechanical oscillations. Presents the equations, procedure for deriving the slosh modes, and methods of period estimation for exciting swimming pool oscillations. (GS)

Macroinvertebrate community assembly in pools created during peatland restoration.

PubMed

Brown, Lee E; Ramchunder, Sorain J; Beadle, Jeannie M; Holden, Joseph

2016-11-01

Many degraded ecosystems are subject to restoration attempts, providing new opportunities to unravel the processes of ecological community assembly. Restoration of previously drained northern peatlands, primarily to promote peat and carbon accumulation, has created hundreds of thousands of new open water pools. We assessed the potential benefits of this wetland restoration for aquatic biodiversity, and how communities reassemble, by comparing pool ecosystems in regions of the UK Pennines on intact (never drained) versus restored (blocked drainage-ditches) peatland. We also evaluated the conceptual idea that comparing reference ecosystems in terms of their compositional similarity to null assemblages (and thus the relative importance of stochastic versus deterministic assembly) can guide evaluations of restoration success better than analyses of community composition or diversity. Community composition data highlighted some differences in the macroinvertebrate composition of restored pools compared to undisturbed peatland pools, which could be used to suggest that alternative end-points to restoration were influenced by stochastic processes. However, widely used diversity metrics indicated no differences between undisturbed and restored pools. Novel evaluations of restoration using null models confirmed the similarity of deterministic assembly processes from the national species pool across all pools. Stochastic elements were important drivers of between-pool differences at the regional-scale but the scale of these effects was also similar across most of the pools studied. The amalgamation of assembly theory into ecosystem restoration monitoring allows us to conclude with more certainty that restoration has been successful from an ecological perspective in these systems. Evaluation of these UK findings compared to those from peatlands across Europe and North America further suggests that restoring peatland pools delivers significant benefits for aquatic fauna by

[Effects of residue management and fertilizer application mode on soil organic carbon pools in an oasis cotton region.

PubMed

Zhang, Peng Peng; Liu, Yan Jie; Pu, Xiao Zhen; Zhang, Guo Juan; Wang, Jin; Zhang, Wang Feng

2016-11-18

To reveal the regulation mechanisms of agricultural management practices on soil organic carbon (SOC) pools and provide scientific basis for improving soil productivity and formulating agricultural fixed carbon and reducing discharge measures, we monitored the changes of SOC pools and organic carbon fractions in an oasis cotton field under different residue management and fertilizer application modes. A split-plot experimental design was used with differing residue management including residue incorporation (S) and residue removing (NS) in the main plots and differing fertilizer application modes including no fertilizer (CK), NPK fertilizer (NPK), organic manure (OM) and NPK fertilizer plus organic manure (NPK+OM) in the subplot. The results showed that fertilization and residue incorporation significantly increased SOC pool, soil organic carbon (C T ), labile carbon (C L ), microbial biomass carbon (C MB ), water-soluble organic carbon (C WS ), hot-water-soluble organic carbon (C HWS ), accumulative amount of soil organic carbon mineralization (C TM ) and carbon management index (CMI). The SOC pool was increased by 20.6% by residue incorporation compared to residue removing. SOC pools were increased by 7.8%, 29.5% and 37.7% in NPK, OM and NPK+OM treatments compared to CK, respectively. The contents of C T , C L , C MB , C WS and C HWS under different fertilization treatments were shown as NPK+OM>OM>NPK>CK. C TM was increased by 5.9% by residue incorporation compared to residue removing and C TM was increased by 32.7%, 59.5% and 97.3% in NPK, OM and NPK+OM treatments compared to CK, respectively. There was a significant correlation between CMI and C T , C MB , C L , C WS , C HWS , C TM , C pool and C sequestration. Therefore, we concluded that CMI is an important index for evaluating the effect of agricultural management practices on soil quality. In order to construct high-standard oasis farmland in arid region and develop cotton production, we should consider

Assessment of Physicochemical and Microbiological Quality of Public Swimming Pools in Addis Ababa, Ethiopia

PubMed Central

Yedeme, Kokebe; Legese, Melese Hailu; Gonfa, Almaz; Girma, Somson

2017-01-01

Background: From swimming pools, bathers may acquire many potential pathogens or may be affected by the physicochemical characteristics of water used during bathing. Hence, this study aimed at assessing the physicochemical and microbiological quality of public swimming pools located at different hotels and recreation center in Addis Ababa, Ethiopia. Method: A cross sectional study was carried out from February to May, 2016. Nine hotels and one recreation center which recognized to have public swimming services were included. A total of 60 swimming pool water samples from 10 swimming pools were collected at deeper, shallow and intake point twice on a weekly basis using a 250 ml sterile bottle containing sodium thiosulphate. PH, residual chlorine and temperature of samples were recorded at the time of collection. Sample containing bottles were transported in ice box to microbiological laboratory and analyzed on the same day. Standard cultural and biochemical methods were used for isolation and characterization of the main microbial groups. Total viable count, total coliform count, fecal coliform count and E. coli were determined. Data was analyzed using SPSS Version 20. Results: Average PH and temperature of swimming pool water samples were 7.1 and 29oC respectively. Of all analyzed water samples, 58.4% (n=35/60) of them had PH range of 7.2-7.8, 58.3% (n=35/60) of samples had temperature in the range of 21oC-32oC and 25% (n=15/60) of water samples had residual chlorine in the range of 2-3mg/l. 73.3% (n=44/60) of the samples had a total viable count below 200 MPN/ml and 70% (n-42/60) of the samples had Total Coliform Count values less than 2 MPN/100 ml. Moreover, 66.7% (n=40/60) of the samples had fecal coliform counts falling below 1 MPN /100 ml. E. coli was absent in 70% (n=42/60) of the samples while it was present in 30% (n=18/60) of the samples. Conclusion: PH, residual chlorine and temperature value of majority of the swimming pools’ water samples were within

Spatially pooled depth-dependent reservoir storage, elevation, and water-quality data for selected reservoirs in Texas, January 1965-January 2010

USGS Publications Warehouse

Burley, Thomas E.; Asquith, William H.; Brooks, Donald L.

2011-01-01

The U.S. Geological Survey (USGS), in cooperation with Texas Tech University, constructed a dataset of selected reservoir storage (daily and instantaneous values), reservoir elevation (daily and instantaneous values), and water-quality data from 59 reservoirs throughout Texas. The period of record for the data is as large as January 1965-January 2010. Data were acquired from existing databases, spreadsheets, delimited text files, and hard-copy reports. The goal was to obtain as much data as possible; therefore, no data acquisition restrictions specifying a particular time window were used. Primary data sources include the USGS National Water Information System, the Texas Commission on Environmental Quality Surface Water-Quality Management Information System, and the Texas Water Development Board monthly Texas Water Condition Reports. Additional water-quality data for six reservoirs were obtained from USGS Texas Annual Water Data Reports. Data were combined from the multiple sources to create as complete a set of properties and constituents as the disparate databases allowed. By devising a unique per-reservoir short name to represent all sites on a reservoir regardless of their source, all sampling sites at a reservoir were spatially pooled by reservoir and temporally combined by date. Reservoir selection was based on various criteria including the availability of water-quality properties and constituents that might affect the trophic status of the reservoir and could also be important for understanding possible effects of climate change in the future. Other considerations in the selection of reservoirs included the general reservoir-specific period of record, the availability of concurrent reservoir storage or elevation data to match with water-quality data, and the availability of sample depth measurements. Additional separate selection criteria included historic information pertaining to blooms of golden algae. Physical properties and constituents were water

46 CFR 401.300 - Authorization for establishment of pools.

Code of Federal Regulations, 2011 CFR

2011-10-01

... longitude 84°33′ W. at the northern approach. (b) The Director shall determine the number of pools that will... United States waters of the St. Lawrence River between the international boundary at St. Regis and a line...

46 CFR 401.300 - Authorization for establishment of pools.

Code of Federal Regulations, 2010 CFR

2010-10-01

... longitude 84°33′ W. at the northern approach. (b) The Director shall determine the number of pools that will... United States waters of the St. Lawrence River between the international boundary at St. Regis and a line...

A critical evaluation of the local-equilibrium assumption in modeling NAPL-pool dissolution

NASA Astrophysics Data System (ADS)

Seagren, Eric A.; Rittmann, Bruce E.; Valocchi, Albert J.

1999-07-01

An analytical modeling analysis was used to assess when local equilibrium (LE) and nonequilibrium (NE) modeling approaches may be appropriate for describing nonaqueous-phase liquid (NAPL) pool dissolution. NE mass-transfer between NAPL pools and groundwater is expected to affect the dissolution flux under conditions corresponding to values of Sh'St (the modified Sherwood number ( Lxkl/ Dz) multiplied by the Stanton number ( kl/ vx))<≈400. A small Sh'St can be brought about by one or more of: a large average pore water velocity ( vx), a large transverse dispersivity ( αz), a small pool length ( Lx), or a small mass-transfer coefficient ( kl). On the other hand, at Sh'St>≈400, the NE and LE solutions converge, and the LE assumption is appropriate. Based on typical groundwater conditions, many cases of interest are expected to fall in this range. The parameter with the greatest impact on Sh'St is kl. The NAPL pool mass-transfer coefficient correlation of Pfannkuch [Pfannkuch, H.-O., 1984. Determination of the contaminant source strength from mass exchange processes at the petroleum-ground-water interface in shallow aquifer systems. In: Proceedings of the NWWA/API Conference on Petroleum Hydrocarbons and Organic Chemicals in Ground Water—Prevention, Detection, and Restoration, Houston, TX. Natl. Water Well Assoc., Worthington, OH, Nov. 1984, pp. 111-129.] was evaluated using the toluene pool data from Seagren et al. [Seagren, E.A., Rittmann, B.E., Valocchi, A.J., 1998. An experimental investigation of NAPL-pool dissolution enhancement by flushing. J. Contam. Hydrol., accepted.]. Dissolution flux predictions made with kl calculated using the Pfannkuch correlation were similar to the LE model predictions, and deviated systematically from predictions made using the average overall kl=4.76 m/day estimated by Seagren et al. [Seagren, E.A., Rittmann, B.E., Valocchi, A.J., 1998. An experimental investigation of NAPL-pool dissolution enhancement by flushing. J. Contam

Hydrology and landscape connectivity of vernal pools. Chapter 3.

Treesearch

Scott G. Liebowitz; Robert T. Brooks

2008-01-01

Hydrology is fundamental to wetland establishment and maintenance of wetland processes (Cole et al. 2002). Hydrology has been shown to affect, if not control, many aspects of wetland ecology, including litter decomposition and the accumulation of organic matter and sediment (Barlocher et al. 1978), the composition and productivity of pool fauna (Paton and Couch 2002),...

Genotoxic Effects in Swimmers Exposed to Disinfection By-products in Indoor Swimming Pools

PubMed Central

Kogevinas, Manolis; Villanueva, Cristina M.; Font-Ribera, Laia; Liviac, Danae; Bustamante, Mariona; Espinoza, Felicidad; Nieuwenhuijsen, Mark J.; Espinosa, Aina; Fernandez, Pilar; DeMarini, David M.; Grimalt, Joan O.; Grummt, Tamara; Marcos, Ricard

2010-01-01

Background Exposure to disinfection by-products (DBPs) in drinking water has been associated with cancer risk. A recent study (Villanueva et al. 2007; Am J Epidemiol 165:148–156) found an increased bladder cancer risk among subjects attending swimming pools relative to those not attending. Objectives We evaluated adults who swam in chlorinated pools to determine whether exposure to DBPs in pool water is associated with biomarkers of genotoxicity. Methods We collected blood, urine, and exhaled air samples from 49 nonsmoking adult volunteers before and after they swam for 40 min in an indoor chlorinated pool. We estimated associations between the concentrations of four trihalomethanes (THMs) in exhaled breath and changes in micronuclei (MN) and DNA damage (comet assay) in peripheral blood lymphocytes before and 1 hr after swimming; urine mutagenicity (Ames assay) before and 2 hr after swimming; and MN in exfoliated urothelial cells before and 2 weeks after swimming. We also estimated associations and interactions with polymorphisms in genes related to DNA repair or to DBP metabolism. Results After swimming, the total concentration of the four THMs in exhaled breath was seven times higher than before swimming. The change in the frequency of micronucleated lymphocytes after swimming increased in association with higher exhaled concentrations of the brominated THMs (p = 0.03 for bromodichloromethane, p = 0.05 for chlorodibromomethane, p = 0.01 for bromoform) but not chloroform. Swimming was not associated with DNA damage detectable by the comet assay. Urine mutagenicity increased significantly after swimming, in association with the higher concentration of exhaled bromoform (p = 0.004). We found no significant associations with changes in micronucleated urothelial cells. Conclusions Our findings support potential genotoxic effects of exposure to DBPs from swimming pools. The positive health effects gained by swimming could be increased by reducing the potential health

33 CFR 207.60 - Federal Dam, Hudson River, Troy, N.Y.; pool level.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Federal Dam, Hudson River, Troy..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.60 Federal Dam, Hudson River, Troy, N.Y.; pool level. (a) Whenever the elevation of the pool created by the Federal dam at Troy, N.Y...

Microbial life in Champagne Pool, a geothermal spring in Waiotapu, New Zealand.

PubMed

Hetzer, Adrian; Morgan, Hugh W; McDonald, Ian R; Daughney, Christopher J

2007-07-01

Surveys of Champagne Pool, one of New Zealand's largest terrestrial hot springs and rich in arsenic ions and compounds, have been restricted to geological and geochemical descriptions, and a few microbiological studies applying culture-independent methods. In the current investigation, a combination of culture and culture-independent approaches were chosen to determine microbial density and diversity in Champagne Pool. Recovered total DNA and adenosine 5'-triphosphate (ATP) content of spring water revealed relatively low values compared to other geothermal springs within New Zealand and are in good agreement with low cell numbers of 5.6 +/- 0.5 x 10(6) cells/ml obtained for Champagne Pool water samples by 4',6-diamidino-2-phenylindole (DAPI) staining. Denaturing Gradient Gel Electrophoresis (DGGE) and 16S rRNA (small-subunit ribosomal nucleic acid) gene clone library analyses of environmental DNA indicated the abundance of Sulfurihydrogenibium, Sulfolobus, and Thermofilum-like populations in Champagne Pool. From these results, media were selected to target the enrichment of hydrogen-oxidizing and sulfur-dependent microorganisms. Three isolates were successfully obtained having 16S rRNA gene sequences with similarities of approximately 98% to Thermoanaerobacter tengcongensis, 94% to Sulfurihydrogenibium azorense, and 99% to Thermococcus waiotapuensis, respectively.

The hydrometeor partitioning and microphysical processes over the Pacific Warm Pool in numerical modeling

NASA Astrophysics Data System (ADS)

Huang, Yi-Chih; Wang, Pao K.

2017-01-01

Numerical modeling is conducted to study the hydrometeor partitioning and microphysical source and sink processes during a quasi-steady state of thunderstorms over the Pacific Warm Pool by utilizing the microphysical model WISCDYMM to simulate selected storm cases. The results show that liquid-phase hydrometeors dominate thunderstorm evolution over the Pacific Warm Pool. The ratio of ice-phase mass to liquid-phase mass is about 41%: 59%, indicating that ice-phase water is not as significant over the Pacific Warm Pool as the liquid water compared to the larger than 50% in the subtropics and 80% in the US High Plains in a previous study. Sensitivity tests support the dominance of liquid-phase hydrometeors over the Pacific Warm Pool. The major rain sources are the key hail sinks: melting of hail and shedding from hail; whereas the crucial rain sinks are evaporation and accretion by hail. The major snow sources are Bergeron-Findeisen process, transfer of cloud ice to snow and accretion of cloud water; whereas the foremost sink of snow is accretion by hail. The essential hail sources are accretions of rain, cloud water, and snow; whereas the critical hail sinks are melting of hail and shedding from hail. The contribution and ranking of sources and sinks of these precipitates are compared with the previous study. Hydrometeors have their own special microphysical processes in the development and depletion over the Pacific Warm Pool. Microphysical budgets depend on atmospheric dynamical and thermodynamical conditions which determine the partitioning of hydrometeors. This knowledge would benefit the microphysics parameterization in cloud models and cumulus parameterization in global circulation models.

[Nitrogen pool in northern taiga larch forests of Central Siberia].

PubMed

Shugaleĭ, L S; Vedrova, E F

2004-01-01

The pools of nitrogen in different blocks of forest ecosystems and its cycle in the soil are considered. It is shown that the bulk of nitrogen concentrates in the soil and dead organic matter (necromass) of an ecosystem. The nitrogen pool of forest litters and soils consists by 83-93% of the inert compounds that cannot be involved in the biological cycle. Mineralization of organic nitrogen-containing substances in the litters and soils usually yields ammonium as an end product. The amount of nitrogen mineralized over the growing season is partially expended for annual plant increment (30-65%) and immobilization (12-17%), with its large proportion being found in the soil.

A general framework for the regression analysis of pooled biomarker assessments.

PubMed

Liu, Yan; McMahan, Christopher; Gallagher, Colin

2017-07-10

As a cost-efficient data collection mechanism, the process of assaying pooled biospecimens is becoming increasingly common in epidemiological research; for example, pooling has been proposed for the purpose of evaluating the diagnostic efficacy of biological markers (biomarkers). To this end, several authors have proposed techniques that allow for the analysis of continuous pooled biomarker assessments. Regretfully, most of these techniques proceed under restrictive assumptions, are unable to account for the effects of measurement error, and fail to control for confounding variables. These limitations are understandably attributable to the complex structure that is inherent to measurements taken on pooled specimens. Consequently, in order to provide practitioners with the tools necessary to accurately and efficiently analyze pooled biomarker assessments, herein, a general Monte Carlo maximum likelihood-based procedure is presented. The proposed approach allows for the regression analysis of pooled data under practically all parametric models and can be used to directly account for the effects of measurement error. Through simulation, it is shown that the proposed approach can accurately and efficiently estimate all unknown parameters and is more computational efficient than existing techniques. This new methodology is further illustrated using monocyte chemotactic protein-1 data collected by the Collaborative Perinatal Project in an effort to assess the relationship between this chemokine and the risk of miscarriage. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Diving into Cold Pools

NASA Astrophysics Data System (ADS)

van den Heever, S. C.; Grant, L. D.; Drager, A. J.

2017-12-01

Cold pools play a significant role in convective storm initiation, organization and longevity. Given their role in convective life cycles, recent efforts have been focused on improving the representation of cold pool processes within weather forecast models, as well as on developing cold pool parameterizations in order to better represent their impacts within global climate models. Understanding the physical processes governing cold pool formation, intensity and dissipation is therefore critical to these efforts. Cold pool characteristics are influenced by numerous factors, including those associated with precipitation formation and evaporation, variations in the environmental moisture and shear, and land surface interactions. The focus of this talk will be on the manner in which the surface characteristics and associated processes impact cold pool genesis and dissipation. In particular, the results from high-resolution modeling studies focusing on the role of sensible and latent heat fluxes, soil moisture and SST will be presented. The results from a recent field campaign examining cold pools over northern Colorado will also be discussed.

Animal and vegetation patterns in natural and man-made bog pools: implications for restoration

USGS Publications Warehouse

Mazerolle, M.J.; Poulin, M.; Lavoie, C.; Rochefort, L.; Desrochers, A.; Drolet, B.

2006-01-01

1. Peatlands have suffered great losses following drainage for agriculture, forestry, urbanisation, or peat mining, near inhabited areas. We evaluated the faunal and vegetation patterns after restoration of a peatland formerly mined for peat. We assessed whether bog pools created during restoration are similar to natural bog pools in terms of water chemistry, vegetation structure and composition, as well as amphibian and arthropod occurrence patterns. 2. Both avian species richness and peatland vegetation cover at the site increased following restoration. Within bog pools, however, the vegetation composition differed between natural and man-made pools. The cover of low shrubs, Sphagnum moss, submerged, emergent and floating vegetation in man-made pools was lower than in natural pools, whereas pH was higher than in typical bog pools. Dominant plant species also differed between man-made and natural pools. 3. Amphibian tadpoles, juveniles and adults occurred more often in man-made pools than natural bog pools. Although some arthropods, including Coleoptera bog specialists, readily colonised the pools, their abundance was two to 26 times lower than in natural bog pools. Plant introduction in bog pools, at the stocking densities we applied, had no effect on the occurrence of most groups. 4. We conclude that our restoration efforts were partially successful. Peatland-wide vegetation patterns following restoration mimicked those of natural peatlands, but 4 years were not sufficient for man-made pools to fully emulate the characteristics of natural bog pools.

Benefits of carbon dioxide as pH reducer in chlorinated indoor swimming pools.

PubMed

Gomà, Anton; Guisasola, Albert; Tayà, Carlota; Baeza, Juan A; Baeza, Mireia; Bartrolí, Albert; Lafuente, Javier; Bartrolí, Jordi

2010-06-01

Carbon dioxide is seldom used as pH reducer in swimming pools. Nevertheless it offers two interesting advantages. First, its use instead of the usual hydrochloric acid avoids the characteristic and serious accident of mixing the disinfectant with that strong acid, which forms a dangerous chlorine gas cloud and, second, it allows the facility to become slightly a depository of that greenhouse gas. This work introduces the experience of using CO(2) as pH reducer in real working swimming pools, showing three more advantages: lower chlorine consumption, lower presence of oxidants in the air above the swimming pool and a diminished formation of trihalomethanes in the swimming pool water. Experiments lasted 4years and they were run in three swimming pools in the Barcelona area, where the conventional system based upon HCl and a system based upon CO(2) were consecutively exchanged.

Enhancing swimming pool safety by the use of range-imaging cameras

NASA Astrophysics Data System (ADS)

Geerardyn, D.; Boulanger, S.; Kuijk, M.

2015-05-01

Drowning is the cause of death of 372.000 people, each year worldwide, according to the report of November 2014 of the World Health Organization.1 Currently, most swimming pools only use lifeguards to detect drowning people. In some modern swimming pools, camera-based detection systems are nowadays being integrated. However, these systems have to be mounted underwater, mostly as a replacement of the underwater lighting. In contrast, we are interested in range imaging cameras mounted on the ceiling of the swimming pool, allowing to distinguish swimmers at the surface from drowning people underwater, while keeping the large field-of-view and minimizing occlusions. However, we have to take into account that the water surface of a swimming pool is not a flat, but mostly rippled surface, and that the water is transparent for visible light, but less transparent for infrared or ultraviolet light. We investigated the use of different types of 3D cameras to detect objects underwater at different depths and with different amplitudes of surface perturbations. Specifically, we performed measurements with a commercial Time-of-Flight camera, a commercial structured-light depth camera and our own Time-of-Flight system. Our own system uses pulsed Time-of-Flight and emits light of 785 nm. The measured distances between the camera and the object are influenced through the perturbations on the water surface. Due to the timing of our Time-of-Flight camera, our system is theoretically able to minimize the influence of the reflections of a partially-reflecting surface. The combination of a post image-acquisition filter compensating for the perturbations and the use of a light source with shorter wavelengths to enlarge the depth range can improve the current commercial cameras. As a result, we can conclude that low-cost range imagers can increase swimming pool safety, by inserting a post-processing filter and the use of another light source.

Pool spacing in forest channels

Treesearch

David R. Montgomery; John M. Buffington; Richard D. Smith; Kevin M. Schmidt; George Pess

1995-01-01

Field surveys of stream channels in forested mountain drainage basins in southeast Alaska and Washington reveal that pool spacing depends on large woody debris (LWD) loading and channel type, slope, and width. Mean pool spacing in pool-riffle, plane-bed, and forced pool-riffle channels systematically decreases from greater than 13 channel widths per pool to less than 1...

Hydric soils in a southeastern Oregon vernal pool

USGS Publications Warehouse

Clausnitzer, D.; Huddleston, J.H.; Horn, E.; Keller, Michael; Leet, C.

2003-01-01

Vernal pools on the High Lava Plain of the northern Great Basin become ponded in most years, but their soils exhibit weak redoximorphic features indicative of hydric conditions. We studied the hydrology, temperature, redox potentials, soil chemistry, and soil morphology of a vernal pool to determine if the soils are hydric, and to evaluate hydric soil field indicators. We collected data for 3 yr from piezometers, Pt electrodes, and thermocouples. Soil and water samples were analyzed for pH, organic C, and extractable Fe and Mn. Soils were ponded from January through April or May, but subsurface saturation was never detected. Soil temperatures 50 cm below the surface rose above 5??C by March. Clayey Bt horizons perched water and limited saturation to the upper 10 cm. Redox potentials at a 5-cm depth were often between 200 and 300 mV, indicating anaerobic conditions, but producing soluble Fe2+ concentrations <1 mg L-1. Extractable soil Fe contents indicated Fe depletion from pool surface horizons and accumulation at or near the upper Bt1 horizon. Depletions and concentrations did not satisfy the criteria of any current hydric soil indicators. We recommend development of new indicators based on acceptance of fewer, less distinct redox concentrations for recognition of a depleted A horizon, and on presence of a thin zone containing redox concentrations located in the upper part of the near-surface perching horizon.

Modeling evaporation from spent nuclear fuel storage pools: A diffusion approach

NASA Astrophysics Data System (ADS)

Hugo, Bruce Robert

Accurate prediction of evaporative losses from light water reactor nuclear power plant (NPP) spent fuel storage pools (SFPs) is important for activities ranging from sizing of water makeup systems during NPP design to predicting the time available to supply emergency makeup water following severe accidents. Existing correlations for predicting evaporation from water surfaces are only optimized for conditions typical of swimming pools. This new approach modeling evaporation as a diffusion process has yielded an evaporation rate model that provided a better fit of published high temperature evaporation data and measurements from two SFPs than other published evaporation correlations. Insights from treating evaporation as a diffusion process include correcting for the effects of air flow and solutes on evaporation rate. An accurate modeling of the effects of air flow on evaporation rate is required to explain the observed temperature data from the Fukushima Daiichi Unit 4 SFP during the 2011 loss of cooling event; the diffusion model of evaporation provides a significantly better fit to this data than existing evaporation models.

Safety Management for Water Play Facilities.

ERIC Educational Resources Information Center

Thompson, Claude

1986-01-01

Modern aquatic facilities, which include wave pools, water slides, and shallow water activity play pools, have a greater potential for injuries and lawsuits than conventional swimming pools. This article outlines comprehensive safety management for such facilities, including potential accident identification and injury control planning. (MT)

Oxygen consumption during exercise in a heated pool.

PubMed

Kirby, R L; Sacamano, J T; Balch, D E; Kriellaars, D J

1984-01-01

The heated hydrotherapy pool is a common exercise site for patients with painful musculoskeletal conditions. Oxygen consumption of swimming is 87 to 89% of maximum in postmyocardial infarction patients according to one recent investigation. We studied 13 able-bodied subjects to test the hypothesis that enough energy could be expended during various forms of hydrotherapy to produce both an aerobic training effect and a risk to patients with coronary artery disease. Oxygen consumption (VO2) was measured in six settings: resting supine; resting seated shoulder deep in the pool (36C); walking at comfortable speed in chest-deep water; running at the fastest speed possible in chest-deep water; using hand paddles; and running in place at shoulder depth. The mean VO2 expressed in ml/kg/min (and metabolic equivalents) were 4.91 (1.00), 4.93 (1.02), 9.34 (2.01), 27.79 (6.23), 18.25 (4.30) and 29.11 (7.09) respectively, suggesting that the more vigorous exercises stress aerobic capacity heavily but not excessively.

Oblique drop impact onto a deep liquid pool

NASA Astrophysics Data System (ADS)

Gielen, Marise V.; Sleutel, Pascal; Benschop, Jos; Riepen, Michel; Voronina, Victoria; Visser, Claas Willem; Lohse, Detlef; Snoeijer, Jacco H.; Versluis, Michel; Gelderblom, Hanneke

2017-08-01

Oblique impact of drops onto a solid or liquid surface is frequently observed in nature. Most studies on drop impact and splashing, however, focus on perpendicular impact. Here we study oblique impact of 100 μ m drops onto a deep liquid pool, where we quantify the splashing threshold, maximum cavity dimensions and cavity collapse by high-speed imaging above and below the water surface. Gravity can be neglected in these experiments. Three different impact regimes are identified: smooth deposition onto the pool, splashing in the direction of impact only, and splashing in all directions. We provide scaling arguments that delineate these regimes by accounting for the drop impact angle and Weber number. The angle of the axis of the cavity created below the water surface follows the impact angle of the drop irrespectively of the Weber number, while the cavity depth and its displacement with respect to the impact position do depend on the Weber number. Weber number dependency of both the cavity depth and displacement is modeled using an energy argument.

Condensation of vapor bubble in subcooled pool

NASA Astrophysics Data System (ADS)

Horiuchi, K.; Koiwa, Y.; Kaneko, T.; Ueno, I.

2017-02-01

We focus on condensation process of vapor bubble exposed to a pooled liquid of subcooled conditions. Two different geometries are employed in the present research; one is the evaporation on the heated surface, that is, subcooled pool boiling, and the other the injection of vapor into the subcooled pool. The test fluid is water, and all series of the experiments are conducted under the atmospheric pressure condition. The degree of subcooling is ranged from 10 to 40 K. Through the boiling experiment, unique phenomenon known as microbubble emission boiling (MEB) is introduced; this phenomenon realizes heat flux about 10 times higher than the critical heat flux. Condensation of the vapor bubble is the key phenomenon to supply ambient cold liquid to the heated surface. In order to understand the condensing process in the MEB, we prepare vapor in the vapor generator instead of the evaporation on the heated surface, and inject the vapor to expose the vapor bubble to the subcooled liquid. Special attention is paid to the dynamics of the vapor bubble detected by the high-speed video camera, and on the enhancement of the heat transfer due to the variation of interface area driven by the condensation.

Real time monitoring of water level and temperature in storage fuel pools through optical fibre sensors.

PubMed

Rizzolo, S; Périsse, J; Boukenter, A; Ouerdane, Y; Marin, E; Macé, J-R; Cannas, M; Girard, S

2017-08-18

We present an innovative architecture of a Rayleigh-based optical fibre sensor for the monitoring of water level and temperature inside storage nuclear fuel pools. This sensor, able to withstand the harsh constraints encountered under accidental conditions such as those pointed-out during the Fukushima-Daiichi event (temperature up to 100 °C and radiation dose level up to ~20 kGy), exploits the Optical Frequency Domain Reflectometry technique to remotely monitor a radiation resistant silica-based optical fibre i.e. its sensing probe. We validate the efficiency and the robustness of water level measurements, which are extrapolated from the temperature profile along the fibre length, in a dedicated test bench allowing the simulation of the environmental operating and accidental conditions. The conceived prototype ensures an easy, practical and no invasive integration into existing nuclear facilities. The obtained results represent a significant breakthrough and comfort the ability of the developed system to overcome both operating and accidental constraints providing the distributed profiles of the water level (0-to-5 m) and temperature (20-to-100 °C) with a resolution that in accidental condition is better than 3 cm and of ~0.5 °C respectively. These new sensors will be able, as safeguards, to contribute and reinforce the safety in existing and future nuclear power plants.

A review of basin morphology and pool hydrology of isolated ponded wetlands: implications for seasonal forest pools of the northeastern United States

Treesearch

Robert T. Brooks; Robert T. Brooks

2005-01-01

Seasonal forest pools (SFPs) are geographically- and hydrologically- isolated ponded wetlands, in that they are topographically isolated from other surface waters. SFPs occur commonly throughout the temperate forests of the eastern United States and adjacent Canada. SFPs are ephemeral in occurrence, typically drying annually. The regular drying of SFPs excludes fish...

Evaluation of the sensitivity of the mineralizable pool of soil organic matter to changes in temperature and moisture

NASA Astrophysics Data System (ADS)

Tulina, A. S.; Semenov, V. M.

2015-08-01

The sensitivity of the potentially mineralizable pool of soil organic matter (Cpm) to changes in temperature and moisture has been assessed from the temperature coefficient ( Q10) and the moisture coefficient ( W 10), which indicate how much the Cpm size changes, when the temperature changes by 10°C and the soil water content changes by 10 wt %, respectively. Samples of gray forest soil, podzolized chernozem, and dark chestnut soil taken from arable plots have been incubated at 8, 18, and 28°C and humidity of 10, 25, and 40 wt %. From the data on the production of C-CO2 by soil samples during incubation for 150 days, the content of Cpm has been calculated. It has been shown that, on average for the three soils, an increase in temperature accounts for 63% of the rise in the pool of potentially mineralizable organic matter, whereas an increase in moisture accounts for 8% of that rise. The temperature coefficients of the potentially mineralizable pool are 2.71 ± 0.64, 1.27 ± 0.20, and 1.85 ± 0.30 in ranges of 8-18, 18-28, and 8-28°C, respectively; the moisture coefficients are 1.19 ± 0.11, 1.09 ± 0.05, and 1.14 ± 0.06 in ranges of 10-25, 25-40, and 10-40 wt %, respectively. The easily mineralizable fraction (C1, k 1 > 0.1 days-1) of the active pool of soil organic matter is less sensitive to temperature than the hardly mineralizable fraction (C3, 0.01 > k 3 > 0.001 days-1); their Q 10 values are 0.91 ± 0.15 and 2.40 ± 0.31, respectively. On the contrary, the easily mineralizable fraction is more sensitive to moistening than the hardly mineralizable fraction: their W 10 values are 1.22 ± 0.06 and 1.03 ± 0.08, respectively. The intensification of mineralization with rising temperature and water content during a long-term incubation results in the exhausting of the active pool, which reduces the production of CO2 by the soils during the repeated incubation under similar conditions nonlimiting mineralization.

Influence of sample pool on interference pattern in defocused interferometric particle imaging.

PubMed

Zhang, Hongxia; Zhou, Ye; Liu, Jing; Jia, Dagong; Liu, Tiegen

2017-04-01

Particles widely exist in various fields. In practical experiments, sometimes it is necessary to dissolve particles in water in a sample pool. This article proposes two typical layouts of the sample pool in defocused interferometric particle imaging (IPI). Layout I is the sample pool surface perpendicular to the incident light and layout II is the sample pool surface perpendicular to the scattered light. For layout I, the scattered light of the particles does not keep symmetric at the meridional and sagittal planes after being refracted by the sample pool surface, and elliptical interference patterns are formed at the defocused IPI image plane. But for layout II, the scattered light keeps symmetric after being refracted, and circular interference patterns are formed. Aimed at the two sample pool layouts, the ray-tracing software ZEMAX was used to simulate the spot shape of particles at different defocus distances. Furthermore, its effect on the ellipticity of the interference pattern with the tilt angle of the sample pool is analyzed. The relative error of the axis ratio for layout I does not exceed 9.2% at different defocus distances. The experimental results have good agreement with the theoretical analyses, and it indicates that layout II is more reasonable for the IPI system.

Influence of sample pool on interference pattern in defocused interferometric particle imaging

NASA Astrophysics Data System (ADS)

Zhang, Hongxia; Zhou, Ye; Liu, Jing; Jia, Dagong; Liu, Tiegen

2017-04-01

Particles widely exist in various fields. In practical experiments, sometimes it is necessary to dissolve particles in water in a sample pool. This article proposes two typical layouts of the sample pool in defocused interferometric particle imaging (IPI). Layout I is the sample pool surface perpendicular to the incident light and layout II is the sample pool surface perpendicular to the scattered light. For layout I, the scattered light of the particles does not keep symmetric at the meridional and sagittal planes after being refracted by the sample pool surface, and elliptical interference patterns are formed at the defocused IPI image plane. But for layout II, the scattered light keeps symmetric after being refracted, and circular interference patterns are formed. Aimed at the two sample pool layouts, the ray-tracing software ZEMAX was used to simulate the spot shape of particles at different defocus distances. Furthermore, its effect on the ellipticity of the interference pattern with the tilt angle of the sample pool is analyzed. The relative error of the axis ratio for layout I does not exceed 9.2% at different defocus distances. The experimental results have good agreement with the theoretical analyses, and it indicates that layout II is more reasonable for the IPI system.

Assessing the Occurrence, Persistence, and Fate of Natural and Synthetic Steroid Estrogens in Vernal Pools

NASA Astrophysics Data System (ADS)

Mina, O.

2015-12-01

The presence of natural and synthetic estrogens in treated wastewater used for irrigation of agricultural fields poses a potential risk to surface water ecosystems. While a large number of recent studies have investigated the occurrence, fate, and transport of estrogens in the environment, the vast majority of these studies have focused on the fate of estrogens in streams and rivers. However, no studies have been conducted assessing the occurrence, persistence, and fate of estrogens in impacted sensitive aquatic ecosystems such as vernal pools. This is of particular importance because vernal pools serve as critical breeding habitat for amphibians, which are known to be sensitive to the presence of endocrine disrupting compounds. A spray irrigation system was implemented over 50 years ago at Penn State's "Living Filter" as an alternative to discharging treated wastewater to a high quality trout stream. This system introduces all of Penn State's treated wastewater onto approximately 250 ha of agricultural and forested land at a rate of ~5 cm/ha/week. More than a dozen vernal pools are impacted by this wastewater irrigation, with some ponds adjacent to irrigation laterals receiving direct inputs of the treated wastewater. The goal of this study was to assess the impact of these weekly irrigation activities on the occurrence, persistence, and fate of estrogens (17α- and 17β-estradiol, estrone, estriol, and ethinylestradiol) in 3 vernal pools during an 8-week field study. The spring 2015 study period coincided with wood frog breeding and metamorphosis. Irrigation wastewater was collected weekly and water samples near the sediment-water interface in each vernal pool were collected daily. Real-time monitoring stations continuously recorded the temperature, pH, redox potential, DO, EC, and water level at each pool. Nearly 100% of the daily samples (n>130) collected contained estrogens, and the concentrations were several times higher compared to the wastewater

Blanketing effect of expansion foam on liquefied natural gas (LNG) spillage pool.

PubMed

Zhang, Bin; Liu, Yi; Olewski, Tomasz; Vechot, Luc; Mannan, M Sam

2014-09-15

With increasing consumption of natural gas, the safety of liquefied natural gas (LNG) utilization has become an issue that requires a comprehensive study on the risk of LNG spillage in facilities with mitigation measures. The immediate hazard associated with an LNG spill is the vapor hazard, i.e., a flammable vapor cloud at the ground level, due to rapid vaporization and dense gas behavior. It was believed that high expansion foam mitigated LNG vapor hazard through warming effect (raising vapor buoyancy), but the boil-off effect increased vaporization rate due to the heat from water drainage of foam. This work reveals the existence of blocking effect (blocking convection and radiation to the pool) to reduce vaporization rate. The blanketing effect on source term (vaporization rate) is a combination of boil-off and blocking effect, which was quantitatively studied through seven tests conducted in a wind tunnel with liquid nitrogen. Since the blocking effect reduces more heat to the pool than the boil-off effect adds, the blanketing effect contributes to the net reduction of heat convection and radiation to the pool by 70%. Water drainage rate of high expansion foam is essential to determine the effectiveness of blanketing effect, since water provides the boil-off effect. Copyright © 2014 Elsevier B.V. All rights reserved.

A Mechanistic Model of Waterfall Plunge Pool Erosion into Bedrock

NASA Astrophysics Data System (ADS)

Scheingross, Joel S.; Lamb, Michael P.

2017-11-01

Landscapes often respond to changes in climate and tectonics through the formation and upstream propagation of knickzones composed of waterfalls. Little work has been done on the mechanics of waterfall erosion, and instead most landscape-scale models neglect waterfalls or use rules for river erosion, such as stream power, that may not be applicable to waterfalls. Here we develop a physically based model to predict waterfall plunge pool erosion into rock by abrasion from particle impacts and test the model against flume experiments. Both the model and experiments show that evolving plunge pools have initially high vertical erosion rates due to energetic particle impacts, and erosion slows and eventually ceases as pools deepen and deposition protects the pool floor from further erosion. Lateral erosion can continue after deposition on the pool floor, but it occurs at slow rates that become negligible as pools widen. Our work points to the importance of vertical drilling of successive plunge pools to drive upstream knickzone propagation in homogenous rock, rather than the classic mechanism of headwall undercutting. For a series of vertically drilling waterfalls, we find that upstream knickzone propagation is faster under higher combined water and sediment fluxes and for knickzones composed of many waterfalls that are closely spaced. Our model differs significantly from stream-power-based erosion rules in that steeper knickzones can retreat faster or more slowly depending on the number and spacing of waterfalls within a knickzone, which has implications for interpreting climatic and tectonic history through analysis of river longitudinal profiles.

Seasonal Patterns of the Insect Community Structure in Urban Rain Pools of Temperate Argentina

PubMed Central

Fontanarrosa, M. Soledad; Collantes, Marta B.; Bachmann, Axel O.

2009-01-01

Temporary aquatic environments are widespread in the world, and although there are considerable regional differences in their type and method of formation they have many physical, chemical and biological properties in common. With the aim to increase knowledge of urban temporary pool fauna, the objectives of this work were to assess the seasonal patterns of species composition, richness, and diversity of the aquatic insect community inhabiting rain pools in urban temperate Argentina, and to identify the environmental variables associated to these patterns. Four temporary pools of an urban green space in Buenos Aires City were studied throughout a 1-year period. Eleven flood cycles with very varied hydroperiods and dry periods, mainly associated with rainfall, were identified. Insect species richness in these temporary urban pools, 86 taxa were documented, was found to be within the range reported for wild temporary water bodies of other regions of the world. The present results provide evidence for the existence of a clear link between habitat and community variability. Hydroperiod and seasonality were the main environmental factors involved in structuring the insect communities of the studied water bodies. Urban pools in green spaces have the potential to act to its dwellers like corridors through the urban matrix. Taking into account these characteristics and their accessibility, urban temporary pools can be considered as promising habitats for the study of ecological processes involving the insect community. PMID:19611261

Swimming pool granuloma

MedlinePlus

... this page: //medlineplus.gov/ency/article/001357.htm Swimming pool granuloma To use the sharing features on this page, please enable JavaScript. A swimming pool granuloma is a long-term (chronic) skin ...

From antidunes to step-pools

NASA Astrophysics Data System (ADS)

Recking, Alain; Leduc, Pauline

2014-05-01

Step-pools are bed morphologies that are typical in high-gradient streams , recognizable by a staircase-like longitudinal profile resulting from accumulation of cobbles and boulders that are transverse to the channel and alternating with pools containing finer sediments. Within the last two decades step-pools have been the subject of increased efforts to characterize their nature; however their origin is still in debate. Researchers have very soon suspected step-pools to be the residual form of antidunes produced during flooding, but this hypothesis was continuously contested. Other theories has been proposed, considering, that step-pool profile develops a maximum flow resistance, or that pools geometry is controlled by the energy of a falling jet, or that steps form by boulders accumulation in a channel-spanning manner. All these theories gave very satisfying results when compared with experimental data, but does it mean that the antidune theory should we abandoned? We performed new flume experiments on steep slopes to investigate the antidune origin for step-pools. Our experiments showed that step-pools can have several origins, depending on the flow conditions and sediment mixture used. In some circumstances antidunes were well observed but did not produce stable step-pools morphology. In many occasions, step-pools obtained in the flume were isolated step-pools, with no real apparent periodicity. Only a few flow and sediment conditions allowed us to reproduce trains of antidunes which stabilized at the flow recession to produce stable periodical step-pools. These conditions are presented and discussed.

Interactions between pool geometry and hydraulics

USGS Publications Warehouse

Thompson, Douglas M.; Nelson, Jonathan M.; Wohl, Ellen E.

1998-01-01

An experimental and computational research approach was used to determine interactions between pool geometry and hydraulics. A 20-m-long, 1.8-m-wide flume was used to investigate the effect of four different geometric aspects of pool shape on flow velocity. Plywood sections were used to systematically alter constriction width, pool depth, pool length, and pool exit-slope gradient, each at two separate levels. Using the resulting 16 unique geometries with measured pool velocities in four-way factorial analyses produced an empirical assessment of the role of the four geometric aspects on the pool flow patterns and hence the stability of the pool. To complement the conclusions of these analyses, a two-dimensional computational flow model was used to investigate the relationships between pool geometry and flow patterns over a wider range of conditions. Both experimental and computational results show that constriction and depth effects dominate in the jet section of the pool and that pool length exhibits an increasing effect within the recirculating-eddy system. The pool exit slope appears to force flow reattachment. Pool length controls recirculating-eddy length and vena contracta strength. In turn, the vena contracta and recirculating eddy control velocities throughout the pool.

13 CFR 120.1706 - Pool Originator's retained interest in Pool.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Pool Originator's retained interest in Pool. 120.1706 Section 120.1706 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS LOANS Establishment of SBA Secondary Market Guarantee Program for First Lien Position 504 Loan...

The Good, the Bad, and the Volatile - Can We Have Both Healthy Pools and Healthy People?

EPA Science Inventory

Given the popularity of swimming for recreation and sport, it is remarkable that we are only in the early stages of understanding swimming pool chemistry, human exposure(s), and potential health risks. This is partly due to the complexity of swimming pool water chemistry, which i...

Carbon dynamics in peatland pool systems: the role of light

NASA Astrophysics Data System (ADS)

Pickard, Amy; Heal, Kate; McLeod, Andy; Dinsmore, Kerry

2016-04-01

Open-water pools are widespread in peatlands and are considered to represent biogeochemical hotspots within the peatland landscape. However the contribution of pool systems to wider peatland C cycling has not been quantified fully and there is a lack of knowledge of the role of photochemical processes in such environments. In this study, light exposure experiments were conducted in two contrasting pools to test the reactivity of aquatic C. The first study site was located at Cross Lochs (CL), Forsinard, in the Flow Country of Northern Scotland, in a 412 m2 pool characterised by low dissolved organic carbon (DOC) concentrations (˜15 mg C L-1). The second site was located at Red Moss of Balerno (RM), a raised bog in central Scotland, in a 48 m2 pool with high DOC concentrations (˜35 mg C L-1). Experiments took place over 9 days in situ at each pool in mid-summer 2015, with 500 mL water samples contained in bags transparent to sunlight and in opaque control bags. After field exposure, optical, chemical and stable C isotope analyses were conducted on the samples. Significant differences in biogeochemical cycling of DOC were detected between the two systems, with DOC losses as a percentage of the total C pool 15% higher at RM than at CL after light exposure. The mean DOC concentration of light exposed samples at RM declined steeply initially, with 83% observed DOC degradation occurring by day 3 of the experiment. Total losses of 7.9 mg DOC L-1were observed in light exposed samples at RM, along with decreasing E4:E6 ratios, suggesting that material remaining at the end of the experiment was humified. Depletion of DOC was positively correlated with production of CO2 at both sites, with concentrations of up to 4.3 mg CO2-C L-1 recorded at RM. Stable C isotope signatures at both sites were altered under light treatment, as demonstrated by the production of enriched δ13C-DOC (+0.46 ‰ relative to opaque bags) and depleted δ13C-DIC (-0.97 ‰ relative to opaque bags) at

Observations of Cold Pool Properties during GoAmazon2014/5

NASA Astrophysics Data System (ADS)

Mayne, S. L.; Schumacher, C.; MacDonald, L.; Turner, D. D.

2017-12-01

Convectively generated cold pools are instrumental in both the development of the sub-cloud layer and the organization of deep convection. Despite this, analyses of cold pools in the tropics are constrained by a lack of observational data; insight into the phenomena therefore relies heavily on numerical models. GoAmazon2014/5, a 2-year DOE-sponsored field campaign centered on Manacapuru, Brazil in the central Amazon, provides a unique opportunity to characterize tropical cold pools and allows for the comparison of observational data with theoretical results from model cold pool simulations and parameterizations. This investigation analyzes radar, disdrometer, and profiler measurements at the DOE mobile facility site to study tropical cold pool characteristics. The Brazilian military (SIPAM) operational S-band radar in Manaus is used to provide a broad context of convective systems, while measurements from Parsivel disdrometers are used to assess drop-size distributions (DSDs) at the surface. A unique aspect of this research is the use of the Atmospheric Emitted Radiance Interferometer (AERI) instrument, which utilizes down-welling IR measurements to obtain vertical profiles of thermodynamic quantities such as temperature and water vapor in the lowest few km of the atmosphere. Combined with surface observations and sounding data, these datasets will result in a thorough investigation of the horizontal and vertical characteristics of cold pools over the tropical rain forest. Preliminary analyses of 20 events reveal a mean cold pool height of 220 m and a mean radius of approximately 8.5 km. The average cold pool experienced a temperature (specific humidity) decrease of approximately 1 K (0.4 g/kg) at the surface. The temperature decrease is consistent with modeling studies and limited observations from previous studies over the tropics. The small decrease in specific humidity is attributed to the high moisture content within the cold pools. AERI retrievals of

Bronx River bed sediments phosphorus pool and phosphorus compound identification

NASA Astrophysics Data System (ADS)

Wang, J.; Pant, H. K.

2008-12-01

Phosphorus (P) transport in the Bronx River degraded water quality, decreased oxygen levels, and resulted in bioaccumulation in sediment potentially resulting in eutrophication, algal blooms and oxygen depletion under certain temperature and pH conditions. The anthropogenic P sources are storm water runoff, raw sewage discharge, fertilizer application in lawn, golf course and New York Botanical Garden; manure from the Bronx zoo; combined sewoverflows (CSO's) from parkway and Hunts Point sewage plant; pollutants from East River. This research was conducted in the urban river system in New York City area, in order to control P source, figure out P transport temporal and spatial variations and the impact on water quality; aimed to regulate P application, sharing data with Bronx River Alliance, EPA, DEP and DEC. The sediment characteristics influence the distribution and bioavailbility of P in the Bronx River. The P sequential extraction gave the quantitative analysis of the P pool, quantifying the inorganic and organic P from the sediments. There were different P pool patterns at the 15 sites, and the substantial amount of inorganic P pool indicated that a large amount P is bioavailable. The 31P- NMR (Nuclear Magnetic Resonance Spectroscopy) technology had been used to identify P species in the 15 sites of the Bronx River, which gave a qualitative analysis on phosphorus transport in the river. The P compounds in the Bronx River bed sediments are mostly glycerophophate (GlyP), nucleoside monophosphates (NMP), polynucleotides (PolyN), and few sites showed the small amount of glucose-6-phosphate (G6P), glycerophosphoethanoamine (GPEA), phosphoenopyruvates (PEP), and inosine monophosphate (IMP). The land use spatial and temporal variations influence local water P levels, P distributions, and P compositions.

Investigation of some disinfection chemicals and water quality parameters in swimming pools in the city center and districts of Canakkale, Turkey.

PubMed

Uysal, Tolga; Yilmaz, Selehattin; Turkoglu, Muhammet; Sadikoglu, Murat

2017-07-01

In this study, the variations in concentrations of some disinfection chemicals such as cyanuric acid (CyA), free chlorine (FC), and residual chlorine (RC), which affect human health, were investigated in the water of swimming pools. In addition, quality parameters such as temperature, pH, and total alkalinity (TA) in 44 swimming pools located in the city center and districts of Canakkale, Turkey, were examined in the summer period. While FC and RC amounts were analyzed using tablet tests with N-N-diethyl phenylenediamine (DPD 1) and potassium iodine (DPD 3) using the colorimetric method in the comparator, TA and CyA levels were measured with a photometric method. Temperature and pH were measured using YSI 556 MPS. Levels of CyA, FC, RC, pH, temperature, and TA varied between 0.00 and 725.0 mg L -1 (108.0 ± 111.4 mg L -1 ), 0.00 and 5.00 mg L -1 (1.60 ± 0.962 mg L -1 ), 0 and 0.55 mg L -1 (0.087 ± 0.059), 6.40 and 8.20 mg L -1 (7.30 ± 0.038 mg L -1 ), 22.0 and 32.0 °C (27.6 ± 1.45 °C), and 0.00 and 391.0 mg L -1 (129.3 ± 89.0), respectively. The findings were compared to standard limit values of the Ministry of Health of the Turkish Republic and other countries. Not only maximum concentrations of CyA but also the average concentrations exceeded the standard limit values of different countries in July and August with high tourism activity in Turkey. Although there is no problem in view of average values of other quality parameters, there are some problems in view of the maximum values in pool waters compared to standard limit values.

Convenient yet not a convenience sample: Jury pools as experimental subject pools.

PubMed

Murray, Gregg R; Rugeley, Cynthia R; Mitchell, Dona-Gene; Mondak, Jeffery J

2013-01-01

Scholars greatly benefit from access to convenient, inexpensive data sources. Many researchers rely on student subject pools, a practice that raises concern about the "college sophomore problem," or the possibility that findings from student subjects do not generalize beyond the campus. As an accessible, low cost, and heterogeneous data source, some researchers have used subjects recruited from jury pools, which are drawn from randomly-selected citizens required by law to appear for jury duty. In this paper, we discuss the strengths and weaknesses of this approach. First, we review pragmatic considerations involving access to jury pools, substantive content, the administration of survey-experiments, and the financial costs and benefits of this approach. Next, we present evidence regarding the quality of jury pool samples in terms of response rates, diversity, and representativeness. We conclude that jury pools, given proper attention to their limitations, offer an attractive addition to the viable sources of experimental data. Copyright © 2012 Elsevier Inc. All rights reserved.

Characteristics of Pool Boiling on Graphite-Copper Composite Surfaces

NASA Technical Reports Server (NTRS)

Zhang, Nengli; Chao, David F.; Yang, Wen-Jei

2002-01-01

Nucleate pool boiling performance of different liquids on graphite-copper composite (Gr-Cu) surfaces has been experimentally studied and modeled. Both highly wetting fluids, such as freon-113 and pentane, and a moderately wetting fluid (water) were tested on the Gr-Cu surfaces with different graphite-fiber volume fractions to reveal the enhancement effects of the composite surfaces on the nucleate pool boiling. Results of the experiments show that the graphite-fiber volume fraction has an optimum value. The Gr-Cu composite surface with 25 percent graphite-fiber volume (f=0.25) has a maximum enhancement effect on the nucleate boiling heat transfer comparing to the pure copper surface. For the highly wetting fluid, the nucleate boiling heat transfer is generally enhanced on the Gr- Cu composite surfaces by 3 to 6 times shown. In the low heat flux region, the enhancement is over 6 times, but in the high heat flux region, the enhancement is reduced to about 40%. For the moderately wetting fluid (water), stronger enhancement of nucleate boiling heat transfer is achieved on the composite surface. It shown the experimental results in which one observes the nucleate boiling heat transfer enhancement of 5 to 10 times in the low heat flux region and an enhancement of 3 to 5 times in the high heat flux region. Photographs of bubble departure during the initial stage of nucleate boiling indicate that the bubbles detached from the composite surface are much smaller in diameter than those detached from the pure copper surface. Typical photographs are presented.It shows that the bubbles departed from the composite surface have diameters of only O(0.1) mm, while those departed from the pure copper surface have diameters of O(1) mm. It is also found that the bubbles depart from the composite surface at a much higher frequency, thus forming vapor columns. These two phenomena combined with high thermal conductivity of the graphite fiber are considered the mechanisms for such a

Vernal Pools Detection Using High-Resolution LiDAR Data and Aerial Imagery in Hubbardston, Massachusetts

NASA Astrophysics Data System (ADS)

Jiang, Jiaxin

Vernal pool refers to temporary or semi-permanent pools that occur in surface depressions without permanent inlets or outlets. Because they periodically dry out, vernal pools are free of fish and essential to amphibians, some reptiles, birds, and mammals for breeding habitats. In Massachusetts, vernal pool habitats are found in woodland depressions, swales or kettle holes where water is contained for at least two months in most years. However, vernal pools are delicate ecosystems. These systems are fragile to human activities such as urbanization. Understanding the current situation of vernal pools helps city planners make wiser decisions. This study focuses on identifying vernal pools in the state of Massachusetts with high-resolution light detection and ranging (LiDAR) data and aerial imagery. By using high-resolution light detection and ranging data, aerial imagery, land use data, the MassDEP Hydrography layer and the Soil Survey Geographic Database, the approach located over 1800 potential vernal pools in a 108 km 2 study area in Massachusetts. The assessment of the study result shows the commission rate was 5.6% and omission rate was 7.1%. This method provides an efficient way of locating vernal pools over large areas.

Vernal Pool Lessons and Activities.

ERIC Educational Resources Information Center

Childs, Nancy; Colburn, Betsy

This curriculum guide accompanies Certified: A Citizen's Step-by-Step Guide to Protecting Vernal Pools which is designed to train volunteers in the process of identifying vernal pool habitat so that as many of these pools as possible can be certified by the Massachusetts Natural Heritage and Endangered Species Program. Vernal pools are a kind of…

Morphology of drying blood pools

NASA Astrophysics Data System (ADS)

Laan, Nick; Smith, Fiona; Nicloux, Celine; Brutin, David; D-Blood project Collaboration

2016-11-01

Often blood pools are found on crime scenes providing information concerning the events and sequence of events that took place on the scene. However, there is a lack of knowledge concerning the drying dynamics of blood pools. This study focuses on the drying process of blood pools to determine what relevant information can be obtained for the forensic application. We recorded the drying process of blood pools with a camera and measured the weight. We found that the drying process can be separated into five different: coagulation, gelation, rim desiccation, centre desiccation, and final desiccation. Moreover, we found that the weight of the blood pool diminishes similarly and in a reproducible way for blood pools created in various conditions. In addition, we verify that the size of the blood pools is directly related to its volume and the wettability of the surface. Our study clearly shows that blood pools dry in a reproducible fashion. This preliminary work highlights the difficult task that represents blood pool analysis in forensic investigations, and how internal and external parameters influence its dynamics. We conclude that understanding the drying process dynamics would be advancement in timeline reconstitution of events. ANR funded project: D-Blood Project.

Annual report, FY 1979 Spent fuel and fuel pool component integrity.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, A.B. Jr.; Bailey, W.J.; Schreiber, R.E.

International meetings under the BEFAST program and under INFCE Working Group No. 6 during 1978 and 1979 continue to indicate that no cases of fuel cladding degradation have developed on pool-stored fuel from water reactors. A section from a spent fuel rack stand, exposed for 1.5 y in the Yankee Rowe (PWR) pool had 0.001- to 0.003-in.-deep (25- to 75-..mu..m) intergranular corrosion in weld heat-affected zones but no evidence of stress corrosion cracking. A section of a 304 stainless steel spent fuel storage rack exposed 6.67 y in the Point Beach reactor (PWR) spent fuel pool showed no significant corrosion.more » A section of 304 stainless steel 8-in.-dia pipe from the Three Mile Island No. 1 (PWR) spent fuel pool heat exchanger plumbing developed a through-wall crack. The crack was intergranular, initiating from the inside surface in a weld heat-affected zone. The zone where the crack occurred was severely sensitized during field welding. The Kraftwerk Union (Erlangen, GFR) disassembled a stainless-steel fuel-handling machine that operated for 12 y in a PWR (boric acid) spent fuel pool. There was no evidence of deterioration, and the fuel-handling machine was reassembled for further use. A spent fuel pool at a Swedish PWR was decontaminated. The procedure is outlined in this report.« less

Surface Flooding from Hurricane Harvey Shown in New SMAP Imagery

NASA Image and Video Library

2017-08-30

A new series of images generated with data from NASA's Soil Moisture Active Passive (SMAP) satellite illustrate the surface flooding caused by Hurricane Harvey from before its initial landfall through August 27, 2017. The SMAP observations detect the proportion of the ground covered by surface water within the satellite's field of view. The sequence of images depicts successive satellite orbital swath observations showing the surface water conditions on August 22, before Harvey's landfall (left), and then on Aug. 27, two days after landfall (middle). The resulting increase in surface flooding from record rainfall over the three-day period, shown at right, depicts regionally heavy flooding around the Houston metropolitan area. The hardest hit areas (blue and purple shades) cover more than 23,000 square miles (about 59,600 square kilometers) and indicate a more than 1,000-fold increase in surface water cover from rainfall-driven flooding. SMAP's low-frequency (L-band) microwave radiometer features enhanced capabilities for detecting surface water changes in nearly all weather conditions and under low-to-moderate vegetation cover. The satellite provides global coverage with one to three-day repeat sampling, which is well suited for monitoring dynamic inland waters around the world. https://photojournal.jpl.nasa.gov/catalog/PIA21930

Adaptive genomic divergence under high gene flow between freshwater and brackish-water ecotypes of prickly sculpin (Cottus asper) revealed by Pool-Seq.

PubMed

Dennenmoser, Stefan; Vamosi, Steven M; Nolte, Arne W; Rogers, Sean M

2017-01-01

Understanding the genomic basis of adaptive divergence in the presence of gene flow remains a major challenge in evolutionary biology. In prickly sculpin (Cottus asper), an abundant euryhaline fish in northwestern North America, high genetic connectivity among brackish-water (estuarine) and freshwater (tributary) habitats of coastal rivers does not preclude the build-up of neutral genetic differentiation and emergence of different life history strategies. Because these two habitats present different osmotic niches, we predicted high genetic differentiation at known teleost candidate genes underlying salinity tolerance and osmoregulation. We applied whole-genome sequencing of pooled DNA samples (Pool-Seq) to explore adaptive divergence between two estuarine and two tributary habitats. Paired-end sequence reads were mapped against genomic contigs of European Cottus, and the gene content of candidate regions was explored based on comparisons with the threespine stickleback genome. Genes showing signals of repeated differentiation among brackish-water and freshwater habitats included functions such as ion transport and structural permeability in freshwater gills, which suggests that local adaptation to different osmotic niches might contribute to genomic divergence among habitats. Overall, the presence of both repeated and unique signatures of differentiation across many loci scattered throughout the genome is consistent with polygenic adaptation from standing genetic variation and locally variable selection pressures in the early stages of life history divergence. © 2016 John Wiley & Sons Ltd.

The Madden-Julian Oscillation and the Indo-Pacific Warm Pool

NASA Astrophysics Data System (ADS)

Raymond, David J.; Fuchs, Željka

2018-04-01

A minimal model of the interaction of the Madden-Julian oscillation (MJO) with the Indo-Pacific warm pool is presented. This model is based on the linear superposition of the flow associated with a highly simplified treatment of the MJO plus the flow induced by the warm pool itself. Both of these components parameterize rainfall as proportional to the column water vapor, which in turn is governed by a linearized moisture equation in which WISHE (wind induced surface heat exchange) plays a governing role. The MJO component has maximum growth rate for planetary wavenumber 1 and is equatorially trapped with purely zonal winds. The warm pool component exhibits a complex flow pattern, differing significantly from the classical Gill model as a result of the mean easterly flow. The combination of the two produce a flow that reproduces many aspects of the observed global flow associated with the MJO.

Potential risks of TiO2 and ZnO nanoparticles released from sunscreens into outdoor swimming pools.

PubMed

Jeon, Soo-Kyung; Kim, Eun-Ju; Lee, Jaesang; Lee, Seunghak

2016-11-05

The potential risks of nanoparticles (NPs) in sunscreens being released into swimming water were evaluated by a series of laboratory experiments simulating the fate and transport of NPs in outdoor swimming pools. NPs released from sunscreen-applied skin were estimated using pig skins covered with five different commercial sunscreens containing TiO2, ZnO, or both at various concentrations. Assuming that the swimming water treatment processes consisted of filtration, UV irradiation, heating, and chlorination, possible removal of the released NPs by each process was estimated. Generation of hydrogen peroxide (H2O2) by the NPs under sunlight and after UV photochemical treatment were measured, and the H2O2 concentration possibly present in the swimming pool was calculated based on some specific scenarios of operating an outdoor swimming pool. It was found that a significant amount of the NPs in sunscreens could be released into the swimming water, and accumulate during circulation through the treatment system. However, the concentration of H2O2 possibly present in the swimming pool should be below the level at which an adverse effect to bathers is concerned. Copyright © 2016 Elsevier B.V. All rights reserved.

STS-52 Payload Specialist MacLean floats in pool during JSC bailout exercises

NASA Technical Reports Server (NTRS)

1992-01-01

STS-52 Columbia, Orbiter Vehicle (OV) 102, Payload Specialist Steven G. MacLean, wearing launch and entry suit (LES) and clamshell helmet, is assisted by SCUBA-equipped divers as he floats in pool during emergency egress (bailout) training exercises in JSC's Weightless Environment Training Facility Bldg 29. Bailout exercises utilize the WETF's 25-foot deep pool as the ocean during this water landing simulation. MacLean represents the Canadian Space Agency (CSA).

Conceptual design for spacelab pool boiling experiment

NASA Technical Reports Server (NTRS)

Lienhard, J. H.; Peck, R. E.

1978-01-01

A pool boiling heat transfer experiment to be incorporated with a larger two-phase flow experiment on Spacelab was designed to confirm (or alter) the results of earth-normal gravity experiments which indicate that the hydrodynamic peak and minimum pool boiling heat fluxes vanish at very low gravity. Twelve small sealed test cells containing water, methanol or Freon 113 and cylindrical heaters of various sizes are to be built. Each cell will be subjected to one or more 45 sec tests in which the surface heat flux on the heaters is increased linearly until the surface temperature reaches a limiting value of 500 C. The entire boiling process will be photographed in slow-motion. Boiling curves will be constructed from thermocouple and electric input data, for comparison with the motion picture records. The conduct of the experiment will require no more than a few hours of operator time.

Color Fringes Bordering Black Stripes at the Bottom of a Swimming Pool

ERIC Educational Resources Information Center

Fuster, Gonzalo; Rojas, Roberto; Slüsarenko, Viktor

2016-01-01

We have observed a nice example of chromatic dispersion due to refraction in water, in the form of color fringes bordering the black stripes that exist at the bottom of a swimming pool. Here we give a qualitative description of the phenomenon, explaining the role of the black stripes and the dispersive index of refraction of water.

Phosphorylation of Synaptojanin Differentially Regulates Endocytosis of Functionally Distinct Synaptic Vesicle Pools

PubMed Central

Geng, Junhua; Wang, Liping; Lee, Joo Yeun; Chen, Chun-Kan

2016-01-01

The rapid replenishment of synaptic vesicles through endocytosis is crucial for sustaining synaptic transmission during intense neuronal activity. Synaptojanin (Synj), a phosphoinositide phosphatase, is known to play an important role in vesicle recycling by promoting the uncoating of clathrin following synaptic vesicle uptake. Synj has been shown to be a substrate of the minibrain (Mnb) kinase, a fly homolog of the dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A); however, the functional impacts of Synj phosphorylation by Mnb are not well understood. Here we identify that Mnb phosphorylates Synj at S1029 in Drosophila. We find that phosphorylation of Synj at S1029 enhances Synj phosphatase activity, alters interaction between Synj and endophilin, and promotes efficient endocytosis of the active cycling vesicle pool (also referred to as exo-endo cycling pool) at the expense of reserve pool vesicle endocytosis. Dephosphorylated Synj, on the other hand, is deficient in the endocytosis of the active recycling pool vesicles but maintains reserve pool vesicle endocytosis to restore total vesicle pool size and sustain synaptic transmission. Together, our findings reveal a novel role for Synj in modulating reserve pool vesicle endocytosis and further indicate that dynamic phosphorylation and dephosphorylation of Synj differentially maintain endocytosis of distinct functional synaptic vesicle pools. SIGNIFICANCE STATEMENT Synaptic vesicle endocytosis sustains communication between neurons during a wide range of neuronal activities by recycling used vesicle membrane and protein components. Here we identify that Synaptojanin, a protein with a known role in synaptic vesicle endocytosis, is phosphorylated at S1029 in vivo by the Minibrain kinase. We further demonstrate that the phosphorylation status of Synaptojanin at S1029 differentially regulates its participation in the recycling of distinct synaptic vesicle pools. Our results reveal a new role for

Numerical Simulation of Hydrodynamics of a Heavy Liquid Drop Covered by Vapor Film in a Water Pool

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, W.M.; Yang, Z.L.; Giri, A.

2002-07-01

A numerical study on the hydrodynamics of a droplet covered by vapor film in water pool is carried out. Two level set functions are used as to implicitly capture the interfaces among three immiscible fluids (melt-drop, vapor and coolant). This approach leaves only one set of conservation equations for the three phases. A high-order Navier-Stokes solver, called Cubic-Interpolated Pseudo-Particle (CIP) algorithm, is employed in combination with level set approach, which allows large density ratios (up to 1000), surface tension and jump in viscosity. By this calculation, the hydrodynamic behavior of a melt droplet falling into a volatile coolant is simulated,more » which is of great significance to reveal the mechanism of steam explosion during a hypothetical severe reactor accident. (authors)« less

Water Purification Systems

NASA Technical Reports Server (NTRS)

1994-01-01

Clearwater Pool Technologies employs NASA-developed silver/copper ionization to purify turtle and dolphin tanks, cooling towers, spas, water recycling systems, etc. The pool purifier consists of a microcomputer to monitor water conditions, a pair of metallic electrodes, and a rheostat controller. Ions are generated by passing a low voltage current through the electrodes; the silver ions kill the bacteria, and the copper ions kill algae. This technology has found broad application because it offers an alternative to chemical disinfectants. It was originally developed to purify water on Apollo spacecraft. Caribbean Clear has been using NASA's silver ionization technology for water purification for more than a decade. Two new products incorporate advancements of the basic technology. One is the AquaKing, a system designed for areas with no source of acceptable drinking water. Another is the Caribbean Clear Controller, designed for commercial pool and water park applications where sanitizing is combined with feedback control of pH and an oxidizer, chlorine or bromine. The technology was originally developed to purify water on Apollo spacecraft.

Data Pool Description

Atmospheric Science Data Center

2016-04-29

ASDC Data Pool   Notices   • DataPool will transition from ...  • Use IE7 for FTP sessions: a) Select "View", "Open FTP site in Windows Explorer" or b) Open Windows Explorer and enter the URL for the FTP site in the address bar ...

33 CFR 207.170 - Federal Dam, Oklawaha River, Moss Bluff, Fla.; pool level.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Federal Dam, Oklawaha River, Moss Bluff, Fla.; pool level. 207.170 Section 207.170 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.170 Federal Dam, Oklawaha River...

33 CFR 207.170 - Federal Dam, Oklawaha River, Moss Bluff, Fla.; pool level.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Federal Dam, Oklawaha River, Moss Bluff, Fla.; pool level. 207.170 Section 207.170 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.170 Federal Dam, Oklawaha River...

33 CFR 207.170 - Federal Dam, Oklawaha River, Moss Bluff, Fla.; pool level.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Federal Dam, Oklawaha River, Moss Bluff, Fla.; pool level. 207.170 Section 207.170 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.170 Federal Dam, Oklawaha River...

Sudden clearing of estuarine waters upon crossing the threshold from transport to supply regulation of sediment transport as an erodible sediment pool is depleted: San Francisco Bay, 1999

USGS Publications Warehouse

Schoellhamer, David H.

2011-01-01

The quantity of suspended sediment in an estuary is regulated either by transport, where energy or time needed to suspend sediment is limiting, or by supply, where the quantity of erodible sediment is limiting. This paper presents a hypothesis that suspended-sediment concentration (SSC) in estuaries can suddenly decrease when the threshold from transport to supply regulation is crossed as an erodible sediment pool is depleted. This study was motivated by a statistically significant 36% step decrease in SSC in San Francisco Bay from water years 1991–1998 to 1999–2007. A quantitative conceptual model of an estuary with an erodible sediment pool and transport or supply regulation of sediment transport is developed. Model results confirm that, if the regulation threshold was crossed in 1999, SSC would decrease rapidly after water year 1999 as observed. Estuaries with a similar history of a depositional sediment pulse followed by erosion may experience sudden clearing.

An efficient modeling method for thermal stratification simulation in a BWR suppression pool

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haihua Zhao; Ling Zou; Hongbin Zhang

2012-09-01

The suppression pool in a BWR plant not only is the major heat sink within the containment system, but also provides major emergency cooling water for the reactor core. In several accident scenarios, such as LOCA and extended station blackout, thermal stratification tends to form in the pool after the initial rapid venting stage. Accurately predicting the pool stratification phenomenon is important because it affects the peak containment pressure; and the pool temperature distribution also affects the NPSHa (Available Net Positive Suction Head) and therefore the performance of the pump which draws cooling water back to the core. Current safetymore » analysis codes use 0-D lumped parameter methods to calculate the energy and mass balance in the pool and therefore have large uncertainty in prediction of scenarios in which stratification and mixing are important. While 3-D CFD methods can be used to analyze realistic 3D configurations, these methods normally require very fine grid resolution to resolve thin substructures such as jets and wall boundaries, therefore long simulation time. For mixing in stably stratified large enclosures, the BMIX++ code has been developed to implement a highly efficient analysis method for stratification where the ambient fluid volume is represented by 1-D transient partial differential equations and substructures such as free or wall jets are modeled with 1-D integral models. This allows very large reductions in computational effort compared to 3-D CFD modeling. The POOLEX experiments at Finland, which was designed to study phenomena relevant to Nordic design BWR suppression pool including thermal stratification and mixing, are used for validation. GOTHIC lumped parameter models are used to obtain boundary conditions for BMIX++ code and CFD simulations. Comparison between the BMIX++, GOTHIC, and CFD calculations against the POOLEX experimental data is discussed in detail.« less

Short time dynamics of water coalescence on a flat water pool

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lim, Su Jin; Gim, Bopil; Fezzaa, Kamel

2016-12-01

Coalescence is an important hydrodynamic event that frequently takes place in nature as well as in industry. Here we provide an experimental study on short time dynamics of water coalescence, particularly when a water droplet comes in contact with a flat water surface, by utilizing high-resolution high-penetration ultrafast X-ray microscopy. Our results demonstrate a possibility that an extreme curvature difference between a drop and a flat surface can significantly modify the hydrodynamics of water coalescence, which is unexpected in the existing theory. We suggest a plausible explanation for why coalescence can be modified by an extreme curvature difference.

Desiccation of a pool of blood: from fluid mechanics to forensic investigations

NASA Astrophysics Data System (ADS)

Nicloux, Celine; Brutin, David

2012-11-01

The evaporation of biological fluids (with droplet configuration) has been studied since a few years due to several applications in medical fields such as medical tests, drug screening, biostabilization... The evaporation of a drop of whole blood leads to the formation of final typical pattern of cracks. Flow motion, adhesion, gelation and fracturation all occur during the evaporation of this complex matter. During the drying, a sol-gel transition develops. The evaporation of a pool of blood is studied in order to link the pattern formation and the evaporation dynamics. We intend to transfer the knowledge acquired for drops on pool to improve the forensic investigations. In this study, we focus on both pool of blood and pure water to determine the transition region from drop to pool and then to characterize the evaporation rate in the pool configuration. The spreading of blood which can be seen as a complex fluid is strongly influenced the substrate nature. The initial contact angle of blood on different substrate nature will influence the maximum thickness of the layer and then will influence the evaporation mass flux. The authors gratefully acknowledge the help and the fruitful discussions raised with A. Boccoz.

Insights into soil carbon dynamics across climatic gradients from carbon-pool specific radiocarbon analyses

NASA Astrophysics Data System (ADS)

van der Voort, Tessa Sophia; Hagedorn, Frank; McIntyre, Cameron; Zell, Claudia; Eglinton, Timothy Ian

2017-04-01

Soil carbon constitutes the largest terrestrial reservoir of organic carbon, and therefore understanding the mechanisms and drivers of carbon stabilization is crucial, especially in the framework of climate change. The understanding of the dependence of soil organic turnover in specific carbon pools as related to e.g. climate, soil texture and mineralogy is limited. In this framework, radiocarbon constitutes a uniquely powerful tool that help to unravel carbon dynamics from decadal to millennial timescales. This project combines bulk and pool-specific radiocarbon analyses in the top and deep soil on a wide range of forested soils that span a large climatic gradient (MAT 1.3-9.2°C, MAP 600 to 2100 mm m-2y-1). These well-studies sites are part of the Long-Term Forest Ecosystem Research (LWF) program of the Swiss Federal Institute for Forest, Snow and Landscape research (WSL). This study aims to combine the insights gained from bulk and pool-specific turnover to environmental conditions and molecular composition of soil carbon. The pools investigated span the mineral-associated (occluded and heavy fractions from density fractionation) and potentially water-soluble (free light fractions from density fractionation and water extractable organic carbon) organic carbon fractions. Pool-specific radiocarbon work is augmented by the measurement of abundance of compounds such as alkanes, fatty acids and lignin phenols on a subset of samples. Initial results show disparate patterns depending on soil type and in particular soil texture, which could be indicative of various stabilization mechanisms in different soils. Overall, this study provides new insights into the controls of soil organic matter dynamics as related to environmental conditions, in particular in specific sub-pools of carbon.

An evaluation of population index and estimation techniques for tadpoles in desert pools

USGS Publications Warehouse

Jung, Robin E.; Dayton, Gage H.; Williamson, Stephen J.; Sauer, John R.; Droege, Sam

2002-01-01

Using visual (VI) and dip net indices (DI) and double-observer (DOE), removal (RE), and neutral red dye capture-recapture (CRE) estimates, we counted, estimated, and censused Couch's spadefoot (Scaphiopus couchii) and canyon treefrog (Hyla arenicolor) tadpole populations in Big Bend National Park, Texas. Initial dye experiments helped us determine appropriate dye concentrations and exposure times to use in mesocosm and field trials. The mesocosm study revealed higher tadpole detection rates, more accurate population estimates, and lower coefficients of variation among pools compared to those from the field study. In both mesocosm and field studies, CRE was the best method for estimating tadpole populations, followed by DOE and RE. In the field, RE, DI, and VI often underestimated populations in pools with higher tadpole numbers. DI improved with increased sampling. Larger pools supported larger tadpole populations, and tadpole detection rates in general decreased with increasing pool volume and surface area. Hence, pool size influenced bias in tadpole sampling. Across all techniques, tadpole detection rates differed among pools, indicating that sampling bias was inherent and techniques did not consistently sample the same proportion of tadpoles in each pool. Estimating bias (i.e., calculating detection rates) therefore was essential in assessing tadpole abundance. Unlike VI and DOE, DI, RE, and CRE could be used in turbid waters in which tadpoles are not visible. The tadpole population estimates we used accommodated differences in detection probabilities in simple desert pool environments but may not work in more complex habitats.

Design of association studies with pooled or un-pooled next-generation sequencing data.

PubMed

Kim, Su Yeon; Li, Yingrui; Guo, Yiran; Li, Ruiqiang; Holmkvist, Johan; Hansen, Torben; Pedersen, Oluf; Wang, Jun; Nielsen, Rasmus

2010-07-01

Most common hereditary diseases in humans are complex and multifactorial. Large-scale genome-wide association studies based on SNP genotyping have only identified a small fraction of the heritable variation of these diseases. One explanation may be that many rare variants (a minor allele frequency, MAF <5%), which are not included in the common genotyping platforms, may contribute substantially to the genetic variation of these diseases. Next-generation sequencing, which would allow the analysis of rare variants, is now becoming so cheap that it provides a viable alternative to SNP genotyping. In this paper, we present cost-effective protocols for using next-generation sequencing in association mapping studies based on pooled and un-pooled samples, and identify optimal designs with respect to total number of individuals, number of individuals per pool, and the sequencing coverage. We perform a small empirical study to evaluate the pooling variance in a realistic setting where pooling is combined with exon-capturing. To test for associations, we develop a likelihood ratio statistic that accounts for the high error rate of next-generation sequencing data. We also perform extensive simulations to determine the power and accuracy of this method. Overall, our findings suggest that with a fixed cost, sequencing many individuals at a more shallow depth with larger pool size achieves higher power than sequencing a small number of individuals in higher depth with smaller pool size, even in the presence of high error rates. Our results provide guidelines for researchers who are developing association mapping studies based on next-generation sequencing. (c) 2010 Wiley-Liss, Inc.

Water Purification

NASA Technical Reports Server (NTRS)

1994-01-01

The Vision Catalyst Purifier employs the basic technology developed by NASA to purify water aboard the Apollo spacecraft. However, it also uses an "erosion" technique. The purifier kills bacteria, viruses, and algae by "catalytic corrosion." A cartridge contains a silver-impregnated alumina bed with a large surface area. The catalyst bed converts oxygen in a pool of water to its most oxidative state, killing over 99 percent of the bacteria within five seconds. The cartridge also releases into the pool low levels of ionic silver and copper through a controlled process of erosion. Because the water becomes electrochemically active, no electricity is required.

Serological responses to Cryptosporidium antigens in inhabitants of Hungary using conventionally filtered surface water and riverbank filtered drinking water.

PubMed

Farkas, K; Plutzer, J; Moltchanova, E; Török, A; Varró, M J; Domokos, K; Frost, F; Hunter, P R

2015-10-01

In this study the putative protective seroprevalence (PPS) of IgG antibodies to the 27-kDa and 15/17-kDa Cryptosporidium antigens in sera of healthy participants who were and were not exposed to Cryptosporidium oocysts via surface water-derived drinking water was compared. The participants completed a questionnaire regarding risk factors that have been shown to be associated with infection. The PPS was significantly greater (49-61%) in settlements where the drinking water originated from surface water, than in the control city where riverbank filtration was used (21% and 23%). Logistic regression analysis on the risk factors showed an association between bathing/swimming in outdoor pools and antibody responses to the 15/17-kDa antigen complex. Hence the elevated responses were most likely due to the use of contaminated water. Results indicate that waterborne Cryptosporidium infections occur more frequently than reported but may derive from multiple sources.

ASCANs Helms and Gregory swim in pool during Elgin AFB survival training

NASA Image and Video Library

1990-09-20

1990 Group 13 Astronaut Candidates (ASCANs) Susan J. Helms (foreground) and William G. Gregory, wearing helmets and flight suits, swim in pool at Elgin Air Force Base (AFB) in Pensacola, Florida, during water survival exercises. The training familiarized the candidates with survival techniques necessary in the event of a water landing. ASCANs participated in the exercises from 08-14-90 through 08-17-90.

Phosphorylation of Synaptojanin Differentially Regulates Endocytosis of Functionally Distinct Synaptic Vesicle Pools.

PubMed

Geng, Junhua; Wang, Liping; Lee, Joo Yeun; Chen, Chun-Kan; Chang, Karen T

2016-08-24

The rapid replenishment of synaptic vesicles through endocytosis is crucial for sustaining synaptic transmission during intense neuronal activity. Synaptojanin (Synj), a phosphoinositide phosphatase, is known to play an important role in vesicle recycling by promoting the uncoating of clathrin following synaptic vesicle uptake. Synj has been shown to be a substrate of the minibrain (Mnb) kinase, a fly homolog of the dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A); however, the functional impacts of Synj phosphorylation by Mnb are not well understood. Here we identify that Mnb phosphorylates Synj at S1029 in Drosophila We find that phosphorylation of Synj at S1029 enhances Synj phosphatase activity, alters interaction between Synj and endophilin, and promotes efficient endocytosis of the active cycling vesicle pool (also referred to as exo-endo cycling pool) at the expense of reserve pool vesicle endocytosis. Dephosphorylated Synj, on the other hand, is deficient in the endocytosis of the active recycling pool vesicles but maintains reserve pool vesicle endocytosis to restore total vesicle pool size and sustain synaptic transmission. Together, our findings reveal a novel role for Synj in modulating reserve pool vesicle endocytosis and further indicate that dynamic phosphorylation and dephosphorylation of Synj differentially maintain endocytosis of distinct functional synaptic vesicle pools. Synaptic vesicle endocytosis sustains communication between neurons during a wide range of neuronal activities by recycling used vesicle membrane and protein components. Here we identify that Synaptojanin, a protein with a known role in synaptic vesicle endocytosis, is phosphorylated at S1029 in vivo by the Minibrain kinase. We further demonstrate that the phosphorylation status of Synaptojanin at S1029 differentially regulates its participation in the recycling of distinct synaptic vesicle pools. Our results reveal a new role for Synaptojanin in

Selective DNA Pooling for Determination of Linkage between a Molecular Marker and a Quantitative Trait Locus

PubMed Central

Darvasi, A.; Soller, M.

1994-01-01

Selective genotyping is a method to reduce costs in marker-quantitative trait locus (QTL) linkage determination by genotyping only those individuals with extreme, and hence most informative, quantitative trait values. The DNA pooling strategy (termed: ``selective DNA pooling'') takes this one step further by pooling DNA from the selected individuals at each of the two phenotypic extremes, and basing the test for linkage on marker allele frequencies as estimated from the pooled samples only. This can reduce genotyping costs of marker-QTL linkage determination by up to two orders of magnitude. Theoretical analysis of selective DNA pooling shows that for experiments involving backcross, F(2) and half-sib designs, the power of selective DNA pooling for detecting genes with large effect, can be the same as that obtained by individual selective genotyping. Power for detecting genes with small effect, however, was found to decrease strongly with increase in the technical error of estimating allele frequencies in the pooled samples. The effect of technical error, however, can be markedly reduced by replication of technical procedures. It is also shown that a proportion selected of 0.1 at each tail will be appropriate for a wide range of experimental conditions. PMID:7896115

Swimming pool cleaner poisoning

MedlinePlus

Swimming pool cleaner poisoning occurs when someone swallows this type of cleaner, touches it, or breathes in ... The harmful substances in swimming pool cleaner are: Bromine ... copper Chlorine Soda ash Sodium bicarbonate Various mild acids

Evaluation of the use of pooled serum, pooled muscle tissue fluid (meat juice) and pooled faeces for monitoring pig herds for Salmonella.

PubMed

Davies, R H; Heath, P J; Coxon, S M; Sayers, A R

2003-01-01

Monitoring for Salmonella in slaughter pigs is important to enable targeted control measures to be applied on problem farms and at the abattoir. The aim of this study was to determine whether pooled serum and meat juice could be used to identify finishing pig herds with a high prevalence of infection. Samples of meat juice, serum, caecal contents, carcase swabs and pooled faeces from pig pens were taken from 20 commercial pig finishing farms and comparisons were made between the results of Salmonella culture, individual ELISA tests on serum and meat juice and pooled samples of serum and meat juice. Salmonella was isolated from samples from 19 of 20 farms. None of the ELISA tests showed a statistically significant correlation with caecal carriage of Salmonella or contamination of carcases. Serum mean optical density (O.D.) from pools of five, 10 or 20 sera showed a significant correlation with the Salmonella status of farm pen faeces. All pooled serum O.D. and sample/positive control ratio results correlated significantly with the results of the conventional individual sample ELISA. There was a statistically significant correlation between the incidence of Salmonella in farm pen pooled faeces and the prevalence of Salmonella in caeca of slaughter pigs. The results show a generally poor correlation between serological and bacteriological results but pooled serum or meat juice samples could be used as a cheaper substitute for serological screening of farms for Salmonella than individual samples. The availability of a cheaper test should allow the costs of Salmonella monitoring of pig farms to be reduced or allow more regular testing to enhance the designation of farm Salmonella risk status.

Effect of medium-pressure UV-lamp treatment on disinfection by-products in chlorinated seawater swimming pool waters.

PubMed

Cheema, Waqas A; Manasfi, Tarek; Kaarsholm, Kamilla M S; Andersen, Henrik R; Boudenne, Jean-Luc

2017-12-01

Several brominated disinfection by-products (DBPs) are formed in chlorinated seawater pools, due to the high concentration of bromide in seawater. UV irradiation is increasingly employed in freshwater pools, because UV treatment photodegrades harmful chloramines. However, in freshwater pools it has been reported that post-UV chlorination promotes the formation of other DBPs. To date, UV-based processes have not been investigated for DBPs in seawater pools. In this study, the effects of UV, followed by chlorination, on the concentration of three groups of DBPs were investigated in laboratory batch experiments using a medium-pressure UV lamp. Chlorine consumption increased following post-UV chlorination, most likely because UV irradiation degraded organic matter in the pool samples to more chlorine-reactive organic matter. Haloacetic acid (HAA) concentrations decreased significantly, due to photo-degradation, but the concentrations of trihalomethanes (THMs) and haloacetonitriles (HANs) increased with post-UV chlorination. Bromine incorporation in HAAs was significantly higher in the control samples chlorinated without UV irradiation but decreased significantly with UV treatment. Bromine incorporation was promoted in THM and HAN after UV and chlorine treatment. Overall, the accumulated bromine incorporation level in DBPs remained essentially unchanged in comparison with the control samples. Toxicity estimates increased with single-dose UV and chlorination, mainly due to increased HAN concentrations. However, brominated HANs are known in the literature to degrade following further UV treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

STS-37 Mission Specialist (MS) Jerome Apt floats in raft in JSC's WETF pool

NASA Technical Reports Server (NTRS)

1990-01-01

STS-37 Mission Specialist (MS) Jerome Apt, wearing launch and entry suit (LES) and launch and entry helmet (LEH), propels his one-person life raft by splashing water during emergency egress exercise in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool. Apt, floating in the life raft, was simulating the steps involved in emergency egress from a Space Shuttle. The WETF's 25-ft pool served as a simulated ocean into which a parachute landing might be made.

Heterogeneity of soil carbon pools and fluxes in a channelized and a restored floodplain section (Thur River, Switzerland)

NASA Astrophysics Data System (ADS)

Samaritani, E.; Shrestha, J.; Fournier, B.; Frossard, E.; Gillet, F.; Guenat, C.; Niklaus, P. A.; Pasquale, N.; Tockner, K.; Mitchell, E. A. D.; Luster, J.

2011-06-01

Due to their spatial complexity and dynamic nature, floodplains provide a wide range of ecosystem functions. However, because of flow regulation, many riverine floodplains have lost their characteristic heterogeneity. Restoration of floodplain habitats and the rehabilitation of key ecosystem functions, many of them linked to organic carbon (C) dynamics in riparian soils, has therefore become a major goal of environmental policy. The fundamental understanding of the factors that drive the processes involved in C cycling in heterogeneous and dynamic systems such as floodplains is however only fragmentary. We quantified soil organic C pools (microbial C and water extractable organic C) and fluxes (soil respiration and net methane production) in functional process zones of adjacent channelized and widened sections of the Thur River, NE Switzerland, on a seasonal basis. The objective was to assess how spatial heterogeneity and temporal variability of these pools and fluxes relate to physicochemical soil properties on one hand, and to soil environmental conditions and flood disturbance on the other hand. Overall, factors related to seasonality and flooding (temperature, water content, organic matter input) affected soil C dynamics more than soil properties did. Coarse-textured soils on gravel bars in the restored section were characterized by low base-levels of organic C pools due to low TOC contents. However, frequent disturbance by flood pulses led to high heterogeneity with temporarily and locally increased C pools and soil respiration. By contrast, in stable riparian forests, the finer texture of the soils and corresponding higher TOC contents and water retention capacity led to high base-levels of C pools. Spatial heterogeneity was low, but major floods and seasonal differences in temperature had additional impacts on both pools and fluxes. Soil properties and base levels of C pools in the dam foreland of the channelized section were similar to the gravel bars of

Heterogeneity of soil carbon pools and fluxes in a channelized and a restored floodplain section (Thur River, Switzerland)

NASA Astrophysics Data System (ADS)

Samaritani, E.; Shrestha, J.; Fournier, B.; Frossard, E.; Gillet, F.; Guenat, C.; Niklaus, P. A.; Tockner, K.; Mitchell, E. A. D.; Luster, J.

2011-01-01

Due to their spatial complexity and dynamic nature, floodplains provide a wide range of ecosystem functions. However, because of flow regulation, many riverine floodplains have lost their characteristic heterogeneity. Restoration of floodplain habitats and the rehabilitation of key ecosystem functions has therefore become a major goal of environmental policy. Many important ecosystem functions are linked to organic carbon (C) dynamics in riparian soils. The fundamental understanding of the factors that drive the processes involved in C cycling in heterogeneous and dynamic systems such as floodplains is however only fragmentary. We quantified soil organic C pools (microbial C and water extractable organic C) and fluxes (soil respiration and net methane production) in functional process zones of adjacent channelized and widened sections of the Thur River, NE Switzerland, on a seasonal basis. The objective was to assess how spatial heterogeneity and temporal variability of these pools and fluxes relate to physicochemical soil properties on one hand, and to soil environmental conditions and flood disturbance on the other hand. Overall, factors related to seasonality and flooding (temperature, water content, organic matter input) affected soil C dynamics more than soil properties did. Coarse-textured soils on gravel bars in the restored section were characterized by low base-levels of organic C pools due to low TOC contents. However, frequent disturbance by flood pulses led to high heterogeneity with temporarily and locally increased pools and soil respiration. By contrast, in stable riparian forests, the finer texture of the soils and corresponding higher TOC contents and water retention capacity led to high base-levels of C pools. Spatial heterogeneity was low, but major floods and seasonal differences in temperature had additional impacts on both pools and fluxes. Soil properties and base levels of C pools in the dam foreland of the channelized section were similar

How to Stay Afloat in the Academic Library Job Pool

ERIC Educational Resources Information Center

Neely, Teresa Y., Ed.

2011-01-01

There's never been a more challenging time to find a position as an academic librarian, especially for those who have recently completed their library education. Whether job-hunters are jumping into the job pool for the very first time, or back in the water after a dry spell, Neely and her crack team of expert contributors have the information…

Increasing Storm Water Capture for Water Supply using Forecast Informed Reservoir Operations (FIRO) in Orange County, California

NASA Astrophysics Data System (ADS)

Hutchinson, A.; Woodside, G.; Ralph, F. M.

2017-12-01

Stormwater represents a significant source of water used by the Orange County Water District (OCWD) to recharge the Orange County groundwater basin. Over the last 20 years, OCWD has captured and recharged an average of 50,000 acre-feet per year (afy) of stormwater. Much of this recharge is made possible by the capture of stormwater in the Prado Dam Conservation Pool. OCWD has and continues to work closely with the US Army Corps of Engineers (USACE) to manage the conservation pool and to increase the amount of water that can be temporarily impounded in the conservation pool. Currently, the Conservation Pool is allowed to rise to elevation 498 ft msl (approx. 10,000 af of storage) during the storm season and to 505 ft msl (approx. 20,000 af of storage) during the non-storm season. OCWD has been working with the USACE on a Feasibility Study to permanently allow for storage of stormwater up to elevation 505 msl year-round. Even though increasing the Conservation Pool will increase the amount of stormwater captured, the weather forecasting used to manage the conservation pool can be improved in order to minimize lost opportunities to capture water or unnecessary releases of water to the ocean. To increase the efficiency of stormwater capture, OCWD is partnering with the Center for Western Weather and Water Extremes (http://cw3e.ucsd.edu/) to study the viability of using Forecast-Informed Reservoir Operations (FIRO) at Prado Dam. FIRO represents the next generation of operating water reservoirs using the best available technology. Moreover, given the importance of atmospheric river (AR) storms on water supplies in California, FIRO represents a methodology to take advantage of our increasing understanding of AR storms which are infrequent but provide a large percentage of total precipitation.

Epistasis in intra- and inter-gene pool crosses of the common bean.

PubMed

Borel, J C; Ramalho, M A P; Abreu, A F B

2016-02-26

Epistasis has been shown to have an important role in the genetic control of several quantitative traits in the common bean. This study aimed to investigate the occurrence of epistasis in intra- and inter-pool gene crosses of the common bean. Four elite lines adapted to Brazilian conditions were used as parents, two from the Andean gene pool (ESAL 686; BRS Radiante) and two from the Mesoamerican gene pool (BRSMG Majestoso; BRS Valente). Four F2 populations were obtained: "A" (ESAL 686 x BRS Radiante), "B" (BRSMG Majestoso x BRS Valente), "C" (BRS Radiante x BRSMG Majestoso), and "D" (BRS Valente x ESAL 686). A random sample of F2 plants from each population was backcrossed to parents and F1 individuals, according to the triple test cross. Three types of progenies from each population were evaluated in contiguous trials. Seed yield and 100-seed weight were evaluated. Dominance genetic variance was predominant in most cases. However, the estimates of genetic variance may be biased by the occurrence of linkage disequilibrium and epistasis. Epistasis was detected for both traits; however, the occurrence differed among the populations and between the two traits. The results of this study reinforce the hypothesis that epistasis is present in the genetic control of traits in the common bean and suggest that the phenomenon is more frequent in inter-gene pool crosses than in intra-gene pool crosses.

Experimental Measurements of the Water Evaporation Rate of a Physical Model

NASA Astrophysics Data System (ADS)

Turza, Róbert; Füri, Belo B.

2017-03-01

As the number of indoor swimming pools and wellness centers are currently growing, it is necessary to concentrate on the parameters of indoor environments. These parameters are necessary for the design of the HVAC systems that operate these premises. In indoor swimming-pool facilities, the energy demand is large due to ventilation losses from exhaust air. Since water evaporates from a pool's surface, exhaust air has a high water content and specific enthalpy. In this paper the results of the water evaporation rate measured from swimming pool surfaces at higher thermal water temperatures are described.

Tidal Pools--Miniature Oceans

ERIC Educational Resources Information Center

Plake, Linda Perry

1977-01-01

A comprehensive discussion of the biological activity in tidal pools is provided. The importance of environmental factors such as oxygen supply, temperature, salinity, and light is detailed. Plants and animals that might be found in a tidal pool are identified and described. (BT)

Pooled Genome-Wide Analysis to Identify Novel Risk Loci for Pediatric Allergic Asthma

PubMed Central

Ricci, Giampaolo; Astolfi, Annalisa; Remondini, Daniel; Cipriani, Francesca; Formica, Serena; Dondi, Arianna; Pession, Andrea

2011-01-01

Background Genome-wide association studies of pooled DNA samples were shown to be a valuable tool to identify candidate SNPs associated to a phenotype. No such study was up to now applied to childhood allergic asthma, even if the very high complexity of asthma genetics is an appropriate field to explore the potential of pooled GWAS approach. Methodology/Principal Findings We performed a pooled GWAS and individual genotyping in 269 children with allergic respiratory diseases comparing allergic children with and without asthma. We used a modular approach to identify the most significant loci associated with asthma by combining silhouette statistics and physical distance method with cluster-adapted thresholding. We found 97% concordance between pooled GWAS and individual genotyping, with 36 out of 37 top-scoring SNPs significant at individual genotyping level. The most significant SNP is located inside the coding sequence of C5, an already identified asthma susceptibility gene, while the other loci regulate functions that are relevant to bronchial physiopathology, as immune- or inflammation-mediated mechanisms and airway smooth muscle contraction. Integration with gene expression data showed that almost half of the putative susceptibility genes are differentially expressed in experimental asthma mouse models. Conclusion/Significance Combined silhouette statistics and cluster-adapted physical distance threshold analysis of pooled GWAS data is an efficient method to identify candidate SNP associated to asthma development in an allergic pediatric population. PMID:21359210

16 CFR Appendix J2 to Part 305 - Pool Heaters-Oil

Code of Federal Regulations, 2013 CFR

2013-01-01

... DISCLOSURES REGARDING ENERGY CONSUMPTION AND WATER USE OF CERTAIN HOME APPLIANCES AND OTHER PRODUCTS REQUIRED UNDER THE ENERGY POLICY AND CONSERVATION ACT (âAPPLIANCE LABELING RULEâ) Pt. 305, App. J2 Appendix J2 to Part 305—Pool Heaters—Oil Range Information Manufacturer's rated heating capacities Range of Thermal...

16 CFR Appendix J1 to Part 305 - Pool Heaters-Gas

Code of Federal Regulations, 2012 CFR

2012-01-01

... DISCLOSURES REGARDING ENERGY CONSUMPTION AND WATER USE OF CERTAIN HOME APPLIANCES AND OTHER PRODUCTS REQUIRED UNDER THE ENERGY POLICY AND CONSERVATION ACT (âAPPLIANCE LABELING RULEâ) Pt. 305, App. J1 Appendix J1 to Part 305—Pool Heaters—Gas Range Information Manufacturer's rated heating capacity Range of Thermal...

16 CFR Appendix J2 to Part 305 - Pool Heaters-Oil

Code of Federal Regulations, 2012 CFR

2012-01-01

... DISCLOSURES REGARDING ENERGY CONSUMPTION AND WATER USE OF CERTAIN HOME APPLIANCES AND OTHER PRODUCTS REQUIRED UNDER THE ENERGY POLICY AND CONSERVATION ACT (âAPPLIANCE LABELING RULEâ) Pt. 305, App. J2 Appendix J2 to Part 305—Pool Heaters—Oil Range Information Manufacturer's rated heating capacities Range of Thermal...

16 CFR Appendix J2 to Part 305 - Pool Heaters-Oil

Code of Federal Regulations, 2010 CFR

2010-01-01

... DISCLOSURES REGARDING ENERGY CONSUMPTION AND WATER USE OF CERTAIN HOME APPLIANCES AND OTHER PRODUCTS REQUIRED UNDER THE ENERGY POLICY AND CONSERVATION ACT (âAPPLIANCE LABELING RULEâ) Pt. 305, App. J2 Appendix J2 to Part 305—Pool Heaters—Oil Range Information Manufacturer's rated heating capacities Range of Thermal...

16 CFR Appendix J1 to Part 305 - Pool Heaters-Gas

Code of Federal Regulations, 2013 CFR

2013-01-01

... DISCLOSURES REGARDING ENERGY CONSUMPTION AND WATER USE OF CERTAIN HOME APPLIANCES AND OTHER PRODUCTS REQUIRED UNDER THE ENERGY POLICY AND CONSERVATION ACT (âAPPLIANCE LABELING RULEâ) Pt. 305, App. J1 Appendix J1 to Part 305—Pool Heaters—Gas Range Information Manufacturer's rated heating capacity Range of Thermal...

16 CFR Appendix J2 to Part 305 - Pool Heaters-Oil

Code of Federal Regulations, 2011 CFR

2011-01-01

... DISCLOSURES REGARDING ENERGY CONSUMPTION AND WATER USE OF CERTAIN HOME APPLIANCES AND OTHER PRODUCTS REQUIRED UNDER THE ENERGY POLICY AND CONSERVATION ACT (âAPPLIANCE LABELING RULEâ) Pt. 305, App. J2 Appendix J2 to Part 305—Pool Heaters—Oil Range Information Manufacturer's rated heating capacities Range of Thermal...

Grazing impacts on infiltration rates at Vernal Pools in the Modoc Plateau

USDA-ARS?s Scientific Manuscript database

Vernal pools are depressions of land that are seasonally inundated with water. They host rare and endemic plant and animal species and are sensitive to livestock grazing management and climate change impacts on hydrology and vegetation. Climate change forecasts predicting a hotter, drier climate sug...

Process, policy, and implementation of pool-wide drawdowns on the Upper Mississippi River: a promising approach for ecological restoration of large impounded rivers

USGS Publications Warehouse

Kenow, Kevin P.; Gretchen Benjamin,; Tim Schlagenhaft,; Ruth Nissen,; Mary Stefanski,; Gary Wege,; Scott A. Jutila,; Newton, Teresa J.

2016-01-01

The Upper Mississippi River (UMR) has been developed and subsequently managed for commercial navigation by the U.S. Army Corps of Engineers (USACE). The navigation pools created by a series of lock and dams initially provided a complex of aquatic habitats that supported a variety of fish and wildlife. However, biological productivity declined as the pools aged. The River Resources Forum, an advisory body to the St. Paul District of the USACE, established a multiagency Water Level Management Task Force (WLMTF) to evaluate the potential of water level management to improve ecological function and restore the distribution and abundance of fish and wildlife habitat. The WLMTF identified several water level management options and concluded that summer growing season drawdowns at the pool scale offered the greatest potential to provide habitat benefits over a large area. Here we summarize the process followed to plan and implement pool-wide drawdowns on the UMR, including involvement of stakeholders in decision making, addressing requirements to modify reservoir operating plans, development and evaluation of drawdown alternatives, pool selection, establishment of a monitoring plan, interagency coordination, and a public information campaign. Three pool-wide drawdowns were implemented within the St. Paul District and deemed successful in providing ecological benefits without adversely affecting commercial navigation and recreational use of the pools. Insights are provided based on more than 17 years of experience in planning and implementing drawdowns on the UMR. 

Rank-based pooling for deep convolutional neural networks.

PubMed

Shi, Zenglin; Ye, Yangdong; Wu, Yunpeng

2016-11-01

Pooling is a key mechanism in deep convolutional neural networks (CNNs) which helps to achieve translation invariance. Numerous studies, both empirically and theoretically, show that pooling consistently boosts the performance of the CNNs. The conventional pooling methods are operated on activation values. In this work, we alternatively propose rank-based pooling. It is derived from the observations that ranking list is invariant under changes of activation values in a pooling region, and thus rank-based pooling operation may achieve more robust performance. In addition, the reasonable usage of rank can avoid the scale problems encountered by value-based methods. The novel pooling mechanism can be regarded as an instance of weighted pooling where a weighted sum of activations is used to generate the pooling output. This pooling mechanism can also be realized as rank-based average pooling (RAP), rank-based weighted pooling (RWP) and rank-based stochastic pooling (RSP) according to different weighting strategies. As another major contribution, we present a novel criterion to analyze the discriminant ability of various pooling methods, which is heavily under-researched in machine learning and computer vision community. Experimental results on several image benchmarks show that rank-based pooling outperforms the existing pooling methods in classification performance. We further demonstrate better performance on CIFAR datasets by integrating RSP into Network-in-Network. Copyright © 2016 Elsevier Ltd. All rights reserved.

Antioxidant pool in beer and kinetics of EPR spin-trapping.

PubMed

Kocherginsky, Nikolai M; Kostetski, Yuri Yu; Smirnov, Alex I

2005-08-24

The kinetics of spin-trap adduct formation in beer oxidation exhibits an induction period if the reaction is carried out at elevated temperatures and in the presence of air. This lag period lasts until the endogenous antioxidants are almost completely depleted, and its duration is used as an indicator of the flavor stability and shelf life of beer. This paper demonstrates that the total kinetics of the process can be characterized by three parameters-the lag period, the rate of spin-trap adduct formation, and, finally, the steady-state spin-adduct concentration. A steady-state chain reaction mechanism is described, and quantitative estimates of the main kinetic parameters such as the initiation rate, antioxidant pool, effective content of organic molecules participating in the chain reactions, and the rate constant of the 1-hydroxyethyl radical EtOH(*) spin-adduct disappearance are given. An additional new dimensionless parameter is suggested to characterize the antioxidant pool-the product of the lag time and the rate of spin-trap radical formation immediately after the lag time, normalized by the steady-state concentration of the adducts. The results of spin-tapping EPR experiments are compared with the nitroxide reduction kinetics measured in the same beer samples. It is shown that although the kinetics of nitroxide reduction in beer can be used to evaluate the reducing power of beer, the latter parameter does not correlate with the antioxidant pool. The relationship of free radical processes, antioxidant pool, reducing power, and beer staling is discussed.

Bacteriological analysis of indoor and outdoor water parks in Wisconsin.

PubMed

Davis, Tracynda L; Standridge, Jon H; Degnan, Alan J

2009-09-01

Water parks are a rapidly growing element of the United States tourist industry. To reduce incidence of abrasion and impact injuries in such parks, designers are searching for padding materials that can withstand the harsh oxidative environments of chlorinated water. Although padded features help reduce physical injuries, they may also compromise the microbiological safety of water attractions. This study describes bacteriological testing performed on 31 different pad materials, play features and pools from 10 Wisconsin water parks. Materials and surrounding pool waters were sampled and tested quantitatively for total coliforms, Escherichia coli, E. coli 0157:H7, enterococci, staphylococci, heterotrophic bacteria, and Pseudomonas aeruginosa, using standard methods. Each location was sampled during three visits, and results were averaged. Pool waters were within acceptable levels of target organisms and disinfectant residuals, but target organisms were found on water features, even those submerged in chlorinated water. Bacteria were detected more frequently in pools using pad materials compared with pools without. These findings provide data that will help the public health community understand the relations between designs, materials and maintenance of water features. Additionally, the information will help state regulators and owner/operators develop guidelines to improve public health and safety at water parks.

47 CFR 13.215 - Question pools.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Question pools. 13.215 Section 13.215 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMERCIAL RADIO OPERATORS Examination System § 13.215 Question pools. The question pool for each written examination element will be composed of questions...

Self-Assembled Nanomicelles as MRI Blood-Pool Contrast Agent.

PubMed

Babič, Andrej; Vorobiev, Vassily; Xayaphoummine, Céline; Lapicorey, Gaëlle; Chauvin, Anne-Sophie; Helm, Lothar; Allémann, Eric

2018-01-26

Gadolinium-loaded nanomicelles show promise as future magnetic resonance imaging (MRI) contrast agents (CAs). Their increased size and high gadolinium (Gd) loading gives them an edge in proton relaxivity over smaller molecular Gd-complexes. Their size and stealth properties are fundamental for their long blood residence time, opening the possibility for use as blood-pool contrast agents. Using l-tyrosine as a three-functional scaffold we synthesized a nanostructure building block 8. The double C18 aliphatic chain on one side, Gd-1,4,7,10-tetraazacyclododecane-1-4-7-triacetic acid (Gd-DO3A) with access to bulk water in the center and 2 kDa PEG on the hydrophilic side gave the amphiphilic properties required for the core-shell nanomicellar architecture. The self-assembly into Gd-loaded monodispersed 10-20 nm nanomicelles occurred spontaneously in water. These nanomicelles (Tyr-MRI) display very high relaxivity at 29 mm -1  s -1 at low field strength and low cytotoxicity. Good contrast enhancement of the blood vessels and the heart together with prolonged circulation time in vivo, makes Tyr-MRI an excellent candidate for a new supramolecular blood-pool MRI CA. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Self-formed waterfall plunge pools in homogeneous rock

NASA Astrophysics Data System (ADS)

Scheingross, Joel S.; Lo, Daniel Y.; Lamb, Michael P.

2017-01-01

Waterfalls are ubiquitous, and their upstream propagation can set the pace of landscape evolution, yet no experimental studies have examined waterfall plunge pool erosion in homogeneous rock. We performed laboratory experiments, using synthetic foam as a bedrock simulant, to produce self-formed waterfall plunge pools via particle impact abrasion. Plunge pool vertical incision exceeded lateral erosion by approximately tenfold until pools deepened to the point that the supplied sediment could not be evacuated and deposition armored the pool bedrock floor. Lateral erosion of plunge pool sidewalls continued after sediment deposition, but primarily at the downstream pool wall, which might lead to undermining of the plunge pool lip, sediment evacuation, and continued vertical pool floor incision in natural streams. Undercutting of the upstream pool wall was absent, and our results suggest that vertical drilling of successive plunge pools is a more efficient waterfall retreat mechanism than the classic model of headwall undercutting and collapse in homogeneous rock.

47 CFR 97.523 - Question pools.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Question pools. 97.523 Section 97.523 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO... question pool for each written examination element. Each question pool must contain at least 10 times the...

Organic and inorganic nitrogen pools in talus fields and subtalus water, Green Lakes Valley, Colorado front range

USGS Publications Warehouse

Williams, M.W.; Davinroy, T.; Brooks, P.D.

1997-01-01

Organic and inorganic pools of nitrogen (N) were measured in talus fines or 'soils' and subtalus water during the summer of 1995 in the alpine Green Lakes Valley catchment of the Colorado Front Range. Nineteen talus soil samples were divided into four classes: subtalus dry, subtalus wet, surface vegetated and surface bare. The size of the individual talus soil patches ranged from 0.5 to 12.0 m2 in area, with bulk density ranging from 0-98 to 1-71 kg m-3 and soil texture ranging from sandy gravel in the subsurface talus to a loam in the vegetated surface. All samples contained KCl-extractable NH4+ and NO3-, organic N and carbon (C), and 17 of 19 samples contained microbial biomass. The mean subtalus values for KCl-extractable NH4-, of 3.2 mg N kg-1, and NO3-, of 1.0 mg N kg-1, were comparable with developed alpine soils on Niwot Ridge. Average microbial biomass in subtalus soils of 5.4 mg N kg-1 and total N of 1000 mg N kg-1 were about an order of magnitude lower than alpine tundra soils, reflecting the reduced amount of vegetation in talus areas. However, these measurements in surface-vegetated patches of talus were comparable with the well-developed soils on Niwot Ridge. These measurements in talus of microbial biomass, total N and KCl-extractable NH4+ and NO3-, show that there is sufficient biotically conditioned 'soil' within talus fields to influence the solute content of interstitial waters. Mean NO3- concentrations of 20 ??eq 1-1 from 29 samples of subtalus water were significantly higher than the 6-7 ??eq 1-1 in snow, while NH4+ concentrations in subtalus water of 0??7 ??eq 1-1 was significantly lower than in snow at 5??2 ??eq 1-1 (p = 0??001). Nitrate concentrations in subtalus water were significantly (p < 0??0001) correlated with concentrations of geochemica??l weathering products such as Ca2+ (r2 = 0??84) and silica (r2 = 0??49). The correlation of NO3- in subtalus water with geochemical weathering products suggests that NO3- concentrations in subtalus

Velocity, water-quality, and bathymetric surveys of the Grays Landing and Maxwell Navigation Pools, and Selected Tributaries to the Monongahela River, Pennsylvania, 2010–11

USGS Publications Warehouse

Hoffman, Scott A.; Roland, Mark A.; Schalk, Luther F.; Fulton, John W.

2013-01-01

The U.S. Geological Survey (USGS) conducted velocity, water-quality, and bathymetric surveys from spring 2010 to summer 2011 in the Grays Landing and Maxwell navigation pools of the Monongahela River, Pennsylvania, and selected tributaries in response to elevated levels of total dissolved solids (TDS) recorded in early September 2009. Velocity data were collected using an Acoustic Doppler Current Profiler. Water-quality surveys included the in-situ collection of specific-conductance, water-temperature, and turbidity data using a water-quality sonde. Additionally, discrete water samples were collected and analyzed for TDS, chloride, and sulfate. Bathymetric data were collected using an echo sounder, and the shoreline was delineated using a laser range finder and electronic compass. The data were geo-referenced using a differential global positioning system and navigational software. Horizontal (x, y) coordinates were referenced to the North American Datum of 1983. Depth (z) elevations were referenced to the North American Vertical Datum of 1988. The data are provided in electronic format (appendix 1) and may be downloaded and can be used in a geographic information system for cartographic display and data analysis.

Experimental investigation of time and repeated cycles in nucleate pool boiling of alumina/water nanofluid on polished and machined surfaces

NASA Astrophysics Data System (ADS)

Rajabzadeh Dareh, F.; Haghshenasfard, M.; Nasr Esfahany, M.; Salimi Jazi, H.

2018-06-01

Pool boiling heat transfer of pure water and nanofluids on a copper block has been studied experimentally. Nanofluids with various concentrations of 0.0025, 0.005 and 0.01 vol.% are employed and two simple surfaces (polished and machined copper surface) are used as the heating surfaces. The results indicated that the critical heat flux (CHF) in boiling of fluids on the polished surface is 7% higher than CHF on the machined surface. In the case of machined surface, the heat transfer coefficient (HTC) of 0.01 vol.% nanofluid is about 37% higher than HTC of base fluid, while in the polished surface the average HTC of 0.01% nanofluid is about 19% lower than HTC of the pure water. The results also showed that the boiling time and boiling cycles on the polished surface changes the heat transfer performance. By increasing the boiling time from 5 to 10 min, the roughness enhances about 150%, but by increasing the boiling time to 15 min, the roughness enhancement is only 8%.

Eco-engineered rock pools: a concrete solution to biodiversity loss and urban sprawl in the marine environment

NASA Astrophysics Data System (ADS)

Firth, Louise B.; Browne, Keith A.; Knights, Antony M.; Hawkins, Stephen J.; Nash, Róisín

2016-09-01

In coastal habitats artificial structures typically support lower biodiversity and can support greater numbers of non-native and opportunistic species than natural rocky reefs. Eco-engineering experiments are typically trialed to succeed; but arguably as much is learnt from failure than from success. Our goal was to trial a generic, cost effective, eco-engineering technique that could be incorporated into rock armouring anywhere in the world. Artificial rock pools were created from manipulated concrete between boulders on the exposed and sheltered sides of a causeway. Experimental treatments were installed in locations where they were expected to fail and compared to controls installed in locations in which they were expected to succeed. Control pools were created lower on the structure where they were immersed on every tidal cycle; experimental pools were created above mean high water spring tide which were only immersed on spring tides. We hypothesised that lower and exposed pools would support significantly higher taxon and functional diversity than upper and sheltered pools. The concrete pools survived the severe winter storms of 2013/14. After 12 months, non-destructive sampling revealed significantly higher mean taxon and functional richness in lower pools than upper pools on the exposed side only. After 24 months the sheltered pools had become inundated with sediments, thus failing to function as rock pools as intended. Destructive sampling on the exposed side revealed significantly higher mean functional richness in lower than upper pools. However, a surprisingly high number of taxa colonised the upper pools leading to no significant difference in mean taxon richness among shore heights. A high number of rare taxa in the lower pools led to total taxon richness being almost twice that of upper pools. These findings highlight that even when expected to fail concrete pools supported diverse assemblages, thus representing an affordable, replicable means of

Deceleration of free aqueous droplets skirting across the surface of a pool of the same fluid

NASA Astrophysics Data System (ADS)

Hale, Jacob; Akers, Caleb

2014-11-01

The non-coalescence of a free droplet atop a pool of the same fluid can be greatly enhanced when the drop has an initial horizontal velocity relative to the pool surface. The glancing impact and viscous interaction between the droplet and the pool impart a significant rotation to the droplet causing it to roll and thus entraining air between the two fluids. The translational speed of such a droplet is shown to decrease exponentially in time but with a time constant that increases linearly in time. This complex deceleration of the drop is in part due to the drop's rotational deceleration, visualized with suspended, neutrally buoyant microbeads. The observed motion is described in terms of viscous dissipation of the rotating drop and a viscous shear force between the droplet and bath.

Evaluating Mineral-Associated Soil Organic Matter Pools as Indicators of Forest Harvesting Disturbance

NASA Astrophysics Data System (ADS)

Kellman, L. M.; Gabriel, C. E.

2015-12-01

Soil organic matter (SOM) in northern forest soils is associated with a suite of minerals that can confer SOM stability, resulting in the potential for long-term storage of carbon. Increasingly, evidence is suggesting that SOM in certain mineral phases is dynamic and vulnerable to soil disturbance. The objective of this research was to investigate changes in a suite of mineral-associated pools of SOM through depth in a temperate forest soil to determine which mineral-associated carbon pools are most sensitive to forest harvesting disturbance. Sequential selective dissolutions representing increasingly stable SOM pools (soluble minerals (deionized water); humus-mineral complexes (Na-pyrophosphate); poorly crystalline minerals (HCl hydroxylamine); and crystalline secondary minerals (Na-dithionite + HCl)) of mineral soils through depth to 50 cm were carried out in podzolic soils sampled from temperate red spruce forests of contrasting stand age in Nova Scotia, Canada. Results of this analysis point to a loss of carbon from SOM within the B-horizon of the most recently harvested site from the pyrophosphate-extracted humus mineral complexed SOM, suggesting that it is this exchangeable pool that appears to be destabilized following clearcut harvesting at these study sites. This suggests that recovery from this landuse disturbance is dependent upon increasing storage of this SOM pool, and that mineral-associated pools, particularly pyrophosphate-extractable SOM, may be a useful indicator of changes to soil carbon storage following land use change.

STS-53 MS Voss, in EMU, in lowered into JSC's WETF pool for EVA simulation

NASA Image and Video Library

1992-08-07

S92-43335 (28 July 1992) --- STS-53 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist James S. Voss, wearing extravehicular mobility unit (EMU), is lowered into JSC?s Weightless Environment Training Facility (WETF) Bldg. 29 pool. Voss waves to his daughter standing on the poolside as the platform he is positioned in is submerged in the pool. Technicians on the poolside and scuba equipped divers in the water monitor activities. Once underwater, Voss will participate in contingency extravehicular activity (EVA) procedures.

STS-45 MS Foale in EMU is lowered into JSC's WETF pool for underwater test

NASA Image and Video Library

1991-02-26

S91-30197 (1 March 1991) --- A wider shot of astronaut C. Michael Foale, mission specialist, standing on a platform which is part of a system that will lower him into a 25-ft. deep pool. Foale used the pool in the weightless environment training facility (WET-F) to rehearse a contingency extravehicular activity (EVA). Two SCUBA-equipped swimmers assist. Astronauts wear pressurized spacesuits configured for achieving a neutrally buoyant condition in the water to simulate both planned and contingency EVAs.

13 CFR 120.1705 - Pool formation requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... requirements. SBA may adjust the Pool characteristics periodically based on program experience and market... a Pool involving a Pool Loan it does not own, it must purchase the Loan Interest it proposes to pool... purchase the Loan Interest and take it into inventory or settle the purchase of the Loan Interest through...

Method of measuring a liquid pool volume

DOEpatents

Garcia, Gabe V.; Carlson, Nancy M.; Donaldson, Alan D.

1991-01-01

A method of measuring a molten metal liquid pool volume and in particular molten titanium liquid pools, including the steps of (a) generating an ultrasonic wave at the surface of the molten metal liquid pool, (b) shining a light on the surface of a molten metal liquid pool, (c) detecting a change in the frequency of light, (d) detecting an ultrasonic wave echo at the surface of the molten metal liquid pool, and (e) computing the volume of the molten metal liquid.

1968 Listing of Swimming Pool Equipment.

ERIC Educational Resources Information Center

National Sanitation Foundation, Ann Arbor, MI. Testing Lab.

An up-to-date listing of swimming pool equipment including--(1) companies authorized to display the National Sanitation Foundation seal of approval, (2) equipment listed as meeting NSF swimming pool equipment standards relating to diatomite type filters, (3) equipment listed as meeting NSF swimming pool equipment standard relating to sand type…

Tradeoffs in Risk and Return of Financial Hedging Solutions to Mitigate Drought-Related Financial Risks for Water Utilities

NASA Astrophysics Data System (ADS)

Baum, R.; Characklis, G. W.

2016-12-01

Financial hedging solutions have been examined as tools for effectively mitigating water scarcity related financial risks for water utilities, and have become more prevalent as conservation (resulting in reduced revenues) and water transfers (resulting in increased costs) play larger roles in drought management. Individualized financial contracts (i.e. designed for a single utility) provide evidence of the potential benefits of financial hedging. However, individualized contracts require substantial time and information to develop, limiting their widespread implementation. More generalized contracts have also shown promise, and would allow the benefits of risk pooling to be more effectively realized, resulting in less expensive contracts. Risk pooling reduces the probability of an insurer making payouts that deviate significantly from the mean, but given that the financial risks of drought are spatially correlated amongst utilities, these more extreme "fat tail" risks remain. Any group offering these hedging contracts, whether a third-party insurer or a "mutual" comprised of many utilities, will need to balance the costs (i.e. additional risk) and benefits (i.e. returns) of alternative approaches to managing the extreme risks (e.g. through insurance layers). The balance of these different approaches will vary depending on the risk pool being considered, including the number, size and exposure of the participating utilities. This work first establishes a baseline of the tradeoffs between risk and expected return in insuring against the financial risks of water scarcity without alternative hedging approaches for water utilities across all climate divisions of the United States. Then various scenarios are analyzed to provide insight into how to maximize returns for risk pooling portfolios at various risk levels through balancing different insurance layers and hedging approaches. This analysis will provide valuable information for designing optimal financial risk

Method of measuring a liquid pool volume

DOEpatents

Garcia, G.V.; Carlson, N.M.; Donaldson, A.D.

1991-03-19

A method of measuring a molten metal liquid pool volume and in particular molten titanium liquid pools is disclosed, including the steps of (a) generating an ultrasonic wave at the surface of the molten metal liquid pool, (b) shining a light on the surface of a molten metal liquid pool, (c) detecting a change in the frequency of light, (d) detecting an ultrasonic wave echo at the surface of the molten metal liquid pool, and (e) computing the volume of the molten metal liquid. 3 figures.

Sex differences on the competitive place task in the water maze: The influence of peripheral pool time on spatial navigation performance in rats.

PubMed

Devan, Bryan D; Tobin, Elizabeth L; Dunn, Emily N; Magalis, Christopher

2016-11-01

This study investigated sex differences on the competitive place version of the Morris water maze task to determine whether potential strategy differences would emerge during any phase of the study but in particular on the competitive place phase. Previous findings indicate that this version of the task is highly sensitive to measures that disrupt NMDA-dependent synaptic plasticity within the hippocampus during memory consolidation (McDonald et al., 2005). The present findings revealed significant sex differences during all phases of the study, including Phase I with standard place training to located a hidden platform/goal, Phase II mass training to a new place with the platform/goal relocated to the diagonally opposite quadrant and Phase III, competitive place probe test with the platform removed to measure spatial behaviour directed at either location. The findings showed no sex difference in escape latency and other standard performance measures during the first two phases, initial place acquisition and mass training to a new location. A very subtle male advantage in visiting both Old and New place locations during the third phase place competition test was observed, however, in the time spent swimming in the periphery of the pool, the pool wall (Zone C - outer third radial distance) was increased for females during all phases of the study, suggesting a general effect may have influenced place location search behaviour of the females. Increased peripheral pool time may represent a female preference for approaching the wall, a local cue. Alternatively, the possibility that increased peripheral swimming/thigmotaxis may represent hormonal influences interacting with strategic preferences were discussed, though no definitive conclusions about sex differences in cognitive-spatial performance or memory consolidation were inferred from the present findings. The findings suggest that mixed results reported in the literature by others may be due in part to an

13 CFR 120.1709 - Transfers of Pool Certificates.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 13 Business Credit and Assistance 1 2012-01-01 2012-01-01 false Transfers of Pool Certificates... Transfers of Pool Certificates. (a) Transfer of Pool Certificates. A Pool Certificate is transferable. A transfer of a Pool Certificate must comply with Article 8 of the Uniform Commercial Code of the State of...

13 CFR 120.1709 - Transfers of Pool Certificates.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Transfers of Pool Certificates... Transfers of Pool Certificates. (a) Transfer of Pool Certificates. A Pool Certificate is transferable. A transfer of a Pool Certificate must comply with Article 8 of the Uniform Commercial Code of the State of...

13 CFR 120.1709 - Transfers of Pool Certificates.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 13 Business Credit and Assistance 1 2014-01-01 2014-01-01 false Transfers of Pool Certificates... Transfers of Pool Certificates. (a) Transfer of Pool Certificates. A Pool Certificate is transferable. A transfer of a Pool Certificate must comply with Article 8 of the Uniform Commercial Code of the State of...

13 CFR 120.1709 - Transfers of Pool Certificates.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false Transfers of Pool Certificates... Transfers of Pool Certificates. (a) Transfer of Pool Certificates. A Pool Certificate is transferable. A transfer of a Pool Certificate must comply with Article 8 of the Uniform Commercial Code of the State of...

7 CFR 1006.7 - Pool plant.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Pool plant. 1006.7 Section 1006.7 Agriculture... Handling Definitions § 1006.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant specified...

7 CFR 1131.7 - Pool plant.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 9 2012-01-01 2012-01-01 false Pool plant. 1131.7 Section 1131.7 Agriculture... Handling Definitions § 1131.7 Pool plant. Pool Plant means a plant or unit of plants specified in paragraphs (a) through (e) of this section, but excluding a plant specified in paragraph (g) of this section...

7 CFR 1007.7 - Pool plant.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 9 2014-01-01 2013-01-01 true Pool plant. 1007.7 Section 1007.7 Agriculture... Handling Definitions § 1007.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant specified...

7 CFR 1006.7 - Pool plant.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 9 2012-01-01 2012-01-01 false Pool plant. 1006.7 Section 1006.7 Agriculture... Handling Definitions § 1006.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant specified...

7 CFR 1124.7 - Pool plant.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 9 2013-01-01 2013-01-01 false Pool plant. 1124.7 Section 1124.7 Agriculture... Regulating Handling Definitions § 1124.7 Pool plant. Pool plant means a plant, unit of plants, or a system of plants as specified in paragraphs (a) through (f) of this section, but excluding a plant specified in...

7 CFR 1124.7 - Pool plant.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 9 2011-01-01 2011-01-01 false Pool plant. 1124.7 Section 1124.7 Agriculture... Regulating Handling Definitions § 1124.7 Pool plant. Pool plant means a plant, unit of plants, or a system of plants as specified in paragraphs (a) through (f) of this section, but excluding a plant specified in...

7 CFR 1124.7 - Pool plant.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Pool plant. 1124.7 Section 1124.7 Agriculture... Regulating Handling Definitions § 1124.7 Pool plant. Pool plant means a plant, unit of plants, or a system of plants as specified in paragraphs (a) through (f) of this section, but excluding a plant specified in...

7 CFR 1007.7 - Pool plant.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Pool plant. 1007.7 Section 1007.7 Agriculture... Handling Definitions § 1007.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant specified...

7 CFR 1005.7 - Pool plant.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 9 2012-01-01 2012-01-01 false Pool plant. 1005.7 Section 1005.7 Agriculture... Handling Definitions § 1005.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant specified...

7 CFR 1007.7 - Pool plant.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 9 2013-01-01 2013-01-01 false Pool plant. 1007.7 Section 1007.7 Agriculture... Handling Definitions § 1007.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant specified...

7 CFR 1124.7 - Pool plant.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 9 2012-01-01 2012-01-01 false Pool plant. 1124.7 Section 1124.7 Agriculture... Regulating Handling Definitions § 1124.7 Pool plant. Pool plant means a plant, unit of plants, or a system of plants as specified in paragraphs (a) through (f) of this section, but excluding a plant specified in...

7 CFR 1126.7 - Pool plant.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 9 2012-01-01 2012-01-01 false Pool plant. 1126.7 Section 1126.7 Agriculture... Handling Definitions § 1126.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant specified...

7 CFR 1126.7 - Pool plant.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 9 2014-01-01 2013-01-01 true Pool plant. 1126.7 Section 1126.7 Agriculture... Handling Definitions § 1126.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant specified...

7 CFR 1005.7 - Pool plant.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 9 2014-01-01 2013-01-01 true Pool plant. 1005.7 Section 1005.7 Agriculture... Handling Definitions § 1005.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant specified...

7 CFR 1131.7 - Pool plant.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 9 2014-01-01 2013-01-01 true Pool plant. 1131.7 Section 1131.7 Agriculture... Handling Definitions § 1131.7 Pool plant. Pool Plant means a plant or unit of plants specified in paragraphs (a) through (e) of this section, but excluding a plant specified in paragraph (g) of this section...

7 CFR 1124.7 - Pool plant.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 9 2014-01-01 2013-01-01 true Pool plant. 1124.7 Section 1124.7 Agriculture... Regulating Handling Definitions § 1124.7 Pool plant. Pool plant means a plant, unit of plants, or a system of plants as specified in paragraphs (a) through (f) of this section, but excluding a plant specified in...

7 CFR 1006.7 - Pool plant.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 9 2011-01-01 2011-01-01 false Pool plant. 1006.7 Section 1006.7 Agriculture... Handling Definitions § 1006.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant specified...

7 CFR 1126.7 - Pool plant.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 9 2011-01-01 2011-01-01 false Pool plant. 1126.7 Section 1126.7 Agriculture... Handling Definitions § 1126.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant specified...

7 CFR 1006.7 - Pool plant.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 9 2014-01-01 2013-01-01 true Pool plant. 1006.7 Section 1006.7 Agriculture... Handling Definitions § 1006.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant specified...

7 CFR 1005.7 - Pool plant.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 9 2011-01-01 2011-01-01 false Pool plant. 1005.7 Section 1005.7 Agriculture... Handling Definitions § 1005.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant specified...

7 CFR 1005.7 - Pool plant.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 9 2013-01-01 2013-01-01 false Pool plant. 1005.7 Section 1005.7 Agriculture... Handling Definitions § 1005.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant specified...

7 CFR 1131.7 - Pool plant.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Pool plant. 1131.7 Section 1131.7 Agriculture... Handling Definitions § 1131.7 Pool plant. Pool Plant means a plant or unit of plants specified in paragraphs (a) through (e) of this section, but excluding a plant specified in paragraph (g) of this section...

7 CFR 1006.7 - Pool plant.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 9 2013-01-01 2013-01-01 false Pool plant. 1006.7 Section 1006.7 Agriculture... Handling Definitions § 1006.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant specified...

7 CFR 1126.7 - Pool plant.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 9 2013-01-01 2013-01-01 false Pool plant. 1126.7 Section 1126.7 Agriculture... Handling Definitions § 1126.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant specified...

7 CFR 1005.7 - Pool plant.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Pool plant. 1005.7 Section 1005.7 Agriculture... Handling Definitions § 1005.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant specified...

7 CFR 1131.7 - Pool plant.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 9 2013-01-01 2013-01-01 false Pool plant. 1131.7 Section 1131.7 Agriculture... Handling Definitions § 1131.7 Pool plant. Pool Plant means a plant or unit of plants specified in paragraphs (a) through (e) of this section, but excluding a plant specified in paragraph (g) of this section...

7 CFR 1007.7 - Pool plant.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 9 2012-01-01 2012-01-01 false Pool plant. 1007.7 Section 1007.7 Agriculture... Handling Definitions § 1007.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant specified...

7 CFR 1007.7 - Pool plant.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 9 2011-01-01 2011-01-01 false Pool plant. 1007.7 Section 1007.7 Agriculture... Handling Definitions § 1007.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant specified...

7 CFR 1126.7 - Pool plant.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Pool plant. 1126.7 Section 1126.7 Agriculture... Handling Definitions § 1126.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant specified...

7 CFR 1131.7 - Pool plant.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 9 2011-01-01 2011-01-01 false Pool plant. 1131.7 Section 1131.7 Agriculture... Handling Definitions § 1131.7 Pool plant. Pool Plant means a plant or unit of plants specified in paragraphs (a) through (e) of this section, but excluding a plant specified in paragraph (g) of this section...

Water immersion and its computer simulation as analogs of weightlessness

NASA Technical Reports Server (NTRS)

Leonard, J. I.

1982-01-01

Experimental studies and computer simulations of water immersion are summarized and discussed with regard to their utility as analogs of weightlessness. Emphasis is placed on describing and interpreting the renal, endocrine, fluid, and circulatory changes that take place during immersion. A mathematical model, based on concepts of fluid volume regulation, is shown to be well suited to simulate the dynamic responses to water immersion. Further, it is shown that such a model provides a means to study specific mechanisms and pathways involved in the immersion response. A number of hypotheses are evaluated with the model related to the effects of dehydration, venous pressure disturbances, the control of ADH, and changes in plasma-interstitial volume. By inference, it is suggested that most of the model's responses to water immersion are plausible predictions of the acute changes expected, but not yet measured, during space flight. One important prediction of the model is that previous attempts to measure a diuresis during space flight failed because astronauts may have been dehydrated and urine samples were pooled over 24-hour periods.

Indo-Pacific Warm Pool Area Expansion, Modoki Activity, and Tropical Cold-Point Tropopause Temperature Variations

PubMed Central

Xie, Fei; Li, Jianping; Tian, Wenshou; Li, Yanjie; Feng, Juan

2014-01-01

The tropical cold-point tropopause temperature (CPTT), a potentially important indicator of global climate change, is of particular importance for understanding changes in stratospheric water vapor levels. Since the 1980s, the tropical CPTT has shown not only interannual variations, but also a decreasing trend. However, the factors controlling the variations in the tropical CPTT since the 1980s remain elusive. The present study reveals that the continuous expansion of the area of the Indo-Pacific warm pool (IPWP) since the 1980s represents an increase in the total heat energy of the IPWP available to heat the tropospheric air, which is likely to expand as a result. This process lifts the tropical cold-point tropopause height (CPTH) and leads to the observed long-term cooling trend of the tropical CPTT. In addition, our analysis shows that Modoki activity is an important factor in modulating the interannual variations of the tropical CPTT through significant effects on overshooting convection. PMID:24686481

7 CFR 1030.7 - Pool plant.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 9 2014-01-01 2013-01-01 true Pool plant. 1030.7 Section 1030.7 Agriculture... Handling Definitions § 1030.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, but excluding a plant specified in paragraph (h) of...

7 CFR 1033.7 - Pool plant.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 9 2014-01-01 2013-01-01 true Pool plant. 1033.7 Section 1033.7 Agriculture... Handling Definitions § 1033.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, or a plant specified in paragraph (j) of this...

7 CFR 1032.7 - Pool plant.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 9 2011-01-01 2011-01-01 false Pool plant. 1032.7 Section 1032.7 Agriculture... Handling Definitions § 1032.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, or a plant specified in paragraph (i) of this...

7 CFR 1030.7 - Pool plant.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 9 2011-01-01 2011-01-01 false Pool plant. 1030.7 Section 1030.7 Agriculture... Handling Definitions § 1030.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, but excluding a plant specified in paragraph (h) of...

7 CFR 1033.7 - Pool plant.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 9 2013-01-01 2013-01-01 false Pool plant. 1033.7 Section 1033.7 Agriculture... Handling Definitions § 1033.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, or a plant specified in paragraph (j) of this...

7 CFR 1032.7 - Pool plant.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Pool plant. 1032.7 Section 1032.7 Agriculture... Handling Definitions § 1032.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, or a plant specified in paragraph (i) of this...

7 CFR 1033.7 - Pool plant.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Pool plant. 1033.7 Section 1033.7 Agriculture... Handling Definitions § 1033.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, or a plant specified in paragraph (j) of this...

7 CFR 1033.7 - Pool plant.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 9 2011-01-01 2011-01-01 false Pool plant. 1033.7 Section 1033.7 Agriculture... Handling Definitions § 1033.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, or a plant specified in paragraph (j) of this...

7 CFR 1001.7 - Pool plant.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 9 2011-01-01 2011-01-01 false Pool plant. 1001.7 Section 1001.7 Agriculture... Handling Definitions § 1001.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, but excluding a plant described in paragraph (h) of...

7 CFR 1030.7 - Pool plant.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 9 2012-01-01 2012-01-01 false Pool plant. 1030.7 Section 1030.7 Agriculture... Handling Definitions § 1030.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, but excluding a plant specified in paragraph (h) of...

7 CFR 1032.7 - Pool plant.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 9 2014-01-01 2013-01-01 true Pool plant. 1032.7 Section 1032.7 Agriculture... Handling Definitions § 1032.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, or a plant specified in paragraph (i) of this...

7 CFR 1001.7 - Pool plant.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 9 2012-01-01 2012-01-01 false Pool plant. 1001.7 Section 1001.7 Agriculture... Handling Definitions § 1001.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, but excluding a plant described in paragraph (h) of...

7 CFR 1030.7 - Pool plant.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 9 2013-01-01 2013-01-01 false Pool plant. 1030.7 Section 1030.7 Agriculture... Handling Definitions § 1030.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, but excluding a plant specified in paragraph (h) of...

7 CFR 1032.7 - Pool plant.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 9 2012-01-01 2012-01-01 false Pool plant. 1032.7 Section 1032.7 Agriculture... Handling Definitions § 1032.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, or a plant specified in paragraph (i) of this...

7 CFR 1033.7 - Pool plant.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 9 2012-01-01 2012-01-01 false Pool plant. 1033.7 Section 1033.7 Agriculture... Handling Definitions § 1033.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, or a plant specified in paragraph (j) of this...

7 CFR 1001.7 - Pool plant.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 9 2013-01-01 2013-01-01 false Pool plant. 1001.7 Section 1001.7 Agriculture... Handling Definitions § 1001.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, but excluding a plant described in paragraph (h) of...

7 CFR 1032.7 - Pool plant.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 9 2013-01-01 2013-01-01 false Pool plant. 1032.7 Section 1032.7 Agriculture... Handling Definitions § 1032.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, or a plant specified in paragraph (i) of this...

7 CFR 1001.7 - Pool plant.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Pool plant. 1001.7 Section 1001.7 Agriculture... Handling Definitions § 1001.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, but excluding a plant described in paragraph (h) of...

7 CFR 1001.7 - Pool plant.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 9 2014-01-01 2013-01-01 true Pool plant. 1001.7 Section 1001.7 Agriculture... Handling Definitions § 1001.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, but excluding a plant described in paragraph (h) of...

7 CFR 1030.7 - Pool plant.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Pool plant. 1030.7 Section 1030.7 Agriculture... Handling Definitions § 1030.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, but excluding a plant specified in paragraph (h) of...

The influence of arc plasma parameters on the form of a welding pool

NASA Astrophysics Data System (ADS)

Frolov, V. Ya.; Toropchin, A. I.

2015-07-01

The influence of the Marangoni force on the form of a welding pool has been considered. Results of computer simulation of the processes of welding arc generation with a non-consumable tungsten electrode in inert gas are shown. The experimental results are reported and comparatively analyzed. The calculations were carried out in a package of applied programs at various currents.

Post-Pool Raise Spillway Prototype Test for Chief Joseph Dam, Columbia River, Washington.

DTIC Science & Technology

1987-04-01

low as -5 and -10 ft of water would exist on the spillway crest under free-flow conditions with pool el 956.0 and 958.8, respectively. 5. Details of...magnitude and irregular frequency, varying from 0.2 to 3.1 ft of water at frequencies of I to 32 Hz. The lowest mean and low pressures recorded were -6.9 and...and -8.0 ft of water , respectively, were measured on the spillway center line at an H/H ratio of 1.31. These low pressures, which d texceed those of

Preliminary assessment of mercury accumulation in Massachusetts and Minnesota seasonal forest pools

Treesearch

Robert T. Brooks; Susan L. Eggert; Keith H. Nislow; Randall K. Kolka; Celia Y. Chen; Darren M. Ward

2012-01-01

Seasonal forest pools (SFPs) are common, widespread, and provide critical habitat for amphibians and invertebrates. The ephemeral hydrology of SFPs has been identified as an important factor in the production of biologically active methylmercury (MeHg). To investigate mercury (Hg) in SFPs, we collected water, fine benthic organic matter (FBOM), detrital materials, and...

Default operational intervention levels (OILs) for severe nuclear power plant or spent fuel pool emergencies.

PubMed

McKenna, T; Kutkov, V; Vilar Welter, P; Dodd, B; Buglova, E

2013-05-01

Experience and studies show that for an emergency at a nuclear power plant involving severe core damage or damage to the fuel in spent fuel pools, the following actions may need to be taken in order to prevent severe deterministic health effects and reduce stochastic health effects: (1) precautionary protective actions and other response actions for those near the facility (i.e., within the zones identified by the International Atomic Energy Agency) taken immediately upon detection of facility conditions indicating possible severe damage to the fuel in the core or in the spent fuel pool; and (2) protective actions and other response actions taken based on environmental monitoring and sampling results following a release. This paper addresses the second item by providing default operational intervention levels [OILs, which are similar to the U.S. derived response levels (DRLs)] for promptly assessing radioactive material deposition, as well as skin, food, milk and drinking water contamination, following a major release of fission products from the core or spent fuel pool of a light water reactor (LWR) or a high power channel reactor (RBMK), based on the International Atomic Energy Agency's guidance.

Centrifugal Pumps for Swimming Pools. National Sanitation Foundation Standard Number 17.

ERIC Educational Resources Information Center

National Sanitation Foundation, Ann Arbor, MI. Committee for Swimming Pool Equipment Standards.

The pumps discussed herein are intended to be used for recirculating water in swimming pools, both public and private. Included are the basic components which may be a part of a pump such as the housing, strainer, impeller, valves, and such other parts as are attached or a part of the pump as supplied by the manufacturer. This standard is intended…

The distribution and public health consequences of releases of chemicals intended for pool use in 17 states, 2001-2009.

PubMed

Anderson, Ayana R; Welles, Wanda Lizak; Drew, James; Orr, Maureen F

2014-05-01

To keep swimming pool water clean and clear, consumers purchase, transport, store, use, and dispose of large amounts of potentially hazardous chemicals. Data about incidents due to the use of these chemicals and the resultant public health impacts are limited. The authors analyzed pool chemical release data from 17 states that participated in the Agency for Toxic Substances and Disease Registry's chemical event surveillance system during 2001-2009. In 400 pool chemical incidents, 60% resulted in injuries. Of the 732 injured persons, 67% were members of the public and 50% were under 18 years old. Incidents occurred most frequently in private residences (39%), but incidents with the most injured persons (34%) occurred at recreational facilities. Human error (71.9%) was the most frequent primary contributing factor, followed by equipment failure (22.8%). Interventions designed to mitigate the public health impact associated with pool chemical releases should target both private pool owners and public pool operators.

Investigation of Processes Controlling Elution of Solutes from Nonaqueous Phase Liquid (NAPL) Pools into Groundwater

NASA Astrophysics Data System (ADS)

Seyedabbasi, M.; Pirestani, K.; Holland, S. B.; Imhoff, P. T.

2005-12-01

Two major processes influencing the elution of solutes from porous media contaminated with nonaqueous phase liquids (NAPLs) are external mass transfer between the NAPL and groundwater and internal diffusion through NAPL ganglia and pools. There is a relatively large body of literature on the dissolution of single-species NAPLs. Less is known about the rates of elution of compounds dissolving from multicomponent NAPLs. We examined the mass transfer of one solute, 2,3-dimethyl-2-butanol (DMB) - a partitioning tracer, between groundwater and a dense NAPL - trichloroethylene (TCE). Diffusion cell experiments were used to measure the molecular diffusion coefficient of DMB in pure TCE and in porous media contaminated with a TCE pool. Measured diffusion coefficients were compared with empirical correlations (pure TCE) and a parallel resistance model (TCE pool). Based on the results from these analyses, a dimensionless Biot number was derived to express the ratio of the external rate of mass transfer from a NAPL pool to the internal rate of diffusion within the pool, which varies with NAPL saturation and NAPL-water partition coefficient. Biot numbers were then estimated for several laboratory scale experiments involving DMB transport between NAPL pools and groundwater. The estimated Biot numbers were in good agreement with experimental results. The expression for the Biot number developed here may be used to assess the processes controlling the elution of solutes from NAPL pools, which has implications on long-term predictions of solute dissolution from NAPLs in the field.

Mapping the transition from catalyst-pool to bamboo-like growth-mechanism in vertically-aligned free-standing films of carbon nanotubes filled with Fe3C: The key role of water

NASA Astrophysics Data System (ADS)

Boi, Filippo S.; Wang, Shanling; He, Yi

2016-08-01

The control of carbon nanotube growth has challenged researchers for more than a decade due to the complex parameters-control necessary in the commonly used CVD approaches. Here we show that a direct transition from the catalyst-pool growth mechanism characterized by graphene-caps in the direction of growth to a bamboo-shaped mechanism characterized by the repetition of periodic elongated graphitic compartments is present when controlled quantities of water are added to ferrocene/dichlorobenzene. Our results suggest that water-addition allows enhancing the level of stress accumulated under the graphitic nanotubes-cap.

Characterisation of the Permafrost Carbon Pool

USGS Publications Warehouse

Kuhry, P.; Grosse, G.; Harden, J.W.; Hugelius, G.; Koven, C.D.; Ping, C.-L.; Schirrmeister, L.; Tarnocai, C.

2013-01-01

The current estimate of the soil organic carbon (SOC) pool in the northern permafrost region of 1672 Petagrams (Pg) C is much larger than previously reported and needs to be incorporated in global soil carbon (C) inventories. The Northern Circumpolar Soil Carbon Database (NCSCD), extended to include the range 0–300 cm, is now available online for wider use by the scientific community. An important future aim is to provide quantitative uncertainty ranges for C pool estimates. Recent studies have greatly improved understanding of the regional patterns, landscape distribution and vertical (soil horizon) partitioning of the permafrost C pool in the upper 3 m of soils. However, the deeper C pools in unconsolidated Quaternary deposits need to be better constrained. A general lability classification of the permafrost C pool should be developed to address potential C release upon thaw. The permafrost C pool and its dynamics are beginning to be incorporated into Earth System models, although key periglacial processes such as thermokarst still need to be properly represented to obtain a better quantification of the full permafrost C feedback on global climate change.

First detection of mycobacteria in African rodents and insectivores, using stratified pool screening.

PubMed

Durnez, Lies; Eddyani, Miriam; Mgode, Georgies F; Katakweba, Abdul; Katholi, Charles R; Machang'u, Robert R; Kazwala, Rudovik R; Portaels, Françoise; Leirs, Herwig

2008-02-01

With the rising number of patients with human immunodeficiency virus (HIV)/AIDS in developing countries, the control of mycobacteria is of growing importance. Previous studies have shown that rodents and insectivores are carriers of mycobacteria. However, it is not clear how widespread mycobacteria are in these animals and what their role is in spreading them. Therefore, the prevalence of mycobacteria in rodents and insectivores was studied in and around Morogoro, Tanzania. Live rodents were trapped, with three types of live traps, in three habitats. Pieces of organs were pooled per habitat, species, and organ type (stratified pooling); these sample pools were examined for the presence of mycobacteria by PCR, microscopy, and culture methods. The mycobacterial isolates were identified using phenotypic techniques and sequencing. In total, 708 small mammals were collected, 31 of which were shrews. By pool prevalence estimation, 2.65% of the animals were carriers of mycobacteria, with a higher prevalence in the urban areas and in Cricetomys gambianus and the insectivore Crocidura hirta. Nontuberculous mycobacteria (Mycobacterium chimaera, M. intracellulare, M. arupense, M. parascrofulaceum, and Mycobacterium spp.) were isolated from C. gambianus, Mastomys natalensis, and C. hirta. This study is the first to report findings of mycobacteria in African rodents and insectivores and the first in mycobacterial ecology to estimate the prevalence of mycobacteria after stratified pool screening. The fact that small mammals in urban areas carry more mycobacteria than those in the fields and that potentially pathogenic mycobacteria were isolated identifies a risk for other animals and humans, especially HIV/AIDS patients, that have a weakened immune system.

Diatomite Type Filters for Swimming Pools. Standard No. 9, Revised October, 1966.

ERIC Educational Resources Information Center

National Sanitation Foundation, Ann Arbor, MI.

Pressure and vacuum diatomite type filters are covered in this standard. The filters herein described are intended to be designed and used specifically for swimming pool water filtration, both public and residential. Included are the basic components which are a necessary part of the diatomite type filter such as filter housing, element supports,…

Sand Type Filters for Swimming Pools. Standard No. 10, Revised October, 1966.

ERIC Educational Resources Information Center

National Sanitation Foundation, Ann Arbor, MI.

Sand type filters are covered in this standard. The filters described are intended to be designed and used specifically for swimming pool water filtration, both public and residential. Included are the basic components which are a necessary part of the sand type filter such as filter housing, upper and lower distribution systems filter media,…

STS-45 MS Foale in EMU prepares for underwater exercises in JSC's WETF pool

NASA Image and Video Library

1991-02-26

S91-30196 (1 March 1991) --- Astronaut C. Michael Foale, mission specialist, and Kathryn D. Sullivan, payload commander (barely visible in background), stand on a platform (out of frame) which is part of a system that will lower them into a 25-ft. deep pool. The payload commander and mission specialist used the pool in the weightless environment training facility (WET-F) to rehearse a contingency extravehicular activity (EVA). Astronauts wear pressurized spacesuits configured for achieving a neutrally buoyant condition in the water to simulate both planned and contingency EVAs. Two SCUBA-equipped swimmers assisting the training are seen in the background.

Removal of haloacetic acids from swimming pool water by reverse osmosis and nanofiltration.

PubMed

Yang, Linyan; She, Qianhong; Wan, Man Pun; Wang, Rong; Chang, Victor W-C; Tang, Chuyang Y

2017-06-01

Recent studies report high concentrations of haloacetic acids (HAAs), a prevalent class of toxic disinfection by-products, in swimming pool water (SPW). We investigated the removal of 9 HAAs by four commercial reverse osmosis (RO) and nanofiltration (NF) membranes. Under typical SPW conditions (pH 7.5 and 50 mM ionic strength), HAA rejections were >60% for NF270 with molecular weight cut-off (MWCO) equal to 266 Da and equal or higher than 90% for XLE, NF90 and SB50 with MWCOs of 96, 118 and 152 Da, respectively, as a result of the combined effects of size exclusion and charge repulsion. We further included 7 neutral hydrophilic surrogates as molecular probes to resolve the rejection mechanisms. In the absence of strong electrostatic interaction (e.g., pH 3.5), the rejection data of HAAs and surrogates by various membranes fall onto an identical size-exclusion (SE) curve when plotted against the relative-size parameter, i.e., the ratio of molecular radius over membrane pore radius. The independence of this SE curve on molecular structures and membrane properties reveals that the relative-size parameter is a more fundamental SE descriptor compared to molecular weight. An effective molecular size with the Stokes radius accounting for size exclusion and the Debye length accounting for electrostatic interaction was further used to evaluate the rejection. The current study provides valuable insights on the rejection of trace contaminants by RO/NF membranes. Copyright © 2017. Published by Elsevier Ltd.

Dynamics of phytoplankton productivity and exopolysaccharides (EPS and TEP) pools in the Seine Estuary (France, Normandy) over tidal cycles and over two contrasting seasons.

PubMed

Morelle, Jérôme; Schapira, Mathilde; Claquin, Pascal

2017-10-01

Exopolysaccharides (EPS) play an important role in the carbon flux and may be directly linked to phytoplankton and microphytobenthos production, most notably in estuarine systems. However the temporal and spatial dynamics of estuarine EPS are still not well understood, nor how primary productivity triggers this variability at these different scales. The aim of this study was to investigate the primary productivity of phytoplankton and EPS dynamics in the Seine estuary over a tidal cycle in three different haline zones over two contrasted seasons. The other objectives was to investigate the origin of pools of soluble carbohydrates (S-EPS) and transparent exopolymeric particles (TEP) in phytoplankton, microphytobenthos or other compartments. High frequency measurements of productivity were made in winter and summer 2015. Physical and chemical parameters, biomass and EPS were measured at hourly intervals in sub-surface waters and just above the water sediment-interface. Our results confirmed that high frequency measurements improve the accuracy of primary productivity estimations and associated carbon fluxes in estuaries. The photosynthetic parameters were shown to be strongly controlled by salinity and by the concentrations of suspended particle matter at the smallest temporal and at spatial scales. At these scales, our results showed an inverse relationship between EPS concentrations and biomass and productivity, and a positive relationship with sediment resuspension. Additionally, the distribution of EPS appears to be linked to hydrodynamics with the tide at daily scale and with the winter at seasonal scale. At spatial scale, the maximum turbidity zone played an important role in the distribution of TEP. Our results suggest that, in the Seine estuary, between 9% and 33% of the S-EPS pool in the water column can be attributed to phytoplankton excretion, while only 0.4%-1.6% (up to 6.14% in exceptional conditions) originates from the microphytobenthos compartments

Formation and maintenance of a forced pool-riffle couplet following loading of large wood

NASA Astrophysics Data System (ADS)

Thompson, D. M.; Fixler, S. A.

2017-11-01

Pool-riffle maintenance has been documented in numerous studies, but it has been almost impossible to characterize detailed natural pool-riffle formation mechanisms because of the lack of baseline data prior to pool establishment. In 2013, a study was conducted on the Blackledge River in Connecticut to document the formation of a new pool-riffle couplet on a section of river that had previously been studied from 1999 to 2001. In 2001, the study reach contained a scour hole with a residual depth of 0.08 ± 0.09 m downstream of a 1930s paired deflector with no identifiable riffle immediately downstream. At this time, a large, severely undercut, hemlock tree was noted along the left bank. Sometime between fall 2001 and 2004, the tree fell perpendicular to flow across the channel and formed a large wood (LW) jam and new pool-riffle couplet several meters downstream of the old scour hole. Pool spacing along the reach decreased from 4.47 bankfull widths (BFW) in 1999 to 3.83 BFW after the new pool-riffle couplet formed. The new pool has a residual depth, the water depth of the streambed depression below the elevation of the immediate downstream hydraulic control, of 1.36 ± 0.075 to 1.59 ± 0.075 m, which resulted from a combination of 1.32 ± 0.09 m or less of incision below the old scour hole (95.6% or less of the depth increase) and up to 0.18 ± 0.09 m of downstream deposition and associated backwater formation (13.2% or less of the depth increase). To assess dynamic stability of the pool-riffle couplet over several flood cycles, surficial fine-sediment and organic material along the reach were quantified. The 23-m-long pool stores 25.7% of the surficial fine grained sediments and 15.4% of organic material along a 214-m-long reach that includes one additional artificially created pool. An adjacent 50-m-long secondary channel impacted by the LW jam stores 65.3% of the surficial fine-grained sediments and 54.8% of organic material along the full reach.

Genotoxicity of Swimming Pool Water and Carcinogenicity of Drinking Water

EPA Science Inventory

Among the 11 disinfection by-products (DBPs) in drinking water that are regulated by the U.S. EPA, (a) 2 DBPs (chloroaceticacid and chlorite) are not carcinogenic-in either of2 species; (b) chlorite is not carcinogenic in 3 rodent assays and has never been tested for genotoxicity...

Genotoxicity of Swimming Pool Water and Carcinogenicity of Drinking Water**

EPA Science Inventory

Among the 11 disinfection by-products (DBPs) in drinking water that are regulated by the U.S. EPA, (a) 2 DBPs (chloroaceticacid and chlorite) are not carcinogenic-in either of2 species; (b) chlorite is not carcinogenic in 3 rodent assays and has never been tested for genotoxicity...

C principal pools and fluxes in the field agroecosystems of Juriev-Polskiy Opolie

NASA Astrophysics Data System (ADS)

Atenbekov, Ramiz; Yashin, Ivan; Vasenev, Ivan

2017-04-01

There are results of 7-year (2010-2016) investigation of the Podzols and Podzoluvisols genesis, dynamics and soil organic carbon (SOC) pools in the representative agrolandscapes of the Yuryev-Polish plain (Yaroslavl region) with estimated environmental risks, including topsoil CO2 emission and the water-soluble organic substances (WSOS) profile and lateral fluxes in conditions of different land-use practice and microclimate conditions. A set of regional stationary plots has been investigated in 5 soil-ecological catenas with different level of erosion and hydromorphic processes. Soil organic matter is poorly fixed to the mineral matrix and has high migration ability, as shown by the sorption lysimeter and model experiments with weak solutions of oxalic acid and water. The total content of soil organic carbon varies in the range of 1.4% to 2.8% in topsoil of the investigated arable Podzols and Podzoluvisols. SOC fractional-group average composition indicates the presence of 37% of fulvic acids and 41% of gumins. The most available for soil microorganisms, enhancing CO2 emission, principal water-soluble organic substances accumulate in the topsoil A1 horizon, whereas the eluvial horizon E serves as a transit barrier to their profile migration and layer of active lateral migration. Modern climate and land-use changes play important role in the spatial-temporal variability of dominant soil GHG fluxes in these landscapes that determines the rising interest in the agroecological monitoring here to develop basic elements of the climate-smart farming systems with sustainable grass, winter wheat and barley production.

How cold pool triggers deep convection?

NASA Astrophysics Data System (ADS)

Yano, Jun-Ichi

2014-05-01

The cold pool in the boundary layer is often considered a major triggering mechanism of convection. Here, presented are basic theoretical considerations on this issue. Observations suggest that cold pool-generated convective cells is available for shallow maritime convection (Warner et al. 1979; Zuidema et al. 2012), maritime deep convection (Barnes and Garstang 1982; Addis et al. 1984; Young et al. 1995) and continental deep convection (e.g., Lima and Wilson 2008; Flamant 2009; Lothon et al. 2011; Dione et al. 2013). Moreover, numerical studies appear to suggest that cold pools promote the organization of clouds into larger structures and thereby aid the transition from shallow to deep convection (Khairoutdinov and Randall 2006, Boing et al. 2012, Schlemmer and Hohenegger, 2014). Even a cold--pool parameterization coupled with convection is already proposed (Grandpeix and Lafore 2010: but see also Yano 2012). However, the suggested link between the cold pool and deep convection so far is phenomenological at the best. A specific process that the cold pool leads to a trigger of deep convection must still to be pinned down. Naively, one may imagine that a cold pool lifts up the air at the front as it propagates. Such an uplifting leads to a trigger of convection. However, one must realize that a shift of air along with its propagation does not necessarily lead to an uplifting, and even if it may happen, it would not far exceed a depth of the cold pool itself. Thus, the uplifting can never be anything vigorous. Its thermodynamic characteristics do help much either for inducing convection. The cold-pool air is rather under rapid recovering process before it can induce convection under a simple parcel-lifting argument. The most likely reason that the cold pool may induce convection is its gust winds that may encounter an air mass from an opposite direction. This induces a strong convergence, also leading to a strong uplifting. This is an argument essentially developed

Understanding the Dynamics of the South Indian Ocean Sea Surface Salinity Maximum Pool From Argo, Rama, Aquarius, SMOS & Other Satellites

NASA Astrophysics Data System (ADS)

Menezes, V. V.; Phillips, H. E.

2016-02-01

Subtropical salinity maximum regions are particularly important because the salty subtropical underwater (STW) is formed by subduction of surface waters in these areas. In all oceans, the STW is transported equatorward from the formation region and are tightly related to the Subtropical-Tropical Cell. In the South Indian Ocean (SIO), the salinity maximum pool is further poleward (25S-38S) and eastward (60E-120E). It significantly impacts the circulation of the eastern basin, because the STW forms a strong haline front with the fresh Indonesian Throughflow waters. This haline front overwhelms the temperature contribution establishing the eastward Eastern Gyral Current, an important upstream source for the Leeuwin Current. In the present work, we analyze the variability of the SSS maximum pool using Aquarius and SMOS satellites, an Argo gridded product and the RAMA mooring located at 25S-100E. OAFLUX, 3B42 TRMM, Ascat/Quikscat winds and OSCAR products complement this study. The salinity maximum pool has a strong seasonal cycle of contraction (min in Oct) and expansion (max in April), and most of this variation occurs in the pool poleward side. Advection and entrainment control the contraction, while expansion is due to atmospheric forcing (E-P). From 2004 to 2014, a clear reduction in the pool area is identified, which might be related to a decadal variability. In this case, the variation is in the equatorward side of the pool. Processes controlling this long-term variability are being investigated.

Vertical Stability of Ephemeral Step-Pool Streams Largely Controlled By Tree Roots, Central Kentucky, USA

NASA Astrophysics Data System (ADS)

Macmannis, K. R.; Hawley, R. J.

2013-12-01

The mechanisms controlling stability on small streams in steep settings are not well documented but have many implications related to stream integrity and water quality. For example, channel instability on first and second order streams is a potential source of sediment in regulated areas with Total Maximum Daily Loads (TMDLs) on water bodies that are impaired for sedimentation, such as the Chesapeake Bay. Management strategies that preserve stream integrity and protect channel stability are critical to communities that may otherwise require large capital investments to meet TMDLs and other water quality criteria. To contribute to an improved understanding of ephemeral step-pool systems, we collected detailed hydrogeomorphic data on 4 steep (0.06 - 0.12 meter/meter) headwater streams draining to lower relief alluvial valleys in Spencer County, Kentucky, USA. The step-pool streams (mean step height of 0.47 meter, mean step spacing of 4 meters) drained small undeveloped catchments dominated by early successional forest. Data collection for each of the 4 streams included 2 to 3 cross section surveys, bed material particle counts at cross section locations, and profile surveys ranging from approximately 125 to 225 meters in length. All survey data was systematically processed to understand geometric parameters such as cross sectional area, depth, and top width; bed material gradations; and detailed profile measurements such as slope, pool and riffle lengths, pool spacing, pool depth, step height, and step length. We documented the location, frequency, and type of step-forming materials (i.e., large woody debris (LWD), rock, and tree roots), compiling a database of approximately 130 total steps. Lastly, we recorded a detailed tree assessment of all trees located within 2 meters of the top of bank, detailing the species of tree, trunk diameter, and approximate distance from the top of bank. Analysis of geometric parameters illustrated correlations between channel

Sulfur geochemistry of hydrothermal waters in Yellowstone National Park, Wyoming, USA. II. Formation and decomposition of thiosulfate and polythionate in Cinder Pool

NASA Astrophysics Data System (ADS)

Xu, Y.; Schoonen, M. A. A.; Nordstrom, D. K.; Cunningham, K. M.; Ball, J. W.

2000-04-01

Cinder Pool is an acid-sulfate-chloride boiling spring in Norris Geyser Basin, Yellowstone National Park. The pool is unique in that its surface is partially covered with mm-size, black, hollow sulfur spherules, while a layer of molten sulfur resides at the bottom of the pool (18 m depth). The sulfur speciation in the pool was determined on four different days over a period of two years. Samples were taken to evaluate changes with depth and to evaluate the importance of the sulfur spherules on sulfur redox chemistry. All analyses were conducted on site using a combination of ion chromatography and colorimetric techniques. Dissolved sulfide (H2S), thiosulfate (S2O32-), polythionates (SxO62-), and sulfate were detected. The polythionate concentration was highly variable in time and space. The highest concentrations were found in surficial samples taken from among the sulfur spherules. With depth, the polythionate concentrations dropped off. The maximum observed polythionate concentration was 8 μM. Thiosulfate was rather uniformly distributed throughout the pool and concentrations ranged from 35 to 45 μM. Total dissolved sulfide concentrations varied with time, concentrations ranged from 16 to 48 μM. Sulfate was relatively constant, with concentrations ranging from 1150 to 1300 μM. The sulfur speciation of Cinder Pool is unique in that the thiosulfate and polythionate concentrations are significantly higher than for any other acid-sulfate spring yet sampled in Yellowstone National Park. Complementary laboratory experiments show that thiosulfate is the intermediate sulfoxyanion formed from sulfur hydrolysis under conditions similar to those found in Cinder Pool and that polythionates are formed via the oxidation of thiosulfate by dissolved oxygen. This last reaction is catalyzed by pyrite that occurs as a minor constituent in the sulfur spherules floating on the pool's surface. Polythionate decomposition proceeds via two pathways: (1) a reaction with H2S, yielding

Sulfur geochemistry of hydrothermal waters in Yellowstone National Park, Wyoming, USA. II. Formation and decomposition of thiosulfate and polythionate in Cinder Pool

USGS Publications Warehouse

Xu, Y.; Schoonen, M.A.A.; Nordstrom, D. Kirk; Cunningham, K.M.; Ball, J.W.

2000-01-01

Cinder Pool is an acid-sulfate-chloride boiling spring in Norris Geyser Basin, Yellowstone National Park. The pool is unique in that its surface is partially covered with mm-size, black, hollow sulfur spherules, while a layer of molten sulfur resides at the bottom of the pool (18 m depth). The sulfur speciation in the pool was determined on four different days over a period of two years. Samples were taken to evaluate changes with depth and to evaluate the importance of the sulfur spherules on sulfur redox chemistry. All analyses were conducted on site using a combination of ion chromatography and colorimetric techniques. Dissolved sulfide (H2S), thiosulfate (S2O32−), polythionates (SxO62−), and sulfate were detected. The polythionate concentration was highly variable in time and space. The highest concentrations were found in surficial samples taken from among the sulfur spherules. With depth, the polythionate concentrations dropped off. The maximum observed polythionate concentration was 8 μM. Thiosulfate was rather uniformly distributed throughout the pool and concentrations ranged from 35 to 45 μM. Total dissolved sulfide concentrations varied with time, concentrations ranged from 16 to 48 μM. Sulfate was relatively constant, with concentrations ranging from 1150 to 1300 μM. The sulfur speciation of Cinder Pool is unique in that the thiosulfate and polythionate concentrations are significantly higher than for any other acid-sulfate spring yet sampled in Yellowstone National Park. Complementary laboratory experiments show that thiosulfate is the intermediate sulfoxyanion formed from sulfur hydrolysis under conditions similar to those found in Cinder Pool and that polythionates are formed via the oxidation of thiosulfate by dissolved oxygen. This last reaction is catalyzed by pyrite that occurs as a minor constituent in the sulfur spherules floating on the pool's surface. Polythionate decomposition proceeds via two pathways: (1) a reaction with H2S

Nucleate pool boiling: High gravity to reduced gravity; liquid metals to cryogens

NASA Technical Reports Server (NTRS)

Merte, Herman, Jr.

1988-01-01

Requirements for the proper functioning of equipment and personnel in reduced gravity associated with space platforms and future space station modules introduce unique problems in temperature control; power generation; energy dissipation; the storage, transfer, control and conditioning of fluids; and liquid-vapor separation. The phase change of boiling is significant in all of these. Although both pool and flow boiling would be involved, research results to date include only pool boiling because buoyancy effects are maximized for this case. The effective application of forced convection boiling heat transfer in the microgravity of space will require a well grounded and cogent understanding of the mechanisms involved. Experimental results are presented for pool boiling from a single geometrical configuration, a flat surface, covering a wide range of body forces from a/g = 20 to 1 to a/g = 0 to -1 for a cryogenic liquid, and from a/g = 20 to 1 for water and a liquid metal. Similarities in behavior are noted for these three fluids at the higher gravity levels, and may reasonably be expected to continue at reduced gravity levels.

Polarimetric thermal emission from periodic water surfaces

NASA Technical Reports Server (NTRS)

Yueh, S. H.; Nghiem, S. V.; Kwok, R.; Wilson, W. J.; Li, F. K.; Johnson, J. T.; Kong, J. A.

1993-01-01

Experimental results and theoretical calculations are presented to study the polarimetric emission from water surfaces with directional features. For our ground-based Ku-band radiometer measurements, a water pool was constructed on the roof of a building in the Jet Propulsion Laboratory, and a fiberglass surface with periodic corrugations in one direction was impressed on the top of the water surface to create a stationary water surface underneath it. It is observed that the measured Stokes parameters of corrugated fiberglass-covered water surfaces are functions of azimuth angles and agree very well with the theoretical calculations. The theory, after being verified by the experimental data, was then used to calculate the Stokes parameters of periodic surfaces without fiberglass surface layer and with rms height of the order of wind-generated water ripples. The magnitudes of the azimuthal variation of the calculated emissivities at horizontal and vertical polarizations corresponding to the first two Stokes parameters are found to be comparable to the values measured by airborne radiometers and SSM/I. In addition, the third Stokes parameter not shown in the literature is seen to have approximately twice the magnitude of the azimuth variation of either T(sub h) or T(sub v), which may make it more sensitive to the row direction, while less susceptive to noises because the atmospheric and system noises tend to be unpolarized and are expected to be cancelled out when the third Stokes parameter is derived as the difference of two or three power measurements, as indicated by another experiment carried out at a swimming pool with complicated surroundings. The results indicate that passive polarimetry is a potential technology in the remote sensing of ocean wind vector which is a crucial component in the understanding of global climate change. Issues related to the application of microwave passive polarimetry to ocean wind are also discussed.

Development of the Chacon Dakota associated pool

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walsh, E.N.

1979-01-01

Discovery and development of the Chacon Dakota associated pool is a very important Dakota formation development outside of the basic Dakota gas pool in the San Juan Basin area. Other Dakota formation developments are not of the magnitude as the Chacon Dakota associated pool.

48 CFR 28.304 - Risk-pooling arrangements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Risk-pooling arrangements... CONTRACTING REQUIREMENTS BONDS AND INSURANCE Insurance 28.304 Risk-pooling arrangements. Agencies may establish risk-pooling arrangements. These arrangements are designed to use the services of the insurance...

Chemically and geographically distinct solid-phase iron pools in the Southern Ocean.

PubMed

von der Heyden, B P; Roychoudhury, A N; Mtshali, T N; Tyliszczak, T; Myneni, S C B

2012-11-30

Iron is a limiting nutrient in many parts of the oceans, including the unproductive regions of the Southern Ocean. Although the dominant fraction of the marine iron pool occurs in the form of solid-phase particles, its chemical speciation and mineralogy are challenging to characterize on a regional scale. We describe a diverse array of iron particles, ranging from 20 to 700 nanometers in diameter, in the waters of the Southern Ocean euphotic zone. Distinct variations in the oxidation state and composition of these iron particles exist between the coasts of South Africa and Antarctica, with different iron pools occurring in different frontal zones. These speciation variations can result in solubility differences that may affect the production of bioavailable dissolved iron.

48 CFR 228.304 - Risk-pooling arrangements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Risk-pooling arrangements..., DEPARTMENT OF DEFENSE GENERAL CONTRACTING REQUIREMENTS BONDS AND INSURANCE Insurance 228.304 Risk-pooling... Insurance Rating Plan, as a risk-pooling arrangement to minimize the cost to the Government of purchasing...

48 CFR 873.114 - Best value pool.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Best value pool. 873.114... SUPPLEMENTARY REGULATIONS SIMPLIFIED ACQUISITION PROCEDURES FOR HEALTH-CARE RESOURCES 873.114 Best value pool... solicitation. These vendors constitute the best value pool. This determination is within the sole discretion of...

Backwater control on riffle pool hydraulics, fish habitat quality, and sediment transport regime in gravel-bed rivers

NASA Astrophysics Data System (ADS)

Pasternack, Gregory B.; Bounrisavong, Michael K.; Parikh, Kaushal K.

2008-07-01

SummaryThe importance of channel non-uniformity to natural hydrogeomorphic and ecological processes in gravel-bed rivers is becoming increasingly known, but its use in channel rehabilitation lags behind. Many projects still use methods that assume steady, uniform flow and simple channel geometries. One aspect of channel non-uniformity that has not been considered much is its role in controlling backwater conditions and thus potentially influencing patterns of physical habitat and channel stability in sequences of riffles and pools. In this study, 2D hydrodynamic models of two non-uniform pool-riffle-pool configurations were used to systematically explore the effects of four different downstream water surface elevations at three different discharges (24 total simulations) on riffle-pool ecohydraulics. Downstream water surface elevations tested included backwater, uniform, accelerating, and critical conditions, which are naturally set by downstream riffle-crest morphology but may also be re-engineered artificially. Discharges included a fish-spawning low flow, summer fish-attraction flow, and a peak snowmelt pulse. It was found that the occurrence of a significant area of high-quality fish spawning habitat at low flow depends on riffles being imposed upon by backwater conditions, which also delay the onset of full bed mobility on riffles during floods. The assumption of steady, uniform flow was found to be inappropriate for gravel-bed rivers, since their non-uniformity controls spatial patterns of habitat and sediment transport. Also, model results indicated that a "reverse domino" mechanism can explain catastrophic failure and re-organization of a sequence of riffles based on the water surface elevation response to scour on downstream riffles, which then increases scour on upstream riffles.

Experiments on the effects of nanoparticles on subcooled nucleate pool boiling

NASA Astrophysics Data System (ADS)

Kangude, Prasad; Bhatt, Dhairya; Srivastava, Atul

2018-05-01

The effect of nanoparticles on a single bubble-based nucleate pool boiling phenomenon under subcooled conditions has been studied. Water (as the base fluid) and two different concentrations of water-silica nanofluids (0.005% and 0.01% V/V) have been employed as the working fluids. The boiling experiments have been conducted in a specially designed chamber, wherein an ITO-coated heater substrate has been used to induce single bubble nucleation. Measurements have been performed in a completely non-intrusive manner using one of the refractive index-based diagnostics techniques, namely, rainbow schlieren deflectometry. Thus, the thermal gradients prevailing in the boiling chamber have directly been mapped as a two-dimensional distribution of hue values that are recorded in the form of rainbow schlieren images. The schlieren-based measurements clearly revealed the plausible influence of nanoparticles on the strength of temperature gradients prevailing in the boiling chamber. As compared to the base fluid, the experiments with dilute nanofluids showed that the suspended nanoparticles tend to diffuse (homogenize) the strength of temperature gradients, both in the vicinity of the heated substrate and in the thermal boundary layer enveloping the vapor bubble. An overall reduction in the bubble volume and dynamic contact angle was seen with increasing concentrations of dilute nanofluids. In addition, the vapor bubble was found to assume a more spherical shape at higher concentrations of dilute nanofluids in comparison to its shape with water-based experiments. Clear oscillations of the vapor bubble in the subcooled pool of liquids (water and/or nanofluids) were observed, the frequency of which was found to be significantly reduced as the nanoparticle concentration was increased from 0% (water) to 0.01% (V/V). A force balance analysis has been performed to elucidate the plausible mechanisms explaining the observed trends of the oscillation frequencies of the vapor bubble.

47 CFR 90.35 - Industrial/Business Pool.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 5 2012-10-01 2012-10-01 false Industrial/Business Pool. 90.35 Section 90.35 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Industrial/Business Radio Pool § 90.35 Industrial/Business Pool. (a) Eligibility. Persons primarily engaged in any of...

47 CFR 90.35 - Industrial/Business Pool.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 5 2014-10-01 2014-10-01 false Industrial/Business Pool. 90.35 Section 90.35 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Industrial/Business Radio Pool § 90.35 Industrial/Business Pool. (a) Eligibility. Persons primarily engaged in any of...

47 CFR 90.35 - Industrial/Business Pool.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Industrial/Business Pool. 90.35 Section 90.35 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Industrial/Business Radio Pool § 90.35 Industrial/Business Pool. (a) Eligibility. Persons primarily engaged in any of...

47 CFR 90.35 - Industrial/Business Pool.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 5 2013-10-01 2013-10-01 false Industrial/Business Pool. 90.35 Section 90.35 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Industrial/Business Radio Pool § 90.35 Industrial/Business Pool. (a) Eligibility. Persons primarily engaged in any of...

47 CFR 90.35 - Industrial/Business Pool.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 5 2011-10-01 2011-10-01 false Industrial/Business Pool. 90.35 Section 90.35 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Industrial/Business Radio Pool § 90.35 Industrial/Business Pool. (a) Eligibility. Persons primarily engaged in any of...

48 CFR 873.114 - Best value pool.

Code of Federal Regulations, 2011 CFR

2011-10-01

... value pool is expected to exceed the number at which an efficient, timely, and economical competition... that the best value pool can be limited for purposes of making an efficient, timely, and economical... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Best value pool. 873.114...