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Sample records for primary water experimental

  1. Effects of genotypic diversity of Phragmites australis on primary productivity and water quality in an experimental wetland.

    PubMed

    Tomimatsu, Hiroshi; Nakano, Kazunori; Yamamoto, Nozomi; Suyama, Yoshihisa

    2014-05-01

    An increasing number of studies have shown that genetic diversity within plant species can influence important ecological processes. Here, we report a two-year wetland mesocosm experiment in which genotypic richness of Phragmites australis was manipulated to examine its effects on primary productivity and nitrogen removal from water. We used six genotypes of P. australis, and compared primary productivity and nitrogen concentration in the outflow water of the mesocosms between monocultures and polycultures of all six genotypes. We also quantified the abundance of denitrifying bacteria, as denitrification is a primary mechanism of nitrogen removal in addition to the biotic uptake by P. australis. Plant productivity was significantly greater in genotypic polycultures compared to what was expected based on monocultures. This richness effect on productivity was driven by both complementary and competitive interactions among genotypes. In addition, nitrogen removal rates of mesocosms were generally greater in genotypic polycultures compared to those expected based on monocultures. This effect, particularly pronounced in autumn, may largely be attributable to the enhanced uptake of nitrogen by P. australis, as the abundance of nitrite reducers did not increase with plant genotypic diversity. Although our effect sizes were relatively small compared to previous experiments, our study emphasizes the effect of genotypic interactions in regulating multiple ecological processes.

  2. Catalytic supercritical water gasification of primary paper sludge using a homogeneous and heterogeneous catalyst: Experimental vs thermodynamic equilibrium results.

    PubMed

    Louw, Jeanne; Schwarz, Cara E; Burger, Andries J

    2016-02-01

    H2, CH4, CO and CO2 yields were measured during supercritical water gasification (SCWG) of primary paper waste sludge (PWS) at 450°C. Comparing these yields with calculated thermodynamic equilibrium values offer an improved understanding of conditions required to produce near-equilibrium yields. Experiments were conducted at different catalyst loads (0-1g/gPWS) and different reaction times (15-120min) in a batch reactor, using either K2CO3 or Ni/Al2O3-SiO2 as catalyst. K2CO3 up to 1g/gPWS increased the H2 yield significantly to 7.5mol/kgPWS. However, these yields and composition were far from equilibrium values, with carbon efficiency (CE) and energy recovery (ER) of only 29% and 20%, respectively. Addition of 0.5-1g/gPWS Ni/Al2O3-SiO2 resulted in high H2 and CH4 yields (6.8 and 14.8mol/kgPWS), CE of 84-90%, ER of 83% and a gas composition relatively close to the equilibrium values (at hold times of 60-120min).

  3. Catalytic supercritical water gasification of primary paper sludge using a homogeneous and heterogeneous catalyst: Experimental vs thermodynamic equilibrium results.

    PubMed

    Louw, Jeanne; Schwarz, Cara E; Burger, Andries J

    2016-02-01

    H2, CH4, CO and CO2 yields were measured during supercritical water gasification (SCWG) of primary paper waste sludge (PWS) at 450°C. Comparing these yields with calculated thermodynamic equilibrium values offer an improved understanding of conditions required to produce near-equilibrium yields. Experiments were conducted at different catalyst loads (0-1g/gPWS) and different reaction times (15-120min) in a batch reactor, using either K2CO3 or Ni/Al2O3-SiO2 as catalyst. K2CO3 up to 1g/gPWS increased the H2 yield significantly to 7.5mol/kgPWS. However, these yields and composition were far from equilibrium values, with carbon efficiency (CE) and energy recovery (ER) of only 29% and 20%, respectively. Addition of 0.5-1g/gPWS Ni/Al2O3-SiO2 resulted in high H2 and CH4 yields (6.8 and 14.8mol/kgPWS), CE of 84-90%, ER of 83% and a gas composition relatively close to the equilibrium values (at hold times of 60-120min). PMID:26638140

  4. EXPERIMENTAL ANIMAL WATERING DEVICE

    DOEpatents

    Finkel, M.P.

    1964-04-01

    A device for watering experimental animals confined in a battery of individual plastic enclosures is described. It consists of a rectangular plastic enclosure having a plurality of fluid-tight compartments, each with a drinking hole near the bottom and a filling hole on the top. The enclosure is immersed in water until filled, its drinking holes sealed with a strip of tape, and it is then placed in the battery. The tape sealing prevents the flow of water from the device, but permits animals to drink by licking the drinking holes. (AEC)

  5. Biogasification of water hyacinth and primary sludge

    SciTech Connect

    Chynoweth, D.P.; Biljetina, R.; Srivastava, V.J.; Hayes, T.D.

    1985-01-01

    This paper describes the results of research to evaluate the use of water hyacinth for wastewater treatment and subsequent conversion of hyacinth and sludge to methane by anaerobic digestion. Laboratory studies have been directed toward evaluating advanced biogasification concepts and establishing a data base for the design and operation of an experimental test unit (ETU). Kinetic experiments have been conducted using continuously stirred tank reactors and a novel non-mixed vertical flow reactor (NMVFR) receiving a hyacinth/sludge blend at retention times of 15 down to 2.1 days. The data suggest that the best performance is achieved in the NMVFR which has longer solids and organism retention. A larger-scale experimental test unit (4.5 m/sup 3/) was used to validate laboratory experiments and to evaluate larger-scale equipment used for chopping, slurry preparation, mixing, and effluent dewatering. The ETU is currently being operated on a 2:1 blend (dry wt basis) of water hyacinth and primary sludge. Performance is good without major operational problems. Results are presented. 12 refs., 6 figs., 5 tabs.

  6. Primary production in Southern Ocean waters

    NASA Astrophysics Data System (ADS)

    Arrigo, Kevin R.; Worthen, Denise; Schnell, Anthony; Lizotte, Michael P.

    1998-07-01

    The Southern Ocean forms a link between major ocean basins, is the site of deep and intermediate water ventilation, and is one of the few areas where macronutrients are underutilized by phytoplankton. Paradoxically, prior estimates of annual primary production are insufficient to support the Antarctic food web. Here we present results from a primary production algorithm based upon monthly climatological phytoplankton pigment concentrations from the coastal zone color scanner (CZCS). Phytoplankton production was forced using monthly temperature profiles and a radiative transfer model that computed changes in photosynthetically usable radiation at each CZCS pixel location. Average daily productivity (g C m-2 d-1) and total monthly production (Tg C month-1) were calculated for each of five geographic sectors (defined by longitude) and three ecological provinces (defined by sea ice coverage and bathymetry as the pelagic province, the marginal ice zone, and the shelf). Annual primary production in the Southern Ocean (south of 50°S) was calculated to be 4414 Tg C yr-1, 4-5 times higher than previous estimates made from in situ data. Primary production was greatest in the month of December (816 Tg C month-1) and in the pelagic province (contributing 88.6% of the annual primary production). Because of their small size the marginal ice zone (MIZ) and the shelf contributed only 9.5% and 1.8%, respectively, despite exhibiting higher daily production rates. The Ross Sea was the most productive region, accounting for 28% of annual production. The fourfold increase in the estimate of primary production for the Southern Ocean likely makes the notion of an "Antarctic paradox" (primary production insufficient to support the populations of Southern Ocean grazers, including krill, copepods, microzooplankton, etc.) obsolete.

  7. Water, acidosis, and experimental pyelonephritis

    PubMed Central

    Andriole, Vincent T.

    1970-01-01

    The effect of water restriction and ammonium chloride acidosis on the course of Escherichia coli pyelonephritis was determined in the nonobstructed kidney of the rat. To alter the chemical composition of the renal medulla, water intake was reduced in rats to one-half the normal daily intake. Water restriction increased the incidence of coliform pyelonephritis. Systemic acidosis, produced by giving a 300 mM solution of ammonium chloride, increased urinary osmolality to values comparable to water restriction and also predisposed to pyelonephritis. However, when rats were fed the same solution of ammonium chloride but were allowed access to tap water ad lib., urinary osmolality values were comparable to those observed in normal animals, and susceptibility to pyelonephritis was reduced or eliminated despite a degree of systemic acidosis similar to that observed in rats fed ammonium chloride solution without access to tap water. These results suggest that water diuresis may overcome the inactivation of complement produced by ammonium chloride acidosis and that renal medullary hypertonicity, produced by either water restriction or ammonium chloride acidosis, is a major determinant of this tissue's unique susceptibility to infection. PMID:4902827

  8. The water dimer I: Experimental characterization

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Anamika; Cole, William T. S.; Saykally, Richard J.

    2015-07-01

    As the archetype of water hydrogen bonding, the water dimer has been studied extensively by both theory and experiment for nearly seven decades. In this article, we present a detailed chronological review of the experimental dimer studies and the insights into the complex nature of water and hydrogen bonding gained from them. A subsequent letter will review the corresponding theoretical advances.

  9. Children's Understanding of Experimental Contrast and Experimental Control: An Inventory for Primary School

    ERIC Educational Resources Information Center

    Osterhaus, Christopher; Koerber, Susanne; Sodian, Beate

    2015-01-01

    Experimentation skills are a central component of scientific thinking, and many studies have investigated whether and when primary-school children develop adequate experimentation strategies. However, the answers to these questions vary substantially depending on the type of task that is used: while discovery tasks, which require children to…

  10. On the experimental investigation on primary atomization of liquid streams

    NASA Astrophysics Data System (ADS)

    Dumouchel, Christophe

    2008-09-01

    The production of a liquid spray can be summarized as the succession of the following three steps; the liquid flow ejection, the primary breakup mechanism and the secondary breakup mechanism. The intermediate step—the primary breakup mechanism—covers the early liquid flow deformation down to the production of the first isolated liquid fragments. This step is very important and requires to be fully understood since it constitutes the link between the flow issuing from the atomizer and the final spray. This paper reviews the experimental investigations dedicated to this early atomization step. Several situations are considered: cylindrical liquid jets, flat liquid sheets, air-assisted cylindrical liquid jets and air-assisted flat liquid sheets. Each fluid stream adopts several atomization regimes according to the operating conditions. These regimes as well as the significant parameters they depend on are listed. The main instability mechanisms, which control primary breakup processes, are rather well described. This review points out the internal geometrical nozzle characteristics and internal flow details that influence the atomization mechanisms. The contributions of these characteristics, which require further investigations to be fully identified and quantified, are believed to be the main reason of experimental discrepancies and explain a lack of universal primary breakup regime categorizations.

  11. Unlocking water markets: an experimental approach

    NASA Astrophysics Data System (ADS)

    Cook, J.; Rabotyagov, S.

    2011-12-01

    Water markets are frequently referred to as a promising approach to alleviate stress on water systems, especially as future hydrologic assessments suggest increasing demand and less reliable supply. Yet, despite decades of advocacy by water resource economists, water markets (leases and sales of water rights between willing buyers and sellers) have largely failed to develop in the western US. Although there are a number of explanations for this failure, we explore one potential reason that has received less attention : farmers as sellers may have preferences for different elements of a water market transaction that are not captured in the relative comparison of their profits from farming and their profits from agreeing to a deal. We test this explanation by recruiting irrigators with senior water rights in the upper Yakima River Basin in Washington state to participate in a series of experimental auctions. In concept, the Yakima Basin is well situated for water market transactions as it has significant water shortages for junior water users ~15% of years and projections show these are likely to increase in the future. Participants were asked a series of questions about the operation of a hypothetical 100-acre timothy hay farm including the type of buyer, how the water bank is managed, the lease type, and the offer price. Results from 7 sessions with irrigators (n=49) and a comparison group of undergraduates (n=38) show that irrigators are more likely to accept split-season than full-season leases (controlling for differences in farm profits) and are more likely to accept a lease from an irrigation district and less likely to accept an offer from a Developer. Most notably, we find farmers were far more likely than students to reject offers from buyers even though it would increase their winnings from the experiment. These results could be used in ongoing water supply policy debates in the Yakima Basin to simulate the amount of water that could be freed by water

  12. THF water hydrate crystallization: an experimental investigation

    NASA Astrophysics Data System (ADS)

    Devarakonda, Surya; Groysman, Alexander; Myerson, Allan S.

    1999-08-01

    Supersaturated solutions of THF-water hydrate system were experimentally studied before and during crystallization, to examine the system's behavior in the metastable zone and observe any anomalies suggesting cluster formation. Nucleation induction time measurements, with and without additives, were performed to screen potential growth inhibitors. Shifts in the onset points of crystallization for water and THF-water mixtures with additives were measured using differential scanning calorimetry (DSC). Aspartame was among one of the few successfully screened inhibitors. Preliminary on-line crystal size distribution (CSD) measurements were performed on this system to monitor the crystal size during crystallization. The CSD data was also used to compute the hydrate crystal growth rates, which were found to be in the order of 145 μm/h.

  13. Environment, Teacher Manual, Primary, Idea 3, Water.

    ERIC Educational Resources Information Center

    Environmental Education Project, Grafton, IL.

    The Environmental Education Project Center has developed these guidelines for teaching a unit in environmental studies. It is their intention that the teacher and student cooperatively plan the approach and content to be used during the course of study. In this unit about water, teacher resource information and student material are combined to…

  14. Experimental demonstration of water based tunable metasurface

    NASA Astrophysics Data System (ADS)

    Odit, Mikhail; Kapitanova, Polina; Andryieuski, Andrei; Belov, Pavel; Lavrinenko, Andrei V.

    2016-07-01

    A simple dynamically tunable metasurface (two-dimensional metamaterial) operating at microwave frequencies is developed and experimentally investigated. Conceptually, the simplicity of the approach is granted by reconfigurable properties of unit cells partially filled with distilled water. The transmission spectra of the metasurface for linear and circular polarizations of the incident wave were experimentally measured under the metasurface rotation around a horizontal axis. The changes in the transmission coefficient magnitude up to 8 dB at 1.25 GHz are reported while rotating the metasurface by the 90° angle. The proposed approach manifests the cheap and accessible route for the electromagnetic wave control in the microwave region with the help of metasurfaces.

  15. Primary experimental infection of riverine buffaloes with Fasciola gigantica.

    PubMed

    Yadav, S C; Sharma, R L; Kalicharan, A; Mehra, U R; Dass, R S; Verma, A K

    1999-05-01

    The clinical course of the primary experimental Fasciola gigantica infection was investigated in riverine buffalo calves of the Murrah breed. Nine male calves aged 12-15 months were randomly assigned to two groups of five (Group I) and four (Group II) animals. Each animal in Group I, was orally infected with 1000 metacercariae (mc) of F. gigantica, whereas Group II animals did not receive any infection dose and served as uninfected controls. No clinical signs of fasciolosis were observed until the sixth week post-infection (PI). Group I animals, however, developed recognised symptoms of acute fasciolosis, comprising apyrexic inappetance, anemia, poor weight gain, diarrhoea and sub-mandibular and facial oedema, respectively, from 5, 6, 8, 16 and 17 weeks PI. The signs were intermittent in nature and of variable duration. The prepatent period was of 92-97 days (mean 95.2 +/- 3.1). One of the five infected animals died on Day 147 PI. At necropsy, 36.8 +/- 11.0% of the infection dose was recovered as adult fluke population. The gross lesions were primarily biliary in nature. Group II, the uninfected controls, throughout the study period of 165 days PI, did not show any symptom and were negative for F. gigantica. The study demonstrated that the onset of adverse effects of F. gigantica on the growth and health of the infected host was mainly noted during late prepatency much before coprological prediction and diagnosis. The significance of preventive therapy against fasciolosis during prepatency has been stressed in endemic areas. PMID:10384904

  16. Environmental Science. An Experimental Programme for Primary Teachers.

    ERIC Educational Resources Information Center

    Linke, R. D.

    An experimental course covering some of the fundamental principles and terminology associated with environmental science and the application of these principles to various contemporary problems is summarized in this report. The course involved a series of lectures together with a program of specific seminar and discussion topics presented by the…

  17. Response of plant community structure and primary productivity to experimental drought and flooding in an Alaskan fen

    USGS Publications Warehouse

    Churchill, A.C.; Turetsky, Merritt R.; McGuire, Anthony; Hollingsworth, Teresa N.

    2014-01-01

    Northern peatlands represent a long-term net sink for atmospheric CO2, but these ecosystems can shift from net carbon (C) sinks to sources based on changing climate and environmental conditions. In particular, changes in water availability associated with climate control peatland vegetation and carbon uptake processes. We examined the influence of changing hydrology on plant species abundance and ecosystem primary production in an Alaskan fen by manipulating the water table in field treatments to mimic either sustained flooding (raised water table) or drought (lowered water table) conditions for 6 years. We found that water table treatments altered plant species abundance by increasing sedge and grass cover in the raised water table treatment and reducing moss cover while increasing vascular green area in the lowered water table treatment. Gross primary productivity was lower in the lowered treatment than in the other plots, although there were no differences in total biomass or vascular net primary productivity among the treatments. Overall, our results indicate that vegetation abundance was more sensitive to variation in water table than total biomass and vascular biomass accrual. Finally, in our experimental peatland, drought had stronger consequences for change in vegetation abundance and ecosystem function than sustained flooding.

  18. AEM investigations of primary water SCC in nickel alloys

    SciTech Connect

    Fish, J.S.; Perry, D.J.; Lewis, N.; Thompson, C.D.; Yang, W.J.S.

    1997-08-01

    The microstructure of nickel alloys, particularly the grain boundary composition and intergranular precipitates, plays an important role in high temperature primary water stress corrosion cracking (SCC) performance. Analytical electron microscopy (AEM) was used to examine SCC cracks in Alloys 600 and X-750 to investigate the role of grain boundary precipitates, dislocations and oxides in primary water SCC (PWSCC). Analysis of oxides by AEM and ESCA/Auger indicates that the crack tip oxides are different than the oxides formed on the outer surfaces. Comparison of heats with good and poor SCC resistance has identified metallurgical features that affect cracking. These AEM results show that the mechanism of PWSCC in nickel-base alloys does not involve void formation or blunting of the crack tip near intergranular carbides. The role of grain boundary composition, the interaction of cracks with carbides and other intergranular precipitates, and observations from AEM examinations ahead of the crack tip are discussed in relation to the mechanism of SCC.

  19. Quasi-Experimental Evaluation of a National Primary School HIV Intervention in Kenya

    ERIC Educational Resources Information Center

    Maticka-Tyndale, Eleanor; Wildish, Janet; Gichuru, Mary

    2007-01-01

    This study examined the impact of a primary-school HIV education initiative on the knowledge, self-efficacy and sexual and condom use activities of upper primary-school pupils in Kenya. A quasi-experimental mixed qualitative-quantitative pre- and 18-month post-design using 40 intervention and 40 matched control schools demonstrated significant…

  20. EBR-II Primary Tank Wash-Water Alternatives Evaluation

    SciTech Connect

    Demmer, R. L.; Heintzelman, J. B.; Merservey, R. H.; Squires, L. N.

    2008-05-01

    The EBR-II reactor at Idaho National Laboratory was a liquid sodium metal cooled reactor that operated for 30 years. It was shut down in 1994; the fuel was removed by 1996; and the bulk of sodium metal coolant was removed from the reactor by 2001. Approximately 1100 kg of residual sodium remained in the primary system after draining the bulk sodium. To stabilize the remaining sodium, both the primary and secondary systems were treated with a purge of moist carbon dioxide. Most of the residual sodium reacted with the carbon dioxide and water vapor to form a passivation layer of primarily sodium bicarbonate. The passivation treatment was stopped in 2005 and the primary system is maintained under a blanket of dry carbon dioxide. Approximately 670 kg of sodium metal remains in the primary system in locations that were inaccessible to passivation treatment or in pools of sodium that were too deep for complete penetration of the passivation treatment. The EBR-II reactor was permitted by the Idaho Department of Environmental Quality (DEQ) in 2002 under a RCRA permit that requires removal of all remaining sodium in the primary and secondary systems by 2022. The proposed baseline closure method would remove the large components from the primary tank, fill the primary system with water, react the remaining sodium with the water and dissolve the reaction products in the wash water. This method would generate a minimum of 100,000 gallons of caustic, liquid, low level radioactive, hazardous waste water that must be disposed of in a permitted facility. On February 19-20, 2008, a workshop was held in Idaho Falls, Idaho, to look at alternatives that could meet the RCRA permit clean closure requirements and minimize the quantity of hazardous waste generated by the cleanup process. The workshop convened a panel of national and international sodium cleanup specialists, subject matter experts from the INL, and the EBR-II Wash Water Project team that organized the workshop. The

  1. Experimental Activities in Primary School to Learn about Microbes in an Oral Health Education Context

    ERIC Educational Resources Information Center

    Mafra, Paulo; Lima, Nelson; Carvalho, Graça S.

    2015-01-01

    Experimental science activities in primary school enable important cross-curricular learning. In this study, experimental activities on microbiology were carried out by 16 pupils in a Portuguese grade-4 classroom (9-10?years old) and were focused on two problem-questions related to microbiology and health: (1) do your teeth carry microbes? (2) why…

  2. Effect of heat treatment on stress corrosion of Alloy 718 in pressurized-water-reactor primary water

    SciTech Connect

    Miglin, M.T.; Monter, J.V.; Wade, C.S.; Nelson, J.L.

    1992-12-31

    Stress corrosion cracking (SCC) tests were conducted in 360{degrees}C pressurized-water-reactor (PWR) primary water using alloy 718 in various heat treatment conditions. Alloy X-750 in the HTH condition and an experimental heat of an alloy 718 variation, Hicoroy, were also tested for comparison. Fatigue-precracked, 12.5-mm-thick compact fracture specimens were subjected to a constant extension rate of 1.3 x 10{sup {minus}9} m/s. Crack growth rate was measured during testing using a reversing DC potential drop technique. Results in the form of SCC crack growth rate versus applied stress intensity demonstrate that the SCC resistance of alloy 718 in the PWR primary-side environment can be improved by changes in heat treatment.

  3. Water movement through an experimental soil liner

    USGS Publications Warehouse

    Krapac, I.G.; Cartwright, K.; Panno, S.V.; Hensel, B.R.; Rehfeldt, K.R.; Herzog, B.L.

    1991-01-01

    A field-scale soil liner was constructed to test whether compacted soil barriers in cover and liner systems could be built to meet the U.S. EPA saturated hydraulic conductivity requirement (???1 x 10-7 cm s-1). The 8 x 15 x 0.9m liner was constructed in 15 cm compacted lifts using a 20,037 kg pad-foot compactor and standard engineering practices. Water infiltration into the liner has been monitored for one year. Monitoring will continue until water break through at the base of the liner occurs. Estimated saturated hydraulic conductivities were 2.5 x 10-9, 4.0 x 10-8, and 5.0 x 10-8 cm s-1 based on measurements of water infiltration into the liner by large- and small-ring infiltrometers and a water balance analysis, respectively. Also investigated in this research was the variability of the liner's hydraulic properties and estimates of the transit times for water and tracers. Small variances exhibited by small-ring flux data suggested that the liner was homogeneous with respect to infiltration fluxes. The predictions of water and tracer breakthrough at the base of the liner ranged from 2.4-12.6 y, depending on the method of calculation and assumptions made. The liner appeared to be saturated to a depth between 18 and 33 cm at the end of the first year of monitoring. Transit time calculations cannot be verified yet, since breakthrough has not occurred. The work conducted so far indicates that compacted soil barriers can be constructed to meet the saturated hydraulic conductivity requirement established by the U.S. EPA.A field-scale soil liner was constructed to test whether compacted soil barriers in cover and liner systems could be built to meet the U.S. EPA saturated hydraulic conductivity requirement (??? 1 ?? 10-7 cm s-1). The 8 ?? 15 ?? 0.9 m liner was constructed in 15 cm compacted lifts using a 20.037 kg pad-foot compactor and standard engineering practices. Water infiltration into the liner has been monitored for one year. Monitoring will continue until water

  4. Upper Washita River Experimental Watersheds: Nutrient Water Quality Data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water quality datasets were acquired by the USDA-ARS in three large research watersheds in Oklahoma: the Southern Great Plains Research Watershed (SGPRW), and the Little Washita River and Fort Cobb Reservoir Experimental Watersheds (LWREW and FCREW, respectively). Water quality data in the SGPRW we...

  5. Experimental Study of Sudden Solidification of Supercooled Water

    ERIC Educational Resources Information Center

    Bochnícek, Zdenek

    2014-01-01

    The two independent methods of measurement of the mass of ice created at sudden solidification of supercooled water are described. One is based on the calorimetric measurement of heat that is necessary for melting the ice and the second interprets the volume change that accompanies the water freezing. Experimental results are compared with the…

  6. Experimental study on the water impact of a symmetrical wedge

    NASA Astrophysics Data System (ADS)

    Yettou, El-Mahdi; Desrochers, Alain; Champoux, Yvan

    2006-01-01

    In this paper, we report the results of our experimental investigation of the pressure distribution on a free-falling wedge upon entering water. Parameters such as the drop height, the deadrise angle and the mass of the wedge are related to the water pressure on the wedge and its dynamic behavior. Existing models that assumed a constant water-entry velocity of the wedge are compared with experimental data. In order to take into account the inherent variation in the velocity of a free-falling wedge, a combination of two models are proposed. This method gives an adequate approximation of the maximum pressures measured.

  7. Discriminating secondary from primary water in volcanic glass using thermogravimetric analysis

    NASA Astrophysics Data System (ADS)

    Giachetti, T.; Gonnermann, H. M.; Gardner, J. E.; Shea, T.; Daniller-Varghese, M.

    2013-12-01

    Matrix-glass water in pyroclasts can include both primary (magmatic) and secondary (meteoric) water. Quantitative discrimination between magmatic and meteoric water is essential to interpret magma degassing processes, but remains challenging. Analyses of D/H isotopic ratios or water speciation help assess whether a texturally intact glass has been rehydrated, but we yet to correct for the extent of rehydration quantitatively, largely because the diffusivity of water at low temperatures (<400°C) is poorly understood. We present new results on the rehydration of rhyolitic pumices using thermogravimetric analysis (TGA). TGA quantifies precisely the mass lost from volatile exsolution (almost exclusively water in our case, as determined by both mass spectrometry and infrared spectroscopy) from a given sample heated to a specified temperature at specified rate. TGA has been used previously to discriminate between magmatic and meteoric water in silicic glasses, under the assumption that exsolution of meteoric water only occurs at T<550°C. Analyzed samples include crystal-free rhyolitic Plinian pumices from Glass Mountain (1.1 ka), Valles Caldera (50-60 ka) and Long Valley caldera (760 ka). All samples were crushed to <125 μm grains, and analyzed by TGA for temperatures up to 1000°C, using a heating rate of 20°C/min. The total weight loss attributed to water ranges from 1.3 wt% in pumice from Glass Mountain to >4.5 wt% in pumice from Valles Caldera. For all samples, >80% of the total water is lost far below 550°C, the first derivative of the mass loss always showing a major degassing peak between 210-320°C, followed by a smaller peak between 430-670°C. Moreover, the TGA curve of an obsidian from Glass Mountain, first dehydrated by heating the sample to 1000°C, and then experimentally hydrated to 3.9 wt% at high temperature and pressure (i.e., containing only ';magmatic' water), also shows that ~85% of the water is lost below 550°C, with a major peak around 380

  8. An Experimental Project on Energy Education for Rural Women, Primary School Children and Teachers Report.

    ERIC Educational Resources Information Center

    Pathak, Yogini; Mankodi, Hina

    One of the University of Baroda's (India) Rural/Tribal Block Placement Program's major aims during the year 1988-89 was to develop energy consciousness in women, primary school children and teachers. An experimental project was designed for a rural Indian village. The objectives were to obtain information on rural energy resources; assess the role…

  9. An experimental study on recovering heat from domestic drain water

    NASA Astrophysics Data System (ADS)

    Ramadan, Mohamad; Al Shaer, Ali; Haddad, Ahmad; Khaled, Mahmoud

    2016-07-01

    This paper concerns an experimental study on a system of heat recovery applied to domestic drain water pipes. The concept suggested consists of using the heat still present in the drain water as a preheating/heating source to the cold water supply of the building. To proceed, an appropriate experimental setup is developed and a coil heat exchanger is used as heat transfer device in the recovery system. Several scenarios are simulated and corresponding parameters are recorded and analyzed. It was shown that the suggested recovery concept can considerably preheat the cold water supply and then decrease the energy consumption. Particularly, up to 8.6 kW of heat were recovered when the cold water supply is initially at 3 °C.

  10. Experimental analysis of blast mitigation associated with water sheets

    NASA Astrophysics Data System (ADS)

    Zakrajsek, Andrew J.; Miklaszewski, Eric J.; Guildenbecher, Daniel R.; Son, Steven F.

    2012-03-01

    An explosion yielding a blast wave can cause catastrophic damage to a building and its personnel. This threat defines an immediate importance for understanding blast mitigation techniques via readily available materials. An unconfined mass of water in the form of a free flowing sheet has been experimentally tested and analyzed as a readily available mitigant. A single water sheet, with an approximate sheet thickness of 3 mm, was experimentally tested with an explosively driven shock tube at three different standoff distances. At the strongest shock strength considered, the water sheet decreased the peak overpressure of the blast wave by 80% and the impulse by 60%. Additionally, the peak overpressure transmitted through the water sheet was roughly constant regardless of standoff distance and explosive strength.

  11. Experimental observation of negative effective gravity in water waves.

    PubMed

    Hu, Xinhua; Yang, Jiong; Zi, Jian; Chan, C T; Ho, Kai-Ming

    2013-01-01

    The gravity of Earth is responsible for the formation of water waves and usually difficult to change. Although negative effective gravity was recently predicted theoretically in water waves, it has not yet been observed in experiments and remains a mathematical curiosity which is difficult to understand. Here we experimentally demonstrate that close to the resonant frequency of purposely-designed resonating units, negative effective gravity can occur for water waves passing through an array of resonators composing of bottom-mounted split tubes, resulting in the prohibition of water wave propagation. It is found that when negative gravity occurs, the averaged displacement of water surface in a unit cell of the array has a phase difference of π to that along the boundary of the unit cell, consistent with theoretical predictions. Our results provide a mechanism to block water waves and may find applications in wave energy conversion and coastal protection.

  12. Experimental Observation of Negative Effective Gravity in Water Waves

    PubMed Central

    Hu, Xinhua; Yang, Jiong; Zi, Jian; Chan, C. T.; Ho, Kai-Ming

    2013-01-01

    The gravity of Earth is responsible for the formation of water waves and usually difficult to change. Although negative effective gravity was recently predicted theoretically in water waves, it has not yet been observed in experiments and remains a mathematical curiosity which is difficult to understand. Here we experimentally demonstrate that close to the resonant frequency of purposely-designed resonating units, negative effective gravity can occur for water waves passing through an array of resonators composing of bottom-mounted split tubes, resulting in the prohibition of water wave propagation. It is found that when negative gravity occurs, the averaged displacement of water surface in a unit cell of the array has a phase difference of π to that along the boundary of the unit cell, consistent with theoretical predictions. Our results provide a mechanism to block water waves and may find applications in wave energy conversion and coastal protection. PMID:23715132

  13. Experimental studies toward the characterization of Inmetro's circulating water channel

    NASA Astrophysics Data System (ADS)

    Santos, A. M.; Alho, A. T. P.; Garcia, D. A.; Farias, M. H.; Massari, P. L.; Silva, V. V. S.

    2016-07-01

    Circulating water channels are facilities which can be used for conducting environmental, metrological and engineering studies. The Brazilian National Institute of Metrology-INMETRO has a water channel of innovative design, and the present work deals with the prior experimental investigation of its hydrodynamics performance. By using the optical technique PIV - Particle Image Velocimetry, under certain conditions, the velocity profile behavior in a region inside the channel was analyzed in order to evaluate the scope of applicability of such bench.

  14. Water-soluble primary amine compounds in rural continental precipitation

    NASA Astrophysics Data System (ADS)

    Gorzelska, Krystyna; Galloway, James N.; Watterson, Karen; Keene, William C.

    Procedures for collecting, storing and analysing precipitation samples for organic nitrogen studies were developed. These procedures preserve chemical integrities of the species of interest, allow for up to 3 months storage and quantitative determination of water-soluble primary amine compounds, with the overall error at the 2 nM detection limit of less than 30%. This methodology was applied to study amino compounds in precipitation samples collected over a period of one year in central Virginia. Nitrogen concentrations of 13 amino acids and 3 aliphatic amines were summed to calculate the total amine nitrogen (TAN). The concentration of TAN ranged from below our detection level to 6658 nM, and possibly reflected a seasonal variation in the source strength of the atmospheric amines. Overall, the most commonly occurring amino compounds were methyl amine, ethyl amine, glutamic acid, glycine and serine. On average, the highest overall contribution to the TAN came from arginine, asparagine, glutamine, methyl amine, serine and alanine. However, large qualitative and quantitative variations observed among samples warrant caution in interpretation and application of the averaged values. TAN in Charlottesville precipitation contributed from less than 1 to ca 10% of the ammonium nitrogen level. However, our estimates show that amino compounds may contribute significantly to reduced nitrogen budget in precipitation in remote regions.

  15. Experimental study of the constituents of space wash water

    NASA Technical Reports Server (NTRS)

    Putnam, D. F.; Colombo, G. V.

    1975-01-01

    This report presents experimental data, obtained under controlled conditions, which quantify the various constituents of human origin that may be expected in space wash water. The experiments were conducted with a simulated crew of two male and two female subjects. The data show that the expected wash water contaminants originating from human secretions are substantially lower than theoretical projections indicated. The data presented are immediately useful and may have considerable impact on the tradeoff comparisons among various unit processes and systems under consideration by NASA for recycling space wash water.

  16. The Strategy to Survive Primary Malaria Infection: An Experimental Study on Behavioural Changes in Parasitized Birds.

    PubMed

    Mukhin, Andrey; Palinauskas, Vaidas; Platonova, Elena; Kobylkov, Dmitry; Vakoliuk, Irina; Valkiūnas, Gediminas

    2016-01-01

    Avian malaria parasites (Haemosporida, Plasmodium) are of cosmopolitan distribution, and they have a significant impact on vertebrate host fitness. Experimental studies show that high parasitemia often develops during primary malaria infections. However, field studies only occasionally reveal high parasitemia in free-living birds sampled using the traditional methods of mist-netting or trapping, and light chronic infections predominate. The reason for this discrepancy between field observation and experimental data remains insufficiently understood. Since mist-netting is a passive capture method, two main parameters determine its success in sampling infected birds in wildlife, i. e. the presence of parasitized birds at a study site and their mobility. In other words, the trapping probability depends on the survival rate of birds and their locomotor activity during infection. Here we test (1) the mortality rate of wild birds infected with Plasmodium relictum (the lineage pSGS1), (2) the changes in their behaviour during presence of an aerial predator, and (3) the changes in their locomotor activity at the stage of high primary parasitemia.We show that some behavioural features which might affect a bird's survival during a predator attack (time of reaction, speed of flush flight and take off angle) did not change significantly during primary infection. However, the locomotor activity of infected birds was almost halved compared to control (non-infected) birds during the peak of parasitemia. We report (1) the markedly reduced mobility and (2) the 20% mortality rate caused by P. relictum and conclude that these factors are responsible for the underrepresentation of birds in mist nets and traps during the stage of high primary parasitemia in wildlife. This study indicates that the widespread parasite, P. relictum (pSGS1) influences the behaviour of birds during primary parasitemia. Experimental studies combined with field observations are needed to better understand the

  17. The Strategy to Survive Primary Malaria Infection: An Experimental Study on Behavioural Changes in Parasitized Birds

    PubMed Central

    Mukhin, Andrey; Palinauskas, Vaidas; Platonova, Elena; Kobylkov, Dmitry; Vakoliuk, Irina; Valkiūnas, Gediminas

    2016-01-01

    Avian malaria parasites (Haemosporida, Plasmodium) are of cosmopolitan distribution, and they have a significant impact on vertebrate host fitness. Experimental studies show that high parasitemia often develops during primary malaria infections. However, field studies only occasionally reveal high parasitemia in free-living birds sampled using the traditional methods of mist-netting or trapping, and light chronic infections predominate. The reason for this discrepancy between field observation and experimental data remains insufficiently understood. Since mist-netting is a passive capture method, two main parameters determine its success in sampling infected birds in wildlife, i. e. the presence of parasitized birds at a study site and their mobility. In other words, the trapping probability depends on the survival rate of birds and their locomotor activity during infection. Here we test (1) the mortality rate of wild birds infected with Plasmodium relictum (the lineage pSGS1), (2) the changes in their behaviour during presence of an aerial predator, and (3) the changes in their locomotor activity at the stage of high primary parasitemia.We show that some behavioural features which might affect a bird's survival during a predator attack (time of reaction, speed of flush flight and take off angle) did not change significantly during primary infection. However, the locomotor activity of infected birds was almost halved compared to control (non-infected) birds during the peak of parasitemia. We report (1) the markedly reduced mobility and (2) the 20% mortality rate caused by P. relictum and conclude that these factors are responsible for the underrepresentation of birds in mist nets and traps during the stage of high primary parasitemia in wildlife. This study indicates that the widespread parasite, P. relictum (pSGS1) influences the behaviour of birds during primary parasitemia. Experimental studies combined with field observations are needed to better understand the

  18. Fabrication of experimental three-meter space telescope primary and secondary mirror support structure

    NASA Technical Reports Server (NTRS)

    Mishler, H. W.

    1974-01-01

    The fabrication of prototype titanium alloy primary and secondary mirror support structures for a proposed experimental three-meter space telescope is discussed. The structure was fabricated entirely of Ti-6Al-4V tubing and plate. Fabrication included the development of procedures including welding, forming, and machining. Most of the structures was fabricated by gas-shielding tungsten-arc (GTA) welding with several major components fabricated by high frequency resistance (HFR) welding.

  19. 75 FR 40925 - National Primary Drinking Water Regulations: Revisions to the Total Coliform Rule

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-14

    ... Environmental Technology Verification FR Federal Register GW Ground Water GWR Ground Water Rule GWS Ground Water... Primary Drinking Water Regulations: Revisions to the Total Coliform Rule AGENCY: Environmental Protection... submitting comments. Mail: Water Docket, Environmental Protection Agency, Mailcode: 4101T, 1200......

  20. Decreased growth-induced water potential: A primary cause of growth inhibition at low water potentials

    SciTech Connect

    Nonami, Hiroshi; Wu, Yajun; Boyer, J.S.

    1997-06-01

    Cell enlargement depends on a growth-induced difference in water potential to move water into the cells. Water deficits decrease this potential difference and inhibit growth. To investigate whether the decrease causes the growth inhibition, pressure was applied to the roots of soybean seedlings and the growth and potential difference were monitored in the stems. In water-limited plants, the inhibited stem growth increased when the roots were pressurized and it reverted to the previous rate when the pressure was released. The pressure around the roots was perceived as an increased turgor in the stem in small cells next to the xylem, but not in outlying cortical cells. This local effect implied that water transport was impeded by the small cells. The diffusivity for water was much less in the small cells than in the outlying cells. The small cells thus were a barrier that caused the growth-induced potential difference to be large during rapid growth, but to reverse locally during the early part of a water deficit. Such a barrier may be a frequent property of meristems. Because stem growth responded to the pressure-induced recovery of the potential difference across this barrier, we conclude that a decrease in the growth-induced potential difference was a primary cause of the inhibition.

  1. Modeling primary dendrite arm spacings in resistance spot welds; Part 2: Experimental studies

    SciTech Connect

    Gould, J.E. )

    1994-05-01

    Hold time sensitivity is a potential concern when cold-rolled high-strength low-alloy sheet steels are used in resistance spot welded applications. Hold time sensitivity is defined by cracking, which occurs along the faying surface of the weld on peel testing when conventional hold times are used, and does not occur when reduces hold times are used. Hold time sensitivity is related to solidification cracking in the steel; however, it is believed that steel hardenability may also play a role. As an aid to understanding of solidification cracking in resistance spot welds, it is necessary to have an understanding of how the solidification structure develops. In this work, solidification structures in resistance spot welds have been characterized by the primary dendrite spacing. In Part 1 of this work, primary dendrite spacings were modeled by using a combination of numerical thermal modeling and closed-form primary dendrite spacings modeling. Numerical thermal modeling was used to predict solidification conditions in these welds. These solidification conditions were then used in the primary dendrite spacings model to predict the local spacings. In this paper, experimental studies were conducted to examine the validity of the modeling described in the previous paper. Experimentally, primary dendrite spacings were characterized for three grades of cold-rolled HSLA steel with nominal compositions of 0.05C-0.3Mn, 0.1C-1Mn and 0.15C-1.5Mn. For each steel, three separate thicknesses (nominally 0.8, 1.25 and 2.0 mm) were investigated. Primary dendrite spacings were determined at nominally the weld faying surface from deep-etched micrographs using an area-averaging technique.

  2. No evidence of complementary water use along a plant species richness gradient in temperate experimental grasslands.

    PubMed

    Bachmann, Dörte; Gockele, Annette; Ravenek, Janneke M; Roscher, Christiane; Strecker, Tanja; Weigelt, Alexandra; Buchmann, Nina

    2015-01-01

    Niche complementarity in resource use has been proposed as a key mechanism to explain the positive effects of increasing plant species richness on ecosystem processes, in particular on primary productivity. Since hardly any information is available for niche complementarity in water use, we tested the effects of plant diversity on spatial and temporal complementarity in water uptake in experimental grasslands by using stable water isotopes. We hypothesized that water uptake from deeper soil depths increases in more diverse compared to low diverse plant species mixtures. We labeled soil water in 8 cm (with 18O) and 28 cm depth (with ²H) three times during the 2011 growing season in 40 temperate grassland communities of varying species richness (2, 4, 8 and 16 species) and functional group number and composition (legumes, grasses, tall herbs, small herbs). Stable isotope analyses of xylem and soil water allowed identifying the preferential depth of water uptake. Higher enrichment in 18O of xylem water than in ²H suggested that the main water uptake was in the upper soil layer. Furthermore, our results revealed no differences in root water uptake among communities with different species richness, different number of functional groups or with time. Thus, our results do not support the hypothesis of increased complementarity in water use in more diverse than in less diverse communities of temperate grassland species.

  3. Oxygen isotope fractionation between analcime and water: An experimental study

    SciTech Connect

    Karlsson, H.R.; Clayton, R.N. )

    1990-05-01

    The fractionation of oxygen isotopes between natural analcime ({approximately}100 {mu}m) and water has been determined at 300, 350, and 400{degree}C at fluid pressures ranging from 1.5 to 5.0 kbar. Isotope ratios were obtained for the analcime framework, the channel water, and bulk water. Analcimes from Surtsey (145{degree}C), DSDP Hole 417A (30 to 55{degree}C), and Guam (25{degree}C) were used to constrain the fractionation factors below 300{degree}C. Analcime channel water exchanged completely with external water in all runs. Although some retrograde exchange may have occurred during quenching, the results indicate that the channel water is depleted in {sup 18}O relative to bulk water by a constant value of {approximately}5{per thousand}, nearly independent of temperature. Analcime is the first hydrated mineral found to have water of hydration depleted in {sup 18}O. Analcime framework oxygen exchanged 80, 90, and 96% at 300{degree}C for 412 h, 350{degree}C for 178 h, and 400{degree}C for 120 h, respectively. Equilibrium {Delta}{sup 18}O ({per thousand}) are as follows: 2.9 (400{degree}C), 4.5 (350{degree}C), and 5.8 (300{degree}C) for the experimental runs and 12.2 (145{degree}C) and 24.2 to 28.2 (30-55{degree}C) for the empirical data. The analcime-water fractionation curve is within experimental error of that of calcite-water. The exchange had little effect on grain morphology and does not involve recrystallization. This is the fastest exchange observed for a silicate. The rapid exchange rates indicate that zeolites in active high-temperature geothermal areas are in oxygen isotopic equilibrium with ambient fluids. Once calibrated, zeolites may be among the best low-temperature oxygen isotope geothermometers.

  4. Experimental characterization of water flow through smooth rectangular microchannels

    NASA Astrophysics Data System (ADS)

    Baviere, R.; Ayela, F.; Le Person, S.; Favre-Marinet, M.

    2005-09-01

    This article presents experimental results obtained in water flows through smooth rectangular microchannels. The experimental setup used in the present study enabled the investigation of both very small length scales (21-4.5μm) and a wide range of Reynolds numbers (0.1-300). The evolution of the friction coefficient was inferred from pressure drop versus flow-rate measurements for two types of water with different electrical conductivities. The channels were made of a silicon engraved substrate anodically bonded to a Pyrex cover. In these structures, pressure losses were measured internally with micromachined Cu-Ni strain gauges. When compared to macroscale correlations, the results demonstrate that in smooth silicon-Pyrex microchannels larger than 4μm in height, the friction law is correctly predicted by the Navier-Stokes equations with the classical no-slip boundary conditions, regardless of the water electrical conductivity (>0.1μScm-1).

  5. Treatment Technology to Meet the Interim Primary Drinking Water Regulations for Inorganics: Part 3.

    ERIC Educational Resources Information Center

    Sorg, Thomas J.; And Others

    1978-01-01

    This article is the third in a series summarizing existing treatment technology to meet the inorganic National Interim Primary Drinking Water Regulations. This report deals specifically with treatment methods for removing cadmium, lead, and silver from drinking water. (CS)

  6. Experimental Investigation of Impact in Landing on Water

    NASA Technical Reports Server (NTRS)

    Kreps, R. L.

    1943-01-01

    The extent of agreement of the theoretical impact computations with the actual phenomenon has not as yet been fully clarified. There is on the one hand a certain imperfection in the theory (simplifying assumptions made) and on the other an insufficiency in the experimental data available. The object of our present paper is to show how far test results agree with the available approximate computation methods, to investigate in greater detail the physical nature of impact on water, and to perfect the experimental method of studying the phenomenon.

  7. Hypoglycemic and antioxidant potential of coconut water in experimental diabetes.

    PubMed

    Preetha, P P; Devi, V Girija; Rajamohan, T

    2012-07-01

    Coconut water is a natural nutritious beverage that contains several biologically active compounds. The present study aims to evaluate the hypoglycemic and antioxidant effects of mature coconut water (MCW) on alloxan-induced diabetes in experimental rats. The experimental animals were divided into four groups - normal control, normal rats treated with MCW, diabetic control and diabetic rats treated with MCW. The blood glucose, plasma insulin, hemoglobin, glycated hemoglobin, activities of the various antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase) and lipid peroxidation markers (malondialdehyde, hydroperoxides and conjugated dienes) were evaluated in all the groups. The results indicate that the diabetic animals treated with MCW had decreased blood glucose levels and reduced oxidative stress induced by alloxan, which was evident from the increased activities of the antioxidant enzymes and the decreased levels of the lipid peroxidation products. The overall results indicate that MCW significantly attenuated hyperglycemia and oxidative stress in alloxan-induced diabetic rats, indicating the therapeutic potential of MCW.

  8. Primary School Pupils' Perceptions of Water in the Context of STS Study Approach

    ERIC Educational Resources Information Center

    Havu-Nuutinen, Sari; Karkkainen, Sirpa; Keinonen, Tuula

    2011-01-01

    This paper focuses on pupils' perceptions of water issues. The instructional situations take place in a Finnish primary school and aim at introducing the Science-Technology-Society (STS) study approach. The primary aim of this study is, in the context of STS instruction, to describe issues that pupils associate with water. This paper involves…

  9. Influence of dispersants on petroleum bioavailability to primary producers in a brackish water food chain

    SciTech Connect

    Younghans-Haug, C.O.; Wolfe, M.F.; Tjeerdema, R.S.; Sowby, M.L.

    1994-12-31

    Petroleum is transported and processed within biologically rich brackish environments worldwide. Past research has investigated disposition of chemically dispersed oil in mammals, fish, and higher invertebrates, yet little is known about how chemical dispersion influences petroleum behavior within primary producers within brackish water food chains. One concern is whether chemical dispersion influences petroleum bioavailability to primary producers and the potential for increased petroleum bioaccumulation. This research examines changes in petroleum bioavailability to the euryhaline phytoplankton Isochrysis galbana by measuring bioconcentration factors (BCFS) including uptake and deputation rates for dispersed and undispersed brackish water oil spills. Isochrysis is a major food source for zooplankton which are consumed by a multitude of larval fish having both ecological and commercial importance. Prudhoe Bay Crude oil, Corexit 9527, and {sup 14}C-naphthalene were used for these studies. Constant-concentration flow-through exposures were employed for the uptake and BCF experiments. Work was performed below the ``no observable effect concentration`` to eliminate stress-induced metabolic altercations that could in themselves influence petroleum behavior. Exposure chamber and experimental design will be discussed, and study results presented. Understanding how chemical dispersion alters petroleum behavior within the lowest levels of the food chain leads to better delineation of consumer risks.

  10. Enabling sustainable urban water management through governance experimentation.

    PubMed

    Bos, J J; Brown, R R; Farrelly, M A; de Haan, F J

    2013-01-01

    A shift towards sustainable urban water management is widely advocated but poorly understood. There is a growing body of literature claiming that social learning is of high importance in restructuring conventional systems. In particular, governance experimentation, which explicitly aims for social learning, has been suggested as an approach for enabling the translation of sustainability ideas into practice. This type of experimentation requires a very different dynamic within societal relations and necessitates a changed role for professionals engaged in such a process. This empirically focused paper investigates a contemporary governance experiment, the Cooks River Sustainability Initiative, and determines its outcome in terms of enabling social learning for attaining sustainable water practice in an urban catchment. Drawing on the qualitative insights of the actors directly involved in this novel process, this paper provides evidence of changes in individual and collective understanding generated through diverse forms of social interaction. Furthermore, the research reveals perceived key-factors that foster and/or hamper the execution of this new form of experimentation, including project complexity, resource intensity and leadership. Overall, this paper highlights that, while implementation of governance experimentation in a conventional setting can be highly challenging, it can also be highly rewarding in terms of learning. PMID:23579824

  11. Experimental investigation on water quality standard of Yangtze River water source heat pump.

    PubMed

    Qin, Zenghu; Tong, Mingwei; Kun, Lin

    2012-01-01

    Due to the surface water in the upper reaches of Yangtze River in China containing large amounts of silt and algae, high content of microorganisms and suspended solids, the water in Yangtze River cannot be used for cooling a heat pump directly. In this paper, the possibility of using Yangtze River, which goes through Chongqing, a city in southwest China, as a heat source-sink was investigated. Water temperature and quality of the Yangtze River in the Chongqing area were analyzed and the performance of water source heat pump units in different sediment concentrations, turbidity and algae material conditions were tested experimentally, and the water quality standards, in particular surface water conditions, in the Yangtze River region that adapt to energy-efficient heat pumps were also proposed. The experimental results show that the coefficient of performance heat pump falls by 3.73% to the greatest extent, and the fouling resistance of cooling water in the heat exchanger increases up to 25.6% in different water conditions. When the sediment concentration and the turbidity in the river water are no more than 100 g/m3 and 50 NTU respectively, the performance of the heat pump is better, which can be used as a suitable river water quality standard for river water source heat pumps.

  12. Experimental investigation on water quality standard of Yangtze River water source heat pump.

    PubMed

    Qin, Zenghu; Tong, Mingwei; Kun, Lin

    2012-01-01

    Due to the surface water in the upper reaches of Yangtze River in China containing large amounts of silt and algae, high content of microorganisms and suspended solids, the water in Yangtze River cannot be used for cooling a heat pump directly. In this paper, the possibility of using Yangtze River, which goes through Chongqing, a city in southwest China, as a heat source-sink was investigated. Water temperature and quality of the Yangtze River in the Chongqing area were analyzed and the performance of water source heat pump units in different sediment concentrations, turbidity and algae material conditions were tested experimentally, and the water quality standards, in particular surface water conditions, in the Yangtze River region that adapt to energy-efficient heat pumps were also proposed. The experimental results show that the coefficient of performance heat pump falls by 3.73% to the greatest extent, and the fouling resistance of cooling water in the heat exchanger increases up to 25.6% in different water conditions. When the sediment concentration and the turbidity in the river water are no more than 100 g/m3 and 50 NTU respectively, the performance of the heat pump is better, which can be used as a suitable river water quality standard for river water source heat pumps. PMID:22797241

  13. Optimization of the water chemistry of the primary coolant at nuclear power plants with VVER

    SciTech Connect

    Barmin, L. F.; Kruglova, T. K.; Sinitsyn, V. P.

    2005-01-15

    Results of the use of automatic hydrogen-content meter for controlling the parameter of 'hydrogen' in the primary coolant circuit of the Kola nuclear power plant are presented. It is shown that the correlation between the 'hydrogen' parameter in the coolant and the 'hydrazine' parameter in the makeup water can be used for controlling the water chemistry of the primary coolant system, which should make it possible to optimize the water chemistry at different power levels.

  14. Primary cell cultures from sea urchin ovaries: a new experimental tool.

    PubMed

    Mercurio, Silvia; Di Benedetto, Cristiano; Sugni, Michela; Candia Carnevali, M Daniela

    2014-02-01

    In the present work, primary cell cultures from ovaries of the edible sea urchin Paracentrotus lividus were developed in order to provide a simple and versatile experimental tool for researches in echinoderm reproductive biology. Ovary cell phenotypes were identified and characterized by different microscopic techniques. Although cell cultures could be produced from ovaries at all stages of maturation, the cells appeared healthier and viable, displaying a higher survival rate, when ovaries at early stages of gametogenesis were used. In terms of culture medium, ovarian cells were successfully cultured in modified Leibovitz-15 medium, whereas poor results were obtained in minimum essential medium Eagle and medium 199. Different substrates were tested, but ovarian cells completely adhered only on poly-L-lysine. To improve in vitro conditions and stimulate cell proliferation, different serum-supplements were tested. Fetal calf serum and an originally developed pluteus extract were detrimental to cell survival, apparently accelerating processes of cell death. In contrast, cells cultured with sea urchin egg extract appeared larger and healthier, displaying an increased longevity that allowed maintaining them for up to 1 month. Overall, our study provides new experimental bases and procedures for producing successfully long-term primary cell cultures from sea urchin ovaries offering a good potential to study echinoid oogenesis in a controlled system and to investigate different aspects of echinoderm endocrinology and reproductive biology.

  15. Primary Datasets for Case Studies of River-Water Quality

    ERIC Educational Resources Information Center

    Goulder, Raymond

    2008-01-01

    Level 6 (final-year BSc) students undertook case studies on between-site and temporal variation in river-water quality. They used professionally-collected datasets supplied by the Environment Agency. The exercise gave students the experience of working with large, real-world datasets and led to their understanding how the quality of river water is…

  16. Experimental study of spatiotemporally localized surface gravity water waves.

    PubMed

    Chabchoub, A; Akhmediev, N; Hoffmann, N P

    2012-07-01

    We present experimental results on the study of spatiotemporally localized surface wave events on deep water that can be modeled using the Peregrine breather solution of the nonlinear Schrödinger equation. These are often considered as prototypes of oceanic rogue waves that can focus wave energy into a single wave packet. For small steepness values of the carrier gravity waves the Peregrine breathers are relatively wide, thus providing an excellent agreement between the theory and experimental results. For larger steepnesses the focusing leads to temporally and spatially shorter events. Nevertheless, agreement between measurements and the Peregrine breather theory remains reasonably good, with discrepancies of modulation gradients and spatiotemporal symmetries being tolerable. Lifetimes and travel distances of the spatiotemporally localized wave events determined from the experiment are in good agreement with the theory.

  17. 75 FR 53267 - National Primary Drinking Water Regulations: Revisions to the Total Coliform Rule; Extension of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-31

    ... published in the Federal Register (75 FR 40926, July 14, 2010). The RTCR applies to all public water systems... for improved water system operation. See the proposal as published in the Federal Register (75 FR... AGENCY 40 CFR Parts 141 and 142 RIN 2040-AD94 National Primary Drinking Water Regulations: Revisions...

  18. A Teacher's Guide to the Study of Water for Primary Youngsters.

    ERIC Educational Resources Information Center

    Laskey, Marilyn

    Compiled in this teacher's guide are suggestions for a unit approach to the study of water in the primary grades. Designed to be utilized with related student documents, it contains the text or script of these works: THE ABC's OF WATER, SE 016 491 and A TRIP TO THE WATER PLANT, SE 016 488. Also, it includes unit objectives; teaching procedures; a…

  19. Water sorption and diffusion coefficient through an experimental dental resin.

    PubMed

    Costella, A M; Trochmann, J L; Oliveira, W S

    2010-01-01

    Polymeric composites have been widely used as dental restorative materials. A fundamental knowledge and understanding of the behavior of these materials in the oral cavity is essential to improve their properties and performance. In this paper we computed the data set of water absorption through an experimental dental resin blend using specimen discs of different thicknesses to estimate the diffusion coefficient. The resins were produced using Bisphenol A glycol dimethacrylate, Bisphenol A ethoxylated dimethacrylate and Triethylene glycol dimethacrylate monomers. The water sorption test method was based on International Standard ISO 4049 "Dentistry-Polymer-based filling materials". Results show a diffusion coefficient around 6.38 x 10(-8) cm(2)/s, within a variance of 0.01%, which is in good agreement with the values reported in the literature and represents a very suitable value.

  20. What is the primary mover of water dynamics?

    PubMed

    Ben Ishai, P; Tripathi, S R; Kawase, K; Puzenko, A; Feldman, Yu

    2015-06-21

    Even today, the H-bonded cluster structure of water still stands as a major point of debate in the science of liquids. Much of this discussion is devoted to understand its dynamic nature. This has a direct impact on deciphering the many anomalies of water such as its exceptional heat capacity. Of these properties, dielectric permittivity and relaxation are of particular interest. The argument rages over whether the almost Debye-like character of the dispersion is the result of the reorientation of an apparent dipole moment of the water cluster or simply the cumulative effect of single water molecule reorientation. Furthermore, like many glass formers, it has a high frequency excess wing that does not fit into the accepted models of a single relaxation time of the main peak. Herein, we present evidence that the microscopic origins of both the excess wing and the main relaxation process of pure water are the same. The origin of these two features is explored and we suggest a new paradigm for water relaxation based on the concept of a proton cascade leading to a cluster reorientation. PMID:26008633

  1. Cardiovascular autonomic dysfunction in primary ovarian insufficiency: clinical and experimental evidence

    PubMed Central

    Goldmeier, Silvia; De Angelis, Kátia; Rabello Casali, Karina; Vilodre, César; Consolim-Colombo, Fernanda; Belló Klein, Adriane; Plentz, Rodrigo; Spritzer, PoliMara; Irigoyen, Maria-Cláudia

    2014-01-01

    Objective: Women with primary ovarian insufficiency (POI) present an increased risk for cardiovascular disease. In this study we tested the hypothesis that POI in women under hormone therapy (HT) are associated with vascular vasodilatation attenuation and cardiovascular autonomic dysfunction and these impairments are related to changes in systemic antioxidant enzymes. Furthermore, the possibility that ovarian hormone deprivation can induce such changes and that HT cannot reverse all of those impairments was examined in an experimental model of POI. Methods: Fifteen control and 17 patients with primary ovarian insufficiency receiving HT were included in the study. To test the systemic and cardiac consequences of ovarian hormone deprivation, ovariectomy was induced in young female rats that were submitted or not to HT. Spectral analysis of RR interval and blood pressure signals were performed and oxidative stress parameters were determined. Results: POI women under HT have increased mean arterial pressure (94±10 vs. 86±5 mmHg) despite normal endothelial and autonomic modulation of vasculature. Additionally, they presented impaired baroreflex sensitivity (3.9±1.38 vs. 7.15±3.62 ms/mmHg) and reduced heart rate variability (2310±1173 vs. 3754±1921 ms2). Similar results obtained in ovariectomized female rats were accompanied by an increased lipoperoxidation (7433±1010 vs. 6180±289 cps/mg protein) and decreased antioxidant enzymes in cardiac tissue. As it was observed in women, the HT in animals did not restore hemodynamic and autonomic dysfunctions. Conclusion: These data provide clinical and experimental evidence that long term HT may not restore all cardiovascular risk factors associated with ovarian hormone deprivation. PMID:24349626

  2. Kinetics and advanced digester design for anaerobic digestion of water hyacinth and primary sludge

    SciTech Connect

    Chynoweth, D.P.; Dolenc, D.A.; Ghosh, S.; Henry, M.P.; Jerger, D.E.; Srivastava, V.J.

    1982-01-01

    A research program centered around a facility located at Walt Disney World (WDW) is in progress to evaluate the use of water hyacinth (WH) for secondary and tertiary wastewater treatment, to optimize growth of WH under these conditions, and to convert the resultant primary sludge (PS) and WH to methane via anaerobic digestion. This article describes the status of the biogasification component of this program, which includes baseline and advanced digestion experiments with individual feeds and blends and the design of an experimental test unit (ETU) to be installed at WDW. Experiments with several blends demonstrated that methane yields can be predicted from the fractional content and methane yield of each component. The process was found to adhere to the Monod kinetic model for microbial growth, and associated kinetic parameters were developed for various feed combinations. A novel upflow digester is achieving significantly higher conversion than a stirred-tank digester. Of several pretreatment techniques used, only alkaline treatment resulted in increased biodegradability. A larger scale (4.5 m/sup 3/) experimental test unit is being designed for installation at WDW in 1982. 13 figures, 4 tables.

  3. Automatic quantitative analysis of experimental primary and secondary retinal neurodegeneration: implications for optic neuropathies

    PubMed Central

    Davis, B M; Guo, L; Brenton, J; Langley, L; Normando, E M; Cordeiro, M F

    2016-01-01

    Secondary neurodegeneration is thought to play an important role in the pathology of neurodegenerative disease, which potential therapies may target. However, the quantitative assessment of the degree of secondary neurodegeneration is difficult. The present study describes a novel algorithm from which estimates of primary and secondary degeneration are computed using well-established rodent models of partial optic nerve transection (pONT) and ocular hypertension (OHT). Brn3-labelled retinal ganglion cells (RGCs) were identified in whole-retinal mounts from which RGC density, nearest neighbour distances and regularity indices were determined. The spatial distribution and rate of RGC loss were assessed and the percentage of primary and secondary degeneration in each non-overlapping segment was calculated. Mean RGC number (82 592±681) and RGC density (1695±23.3 RGC/mm2) in naïve eyes were comparable with previous studies, with an average decline in RGC density of 71±17 and 23±5% over the time course of pONT and OHT models, respectively. Spatial analysis revealed greatest RGC loss in the superior and central retina in pONT, but significant RGC loss in the inferior retina from 3 days post model induction. In comparison, there was no significant difference between superior and inferior retina after OHT induction, and RGC loss occurred mainly along the superior/inferior axis (~30%) versus the nasal–temporal axis (~15%). Intriguingly, a significant loss of RGCs was also observed in contralateral eyes in experimental OHT. In conclusion, a novel algorithm to automatically segment Brn3a-labelled retinal whole-mounts into non-overlapping segments is described, which enables automated spatial and temporal segmentation of RGCs, revealing heterogeneity in the spatial distribution of primary and secondary degenerative processes. This method provides an attractive means to rapidly determine the efficacy of neuroprotective therapies with implications for any

  4. Experimental stability analysis of different water-based nanofluids

    PubMed Central

    2011-01-01

    In the recent years, great interest has been devoted to the unique properties of nanofluids. The dispersion process and the nanoparticle suspension stability have been found to be critical points in the development of these new fluids. For this reason, an experimental study on the stability of water-based dispersions containing different nanoparticles, i.e. single wall carbon nanohorns (SWCNHs), titanium dioxide (TiO2) and copper oxide (CuO), has been developed in this study. The aim of this study is to provide stable nanofluids for selecting suitable fluids with enhanced thermal characteristics. Different dispersion techniques were considered in this study, including sonication, ball milling and high-pressure homogenization. Both the dispersion process and the use of some dispersants were investigated as a function of the nanoparticle concentration. The high-pressure homogenization was found to be the best method, and the addition of n-dodecyl sulphate and polyethylene glycol as dispersants, respectively in SWCNHs-water and TiO2-water nanofluids, improved the nanofluid stability. PMID:21711817

  5. Experimental Study of the PVTX Properties of Water-Methane

    NASA Astrophysics Data System (ADS)

    Lin, F.; Bodnar, R. J.

    2004-12-01

    Hydrothermal fluids containing small amounts of methane are common in many geological environments, including sedimentary basins, submarine hydrothermal systems and low grade metamorphic rocks. To better understand the behavior of these fluids, the phase equilibrium properties of water containing small amounts of methane (< 4 mol%) were determined using the synthetic fluid inclusion technique. Methane in the experiments was generated by the reaction of aluminum carbide with water to produce methane and aluminum hydroxide. Reaction products (methane and aluminum hydroxide) were verified by Raman spectroscopy and X-ray powder diffraction analyses, respectively. Concentrations of methane in the inclusions were calculated based on the reaction stoichiometry. A series of experiments demonstrated that using fresh aluminum carbide (from newly opened container) was critical to obtaining accurate compositions. This is because aluminum carbide decomposes slowly when exposed to humid air. Error analyses based on mass balance showed that with appropriate sample handling, the errors associated with the experimental technique were < 5% (relative) for methane concentrations < 4 mol%. Synthetic fluid inclusions containing < 4 mol% methane were trapped at 500-700° C, 1-3 kilobars. For a given formation temperature and pressure, the homogenization temperature decreases with increasing methane concentration. This behavior reflects both the changing slope of the fluid isochore as well as the increasing pressure on the solvus with increasing methane. Phase diagrams summarizing the PTX properties of the water-methane system will be presented.

  6. Recent Experimental Advances to Determine (noble) Gases in Waters

    NASA Astrophysics Data System (ADS)

    Kipfer, R.; Brennwald, M. S.; Huxol, S.; Mächler, L.; Maden, C.; Vogel, N.; Tomonaga, Y.

    2013-12-01

    In aquatic systems noble gases, radon, and bio-geochemically conservative transient trace gases (SF6, CFCs) are frequently applied to determine water residence times and to reconstruct past environmental and climatic conditions. Recent experimental breakthroughs now enable ● to apply the well-established concepts of terrestrial noble gas geochemistry in waters to the minute water amounts stored in sediment pore space and in fluid inclusions (A), ● to determine gas exchange processes on the bio-geochemical relevant time scales of minutes - hours (B), and ● to separate diffusive and advective gas transport in soil air (C). A. Noble-gas analysis in water samples (< 1 g) facilitates determining the solute transport in the pore space and identifying the origin of bio- and geogenic fluids in (un) consolidated sediments [1]. Advanced techniques that combine crushing and sieving speleothem samples in ultra-high-vacuum to a specific grain size allow to separate air and water-bearing fluid inclusions and thus enables noble-gas-based reconstruction of environmental conditions from water masses as small as 1mg [2]. B. The coupling of noble gas analysis with approaches of gas chromatography permits combined analysis of noble gases and other gases species (e.g., SF6, CFCs, O2, N2) from a single water sample. The new method substantially improves ground water dating by SF6 and CFCs as excess air is quantified from the same sample and hence can adequately be corrected for [3]. Portable membrane-inlet mass spectrometers enable the quasi-continuous and real-time analysis of noble gases and other dissolved gases directly in the field, allowing, for instance, quantification of O2 turnover rates on small time scales [4]. C. New technical developments perfect 222Rn analysis in water by the synchronous the determination of the short-lived 220Rn. The combined 220,222Rn analysis sheds light on the emanation behaviour of radon by identifying soil water content to be the crucial

  7. Experimental inoculation of Neospora caninum in pregnant water buffalo.

    PubMed

    Konrad, J L; Moore, D P; Crudeli, G; Caspe, S G; Cano, D B; Leunda, M R; Lischinsky, L; Regidor-Cerrillo, J; Odeón, A C; Ortega-Mora, L M; Echaide, I; Campero, C M

    2012-06-01

    The aim of this study was to characterize the pathogenesis of Neospora caninum in experimentally inoculated pregnant water buffalo (Bubalus bubalis). Twelve Mediterranean female water buffaloes ranging in age from 4 to 14 years old and seronegative to N. caninum by indirect fluorescent antibody test (IFAT) were involved. Ten females were intravenously inoculated with 10(8) tachyzoites of NC-1 strain at 70 (n=3) or 90 (n=7) days of pregnancy (dp). Two control animals were inoculated with placebo at 70 and 90 dp, respectively. Serum samples were obtained weekly following inoculation to the end of the experiment. Three animals inoculated at 70 dp were slaughtered at 28 days post inoculation (dpi), three animals inoculated at 90 dp were slaughtered at 28 dpi and the remaining four animals inoculated at 90 dp were slaughtered at 42 dpi. Fetal fluids from cavities and tissue samples were recovered for IFAT and histopathology, immunohistochemistry and PCR, respectively. Genomic DNA from fetal tissues was used for parasite DNA detection and microsatellite genotyping in order to confirm the NC-1 specific-infection. Dams developed specific antibodies one week after the inoculation and serological titers did not decrease significantly to the end of the experiment. No abortions were recorded during the experimental time; however, one fetus from a dam inoculated at 70 dp was not viable at necropsy. Specific antibodies were detected in only two fetuses from dams inoculated at 90 dp that were slaughtered at 42 dpi. No macroscopic changes in the placentas and organs of viable fetuses were observed. Nonsuppurative placentitis was a common microscopic observation in Neospora-inoculated specimens. Microscopic fetal lesions included nonsuppurative peribronchiolar interstitial pneumonia, epicarditis and myocarditis, interstitial nephritis, myositis and periportal hepatitis. Positive IHC results were obtained in two fetuses from dams inoculated at 70 dp and slaughtered at 28 dpi. N

  8. Experimental inoculation of Neospora caninum in pregnant water buffalo.

    PubMed

    Konrad, J L; Moore, D P; Crudeli, G; Caspe, S G; Cano, D B; Leunda, M R; Lischinsky, L; Regidor-Cerrillo, J; Odeón, A C; Ortega-Mora, L M; Echaide, I; Campero, C M

    2012-06-01

    The aim of this study was to characterize the pathogenesis of Neospora caninum in experimentally inoculated pregnant water buffalo (Bubalus bubalis). Twelve Mediterranean female water buffaloes ranging in age from 4 to 14 years old and seronegative to N. caninum by indirect fluorescent antibody test (IFAT) were involved. Ten females were intravenously inoculated with 10(8) tachyzoites of NC-1 strain at 70 (n=3) or 90 (n=7) days of pregnancy (dp). Two control animals were inoculated with placebo at 70 and 90 dp, respectively. Serum samples were obtained weekly following inoculation to the end of the experiment. Three animals inoculated at 70 dp were slaughtered at 28 days post inoculation (dpi), three animals inoculated at 90 dp were slaughtered at 28 dpi and the remaining four animals inoculated at 90 dp were slaughtered at 42 dpi. Fetal fluids from cavities and tissue samples were recovered for IFAT and histopathology, immunohistochemistry and PCR, respectively. Genomic DNA from fetal tissues was used for parasite DNA detection and microsatellite genotyping in order to confirm the NC-1 specific-infection. Dams developed specific antibodies one week after the inoculation and serological titers did not decrease significantly to the end of the experiment. No abortions were recorded during the experimental time; however, one fetus from a dam inoculated at 70 dp was not viable at necropsy. Specific antibodies were detected in only two fetuses from dams inoculated at 90 dp that were slaughtered at 42 dpi. No macroscopic changes in the placentas and organs of viable fetuses were observed. Nonsuppurative placentitis was a common microscopic observation in Neospora-inoculated specimens. Microscopic fetal lesions included nonsuppurative peribronchiolar interstitial pneumonia, epicarditis and myocarditis, interstitial nephritis, myositis and periportal hepatitis. Positive IHC results were obtained in two fetuses from dams inoculated at 70 dp and slaughtered at 28 dpi. N

  9. Microbial Biodiversity: Approaches to Experimental Design and Hypothesis Testing in Primary Scientific Literature from 1975 to 1999

    PubMed Central

    Morris, Cindy E.; Bardin, Marc; Berge, Odile; Frey-Klett, Pascale; Fromin, Nathalie; Girardin, Hélène; Guinebretière, Marie-Hélène; Lebaron, Philippe; Thiéry, Jean M.; Troussellier, Marc

    2002-01-01

    Research interest in microbial biodiversity over the past 25 years has increased markedly as microbiologists have become interested in the significance of biodiversity for ecological processes and as the industrial, medical, and agricultural applications of this diversity have evolved. One major challenge for studies of microbial habitats is how to account for the diversity of extremely large and heterogeneous populations with samples that represent only a very small fraction of these populations. This review presents an analysis of the way in which the field of microbial biodiversity has exploited sampling, experimental design, and the process of hypothesis testing to meet this challenge. This review is based on a systematic analysis of 753 publications randomly sampled from the primary scientific literature from 1975 to 1999 concerning the microbial biodiversity of eight habitats related to water, soil, plants, and food. These publications illustrate a dominant and growing interest in questions concerning the effect of specific environmental factors on microbial biodiversity, the spatial and temporal heterogeneity of this biodiversity, and quantitative measures of population structure for most of the habitats covered here. Nevertheless, our analysis reveals that descriptions of sampling strategies or other information concerning the representativeness of the sample are often missing from publications, that there is very limited use of statistical tests of hypotheses, and that only a very few publications report the results of multiple independent tests of hypotheses. Examples are cited of different approaches and constraints to experimental design and hypothesis testing in studies of microbial biodiversity. To prompt a more rigorous approach to unambiguous evaluation of the impact of microbial biodiversity on ecological processes, we present guidelines for reporting information about experimental design, sampling strategies, and analyses of results in

  10. Experimental Sarcocystis hominis infection in a water buffalo (Bubalus bubalis).

    PubMed

    Chen, X W; Zuo, Y X; Hu, J J

    2003-04-01

    A water buffalo (Bubalus bubalis) was fed 5.0 x 10(5) Sarcocystis hominis sporocysts from a human volunteer who had ingested S. hominis cysts from naturally infected cattle. A necropsy was performed on the buffalo 119 days after inoculation, and a large number of microscopic sarcocysts (approximately 5,000/g) were found in skeletal muscles. Ultrastructurally, the sarcocyst wall from buffalo muscles has upright villar protrusions measuring about 5.6 x 0.8 microm with numerous microtubules that run from the base to the apex. Sarcocysts from this buffalo were infective to 2 human volunteers, confirming their identity as S. hominis. Therefore, we believe that buffaloes can act experimentally as the intermediate host for S. hominis.

  11. Experimental Study of Water Transport through Hydrophilic Nanochannels

    NASA Astrophysics Data System (ADS)

    Alibakhshi, Mohammad Amin; Xie, Quan; Li, Yinxiao; Duan, Chuanhua

    2015-11-01

    In this paper, we investigate one of the fundamental aspects of Nanofluidics, which is the experimental study of water transport through nanoscale hydrophilic conduits. A new method based on spontaneous filling and a novel hybrid nanochannel design is developed to measure the pure mass flow resistance of single nanofluidic channels/tubes. This method does not require any pressure and flow sensors and also does not rely on any theoretical estimations, holding the potential to be standards for nanofluidic flow characterization. We have used this method to measure the pure mass flow resistance of single 2-D hydrophilic silica nanochannels with heights down to 7 nm. Our experimental results quantify the increased mass flow resistance as a function of nanochannel height, showing a 45% increase for a 7nm channel compared with classical hydrodynamics, and suggest that the increased resistance is possibly due to formation of a 7-angstrom-thick stagnant hydration layer on the hydrophilic surfaces. It has been further shown that this method can reliably measure a wide range of pure mass flow resistances of nanoscale conduits, and thus is promising for advancing studies of liquid transport in hydrophobic graphene nanochannels, CNTs, as well as nanoporous media. The work is supported by the American Chemical Society Petroleum Research Fund (ACS PRF # 54118-DNI7) and the Faculty Startup Fund (Boston University, USA).

  12. Perceptions of the Water Cycle among Primary School Children in Botswana.

    ERIC Educational Resources Information Center

    Taiwo, A. A.; Motswiri, M. J.; Masene, R.

    1999-01-01

    Describes qualitative and quantitative methods used to elucidate the nature of the perception of the water cycle held by Botswana primary-grade pupils in three different geographic areas. Concludes that the students' perception of the water cycle was positively influenced by schooling but negatively impacted upon, to some extent, by the untutored…

  13. Water-Free Shale Stimulation: Experimental Studies of Electrofracturing

    NASA Astrophysics Data System (ADS)

    Bauer, S. J.; Geilikman, M. B.; Gardner, W. P.; Broome, S. T.; Glover, S.; Williamson, K.; Su, J.

    2015-12-01

    Electrofracturing is a water-free stimulation method that might be applicable to hydrocarbon reservoirs. This method of dynamic fragmentation uses high-voltage pulses applied to rock via a pair of electrodes. Fragmentation occurs through two general processes (Cho et al, 2006): 1) electrohydraulic shock and 2) internal breakdown inside bulk solid dielectrics. In the first process, electrical current passing through brackish or salty water found naturally in the formation generates a shock wave of sufficient magnitude to crush/fail the rock as the wave travels through it. In the second process, the electric current flows through the rock preferentially along mineral interfaces; tensile and branching cracks are induced at the boundary interfaces either by heating and differential expansion, or by a shock wave induced by the electrical impulse itself. Both processes have been examined experimentally on rocks and on concrete starting in the late 1980's.In light of the "shale revolution" that has reinvigorated the North American petroleum resource base over the last decade, we developed a laboratory based experimental system to study coupled deformation and gas flow during high-voltage pulse application at elevated confining pressure (to 70 MPa). We deformed twelve samples using 6.5 μs full width at half maximum exponential voltage pulses from 80 to 200 kV. Exponential decay loading was shown to fracture shale at pressure, producing a 5-8 order-of-magnitude increase in permeability (initiating in the nD range) with significant fracturing. Fractures were documented using CT and SEM. The preponderance of fractures are parallel to bedding with fractures often extending from end to end in the samples, which were up to 9 cm in length. The bedding-parallel fractures are adjacent to, or off centered to, the input pulse location. Fractures oblique to bedding planes are present as well, but are fewer in number. The test system, and experimental and observational methods and

  14. Physico-chemical quality of drinking water in villages of Primary Health Centre, Waghodia, Gujarat (India).

    PubMed

    Desai, Gaurav; Vasisth, Smriti; Patel, Maharshi; Mehta, Vaibhav; Bhavsar, Bharat

    2012-07-01

    16 water samples were collected to study the physical and chemical quality of water of main source of drinking water in the villages of Primary Health Centre, Waghodia of Vadodara district of Gujarat. The values recommended by Indian Standard for Drinking Water (IS 10500:1991) were used for comparison of observed values. The study indicates that the contamination problem in these villages is not alarming at present, but Waghodia being industrial town, ground water quality may deteriorate with passage of time, which needs periodical monitoring. The study provides the local area baseline data which may be useful for the comparison of future study.

  15. Experimental study of choking flow of water at supercritical conditions

    NASA Astrophysics Data System (ADS)

    Muftuoglu, Altan

    Future nuclear reactors will operate at a coolant pressure close to 25 MPa and at outlet temperatures ranging from 500°C to 625°C. As a result, the outlet flow enthalpy in future Supercritical Water-Cooled Reactors (SCWR) will be much higher than those of actual ones which can increase overall nuclear plant efficiencies up to 48%. However, under such flow conditions, the thermal-hydraulic behavior of supercritical water is not fully known, e.g., pressure drop, forced convection and heat transfer deterioration, critical and blowdown flow rate, etc. Up to now, only a very limited number of studies have been performed under supercritical conditions. Moreover, these studies are conducted at conditions that are not representative of future SCWRs. In addition, existing choked flow data have been collected from experiments at atmospheric discharge pressure conditions and in most cases by using working fluids different than water which constrain researchers to analyze the data correctly. In particular, the knowledge of critical (choked) discharge of supercritical fluids is mandatory to perform nuclear reactor safety analyses and to design key mechanical components (e.g., control and safety relief valves, etc.). Hence, an experimental supercritical water facility has been built at Ecole Polytechnique de Montreal which allows researchers to perform choking flow experiments under supercritical conditions. The facility can also be used to carry out heat transfer and pressure drop experiments under supercritical conditions. In this thesis, we present the results obtained at this facility using a test section that contains a 1 mm inside diameter, 3.17 mm long orifice plate with sharp edges. Thus, 545 choking flow of water data points are obtained under supercritical conditions for flow pressures ranging from 22.1 MPa to 32.1 MPa, flow temperatures ranging from 50°C to 502°C and for discharge pressures from 0.1 MPa to 3.6 MPa. Obtained data are compared with the data given in

  16. Primary-secondary pumping conversion: Retrofit of an existing campus chilled water distribution system

    SciTech Connect

    Sczomak, D.P.; Nguyen, P.N.

    1996-08-01

    The chilled water distribution system within an existing 8,300 ton (29,200 kW) capacity regional chilled water plant at Michigan State University (MSU) is being converted from a primary pumping arrangement to a primary-secondary arrangement. The plant presently provides chilled water for air conditioning to twelve remote buildings. In the future, MSU plans to increase the plant`s capacity to 10,800 tons (38,000 kW) in order to serve seven more buildings. The addition of buildings to the distribution system has caused the existing primary pumps to be incapable of producing enough pressure to offset system losses at design flow rates. The existing system has become unable to concurrently provide adequate flow, design supply water temperature and efficient chiller operation due to the distribution system deficiencies. The primary-secondary pumping conversion will include modifications to the distribution piping, the addition of five variable speed secondary pumps, additions and modifications to the control systems, the trimming of impellers on six of the existing primary pumps and replacement of two primary pumps. The campus central control system will be utilized to provide automatic chiller staging, interface with the packaged secondary pump control systems, and control of the building interconnections. The total construction cost is approximately $1,400,000 and is scheduled for completion prior to the 1996 cooling season. Provisions have been made for two additional secondary pumps to accommodate the connection of additional buildings to the distribution system in the future.

  17. Aquaporin 4-specific T cells and NMO-IgG cause primary retinal damage in experimental NMO/SD.

    PubMed

    Zeka, Bleranda; Hastermann, Maria; Kaufmann, Nathalie; Schanda, Kathrin; Pende, Marko; Misu, Tatsuro; Rommer, Paulus; Fujihara, Kazuo; Nakashima, Ichiro; Dahle, Charlotte; Leutmezer, Fritz; Reindl, Markus; Lassmann, Hans; Bradl, Monika

    2016-01-01

    Neuromyelitis optica/spectrum disorder (NMO/SD) is a severe, inflammatory disease of the central nervous system (CNS). In the majority of patients, it is associated with the presence of pathogenic serum autoantibodies (the so-called NMO-IgGs) directed against the water channel aquaporin 4 (AQP4), and with the formation of large, astrocyte-destructive lesions in spinal cord and optic nerves. A large number of recent studies using optical coherence tomography (OCT) demonstrated that damage to optic nerves in NMO/SD is also associated with retinal injury, as evidenced by retinal nerve fiber layer (RNFL) thinning and microcystic inner nuclear layer abnormalities. These studies concluded that retinal injury in NMO/SD patients results from secondary neurodegeneration triggered by optic neuritis.However, the eye also contains cells expressing AQP4, i.e., Müller cells and astrocytes in the retina, epithelial cells of the ciliary body, and epithelial cells of the iris, which raised the question whether the eye can also be a primary target in NMO/SD. Here, we addressed this point in experimental NMO/SD (ENMO) induced in Lewis rat by transfer of AQP4268-285-specific T cells and NMO-IgG.We show that these animals show retinitis and subsequent dysfunction/damage of retinal axons and neurons, and that this pathology occurs independently of the action of NMO-IgG. We further show that in the retinae of ENMO animals Müller cell side branches lose AQP4 reactivity, while retinal astrocytes and Müller cell processes in the RNFL/ganglionic cell layers are spared. These changes only occur in the presence of both AQP4268-285-specific T cells and NMO-IgG.Cumulatively, our data show that damage to retinal cells can be a primary event in NMO/SD. PMID:27503347

  18. Preliminary experimental results of tungsten wire-array Z-pinches on primary test stand

    SciTech Connect

    Huang, Xian-Bin; Zhou, Shao-Tong; Dan, Jia-Kun; Ren, Xiao-Dong Wang, Kun-Lun; Zhang, Si-Qun; Li, Jing; Xu, Qiang; Cai, Hong-Chun; Duan, Shu-Chao; Ouyang, Kai; Chen, Guang-Hua; Ji, Ce; Wei, Bing; Feng, Shu-Ping; Wang, Meng; Xie, Wei-Ping; Deng, Jian-Jun; Zhou, Xiu-Wen; Yang, Yi

    2015-07-15

    The Primary Test Stand (PTS) developed at the China Academy of Engineering Physics is a 20 TW pulsed power driver, which can deliver a ∼10 MA, 70 ns rise-time (10%–90%) current to a short-circuit load and has important applications in Z-pinch driven inertial confinement fusion and high energy density physics. Preliminary results of tungsten wire-array Z-pinch experiments on PTS are presented. The load geometries investigated include 15-mm-tall cylindrical single and nested arrays with diameter ranging from 13 mm to 30 mm, consisting of 132–300 tungsten wires with 5–10 μm in diameter. Multiple diagnostics were fielded to characterize the x-ray radiation from wire-array Z pinches. The x-ray peak power (∼50 TW) and total radiated energy (∼500 kJ) were obtained from a single 20-mm-diam array with 80-ns stagnation time. The highest x-ray peak power up to 80 TW with 2.4 ns FWHM was achieved by using a nested array with 20-mm outer diameter, and the total x-ray energy from the nested array is comparable to that of single array. Implosion velocity estimated from the time-resolved image measurement exceeds 30 cm/μs. The detailed experimental results and other findings are presented and discussed.

  19. Does Improved Water Access Increase Child School Attendance? A Quasi-Experimental Approach From Rural Ethiopia

    NASA Astrophysics Data System (ADS)

    Masuda, Y.; Cook, J.

    2012-12-01

    This paper analyzes the impact of improved water access on child school attendance using two years of primary panel data from a quasi-experimental study in Oromiya, Ethiopia. A predominant form of child labor in rural poor households in least developed countries is water collection. Girls are often the primary water collectors for households, and because of the time intensive nature of water collection improved water access may allow for time to be reallocated to schooling (Rosen and Vincent 1999; Nankhuni and Findeis 2004). Understanding how improved water access may increase schooling for girls has important development policy implications. Indeed, abundant research on returns to education suggests increased schooling for girls is tied to improved future child and maternal health, economic opportunities, and lower fertility rates (Handa 1996; Schultz 1998; Michaelowa 2000). The literature to date finds that improved water access leads to increased schooling; however, there still exists a clear gap in the literature for understanding this relationship for two reasons. First, only four studies have directly examined the relationship between improved water access and schooling in sub-Saharan Africa, and analyses have been limited due to the use of cross-sectional data and research designs (Nankhuni and Findeis 2004; Koolwal and Van de Walle 2010; Ndiritu and Nyangan 2011; Nauges and Strand 2011). Indeed, only two studies have attempted to control for the endogenous nature of water access. Second, all studies use a binary school enrollment indicator from household surveys, which may suffer from response bias and may be an imperfect measure for actual schooling. Respondents may feel pressured to report that their children are enrolled in school if, like in Ethiopia, there are compulsory education laws. This may result in an overestimation of school enrollment. In addition, most children from rural poor households combine work and school, and a binary indicator does

  20. Glass polymorphism in glycerol–water mixtures: II. Experimental studies

    PubMed Central

    Bachler, Johannes; Fuentes-Landete, Violeta; Jahn, David A.; Wong, Jessina; Giovambattista, Nicolas

    2016-01-01

    We report a detailed experimental study of (i) pressure-induced transformations in glycerol–water mixtures at T = 77 K and P = 0–1.8 GPa, and (ii) heating-induced transformations of glycerol–water mixtures recovered at 1 atm and T = 77 K. Our samples are prepared by cooling the solutions at ambient pressure at various cooling rates (100 K s–1–10 K h–1) and for the whole range of glycerol mole fractions, χ g. Depending on concentration and cooling rates, cooling leads to samples containing amorphous ice (χ g ≥ 0.20), ice (χ g ≤ 0.32), and/or “distorted ice” (0 < χ g ≤ 0.38). Upon compression, we find that (a) fully vitrified samples at χ g ≥ 0.20 do not show glass polymorphism, in agreement with previous works; (b) samples containing ice show pressure-induced amorphization (PIA) leading to the formation of high-density amorphous ice (HDA). PIA of ice domains within the glycerol–water mixtures is shown to be possible only up to χ g ≈ 0.32 (T = 77 K). This is rather surprising since it has been known that at χ g < 0.38, cooling leads to phase-separated samples with ice and maximally freeze-concentrated solution of χ g ≈ 0.38. Accordingly, in the range 0.32 < χ g < 0.38, we suggest that the water domains freeze into an interfacial ice, i.e., a highly-distorted form of layered ice, which is unable to transform to HDA upon compression. Upon heating samples recovered at 1 atm, we observe a rich phase behavior. Differential scanning calorimetry indicates that only at χ g ≤ 0.15, the water domains within the sample exhibit polyamorphism, i.e., the HDA-to-LDA (low-density amorphous ice) transformation. At 0.15 < χ g ≤ 0.38, samples contain ice, interfacial ice, and/or HDA domains. All samples (χ g ≤ 0.38) show: the crystallization of amorphous ice domains, followed by the glass transition of the vitrified glycerol–water domains and, finally, the melting of ice at high temperatures. Our work exemplifies the complex

  1. Glass polymorphism in glycerol-water mixtures: II. Experimental studies.

    PubMed

    Bachler, Johannes; Fuentes-Landete, Violeta; Jahn, David A; Wong, Jessina; Giovambattista, Nicolas; Loerting, Thomas

    2016-04-28

    We report a detailed experimental study of (i) pressure-induced transformations in glycerol-water mixtures at T = 77 K and P = 0-1.8 GPa, and (ii) heating-induced transformations of glycerol-water mixtures recovered at 1 atm and T = 77 K. Our samples are prepared by cooling the solutions at ambient pressure at various cooling rates (100 K s(-1)-10 K h(-1)) and for the whole range of glycerol mole fractions, χ(g). Depending on concentration and cooling rates, cooling leads to samples containing amorphous ice (χg ≥ 0.20), ice (χ(g) ≤ 0.32), and/or "distorted ice" (0 < χ(g) ≤ 0.38). Upon compression, we find that (a) fully vitrified samples at χ(g) ≥ 0.20 do not show glass polymorphism, in agreement with previous works; (b) samples containing ice show pressure-induced amorphization (PIA) leading to the formation of high-density amorphous ice (HDA). PIA of ice domains within the glycerol-water mixtures is shown to be possible only up to χ(g) ≈ 0.32 (T = 77 K). This is rather surprising since it has been known that at χ(g) < 0.38, cooling leads to phase-separated samples with ice and maximally freeze-concentrated solution of χ(g) ≈ 0.38. Accordingly, in the range 0.32 < χ(g) < 0.38, we suggest that the water domains freeze into an interfacial ice, i.e., a highly-distorted form of layered ice, which is unable to transform to HDA upon compression. Upon heating samples recovered at 1 atm, we observe a rich phase behavior. Differential scanning calorimetry indicates that only at χ(g) ≤ 0.15, the water domains within the sample exhibit polyamorphism, i.e., the HDA-to-LDA (low-density amorphous ice) transformation. At 0.15 < χ(g) ≤ 0.38, samples contain ice, interfacial ice, and/or HDA domains. All samples (χ(g) ≤ 0.38) show: the crystallization of amorphous ice domains, followed by the glass transition of the vitrified glycerol-water domains and, finally, the melting of ice at high temperatures. Our work exemplifies the complex "phase" behavior

  2. Glass polymorphism in glycerol-water mixtures: II. Experimental studies.

    PubMed

    Bachler, Johannes; Fuentes-Landete, Violeta; Jahn, David A; Wong, Jessina; Giovambattista, Nicolas; Loerting, Thomas

    2016-04-28

    We report a detailed experimental study of (i) pressure-induced transformations in glycerol-water mixtures at T = 77 K and P = 0-1.8 GPa, and (ii) heating-induced transformations of glycerol-water mixtures recovered at 1 atm and T = 77 K. Our samples are prepared by cooling the solutions at ambient pressure at various cooling rates (100 K s(-1)-10 K h(-1)) and for the whole range of glycerol mole fractions, χ(g). Depending on concentration and cooling rates, cooling leads to samples containing amorphous ice (χg ≥ 0.20), ice (χ(g) ≤ 0.32), and/or "distorted ice" (0 < χ(g) ≤ 0.38). Upon compression, we find that (a) fully vitrified samples at χ(g) ≥ 0.20 do not show glass polymorphism, in agreement with previous works; (b) samples containing ice show pressure-induced amorphization (PIA) leading to the formation of high-density amorphous ice (HDA). PIA of ice domains within the glycerol-water mixtures is shown to be possible only up to χ(g) ≈ 0.32 (T = 77 K). This is rather surprising since it has been known that at χ(g) < 0.38, cooling leads to phase-separated samples with ice and maximally freeze-concentrated solution of χ(g) ≈ 0.38. Accordingly, in the range 0.32 < χ(g) < 0.38, we suggest that the water domains freeze into an interfacial ice, i.e., a highly-distorted form of layered ice, which is unable to transform to HDA upon compression. Upon heating samples recovered at 1 atm, we observe a rich phase behavior. Differential scanning calorimetry indicates that only at χ(g) ≤ 0.15, the water domains within the sample exhibit polyamorphism, i.e., the HDA-to-LDA (low-density amorphous ice) transformation. At 0.15 < χ(g) ≤ 0.38, samples contain ice, interfacial ice, and/or HDA domains. All samples (χ(g) ≤ 0.38) show: the crystallization of amorphous ice domains, followed by the glass transition of the vitrified glycerol-water domains and, finally, the melting of ice at high temperatures. Our work exemplifies the complex "phase" behavior

  3. Experimental constraints on CO2 and H2O in the Martian mantle and primary magmas

    NASA Technical Reports Server (NTRS)

    Holloway, John R.; Domanik, Kenneth J.; Cocheo, Peter A.

    1993-01-01

    We present new data on the stability of hornblende in a Martian mantle composition, on CO2 solubility in iron-rich basaltic magmas, and on the solubility of H2O in an alkalic basaltic magma. These new data are combined with a summary of data from the literature to present a summary of the current state of our estimates of solubilities of H2O and CO2 in probable Martian magmas and the stability of hornblende in a slightly hydrous mantle. The new results suggest that hornblende stability is not sensitive to the Mg/(Mg+Fe) ratio (mg#) of the mantle, that is the results for terrestrial mantle compositions are similar to the more iron-rich Martian composition. Likewise, CO2 solubility in iron-rich tholeiitic basaltic magmas is similar to iron-poor terrestrial compositions. The solubility of H2O has been measured in an alkalic basaltic (basanite) composition for the first time, and it is significantly lower than predicted for models of water solubility in magmas. The lack of mg# dependence observed in hornblende stability and on CO2 solubility that in many cases terrestrial results can be applied to Martian compositions. This conclusion does not apply to other phenomena such as primary magma compositions and major mantle mineral mineralogy.

  4. Experimental and Computational Study of Water Blast Mitigation Associated with Different Water Configurations

    NASA Astrophysics Data System (ADS)

    Zakrajsek, Andrew; Miklaszewski, Eric; Son, Steven

    2011-06-01

    An explosion yielding a shock wave is just one of the many threats the US faces. This threat can cause damage to equipment, structures, and cause significant risk to personnel. These threats define an immediate importance for understanding blast mitigation techniques via readily available mitigants. Specific blast mitigation techniques using water are being studied. Four fundamentally different water configurations are being considered. The fundamental mitigation mechanisms such as momentum transfer, large impedance differences, and evaporation are being explored. Laboratory testing using an explosively driven shock tube and a pressurized air shock tube are used for configurations including: solid water barriers, water sprays, water sheets, and individual droplets of water. Trends observed will be explained based on simulations coupled with known droplet breakup phenomena and analysis. We will report on experimental results and analysis, in addition to discussing the various blast mechanisms associated with each testing configuration. Funded by the Department of Homeland Security under the Center of Excellence for Explosive Detection, Mitigation and Response. Sponsor Award No. 080409/0002251.

  5. Response of millet and sorghum to a varying water supply around the primary and nodal roots

    PubMed Central

    Rostamza, M.; Richards, R. A.; Watt, M.

    2013-01-01

    Background and Aims Cereals have two root systems. The primary system originates from the embryo when the seed germinates and can support the plant until it produces grain. The nodal system can emerge from stem nodes throughout the plant's life; its value for yield is unclear and depends on the environment. The aim of this study was to test the role of nodal roots of sorghum and millet in plant growth in response to variation in soil moisture. Sorghum and millet were chosen as both are adapted to dry conditions. Methods Sorghum and millet were grown in a split-pot system that allowed the primary and nodal roots to be watered separately. Key Results When primary and nodal roots were watered (12 % soil water content; SWC), millet nodal roots were seven times longer than those of sorghum and six times longer than millet plants in dry treatments, mainly from an 8-fold increase in branch root length. When soil was allowed to dry in both compartments, millet nodal roots responded and grew 20 % longer branch roots than in the well-watered control. Sorghum nodal roots were unchanged. When only primary roots received water, nodal roots of both species emerged and elongated into extremely dry soil (0·6–1·5 % SWC), possibly with phloem-delivered water from the primary roots in the moist inner pot. Nodal roots were thick, short, branchless and vertical, indicating a tropism that was more pronounced in millet. Total nodal root length increased in both species when the dry soil was covered with plastic, suggesting that stubble retention or leaf mulching could facilitate nodal roots reaching deeper moist layers in dry climates. Greater nodal root length in millet than in sorghum was associated with increased shoot biomass, water uptake and water use efficiency (shoot mass per water). Millet had a more plastic response than sorghum to moisture around the nodal roots due to (1) faster growth and progression through ontogeny for earlier nodal root branch length and (2

  6. Experimental Study of Water Droplet Vaporization on Nanostructured Surfaces

    NASA Astrophysics Data System (ADS)

    Padilla, Jorge, Jr.

    This dissertation summarizes results of an experimental exploration of heat transfer during vaporization of a water droplet deposited on a nanostructured surface at a temperature approaching and exceeding the Leidenfrost point for the surface and at lower surface temperatures 10-40 degrees C above the saturated temperature of the water droplet at approximately 101 kPa. The results of these experiments were compared to those performed on bare smooth copper and aluminum surfaces in this and other studies. The nanostructured surfaces were composed of a vast array of zinc oxide (ZnO) nanocrystals grown by hydrothermal synthesis on a smooth copper substrate having an average surface roughness of approximately 0.06 micrometer. Various nanostructured surface array geometries were produced on the copper substrate by performing the hydrothermal synthesis for 4, 10 and 24 hours. The individual nanostructures were randomly-oriented and, depending on hydrothermal synthesis time, had a mean diameter of about 500-700 nm, a mean length of 1.7-3.3 micrometers,and porosities of approximately 0.04-0.58. Surface wetting was characterized by macroscopic measurements of contact angle based on the droplet profile and calculations based on measurements of liquid film spread area. Scanning electron microscope imaging was used to document the nanoscale features of the surface before and after the experiments. The nanostructured surfaces grown by hydrothermal synthesis for 4 and 24 hours exhibited contact angles of approximately 10, whereas the surfaces grown for 10 hours were superhydrophilic, exhibiting contact angles typically less than 3 degrees. In single droplet deposition experiments at 101 kPa, a high-speed video camera was used to document the droplet-surface interaction. Distilled and degassed water droplets ranging in size from 2.5-4.0 mm were deposited onto the surface from heights ranging from approximately 0.2-8.1 cm, such that Weber numbers spanned a range of approximately 0

  7. Thermal analysis of hydrated volcanic glasses: can primary and secondary water be distinguished?

    NASA Astrophysics Data System (ADS)

    Tuffen, H.

    2012-12-01

    The overwhelming majority of glassy volcanic rocks have undergone extensive post-quenching hydration by meteoric water. In order to unlock the record of magma degassing in hydrated glasses we require techniques to characterise and separate primary (magmatic) and secondary (meteoric) water. Possible approaches include mapping of spatial heterogeneities with micro-analytical tools, determination of bulk degassing behaviour using thermal analysis, measurement of water speciation using infra-red spectroscopy, and measurement of isotopic compositions to separate endmembers. Here I provide an overview of thermal analysis (TGA-MS) carried out on variably hydrated volcanic glasses from Taupo, Torfajökull, Vesuvius and Chaitén. Glasses span a range of compositions (phonolitic, rhyodacitic and rhyolitic), grainsizes (metre-scale lava bodies to fine-grained ashes) and ages (~95 ka to 2008). Powdered samples were heated to 1250 °C at 5 °C/min and the patterns of weight loss determined, whilst exsolved gases were analysed by mass spectrometry. Degassing from samples is characterised by the dTGA and TGA curves (rate and total amount of weight loss during heating). The nature of the dTGA curve is determined by the spatial distribution of water within samples (distance to surfaces), its speciation, and the concentration-and temperature-dependent water diffusivity. Hydration experiments on fresh, non-hydrated ash collected directly after the 2008 Chaitén eruption illustrate how rapidly fresh glasses can become hydrated post-eruption. In TGA-MS measurements this secondary water is degassed at lower temperatures than magmatic water, allowing primary and secondary degassing peaks to be separated. This indicates that thermal analysis can allow determination of bulk magmatic water concentrations in young, incipiently hydrated glasses. Hydration in older glasses becomes far more pervasive, as demonstrated by SIMS mapping of water concentration heterogeneities in Taupo AD181 pumices

  8. Spatiotemporal analysis of propagation mechanism of positive primary streamer in water

    NASA Astrophysics Data System (ADS)

    Fujita, Hidemasa; Kanazawa, Seiji; Ohtani, Kiyonobu; Komiya, Atsuki; Sato, Takehiko

    2013-03-01

    Currently, further clarification of pre-breakdown phenomena in water such as propagation mechanisms of primary and secondary streamers are needed because applications of aqueous plasma to environmental and medical treatments are increasing. In this study, a series of primary streamer propagations in ultrapure water was visualized at 100-Mega frames per second (100 Mfps) in the range of 400 μm square using an ultra high-speed camera with a microscope lens when a single-shot pulsed positive voltage was applied to a needle electrode placed in a quartz cell. Every observation was synchronized with the waveforms of the applied voltage and the discharge current. The primary streamer, having many filamentary channels, started to propagate semi-spherically with a velocity of about 2 km/s when the pulsed currents occurred. Although most filamentary channels disappeared 400 ns after the beginning of the primary streamer, a few of them continued propagating with almost the same velocity (about 2 km/s) as long as the repetitive pulsed currents flowed. Shock waves were iteratively generated and streamer channels were formed while the repetitive pulsed currents were flowing. Thus, we concluded that the positive primary streamer in water propagates progressively with each repetitive pulsed current.

  9. Effect of dissolved oxygen content on stress corrosion cracking of a cold worked 316L stainless steel in simulated pressurized water reactor primary water environment

    NASA Astrophysics Data System (ADS)

    Zhang, Litao; Wang, Jianqiu

    2014-03-01

    Stress corrosion crack growth tests of a cold worked nuclear grade 316L stainless steel were conducted in simulated pressurized water reactor (PWR) primary water environment containing various dissolved oxygen (DO) contents but no dissolved hydrogen. The crack growth rate (CGR) increased with increasing DO content in the simulated PWR primary water. The fracture surface exhibited typical intergranular stress corrosion cracking (IGSCC) characteristics.

  10. Bioremediating oil spills in nutrient poor ocean waters using fertilized clay mineral flakes: some experimental constraints.

    PubMed

    Warr, Laurence N; Friese, André; Schwarz, Florian; Schauer, Frieder; Portier, Ralph J; Basirico, Laura M; Olson, Gregory M

    2013-01-01

    Much oil spill research has focused on fertilizing hydrocarbon oxidising bacteria, but a primary limitation is the rapid dilution of additives in open waters. A new technique is presented for bioremediation by adding nutrient amendments to the oil spill using thin filmed minerals comprised largely of Fullers Earth clay. Together with adsorbed N and P fertilizers, filming additives, and organoclay, clay flakes can be engineered to float on seawater, attach to the oil, and slowly release contained nutrients. Our laboratory experiments of microbial activity on weathered source oil from the Deepwater Horizon spill in the Gulf of Mexico show fertilized clay treatment significantly enhanced bacterial respiration and consumption of alkanes compared to untreated oil-in-water conditions and reacted faster than straight fertilization. Whereas a major portion (up to 98%) of the alkane content was removed during the 1 month period of experimentation by fertilized clay flake interaction; the reduced concentration of polyaromatic hydrocarbons was not significantly different from the non-clay bearing samples. Such clay flake treatment could offer a way to more effectively apply the fertilizer to the spill in open nutrient poor waters and thus significantly reduce the extent and duration of marine oil spills, but this method is not expected to impact hydrocarbon toxicity.

  11. Bioremediating oil spills in nutrient poor ocean waters using fertilized clay mineral flakes: some experimental constraints.

    PubMed

    Warr, Laurence N; Friese, André; Schwarz, Florian; Schauer, Frieder; Portier, Ralph J; Basirico, Laura M; Olson, Gregory M

    2013-01-01

    Much oil spill research has focused on fertilizing hydrocarbon oxidising bacteria, but a primary limitation is the rapid dilution of additives in open waters. A new technique is presented for bioremediation by adding nutrient amendments to the oil spill using thin filmed minerals comprised largely of Fullers Earth clay. Together with adsorbed N and P fertilizers, filming additives, and organoclay, clay flakes can be engineered to float on seawater, attach to the oil, and slowly release contained nutrients. Our laboratory experiments of microbial activity on weathered source oil from the Deepwater Horizon spill in the Gulf of Mexico show fertilized clay treatment significantly enhanced bacterial respiration and consumption of alkanes compared to untreated oil-in-water conditions and reacted faster than straight fertilization. Whereas a major portion (up to 98%) of the alkane content was removed during the 1 month period of experimentation by fertilized clay flake interaction; the reduced concentration of polyaromatic hydrocarbons was not significantly different from the non-clay bearing samples. Such clay flake treatment could offer a way to more effectively apply the fertilizer to the spill in open nutrient poor waters and thus significantly reduce the extent and duration of marine oil spills, but this method is not expected to impact hydrocarbon toxicity. PMID:23864952

  12. Bioremediating Oil Spills in Nutrient Poor Ocean Waters Using Fertilized Clay Mineral Flakes: Some Experimental Constraints

    PubMed Central

    Warr, Laurence N.; Friese, André; Schwarz, Florian; Schauer, Frieder; Portier, Ralph J.; Basirico, Laura M.; Olson, Gregory M.

    2013-01-01

    Much oil spill research has focused on fertilizing hydrocarbon oxidising bacteria, but a primary limitation is the rapid dilution of additives in open waters. A new technique is presented for bioremediation by adding nutrient amendments to the oil spill using thin filmed minerals comprised largely of Fullers Earth clay. Together with adsorbed N and P fertilizers, filming additives, and organoclay, clay flakes can be engineered to float on seawater, attach to the oil, and slowly release contained nutrients. Our laboratory experiments of microbial activity on weathered source oil from the Deepwater Horizon spill in the Gulf of Mexico show fertilized clay treatment significantly enhanced bacterial respiration and consumption of alkanes compared to untreated oil-in-water conditions and reacted faster than straight fertilization. Whereas a major portion (up to 98%) of the alkane content was removed during the 1 month period of experimentation by fertilized clay flake interaction; the reduced concentration of polyaromatic hydrocarbons was not significantly different from the non-clay bearing samples. Such clay flake treatment could offer a way to more effectively apply the fertilizer to the spill in open nutrient poor waters and thus significantly reduce the extent and duration of marine oil spills, but this method is not expected to impact hydrocarbon toxicity. PMID:23864952

  13. Learning to Teach Geography for Primary Education: Results of an Experimental Programme

    ERIC Educational Resources Information Center

    Blankman, Marian; Schoonenboom, Judith; van der Schee, Joop; Boogaard, Marianne; Volman, Monique

    2016-01-01

    Students training to become primary school teachers appear to have little awareness of the core concepts of geography (teaching). To ensure that future primary school teachers are able to develop their pupils' geographical awareness, a six weeks programme was developed. The characteristics of this programme -- named Consciously Teaching Geography…

  14. Primary events regulating stem growth at low water potentials. [Glycine max (L. )

    SciTech Connect

    Nonami, Hiroshi; Boyer, J.S. )

    1990-08-01

    Cell enlargement is inhibited by inadequate water. As a first step toward understanding the mechanism, all the physical parameters affecting enlargement were monitored to identify those that changed first, particularly in coincidence with the inhibition. The osmotic potential, turgor, yield threshold turgor, growth-induced water potential, wall extensibility, and conductance to water were measured in the elongating region, and the water potential was measured in the xylem of stems of dark-grown soybean (Glycine max (L.) Merr.) seedlings. The results indicate that the primary event during the growth inhibition was the change in the growth-induced water potential. Because the growth limitation subsequently shifted to the low wall extensibility and tissue conductance for water, the initial change in potential may have set in motion subsequent metabolic changes that altered the characteristics of the wall and cell membranes.

  15. Experimental research of "microcable in a microconduct" system stability to effect of freezing water

    NASA Astrophysics Data System (ADS)

    Andreev, Vladimir A.; Burdin, Vladimir A.; Nikulina, Tatiana G.; Alekhin, Ivan N.; Gavryushin, Sergey A.; Nikulin, Aleksey G.; Praporshchikov, Denis E.

    2011-12-01

    Results of experimental researches of "optical microcable in a microduct" system stability to effect of freezing water are presented. It is shown this system is steadier to water freezing in comparison to lighten optical cable in protective polymer tube.

  16. Theoretical and Experimental Analysis of the Physics of Water Rockets

    ERIC Educational Resources Information Center

    Barrio-Perotti, R.; Blanco-Marigorta, E.; Fernandez-Francos, J.; Galdo-Vega, M.

    2010-01-01

    A simple rocket can be made using a plastic bottle filled with a volume of water and pressurized air. When opened, the air pressure pushes the water out of the bottle. This causes an increase in the bottle momentum so that it can be propelled to fairly long distances or heights. Water rockets are widely used as an educational activity, and several…

  17. Influence of oxide films on primary water stress corrosion cracking initiation of alloy 600

    NASA Astrophysics Data System (ADS)

    Panter, J.; Viguier, B.; Cloué, J.-M.; Foucault, M.; Combrade, P.; Andrieu, E.

    2006-01-01

    In the present study alloy 600 was tested in simulated pressurised water reactor (PWR) primary water, at 360 °C, under an hydrogen partial pressure of 30 kPa. These testing conditions correspond to the maximum sensitivity of alloy 600 to crack initiation. The resulting oxidised structures (corrosion scale and underlying metal) were characterised. A chromium rich oxide layer was revealed, the underlying metal being chromium depleted. In addition, analysis of the chemical composition of the metal close to the oxide scale had allowed to detect oxygen under the oxide scale and particularly in a triple grain boundary. Implication of such a finding on the crack initiation of alloy 600 is discussed. Significant diminution of the crack initiation time was observed for sample oxidised before stress corrosion tests. In view of these results, a mechanism for stress corrosion crack initiation of alloy 600 in PWR primary water was proposed.

  18. Bioavailability of fluoride in drinking water: a human experimental study.

    PubMed

    Maguire, A; Zohouri, F V; Mathers, J C; Steen, I N; Hindmarch, P N; Moynihan, P J

    2005-11-01

    It has been suggested that systemic fluoride absorption from drinking water may be influenced by the type of fluoride compound in the water and by water hardness. Using a human double-blind cross-over trial, we conducted this study to measure c(max), T(max), and Area Under the Curve (AUC) for plasma F concentration against time, following the ingestion of naturally fluoridated hard and soft waters, artificially fluoridated hard and soft waters, and a reference water. Mean AUC over 0 to 8 hours was 1330, 1440, 1679, 1566, and 1328 ng F.min.mL(-1) for naturally fluoridated soft, naturally fluoridated hard, artificially fluoridated soft, artificially fluoridated hard, and reference waters, respectively, with no statistically significant differences among waters for AUC, c(max), or T(max). Any differences in fluoride bioavailability between drinking waters in which fluoride is present naturally or added artificially, or the waters are hard or soft, were small compared with large within- and between-subject variations in F absorption. Abbreviations used: F, fluoride; AUC, Area under the Curve for plasma F concentration against time; AUC(0-3), Area under the Curve for plasma F concentration against time for 0 to 3 hours following water ingestion; AUC(0-8), Area under the Curve for plasma F concentration against time for 0 to 8 hours following water ingestion; c(max), maximum plasma F concentration corrected for baseline plasma F and dose (i.e., F concentration of individual waters); T(max), time of c(max).

  19. Is litter decomposition 'primed' by primary producer-release of labile carbon in terrestrial and aquatic experimental systems?

    NASA Astrophysics Data System (ADS)

    Soares, A. Margarida P. M.; Kritzberg, Emma S.; Rousk, Johannes

    2015-04-01

    It is possible that recalcitrant organic matter (ROM) can be 'activated' by inputs of labile organic matter (LOM) through the priming effect (PE). Investigating the PE is of major importance to fully understand the microbial use of ROM and its role on carbon (C) and nutrient cycling in both aquatic and terrestrial ecosystems. In aquatic ecosystems it is thought that the PE is triggered by periphytic algae release of LOM. Analogously, in terrestrial systems it is hypothesized that the LOM released in plant rhizospheres, or from the green crusts on the surface of agricultural soils, stimulate the activity and growth of ROM decomposers. Most previous studies on PE have utilised pulse additions of single substrates at high concentrations. However, to achieve an assessment of the true importance of the PE, it is important to simulate a realistic delivery of LOM. We investigated, in a series of 2-week laboratory experiments, how primary producer (PP)-release of LOM influence litter degradation in terrestrial and aquatic experimental systems. We used soil (terrestrial) and pond water (aquatic) microbial communities to which litter was added under light and dark conditions. In addition, glucose was added at PP delivery rates in dark treatments to test if the putative PE in light systems could be reproduced. We observed an initial peak of bacterial growth rate followed by an overall decrease over time with no treatment differences. In light treatments, periphytic algae growth and increased fungal production was stimulated when bacterial growth declined. In contrast, both fungal growth and algal production were negligible in dark treatments. This reveals a direct positive influence of photosynthesis on fungal growth. To investigate if PP LOM supplements, and the associated fungal growth, translate into a modulated litter decomposition, we are using stable isotopes to track the use of litter and algal-derived carbon by determining the δ13C in produced CO2. Fungi and bacteria

  20. Recent experimental advances on hydrophobic interactions at solid/water and fluid/water interfaces.

    PubMed

    Zeng, Hongbo; Shi, Chen; Huang, Jun; Li, Lin; Liu, Guangyi; Zhong, Hong

    2016-03-01

    Hydrophobic effects play important roles in a wide range of natural phenomena and engineering processes such as coalescence of oil droplets in water, air flotation of mineral particles, and folding and assembly of proteins and biomembranes. In this work, the authors highlight recent experimental attempts to reveal the physical origin of hydrophobic effects by directly quantifying the hydrophobic interaction on both solid/water and fluid/water interfaces using state-of-art nanomechanical techniques such as surface forces apparatus and atomic force microscopy (AFM). For solid hydrophobic surfaces of different hydrophobicity, the range of hydrophobic interaction was reported to vary from ∼10 to >100 nm. With various characterization techniques, the very long-ranged attraction (>100 nm) has been demonstrated to be mainly attributed to nonhydrophobic interaction mechanisms such as pre-existing nanobubbles and molecular rearrangement. By ruling out these factors, intrinsic hydrophobic interaction was measured to follow an exponential law with decay length of 1-2 nm with effective range less than 20 nm. On the other hand, hydrophobic interaction measured at fluid interfaces using AFM droplet/bubble probe technique was found to decay with a much shorter length of ∼0.3 nm. This discrepancy of measured decay lengths is proposed to be attributed to inherent physical distinction between solid and fluid interfaces, which impacts the structure of interface-adjacent water molecules. Direct measurement of hydrophobic interaction on a broader range of interfaces and characterization of interfacial water molecular structure using spectroscopic techniques are anticipated to help unravel the origin of this rigidity-related mismatch of hydrophobic interaction and hold promise to uncover the physical nature of hydrophobic effects. With improved understanding of hydrophobic interaction, intrinsic interaction mechanisms of many biological and chemical pathways can be better

  1. Experimental determination of the absorbed dose to water in a scanned proton beam using a water calorimeter and an ionization chamber

    NASA Astrophysics Data System (ADS)

    Gagnebin, Solange; Twerenbold, Damian; Pedroni, Eros; Meer, David; Zenklusen, Silvan; Bula, Christian

    2010-03-01

    The absorbed dose to water is the reference physical quantity for the energy absorbed in tissue when exposed to beams of ionizing radiation in radiotherapy. The SI unit of absorbed dose to water is the gray (Gy = 1 J/kg). Ionization chambers are used as the dosimeters of choice in the clinical environment because they show a high reproducibility and are easy to use. However, ionization chambers have to be calibrated in order to convert the measured electrical charge into absorbed dose to water. In addition, protocols require these conversion factors to be SI traceable to a primary standard of absorbed dose to water. We present experimental results where the ionization chamber used for the dosimetry for the scanned proton beam facility at PSI is compared with the direct determination of absorbed dose to water from the METAS primary standard water calorimeter. The agreement of 3.2% of the dose values measured by the two techniques are within their respective statistical uncertainties.

  2. Experimental study of the constituents of space wash water

    NASA Technical Reports Server (NTRS)

    Colombo, G. V.; Putnam, D. F.

    1976-01-01

    Data are presented that quantify some of the various constituents of human origin that may be expected in space wash water. The experiments were conducted under controlled conditions with a simulated crew of two male and two female subjects. The data show that the expected wash water constituents originating from human secretions are substantially lower than theoretical projections have indicated. Average daily quantities as well as individual extremes are given for both shower and laundry water. In addition, concentrations are presented for a projected model of wash water usage in a space station.

  3. Water erosion monitoring and experimentation for global change studies

    SciTech Connect

    Poesen, J.W.; Boardman, J.; Wilcox, B.

    1996-09-01

    This report describes the need for monitoring the effects of climatic change on soil erosion. The importance of monitoring not only runoff, but monitoring and experimental studies at the larger scale of hillslope and catchments is stressed.

  4. Upwelling-Induced Primary Productivity in Coastal Waters of the Black Sea: Impact on Algorithms for Remote Sensing

    NASA Technical Reports Server (NTRS)

    Goldman, Joel C.; Brink, Kenneth K.; Gawarkiewicz, Glen; Sosik, Heidi M.

    1997-01-01

    This research program was a collaborative effort to investigate the impact of rapid changes in the water column during coastal upwelling, on biological and optical properties. These properties are important for constructing region or event-specific algorithms for remote sensing of pigment concentration and primary productivity and for comparing these algorithms with those used for the development of large scale maps from ocean color. We successfully achieved the primary objective of this research project which was to study in situ the dynamics of rapid spatial and temporal changes in properties of the water column during, coastal upwelling off the Crimean Coast in the Black Sea. The work was a collaborative effort between a group of biological and physical oceanographers from the Woods Hole Oceanographic Institution and from two oceanographic research institutions in the Crimea, Ukraine, located near the study site, the Marine Hydrophysical Institute (MHI) and the Institute of Biology of the Southern Seas (IBSS). The site was an ideal experimental model, both from a technical and economic standpoint, because of the predictable summer upwelling that occurs in the region and because of the availability of both a ship on call and laboratory and remote sensing facilities at the nearby marine institutes. We used a combination of shipboard measurements and remote sensing to investigate the physical evolution of rapid upwelling events and their impact on photoplankton and water column optical properties. The field work involved a two day cruise for mooring, deployment and a three day baseline survey cruise, followed by an eleven day primary cruise during, a summer upwelling event (anticipated by monitoring local winds and tracked by remote sensing imaging). An MHI ship was outfitted and used for these purposes.

  5. Experimental investigation of primary and corner shock boundary layer interactions at mild back pressure ratios

    NASA Astrophysics Data System (ADS)

    Funderburk, M.; Narayanaswamy, V.

    2016-08-01

    Unstart of rectangular inlets occurs as a result of interactions between shock-induced separation units along the floor/ceiling, corner, and sidewalls. While a significant body of literature exists regarding the individual flow interactions at the inlet floor/ceiling (called primary separation) and sidewalls, limited efforts have focused on the mean and dynamic features of the corner separation. Experiments are conducted to investigate primary and corner shock boundary layer interactions (SBLI) with the objectives of elucidating the flow interactions that occur in the corner, and characterizing the interaction between the corner and primary separation units at mild back pressure ratios. Surface streakline flow visualization and high-frequency wall static pressure measurements are performed along the centerline and corner regions of shock-induced flow separation generated by a 12° compression ramp in a Mach 2.5 flow. Sidewall fences that extend upstream of the leading edge of the flat plate generate corner separation of adequate size to determine the mean flow structures, characterize the unsteady motions, and investigate the mechanisms that drive the unsteadiness of primary and corner SBLI. Results show that the corner and primary SBLI units differ fundamentally in both their mean and unsteady features and their response to upstream and downstream flow perturbations. These observations suggest that the two behave as independent units at this relatively low shock-induced back pressure ratio.

  6. Water weakening during semibrittle flow and faulting of experimentally deformed quartz sandstone

    NASA Astrophysics Data System (ADS)

    Kanaya, T.; Hirth, G.

    2015-12-01

    Triaxial compression experiments were conducted on Fontainebleau sandstone at temperatures to 900°C and effective pressures to 175 MPa with varying water contents. Both yield and peak strengths associated with semibrittle faulting decrease linearly with an increase in intragranular water concentration (COH); COH is determined from infrared spectroscopy. Microstructural observations and the influence of strain rate, temperature, and COH on peak strength suggest that transient semibrittle flow is accommodated through cataclasis assisted by stress-corrosion microcracking. The roles of the experimental variables on the constitutive behavior are similar to those reported for subcritical cracking of quartz single crystals. At high COH, microstructural observations indicate an increase in the relative contribution of mm-scale distributed shear fractures (bands) to axial strain, reflecting a reduction in grain-scale fracture toughness. This is consistent with the inference that highly dissipative shear fractures lead to the observed reduction in strength at high COH. Stress vs. strain rate data for transient semibrittle flow show temperature-dependent rate behavior, and are well fit by an exponential law with an activation enthalpy of 185 to 250 kJ/mol and Peierls stress of 2.5 to 7.5 GPa. Using these constraints, we infer that stress-corrosion cracking is rate-limited by the dislocation activity at crack tips. Correlation of microscale COH maps to microstructures suggests that intragranular water in the undeformed sandstone is associated mainly with clusters of fluid inclusions, resulting in a highly nonuniform distribution of COH both within and between grains. Axially deformed samples show a reduction in the median and variability of COH over a range of length scales. We observe that a local reduction in COH correlates with fluid inclusions that are decrepitated and crosscut by intragranular fractures. We conclude that intragranular fracture is the primary mechanism of

  7. Biodiversity effects on the water balance of an experimental grassland

    NASA Astrophysics Data System (ADS)

    Leimer, Sophia; Kreutziger, Yvonne; Rosenkranz, Stephan; Beßler, Holger; Engels, Christof; Oelmann, Yvonne; Weisser, Wolfgang W.; Wirth, Christian; Wilcke, Wolfgang

    2013-04-01

    Plant species richness increases aboveground biomass production in biodiversity experiments. Biomass production depends on and feeds back to the water balance, but it remains unclear how plant species richness influences soil water contents and water fluxes (actual evapotranspiration (ETa), downward flux (DF), and upward flux (UF)). Our objective was to determine the effects of plant species and functional richness and functional identity on soil water contents and water fluxes for two soil depths (0-0.3 and 0.3.-0.7 m). To achieve this, we used a water balance model in connection with Bayesian hierarchical modeling. We monitored soil water contents on 86 plots of a grassland plant diversity experiment in Jena, Germany between July 2002 and January 2006. In the field experiment, plant species richness (0, 1, 2, 4, 8, 16, 60) and functional group composition (0-4 functional groups: legumes, grasses, non-leguminous tall herbs, non-leguminous small herbs) were manipulated in a factorial design. Climate data (air temperature, precipitation, wind velocity, relative humidity, global radiation, soil moisture) was measured at a central climate station between July 2002 and December 2007. Root biomass data from July 2006 was available per plot. Missing water contents per plot and depth were estimated in weekly resolution for the years 2003-2007 with a Bayesian hierarchical model using measured water contents per plot and centrally measured soil moisture. To obtain ETa, DF, and UF of the two different soil depths, we modified a soil water balance model which had been developed for our study site. The model is based on changes in soil water content between subsequent observation dates and modeled potential evapotranspiration which was partitioned between soil layers according to percentage of root biomass. The presence of specific functional groups significantly changed water contents and fluxes with partly opposing effects in the two soil depths. Presence of grasses

  8. Experimental and Theoretical Study of Thermodynamics of the Reaction of Titania and Water at High Temperatures

    NASA Technical Reports Server (NTRS)

    Nguyen, Quynhgiao N.; Myers, Dwight L.; Jacobson, Nathan S.; Opila, Elizabeth J.

    2014-01-01

    The transpiration method was used to determine the volatility of titanium dioxide (TiO2) in water vapor-containing environments at temperatures between 1473 and 1673 K. Water contents ranged from 0 to 76 mole % in oxygen or argon carrier gases for 20 to 250 hr exposure times. Results indicate that oxygen is not a key contributor to volatilization and the primary reaction for volatilization in this temperature range is: TiO2(s) + H2O(g) = TiO(OH)2(g). Data were analyzed with both the second and third law methods to extract an enthalpy and entropy of formation. The geometry and vibrational frequencies of TiO(OH)2(g) were computed using B3LYP density functional theory, and the enthalpy of formation was computed using the coupled-cluster singles and doubles method with a perturbative correction for connected triple substitutions [CCSD(T)]. Thermal functions are calculated using both a structure with bent and linear hydroxyl groups. Calculated second and third heats show closer agreement with the linear hydroxyl group, suggesting more experimental and computational spectroscopic and structural work is needed on this system.

  9. Experimental remote sensing of subsurface temperature in natural ocean water

    NASA Technical Reports Server (NTRS)

    Leonard, D. A.; Caputo, B.; Johnson, R. L.; Hoge, F. E.

    1977-01-01

    The first successful depth-resolved remote sensing measurements of subsurface ocean water temperature were obtained by spectral analysis of the 3400 per cm O-H stretching Raman band of liquid water. Raman spectral data were obtained from a research vessel at various depths from the surface to 10 meters below the surface in a tidal estuary. The temperature inferred from the spectra was consistent with ground truth temperature to within the shot noise limited accuracy of plus or minus 2 C. The performance of a future fully developed airborne laser Raman water temperature measurement system is estimated on the basis of these first tests.

  10. Structure of electron tracks in water. 2. Distribution of primary ionizations and excitations in water radiolysis. [accelerated electrons

    SciTech Connect

    Pimblott, S.M.; Mozumder, A. )

    1991-09-19

    A procedure for the calculation of entity-specific ionization and excitation probabilities for water radiolysis at low linear energy transfer (LET) has been developed. The technique pays due attention to the effects of the ionization threshold and the energy dependence of the ionization efficiency. The numbers of primary ionizations and excitations are not directly proportional to the spur energy. At a given spur energy, ionization follows a binomial distribution subject to an energetically possible maximum. The excitation distribution for a spur of given energy and with a given number of ionizations is given by a geometric series. The occurrence probabilities depend upon the cross sections of ionization, excitation, and other inferior processes. Following the low-LET radiolysis of liquid water the most probable spurs contain one ionization, two ionizations, or one ionization and one excitation, while in water vapor they contain either one ionization or one excitation. In liquid water the most probable outcomes for spurs corresponding to the most probable energy loss (22 eV) and to the mean energy loss (38 eV) are one ionization and one excitation, and two ionizations and one excitation, respectively. In the vapor, the most probable energy loss is 14 eV which results in one ionization or one excitation and the mean energy loss is 34 eV for which the spur of maximum probability contains one ionization and two excitations. The total calculated primary yields for low-LET radiolysis are in approximate agreement with experiment in both phases.

  11. Experimental study of organically contaminated water in a cooling tower

    SciTech Connect

    Goldstein, D.J.; Aiyegbusi, O.

    1982-12-01

    A pilot model cooling system was set up and run so as to simultaneously cool heat exchanger tubes and biologically degrade phenol in the makeup water. The cooling tower used 1 ft/sup 2/ by 3 ft high, wetted film, polygrid, PVC packing. Water was circulated at 2.5 gpm (5.6 ft/sec) through two parallel heat exchange tubes immersed in a water bath controlled at 150/sup 0/F. Total water flow was 5 gpm/ft/sup 2/ of tower. Air was forced through the tower to give a liquid to gas mass ratio of 1.3. The cooling water circulated with an average temperature rise of 10/sup 0/F and an average approach to the air wet bulb temperature of 12/sup 0/F. Conclusions of this study are: (1) The pilot cooling tower was successfully operated to simultaneously cool and biodegrade phenol in the makeup water. Operation was not difficult and the experiments were reasonably reproducible. (2) An equivalent average concentration of phenol in the makeup water of 165 ppM (300 ppM BOD) should present little problem in commercial practice. An equivalent average concentration of up to 600 ppM phenol (1200 ppM BOD) may be acceptable in practice. Concentrations higher than 600 ppM phenol will cause such rapid biofouling and such rapid production of suspended solids in the circulating water as to be impractical. (3) More than 85 percent of the phenol removed was by biodegradation. Not more than 15 percent was stripped into the atmosphere. 12 figures, 12 tables.

  12. Experimental Analysis of the Mechanism of Hearing under Water

    PubMed Central

    Chordekar, Shai; Kishon-Rabin, Liat; Kriksunov, Leonid; Adelman, Cahtia; Sohmer, Haim

    2015-01-01

    The mechanism of human hearing under water is debated. Some suggest it is by air conduction (AC), others by bone conduction (BC), and others by a combination of AC and BC. A clinical bone vibrator applied to soft tissue sites on the head, neck, and thorax also elicits hearing by a mechanism called soft tissue conduction (STC) or nonosseous BC. The present study was designed to test whether underwater hearing at low intensities is by AC or by osseous BC based on bone vibrations or by nonosseous BC (STC). Thresholds of normal hearing participants to bone vibrator stimulation with their forehead in air were recorded and again when forehead and bone vibrator were under water. A vibrometer detected vibrations of a dry human skull in all similar conditions (in air and under water) but not when water was the intermediary between the sound source and the skull forehead. Therefore, the intensities required to induce vibrations of the dry skull in water were significantly higher than the underwater hearing thresholds of the participants, under conditions when hearing by AC and osseous BC is not likely. The results support the hypothesis that hearing under water at low sound intensities may be attributed to nonosseous BC (STC). PMID:26770975

  13. Experimental Analysis of the Mechanism of Hearing under Water.

    PubMed

    Chordekar, Shai; Kishon-Rabin, Liat; Kriksunov, Leonid; Adelman, Cahtia; Sohmer, Haim

    2015-01-01

    The mechanism of human hearing under water is debated. Some suggest it is by air conduction (AC), others by bone conduction (BC), and others by a combination of AC and BC. A clinical bone vibrator applied to soft tissue sites on the head, neck, and thorax also elicits hearing by a mechanism called soft tissue conduction (STC) or nonosseous BC. The present study was designed to test whether underwater hearing at low intensities is by AC or by osseous BC based on bone vibrations or by nonosseous BC (STC). Thresholds of normal hearing participants to bone vibrator stimulation with their forehead in air were recorded and again when forehead and bone vibrator were under water. A vibrometer detected vibrations of a dry human skull in all similar conditions (in air and under water) but not when water was the intermediary between the sound source and the skull forehead. Therefore, the intensities required to induce vibrations of the dry skull in water were significantly higher than the underwater hearing thresholds of the participants, under conditions when hearing by AC and osseous BC is not likely. The results support the hypothesis that hearing under water at low sound intensities may be attributed to nonosseous BC (STC).

  14. The risk of biomaterial-associated infection after revision surgery due to an experimental primary implant infection.

    PubMed

    Engelsman, Anton F; Saldarriaga-Fernandez, Isabel C; Nejadnik, M Reza; van Dam, Gooitzen M; Francis, Kevin P; Ploeg, Rutger J; Busscher, Henk J; van der Mei, Henny C

    2010-10-01

    The fate of secondary biomaterial implants was determined by bio-optical imaging and plate counting, after antibiotic treatment of biomaterials-associated-infection (BAI) and surgical removal of an experimentally infected, primary implant. All primary implants and tissue samples from control mice showed bioluminescence and were culture-positive. In an antibiotic treated group, no bioluminescence was detected and only 20% of all primary implants and no tissue samples were culture-positive. After revision surgery, bioluminescence was detected in all control mice. All the implants and 80% of all tissue samples were culture-positive. In contrast, in the antibiotic treated group, 17% of all secondary implants and 33% of all tissue samples were culture-positive, despite antibiotic treatment. The study illustrates that due to the BAI of a primary implant, the infection risk of biomaterial implants is higher in revision surgery than in primary surgery, emphasizing the need for full clearance of the infection, as well as from surrounding tissues prior to implantation of a secondary implant.

  15. Theoretical and Experimental Study of the Primary Current Distribution in Parallel-Plate Electrochemical Reactors

    ERIC Educational Resources Information Center

    Vazquez Aranda, Armando I.; Henquin, Eduardo R.; Torres, Israel Rodriguez; Bisang, Jose M.

    2012-01-01

    A laboratory experiment is described to determine the primary current distribution in parallel-plate electrochemical reactors. The electrolyte is simulated by conductive paper and the electrodes are segmented to measure the current distribution. Experiments are reported with the electrolyte confined to the interelectrode gap, where the current…

  16. Isolation of the etiological agent of primary amoebic meningoencephalitis from artifically heated waters.

    PubMed

    Stevens, A R; Tyndall, R L; Coutant, C C; Willaert, E

    1977-12-01

    To determine whether artificial heating of water by power plant discharges facilitates proliferation of the pathogenic free-living amoebae that cause primary amoebic meningoencephalitis, water samples (250 ml) were taken from discharges within 3,000 feet (ca. 914.4 m) of power plants and were processed for amoeba culture. Pathogenic Naegleria fowleri grew out of water samples from two of five lakes and rivers in Florida and from one of eight man-made lakes in Texas. Pathogenic N. fowleri did not grow from water samples taken from cooling towers and control lakes, the latter of which had no associated power plants. The identification of N. fowleri was confirmed by pathogenicity in mice and by indirect immunofluorescence analyses, by using a specific antiserum. PMID:596872

  17. Effects of resident water and non-equilibrium adsorption on the primary and enhanced coalbed methane gas recovery

    NASA Astrophysics Data System (ADS)

    Jahediesfanjani, Hossein

    The major part of the gas in coalbed methane and shale gas reservoirs is stored as the adsorbed gas in the coal and organic materials of the black shale internal surfaces. The sorption sites in both reservoirs are composed of several macropores that contain very small pore sizes. Therefore, the adsorption/desorption is very slow process and follows a non-equilibrium trend. The time-dependency of the sorption process is further affected by the reservoir resident water. Water can diffuse into the matrix and adsorption sites, plug the pores and affect the reservoir gas production. This study presents an experimental and theoretical procedure to investigate the effects of the resident water and time-dependency of the sorption process on coalbed and shale gas primary and enhanced recovery by simultaneous CO 2/N2 injection. Series of the experiments are conducted to construct both equilibrium and non-equilibrium single and multi-component isotherms with the presence of water. A novel and rapid data interpretation technique is developed based on the nonequilibrium adsorption/desorption thermodynamics, mass conservation law, and volume filling adsorption theory. The developed technique is implemented to construct both equilibrium and non-equilibrium multi-component multi-phase isotherms from the early time experimental measurements. The non-equilibrium isotherms are incorporated in the coalbed methane/shale gas reservoir simulations to account for the time-dependency of the sorption process. The experimental results indicate that the presence of water in the sorption system reduces both carbon dioxide and nitrogen adsorption rates. Reduction in the adsorption rate for carbon dioxide is more than nitrogen. The results also indicate that the resident water reduces the adsorption ability of low rank coals more than high rank ones. The results of the multi-component sorption tests indicate that increasing the initial mole fraction of the nitrogen gas in the injected CO2/N2

  18. Extensive tissue-specific transcriptomic plasticity in maize primary roots upon water deficit

    PubMed Central

    Opitz, Nina; Marcon, Caroline; Paschold, Anja; Malik, Waqas Ahmed; Lithio, Andrew; Brandt, Ronny; Piepho, Hans-Peter; Nettleton, Dan; Hochholdinger, Frank

    2016-01-01

    Water deficit is the most important environmental constraint severely limiting global crop growth and productivity. This study investigated early transcriptome changes in maize (Zea mays L.) primary root tissues in response to moderate water deficit conditions by RNA-Sequencing. Differential gene expression analyses revealed a high degree of plasticity of the water deficit response. The activity status of genes (active/inactive) was determined by a Bayesian hierarchical model. In total, 70% of expressed genes were constitutively active in all tissues. In contrast, <3% (50 genes) of water deficit-responsive genes (1915) were consistently regulated in all tissues, while >75% (1501 genes) were specifically regulated in a single root tissue. Water deficit-responsive genes were most numerous in the cortex of the mature root zone and in the elongation zone. The most prominent functional categories among differentially expressed genes in all tissues were ‘transcriptional regulation’ and ‘hormone metabolism’, indicating global reprogramming of cellular metabolism as an adaptation to water deficit. Additionally, the most significant transcriptomic changes in the root tip were associated with cell wall reorganization, leading to continued root growth despite water deficit conditions. This study provides insight into tissue-specific water deficit responses and will be a resource for future genetic analyses and breeding strategies to develop more drought-tolerant maize cultivars. PMID:26463995

  19. Water supply and not nitrate concentration determines primary root growth in Arabidopsis.

    PubMed

    Chapman, Nick; Whalley, W Richard; Lindsey, Keith; Miller, Anthony J

    2011-10-01

    Understanding how root system architecture (RSA) adapts to changing nitrogen and water availability is important for improving acquisition. A sand rhizotron system was developed to study RSA in a porous substrate under tightly regulated nutrient supply. The RSA of Arabidopsis seedlings under differing nitrate (NO₃⁻) and water supplies in agar and sand was described. The hydraulic conductivity of the root environment was manipulated by using altered sand particle size and matric potentials. Ion-selective microelectrodes were used to quantify NO₃⁻ at the surface of growing primary roots in sands of different particle sizes. Differences in RSA were observed between seedlings grown on agar and sand, and the influence of NO₃⁻ (0.1-10.0 mm) and water on RSA was determined. Primary root length (PRL) was a function of water flux and independent of NO₃⁻. The percentage of roots with laterals correlated with water flux, whereas NO₃⁻ supply was important for basal root (BR) growth. In agar and sand, the NO₃⁻ activities at the root surface were higher than those supplied in the nutrient solution. The sand rhizotron system is a useful tool for the study of RSA, providing a porous growth environment that can be used to simulate the effects of hydraulic conductivity on growth.

  20. Financial analysis of experimental releases conducted at Glen Canyon Dam during Water Year 2013

    SciTech Connect

    Graziano, D. J.; Poch, L. A.; Veselka, T. D.; Palmer, C. S.; Loftin, S.; Osiek, B.

    2014-08-18

    This report examines the financial implications of experimental flows conducted at the Glen Canyon Dam (GCD) in water year 2013. It is the fifth report in a series examining the financial implications of experimental flows conducted since the Record of Decision (ROD) was adopted in February 1997 (Reclamation 1996). A report released in January 2011 examined water years 1997 to 2005 (Veselka et al. 2011), a report released in August 2011 examined water years 2006 to 2010 (Poch et al. 2011), a report released June 2012 examined water year 2011 (Poch et al. 2012), and a report released April 2013 examined water year 2012 (Poch et al. 2013).

  1. Experimental shock lithification of water-bearing rock powders

    NASA Technical Reports Server (NTRS)

    Allen, C. C.; Jercinovic, M. J.; Keil, K.; See, T.

    1982-01-01

    The geology and morphology of the terrestrial planets and their moons have been profoundly affected by impact cratering. Some of these bodies contain substantial quantities of water or ice in their regoliths. It is pointed out that the effects of impacts into water-bearing target rocks are not well understood, and may be significantly different from those produced by identical impacts on a desiccated surface. The present investigation has the objective to determine the effects of water on targets of powdered rock and to seek evidence of impact-induced hydration or clay formation. Samples of andesitic basalt were crushed and sieved, and experiments were conducted on the material smaller than 150 micrometers. These experiments show that the water content of a powdered rock target can strongly affect its physical condition following an impact. A relatively small component (5-15 wt %) of water or ice in planetary surface material could inhibit or prevent lithification throughout much of the shocked volume at an impact site.

  2. Upper Washita River experimental watersheds: Multiyear stability of soil water content profiles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Scaling in situ soil water content time series data to a large spatial domain is a key element of watershed environmental monitoring and modeling. The primary method of estimating and monitoring large-scale soil water content distributions is via in situ networks. It is critical to establish the s...

  3. Use of TV in space science activities - Some considerations. [onboard primary experimental data recording

    NASA Technical Reports Server (NTRS)

    Bannister, T. C.

    1977-01-01

    Advantages in the use of TV on board satellites as the primary data-recording system in a manned space laboratory when certain types of experiments are flown are indicated. Real-time or near-real-time validation, elimination of film weight, improved depth of field and low-light sensitivity, and better adaptability to computer and electronic processing of data are spelled out as advantages of TV over photographic techniques, say, in fluid dynamics experiments, and weightlessness studies.

  4. Theoretical and experimental analysis of the physics of water rockets

    NASA Astrophysics Data System (ADS)

    Barrio-Perotti, R.; Blanco-Marigorta, E.; Fernández-Francos, J.; Galdo-Vega, M.

    2010-09-01

    A simple rocket can be made using a plastic bottle filled with a volume of water and pressurized air. When opened, the air pressure pushes the water out of the bottle. This causes an increase in the bottle momentum so that it can be propelled to fairly long distances or heights. Water rockets are widely used as an educational activity, and several mathematical models have been proposed to investigate and predict their physics. However, the real equations that describe the physics of the rockets are so complicated that certain assumptions are usually made to obtain models that are easier to use. These models provide relatively good predictions but fail in describing the complex physics of the flow. This paper presents a detailed theoretical analysis of the physics of water rockets that concludes with the proposal of a physical model. The validity of the model is checked by a series of field tests. The tests showed maximum differences with predictions of about 6%. The proposed model is finally used to investigate the temporal evolution of some significant variables during the propulsion and flight of the rocket. The experience and procedure described in this paper can be proposed to graduate students and also at undergraduate level if certain simplifications are assumed in the general equations.

  5. Superoxygenated Water as an Experimental Sample for NMR Relaxometry

    ERIC Educational Resources Information Center

    Nestle, Nikolaus; Dakkouri, Marwan; Rauscher, Hubert

    2004-01-01

    The increase in NMR relaxation rates as a result of dissolved paramagnetic species on the sample of superoxygenated drinking water is demonstrated. It is concluded that oxygen content in NMR samples is an important issue and can give rise to various problems in the interpretation of both spectroscopic and NMR imaging or relaxation experiments.

  6. Experimental study of hydrogen production by direct decomposition of water

    NASA Astrophysics Data System (ADS)

    Bilgen, E.; Galindo, J.; Baykara, S. Z.

    The hydrogen production by direct decomposition of water in a solar furnace is studied. The set-up is a horizontal axis system consisting of two 1.0 kW parabolic concentrators, both powered by a single heliostat. A temperature of 3000 K is possible. The water is fed to the reactor installed at the focal space of the concentrator, and the steam is decomposed at about 2500 K. The reactor consisted of a cylindrical cavity type refractory receiver covered with a silica cupola. The steam was introduced at a known rate into the cavity and the product gases were quenched. After the condensation of steam, hydrogen and oxygen were collected in a reservoir. Results indicate that with an optimized system, it is possible to produce hydrogen at about 70 percent rate of the theoretical value at the temperature level studied.

  7. Experimental Values of the Surface Tension of Supercooled Water

    NASA Technical Reports Server (NTRS)

    Hacker, P. T.

    1951-01-01

    The results of surface-tension measurements for supercooled water are presented. A total of 702 individual measurements of surface tension of triple-distilled water were made in the temperature range, 27 to -22.2 C, with 404 of these measurements at temperatures below 0 C. The increase in magnitude of surface tension with decreasing temperature, as indicated by measurements above 0 C, continues to -22.2 C. The inflection point in the surface-tension - temperature relation in the vicinity of 0 C, as indicated by the International Critical Table values for temperatures down to -8 C, is substantiated by the measurements in the temperature range, 0 to -22.2 C. The surface tension increases at approximately a linear rate from a value of 76.96+/-0.06 dynes per centimeter at -8 C to 79.67+/-0.06 dynes per centimeter at -22.2 C.

  8. Combustion of oil on water: an experimental program

    SciTech Connect

    1982-02-01

    This study determined how well crude and fuel oils burn on water. Objectives were: (1) to measure the burning rates for several oils; (2) to determine whether adding heat improves the oils' combustibility; (3) to identify the conditions necessary to ignite fuels known to be difficult to ignite on ocean waters (e.g., diesel and Bunker C fuel oils); and (4) to evaluate the accuracy of an oil-burning model proposed by Thompson, Dawson, and Goodier (1979). Observations were made about how weathering and the thickness of the oil layer affect the combustion of crude and fuel oils. Nine oils commonly transported on the world's major waterways were tested. Burns were first conducted in Oklahoma under warm-weather conditions (approx. 30/sup 0/C) and later in Ohio under cold-weather conditions (approx. 0/sup 0/C to 10/sup 0/C).

  9. Transcriptomic Analysis of the Primary Roots of Alhagi sparsifolia in Response to Water Stress

    PubMed Central

    Pei, Xinwu; Zhang, Chao; Jia, Shirong; Li, Weimin

    2015-01-01

    Background Alhagi sparsifolia is a typical desert phreatophyte and has evolved to withstand extreme dry, cold and hot weather. While A. sparsifolia represents an ideal model to study the molecular mechanism of plant adaption to abiotic stress, no research has been done in this aspect to date. Here we took advantage of Illumina platform to survey transcriptome in primary roots of A. sparsifolia under water stress conditions in aim to facilitate the exploration of its genetic basis for drought tolerance. Methodology and Principal Findings We sequenced four primary roots samples individually collected at 0, 6, 24 and 30h from the A. sparsifolia seedlings in the course of 24h of water stress following 6h of rehydration. The resulting 38,763,230, 67,511,150, 49,259,804 and 54,744,906 clean reads were pooled and assembled into 33,255 unigenes with an average length of 1,057 bp. All-unigenes were subjected to functional annotation by searching against the public databases. Based on the established transcriptome database, we further evaluated the gene expression profiles in the four different primary roots samples, and identified numbers of differently expressed genes (DEGs) reflecting the early response to water stress (6h vs. 0h), the late response to water stress (24h vs. 0h) and the response to post water stress rehydration (30h vs. 24h). Moreover, the DEGs specifically regulated at 6, 24 and 30h were captured in order to depict the dynamic changes of gene expression during water stress and subsequent rehydration. Functional categorization of the DEGs indicated the activation of oxidoreductase system, and particularly emphasized the significance of the ‘Glutathione metabolism pathway’ in response to water stress. Conclusions This is the first description of the genetic makeup of A. sparsifolia, thus providing a substantial contribution to the sequence resources for this species. The identified DEGs offer a deep insight into the molecular mechanism of A. sparsifolia

  10. Experimental results of water film formation on various fuel forms from a fire suppression system

    SciTech Connect

    Ross, R.H.; Davis, J.R.

    1993-12-31

    The purpose of the study was to determine the thickness and coverage of water film formations on various materials during fire sprinkler deluge. An exhaustive literature search revealed that no applicable research data exists that governs water film formations from fire protection systems. Therefore, a controlled, infield, mockup was created to predict the thickness and coverage of water film on fissile material forms. This paper discusses the background, experimental procedure and the characterization of these water films.

  11. Analysis of the water film behavior and its breakup on profile using experimental and numerical methods

    NASA Astrophysics Data System (ADS)

    Muzik, Tomas; Safarik, Pavel; Tucek, Antonín

    2014-08-01

    This paper deals with the description of water film behaviour on the airfoil NACA0012 using experimental and numerical methods. Properties of the water film on the profile and its breakup into droplets behind the profile are investigated in the aerodynamic tunnel and using CFD methods. The characteristic parameters of the water film, like its thickness and shape for different flow modes are described. Hereafter are described droplets drifted by the air, which water film is broken behind the profile.

  12. Experimental and Theoretical Investigations of Cavitation in Water

    NASA Technical Reports Server (NTRS)

    Ackeret, J.

    1945-01-01

    The cavitation in nozzles on airfoils of various shape and on a sphere are experimentally investigated. The limits of cavitation and the extension of the zone of the bubbles in different stages of cavitation are photographically established. The pressure in the bubble area is constant and very low, jumping to high values at the end of the area. The analogy with the gas compression shock is adduced and discussed. The collapse of the bubbles under compression shock produces very high pressures internally, which must be contributory factors to corrosion. The pressure required for purely mechanical corrosion is also discussed.

  13. The PTB primary standard for the absorbed-dose to water for I-125 interstitial brachytherapy sources

    NASA Astrophysics Data System (ADS)

    Schneider, T.

    2012-10-01

    The German national metrology institute (PTB) developed a primary standard in terms of absorbed-dose to water Dw for low-energy interstitial brachytherapy sources, which is based on an extrapolation chamber in a phantom of water-equivalent material. The method to determine Dw from extrapolation chamber measurements has been newly developed and is already described in the literature. With the chamber the absorbed-dose at 30 cm distance from the source is measured and the quantity is converted into the desired quantity, the absorbed-dose to water measured at 1 cm distance perpendicular to the source axis. In this paper, a synthesis of the work done within the EMRP Project: ‘TP2.JRP6: Increasing Cancer Treatment Efficacy Using 3D Brachytherapy’ is given and the final results and the final uncertainty budget are presented. Furthermore, an experimentally determined dose-rate constant for this seed type (BEBIG Symmetra I25.S16) is given based on the measurement of four different instances.

  14. Primary experimental results of wire-array Z-pinches on PTS

    SciTech Connect

    Huang, X. B. Zhou, S. T. Ren, X. D. Dan, J. K. Wang, K. L. Zhang, S. Q. Li, J. Xu, Q. Cai, H. C. Duan, S. C. Ouyang, K. Chen, G. H. Ji, C. Wang, M. Feng, S. P. Yang, L. B. Xie, W. P. Deng, J. J.

    2014-12-15

    The Primary Test Stand (PTS) developed at the China Academy of Engineering Physics is a multiterawatt pulsed power driver, which can deliver a ∼10 MA, 70 ns rise-time (10%-90%) current to a short circuit load and has important applications in Z-pinch driven inertial confinement fusion and high energy density physics. In this paper, primary results of tungsten wire-array Z-pinch experiments on PTS are presented. The load geometries investigated include 15-mm-tall cylindrical single and nested arrays with diameter ranging from 14.4-26.4 mm, and consisting of 132∼276 tungsten wires with 5∼10 μm in diameter. Multiple diagnostics were fielded to determine the characteristics of x-ray radiations and to obtain self-emitting images of imploding plasmas. X-ray power up to 80 TW with ∼3 ns FWMH is achieved by using nested wire arrays. The total x-ray energy exceeds 500 kJ and the peak radiation temperature is about 150 eV. Typical velocity of imploding plasmas goes around 3∼5×10{sup 7} cm/s and the radial convergence ratio is between 10 and 20.

  15. Laminar burning velocities at high pressure for primary reference fuels and gasoline: Experimental and numerical investigation

    SciTech Connect

    Jerzembeck, S.; Peters, N.; Pepiot-Desjardins, P.; Pitsch, H.

    2009-02-15

    Spherical flames of n-heptane, iso-octane, PRF 87 and gasoline/air mixtures are experimentally investigated to determine laminar burning velocities and Markstein lengths under engine-relevant conditions by using the constant volume bomb method. Data are obtained for an initial temperature of 373 K, equivalence ratios varying from {phi}=0.7 to {phi}=1.2, and initial pressures from 10 to 25 bar. To track the flame front in the vessel a dark field He-Ne laser Schlieren measurement technique and digital image processing were used. The propagating speed with respect to the burned gases and the stretch rate are determined from the rate of change of the flame radius. The laminar burning velocities are obtained through a linear extrapolation to zero stretch. The experimentally determined Markstein numbers are compared to theoretical predictions. A reduced chemical kinetic mechanism for n-heptane and iso-octane was derived from the Lawrence Livermore comprehensive mechanisms. This mechanism was validated for ignition delay times and flame propagation at low and high pressures. In summary an overall good agreement with the various experimental data sets used in the validation was obtained. (author)

  16. Experimental observation of rainbow scattering by a coated cylinder: twin primary rainbows and thin-film interference.

    PubMed

    Adler, C L; Lock, J A; Nash, J K; Saunders, K W

    2001-03-20

    We experimentally examine the primary rainbow created by the illumination of a coated cylinder. We present a simple technique for varying the coating thickness over a wide range of values, and we see evidence for two different scattering regimes. In one, where the coating thickness is large, twin rainbows are produced. In the second, where the coating is thin enough to act as a thin film, a single rainbow is produced whose intensity varies periodically as the coating thickness varies. We find good agreement with previous theoretical predictions. PMID:18357147

  17. 76 FR 33756 - Notice of Approval of the Primacy Application for National Primary Drinking Water Regulations for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-09

    ... AGENCY Notice of Approval of the Primacy Application for National Primary Drinking Water Regulations for... following offices: (1) Missouri Department of Natural Resources, Public Drinking Water Branch, 1101... Pesticides Division, Drinking Water Management Branch, 901 North 5th Street, Kansas City, Kansas 66101....

  18. Experimental study on mixing efficiency in water supply rectangular tanks

    NASA Astrophysics Data System (ADS)

    Bateman, A.; Medina, V.; Mujal, A.

    2009-04-01

    Phenomenon of mixing in drinking water storage tanks and reservoirs has a direct effect on the quality of water. Creation of poor mixing zones and volume stratification can have negative effects in public health. The design of a storage tank must consider the conditions of the inlet and outlets, and also their orientation (vertical or horizontal) to prevent the formation of these zones. Experiments done in a reduced scaled-model with a rectangular base and three different inlets (two waterfalls and a pipe inlet) had the objective to decide which of these inlets achieved the best mixing efficiency. Four situations were considered while three entrances, two unsteady: filling and drawing, and two steady with different outlets. Moreover the effects of columns that support the roof of the tank were studied by running the three entrances with and without columns in the four situations. Neglecting the viscous scale effects, the time taken to mix the volume stored depends on the distance between the inlet and the opposite wall as though as its orientation. Taking into account the whole tank columns have a negative effect on mixing efficiency although they divide the flux and create local zones of turbulence around them, increasing local mixing. Using a digital treating image technique the results are found in a quantitative way.

  19. Simulation of Water Balance and Forest Treatment Effects at the H.J. Andrews Experimental Forest

    SciTech Connect

    Waichler, Scott R.; Wemple, Beverley C.; Wigmosta, Mark S.

    2005-10-30

    The watershed model DHSVM was applied to the small watersheds WS1,2,3 in H.J. Andrews Experimental Forest (HJA), Oregon and tested for skill in simulating observed forest treatment effects on streamflow. These watersheds in the rain-snow transition zone underwent road and clearcut treatments during 1959-66 and subsequent natural regeneration. DHSVM was applied with 10 m and 1 hr resolution to 1958-98, most of the period of record. Water balance for old-growth WS2 indicated that evapotranspiration and streamflow were unlikely to be the only loss terms, and groundwater recharge was included to account for about 12% of precipitation; this term was assumed zero in previous studies. After limited calibration, overall efficiency in simulating hourly streamflow exceeded 0.7, and mean annual error was less than 10%. Model skill decreased at the margins, with overprediction of low flows and underprediction of high flows. However, statistical analyses of simulated and observed peakflows yielded similar characterizations of treatment effects. Primary simulation weaknesses were snowpack accumulation, snowmelt under rain-on-snow conditions, and production of quickflow. This challenging test of DHSVM moved the model closer to a practical tool for forest management.

  20. MICROBIAL CHARACTERIZATION OF DRINKING WATER SYSTEMS RECEIVING GROUNDWATER AND SURFACE WATER AS THE PRIMARY SOURCES OF WATER

    EPA Science Inventory

    Earlier descriptions of water distribution systems (WDS) microbial communities have relied on culturing techniques. These techniques are known to be highly selective in nature, but more importantly, they tend to grossly underestimate the microbial diversity of most environments. ...

  1. Numerical and experimental study on the flow distribution in a water manifold

    NASA Astrophysics Data System (ADS)

    Min, Gwansik; Jong Lee, Pil; Kang, Jong Hoon

    2016-03-01

    This study presents water distribution analysis of the device for spraying cooling water through specific nozzles numerically and experimentally. Numerical analysis was performed using the 3-D incompressible, multi-phase flow model, for different Reynolds numbers of 4 × 105, 8 × 105. Experimental analysis was performed at real-size, under the same conditions. The calculated results and the measured results for the distribution of flow were matched relatively well. The distribution of the nozzle flow depends on the Reynolds number.

  2. Theoretical and experimental studies of water interaction in acetate based ionic liquids.

    PubMed

    Shi, Wei; Damodaran, Krishnan; Nulwala, Hunaid B; Luebke, David R

    2012-12-01

    Water interactions in 1-ethyl-3-methylimidazolium acetate ([emim][CH(3)COO]) were studied utilizing classical and ab initio simulation methods. The self-diffusivities for water and the ionic liquid (IL) were studied experimentally using pulse field gradient NMR spectroscopy and correlated with computational results. Water forms hydrogen bonding networks with the ionic liquid, and depending on the concentration of water, there are profound effects on the self-diffusivities of the various species. Both simulation and experiments show that the self-diffusivities for species in the water-[emim][CH(3)COO] system exhibit minima at 40-50 mol% water. Water interaction with the [CH(3)COO](-) anion predominates over the water-water and water-cation interactions at most water concentrations. Simulations further indicate that decreasing water-[CH(3)COO](-) interaction will increase the IL and water self-diffusivities. Self-diffusivities in the water-IL systems are dependent upon the cation in a complex way. Water interactions with [P(4444)][CH(3)COO] are reduced compared to [emim][CH(3)COO]. The [P(4444)](+) cation is bulkier than the [emim](+) cation and has a smaller self-diffusivity, but when water was introduced to [P(4444)] [CH(3)COO], the water-[CH(3)COO](-) hydrogen bonding network in the [P(4444)][CH(3)COO] was much smaller than the one observed in [emim][CH(3)COO]. PMID:23093293

  3. Experimental Studies of NGNP Reactor Cavity Cooling System With Water

    SciTech Connect

    Corradini, Michael; Anderson, Mark; Hassan, Yassin; Tokuhiro, Akira

    2013-01-16

    This project will investigate the flow behavior that can occur in the reactor cavity cooling system (RCCS) with water coolant under the passive cooling-mode of operation. The team will conduct separate-effects tests and develop associated scaling analyses, and provide system-level phenomenological and computational models that describe key flow phenomena during RCCS operation, from forced to natural circulation, single-phase flow and two-phase flow and flashing. The project consists of the following tasks: Task 1. Conduct separate-effects, single-phase flow experiments and develop scaling analyses for comparison to system-level computational modeling for the RCCS standpipe design. A transition from forced to natural convection cooling occurs in the standpipe under accident conditions. These tests will measure global flow behavior and local flow velocities, as well as develop instrumentation for use in larger scale tests, thereby providing proper flow distribution among standpipes for decay heat removal. Task 2. Conduct separate-effects experiments for the RCCS standpipe design as two-phase flashing occurs and flow develops. As natural circulation cooling continues without an ultimate heat sink, water within the system will heat to temperatures approaching saturation , at which point two-phase flashing and flow will begin. The focus is to develop a phenomenological model from these tests that will describe the flashing and flow stability phenomena. In addition, one could determine the efficiency of phase separation in the RCCS storage tank as the two-phase flashing phenomena ensues and the storage tank vents the steam produced. Task 3. Develop a system-level computational model that will describe the overall RCCS behavior as it transitions from forced flow to natural circulation and eventual two-phase flow in the passive cooling-mode of operation. This modeling can then be used to test the phenomenological models developed as a function of scale.

  4. Determinants of the spatial covariation of primary productivity and water table depth

    NASA Astrophysics Data System (ADS)

    Koirala, S.; Jung, M.; de Graaf, I. E. M.; Reichstein, M.; Carvalhais, N.

    2015-12-01

    This study explores when, where and how the spatial variations of gross primary productivity (GPP) and water table depth (WTD) are linked at the global scale. Latest observation-based global datasets, at a relatively high resolution of ~10 km (5 arc-minutes), are used to analyse spatial partial correlations between GPP and WTD. Results indicate that strength, direction, and spatial distribution of the partial correlation change with climate, vegetation cover, and seasonal availability of precipitation and radiation. Shallower water table depth is associated with larger GPP (negative correlation) in 14.3-23.9% of the global land area in different seasons. Such negative correlations between GPP and WTD seem to prevail in arid to temperate climatic regions with crop, shrub, or Savanna vegetation covers. These regions often have WTD shallower than 15-20 m. Positive correlations, on the other hand, mostly occur in relatively humid forested regions, suggesting that large water uptake by tree roots decreases groundwater recharge and thus draws the water table down. Gradients of primarily positive to primarily negative correlations are arranged along decreasing tree cover, and increasing coverage of plants with C4-photosynthesis. This possibly indicates that the water use efficiency of ecosystems may also play a critical role in determining productivity-groundwater relationships.

  5. Lead in drinking water: sampling in primary schools and preschools in south central Kansas.

    PubMed

    Massey, Anne R; Steele, Janet E

    2012-03-01

    Studies in Philadelphia, New York City, Houston, Washington, DC, and Greenville, North Carolina, have revealed high lead levels in drinking water. Unlike urban areas, lead levels in drinking water in suburban and rural areas have not been adequately studied. In the study described in this article, drinking water in primary schools and preschools in five suburban and rural south central Kansas towns was sampled to determine if any exceeded the U.S. Environmental Protection Agency (U.S. EPA) guidance level for schools and child care facilities of 20 parts per billion (ppb). The results showed a total of 32.1% of the samples had detectable lead levels and 3.6% exceeded the U.S. EPA guidance level for schools and child care providers of 20 ppb. These results indicate that about one-third of the drinking water consumed by children age six and under in the five suburban and rural south central Kansas towns studied has some lead contamination, exposing these children to both short-term and long-term health risks. The authors suggest a need for increased surveillance of children's drinking water in these facilities.

  6. Experimental studies on the impact properties of water ice

    NASA Technical Reports Server (NTRS)

    Bridges, F. G.; Lin, D. N. C.; Hatzes, A. P.

    1987-01-01

    Experimental studies on the impact of ice particles at very low velocity were continued. These measurements have applications in the dynamics of Saturn's rings. Initially data were obtained on the coefficient of restitution for ice spheres of one radius of curvature. The type of measurements were expanded to include restitution data for balls with a variety of surfaces as well as sticking forces between ice particles. Significant improvements were made to this experiment, the most important being the construction of a new apparatus. The new apparatus consists of a smaller version of the disk pendulum and a stainless steel, double-walled cryostat. The apparatus has proved to be a significant improvement over the old one. Measurements can now be made at temperatures near 90 K, comparable to the temperature of the environment of Saturn's rings, and with much greater temperature stability. It was found that a roughened contact surface or the presence of frost can cause a much larger change in the restitution measure than the geometrical effect of the radius of curvature.

  7. FEM Analysis and Experimental Verification of the Integral Forging Process for AP1000 Primary Coolant Pipe

    NASA Astrophysics Data System (ADS)

    Wang, Shenglong; Yu, Xiaoyi; Yang, Bin; Zhang, Mingxian; Wu, Huanchun

    2016-10-01

    AP1000 primary coolant pipes must be manufactured by integral forging technology according to the designer—Westinghouse Electric Co. The characteristics of these large, special-shaped pipes create nonuniform temperatures, effective stress, and effective strain during shaping of the pipes. This paper presents a three-dimensional finite element simulation (3D FEM) of the integral forging process, and qualitatively evaluates the likelihood of forging defects. By analyzing the evolution histories of the three field variables, we concluded that the initial forging temperature should be strictly controlled within the interval 1123 K to 1423 K (850 °C to 1150 °C) to avoid second-phase precipitation. In the hard deformation zones, small strains do not contribute to recrystallization resulting in coarse grains. Conversely, in the free deformation zone, the large strains can contribute to the dynamic recrystallization, favoring grain refinement and closure of voids. Cracks are likely to appear, however, on the workpiece surface when forging leads to large deformations. Based on the simulation results, an eligible workpiece with good mechanical properties, few macroscopic defects, and favorable grain size has been successfully forged by experiments at an industrial scale, which validates the FEM simulation.

  8. E. coli Induced Experimental Model of Primary Biliary Cirrhosis: At Last.

    PubMed

    Koutsoumpas, Andreas L; Smyk, Daniel S; Bogdanos, Dimitrios P

    2014-01-01

    Recurrent urinary tract infections (UTI) have been considered potential triggers of primary biliary cirrhosis (PBC), an autoimmune cholestatic liver disease characterised by progressive destruction of intrahepatic bile ducts. Additional support for the link made between PBC and UTI was based on early observations of recurrent episodes of bacteriuria in female patients with PBC. A series of large epidemiological studies demonstrated a strong correlation between recurrent UTI and PBC, initiating a series of studies investigating the role of Escherichia coli (E. coli, the most prevalent organism isolated in women with UTI) as a trigger of PBC. Immunological evidence of B- and T-cell cross-reactive responses implicating PBC-specific autoantigens and E. coli mimics have been clearly demonstrated, adding support to the notion that E. coli is a potential infectious inducer of PBC in susceptible individuals. One of the major limitations in proving the E. coli/PBC association was the lack of reliable E. coli-infected animal models of PBC. This review provides an overview of the evidence linking this infectious agent with PBC and discusses the pros and cons of a recently developed E. coli-infected animal model of PBC.

  9. Biological factors and age-dependence of primary motor cortex experimental plasticity.

    PubMed

    Polimanti, Renato; Simonelli, Ilaria; Zappasodi, Filippo; Ventriglia, Mariacarla; Pellicciari, Maria Concetta; Benussi, Luisa; Squitti, Rosanna; Rossini, Paolo Maria; Tecchio, Franca

    2016-02-01

    To evaluate whether the age-dependence of brain plasticity correlates with the levels of proteins involved in hormone and brain functions we executed a paired associative stimulation (PAS) protocol and blood tests. We measured the PAS-induced plasticity in the primary motor cortex. Blood levels of the brain-derived neurotrophic factor (BDNF), estradiol, the insulin-like growth factor (IGF)-1, the insulin-like growth factor binding protein (IGFBP)-3, progesterone, sex hormone-binding globulin (SHBG), testosterone, and the transforming growth factor beta 1 (TGF-β1) were determined in 15 healthy men and 20 healthy women. We observed an age-related reduction of PAS-induced plasticity in females that it is not present in males. In females, PAS-induced plasticity displayed a correlation with testosterone (p = 0.006) that became a trend after the adjustment for the age effect (p = 0.078). In males, IGF-1 showed a nominally significant correlation with the PAS-induced plasticity (p = 0.043). In conclusion, we observed that hormone blood levels (testosterone in females and IGF-1 in males) may be involved in the age-dependence of brain plasticity.

  10. Effect of Carnosine in Experimental Arthritis and on Primary Culture Chondrocytes.

    PubMed

    Ponist, S; Drafi, F; Kuncirova, V; Mihalova, D; Rackova, L; Danisovic, L; Ondrejickova, O; Tumova, I; Trunova, O; Fedorova, T; Bauerova, K

    2016-01-01

    Carnosine's (CARN) anti-inflammatory potential in autoimmune diseases has been but scarcely investigated as yet. The aim of this study was to evaluate the therapeutic potential of CARN in rat adjuvant arthritis, in the model of carrageenan induced hind paw edema (CARA), and also in primary culture of chondrocytes under H2O2 injury. The experiments were done on healthy animals, arthritic animals, and arthritic animals with oral administration of CARN in a daily dose of 150 mg/kg b.w. during 28 days as well as animals with CARA treated by a single administration of CARN in the same dose. CARN beneficially affected hind paw volume and changes in body weight on day 14 and reduced hind paw swelling in CARA. Markers of oxidative stress in plasma and brain (malondialdehyde, 4-hydroxynonenal, protein carbonyls, and lag time of lipid peroxidation) and also activity of gamma-glutamyltransferase were significantly corrected by CARN. CARN also reduced IL-1alpha in plasma. Suppression of intracellular oxidant levels was also observed in chondrocytes pretreated with CARN. Our results obtained on two animal models showed that CARN has systemic anti-inflammatory activity and protected rat brain and chondrocytes from oxidative stress. This finding suggests that CARN might be beneficial for treatment of arthritic diseases. PMID:26885252

  11. An experimental model for Naegleria fowleri-induced primary amebic meningoencephalitis in rabbits.

    PubMed

    Smego, R A; Durack, D T

    1984-02-01

    A new model was developed in rabbits for primary amebic meningoencephalitis, a rare disease caused by the free-living ameba, Naegleria fowleri. Naegleria fowleri was cultured in a liquid axenic medium, and then injected intracisternally into New Zealand White rabbits. Inocula of 10(3) or 10(5) trophozoites consistently produced a sanguinopurulent meningitis; duration of survival of rabbits was 57 or 45 hr, respectively. Counts of cells in cerebrospinal fluid were proportional to the size of inoculum used; white blood cell counts ranged from 30 to 1,055 cells/mm3, and red blood cell counts from five to 8,640 cells/mm3. Necropsies revealed severe basilar meningoencephalitis with extensive hemorrhagic necrosis and polymorphonuclear cell infiltration. Trophozoites of N. fowleri were seen within the meningeal exudate and the brain parenchyma. Potential applications of this model include studies of the host response to amebae in the CSF, evaluation of the optimal route of administration of amphotericin B, and in vivo studies of other chemotherapeutic agents that show in vitro efficacy. PMID:6737174

  12. An experimental model for Naegleria fowleri-induced primary amebic meningoencephalitis in rabbits.

    PubMed

    Smego, R A; Durack, D T

    1984-02-01

    A new model was developed in rabbits for primary amebic meningoencephalitis, a rare disease caused by the free-living ameba, Naegleria fowleri. Naegleria fowleri was cultured in a liquid axenic medium, and then injected intracisternally into New Zealand White rabbits. Inocula of 10(3) or 10(5) trophozoites consistently produced a sanguinopurulent meningitis; duration of survival of rabbits was 57 or 45 hr, respectively. Counts of cells in cerebrospinal fluid were proportional to the size of inoculum used; white blood cell counts ranged from 30 to 1,055 cells/mm3, and red blood cell counts from five to 8,640 cells/mm3. Necropsies revealed severe basilar meningoencephalitis with extensive hemorrhagic necrosis and polymorphonuclear cell infiltration. Trophozoites of N. fowleri were seen within the meningeal exudate and the brain parenchyma. Potential applications of this model include studies of the host response to amebae in the CSF, evaluation of the optimal route of administration of amphotericin B, and in vivo studies of other chemotherapeutic agents that show in vitro efficacy.

  13. Effect of Carnosine in Experimental Arthritis and on Primary Culture Chondrocytes

    PubMed Central

    Ponist, S.; Drafi, F.; Kuncirova, V.; Mihalova, D.; Rackova, L.; Danisovic, L.; Ondrejickova, O.; Tumova, I.; Trunova, O.; Fedorova, T.; Bauerova, K.

    2016-01-01

    Carnosine's (CARN) anti-inflammatory potential in autoimmune diseases has been but scarcely investigated as yet. The aim of this study was to evaluate the therapeutic potential of CARN in rat adjuvant arthritis, in the model of carrageenan induced hind paw edema (CARA), and also in primary culture of chondrocytes under H2O2 injury. The experiments were done on healthy animals, arthritic animals, and arthritic animals with oral administration of CARN in a daily dose of 150 mg/kg b.w. during 28 days as well as animals with CARA treated by a single administration of CARN in the same dose. CARN beneficially affected hind paw volume and changes in body weight on day 14 and reduced hind paw swelling in CARA. Markers of oxidative stress in plasma and brain (malondialdehyde, 4-hydroxynonenal, protein carbonyls, and lag time of lipid peroxidation) and also activity of gamma-glutamyltransferase were significantly corrected by CARN. CARN also reduced IL-1alpha in plasma. Suppression of intracellular oxidant levels was also observed in chondrocytes pretreated with CARN. Our results obtained on two animal models showed that CARN has systemic anti-inflammatory activity and protected rat brain and chondrocytes from oxidative stress. This finding suggests that CARN might be beneficial for treatment of arthritic diseases. PMID:26885252

  14. FEM Analysis and Experimental Verification of the Integral Forging Process for AP1000 Primary Coolant Pipe

    NASA Astrophysics Data System (ADS)

    Wang, Shenglong; Yu, Xiaoyi; Yang, Bin; Zhang, Mingxian; Wu, Huanchun

    2016-08-01

    AP1000 primary coolant pipes must be manufactured by integral forging technology according to the designer—Westinghouse Electric Co. The characteristics of these large, special-shaped pipes create nonuniform temperatures, effective stress, and effective strain during shaping of the pipes. This paper presents a three-dimensional finite element simulation (3D FEM) of the integral forging process, and qualitatively evaluates the likelihood of forging defects. By analyzing the evolution histories of the three field variables, we concluded that the initial forging temperature should be strictly controlled within the interval 1123 K to 1423 K (850 °C to 1150 °C) to avoid second-phase precipitation. In the hard deformation zones, small strains do not contribute to recrystallization resulting in coarse grains. Conversely, in the free deformation zone, the large strains can contribute to the dynamic recrystallization, favoring grain refinement and closure of voids. Cracks are likely to appear, however, on the workpiece surface when forging leads to large deformations. Based on the simulation results, an eligible workpiece with good mechanical properties, few macroscopic defects, and favorable grain size has been successfully forged by experiments at an industrial scale, which validates the FEM simulation.

  15. Experimental critical parameters of plutonium metal cylinders flooded with water

    SciTech Connect

    1996-07-01

    Forty-nine critical configurations are reported for experiments involving arrays of 3 kg plutonium metal cylinders moderated and reflected by water. Thirty-four of these describe systems assembled in the laboratory, while 15 others are derived critical parameters inferred from 46 subcritical cases. The arrays included 2x2xN, N = 2, 3, 4, and 5, in one program and 3x3x3 configurations in a later study. All were three-dimensional, nearly square arrays with equal horizontal lattice spacings but a different vertical lattice spacing. Horizontal spacings ranged from units in contact to 180 mm center-to-center; and vertical spacings ranged from about 80 mm to almost 400 mm center-to-center. Several nearly-equilateral 3x3x3 arrays exhibit an extremely sensitive dependence upon horizontal separation for identical vertical spacings. A line array of unreflected and essentially unmoderated canned plutonium metal units appeared to be well subcritical based on measurements made to assure safety during the manual assembly operations. All experiments were performed at two widely separated times in the mid-1970s and early 1980s under two programs at the Rocky Flats Plant`s Critical Mass Laboratory.

  16. Water Quality Effects of Simulated Conservation Practice Scenarios in the Little River Experimental Watershed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study, we evaluated the water quality effects of alternative conservation practice scenarios using the SWAT model in the Little River Experimental Watershed (LREW), a representative coastal plain watershed located in southern Georgia. We simulated the water quality effect of two suites of u...

  17. Financial Analysis of Experimental Releases Conducted at Glen Canyon Dam during Water Year 2014

    SciTech Connect

    Graziano, D. J.; Poch, L. A.; Veselka, T. D.; Palmer, C. S.; Loftin, S.; Osiek, B.

    2015-09-01

    This report examines the financial implications of experimental flows conducted at the Glen Canyon Dam (GCD) in water year (WY) 2014. It is the sixth report in a series examining the financial implications of experimental flows conducted since the Record of Decision (ROD) was adopted in February 1997 (Reclamation 1996). A report released in January 2011 examined water years 1997 to 2005 (Veselka et al. 2011), a report released in August 2011 examined water years 2006 to 2010 (Poch et al. 2011), a report released June 2012 examined water year 2011 (Poch et al. 2012), a report released April 2013 examined water year 2012 (Poch et al. 2013), and a report released June 2014 examined water year 2013 (Graziano et al. 2014).

  18. Experimental determination of cavitation thresholds in liquid water and mercury

    SciTech Connect

    Taleyarkhan, R.P.; Gulec, K.; West, C.D.; Haines, J.

    1998-09-01

    It is well-known that fluids (like solids) will break apart or form voids when put under sufficient tension. The present study has been motivated by the need to evaluate the impact of fluid cavitation in spallation neutron source target systems, more specifically for the proposed 1-MW Spallation Neutron Source (SNS) project, which is being designed in collaboration between Oak Ridge National Laboratory (ORNL), Los Alamos National Laboratory, Lawrence Berkeley National Laboratory, Brookhaven National Laboratory, and Argonne National Laboratory. Indeed, results of SNS-specific simulations have indicated that the onset of cavitation could play a very significant role in reducing imposed stresses in structural components of the SNS. In general, the cavitation of fluids is target systems is important to consider for a variety of reasons. Its occurrence can have significant impact on heat transfer, pressure pulse generation, fluid jetting on to structures, surface erosion, stresses induced in enclosures, etc. Therefore, it is important to evaluate the threshold pressure under which the fluid in tension will undergo cavitation. Another major aspect concerns the possible onset of cavitation in an oscillating pressure field; i.e., one would need to know if fluids such as mercury and water will cavitate if the imposed tensile pressure in the fluid is of short duration. If indeed it takes sufficiently long for cavitation bubbles to nucleate, then it would be possible to disregard the complexities involved with addressing cavitation-related issues. This paper provides an overview of preliminary work done to date to derive information on cavitation onset in a relatively static and in a high-frequency environment.

  19. Water weakening in experimentally deformed milky quartz single crystals

    NASA Astrophysics Data System (ADS)

    Stunitz, H.; Thust, A.; Kilian, R.; Heilbronner, R.; Behrens, H.; Tarantola, A.; Fitz Gerald, J. D.

    2015-12-01

    Natural single crystals of quartz have been experimentally deformed in two orientations: (1) normal to one prism-plane, (2) In O+ orientation at temperatures of 900 and 1000°C, pressures of 1.0 and 1.5 GPa, and strain rates of ~1 x 10-6s-1. The starting material is milky quartz, consisting of dry quartz (H2O contents of <150 H/106Si) with fluid inclusions (FI). During pressurization many FI´s decrepitate. Cracks heal and small neonate FI´s form, increasing the number of FI´s drastically. During subsequent deformation, the size of FI´s is further reduced (down to ~10 nm). Sample deformation occurs by dominant dislocation glide on selected slip systems, accompanied by some dynamic recovery. Strongly deformed regions show FTIR spectra with a pointed broad absorption band in the ~3400 cm-1 region as a superposition of molecular H2O bands and three discrete absorption bands (at 3367, 3400, and 3434 cm-1). In addition, there is a discrete absorption band at 3585 cm-1, which only occurs in deformed regions. The 3585 cm-1 band is reduced or even disappears after annealing. This band is polarized and represents structurally bound H, its H-content is estimated to be 1-3% of the total H2O-content and appears to be associated with dislocations. The H2O weakening effect in our FI-bearing natural quartz crystals is assigned to the processes of dislocation generation and multiplication at small FI´s. The deformation processes in these crystals represent a recycling of H2O between FI´s, dislocation generation at very small fluid inclusions, incorporation of structurally bound H into dislocation cores, and release of H2O from dislocations back into FI´s during recovery. Cracking and crack healing play an important role in the recycling process and imply a close interrelationship between brittle and crystal plastic deformation. The H2O weakening by this process is of a disequilibrium nature and thus depends on the amount of H2O available.

  20. Experimental study of iron and multivitamin drops on enamel microhardness of primary tooth

    PubMed Central

    Pasdar, Nilgoon; Alaghehmand, Homayoon; Mottaghi, Fattane; Tavassoli, Maryam

    2015-01-01

    Objectives: Iron and multivitamin drops are being frequently prescribed in children less than 2 years of age. Due to their low pH levels, these drops may lead to the softening of enamel and accelerate the destructive process. The aim of the present study was to investigate the enamel microhardness of primary teeth after exposing them to iron and multivitamin drops. Materials and Methods: Forty healthy anterior teeth were randomly divided into four groups of 10 samples each. Samples were exposed to two iron drops of Kharazmi (Iran) and Ironorm (UK) and two multivitamin drops of Shahdarou (Iran) and Eurovit (Germany) for 5 min. The surface microhardness was measured before and after exposure and data processing was done using statistical paired t-test and analysis of variance (ANOVA) test. The surface structure of the teeth was examined by scanning electron microscope (SEM). Results: In all groups, microhardness was decreased, but it was not significant in Eurovit multivitamin group (P = 0.088). The reduction rate in Kharazmi iron group was significant compared to that in other groups (P < 0.005). Hardness reduction percent for Kharazmi iron drop was 28/12 ± 47/43. In SEM analysis, irregular granular appearance was observed in the enamel exposed to Kharazmi iron drop. Conclusion: The results showed that all the studied drugs have the potential to cause erosion; this potential is the most in Kharazmi iron drop and the least in Eurovit multivitamin drops. Therefore, after using these kinds of drops, preventive measures should be used in children. PMID:26759808

  1. Swashplateless Helicopter Experimental Investigation: Primary Control with Trailing Edge Flaps Actuated with Piezobenders

    NASA Astrophysics Data System (ADS)

    Copp, Peter

    Helicopter rotor primary control is conventionally carried out using a swashplate with pitch links. Eliminating the swashplate promises to reduce the helicopter's parasitic power in high speed forward flight, as well as may lead to a hydraulic-less vehicle. A Mach-scale swashplateless rotor is designed with integrated piezobender-actuated trailing edge flaps and systematically tested on the benchtop, in the vacuum chamber and on the hoverstand. The blade is nominally based on the UH-60 rotor with a hover tip Mach number of 0.64. The blade diameter is 66 inches requiring 2400 RPM for Mach scale simulation. The rotor hub is modified to reduce the blade fundamental torsional frequency to less than 2.0/rev by replacing the rigid pitch links with linear springs, which results in an increase of the blade pitching response to the trailing edge flaps. Piezoelectric multilayer benders provide the necessary bandwidth, stroke and stiffness to drive the flaps for primary control while fitting inside the blade profile and withstanding the high centrifugal forces. This work focuses on several key issues. A piezobender designed from a soft piezoelectric material, PZT-5K4, is constructed. The new material is used to construct multi-layer benders with increased stroke for the same stiffness relative to hard materials such as PZT-5H2. Each layer has a thickness of 10 mils. The soft material with gold electrodes requires a different bonding method than hard material with nickel electrodes. With this new bonding method, the measured stiffness matches precisely the predicted stiffness for a 12 layer bender with 1.26 inch length and 1.0 inch width with a stiffness of 1.04 lb/mil. The final in-blade bender has a length of 1.38 inches and 1.0 inch width with a stiffness of 0.325 lb/mil and stroke of 20.2 mils for an energy output of 66.3 lb-mil. The behavior of piezobenders under very high electric fields is investigated. High field means +18.9 kV/cm (limited by arcing in air) and -3.54k

  2. Financial analysis of experimental releases conducted at Glen Canyon Dam during water year 2011

    SciTech Connect

    Poch, L. A.; Veselka, T. D.; Palmer, C. S.; Loftin, S.; Osiek, B.

    2012-07-16

    This report examines the financial implications of experimental flows conducted at the Glen Canyon Dam (GCD) in water year 2011. It is the third report in a series examining financial implications of experimental flows conducted since the Record of Decision (ROD) was adopted in February 1997 (Reclamation 1996). A report released in January 2011 examined water years 1997 to 2005 (Veselka et al. 2011), and a report released in August 2011 examined water years 2006 to 2010 (Poch et al. 2011). An experimental release may have either a positive or negative impact on the financial value of energy production. This study estimates the financial costs of experimental releases, identifies the main factors that contribute to these costs, and compares the interdependencies among these factors. An integrated set of tools was used to compute the financial impacts of the experimental releases by simulating the operation of the GCD under two scenarios, namely, (1) a baseline scenario that assumes both that operations comply with the ROD operating criteria and the experimental releases that actually took place during the study period, and (2) a 'without experiments' scenario that is identical to the baseline scenario of operations that comply with the GCD ROD, except it assumes that experimental releases did not occur. The Generation and Transmission Maximization (GTMax) model was the main simulation tool used to dispatch GCD and other hydropower plants that comprise the Salt Lake City Area Integrated Projects (SLCA/IP). Extensive data sets and historical information on SLCA/IP powerplant characteristics, hydrologic conditions, and Western Area Power Administration's (Western's) power purchase prices were used for the simulation. In addition to estimating the financial impact of experimental releases, the GTMax model was also used to gain insights into the interplay among ROD operating criteria, exceptions that were made to criteria to accommodate the experimental releases, and

  3. Effects of experimental water table and temperature manipulations on ecosystem CO2 fluxes in an Alaskan rich fen

    USGS Publications Warehouse

    Chivers, M.R.; Turetsky, M.R.; Waddington, J.M.; Harden, J.W.; McGuire, A.D.

    2009-01-01

    Peatlands store 30% of the world's terrestrial soil carbon (C) and those located at northern latitudes are expected to experience rapid climate warming. We monitored growing season carbon dioxide (CO2) fluxes across a factorial design of in situ water table (control, drought, and flooded plots) and soil warming (control vs. warming via open top chambers) treatments for 2 years in a rich fen located just outside the Bonanza Creek Experimental Forest in interior Alaska. The drought (lowered water table position) treatment was a weak sink or small source of atmospheric CO2 compared to the moderate atmospheric CO2 sink at our control. This change in net ecosystem exchange was due to lower gross primary production and light-saturated photosynthesis rather than increased ecosystem respiration. The flooded (raised water table position) treatment was a greater CO2 sink in 2006 due largely to increased early season gross primary production and higher light-saturated photosynthesis. Although flooding did not have substantial effects on rates of ecosystem respiration, this water table treatment had lower maximum respiration rates and a higher temperature sensitivity of ecosystem respiration than the control plot. Surface soil warming increased both ecosystem respiration and gross primary production by approximately 16% compared to control (ambient temperature) plots, with no net effect on net ecosystem exchange. Results from this rich fen manipulation suggest that fast responses to drought will include reduced ecosystem C storage driven by plant stress, whereas inundation will increase ecosystem C storage by stimulating plant growth. ?? 2009 Springer Science+Business Media, LLC.

  4. Understanding flocculation mechanism of graphene oxide for organic dyes from water: Experimental and molecular dynamics simulation

    NASA Astrophysics Data System (ADS)

    Liu, Jun; Li, Peng; Xiao, Hang; Zhang, Yayun; Shi, Xiaoyang; Lü, Xiaomeng; Chen, Xi

    2015-11-01

    Flocculation treatment processes play an important role in water and wastewater pretreatment. Here we investigate experimentally and theoretically the possibility of using graphene oxide (GO) as a flocculant to remove methylene blue (MB) from water. Experimental results show that GO can remove almost all MB from aqueous solutions at its optimal dosages and molecular dynamics simulations indicate that MB cations quickly congregate around GO in water. Furthermore, PIXEL energy contribution analysis reveals that most of the strong interactions between GO and MB are of a van der Waals (London dispersion) character. These results offer new insights for shedding light on the molecular mechanism of interaction between GO and organic pollutants.

  5. Consumers mediate the effects of experimental ocean acidification and warming on primary producers.

    PubMed

    Alsterberg, Christian; Eklöf, Johan S; Gamfeldt, Lars; Havenhand, Jonathan N; Sundbäck, Kristina

    2013-05-21

    It is well known that ocean acidification can have profound impacts on marine organisms. However, we know little about the direct and indirect effects of ocean acidification and also how these effects interact with other features of environmental change such as warming and declining consumer pressure. In this study, we tested whether the presence of consumers (invertebrate mesograzers) influenced the interactive effects of ocean acidification and warming on benthic microalgae in a seagrass community mesocosm experiment. Net effects of acidification and warming on benthic microalgal biomass and production, as assessed by analysis of variance, were relatively weak regardless of grazer presence. However, partitioning these net effects into direct and indirect effects using structural equation modeling revealed several strong relationships. In the absence of grazers, benthic microalgae were negatively and indirectly affected by sediment-associated microalgal grazers and macroalgal shading, but directly and positively affected by acidification and warming. Combining indirect and direct effects yielded no or weak net effects. In the presence of grazers, almost all direct and indirect climate effects were nonsignificant. Our analyses highlight that (i) indirect effects of climate change may be at least as strong as direct effects, (ii) grazers are crucial in mediating these effects, and (iii) effects of ocean acidification may be apparent only through indirect effects and in combination with other variables (e.g., warming). These findings highlight the importance of experimental designs and statistical analyses that allow us to separate and quantify the direct and indirect effects of multiple climate variables on natural communities.

  6. Vitamins and nutrients as primary treatments in experimental brain injury: Clinical implications for nutraceutical therapies.

    PubMed

    Vonder Haar, Cole; Peterson, Todd C; Martens, Kris M; Hoane, Michael R

    2016-06-01

    With the numerous failures of pharmaceuticals to treat traumatic brain injury in humans, more researchers have become interested in combination therapies. This is largely due to the multimodal nature of damage from injury, which causes excitotoxicity, oxidative stress, edema, neuroinflammation and cell death. Polydrug treatments have the potential to target multiple aspects of the secondary injury cascade, while many previous therapies focused on one particular aspect. Of specific note are vitamins, minerals and nutrients that can be utilized to supplement other therapies. Many of these have low toxicity, are already FDA approved and have minimal interactions with other drugs, making them attractive targets for therapeutics. Over the past 20 years, interest in supplementation and supraphysiologic dosing of nutrients for brain injury has increased and indeed many vitamins and nutrients now have a considerable body of the literature backing their use. Here, we review several of the prominent therapies in the category of nutraceutical treatment for brain injury in experimental models, including vitamins (B2, B3, B6, B9, C, D, E), herbs and traditional medicines (ginseng, Gingko biloba), flavonoids, and other nutrients (magnesium, zinc, carnitine, omega-3 fatty acids). While there is still much work to be done, several of these have strong potential for clinical therapies, particularly with regard to polydrug regimens. This article is part of a Special Issue entitled SI:Brain injury and recovery. PMID:26723564

  7. Mechanism for the primary transformation of acetaminophen in a soil/water system.

    PubMed

    Liang, Chuanzhou; Lan, Zhonghui; Zhang, Xu; Liu, Yingbao

    2016-07-01

    The transformation of acetaminophen (APAP) in a soil/water system was systematically investigated by a combination of kinetic studies and a quantitative analysis of the reaction intermediates. Biotransformation was the predominant pathway for the elimination of APAP, whereas hydrolysis or other chemical transformation, and adsorption processes made almost no contribution to the transformation under a dark incubation. Bacillus aryabhattai strain 1-Sj-5-2-5-M, Klebsiella pneumoniae strain S001, and Bacillus subtilis strain HJ5 were the main bacteria identified in the biotransformation of APAP. The soil-to-water ratio and soil preincubation were able to alter the transformation kinetic pattern. Light irradiation promoted the overall transformation kinetics through enhanced biotransformation and extra photosensitized chemical reactions. The transformation pathways were strongly dependent on the initial concentration of APAP. The main primary transformation products were APAP oligomers and p-aminophenol, with the initial addition of 26.5 and 530 μM APAP, respectively. APAP oligomers accounted for more than 95% of transformed APAP, indicating that almost no bound residues were generated through the transformation of APAP in the soil/water system. The potential environmental risks of APAP could increase following the transformation of APAP in the soil/water system because of the higher toxicity of the transformation intermediates. PMID:27107139

  8. Estimation of water quality and plant primary production in Arctic wetlands using ground based spectrometry

    NASA Astrophysics Data System (ADS)

    Andresen, C.; Lougheed, V.; Tweedie, C.

    2010-12-01

    Wetlands represent a significant portion of the Arctic tundra landscape, which is experiencing warming at an unprecedented rate. Understanding of primary production in these ecosystems is essential for assessing carbon fluxes and climate change effects. Remote sensing techniques are known to be accurate and cost effective to monitor aquatic vegetation and water quality parameters; however, their utility in mapping these ecosystems is unknown. We used a handheld hyperspectral radiometer (Unispec, PP Systems) to measure reflectance across the visible and near-infrared spectrum (400-1100nm) of two predominant aquatic graminoid species (Carex aquatilis and Arctophila fulva) along an anthropogenic disturbance gradient in tundra ponds of Barrow, Alaska. Spectral measurements were validated with in situ biomass harvest and water quality monitoring (e.g DOC, nutrients, algal chlorophyll). Reflectance of the two plant species exhibited spectral differences in the near-infrared portion of the spectrum. These reflectance measurements were also associated with water quality and plant biomass. Future efforts will involve the extrapolation of these ground based observations to a regional level using airborne and satellite imagery. This study advances large scale quantification and monitoring of water quality and aquatic plant production in the Arctic tundra and aids understanding of anthropogenic and climate effects in this rapidly changing ecosystem.

  9. Experimental Observation of Bulk Liquid Water Structure in ``No Man's Land''

    NASA Astrophysics Data System (ADS)

    Sellberg, Jonas; McQueen, Trevor; Huang, Congcong; Loh, Duane; Laksmono, Hartawan; Sierra, Raymond; Hampton, Christina; Starodub, Dmitri; Deponte, Daniel; Martin, Andrew; Barty, Anton; Wikfeldt, Thor; Schlesinger, Daniel; Pettersson, Lars; Beye, Martin; Nordlund, Dennis; Weiss, Thomas; Feldkamp, Jan; Caronna, Chiara; Seibert, Marvin; Messerschmidt, Marc; Williams, Garth; Boutet, Sebastien; Bogan, Michael; Nilsson, Anders

    2013-03-01

    Experiments on pure bulk water below about 235 K have so far been difficult: water crystallization occurs very rapidly below the homogeneous nucleation temperature of 232 K and above 160 K, leading to a ``no man's land'' devoid of experimental results regarding the structure. Here, we demonstrate a new, general experimental approach to study the structure of liquid states at supercooled conditions below their limit of homogeneous nucleation. We use femtosecond x-ray pulses generated by the LCLS x-ray laser to probe evaporatively cooled droplets of supercooled bulk water and find experimental evidence for the existence of metastable bulk liquid water down to temperatures of 223 K in the previously largely unexplored ``no man's land''. We acknoweledge NSF (CHE-0809324), Office of Basic Energy Sciences, and the Swedish Research Council for financial support.

  10. DETECTORS AND EXPERIMENTAL METHODS: Circulation model for water circulation and purification in a water Cerenkov detector

    NASA Astrophysics Data System (ADS)

    Lu, Hao-Qi; Yang, Chang-Gen; Wang, Ling-Yu; Xu, Ji-Lei; Wang, Rui-Guang; Wang, Zhi-Min; Wang, Yi-Fang

    2009-07-01

    Owing to its low cost and good transparency, highly purified water is widely used as a medium in large water Cerenkov detector experiments. The water circulation and purification system is usually needed to keep the water in good quality. In this work, a practical circulation model is built to describe the variation of the water resistivity in the circulation process and compared with the data obtained from a prototype experiment. The successful test of the model makes it useful in the future design and optimization of the circulation/purification system.

  11. Experimentally probing the libration of interfacial water: the rotational potential of water is stiffer at the air/water interface than in bulk liquid.

    PubMed

    Tong, Yujin; Kampfrath, Tobias; Campen, R Kramer

    2016-07-21

    Most properties of liquid water are determined by its hydrogen-bond network. Because forming an aqueous interface requires termination of this network, one might expect the molecular level properties of interfacial water to markedly differ from water in bulk. Intriguingly, much prior experimental and theoretical work has found that, from the perspective of their time-averaged structure and picosecond structural dynamics, hydrogen-bonded OH groups at an air/water interface behave the same as hydrogen-bonded OH groups in bulk liquid water. Here we report the first experimental observation of interfacial water's libration (i.e. frustrated rotation) using the laser-based technique vibrational sum frequency spectroscopy. We find this mode has a frequency of 834 cm(-1), ≈165 cm(-1) higher than in bulk liquid water at the same temperature and similar to bulk ice. Because libration frequency is proportional to the stiffness of water's rotational potential, this increase suggests that one effect of terminating bulk water's hydrogen bonding network at the air/water interface is retarding rotation of water around intact hydrogen bonds. Because in bulk liquid water the libration plays a key role in stabilizing reaction intermediates and dissipating excess vibrational energy, we expect the ability to probe this mode in interfacial water to open new perspectives on the kinetics of heterogeneous reactions at aqueous interfaces. PMID:27339861

  12. Design-development and operation of the Experimental Boiling-Water Reactor (EBWR) facility, 1955--1967

    SciTech Connect

    Boing, L.E.; Wimunc, E.A.; Whittington, G.A.

    1990-11-01

    The Experimental Boiling-Water Reactor (EBWR) was designed, built, and operated to provide experience and engineering data that would demonstrate the feasibility of the direct-cycle, boiling-water reactor and be applicable to improved, larger nuclear power stations; and was based on information obtained in the first test boiling-water reactors, the BORAX series. EBWR initially produced 20 MW(t), 5 MW(e); later modified and upgraded, as described and illustrated, it was operated at up to 100 MW(t). The facility fulfilled its primary mission -- demonstrating the practicality of the direct-boiling concept -- and, in fact, was the prototype of some of the first commercial plants and of reactor programs in some other countries. After successful completion of the Water-Cooled Reactor Program, EBWR was utilized in the joint Argonne-Hanford Plutonium Recycle Program to develop data for the utilization of plutonium as a fuel in light- water thermal systems. Final shutdown of the EBWR facility followed the termination of the latter program. 13 refs., 12 figs.

  13. The exchange of water between the Faroe Shelf and the surrounding waters and its effect on the primary production

    NASA Astrophysics Data System (ADS)

    Eliasen, Sólvá Karadóttir; Hansen, Bogi; Larsen, Karin Margretha Húsgarð; Hátún, Hjálmar

    2016-01-01

    The interannual variation of the spring bloom and its effect on the marine ecosystem on the Faroe Shelf has been observed for a couple of decades. However, the mechanism controlling the spring bloom has so far not been known and attempts to explain the mechanism have mostly ruled out possibilities. The Faroe Shelf is to a variable degree isolated from the surrounding waters by a tidal front. It has previously been suggested that variations in the density difference across the front and how water masses are transferred across it affect the spring primary production, which is thought to be a driver of the shelf ecosystem. Using air-sea heat flux data and sea temperature observations on the shelf and off the shelf, we estimate the cross-frontal volume exchange in January-April and find that it increases with the tidal current speed and decreases with the cross-frontal temperature difference. Using the observed exchange rates, we show that the phytoplankton growth rate may be reduced by more than 0.05 day- 1 when the exchange is intense and off-shelf production is still low. Based on frontal dynamics theory, we suggest that the cross-frontal exchange rate in the above mentioned period is determined by the rate of vertical turbulent diffusion through the front. A simple theoretical model is found to support this hypothesis qualitatively as well as quantitatively. This supports that variations in horizontal exchange are an important controlling factor of the initial spring bloom and that the horizontal exchange during the winter can be determined by vertical turbulent diffusion. Our results will be relevant for the primary production in other similar systems of small geographical extent and also for other problems involving cross-shelf exchange, such as oil spill dispersal.

  14. Incorporating Social and Human Capital into an Experimental Approach to Urban Water Resources Management

    EPA Science Inventory

    To test the benefits of decentralized Green Infrastructure (GI) in an urban setting, we aimed to install GI in the Shepherd Creek Watershed of Cincinnati. The primary stressor in Shepherd Creek is stormwater runoff. An assessment of the total impervious surface area in the waters...

  15. Small-scale experimental study of vaporization flux of liquid nitrogen released on water.

    PubMed

    Gopalaswami, Nirupama; Olewski, Tomasz; Véchot, Luc N; Mannan, M Sam

    2015-10-30

    A small-scale experimental study was conducted using liquid nitrogen to investigate the convective heat transfer behavior of cryogenic liquids released on water. The experiment was performed by spilling five different amounts of liquid nitrogen at different release rates and initial water temperatures. The vaporization mass fluxes of liquid nitrogen were determined directly from the mass loss measured during the experiment. A variation of initial vaporization fluxes and a subsequent shift in heat transfer mechanism were observed with changes in initial water temperature. The initial vaporization fluxes were directly dependent on the liquid nitrogen spill rate. The heat flux from water to liquid nitrogen determined from experimental data was validated with two theoretical correlations for convective boiling. It was also observed from validation with correlations that liquid nitrogen was found to be predominantly in the film boiling regime. The substantial results provide a suitable procedure for predicting the heat flux from water to cryogenic liquids that is required for source term modeling.

  16. Experimental Analysis of Desalination Unit Coupled with Solar Water Lens Concentrator

    NASA Astrophysics Data System (ADS)

    Chaithanya, K. K.; Rajesh, V. R.; Suresh, Rahul

    2016-09-01

    The main problem that the world faces in this scenario is shortage of potable water. Hence this research work rivets to increase the yield of desalination system in an economical way. The integration of solar concentrator and desalination unit can project the desired yield, but the commercially available concentrated solar power technologies (CSP) are not economically viable. So this study proposes a novel method to concentrate ample amount of solar radiation in a cost effective way. Water acting as lens is a highlighted technology initiated in this work, which can be a substitute for CSP systems. And water lens can accelerate the desalination process so as to increase the yield economically. The solar irradiance passing through the water will be concentrated at a focal point, and the concentration depends on curvature of water lens. The experimental analysis of water lens makes use of transparent thin sheet, supported on a metallic structure. The Plano convex shape of water lens is developed by varying the volume of water that is being poured on the transparent thin sheet. From the experimental analysis it is inferred that, as the curvature of water lens increases, solar irradiance can be focused more accurately on to the focus and a higher water temperature is obtained inside the solar still.

  17. SWAP Modeling Results of Monitored Soil Water Moisture Data of Irrigation Experimental Study

    NASA Astrophysics Data System (ADS)

    Zeiliger, A.; Garsia-Orenes, F.; van den Elsen, E.; Mataix-Solera, J.; Semenov, V.

    2009-04-01

    In arid and semiarid zones of the Mediterranean regions a shortage of fresh water resources constitutes some time dramatic problem. In these regions with growing population and the scarce of rainfall irregularity in time during growing season an efficient use of water irrigation became a main challenge for future extensive agriculture development. In the frame of FP6 Water-Reuse project 516731 project a special field experimentation has been carried out in Alicante Region of Spain (Location UTM X: 693.809, Y: 4.279.922, Z: 626) on a Sandy Typic Xerofkuvent (Soil Survey Staff, 1999), Calcaric Fluvisol (WRB, FAO, 1989). with aim to investigate water regime in water repellent soils under irrigation of vine Vitus Labrusca. During field experimentation from 2006 till 2008 on 9 plots, there the same regime of irrigation water application was maintained, a monitoring of weather parameters was done by automatic meteorological station as well as a monitoring of soil water moisture was done by set of data-loggers and TDR-soil moisture sensors ECO-2 installed at different depts. SWAP model was used to simulate water regime of irrigated plots. Empirical coefficients of van Genuchten-Mualem's equations were calculated by pedotransfer functions derived from HYPRES data base using measured values of bulk density, organic matter content and soil texture. Testing of validity of the use of estimated curves was done by comparison with unsaturated soil hydraulic parameters of water retention and hydraulic conductivity measured in vitro by Wind's method on soil samples. Calibration of SWAP model for each plot was done on measured soil moisture data of irrigation events by adjusting a value of saturated hydraulic coefficient. Verification of the SWAP model was done by full range of experimental data. Similarity and non-similarity of the water regime at experimental plots as well as results of verification of SWAP model were analyzed

  18. Experimental study of natural convection enhancement using a Fe3O4-water based magnetic nanofluid.

    PubMed

    Stoian, Floriana D; Holotescu, Sorin

    2012-10-01

    The effect of nanoparticles dispersed in a carrier fluid on the natural convection heat transfer is still raising controversies. While the reported experimental results show no improvement or even worsening of the heat transfer performance of nanofluids, the numerical simulations show an increase of the heat transfer coefficient, at least for certain ranges of Ra number. We report an experimental investigation regarding the natural convection heat transfer performance of a Fe3O4-water based nanofluid, in a cylindrical enclosure. The fluid was heated linearly from the bottom wall using an electric heater and cooled from the upper wall by a constant flow of water, such that a constant temperature difference between the upper and bottom walls was obtained at steady-state. The experiment was also carried out using water, in order to observe the effect of the addition of Fe3O4 nanoparticles on the heat transfer coefficient. Several regimes were tested, both for water and nanofluid. The experimental results showed that values obtained for the heat transfer coefficient for Fe3O4-water nanofluid were higher than those for water, at the same temperature difference. The present experimental results are also compared with our previous work and the reference literature. PMID:23421199

  19. Parameterizing ecosystem light use efficiency and water use efficiency to estimate maize gross primary production and evapotranspiration using MODIS EVI

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantifying global carbon and water balances requires accurate estimation of gross primary production (GPP) and evapotranspiration (ET), respectively, across space and time. Models that are based on the theory of light use efficiency (LUE) and water use efficiency (WUE) have emerged as efficient met...

  20. Carbon and oxygen dynamics on the Louisiana continental shelf: role of water column primary production and respiration

    EPA Science Inventory

    We conducted a multi-year study of the Louisiana continental shelf (LCS) to better understand the linkages between water column net metabolism and the formation of hypoxia (dissolved oxygen <2 ml O2 L-1) in the region. Rates of water column community respiration (R) and primary p...

  1. Primary portal vein hypoplasia and SLC2A9 mutation associated with urate urolithiasis in a Spanish water dog.

    PubMed

    Cosgrove, Laura; Hammond, Gawain; Mclauchlan, Gerard

    2015-11-01

    This report describes a Spanish water dog with an ammonium urate urethrolith which was diagnosed with primary portal vein hypoplasia and was found to be homozygous for the mutated SLC2A9 gene. This is the first Spanish water dog described with the SLC2A9 mutation and the first case of concurrent portal vascular abnormalities and SLC2A9 mutation.

  2. The role of intergranular chromium carbides on intergranular oxidation of nickel based alloys in pressurized water reactors primary water

    NASA Astrophysics Data System (ADS)

    Gaslain, F. O. M.; Le, H. T.; Duhamel, C.; Guerre, C.; Laghoutaris, P.

    2016-02-01

    Alloy 600 is used in pressurized water reactors (PWRs) but is susceptible to primary water stress corrosion cracking (PWSCC). Intergranular chromium carbides have been found beneficial to reduce PWSCC. Focussed ion beam coupled with scanning electron microscopy (FIB/SEM) 3D tomography has been used to reconstruct the morphology of grain boundary oxide penetrations and their interaction with intergranular Cr carbides in Alloy 600 subjected to a PWR environment. In presence of intergranular Cr carbides, the intergranular oxide penetrations are less deep but larger than without carbide. However, the intergranular oxide volumes normalized by the grain boundary length for both samples are similar, which suggest that intergranular oxidation growth rate is not affected by carbides. Analytical transmission electron microscopy (TEM) shows that the intergranular oxide consists mainly in a spinel-type oxide containing nickel and chromium, except in the vicinity of Cr carbides where Cr2O3 was evidenced. The formation of chromium oxide may explain the lower intergranular oxide depth observed in grain boundaries containing Cr carbides.

  3. Drinking water is a significant predictor of Blastocystis infection among rural Malaysian primary schoolchildren.

    PubMed

    Abdulsalam, Awatif M; Ithoi, Init; Al-Mekhlafi, Hesham M; Ahmed, Abdulhamid; Surin, Johari; Mak, Joon-Wah

    2012-07-01

    Blastocystis infection has a worldwide distribution especially among the disadvantaged population and immunocompromised subjects. This study was carried out to determine the prevalence and the association of Blastocystis infection with the socio-economic characteristics among 300 primary schoolchildren, living in rural communities in Lipis and Raub districts of Pahang state, Malaysia. Stool samples were collected and examined for the presence of Blastocystis using direct smear microscopy after in vitro cultivation in Jones' medium. The overall prevalence of Blastocystis infection was found to be as high as 25.7%. The prevalence was significantly higher among children with gastrointestinal symptoms as compared to asymptomatic children (x2 =4.246; P=0.039). Univariate and multivariate analyses showed that absence of a piped water supply (OR=3.13; 95% CI=1.78, 5.46; P<0.001) and low levels of mothers' education (OR=3.41; 95% CI=1.62, 7.18; P<0.01) were the significant predictors of Blastocystis infection. In conclusion, Blastocystis is prevalent among rural children and the important factors that determine the infection were the sources of drinking water and mothers' educational level. Interventions with provision of clean water supply and health education especially to mothers are required. PMID:22444778

  4. Drinking water is a significant predictor of Blastocystis infection among rural Malaysian primary schoolchildren.

    PubMed

    Abdulsalam, Awatif M; Ithoi, Init; Al-Mekhlafi, Hesham M; Ahmed, Abdulhamid; Surin, Johari; Mak, Joon-Wah

    2012-07-01

    Blastocystis infection has a worldwide distribution especially among the disadvantaged population and immunocompromised subjects. This study was carried out to determine the prevalence and the association of Blastocystis infection with the socio-economic characteristics among 300 primary schoolchildren, living in rural communities in Lipis and Raub districts of Pahang state, Malaysia. Stool samples were collected and examined for the presence of Blastocystis using direct smear microscopy after in vitro cultivation in Jones' medium. The overall prevalence of Blastocystis infection was found to be as high as 25.7%. The prevalence was significantly higher among children with gastrointestinal symptoms as compared to asymptomatic children (x2 =4.246; P=0.039). Univariate and multivariate analyses showed that absence of a piped water supply (OR=3.13; 95% CI=1.78, 5.46; P<0.001) and low levels of mothers' education (OR=3.41; 95% CI=1.62, 7.18; P<0.01) were the significant predictors of Blastocystis infection. In conclusion, Blastocystis is prevalent among rural children and the important factors that determine the infection were the sources of drinking water and mothers' educational level. Interventions with provision of clean water supply and health education especially to mothers are required.

  5. Generation of Hydrogen and Methane during Experimental Low-Temperature Reaction of Ultramafic Rocks with Water

    NASA Astrophysics Data System (ADS)

    McCollom, Thomas M.; Donaldson, Christopher

    2016-06-01

    Serpentinization of ultramafic rocks is widely recognized as a source of molecular hydrogen (H2) and methane (CH4) to support microbial activity, but the extent and rates of formation of these compounds in low-temperature, near-surface environments are poorly understood. Laboratory experiments were conducted to examine the production of H2 and CH4 during low-temperature reaction of water with ultramafic rocks and minerals. Experiments were performed by heating olivine or harzburgite with aqueous solutions at 90°C for up to 213 days in glass bottles sealed with butyl rubber stoppers. Although H2 and CH4 increased steadily throughout the experiments, the levels were very similar to those found in mineral-free controls, indicating that the rubber stoppers were the predominant source of these compounds. Levels of H2 above background were observed only during the first few days of reaction of harzburgite when CO2 was added to the headspace, with no detectable production of H2 or CH4 above background during further heating of the harzburgite or in experiments with other mineral reactants. Consequently, our results indicate that production of H2 and CH4 during low-temperature alteration of ultramafic rocks may be much more limited than some recent experimental studies have suggested. We also found no evidence to support a recent report suggesting that spinels in ultramafic rocks may stimulate H2 production. While secondary silicates were observed to precipitate during the experiments, formation of these deposits was dominated by Si released by dissolution of the glass bottles, and reaction of the primary silicate minerals appeared to be very limited. While use of glass bottles and rubber stoppers has become commonplace in experiments intended to study processes that occur during serpentinization of ultramafic rocks at low temperatures, the high levels of H2, CH4, and SiO2 released during heating indicate that these reactor materials are unsuitable for this purpose.

  6. Experimental determination of viscosity of water based magnetite nanofluid for application in heating and cooling systems

    NASA Astrophysics Data System (ADS)

    Toghraie, Davood; Alempour, Seyed Mohammadbagher; Afrand, Masoud

    2016-11-01

    In this paper, experimental determination of dynamic viscosity of water based magnetite nanofluid (Fe3O4/water) was performed. The viscosity was measured in the temperature range of 20-55 °C for various samples with solid volume fractions of 0.1%, 0.2%, 0.4%, 1%, 2% and 3%. The results showed that the viscosity considerably decreases with increasing temperature. Moreover, the viscosity enhances with an increase in the solid volume fraction, remarkably. The calculated viscosity ratios showed that the maximum viscosity enhancement was 129.7%. Using experimental data, a new correlation has been proposed to predict the viscosity of magnetite nanofluid (Fe3O4/water). A comparison between the experimental results and the correlation outputs showed that the proposed model has a suitable accuracy.

  7. The Fricke dosimeter as an absorbed dose to water primary standard for Ir-192 brachytherapy

    NASA Astrophysics Data System (ADS)

    El Gamal, Islam; Cojocaru, Claudiu; Mainegra-Hing, Ernesto; McEwen, Malcolm

    2015-06-01

    The aim of this project was to develop an absorbed dose to water primary standard for Ir-192 brachytherapy based on the Fricke dosimeter. To achieve this within the framework of the existing TG-43 protocol, a determination of the absorbed dose to water at the reference position, D(r0,θ0), was undertaken. Prior to this investigation, the radiation chemical yield of the ferric ions (G-value) at the Ir-192 equivalent photon energy (0.380 MeV) was established by interpolating between G-values obtained for Co-60 and 250 kV x-rays. An irradiation geometry was developed with a cylindrical holder to contain the Fricke solution and allow irradiations in a water phantom to be conducted using a standard Nucletron microSelectron V2 HDR Ir-192 afterloader. Once the geometry and holder were optimized, the dose obtained with the Fricke system was compared to the standard method used in North America, based on air-kerma strength. Initial investigations focused on reproducible positioning of the ring-shaped holder for the Fricke solution with respect to the Ir-192 source and obtaining an acceptable type A uncertainty in the optical density measurements required to yield the absorbed dose. Source positioning was found to be reproducible to better than 0.3 mm, and a careful cleaning and control procedure reduced the variation in optical density reading due to contamination of the Fricke solution by the PMMA holder. It was found that fewer than 10 irradiations were required to yield a type A standard uncertainty of less than 0.5%. Correction factors to take account of the non-water components of the geometry and the volume averaging effect of the Fricke solution volume were obtained from Monte Carlo calculations. A sensitivity analysis showed that the dependence on the input data used (e.g. interaction cross-sections) was small with a type B uncertainty for these corrections estimated to be 0.2%. The combined standard uncertainty in the determination of absorbed dose to water

  8. The Fricke dosimeter as an absorbed dose to water primary standard for Ir-192 brachytherapy.

    PubMed

    El Gamal, Islam; Cojocaru, Claudiu; Mainegra-Hing, Ernesto; McEwen, Malcolm

    2015-06-01

    The aim of this project was to develop an absorbed dose to water primary standard for Ir-192 brachytherapy based on the Fricke dosimeter. To achieve this within the framework of the existing TG-43 protocol, a determination of the absorbed dose to water at the reference position, D(r0,θ0), was undertaken. Prior to this investigation, the radiation chemical yield of the ferric ions (G-value) at the Ir-192 equivalent photon energy (0.380 MeV) was established by interpolating between G-values obtained for Co-60 and 250 kV x-rays.An irradiation geometry was developed with a cylindrical holder to contain the Fricke solution and allow irradiations in a water phantom to be conducted using a standard Nucletron microSelectron V2 HDR Ir-192 afterloader. Once the geometry and holder were optimized, the dose obtained with the Fricke system was compared to the standard method used in North America, based on air-kerma strength.Initial investigations focused on reproducible positioning of the ring-shaped holder for the Fricke solution with respect to the Ir-192 source and obtaining an acceptable type A uncertainty in the optical density measurements required to yield the absorbed dose. Source positioning was found to be reproducible to better than 0.3 mm, and a careful cleaning and control procedure reduced the variation in optical density reading due to contamination of the Fricke solution by the PMMA holder. It was found that fewer than 10 irradiations were required to yield a type A standard uncertainty of less than 0.5%.Correction factors to take account of the non-water components of the geometry and the volume averaging effect of the Fricke solution volume were obtained from Monte Carlo calculations. A sensitivity analysis showed that the dependence on the input data used (e.g. interaction cross-sections) was small with a type B uncertainty for these corrections estimated to be 0.2%.The combined standard uncertainty in the determination of absorbed dose to water at

  9. Water balance of rice plots under three different water treatments: monitoring activity and experimental results

    NASA Astrophysics Data System (ADS)

    Chiaradia, Enrico Antonio; Romani, Marco; Facchi, Arianna; Gharsallah, Olfa; Cesari de Maria, Sandra; Ferrari, Daniele; Masseroni, Daniele; Rienzner, Michele; Battista Bischetti, Gian; Gandolfi, Claudio

    2014-05-01

    In the agricultural seasons 2012 and 2013, a broad monitoring activity was carried out at the Rice Research Centre of Ente Nazionale Risi (CRR-ENR) located in Castello d'Agogna (PV, Italy) with the purpose of comparing the water balance components of paddy rice (Gladio cv.) under different water regimes and assessing the possibility of reducing the high water inputs related to the conventional practice of continuous submergence. The experiments were laid out in six plots of about 20 m x 80 m each, with two replicates for each of the following water regimes: i) continuous flooding with wet-seeded rice (FLD), ii) continuous flooding from around the 3-leaf stage with dry-seeded rice (3L-FLD), and iii) surface irrigation every 7-10 days with dry-seeded rice (IRR). One out of the two replicates of each treatment was instrumented with: water inflow and outflow meters, set of piezometers, set of tensiometers and multi-sensor moisture probes. Moreover, an eddy covariance station was installed on the bund between the treatments FLD and IRR. Data were automatically recorded and sent by a wireless connection to a PC, so as to be remotely controlled thanks to the development of a Java interface. Furthermore, periodic measurements of crop biometric parameters (LAI, crop height and rooting depth) were performed in both 2012 and 2013 (11 and 14 campaigns respectively). Cumulative water balance components from dry-seeding (3L-FLD and IRR), or flooding (FLD), to harvest were calculated for each plot by either measurements (i.e. rainfall, irrigation and surface drainage) or estimations (i.e. difference in the field water storage, evaporation from both the soil and the water surface and transpiration), whereas the sum of percolation and capillary rise (i.e. the 'net percolation') was obtained as the residual term of the water balance. Incidentally, indices of water application efficiency (evapotranspiration over net water input) and water productivity (grain production over net water

  10. Influence of localized plasticity on oxidation behaviour of austenitic stainless steels under primary water reactor

    NASA Astrophysics Data System (ADS)

    Cissé, Sarata; Laffont, Lydia; Lafont, Marie-Christine; Tanguy, Benoit; Andrieu, Eric

    2013-02-01

    The sensitivity of precipitation-strengthened A286 austenitic stainless steel to stress corrosion cracking was studied by means of slow-strain-rate tests. First, alloy cold working by low cycle fatigue (LCF) was investigated. Fatigue tests under plastic strain control were performed at different strain levels (Δɛp/2 = 0.2%, 0.5%, 0.8% and 2%) to establish correlations between stress softening and the deformation microstructure resulting from the LCF tests. Deformed microstructures were identified through TEM investigations. The interaction between oxidation and localized deformation bands was also studied and it resulted that localized deformation bands are not preferential oxide growth channels. The pre-cycling of the alloy did not modify its oxidation behaviour. However, intergranular oxidation in the subsurface under the oxide layer formed after exposure to PWR primary water was shown.

  11. Primary structures of pancreatic ribonucleases from Bovidae. Impala, Thomson's gazelle, nilgai and water buffalo.

    PubMed

    Beintema, J J

    1980-01-24

    The amino acid sequences of the pancreatic ribonucleases from impala Thomson's gazelle, nilgai and two types of water buffalo were studied from several enzymic digests. Peptides were positioned by homology with other ribonucleases of known sequence. Only peptides that differ in amino acid composition from the corresponding peptides of ox and goat ribonuclease were sequenced. The primary structures of pancreatic ribonucleases from 11 species of the Bovidae family are known to date. The evolutionary rate of bovid ribonucleases is 2--3 times lower than the average rate observed in all mammals. A possible explanation is that the presence of a stable symbiotic system in the rumen of grass-eating ruminants has caused a slowing down of the evolutionary rate of pancreatic ribonuclease in this taxon. The subfamily of the Bovinae (five species) exhibits a slightly higher evolutionary rate; most replacements in the Bovinae occur near residues 34--36, the most commonly observed carbohydrate attachment site in ribonucleases.

  12. Materials Reliability Program: Environmental Fatigue Testing of Type 304L Stainless Steel U-Bends in Simulated PWR Primary Water (MRP-137)

    SciTech Connect

    R.Kilian

    2004-12-01

    Laboratory data generated in the past decade indicate a significant reduction in component fatigue life when reactor water environmental effects are experimentally simulated. However, these laboratory data have not been supported by nuclear power plant component operating experience. In recent comprehensive review of laboratory, component and structural test data performed through the EPRI Materials Reliability Program, flow rate was identified as a critical variable that was generally not considered in laboratory studies but applicable in plant operating environments. Available data for carbon/low-alloy steel piping components suggest that high flow is beneficial regarding the effects of a reactor water environment. Similar information is lacking for stainless steel piping materials. This report documents progress made to date in an extensive testing program underway to evaluate the effects of flow rate on the corrosion fatigue of 304L stainless steel under simulated PWR primary water environmental conditions.

  13. An experimental and calculated dose distribution in water around CDC K-type caesium-137 sources.

    PubMed

    Diffey, B L; Klevenhagen, S C

    1975-05-01

    The radiation distribution in water around caesium-137 K-type sources has been measured and the experimental results used to provide data for an expression for dose calculations which may be conveniently applied in computer programs. The calculated absorbed dose rate obtained in this manner is estimated to be within 3% of the actual dose rate for any point in water up to 8 cm from the source. It is also suggested that the strength of a brachytherapy source be expressed in terms of an experimental exposure rate at some well-defined distance since this quantity may be determined more precisely and with less ambiguity than source activity.

  14. Experimental Confirmation of Water Column Natural Resonance Migration in a BBDB Device

    SciTech Connect

    Bull, Diana L.; Gunawan, Budi; Holmes, Brian

    2014-09-01

    Experiments were conducted with a Backward Bent Duct Buoy (BBDB) oscillating water column wave energy conversion device with a scaling factor of 50 at HMRC at University College Cork, Ireland. Results were compared to numerical performance models. This work experimentally verified the migration of the natural resonance location of the water column due to hydrodynamic coupling for a floating non- axisymmetric device without a power conversion chain PCC present. In addition, the experimental results verified the performance model with a PCC of the same non- axisymmetric device when both floating and grounded.

  15. Cenozoic magmatism of north Victoria Land, Antarctica: an experimental study on the mantle source of a primary basanite from the McMurdo Volcanic Group

    NASA Astrophysics Data System (ADS)

    Armienti, P.; Freda, C.; Misiti, V.; Perinelli, C.

    2009-04-01

    Volcanoes of the McMurdo Vocanic Group (MMVG) (Antarctica) dot the eastern shoulder of Ross Sea Rift System giving rise to alkaline transitional volcanic suites which in north Victoria Land are emplaced since Early Cenozoic. Geochemical geological, geophysical and geochronological data on Cenozoic volcanic activity in NVL suggest that the region is a site of passive astenospheric rise, rather than affected by a thermally active mantle plume. Furthermore the comparison of geochemical and isotopical data of basic lavas with those provided by mantle xenoliths they carry to the surface, document the compositional heterogeneity of sublithospheric mantle caused by the coupled action of partial melting and metasomatism. In particular the metasomatic episode is probably linked to the amagmatic extensional event that affected the West Antarctic Rift System in the Late Cretaceous. The astenospheric melts generated during this event, moving through the upper mantle, can have crystallized as veins or may have led to the formation of metasomatic minerals such as amphibole or phlogopite. In this scenario the mineralogical and chemical composition of sources responsible for Cenozoic magmatism, amphibole-bearing spinel-peridotite versus pyroxenite in the garnet stability field, it is still a matter of debate. To shed light on this argument a previous experimental study on a basanite of MMVG, representative of primary magma (Orlando et al., 2000) has been integrated with new experimental investigation on the same basanitic composition. The preliminary experiments were conducted to pressures of 1.0 - 2.0GPa in the presence of 0-1% of added water and indicate olivine on the liquidus at 1.0 GPa that is substitute by clinopyroxene at 2.0GPa. The addition of 1% of water induces a decrease of liquidus temperature of about 40°C shifting its value in the T range (1280-1310°C) the same that was inferred by melt inclusions hosted in the olivine phenocrysts of the studied basanite.

  16. Permanent dissipative structures in water: the matrix of life? Experimental evidences and their quantum origin.

    PubMed

    Elia, V; Germano, R; Napoli, E

    2015-01-01

    This paper presents a short review of the evidence - both experimental and theoretical - of the formation of dissipative structures in liquid water induced by three kinds of physical perturbations having a low energy content: extremely diluted solution (EDS), iteratively filtered water (IFW), and iteratively nafionated water (INW). Particular attention is devoted to the very recent discovery that such structures are tremendously persistent even in the solid phase: large ponderal quantities of supramolecular aggregates of water (with each nucleus hundreds of nanometers in size) have been observed - at ambient pressure and temperature - using easily-reproducible experimental methods. The nature of these dissipative structures is analyzed and explained in terms of the thermodynamics of far-from-equilibrium systems and irreversible processes, showing their spontaneous quantum origin. Are these kinds of structures the matrix itself of life?.

  17. Experimental and numerical analysis of the cooling performance of water spraying systems during a fire.

    PubMed

    Chen, YaoHan; Su, ChungHwei; Tseng, JoMing; Li, WunJie

    2015-01-01

    The water spray systems are effective protection systems in the confined or unconfined spaces to avoid the damage to building structures since the high temperature when fires occur. NFPA 15 and 502 have suggested respectively that the factories or vehicle tunnels install water spray systems to protect the machinery and structures. This study discussed the cooling effect of water spray systems in experimental and numerical analyses. The actual combustion of woods were compared with the numerical simulations. The results showed that although the flame continued, the cooling effects by water spraying process within 120 seconds were obvious. The results also indicated that the simulation results of the fifth version Fire Dynamics Simulator (FDS) overestimated the space temperature before water spraying in the case of the same water spray system.

  18. Experimental determination of the transport number of water in Nafion 117 membrane

    SciTech Connect

    Fuller, T.F.; Newman, J. . Dept. of Chemical Engineering)

    1992-05-01

    The transport number of water in Nafion 117 membrane over a wide range of water contents is determined experimentally using a concentration cell. The transport number of water, the ratio f[sup m][sub o]/Z[sub o], is about 1.4 for a membrane equilibrated with saturated water vapor at 25[degrees]C, decreases slowly as the membrane is dehydrated, and falls sharply toward zero as the concentration of water approaches zero. In this paper, the relationship between the transference number, the transport number, and the electro-osmotic drag coefficient is presented, and their relevance to water management is solid-polymer-electrolyte fuel cells is discussed. Results are compared with other data available in the literature and with the theoretical maximum.

  19. Experimental and numerical analysis of the cooling performance of water spraying systems during a fire.

    PubMed

    Chen, YaoHan; Su, ChungHwei; Tseng, JoMing; Li, WunJie

    2015-01-01

    The water spray systems are effective protection systems in the confined or unconfined spaces to avoid the damage to building structures since the high temperature when fires occur. NFPA 15 and 502 have suggested respectively that the factories or vehicle tunnels install water spray systems to protect the machinery and structures. This study discussed the cooling effect of water spray systems in experimental and numerical analyses. The actual combustion of woods were compared with the numerical simulations. The results showed that although the flame continued, the cooling effects by water spraying process within 120 seconds were obvious. The results also indicated that the simulation results of the fifth version Fire Dynamics Simulator (FDS) overestimated the space temperature before water spraying in the case of the same water spray system. PMID:25723519

  20. Experimental and Numerical Analysis of the Cooling Performance of Water Spraying Systems during a Fire

    PubMed Central

    Chen, YaoHan; Su, ChungHwei; Tseng, JoMing; Li, WunJie

    2015-01-01

    The water spray systems are effective protection systems in the confined or unconfined spaces to avoid the damage to building structures since the high temperature when fires occur. NFPA 15 and 502 have suggested respectively that the factories or vehicle tunnels install water spray systems to protect the machinery and structures. This study discussed the cooling effect of water spray systems in experimental and numerical analyses. The actual combustion of woods were compared with the numerical simulations. The results showed that although the flame continued, the cooling effects by water spraying process within 120 seconds were obvious. The results also indicated that the simulation results of the fifth version Fire Dynamics Simulator (FDS) overestimated the space temperature before water spraying in the case of the same water spray system. PMID:25723519

  1. An experimental test of voluntary strategies to promote urban water demand management.

    PubMed

    Fielding, Kelly S; Spinks, Anneliese; Russell, Sally; McCrea, Rod; Stewart, Rodney; Gardner, John

    2013-01-15

    In light of the current and future threats to global water security the current research focuses on trialing interventions to promote urban water conservation. We report an experimental study designed to test the long-term impact of three different interventions on household water consumption in South East Queensland. Participants from 221 households were recruited and completed an initial survey, and their houses were fitted with smart water meters which measured total water usage at 5 s intervals. Households were allocated into one of four conditions: a control group and three interventions groups (water saving information alone, information plus a descriptive norm manipulation, and information plus tailored end-user feedback). The study is the first to use smart water metering technology as a tool for behaviour change as well as a way to test the effectiveness of demand management interventions. Growth curve modelling revealed that compared to the control, the three intervention groups all showed reduced levels of household consumption (an average reduction of 11.3 L per person per day) over the course of the interventions, and for some months afterwards. All interventions led to significant water savings, but long-term household usage data showed that in all cases, the reduction in water use resulting from the interventions eventually dissipated, with water consumption returning to pre-intervention levels after approximately 12 months. Implications for water demand management programs are discussed.

  2. Experimental Study on Behavior of Bow-tie Tree Generation by Using Heavy Water

    NASA Astrophysics Data System (ADS)

    Kumazawa, Takao; Nakagawa, Wataru; Tsurumaru, Hidekazu

    Bow-tie tree (BTT) generated from contaminant, e.g., metal, carbon, amber(over cured resin) or void in insulator is a significant deterioration factor of XLPE power cable. However, essential role of water in generation and progress of BTT is not yet sufficiently cleared. In order to investigate the role of water we paid attention to difference in chemical properties of light water (H2O) and heavy water (D2O), moreover we evaluated influence of isotopic effect due to hydrogen and deuterium on behavior of BTT generation. In accelerated aging test the number of BTT in XLPE sample, in which copper powder of 500ppm was contaminated as BTT cores, dipped in heavy water (D2O:100wt%) decreased to one third compared with light water(D2O:0wt%). Furthermore, the maximum length of BTT decreased with increase in concentration of heavy water. The experimental results show that heavy water exerted a depression effect on generation and progress of BTT. We considered that the depression effect due to hydrogen isotope appeared by inhibiting ionization and elution of BTT cores, because salt-solubility and ionic mobility of heavy water are about 15 to 20% smaller than those of light water. Therefore, the essential role of water seemed to be production and transport of ions in XLPE.

  3. Experimental Analysis of the Feasibility of Polydisperse Droplet Water Flow Using at Fire Extinguishing

    NASA Astrophysics Data System (ADS)

    Voitkov, Ivan S.; Zabelin, Maxim V.; Zhdanova, Alena O.

    2016-02-01

    With use of modern diagnostic methods the experimental researches of the process of the sprayed water evaporation at its movement through a flame of the fixed height was conducted. The change ranges of the main integrated evaporation characteristics of the sprayed water droplets (rates, sizes, concentration in a flow) are established. It is shown that at the extinguishing of fires the most expedient decision is the use of polydisperse droplet flows.

  4. Experimental research of fluorescence spectra of watercress stressed by lack or excess of watering

    NASA Astrophysics Data System (ADS)

    Bullo, O. A.; Fedotov, Yu. V.; Belov, M. L.; Gorodnichev, V. A.

    2015-11-01

    Experimental laboratory investigations of the laser-induced fluorescence spectra of watercress were conducted. The fluorescence spectra were excited by a YAG:Nd laser emitting at 532 nm. The laboratory setup was described and fluorescence spectra of watercress in stressed states caused by lack and excess of water were presented. It was established that the influence of stress caused by lack and excess of watering is manifested in changes of fluorescence spectra.

  5. Experimental study of electric discharge treatment of nanodiamond particles in water

    NASA Astrophysics Data System (ADS)

    Medvedev, Dmitry; Sapunov, Dmitry; Potapkin, Boris; Korobtsev, Sergey

    2012-08-01

    A novel type of high voltage pulsed electric discharge in water flow in a Venturi tube is proposed. The influence of the novel discharge on sizes and properties of nanodiamond particles has been studied. Experiments were carried out in water media with purified detonation nanodiamonds made impure by non-diamond carbon material. The ability of high voltage pulsed electric discharge in water to modify nanoparticle conglomerates in water solution and to relieve spherically shaped nanodiamond conglomerates from the initial mixture with non-diamond material can be seen. Prolonged treatment of the suspension made it possible to relieve primary nanodiamond crystals from conglomerates. Formation of ordered and unordered structures from primary (3-5 nm) nanodiamond crystals has been observed. Study of the electric discharge in water was carried out at the pressure region from atmospheric down to 0.02 atm to reproduce conditions which are typical for the discharge in the Venturi tube in liquid flow and different gap lengths. Two `types' of discharge behavior depending on the geometry of the discharge system and other external parameters have been observed. Characteristics that are critical for understanding the behavior of the discharge in the Venturi tube in water flow have been investigated.

  6. Cattle-derived microbial input to source water catchments: An experimental assessment of stream crossing modification.

    PubMed

    Smolders, Andrew; Rolls, Robert J; Ryder, Darren; Watkinson, Andrew; Mackenzie, Mark

    2015-06-01

    The provision of safe drinking water is a global issue, and animal production is recognized as a significant potential origin of human infectious pathogenic microorganisms within source water catchments. On-farm management can be used to mitigate livestock-derived microbial pollution in source water catchments to reduce the risk of contamination to potable water supplies. We applied a modified Before-After Control Impact (BACI) design to test if restricting the access of livestock to direct contact with streams prevented longitudinal increases in the concentrations of faecal indicator bacteria and suspended solids. Significant longitudinal increases in pollutant concentrations were detected between upstream and downstream reaches of the control crossing, whereas such increases were not detected at the treatment crossing. Therefore, while the crossing upgrade was effective in preventing cattle-derived point source pollution by between 112 and 158%, diffuse source pollution to water supplies from livestock is not ameliorated by this intervention alone. Our findings indicate that stream crossings that prevent direct contact between livestock and waterways provide a simple method for reducing pollutant loads in source water catchments, which ultimately minimises the likelihood of pathogenic microorganisms passing through source water catchments and the drinking water supply system. The efficacy of the catchment as a primary barrier to pathogenic risks to drinking water supplies would be improved with the integration of management interventions that minimise direct contact between livestock and waterways, combined with the mitigation of diffuse sources of livestock-derived faecal matter from farmland runoff to the aquatic environment.

  7. Cattle-derived microbial input to source water catchments: An experimental assessment of stream crossing modification.

    PubMed

    Smolders, Andrew; Rolls, Robert J; Ryder, Darren; Watkinson, Andrew; Mackenzie, Mark

    2015-06-01

    The provision of safe drinking water is a global issue, and animal production is recognized as a significant potential origin of human infectious pathogenic microorganisms within source water catchments. On-farm management can be used to mitigate livestock-derived microbial pollution in source water catchments to reduce the risk of contamination to potable water supplies. We applied a modified Before-After Control Impact (BACI) design to test if restricting the access of livestock to direct contact with streams prevented longitudinal increases in the concentrations of faecal indicator bacteria and suspended solids. Significant longitudinal increases in pollutant concentrations were detected between upstream and downstream reaches of the control crossing, whereas such increases were not detected at the treatment crossing. Therefore, while the crossing upgrade was effective in preventing cattle-derived point source pollution by between 112 and 158%, diffuse source pollution to water supplies from livestock is not ameliorated by this intervention alone. Our findings indicate that stream crossings that prevent direct contact between livestock and waterways provide a simple method for reducing pollutant loads in source water catchments, which ultimately minimises the likelihood of pathogenic microorganisms passing through source water catchments and the drinking water supply system. The efficacy of the catchment as a primary barrier to pathogenic risks to drinking water supplies would be improved with the integration of management interventions that minimise direct contact between livestock and waterways, combined with the mitigation of diffuse sources of livestock-derived faecal matter from farmland runoff to the aquatic environment. PMID:25841195

  8. Water-hyacinth production primary and advanced treatment of wastewater. Final report

    SciTech Connect

    Schwegler, B.R. Jr.

    1983-01-01

    A prototype water hyacinth wastewater treatment system has been in operation for two years at Walt Disney World, near Orlando, Florida. Typically, the hyacinth system removes 80-90% total suspended solids and B.O.D. from the influent stream. Major impacts on water quality exiting the system are: seasonal variations in solar radiation, air and water temperature; operational problems, particularly harvesting equipment breakdown, and retention time in the ponds. Phosphorus and nitrogen removal show a strong seasonal dependence, with removal rates varying from 0.08 to 1.11 g/m/sup 2//day for N and from 0.05 to 0.29 g/m/sup 2//day for P. Nitrogen removal rates show a strong dependence on retention times, with a retention time of 5 days appearing to be a critical limit for the establishment of an active population of denitrifying bacteria. Hyacinth biomass productivity of the system was approximately 66.7 dry metric tons per hectare year (30 dry tons/acre year) during the second year of operation. An Experimental Test Unit (ETU) for anaerobic digestion of hyacinths to methane will be installed by late 1983.

  9. Uncertainty analysis of primary water pollutant control in China's pulp and paper industry.

    PubMed

    Wen, Zong-guo; Di, Jing-han; Zhang, Xue-ying

    2016-03-15

    The total emission control target of water pollutants (e.g., COD and NH4-N) for a certain industrial sector can be predicted and analysed using the popular technology-based bottom-up modelling. However, this methodology has obvious uncertainty regarding the attainment of mitigation targets. The primary uncertainty comes from macro-production, pollutant reduction roadmap, and technical parameters. This research takes the paper and pulp industry in China as an example, and builds 5 mitigation scenarios via different combinations of raw material structure, scale structure, procedure mitigation technology, and end-of-pipe treatment technology. Using the methodology of uncertainty analysis via Monte Carlo, random sampling was conducted over a hundred thousand times. According to key parameters, sensitive parameters that impact total emission control targets such as industrial output, technique structure, cleaner production technology, and end-of-pipe treatment technology are discussed in this article. It appears that scenario uncertainty has a larger influence on COD emission than NH4-N, hence it is recommended that a looser total emission control target for COD is necessary to increase its feasibility and availability while maintaining the status quo of NH4-N. Consequently, from uncertainty analysis, this research recognizes the sensitive products, techniques, and technologies affecting industrial water pollution.

  10. Thermodynamics of water condensation on a primary marine aerosol coated by surfactant organic molecules.

    PubMed

    Djikaev, Yuri S; Ruckenstein, Eli

    2014-10-23

    A large subset of primary marine aerosols can be initially (immediately upon formation) treated using an "inverted micelle" model. We study the thermodynamics of heterogeneous water condensation on such a marine aerosol. Its hydrophobic organic coating can be processed by chemical reactions with atmospheric species; this enables the marine aerosol to serve as a nucleating center for water condensation. The most probable pathway of such "aging" involves atmospheric hydroxyl radicals that abstract hydrogen atoms from organic molecules coating the aerosol (first step), the resulting radicals being quickly oxidized by ubiquitous atmospheric oxygen molecules to produce surface-bound peroxyl radicals (second step). Taking these two reactions into account, we derive an expression for the free energy of formation of an aqueous droplet on a marine aerosol. The model is illustrated by numerical calculations. The results suggest that the formation of aqueous droplets on marine aerosols is most likely to occur via Köhler activation rather than via nucleation. The model allows one to determine the threshold parameters necessary for the Köhler activation of such aerosols. Numerical results also corroborate previous suggestions that one can omit some chemical species of aerosols (and other details of their chemical composition) in investigating aerosol effects on climate.

  11. Experimental Evaluation the Effectiveness of Water Mist Fire Extinguishing Systems at Oil and Gas Industry

    NASA Astrophysics Data System (ADS)

    Nyashina, G. S.; Medvedev, V. V.; Shevyrev, S. A.; Vysokomornaya, O. V.

    2016-02-01

    Currently mist water is one of the most promising areas of fire protection. We performed an experimental study of phase transformations drops of water mist (range 50 - 500 microns) in motion in a high-temperature (500 - 2000 K) typical products of combustion of petroleum products (gasoline, kerosene, acetone, alcohol). We used high speed (the speed of shooting at least 105 frames per second) and optical methods of recording streams of liquid and gas medium. We determined the effect of the parameters of the test process (the initial temperature and the initial droplet size) at the rate of evaporation of atomized water under these conditions.

  12. A vegetation sensitivity approximation for gross primary production in water limited conditions.

    NASA Astrophysics Data System (ADS)

    Claesson, Jonas; Nycander, Jonas

    2013-04-01

    The most severe impact of climate change on vegetation growth and agriculture is likely to occur under water-limited conditions. Under such conditions the plants optimize the inward flux of CO2 and the outward flux of water vapor (the transpiration) by regulating the size of the stomata openings. Higher temperature increases water loss through transpiration, forcing the plants to diminish the stomata openings, which decreases photosynthesis. This is counteracted by higher CO2 concentration, which allows plants to maintain the inward flux of CO2 through the smaller openings. These two counteracting effects, combined with the change in precipitation, determine the net change of biological productivity in a changed climate. Here, a vegetation sensitivity approximation (VSA) is introduced, in order to understand and estimate the combined effect of changed temperature, CO2-concentration and precipitation on gross primary production (GPP) to first order. According to the VSA, we have: ( ) ?CO2atm ν GP P = ?0 P Here ?CO2atm is the atmospheric CO2 concentration, ?0 is the baseline for atmospheric CO2 concentration, P is precipitation and ν is defined by: -s- ν = 1 - 11°C where s is the climate sensitivity i.e. the increase in temperature when atmospheric CO2 is doubled. The VSA is based on the physical laws of gas flux through the stomata openings, and is only valid under water-limited conditions. It assumes that the temperature depends logarithmically on the CO2 concentration with a given climate sensitivity. Transpiration is assumed to be a constant fraction of precipitation, which is reasonable under water-limited conditions. The VSA is compared to simulations with the dynamic vegetation model LPJ. The agreement is reasonable, and the deviations can be understood by comparison with Köppen's definition of arid climate: in an arid climate growth increases more according to LPJ than according to the VSA, and in non-arid conditions the reverse is true. Both the VSA and

  13. Experimental Evaluation of the Drag Coefficient of Water Rockets by a Simple Free-Fall Test

    ERIC Educational Resources Information Center

    Barrio-Perotti, R.; Blanco-Marigorta, E. Arguelles-Diaz, K.; Fernandez-Oro, J.

    2009-01-01

    The flight trajectory of a water rocket can be reasonably calculated if the magnitude of the drag coefficient is known. The experimental determination of this coefficient with enough precision is usually quite difficult, but in this paper we propose a simple free-fall experiment for undergraduate students to reasonably estimate the drag…

  14. Experimental Evaluation of the Thermal Performance of a Water Shield for a Surface Power Reactor

    NASA Technical Reports Server (NTRS)

    Pearson, J. Boise; Stewart, Eric T.; Reid, Robert S.

    2007-01-01

    A water based shielding system is being investigated for use on initial lunar surface power systems. The use of water may lower overall cost (as compared to development cost for other materials) and simplify operations in the setup and handling. The thermal hydraulic performance of the shield is of significant interest. The mechanism for transferring heat through the shield is natural convection. Natural convection in a representative lunar surface reactor shield design is evaluated at various power levels in the Water Shield Testbed (WST) at the NASA Marshall Space Flight Center. The experimental data from the WST is used to anchor a CFD model. Performance of a water shield on the lunar surface is then predicted by CFD models anchored to test data. The accompanying viewgraph presentation includes the following topics: 1) Testbed Configuration; 2) Core Heater Placement and Instrumentation; 3) Thermocouple Placement; 4) Core Thermocouple Placement; 5) Outer Tank Thermocouple Placement; 6) Integrated Testbed; 7) Methodology; 8) Experimental Results: Core Temperatures; 9) Experimental Results; Outer Tank Temperatures; 10) CFD Modeling; 11) CFD Model: Anchored to Experimental Results (1-g); 12) CFD MOdel: Prediction for 1/6-g; and 13) CFD Model: Comparison of 1-g to 1/6-g.

  15. Anticoccidial efficacy of drinking water soluble diclazuril on experimental and field coccidiosis in broiler chickens.

    PubMed

    El-Banna, H A; El-Bahy, M M; El-Zorba, H Y; El-Hady, M

    2005-08-01

    Prophylactic and curative capacity of water soluble formulation of Diclazuril (Diclosol 1%) and feed additive form (Clinacox, 0.5%) were tested against Eimeria infection in broiler chickens. Such testing was performed both experimentally and in the field. Toltrazuril (Baycox, 2.5%) was used as reference control drug. Water soluble formulation of Diclazuril induced a marked inhibitory effect on the different stages of the parasite life cycle in experimentally infected treated birds especially when applied on the day when blood first appeared in the faeces [fifth day post-infection (d.p.i.)] as well as on the second day of blood dropping (6 d.p.i.). Both tested dosage levels of Diclazuril water soluble formulation in drinking water (5 and 10 ppm) showed the same effect in controlling coccidial infection and reducing the total oocyst numbers, lesion and faecal scores. Moreover, there was no significant difference in the efficacy of water soluble form of Diclazuril and the reference control drug (Toltrazuril, 25 ppm). In addition, testing the water soluble formulation (5 ppm) in naturally infected poultry farm (20,000 birds), showed the same anticoccidial effect observed when using Toltrazuril, as a treatment for coccidiosis. In conclusion, addition of Diclazuril at the dose of 5 ppm in the drinking water of naturally coccidia infected bird induced the same effect as 25 ppm of Toltrazuril as a treatment for coccidiosis in chickens.

  16. EXPERIMENTAL EVIDENCE FOR WATER FORMATION VIA OZONE HYDROGENATION ON DUST GRAINS AT 10 K

    SciTech Connect

    Mokrane, H.; Chaabouni, H.; Accolla, M.; Congiu, E.; Dulieu, F.; Chehrouri, M.; Lemaire, J. L.

    2009-11-10

    The formation of water molecules from the reaction between ozone (O{sub 3}) and D-atoms is studied experimentally for the first time. Ozone is deposited on non-porous amorphous solid water ice (H{sub 2}O), and D-atoms are then sent onto the sample held at 10 K. HDO molecules are detected during the desorption of the whole substrate where isotope mixing takes place, indicating that water synthesis has occurred. The efficiency of water formation via hydrogenation of ozone is of the same order of magnitude as that found for reactions involving O-atoms or O{sub 2} molecules and exhibits no apparent activation barrier. These experiments validate the assumption made by models using ozone as one of the precursors of water formation via solid-state chemistry on interstellar dust grains.

  17. Experimental simulation of the water cooling of corium spread over the floor of a BWR containment

    SciTech Connect

    Morage, F.; Lahey, R.T. Jr.; Podowski, M.Z.

    1995-09-01

    This paper is concerned with an experimental investigation of the cooling effect of water collected on the surface of corium released onto the floor of a BWR drywell. In the present experiments, the actual reactor materials were replaced by simulant materials. Specifically, the results are shown for Freon-11 film boiling over liquid Wood`s metal spread above a solid porous surface through which argon gas was injected. An analysis of the obtained experimental data revealed that the actual film boiling heat transfer between a molten pool of corium and the water above the pool should be more efficient than predicted by using standard correlations for boiling over solid surfaces. This effect will be further augmented by the gas released due to the ablation of concrete floor beneath the corium and percolating towards its upper surface and into through the water layer above.

  18. [The hepatotropic action of sodium chloride and hydrocarbonate mineral water containing humic acids (an experimental study)].

    PubMed

    Verigo, N S; Ulashchik, V S

    2015-01-01

    The present article summarizes the results of experimental studies on the hepatotropic action of native and modified low-mineralized sodium chloride and bicarbonate waters differing in the content of humic acids. It was found that the most beneficial changes after a course of 21 day therapy with the use of such mineral waters for the treatment of experimental hepatitis were observed after the application of the water with a humic acid content of roughly 20 g/dm3. Such treatment resulted in the significant improvement of the liver antitoxic function, intensification of basal metabolism, reduction of the inflammatory processes, normalization of the hepatic enzyme activity, and stimulation of proteinsynthetic function in parallel with positive dynamics of the morphological and histochemical characteristics of the liver.

  19. Information collection request for proposed National Primary Drinking Water Regulations for synthetic organic chemicals (draft), April 1989

    SciTech Connect

    Not Available

    1989-04-01

    The Environmental Protection Agency (EPA), under the requirements of the Safe Drinking Water Act (Section 1401 and 1412, P.L. 99-339, as amended in 1986), has proposed National Primary Drinking Water Regulations (NPDWR) pertaining to the contamination of public water systems by synthetic organic chemical (SOCs) contaminants. The proposed regulations require the collection of information by public water systems, states, and the EPA. Information collection requirements include monitoring, reporting, and recordkeeping activities that are discussed in this Information Collection Requests (ICR) document.

  20. Comparison of GEANT4 very low energy cross section models with experimental data in water

    SciTech Connect

    Incerti, S.; Ivanchenko, A.; Karamitros, M.; Mantero, A.; Moretto, P.; Tran, H. N.; Mascialino, B.; Champion, C.; Ivanchenko, V. N.; Bernal, M. A.; Francis, Z.; Villagrasa, C.; Baldacchino, G.; Gueye, P.; Capra, R.; Nieminen, P.; Zacharatou, C.

    2010-09-15

    Purpose: The GEANT4 general-purpose Monte Carlo simulation toolkit is able to simulate physical interaction processes of electrons, hydrogen and helium atoms with charge states (H{sup 0}, H{sup +}) and (He{sup 0}, He{sup +}, He{sup 2+}), respectively, in liquid water, the main component of biological systems, down to the electron volt regime and the submicrometer scale, providing GEANT4 users with the so-called ''GEANT4-DNA'' physics models suitable for microdosimetry simulation applications. The corresponding software has been recently re-engineered in order to provide GEANT4 users with a coherent and unique approach to the simulation of electromagnetic interactions within the GEANT4 toolkit framework (since GEANT4 version 9.3 beta). This work presents a quantitative comparison of these physics models with a collection of experimental data in water collected from the literature. Methods: An evaluation of the closeness between the total and differential cross section models available in the GEANT4 toolkit for microdosimetry and experimental reference data is performed using a dedicated statistical toolkit that includes the Kolmogorov-Smirnov statistical test. The authors used experimental data acquired in water vapor as direct measurements in the liquid phase are not yet available in the literature. Comparisons with several recommendations are also presented. Results: The authors have assessed the compatibility of experimental data with GEANT4 microdosimetry models by means of quantitative methods. The results show that microdosimetric measurements in liquid water are necessary to assess quantitatively the validity of the software implementation for the liquid water phase. Nevertheless, a comparison with existing experimental data in water vapor provides a qualitative appreciation of the plausibility of the simulation models. The existing reference data themselves should undergo a critical interpretation and selection, as some of the series exhibit significant

  1. Experimental and Numerical Simulation of Water Vapor Adsorption and Diffusion in Shale Grains

    NASA Astrophysics Data System (ADS)

    Shen, W.; Tokunaga, T. K.; Cihan, A.; Wan, J.; Zheng, L.; Oldenburg, C. M.

    2015-12-01

    Advances in deep horizontal drilling and hydraulic fracturing have lead to large increases in production from unconventional shale gas reservoirs. Despite the success of this technology, uncertainties associated with basic transport processes require understanding in order to improve efficiency and minimize environmental impacts. The hydraulic fracturing process introduces large volumes of water into shale gas reservoirs. Most of the fracturing water remains in reservoirs to interfere with gas production. The quantification of the amount of water retained in shale gas reservoirs is crucial for predicting gas shale formation productivity and for optimizing extraction conditions. In this study, water vapor adsorption isotherms were gravimetrically measured on granular fractions of Woodford formation shales sieved after crushing. The isotherms were obtained at 30℃ and 50℃, for relative humidities from 11.1% to 97.0%. Water adsorption in these shale grains conformed to the typeⅡisotherm, and were nearly identical for the two experimental temperatures. In order to better understand the isotherms, a computational model based on the Maxwell-Stefan Diffusion equations (MSDM) was constructed to analyze the water adsorption and gas diffusion in shale grains. Based on the experimental results, the Guggenheim-Anderson-de Boer (GAB) isotherm model for gas adsorption was included in the model.

  2. Optical Kerr effect of liquid and supercooled water: the experimental and data analysis perspective.

    PubMed

    Taschin, A; Bartolini, P; Eramo, R; Righini, R; Torre, R

    2014-08-28

    The time-resolved optical Kerr effect spectroscopy (OKE) is a powerful experimental tool enabling accurate investigations of the dynamic phenomena in molecular liquids. We introduced innovative experimental and fitting procedures, that enable a safe deconvolution of sample response function from the instrumental function. This is a critical issue in order to measure the dynamics of liquid water. We report OKE data on water measuring intermolecular vibrations and the structural relaxation processes in an extended temperature range, inclusive of the supercooled states. The unpreceded data quality makes possible a solid comparison with few theoretical models: the multi-mode Brownian oscillator model, the Kubo's discrete random jump model, and the schematic mode-coupling model. All these models produce reasonable good fits of the OKE data of stable liquid water, i.e., over the freezing point. The features of water dynamics in the OKE data becomes unambiguous only at lower temperatures, i.e., for water in the metastable supercooled phase. We found that the schematic mode-coupling model provides the more rigorous and complete model for water dynamics, even if its intrinsic hydrodynamic approach does not give a direct access to the molecular information. PMID:25173021

  3. Optical Kerr effect of liquid and supercooled water: The experimental and data analysis perspective

    NASA Astrophysics Data System (ADS)

    Taschin, A.; Bartolini, P.; Eramo, R.; Righini, R.; Torre, R.

    2014-08-01

    The time-resolved optical Kerr effect spectroscopy (OKE) is a powerful experimental tool enabling accurate investigations of the dynamic phenomena in molecular liquids. We introduced innovative experimental and fitting procedures, that enable a safe deconvolution of sample response function from the instrumental function. This is a critical issue in order to measure the dynamics of liquid water. We report OKE data on water measuring intermolecular vibrations and the structural relaxation processes in an extended temperature range, inclusive of the supercooled states. The unpreceded data quality makes possible a solid comparison with few theoretical models: the multi-mode Brownian oscillator model, the Kubo's discrete random jump model, and the schematic mode-coupling model. All these models produce reasonable good fits of the OKE data of stable liquid water, i.e., over the freezing point. The features of water dynamics in the OKE data becomes unambiguous only at lower temperatures, i.e., for water in the metastable supercooled phase. We found that the schematic mode-coupling model provides the more rigorous and complete model for water dynamics, even if its intrinsic hydrodynamic approach does not give a direct access to the molecular information.

  4. Optical Kerr effect of liquid and supercooled water: the experimental and data analysis perspective.

    PubMed

    Taschin, A; Bartolini, P; Eramo, R; Righini, R; Torre, R

    2014-08-28

    The time-resolved optical Kerr effect spectroscopy (OKE) is a powerful experimental tool enabling accurate investigations of the dynamic phenomena in molecular liquids. We introduced innovative experimental and fitting procedures, that enable a safe deconvolution of sample response function from the instrumental function. This is a critical issue in order to measure the dynamics of liquid water. We report OKE data on water measuring intermolecular vibrations and the structural relaxation processes in an extended temperature range, inclusive of the supercooled states. The unpreceded data quality makes possible a solid comparison with few theoretical models: the multi-mode Brownian oscillator model, the Kubo's discrete random jump model, and the schematic mode-coupling model. All these models produce reasonable good fits of the OKE data of stable liquid water, i.e., over the freezing point. The features of water dynamics in the OKE data becomes unambiguous only at lower temperatures, i.e., for water in the metastable supercooled phase. We found that the schematic mode-coupling model provides the more rigorous and complete model for water dynamics, even if its intrinsic hydrodynamic approach does not give a direct access to the molecular information.

  5. Seasonal Shifts in Primary Water Source Type: A Comparison of Largely Pastoral Communities in Uganda and Tanzania.

    PubMed

    Pearson, Amber L; Zwickle, Adam; Namanya, Judith; Rzotkiewicz, Amanda; Mwita, Emiliana

    2016-02-01

    Many water-related illnesses show an increase during the wet season. This is often due to fecal contamination from runoff, yet, it is unknown whether seasonal changes in water availability may also play a role in increased illness via changes in the type of primary water source used by households. Very little is known about the dynamic aspects of access to water and changes in source type across seasons, particularly in semi-arid regions with annual water scarcity. The research questions in this study were: (1) To what degree do households in Uganda (UG) and Tanzania (TZ) change primary water source type between wet and dry seasons?; and (2) How might seasonal changes relate to water quality and health? Using spatial survey data from 92 households each in UG and TZ this study found that, from wet to dry season, 26% (UG) and 9% (TZ) of households switched from a source with higher risk of contamination to a source with lower risk. By comparison, only 20% (UG) and 0% (TZ) of households switched from a source with lower risk of contamination to a source with higher risk of contamination. This research suggests that one pathway through which water-related disease prevalence may differ across seasons is the use of water sources with higher risk contamination, and that households with access to sources with lower risks of contamination sometimes choose to use more contaminated sources. PMID:26828507

  6. Experimental manipulation of water levels in two French riverine grassland soils

    NASA Astrophysics Data System (ADS)

    van Oorschot, Mark; van Gaalen, Nils; Maltby, Ed; Mockler, Natalie; Spink, Andrew; Verhoeven, Jos T. A.

    2000-01-01

    In this experimental study, we simulated the effects of different river flooding regimes on soil nutrient availability, decomposition and plant production in floodplain grasslands. This was done to investigate the influences of soil water contents on nutrient cycling. Water levels were manipulated in mesocosms with intact soil turfs from two French floodplain grasslands. Three water levels were established: a `wet' (water level at the soil surface), an `intermediate' (water level at -20 cm) and a `dry' treatment (water level at -120 cm). With increasing soil moisture, soil pH became more neutral, while redox-potential and oxygen concentration decreased. The `dry' treatment showed much lower values for process rates in soil and vegetation than the `intermediate' and `wet' treatments. Regressions showed that soil C-evolution and N-mineralization were positively related to soil moisture content. Not all mineralized N was available for plant uptake in the wet treatment, as a considerable part was denitrified here. Denitrification was especially high as soil water contents increased to levels above field capacity, where redox-potentials sharply dropped. Further, soil P availability was higher under wet conditions. In the `dry' treatment, soil water content was close to the wilting point and plant production was low. In the `intermediate' treatment, plant production was most likely limited by nitrogen. The `wet' treatment did not result in a further increase in plant production. Dam construction and river bed degradation can result in lower river levels and summer drought on floodplains. This experimental study suggests that summer drought on floodplain soils reduces decomposition of soil organic matter, nutrient availability, denitrification, plant production and nutrient uptake. This can affect the capacity of floodplains to remove or retain nutrients from river water in a negative way.

  7. Primary portal vein hypoplasia and SLC2A9 mutation associated with urate urolithiasis in a Spanish water dog

    PubMed Central

    Cosgrove, Laura; Hammond, Gawain; Mclauchlan, Gerard

    2015-01-01

    This report describes a Spanish water dog with an ammonium urate urethrolith which was diagnosed with primary portal vein hypoplasia and was found to be homozygous for the mutated SLC2A9 gene. This is the first Spanish water dog described with the SLC2A9 mutation and the first case of concurrent portal vascular abnormalities and SLC2A9 mutation. PMID:26538670

  8. Experimental Evaluation of the Thermal Performance of a Water Shield for a Surface Power Reactor

    SciTech Connect

    Pearson, J. Boise; Stewart, Eric T.; Reid, Robert S.

    2007-01-30

    Water based reactor shielding is being investigated for use on initial lunar surface power systems. A water shield may lower overall cost (as compared to development cost for other materials) and simplify operations in the setup and handling. The thermal hydraulic performance of the shield is of significant interest. The mechanism for transferring heat through the shield is natural convection. Natural convection in a 100 kWt lunar surface reactor shield design is evaluated with 2 kW power input to the water in the Water Shield Testbed (WST) at the NASA Marshall Space Flight Center. The experimental data from the WST is used to validate a CFD model. Performance of the water shield on the lunar surface is then predicted with a CFD model anchored to test data. The experiment had a maximum water temperature of 75 deg. C. The CFD model with 1/6-g predicts a maximum water temperature of 88 deg. C with the same heat load and external boundary conditions. This difference in maximum temperature does not greatly affect the structural design of the shield, and demonstrates that it may be possible to use water for a lunar reactor shield.

  9. EXPERIMENTAL EVALUATION OF THE THERMAL PERFORMANCE OF A WATER SHIELD FOR A SURFACE POWER REACTOR

    SciTech Connect

    REID, ROBERT S.; PEARSON, J. BOSIE; STEWART, ERIC T.

    2007-01-16

    Water based reactor shielding is being investigated for use on initial lunar surface power systems. A water shield may lower overall cost (as compared to development cost for other materials) and simplify operations in the setup and handling. The thermal hydraulic performance of the shield is of significant interest. The mechanism for transferring heat through the shield is natural convection. Natural convection in a 100 kWt lunar surface reactor shield design is evaluated with 2 kW power input to the water in the Water Shield Testbed (WST) at the NASA Marshall Space Flight Center. The experimental data from the WST is used to validate a CFD model. Performance of the water shield on the lunar surface is then predicted with a CFD model anchored to test data. The experiment had a maximum water temperature of 75 C. The CFD model with 1/6-g predicts a maximum water temperature of 88 C with the same heat load and external boundary conditions. This difference in maximum temperature does not greatly affect the structural design of the shield, and demonstrates that it may be possible to use water for a lunar reactor shield.

  10. The Life-Cycle Costs of School Water, Sanitation and Hygiene Access in Kenyan Primary Schools

    PubMed Central

    Alexander, Kelly T.; Mwaki, Alex; Adhiambo, Dorothy; Cheney-Coker, Malaika; Muga, Richard; Freeman, Matthew C.

    2016-01-01

    Water, Sanitation and Hygiene (WASH) programs in schools can increase the health, dignity and comfort of students and teachers. Understanding the costs of WASH facilities and services in schools is one essential piece for policy makers to utilize when budgeting for schools and helping to make WASH programs more sustainable. In this study we collected data from NGO and government offices, local hardware shops and 89 rural primary schools across three Kenyan counties. Current expenditures on WASH, from school and external (NGO, government, parent) sources, averaged 1.83 USD per student per year. After reviewing current expenditures, estimated costs of operations and maintenance for bringing schools up to basic WASH standards, were calculated to be 3.03 USD per student per year. This includes recurrent costs, but not the cost of installing or setting up WASH infrastructure, which was 18,916 USD per school, for a school of 400 students (4.92 USD per student, per year). These findings demonstrate the need for increases in allocations to schools in Kenya, and stricter guidance on how money should be spent on WASH inputs to enable all schools to provide basic WASH for all students. PMID:27355962

  11. The Life-Cycle Costs of School Water, Sanitation and Hygiene Access in Kenyan Primary Schools.

    PubMed

    Alexander, Kelly T; Mwaki, Alex; Adhiambo, Dorothy; Cheney-Coker, Malaika; Muga, Richard; Freeman, Matthew C

    2016-06-27

    Water, Sanitation and Hygiene (WASH) programs in schools can increase the health, dignity and comfort of students and teachers. Understanding the costs of WASH facilities and services in schools is one essential piece for policy makers to utilize when budgeting for schools and helping to make WASH programs more sustainable. In this study we collected data from NGO and government offices, local hardware shops and 89 rural primary schools across three Kenyan counties. Current expenditures on WASH, from school and external (NGO, government, parent) sources, averaged 1.83 USD per student per year. After reviewing current expenditures, estimated costs of operations and maintenance for bringing schools up to basic WASH standards, were calculated to be 3.03 USD per student per year. This includes recurrent costs, but not the cost of installing or setting up WASH infrastructure, which was 18,916 USD per school, for a school of 400 students (4.92 USD per student, per year). These findings demonstrate the need for increases in allocations to schools in Kenya, and stricter guidance on how money should be spent on WASH inputs to enable all schools to provide basic WASH for all students.

  12. Assessment of Field Experience Related to Pressurized Water Reactor Primary System Leaks

    SciTech Connect

    Shah, Vikram Naginbhai; Ware, Arthur Gates; Atwood, Corwin Lee; Sattison, Martin Blaine; Hartley, Robert Scott; Hsu, C.

    1999-08-01

    This paper presents our assessment of field experience related to pressurized water reactor (PWR) primary system leaks in terms of their number of rates, how aging affects frequency of leak events, the safety significance of such leaks, industry efforts to reduce leaks, and effectiveness of current leak detection systems. We have reviewed the licensee event reports to identify the events that took place during 1985 to the third quarter of 1996, and reviewed related technical literature and visited PWR plants to analyze these events. Our assessment shows that USNRC licensees have taken effective actions to reduce the number of leak events. One main reason for this decreasing trend was the elimination or reportable leakages from valve stem packing after 1991. Our review of leak events related to vibratory fatigue reveals a statistically significant decreasing trend with age (years of operation), but not in calendar time. Our assessment of worldwide data on leakage caused by thermal fatigue cracking is that the fatigue of aging piping is a safety significant issue. Our review of leak events has identified several susceptible sites in piping having high safety significance; but the inspection of some of these sites is not required by the ASME Code. These sites may be included in the risk-informed inspection programs.

  13. Assessment of Field Experience Related to Pressurized Water Reactor Primary System Leaks

    SciTech Connect

    A. G. Ware; C. Hsu; C. L. Atwood; M. B. Sattison; R. S. Hartley; V. N. Shah

    1999-02-01

    This paper presents our assessment of field experience related to pressurized water reactor (PWR) primary system leaks in terms of their number and rates, how aging affects frequency of leak events, the safety significance of such leaks, industry efforts to reduce leaks, and effectiveness of current leak detection systems. We have reviewed the licensee event reports to identify the events that took place during 1985 to the third quarter of 1996, and reviewed related technical literature and visited PWR plants to analyze these events. Our assessment shows that USNRC licensees have taken effective actions to reduce the number of leak events. One main reason for this decreasing trend was the elimination or reportable leakages from valve stem packing after 1991. Our review of leak events related to vibratory fatigue reveals a statistically significant decreasing trend with age (years of operation), but not in calendar time. Our assessment of worldwide data on leakage caused by thermal fatigue cracking is that the fatigue of aging piping is a safety significant issue. Our review of leak events has identified several susceptible sites in piping having high safety significance; but the inspection of some of these sites is not required by the ASME Code. These sites may be included in the risk-informed inspection programs.

  14. The Life-Cycle Costs of School Water, Sanitation and Hygiene Access in Kenyan Primary Schools.

    PubMed

    Alexander, Kelly T; Mwaki, Alex; Adhiambo, Dorothy; Cheney-Coker, Malaika; Muga, Richard; Freeman, Matthew C

    2016-01-01

    Water, Sanitation and Hygiene (WASH) programs in schools can increase the health, dignity and comfort of students and teachers. Understanding the costs of WASH facilities and services in schools is one essential piece for policy makers to utilize when budgeting for schools and helping to make WASH programs more sustainable. In this study we collected data from NGO and government offices, local hardware shops and 89 rural primary schools across three Kenyan counties. Current expenditures on WASH, from school and external (NGO, government, parent) sources, averaged 1.83 USD per student per year. After reviewing current expenditures, estimated costs of operations and maintenance for bringing schools up to basic WASH standards, were calculated to be 3.03 USD per student per year. This includes recurrent costs, but not the cost of installing or setting up WASH infrastructure, which was 18,916 USD per school, for a school of 400 students (4.92 USD per student, per year). These findings demonstrate the need for increases in allocations to schools in Kenya, and stricter guidance on how money should be spent on WASH inputs to enable all schools to provide basic WASH for all students. PMID:27355962

  15. Genotoxic and clastogenic effects of monohaloacetic acid drinking water disinfection by-products in primary human lymphocytes.

    PubMed

    Escobar-Hoyos, Luisa F; Hoyos-Giraldo, Luz Stella; Londoño-Velasco, Elizabeth; Reyes-Carvajal, Ingrid; Saavedra-Trujillo, Diana; Carvajal-Varona, Silvio; Sánchez-Gómez, Adalberto; Wagner, Elizabeth D; Plewa, Michael J

    2013-06-15

    The haloacetic acids (HAAs) are the second-most prevalent class of drinking water disinfection by-products formed by chemical disinfectants. Previous studies have determined DNA damage and repair of HAA-induced lesions in mammalian and human cell lines; however, little is known of the genomic DNA and chromosome damage induced by these compounds in primary human cells. The aim of this study was to evaluate the genotoxic and clastogenic effects of the monoHAA disinfection by-products in primary human lymphocytes. All monoHAAs were genotoxic in primary human lymphocytes, the rank order of genotoxicity and cytotoxicity was IAA > BAA > CAA. After 6 h of repair time, only 50% of the DNA damage (maximum decrease in DNA damage) was repaired compared to the control. This demonstrates that primary human lymphocytes are less efficient in repairing the induced damage by monoHAAs than previous studies with mammalian cell lines. In addition, the monoHAAs induced an increase in the chromosome aberration frequency as a measurement of the clastogenic effect of these compounds. These results coupled with genomic technologies in primary human cells and other mammalian non-cancerous cell lines may lead to the identification of biomarkers that may be employed in feedback loops to aid water chemists and engineers in the overall goal of producing safer drinking water.

  16. Experimental investigation of over-expanded supersonic steam jet submerged in quiescent water

    SciTech Connect

    Wu, Xin-Zhuang; Yan, Jun-Jie; Li, Wen-Jun; Pan, Dong-Dong; Liu, Guang-Yao

    2010-01-15

    This study was designed to determine the behaviour of an over-expanded supersonic steam jet in quiescent water. Only two shapes of steam plume were observed and an analytical model was constructed. The axial and radial temperature distributions were measured in the steam plume and in the surrounding water. The flow pattern and temperature distributions were influenced mainly by steam mass flux and water temperature. The results confirmed the occurrence of compression and expansion waves in the steam plume, and indicated that the temperature distributions reflected the steam plume shapes. The axial temperature distributions in the forepart of the steam plume were independent of water temperature. Empirical correlations were found that predicted the dimensionless axial and radial temperatures of the turbulent jet region. Moreover, prediction of the steam plume length by the dimensionless axial temperature showed good agreement with the experimental results. (author)

  17. Experimental study of the water jet induced by underwater electrical discharge in a narrow rectangular tube

    NASA Astrophysics Data System (ADS)

    Koita, T.; Zhu, Y.; Sun, M.

    2016-05-01

    This paper reports an experimental investigation on the effects of explosion depth and tube width on the water jet induced by an underwater electrical discharge in a narrow rectangular tube. The water jet formation and bubble structure were evaluated from the images recorded by a high-speed video camera. Two typical patterns of jet formation and four general patterns of bubble implosion were observed, depending on the explosion depth and tube width. The velocity of the water jet was calculated from the recorded images. The jet velocity was observed to depend on not only the explosion depth and energy, but also on the tube width. We proposed an empirical formula defining the water jet velocity in the tube as a function of the tube width and explosion depth and energy.

  18. Experimental Evaluation of a Water Shield for a Surface Power Reactor

    NASA Technical Reports Server (NTRS)

    Pearson, J. B.; Reid, R.; Sadasivan, P.; Stewart, E.

    2007-01-01

    A water based shielding system is being investigated for use on initial lunar surface power systems. The use of water may lower overall cost (as compared to development cost for other materials) and simplify operations in the setup and handling. The thermal hydraulic performance of the shield is of significant interest. The mechanism for transferring heat through the shield is natural convection. A representative lunar surface reactor design is evaluated at various power levels in the Water Shield Testbed (WST) at the NASA Marshall Space Flight Center. The evaluation compares the experimental data from the WST to CFD models. Performance of a water shield on the lunar surface is predicted by CFD models anchored to test data, and by matching relevant dimensionless parameters.

  19. An experimental study of freezing of supercooled water droplet on solid surface

    NASA Astrophysics Data System (ADS)

    Alekseenko, S. V.; Mendig, C.; Schulz, M.; Sinapius, M.; Prykhodko, O. A.

    2016-05-01

    Results of experimental investigations of the freezing of immobile water droplet on an aluminum plate are presented. The process was studied with the aid of a high-speed photo camera. The freezing of supercooled water contained in the surface droplet proceeds in a few stages: (i) preliminary heating of water and nucleation of ice microcrystals, (ii) relatively fast formation of the ice-liquid system with a transition to the state of thermodynamic equilibrium near the freezing temperature, and (iii) slow process of complete freezing. The rate and duration of each stage and the time of delay between the moment of action upon the supercooled droplet and the onset of freezing are estimated. Processes of supercooled and nonsupercooled water solidification are compared.

  20. Water use efficiency of net primary production in global terrestrial ecosystems

    NASA Astrophysics Data System (ADS)

    Xia, Lei; Wang, Fei; Mu, Xingmin; Jin, Kai; Sun, Wenyi; Gao, Peng; Zhao, Guangju

    2015-07-01

    The carbon and water cycles of terrestrial ecosystems, which are strongly coupled via water use efficiency (WUE), are influenced by global climate change. To explore the relationship between the carbon and water cycles and predict the effect of climate change on terrestrial ecosystems, it is necessary to study the WUE in global terrestrial ecosystems. In this study, the 13-year WUE (i.e., net primary production (NPP)/evapotranspiration (ET)) of global terrestrial ecosystems was calculated based on the Moderate Resolution Imaging Spectro-radiometer (MODIS) NPP (MOD17A3) and ET (MOD16A3) products from 2000 to 2012. The results indicate that the annual average WUE decreased but not significantly, and the 13-year mean value was 868.88 mg C m -2 mm -1. The variation trend of WUE value for each pixel differed greatly across the terrestrial ecosystems. A significant variation ( P<0.05) occurred in about 18.50% of the land surface. WUE was spatially distributed from 0 to 2541 mg C m -2 mm -1, and 58.78% of the WUE values were concentrated in the interval of 600-1200 mg C m -2 mm -1. The WUE increased from north to south in Africa and Oceania and from east to west in Europe and South America. Both latitudinal and longitudinal gradients existed in Asia and North America. The following trends in the WUE of different continents and Köppen-Geiger climates were observed: Europe (1129.71 mg C m -2 mm -1)> Oceania (1084.46 mg C m -2 mm -1)> Africa (893.51 mg C m -2 mm -1)> South America (893.07 mg C m -2 mm -1)> North America (870.79 mg C m -2 mm -1)> Asia (738.98 mg C m -2 mm -1) and warm temperate climates (1094 mg C m -2 mm -1)> snowy climates (862 mg C m -2 mm -1)> arid climates (785 mg C m -2 mm -1)> equatorial climates (732 mg C m -2 mm -1)> polar climates (435 mg C m -2 mm -1). Based on the WUE value and the present or future rainfall, the maximum carbon that fixed in one region may be theoretically calculated. Also, under the background of global climatic change, WUE may

  1. Numerical modeling and experimental measurements of water spray impact and transport over a cylinder.

    SciTech Connect

    Avedisian, C. T.; Presser, Cary; DesJardin, Paul Edward; Hewson, John C.; Yoon, Sam Sukgoo

    2005-03-01

    This study compares experimental measurements and numerical simulations of liquid droplets over heated (to a near surface temperature of 423 K) and unheated cylinders. The numerical model is based on an unsteady Reynolds-averaged Navier-Stokes (RANS) formulation using a stochastic separated flow (SSF) approach for the droplets that includes submodels for droplet dispersion, heat and mass transfer, and impact on a solid surface. The details of the droplet impact model are presented and the model is used to simulate water spray impingement on a cylinder. Computational results are compared with experimental measurements using phase Doppler interferometry (PDI).

  2. Experimental evidence of wave chaos from a double slit experiment with water surface waves.

    PubMed

    Tang, Yunfei; Shen, Yifeng; Yang, Jiong; Liu, Xiaohan; Zi, Jian; Li, Baowen

    2008-10-01

    In this paper, we report experimental evidence of wave chaos using the double slit water surface wave experiment. We demonstrate that classical dynamics of a domain manifests itself in the interference patterns after the diffraction behind the double slit. For a domain whose classical dynamics is integrable clear interference fringes can be observed behind the double slits; for a domain whose classical dynamics is chaotic, however, interference fringes can totally disappear. Our experimental results clearly demonstrate that the centuries-old double slit experiment can render an excellent tool to observe the manifestations of wave chaos.

  3. Plasma membrane proteomics in the maize primary root growth zone: novel insights into root growth adaptation to water stress.

    PubMed

    Voothuluru, Priyamvada; Anderson, Jeffrey C; Sharp, Robert E; Peck, Scott C

    2016-09-01

    Previous work on maize (Zea mays L.) primary root growth under water stress showed that cell elongation is maintained in the apical region of the growth zone but progressively inhibited further from the apex. These responses involve spatially differential and coordinated regulation of osmotic adjustment, modification of cell wall extensibility, and other cellular growth processes that are required for root growth under water-stressed conditions. As the interface between the cytoplasm and the apoplast (including the cell wall), the plasma membrane likely plays critical roles in these responses. Using a simplified method for enrichment of plasma membrane proteins, the developmental distribution of plasma membrane proteins was analysed in the growth zone of well-watered and water-stressed maize primary roots. The results identified 432 proteins with differential abundances in well-watered and water-stressed roots. The majority of changes involved region-specific patterns of response, and the identities of the water stress-responsive proteins suggest involvement in diverse biological processes including modification of sugar and nutrient transport, ion homeostasis, lipid metabolism, and cell wall composition. Integration of the distinct, region-specific plasma membrane protein abundance patterns with results from previous physiological, transcriptomic and cell wall proteomic studies reveals novel insights into root growth adaptation to water stress.

  4. Plasma membrane proteomics in the maize primary root growth zone: novel insights into root growth adaptation to water stress.

    PubMed

    Voothuluru, Priyamvada; Anderson, Jeffrey C; Sharp, Robert E; Peck, Scott C

    2016-09-01

    Previous work on maize (Zea mays L.) primary root growth under water stress showed that cell elongation is maintained in the apical region of the growth zone but progressively inhibited further from the apex. These responses involve spatially differential and coordinated regulation of osmotic adjustment, modification of cell wall extensibility, and other cellular growth processes that are required for root growth under water-stressed conditions. As the interface between the cytoplasm and the apoplast (including the cell wall), the plasma membrane likely plays critical roles in these responses. Using a simplified method for enrichment of plasma membrane proteins, the developmental distribution of plasma membrane proteins was analysed in the growth zone of well-watered and water-stressed maize primary roots. The results identified 432 proteins with differential abundances in well-watered and water-stressed roots. The majority of changes involved region-specific patterns of response, and the identities of the water stress-responsive proteins suggest involvement in diverse biological processes including modification of sugar and nutrient transport, ion homeostasis, lipid metabolism, and cell wall composition. Integration of the distinct, region-specific plasma membrane protein abundance patterns with results from previous physiological, transcriptomic and cell wall proteomic studies reveals novel insights into root growth adaptation to water stress. PMID:27341663

  5. Bidirectional reflectance spectroscopy of carbonaceous chondrites: Implications for water quantification and primary composition

    NASA Astrophysics Data System (ADS)

    Garenne, A.; Beck, P.; Montes-Hernandez, G.; Brissaud, O.; Schmitt, B.; Quirico, E.; Bonal, L.; Beck, C.; Howard, K. T.

    2016-01-01

    In this study, we measured bidirectional reflectance spectra (0.5-4.0 μm) of 24 CMs, five CRs, one CI, one CV, and one C2 carbonaceous chondrites. These meteorites are known to have experienced an important variability in their relative degrees of aqueous alteration degree (Rubin et al. [2007]. Geochim. Cosmochim. Acta 71, 2361-2382; Howard et al. [2009]. Geochim. Cosmochim. Acta 73, 4576-4589; Howard et al. [2011]. Geochim. Cosmochim. Acta 75, 2735-2751; Alexander et al. [2013]. Geochim. Cosmochim. Acta 123, 244-260). These measurements were performed on meteorite powders inside an environmental cell under a primary vacuum and heated at 60 °C in order to minimize adsorbed terrestrial water. This protocol allows controlling of atmospheric conditions (i.e. humidity) in order to avoid contamination by terrestrial water. We discuss various spectral metrics (e.g. reflectance, band depth, single-scattering albedo, …) in the light of recent bulk composition characterization (Howard et al. [2009]. Geochim. Cosmochim. Acta 73, 4576-4589; Howard et al. [2015]. Geochim. Cosmochim. Acta 149, 206-222; Alexander et al. [2012]. Science 337, 721; Beck et al. [2014]. Icarus 229, 263-277; Garenne et al. [2014]. Geochim. Cosmochim. Acta 137, 93-112). This study reveals variability of reflectance among meteorite groups. The reflectance is not correlated with carbon or hydrogen abundance neither with measured grain size distribution. We suggest that it is rather controlled by the nature of accreted components, in particular the initial matrix/chondrule proportion. Band depth, integrated band depth, mean optical path length, normalized optical path length, effective single-particle absorption thickness were calculated on the so called 3-μm band for reflectance spectra and for single scattering albedo spectra. They were compared with hydrated phase proportions from previous study on the same meteorites by thermogravimetric analyses and infrared spectroscopy in transmission. We find

  6. Enhanced Control of PWR Primary Coolant Water Chemistry Using Selective Separation Systems for Recovery and Recycle of Enriched Boric Acid

    SciTech Connect

    Ken Czerwinski; Charels Yeamans; Don Olander; Kenneth Raymond; Norman Schroeder; Thomas Robison; Bryan Carlson; Barbara Smit; Pat Robinson

    2006-02-28

    The objective of this project is to develop systems that will allow for increased nuclear energy production through the use of enriched fuels. The developed systems will allow for the efficient and selective recover of selected isotopes that are additives to power water reactors' primary coolant chemistry for suppression of corrosion attack on reactor materials.

  7. Genetic variability of oxalate oxidase activity and elongation in water-stressed primary roots of diverse maize and rice lines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous work on maize primary roots under water stress showed that cell elongation is maintained in the apical region of the growth zone but progressively inhibited further from the apex. In association with these responses, several proteins related to reactive oxygen species (ROS) production, part...

  8. Impact of animal waste application on runoff water quality in field experimental plots.

    PubMed

    Hill, Dagne D; Owens, William E; Tchoounwou, Paul B

    2005-08-01

    Animal waste from dairy and poultry operations is an economical and commonly used fertilizer in the state of Louisiana. The application of animal waste to pasture lands not only is a source of fertilizer, but also allows for a convenient method of waste disposal. The disposal of animal wastes on land is a potential nonpoint source of water degradation. Water degradation and human health is a major concern when considering the disposal of large quantities of animal waste. The objective of this research was to determine the effect of animal waste application on biological (fecal coliform, Enterobacter spp. and Escherichia coli) and physical/chemical (temperature, pH, nitrate nitrogen, ammonia nitrogen, phosphate, copper, zinc, and sulfate) characteristics of runoff water in experimental plots. The effects of the application of animal waste have been evaluated by utilizing experimental plots and simulated rainfall events. Samples of runoff water were collected and analyzed for fecal coliforms. Fecal coliforms isolated from these samples were identified to the species level. Chemical analysis was performed following standard test protocols. An analysis of temperature, ammonia nitrogen, nitrate nitrogen, iron, copper, phosphate, potassium, sulfate, zinc and bacterial levels was performed following standard test protocols as presented in Standard Methods for the Examination of Water and Wastewater [1]. In the experimental plots, less time was required in the tilled broiler litter plots for the measured chemicals to decrease below the initial pre-treatment levels. A decrease of over 50% was noted between the first and second rainfall events for sulfate levels. This decrease was seen after only four simulated rainfall events in tilled broiler litter plots whereas broiler litter plots required eight simulated rainfall events to show this same type of reduction. A reverse trend was seen in the broiler litter plots and the tilled broiler plots for potassium. Bacteria numbers

  9. Impact of animal waste application on runoff water quality in field experimental plots.

    PubMed

    Hill, Dagne D; Owens, William E; Tchoounwou, Paul B

    2005-08-01

    Animal waste from dairy and poultry operations is an economical and commonly used fertilizer in the state of Louisiana. The application of animal waste to pasture lands not only is a source of fertilizer, but also allows for a convenient method of waste disposal. The disposal of animal wastes on land is a potential nonpoint source of water degradation. Water degradation and human health is a major concern when considering the disposal of large quantities of animal waste. The objective of this research was to determine the effect of animal waste application on biological (fecal coliform, Enterobacter spp. and Escherichia coli) and physical/chemical (temperature, pH, nitrate nitrogen, ammonia nitrogen, phosphate, copper, zinc, and sulfate) characteristics of runoff water in experimental plots. The effects of the application of animal waste have been evaluated by utilizing experimental plots and simulated rainfall events. Samples of runoff water were collected and analyzed for fecal coliforms. Fecal coliforms isolated from these samples were identified to the species level. Chemical analysis was performed following standard test protocols. An analysis of temperature, ammonia nitrogen, nitrate nitrogen, iron, copper, phosphate, potassium, sulfate, zinc and bacterial levels was performed following standard test protocols as presented in Standard Methods for the Examination of Water and Wastewater [1]. In the experimental plots, less time was required in the tilled broiler litter plots for the measured chemicals to decrease below the initial pre-treatment levels. A decrease of over 50% was noted between the first and second rainfall events for sulfate levels. This decrease was seen after only four simulated rainfall events in tilled broiler litter plots whereas broiler litter plots required eight simulated rainfall events to show this same type of reduction. A reverse trend was seen in the broiler litter plots and the tilled broiler plots for potassium. Bacteria numbers

  10. Water age and stream solute dynamics at the Hubbard Brook Experimental Forest (US)

    NASA Astrophysics Data System (ADS)

    Botter, Gianluca; Benettin, Paolo; McGuire, Kevin; Rinaldo, Andrea

    2016-04-01

    The contribution discusses experimental and modeling results from a headwater catchment at the Hubbard Brook Experimental Forest (New Hampshire, USA) to explore the link between stream solute dynamics and water age. A theoretical framework based on water age dynamics, which represents a general basis for characterizing solute transport at the catchment scale, is used to model both conservative and weathering-derived solutes. Based on the available information about the hydrology of the site, an integrated transport model was developed and used to estimate the relevant hydrochemical fluxes. The model was designed to reproduce the deuterium content of streamflow and allowed for the estimate of catchment water storage and dynamic travel time distributions (TTDs). Within this framework, dissolved silicon and sodium concentration in streamflow were simulated by implementing first-order chemical kinetics based explicitly on dynamic TTD, thus upscaling local geochemical processes to catchment scale. Our results highlight the key role of water stored within the subsoil glacial material in both the short-term and long-term solute circulation at Hubbard Brook. The analysis of the results provided by the calibrated model allowed a robust estimate of the emerging concentration-discharge relationship, streamflow age distributions (including the fraction of event water) and storage size, and their evolution in time due to hydrologic variability.

  11. Evaporation of Water from Particles in the Aerodynamic Lens Inlet: An Experimental Study

    SciTech Connect

    Zelenyuk, Alla; Imre, Dan G.; Cuadra-Rodriguez, Luis A.

    2006-10-01

    The extremely high particle transmission efficiency of aerodynamic lens inlets resulted in their wide use in aerosol mass spectrometers. One of the consequences of a transport of particles from high ambient pressure into the vacuum is that it is accompanied by a rapid drop in relative humidity (RH). Since many atmospheric particles exist in the form of hygroscopic water droplets, a drop in RH may result in a significant loss of water and even a change in phase. To predict how much water will be evaporated is not feasible. Because water loss can effect in addition to particle size, its transmission efficiency, ionization probability and mass spectrum it is imperative to provide definitive experimental data that can serve to guide the field to a reasonable and uniform sampling approach. In this study we present the results of a number of carefully conducted measurements that provide the first experimentally determined benchmark of water evaporation from a range of particles, during their transport through an aerodynamic lens inlet. We conclude that the only sure way to avoid ambiguities during measurements of aerodynamic diameter in instruments that utilize low pressure aerodynamic lens inlets is to dry the particles prior to sampling.

  12. Artificial primary marine aerosol production: a laboratory study with varying water temperature, salinity, and succinic acid concentration

    NASA Astrophysics Data System (ADS)

    Zábori, J.; Matisāns, M.; Krejci, R.; Nilsson, E. D.; Ström, J.

    2012-11-01

    Primary marine aerosols are an important component of the climate system, especially in the remote marine environment. With diminishing sea-ice cover, better understanding of the role of sea spray aerosol on climate in the polar regions is required. As for Arctic Ocean water, laboratory experiments with NaCl water confirm that a few degrees change in the water temperature (Tw) gives a large change in the number of primary particles. Small particles with a dry diameter between 0.01 μm and 0.25 μm dominate the aerosol number density, but their relative dominance decreases with increasing water temperature from 0 °C where they represent 85-90% of the total aerosol number to 10 °C, where they represent 60-70% of the total aerosol number. This effect is most likely related to a change in physical properties and not to modification of sea water chemistry. A change of salinity between 15 g kg-1 and 35 g kg-1 did not influence the shape of a particle number size distribution. Although the magnitude of the size distribution for a water temperature change between 0 °C and 16 °C changed, the shape did not. An experiment where succinic acid was added to a NaCl water solution showed, that the number concentration of particles with 0.010 μm < Dp < 4.5 μm decreased on average by 10% when the succinic acid concentration in NaCl water at a water temperature of 0 °C was increased from 0 μmol L-1 to 94 μmol L-1. A shift to larger sizes in the particle number size distribution is observed from pure NaCl water to Arctic Ocean water. This is likely a consequence of organics and different inorganic salts present in Arctic Ocean water in addition to the NaCl.

  13. Experimental evaluation of the effectiveness of water mist automated fire extinguishing systems for oil transportation

    NASA Astrophysics Data System (ADS)

    Glushkov, D. O.; Nyashina, G. S.; Strizhak, P. A.; Volkov, R. S.

    2015-11-01

    Experimental investigation of regularities of carryover of water mist droplets (radius of 50 - 500 μm) by high temperature (500 - 1800 K) products of combustion of typical petroleum products (oil, gasoline, kerosene, etc.) was carried out. The panoramic optical methods and high-speed hardware and software systems were used. Speeds of droplets after mixing with oncoming high temperature gases were determined. Conditions of continuation of droplets movement through combustion products with preservation of initial trajectory in spite of intensive evaporation and braking were found. The predictive evaluation of effectiveness of water mist use for extinguishing of fires involving oil and typical petroleum products.

  14. Structural properties of geminal dicationic ionic liquid/water mixtures: a theoretical and experimental insight.

    PubMed

    Serva, Alessandra; Migliorati, Valentina; Lapi, Andrea; Aquilanti, Giuliana; Arcovito, Alessandro; D'Angelo, Paola

    2016-06-28

    The structural behavior of geminal dicationic ionic liquid 1,n-bis[3-methylimidazolium-1-yl] alkane bromide ([Cn(mim)2]Br2)/water mixtures has been studied using extended X-ray absorption fine structure (EXAFS) spectroscopy in combination with molecular dynamics (MD) simulations. The properties of the mixtures are investigated as a function of both water concentration and alkyl-bridge chain length. The very good agreement between the EXAFS experimental data and the theoretical curves calculated from the MD structural results has proven the validity of the theoretical framework used for all of the investigated systems. In all the solutions the water molecules are preferentially coordinated with the Br(-) ion, even if a complex network of interactions among dications, anions and water molecules takes place. The local molecular arrangement around the bromide ion is found to change with increasing water content, as more and more water molecules are accomodated in the Br(-) first coordination shell. Moreover, with the decrease of the alkyl-bridge chain length, the interactions between dications and anions increase, with Br(-) forming a bridge between the two imidazolium rings of the same dication. On the other hand, in [Cn(mim)2]Br2/water mixtures with long alkyl-bridge chains peculiar internal arrangements of the dications are found, leading to different structural features of geminal dicationic ionic liquids as compared to their monocationic counterparts.

  15. A cardiovascular educational intervention for primary care professionals in Spain: positive impact in a quasi-experimental study

    PubMed Central

    Gil-Guillén, Vicente; Hermida, Enrique; Pita-Fernandez, Salvador; Palazon-Bru, Antonio; Durazo-Arvizu, Ramon; Pallares-Carratala, Vicente; Orozco-Beltran, Domingo; Carratala-Munuera, Concepcion; Lopez-Pineda, Adriana; Navarro, Jorge

    2015-01-01

    Background Routine general practice data collection can help identify patients at risk of cardiovascular disease. Aim To determine whether a training programme for primary care professionals improves the recording of cardiovascular disease risk factors in electronic health records. Design and setting A quasi-experimental study without random assignment of professionals. This was an educational intervention study, consisting of an online-classroom 1-year training programme, and carried out in the Valencian community in Spain. Method The prevalence rates of recording of cardiovascular factors (recorded every 6 months over a 4-year period) were compared between intervention and control group. Clinical relevance was calculated by absolute risk reduction (ARR), relative risk reduction (RRR), and number of patients needed-to-attend (NNA), to avoid under-recording, with their 95% confidence intervals (CIs). Linear regression models were used for each of the variables. Results Of the 941 professionals initially registered, 78.1% completed the programme. The ARR ranged from 1.87% (95% CI = 1.79 to 1.94) in the diagnosis of diabetes to 15.27% (95% CI = 15.14 to 15.40) in the recording of basal blood glucose. The NNA ranged from 7 in blood pressure, cholesterol, and blood glucose recording to 54 in the diagnosis of diabetes. The RRR ranged from 26.7% in the diagnosis of diabetes to 177.1% in the recording of the Systematic Coronary Risk Evaluation (SCORE). The rates of change were greater in the intervention group and the differences were significant for recording of cholesterol (P<0.001), basal blood glucose (P<0.001), smoking (P<0.001), alcohol (P<0.001), microalbuminuria (P = 0.001), abdominal circumference (P<0.001), and SCORE (P<0.001). Conclusion The education programme had a beneficial effect at the end of the follow-up that was significant and clinically relevant. PMID:25548314

  16. LBE water interaction in sub-critical reactors: First experimental and modelling results

    NASA Astrophysics Data System (ADS)

    Ciampichetti, A.; Agostini, P.; Benamati, G.; Bandini, G.; Pellini, D.; Forgione, N.; Oriolo, F.; Ambrosini, W.

    2008-06-01

    This paper concerns the study of the phenomena involved in the interaction between LBE and pressurised water which could occur in some hypothetical accidents in accelerator driven system type reactors. The LIFUS 5 facility was designed and built at ENEA-Brasimone to reproduce this kind of interaction in a wide range of conditions. The first test of the experimental program was carried out injecting water at 70 bar and 235 °C in a reaction vessel containing LBE at 1 bar and 350 °C. A pressurisation up to 80 bar was observed in the test section during the considered transient. The SIMMER III code was used to simulate the performed test. The calculated data agree in a satisfactory way with the experimental results giving confidence in the possibility to use this code for safety analyses of heavy liquid metal cooled reactors.

  17. Nondestructive experimental determination of bimaterial rectangular cantilever spring constants in water

    SciTech Connect

    Snow, David E.; Kim, Dae Jung; Hope-Weeks, Louisa J.; Weeks, Brandon L.; Pitchimani, Rajasekar

    2008-08-15

    In order to address the issue of spring constant calibration in viscous fluids such as water, a new method is presented that allows for the experimental calibration of bimaterial cantilever spring constants. This method is based on modeling rectangular cantilever beam bending as a function of changing temperature. The temperature change is accomplished by heating water as it flows around the cantilever beams in an enclosed compartment. The optical static method of detection is used to measure the deflection of cantilever at the free end. Experimentally determined results are compared to Sader's method and to the Thermotune method most commonly used in cantilever calibrations. Results indicate that the new bimaterial thermal expansion method is accurate within 15%-20% of the actual cantilever spring constant, which is comparable to other nondestructive calibration techniques.

  18. Experimental, Numerical, and Analytical Slosh Dynamics of Water and Liquid Nitrogen in a Spherical Tank

    NASA Technical Reports Server (NTRS)

    Storey, Jedediah Morse

    2016-01-01

    Understanding, predicting, and controlling fluid slosh dynamics is critical to safety and improving performance of space missions when a significant percentage of the spacecraft's mass is a liquid. Computational fluid dynamics simulations can be used to predict the dynamics of slosh, but these programs require extensive validation. Many experimental and numerical studies of water slosh have been conducted. However, slosh data for cryogenic liquids is lacking. Water and cryogenic liquid nitrogen are used in various ground-based tests with a spherical tank to characterize damping, slosh mode frequencies, and slosh forces. A single ring baffle is installed in the tank for some of the tests. Analytical models for slosh modes, slosh forces, and baffle damping are constructed based on prior work. Select experiments are simulated using a commercial CFD software, and the numerical results are compared to the analytical and experimental results for the purposes of validation and methodology-improvement.

  19. Wavelength-modulated differential photothermal radiometry: Theory and experimental applications to glucose detection in water

    NASA Astrophysics Data System (ADS)

    Mandelis, Andreas; Guo, Xinxin

    2011-10-01

    A differential photothermal radiometry method, wavelength-modulated differential photothermal radiometry (WM-DPTR), has been developed theoretically and experimentally for noninvasive, noncontact biological analyte detection, such as blood glucose monitoring. WM-DPTR features analyte specificity and sensitivity by combining laser excitation by two out-of-phase modulated beams at wavelengths near the peak and the base line of a prominent and isolated mid-IR analyte absorption band (here the carbon-oxygen-carbon bond in the pyran ring of the glucose molecule). A theoretical photothermal model of WM-DPTR signal generation and detection has been developed. Simulation results on water-glucose phantoms with the human blood range (0-300 mg/dl) glucose concentration demonstrated high sensitivity and resolution to meet wide clinical detection requirements. The model has also been validated by experimental data of the glucose-water system obtained using WM-DPTR.

  20. In-situ tuff water migration/heater experiment: experimental plan

    SciTech Connect

    Johnstone, J.K.

    1980-08-01

    Tuffs on the Nevada Test Site (NTS) are currently under investigation as a potential isolation medium for heat-producing nuclear wastes. The National Academy of Sciences has concurred in our identification of the potentially large water content ({le}40 vol %) of tuffs as one of the important issues affecting their suitability for a repository. This Experimental Plan describes an in-situ experiment intended as an initial assessment of water generation/migration in response to a thermal input. The experiment will be conducted in the Grouse Canyon Welded Tuff in Tunnel U12g (G-Tunnel) located in the north-central region of the NTS. While the Grouse Canyon Welded Tuff is not a potential repository medium, it has physical, thermal, and mechanical properties very similar to those tuffs currently under consideration and is accessible at depth (400 m below the surface) in an existing facility. Other goals of the experiment are to support computer-code and instrumentation development, and to measure in-situ thermal properties. The experimental array consists of a central electrical heater, 1.2 m long x 10.2 cm diameter, surrounded by three holes for measuring water-migration behavior, two holes for measuring temperature profiles, one hole for measuring thermally induced stress in the rock, and one hole perpendicular to the heater to measure displacement with a laser. This Experimental Plan describes the experimental objectives, the technical issues, the site, the experimental array, thermal and thermomechanical modeling results, the instrumentation, the data-acquisition system, posttest characterization, and the organizational details.

  1. Experimental determination of the temperature dependence of water activities for a selection of aqueous organic solutions

    NASA Astrophysics Data System (ADS)

    Ganbavale, G.; Marcolli, C.; Krieger, U. K.; Zuend, A.; Stratmann, G.; Peter, T.

    2014-09-01

    This work presents experimental data of the temperature dependence of water activity in aqueous organic solutions relevant for tropospheric conditions (200-273 K). Water activity (aw) at low temperatures (T) is a crucial parameter for predicting homogeneous ice nucleation. We investigated temperature-dependent water activities, ice freezing and melting temperatures of solutions, and vapour pressures of a selection of atmospherically relevant aqueous organic systems. To measure aw over a wide composition range and with a focus on low temperatures, we use various aw measurement techniques and instruments: a dew point water activity meter, an electrodynamic balance (EDB), differential scanning calorimetry (DSC), and a setup to measure the total gas phase pressure at equilibrium over aqueous solutions. Water activity measurements were performed for aqueous multicomponent and multifunctional organic mixtures containing the functional groups typically found in atmospheric organic aerosols, such as hydroxyl, carboxyl, ketone, ether, ester, and aromatic groups. The aqueous organic systems studied at several fixed compositions over a considerable temperature range differ significantly in their temperature dependence. Aqueous organic systems of 1,4-butanediol and methoxyacetic acid show a moderate decrease in aw with decreasing temperature. The aqueous M5 system (a multicomponent system containing five different dicarboxylic acids) and aqueous 2-(2-ethoxyethoxy)ethanol solutions both show a strong increase of water activity with decreasing temperature at high solute concentrations for T < 270 K and T < 260 K, respectively. These measurements show that the temperature trend of aw can be reversed at low temperatures and that linear extrapolations of high-temperature data may lead to erroneous predictions. To avoid this, experimentally determined aw at low temperature are needed to improve thermodynamic models towards lower temperatures and for improved predictions of the ice

  2. Experimental determination of the temperature dependence of water activities for a selection of aqueous organic solutions

    NASA Astrophysics Data System (ADS)

    Ganbavale, G.; Marcolli, C.; Krieger, U. K.; Zuend, A.; Stratmann, G.; Peter, T.

    2014-05-01

    This work presents experimental data of the temperature dependence of water activity in aqueous organic solutions relevant for tropospheric conditions (200-273 K). Water activity (aw) at low temperatures (T) is a crucial parameter for predicting homogeneous ice nucleation. We investigated temperature dependent water activities, ice freezing and melting temperatures of solutions, and vapour pressures of a selection of atmospherically relevant aqueous organic systems. To measure aw over a wide composition range and with a focus on low temperatures, we use various aw measurement techniques and instruments: a dew point water activity meter, an electrodynamic balance (EDB), differential scanning calorimetry (DSC), and a setup to measure the total gas phase pressure at equilibrium over aqueous solutions. Water activity measurements were performed for aqueous multicomponent and multifunctional organic mixtures containing the functional groups typically found in atmospheric organic aerosols, such as hydroxyl, carboxyl, ketone, ether, ester, and aromatic groups. The aqueous organic systems studied at several fixed compositions over a considerable temperature range differ significantly in their temperature dependence. Aqueous organic systems of 1,4-butanediol and methoxyacetic acid show a moderate decrease in aw with decreasing temperature. The aqueous M5 system (a multicomponent system containing five different dicarboxylic acids) and aqueous 2-(2-ethoxyethoxy)ethanol solutions both show a strong increase of water activity with decreasing temperature at high solute concentrations for T<270 K and T<260 K, respectively. These measurements show that the temperature trend of aw can be reversed at low temperatures and that linear extrapolations of high temperature data may lead to erroneous predictions. To avoid this, experimentally determined aw at low temperature are needed to improve thermodynamic models towards lower temperatures and for improved predictions of the ice

  3. Modelling and experimental verification of a water alleviation system for the NASP. [National Aerospace Plane

    NASA Technical Reports Server (NTRS)

    Vanfossen, G. James

    1992-01-01

    One possible low speed propulsion system for the National Aerospace Plane is a liquid air cycle engine (LACE). The LACE system uses the heat sink in the liquid hydrogen propellant to liquefy air in a heat exchanger which is then pumped up to high pressure and used as the oxidizer in a hydrogen liquid air rocket. The inlet airstream must be dehumidified or moisture could freeze on the cryogenic heat exchangers and block them. The main objective of this research has been to develop a computer simulation of the cold tube/antifreeze-spray water alleviation system and to verify the model with experimental data. An experimental facility has been built and humid air tests were conducted on a generic heat exchanger to obtain condensing data for code development. The paper describes the experimental setup, outlines the method of calculation used in the code, and presents comparisons of the calculations and measurements. Cause of discrepancies between the model and data are explained.

  4. Financial analysis of experimental releases conducted at Glen Canyon Dam during water years 2006 through 2010.

    SciTech Connect

    Poch, L. A.; Veselka, T. D.; Palmer, C. S.; Loftin, S.; Osiek, B.

    2011-08-22

    Power Administration's (Western's) power purchase prices were used for the simulation. In addition to estimating the financial impact of experimental releases, the GTMax model was also used to gain insights into the interplay among ROD operating criteria, exceptions that were made to criteria to accommodate the experimental releases, and Western operating practices. Experimental releases in some water years resulted in financial benefits to Western while others resulted in financial costs. During the study period, the total financial costs of all experimental releases were more than $4.8 million.

  5. Theoretical and experimental comparison of the Soret coefficient for water-methanol and water-ethanol binary mixtures

    NASA Astrophysics Data System (ADS)

    Saghir, M. Z.; Jiang, C. G.; Derawi, S. O.; Stenby, E. H.; Kawaji, M.

    2004-11-01

    In multicomponent mixtures, a much richer variety of phenomena can occur than in simple (single-component) fluids. Natural convection in single-component fluids is due to buoyancy forces caused by temperature gradients. In multicomponent mixtures, buoyancy forces may also be caused by concentration gradients. Because natural convection, molecular diffusion, and thermal conduction have different relaxation time scales, a wide variety of resulting convective motions and heat and mass distributions might occur. In some fluid mixtures such as water-ethanol system, for instance, ethanol diffuses much more slowly than heat, and because of this difference in time scales oscillatory convection might occur. In a multicomponent mixture, the total molar flux consists of two parts: the convective molar flux and the diffusive molar flux (resulting from the difference between the component velocity and the bulk velocity). The diffusion molar flux of a component depends, not only on its own mole fraction gradient (Fickian diffusion), but also on the gradient of all the components present in the mixture (cross-molecular diffusion). The diffusion flux depends also on the pressure gradient (pressure diffusion; the so-called gravitational effect) and temperature gradient (thermal diffusion; the so-called Soret effect). Firoozabadi's thermal diffusion model was applied to calculate the Soret coefficient, as well as the thermal diffusion coefficient and molecular diffusion coefficient for methanol-water and ethanol-water mixtures at 310.65 K temperature and 1 bar pressure with 10% water mass fraction. The results were compared with experimental data (J.K. Platten, in Proceedings of the 5th International Meeting on Thermodiffusion (IMT5), Lyngby, Aug. 2002, Philos. Mag. 83, Nos. 17-18 (2003)), as well as theoretical predictions with other models. A better agreement with the experimental data using the Firoozabadi model was achieved.

  6. Experimental Study on Isotope Fractionation of Soil water in Arid Environments

    NASA Astrophysics Data System (ADS)

    Horita, J.; Lin, Y.

    2015-12-01

    Soil water dynamics within a thick vadose (unsaturated) zone is a key component in the hydrologic cycle in arid regions. The partitioning of precipitation and soil water into fluxes of percolation to the subsurface, surface runoff and evapotranspiration at the land-atmosphere-vegetation interface is accompanied by characteristic δ2H and δ18O values of water. The isotopic composition of the transpiration flux is very similar to soil water, since the uptake by plant roots is usually not associated with isotope fractionation. The isotopic composition of evaporation flux from unsaturated soils, which becomes an important flux in arid regions, has extensively been modeled by the Craig-Gordon model with the assumption that equilibrium isotopic fractionation between adsorbed/pored condensed water within soils and water vapor is identical to that between bulk liquid water and vapor. To test this critical assumption, we have conducted laboratory experiments on equilibrium isotope fractionation between adsorbed water in mesoporous silica (15nm pore, as soil analog) and the vapor. Firstly, the adsorption/desorption isotherms of H2O and N2 in the silica are determined at 30°C and liq-N2 temperature, respectively, and large hysteresis loops were observed. Secondly, the isotope fractionation factors between condensed water in the silica pores and the vapor (18αsilica water-vapor and 2αsilica water-vapor for oxygen and hydrogen isotopes, respectively) were determined at 30°C along the adsorption curve from near saturation pressure (p/po=1). We found that 18αsilica water-vapor values are smaller than that between free liquid-vapor (1.0088) and progressively decreased from1.0083 at p/po= 0.9 to 1.0054 at p/po=0.5, establishing a trend very similar to the isotherm curve. The corresponding 2αsilica water-vapor values are also smaller than that of free liquid-vapor system (1.0740) and decreased from 1.0651 at p/po=0.9 to 1.0295 at p/po=0.5. Our experimental results challenge

  7. Nickel Alloy Primary Water Bulk Surface and SCC Corrosion Film Analytical Characterization and SCC Mechanistic Implications

    SciTech Connect

    Morton, D.; Lewis, N.; Hanson, M.; Rice, S.; Sanders, P.

    2007-04-18

    Alloy 600 corrosion coupon tests were performed: (1) to quantify the temperature dependency of general corrosion and (2) to characterize the composition and structure of bulk surface corrosion films for comparison with ongoing primary water SCC (PWSCC) crack tip corrosion film analyses. Results suggest that the thermal activation energy of Alloy 600 corrosion is consistent with the thermal activation energy of nickel alloy PWSCC. Analytical investigations of the structure and composition of Alloy 600 bulk surface corrosion oxides revealed a duplex (inner and outer) oxide layer structure. The outer layer is discontinuous and comprised of relatively large (1 to 3 {micro}m) nickel ferrite crystals and smaller ({approx}0.1 {micro}m) chromium containing nickel ferrite crystals. The inner layer consists of a relatively continuous chromite spinel (major phase) and chromia (Cr{sub 2}O{sub 3} minor phase) which formed through non-selective oxidation. Chromia and dealloyed Alloy 600 (highly Ni enriched metal) were only observed at 337 C (640 F) and only along the boundaries of deformation induced fine grains and subcells. Specimens having deformation free surfaces exhibited continuous uniform inner chromite spinel oxide layers. Specimens with machining induced surface deformation produced non-uniform inner layer oxides (chromite spinel, Cr{sub 2}O{sub 3} and unoxidized material). PWSCC crack tip oxides, in contrast, were fine grain (no duplex structure) and consisted of both chromium rich spinels and ''NiO'' structure oxides. Generally, nickel rich oxides were more abundant under more oxidized conditions (reduced coolant hydrogen) and spinel rich crack tip oxides were favored under more reducing conditions (increased coolant hydrogen). Bulk surface corrosion film thickness did not correlate with observed SCC growth rates. These results suggest that corrosion is not the rate controlling step of PWSCC but rather that PWSCC and corrosion have a common rate controlling sub

  8. Modification of expansin transcript levels in the maize primary root at low water potentials.

    PubMed

    Wu, Y; Thorne, E T; Sharp, R E; Cosgrove, D J

    2001-08-01

    We previously demonstrated that maintenance of cell elongation in the apical region of maize primary roots at low water potentials (psi(w)) was associated with an increase in expansin activity and extractable expansin protein. Here, we characterized the spatial pattern of expansin gene expression along the growing maize root and studied the effect of low psi(w) on expansin gene expression. Roots were divided into three segments: apical 0 to 5 mm, subapical 5 to 10 mm, and non-growing 10 to 20 mm. Of the five expansin genes expressed in control roots, two alpha-expansins (Exp1 and Exp5) and two beta-expansins (ExpB2 and ExpB8) are expressed specifically in the growing region, whereas expression of beta-expansin ExpB6 is shifted basipetally. After seedlings were transplanted to vermiculite with a psi(w) of -1.6 MPa, transcripts for Exp1, Exp5, and ExpB8 rapidly accumulated in the apical region of the root. These mRNA changes correlated with the maintenance of root elongation and increases in wall extensibility found previously. The beta-expansins ExpB2 and ExpB6 showed distinctive patterns of expression and responses to low psi(w,) indicative of distinctive functions. Inhibition of abscisic acid (ABA) accumulation at low psi(w) (by fluridone treatment) had no effect on expansin expression, except that ExpB2 transcript level showed a minor dependence on ABA. Gene-specific regulation of alpha- and beta-expansin mRNA pools likely contributes to growth alterations of the maize (Zea mays) root as it adapts to a low psi(w), but these changes do not appear to be mediated by changes in ABA content.

  9. Screening and Quantification of Aliphatic Primary Alkyl Corrosion Inhibitor Amines in Water Samples by Paper Spray Mass Spectrometry.

    PubMed

    Jjunju, Fred P M; Maher, Simon; Damon, Deidre E; Barrett, Richard M; Syed, S U; Heeren, Ron M A; Taylor, Stephen; Badu-Tawiah, Abraham K

    2016-01-19

    Direct analysis and identification of long chain aliphatic primary diamine Duomeen O (n-oleyl-1,3-diaminopropane), corrosion inhibitor in raw water samples taken from a large medium pressure water tube boiler plant water samples at low LODs (<0.1 pg) has been demonstrated for the first time, without any sample preparation using paper spray mass spectrometry (PS-MS). The presence of Duomeen O in water samples was confirmed via tandem mass spectrometry using collision-induced dissociation and supported by exact mass measurement and reactive paper spray experiments using an LTQ Orbitrap Exactive instrument. Data shown herein indicate that paper spray ambient ionization can be readily used as a rapid and robust method for in situ direct analysis of polymanine corrosion inhibitors in an industrial water boiler plant and other related samples in the water treatment industry. This approach was applied for the analysis of three complex water samples including feedwater, condensate water, and boiler water, all collected from large medium pressure (MP) water tube boiler plants, known to be dosed with varying amounts of polyamine and amine corrosion inhibitor components. Polyamine chemistry is widely used for example in large high pressure (HP) boilers operating in municipal waste and recycling facilities to prevent corrosion of metals. The samples used in this study are from such a facility in Coventry waste treatment facility, U.K., which has 3 × 40 tonne/hour boilers operating at 17.5 bar. PMID:26727190

  10. Screening and Quantification of Aliphatic Primary Alkyl Corrosion Inhibitor Amines in Water Samples by Paper Spray Mass Spectrometry.

    PubMed

    Jjunju, Fred P M; Maher, Simon; Damon, Deidre E; Barrett, Richard M; Syed, S U; Heeren, Ron M A; Taylor, Stephen; Badu-Tawiah, Abraham K

    2016-01-19

    Direct analysis and identification of long chain aliphatic primary diamine Duomeen O (n-oleyl-1,3-diaminopropane), corrosion inhibitor in raw water samples taken from a large medium pressure water tube boiler plant water samples at low LODs (<0.1 pg) has been demonstrated for the first time, without any sample preparation using paper spray mass spectrometry (PS-MS). The presence of Duomeen O in water samples was confirmed via tandem mass spectrometry using collision-induced dissociation and supported by exact mass measurement and reactive paper spray experiments using an LTQ Orbitrap Exactive instrument. Data shown herein indicate that paper spray ambient ionization can be readily used as a rapid and robust method for in situ direct analysis of polymanine corrosion inhibitors in an industrial water boiler plant and other related samples in the water treatment industry. This approach was applied for the analysis of three complex water samples including feedwater, condensate water, and boiler water, all collected from large medium pressure (MP) water tube boiler plants, known to be dosed with varying amounts of polyamine and amine corrosion inhibitor components. Polyamine chemistry is widely used for example in large high pressure (HP) boilers operating in municipal waste and recycling facilities to prevent corrosion of metals. The samples used in this study are from such a facility in Coventry waste treatment facility, U.K., which has 3 × 40 tonne/hour boilers operating at 17.5 bar.

  11. Experimental dehydration of natural obsidian and estimation of DH2O at low water contents.

    PubMed

    Jambon, A; Zhang, Y; Stolper, E M

    1992-01-01

    Water diffusion experiments were carried out by dehydrating rhyolitic obsidian from Valles Caldera (New Mexico, USA) at 510-980 degrees C. The starting glass wafers contained approximately 0.114 wt% total water, lower than any glasses previously investigated for water diffusion. Weight loss due to dehydration was measured as a function of experiment duration, which permits determination of mean bulk water diffusivity, mean Dw. These diffusivities are in the range of 2.6 to 18 X 10(-14) m2/s and can be fit with the following Arrhenius equation: ln mean Dw (m2/s) = -(25.10 +/- 1.29) - (46,480 +/- 11,400) (J/mol) / RT, except for two replicate runs at 510 degrees C which give mean Dw values much lower than that defined by the above equation. When interpreted according to a model of water speciation in which molecular H2O is the diffusing species with concentration-independent diffusivity while OH units do not contribute to the transport but react to provide H2O, the data (except for the 510 degrees C data) are in agreement with extrapolation from previous results and hence extend the previous data base and provide a test of the applicability of the model to very low water contents. Mean bulk water diffusivities are about two orders of magnitude less than molecular H2O diffusivities because the fraction of molecular H2O out of total water is very small at 0.114 wt% total water and less. The 510 degrees C experimental results can be interpreted as due to slow kinetics of OH to H2O interconversion at low temperatures. PMID:11537205

  12. Experimental dehydration of natural obsidian and estimation of DH2O at low water contents

    NASA Technical Reports Server (NTRS)

    Jambon, A.; Zhang, Y.; Stolper, E. M.

    1992-01-01

    Water diffusion experiments were carried out by dehydrating rhyolitic obsidian from Valles Caldera (New Mexico, USA) at 510-980 degrees C. The starting glass wafers contained approximately 0.114 wt% total water, lower than any glasses previously investigated for water diffusion. Weight loss due to dehydration was measured as a function of experiment duration, which permits determination of mean bulk water diffusivity, mean Dw. These diffusivities are in the range of 2.6 to 18 X 10(-14) m2/s and can be fit with the following Arrhenius equation: ln mean Dw (m2/s) = -(25.10 +/- 1.29) - (46,480 +/- 11,400) (J/mol) / RT, except for two replicate runs at 510 degrees C which give mean Dw values much lower than that defined by the above equation. When interpreted according to a model of water speciation in which molecular H2O is the diffusing species with concentration-independent diffusivity while OH units do not contribute to the transport but react to provide H2O, the data (except for the 510 degrees C data) are in agreement with extrapolation from previous results and hence extend the previous data base and provide a test of the applicability of the model to very low water contents. Mean bulk water diffusivities are about two orders of magnitude less than molecular H2O diffusivities because the fraction of molecular H2O out of total water is very small at 0.114 wt% total water and less. The 510 degrees C experimental results can be interpreted as due to slow kinetics of OH to H2O interconversion at low temperatures.

  13. Experimental dehydration of natural obsidian and estimation of DH2O at low water contents.

    PubMed

    Jambon, A; Zhang, Y; Stolper, E M

    1992-01-01

    Water diffusion experiments were carried out by dehydrating rhyolitic obsidian from Valles Caldera (New Mexico, USA) at 510-980 degrees C. The starting glass wafers contained approximately 0.114 wt% total water, lower than any glasses previously investigated for water diffusion. Weight loss due to dehydration was measured as a function of experiment duration, which permits determination of mean bulk water diffusivity, mean Dw. These diffusivities are in the range of 2.6 to 18 X 10(-14) m2/s and can be fit with the following Arrhenius equation: ln mean Dw (m2/s) = -(25.10 +/- 1.29) - (46,480 +/- 11,400) (J/mol) / RT, except for two replicate runs at 510 degrees C which give mean Dw values much lower than that defined by the above equation. When interpreted according to a model of water speciation in which molecular H2O is the diffusing species with concentration-independent diffusivity while OH units do not contribute to the transport but react to provide H2O, the data (except for the 510 degrees C data) are in agreement with extrapolation from previous results and hence extend the previous data base and provide a test of the applicability of the model to very low water contents. Mean bulk water diffusivities are about two orders of magnitude less than molecular H2O diffusivities because the fraction of molecular H2O out of total water is very small at 0.114 wt% total water and less. The 510 degrees C experimental results can be interpreted as due to slow kinetics of OH to H2O interconversion at low temperatures.

  14. Experimental vs. modeled water use in mature Norway spruce (Picea abies) exposed to elevated CO2

    PubMed Central

    Leuzinger, Sebastian; Bader, Martin K.-F.

    2012-01-01

    Rising levels of atmospheric CO2 have often been reported to reduce plant water use. Such behavior is also predicted by standard equations relating photosynthesis, stomatal conductance, and atmospheric CO2 concentration, which form the core of dynamic global vegetation models (DGVMs). Here, we provide first results from a free air CO2 enrichment (FACE) experiment with naturally growing, mature (35 m) Picea abies (L.) (Norway spruce) and compare them to simulations by the DGVM LPJ-GUESS. We monitored sap flow, stem water deficit, stomatal conductance, leaf water potential, and soil moisture in five 35–40 m tall CO2-treated (550 ppm) trees over two seasons. Using LPJ-GUESS, we simulated this experiment using climate data from a nearby weather station. While the model predicted a stable reduction of transpiration of between 9% and 18% (at concentrations of 550–700 ppm atmospheric CO2), the combined evidence from various methods characterizing water use in our experimental trees suggest no changes in response to future CO2 concentrations. The discrepancy between the modeled and the experimental results may be a scaling issue: while dynamic vegetation models correctly predict leaf-level responses, they may not sufficiently account for the processes involved at the canopy and ecosystem scale, which could offset the first-order stomatal response. PMID:23087696

  15. Combustion behavior of single coal-water slurry droplets, Part 1: Experimental techniques

    SciTech Connect

    Levendis, Y.A.; Metghalchi, M.; Wise, D.

    1991-12-31

    Techniques to produce single droplets of coal-water slurries have been developed in order to study the combustion behavior of the slurries. All stages of slurry combustion are of interest to the present study, however, emphasis will be given to the combustion of the solid agglomerate char which remains upon the termination of the water evaporation and the devolatilization periods. An experimental facility is under construction where combustion of coal-water slurries will be monitored in a variety of furnace temperatures and oxidizing atmospheres. The effect of the initial size of the slurry droplet and the solids loading (coal to water ratio) will be investigated. A drop tube, laminar flow furnace coupled to a near-infrared, ratio pyrometer win be used to monitor temperature-time histories of single particles from ignition to extinction. This paper describes the experimental built-up to this date and presents results obtained by numerical analysis that help understanding the convective and radiating environment in the furnace.

  16. Experimental vs. modeled water use in mature Norway spruce (Picea abies) exposed to elevated CO(2).

    PubMed

    Leuzinger, Sebastian; Bader, Martin K-F

    2012-01-01

    Rising levels of atmospheric CO(2) have often been reported to reduce plant water use. Such behavior is also predicted by standard equations relating photosynthesis, stomatal conductance, and atmospheric CO(2) concentration, which form the core of dynamic global vegetation models (DGVMs). Here, we provide first results from a free air CO(2) enrichment (FACE) experiment with naturally growing, mature (35 m) Picea abies (L.) (Norway spruce) and compare them to simulations by the DGVM LPJ-GUESS. We monitored sap flow, stem water deficit, stomatal conductance, leaf water potential, and soil moisture in five 35-40 m tall CO(2)-treated (550 ppm) trees over two seasons. Using LPJ-GUESS, we simulated this experiment using climate data from a nearby weather station. While the model predicted a stable reduction of transpiration of between 9% and 18% (at concentrations of 550-700 ppm atmospheric CO(2)), the combined evidence from various methods characterizing water use in our experimental trees suggest no changes in response to future CO(2) concentrations. The discrepancy between the modeled and the experimental results may be a scaling issue: while dynamic vegetation models correctly predict leaf-level responses, they may not sufficiently account for the processes involved at the canopy and ecosystem scale, which could offset the first-order stomatal response. PMID:23087696

  17. Experimental/numerical study of anisotropic water diffusion in glass/epoxy composites

    NASA Astrophysics Data System (ADS)

    Rocha, I. B. C. M.; Raijmaekers, S.; Nijssen, R. P. L.; van der Meer, F. P.; Sluys, L. J.

    2016-07-01

    In this work a glass/epoxy composite commonly used in wind turbine blades is exposed to a humid environment at an elevated temperature. To research the anisotropic diffusion behaviour observed in unidirectional composite specimens, experimental results of slices cut along the three directional planes of the laminate immersed in demineralised water at 50° C are coupled with numerical modelling. The weight of the slices was measured at regular intervals, from which the uptake behaviour could be deduced. The process was modelled using a 3-dimensional RVE of the material, where diffusion is modelled as steady-state and the diffusivity in each direction was measured by applying concentration gradients to the model. The experimental data shows similar water uptake behaviour for samples in both transverse directions, while the water uptake in the fibre direction was significantly faster. A proper fit according to Fick's law was obtained for the transverse direction, while this was not possible for the samples in fibre direction, suggesting a strong dependency of the diffusion behaviour on the fibre orientation. Results from the proposed numerical models show that the geometric effect of fibres acting as barriers for the water movement is indeed responsible for part of the observed anisotropy.

  18. Experimental evidence for a liquid-liquid crossover in deeply cooled confined water.

    PubMed

    Cupane, Antonio; Fomina, Margarita; Piazza, Irina; Peters, Judith; Schirò, Giorgio

    2014-11-21

    In this work we investigate, by means of elastic neutron scattering, the pressure dependence of mean square displacements (MSD) of hydrogen atoms of deeply cooled water confined in the pores of a three-dimensional disordered SiO2 xerogel; experiments have been performed at 250 and 210 K from atmospheric pressure to 1200 bar. The "pressure anomaly" of supercooled water (i.e., a mean square displacement increase with increasing pressure) is observed in our sample at both temperatures; however, contrary to previous simulation results and to the experimental trend observed in bulk water, the pressure effect is smaller at lower (210 K) than at higher (250 K) temperature. Elastic neutron scattering results are complemented by differential scanning calorimetry data that put in evidence, besides the glass transition at about 170 K, a first-order-like endothermic transition occurring at about 230 K that, in view of the neutron scattering results, can be attributed to a liquid-liquid crossover. Our results give experimental evidence for the presence, in deeply cooled confined water, of a crossover occurring at about 230 K (at ambient pressure) from a liquid phase predominant at 210 K to another liquid phase predominant at 250 K; therefore, they are fully consistent with the liquid-liquid transition hypothesis.

  19. An Experimental Method for Measuring Water Droplet Impingement Efficiency on Two- and Three-dimensional Bodies

    NASA Technical Reports Server (NTRS)

    Papadakis, M.; Zumwalt, G. W.; Elangonan, R.; Freund, G. A., Jr.; Breer, M.; Whitmer, L.

    1989-01-01

    An experimental method was developed to determine the droplet impingement characteristics on 2-D and 3-D bodies. The experimental results provide the essential droplet impingement data required to validate water droplet trajectory codes, which are used in the analysis of aircraft icing. A body, whose water droplet impingement characteristics are required, is covered at strategic locations by thin strips of moisture absorbing (blotter) paper, and is exposed to an air stream containing a water dye solution spray cloud. Water droplet impingement data are extracted from the dyed blotter strips by measuring the optical reflectance of the dye deposit on the strips, using an automated reflectometer. Models tested include a 4-inch diameter cylinder, a NACA 652015 airfoil section, a MS(1)-0317 supercritical airfoil section, three simulated ice shapes, an axisymmetric inlet and a Boeing 737-300 inlet model. Detailed descriptions of the dye tracer technique, instrumentation, data reduction method and the results obtained are presented. Analytical predictions of collection efficiency characteristics for most test configurations are included for comparison.

  20. The First Association of a Primary Amebic Meningoencephalitis Death with Culturable Naegleria fowleri in Tap Water from a U.S. Treated Public Drinking Water System

    PubMed Central

    Cope, Jennifer R.; Ratard, Raoult C.; Hill, Vincent R.; Sokol, Theresa; Causey, Jonathan Jake; Yoder, Jonathan S.; Mirani, Gayatri; Mull, Bonnie; Mukerjee, Kimberly A.; Narayanan, Jothikumar; Doucet, Meggie; Qvarnstrom, Yvonne; Poole, Charla N.; Akingbola, Olugbenga A.; Ritter, Jana; Xiong, Zhenggang; da Silva, Alexandre; Roellig, Dawn; Van Dyke, Russell; Stern, Harlan; Xiao, Lihua; Beach, Michael J.

    2015-01-01

    Background Naegleria fowleri is a climate-sensitive, thermophilic ameba found in warm, freshwater lakes and rivers. Primary amebic meningoencephalitis (PAM), which is almost universally fatal, occurs when N. fowleri–containing water enters the nose, typically during swimming, and N. fowleri migrates to the brain via the olfactory nerve. In August 2013, a 4-year-old child died of meningoencephalitis of unknown etiology in a Louisiana hospital. Methods Clinical and environmental testing and a case investigation were initiated to determine the cause of death and to identify potential exposures. Results Based on testing of CSF and brain specimens, the child was diagnosed with PAM. His only reported water exposure was tap water; in particular, tap water that was used to supply water to a lawn water slide on which the child had played extensively prior to becoming ill. Water samples were collected from both the home and the water distribution system that supplied the home and tested; N. fowleri were identified in water samples from both the home and the water distribution system. Conclusions This case is the first reported PAM death associated with culturable N. fowleri in tap water from a U.S. treated drinking water system. This case occurred in the context of an expanding geographic range for PAM beyond southern tier states with recent case reports from Minnesota, Kansas, and Indiana. This case also highlights the role of adequate disinfection throughout drinking water distribution systems and the importance of maintaining vigilance when operating drinking water systems using source waters with elevated temperatures. PMID:25595746

  1. Experimental and numerical simulations of heat transfers between flowing water and a frozen porous medium

    NASA Astrophysics Data System (ADS)

    Roux, Nicolas; Grenier, Christophe; Costard, François

    2015-04-01

    In permafrost-affected regions, hydrological changes due to global warming are still under investigation. But yet, we can already foresee from recent studies that for example, the variability and intensity of surface/subsurface flow are likely to be affected by permafrost degradation. The feedback induced by such changes on permafrost degradation is still not clearly assessed. Of particular interest are lake and river's taliks. A talik is a permanently unfrozen zone that lies below rivers or lakes. They are likely to play a key role in the formerly presented interactions, given that they are the only paths for groundwater flow in permafrost regions. Thus heat transfers on a regional scale are influenced by groundwater circulation. The aim of our study is therefore to investigate the evolution of river's taliks. In addition, they are the only perennial liquid water resources in continuous permafrost environments. The issue associated is to what extent can taliks develop into the future because of climate change and how likely are they to become open taliks, connecting sub-permafrost water with surface water with potentially strong geochemical changes? We developed a multidisciplinary approach coupling field investigation, experimental studies in a cold room and numerical modeling. The field investigation concerns Central Yakutia, Siberia, where we have installed instruments to monitor ground temperatures and water pressure in a small river's talik between two thermokarst lakes. We present here the results corresponding to the cold room experimental work, associating numerical modeling and laboratory experiments in order to look after the main parameters controlling river's talik installation and validate our numerical simulation approach. In a cold room at GEOPS, where a metric scale channel is filled with a porous medium (sand or silty-clay), we are able to control air, water and permafrost initial temperature, but also water flow. At initial time, the "river

  2. Experimental and theoretical investigation of water removal from DMAZ liquid fuel by an adsorption process

    NASA Astrophysics Data System (ADS)

    Ghanbari, Shahram; Vaferi, Behzad

    2015-07-01

    2-dimethylaminoethylazide (DMAZ) is a new liquid fuel that has made significant progress in bio/mono propellant rocket engines in recent years. Purification of DMAZ fuel by reducing its water content using various adsorbents including zeolites, calcium chloride and nano-particles is experimentally and theoretically investigated. The highest water adsorption of 92.6% from the DMAZ solution is obtained by the CaCl2 adsorbent within 10 min. Four different artificial neural networks (ANN) are examined to correlate an extent of removed water from the DMAZ solution to its affecting parameters. The performed regression analysis indicated that water initial concentration (WIC), adsorbent types, solution temperature, contact time and adsorbent dosage are the most important affecting variables for water sorption from the DMAZ solution. The accomplished statistical analysis demonstrated a multi-layer perceptron neural network (MLPNN) with seven hidden neurons and is the most accurate approach for modeling the considered task. The obtained results showed that the proposed MLPNN model could be successfully employed for accurate prediction of an amount of water removal from the DMAZ fuel solution by the adsorption process.

  3. Experimentally determined blood and water flow limitations for hydrophobic compounds using perfused gills of trout

    SciTech Connect

    Sijm, D.T.H.M.; Verberne, M.E.; Paert, P.; Opperhuizen, A.

    1995-12-31

    The influence of physiologically relevant water and blood flows on the uptake of a number of hydrophobic compounds was investigated using perfused gills of rainbow trout. For all compounds studied, the uptake rate constants increased with water flow at lower flow and remained constant at higher flow. The uptake rate constants did not change when blood flow decreased at lower flow, while they increased at higher flow. Both water and blood flows thus influence the uptake of hydrophobic chemicals. using these experimental data and allometric relations, it was established that the water flow can limit the uptake of hydrophobic chemicals for fish weighing more than 5 g. The flow of water will not limit uptake in fish < 5 g, irrespective of physiological conditions and oxygen concentration. At low oxygen concentration, which will increase the water flow in large fish, the uptake of hydrophobic chemicals may increase with a factor of 5 or more. Increasing the blood flow may maximally increase the uptake of hydrophobic chemicals two-fold, in small as well as in large fish.

  4. Experimental study on bi-phase flow Air-Oil in Water Emulsion

    NASA Astrophysics Data System (ADS)

    Arnone, Davide; Poesio, Pietro

    2015-11-01

    Bi-phase slug flow oil-in-water emulsion [5%-20%] and air through a horizontal pipe (inner diameter 22mm) is experimentally studied. A test with water and air has been performed as comparison. First we create and analyze the flow pattern map to identify slug flow liquid and air inlet conditions. Flow maps are similar for all the used liquid. A video analysis procedure using an high speed camera has been created to obtain all the characteristics of unit slugs: slug velocity, slug length, bubble velocity, bubbles length and slug frequency. We compare translational velocity and frequency with models finding a good agreement. We calculate the pdfs of the lengths to find the correlations between mean values and STD on different air and liquid superficial velocities. We also perform pressure measurements along the pipe. We conclude that the percentage of oil-in- water has no influence on results in terms of velocity, lengths, frequency and pressure drop.

  5. Contaminated water delivery as a simple and effective method of experimental Salmonella infection

    PubMed Central

    O’Donnell, Hope; Pham, Oanh H.; Benoun, Joseph M.; Ravesloot-Chávez, Marietta M.; McSorley, Stephen J.

    2016-01-01

    Aims In most infectious disease models, it is assumed that gavage needle infection is the most reliable means of pathogen delivery to the gastrointestinal tract. However, this methodology can cause esophageal tearing and induces stress in experimental animals, both of which have the potential to impact early infection and the subsequent immune response. Materials and Methods C57BL/6 mice were orally infected with virulent Salmonella Typhimurium SL1344 either by intragastric gavage preceded by sodium bicarbonate, or by contamination of drinking water. Results We demonstrate that water contamination delivery of Salmonella is equivalent to gavage inoculation in providing a consistent model of infection. Furthermore, exposure of mice to contaminated drinking water for as little as 4 hours allowed maximal mucosal and systemic infection, suggesting an abbreviated window exists for natural intestinal entry. Conclusions Together, these data question the need for gavage delivery for infection with oral pathogens. PMID:26439708

  6. Measuring transient water flow in unsaturated municipal solid waste - A new experimental approach

    SciTech Connect

    Capelo, J. Castro, M.A.H. de

    2007-07-01

    This research investigated transient water flow in unsaturated municipal solid waste (MSW) packed in columns using neutron scattering. The method developed was able to measure absolute moisture content and moisture variation in a sample of MSW produced in the city of Fortaleza (Brazil) during a simulated tropical rain event. The technique was proven to be efficient, showing that channeling flow accounts for most of the unsaturated flow conditions. The most important effect of micro-porous flow was on water accumulation and small long-term outflow. Furthermore, the definition of field capacity used in soil sciences does not seem to apply to flow in unsaturated MSW; the MSW layers kept increasing in moisture content long after water was allowed through. Finally, the long-term draining experiment demonstrated that the macro-porous matrix may not be a continuous medium, which makes experimental procedures that rely on matrix potential in specific points of the solid waste mass inaccurate.

  7. Abortion and foetal lesions induced by Neospora caninum in experimentally infected water buffalos (Bubalus bubalis).

    PubMed

    Chryssafidis, Andreas L; Cantón, Germán; Chianini, Francesca; Innes, Elisabeth A; Madureira, Ed H; Soares, Rodrigo M; Gennari, Solange M

    2015-01-01

    The water buffalo (Bubalus bubalis) is an important species in several countries for its milk and meat production, as well as for transport and other agricultural activities. It is, in general, considered more resistant than cattle to different parasitic diseases, also less demanding for forage quality. It has been postulated that buffalo may be resistant to abortion caused by neosporosis, because of high serological prevalences found in buffalo herds from different localities, with no description of Neospora caninum-related abortion. Recent studies have demonstrated the potential impact of neosporosis in pregnant water buffalo cows. In this work, three pregnant buffalo cows were experimentally infected with Nc-1 strain of N. caninum, and abortion was detected 35 days post-infection. Molecular and histopathological results found in post-mortem tissues are described and discussed, confirming the susceptibility of water buffalos to abortion caused by N. caninum.

  8. Experimental Investigation on the Basic Law of Hydraulic Fracturing After Water Pressure Control Blasting

    NASA Astrophysics Data System (ADS)

    Huang, Bingxiang; Li, Pengfeng; Ma, Jian; Chen, Shuliang

    2014-07-01

    Because of the advantages of integrating water pressure blasting and hydraulic fracturing, the use of hydraulic fracturing after water pressure control blasting is a method that is used to fully transform the structure of a coal-rock mass by increasing the number and range of hydraulic cracks. An experiment to study hydraulic fracturing after water pressure blasting on cement mortar samples (300 × 300 × 300 mm3) was conducted using a large-sized true triaxial hydraulic fracturing experimental system. A traditional hydraulic fracturing experiment was also performed for comparison. The experimental results show that water pressure blasting produces many blasting cracks, and follow-up hydraulic fracturing forces blasting cracks to propagate further and to form numerous multidirectional hydraulic cracks. Four macroscopic main hydraulic cracks in total were noted along the borehole axial and radial directions on the sample surfaces. Axial and radial main failure planes induced by macroscopic main hydraulic cracks split the sample into three big parts. Meanwhile, numerous local hydraulic cracks were formed on the main failure planes, in different directions and of different types. Local hydraulic cracks are mainly of three types: local hydraulic crack bands, local branched hydraulic cracks, and axial layered cracks. Because local hydraulic cracks produce multiple local layered failure planes and lamellar ruptures inside the sample, the integrity of the sample decreases greatly. The formation and propagation process of many multidirectional hydraulic cracks is affected by a combination of water pressure blasting, water pressure of fracturing, and the stress field of the surrounding rock. To a certain degree, the stress field of surrounding rock guides the formation and propagation process of the blasting crack and the follow-up hydraulic crack. Following hydraulic fracturing that has been conducted after water pressure blasting, the integrity of the sample is found to

  9. Financial analysis of experimental releases conducted at Glen Canyon Dam during water years 1997 through 2005.

    SciTech Connect

    Veselka, T. D.; Poch, L. A.; Palmer, C. S.; Loftin, S.; Osiek, B.; Decision and Information Sciences; Western Area Power Administration

    2010-04-21

    also used to gain insights into the interplay among ROD operating criteria, exceptions that were made to criteria to accommodate the experimental releases, and Western operating practices. Experimental releases in some water years resulted in financial benefits to Western while others resulted in financial costs. During the study period, the total financial costs of all experimental releases were $11.9 million.

  10. Increased expression of host iron-binding proteins precedes iron accumulation and calcification of primary lung lesions in experimental tuberculosis in the guinea pig.

    PubMed

    Basaraba, Randall J; Bielefeldt-Ohmann, Helle; Eschelbach, Ellie K; Reisenhauer, Claire; Tolnay, Airn E; Taraba, Lauren C; Shanley, Crystal A; Smith, Erin A; Bedwell, Cathy L; Chlipala, Elizabeth A; Orme, Ian M

    2008-01-01

    The growth and virulence of Mycobacterium tuberculosis depends on its ability to scavenge host iron, an essential and limited micronutrient in vivo. In this study, we show that ferric iron accumulates both intra- and extra-cellularly in the primary lung lesions of guinea pigs aerosol-infected with the H37Rv strain of M. tuberculosis. Iron accumulated within macrophages at the periphery of the primary granulomatous lesions while extra-cellular ferric iron was concentrated in areas of lesion necrosis. Accumulation of iron within primary lesions was preceded by an increase in expression of heavy chain (H) ferritin, lactoferrin and receptors for transferrin, primarily by macrophages and granulocytes. The increased expression of intra-cellular H ferritin and extra-cellular lactoferrin, more so than transferrin receptor, paralleled the development of necrosis within primary lesions. The deposition of extra-cellular ferric iron within necrotic foci coincided with the accumulation of calcium and phosphorus and other cations in the form of dystrophic calcification. Primary lung lesions from guinea pigs vaccinated with Mycobactrium bovis BCG prior to experimental infection, had reduced iron accumulation as well as H ferritin, lactoferrin and transferrin receptor expression. The amelioration of primary lesion necrosis and dystrophic calcification by BCG vaccination was coincident with the lack of extra-cellular ferric iron and lactoferrin accumulation. These data demonstrate that BCG vaccination ameliorates primary lesion necrosis, dystrophic mineralization and iron accumulation, in part by down-regulating the expression of macrophage H ferritin, lactoferrin and transferrin receptors, in vivo.

  11. Experimental determination of solvent-water partition coefficients and Abraham parameters for munition constituents.

    PubMed

    Liang, Yuzhen; Kuo, Dave T F; Allen, Herbert E; Di Toro, Dominic M

    2016-10-01

    There is concern about the environmental fate and effects of munition constituents (MCs). Polyparameter linear free energy relationships (pp-LFERs) that employ Abraham solute parameters can aid in evaluating the risk of MCs to the environment. However, poor predictions using pp-LFERs and ABSOLV estimated Abraham solute parameters are found for some key physico-chemical properties. In this work, the Abraham solute parameters are determined using experimental partition coefficients in various solvent-water systems. The compounds investigated include hexahydro-1,3,5-trinitro-1,3,5-triazacyclohexane (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX), hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX), hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX), hexahydro-1,3-dinitroso-5- nitro-1,3,5-triazine (DNX), 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitrobenzene (TNB), and 4-nitroanisole. The solvents in the solvent-water systems are hexane, dichloromethane, trichloromethane, octanol, and toluene. The only available reported solvent-water partition coefficients are for octanol-water for some of the investigated compounds and they are in good agreement with the experimental measurements from this study. Solvent-water partition coefficients fitted using experimentally derived solute parameters from this study have significantly smaller root mean square errors (RMSE = 0.38) than predictions using ABSOLV estimated solute parameters (RMSE = 3.56) for the investigated compounds. Additionally, the predictions for various physico-chemical properties using the experimentally derived solute parameters agree with available literature reported values with prediction errors within 0.79 log units except for water solubility of RDX and HMX with errors of 1.48 and 2.16 log units respectively. However, predictions using ABSOLV estimated solute parameters have larger prediction errors of up to 7.68 log units. This large discrepancy is probably due to the missing R2NNO2

  12. Evaluation of hollow-fiber ultrafiltration primary concentration of pathogens and secondary concentration of viruses from water.

    PubMed

    Rhodes, Eric R; Hamilton, Douglas W; See, Mary Jean; Wymer, Larry

    2011-09-01

    Tangential flow hollow-fiber ultrafiltration (HFUF) was evaluated for virus and Cryptosporidium parvum concentration from water. Recovery of viruses at a low filtration rate was found to be significantly greater than at a higher filtration rate, with the recoveries of bacteriophage MS2 at high and low filtration rates shown to be 64.7% and 98.7%, respectively. Poliovirus recoveries from tap water were similar to MS2, with recoveries of 62.9% and 104.5% for high and low filtration rates, respectively. C. parvum, which was only tested at high filtration rates, had an average recovery was 105.1%. In addition to the optimization of the primary concentration technique, this study also compared several secondary concentration procedures. The highest recovery (89.5%) of poliovirus from tap water concentrates was obtained when a beef extract-celite method was used and the virus was eluted from the celite with phosphate buffered saline, pH 9.0. When HFUF primary concentration and the optimal secondary concentration methods were combined, an average recovery of 97.0 ± 35.6% or 89.3 ± 19.3%, depending on spike level, was achieved for poliovirus. This study demonstrated that HFUF primary concentration method is effective at recovering MS2, poliovirus and C. parvum from large volumes of water and that beef extract-celite method is an effective secondary concentration method for the poliovirus tested.

  13. Computational and experimental platform for understanding and optimizing water flux and salt rejection in nanoporous membranes.

    SciTech Connect

    Rempe, Susan B.

    2010-09-01

    Affordable clean water is both a global and a national security issue as lack of it can cause death, disease, and international tension. Furthermore, efficient water filtration reduces the demand for energy, another national issue. The best current solution to clean water lies in reverse osmosis (RO) membranes that remove salts from water with applied pressure, but widely used polymeric membrane technology is energy intensive and produces water depleted in useful electrolytes. Furthermore incremental improvements, based on engineering solutions rather than new materials, have yielded only modest gains in performance over the last 25 years. We have pursued a creative and innovative new approach to membrane design and development for cheap desalination membranes by approaching the problem at the molecular level of pore design. Our inspiration comes from natural biological channels, which permit faster water transport than current reverse osmosis membranes and selectively pass healthy ions. Aiming for an order-of-magnitude improvement over mature polymer technology carries significant inherent risks. The success of our fundamental research effort lies in our exploiting, extending, and integrating recent advances by our team in theory, modeling, nano-fabrication and platform development. A combined theoretical and experimental platform has been developed to understand the interplay between water flux and ion rejection in precisely-defined nano-channels. Our innovative functionalization of solid state nanoporous membranes with organic protein-mimetic polymers achieves 3-fold improvement in water flux over commercial RO membranes and has yielded a pending patent and industrial interest. Our success has generated useful contributions to energy storage, nanoscience, and membrane technology research and development important for national health and prosperity.

  14. Experimental and Modeling Studies of Water-Silica-PDMS Interactions in M97-Based Stress Cushions

    SciTech Connect

    Maxwell, R; Dinh, L; Gee, R; Balazs, B

    2002-04-18

    In filled PDMS based composites, such as M97XX stress cushions, significant mechanical reinforcement of the polymer component is obtained from hydrogen bonding between the silica filler surface hydroxyls and the siloxane polymer backbone. It is expected that these interactions are influenced by the amount and structure of interfacial water. We have chosen to investigate in detail the effect of chemisorbed and physisorbed water on the interfacial structure and dynamics in silica-filled PDMS-based composites. Toward this end, we have combined classical molecular dynamics simulations and experimental studies employing nanoindentation, temperature programmed desorption (TPD), Dynamic Mechanical Analysis (DMA), and Nuclear Magnetic Resonance (NMR) analyses. Our TPD results suggest that moisture desorption and adsorption in M9787 can be approximated by the interaction of its silica constituents (Cab-0-Sil-M-7D and Hi-Sil-233) with moisture. Our experimental data also reveal that, in general, as heat-treated silica particles are exposed to moisture, chemisorbed states, then physisorbed states are gradually filled up in that order. Molecular modeling results suggest that the polymer-silica contact distance and the mobility of interfacial polymer chains significantly decreased as the hydration level at the interface was reduced. The reduced mobility of the PDMS chains in the interfacial domain reduced the bulk motional properties of the polymer, thus causing an effective ''stiffening'' of the polymer matrix. This finding is consistent with both NMR and modal analysis experimental data on desiccated M97XX samples. We show that both the motional dynamics of the polymer and the structure in the interfacial region are indeed controlled by the concentration of water in this region and that by considering the thermodynamic and kinetic parameters derived from TPD experiments, we can begin to approach a predictive capability for the time dependence of water speciation and thus the

  15. Experimental and predicted cavitation performance of an 80.6 deg helical inducer in high temperature water

    NASA Technical Reports Server (NTRS)

    Kovich, G.

    1972-01-01

    The cavitating performance of a stainless steel 80.6 degree flat-plate helical inducer was investigated in water over a range of liquid temperatures and flow coefficients. A semi-empirical prediction method was used to compare predicted values of required net positive suction head in water with experimental values obtained in water. Good agreement was obtained between predicted and experimental data in water. The required net positive suction head in water decreased with increasing temperature and increased with flow coefficient, similar to that observed for a like inducer in liquid hydrogen.

  16. Assessment of water consumptions in small mediterranean islands' primary schools by means of a long-term online monitoring

    NASA Astrophysics Data System (ADS)

    Ferraris, Marco; De Gisi, Sabino; Farina, Roberto

    2016-09-01

    A key challenge of our society is improving schools through the sustainable use of resources especially in countries at risk of desertification. The estimation of water consumption is the starting point for the correct dimensioning of water recovery systems. To date, unlike the energy sector, there is a lack of scientific information regarding water consumption in school buildings. Available data refer roughly to indirect estimates by means of utility bills and therefore no information on the role of water leakage in the internal network of the school is provided. In this context, the aim of the work was to define and implement an on-line monitoring system for the assessment of water consumptions in a small Mediterranean island primary school to achieve the following sub-goals: (1) definition of water consumption profile considering teaching activities and secretarial work; (2) direct assessment of water consumptions and leakages and, (3) quantification of the behaviour parameters. The installed monitoring system consisted of 33 water metres (3.24 persons per water metre) equipped with sensors set on 1-L impulse signal and connected to a data logging system. Results showed consumptions in the range 13.6-14.2 L/student/day and leakage equal to 54.8 % of the total water consumptions. Considering the behavioural parameters, the consumptions related to toilet flushing, personal, and building cleaning were, respectively, 54, 43 and 3 % of the total water ones. Finally, the obtained results could be used for dimensioning the most suitable water recovery strategies at school level such as grey water or rainwater recovery systems.

  17. Primary viraemia responses of herons to experimental infection with Murray Valley encephalitis, Kunjin and Japanese encephalitis viruses.

    PubMed

    Boyle, D B; Dickerman, R W; Marshall, I D

    1983-12-01

    Rufous night herons, Pacific herons, little egrets and intermediate egrets were experimentally infected with Murray Valley encephalitis, Kunjin or Japanese encephalitis viruses. Viraemias of at least one day's duration were detected in all birds except two intermediate egrets inoculated with a very low dose of Kunjin virus and one rufous night heron inoculated with Japanese encephalitis virus. there was usually a viraemia of 3 to 5 days' duration commencing on the first or second day and continuing until day 5 or 6 and rarely until day 7. Maximum titres tended to be higher in young birds, up to 2-5 months of age (10(4)-10(5) mouse LD50/ml), than in older birds more than 8 months of age (10(3)-10(4) mouse LD50/ml). Significant differences in maximum viraemia titres were not observed in the different species or between Murray Valley encephalitis and Kunjin viruses. Japanese encephalitis viraemias were significantly lower, but this was probably due to the high mouse brain passage level of the strain used. The onset of viraemia was earlier in intermediate egrets than in rufous night herons inoculated with similar doses of Murray Valley encephalitis virus, but no difference in the susceptibility to infection was observed. With Kunjin virus there was a significant difference in the susceptibility of intermediate egrets and rufous night herons, with rufous night herons being more susceptible to infection with low doses of virus. This difference in threshold of infection, if it extends to other species with both Kunjin and Murray Valley encephalitis viruses, may, in part, be an explanation for the greater incidence of natural infections observed in rufous night herons compared with other species and orders of water birds.

  18. Numerical and experimental study of dissociation in an air-water single-bubble sonoluminescence system.

    PubMed

    Puente, Gabriela F; Urteaga, Raúl; Bonetto, Fabián J

    2005-10-01

    We performed a comprehensive numerical and experimental analysis of dissociation effects in an air bubble in water acoustically levitated in a spherical resonator. Our numerical approach is based on suitable models for the different effects considered. We compared model predictions with experimental results obtained in our laboratory in the whole phase parameter space, for acoustic pressures from the bubble dissolution limit up to bubble extinction. The effects were taken into account simultaneously to consider the transition from nonsonoluminescence to sonoluminescence bubbles. The model includes (1) inside the bubble, transient and spatially nonuniform heat transfer using a collocation points method, dissociation of O2 and N2, and mass diffusion of vapor in the noncondensable gases; (2) at the bubble interface, nonequilibrium evaporation and condensation of water and a temperature jump due to the accommodation coefficient; (3) in the liquid, transient and spatially nonuniform heat transfer using a collocation points method, and mass diffusion of the gas in the liquid. The model is completed with a Rayleigh-Plesset equation with liquid compressible terms and vapor mass transfer. We computed the boundary for the shape instability based on the temporal evolution of the computed radius. The model is valid for an arbitrary number of dissociable gases dissolved in the liquid. We also obtained absolute measurements for R(t) using two photodetectors and Mie scattering calculations. The robust technique used allows the estimation of experimental results of absolute R0 and P(a). The technique is based on identifying the bubble dissolution limit coincident with the parametric instability in (P(a),R0) parameter space. We take advantage of the fact that this point can be determined experimentally with high precision and replicability. We computed the equilibrium concentration of the different gaseous species and water vapor during collapse as a function of P(a) and R0. The

  19. Hot Water Distribution System Program Documentation and Comparison to Experimental Data

    SciTech Connect

    Baskin, Evelyn; Craddick, William G; Lenarduzzi, Roberto; Wendt, Robert L; Woodbury, Professor Keith A.

    2007-09-01

    In 2003, the California Energy Commission s (CEC s) Public Interest Energy Research (PIER) program funded Oak Ridge National Laboratory (ORNL) to create a computer program to analyze hot water distribution systems for single family residences, and to perform such analyses for a selection of houses. This effort and its results were documented in a report provided to CEC in March, 2004 [1]. The principal objective of effort was to compare the water and energy wasted between various possible hot water distribution systems for various different house designs. It was presumed that water being provided to a user would be considered suitably warm when it reached 105 F. Therefore, what was needed was a tool which could compute the time it takes for water reaching the draw point to reach 105 F, and the energy wasted during this wait. The computer program used to perform the analyses was a combination of a calculational core, produced by Dr. Keith A. Woodbury, Professor of Mechanical Engineering and Director, Alabama Industrial Assessment Center, University of Alabama, and a user interface based on LabVIEW, created by Dr. Roberto Lenarduzzi of ORNL. At that time, the computer program was in a relatively rough and undocumented form adequate to perform the contracted work but not in a condition where it could be readily used by those not involved in its generation. Subsequently, the CEC provided funding through Lawrence Berkeley National Laboratory (LBNL) to improve the program s documentation and user interface to facilitate use by others, and to compare the program s results to experimental data generated by Dr. Carl Hiller. This report describes the program and provides user guidance. It also summarizes the comparisons made to experimental data, along with options built into the program specifically to allow these comparisons. These options were necessitated by the fact that some of the experimental data required options and features not originally included in the program

  20. Spectral changes in conifers subjected to air pollution and water stress: Experimental studies

    NASA Technical Reports Server (NTRS)

    Westman, Walter E.; Price, Curtis V.

    1988-01-01

    The roles of leaf anatomy, moisture and pigment content, and number of leaf layers on spectral reflectance in healthy, pollution-stressed, and water-stressed conifer needles were examined experimentally. Jeffrey pine (Pinus jeffreyi) and giant sequoia (Sequoiadendron gigantea) were exposed to ozone and acid mist treatments in fumigation chambers; red pine (Pinus resinosa) needles were artificially dried. Infrared reflectance from stacked needles rose with free water loss. In an air-drying experiment, cell volume reductions induced by loss of turgor caused near-infrared reflectance (TM band 4) to drop after most free water was lost. Under acid mist fumigation, stunting of tissue development similarly reduced band 4 reflectance. Both artificial drying and pollutant fumigation caused a blue shift of the red edge of spectral reflectance curves in conifers, attributable to chlorophyll denaturation. Thematic mapper band ratio 4/3 fell and 5/4 rose with increasing pollution stress on artificial drying. Loss of water by air-drying, freeze-drying, or oven-drying enhanced spectral features, due in part to greater scattering and reduced water absorption. Grinding of the leaf tissue further enhanced the spectral features by increasing reflecting surfaces and path length. In a leaf-stacking experiment, an asymptote in visible and infrared reflectance was reached at 7-8 needle layers of red pine.

  1. A green roof experimental site in the Mediterranean climate: the storm water quality issue.

    PubMed

    Gnecco, Ilaria; Palla, Anna; Lanza, Luca G; La Barbera, Paolo

    2013-01-01

    Since 2007, the University of Genoa has been carrying out a monitoring programme to investigate the hydrologic response of green roofs in the Mediterranean climate by installing a green roof experimental site. In order to assess the influence of green roofs on the storm water runoff quality, water chemistry data have been included in the monitoring programme since 2010, providing rainfall and outflow data. For atmospheric source, the bulk deposition is collected to evaluate the role of the overall atmospheric deposition in storm water runoff quality. For subsurface outflow, a maximum of 24 composite samples are taken on an event basis, thus aiming at a full characterization of the outflow hydrograph. Water chemistry data reveal that the pollutant loads associated with green roof outflow is low; in particular, solids and metal concentrations are lower than values generally observed in storm water runoff from traditional rooftops. The concentration values of chemical oxygen demand, total dissolved solids, Fe, Ca and K measured in the subsurface outflow are significantly higher than those observed in the bulk deposition (p < 0.05). With respect to the atmospheric deposition, the green roof behaviour as a sink/source of pollutants is investigated based on both concentration and mass.

  2. Relationship of drinking water disinfectants to plasma cholesterol and thyroid hormone levels in experimental studies

    SciTech Connect

    Revis, N.W.; McCauley, P.; Bull, R.; Holdsworth, G.

    1986-03-01

    The effects of drinking water containing 2 or 15 ppm chlorine (pH 6.5 and 8.5), chlorine dioxide, and monochloramine on thyroid function and plasma cholesterol were studied because previous investigators have reported cardiovascular abnormalities in experimental animals exposed to chlorinated water. Plasma thyroxine (T4) levels, as compared to controls, were significantly decreased in pigeons fed a normal or high-cholesterol diet and drinking water containing these drinking water disinfectants at a concentration of 15 ppm (the exception was chlorine at pH 6.5) for 3 months. In most of the treatment groups, T4 levels were significantly lower following the exposure to drinking water containing the 2 ppm dose. Increase in plasma cholesterol were frequently observed in the groups with lower T4 levels. This association was most evident in pigeons fed the high-cholesterol diet and exposed to these disinfectants at a dose of 15 ppm. The factor(s) associated with the effect of these disinfectants on plasma T4 and cholesterol is not known. The authors suggest however that these effects are probably mediated by products formed when these disinfectants react with organic matter in the upper gastrointestinal tract.

  3. Experimental Evaluation of a Water Shield for a Surface Power Reactor

    NASA Technical Reports Server (NTRS)

    Pearson, J. Boise; Reid, Robert S.

    2006-01-01

    As part of the Vision for Space Exploration the end of the next decade will bring man back to the surface of the moon. One of the most critical issues for the establishment of human presence on the moon will be the availability of compact power sources. The establishment of man on the moon will require power from greater than 10's of kWt's in follow on years. Nuclear reactors are extremely we11 suited to meet the needs for power generation on the lunar or Martian surface. reactor system. Several competing concepts exist for lightweight, safe, robust shielding systems such as a water shield, lithium hydride (LiH), Boron Carbide, and others. Water offers several potential advantages, including reduced cost, reduced technical risk, and reduced mass. Water has not typically been considered for space reactor applications because of the need for gravity to remove the potential for radiation streaming paths. The water shield concept relies on predictions of passive circulation of the shield water by natural convection to adequately cool the shield. This prediction needs to be experimentally evaluated, especially for shields with complex geometries. MSFC has developed the experience and fac necessary to do this evaluation in the Early Flight Fission - Test Facility (EFF-TF).

  4. Controls on water drop volume at speleothem drip sites: An experimental study

    NASA Astrophysics Data System (ADS)

    Collister, Christopher; Mattey, David

    2008-09-01

    SummaryThe growth of speleothem under cave drip sites is closely related to local climate events and provides an increasingly important means of deciphering past climate change. Since calcite precipitation rates depend on the water discharge at the drip site, the drip rate and mass of water drops detaching from stalactites are fundamental controls on speleothem growth and we have investigated factors that control the volume of water drops in this environment. The classical investigations on the volume of falling water drops are reviewed but there have been no measurements of the volume of drops detaching from curved surfaces equivalent to tips of stalactites. In this study we have used an acoustic drop counting method to measure the variation of the mass of water drops detaching from tubes (representing 'soda straw' stalactites) and artificial stalactites with spherical terminations (representing massive stalactites) as a function of tube radius or surface curvature and the drip rate. The experimental method corroborates classical measurements of drop mass detaching from tubes and, for massive stalactites, we derive a simple empirical relationship between drop mass and radius of curvature of a spherical surface, based on 100,000 drop counts from artificial stalactites with 19 different radii ranging from 3.6 mm to 500 mm. The results of this study allow discharge to be calculated from drip interval measurements and provide a quantitative basis for theoretical modelling of speleothem growth from drip sites.

  5. Experimental reconstruction of three-dimensional hydrodynamic loading in water entry problems through particle image velocimetry

    NASA Astrophysics Data System (ADS)

    Jalalisendi, Mohammad; Shams, Adel; Panciroli, Riccardo; Porfiri, Maurizio

    2015-02-01

    Predicting the hydrodynamic loading during water impact is of fundamental importance for the design of offshore and aerospace structures. Here, we experimentally characterize the 3D hydrodynamic loading on a rigid wedge vertically impacting a quiescent water surface. Planar particle image velocimetry is used to measure the velocity field on several planes, along the width and the length of the impacting wedge. Such data are ultimately utilized to estimate the 3D velocity field in the whole fluid domain, where the pressure field is reconstructed from the solution of the incompressible Navier-Stokes equations. Experimental results confirm that the velocity field is nearly 2D at the mid-span of the wedge, while the axial velocity along the length of the wedge becomes significant in the proximity of the edges. The variation of the fluid flow along the length of the wedge regulates the hydrodynamic loading experienced during the impact. Specifically, the hydrodynamic loading is maximized at the mid-span of the wedge and considerably decreases toward the edges. The method proposed in this study can find application in several areas of experimental fluid mechanics, where the analysis of unsteady 3D fluid-structure interactions is of interest.

  6. Experimental oxygen isotope fractionation between siderite-water and phosphoric acid liberated CO2-siderite

    USGS Publications Warehouse

    Carothers, W.W.; Adami, L.H.; Rosenbauer, R.J.

    1988-01-01

    The equilibrium fractionation of O isotopes between synthetic siderite and water has been measured at temperatures ranging from 33?? to 197??C. The fractionation between siderite and water over this temperature range can be represented by the equation: 103 ln ?? = 3.13 ?? 106T-2 - 3.50. Comparison between the experimental and theoretical fractionations is favorable only at approximately 200??C; at lower temperatures, they generally differ by up to 2 permil. Siderite was prepared by the slow addition of ferrous chloride solutions to sodium bicarbonate solutions at the experimental temperatures. It was also used to determine the O isotope fractionation factors between phosphoric acid liberated CO2 and siderite. The fractionation factors for this pair at 25?? and 50??C are 1.01175 and 1.01075, respectively. Preliminary results of the measured C isotope fractionation between siderite and Co2 also indicate C isotopic equilibrium during precipitation of siderite. The measured distribution of 13C between siderite and CO2 coincides with the theoretical values only at about 120??C. Experimental and theoretical C fractionations differ up to 3 permil at higher and lower temperatures. ?? 1988.

  7. Analysis of water movement in paddy rice fields (I) experimental studies

    NASA Astrophysics Data System (ADS)

    Chen, Shih-Kai; Liu, Chen Wuing

    2002-03-01

    For the purpose of increasing the amount of ground water recharge, we investigated the hydraulic characteristics of water infiltration in a flooded paddy rice field in Ten-Chung, Chung-Hwa county, Taiwan. Experimental results based on mini-tensiometers and double ring infiltrometer measurements indicated that the least permeable layer occurred at the interface of the puddled topsoil and non-puddled subsoil. The average thickness of this layer was about 7.5 cm and saturated hydraulic conductivity ranged from 0.034 to 0.083 cm/day. Vertical infiltration flow was saturated within the plow sole layer and became unsaturated in the subsoil below the plow sole layer. The hydraulic conductivity of the subsoil, 20-30 times greater than that of the plow sole layer, revealed that the subsoil was more permeable than the plow sole layer. In situ measurements also demonstrated that breakage of the plow sole layer increased infiltration rate by a factor of 3.7. Increasing ponded water depth from 6 to 16 cm increased infiltration 1.5 fold. It is suggested that using the fallow paddy rice fields without puddling is a feasible way to enhance groundwater recharge, but for cultivated paddy rice fields, breaking the plow sole needs further study in terms of its recoverability and because of the potential contamination of the shallow aquifer by agrochemicals. The experimental data can be applied in numerical simulation models to quantify detailed water movement mechanisms and accurately estimate the amount of ground water recharge in paddy rice fields.

  8. Linking water age and solute dynamics in streamflow at the Hubbard Brook Experimental Forest, NH, USA

    NASA Astrophysics Data System (ADS)

    Benettin, Paolo; Bailey, Scott W.; Campbell, John L.; Green, Mark B.; Rinaldo, Andrea; Likens, Gene E.; McGuire, Kevin J.; Botter, Gianluca

    2015-11-01

    We combine experimental and modeling results from a headwater catchment at the Hubbard Brook Experimental Forest (HBEF), New Hampshire, USA, to explore the link between stream solute dynamics and water age. A theoretical framework based on water age dynamics, which represents a general basis for characterizing solute transport at the catchment scale, is here applied to conservative and weathering-derived solutes. Based on the available information about the hydrology of the site, an integrated transport model was developed and used to compute hydrochemical fluxes. The model was designed to reproduce the deuterium content of streamflow and allowed for the estimate of catchment water storage and dynamic travel time distributions (TTDs). The innovative contribution of this paper is the simulation of dissolved silicon and sodium concentration in streamflow, achieved by implementing first-order chemical kinetics based explicitly on dynamic TTD, thus upscaling local geochemical processes to catchment scale. Our results highlight the key role of water stored within the subsoil glacial material in both the short-term and long-term solute circulation. The travel time analysis provided an estimate of streamflow age distributions and their evolution in time related to catchment wetness conditions. The use of age information to reproduce a 14 year data set of silicon and sodium stream concentration shows that, at catchment scales, the dynamics of such geogenic solutes are mostly controlled by hydrologic drivers, which determine the contact times between the water and mineral interfaces. Justifications and limitations toward a general theory of reactive solute circulation at catchment scales are discussed.

  9. COMPARISON OF FILTRATION METHODS FOR PRIMARY RECOVERY OF CRYPTOSPORIIDUM PARVUM FROM WATER

    EPA Science Inventory

    Waterborne disease outbreaks from contaminated drinking water have been linked to the protozoan parasite, Cryptosporidium parvum. To improve monitoring for this agent, the USEPA developed Method 1622 for isolation and detection of Cryptosporidium oocysts in water. Method 1622 i...

  10. Science in an Integrated Primary School Project on Water: Part 1.

    ERIC Educational Resources Information Center

    Ward, Alan

    1984-01-01

    Describes water-related activities in an elementary school science project. These activities focus on electric generators, rainfall, erosion, floating, water conservation, and other areas. Brief comments on developing such a project are included. (JN)

  11. The Water Retention Curves in THF Hydrate-Bearing Sediments - Experimental Measurement and Pore Scale Simulation

    NASA Astrophysics Data System (ADS)

    Mahabadi, N.; Zheng, X.; Dai, S.; Seol, Y.; Zapata, C.; Yun, T.; Jang, J.

    2015-12-01

    The water retention curve (WRC) of hydrate-bearing sediments is critically important to understand the behaviour of hydrate dissociation for gas production. Most gas hydrates in marine environment have been formed from an aqueous phase (gas-dissolved water). However, the gas hydrate formation from an aqueous phase in a laboratory requires long period due to low gas solubility in water and is also associated with many experimental difficulties such as hydrate dissolution, difficult hydrate saturation control, and dynamic hydrate dissolution and formation. In this study, tetrahydrofuran (THF) is chosen to form THF hydrate because the formation process is faster than gas hydrate formation and hydrate saturation is easy to control. THF hydrate is formed at water-excess condition. Therefore, there is only water in the pore space after a target THF hydrate saturation is obtained. The pore habit of THF hydrate is investigated by visual observation in a transparent micromodel and X-ray computed tomography images; and the water retention curves are obtained under different THF hydrate saturation conditions. Targeted THF hydrate saturations are Sh=0, 0.2, 0.4, 0.6 and 0.8. Results shown that at a given water saturation the capillary pressure increases as THF hydrate saturation increases. And the gas entry pressure increases with increasing hydrate saturation. The WRC obtained by experiments is also compared with the results of a pore-network model simulation and Lattice Boltzmann Method. The fitting parameters of van Genuchten equation for different hydrate saturation conditions are suggested for the use as input parameters of reservoir simulators.

  12. Information-collection request for: National Primary Drinking Water Regulations for inorganic chemicals. Phase 2, March 1989

    SciTech Connect

    Not Available

    1989-03-31

    The Environmental Protection Agency (EPA), under the requirements of the Safe Drinking Water Act Section 1401 and 1412, P.L. 99-339, as amended in 1986, has proposed a National Primary Drinking Water Regulation (NPDWR) pertaining to the contamination of public-water systems by inorganic chemical contaminants. The proposed IOCs Rule includes information collection requirements for eight inorganic chemicals -- asbestos, barium, cadmium, chromium, mercury, nitrate, nitrite, and selenium. The information collection request analyzes the information burden imposed on public-water systems and States as a result of the regulation. EPA is proposing only to regulate source-related inorganics under this rule, as opposed to inorganics which predominately occur as corrosion by-products and naturally occurring copper and lead are analyzed in the RIA and ICR for lead and corrosion by-products. Note also that EPA has already promulgated a NPDWR for fluoride.

  13. Assessment of primary production and optical variability in shelf and slope waters near Cape Hatteras, North Carolina. Final project report

    SciTech Connect

    Redalje, Donald G.; Lohrenz, Stevern E.

    2001-02-12

    In this project we determined primary production and optical variability in the shelf and slope waters off of Cape Hatteras, N.C. These processes were addressed in conjunction with other Ocean Margins Program investigators, during the Spring Transition period and during Summer. We found that there were significant differences in measured parameters between Spring and Summer, enabling us to develop seasonally specific carbon production and ecosystem models as well as seasonal and regional algorithm improvements for use in remote sensing applications.

  14. Experimental and numerical modelling of surface water-groundwater flow and pollution interactions under tidal forcing

    NASA Astrophysics Data System (ADS)

    Spanoudaki, Katerina; Bockelmann-Evans, Bettina; Schaefer, Florian; Kampanis, Nikolaos; Nanou-Giannarou, Aikaterini; Stamou, Anastasios; Falconer, Roger

    2015-04-01

    Surface water and groundwater are integral components of the hydrologic continuum and the interaction between them affects both their quantity and quality. However, surface water and groundwater are often considered as two separate systems and are analysed independently. This separation is partly due to the different time scales, which apply in surface water and groundwater flows and partly due to the difficulties in measuring and modelling their interactions (Winter et al., 1998). Coastal areas in particular are a difficult hydrologic environment to represent with a mathematical model due to the large number of contributing hydrologic processes. Accurate prediction of interactions between coastal waters, groundwater and neighbouring wetlands, for example, requires the use of integrated surface water-groundwater models. In the past few decades a large number of mathematical models and field methods have been developed in order to quantify the interaction between groundwater and hydraulically connected surface water bodies. Field studies may provide the best data (Hughes, 1995) but are usually expensive and involve too many parameters. In addition, the interpretation of field measurements and linking with modelling tools often proves to be difficult. In contrast, experimental studies are less expensive and provide controlled data. However, experimental studies of surface water-groundwater interaction are less frequently encountered in the literature than filed studies (e.g. Ebrahimi et al., 2007; Kuan et al., 2012; Sparks et al., 2013). To this end, an experimental model has been constructed at the Hyder Hydraulics Laboratory at Cardiff University to enable measurements to be made of groundwater transport through a sand embankment between a tidal water body such as an estuary and a non-tidal water body such as a wetland. The transport behaviour of a conservative tracer was studied for a constant water level on the wetland side of the embankment, while running a

  15. Preliminary results of an experimental study of the interactions of basalt glass and a water vapor atmosphere: Implications for weathering on Mars

    NASA Technical Reports Server (NTRS)

    Mazer, J. J.; Bates, J. K.; Bradley, C. R.

    1992-01-01

    Models of weathering processes on the surface of Mars invoke hydrothermal alteration as the primary mechanism responsible for clay formation. Previous experimental studies of basalt glass interactions with water under hydrothermal conditions demonstrate that phyllosilicates and zeolites are the primary alteration minerals. Gas-solid weathering is thought to be less thermodynamically favorable and relatively unimportant, however, the experimental alteration of basalt glass under vapor ion conditions (large SA/V) can result in the formation of clay minerals, zeolites, and hydrated calcium silicates. We have undertaken a study of the reacted layers formed on basalt glasses experimentally altered under vapor hydration conditions to resolve this issue. High SA/V ratios promote reaction product buildup in solution and promote alteration mineral formation. It was previously shown that these reaction conditions promote weathering processes similar to those found in nature for tektite glasses, rhyolitic glasses, and basalt glasses. The hydration of basalt glass is described for 100 percent relative humidity experiments at temperatures of 150, 175, and 200 C for up to 400 days. Preliminary characterization of the alteration layers with analytical electron and scanning microscopy suggest that the reaction mechanism includes precipitation of a smectite clay on the outermost surface of the glass. Between the clay and the unreacted glass is an amorphous gel-like phase (palagonite). Our results provide an experimental basis for proposing that basalt glass interactions with vapor atmospheres can be an important source of clay minerals.

  16. Experimental study of steam condensation on water in countercurrent flow in presence of inert gases

    NASA Astrophysics Data System (ADS)

    Bharathan, D.; Althof, J.

    1984-08-01

    Experimental results of investigating steam condensation on water in the presence of (noncondensable) inert gases at low temperatures and pressures relevant to open-cycle ocean thermal energy conversion (OTEC) systems are reported. Seven different condenser configurations were tested. The experimental data are correlated using a liquid flow fraction and a vent fraction to yield simple relationships of condenser performance over a wide range of test conditions. Performance maps and envelopes are provided for evaluating the relative merits of tested configurations. The height of transfer unit (HTU) for condensation ranges from 0.2 to 0.3 m among the various condenser geometries. Also reported are the pressure-loss coefficients for all the tested geometries.

  17. INRA Constellation of Experimental Watersheds: Cyberinfrastructure to Support Publication of Water Resources Data

    NASA Astrophysics Data System (ADS)

    Horsburgh, J. S.; Tarboton, D. G.; Schreuders, K.; Ames, D. P.; McNamara, J. P.; Marshall, L. A.; McGlynn, B. L.; Kane, D. L.; Tidwell, A.; Boll, J.; Hinman, N. W.; Barber, M. E.

    2009-12-01

    Over the past several years, researchers at universities affiliated with the Inland Northwest Research Alliance (INRA) have been collecting water resources datasets at a number of experimental watersheds in the western United States. Experimental watersheds in the INRA region span a number of climate, human development, and disturbance gradients, and researchers are investigating several different research themes, including snowmelt responses to climate change, groundwater - surface water interactions, modeling of hydrologic response, land use change, and arctic river processes. Integration of data from these watersheds will facilitate cross-site comparisons and large scale studies that synthesize information from diverse settings, making the network as a whole greater than the sum of its parts. In this presentation, we will describe efforts towards establishing and supporting the INRA Water Resources Consortium Constellation of Experimental Watersheds (ICEWATER) Information System Network. The ICEWATER Information System Network is a distributed network of computer servers built using components of the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) Hydrologic Information System (HIS) technology to publish and integrate the data holdings from ICEWATER. The sharing of data in a common format is one way to stimulate interdisciplinary collaboration. The goals of the ICEWATER Information System network are: establishment of a common information system for data sharing, analysis and archiving, building upon and extending the CUAHSI Hydrologic Information System; establishment of a common modeling framework to facilitate sharing and model interoperability; and establishment of common base characterization datasets such as digital elevation models (DEMs) from LIDAR, land cover and land use from remote sensing, that provide detail beyond nationally available information. The ICEWATER Information System will comprise centralized

  18. Oxygenated drinking water enhances immune activity in broiler chicks and increases survivability against Salmonella Gallinarum in experimentally infected broiler chicks.

    PubMed

    Jung, Bock-Gie; Lee, Jin-A; Nam, Kyoung-Woo; Lee, Bong-Joo

    2012-03-01

    It has been suggested that drinking oxygenated water may improve oxygen availability, which may increase vitality and improving immune activity. The present study evaluated the immune enhancing effects of oxygenated drinking water in broiler chicks and demonstrated the protective efficacy of oxygenated drinking water against Salmonella Gallinarum in experimentally infected broiler chicks. Continuous drinking of oxygenated water markedly increased serum lysozyme activity, peripheral blood mononuclear cell proliferation and the CD4(+)/CD8(+) splenocyte ratio in broiler chicks. In the chicks experimentally infected with S. Gallinarum, oxygenated drinking water alleviated symptoms and increased survival. These findings suggest that oxygenated drinking water enhances immune activity in broiler chicks, and increases survivability against S. Gallinarum in experimentally infected broiler chicks.

  19. Testing the effect of increased temperature and river water input on benthic and pelagic metabolism using a large scale experimental pond ecosystem

    NASA Astrophysics Data System (ADS)

    Rodriguez, Patricia; Geibrink, Erik; Vasconcelos, Francisco; Hedström, Per; Byström, Pär; Karlsson, Jan

    2013-04-01

    We performed a large scale experimental study to test the effect of increased temperatures and concentration of allochthonous dissolved organic carbon (DOC) on benthic and pelagic primary production and respiration. The experiment was carried out during one ice-free season (May-October 2012) in a clear-water pond ecosystem divided into 16 enclosures (each 120 m3 and 1.6 m deep) including natural benthic and pelagic habitats and fish as top consumers (40 adult three-spine sticklebacks were introduced at the beginning of the experiment). Treatments included input of brown river water (23 mg/L in DOC) and heating (3° C above ambient temperature) in a factorial design: 4 enclosures were kept as controls (clear-cold), 4 enclosures were heated (clear-hot), 4 received river water (dark-cold) and 4 were both heated and received river water (dark-hot). Physical and chemical variables were monitored weekly meanwhile benthic, pelagic and ecosystems metabolism were estimated from free-water oxygen data and incubation studies. The 3° C difference in temperature between hot and cold enclosures was consistent during the study and DOC concentrations averaged 4 and 8 mg/L in clear water and dark enclosures, respectively; without any interaction effect between temperature and DOC concentration. Vertical light attenuation coefficient (Kd) showed significant differences between treatments with (0.62±0.40 m-1) and without river water (0.24±0.13 m-1). Total nitrogen concentrations ranged between 187 and 300 μg/L, with higher values in the dark-cold enclosures. The same pattern of higher values in dark-cold enclosures was found in phytoplankton chlorophyll a and primary production. Preliminary results show that gross benthic primary production (higher in clear-cold enclosures) largely exceeded phytoplankton production at the beginning of the experiment. Due to high respiration compared to gross primary production the net ecosystem production was in general negative in the pelagic

  20. Experimental study of the atomizing performance of a new type of nozzle for coal water slurry

    SciTech Connect

    Yu Hai-long; Zhang Chao; Liu Jian-zhong; Cen Ke-fa

    2008-03-15

    In this paper, a new type of coal water slurry nozzle for gasification has been developed by us, and its atomizing performance has been studied experimentally. The influences of the nozzle work load and gas flow on the atomizing particle distribution, Sauter mean diameter (SMD), and nozzle atomizing angle are discussed. The results show that there is a double-peak distribution of the atomizing particle in the flow field of atomization. In addition, the SMD will decrease, and the uniformity of the atomizing particle becomes better as the nozzle work load decreases and the gas flow increases. Also, the atomizing quality is clearly improved. 12 refs., 7 figs., 2 tabs.

  1. Numerical and experimental study of an invisibility carpet in a water channel

    NASA Astrophysics Data System (ADS)

    Dupont, Guillaume; Kimmoun, Olivier; Molin, Bernard; Guenneau, Sebastien; Enoch, Stefan

    2015-02-01

    We propose a numerical and an experimental study of an invisibility carpet for linear water waves. In the first part, we introduce the concept of an invisibility carpet in the case of linear water waves and apply this concept for a bounded problem: a wavetank. In the second part, we study a simpler case where we attempt to render invisible a vertical dihedral at the end of a wavetank. This is done by placing a structure consisting of 18 vertical poles with trapezoidal cross-sections in front of the dihedral. For these two configurations, with and without the carpet, we focus on the far-field reflected wave consisting of an inline mode and the first sloshing (plus progressive) mode. We show that our design achieves invisibility.

  2. Summary of experimental data for critical arrays of water moderated Fast Test Reactor fuel

    SciTech Connect

    Durst, B.M.; Bierman, S.R.; Clayton, E.D.; Mincey, J.F.; Primm, R.T. III

    1981-05-01

    A research program, funded by the Consolidated Fuel Reprocessing Program (CFRP) of Oak Ridge National Laboratory (ORNL), was initiated at Battelle Pacific Northwest Laboratory (PNL) to acquire experimental data on heterogeneous water moderated arrays of Fast Test Reactor (FTR) fuel pins. The objective of this program is to provide critical experiment data for validating calculational techniques used in criticality assessments of reprocessing equipment containing FTR-type fuels. Consequently, the experiments were designed to permit accurate definition in Monte Carlo computer codes currently used in these assessments. Square and triangular pitched lattices of fuel have been constructed under a variety of conditions covering the range from undermoderated to overmoderated arrays. Experiments were conducted composed of arrays which were water reflected, partially concrete reflected, and arrays with interspersed solid neutron absorbers. The absorbers utilized were Boral, and cadmium plates and gadolinium cylindrical rods. Data from non-CFRP sponsored subcritical experiments (previously performed at Hanford) also are included.

  3. Experimental study of evaporation of sessile water droplet on PDMS surfaces

    NASA Astrophysics Data System (ADS)

    Yu, Ying-Song; Wang, Zi-Qian; Zhao, Ya-Pu

    2013-12-01

    Evaporation of sessile water droplet on polydimethylsiloxane (PDMS) surfaces with three different curing ratios (5: 1, 10: 1, and 20: 1) was experimentally investigated in this paper. We show that the constant contact radius (CCR) evaporation on surface with high curing ratio lasts longer than that with low curing ratio. We also measured Young's moduli of PDMS films by using atomic force microscopy (AFM) and simulated surface deformation of PDMS films induced by sessile water droplet. With increasing curing ratio of PDMS film, Young's modulus of PDMS film is getting lower, and then there will be larger surface deformation and more elastic stored energy. Since such energy acts as a barrier to keep the three-phase contact line pinned, thus it will result in longer CCR evaporation on PDMS surface with higher curing ratio.

  4. Experimental and theoretical investigations of evaporation of sessile water droplet on hydrophobic surfaces.

    PubMed

    Yu, Ying-Song; Wang, Ziqian; Zhao, Ya-Pu

    2012-01-01

    Experiments of sessile water droplet evaporation on both polydimethylsiloxane (PDMS) and Teflon surfaces were conducted. All experiments begin with constant contact area mode (the initial contact angle is greater than 90°), switch to constant contact angle mode and end with mixed mode. Based on the assumptions of spherical droplet and uniform concentration gradient, theoretical analyses for both constant contact area and constant contact angle modes are made and theoretical solutions are derived accordingly, especially a theoretical solution of contact angle is presented first for CCR stage with any value of the initial contact angle. Moreover, comparisons between the theoretical solutions and experimental data of contact angle in CCR stage demonstrate the validity of the theoretical solution and it would help for a better understanding and application of water droplet on solid surfaces, which is quite often encountered in lab-on-a-chip, polymerase chain reaction (PCR) and other micro-fluidics devices.

  5. Effect of experimental fasciolosis on antipyrine metabolism and clearance in water buffaloes.

    PubMed

    Jiang, S X; Bayón, J E; Ferre, I; Mao, X Z; González-Gallego, J

    2000-03-01

    The effect of chronic Fasciola hepatica infection on the metabolism of antipyrine, a marker of microsomal oxidative metabolism, was investigated in male water buffaloes dosed daily with 60 F. hepatica metacercariae over 20 days. The plasma elimination half-life of antipyrine was significantly elevated by 23% at 11 weeks postinfection (p.i.) but did not significantly differ from the control period at 20 weeks p.i. The systemic clearance of antipyrine decreased by 48% at 11 weeks p.i. and then returned to normal. The renal clearance for each of the main antipyrine metabolites decreased at 11 weeks p.i. (hydroxymethylantipyrine (HMA), -42%; norantipyrine (NORA), -58%; and 4-hydroxyantipyrine (OHA), -70%) and did not significantly differ from the control period at 20 weeks p.i. These findings indicate that experimental subclinical fasciolosis leads to altered antipyrine kinetics and to an inhibition of the different antipyrine metabolic pathways in water buffaloes.

  6. Experimental investigation of inclined liquid water jet flow onto vertically located superhydrophobic surfaces

    NASA Astrophysics Data System (ADS)

    Kibar, Ali; Karabay, Hasan; Yiğit, K. Süleyman; Ucar, Ikrime O.; Erbil, H. Yıldırım

    2010-11-01

    In this study, the behaviour of an inclined water jet, which is impinged onto hydrophobic and superhydrophobic surfaces, has been investigated experimentally. Water jet was impinged with different inclination angles (15°-45°) onto five different hydrophobic surfaces made of rough polymer, which were held vertically. The water contact angles on these surfaces were measured as 102°, 112°, 123°, 145° and 167° showing that the last surface was superhydrophobic. Two different nozzles with 1.75 and 4 mm in diameters were used to create the water jet. Water jet velocity was within the range of 0.5-5 m/s, thus the Weber number varied from 5 to 650 and Reynolds number from 500 to 8,000 during the experiments. Hydrophobic surfaces reflected the liquid jet depending on the surface contact angle, jet inclination angle and the Weber number. The variation of the reflection angle with the Weber number showed a maximum value for a constant jet angle. The maximum value of the reflection angle was nearly equal to half of the jet angle. It was determined that the viscous drag decreases as the contact angle of the hydrophobic surface increases. The drag force on the wall is reduced dramatically with superhydrophobic surfaces. The amount of reduction of the average shear stress on the wall was about 40%, when the contact angle of the surface was increased from 145° to 167°. The area of the spreading water layer decreased as the contact angle of the surface increased and as the jet inclination angle, Weber number and Reynolds number decreased.

  7. Experimental Study and CFD modeling of high speed water jets in air

    NASA Astrophysics Data System (ADS)

    Guha, Anirban; Barron, R. M.; Balachandar, R.

    2007-11-01

    High speed turbulent water jets are extensively used in industrial cleaning applications. They interact vigorously with the surrounding air and loose mass in the form of water droplets which moves along with the entrained air stream. The transfer of momentum to the surroundings reduces the jet velocity and thus the pressure at the impinging surface is significantly lower than the supply pressure. Laser Doppler Anemometer (LDA) measurements of velocity field and pressure measurements at different axial and radial locations were performed. The potential core of the jet was found to extend to around 100 nozzle diameters. The dynamic pressure along the centerline was found to decay linearly, which can be used to estimate the decay of water volume fraction along the centerline. An empirical formulation of mass transfer (in the form of droplets) from water phase to the surroundings has been developed and incorporated into the commercial CFD code FLUENT. The flow was simulated using the RNG k-ɛ turbulence model and Eulerian-Eulerian multiphase model. The predicted pressure distribution at the impinging surface was found to match closely with the experimental findings.

  8. Uranium speciation in moorland river water samples: a comparison of experimental results and computer model predictions.

    PubMed

    Unsworth, Emily R; Jones, Phil; Cook, Jennifer M; Hill, Steve J

    2005-06-01

    An on-line method has been developed for separating inorganic and organic bound uranium species present in river water samples. The method utilised a small chelating resin (Hyphan) column incorporated into the sample introduction manifold of an ICP-MS instrument. The method was evaluated for samples from rivers on Dartmoor (Devon, UK), an area of granite overlain with peat bogs. The results indicate that organic-uranium species form a major proportion (80%) of the total dissolved uranium present. Further work with synthetic water samples indicated that the level of dissolved organic carbon played a greater role in determining the level of organic-uranium species than did sample pH. Computer models for the water samples were constructed using the WHAM program (incorporating uranium data from the Nuclear Energy Agency Thermochemical Database project) in order to predict the levels of organic-uranium species that would form. By varying the proportion of humic and fulvic acids used in the humic component, predictions within 10% of the experimental results were obtained. The program did exhibit a low bias at higher pH values (7.5) and low organic carbon concentrations (0.5 microg ml(-1)), but under the natural conditions prevalent in the Dartmoor water samples, the model predictions were successful.

  9. Experimental and numerical study of water-filled vessel impacted by flat projectiles

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Ren, Peng; Huang, Wei; Gao, Yu Bo

    2014-05-01

    To understand the failure modes and impact resistance of double-layer plates separated by water, a flat-nosed projectile was accelerated by a two-stage light gas gun against a water-filled vessel which was placed in an air-filled tank. Targets consisted of a tank made of two flat 5A06 aluminum alloy plates held by a high strength steel frame. The penetration process was recorded by a digital high-speed camera. The same projectile-target system was also used to fire the targets placed directly in air for comparison. Parallel numerical tests were also carried out. The result indicated that experimental and numerical results were in good agreement. Numerical simulations were able to capture the main physical behavior. It was also found that the impact resistance of double layer plates separated by water was lager than that of the target plates in air. Tearing was the main failure models of the water-filled vessel targets which was different from that of the target plates in air where the shear plugging was in dominate.

  10. Experimental and Numerical Study of Water-Filled Vessel Impacted by Flat Projectiles

    NASA Astrophysics Data System (ADS)

    Ren, Peng; Zhang, Wei; Guo, Zitao; Wei, Gang

    2011-06-01

    To understand the failure patterns and impact resistance of watertight vessel, a flat-nosed projectile was accelerated by a two-stage light gas gun against a vessel filled with water which was placed in an air-filled tank. The targets were the 5A06 aluminum which were installed on two opposite sides of the vessel. The penetration process was recorded by a digital high-speed camera. In order to compare, numerical simulations for the vessel with and without water impacted by projectiles were conducted by AUTODYN-3D. The material parameters of targets and projectiles used in the simulation were obtained from several previous studies. The result indicated that experimental and numerical results were in good agreement. Numerical simulations were capable to capture the main physical behavior. It was also found that the impact resistance of targets in the water-filled vessel was lager than that of the empty vessel. Tearing was the main failure models of the water-filled vessel targets which was different from that of the empty vessel where the shear plugging was in dominate.

  11. Experimental and Numerical Study of Water-Filled Vessel Impacted by Flat Projectiles

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Ren, Peng; Huang, Wei; Gao, Yubo

    2013-06-01

    To understand the failure patterns and impact resistance of watertight vessel, a flat-nosed projectile was accelerated by a two-stage light gas gun against a vessel filled with water which was placed in an air-filled tank. The targets were the 5A06 aluminum which were installed on two opposite sides of the vessel. The penetration process was recorded by a digital high-speed camera. In order to compare, numerical simulations for the vessel with and without water impacted by projectiles were conducted by AUTODYN-3D. The material parameters of targets and projectiles used in the simulation were obtained from several previous studies. The result indicated that experimental and numerical results were in good agreement. Numerical simulations were capable to capture the main physical behavior. It was also found that the impact resistance of targets in the water-filled vessel was lager than that of the empty vessel. Tearing was the main failure models of the water-filled vessel targets which was different from that of the empty vessel where the shear plugging was in dominate. National Natural Science Foundation of China (NO.:11072072).

  12. Theoretical and experimental investigation of the interactions between [emim]Ac and water molecules

    NASA Astrophysics Data System (ADS)

    Ding, Zhen-Dong; Chi, Zhen; Gu, Wen-Xiu; Gu, Sheng-Ming; Wang, Hai-Jun

    2012-05-01

    Density functional theory (DFT) calculations, atom in molecules (AIM) theory, natural bond orbital (NBO) analysis and infrared (IR) spectroscopy were performed to investigate the interactions between water molecules and ionic liquid 1-ethyl-3-methylimidazolium acetate ([emim]Ac). It was found that [emim]Ac interacts with water molecules mainly via H-bonds, and the anionic part of [emim]Ac plays a major role in the interaction with H2O. The energies of H-bonds were estimated from spectral shifts of hydroxy antisymmetric stretching vibration. Moreover, the experimental results also indicated that hydroxy of water mainly interacts with the COO- of [emim]Ac. Further studies indicated that the intensity of hydroxy stretching vibrations tend to be stronger with the increase of the concentration of water. In addition, the frequency of hydroxy stretching vibrations showed clearly red-shift, and the COO- vibrational frequency gradually shifted to the lower wavenumber region, which were indicative of extended hydrogen bonded network.

  13. Responses of amphibian populations to water and soil factors in experimentally-treated aquatic macrocosms

    USGS Publications Warehouse

    Sparling, D.W.; Lowe, T.P.; Day, D.; Dolan, K.

    1995-01-01

    Survival of anuran embryos and tadpoles is reduced in acidic (pH < 5.0) waters under laboratory conditions. However, field data on the presence-absence of amphibian species and acidity are equivocal. This study attempts to reconcile some of this discrepancy by using macrocosms to examine the interaction of soil type and water acidification on free-ranging tadpole populations. Tadpoles were caught with activity traps in 24 aquatic macrocosms experimentally treated with H2SO4 and Al2(SO4)3 and lined with either comparatively high metal, Iow organic matter clay soils or lower metal, higher organic matter loams. Northern cricket frog (Acris crepitans) tadpole abundance was less in acidified macrocosms than in circumneutral ones (p < 0.05) and less in those with loam soils than in macrocosms with clay soils (p < 0.04). Gray treefrog (Hyla versicolor) abundance was affected by an interaction between soil and acidification (p < 0.07) in that treatment effects were only observed in macrocosms with clay soils (p < 0.01). No differences were observed among treatments for green frog (Rana clamitans) or southern leopard frog (R. utricularia) tadpoles. The study shows that soil type may interact with water conditions to affect amphibian populations in acidified waters

  14. Experimental evaluation of sorptive removal of fluoride from drinking water using iron ore

    NASA Astrophysics Data System (ADS)

    Kebede, Beekam; Beyene, Abebe; Fufa, Fekadu; Megersa, Moa; Behm, Michael

    2016-03-01

    High concentrations of fluoride in drinking water is a public health concern globally and of critical importance in the Rift Valley region. As a low-cost water treatment option, the defluoridation capacity of locally available iron ore was investigated. Residence time, pH, agitation rate, particle size of the adsorbent, sorbent dose, initial fluoride concentration and the effect of co-existing anions were assessed. The sorption kinetics was found to follow pseudo-first-order rate and the experimental equilibrium sorption data fitted reasonably well to the Freundlich model. The sorption capacity of iron ore for fluoride was 1.72 mg/g and the equilibrium was attained after 120 min at the optimum pH of 6. The sorption study was also carried out at natural pH conditions using natural ground water samples and the fluoride level was reduced from 14.22 to 1.17 mg/L (below the WHO maximum permissible limit). Overall, we concluded that iron ore can be used in water treatment for fluoride removal in the Rift Valley region and beyond.

  15. Experimental studies of thermal and chemical interactions between molten aluminum and water

    SciTech Connect

    Farahani, A.A.; Corradini, M.L.

    1995-09-01

    The possibility of rapid physical and chemical aluminum/water interactions during a core melt accident in a noncommercial reactor (e.g., HFIR, ATR) has resulted in extensive research to determine the mechanism by which these interactions occur and propagate on an explosive time scale. These events have been reported in nuclear testing facilities, i.e., during SPERT 1D experiment, and also in aluminum casting industries. Although rapid chemical reactions between molten aluminum and water have been subject of many studies, very few reliable measurements of the extent of the chemical reactions have thus far been made. We have modified an existing 1-D shock tube facility to perform experiments in order to determine the extent of the explosive thermal/chemical interactions between molton aluminum and water by measuring important physical quantities such as the maximum dynamic pressure and the amount of the generated hydrogen. Experimental results show that transient pressures greater than 69 MPa with a rise time of less than 125 {mu}sec can occur as the result of the chemical reaction of 4.2 grams of molton aluminum (approximately 15% of the total mass of the fuel of 28 grams) at 980 C with room temperature water.

  16. Experimental evidence for the formation of liquid saline water on Mars

    PubMed Central

    Fischer, Erik; Martínez, Germán M; Elliott, Harvey M; Rennó, Nilton O

    2014-01-01

    Evidence for deliquescence of perchlorate salts has been discovered in the Martian polar region while possible brine flows have been observed in the equatorial region. This appears to contradict the idea that bulk deliquescence is too slow to occur during the short periods of the Martian diurnal cycle during which conditions are favorable for it. We conduct laboratory experiments to study the formation of liquid brines at Mars environmental conditions. We find that when water vapor is the only source of water, bulk deliquescence of perchlorates is not rapid enough to occur during the short periods of the day during which the temperature is above the salts' eutectic value, and the humidity is above the salts' deliquescence value. However, when the salts are in contact with water ice, liquid brine forms in minutes, indicating that aqueous solutions could form temporarily where salts and ice coexist on the Martian surface and in the shallow subsurface. Key Points The formation of brines at Martian conditions was studied experimentally Bulk deliquescence from water vapor is too slow to occur diurnally on Mars Brines form in minutes when salts are placed in direct contact with ice PMID:25821267

  17. [Experimental study on crop photosynthesis, transpiration and high efficient water use].

    PubMed

    Wang, Huixiao; Liu, Changming

    2003-10-01

    It is well known that the development of water-saving agriculture is a strategic choice for getting rid of the crisis of water shortage. In this paper, the crop photosynthesis, transpiration, stomatic behavior, and their affecting factors were studied in view of increasing the crop water use efficiency. The experimental results showed that there was a parabola relationship between photosynthesis and transpiration. The transpiration at the maximum photosynthesis was a critical value, above which, transpiration was the luxurious part. The luxurious transpiration could be controlled without affecting photosynthetic production. It is possible that the measures for increasing stomatic resistance and preventing transpiration could save water, and improve photosynthesis and yield as well. The photosynthesis rate increased with photosynthetic active radiation, and the light saturation point for photosynthesis existed. The light saturation point of dry treatment was much lower than that of wet treatment, and the relationship between transpiration and radiation was linear. When the photosynthetic active radiation was bigger than 1,000 mumol.m-2.s-1, some treatments could be carried out for decreasing transpiration and improving photosynthesis.

  18. Integrated economic and experimental framework for screening of primary recovery technologies for high cell density CHO cultures.

    PubMed

    Popova, Daria; Stonier, Adam; Pain, David; Titchener-Hooker, Nigel J; Farid, Suzanne S

    2016-07-01

    Increases in mammalian cell culture titres and densities have placed significant demands on primary recovery operation performance. This article presents a methodology which aims to screen rapidly and evaluate primary recovery technologies for their scope for technically feasible and cost-effective operation in the context of high cell density mammalian cell cultures. It was applied to assess the performance of current (centrifugation and depth filtration options) and alternative (tangential flow filtration (TFF)) primary recovery strategies. Cell culture test materials (CCTM) were generated to simulate the most demanding cell culture conditions selected as a screening challenge for the technologies. The performance of these technology options was assessed using lab scale and ultra scale-down (USD) mimics requiring 25-110mL volumes for centrifugation and depth filtration and TFF screening experiments respectively. A centrifugation and depth filtration combination as well as both of the alternative technologies met the performance selection criteria. A detailed process economics evaluation was carried out at three scales of manufacturing (2,000L, 10,000L, 20,000L), where alternative primary recovery options were shown to potentially provide a more cost-effective primary recovery process in the future. This assessment process and the study results can aid technology selection to identify the most effective option for a specific scenario.

  19. Integrated economic and experimental framework for screening of primary recovery technologies for high cell density CHO cultures

    PubMed Central

    Popova, Daria; Stonier, Adam; Pain, David; Titchener‐Hooker, Nigel J.

    2016-01-01

    Abstract Increases in mammalian cell culture titres and densities have placed significant demands on primary recovery operation performance. This article presents a methodology which aims to screen rapidly and evaluate primary recovery technologies for their scope for technically feasible and cost‐effective operation in the context of high cell density mammalian cell cultures. It was applied to assess the performance of current (centrifugation and depth filtration options) and alternative (tangential flow filtration (TFF)) primary recovery strategies. Cell culture test materials (CCTM) were generated to simulate the most demanding cell culture conditions selected as a screening challenge for the technologies. The performance of these technology options was assessed using lab scale and ultra scale‐down (USD) mimics requiring 25–110mL volumes for centrifugation and depth filtration and TFF screening experiments respectively. A centrifugation and depth filtration combination as well as both of the alternative technologies met the performance selection criteria. A detailed process economics evaluation was carried out at three scales of manufacturing (2,000L, 10,000L, 20,000L), where alternative primary recovery options were shown to potentially provide a more cost‐effective primary recovery process in the future. This assessment process and the study results can aid technology selection to identify the most effective option for a specific scenario. PMID:27067803

  20. Integrated economic and experimental framework for screening of primary recovery technologies for high cell density CHO cultures.

    PubMed

    Popova, Daria; Stonier, Adam; Pain, David; Titchener-Hooker, Nigel J; Farid, Suzanne S

    2016-07-01

    Increases in mammalian cell culture titres and densities have placed significant demands on primary recovery operation performance. This article presents a methodology which aims to screen rapidly and evaluate primary recovery technologies for their scope for technically feasible and cost-effective operation in the context of high cell density mammalian cell cultures. It was applied to assess the performance of current (centrifugation and depth filtration options) and alternative (tangential flow filtration (TFF)) primary recovery strategies. Cell culture test materials (CCTM) were generated to simulate the most demanding cell culture conditions selected as a screening challenge for the technologies. The performance of these technology options was assessed using lab scale and ultra scale-down (USD) mimics requiring 25-110mL volumes for centrifugation and depth filtration and TFF screening experiments respectively. A centrifugation and depth filtration combination as well as both of the alternative technologies met the performance selection criteria. A detailed process economics evaluation was carried out at three scales of manufacturing (2,000L, 10,000L, 20,000L), where alternative primary recovery options were shown to potentially provide a more cost-effective primary recovery process in the future. This assessment process and the study results can aid technology selection to identify the most effective option for a specific scenario. PMID:27067803

  1. Experimental comparison of a nearly azeotropic refrigerant blend and R-22 in a water-to-water laboratory test rig

    SciTech Connect

    Baxter, V.D.; Chen, D.T.; Linkous, R.L.; Nimitz, J.

    1998-11-01

    A newly developed, non-ozone-depleting refrigerant blend containing a fluoroiodocarbon compound was compared with R-22 in a laboratory-scale, water-to-water refrigeration cycle test loop. The loop is equipped with a coaxial tube-in-tube condenser, a baffled shell-in-tube evaporator, and a variable-speed compressor. The blend and R-22 were tested at saturated evaporator temperature conditions of about {minus}10 F to {minus}20 F and saturated condenser temperature conditions from about 80--100 F. The compressor speed was varied such that evaporator (cooling) capacity was held constant at approximately the same value for both refrigerants for each test condition. To maintain equal capacity, results showed the compressor speed for the blend to be at least 53% greater than that for R-22. Measured system efficiency with the blend was at least 25% better than for R-22 for near equal operating temperature and capacity conditions. When allowing for maximum impact of the experimental uncertainties, the minimum COP improvement observed for the blend was about 10%. Ideal cycle calculations using the best available property estimates for the blend and the compressor efficiencies observed during the tests also suggested a 10% improvement for the blend over R-22 (almost all due to better isentropic efficiency of the compressor with the blend). Better thermodynamic property data are needed for the blend and further investigations are needed to fully assess its potential for refrigeration equipment applications.

  2. Water permeability of primary mouse keratinocyte cultures grown at the air-liquid interface

    SciTech Connect

    Cumpstone, M.B.; Kennedy, A.H.; Harmon, C.S.; Potts, R.O.

    1989-04-01

    In order to study the development of the epidermal permeability barrier in vitro, tritiated water (HTO) flux was measured across murine keratinocytes cultured at the air-liquid interface. Using a micro-diffusion technique, it was shown that air-liquid cultures form areas where the water diffusion is comparable to that of intact neonatal mouse skin. When water permeability is measured over a large area of the culture surface, however, significantly higher flux is obtained. These results show that under the culture conditions used, areas of water barrier comparable to intact neonatal mouse skin coexist with regions of less complete barrier formation.

  3. Biodiversity and ecosystem processes in shallow coastal waters: an experimental approach

    NASA Astrophysics Data System (ADS)

    Raffaelli, D.; Emmerson, M.; Solan, M.; Biles, C.; Paterson, D.

    2003-03-01

    The relationship between biodiversity and ecological processes is currently the focus of considerable research effort, made all the more urgent by the rate of biodiversity loss world-wide. Rigorous experimental approaches to this question have been dominated by terrestrial ecologists, but shallow-water marine systems offer great opportunities by virtue of their relative ease of manipulation, fast response times and well-understood effects of macrofauna on sediment processes. In this paper, we describe a series of experiments whereby species richness has been manipulated in a controlled way and the concentrations of nutrients (ammonium, nitrate and phosphate) in the overlying water measured under these different treatments. The results indicate variable effects of species and location on ecosystem processes, and are discussed in the context of emerging mainstream ecological theory on biodiversity and ecosystem relations. Extensions of the application of the experimental approach to species-rich, large-scale benthic systems are discussed and the potential for novel analyses of existing data sets is highlighted.

  4. Modelling and experimental investigation on the application of water super adsorbents in waste air biofilters.

    PubMed

    Danaee, Soroosh; Fazaelipoor, Mohammad Hassan; Gholami, Abdollah; Ataei, Seyed Ahmad; Afzali, Daryoush

    2015-01-01

    In this research work, a synthetic water super absorbent polymer was included in the bed of a perlite-based biofilter for the removal of ethanol from air. The performance of this biofilter was compared with the performance of a control perlite-based biofilter lacking the water super absorbent. With the empty bed residence time of 2 min, both biofilters were able to remove more than 90% of the entering pollutant with the concentration of 1 g /m3, when regular moistening was applied. After last irrigation on day 23, the performance of the control biofilter was unchanged until day 35. From day 36 onwards, the control biofilter lost its activity gradually and became totally inactive on day 45. The performance of the super absorbent containing biofilter, however, was unchanged until day 58 before starting to lose its activity. A mechanistic model was developed to describe the performance of a biofilter under drying effects. The model could predict the trends of experimental results reasonably well. The model was also applied to predict the trends of experimental data from a published paper on the removal of hexane in a perlite/super absorbent containing biofilter.

  5. Experimental Study on Hydrothermal Plume Dynamics in a Stratified Salt Water Tank

    NASA Astrophysics Data System (ADS)

    Zhang, W.; He, Z.; Jiang, H.

    2014-12-01

    Hydrothermal plumes are generated by high temperature hydrothermal venting systems occurred at many places along the mid-ocean ridges. The understanding of interaction between plumes and surrounding seawater are important since plumes transport significant heat and chemicals from the lithosphere to the ocean. This paper presents an experimental study on plume generation, mixing, entrainment and rising in a stratified salt water tank. The two-tank method is first improved to produce a stable linear stratification in the tank. A series of plume experiments using different orifice diameters and fluxes are then carried out to evaluate the characteristics of plumes. The stratification of salt water is measured and buoyancy frequency is calculated to provide the background information. The plume shape, flow field, rise height, and buoyancy flux are analyzed using image processing methods. The results show that the established experimental system is capable of providing stable linear stratifications for laboratory studies of hydrothermal plumes. The measured plume shapes and rise heights are in good agreement with available empirical formulae in the literature.

  6. Jarosite-water oxygen and hydrogen isotope fractionations: preliminary experimental data

    USGS Publications Warehouse

    Rye, R.O.; Stoffregen, R.E.

    1995-01-01

    Stable isotope studies of alunite have added a powerful tool for understanding geochemical processes in the surficial environment. Jarosite [KFe3(SO4)2(OH)6], like alunite, is a common mineral in the weathered portions of many sulfide-bearing ore deposits and mine drainages where its formation reflects acidic conditions produced by the oxidation of sulfides. This paper describes oxygen and hydrogen isotope fractionations in jarosite-water experiments over a temperature range of 100?? to 250??C and the extrapolation of the results to surface conditions. It also includes some general observations on the exchange reaction mechanism that are important for evaluating how well natural samples of jarosite retain primary isotopic compositions. -from Authors

  7. A modern vs. Permian black shale - the hydrography, primary productivity, and water-column chemistry of deposition

    USGS Publications Warehouse

    Piper, D.Z.; Perkins, R.B.

    2004-01-01

    The sediment currently accumulating in the Cariaco Basin, on the continental shelf of Venezuela, has an elevated organic-carbon content of approximately 5%; is accumulating under O2-depleted bottom-water conditions (SO42- reduction); is composed dominantly of foraminiferal calcite, diatomaceous silica, clay, and silt; and is dark greenish gray in color. Upon lithification, it will become a black shale. Recent studies have established the hydrography of the basin and the level of primary productivity and bottom-water redox conditions. These properties are used to model accumulation rates of Cd, Cr, Cu, Mo, Ni, V, and Zn on the seafloor. The model rates agree closely with measured rates for the uppermost surface sediment.The model is applied to the Meade Peak Phosphatic Shale Member of the Phosphoria Formation, a phosphate deposit of Permian age in the northwest United States. It too has all of the requisite properties of a black shale. Although the deposit is a world-class phosphorite, it is composed mostly of phosphatic mudstone and siltstone, chert, limestone, and dolomite. It has organic-carbon concentrations of up to 15%, is strongly enriched in several trace elements above a terrigenous contribution and is black. The trace-element accumulation defines a mean primary productivity in the photic zone of the Phosphoria Basin as moderate, at 500 g m-2 year-1 organic carbon, comparable to primary productivity in the Cariaco Basin. The source of nutrient-enriched water that was imported into the Phosphoria Basin, upwelled into the photic zone, and supported primary productivity was an O2 minimum zone of the open ocean. The depth range over which the water was imported would have been between approximately 100 and 600 m. The mean residence time of bottom water in the basin was approximately 4 years vs. 100 years in the Cariaco Basin. The bottom water was O2 depleted, but it was denitrifying, or NO3- reducing, rather than SO42- reducing. Published by Elsevier B.V.

  8. Functioning of a Shallow-Water Sediment System during Experimental Warming and Nutrient Enrichment

    PubMed Central

    Alsterberg, Christian; Sundbäck, Kristina; Hulth, Stefan

    2012-01-01

    Effects of warming and nutrient enrichment on intact unvegetated shallow-water sediment were investigated for 5 weeks in the autumn under simulated natural field conditions, with a main focus on trophic state and benthic nitrogen cycling. In a flow-through system, sediment was exposed to either seawater at ambient temperature or seawater heated 4°C above ambient, with either natural or nutrient enriched water. Sediment–water fluxes of oxygen and inorganic nutrients, nitrogen mineralization, and denitrification were measured. Warming resulted in an earlier shift to net heterotrophy due to increased community respiration; primary production was not affected by temperature but (slightly) by nutrient enrichment. The heterotrophic state was, however, not further strengthened by warming, but was rather weakened, probably because increased mineralization induced a shortage of labile organic matter. Climate-related warming of seawater during autumn could therefore, in contrast to previous predictions, induce shorter but more intensive heterotrophic periods in shallow-water sediments, followed by longer autotrophic periods. Increased nitrogen mineralization and subsequent effluxes of ammonium during warming suggested a preferential response of organisms driving nitrogen mineralization when compared to sinks of ammonium such as nitrification and algal assimilation. Warming and nutrient enrichment resulted in non-additive effects on nitrogen mineralization and denitrification (synergism), as well as on benthic fluxes of phosphate (antagonism). The mode of interaction appears to be related to the trophic level of the organisms that are the main drivers of the affected processes. Despite the weak response of benthic microalgae to both warming and nutrient enrichment, the assimilation of nitrogen by microalgae was similar in magnitude to rates of nitrogen mineralization. This implies a sustained filter function and retention capacity of nutrients by the sediment. PMID

  9. Functioning of a shallow-water sediment system during experimental warming and nutrient enrichment.

    PubMed

    Alsterberg, Christian; Sundbäck, Kristina; Hulth, Stefan

    2012-01-01

    Effects of warming and nutrient enrichment on intact unvegetated shallow-water sediment were investigated for 5 weeks in the autumn under simulated natural field conditions, with a main focus on trophic state and benthic nitrogen cycling. In a flow-through system, sediment was exposed to either seawater at ambient temperature or seawater heated 4°C above ambient, with either natural or nutrient enriched water. Sediment-water fluxes of oxygen and inorganic nutrients, nitrogen mineralization, and denitrification were measured. Warming resulted in an earlier shift to net heterotrophy due to increased community respiration; primary production was not affected by temperature but (slightly) by nutrient enrichment. The heterotrophic state was, however, not further strengthened by warming, but was rather weakened, probably because increased mineralization induced a shortage of labile organic matter. Climate-related warming of seawater during autumn could therefore, in contrast to previous predictions, induce shorter but more intensive heterotrophic periods in shallow-water sediments, followed by longer autotrophic periods. Increased nitrogen mineralization and subsequent effluxes of ammonium during warming suggested a preferential response of organisms driving nitrogen mineralization when compared to sinks of ammonium such as nitrification and algal assimilation. Warming and nutrient enrichment resulted in non-additive effects on nitrogen mineralization and denitrification (synergism), as well as on benthic fluxes of phosphate (antagonism). The mode of interaction appears to be related to the trophic level of the organisms that are the main drivers of the affected processes. Despite the weak response of benthic microalgae to both warming and nutrient enrichment, the assimilation of nitrogen by microalgae was similar in magnitude to rates of nitrogen mineralization. This implies a sustained filter function and retention capacity of nutrients by the sediment.

  10. Iron-rich drinking water and ascorbic acid supplementation improved hemolytic anemia in experimental Wistar rats.

    PubMed

    Chaturvedi, Richa; Chattopadhyay, Pronobesh; Banerjee, Saumen; Bhattacharjee, Chira R; Raul, Prasanta; Borah, Kusum; Singh, Lokendra; Veer, Vijay

    2014-11-01

    Anemia is a frequent problem in both the primary and secondary health care programs. In contrast, most areas of northeast India are vulnerable to iron toxicity. In the present study, we documented the effect of administration of iron rich water on hemolytic anemia in a Wistar rats' animal model. Hemolytic anemia was induced by phenyl hydrazine through intraperitoneal route and diagnosed by the lowering of blood hemoglobin. After inducing the hemolytic anemia, 24 Wistar rats (n = 6 in four groups) were randomly assigned to 1 mg/l, 5 mg/l, and 10 mg/l ferric oxide iron along with 1 mg/ml ascorbic acid administered through drinking water; a control group was treated with iron-free water. The hematological and biochemical parameters, iron levels in liver, spleen, and kidney were estimated after 30 d of treatment. In the group treated with 5 mg/l iron and ascorbic acid, a significant increase of serum iron and ferritin, and a decrease of TIBC (total iron binding capacity) were observed without changes in other biochemical parameters and histopathological findings. However, in the group treated with 10 mg/l iron and ascorbic acid, hematological changes with significantly higher values for white blood cell count, serum glutamic phospho transaminase, serum glutamic oxaloacetic transaminase, alkaline phosphatase, glucose, splenic, and liver iron content, indicate potential toxicity at this supplementation level. Data suggest that the optimum concentration of iron (5 mg/l) and ascorbic acid solution may improve anemic conditions and may be therapeutically beneficial in the treatment of iron deficiency anemia without any negative impact, while 10 mg/l in drinking water seems to be the threshold for the initiation of toxicity.

  11. Functioning of a shallow-water sediment system during experimental warming and nutrient enrichment.

    PubMed

    Alsterberg, Christian; Sundbäck, Kristina; Hulth, Stefan

    2012-01-01

    Effects of warming and nutrient enrichment on intact unvegetated shallow-water sediment were investigated for 5 weeks in the autumn under simulated natural field conditions, with a main focus on trophic state and benthic nitrogen cycling. In a flow-through system, sediment was exposed to either seawater at ambient temperature or seawater heated 4°C above ambient, with either natural or nutrient enriched water. Sediment-water fluxes of oxygen and inorganic nutrients, nitrogen mineralization, and denitrification were measured. Warming resulted in an earlier shift to net heterotrophy due to increased community respiration; primary production was not affected by temperature but (slightly) by nutrient enrichment. The heterotrophic state was, however, not further strengthened by warming, but was rather weakened, probably because increased mineralization induced a shortage of labile organic matter. Climate-related warming of seawater during autumn could therefore, in contrast to previous predictions, induce shorter but more intensive heterotrophic periods in shallow-water sediments, followed by longer autotrophic periods. Increased nitrogen mineralization and subsequent effluxes of ammonium during warming suggested a preferential response of organisms driving nitrogen mineralization when compared to sinks of ammonium such as nitrification and algal assimilation. Warming and nutrient enrichment resulted in non-additive effects on nitrogen mineralization and denitrification (synergism), as well as on benthic fluxes of phosphate (antagonism). The mode of interaction appears to be related to the trophic level of the organisms that are the main drivers of the affected processes. Despite the weak response of benthic microalgae to both warming and nutrient enrichment, the assimilation of nitrogen by microalgae was similar in magnitude to rates of nitrogen mineralization. This implies a sustained filter function and retention capacity of nutrients by the sediment. PMID:23240032

  12. Water budget comparison of global climate models and experimental data in Onça Creek basin, Brazil

    NASA Astrophysics Data System (ADS)

    Melo, D. C. D.; Marin, I. S. P.; Wendland, E.

    2014-09-01

    Groundwater is an important part of the hydrological cycle, accounting for more than 25% of human needs on the global scale. As a result of aquifer overexploitation associated with climate change, even in the most conservative future climate scenarios, mean water-table levels can experience drastic drops. Although there are efforts to include groundwater dynamics in global climate models (GCMs), its influence is still not taken into full account in GCM water budgets, although it is as important as the other water sources considered. To assess the role of percolation in the water balance, we compared the water budget from climate forcing scenarios using 10 GCMs with the water budget from experimental data of a basin in São Paulo state, Brazil. We used the delta factor approach to correct the bias of the model's temperature and precipitation for a control period from 1970 to 1999, and calculated evapotranspiration using the Thornthwaite method. Experimental data for runoff and interception were derived for the basin's representative crops (sugar cane and pasture) for both water budgets. As the GCMs ignore subsurface flow and the only input considered is precipitation and snow melt, the excess surface water is assumed to be redistributed among the other water budget components. The experimental data shows that there is enough available water for infiltration, indicating that recharge cannot be ignored in the water balance. This leads to the possibility of the models' overestimating the other components to compensate for the ignored recharge.

  13. Do conservative and reactive tracers take the same water flow pathways? An experimental approach

    NASA Astrophysics Data System (ADS)

    Kasteel, Roy; Koestel, Johannes; Vereecken, Harry

    2010-05-01

    Reactive transport modelling heavily relies on the assumption that the soil's hydraulic behavior, i.e. the solute transport volume (water content) and the water flow pathways (dispersivity), can be characterized by the use of a conservative tracer. However, there exits ample experimental evidence in the literature whether this assumption holds, mainly because of the lack of detection methods that are able to monitor solute transport with a high resolution in space and time. Time-lapse electrical resistivity tomography (ERT) supplies three-dimensional spatio-temporally resolved image data through minimally invasive measurements. ERT has proved to be a valuable tool for imaging solute transport processes in the subsurface and has the potential to resolve the above-mentioned issue. The goals of this study are to verify to what extent ERT can be used to compare flow pathways of a conservative tracer (chloride) and a reactive tracer (food-dye Brilliant Blue) in the same large soil monolith filled with an undisturbed loamy sand and eventually address the question whether they take the same flow pathways. A constant water flow field was established in the soil monolith by means of an irrigation device. The tracers chloride and Brilliant Blue were successively added to the irrigation water. The negative charge of both tracer provides an electrical conductivity contrast that can be detected by means of ERT. Time-lapse ERT provides a qualitative comparison between both tracers, by visualizing the three-dimensional transport behavior. A quantitative analysis was performed by parameterizing the voxel-scale breakthrough curves using the convection-dispersion equation, which includes retardation and sorption kinetics for the reactive tracer. At the voxel-scale, heterogeneous water flow was observed, identified by regions with different pore-water velocities. In the subsoil, these regions were aligned to soil structural features of the plough pan. We discuss the comparison of the

  14. Growth of volcanic ash aggregates in the presence of liquid water and ice: an experimental approach

    NASA Astrophysics Data System (ADS)

    Van Eaton, Alexa R.; Muirhead, James D.; Wilson, Colin J. N.; Cimarelli, Corrado

    2012-11-01

    Key processes influencing the aggregation of volcanic ash and hydrometeors are examined with an experimental method employing vibratory pan aggregation. Mechanisms of aggregation in the presence of hail and ice pellets, liquid water (≤30 wt%), and mixed water phases are investigated at temperatures of 18 and -20 °C. The experimentally generated aggregates, examined in hand sample, impregnated thin sections, SEM imagery, and X-ray microtomography, closely match natural examples from phreatomagmatic phases of the 27 ka Oruanui and 2010 Eyjafjallajökull eruptions. Laser diffraction particle size analysis of parent ash and aggregates is also used to calculate the first experimentally derived aggregation coefficients that account for changing liquid water contents and subzero temperatures. These indicate that dry conditions (<5-10 wt% liquid) promote strongly size selective collection of sub-63 μm particles into aggregates (given by aggregation coefficients >1). In contrast, liquid-saturated conditions (>15-20 wt% liquid) promote less size selective processes. Crystalline ice was also capable of preferentially selecting volcanic ash <31 μm under liquid-free conditions in a two-stage process of electrostatic attraction followed by ice sintering. However, this did not accumulate more than a monolayer of ash at the ice surface. These quantitative relationships may be used to predict the timescales and characteristics of aggregation, such as aggregate size spectra, densities, and constituent particle size characteristics, when the initial size distribution and water content of a volcanic cloud are known. The presence of an irregularly shaped, millimeter-scale vacuole at the center of natural aggregates was also replicated during interaction of ash and melting ice pellets, followed by sublimation. Fine-grained rims were formed by adding moist aggregates to a dry mixture of sub-31 μm ash, which adhered by electrostatic forces and sparse liquid bridges. From this, we

  15. Experimental study of Cu-water nanofluid forced convective flow inside a louvered channel

    NASA Astrophysics Data System (ADS)

    Khoshvaght-Aliabadi, M.; Hormozi, F.; Zamzamian, A.

    2015-03-01

    Heat transfer enhancement plays a very important role for energy saving in plate-fin heat exchangers. In the present study, the influences of simultaneous utilization of a louvered plate-fin channel and copper-base deionized water nanofluid on performance of these exchangers are experimentally explored. The effects of flow rate (2-5 l/min) and nanoparticles weight fraction (0-0.4 %) on heat transfer and pressure drop characteristics are determined. Experimental results indicate that the use of louvered channel instead of the plain one can improve the heat transfer performance. Likewise, addition of small amounts of copper nanoparticles to the base fluid augments the convective heat transfer coefficient remarkably. The maximum rise of 21.7 % in the convective heat transfer coefficient is observed for the 0.4 % wt nanofluid compared to the base fluid. Also, pumping power for the base fluid and nanofluids are calculated based on the measured pressure drop in the louvered channel. The average increase in pumping power is 11.8 % for the nanofluid with 0.4 % wt compared to the base fluid. Applied performance criterion shows a maximum performance index of 1.167 for the nanofluid with 0.1 % wt Finally, two correlations are proposed for Nusselt number and friction factor which fit the experimental data with in ±10 %.

  16. Experimental study of Cu-water nanofluid forced convective flow inside a louvered channel

    NASA Astrophysics Data System (ADS)

    Khoshvaght-Aliabadi, M.; Hormozi, F.; Zamzamian, A.

    2014-09-01

    Heat transfer enhancement plays a very important role for energy saving in plate-fin heat exchangers. In the present study, the influences of simultaneous utilization of a louvered plate-fin channel and copper-base deionized water nanofluid on performance of these exchangers are experimentally explored. The effects of flow rate (2-5 l/min) and nanoparticles weight fraction (0-0.4 %) on heat transfer and pressure drop characteristics are determined. Experimental results indicate that the use of louvered channel instead of the plain one can improve the heat transfer performance. Likewise, addition of small amounts of copper nanoparticles to the base fluid augments the convective heat transfer coefficient remarkably. The maximum rise of 21.7 % in the convective heat transfer coefficient is observed for the 0.4 % wt nanofluid compared to the base fluid. Also, pumping power for the base fluid and nanofluids are calculated based on the measured pressure drop in the louvered channel. The average increase in pumping power is 11.8 % for the nanofluid with 0.4 % wt compared to the base fluid. Applied performance criterion shows a maximum performance index of 1.167 for the nanofluid with 0.1 % wt Finally, two correlations are proposed for Nusselt number and friction factor which fit the experimental data with in ±10 %.

  17. [Experimental research of turbidity influence on water quality monitoring of COD in UV-visible spectroscopy].

    PubMed

    Tang, Bin; Wei, Biao; Wu, De-Cao; Mi, De-Ling; Zhao, Jing-Xiao; Feng, Peng; Jiang, Shang-Hai; Mao, Ben-Jiang

    2014-11-01

    Eliminating turbidity is a direct effect spectroscopy detection of COD key technical problems. This stems from the UV-visible spectroscopy detected key quality parameters depend on an accurate and effective analysis of water quality parameters analytical model, and turbidity is an important parameter that affects the modeling. In this paper, we selected formazine turbidity solution and standard solution of potassium hydrogen phthalate to study the turbidity affect of UV--visible absorption spectroscopy detection of COD, at the characteristics wavelength of 245, 300, 360 and 560 nm wavelength point several characteristics with the turbidity change in absorbance method of least squares curve fitting, thus analyzes the variation of absorbance with turbidity. The results show, In the ultraviolet range of 240 to 380 nm, as the turbidity caused by particle produces compounds to the organics, it is relatively complicated to test the turbidity affections on the water Ultraviolet spectra; in the visible region of 380 to 780 nm, the turbidity of the spectrum weakens with wavelength increases. Based on this, this paper we study the multiplicative scatter correction method affected by the turbidity of the water sample spectra calibration test, this method can correct water samples spectral affected by turbidity. After treatment, by comparing the spectra before, the results showed that the turbidity caused by wavelength baseline shift points have been effectively corrected, and features in the ultraviolet region has not diminished. Then we make multiplicative scatter correction for the three selected UV liquid-visible absorption spectroscopy, experimental results shows that on the premise of saving the characteristic of the Ultraviolet-Visible absorption spectrum of water samples, which not only improve the quality of COD spectroscopy detection SNR, but also for providing an efficient data conditioning regimen for establishing an accurate of the chemical measurement methods.

  18. Effect of experimental chlorate product administration in the drinking water on Salmonella typhimurium contamination of broilers.

    PubMed

    Byrd, J A; Anderson, R C; Callaway, T R; Moore, R W; Knape, K D; Kubena, L F; Ziprin, R L; Nisbet, D J

    2003-09-01

    The crop is a known source of Salmonella and Campylobacter contamination. Previously, we evaluated lactic acid in the drinking water during a simulated pretransport feed withdrawal (FW) and reported 0.44% lactic acid significantly (P < 0.05) reduced the number of Salmonella recovered in market-age broiler crops. However, total consumption of the organic acid-treated drinking water was reduced. Presently, we evaluated the effect of experimental chlorate product (ECP; 1x ECP is equivalent to a 15 mM chlorate ion concentration) during a 10-h pretransport FW. Market-age broilers were obtained from a commercial processing plant and randomly assigned to ECP-treated or control (nontreated) groups. Broilers were challenged by crop gavage with 10(8) Salmonella Typhimurium (ST) immediately upon arrival and 1 d prior to termination of the experiment. One day later, broilers were killed for ST enumeration (cfu) in the crop and ceca. Broilers provided ECP 24 h prior to slaughter consumed slightly more ECP water than broilers provided distilled water. Treatment with ECP caused a significant decrease (P < 0.05) in the incidence of ST in crop contents (2%) as compared to the controls (36.7%). Similarly, ECP treatment caused a significant decrease (P < 0.05) in number of ST (0.96 log10 ST/g cecal content) detected in the ceca when compared to controls (2.52 log10 ST). This study suggested that incorporation of ECP in the drinking water 24 to 48 h prior to slaughter could reduce Salmonella contamination in broilers.

  19. Ultrafast solvation dynamics in water: Isotope effects and comparison with experimental results

    NASA Astrophysics Data System (ADS)

    Nandi, Nilashis; Roy, Srabani; Bagchi, Biman

    1995-01-01

    A detailed theoretical study of solvation dynamics in water is presented. The motivation of the present study comes from the recent experimental observation that the dynamics of solvation of an ion in water is ultrafast and the solvation time correlation function decays with a time constant of about 55 fs. The slower decay in the long time can be described by a sum of two exponentials with time constants equal to 126 and 880 fs. The molecular theory (developed earlier) predicts a time constant equal to 52 fs for the initial Gaussian decay and time constants equal to 134 and 886 fs for the two exponential components at the long time. This nearly perfect agreement is obtained by using the most detailed dynamical information available in the literature. The present study emphasizes the importance of the intermolecular vibrational band originating from the O...O stretching mode of the O-H...O units in the initial dynamics and raises several interesting questions regarding the nature of the decay of this mode. We have also studied the effects of isotope substitution on solvation dynamics. It is predicted that a significant isotope effect may be observed in the long time. The experimental results have also been compared with the prediction of the dynamic mean spherical approximation (DMSA); the agreement is not satisfactory at the long time. It is further found that the molecular theory and the DMSA lead to virtually identical results if the translational modes of the solvent molecules are neglected in the former. DMSA has also been used to investigate the dynamics of solvation of a dipolar solute in water. It is found that the dynamics of dipolar solvation exhibit features rather different from those of ion solvation.

  20. Experimental feature in the primary-proton flux at energies above 10 TeV according to the results of searches for primary particles in nuclear emulsions exposed in the stratosphere (RUNJOB Experiment)

    SciTech Connect

    Zayarnaya, I. S.

    2008-02-15

    In the RUNJOB experiment, a long-term exposure of x-ray emulsion chambers in the stratosphere from 1995 to 1999 with the aim of studying the composition and spectra of primary cosmic particles in the energy range 10-1000 TeV per nucleon revealed about 50% proton tracks. The remaining events of the proton group did not feature any candidate for a track of a singly charged particle within the search region determined from measurements of the coordinates of background nuclei going close to the sought track. Methodological factors that could explain this experimental observation are considered. A possible physical reason associated with the presence of a neutral component in the flux of primary protons in the energy region above 10 TeV is also analyzed.

  1. Pore water pressure variations in Subpermafrost groundwater : Numerical modeling compared with experimental modeling

    NASA Astrophysics Data System (ADS)

    Rivière, Agnès.; Goncalves, Julio; Jost, Anne; Font, Marianne

    2010-05-01

    Development and degradation of permafrost directly affect numerous hydrogeological processes such as thermal regime, exchange between river and groundwater, groundwater flows patterns and groundwater recharge (Michel, 1994). Groundwater in permafrost area is subdivided into two zones: suprapermafrost and subpermafrost which are separated by permafrost. As a result of the volumetric expansion of water upon freezing and assuming ice lenses and frost heave do not form freezing in a saturated aquifer, the progressive formation of permafrost leads to the pressurization of the subpermafrost groundwater (Wang, 2006). Therefore disappearance or aggradation of permafrost modifies the confined or unconfined state of subpermafrost groundwater. Our study focuses on modifications of pore water pressure of subpermafrost groundwater which could appear during thawing and freezing of soil. Numerical simulation allows elucidation of some of these processes. Our numerical model accounts for phase changes for coupled heat transport and variably saturated flow involving cycles of freezing and thawing. The flow model is a combination of a one-dimensional channel flow model which uses Manning-Strickler equation and a two-dimensional vertically groundwater flow model using Richards equation. Numerical simulation of heat transport consisted in a two dimensional model accounting for the effects of latent heat of phase change of water associated with melting/freezing cycles which incorporated the advection-diffusion equation describing heat-transfer in porous media. The change of hydraulic conductivity and thermal conductivity are considered by our numerical model. The model was evaluated by comparing predictions with data from laboratory freezing experiments. Experimental design was undertaken at the Laboratory M2C (Univesité de Caen-Basse Normandie, CNRS, France). The device consisted of a Plexiglas box insulated on all sides except on the top. Precipitation and ambient temperature are

  2. Experimental study of residence time distributions of ball-mill circuits grinding coal-water mixtures

    SciTech Connect

    Shoji, K.; Takahashi, Y.; Ohtake, A.; Austin, L.G.

    2008-08-15

    Residence time distributions (RTDs) were estimated by water tracing in a number of wet overflow ball mills (diameters 0.38 to 4.65 m) producing dense, coal-water slurries. In open-circuit mills of 0.38 m diameter and various length-diameter (LID) ratios, the mean residence times of solid were also determined from measured mill holdups. Holdup increased with increased mill feed rate, but the mean residence times of coal and water were still equal to each other. The experimental residence time distributions were fitted to the Mori-Jimbo-Yamazaki semi-infinite, axial mixing model, and the dimensionless mixing coefficient was determined for each of 25 tests in single- and two-compartment mills. This coefficient was found to be independent to the feed rate but linearly proportional to the D/L ratio. The mixing coefficient was smaller for two-compartment mills than for single-compartment mills, showing that there was reduced mixing introduced by the diaphragm separating the compartments. Equations are given to scale residence time distributions for changes in mill diameter and length.

  3. An investigation on characterizing dense coal-water slurry with ultrasound: theoretical and experimental method

    SciTech Connect

    Xue, M.H.; Su, M.X.; Dong, L.L.; Shang, Z.T.; Cai, X.S.

    2010-07-01

    Particle size distribution and concentration in particulate two-phase flow are important parameters in a wide variety of industrial areas. For the purpose of online characterization in dense coal-water slurries, ultrasonic methods have many advantages such as avoiding dilution, the capability for being used in real time, and noninvasive testing, while light-based techniques are not capable of providing information because optical methods often require the slurry to be diluted. In this article, the modified Urick equation including temperature modification, which can be used to determine the concentration by means of the measurement of ultrasonic velocity in a coal-water slurry, is evaluated on the basis of theoretical analysis and experimental study. A combination of the coupled-phase model and the Bouguer-Lambert-Beer law is employed in this work, and the attenuation spectrum is measured within the frequency region from 3 to 12 MHz. Particle size distributions of the coal-water slurry at different volume fractions are obtained with the optimum regularization technique. Therefore, the ultrasonic technique presented in this work brings the possibility of using ultrasound for online measurements of dense slurries.

  4. Experimental evaluation of the drag coefficient of water rockets by a simple free-fall test

    NASA Astrophysics Data System (ADS)

    Barrio-Perotti, R.; Blanco-Marigorta, E.; Argüelles-Díaz, K.; Fernández-Oro, J.

    2009-09-01

    The flight trajectory of a water rocket can be reasonably calculated if the magnitude of the drag coefficient is known. The experimental determination of this coefficient with enough precision is usually quite difficult, but in this paper we propose a simple free-fall experiment for undergraduate students to reasonably estimate the drag coefficient of water rockets made from plastic soft drink bottles. The experiment is performed using relatively small fall distances (only about 14 m) in addition with a simple digital-sound-recording device. The fall time is inferred from the recorded signal with quite good precision, and it is subsequently introduced as an input of a Matlab® program that estimates the magnitude of the drag coefficient. This procedure was tested first with a toy ball, obtaining a result with a deviation from the typical sphere value of only about 3%. For the particular water rocket used in the present investigation, a drag coefficient of 0.345 was estimated.

  5. Experimental and numerical study of shock wave propagation in water generated by pulsed arc electrohydraulic discharges

    NASA Astrophysics Data System (ADS)

    Chen, Wen; Maurel, Olivier; La Borderie, Christian; Reess, Thierry; De Ferron, Antoine; Matallah, Mohammed; Pijaudier-Cabot, Gilles; Jacques, Antoine; Rey-Bethbeder, Frank

    2014-05-01

    The objective of this study is to simulate the propagation of the shock wave in water due to an explosion. The study is part of a global research program on the development of an alternative stimulation technique to conventional hydraulic fracturing in tight gas reservoirs aimed at inducing a distributed state of microcracking of rocks instead of localized fracture. We consider the possibility of increasing the permeability of rocks with dynamic blasts. The blast is a shock wave generated in water by pulsed arc electrohydraulic discharges. The amplitude of these shock waves is prescribed by the electrohydraulic discharges which generate high pressures of several kilobars within microseconds. A simplified method has been used to simulate the injected electrical energy as augmentation of enthalpy in water locally. The finite element code EUROPLEXUS is used to perform fluid fast dynamic computation. The predicted pressure is consistent with the experimental results. In addition, shock wave propagation characteristics predicted with simulation can be valuable reference for design of underwater structural elements and engineering of underwater explosion.

  6. Experimental and numerical investigations on reliability of air barrier on oil containment in flowing water.

    PubMed

    Lu, Jinshu; Xu, Zhenfeng; Xu, Song; Xie, Sensen; Wu, Haoxiao; Yang, Zhenbo; Liu, Xueqiang

    2015-06-15

    Air barriers have been recently developed and employed as a new type of oil containment boom. This paper presents systematic investigations on the reliability of air barriers on oil containments with the involvement of flowing water, which represents the commonly-seen shearing current in reality, by using both laboratory experiments and numerical simulations. Both the numerical and experimental investigations are carried out in a model scale. In the investigations, a submerged pipe with apertures is installed near the bottom of a tank to generate the air bubbles forming the air curtain; and, the shearing water flow is introduced by a narrow inlet near the mean free surface. The effects of the aperture configurations (including the size and the spacing of the aperture) and the location of the pipe on the effectiveness of the air barrier on preventing oil spreading are discussed in details with consideration of different air discharges and velocities of the flowing water. The research outcome provides a foundation for evaluating and/or improve the reliability of a air barrier on preventing spilled oil from further spreading.

  7. Experimental study on heat transfer to supercritical water flowing through tubes

    SciTech Connect

    Zhao, M.; Gu, H.; Cheng, X.

    2012-07-01

    A test facility named SWAMUP (Supercritical Water Multi-Purpose Loop) has been constructed in Shanghai Jiao Tong Univ. to investigate heat transfer and pressure drop through tubes and rod bundles. SWAMUP is a closed loop with operating pressure up to 30 MPa, outlet-water temperature up to 550 deg. C, and mass flow rate up to 5 t/h. In this paper, experimental study has been carried out on heat transfer of supercritical water flowing vertically through tubes (ID=7.6 and 10 mm). A large number of test points in tubes has been obtained with a wide range of heat flux (200-1500 kw/m{sup 2}) and mass flux (450-2000 kg/m{sup 2}s). Test results showed that heat transfer deterioration (HTD) caused by buoyancy effect only appears in upward flow and HTD caused by acceleration effect appears both in upward flow and downward flow. The heat transfer coefficients (HTC) produced in tube tests were compared with existing heat transfer correlations. (authors)

  8. An experimental study of hydromagmatic fragmentation through energetic, non-explosive magma-water mixing

    USGS Publications Warehouse

    Mastin, L.G.; Spieler, O.; Downey, W.S.

    2009-01-01

    In this paper we report the first experimental investigation of non-explosive hydromagmatic fragmentation during energetic mixing with water. We mix magma and water by two methods: (1) pouring a basaltic melt between two converging water sprays; and (2) jetting basaltic melt at high pressure (3??MPa) through a nozzle into a tank of stagnant water. These experiments involved shear at relative velocities of ~ 5-16??m/s and vigorous mixing for less than a second, providing sufficient time for glassy rinds to grow but insufficient time for clot interiors to cool. In resulting fragments, we examined the gross morphology, which reflects fluid deformation during mixing, and surface textures, which reflect the growth and disruption of glassy rinds. We find major differences in both fragment morphology and surface texture between experiments. Water-spray experiments produced Pele's hair, thin bubble shards, melt droplets, and angular, fracture-bound droplet pieces. Melt-jet experiments produced mostly coarse (> 1??mm diameter), wavy fluidal fragments with broken ends. Fluidal surfaces of fragments produced by water-spray experiments were generally shiny under reflected light and, in microscopic examination, smooth down to micron scale, implying no disruption of glassy rinds, except for (a) rare flaking on Pele's hair that was bent prior to solidification; or (b) cracking and alligator-skin textures on segments of melt balls that had expanded before complete cooling. In contrast, textures of fluidal surfaces on fragments produced by melt-jet experiments are dull in reflected light and, in scanning electron images, exhibit ubiquitous discontinuous skins ("rinds") that are flaked, peeled, or smeared away in stripes. Adhering to these surfaces are flakes, blocks, and blobs of detached material microns to tens of microns in diameter. In the water-spray fragments, we interpret the scarcity of disrupted surface rinds to result from lack of bending after surfaces formed. In the

  9. An experimental study of hydromagmatic fragmentation through energetic, non-explosive magma-water mixing

    NASA Astrophysics Data System (ADS)

    Mastin, L. G.; Spieler, O.; Downey, W. S.

    2009-03-01

    In this paper we report the first experimental investigation of non-explosive hydromagmatic fragmentation during energetic mixing with water. We mix magma and water by two methods: (1) pouring a basaltic melt between two converging water sprays; and (2) jetting basaltic melt at high pressure (3 MPa) through a nozzle into a tank of stagnant water. These experiments involved shear at relative velocities of ~ 5-16 m/s and vigorous mixing for less than a second, providing sufficient time for glassy rinds to grow but insufficient time for clot interiors to cool. In resulting fragments, we examined the gross morphology, which reflects fluid deformation during mixing, and surface textures, which reflect the growth and disruption of glassy rinds. We find major differences in both fragment morphology and surface texture between experiments. Water-spray experiments produced Pele's hair, thin bubble shards, melt droplets, and angular, fracture-bound droplet pieces. Melt-jet experiments produced mostly coarse (> 1 mm diameter), wavy fluidal fragments with broken ends. Fluidal surfaces of fragments produced by water-spray experiments were generally shiny under reflected light and, in microscopic examination, smooth down to micron scale, implying no disruption of glassy rinds, except for (a) rare flaking on Pele's hair that was bent prior to solidification; or (b) cracking and alligator-skin textures on segments of melt balls that had expanded before complete cooling. In contrast, textures of fluidal surfaces on fragments produced by melt-jet experiments are dull in reflected light and, in scanning electron images, exhibit ubiquitous discontinuous skins ("rinds") that are flaked, peeled, or smeared away in stripes. Adhering to these surfaces are flakes, blocks, and blobs of detached material microns to tens of microns in diameter. In the water-spray fragments, we interpret the scarcity of disrupted surface rinds to result from lack of bending after surfaces formed. In the melt

  10. Building an understanding of water use innovation adoption processes through farmer-driven experimentation

    NASA Astrophysics Data System (ADS)

    Sturdy, Jody D.; Jewitt, Graham P. W.; Lorentz, Simon A.

    Smallholder farmers in Southern Africa are faced with the challenge of securing their livelihoods within the context of a wide variety of biophysical and socio-economic constraints. Agriculture is inherently risky, particularly in regions prone to drought or dry spells, and risk-averse farmers may be viewed by researchers or extension agents as reluctant to invest in agricultural innovations that have potential to improve their livelihoods. However, farmers themselves are more interested in personal livelihood security than any other stakeholder and it is the farmers’ perceptions of needs, investment options and risks that drive their decision-making process. A holistic approach to agricultural innovation development and extension is needed to address both socio-economic and biophysical dynamics that influence adoption and dissemination of innovations. This paper, presents a methodology for involving farmers from the Bergville district of South Africa in the process of innovation development through facilitation of farmer-driven gardening experiments. Facilitating farmer-driven experimentation allows farmers to methodically assess the value of innovations they choose to study while providing researchers with a venue for learning about socio-economic as well as biophysical influences on farmers’ decisions. With this knowledge, researchers can focus on developing innovations that are socially and economically appropriate and therefore, more readily adoptable. The participatory process gave farmers the tools they needed to make informed decisions through critical thinking and analysis and improved their confidence in explaining the function of innovations to others. Researchers were able to use farmers’ manually collected data and observations to supplement laboratory generated and electronically recorded information about soil water dynamics to understand water balances associated with different garden bed designs, and to investigate whether trench beds, drip

  11. Can product water footprints indicate the hydrological impact of primary production? - A case study of New Zealand kiwifruit

    NASA Astrophysics Data System (ADS)

    Deurer, M.; Green, S. R.; Clothier, B. E.; Mowat, A.

    2011-10-01

    SummaryWater footprints have been discussed as indicators for the influence of primary products on water scarcity and water quality. We assessed the impact of New Zealand kiwifruit on the scarcity and quality of freshwater resources and evaluated how the green-, blue- and grey-water footprints represented this impact. Water scarcity relates to the freshwater stored in soil and groundwater over a yearly timeframe. We found a negligible net change in soil water, as the freshwater in the soil is replenished every year by rain. The dynamics of freshwater in soil is indicated by the green-water footprint. Kiwifruit production has no impact on freshwater scarcity in soils, and we suggest, therefore, discarding the green-water footprint in this and similar studies. The groundwater recharge below kiwifruit orchards showed a large regional variation. A net depletion of groundwater resources occurs only in two kiwifruit growing regions, and only when the orchards are over-irrigated. The blue-water footprint indicates the status of the freshwater resources stored in the groundwater. We compared two different concepts. Our hydrologically based concept (Approach 1) quantifies the net change in the resources, whereas the Water Footprint Network (Approach 2) only accounts for the consumption. The blue-water footprint calculated by Approach 1 could explain 97% and by Approach 2 only 63% of the regional variation of net groundwater recharge below kiwifruit orchards. The values of the blue-water footprints are, on a regional average, about -500 L and 100 L per tray of kiwifruit with Approaches 1 and 2, respectively. According to Approach 1, a tray of kiwifruit delivers a net groundwater recharge of 500 L per tray, whereas according to Approach 2 the production of a tray of kiwifruit consumes 100 L of groundwater. Only Approach 1 contains all the hydrological processes making up the water balance that relates to groundwater. We assessed the impact of regional kiwifruit production on

  12. Evaluation and Repair of Primary Water Stress Corrosion Cracking in Alloy 600/182 Control Rod Drive Mechanism Nozzles

    SciTech Connect

    Frye, Charles R.; Arey, Melvin L. Jr.; Robinson, Michael R.; Whitaker, David E.

    2002-07-01

    In February 2001, a routine visual inspection of the reactor vessel head of Oconee Nuclear Station Unit 3 identified boric acid crystals at nine of sixty-nine locations where control rod drive mechanism housings (CRDM nozzles) penetrate the head. The boric acid deposits resulted from primary coolant leaking from cracks in the nozzle attachment weld and from through-thickness cracks in the nozzle wall. A general overview of the inspection and repair process is presented and results of the metallurgical analysis are discussed in more detail. The analysis confirmed that primary water stress corrosion cracking (PWSCC) is the mechanism of failure of both the Alloy 182 weld filler material and the alloy 600 wrought base material. (authors)

  13. Pathogenesis of solute-free water retention in experimental ascitic cirrhosis: is vasopressin the only culprit?

    PubMed

    Sansoè, Giovanni; Aragno, Manuela; Mastrocola, Raffaella; Parola, Maurizio

    2016-01-01

    Catecholamines trigger proximal tubular fluid retention and reduce renal excretion of solute-free water. In advanced cirrhosis, non-osmotic hypersecretion of vasopressin (antidiuretic hormone or ADH) is considered the cause of dilutional hyponatraemia, but ADH V2 receptor antagonists are not beneficial in long-term treatment of ascites. To test the hypothesis that water retention in experimental ascitic cirrhosis might depend primarily on adrenergic hyper-function, hormonal status, renal function and tubular free-water reabsorption (TFWR) were assessed in six groups of rats with ascitic cirrhosis: rats with cirrhosis due to 13-week CCl4 (carbon tetrachloride) administration (group G1); cirrhotic rats receiving daily diuretics (0.5 mg/kg furosemide plus 2 mg/kg K(+)-canrenoate) from the 11th to the 13th week of CCl4 (G2), diuretics associated with guanfacine oral prodrug (α2A-adrenergic receptor agonist and sympatholytic agent) at 2 (G3), 7 (G4) or 10 (G5) mg/kg, or with SSP-004240F1 (V2 receptor antagonist) at 1 mg/kg (G6). Natriuresis was lower in G1 than in G2, G4 and G6 (all P<0.05). Guanfacine, added to diuretics (i.e. G3 compared with G2), reduced serum noradrenaline from 423±22 to 211±41 ng/l (P<0.05), plasma renin activity (PRA) from 35±8 to 9±2 ng/ml/h (P<0.05) and TFWR from 45±8 to 20±6 μl/min (P<0.01). TFWR correlated with plasma aldosterone (r=0.51, P<0.01) and urinary potassium excretion (r=0.90, P<0.001). In ascitic cirrhosis, reduced volaemia, use of diuretics (especially furosemide) and adrenergic hyper-function cause tubular retention of water. Suitable doses of sympatholytic agents are effective aquaretics. PMID:26519424

  14. Heat and Water Transfer at the Land-Atmosphere Interface - Interweaving Experimental and Modeling Approaches

    NASA Astrophysics Data System (ADS)

    Smits, K. M.; Trautz, A.; Cihan, A.; Wallen, B.

    2015-12-01

    In the absence of vegetation, evaporation occurs entirely from the soil and can lead to considerable water losses. Considering the increase of water limited environments throughout the world and their potential for expansion over the coming years, it is critical that we are able to properly understand and model evaporation. Evaporation is affected by atmospheric conditions (e.g., humidity, temperature, wind velocity, solar radiation) and soil thermal and hydraulic properties (e.g., thermal and hydraulic conductivity, porosity), all of which are strongly coupled. However, for most conventional models, many of these mechanisms are crudely parameterized and inconsistent with current physical understanding due to the complexity of the problem in field scenarios and the scarcity of field or laboratory data capable of testing and refining energy and mass transfer theories. In this work, we investigated different physical processes that are often overlooked in models of flux exchange and how these processes may become significant in modeling arid and semi-arid environments. A non-isothermal model that allows for the coupling of single-phase (gas) two-component (air and water vapor) atmospheric flow and two-phase (gas, liquid) two-component (air and water vapor) flow in porous media was modified to better account for dry soil conditions. Numerical results were tested with precision experimental data. Results demonstrate that proper coupling of the thermal and mass flux processes allows us to better understand vapor transport and phase change processes that control shallow subsurface soil moisture and ultimately improve models predicting mass and energy fluxes.

  15. Transport behaviour of xenobiotic micropollutants in surface waters - an experimental assessment

    NASA Astrophysics Data System (ADS)

    Schwientek, Marc; Kuch, Bertram; Rügner, Hermann; Dobramysl, Lorenz; Grathwohl, Peter

    2013-04-01

    Xenobiotics are substances that do not exist in natural systems but are increasingly produced by industrial processes and introduced into the environment. While many of these compounds are eliminated in waste water treatment plants, some are only barely degraded and are discharged into receiving water bodies. Often little is known about their acute or chronic toxicity and even less about their persistence or transport behaviour in aquatic systems. In the present study, the stability and turnover of selected micropollutants along a 7.5 km long segment of the River Ammer in Southwest Germany was investigated (catchment area 134 km²). This stream carries a proportion of treated wastewater which is clearly above the average in German rivers, mainly supplied by a major waste water treatment plant at the upstream end of the studied stream segment. An experimental mass balance approach was chosen where in- and outflow of water and target compounds into and out of the balanced stream segment was measured during base flow conditions. To cover a complete diurnal cycle of wastewater input, pooled samples were collected every 2 h over a sampling period of 24 h. A comparison of bulk mass fluxes showed that carbamazepine, a pharmaceutical, and phosphorous flame retardants, such as TCPP, behave conservative under the given conditions. Some retention was observed for the disinfectant product Triclosan and some polycyclic musk fragrances (e.g., HHCB). TAED, a bleaching activator used in detergents, was completely eliminated along the stream segment. The outcome of the experiment demonstrates the very different persistence of some widely-used micropollutants in aquatic systems. However, the mechanisms involved in their attenuation as well as the fate of the most persistent compounds still remain subject to further research.

  16. Experimental measurement of wind and water erosion in Aragón and Andalusia, Spain

    NASA Astrophysics Data System (ADS)

    Fister, Wolfgang; Iserloh, Thomas; Marzen, Miriam; Ries, Johannes B.; Schmidt, Reinhard-G.

    2010-05-01

    For more than 50 years rainfall simulators and wind tunnels are important tools for soil erosion studies in the field. Laboratory investigations in wind tunnels with the ability of simultaneous rainfall production showed that wind significantly alters drop sizes, drop fall velocities and impact angles of falling raindrops. Leading to higher kinetic energies and increased soil detachment in comparison to falling drops with no wind influence. In most simulators this combined effect of wind and water is either not taken into account or deliberately excluded from the system, because of increasing complexity of processes involved. Within the project Ri 835/3-1, founded by the Deutsche Forschungsgemeinschaft, a portable combined wind an rainfall simulator for in-situ soil erosion studies was developed and used in Spain (Aragón, Andalusia), Morocco (Souss valley), and Germany (Eifel). The main objective of these field experiments was to quantify the susceptibility of different soil surface conditions and soil surface treatments to soil erosion by wind, water, and the combined effect of wind and water. Here, an overview of the results of the experimental measurements in Spain is given. The results show that wind erosion in Aragón is more or less negligible on undisturbed, crusted soil surfaces, but it can reach high amounts of up to 50 g m-² on rolled and grazed fields. Measurements in Andalusia show mean erosion rates of 24 g m-² on crusted soil surfaces. The expected increase of soil detachment, due to the combined force of wind and water in comparison to solely rainfall simulations, is apparent in most of the simulated runs. In total, the results proof that this combined wind and rainfall simulator is a valuable tool for soil erosion studies in the field and that it can be used to investigate various research questions.

  17. Ocular and orbital trauma from water balloon slingshots: a clinical, epidemiological, experimental, and theoretical study.

    PubMed Central

    Bullock, J D; Johnson, D A; Ballal, D R; Bullock, R J

    1996-01-01

    PURPOSE: To report the clinical findings of 17 patients with ocular/orbital injuries produced by launched water balloons; to determine water balloon kinetic energies in experimental and theoretical studies. METHODS: Six case histories are presented, 1 case was retrieved from the medical literature, and 10 cases were reported to the National Injury Information Clearinghouse of the United States Consumer Product Safety Commission. The energies were determined by field trials and calculations. RESULTS: Injuries included orbital contusions and hematomas, facial hypesthesia, eyelid lacerations, subconjunctival hemorrhages, corneal edema and abrasion, hyphemas, traumatic iritis, iris sphincter ruptures, iris atrophy, angle recession, iridodialyses, traumatic cataract, vitreous hemorrhages, retinal hemorrhages, macular hole formation, optic atrophy, and bony orbital wall fractures. Epidemiological analysis revealed that children and young adults, more often males, were injured, most commonly in the warm weather months (May through September). In field trials, maximum water balloon velocities ranged from 38 to 41 m/sec (85 to 92 mph) with kinetic energies from 176 to 245 J; by calculation, maximum velocities ranged from 42 to 54 m/sec (95 to 121 mph) with kinetic energies from 141 to 232 J. In a field demonstration a 300-g water balloon launched horizontally from a distance of 20 ft exploded a 12-kg watermelon. Classic physics calculations are presented to explain the complex bio-mechanical interactions between the water balloon and the eye. CONCLUSION: Kinetic energies of launched water balloons are comparable to or greater than kinetic energies experienced with a variety of common objects, including file bullets, which are well known to cause serious ocular and orbital injuries. In addition, these energies are far in excess of those required to perforate a cornea (0.7 to 1.7 J), rupture a globe (1 to 5.3 J), or fracture the bony orbit (1.8 to 14.7 j). Thus, this study

  18. Influence of stress intensity and loading mode on intergranular stress corrosion cracking of Alloy 600 in primary waters of pressurized water reactors

    SciTech Connect

    Rebak, R.B.; Szklarska-Smialowska, Z. . Fontana Corrosion Center)

    1994-05-01

    The steam generator in a pressurized water reactor (PWR) of a nuclear power plant consists mainly of a shell made of carbon (C) steel and tubes made of alloy 600 (UNS N06600). However, alloy 600 suffers environmentally induced cracking with exposure to high-temperature primary water. The susceptibility of alloy 600 to integranular stress corrosion cracking (IGSCC) was investigated as a function of the level of applied stresses and mode of loading. Constant load tests were conducted with specimens prepared from thin wall tubes, and constant deformation tests were conducted using specimens prepared from plates. With tubes exposed to primary water at 330 C, the crack propagation rate (CPR) was found to increase from 1 [times] 10[sup [minus]11] m/s at a stress intensity (K[sub i]) of 10 MPa[radical]m to 1 [times] 10[sup [minus]9] at K[sub i] = 60 MPa[radical]m. CPR obtained using compact specimens prepared from plates were 1 order of magnitude lower than values measured in tubes at the same temperature and in the same solution at each stress intensity. The corollary was that values of crack propagation and threshold stress intensities obtained using compact specimens could not be extrapolated to the behavior of thin wall tubes.

  19. Experimental Research on Mathematics Teaching of "Situated Creation and Problem-Based Instruction" in Chinese Primary and Secondary Schools

    ERIC Educational Resources Information Center

    Xia, Xiaogang; Lu, Chuanhan; Wang, Bingyi; Song, Yunming

    2007-01-01

    This research tends to make the experimental study on the mathematics teaching model of "situated creation and problem-based instruction" (SCPBI), namely, the teaching process of "creating situations--posing problems--solving problems--applying mathematics". It is aimed at changing the situation where students generally lack problem-based learning…

  20. Experimental and Thermalhydraulic Code Assessment of the Transient Behavior of the Passive Condenser System in an Advanced Boiling Water Reactor

    SciTech Connect

    S.T. Revankar; W. Zhou; Gavin Henderson

    2008-07-08

    The main goal of the project was to study analytically and experimentally the condensation heat transfer for the passive condenser system such as GE Economic Simplified Boiling Water Reactor (ESBWR). The effect of noncondensable gas in condenser tube and the reduction of secondary pool water level to the condensation heat transfer coefficient was the main focus in this research. The objectives of this research were to : 1) obtain experimental data on the local and tube averaged condensation heat transfer rates for the PCCS with non-condensable and with change in the secondary pool water, 2) assess the RELAP5 and TRACE computer code against the experimental data, and 3) develop mathematical model and ehat transfer correlation for the condensation phenomena for system code application. The project involves experimentation, theoretical model development and verification, and thermal- hydraulic codes assessment.

  1. Concerted changes in N and C primary metabolism in alfalfa (Medicago sativa) under water restriction.

    PubMed

    Aranjuelo, Iker; Tcherkez, Guillaume; Molero, Gemma; Gilard, Françoise; Avice, Jean-Christophe; Nogués, Salvador

    2013-02-01

    Although the mechanisms of nodule N(2) fixation in legumes are now well documented, some uncertainty remains on the metabolic consequences of water deficit. In most cases, little consideration is given to other organs and, therefore, the coordinated changes in metabolism in leaves, roots, and nodules are not well known. Here, the effect of water restriction on exclusively N(2)-fixing alfalfa (Medicago sativa L.) plants was investigated, and proteomic, metabolomic, and physiological analyses were carried out. It is shown that the inhibition of nitrogenase activity caused by water restriction was accompanied by concerted alterations in metabolic pathways in nodules, leaves, and roots. The data suggest that nodule metabolism and metabolic exchange between plant organs nearly reached homeostasis in asparagine synthesis and partitioning, as well as the N demand from leaves. Typically, there was (i) a stimulation of the anaplerotic pathway to sustain the provision of C skeletons for amino acid (e.g. glutamate and proline) synthesis; (ii) re-allocation of glycolytic products to alanine and serine/glycine; and (iii) subtle changes in redox metabolites suggesting the implication of a slight oxidative stress. Furthermore, water restriction caused little change in both photosynthetic efficiency and respiratory cost of N(2) fixation by nodules. In other words, the results suggest that under water stress, nodule metabolism follows a compromise between physiological imperatives (N demand, oxidative stress) and the lower input to sustain catabolism.

  2. Concerted changes in N and C primary metabolism in alfalfa (Medicago sativa) under water restriction

    PubMed Central

    Aranjuelo, Iker

    2013-01-01

    Although the mechanisms of nodule N2 fixation in legumes are now well documented, some uncertainty remains on the metabolic consequences of water deficit. In most cases, little consideration is given to other organs and, therefore, the coordinated changes in metabolism in leaves, roots, and nodules are not well known. Here, the effect of water restriction on exclusively N2-fixing alfalfa (Medicago sativa L.) plants was investigated, and proteomic, metabolomic, and physiological analyses were carried out. It is shown that the inhibition of nitrogenase activity caused by water restriction was accompanied by concerted alterations in metabolic pathways in nodules, leaves, and roots. The data suggest that nodule metabolism and metabolic exchange between plant organs nearly reached homeostasis in asparagine synthesis and partitioning, as well as the N demand from leaves. Typically, there was (i) a stimulation of the anaplerotic pathway to sustain the provision of C skeletons for amino acid (e.g. glutamate and proline) synthesis; (ii) re-allocation of glycolytic products to alanine and serine/glycine; and (iii) subtle changes in redox metabolites suggesting the implication of a slight oxidative stress. Furthermore, water restriction caused little change in both photosynthetic efficiency and respiratory cost of N2 fixation by nodules. In other words, the results suggest that under water stress, nodule metabolism follows a compromise between physiological imperatives (N demand, oxidative stress) and the lower input to sustain catabolism. PMID:23440170

  3. Experimental investigation of freezing blowby in a copper/water heat pipe

    NASA Technical Reports Server (NTRS)

    Ochterbeck, J. M.; Peterson, G. P.

    1992-01-01

    An experimental investigation designed to evaluate and better define the overall characteristics of freezing blowby in a copper/water heat pipe was conducted. The results from various rates of restart heat addition and channel blockage, indicate that upon breakthrough the depressurization of the evaporator may result in an effective heat transport capacity far in excess of the steady-state transport limit. The resulting transient conditions imposed on the heat pipe by the effective increased heat transport capacity can cause a loss of liquid in the evaporator and potential dryout. Evidence is presented which indicates that in order to prevent either temporary or permanent dryout, sufficient liquid inventory must be present in the evaporator wicking structure to accommodate the increased transient thermal load and allow sufficient time for the capillary wicking structure to reprime.

  4. Experimental investigation of the wake behind a model of wind turbine in a water flume

    NASA Astrophysics Data System (ADS)

    Okulov, V. L.; Naumov, I. N.; Kabardin, I.; Mikkelsen, R.; Sørensen, J. N.

    2014-12-01

    The flow behind the model of wind turbine rotor is investigated experimentally in a water flume using Particle Image Velocimetry. The study carried out involves rotors of three bladed wind turbine designed using Glauert's optimization. The transitional regime, generally characterized as in between the regime governed by stable organized vortical structures and the turbulent wake, develops from disturbances of the tip and root vorticies through vortex paring and further complex behaviour towards the fully turbulent wake. Our PIV measurements pay special attention to the onset of the instabilities. The near wake characteristics (development of expansion, tip vortex position, deficit velocity and rotation in the wake) have been measured for different tip speed ratio to compare with main assumptions and conclusions of various rotor theories.

  5. Interaction of cinnamic acid derivatives with β-cyclodextrin in water: experimental and molecular modeling studies.

    PubMed

    Liu, Benguo; Zeng, Jie; Chen, Chen; Liu, Yonglan; Ma, Hanjun; Mo, Haizhen; Liang, Guizhao

    2016-03-01

    Cyclodextrins (CDs) can be used to improve the solubility and stability of cinnamic acid derivatives (CAs). However, there was no detailed report about understanding the effects of the substituent groups in the benzene ring on the inclusion behavior between CAs and CDs in aqueous solution. Here, the interaction of β-CD with CAs, including caffeic acid, ferulic acid, and p-coumaric acid, in water was investigated by phase-solubility method, UV, fluorescence, and (1)H NMR spectroscopy, together with ONIOM (our Own N-layer Integrated Orbital molecular Mechanics)-based QM/MM (Quantum Mechanics/Molecular Mechanics) calculations. Experimental results demonstrated that CAs could form 1:1 stoichiometric inclusion complex with β-CD by non-covalent bonds, and that the maximum apparent stability constants were found in caffeic acid (176M(-1)) followed by p-coumaric acid (160M(-1)) and ferulic acid (133M(-1)). Moreover, our calculations reasonably illustrated the binding orientations of β-CD with CAs determined by experimental observations.

  6. Experimental study of high-speed imaging detection system for small bubbles in water

    NASA Astrophysics Data System (ADS)

    Du, Peng; Yang, Kecheng; Xia, Min; Li, Wei

    2015-10-01

    Small bubbles are widely present in the marine environment, the presence of small bubbles generated by whitecaps, microorganisms, ships sailing will greatly affect the optical properties of seawater. A lot of work has been carried out around the detection of small bubbles, this article will introduce a method of detecting small bubbles underwater with the way of high-speed imaging underwater. The optical mechanisms to measure the parameters of small bubbles are mainly high-speed photography, laser interferometry and holography. The advantages of high-speed photography are intuitive and low cost, the experimenters can real-time monitor the shooting circumstances, and can obtain more detailed parameters concerning the small bubbles. The paper also discusses an experimental method of high-speed imaging for small bubbles in water, that is to get a cooperative target in the back of the bubbles, then shoot the bubbles, and a lot of experiments with the two methods have been done. In order to compare the imaging quality of the two sets of experiments intuitively, the histograms and the results of edge detecting of the pictures have been given. After compared the results, it is found that the images are clearer and higher in contrast in the case of there is a cooperative target behind the bubbles, and with the imaging rate of the high-speed camera increases, the image quality is significantly reduced.

  7. Experimental Testing of Water Disinfection Models under Varying Hydraulic and Kinetic Conditions.

    PubMed

    Teixeira, Edmilson C; Rauen, William B; Fonseca, Ismênia; Figueiredo, Iene

    2016-06-01

    The concomitant effects of hydraulics and reaction kinetics on the disinfection efficiency (DE) of Chlorine Contact Tank (CCT) setups were experimentally assessed, to test the predictive-ability of first order kinetics models: Chick-Watson (C-W), C-t rule and Wehner-Wilhelm (W-W). Prototype tests were conducted using river water characterised for quality parameters, chlorine demand and inactivation rates of total and thermotolerant coliform. Poor, average and superior CCT baffling conditions were assessed by tracer experimentation and for their DE under three chlorine dosages. The models' DE predictive-ability was comparable and high for superior baffling, but decreased differently with the hydraulic efficiency (maximum errors of +15.3% with W-W, +26.0% with C-W and -36.6% with C-t). The positive bias shown by W-W renders it unsafe for CCT design, so the results favoured the C-t rule as the preferred analytical tool of comparable complexity. Potential refinements to these models that could lead to operational savings are identified. PMID:26773311

  8. Prevention of experimental autoimmune encephalomyelitis in DA rats by grafting primary skin fibroblasts engineered to express transforming growth factor-beta1.

    PubMed

    Zargarova, T; Kulakova, O; Prassolov, V; Zharmukhamedova, T; Tsyganova, V; Turobov, V; Ivanov, D; Parfenov, M; Sudomoina, M; Chernajovsky, Y; Favorova, O

    2004-08-01

    To determine whether primary fibroblasts producing latent transforming growth factor beta1 (TGF-beta1) are capable of down-regulating experimental autoimmune encephalomyelitis (EAE), a retroviral vector TGF-beta1-pBabe-neo (-5'UTR) was used for efficient gene transfer into primary skin fibroblasts of DA rats. After heat activation, conditioned medium from the transduced fibroblasts was found to inhibit significantly in vitro proliferation of lymphocytes from lymph nodes of DA rats with EAE. Intraperitoneal administration of TGF-beta1-transduced fibroblasts into DA rats during the priming phase of EAE resulted in a significant reduction in mortality and in the mean clinical and EAE scores versus the control immunized animals treated with non-transduced fibroblasts.

  9. Prevention of experimental autoimmune encephalomyelitis in DA rats by grafting primary skin fibroblasts engineered to express transforming growth factor-β1

    PubMed Central

    Zargarova, T; Kulakova, O; Prassolov, V; Zharmukhamedova, T; Tsyganova, V; Turobov, V; Ivanov, D; Parfenov, M; Sudomoina, M; Chernajovsky, Y; Favorova, O

    2004-01-01

    To determine whether primary fibroblasts producing latent transforming growth factor β1 (TGF-β1) are capable of down-regulating experimental autoimmune encephalomyelitis (EAE), a retroviral vector TGF-β1-pBabe-neo (−5′UTR) was used for efficient gene transfer into primary skin fibroblasts of DA rats. After heat activation, conditioned medium from the transduced fibroblasts was found to inhibit significantly in vitro proliferation of lymphocytes from lymph nodes of DA rats with EAE. Intraperitoneal administration of TGF-β1-transduced fibroblasts into DA rats during the priming phase of EAE resulted in a significant reduction in mortality and in the mean clinical and EAE scores versus the control immunized animals treated with non-transduced fibroblasts. PMID:15270848

  10. Experimental support and estimate of the accuracy of the water flow model in structured soils

    NASA Astrophysics Data System (ADS)

    Nikulina, M.

    2003-04-01

    The set of models of water flow and solute transport was developed. It takes into account spatial and time variability of soil properties and a complex structure of a soil pore space. However, its limited by physically justified methods of experimental definition of parameters. The important stage of the work with the models is checking their adequacy to described processes. It is possible only at a presence of the qualitative experi-mental data received under conditions, reproduced by model. According to this, the aim of the work is the support of methods of experimental maintenance of water flow models with taking into account of structure of soil porosity and evaluation of conditions of application of mathematical models of a dif-ferent level. The field experiments were conducted in Suzdal (Russia, Vladimirskaja oblast), in June and July 1997. The soil cover of this region has high complexity, in which grey forest soils are dominant. Genetic horizons of the grey forest soils are well structured, this causes the presence in soil profile the macropores. The field investigation consisted of three big parts: (1) the morphological research of the genetic horizons of the grey forest soil; (2) investigation of the soil filtration properties by the tube with a constant head and vacuum-infiltrometer methods; (3) study of water movement at different intensity of the irrigation. Experiments were conducted on three sets called <А>, <В > and <С>. The plots had 1m x 1m a size and were equipped with the hole for measurement of soil water content by the neutron hygrometer and by the tensiometers. In labo-ratory conditions the following properties of soil were determined: density of soil, texture, porosity of the aggregates, shrinkage characteristics of soil fraction in diameter of 3-5 mm. For the simulation the model "MACRO" (Jarvis et al, 1991) was used in the work. Adequacy of the model descriptions of the field data were estimated by visual comparison of measured and

  11. Water quality and quantity assessment of pervious pavements performance in experimental car park areas.

    PubMed

    Sañudo-Fontaneda, Luis A; Charlesworth, Susanne M; Castro-Fresno, Daniel; Andres-Valeri, Valerio C A; Rodriguez-Hernandez, Jorge

    2014-01-01

    Pervious pavements have become one of the most used sustainable urban drainage system (SUDS) techniques in car parks. This research paper presents the results of monitoring water quality from several experimental car park areas designed and constructed in Spain with bays made of interlocking concrete block pavement, porous asphalt, polymer-modified porous concrete and reinforced grass with plastic and concrete cells. Moreover, two different sub-base materials were used (limestone aggregates and basic oxygen furnace slag). This study therefore encompasses the majority of the materials used as permeable surfaces and sub-base layers all over the world. Effluent from the test bays was monitored for dissolved oxygen, pH, electric conductivity, total suspended solids, turbidity and total petroleum hydrocarbons in order to analyze the behaviour shown by each combination of surface and sub-base materials. In addition, permeability tests were undertaken in all car parks using the 'Laboratorio Caminos Santander' permeameter and the Cantabrian Portable Infiltrometer. All results are presented together with the influence of surface and sub-base materials on water quality indicators using bivariate correlation statistical analysis at a confidence level of 95%. The polymer-modified porous concrete surface course in combination with limestone aggregate sub-base presented the best performance. PMID:24718346

  12. Water quality and quantity assessment of pervious pavements performance in experimental car park areas.

    PubMed

    Sañudo-Fontaneda, Luis A; Charlesworth, Susanne M; Castro-Fresno, Daniel; Andres-Valeri, Valerio C A; Rodriguez-Hernandez, Jorge

    2014-01-01

    Pervious pavements have become one of the most used sustainable urban drainage system (SUDS) techniques in car parks. This research paper presents the results of monitoring water quality from several experimental car park areas designed and constructed in Spain with bays made of interlocking concrete block pavement, porous asphalt, polymer-modified porous concrete and reinforced grass with plastic and concrete cells. Moreover, two different sub-base materials were used (limestone aggregates and basic oxygen furnace slag). This study therefore encompasses the majority of the materials used as permeable surfaces and sub-base layers all over the world. Effluent from the test bays was monitored for dissolved oxygen, pH, electric conductivity, total suspended solids, turbidity and total petroleum hydrocarbons in order to analyze the behaviour shown by each combination of surface and sub-base materials. In addition, permeability tests were undertaken in all car parks using the 'Laboratorio Caminos Santander' permeameter and the Cantabrian Portable Infiltrometer. All results are presented together with the influence of surface and sub-base materials on water quality indicators using bivariate correlation statistical analysis at a confidence level of 95%. The polymer-modified porous concrete surface course in combination with limestone aggregate sub-base presented the best performance.

  13. Experimental demonstration of coupling of heat and matter fluxes at a gas-water interface

    NASA Astrophysics Data System (ADS)

    Phillips, Leon F.

    1994-09-01

    Air-water fluxes of oxygen and carbon dioxide have been calculated for a model which incorporates a turbulent air layer and takes into account the effects of the fluxes of sensible and latent heat on the temperature of the liquid surface. The calculated fluxes are compared with the experimental results of Liss et al (1981), Smith and Jones (1985), and Smith et al. (1991). The results of this comparison clearly demonstrate both the importance of coupling, in the sense of irreversible thermodynamics, of heat and matter fluxes at the gas-water interface and the important role of the surface temperature of the liquid in controlling the magnitude and sometimes even the direction of the gas flux. The large carbon dioxide fluxes found by Smith and coworkers can be accounted for by assuming eddy diffusion, rather than molecular diffusion, on the seaside of the interface. This is consistent with an earlier suggestion that their measurements were affected by proximity to a surf zone. The present calculations might serve as the basis of a practical method of determining air-sea fluxes of CO2 and other trace gases.

  14. Embolism spread in the primary xylem of Polystichum munitum: implications for water transport during seasonal drought.

    PubMed

    Brodersen, Craig R; Rico, Christopher; Guenni, Orlando; Pittermann, Jarmila

    2016-02-01

    Xylem network structure and function have been characterized for many woody plants, but less is known about fern xylem, particularly in species endemic to climates where water is a limiting resource for months at a time. We characterized seasonal variability in soil moisture and frond water status in a common perennial fern in the redwood understory of a costal California, and then investigated the consequences of drought-induced embolism on vascular function. Seasonal variability in air temperature and soil water content was minimal, and frond water potential declined slowly over the observational period. Our data show that Polystichum munitum was protected from significant drought-induced hydraulic dysfunction during this growing season because of a combination of cavitation resistant conduits (Air-seeding threshold (ASP) = -1.53 MPa; xylem pressure inducing 50% loss of hydraulic conductivity (P50 ) = -3.02 MPa) and a soil with low moisture variability. High resolution micro-computed tomography (MicroCT) imaging revealed patterns of embolism formation in vivo for the first time in ferns providing insight into the functional status of the xylem network under drought conditions. Together with stomatal conductance measurements, these data suggest that P. munitum is adapted to tolerate drier conditions than what was observed during the growing season.

  15. The Design and Development of a Simulation to Teach Water Conservation to Primary School Students

    ERIC Educational Resources Information Center

    Campbell, Lee

    2004-01-01

    Information and Communications Technology (ICT) plays a dominant role in enhancing teaching and learning. Similar advances have been made in the use of multimedia in the classroom. These advances are coupled with newer developmental tools and techniques. This paper examines the design and development of a simulation on water conservation. Science…

  16. Primary structure of water buffalo beta-casein tryptic and CNBr peptides.

    PubMed

    Petrilli, P; Addeo, F; Chianese, L

    1983-01-01

    The partial amino acid sequence (70%) of water buffalo beta-casein has been determined by aligning the sequences of tryptic and CNBr peptides along the polypeptide chain of bovine beta-casein. Only five amino acid substitutions are observed. Moreover, as in all the beta-caseins so far investigated, a morphine-like peptide is present.

  17. Pre-Service Primary Science Teachers' Understandings of the Effect of Temperature and Pressure on Solid-Liquid Phase Transition of Water

    ERIC Educational Resources Information Center

    Yalcin, Fatma Aggul

    2012-01-01

    The aim of this study was to explore pre-service primary teachers' understandings of the effect of temperature and pressure on the solid-liquid phase transition of water. In the study a survey approach was used, and the sample consisted of one-hundred and three, third year pre-service primary science teachers. As a tool for data collection, a test…

  18. Water temperature affects pathogenicity of different betanodavirus genotypes in experimentally challenged Dicentrarchus labrax.

    PubMed

    Toffan, Anna; Panzarin, Valentina; Toson, Marica; Cecchettin, Krizia; Pascoli, Francesco

    2016-05-26

    Betanodaviruses are the causative agents of a highly infectious disease of fish known as viral nervous necrosis (VNN). To date, 4 different nervous necrosis virus (NNV) genotypes have been described, but natural reassortant viruses have also been detected, which further increase viral variability. Water temperature plays an important role in determining the appearance and the severity of VNN disease. We assessed the effect of temperature (20°, 25° and 30°C) on mortality and virus load in the brain of European sea bass Dicentrarchus labrax experimentally infected with 4 genetically different betanodaviruses, namely red-spotted grouper NNV (RGNNV), striped jack NNV (SJNNV) and the reassortant strains RGNNV/SJNNV and SJNNV/RGNNV. The RGNNV/SJNNV virus possesses the polymerase gene of RGNNV and the coat protein gene of SJNNV, and vice versa for the SJNNV/RGNNV virus. The obtained results showed that the RGNNV strain is the most pathogenic for juvenile sea bass, but clinical disease and mortality appeared only at higher temperatures. The SJNNV strain is weakly pathogenic for D. labrax regardless of the temperature used, while virus replication was detected in the brain of survivors only at 20°C. Finally, reassortant strains caused low mortality, independent of the temperature used, but the viral load in the brain was strongly influenced by water temperature and the genetic type of the polymerase gene. Taken together, these data show that nodavirus replication in vivo is a composite process regulated by both the genetic features of the viral strain and water temperatures. PMID:27225206

  19. A combined experimental and computational study of the molecular interactions between anionic ibuprofen and water

    SciTech Connect

    Zapata-Escobar, Andy; Manrique-Moreno, Marcela; Guerra, Doris; Hadad, C. Z.; Restrepo, Albeiro

    2014-05-14

    In this work, we report a detailed study of the microsolvation of anionic ibuprofen, Ibu{sup −}. Stochastic explorations of the configurational spaces for the interactions of Ibu{sup −} with up to three water molecules at the DFT level lead to very rich and complex potential energy surfaces. Our results suggest that instead of only one preponderant structure, a collection of isomers with very similar energies would have significant contributions to the properties of the solvated drug. One of these properties is the shift on the vibrational frequencies of the asymmetric stretching band of the carboxylate group in hydrated Ibu{sup −} with respect to the anhydrous drug, whose experimental values are nicely reproduced using the weighted contribution of the structures. We found at least three types of stabilizing interactions, including conventional CO {sub 2}{sup −}⋯H{sub 2}O, H{sub 2}O⋯H{sub 2}O charge assisted hydrogen bonds (HBs), and less common H{sub 2}O⋯H–C and H{sub 2}O⋯π interactions. Biological water molecules, those in direct contact with Ibu{sup −}, prefer to cluster around the carboxylate oxygen atoms via cyclic or bridged charge assisted hydrogen bonds. Many of those interactions are strongly affected by the formal carboxylate charge, resulting in “enhanced” HBs with increased strengths and degree of covalency. We found striking similarities between this case and the microsolvation of dymethylphosphate, which lead us to hypothesize that since microsolvation of phosphatidylcholine depends mainly on the formal charge of its ionic PO {sub 2}{sup −} group in the polar head, then microsolvation of anionic ibuprofen and interactions of water molecules with eukaryotic cell membranes are governed by the same types of physical interactions.

  20. Water temperature affects pathogenicity of different betanodavirus genotypes in experimentally challenged Dicentrarchus labrax.

    PubMed

    Toffan, Anna; Panzarin, Valentina; Toson, Marica; Cecchettin, Krizia; Pascoli, Francesco

    2016-05-26

    Betanodaviruses are the causative agents of a highly infectious disease of fish known as viral nervous necrosis (VNN). To date, 4 different nervous necrosis virus (NNV) genotypes have been described, but natural reassortant viruses have also been detected, which further increase viral variability. Water temperature plays an important role in determining the appearance and the severity of VNN disease. We assessed the effect of temperature (20°, 25° and 30°C) on mortality and virus load in the brain of European sea bass Dicentrarchus labrax experimentally infected with 4 genetically different betanodaviruses, namely red-spotted grouper NNV (RGNNV), striped jack NNV (SJNNV) and the reassortant strains RGNNV/SJNNV and SJNNV/RGNNV. The RGNNV/SJNNV virus possesses the polymerase gene of RGNNV and the coat protein gene of SJNNV, and vice versa for the SJNNV/RGNNV virus. The obtained results showed that the RGNNV strain is the most pathogenic for juvenile sea bass, but clinical disease and mortality appeared only at higher temperatures. The SJNNV strain is weakly pathogenic for D. labrax regardless of the temperature used, while virus replication was detected in the brain of survivors only at 20°C. Finally, reassortant strains caused low mortality, independent of the temperature used, but the viral load in the brain was strongly influenced by water temperature and the genetic type of the polymerase gene. Taken together, these data show that nodavirus replication in vivo is a composite process regulated by both the genetic features of the viral strain and water temperatures.

  1. Stimulation of fecal bacteria in ambient waters by experimental inputs of organic and inorganic phosphorus.

    PubMed

    Chudoba, Elizabeth A; Mallin, Michael A; Cahoon, Lawrence B; Skrabal, Stephen A

    2013-06-15

    Fecal microbial pollution of recreational and shellfishing waters is a major human health and economic issue. Microbial pollution sourced from stormwater runoff is especially widespread, and strongly associated with urbanization. However, non-point source nutrient pollution is also problematic, and may come from sources different from fecal-derived pollution (i.e. fertilization of farm fields, lawns and gardens, and ornamental urban areas). Fecal bacteria require nutrients; thus the impact of such nutrient loading on survival and abundance of fecal coliform bacteria in ambient waters was experimentally investigated in a constructed wetland in coastal North Carolina, USA. A series of nutrient-addition bioassays testing impacts of inorganic and organic nitrogen and phosphorus demonstrated that additions of neither organic nor inorganic nitrogen stimulated fecal coliform bacteria. However, phosphorus additions provided significant stimulation of fecal coliform growth at times; on other occasions such additions did not. Dilution bioassays combined with nutrient additions were subsequently devised to assess potential impacts of microzooplankton grazing on the target fecal bacteria populations. Results demonstrated grazing to be a significant bacterial reduction factor in 63% of tests, potentially obscuring nutrient effects. Thus, combining dilution experiments with nutrient addition bioassays yielded simultaneous information on microzooplankton grazing rates on fecal bacteria, fecal bacterial growth rates, and nutrient limitation. Overall, when tested against a non-amended control, additions of either organic or inorganic phosphorus significantly stimulated fecal coliform bacterial growth on 50% of occasions tested, with organic phosphorus generally providing greater stimulation. The finding of significant phosphorus stimulation of fecal bacteria indicates that extraneous nutrient loading can, at times, augment the impacts of fecal microbial pollution of shellfishing

  2. A combined experimental and computational study of the molecular interactions between anionic ibuprofen and water

    NASA Astrophysics Data System (ADS)

    Zapata-Escobar, Andy; Manrique-Moreno, Marcela; Guerra, Doris; Hadad, C. Z.; Restrepo, Albeiro

    2014-05-01

    In this work, we report a detailed study of the microsolvation of anionic ibuprofen, Ibu-. Stochastic explorations of the configurational spaces for the interactions of Ibu- with up to three water molecules at the DFT level lead to very rich and complex potential energy surfaces. Our results suggest that instead of only one preponderant structure, a collection of isomers with very similar energies would have significant contributions to the properties of the solvated drug. One of these properties is the shift on the vibrational frequencies of the asymmetric stretching band of the carboxylate group in hydrated Ibu- with respect to the anhydrous drug, whose experimental values are nicely reproduced using the weighted contribution of the structures. We found at least three types of stabilizing interactions, including conventional CO_2^-\\cdotsH2O, H2O⋯H2O charge assisted hydrogen bonds (HBs), and less common H2O⋯H-C and H2O⋯π interactions. Biological water molecules, those in direct contact with Ibu-, prefer to cluster around the carboxylate oxygen atoms via cyclic or bridged charge assisted hydrogen bonds. Many of those interactions are strongly affected by the formal carboxylate charge, resulting in "enhanced" HBs with increased strengths and degree of covalency. We found striking similarities between this case and the microsolvation of dymethylphosphate, which lead us to hypothesize that since microsolvation of phosphatidylcholine depends mainly on the formal charge of its ionic PO_2^- group in the polar head, then microsolvation of anionic ibuprofen and interactions of water molecules with eukaryotic cell membranes are governed by the same types of physical interactions.

  3. The CTFA Evaluation of Alternatives Program: an evaluation of in vitro alternatives to the Draize primary eye irritation test. (Phase II) oil/water emulsions.

    PubMed

    Gettings, S D; Dipasquale, L C; Bagley, D M; Casterton, P L; Chudkowski, M; Curren, R D; Demetrulias, J L; Feder, P I; Galli, C L; Gay, R

    1994-10-01

    The Cosmetic, Toiletry and Fragrance Association (CTFA) Evaluation of Alternatives Program is an evaluation of the relationship between Draize ocular safety test data and comparable data from a selection of in vitro tests. In Phase II, 18 representative oil/water-based personal-care formulations were subjected to the Draize primary eye safety test and 30 in vitro assay protocols (14 different types of in vitro endpoints were evaluated; the remainder were protocol variations). Correlation of in vitro with in vivo data was evaluated using analysis of sensitivity/specificity and statistical analysis of the relationship between maximum average Draize score (MAS) and in vitro endpoint. Regression modelling is the primary approach adopted in the CTFA Program for evaluating in vitro assay performance. The objective of regression analysis is to predict MAS for a given test material (and to place upper and lower prediction interval bounds on the range in which the MAS is anticipated to fall with high probability) conditional on observing an in vitro assay score for that material. The degree of confidence in prediction is quantified in terms of the relative widths of prediction intervals constructed about the fitted regression curves: the narrower the prediction interval, the more predictive of the Draize score is the in vitro test result. 16 assays were shown to have the greatest agreement with the Draize procedure and were therefore selected for regression analysis. Based on the magnitude of the 95% prediction bounds of each of the 16 selected assays over the range of test data, it may be inferred that prediction of MAS values from experimentally determined in vitro scores is more accurate for oil/water-based formulations with lower rather than higher irritancy potential. The assays selected for modelling in Phase II generally exhibited weaker relationships with MAS than those selected in Phase I (evaluated using hydroalcoholic formulations), even though several assays

  4. Determination of ammonia and primary amine compounds and Kjeldahl nitrogen in water samples with a modified Roth's fluorimetric method.

    PubMed

    Lloret, S Meseguer; Andrés, J Verdú; Legua, C Molins; Falcó, P Campíns

    2005-02-28

    A method for the simultaneous determination of primary amino groups and ammonium ion has been proposed. The method is based in solution derivatization with o-Phthaldialdehyde/N-acetyl-cisteine (OPA/NAC) and fluorescence measurement of the formed isoindols. Analytical characteristics and description of the developed procedure have been provided. The calibration graphs for ammonium (up to 1.44mgL(-1) of N) and methylamine as primary amino model compound (up to 0.282mgL(-1) of N), were obtained. Bivariate and multivariate calibration models have been tested. The limits of detection were 0.07mgL(-1) of N and 0.004mgL(-1) of N for ammonium and amine, respectively. The procedure was first applied directly to standard solutions containing ammonium and amines and secondly to digested solutions by Kjeldahl method. The results obtained allowed to establish the best digestion conditions in order to perform the total amine conversion into ammonium. This procedure has been also applied to real samples (irrigation ditch, residual and fountain waters) and the concentrations of primary amine groups and ammonium have been evaluated. The results obtained after Kjeldahl digestion allowed to estimate the total Kjeldahl N contained in the samples. The samples were also analysed by Nessler method and similar results were obtained.

  5. Combined Experimental and Computational Approach to Predict the Glass-Water Reaction

    SciTech Connect

    Pierce, Eric M; Bacon, Diana

    2011-01-01

    The use of mineral and glass dissolution rates measured in laboratory experiments to predict the weathering of primary minerals and volcanic and nuclear waste glasses in field studies requires the construction of rate models that accurately describe the weathering process over geologic time-scales. Additionally, the need to model the long-term behavior of nuclear waste glass for the purpose of estimating radionuclide release rates requires that rate models are validated with long-term experiments. Several long-term test methods have been developed to accelerate the glass-water reaction [drip test, vapor hydration test, product consistency test-B, and pressurized unsaturated flow (PUF)], thereby reducing the duration required to evaluate long-term performance. Currently, the PUF test is the only method that mimics the unsaturated hydraulic properties expected in a subsurface disposal facility and simultaneously monitors the glass-water reaction. PUF tests are being conducted to accelerate the weathering of glass and validate the model parameters being used to predict long-term glass behavior. A one-dimensional reactive chemical transport simulation of glass dissolution and secondary phase formation during a 1.5-year long PUF experiment was conducted with the subsurface transport over reactive multi-phases code. Results show that parameterization of the computer model by combining direct bench-scale laboratory measurements and thermodynamic data provides an integrated approach to predicting glass behavior over the length of the experiment. Over the 1.5-year long test duration, the rate decreased from 0.2 to 0.01 g/(m2 d) base on B release. The observed decrease is approximately two orders of magnitude higher than the decrease observed under static conditions with the SON68 glass (estimated to be a decrease by 4 orders of magnitude) and suggest the gel-layer properties are less protective under these dynamic conditions.

  6. Combined Experimental and Computational Approach to Predict the Glass-Water Reaction

    SciTech Connect

    Pierce, Eric M.; Bacon, Diana H.

    2011-10-01

    The use of mineral and glass dissolution rates measured in laboratory experiments to predict the weathering of primary minerals and volcanic and nuclear waste glasses in field studies requires the construction of rate models that accurately describe the weathering process over geologic timescales. Additionally, the need to model the long-term behavior of nuclear waste glass for the purpose of estimating radionuclide release rates requires that rate models be validated with long-term experiments. Several long-term test methods have been developed to accelerate the glass-water reaction [drip test, vapor hydration test, product consistency test B, and pressurized unsaturated flow (PUF)], thereby reducing the duration required to evaluate long-term performance. Currently, the PUF test is the only method that mimics the unsaturated hydraulic properties expected in a subsurface disposal facility and simultaneously monitors the glass-water reaction. PUF tests are being conducted to accelerate the weathering of glass and validate the model parameters being used to predict long-term glass behavior. A one-dimensional reactive chemical transport simulation of glass dissolution and secondary phase formation during a 1.5-year-long PUF experiment was conducted with the Subsurface Transport Over Reactive Multiphases (STORM) code. Results show that parameterization of the computer model by combining direct bench scale laboratory measurements and thermodynamic data provides an integrated approach to predicting glass behavior over the length of the experiment. Over the 1.5-year-long test duration, the rate decreased from 0.2 to 0.01 g/(m2 day) based on B release for low-activity waste glass LAWA44. The observed decrease is approximately two orders of magnitude higher than the decrease observed under static conditions with the SON68 glass (estimated to be a decrease by four orders of magnitude) and suggests that the gel-layer properties are less protective under these dynamic

  7. Gravitropic reaction of primary seminal roots of Zea mays L. influenced by temperature and soil water potential.

    PubMed

    Nakamoto, T

    1995-03-01

    The growth of the primary seminal root of maize (Zea mays L.) is characterized by an initial negative gravitropic reaction and a later positive one that attains a plagiotropic liminal angle. The effects of temperature and water potential of the surrounding soil on these gravitropic reactions were studied. Temperatures of 32, 25, and 18C and soil water potentials of -5, -38, and -67 kPa were imposed and the direction of growth was measured for every 1 cm length of the root. The initial negative gravitropic reaction extended to a distance of about 10 cm from the grain. Higher temperatures reduced the initial negative gravitropic reaction. Lower soil water potential induced a downward growth at root emergence. A mathematical model, in which it was assumed that the rate of the directional change of root growth was a sum of a time-dependent negative gravitropic reaction and an establishment of the liminal angle, adequately fitted the distance-angle relations. It was suggested that higher temperatures and/or a lower water potential accelerated the diminution of the initial negative gravitropic reaction. PMID:11540141

  8. Gravitropic reaction of primary seminal roots of Zea mays L. influenced by temperature and soil water potential.

    PubMed

    Nakamoto, T

    1995-03-01

    The growth of the primary seminal root of maize (Zea mays L.) is characterized by an initial negative gravitropic reaction and a later positive one that attains a plagiotropic liminal angle. The effects of temperature and water potential of the surrounding soil on these gravitropic reactions were studied. Temperatures of 32, 25, and 18C and soil water potentials of -5, -38, and -67 kPa were imposed and the direction of growth was measured for every 1 cm length of the root. The initial negative gravitropic reaction extended to a distance of about 10 cm from the grain. Higher temperatures reduced the initial negative gravitropic reaction. Lower soil water potential induced a downward growth at root emergence. A mathematical model, in which it was assumed that the rate of the directional change of root growth was a sum of a time-dependent negative gravitropic reaction and an establishment of the liminal angle, adequately fitted the distance-angle relations. It was suggested that higher temperatures and/or a lower water potential accelerated the diminution of the initial negative gravitropic reaction.

  9. Detection of a water molecule in the active-site of bacteriorhodopsin: hydrogen bonding changes during the primary photoreaction.

    PubMed

    Fischer, W B; Sonar, S; Marti, T; Khorana, H G; Rothschild, K J

    1994-11-01

    FTIR-difference spectroscopy in combination with site-directed mutagenesis has been used to investigate the role of water during the photocycle of bacteriorhodopsin. At least one water molecule is detected which undergoes an increase in H-bonding during the primary bR-->K phototransition. Bands due to water appear in the OH stretch region of the bR-->K FTIR-difference spectrum which downshift by approximately 12 cm-1 when the sample is hydrated with H2(18)O. In contrast to 2H2O, the H2(18)O-induced shift is not complete, even after 24 h of hydration. This indicates that even though water is still able to exchange protons with the outside medium, it is partially trapped in the interior of the protein. In the mutant Y57D, these bands are absent while a new set of bands appear at much lower frequencies which undergo H2(18)O-induced shifts. It is concluded that the water molecule we detect is located inside the bR active-site and may interact with Tyr-57. The change in its hydrogen-bonding strength is most likely due to the photoinduced all-trans-->13-cis isomerization of the retinal chromophore and the associated movement of the positively charged Schiff base during the bR-->K transition. In contrast, a second water molecule, whose infrared difference bands are not affected by the Y57D mutation, appears to undergo a decrease in hydrogen bonding during the K-->L and L-->M transitions.

  10. Primary factors affecting water quality and quantity in four watersheds in Eastern Puerto Rico

    USGS Publications Warehouse

    Murphy, Sheila F.; Stallard, Robert F.

    2009-01-01

    As part of the U.S. Geological Survey (USGS) Water, Energy, and Biogeochemical Budgets (WEBB) program, four small watersheds in eastern Puerto Rico were monitored to identify and evaluate the effects of geology, landcover, atmospheric deposition, and other factors on stream water quality and quantity. Two catchments are located on coarse-grained granitic plutonic rocks, which weather to quartz- and clay-rich, sandy soils, and two are located on fine-grained volcanic rocks and volcaniclastic sediments, which weather to quartz-poor, fine-grained soils. These differing soil materials result in different hydrologic regimes. Soils on the granitic rocks have greater permeability than those developed on the volcaniclastic rocks, allowing more water infiltration and potentially greater landslide erosion rates. For each bedrock type, one catchment was covered with mature rainforest, and the other catchment was affected by agricultural practices typical of eastern Puerto Rico. These practices led to the erosion of much of the original surface soil in the agricultural watersheds, which introduced large quantities of sediment to stream channels. The agricultural watersheds are undergoing natural reforestation, like much of Puerto Rico. Eastern Puerto Rico receives large atmospheric inputs of marine salts, pollutants from the Northern Hemisphere, and Saharan Desert dust. Marine salts contribute over 80 percent of the ionic charge in precipitation, with peak inputs in January. Intense storms, mostly hurricanes, are associated with exceptionally high chloride concentrations in stream waters. Temperate pollution contributes nitrate, ammonia, and sulfate, with maximum inputs during northern cold fronts in January, April, and May. Pollution inputs have increased through time. Desert dust peaks in June and July, during times of maximum dust transport from the Saharan Desert across the Atlantic Ocean.

  11. Hydrogen-enriched water restoration of impaired calcium propagation by arsenic in primary keratinocytes

    NASA Astrophysics Data System (ADS)

    Yu, Wei-Tai; Chiu, Yi-Ching; Lee, Chih-Hung; Yoshioka, Tohru; Yu, Hsin-Su

    2013-11-01

    Endemic contamination of artesian water for drinking by arsenic is known to cause several human cancers, including cancers of the skin, bladder, and lungs. In skin, multiple arsenic-induced Bowen's disease (As-BD) can develop into invasive cancers after decades of arsenic exposure. The characteristic histological features of As-BD include full-layer epidermal dysplasia, apoptosis, and abnormal proliferation. Calcium propagation is an essential cellular event contributing to keratinocyte differentiation, proliferation, and apoptosis, all of which occur in As-BD. This study investigated how arsenic interferes calcium propagation of skin keratinocytes through ROS production and whether hydrogen-enriched water would restore arsenic-impaired calcium propagation. Arsenic was found to induce oxidative stress and inhibit ATP- and thapsigaragin-induced calcium propagation. Pretreatment of arsenic-treated keratinocytes by hydrogen-enriched water or beta-mercaptoethanol with potent anti-oxidative effects partially restored the propagation of calcium by ATP and by thapsigaragin. It was concluded that arsenic may impair calcium propagation, likely through oxidative stress and interactions with thiol groups in membrane proteins.

  12. The LuNa project: experimental didactic modules exploiting portable setups to teach optics in primary and secondary schools

    NASA Astrophysics Data System (ADS)

    Bondani, Maria; Allevi, Alessia; Nardo, Luca; Favale, Fabrizio

    2014-07-01

    The "LuNa" (La natura della Luce nella luce della Natura - The nature of Light in the light of Nature) Project is devoted to the experimental teaching of optics in the different school grades. The basic idea of the Project is that the history of optics and the debate about the nature of light are a meaningful example of how science proceeds in the development of a physical model. Moreover optical phenomena can be presented at different levels of complexity in order to be accessible to students of different age. At the core of the Project are several portable setups that support experimental and partially interactive lectures covering all the aspects of optical phenomena, from geometrical optics to single-photon interference passing through atmospheric optics, spectroscopy, holography and theory of perception. When possible, the setups are realized with simple and easy to find materials so as to be reproducible by teachers and students. Of course, for the most complicated setups (interferometers and holography) research materials are used. Each module is calibrated to fit teachers' requirements either to be included in the curricula of their classes or to be used as an expansion of the optics program.

  13. Experimental study of plane turbulent wakes in a shallow water layer

    NASA Astrophysics Data System (ADS)

    Chen, Daoyi; Jirka, Gerhard H.

    1995-07-01

    Shallow two-dimensional turbulent wake flows have been studied experimentally on a large water table. In the experiments, the ambient Reynolds number Re h = UaH/ ν, in which Ua is the depth-averaged ambient velocity, H the water depth, and ν the kinematic viscosity, is large, well above a lower critical value of the order of 500 for open-channel flows so that the ambient base flow is fully turbulent. Different types of blunt bodies extending over the full depth are inserted in that base flow, including cylinders and flat solid and porous plates oriented transversely to the ambient flow. In all cases, the transverse body dimension D greatly exceeds the water depthy, D/H ≫ 1 . With that condition, the wake Reynolds number Re d = UaD/ ν is very large, greater than 10 4. The shallow near-wake characteristics of plane wakes from blunt bodies extending over the full water depth have been found to fall into one of three classes: (i) the vortex street (VS) type with an oscillating vortex shedding mechanism, (ii) the unsteady bubble (UB) wake type with flow instabilities growing downstream of a recirculating bubble attached to the body, and (iii) the steady bubble (SB) wake type with an attached bubble followed by a turbulent wake that contains no growing instabilities. When Re h > 1500, the flow classification is uniquely dependent on a shallow wake parameter, S = c fD/H in which cf is a quadratic law friction coefficient. For circular cylindrical bodies the VS-UB transition is characterized by a critical value, Sca ≈ 0.2, and the UB-SB transition by Scc ≈ 0.5. Solid plates, oriented transversely, differ by a factor of 1.25. The shallow far-wake behavior has been investigated with a special variable porosity wake device that reduces the wake velocity deficit and completely suppresses the VS instabilities in the near-field. Thus, only UB and SB wake types are found in that case. Furthermore, the shallow plane wake is obsserved to "stabilize" for large downstream

  14. Carbon dioxide flux and net primary production of a boreal treed bog: Responses to warming and water-table-lowering simulations of climate change

    NASA Astrophysics Data System (ADS)

    Munir, T. M.; Perkins, M.; Kaing, E.; Strack, M.

    2015-02-01

    Midlatitude treed bogs represent significant carbon (C) stocks and are highly sensitive to global climate change. In a dry continental treed bog, we compared three sites: control, recent (1-3 years; experimental) and older drained (10-13 years), with water levels at 38, 74 and 120 cm below the surface, respectively. At each site we measured carbon dioxide (CO2) fluxes and estimated tree root respiration (Rr; across hummock-hollow microtopography of the forest floor) and net primary production (NPP) of trees during the growing seasons (May to October) of 2011-2013. The CO2-C balance was calculated by adding the net CO2 exchange of the forest floor (NEff-Rr) to the NPP of the trees. From cooler and wetter 2011 to the driest and the warmest 2013, the control site was a CO2-C sink of 92, 70 and 76 g m-2, the experimental site was a CO2-C source of 14, 57 and 135 g m-2, and the drained site was a progressively smaller source of 26, 23 and 13 g CO2-C m-2. The short-term drainage at the experimental site resulted in small changes in vegetation coverage and large net CO2 emissions at the microforms. In contrast, the longer-term drainage and deeper water level at the drained site resulted in the replacement of mosses with vascular plants (shrubs) on the hummocks and lichen in the hollows leading to the highest CO2 uptake at the drained hummocks and significant losses in the hollows. The tree NPP (including above- and below-ground growth and litter fall) in 2011 and 2012 was significantly higher at the drained site (92 and 83 g C m-2) than at the experimental (58 and 55 g C m-2) and control (52 and 46 g C m-2) sites. We also quantified the impact of climatic warming at all water table treatments by equipping additional plots with open-top chambers (OTCs) that caused a passive warming on average of ~ 1 °C and differential air warming of ~ 6 °C at midday full sun over the study years. Warming significantly enhanced shrub growth and the CO2 sink function of the drained

  15. A Review of the Experimental and Modeling Development of a Water Phase Change Heat Exchanger for Future Exploration Support Vehicles

    NASA Technical Reports Server (NTRS)

    Cognata, Thomas; Leimkuehler, Thomas; Ramaswamy, Balasubramaniam; Nayagam, Vedha; Hasan, Mohammad; Stephan, Ryan

    2011-01-01

    Water affords manifold benefits for human space exploration. Its properties make it useful for the storage of thermal energy as a Phase Change Material (PCM) in thermal control systems, in radiation shielding against Solar Particle Events (SPE) for the protection of crew members, and it is indisputably necessary for human life support. This paper envisions a single application for water which addresses these benefits for future exploration support vehicles and it describes recent experimental and modeling work that has been performed in order to arrive at a description of the thermal behavior of such a system. Experimental units have been developed and tested which permit the evaluation of the many parameters of design for such a system with emphasis on the latent energy content, temperature rise, mass, and interstitial material geometry. The experimental results are used to develop a robust and well correlated model which is intended to guide future design efforts toward the multi-purposed water PCM heat exchanger envisioned.

  16. Correlations between ab initio and experimental data for isolated H-bonded complexes of water with nitrogen bases

    NASA Astrophysics Data System (ADS)

    Maes, G.; Smets, J.; Adamowicz, L.; McCarthy, W.; Van Bael, M. K.; Houben, L.; Schoone, K.

    1997-06-01

    Correlations between selected ab initio predicted and experimentally observed properties of 1:1 H-bonded complexes of pyridines, pyrimidines, and imidazoles with water are investigated. Relationships are found between the experimental properties of proton affinity and water frequency shift, and the ab initio calculated bond distances, interaction energies and water frequency shifts. It is also found that well-defined relations can be established between calculated and observed properties for the pyridine complexes, but these cannot be reliably extended to the other N-base systems. The similarities demonstrate that the presently available ab initio methods are useful in predicting the experimental behaviour of H-bonded systems, but only for closely related molecules.

  17. Toward Obtaining the Experimental Constraints on the Role of Water on Melting Under the Lower Mantle Conditions

    NASA Astrophysics Data System (ADS)

    Amulele, G.; Lee, K. K.; Karato, S.

    2012-12-01

    Water and other volatile components (such as carbon dioxide) are known to have important influence on the melting behavior of silicates. The role of these components on the melting under the upper mantle conditions is now reasonably well understood. Recent experimental studies in our lab as well as some of the previous studies do show that water has an important influence on the melting relationship under the lower mantle conditions. The influence of water is not only to reduce the solidus but also to change the composition of the melt to (Mg,Fe)O rich. Quantifying these observations is essential in the understanding of chemical evolution of Earth and other planets. However, there are several challenges in performing these experimental studies. In this presentation, we discuss the issue of quantifying the water effects with special attention to the capability of preserving water content during the high pressure-temperature experiments. The issue of the preservation of water is important firstly because water could escape from a capsule during an experiment, and secondly because the melt is unquenchable in a commonly used processes under the lower mantle conditions. A commonly used practice is to identify the deficit of EPMA measurement from 100% to the water content, but there is no sound basis for this practice. In this presentation, we will show some preliminary results of our new approach to quantify the water content from the high-pressure run products containing melts.

  18. [EXPERIMENTAL GROUNDS ON POSSIBILITY TO MAKE AND TO USE PREDICTION MODELS OF PESTICIDES DESIGN STANDARD IN THE WATER OF PONDS USED FOR HOUSEHOLD AND DRINKING WATER SUPPLY].

    PubMed

    Vavrinevych, O P; Omel'chuk, S T

    2015-01-01

    Taking into account the fact that current calculation methods for substantiation of standards in the water of water reservoirs valid in Ukraine are outdated the aim of our research was to scientifically substantiate the possibility to make and to use prediction models of pesticides design standard in the water of ponds used for household and drinking water supply. Array of experimentally substantiated and approved to use in Ukraine maximum allowable concentrations (MAC) of organic pesticides active ingredients in the water was analyzed (n = 201). Analysis of dependence between MAC value of pesticides in the water and its physical and chemical properties, indices of ecotoxicological hazard and persistency in the water was carried out using correlation and regression analysis methods. Twelve regression equations to establish design value of pesticides MAC in the water were proposed on the grounds of performed analysis. The results of reliability testing of proposed procedure on pesticides design tentatively allowable levels (TAL) in the water indicate on needs to apply the least value of TAL obtained in the process of calculations using proposed equations. It was proved that mathematical models proposed for prediction of pesticide design standard in the water are adequate and significant by Fisher's test (P < 0.05). Proposed algorithm allows considerably simplify procedure of obtaining temporary hygienic standard in the water for new pesticides. PMID:27491169

  19. [EXPERIMENTAL GROUNDS ON POSSIBILITY TO MAKE AND TO USE PREDICTION MODELS OF PESTICIDES DESIGN STANDARD IN THE WATER OF PONDS USED FOR HOUSEHOLD AND DRINKING WATER SUPPLY].

    PubMed

    Vavrinevych, O P; Omel'chuk, S T

    2015-01-01

    Taking into account the fact that current calculation methods for substantiation of standards in the water of water reservoirs valid in Ukraine are outdated the aim of our research was to scientifically substantiate the possibility to make and to use prediction models of pesticides design standard in the water of ponds used for household and drinking water supply. Array of experimentally substantiated and approved to use in Ukraine maximum allowable concentrations (MAC) of organic pesticides active ingredients in the water was analyzed (n = 201). Analysis of dependence between MAC value of pesticides in the water and its physical and chemical properties, indices of ecotoxicological hazard and persistency in the water was carried out using correlation and regression analysis methods. Twelve regression equations to establish design value of pesticides MAC in the water were proposed on the grounds of performed analysis. The results of reliability testing of proposed procedure on pesticides design tentatively allowable levels (TAL) in the water indicate on needs to apply the least value of TAL obtained in the process of calculations using proposed equations. It was proved that mathematical models proposed for prediction of pesticide design standard in the water are adequate and significant by Fisher's test (P < 0.05). Proposed algorithm allows considerably simplify procedure of obtaining temporary hygienic standard in the water for new pesticides.

  20. Temporal trends in aboveground net primary production of semi-arid shrublands exposed to experimental N deposition

    NASA Astrophysics Data System (ADS)

    Vourlitis, G. L.

    2011-12-01

    Southern Californian chaparral and coastal sage scrub (CSS) shrublands are exposed to high-levels of dry-atmospheric nitrogen (N) deposition. A field experiment was conducted over 8 years in a post-fire chaparral and a mature CSS stand to assess the effects of cumulative, dry-season N inputs on aboveground net primary production (NPP). We hypothesized that the NPP chaparral and CSS would significantly increase in response to N exposure because previous research indicated to the productivity of these semi-arid shrublands was limited by N. Our results indicate that N addition eventually increased the NPP of both shrublands; however, trends in NPP varied over time and were affected by interannual variations in rainfall. For example, added N in post-fire chaparral initially inhibited NPP, but over time NPP increased consistently in plots exposed to added N. For CSS, temporal trends in NPP were independent of cumulative N exposure; however, a pattern emerged where the effect of N exposure was significantly related to annual rainfall. NPP increased significantly to N exposure when rainfall exceeded approximately 400 mm year-1 but declined with N exposure during dry years. These results support our hypothesis that N enrichment will increase the NPP of these semi-arid shrublands; however, temporal patterns may take years to emerge (chaparral) or be modified by annual variations in rainfall (CSS).

  1. Experimental study on the heat transfer characteristics of a nuclear reactor containment wall cooled by gravitationally falling water

    NASA Astrophysics Data System (ADS)

    Pasek, Ari D.; Umar, Efrison; Suwono, Aryadi; Manalu, Reinhard E. E.

    2012-06-01

    Gravitationally falling water cooling is one of mechanism utilized by a modern nuclear Pressurized Water Reactor (PWR) for its Passive Containment Cooling System (PCCS). Since the cooling is closely related to the safety, water film cooling characteristics of the PCCS should be studied. This paper deals with the experimental study of laminar water film cooling on the containment model wall. The influences of water mass flow rate and wall heat rate on the heat transfer characteristic were studied. This research was started with design and assembly of a containment model equipped with the water cooling system, and calibration of all measurement devices. The containment model is a scaled down model of AP 1000 reactor. Below the containment steam is generated using electrical heaters. The steam heated the containment wall, and then the temperatures of the wall in several positions were measure transiently using thermocouples and data acquisition. The containment was then cooled by falling water sprayed from the top of the containment. The experiments were done for various wall heat rate and cooling water flow rate. The objective of the research is to find the temperature profile along the wall before and after the water cooling applied, prediction of the water film characteristic such as means velocity, thickness and their influence to the heat transfer coefficient. The result of the experiments shows that the wall temperatures significantly drop after being sprayed with water. The thickness of water film increases with increasing water flow rate and remained constant with increasing wall heat rate. The heat transfer coefficient decreases as film mass flow rate increase due to the increases of the film thickness which causes the increasing of the thermal resistance. The heat transfer coefficient increases slightly as the wall heat rate increases. The experimental results were then compared with previous theoretical studied.

  2. Thermal Hydraulic Analysis of an Experimental Reactor Cavity Cooling System with Water: Performance and Stability

    NASA Astrophysics Data System (ADS)

    Lisowski, Darius D.

    This experimental study investigated the thermal hydraulic behavior and boiling mechanisms present in a scaled reactor cavity cooling system (RCCS). The experimental facility reflects a ¼ scale model of one conceptual design for decay heat removal in advanced GenIV nuclear reactors. Radiant heaters supply up to 25 kW/m2 onto a three parallel riser tube and cooling panel test section assembly, representative of a 5° sector model of the full scale concept. Derived similarity relations have preserved the thermal hydraulic flow patterns and integral system response, ensuring relevant data and similarity among scales. Attention will first be given to the characterization of design features, form and heat losses, nominal behavior, repeatability, and data uncertainty. Then, tests performed in single-phase have evaluated the steady-state behavior. Following, the transition to saturation and subsequent boiling allowed investigations onto four parametric effects at two-phase flow and will be the primary focus area of remaining analysis. Baseline conditions at two-phase flow were defined by 15.19 kW of heated power and 80% coolant inventory, and resulted in semi-periodic system oscillations by the mechanism of hydrostatic head fluctuations. Void generation was the result of adiabatic expansion of the fluid due to a reduction in hydrostatic head pressure, a phenomena similar to flashing. At higher powers of 17.84 and 20.49 kW, this effect was augmented, creating large flow excursions that followed a smooth and sinusoidal shaped path. Stabilization can occur if the steam outflow condition incorporates a nominal restriction, as it will serve to buffer the short time scale excursions of the gas space pressure and dampen oscillations. The influences of an inlet restriction, imposed by an orifice plate, introduced subcooling boiling within the heated core and resulted in chaotic interactions among the parallel risers. The penultimate parametric examined effects of boil-off and

  3. Kinetic and Statistical Analysis of Primary Circuit Water Chemistry Data in a VVER Power Plant

    SciTech Connect

    Nagy, Gabor; Tilky, Peter; Horvath, Akos; Pinter, Tamas; Schiller, Robert

    2001-12-15

    The results of chemical and radiochemical analyses of the primary circuit coolant liquid, obtained between 1995 and 1999 at the four VVER-type blocks of the Paks (Hungary) nuclear power station, are assessed. A model has been developed regarding the pressure vessel with its auxiliary parts plus the fuel elements as the zone, with the six steam generators as one single unit. The stream from the steam generator is split, with its larger part returning to the zone through the main circulating pump and the smaller one passing through the purifier column. Based on this flowchart, the formation kinetics of corrosion products and of radioactive substances are evaluated. Correlation analysis is applied to reveal any eventual interdependence of the processes, whereas the range-per-scatter (R/S) method is used to characterize the random or deterministic nature of a process. The evaluation of the t {yields} {infinity} limits of the kinetic equations enables one to conclude that (a) the total amount of corrosion products per element during one cycle is almost always <15 kg and (b) the zone acts as a highly efficient filter with an efficiency of {approx}1. The R/S results show that the fluctuations in the concentrations of the corrosion products are persistent; this finding indicates that random effects play here little if any role and that the processes in the coolant are under control. Correlation analyses show that the variations of the concentrations are practically uncorrelated and that the processes are independent of each other.

  4. Serological responses to Neospora caninum in experimentally and naturally infected water buffaloes (Bubalus bubalis).

    PubMed

    Rodrigues, A A R; Gennari, S M; Paula, V S O; Aguiar, D M; Fujii, T U; Starke-Buzeti, W; Machado, R Z; Dubey, J P

    2005-04-20

    The water buffalo (Bubalus bubalis) is an important natural host for Neospora caninum. Serologic responses to N. caninum were studied in experimentally and naturally infected water buffaloes in Brazil. Antibodies were assayed by the indirect fluorescent antibody test (IFAT) using a cut off value of 1:25. Six buffaloes were each inoculated subcutaneously with 5 x 10(6) live culture-derived tachyzoites of the cattle Illinois strain of N. caninum, and two calves were kept as uninoculated controls. Post-inoculation (p.i.) blood samples were collected weekly for 8 weeks and then monthly until 1 year p.i. All inoculated buffaloes developed IFAT titers of 1:100 or more between 7 and 11 days p.i. and the titers remained elevated until 7 weeks p.i. Antibody titers peaked to 1:1600 in 1, 1:800 in 3 and 1:400 in 2, usually by 3 weeks p.i. Antibody titers declined to 1:25 or 1:50 in all the six buffaloes by 12 months p.i. IFAT titers to N. caninum remained at an undetectable level (< 1:25) in both control uninoculated buffaloes. To follow the dynamics of N. caninum antibodies, sera from 29 buffaloes and their calves were collected for 1 year and assayed for N. caninum antibodies; 23 of 29 calves were seropositive (IFAT of 1:100 or more) at 1-2 day of age. Of these 23 calves, 17 remained seropositive during the study, while six became seronegative at four (two calves), six (one calf) seven (two calves) and eight (one calf) months of age. These findings suggest a high rate of neonatal transmission of N. caninum in buffaloes.

  5. First international comparison of primary absorbed dose to water standards in the medium-energy X-ray range

    NASA Astrophysics Data System (ADS)

    Büermann, Ludwig; Guerra, Antonio Stefano; Pimpinella, Maria; Pinto, Massimo; de Pooter, Jacco; de Prez, Leon; Jansen, Bartel; Denoziere, Marc; Rapp, Benjamin

    2016-01-01

    This report presents the results of the first international comparison of primary measurement standards of absorbed dose to water for the medium-energy X-ray range. Three of the participants (VSL, PTB, LNE-LNHB) used their existing water calorimeter based standards and one participant (ENEA) recently developed a new standard based on a water-graphite calorimeter. The participants calibrated three transfer chambers of the same type in terms of absorbed dose to water (NDw) and in addition in terms of air kerma (NK) using the CCRI radiation qualities in the range 100 kV to 250 kV. The additional NK values were intended to be used for a physical analysis of the ratios NDw/NK. All participants had previously participated in the BIPM.RI(I)-K3 key comparison of air kerma standards. Ratios of pairs of NMI's NK results of the current comparison were found to be consistent with the corresponding key comparison results within the expanded uncertainties of 0.6 % - 1 %. The NDw results were analysed in terms of the degrees of equivalence with the comparison reference values which were calculated for each beam quality as the weighted means of all results. The participant's results were consistent with the reference value within the expanded uncertainties. However, these expanded uncertainties varied significantly and ranged between about 1-1.8 % for the water calorimeter based standards and were estimated at 3.7 % for the water-graphite calorimeter. It was shown previously that the ratios NDw/NK for the type of ionization chamber used as transfer chamber in this comparison were very close (within less than 1 %) to the calculated values of (bar muen/ρ)w,ad, the mean values of the water-to-air ratio of the mass-energy-absorption coefficients at the depth d in water. Some of the participant's results deviated significantly from the expected behavior. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of

  6. Testing geochemical models of bentonite pore water evolution against laboratory experimental data

    NASA Astrophysics Data System (ADS)

    Savage, David; Arthur, Randy; Watson, Claire; Wilson, James; Strömberg, Bo

    The determination of a bentonite pore water composition and understanding its evolution with time underpins many radioactive waste disposal issues, such as buffer erosion, canister corrosion, and radionuclide solubility, sorption, and diffusion, inter alia. Previous modelling approaches have tended to ignore clay dissolution-precipitation reactions, a consequence of which is that montmorillonite is theoretically preserved indefinitely in the repository system. Here, we investigate the applicability of an alternative clay pore fluid evolution model, that incorporates clay dissolution-precipitation reactions as an integral component and test it against well-characterised laboratory experimental data, where key geochemical parameters, Eh and pH, have been measured directly in compacted bentonite. Simulations have been conducted using different computer codes (Geochemist’s Workbench, PHREEQC, and QPAC) to test the applicability of this model. Thermodynamic data for the Gibb’s free energy of formation of MX-80 smectite used in the calculations were estimated using two different methods (‘Polymer’ and ‘Vieillard’ Models). Simulations of ‘end-point’ pH measurements in batch bentonite-water slurry experiments showed different pH values according to the complexity of the system studied. The most complete system investigated revealed pH values were a strong function of partial pressure of carbon dioxide, with pH increasing with decreasing PCO 2 (with log PCO 2 values ranging from -3.5 to -7.5 bars produced pH values ranging from 7.9 to 9.6). A second set of calculations investigated disequilibrium between clay and pore fluid in laboratory squeezing cell tests involving pure water (pH = 9.0) or a 1 M NaOH solution (pH = 12.1). Simulations carried out for 100 days (the same timescale as the experiments) showed that smectite remained far from equilibrium throughout, and that the lowering of pH due to smectite hydrolysis was trivial. However, extending the

  7. Effect of Water Stress on Cortical Cell Division Rates within the Apical Meristem of Primary Roots of Maize.

    PubMed Central

    Sacks, M. M.; Silk, W. K.; Burman, P.

    1997-01-01

    We characterized the effect of water stress on cell division rates within the meristem of the primary root of maize (Zea mays L.) seedlings. As usual in growth kinematics, cell number density is found by counting the number of cells per small unit length of the root; growth velocity is the rate of displacement of a cellular particle found at a given distance from the apex; and the cell flux, representing the rate at which cells are moving past a spatial point, is defined as the product of velocity and cell number density. The local cell division rate is estimated by summing the derivative of cell density with respect to time, and the derivative of the cell flux with respect to distance. Relatively long (2-h) intervals were required for time-lapse photography to resolve growth velocity within the meristem. Water stress caused meristematic cells to be longer and reduced the rates of cell division, per unit length of tissue and per cell, throughout most of the meristem. Peak cell division rate was 8.2 cells mm-1 h-1 (0.10 cells cell-1 h-1) at 0.8 mm from the apex for cells under water stress, compared with 13 cells mm-1 h-1 (0.14 cells cell-1 h-1) at 1.0 mm for controls. PMID:12223725

  8. Liquid chromatographic determination of chloramine-T and its primary degradation product, p-toluenesulfonamide, in water

    USGS Publications Warehouse

    Dawson, V.K.; Davis, R.A.

    1997-01-01

    N-sodium-N-chloro-rho-toluenesulfonamide (chloramine-T) effectively controls bacterial gill disease (BGD) in cultured fishes, BGD, a common disease of hatchery-reared salmonids, causes more fish losses than any other disease among these species, This study describes a liquid chromatographic (LC) method that is capable of direct, simultaneous analysis of chloramine-T and its primary degradation product, rho-toluenesulfonamide (rho-TSA), in water. The procedure involves reversed-phase (C-18) LC analysis with ion suppression, using 0.01 M phosphate buffer at pH 3. The mobile phase is phosphate buffer-acetonitrile (60 + 40) at 1 mL/min. Both chemicals can be detected with a UV spectrophotometer at 229 nm; the method is linear up to 40 mg, chloramine-T or rho-TSA/L. Mean recoveries were 96.4 +/- 6.1% for water samples fortified with 0.03 mg chloramine-T/L and 95.3 +/- 4.6% for water samples fortified with 0.005 mg rho-TSA/L. Limits of detection without sample enrichment for chloramine-T and rho-TSA are 0.01 mg/L and 0.001 mg/L, respectively.

  9. Liquid chromatographic determination of chloramine-T and its primary degradation product, p-toluenesulfonamide, in water

    USGS Publications Warehouse

    Dawson, Verdel K.; Davis, Ruth A.

    1997-01-01

    N-sodium-N-chloro-rho-toluenesulfonamide (chloramine-T) effectively controls bacterial gill disease (BGD) in cultured fishes, BGD, a common disease of hatchery-reared salmonids, causes more fish losses than any other disease among these species. This study describes a liquid chromatographic (LC) method that is capable of direct, simultaneous analysis of chloramine-T and its primary degradation product, rho-toluenesulfonamide (rho-TSA), in water. The procedure involves reversed-phase (C-18) LC analysis with ion suppression, using 0.01 M phosphate buffer at pH 3. The mobile phase is phosphate buffer-acetonitrile (60 + 40) at 1 mL/min. Both chemicals can be detected with a UV spectrophotometer at 229 nm; the method is linear up to 40 mg, chloramine-T or rho-TSA/L. Mean recoveries were 96.4 +/- 6.1% for water samples fortified with 0.03 mg chloramine-T/L and 95.3 +/- 4.6% for water samples fortified with 0.005 mg rho-TSA/L. Limits of detection without sample enrichment for chloramine-T and rho-TSA are 0.01 mg/L and 0.001 mg/L, respectively.

  10. Inactivation and injury of total coliform bacteria after primary disinfection of drinking water by TiO2 photocatalysis.

    PubMed

    Rizzo, Luigi

    2009-06-15

    In this study the potential application of TiO(2) photocatalysis as primary disinfection system of drinking water was investigated in terms of coliform bacteria inactivation and injury. As model water the effluent of biological denitrification unit for nitrate removal from groundwater, which is characterized by high organic matter and bacteria release, was used. The injury of photocatalysis on coliform bacteria was characterized by means of selective (mEndo) and less selective (mT7) culture media. Different catalyst loadings as well as photolysis and adsorption effects were investigated. Photocatalysis was effective in coliform bacteria inactivation (91-99% after 60 min irradiation time, depending on both catalyst loading and initial density of coliform bacteria detected by mEndo), although no total removal was observed after 60 min irradiation time. The contribution of adsorption mechanism was significant (60-98% after 60 min, depending on catalyst loading) compared to previous investigations probably due to the nature of source water rich in particulate organic matter and biofilm. Photocatalysis process did not result in any irreversible injury (98.8% being the higher injury) under investigated conditions, thus a bacteria regrowth may take place under optimum environment conditions if any final disinfection process (e.g., chlorine or chlorine dioxide) is not used.

  11. Primary blast causes mild, moderate, severe and lethal TBI with increasing blast overpressures: Experimental rat injury model

    PubMed Central

    Mishra, Vikas; Skotak, Maciej; Schuetz, Heather; Heller, Abi; Haorah, James; Chandra, Namas

    2016-01-01

    Injury severity in blast induced Traumatic Brain Injury (bTBI) increases with blast overpressure (BOP) and impulse in dose-dependent manner. Pure primary blast waves were simulated in compressed gas shock-tubes in discrete increments. Present work demonstrates 24 hour survival of rats in 0–450 kPa (0–800 Pa∙s impulse) range at 10 discrete levels (60, 100, 130, 160, 190, 230, 250, 290, 350 and 420 kPa) and determines the mortality rate as a non-linear function of BOP. Using logistic regression model, predicted mortality rate (PMR) function was calculated, and used to establish TBI severities. We determined a BOP of 145 kPa as upper mild TBI threshold (5% PMR). Also we determined 146–220 kPa and 221–290 kPa levels as moderate and severe TBI based on 35%, and 70% PMR, respectively, while BOP above 290 kPa is lethal. Since there are no standards for animal bTBI injury severity, these thresholds need further refinements using histopathology, immunohistochemistry and behavior. Further, we specifically investigated mild TBI range (0–145 kPa) using physiological (heart rate), pathological (lung injury), immuno-histochemical (oxidative/nitrosative and blood-brain barrier markers) as well as blood borne biomarkers. With these additional data, we conclude that mild bTBI occurs in rats when the BOP is in the range of 85–145 kPa. PMID:27270403

  12. Primary blast causes mild, moderate, severe and lethal TBI with increasing blast overpressures: Experimental rat injury model

    NASA Astrophysics Data System (ADS)

    Mishra, Vikas; Skotak, Maciej; Schuetz, Heather; Heller, Abi; Haorah, James; Chandra, Namas

    2016-06-01

    Injury severity in blast induced Traumatic Brain Injury (bTBI) increases with blast overpressure (BOP) and impulse in dose-dependent manner. Pure primary blast waves were simulated in compressed gas shock-tubes in discrete increments. Present work demonstrates 24 hour survival of rats in 0–450 kPa (0–800 Pa•s impulse) range at 10 discrete levels (60, 100, 130, 160, 190, 230, 250, 290, 350 and 420 kPa) and determines the mortality rate as a non-linear function of BOP. Using logistic regression model, predicted mortality rate (PMR) function was calculated, and used to establish TBI severities. We determined a BOP of 145 kPa as upper mild TBI threshold (5% PMR). Also we determined 146–220 kPa and 221–290 kPa levels as moderate and severe TBI based on 35%, and 70% PMR, respectively, while BOP above 290 kPa is lethal. Since there are no standards for animal bTBI injury severity, these thresholds need further refinements using histopathology, immunohistochemistry and behavior. Further, we specifically investigated mild TBI range (0–145 kPa) using physiological (heart rate), pathological (lung injury), immuno-histochemical (oxidative/nitrosative and blood-brain barrier markers) as well as blood borne biomarkers. With these additional data, we conclude that mild bTBI occurs in rats when the BOP is in the range of 85–145 kPa.

  13. Primary blast causes mild, moderate, severe and lethal TBI with increasing blast overpressures: Experimental rat injury model.

    PubMed

    Mishra, Vikas; Skotak, Maciej; Schuetz, Heather; Heller, Abi; Haorah, James; Chandra, Namas

    2016-01-01

    Injury severity in blast induced Traumatic Brain Injury (bTBI) increases with blast overpressure (BOP) and impulse in dose-dependent manner. Pure primary blast waves were simulated in compressed gas shock-tubes in discrete increments. Present work demonstrates 24 hour survival of rats in 0-450 kPa (0-800 Pa∙s impulse) range at 10 discrete levels (60, 100, 130, 160, 190, 230, 250, 290, 350 and 420 kPa) and determines the mortality rate as a non-linear function of BOP. Using logistic regression model, predicted mortality rate (PMR) function was calculated, and used to establish TBI severities. We determined a BOP of 145 kPa as upper mild TBI threshold (5% PMR). Also we determined 146-220 kPa and 221-290 kPa levels as moderate and severe TBI based on 35%, and 70% PMR, respectively, while BOP above 290 kPa is lethal. Since there are no standards for animal bTBI injury severity, these thresholds need further refinements using histopathology, immunohistochemistry and behavior. Further, we specifically investigated mild TBI range (0-145 kPa) using physiological (heart rate), pathological (lung injury), immuno-histochemical (oxidative/nitrosative and blood-brain barrier markers) as well as blood borne biomarkers. With these additional data, we conclude that mild bTBI occurs in rats when the BOP is in the range of 85-145 kPa. PMID:27270403

  14. Primary structure of water buffalo alpha-lactalbumin variants A and B.

    PubMed

    Chianese, Lina; Caira, Simonetta; Lilla, Sergio; Pizzolongo, Fabiana; Ferranti, Pasquale; Pugliano, Giovanni; Addeo, Francesco

    2004-02-01

    A novel electrophoretic alpha-lactalbumin (alpha-la) variant was detected in the Italian water buffalo breed. The isoelectric point of the variant, labelled A, was lower than the most frequent variant B. It presented an allelic frequency of 0.5% compared with the 97.1% of the BB allele. From Liquid Chromatography-Electrospray Ionization/Mass spectrometry, the molecular mass of the two alpha-la A and B variants were measured as 14,235.1+/-0.8 and 14,236.1+/-0.9 Da, respectively. The two proteins were sequenced and differentiated from one another by a single amino acid substitution, Asn45(B)-->Asp45(A). As this amino acid substitution altered the N-glycosylation sequence consensus Asn45-X-Ser46 it may be deduced that the protein glycosylation level of the alpha-la A would decrease.

  15. Modeling the radiolysis of supercritical water by fast neutrons: density dependence of the yields of primary species at 400°c.

    PubMed

    Butarbutar, Sofia Loren; Meesungnoen, Jintana; Guzonas, David A; Stuart, Craig R; Jay-Gerin, Jean-Paul

    2014-12-01

    A reliable understanding of radiolysis processes in supercritical water (SCW)-cooled reactors is crucial to developing chemistry control strategies that minimize the corrosion and degradation of materials. However, directly measuring the chemistry in reactor cores is difficult due to the extreme conditions of high temperature and pressure and mixed neutron and gamma-radiation fields, which are incompatible with normal chemical instrumentation. Thus, chemical models and computer simulations are an important route of investigation for predicting the detailed radiation chemistry of the coolant in a SCW reactor and the consequences for materials. Surprisingly, information on the fast neutron radiolysis of water at high temperatures is limited, and even more so for fast neutron irradiation of SCW. In this work, Monte Carlo simulations were used to predict the G values for the primary species e(-)aq, H(•), H2, (•)OH and H2O2 formed from the radiolysis of pure, deaerated SCW (H2O) by 2 MeV monoenergetic neutrons at 400°C as a function of water density in the range of ∼0.15-0.6 g/cm(3). The 2 MeV neutron was taken as representative of a fast neutron flux in a reactor. For light water, the moderation of these neutrons after knock-on collisions with water molecules generated mostly recoil protons of 1.264, 0.465, 0.171 and 0.063 MeV. Neglecting oxygen ion recoils and assuming that the most significant contribution to the radiolysis came from these first four recoil protons, the fast neutron yields were estimated as the sum of the G values for these protons after appropriate weightings were applied according to their energy. Calculated yields were compared with available experimental data and with data obtained for low-LET radiation. Most interestingly, the reaction of H(•) atoms with water was found to play a critical role in the formation yields of H2 and (•)OH at 400°C. Recent work has underscored the potential importance of this reaction above 200°C, but its

  16. Impacts of climate and land use change on ecosystem hydrology and net primary productivity: Linking water availability to food security in Asia

    NASA Astrophysics Data System (ADS)

    Dangal, S. R. S.; Tian, H.; Pan, S.; Zhang, B.; Yang, J.

    2015-12-01

    The nexus approach to food, water and energy security in Asia is extremely important and relevant as the region has to feed two-third of the world's population and accounts for 59% of the global water consumption. The distribution pattern of food, water and energy resources have been shaped by the legacy effect of both natural and anthropogenic disturbances and therefore are vulnerable to climate change and human activities including land use/cover change (LUCC) and land management (irrigation and nitrogen fertilization). In this study, we used the Dynamic Land Ecosystem Model (DLEM) to examine the effects of climate change, land use/cover change, and land management practices (irrigation and nitrogen fertilization) on the spatiotemporal trends and variability in water availability and its role in limiting net primary productivity (NPP) and food security in the 20th and early 21st centuries. Our specific objectives are to quantify how climate change, LUCC and other environmental changes have interactively affected carbon and water dynamics across the Asian region. In particular, we separated the Asian region into several sub-region based on the primary limiting factor - water, food and energy. We then quantified how changes in environmental factors have altered the water and food resources during the past century. We particularly focused on Net Primary Productivity (NPP) and water cycle (Evapotranspiration, discharge, and runoff) as a measure of available food and water resources, respectively while understanding the linkage between food and water resources in Asia.

  17. Experimental studies of alunite: II. Rates of alunite-water alkali and isotope exchange

    USGS Publications Warehouse

    Stoffregen, R.E.; Rye, R.O.; Wasserman, M.D.

    1994-01-01

    Rates of alkali exchange between alunite and water have been measured in hydrothermal experiments of 1 hour to 259 days duration at 150 to 400??C. Examination of run products by scanning electron microscope indicates that the reaction takes place by dissolution-reprecipitation. This exchange is modeled with an empirical rate equation which assumes a linear decrease in mineral surface area with percent exchange (f) and a linear dependence of the rate on the square root of the affinity for the alkali exchange reaction. This equation provides a good fit of the experimental data for f = 17% to 90% and yields log rate constants which range from -6.25 moles alkali m-2s-1 at 400??C to - 11.7 moles alkali m-2s-1 at 200??C. The variation in these rates with temperature is given by the equation log k* = -8.17(1000/T(K)) + 5.54 (r2 = 0.987) which yields an activation energy of 37.4 ?? 1.5 kcal/mol. For comparison, data from O'Neil and Taylor (1967) and Merigoux (1968) modeled with a pseudo-second-order rate expression give an activation energy of 36.1 ?? 2.9 kcal/mol for alkali-feldspar water Na-K exchange. In the absence of coupled alkali exchange, oxygen isotope exchange between alunite and water also occurs by dissolution-reprecipitation but rates are one to three orders of magnitude lower than those for alkali exchange. In fine-grained alunites, significant D-H exchange occurs by hydrogen diffusion at temperatures as low as 100??C. Computed hydrogen diffusion coefficients range from -15.7 to -17.3 cm2s-1 and suggest that the activation energy for hydrogen diffusion may be as low as 6 kcal/mol. These experiments indicate that rates of alkali exchange in the relatively coarse-grained alunites typical of hydrothermal ore deposits are insignificant, and support the reliability of K-Ar age data from such samples. However, the fine-grained alunites typical of low temperature settings may be susceptible to limited alkali exchange at surficial conditions which could cause

  18. Experimental burial inhibits methanogenesis and anaerobic decomposition in water-saturated peats.

    PubMed

    Blodau, Christian; Siems, Melanie; Beer, Julia

    2011-12-01

    A mechanistic understanding of carbon (C) sequestration and methane (CH(4)) production is of great interest due to the importance of these processes for the global C budget. Here we demonstrate experimentally, by means of column experiments, that burial of water saturated, anoxic bog peat leads to inactivation of anaerobic respiration and methanogenesis. This effect can be related to the slowness of diffusive transport of solutes and evolving energetic constraints on anaerobic respiration. Burial lowered decomposition constants in homogenized peat sand mixtures from about 10(-5) to 10(-7) yr(-1), which is considerably slower than previously assumed, and methanogenesis slowed down in a similar manner. The latter effect could be related to acetoclastic methanogenesis approaching a minimum energy quantum of -25 kJ mol(-1) (CH(4)). Given the robustness of hydraulic properties that locate the oxic-anoxic boundary near the peatland surface and constrain solute transport deeper into the peat, this effect has likely been critical for building the peatland C store and will continue supporting long-term C sequestration in northern peatlands even under moderately changing climatic conditions. PMID:21958021

  19. The water maze paradigm in experimental studies of chronic cognitive disorders: Theory, protocols, analysis, and inference.

    PubMed

    Kapadia, Minesh; Xu, Josie; Sakic, Boris

    2016-09-01

    An instrumental step in assessing the validity of animal models of chronic cognitive disorders is to document disease-related deficits in learning/memory capacity. The water maze (WM) is a popular paradigm because of its low cost, relatively simple protocol and short procedure time. Despite being broadly accepted as a spatial learning task, inference of generalized, bona fide "cognitive" dysfunction can be challenging because task accomplishment is also reliant on non-cognitive processes. We review theoretical background, testing procedures, confounding factors, as well as approaches to data analysis and interpretation. We also describe an extended protocol that has proven useful in detecting early performance deficits in murine models of neuropsychiatric lupus and Alzheimer's disease. Lastly, we highlight the need for standardization of inferential criteria on "cognitive" dysfunction in experimental rodents and exclusion of preparations of a limited scientific merit. A deeper appreciation for the multifactorial nature of performance in WM may also help to reveal other deficits that herald the onset of neurodegenerative brain disorders. PMID:27229758

  20. Simultaneous flow of water and solutes through geological membranes-I. Experimental investigation

    USGS Publications Warehouse

    Kharaka, Y.K.; Berry, F.A.P.

    1973-01-01

    The relative retardation by geological membranes of cations and anions generally present in subsurface waters was investigated using a high pressure and high temperature 'filtration cell'. The solutions were forced through different clays and a disaggregated shale subjected to compaction pressures up to 9500 psi and to temperatures from 20 to 70??C. The overall efficiences measured increased with increase of exchange capacity of the material used and with decrease in concentration of the input solution. The efficiency of a given membrane increased with increasing compaction pressure but decreased slightly at higher temperatures for solutions of the same ionic concentration. The results further show that geological membranes are specific for different dissolved species. The retardation sequences varied depending on the material used and on experimental conditions. The sequences for monovalent and divalent cations at laboratory temperatures were generally as follows: Li < Na < NH3 < K < Rb < Cs Mg < Ca < Sr < Ba. The sequences for anions at room temperature were variable, but at 70??C, the sequence was: HCO3 < I < B < SO4 < Cl < Br. Monovalent cations contrary to some field data were generally retarded with respect to divalent cations. The differences in the filtration ratios among the divalent cations were smaller than those between the monovalent cations. The passage rate of B, HCO3, I and NH3 was greatly increased at 70??C. ?? 1973.

  1. Decontamination and decommissioning of the Experimental Boiling Water Reactor (EBWR): Project final report, Argonne National Laboratory

    SciTech Connect

    Fellhauer, C.R.; Boing, L.E.; Aldana, J.

    1997-03-01

    The Final Report for the Decontamination and Decommissioning (D&D) of the Argonne National Laboratory - East (ANL-E) Experimental Boiling Water Reactor (EBWR) facility contains the descriptions and evaluations of the activities and the results of the EBWR D&D project. It provides the following information: (1) An overall description of the ANL-E site and EBWR facility. (2) The history of the EBWR facility. (3) A description of the D&D activities conducted during the EBWR project. (4) A summary of the final status of the facility, including the final and confirmation surveys. (5) A summary of the final cost, schedule, and personnel exposure associated with the project, including a summary of the total waste generated. This project report covers the entire EBWR D&D project, from the initiation of Phase I activities to final project closeout. After the confirmation survey, the EBWR facility was released as a {open_quotes}Radiologically Controlled Area,{close_quotes} noting residual elevated activity remains in inaccessible areas. However, exposure levels in accessible areas are at background levels. Personnel working in accessible areas do not need Radiation Work Permits, radiation monitors, or other radiological controls. Planned use for the containment structure is as an interim transuranic waste storage facility (after conversion).

  2. Experimental studies of thermal and chemical interactions between oxide and silicide nuclear fuels with water

    SciTech Connect

    farahani, A.A.; Corradini, M.L.

    1995-09-01

    Given some transient power/cooling mismatch is a nuclear reactor and its inability to establish the necessary core cooling, energetic fuel-coolant interactions (FCI`s commonly called `vapor explosions`) could occur as a result of the core melting and coolant contact. Although a large number of studies have been done on energetic FCI`s, very few experiments have been performed with the actual fuel materials postulated to be produced in severe accidents. Because of the scarcity of well-characterized FCI data for uranium allows in noncommercial reactors (cermet and silicide fuels), we have conducted a series of experiments to provide a data base for the foregoing materials. An existing 1-D shock-tube facility was modified to handle depleted radioactive materials (U{sub 3}O{sub 8}-Al, and U{sub 3}Si{sub 2}-Al). Our objectives have been to determine the effects of the initial fuel composition and temperature and the driving pressure (triggering) on the explosion work output, dynamic pressures, transient temperatures, and the hydrogen production. Experimental results indicate limited energetics, mainly thermal interactions, for these fuel materials as compared to aluminum where more chemical reactions occur between the molten aluminum and water.

  3. Determination of pharmaceuticals in drinking water by CD-modified MEKC: separation optimization using experimental design.

    PubMed

    Drover, Vincent J; Bottaro, Christina S

    2008-12-01

    A suite of 12 widely used pharmaceuticals (ibuprofen, diclofenac, naproxen, bezafibrate, gemfibrozil, ofloxacin, norfloxacin, carbamazepine, primidone, sulphamethazine, sulphadimethoxine and sulphamethoxazole) commonly found in environmental waters were separated by highly sulphated CD-modified MEKC (CD-MEKC) with UV detection. An experimental design method, face-centred composite design, was employed to minimize run time without sacrificing resolution. Using an optimized BGE composed of 10 mM ammonium hydrogen phosphate, pH 11.5, 69 mM SDS, 6 mg/mL sulphated beta-CD and 8.5% v/v isopropanol, a separation voltage of 30 kV and a 48.5 cm x 50 microm id bare silica capillary at 30 degrees C allowed baseline separation of the 12 analytes in a total analysis time of 6.7 min. Instrument LODs in the low milligram per litre range were obtained, and when combined with offline preconcentration by SPE, LODs were between 4 and 30 microg/L.

  4. Experimental investigation on effects of acid/base waters on the bottom sediment of Kaita Cove (Hiroshima, Japan)

    NASA Astrophysics Data System (ADS)

    Touch, Narong; Hibino, Tadashi; Ueno, Kohei; Fukui, Shogo

    2013-12-01

    The decomposition of organic matter existing in bottom sediment produces reduced substances, and this has an influence on the water environment. Recently, it has been pointed out that the water environment can be improved after covering the bottom sediment with alkaline material. In this study, we experimentally investigate the effects of acid and base waters (hydrogen peroxide and calcium oxide solutions, respectively) on bottom sediment. The bottom sediment of Kaita Cove (Hiroshima, Japan) was mixed and stirred with the acid or base water, and then the dissolved carbon content (DCC), the pH, and the ammonium nitrogen (NH4-N) of the overlying solution were analyzed along with the particle size distribution, particulate carbon content (PCC), and particulate nitrogen content (PNC) of the sediment. It was found that particulate organic matter was decomposed under acid water conditions, leading to large decreases in PCC and PNC, and to large increases in pH, DCC, and NH4-N. Importantly, there were no variations in PCC, PNC, or particle size under base water conditions. However, there were increases in NH4-N, and large amounts of DCC remained in the overlying solution. It is evident from the experimental results that base water conditions enhanced both the elution of nutrient salts and the dissolved organic matter from the sediment, but retarded the decomposition of organic matter. These are considered as important factors associated with the improvement of water environments.

  5. Primary production of the ocean water column as a function of surface light intensity: algorithms for remote sensing

    NASA Astrophysics Data System (ADS)

    Platt, Trevor

    1986-02-01

    Empirically, the phytoplankton production per unit area of sea surface, normalised to total pigment biomass in the water column, is a linear function of the surface insolation. The slope ψ varies by only a factor of two in samples from a variety of environments. A theory is developed that describes the empirical results. A simplifying assumption of the theory, that photosynthesis is a linear function of available light, leads to a bias (overestimate) that can be calculated as a function of a measureable dimensionless parameter. With the bias corrected, ψ is shown to be equal, to within a dimensionless constant, to the initial slope α of the photosynthesis-light curve. The theory can be applied to the calculation of primary production from satellite surveys of ocean colour or from survey data collected by ship.

  6. Landscape configuration is the primary driver of impacts on water quality associated with agricultural expansion

    NASA Astrophysics Data System (ADS)

    Chaplin-Kramer, Rebecca; Hamel, Perrine; Sharp, Richard; Kowal, Virgina; Wolny, Stacie; Sim, Sarah; Mueller, Carina

    2016-07-01

    Corporations and other multinational institutions are increasingly looking to evaluate their innovation and procurement decisions over a range of environmental criteria, including impacts on ecosystem services according to the spatial configuration of activities on the landscape. We have developed a spatially explicit approach and modeled a hypothetical corporate supply chain decision representing contrasting patterns of land-use change in four regions of the globe. This illustrates the effect of introducing spatial considerations in the analysis of ecosystem services, specifically sediment retention. We explored a wide variety of contexts (Iowa, USA; Mato Grosso, Brazil; and Jiangxi and Heilongjiang in China) and these show that per-area representation of impacts based on the physical characterization of a region can be misleading. We found two- to five-fold differences in sediment export for the same amount of habitat conversion within regions characterized by similar physical traits. These differences were mainly determined by the distance between land use changes and streams. The influence of landscape configuration is so dramatic that it can override wide variation in erosion potential driven by physical factors like soil type, slope, and climate. To minimize damage to spatially-dependent ecosystem services like water purification, sustainable sourcing strategies should not assume a direct correlation between impact and area but rather allow for possible nonlinearity in impacts, especially in regions with little remaining habitat and highly variable hydrological connectivity.

  7. Primary description of surface water phytoplankton pigment patterns in the Bay of Bengal

    NASA Astrophysics Data System (ADS)

    Naik, R. K.; Anil, A. C.; Narale, D. D.; Chitari, R. R.; Kulkarni, V. V.

    2011-05-01

    Spatial and temporal variations in surface water phytoplankton pigment distribution in the Bay of Bengal were studied during the spring intermonsoon (SpIM, February-April) and the commencement of the summer monsoon (CSM, May-June), using pigment and diagnostic indices. The Prokaryotic pigment index (Prok DP) was dominant at all the oceanic stations whereas the Flagellate pigment index (Flag DP) was dominant at the near coastal stations. However, during the commencement of summer monsoon, an oscillation in the dominance of Prok DP and Flag DP was observed in the central oceanic bay, whereas flagellates and diatoms were dominant at the near coastal stations. This change in pigment pattern is possibly related to the influence of rainfall. Comparison of pigment data with microscopic cell counts indicated a significant relationship between the diatom pigment index (Diat DP) and diatom abundance. However, the relationship between the dinoflagellate pigment index (Dino DP) and dinoflagellate abundance was not significant. Studies coupling pigment composition analysis with microscopic analysis of phytoplankton in natural conditions should thus be a prerequisite in establishing valid biogeochemical and ecosystem models.

  8. Coupling gross primary production and transpiration for a consistent estimate of canopy water use efficiency

    NASA Astrophysics Data System (ADS)

    Yebra, Marta; van Dijk, Albert

    2015-04-01

    Water use efficiency (WUE, the amount of transpiration or evapotranspiration per unit gross (GPP) or net CO2 uptake) is key in all areas of plant production and forest management applications. Therefore, mutually consistent estimates of GPP and transpiration are needed to analysed WUE without introducing any artefacts that might arise by combining independently derived GPP and ET estimates. GPP and transpiration are physiologically linked at ecosystem level by the canopy conductance (Gc). Estimates of Gc can be obtained by scaling stomatal conductance (Kelliher et al. 1995) or inferred from ecosystem level measurements of gas exchange (Baldocchi et al., 2008). To derive large-scale or indeed global estimates of Gc, satellite remote sensing based methods are needed. In a previous study, we used water vapour flux estimates derived from eddy covariance flux tower measurements at 16 Fluxnet sites world-wide to develop a method to estimate Gc using MODIS reflectance observations (Yebra et al. 2013). We combined those estimates with the Penman-Monteith combination equation to derive transpiration (T). The resulting T estimates compared favourably with flux tower estimates (R2=0.82, RMSE=29.8 W m-2). Moreover, the method allowed a single parameterisation for all land cover types, which avoids artefacts resulting from land cover classification. In subsequent research (Yebra et al, in preparation) we used the same satellite-derived Gc values within a process-based but simple canopy GPP model to constrain GPP predictions. The developed model uses a 'big-leaf' description of the plant canopy to estimate the mean GPP flux as the lesser of a conductance-limited and radiation-limited GPP rate. The conductance-limited rate was derived assuming that transport of CO2 from the bulk air to the intercellular leaf space is limited by molecular diffusion through the stomata. The radiation-limited rate was estimated assuming that it is proportional to the absorbed photosynthetically

  9. An experimental study of on-line measurement of water fraction in gas-oil-water three-phase flow

    NASA Astrophysics Data System (ADS)

    Chen, K.; Guo, L. J.; Ye, J.

    2012-03-01

    Gas-oil-water two-or three-phase flow is widely encountered in industry, such as petroleum chemical industry, bio-chemicals, food chemicals, and mineral engineering and energy projects. Two kinds of on-line measurement technique, which are double-ring conductance sensor and double-helical capacitance sensor, for water fraction in oil-water two-phase flow and gas-oil-water three-phase flow were developed in this paper. The calibration results shows that the responses of the two sensors are good enough as the variation of water fraction. And on the other hand, it is possible that the oil and the gas regard as one phase in gas-oil-water three-phase flow by using double-helical capacitance sensor, and the ratio between water and gas has no effect with the output signal. The range of water fraction which can be measured becomes bigger and bigger because of the using of new circuit. So the capacitance sensor is better enough to measure water fraction in the three phases flow. During dynamic experiment, because of phase inversion phenomenon between oil and water, the conductance sensor outputs poorly, however the capacitance sensor performs somewhat fine. The reason for the error using capacitance sensor is the edge effect of the capacitance. The experiment results show that the edge effect of the double-helical capacitance sensor causes that the output is smaller so that the measuring water fraction is a litter larger than the actual value. And when the variation of water fraction is above 10%, the edge effect of capacitance sensor can be almost neglected. On the contrary, when the variation of water fraction is below 10%, the edge effect is so lager than the results above that it cannot be ignored. Consequently, the double-helical capacitance probe is more suitable for measuring water fraction in slug flow and oil-water emulsion, in which the results agree better with static calibration than that in bubble flow.

  10. Effects of ammonium effluents on planktonic primary production and decomposition in a coastal brackish water environment I. Nutrient balance of the water body and effluent tests

    NASA Astrophysics Data System (ADS)

    Tamminen, T.

    Effects of ammonium discharge on the regulation of photosynthetic production was studied from June to October 1979 in the Archipelago Sea, near the entrance of the Gulf of Finland. Sampled were the inner archipelago loaded with ammonium-rich industry effluents and some stations towards the open sea. Acute effects of effluent on natural algal and bacterial communities were tested by measurements of primary productivity and heterotrophic activity. Effluent tests were also conducted with a test alga ( Chorella sp.). Nutrient ratios and AGP tests indicated that nitrogen was the principal limiting nutrient for algal growth even in the ammonium-loaded regions. Therefore, the discharge causes a considerable eutrophication in the area. Effluent concentrations from 0.01 to 1% stimulated primary productivity of natural algal communities up to 230% of the control, whereas 10% concentrations were toxic. Test algae tolerated also 10% of effluent in some cases, and showed stimulations up to 960% of the control. No stimulation of heterotrophic activity was usually detected in effluent tests, and the threshold of toxicity was considerably lower than with algae. The effect of effluents on heterotrophic bacteria of the water body is therefore likely to be mediated through autotrophic production.

  11. [Interactions of DNA bases with individual water molecules. Molecular mechanics and quantum mechanics computation results vs. experimental data].

    PubMed

    Gonzalez, E; Lino, J; Deriabina, A; Herrera, J N F; Poltev, V I

    2013-01-01

    To elucidate details of the DNA-water interactions we performed the calculations and systemaitic search for minima of interaction energy of the systems consisting of one of DNA bases and one or two water molecules. The results of calculations using two force fields of molecular mechanics (MM) and correlated ab initio method MP2/6-31G(d, p) of quantum mechanics (QM) have been compared with one another and with experimental data. The calculations demonstrated a qualitative agreement between geometry characteristics of the most of local energy minima obtained via different methods. The deepest minima revealed by MM and QM methods correspond to water molecule position between two neighbor hydrophilic centers of the base and to the formation by water molecule of hydrogen bonds with them. Nevertheless, the relative depth of some minima and peculiarities of mutual water-base positions in' these minima depend on the method used. The analysis revealed insignificance of some differences in the results of calculations performed via different methods and the importance of other ones for the description of DNA hydration. The calculations via MM methods enable us to reproduce quantitatively all the experimental data on the enthalpies of complex formation of single water molecule with the set of mono-, di-, and trimethylated bases, as well as on water molecule locations near base hydrophilic atoms in the crystals of DNA duplex fragments, while some of these data cannot be rationalized by QM calculations.

  12. Calculation of the yields for the primary species formed from the radiolysis of liquid water by fast neutrons at temperatures between 25-350°C.

    PubMed

    Butarbutar, Sofia Loren; Sanguanmith, Sunuchakan; Meesungnoen, Jintana; Sunaryo, Geni Rina; Jay-Gerin, Jean-Paul

    2014-06-01

    Monte Carlo simulations were used to calculate the yields for the primary species (e(-)aq, H(•), H2, (•)OH and H2O2) formed from the radiolysis of neutral liquid water by mono-energetic 2 MeV neutrons at temperatures between 25-350°C. The 2 MeV neutron was taken as representative of a fast neutron flux in a reactor. For light water, the moderation of these neutrons generated elastically scattered recoil protons of ∼1.264, 0.465, 0.171 and 0.063 MeV, which at 25°C, had linear energy transfers (LETs) of ∼22, 43, 69 and 76 keV/μm, respectively. Neglecting the radiation effects due to oxygen ion recoils and assuming that the most significant contribution to the radiolysis came from these first four recoil protons, the fast neutron yields could be estimated as the sum of the yields for these protons after allowance was made for the appropriate weightings according to their energy. Yields were calculated at 10(-7), 10(-6) and 10(-5) s after the ionization event at all temperatures, in accordance with the time range associated with the scavenging capacities generally used for fast neutron radiolysis experiments. The results of the simulations agreed reasonably well with the experimental data, taking into account the relatively large uncertainties in the experimental measurements, the relatively small number of reported radiolysis yields, and the simplifications included in the model. Compared with data obtained for low-LET radiation ((60)Co γ rays or fast electrons), our computed yields for fast neutron radiation showed essentially similar temperature dependences over the range of temperatures studied, but with lower values for yields of free radicals and higher values for molecular yields. This general trend is a reflection of the high-LET character of fast neutrons. Although the results of the simulations were consistent with the experiment, more experimental data are required to better describe the dependence of radiolytic yields on temperature and to test

  13. Calculation of the yields for the primary species formed from the radiolysis of liquid water by fast neutrons at temperatures between 25-350°C.

    PubMed

    Butarbutar, Sofia Loren; Sanguanmith, Sunuchakan; Meesungnoen, Jintana; Sunaryo, Geni Rina; Jay-Gerin, Jean-Paul

    2014-06-01

    Monte Carlo simulations were used to calculate the yields for the primary species (e(-)aq, H(•), H2, (•)OH and H2O2) formed from the radiolysis of neutral liquid water by mono-energetic 2 MeV neutrons at temperatures between 25-350°C. The 2 MeV neutron was taken as representative of a fast neutron flux in a reactor. For light water, the moderation of these neutrons generated elastically scattered recoil protons of ∼1.264, 0.465, 0.171 and 0.063 MeV, which at 25°C, had linear energy transfers (LETs) of ∼22, 43, 69 and 76 keV/μm, respectively. Neglecting the radiation effects due to oxygen ion recoils and assuming that the most significant contribution to the radiolysis came from these first four recoil protons, the fast neutron yields could be estimated as the sum of the yields for these protons after allowance was made for the appropriate weightings according to their energy. Yields were calculated at 10(-7), 10(-6) and 10(-5) s after the ionization event at all temperatures, in accordance with the time range associated with the scavenging capacities generally used for fast neutron radiolysis experiments. The results of the simulations agreed reasonably well with the experimental data, taking into account the relatively large uncertainties in the experimental measurements, the relatively small number of reported radiolysis yields, and the simplifications included in the model. Compared with data obtained for low-LET radiation ((60)Co γ rays or fast electrons), our computed yields for fast neutron radiation showed essentially similar temperature dependences over the range of temperatures studied, but with lower values for yields of free radicals and higher values for molecular yields. This general trend is a reflection of the high-LET character of fast neutrons. Although the results of the simulations were consistent with the experiment, more experimental data are required to better describe the dependence of radiolytic yields on temperature and to test

  14. Effect of novel water soluble curcumin derivative on experimental type- 1 diabetes mellitus (short term study)

    PubMed Central

    2012-01-01

    Background Diabetes mellitus type 1 is an autoimmune disorder caused by lymphocytic infiltration and beta cells destruction. Curcumin has been identified as a potent inducer of heme-oxygenase-1 (HO-1), a redoxsensitive inducible protein that provides protection against various forms of stress. A novel water soluble curcumin derivative (NCD) has been developed to overcome low in vivo bioavailability of curcumin. The aim of the present work is to evaluate the anti diabetic effects of the “NCD” and its effects on diabetes-induced ROS generation and lipid peroxidation in experimental type- 1 diabetes mellitus. We also examine whether the up regulation of HO-1 accompanied by increased HO activity mediates these antidiabetic and anti oxidant actions. Materials and methods Rats were divided into control group, control group receiving curcumin derivative, diabetic group, diabetic group receiving curcumin derivative and diabetic group receiving curcumin derivative and HO inhibitor ZnPP. Type-1 diabetes was induced by intraperitoneal injection of streptozotocin. Curcumin derivative was given orally for 45 days. At the planned sacrification time (after 45 days), fasting blood samples were withdrawn for estimation of plasma glucose, plasma insulin and lipid profile . Animals were sacrificed; pancreas, aorta and liver were excised for the heme oxygenase - 1 expression, activity and malondialdehyde estimation. Results NCD supplementation to diabetic rats significantly lowered the plasma glucose by 27.5% and increased plasma insulin by 66.67%. On the other hand, the mean plasma glucose level in the control group showed no significant difference compared to the control group receiving the oral NCD whereas, NCD supplementation to the control rats significantly increased the plasma insulin by 47.13% compared to the control. NCD decreased total cholesterol, triglycerides, LDL cholesterol and increased HDL cholesterol levels. Also, it decreased lipid peroxides (malondialdehyde

  15. [Experimental study of vibrio parahaemolyticus (biotype 2) transfer from water and sediments to benthic marine food chain organisms].

    PubMed

    Gauthier, M J; Clement, R

    1979-04-01

    Transfer of Vibrio parahaemolyticus (biotype 2) from sediments to water and from water to benthic marine organisms was studied experimentally using a streptomycin-resistant strain. Transmission by trophic pathways was also studied using reconstituted marine food chains (Mytilus edulis, Nereis diversicolor, Carcinus maenas, Scorpaena porcus, Mus musculus). Water colonization by sediments could be observed only at temperatures above 16 degrees C. Sediments could well constitute a disseminating reservoir for these germs, their cycle in water being dependent of the cycle followed in the sediments. Contamination of animal organisms is essentially effected by a direct mean, either water or sediments; transfer by trophic pathways being negligible. Infection of land consumers (mice) is linked quantitatively to the nature of the last marine organism of the food chain since bacteria can flourish in the digestive tract of certain animals (Carcinus maenas). PMID:487292

  16. Nonlinear low frequency water waves in a cylindrical shell subjected to high frequency excitations - Part I: Experimental study

    NASA Astrophysics Data System (ADS)

    Dajun, Wang; Chunyan, Zhou; Li, Junbao; Shen, Song; Li, Min; Liu, Xijun

    2013-07-01

    This paper presents an experimental investigation on nonlinear low frequency gravity water waves in a partially filled cylindrical shell subjected to high frequency horizontal excitations. The characteristics of natural frequencies and mode shapes of the water-shell coupled system are discussed. The boundaries for onset of gravity waves are measured and plotted by curves of critical excitation force magnitude with respect to excitation frequency. For nonlinear water waves, the time history signals and their spectrums of motion on both water surface and shell are recorded. The shapes of water surface are also measured using scanning laser vibrometer. In particular, the phenomenon of transitions between different gravity wave patterns is observed and expressed by the waterfall graphs. These results exhibit pronounced nonlinear properties of shell-fluid coupled system.

  17. Effects of elevated CO2 on predator avoidance behaviour by reef fishes is not altered by experimental test water

    PubMed Central

    Welch, Megan J.; Allan, Bridie J.M.; Watson, Sue-Ann; McMahon, Shannon J.; McCormick, Mark I.

    2016-01-01

    Pioneering studies into the effects of elevated CO2 on the behaviour of reef fishes often tested high-CO2 reared fish using control water in the test arena. While subsequent studies using rearing treatment water (control or high CO2) in the test arena have confirmed the effects of high CO2 on a range of reef fish behaviours, a further investigation into the use of different test water in the experimental arena is warranted. Here, we used a fully factorial design to test the effect of rearing treatment water (control or high CO2) and experimental test water (control or high CO2) on antipredator responses of larval reef fishes. We tested antipredator behaviour in larval clownfish Amphiprion percula and ambon damselfish Pomacentrus amboinensis, two species that have been used in previous high CO2 experiments. Specifically, we tested if: (1) using control or high CO2 water in a two channel flume influenced the response of larval clownfish to predator odour; and (2) using control or high CO2 water in the test arena influenced the escape response of larval damselfish to a startle stimulus. Finally, (3) because the effects of high CO2 on fish behaviour appear to be caused by altered function of the GABA-A neurotransmitter we tested if antipredator behaviours were restored in clownfish treated with a GABA antagonist (gabazine) in high CO2 water. Larval clownfish reared from hatching in control water (496 µatm) strongly avoided predator cue whereas larval clownfish reared from hatching in high CO2 (1,022 µatm) were attracted to the predator cue, as has been reported in previous studies. There was no effect on fish responses of using either control or high CO2 water in the flume. Larval damselfish reared for four days in high CO2 (1,051 µatm) exhibited a slower response to a startle stimulus and slower escape speed compared with fish reared in control conditions (464 µatm). There was no effect of test water on escape responses. Treatment of high-CO2 reared clownfish with

  18. Indoor/outdoor of PM10 relationships and its water-soluble ions composition in selected primary schools in Malaysia

    NASA Astrophysics Data System (ADS)

    Mohamad, Noorlin; Latif, Mohd Talib

    2013-11-01

    Measurements of PM10 and water-soluble ions were carried out on indoor and outdoor PM10 (particles > 10 μm in aerodynamic diameter) aerosols sampled at selected primary schools of Kuala Lumpur (S1) and Putrajaya (S2), respectively. Samples were collected using a low volume sampler on Teflon filters. The water-soluble ions chloride (Cl-), nitrate (NO3-), sulfate (SO42-), calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+) and ammonium (NH4+) was analyzed using ion chromatography. The results showed that the indoor PM10 mass concentrations in S1 and S2 were 96.6 and 69.5 μg/m3, while the outdoor PM10 mass concentrations were 80.1 and 85.2 μg/m3, respectively. This indicated that NO3- were the most dominant ions, followed by SO42-, Ca2+, K+ and Na+, while Cl-, Mg2+ and Na+ were present at low concentrations. Pearson's correlation test applied to all the data showed high correlation between SO42- and NO3-, indicating a common anthropogenic origin. In addition, the correlations between Na+ and Ca2+ indicated crustal origins that significantly contributed to human exposure.

  19. Experimental Measurement of Frozen and Partially Melted Water Droplet Impact Dynamics

    NASA Technical Reports Server (NTRS)

    Palacios, Jose; Yan, Sihong; Tan, Jason; Kreeger, Richard E.

    2014-01-01

    High-speed video of single frozen water droplets impacting a surface was acquired. The droplets diameter ranged from 0.4 mm to 0.9 mm and impacted at velocities ranging from 140 m/sec to 309 m/sec. The techniques used to freeze the droplets and launch the particles against the surfaces is described in this paper. High-speed video was used to quantify the ice accretion area to the surface for varying impact angles (30 deg, 45 deg, 60 deg), impacting velocities, and break-up angles. An oxygen /acetylene cross-flow flame used to ensure partial melting of the traveling frozen droplets is also discussed. A linear relationship between impact angle and ice accretion is identified for fully frozen particles. The slope of the relationship is affected by impact speed. Perpendicular impacts, i.e. 30 deg, exhibited small differences in ice accretion for varying velocities, while an increase of 60% in velocity from 161 m/sec to 259 m/sec, provided an increase on ice accretion area of 96% at an impact angle of 60 deg. The increase accretion area highlights the importance of impact angle and velocity on the ice accretion process of ice crystals. It was experimentally observed that partial melting was not required for ice accretion at the tested velocities when high impact angles were used (45 and 60 deg). Partially melted droplets doubled the ice accretion areas on the impacting surface when 0.0023 Joules were applied to the particle. The partially melted state of the droplets and a method to quantify the percentage increase in ice accretion area is also described in the paper.

  20. The San Dimas Experimental Forest - Long Term Study of Fire, Water and Vegetation

    NASA Astrophysics Data System (ADS)

    Meixner, T.; Wohlgemuth, P.

    2001-12-01

    The San Dimas Experimental Forest was established in 1934. A large data base of fire history and stream flow has been generated for the forest. This database is now available electronically. San Dimas was selected as a perfect example of the hydrology, geology, and ecology of the mountains of southern California. As such the long term data set provides the best examples available of rainfall runoff relationships in a mountainous Mediterannean climate. The effect of fire on streamflow is a pertinent topic considering the current national discussion about changes in fire policy in the western United States. The data sets at San Dimas provide an opportunity to investigate what the short and long term impacts of fire are on water resources in chaparral ecosystems. In particular the fires of 1938 and 1960 provide an opportunity to investigate the effect of fire and the differential response of streamflow after each of these fires. Immediately after the fires the well known fire-flood response of chaparral watersheds is noted with extremely large flood peaks possibly due to the combined effects of removal of vegetation and litter by fire as well as the presence of hydrophobic soils. However longer term impacts of fire are notciable, lasting as long as 20 years and are most likely related to decreases in vegetation coverage and the linked decrease in evapotranspiration. After the 1960 fire several watersheds were type converted to annual and perrenial grasslands from their native chaparral. The increased streamflow caused by these conversions is still observable during both storm and baseflow periods. The known fire history and streamflow records of the forest permit continuing study on the effect of fire frequency on watershed hydrology, biogeochemistry, and geomorphology. >http://www.rfl.psw.fs.fed.us/prefire/sdefhtml/

  1. An experimental investigation on the surface water transport process over an airfoil by using a digital image projection technique

    NASA Astrophysics Data System (ADS)

    Zhang, Kai; Wei, Tian; Hu, Hui

    2015-09-01

    In the present study, an experimental investigation was conducted to characterize the transient behavior of the surface water film and rivulet flows driven by boundary layer airflows over a NACA0012 airfoil in order to elucidate underlying physics of the important micro-physical processes pertinent to aircraft icing phenomena. A digital image projection (DIP) technique was developed to quantitatively measure the film thickness distribution of the surface water film/rivulet flows over the airfoil at different test conditions. The time-resolved DIP measurements reveal that micro-sized water droplets carried by the oncoming airflow impinged onto the airfoil surface, mainly in the region near the airfoil leading edge. After impingement, the water droplets formed thin water film that runs back over the airfoil surface, driven by the boundary layer airflow. As the water film advanced downstream, the contact line was found to bugle locally and developed into isolated water rivulets further downstream. The front lobes of the rivulets quickly advanced along the airfoil and then shed from the airfoil trailing edge, resulting in isolated water transport channels over the airfoil surface. The water channels were responsible for transporting the water mass impinging at the airfoil leading edge. Additionally, the transition location of the surface water transport process from film flows to rivulet flows was found to occur further upstream with increasing velocity of the oncoming airflow. The thickness of the water film/rivulet flows was found to increase monotonically with the increasing distance away from the airfoil leading edge. The runback velocity of the water rivulets was found to increase rapidly with the increasing airflow velocity, while the rivulet width and the gap between the neighboring rivulets decreased as the airflow velocity increased.

  2. Changing forest water yields in response to climate warming: results from long-term experimental watershed sites across North America

    PubMed Central

    Creed, Irena F; Spargo, Adam T; Jones, Julia A; Buttle, Jim M; Adams, Mary B; Beall, Fred D; Booth, Eric G; Campbell, John L; Clow, Dave; Elder, Kelly; Green, Mark B; Grimm, Nancy B; Miniat, Chelcy; Ramlal, Patricia; Saha, Amartya; Sebestyen, Stephen; Spittlehouse, Dave; Sterling, Shannon; Williams, Mark W; Winkler, Rita; Yao, Huaxia

    2014-01-01

    Climate warming is projected to affect forest water yields but the effects are expected to vary. We investigated how forest type and age affect water yield resilience to climate warming. To answer this question, we examined the variability in historical water yields at long-term experimental catchments across Canada and the United States over 5-year cool and warm periods. Using the theoretical framework of the Budyko curve, we calculated the effects of climate warming on the annual partitioning of precipitation (P) into evapotranspiration (ET) and water yield. Deviation (d) was defined as a catchment's change in actual ET divided by P [AET/P; evaporative index (EI)] coincident with a shift from a cool to a warm period – a positive d indicates an upward shift in EI and smaller than expected water yields, and a negative d indicates a downward shift in EI and larger than expected water yields. Elasticity was defined as the ratio of interannual variation in potential ET divided by P (PET/P; dryness index) to interannual variation in the EI – high elasticity indicates low d despite large range in drying index (i.e., resilient water yields), low elasticity indicates high d despite small range in drying index (i.e., nonresilient water yields). Although the data needed to fully evaluate ecosystems based on these metrics are limited, we were able to identify some characteristics of response among forest types. Alpine sites showed the greatest sensitivity to climate warming with any warming leading to increased water yields. Conifer forests included catchments with lowest elasticity and stable to larger water yields. Deciduous forests included catchments with intermediate elasticity and stable to smaller water yields. Mixed coniferous/deciduous forests included catchments with highest elasticity and stable water yields. Forest type appeared to influence the resilience of catchment water yields to climate warming, with conifer and deciduous catchments more susceptible to

  3. Changing forest water yields in response to climate warming: results from long-term experimental watershed sites across North America.

    PubMed

    Creed, Irena F; Spargo, Adam T; Jones, Julia A; Buttle, Jim M; Adams, Mary B; Beall, Fred D; Booth, Eric G; Campbell, John L; Clow, Dave; Elder, Kelly; Green, Mark B; Grimm, Nancy B; Miniat, Chelcy; Ramlal, Patricia; Saha, Amartya; Sebestyen, Stephen; Spittlehouse, Dave; Sterling, Shannon; Williams, Mark W; Winkler, Rita; Yao, Huaxia

    2014-10-01

    Climate warming is projected to affect forest water yields but the effects are expected to vary. We investigated how forest type and age affect water yield resilience to climate warming. To answer this question, we examined the variability in historical water yields at long-term experimental catchments across Canada and the United States over 5-year cool and warm periods. Using the theoretical framework of the Budyko curve, we calculated the effects of climate warming on the annual partitioning of precipitation (P) into evapotranspiration (ET) and water yield. Deviation (d) was defined as a catchment's change in actual ET divided by P [AET/P; evaporative index (EI)] coincident with a shift from a cool to a warm period - a positive d indicates an upward shift in EI and smaller than expected water yields, and a negative d indicates a downward shift in EI and larger than expected water yields. Elasticity was defined as the ratio of interannual variation in potential ET divided by P (PET/P; dryness index) to interannual variation in the EI - high elasticity indicates low d despite large range in drying index (i.e., resilient water yields), low elasticity indicates high d despite small range in drying index (i.e., nonresilient water yields). Although the data needed to fully evaluate ecosystems based on these metrics are limited, we were able to identify some characteristics of response among forest types. Alpine sites showed the greatest sensitivity to climate warming with any warming leading to increased water yields. Conifer forests included catchments with lowest elasticity and stable to larger water yields. Deciduous forests included catchments with intermediate elasticity and stable to smaller water yields. Mixed coniferous/deciduous forests included catchments with highest elasticity and stable water yields. Forest type appeared to influence the resilience of catchment water yields to climate warming, with conifer and deciduous catchments more susceptible to

  4. Comparative experimental investigation on the actuation mechanisms of ionic polymer-metal composites with different backbones and water contents

    NASA Astrophysics Data System (ADS)

    Zhu, Zicai; Chang, Longfei; Asaka, Kinji; Wang, Yanjie; Chen, Hualing; Zhao, Hongxia; Li, Dichen

    2014-03-01

    Water-based ionic polymer-metal composites (IPMCs) exhibit complex deformation properties, especially when the water content changes. To explore the general actuation mechanisms, both Nafion and Flemion membranes are used as the polymer backbones. IPMC deformation includes three stages: fast anode deformation, relaxation deformation, and slow anode deformation, which is mainly dependent on the water content and the backbone. When the water content decreases from 21 to 14 wt. %, Nafion-IPMC exhibits a large negative relaxation deformation, zero deformation, a positive relaxation deformation, and a positive steady deformation without relaxation in sequence. Despite the slow anode deformation, Flemion-IPMC also shows a slight relaxation deformation, which disappears when the water content is less than 13 wt. %. The different water states are investigated at different water contents using nuclear magnetic resonance spectroscopy. The free water, which decreases rapidly at the beginning through evaporation, is proven to be critical for relaxation deformation. For the backbone, indirect evidence from the steady current response is correlated with the slow anode deformation of Flemion-IPMC. The latter is explained by the secondary dissociation of the weak acid group -COOH. Finally, we thoroughly explain not only the three deformations by swelling but also their evolvement with decreasing water content. A fitting model is also presented based on a multi-diffusion equation to reveal the deformation processes more clearly, the results from which are in good agreement with the experimental results.

  5. Comparative experimental investigation on the actuation mechanisms of ionic polymer–metal composites with different backbones and water contents

    SciTech Connect

    Zhu, Zicai; Chang, Longfei; Wang, Yanjie; Chen, Hualing; Asaka, Kinji; Zhao, Hongxia; Li, Dichen

    2014-03-28

    Water-based ionic polymer–metal composites (IPMCs) exhibit complex deformation properties, especially when the water content changes. To explore the general actuation mechanisms, both Nafion and Flemion membranes are used as the polymer backbones. IPMC deformation includes three stages: fast anode deformation, relaxation deformation, and slow anode deformation, which is mainly dependent on the water content and the backbone. When the water content decreases from 21 to 14 wt. %, Nafion–IPMC exhibits a large negative relaxation deformation, zero deformation, a positive relaxation deformation, and a positive steady deformation without relaxation in sequence. Despite the slow anode deformation, Flemion–IPMC also shows a slight relaxation deformation, which disappears when the water content is less than 13 wt. %. The different water states are investigated at different water contents using nuclear magnetic resonance spectroscopy. The free water, which decreases rapidly at the beginning through evaporation, is proven to be critical for relaxation deformation. For the backbone, indirect evidence from the steady current response is correlated with the slow anode deformation of Flemion-IPMC. The latter is explained by the secondary dissociation of the weak acid group –COOH. Finally, we thoroughly explain not only the three deformations by swelling but also their evolvement with decreasing water content. A fitting model is also presented based on a multi-diffusion equation to reveal the deformation processes more clearly, the results from which are in good agreement with the experimental results.

  6. Removal of TiO2 Nanoparticles During Primary Water Treatment: Role of Coagulant Type, Dose, and Nanoparticle Concentration

    PubMed Central

    Honda, Ryan J.; Keene, Valerie; Daniels, Louise; Walker, Sharon L.

    2014-01-01

    Abstract Nanomaterials from consumer products (i.e., paints, sunscreens, toothpastes, and food grade titanium dioxide [TiO2]) have the capacity to end up in groundwater and surface water, which is of concern because the effectiveness of removing them via traditional treatment is uncertain. Although aggregation and transport of nanomaterials have been investigated, studies on their removal from suspension are limited. Hence, this study involves the development of scaled-down jar tests to determine the mechanisms involved in the removal of a model metal oxide nanoparticle (NP), TiO2, in artificial groundwater (AGW), and artificial surface water (ASW) at the primary stages of treatment: coagulation, flocculation, and sedimentation. Total removal was quantified at the end of each treatment stage by spectroscopy. Three different coagulants—iron chloride (FeCl3), iron sulfate (FeSO4), and alum [Al2(SO4)3]—destabilized the TiO2 NPs in both source waters. Overall, greater than one-log removal was seen in groundwater for all coagulants at a constant dose of 50 mg/L and across the range of particle concentrations (10, 25, 50, and 100 mg/L). In surface water, greater than 90% removal was seen with FeSO4 and Al2(SO4)3, but less than 60% when using FeCl3. Additionally, removal was most effective at higher NP concentrations (50 and 100 mg/L) in AGW when compared with ASW. Zeta potential was measured and compared between AGW and ASW with the presence of all three coagulants at the same treatment stage times as in the removal studies. These electrokinetic trends confirm that the greatest total removal of NPs occurred when the magnitude of charge was smallest (<10 mV) and conversely, higher zeta potential values (>35 mV) measured were under conditions with poor removal (<90%). These results are anticipated to be of considerable interest to practitioners for the assessment of traditional treatment processes' capacity to remove nanomaterials prior to subsequent

  7. Influence of hydraulic regimes on bacterial community structure and composition in an experimental drinking water distribution system.

    PubMed

    Douterelo, I; Sharpe, R L; Boxall, J B

    2013-02-01

    Microbial biofilms formed on the inner-pipe surfaces of drinking water distribution systems (DWDS) can alter drinking water quality, particularly if they are mechanically detached from the pipe wall to the bulk water, such as due to changes in hydraulic conditions. Results are presented here from applying 454 pyrosequencing of the 16S ribosomal RNA (rRNA) gene to investigate the influence of different hydrological regimes on bacterial community structure and to study the potential mobilisation of material from the pipe walls to the network using a full scale, temperature-controlled experimental pipeline facility accurately representative of live DWDS. Analysis of pyrosequencing and water physico-chemical data showed that habitat type (water vs. biofilm) and hydraulic conditions influenced bacterial community structure and composition in our experimental DWDS. Bacterial community composition clearly differed between biofilms and bulk water samples. Gammaproteobacteria and Betaproteobacteria were the most abundant phyla in biofilms while Alphaproteobacteria was predominant in bulk water samples. This suggests that bacteria inhabiting biofilms, predominantly species belonging to genera Pseudomonas, Zooglea and Janthinobacterium, have an enhanced ability to express extracellular polymeric substances to adhere to surfaces and to favour co-aggregation between cells than those found in the bulk water. Highest species richness and diversity were detected in 28 days old biofilms with this being accentuated at highly varied flow conditions. Flushing altered the pipe-wall bacterial community structure but did not completely remove bacteria from the pipe walls, particularly under highly varied flow conditions, suggesting that under these conditions more compact biofilms were generated. This research brings new knowledge regarding the influence of different hydraulic regimes on the composition and structure of bacterial communities within DWDS and the implication that this

  8. Influence of hydraulic regimes on bacterial community structure and composition in an experimental drinking water distribution system.

    PubMed

    Douterelo, I; Sharpe, R L; Boxall, J B

    2013-02-01

    Microbial biofilms formed on the inner-pipe surfaces of drinking water distribution systems (DWDS) can alter drinking water quality, particularly if they are mechanically detached from the pipe wall to the bulk water, such as due to changes in hydraulic conditions. Results are presented here from applying 454 pyrosequencing of the 16S ribosomal RNA (rRNA) gene to investigate the influence of different hydrological regimes on bacterial community structure and to study the potential mobilisation of material from the pipe walls to the network using a full scale, temperature-controlled experimental pipeline facility accurately representative of live DWDS. Analysis of pyrosequencing and water physico-chemical data showed that habitat type (water vs. biofilm) and hydraulic conditions influenced bacterial community structure and composition in our experimental DWDS. Bacterial community composition clearly differed between biofilms and bulk water samples. Gammaproteobacteria and Betaproteobacteria were the most abundant phyla in biofilms while Alphaproteobacteria was predominant in bulk water samples. This suggests that bacteria inhabiting biofilms, predominantly species belonging to genera Pseudomonas, Zooglea and Janthinobacterium, have an enhanced ability to express extracellular polymeric substances to adhere to surfaces and to favour co-aggregation between cells than those found in the bulk water. Highest species richness and diversity were detected in 28 days old biofilms with this being accentuated at highly varied flow conditions. Flushing altered the pipe-wall bacterial community structure but did not completely remove bacteria from the pipe walls, particularly under highly varied flow conditions, suggesting that under these conditions more compact biofilms were generated. This research brings new knowledge regarding the influence of different hydraulic regimes on the composition and structure of bacterial communities within DWDS and the implication that this

  9. Tracing spatial variation of canopy water fluxes to the soil: An experimental approach to assessing heterogeneity with high resolution data

    NASA Astrophysics Data System (ADS)

    Metzger, Johanna Clara; Dalla Valle, Nicolas; Wutzler, Thomas; Filipzik, Janett; Weckmüller, Josef; Schelhorn, Danny; Grauer, Christoph; Hildebrandt, Anke

    2016-04-01

    Due to the mechanisms of interception, stemflow and canopy throughfall, precipitation reaches a forest soil surface in an altered temporal and spatial distribution. The retention of water by canopies is contrasted by the formation of dynamic hotspots, which channel rain water down to the soil, e.g. canopy dripping points and stemflow. Throughfall patterns are often assumed to be the main driver for soil water content heterogeneity in forests, yet this relation has not been studied extensively and there is no prove to this theory. Because it is impossible to measure net precipitation input and soil water content in the same place at the same time, elaborate sampling is necessary for a data set allowing to address this subject. Within the last two years, in the framework of the Collaborative Research Centre AquaDiva, our group has established a new experimental site to investigate on the relationship of forest precipitation and soil water. We have developed an experimental design combining the measurement of throughfall, stemflow and soil water content on a 1 ha plot in a manner so all measurements are representative for the plot yet do not disturb each other. We adapted a statistical sampling method common for throughfall measurement to soil water content measurement comprising a high number of measurement points (throughfall: 350, soil water content: 210). To gain good insights in soil water dynamics and to capture preferential flow, soil water content was recorded in a high frequency (1* 6‑1 min‑1) in two soil depths. Stemflow was measured area-based on regular subplots (11% of the total plot area, 65 trees). Stand and soil surveys were made to investigate canopy impacts and identify soil-born patterns in soil water content. The plot is located in a mixed beech forest of the Hainich national park in Thuringia, Germany. Shallow loamy soils cover the lime- and marlstone bedrock. The forest plot is complemented by a smaller neighboring grassland plot acting as a

  10. Tracing spatial variation of canopy water fluxes to the soil: An experimental approach to assessing heterogeneity with high resolution data

    NASA Astrophysics Data System (ADS)

    Metzger, Johanna Clara; Dalla Valle, Nicolas; Wutzler, Thomas; Filipzik, Janett; Weckmüller, Josef; Schelhorn, Danny; Grauer, Christoph; Hildebrandt, Anke

    2016-04-01

    Due to the mechanisms of interception, stemflow and canopy throughfall, precipitation reaches a forest soil surface in an altered temporal and spatial distribution. The retention of water by canopies is contrasted by the formation of dynamic hotspots, which channel rain water down to the soil, e.g. canopy dripping points and stemflow. Throughfall patterns are often assumed to be the main driver for soil water content heterogeneity in forests, yet this relation has not been studied extensively and there is no prove to this theory. Because it is impossible to measure net precipitation input and soil water content in the same place at the same time, elaborate sampling is necessary for a data set allowing to address this subject. Within the last two years, in the framework of the Collaborative Research Centre AquaDiva, our group has established a new experimental site to investigate on the relationship of forest precipitation and soil water. We have developed an experimental design combining the measurement of throughfall, stemflow and soil water content on a 1 ha plot in a manner so all measurements are representative for the plot yet do not disturb each other. We adapted a statistical sampling method common for throughfall measurement to soil water content measurement comprising a high number of measurement points (throughfall: 350, soil water content: 210). To gain good insights in soil water dynamics and to capture preferential flow, soil water content was recorded in a high frequency (1* 6-1 min-1) in two soil depths. Stemflow was measured area-based on regular subplots (11% of the total plot area, 65 trees). Stand and soil surveys were made to investigate canopy impacts and identify soil-born patterns in soil water content. The plot is located in a mixed beech forest of the Hainich national park in Thuringia, Germany. Shallow loamy soils cover the lime- and marlstone bedrock. The forest plot is complemented by a smaller neighboring grassland plot acting as a

  11. The fast-spectrum transmutation experimental facility FASTEF: Main design achievements (Part 1: Core and primary system) within the FP7-CDT collaborative project of the European Commission

    SciTech Connect

    De Bruyn, D.; Fernandez, R.; Mansani, L.; Woaye-Hune, A.; Sarotto, M.; Bubelis, E.

    2012-07-01

    MYRRHA (Multi-purpose hybrid Research Reactor for High-tech Applications) is the flexible experimental accelerator-driven system (ADS) in development at SCK CEN in replacement of its material testing reactor BR2. SCK CEN in association with 17 European partners from industry, research centres and academia, responded to the FP7 (Seventh Framework Programme) call from the European Commission to establish a Central Design Team (CDT) for the design of a Fast Spectrum Transmutation Experimental Facility (FASTEF) able to demonstrate efficient transmutation and associated technology through a system working in subcritical and/or critical mode. The project has started on April 01, 2009 for a period of three years. In this paper, we present the latest configuration of the reactor core and primary system. The FASTEF facility has evolved quite a lot since the intermediate reporting done at the ICAPP'10 and ICAPP'11 conferences 1 2. If it remains a small-scale facility, the core power amounts now up to 100 MWth in critical mode. In a companion paper 3, we present the concept of the reactor building and the plant layout. (authors)

  12. Thermodynamic and Experimental Study of the Energetic Cost Involved in the Capture of Carbon Dioxide by Aqueous Mixtures of Commonly Used Primary and Tertiary Amines.

    PubMed

    Arcis, Hugues; Coulier, Yohann; Coxam, Jean-Yves

    2016-01-01

    The capture of carbon dioxide with chemical solvents is one solution to mitigate greenhouse gas emissions from anthropogenic sources and thus tackle climate change. Recent research has been focused on optimizing new kinds of advanced absorbents including aqueous amine blends, but critical downsides such as the large energetic cost involved with the industrial process remain. To address this issue, a better understanding of the energetic interactions existing in solution is necessary. In this paper, we report direct experimental measurements of the energy cost involved in the solvation of CO2 in two aqueous amine blends at different temperatures. The chemical solvents were designed as aqueous mixtures of commonly used primary and tertiary amines to study the influence of the different chemical properties inferred by the amine class. We have also applied a thermodynamic model to represent the energetic effects that take place in solution during CO2 dissolution in these mixtures, where all parameters were taken from previous studies focused on single amine absorbents. The noteworthy agreement observed with the reported experimental heats of absorption and with literature vapor liquid equilibrium properties confirmed the relevance of the underlying molecular mechanisms considered in our model, and suggest that this model would prove useful to investigate CO2 dissolution in other amine blends.

  13. Does Water Temperature Affect the Timing and Duration of Remigial Moult in Sea Ducks? An Experimental Approach

    PubMed Central

    Viain, Anouck; Guillemette, Magella

    2016-01-01

    Aquatic birds have high cost of thermoregulation, especially during the moulting period, yet the effect of water temperature on the moulting strategy of aquatic birds has rarely been studied. Our general hypothesis is that energy savings associated with lower thermoregulation costs would be allocated to moulting processes. We predicted that aquatic birds moulting in warm water would have a higher level of body reserves, a faster growth rate of feathers, and an earlier remigial moult onset compared with birds moulting in cold water. We used the common eider (Somateria mollissima dresseri), a large sea duck, as the model species. Captive individuals were experimentally exposed to warm (18°C) and cold (8°C) water treatments during a three year period with individuals swapped between treatments. We found a similar feather growth rate for the two water temperature treatments and in contrast to our predictions, eiders exposed to warm water had a lower body mass and showed a delayed onset of remigial moult of approximately 7 days compared with those exposed to cold water. Our data indicate that body mass variations influence the timing of moult in unexpected ways and we suggest that it likely controls the occurrence of wing moult through a hormonal cascade. This study emphasizes the importance of improving our knowledge of the effects of water temperature on remigial moult of aquatic birds, to better assert the potential effects of global warming on their survival. PMID:27177039

  14. Modeling of experimental treatment of acetaldehyde-laden air and phenol-containing water using corona discharge technique.

    PubMed

    Faungnawakij, Kajornsak; Sano, Noriaki; Charinpanitkul, Tawatchai; Tanthapanichakoon, Wiwut

    2006-03-01

    Acetaldehyde-laden air and phenol-contaminated water were experimentally treated using corona discharge reactions and gas absorption in a single water-film column. Mathematical modeling of the combined treatment was developed in this work. Efficient removal of the gaseous acetaldehyde was achieved while the corona discharge reactions produced short-lived species such as O and O- as well as ozone. Direct contact of the radicals and ions with water was known to produce aqueous OH radical, which contributes to the decomposition of organic contaminants: phenol, absorbed acetaldehyde, and intermediate byproducts in the water. The influence of initial phenol concentration ranging from 15 to 50 mg L(-1) and that of influent acetaldehyde ranging from 0 to 200 ppm were experimentally investigated and used to build the math model. The maximum energetic efficiency of TOC, phenol, and acetaldehyde were obtained at 25.6 x 10(-9) mol carbon J(-1), 25.0 x 10(-9) mol phenol J(-1), and 2.0 x 10(-9) mol acetaldehyde J(-1), respectively. The predictions for the decomposition of acetaldehyde, phenol, and their intermediates were found to be in good agreement with the experimental results. PMID:16568779

  15. Experimental Water Droplet Impingement Data on Airfoils, Simulated Ice Shapes, an Engine Inlet and a Finite Wing

    NASA Technical Reports Server (NTRS)

    Papadakis, M.; Breer, M.; Craig, N.; Liu, X.

    1994-01-01

    An experimental method has been developed to determine the water droplet impingement characteristics on two- and three-dimensional aircraft surfaces. The experimental water droplet impingement data are used to validate particle trajectory analysis codes that are used in aircraft icing analyses and engine inlet particle separator analyses. The aircraft surface is covered with thin strips of blotter paper in areas of interest. The surface is then exposed to an airstream that contains a dyed-water spray cloud. The water droplet impingement data are extracted from the dyed blotter paper strips by measuring the optical reflectance of each strip with an automated reflectometer. Experimental impingement efficiency data represented for a NLF (1)-0414 airfoil, a swept MS (1)-0317 airfoil, a Boeing 737-300 engine inlet model, two simulated ice shapes and a swept NACA 0012 wingtip. Analytical impingement efficiency data are also presented for the NLF (1)-0414 airfoil and the Boeing 737-300 engine inlet model.

  16. Experimental investigation on the photovoltaic-thermal solar heat pump air-conditioning system on water-heating mode

    SciTech Connect

    Fang, Guiyin; Hu, Hainan; Liu, Xu

    2010-09-15

    An experimental study on operation performance of photovoltaic-thermal solar heat pump air-conditioning system was conducted in this paper. The experimental system of photovoltaic-thermal solar heat pump air-conditioning system was set up. The performance parameters such as the evaporation pressure, the condensation pressure and the coefficient of performance (COP) of heat pump air-conditioning system, the water temperature and receiving heat capacity in water heater, the photovoltaic (PV) module temperature and the photovoltaic efficiency were investigated. The experimental results show that the mean photovoltaic efficiency of photovoltaic-thermal (PV/T) solar heat pump air-conditioning system reaches 10.4%, and can improve 23.8% in comparison with that of the conventional photovoltaic module, the mean COP of heat pump air-conditioning system may attain 2.88 and the water temperature in water heater can increase to 42 C. These results indicate that the photovoltaic-thermal solar heat pump air-conditioning system has better performances and can stably work. (author)

  17. Experimental investigation of binary nucleation rates of water-n-propanol and water-n-butanol vapors by means of a pex-tube

    NASA Astrophysics Data System (ADS)

    Rodemann, T.; Peters, F.

    1996-09-01

    Measurements of homogeneous nucleation rates of two binary vapor mixtures of water and alcohol carried in nitrogen have been performed with a new instrument for nucleation and droplet growth studies, the piston expansion tube (pex-tube). The pex-tube subjects the vapors to short supersaturation pulses generating a limited number of nuclei which grow into monodisperse droplets. The droplets are detected in number and size by Mie light scattering. The results provide nucleation rates between 105 and 109 cm-3 s-1 at constant temperature as a function of the vapor phase activities a1 and a2 of water and alcohol, respectively. Comparison with published experimental data exhibits good agreement.

  18. Experimental investigation of heat transfer and pressure drop characteristics of water and glycol-water mixture in multi-port serpentine microchannel slab heat exchangers

    NASA Astrophysics Data System (ADS)

    Khan, Md Mesbah-ul Ghani

    Microchannels have several advantages over traditional large tubes. Heat transfer using microchannels recently have attracted significant research and industrial design interests. Open literatures leave with question on the applicability of classical macroscale theory in microchannels. Better understanding of heat transfer in various microchannel geometries and building experimental database are continuously urged. The purpose of this study is to contribute the findings and data to this emerging area through carefully designed and well controlled experimental works. The commercially important glycol-water mixture heat transfer fluid and multiport slab serpentine heat exchangers are encountered in heating and cooling areas, e.g. in automotive, aircraft, and HVAC industries. For a given heat duty, the large diameter tubes experience turbulent flow whereas the narrow channels face laminar flow and often developing flow. Study of low Reynolds number developing glycol-water mixture laminar flow in serpentine microchannel heat exchanger with parallel multi-port slab is not available in the open literature. Current research therefore experimentally investigates glycol-water mixture and water in simultaneously developing laminar flows. Three multiport microchannel heat exchangers; straight and serpentine slabs, are used for each fluid. Friction factors of glycol-water mixture and water flows in straight slabs are higher than conventional fully developed laminar flow. If a comprehensive pressure balance is introduced, the results are well compared with conventional Poiseuille theory. Similar results are found in serpentine slab. The pressure drop for the straight core is the highest, manifolds are the intermediate, and serpentine is the least; which are beneficial for heat exchangers. The heat transfer results in serpentine slab for glycol-water mixture and water are higher and could not be compared with conventional fully developed and developing flow correlations. New

  19. Vegetation Responses to Future Climates: Global Variability in Water Use Efficiency and Primary Productivity in a CMIP5 Multimodel Ensemble

    NASA Astrophysics Data System (ADS)

    Bernardes, S.; Campbell, P. K. E.; Zhang, Q.; Middleton, E.

    2015-12-01

    Climate projections for the 21st century predict substantial changes in temperature and in the quantity and spatiotemporal distribution of precipitation for large regions on the planet. Reductions in water availability resulting from decreased precipitation and increased water demand by the atmosphere can negatively affect plant metabolism, reduce carbon uptake, and limit services of entire ecosystems. Future increases in temperature and in atmospheric carbon dioxide concentrations may help offset some of these impacts on vegetation. In particular, plants may adjust their water use efficiency (WUE, plant production per water loss by evapotranspiration) in response to changing environmental conditions. We assessed an ensemble of thirteen models from the Coupled Model Intercomparison Project 5 (CMIP5) and analyzed future changes in climate variables, carbon mass in vegetation, vegetation primary productivity and WUE. The analysis considered two representative concentration pathways (RCP4.5 and RCP8.5) for the period 2006-2099 and compared projections to historical values (1850-2005). Results include differences between historical and projected conditions for global, regional and latitudinal distributions of model outputs, for both RCPs. We observed significant intermodel variability when representing changes in WUE over the century, including high model sensitivity to different greenhouse concentration scenarios. Model agreement varied with RCP (higher agreement for RCP4.5), as well as regionally (higher agreement in Southeast Asia, lower agreement in arid areas, including the Sahara and Western Australia). The majority of models point to an increase in GPP and WUE for most of the planet under both concentration pathways, with changes ranging from zero to 100% of their historical values. These increases were observed to be consistently higher for RCP8.5. In addition, higher increases in GPP and WUE are predicted to occur over higher latitudes in the northern

  20. Experimental study of the interaction of THz radiation FEL with the atmosphere and water droplet aerosol

    NASA Astrophysics Data System (ADS)

    Matvienko, G. G.; Lisenko, A. A.; Babchenko, S. V.; Kargin, B. A.; Kablukova, E. G.; Kubarev, V. V.

    2015-11-01

    The interaction of radiation of the Novosibirsk Free Electron Laser (FEL) at a wavelength of 130 μm in the atmospheric transmission window with a model aerosol cloud having the known droplet size distribution function has been studied experimentally. The experimental findings are compared with theoretical calculations obtained from solution of the lidar equation for the conditions of the experiment.

  1. Water adsorption on charcoal: New approach in experimental studies and data representation

    SciTech Connect

    Geynisman, M.; Walker, R.

    1991-08-01

    The experimental apparatus was built to study the H{sub 2}O adsorption on charcoal at very low concentrations and collect the data in the form of isosteres. Experimental method is discussed and the global three-dimensional fit is constructed to predict the post-regeneration conditions of charcoal absorbers. 11 refs.

  2. Extraction and Capture of Water from Martian Regolith Experimental Proof-of-Concept

    NASA Technical Reports Server (NTRS)

    Linne, Diane L.; Kleinhenz, Julie E.; Bauman, Steven W.; Johnson, Kyle A.

    2016-01-01

    A novel concept for extraction of water from the Mars soil in a real-time, open-air process was demonstrated in a Mars environment chamber. The concept breadboard uses radiative heating to bake off water from exposed soil contained in a bin. An enclosure, intended to mimic the bottom of a rover, covers the bin. A fan continuously blows the Mars atmospheric gases through the enclosure to collect the evolved water while a tiller was used to churn up moist subsurface soil. These initial tests verified concept feasibility. The sweep gas generated by commercially available muffin fans at 7 Torr was sufficient to transfer water vapor into a condenser flow loop. The radiative heating, while non-optimized, heated the soil surface to 60 C to generate water vapor. A rototiller working through the soil bin brought sufficient amounts of new moist soil to the heated surface to show an increase in rate of water extraction.

  3. EXPERIMENTAL STUDY ON WATER BALANCE IN A NEGATIVE PRESSURE DIFFERENCE IRRIGATION SYSTEM

    NASA Astrophysics Data System (ADS)

    Moniruzzaman, S. M.; Fukuhara, Teruyuki; Terasaki, Hiroaki

    Negative pressure difference irrigation (NPDI) is considered to be an attractive mode of irrigation because water use efficiency in this case is higher than that in conventional irrigation meth