Sample records for water absorption capacity

  1. Determination of water absorption and water holding capacities of different soil mixtures with MINIDRAIN system to enhance the plant growth

    NASA Astrophysics Data System (ADS)

    Sudan Acharya, Madhu; Rauchecker, Markus; Wu, Wei

    2014-05-01

    Soil water holding capacity is the amount of water that a given soil can hold against the force of gravity. Soil texture and organic matter are the key components that determine soil water holding capacity. Soils with smaller particle sizes, such as silt and clay have larger surface area can hold more water compared to sand which has large particle sizes which results in smaller surface area. A study report showed that 1% increase in soil humus will result in a 4% increase in stored soil water (Morris, 2004) and 1 part humus holds 4 parts of water (Wheeler and Ward, 1998). Therefore, the more humus that can be added to the soil, the greater the water holding capacity of the soil. As the level of organic matter increases in a soil, the water holding capacity also increases due to the affinity of organic matter for water. The water holding capacity of the soil is determined by the amount of water held in the soil sample vs. the dry weight of the sample. MINIDRAIN is a patented system made of geo-fabric (fleece) or combination of geosynthetics and humus. MINIDRAIN and vegetation nets developed by the company ÖKO-TEX (Linz, Austria) will improve the distribution of water and air in the soils, increase the growth of vegetation and reduce the soil erosion. Depending on the physical configuration, there are four different combinations of MINIDRAIN systems developed by ÖKO-TEX. a) Geotextile (fleece) strips of different sizes (e.g. 5x10x250 mm) b) Net formed strips (drainage nets) of different sizes c) Multilayer geotextile mats with humus, seeds or compost of different sizes (e.g. 10x30x200 mm) d) Multilayer geotextile net formed mats with humus, seeds or compost This paper describes the experimental results of the water absorption and water holding capacity of different forms of MINIDRAIN under different soil mixes. In this experiment, potting soil, coarse sand and LECA (Light weight clay aggregates) balls are mixed with different proportion of MINIDRAIN systems and the water absorption and water holding capacities are measured. A comparison of the results for an optimal combination of soil and MINIDRAIN system has also been made. The results show that, the soil mix with MINIDRAIN system with multilayer mats (with humus) have highest water absorption and water holding capacity among the tested soil mix combinations.

  2. Capacity for Absorption of Water-Soluble Secondary Metabolites Greater in Birds than in Rodents

    PubMed Central

    Karasov, William H.; Caviedes-Vidal, Enrique; Bakken, Bradley Hartman; Izhaki, Ido; Samuni-Blank, Michal; Arad, Zeev

    2012-01-01

    Plant secondary metabolites (SMs) are pervasive in animal foods and potentially influence feeding behavior, interspecies interactions, and the distribution and abundance of animals. Some of the major classes of naturally occurring SMs in plants include many water-soluble compounds in the molecular size range that could cross the intestinal epithelium via the paracellular space by diffusion or solvent drag. There are differences among species in paracellular permeability. Using Middle Eastern rodent and avian consumers of fruits containing SMs, we tested the hypothesis that avian species would have significantly higher paracellular permeability than rodent species. Permeability in intact animals was assessed using standard pharmacological methodology to measure absorption of two radiolabeled, inert, neutral water-soluble probes that do not interact with intestinal nutrient transporters, L-arabinose (Mr?=?150.1 Da) and lactulose (Mr?=?342.3 Da). We also measured absorption of labeled 3-O-methyl-D-glucose (3OMD-glucose; Mr?=?194.2 Da), which is a nonmetabolized analogue of D-glucose that is passively absorbed through the paracellular space but also transported across the enterocyte membranes. Most glucose was absorbed by all species, but arabinose fractional absorption (f) was nearly three times higher in birds (1.03±0.17, n?=?15 in two species) compared to rodents (0.37±0.06, n?=?10 in two species) (P<0.001). Surprisingly, the apparent rates of absorption in birds of arabinose exceeded those of 3OMD-glucose. Our findings are in agreement with previous work showing that the paracellular pathway is more prominent in birds relative to nonflying mammals, and suggests that birds may be challenged by greater absorption of water-soluble, dietary SMs. The increased expression of the paracellular pathway in birds hints at a tradeoff: the free energy birds gain by absorbing water-soluble nutrients passively may be offset by the metabolic demands placed on them to eliminate concomitantly absorbed SMs. PMID:22389702

  3. Absorptive Capacity and Achieving the MDGs

    Microsoft Academic Search

    François Bourguignon; Mark Sundberg

    2006-01-01

    The ability of low-income countries to productively absorb large amounts of external assistance is a central issue for efforts to scale-up aid. This paper examines absorptive capacity in the context of MDG-based development programmes in low-income countries. It first defines absorptive capacity, and proposes a framework for measuring it. Applying a dynamic computable general equilibrium model to link the macro

  4. Water relations in eggs of the lone star tick, Amblyomma americanum , with experimental work on the capacity for water vapor absorption

    Microsoft Academic Search

    Jay A. Yoder; Joshua B. Benoit; Amanda M. Opaluch

    2004-01-01

    This study shows that water stress is not countered in eggs of the lone star tick, Amblyomma\\u000aamericanum (L.), using water vapor, and suggests involvement of liquid water as a developmental cue. Eggs fail to maintain an equilibrium water content in subsaturated air, hence, gainloss, with net water losses occurring at relative humidities near saturation and these eggs exhibit a

  5. Pronounced energy absorption capacity of cellular bulk metallic glasses

    NASA Astrophysics Data System (ADS)

    Chen, S. H.; Chan, K. C.; Wu, F. F.; Xia, L.

    2014-03-01

    Cellular bulk metallic glasses (BMGs) with macroscopic cellular structures were designed and fabricated. The cellular BMGs exhibited remarkable energy absorption capacity as compared with reported BMG foams and honeycombs. The enhanced energy absorption capability is attributed to the large plastic bending of the struts, the blunting of the cracks, and the large plastic deformation at the nodes. This work shows that, in cellular BMGs, the macroscopic cellular structures are more efficient in dissipating mechanical energy than microscopic cellular structures, opening a window for developing energy absorption devices using BMGs.

  6. A REFERENCE FRAMEWORK TO SUPPORT ABSORPTIVE CAPACITY DEVELOPMENT

    Microsoft Academic Search

    RAFAEL CLEMENTE; HEITOR CAULLIRAUX; LUIZ ANTONIO MEIRELLES; ADRIANO PROENÇA

    The main objective of this paper is to present a reference framework to support absorptive capacity development. This research is performed in a context in which innovations are of increasing importance to competitive success and in which environment dynamics compel organizations to frequently reconfigure their resource base in order to achieve competitive advantage, a concept known as dynamic capability. In

  7. Computer-Aided Method of Visual Absorption Capacity Estimation

    Microsoft Academic Search

    Agnieszka OZIMEK; Pawel OZIMEK

    In this paper, a novel method of computer aided VAC (Visual Absorption Capacity) estimation is presented which was applied to an investigation in Bad Muskau - ??knica region. English style Muskauer Park, located in the vicinity, possesses a wide world known values, which a fact was confirmed by its inscribing in UNESCO list in 2004. Therefore, during the process of

  8. Absorption Capacities and Limits of Stability for Hybrid CES

    NASA Astrophysics Data System (ADS)

    Rygalov, V.; Carras, G.

    Naturally developed in the process of evolution mechanisms for biomass degradation are too slow for application inside intensive Closed Eco-Systems CES for Life Support in space So it is suggested different methods of catalytic degradation for plant biomass to accelerate CES material turnover The work is an attempt to analyze the process of inedible plant biomass catalytic incineration as a source of CO 2 for new plant generation photosynthesis and growth It is a common knowledge now that incineration of phyto-mass supplies into the atmosphere of CES not only CO 2 but also gaseous toxic agents such as SO 2 NO x etc inhibiting photosynthetic processes Mathematical modeling has demonstrated that when the limit value of intensity of production processes and matter turnover specific for every closed system is exceeded the gaseous toxic agents destroy the system This value is directly proportional to system specific material turnover rate CES buffer absorption capacity and non-linearly dependant on the tolerance of the plant component to the impact of flue gases Ratios have been derived by assigned intensity of matter turnover to evaluate buffer absorption capacities required for designing stable CES functioning

  9. Absorptive Capacity and Productivity Spillovers from FDI: A Threshold Regression Analysis

    Microsoft Academic Search

    Sourafel Girma

    2005-01-01

    This paper explores whether the effect of foreign direct investment (FDI) on productivity growth is dependent on absorptive capacity using recently developed threshold regression techniques. In manufacturing sectors where technology-exploiting multinationals are prevalent, the results point to the presence of nonlinear threshold effects: the productivity benefit from FDI increases with absorptive capacity until some threshold level beyond which it becomes

  10. Absorptive Capacity at the Individual Level: Linking Creativity to Innovation in Academia

    ERIC Educational Resources Information Center

    Da Silva, Nancy; Davis, Ashley R.

    2011-01-01

    The absorptive capacity construct has been examined across various country, interorganization, and organizational level phenomena. This paper presents a framework that adopts the absorptive capacity framework to explain the relationship between creative and innovative performance at the individual level. The framework is illustrated by predicting…

  11. Scaling-Up Aid to Education: Is Absorptive Capacity a Constraint?

    ERIC Educational Resources Information Center

    Rose, Pauline

    2009-01-01

    "Absorptive capacity" is a frequently used term amongst development practitioners in education. It is adopted by some as a reason for caution over scaling up aid. Others are of the view that absorptive capacity is an excuse by some donors for not delivering on their Education for All financing commitments. Drawing on interviews with…

  12. Networking, absorptive capacity, science parks ? a proposed conceptual model for firm innovative performance

    Microsoft Academic Search

    K. Y. Chan; M. W. Pretorius

    2007-01-01

    This paper elaborates on current literature on science parks, focusing on how networking and absorptive capacity affect firm innovative performance. To fulfill the purpose of providing a systematic literature review, selections of existing empirical studies and literature studies have been organized on the basis of the following three dimensions: (1) science parks; (2) networks; and (3) absorptive capacity. In the

  13. Vitamin B12 absorption capacity in healthy children

    SciTech Connect

    Hjelt, K.; Krasilnikoff, P.A.

    1986-03-01

    B12 absorption was investigated in 47 healthy children aged 7 months to 15.8 years (median 4.9 years). The patients had either recovered from giardiasis, the post-gastroenteritis syndrome, or had celiac disease in remission (treated with a gluten-free diet). The B12 absorption was measured by a double-isotope technique using /sup 57/CoB12 and /sup 51/CrCl/sub 3/, the latter being the inabsorbable marker. The radiation dose was minimal. The results were presented as fractional absorption of B12 (FAB12). Within the different age groups, the absorption test was performed by means of the following oral amounts of B12: 0- less than 1 year, 0.5 microgram; 1-3 years: 1.7 micrograms, 4-6 years, 2.5 micrograms; 7-10 years; 3.3 micrograms; and 11-15 years, 4.5 micrograms. When using these oral amounts of B12, the medians (and ranges) of FAB12 were found to be: 1-3 years (n = 18), 37% (16-80%); 4-6 years (n = 10), 27% (19-40%); 7-10 years (n = 9), 32% (21-44%); and 11-15 years (n = 8), 27% (19-59%). The FAB12 in two children aged 7 and 11 months was 31% and 32%, respectively. These results may be interpretated as reference values for B12 absorption in children. Further absorption tests were performed in seven children representing the four age groups from 1 to 15 years. When a high oral amount of B12 was given (i.e., three times the saturation dose), the FAB12 ranged from 0 to 20% (median 9%), whereas a low amount (i.e., one-ninth of the saturation dose) produced fractional absorptions from 65 to 82% (median 74%).

  14. Atmospheric absorption of terahertz radiation and water vapor continuum effects

    E-print Network

    Massachusetts at Lowell, University of

    Atmospheric absorption of terahertz radiation and water vapor continuum effects David M. Slocum a vapor Absorption Continuum Terahertz Spectroscopy a b s t r a c t The water vapor continuum absorption. The absorption coefficient as a function of frequency was determined and compared with theoretical predictions

  15. Water Absorption by Cracked Mustard 1

    Microsoft Academic Search

    X. ZHANG; G. H. BRUSEWITZ

    1993-01-01

    Cereal Chem. 70(2):133-136 The water absorption rate was determined for whole mustard seed to be 1.58 X 10-7 cm 2 \\/sec for whole seeds, was used in the diffusion and for seed cracked by seven cracking treatments, including two types equation to derive an equivalent average particle diameter. The equivalent of mills, three roller-mill gaps, two hammer-mill feed rates, three

  16. Water- Lithium Bromide-?- Butyrolactone Absorption Refrigerating Machine

    NASA Astrophysics Data System (ADS)

    Iyoki, Shigeki; Uemura, Tadashi

    This investigation was carried out in order to find corrosion inhibitors which would be effective in controlling the corrosion for the water-lithium bromide-?-butyrolactone (20 moles water/1 mole ?-butyrolactone) absorption refrigerating machine. The experiments were carried out on continuous boiling test, intermittent boiling test and galvanic corrosion test with the use of organic inhibitors and inorganic inhibitors in ?-butyrolactone aqueous solution of lithium bromide. The metals used in these corrosion tests were mainly SS 41 and copper. From these experimental results, the most suitable corrosion inhibitors for SS 41 and copper in ?-butyrolactone aqueous solution of lithium bromide Were recognized to be benzotriazole, tolyltriazole and lithium molybdate.

  17. Atmospheric absorption of terahertz radiation and water vapor continuum effects

    E-print Network

    Massachusetts at Lowell, University of

    Atmospheric absorption of terahertz radiation and water vapor continuum effects David M. Slocum a April 2013 Keywords: Water vapor Absorption Continuum Terahertz Spectroscopy a b s t r a c t The water vapor continuum absorption spectrum was investigated using Fourier Trans- form Spectroscopy

  18. Toward improving global estimates of field soil water capacity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field capacity or field water capacity (FC) is defined as the water content of a soil after having been wetted with water and after free drainage is negligible. Different recommendations exist world-wide on which, if any, pressure head should be used in laboratory measurements to approximate the FC ...

  19. Absorption

    NSDL National Science Digital Library

    Katie Hale (CSUF; )

    2002-09-26

    The process of absorption is a cellular process (microscopic). Absorption cells line the stomach and intestine walls and allow small nutrients (broken down from the food we eat) to pass through and into our blood. The process of absorption is much like a leaking balloon filled with water. The balloon is the stomach or intestine, the tiny holes are the absorption cells, and the water is nutrients leaving.

  20. Optimum hot water temperature for absorption solar cooling

    SciTech Connect

    Lecuona, A.; Ventas, R.; Venegas, M.; Salgado, R. [Dpto. Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911 Leganes, Madrid (Spain); Zacarias, A. [ESIME UPA, IPN, Av. de las Granjas 682, Col. Santa Catarina, 02550, D.F. Mexico (Mexico)

    2009-10-15

    The hot water temperature that maximizes the overall instantaneous efficiency of a solar cooling facility is determined. A modified characteristic equation model is used and applied to single-effect lithium bromide-water absorption chillers. This model is based on the characteristic temperature difference and serves to empirically calculate the performance of real chillers. This paper provides an explicit equation for the optimum temperature of vapor generation, in terms of only the external temperatures of the chiller. The additional data required are the four performance parameters of the chiller and essentially a modified stagnation temperature from the detailed model of the thermal collector operation. This paper presents and discusses the results for small capacity machines for air conditioning of homes and small buildings. The discussion highlights the influence of the relevant parameters. (author)

  1. D-Xylose absorption capacity of broiler intestine in response to phytic acid

    Microsoft Academic Search

    B. Mansoori

    2010-01-01

    1?Dietary phytic acid (PA) reduces the apparent digestion and of dietary nutrients, increases the excretion of endogenous amino acids and minerals and reduces the concentration of blood glucose.2?An experiment was conducted to examine the effect of phytic acid on the absorption capacity of the intestine in broiler chicken, using a D-xylose absorption test.3?Three groups of ten 26-d-old apparently healthy broiler

  2. The heat capacity of water near solid surfaces

    NASA Astrophysics Data System (ADS)

    Vu?eli?, V.; Vu?eli?, D.

    1983-11-01

    Anomalous heat capacities of water at solid/water interfaces have been obtained. The solids vary from inorganic (zeolites, porous class, silica gel, activated carbon) to biological (protein lysozyme and adrenal gland). Water heat capacities at all interfaces exhibit the same pattern. At room temperature the small values are close to ice and increase with temperature, reaching the value of free water between 380 and 440 K.

  3. Absorptive capacity of iron-based magnetic carriers for blood detoxification

    NASA Astrophysics Data System (ADS)

    Komissarova, Lubov Kh; Kuznetsov, Anatoly A.; Gluchoedov, Nikolas P.; Kutushov, Michael V.; Pluzan, Maria A.

    2001-01-01

    The absorptive capacity of different magnetic carriers was investigated. Restored-iron, iron-carbon and iron-silica do not cause changes in erythrocytes' osmotic resistance and possess high sorption efficiency for substances of different molecular mass. These magnetic carriers can be recommended for extracorporeal blood detoxification of low (barbiturates), middle (bilirubin) and high (heme proteins) molecular weight substances.

  4. Absorption capacity of fructose in healthy adults. Comparison with sucrose and its constituent monosaccharides

    Microsoft Academic Search

    J J Rumessen; E Gudmand-Høyer

    1986-01-01

    The capacity to absorb fructose in 10 healthy adults was investigated by means of hydrogen breath analysis. Fructose absorption was quantified with lactulose standards. Significant hydrogen production (greater than or equal to 20 ppm rise of breath hydrogen) was found after challenge with 10% solutions of 50, 37.5, 25, 20, and 15 g fructose in eight, seven, five, four and

  5. Absorption of water by thin, ionic films of gelatin.

    PubMed

    Fialkowski, M; Campbell, C J; Bensemann, I T; Grzybowski, B A

    2004-04-27

    This paper discusses absorption of water by thin, dry films of gelatin. Experiments using a wet-stamping technique were performed to characterize water uptake in terms of (i) equilibrium profiles of the water density inside the gel and (ii) the kinetics of water absorption. It was found that, in contrast to pure gelatin films, which absorb water approximately uniformly, films of gelatin doped with ionic additives have exponentially decaying equilibrium water profiles. The process of water absorption by both doped and undoped gels was described by a theoretical model based on the minimization of grand potential functional. The results of this model are in agreement with the experiment. PMID:15875375

  6. Economic performance of water storage capacity expansion for food security

    NASA Astrophysics Data System (ADS)

    Gohar, Abdelaziz A.; Ward, Frank A.; Amer, Saud A.

    2013-03-01

    SummaryContinued climate variability, population growth, and rising food prices present ongoing challenges for achieving food and water security in poor countries that lack adequate water infrastructure. Undeveloped storage infrastructure presents a special challenge in northern Afghanistan, where food security is undermined by highly variable water supplies, inefficient water allocation rules, and a damaged irrigation system due three decades of war and conflict. Little peer-reviewed research to date has analyzed the economic benefits of water storage capacity expansions as a mechanism to sustain food security over long periods of variable climate and growing food demands needed to feed growing populations. This paper develops and applies an integrated water resources management framework that analyzes impacts of storage capacity expansions for sustaining farm income and food security in the face of highly fluctuating water supplies. Findings illustrate that in Afghanistan's Balkh Basin, total farm income and food security from crop irrigation increase, but at a declining rate as water storage capacity increases from zero to an amount equal to six times the basin's long term water supply. Total farm income increases by 21%, 41%, and 42% for small, medium, and large reservoir capacity, respectively, compared to the existing irrigation system unassisted by reservoir storage capacity. Results provide a framework to target water infrastructure investments that improve food security for river basins in the world's dry regions with low existing storage capacity that face ongoing climate variability and increased demands for food security for growing populations.

  7. Predicting and mapping soil available water capacity in Korea

    PubMed Central

    Hong, Suk Young; Han, Kyung Hwa; Kim, Yihyun; Lee, Kyungdo

    2013-01-01

    The knowledge on the spatial distribution of soil available water capacity at a regional or national extent is essential, as soil water capacity is a component of the water and energy balances in the terrestrial ecosystem. It controls the evapotranspiration rate, and has a major impact on climate. This paper demonstrates a protocol for mapping soil available water capacity in South Korea at a fine scale using data available from surveys. The procedures combined digital soil mapping technology with the available soil map of 1:25,000. We used the modal profile data from the Taxonomical Classification of Korean Soils. The data consist of profile description along with physical and chemical analysis for the modal profiles of the 380 soil series. However not all soil samples have measured bulk density and water content at ?10 and ?1500 kPa. Thus they need to be predicted using pedotransfer functions. Furthermore, water content at ?10 kPa was measured using ground samples. Thus a correction factor is derived to take into account the effect of bulk density. Results showed that Andisols has the highest mean water storage capacity, followed by Entisols and Inceptisols which have loamy texture. The lowest water retention is Entisols which are dominated by sandy materials. Profile available water capacity to a depth of 1 m was calculated and mapped for Korea. The western part of the country shows higher available water capacity than the eastern part which is mountainous and has shallower soils. The highest water storage capacity soils are the Ultisols and Alfisols (mean of 206 and 205 mm, respectively). Validation of the maps showed promising results. The map produced can be used as an indication of soil physical quality of Korean soils. PMID:23646290

  8. FIELD CAPACITY OF WATER IN SOILS: CONCEPTS, MEASUREMENT, AND APPROXIMATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We propose to use field capacity as an operational concept for root zone water management, and avoid treating it as an intrinsic soil property. Field capacity is reached when downward drainage flux is negligibly small (while recognizing that drainage may not cease completely) so that evaporation and...

  9. WATER DIVERSION CAPACITY OF INCLINED CAPILLARY BARRIERS

    Microsoft Academic Search

    Bruno Bussière; Senami Aurore Apithy; Michel Aubertin; Robert P. Chapuis

    Covers with capillary barrier effects (CCBE) are an interesting alternative to low hydraulic conductivity covers to limit water infiltration into waste disposal sites, especially for arid and semi-arid climates. This type of cover system typically includes a fine-grained material layer overlying a coarser one. In sloping systems, water can be diverted at the interface between the two materials, hence reducing

  10. Water absorption properties of ultrasonic treated brown rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To understand the effect of ultrasonic treated on brown rice, it is important to research the water absorption processing of brown rice before and after ultrasonic treatment. The objective of this study was investigate and modeling water absorption characteristics of brown rice using Peleg’s equatio...

  11. GASTROINTESTINAL ABSORPTION OF SOLUBLE URANIUM FROM DRINKING WATER

    EPA Science Inventory

    The manuscript describes results of an experiment to determine the gastrointestinal absorption of uranium from drinking water in 12 health adults. Most of the uranium ingested was excreted in feces in the first 2 days following ingestion of the water. The absorption was the same ...

  12. New constraints in absorptive capacity and the optimum rate of petroleum output

    SciTech Connect

    El Mallakh, R

    1980-01-01

    Economic policy in four oil-producing countries is analyzed within a framework that combines a qualitative assessment of the policy-making process with an empirical formulation based on historical and current trends in these countries. The concept of absorptive capacity is used to analyze the optimum rates of petroleum production in Iran, Iraq, Saudi Arabia, and Kuwait. A control solution with an econometric model is developed which is then modified for alternative development strategies based on analysis of factors influencing production decisions. The study shows the consistencies and inconsistencies between the goals of economic growth, oil production, and exports, and the constraints on economic development. Simulation experiments incorporated a number of the constraints on absorptive capacity. Impact of other constraints such as income distribution and political stability is considered qualitatively. (DLC)

  13. Effect of water absorption on pollen adhesion.

    PubMed

    Lin, Haisheng; Lizarraga, Leonardo; Bottomley, Lawrence A; Carson Meredith, J

    2015-03-15

    Pollens possess a thin liquid coating, pollenkitt, which plays a major role in adhesion by forming capillary menisci at interfaces. Unfortunately, the influence of humidity on pollenkitt properties and capillary adhesion is unknown. Because humidity varies widely in the environment, the answers have important implications for better understanding plant reproduction, allergy and asthma, and pollen as atmospheric condensation nuclei. Here, pollenkitt-mediated adhesion of sunflower pollen to hydrophilic and hydrophobic surfaces was measured as a function of humidity. The results quantify for the first time the significant water absorption of pollenkitt and the resulting complex dependence of adhesion on humidity. On hydrophilic Si, adhesion increased with increasing RH for pollens with or without pollenkitt, up to 200nN at 70% RH. In contrast, on hydrophobic PS, adhesion of pollenkitt-free pollen is independent of RH. Surprisingly, when pollenkitt was present adhesion forces on hydrophobic PS first increased with RH up to a maximum value at 35% RH (?160nN), and then decreased with further increases in RH. Independent measurement of pollenkitt properties is used with models of capillary adhesion to show that humidity-dependent changes in pollenkitt wetting and viscosity are responsible for this complex adhesion behavior. PMID:25524008

  14. Plasma Citrulline Concentration: A Reliable Marker of Small Bowel Absorptive Capacity Independent of Intestinal Inflammation

    Microsoft Academic Search

    Cinzia Papadia; Roy A. Sherwood; Chrysostomos Kalantzis; Katharina Wallis; Umberto Volta; Erica Fiorini; Alastair Forbes

    2007-01-01

    OBJECTIVES:Postabsorptive plasma citrulline concentration has been proposed as a reliable marker of small bowel absorptive capacity in short bowel patients. The aim of this study was to address the potentially confounding impact of intestinal inflammation.METHODS:Fifty-five patients were selected according to diagnosis, small bowel length, and degree of bowel inflammation. (a) Crohn's disease (CD) with massive small bowel resection leaving ?50

  15. CFCs and electric chillers: Selection of large-capacity water chillers in the 1990s

    SciTech Connect

    Not Available

    1993-05-01

    This handbook offers a single source of useful information for understanding CFC and HCFC phaseout issues and selecting large- capacity water chillers for cooling commercial buildings. It evaluates the performance of electric, absorption, and natural-gas-engine driven water chillers. An economic evaluation checklist and example are included, using the EPRI COMTECH screening tool. Peak shaving with gas chillers and load shifting with chilled water storage are examined. The handbook, written for a diverse audience, covers chiller hardware, function, performance, and typical installed costs. It provides guidelines and checklists for chiller selection, economic comparison, and operation and maintenance.

  16. CFCS and electric chillers: Selection of large-capacity water chillers in the 1990s

    SciTech Connect

    Niess, R.C. (Gilbert and Associates, Gloucester Point, VA (United States))

    1992-03-01

    This handbook offers a single source of useful information for understanding CFC and HCFC phaseout issues and selecting large-capacity water chillers for cooling commercial buildings. It evaluates the performance of electric, absorption, and natural-gas-engine driven water chillers. An economic evaluation checklist and example are included, using the EPRI COMTECH screening tool. Peak shaving with gas chillers and load shifting with chilled water storage are examined. The handbook, written for a diverse audience, covers chiller hardware, function, performance, and typical installed costs. It provides guidelines and checklists for chiller selection, economic comparison, and operation and maintenance.

  17. Absorption refrigeration: cooling with hot water

    Microsoft Academic Search

    Rafferty

    1984-01-01

    The absorption cycle is a process by which refrigeration effect is produced through the use of two fluids and some quantity of heat input, rather than electrical input as in the more familiar vapor compression cycle. Both vapor compression and absorption refrigeration cycles accomplish the removal of heat through the evaporation of a refrigerant at a low pressure and the

  18. Isochoric heat capacity of an n-hexane + water system

    NASA Astrophysics Data System (ADS)

    Bezgomonova, E. I.; Saidov, S. M.; Stepanov, G. V.

    2015-01-01

    The isochoric heat capacity of an n-hexane + water system at water contents of 0.121, 0.166, 0.2, 0.234, 0.256, and 0.3 mole fraction is studied along different isochors at different temperatures in the 140 to 550 kg/m3 range of densities using a high-temperature adiabatic calorimeter designed at the Amirkhanov Institute of Physics. The tabulated values of isochoric heat capacity C v, x are presented for an H2O concentration of 0.3 mole fraction. The curves of liquid-liquid and liquid-gas phase equilibria are constructed.

  19. Climate Adaptation Capacity for Conventional Drinking Water Treatment Facilities

    NASA Astrophysics Data System (ADS)

    Levine, A.; Goodrich, J.; Yang, J.

    2013-12-01

    Water supplies are vulnerable to a host of climate- and weather-related stressors such as droughts, intense storms/flooding, snowpack depletion, sea level changes, and consequences from fires, landslides, and excessive heat or cold. Surface water resources (lakes, reservoirs, rivers, and streams) are especially susceptible to weather-induced changes in water availability and quality. The risks to groundwater systems may also be significant. Typically, water treatment facilities are designed with an underlying assumption that water quality from a given source is relatively predictable based on historical data. However, increasing evidence of the lack of stationarity is raising questions about the validity of traditional design assumptions, particularly since the service life of many facilities can exceed fifty years. Given that there are over 150,000 public water systems in the US that deliver drinking water to over 300 million people every day, it is important to evaluate the capacity for adapting to the impacts of a changing climate. Climate and weather can induce or amplify changes in physical, chemical, and biological water quality, reaction rates, the extent of water-sediment-air interactions, and also impact the performance of treatment technologies. The specific impacts depend on the watershed characteristics and local hydrological and land-use factors. Water quality responses can be transient, such as erosion-induced increases in sediment and runoff. Longer-term impacts include changes in the frequency and intensity of algal blooms, gradual changes in the nature and concentration of dissolved organic matter, dissolved solids, and modulation of the microbiological community structure, sources and survival of pathogens. In addition, waterborne contaminants associated with municipal, industrial, and agricultural activities can also impact water quality. This presentation evaluates relationships between climate and weather induced water quality variability and the capacity of treatment facilities and supporting water infrastructure to deliver safe drinking water consistently and reliably. Simulation models of water treatment facilities are used to evaluate the outcome of specific source water quality scenarios on treatment system performance and reliability. Modeling results are used to evaluate the process and operational capacity to respond to transient water quality changes and adapt to longer-term variability in water quality and availability. In some cases, changes in temperature and mineral content serve to improve the overall treatment performance. In addition, the integration of microbially enhanced treatment systems such as biological filtration can provide additional capacity. Conversely, changes in the nutrient and temperature dynamics can trigger algal and cyanobacterial blooms that can impair performance. Research needs are identified and the importance of developing more integrated modeling systems is highlighted.

  20. Absorption of water and lubricating oils into porous nylon

    NASA Technical Reports Server (NTRS)

    Bertrand, P. A.

    1995-01-01

    Oil and water absorption from air into sintered porous nylon can be described by infiltration into the pores of the material. This process can be modeled by a diffusion-like mechanism. For water absorption, we find a formal diffusion coefficient of 1.5 x 10(exp -4)sq cm/min when the nylon is initially dry. The diffusion coefficient is 4 x 10(exp -6)sq cm/min when the nylon is oil-impregnated prior to air exposure. In a 52% RH atmosphere, dry nylon absorbs 3% w/w water, and oil-impregnated nylon absorbs 0.6% w/w water. For oil absorption there are three steps: (1) surface absorption and infiltration into (2) larger and (3) smaller pores. Surface absorption is too fast to be measured in these experiments. The diffusion coefficient for the second step is 6 x 10(exp -4)sq cm/min for SRG-60 oil into dry nylon and 4 x 10(exp -4)sq cm/min for air-equilibrated nylon. The diffusion coefficient for the third step is about 1 x 10(exp -6)sq cm/min for both cases. The total amount of oil absorbed is 31% w/w. The interaction between water and nylon is not as strong as that between water and cotton-phenolic: oil can replace water, and only a small amount of water can enter previously oil-impregnated nylon.

  1. 30 CFR 75.1107-7 - Water spray devices; capacity; water supply; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment § 75.1107-7 Water spray devices; capacity; water supply; minimum...

  2. Heat exchange model in absorption chamber of water-direct-absorption-typed laser energy meter

    NASA Astrophysics Data System (ADS)

    Feng Wei, Ji; Qun Sun, Li; Zhang, Kai; Hu, XiaoYang; Zhou, Shan

    2015-04-01

    The interaction between laser and water flow is very complicated in the absorption chamber of a high energy laser (HEL) energy meter which directly uses water as an absorbing medium. Therefore, the heat exchange model cannot be studied through traditional methods, but it is the most important factor to improve heat exchange efficiency in the absorption chamber. After the exchanges of heat and mass were deeply analyzed, experimental study and numerical fitting were brought out. The original testing data of laser power and water flow temperature at one moment were utilized to calculate those at the next moment, and then the calculated temperature curve was compared with the measured one. If the two curves matched well, the corresponding coefficient was obtained. Meanwhile, numerous experiments were performed to study the effects of laser power, duration, focal spot scale, and water flow rate on heat exchange coefficient. In addition, the relationship between water phase change and heat exchange was analyzed. The heat exchange coefficient was increased by optimizing the construction of the absorption chamber or increasing water flow rate. The results provide the reference for design of water-direct-absorption-typed HEL energy meters, as well as for analysis of the interaction between other similar lasers and water flow.

  3. Absorptive removal of biomass tar using water and oily materials.

    PubMed

    Phuphuakrat, Thana; Namioka, Tomoaki; Yoshikawa, Kunio

    2011-01-01

    Water is the most common choice of absorption medium selected in many gasification systems. Because of poor solubility of tar in water, hydrophobic absorbents (diesel fuel, biodiesel fuel, vegetable oil, and engine oil) were studied on their absorption efficiency of biomass tar and compared with water. The results showed that only 31.8% of gravimetric tar was removed by the water scrubber, whereas the highest removal of gravimetric tar was obtained by a vegetable oil scrubber with a removal efficiency of 60.4%. When focusing on light PAH tar removal, the absorption efficiency can be ranked in the following order; diesel fuel>vegetable oil>biodiesel fuel>engine oil>water. On the other hand, an increase in gravimetric tar was observed for diesel fuel and biodiesel fuel scrubbers because of their easy evaporation. Therefore, the vegetable oil is recommended as the best absorbent to be used in gasification systems. PMID:20801021

  4. Ethanol and water capacities of alcohols: a molecular dynamics study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The extended hydrogen bond networks formed by alcohols are good indicators of their capacities to hold water. Results from molecular dynamics simulations on 24 linear alcohol isomers containing from 6 to 12 carbon atoms show the effects of the hydroxyl location on bulk hydrogen-bonded structures. ...

  5. Surface Water Storage Capacity of Street Trees in Davis, California

    NASA Astrophysics Data System (ADS)

    Xiao, Q.

    2012-12-01

    Rainfall interception plays an important role in water resources redistribution of the hydrologic cycle. Canopy surface water detention and saturation storage capacities are important parameters that affect rainfall interception processes. Two types of surface water storage capacities that influence the interception dynamic processes are the surface water saturation storage capacity and the maximum surface storage capacity. Studies of rainfall interception in rural forest show that these values vary widely among tree species and geographic locations. Understanding the magnitude and dynamic of these storages are important for modeling urban hydrological processes. In this study, 20 urban tree species in Davis, California were measured in laboratory. The computer controlled measurement system included a rainfall simulator, a weighting measurement, and image collector components. The surface storages were calculated based on sample's weighing change of different rainfall intensity and sample's surface area which was estimated based image analysis method. Twelve rainfall intensities varied from 3.48 to 139.49 mm/hr were used in each tree species' measurement. The results shown that the surface storages varied widely among tree species and different grow seasons.

  6. Physicochemical properties of macrogol ointment and emulsion ointment blend developed for regulation of water absorption.

    PubMed

    Noda, Yasuhiro; Watanabe, Kazuya; Sanagawa, Akimasa; Sobajima, Yu; Fujii, Satoshi

    2011-10-31

    Pressure ulcers can form with excess pressure and shearing stress on skin tissue. Because pressure ulcer is often accompanies by exudates, selection of appropriate topical emulsion ointment is difficult. Blended ointments consisting of emulsion base and water-soluble base are clinically used for adjustment of wound moist environment. Because regulating the amount of wound exudates can enhance treatment efficacy, two new blended ointments were developed. LY-SL blended ointment consisted of lysozyme hydrochloride water-in-oil (w/o) emulsion (LY-cream) and sulfadiazine macrogol (polyethylene glycol) ointment (SL-pasta). TR-SL blended ointment consisted of tretinoin tocoferil oil-in-water (o/w) emulsion (TR-cream) and SL-pasta (TR-SL). LY-SL and TR-SL were applied to Franz diffusion cell with cellulose membranes for the evaluation of water absorption characteristics at 32 °C. Water absorption rate constants (mg/cm(2)/min(0.5)) were 12.5, 16.3 and 34.6 for LY-cream, TR-cream and SL-pasta, respectively. Water absorption rate constants for LY-SL and TR-SL (SL-pasta 70%) exhibited intermediate values of 21.2 and 27.2, as compared to each ointment alone, respectively. Because amount of water absorbed was linearly related to square root of time, it was suggested that water-absorbable macrogol was surrounded by oily ingredients forming matrix structure. This diffusion-limited structure may regulate water absorption capacity. This is the first report of physicochemical properties of macrogol ointment and emulsion ointment blend developed for regulation of water absorption. The blended ointment can properly regulate amount of exudates in wounds and may be useful for treatment of pressure ulcers. PMID:21820500

  7. Sensitivity of the global water cycle to the water-holding capacity of land

    Microsoft Academic Search

    P. C. D. Milly; K. A. Dunne

    1994-01-01

    The sensitivity of the global water cycle to the water-holding capacity of the plant-root zone of continental soils is estimated by simulations using a mathematical model of the general circulation of the atmosphere, with prescribed ocean surface temperatures and prescribed cloud. With an increase of the globally constant storage capacity, evaporation from the continents rises and runoff falls, because a

  8. Characteristics of Nasal-Associated Lymphoid Tissue (NALT) and Nasal Absorption Capacity in Chicken

    PubMed Central

    Kang, Haihong; Yan, Mengfei; Yu, Qinghua; Yang, Qian

    2013-01-01

    As the main mucosal immune inductive site of nasal cavity, nasal-associated lymphoid tissue (NALT) plays an important role in both antigen recognition and immune activation after intranasal immunization. However, the efficiency of intranasal vaccines is commonly restricted by the insufficient intake of antigen by the nasal mucosa, resulting from the nasal mucosal barrier and the nasal mucociliary clearance. The distribution of NALT and the characteristic of nasal cavity have already been described in humans and many laboratory rodents, while data about poultry are scarce. For this purpose, histological sections of the chicken nasal cavities were used to examine the anatomical structure and histological characteristics of nasal cavity. Besides, the absorptive capacity of chicken nasal mucosa was also studied using the materials with different particle size. Results showed that the NALT of chicken was located on the bottom of nasal septum and both sides of choanal cleft, which mainly consisted of second lymphoid follicle. A large number of lymphocytes were distributed under the mucosal epithelium of inferior nasal meatus. In addition, there were also diffuse lymphoid tissues located under the epithelium of the concha nasalis media and the walls of nasal cavity. The results of absorption experiment showed that the chicken nasal mucosa was capable to absorb trypan blue, OVA, and fluorescent latex particles. Inactivated avian influenza virus (IAIV) could be taken up by chicken nasal mucosa except for the stratified squamous epithelium sites located on the forepart of nasal cavity. The intake of IAIV by NALT was greater than that of the nasal mucosa covering on non-lymphoid tissue, which could be further enhanced after intranasal inoculation combined with sodium cholate or CpG DNA. The study on NALT and nasal absorptive capacity will be benefit for further understanding of immune mechanisms after nasal vaccination and development of nasal vaccines for poultry. PMID:24391892

  9. A simplified method for forest water storage capacity measurement

    NASA Astrophysics Data System (ADS)

    Llorens, P.; Gallart, F.

    2000-12-01

    A simplification of direct methods to measure canopy storage capacity is presented. It is based on measurement of water retained by vegetal entities (needles, stems and branches) and the up-scaling of these measurements using the determination of the surface of canopy elements from common vertical photographs taken from the ground. The specific water retention capacities of Pinus sylvestris pine needles ranged between 0.104 and 0.043 mm, depending on the simulation of still air or windy conditions. These values are low when compared with the specific water retention capacity of branches and stems, 0.62 mm. The water retained in branches and stems, therefore, plays a key role in rainfall interception. The canopy storage results obtained are consistent with the spatial distribution of throughfall measured in five experimental plots located in a heterogeneous 40-year-old Pinus sylvestris stand in a Mediterranean mountain area of the South Eastern Pyrenees (Catalonia, Spain), and are 30% higher than the values estimated through indirect methods.

  10. Soil water availability for plants as quantified by conventional available water, least limiting water range and integral water capacity

    Microsoft Academic Search

    Hossein Asgarzadeh; Mohammad Reza Mosaddeghi; Ali Akbar Mahboubi; Akram Nosrati; Anthony Roger Dexter

    2010-01-01

    There are different approaches to define the soil available water (SAW) for plants. The objectives of this study are to evaluate\\u000a the SAW values of 12 arable soils from Hamadan province (western Iran) calculated by plant available water (PAW), least limiting\\u000a water range (LLWR) and integral water capacity (IWC) approaches and to explore their relations with Dexter’s index of soil

  11. ERP and Four Dimensions of Absorptive Capacity: Lessons from a Developing Country

    NASA Astrophysics Data System (ADS)

    Gil, María José Álvarez; Aksoy, Dilan; Kulcsar, Borbala

    Enterprise resource planning systems can grant crucial strategic, operational and information-based benefits to adopting firms when implemented successfully. However, a failed implementation can often result in financial losses rather than profits. Until now, the research on the failures and successes were focused on implementations in large manufacturing and service organizations firms located in western countries, particularly in USA. Nevertheless, IT has gained intense diffusion to developing countries through declining hardware costs and increasing benefits that merits attention as much as developed countries. The aim of this study is to examine the implications of knowledge transfer in a developing country, Turkey, as a paradigm in the knowledge society with a focus on the implementation activities that foster successful installations. We suggest that absorptive capacity is an important characteristic of a firm that explains the success level of such a knowledge transfer.

  12. Determination of fixed water in rocks by infrared absorption

    USGS Publications Warehouse

    Breger, I.A.; Chandler, J.C.

    1969-01-01

    An infrared absorption technique has been developed for the quantitative determination of "fixed water" (H2O+) in rocks. Potassium bromide disks containing 2-mg samples are scanned in the 3-??m spectral region and absorption at 2.96 ??m is determined. Although the exact nature of this peak is not known, other than that it is caused by an interaction between the potassium bromide and hydroxyl groups and water, it can be used for quantitative analysis. Rock samples, other than those containing significant percentages of clay minerals, can be analyzed with a standard deviation of 0.26%.

  13. Ground water applications of the heat capacity mapping mission

    NASA Technical Reports Server (NTRS)

    Heilman, J. L.; Moore, D. G.

    1981-01-01

    The paper discusses the ground water portion of a hydrologic investigation of eastern South Dakota using data from the Heat Capacity Mapping Mission (HCMM) satellite. The satellite carries a two-channel radiometer (0.5-1.1 and 10.5-12.5 microns) in a sun synchronous orbit and collects data at approximately 0230 and 1330 local standard time with repeat coverage of 5 to 16 days depending on latitude. It is shown that HCMM data acquired at appropriate periods of the diurnal and annual temperature cycle can provide useful information on shallow ground water.

  14. Achieving Rapid Absorption and Extensive Liquid Uptake Capacity in Porous Structures by Decoupling Capillarity and Permeability: Nanoporous Modified Calcium Carbonate

    Microsoft Academic Search

    Cathy J. Ridgway; Patrick A. C. Gane; Joachim Schoelkopf

    2006-01-01

    Porous media with rapid absorption properties are greatly sought after in the fields of super absorbers and catalysts. Natural\\u000a materials, such as diatomite, or synthetic zeolite feature strongly in industrial reaction processes. Most, or all, of such\\u000a materials, however, are surface acidic. A novel rapidly absorbing alkaline porous structure, with a high absorption capacity,\\u000a is presented here. As in the

  15. Water Vapor Absorption in Early M-type Stars

    E-print Network

    M. Matsuura; I. Yamamura; H. Murakami; M. M. Freund; M. Tanaka

    1999-06-16

    The spectrometers onboard the Infrared Telescope in Space (IRTS) reveal water vapor absorption in early M-type stars, as early as M2. Previous observations detected H_2O vapor absorption only in stars later than M6, with the exception of the recent detection of H_2O in beta Peg (M2.5 II-III). In our sample of 108 stars, 67 stars have spectral types earlier than M6. The spectral types are established by means of their near-infrared colors on a statistical basis. Among the 67 stars of spectral types earlier than M6, we find water vapor absorption in six stars. The observed absorption features are interpreted using a local thermodynamic equilibrium model. The features are reasonably fitted by model spectra with excitation temperatures of 1000-1500 K and water column densities of 5x10^19 to 1x10^20 cm^-2. These numbers imply that the H_2O molecules are present in a region of the atmosphere, located above the photosphere. Furthermore, our analysis shows a good correlation between the H_2O absorption band strength, and the mid-infrared excess due to the circumstellar dust. We discuss the relation between the outer atmosphere and the mass loss.

  16. An environmentally friendly method for the fabrication of reduced graphene oxide foam with a super oil absorption capacity.

    PubMed

    He, Yongqiang; Liu, Yue; Wu, Tao; Ma, Junkui; Wang, Xingrui; Gong, Qiaojuan; Kong, Weina; Xing, Fubao; Liu, Yu; Gao, Jianping

    2013-09-15

    Three kinds of graphene oxide (GO) foams were fabricated using different freezing methods (unidirectional freezing drying (UDF), non-directional freezing drying, and air freezing drying), and the corresponding reduced graphene oxide (RGO) foams were prepared by their thermal reduction of those GO foams. These RGO foams were characterized by Fourier transform infrared spectroscopy, thermal gravimetric analysis, X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. The absorption process and the factors that influence the absorption capacity were investigated. The RGO foams are hydrophobic and showed extremely high absorbing abilities for organic liquids. The absorption capacity of the RGO foams made by UDF was higher than 100 g g(-1) for all the oils tested (gasoline, diesel oil, pump oil, lubricating oil and olive oil) and had the highest value of about 122 g g(-1) for olive oil. The oil absorption capacity of the GO foams was lower than that of the RGO foams, but for olive oil, the absorption capacity was still high than 70 g g(-1), which is higher than that of most oil absorbents. PMID:23856309

  17. Water vapor continuum: Whether collision-induced absorption is involved?

    NASA Astrophysics Data System (ADS)

    Vigasin, A. A.

    2014-11-01

    In a series of recent publications, the idea is pursued to shed a new light on the theory of the water vapor continuum absorption invoking the mechanism of collision-induced absorption. In the opinion of the present author, a portion of theoretical suggestions on this subject is biased and may thus lead to untenable conclusions about the nature of the continuum. The most typical drawback consists of improper consideration of statistics in the ensemble of interacting monomers that lead to embedding incorrect statistical weights to various types of molecular pairs which can form. The current note aims at clarifying the term “collision-induced absorption” in order to avoid incongruity in understanding the nature of the water vapor continuum.

  18. A Novel Absorption Cycle for Combined Water Heating, Dehumidification, and Evaporative Cooling

    SciTech Connect

    CHUGH, Devesh [University of Florida, Gainesville; Gluesenkamp, Kyle R [ORNL; Abdelaziz, Omar [ORNL; Moghaddam, Saeed [University of Florida, Gainesville

    2014-01-01

    In this study, development of a novel system for combined water heating, dehumidification, and space evaporative cooling is discussed. Ambient water vapor is used as a working fluid in an open system. First, water vapor is absorbed from an air stream into an absorbent solution. The latent heat of absorption is transferred into the process water that cools the absorber. The solution is then regenerated in the desorber, where it is heated by a heating fluid. The water vapor generated in the desorber is condensed and its heat of phase change is transferred to the process water in the condenser. The condensed water can then be used in an evaporative cooling process to cool the dehumidified air exiting the absorber, or it can be drained if primarily dehumidification is desired. Essentially, this open absorption cycle collects space heat and transfers it to process water. This technology is enabled by a membrane-based absorption/desorption process in which the absorbent is constrained by hydrophobic vapor-permeable membranes. Constraining the absorbent film has enabled fabrication of the absorber and desorber in a plate-and-frame configuration. An air stream can flow against the membrane at high speed without entraining the absorbent, which is a challenge in conventional dehumidifiers. Furthermore, the absorption and desorption rates of an absorbent constrained by a membrane are greatly enhanced. Isfahani and Moghaddam (Int. J. Heat Mass Transfer, 2013) demonstrated absorption rates of up to 0.008 kg/m2s in a membrane-based absorber and Isfahani et al. (Int. J. Multiphase Flow, 2013) have reported a desorption rate of 0.01 kg/m2s in a membrane-based desorber. The membrane-based architecture also enables economical small-scale systems, novel cycle configurations, and high efficiencies. The absorber, solution heat exchanger, and desorber are fabricated on a single metal sheet. In addition to the open arrangement and membrane-based architecture, another novel feature of the cycle is recovery of the solution heat energy exiting the desorber by process water (a process-solution heat exchanger ) rather than the absorber exiting solution (the conventional solution heat exchanger ). This approach has enabled heating the process water from an inlet temperature of 15 C to 57 C (conforming to the DOE water heater test standard) and interfacing the process water with absorbent on the opposite side of a single metal sheet encompassing the absorber, process-solution heat exchanger, and desorber. The system under development has a 3.2 kW water heating capacity and a target thermal coefficient of performance (COP) of 1.6.

  19. Absorption characteristics of optically complex inland waters: Implications for water optical classification

    NASA Astrophysics Data System (ADS)

    Shi, Kun; Li, Yunmei; Li, Lin; Lu, Heng

    2013-06-01

    Multiple bio-optical measurements were conducted in inland waters of China, including Lake Taihu [spring and autumn], Lake Chaohu, Lake Dianchi, and Three Gorges Reservoirs. The variations in the absorption characteristics of chromophoric dissolved organic matter (CDOM), phytoplankton, and non-algal particles (NAP) and their relative contributions to total absorption among these waters were analyzed. The obtained results indicated that these areas are representative of the optically complex inland waters characterized by strong regional variations of their absorption properties. By means of the relative contributions of NAP and phytoplankton to the total water absorption at 550 and 675 nm, these waters were classified into three optical water types, each one having specific biogeochemical and optical properties. Two of the types were distinct and corresponded to waters that are optically controlled by NAP (Type I) and dominated by phytoplankton (Type III). Type II was related to relatively optically mixed waters where the absorption properties are controlled by NAP and phytoplankton. Additionally, the differences in remote-sensing reflectance (Rrs) spectra among the three classified water types were clarified to establish optical criteria for identifying these water types. On this basis, the classification criteria for MERIS images were developed, which allowed one to cluster every Rrs spectrum into one of the three water types by comparing the values from band 6, band 8, and band 9 of MERIS images. The proposed criteria were subsequently conducted to map the water types of Lake Taihu using MERIS images.

  20. The Role of Cross-Cultural Absorptive Capacity in the Effectiveness of In-Country Cross-Cultural Training

    ERIC Educational Resources Information Center

    Tarique, Ibraiz; Caligiuri, Paula

    2009-01-01

    Based on the theory of absorptive capacity, this study examines the following question. In the context of cross-cultural training, can the amount of previously accumulated cultural knowledge affect the ability of a trainee to absorb further learning about a new culture, thus enhancing total knowledge and presumably cross-cultural adjustment?…

  1. Water Absorption by Atmospheric Organic Particles: Evidence, Causes and Simulations

    NASA Astrophysics Data System (ADS)

    Saxena, Pradeep

    The optical and chemical properties of atmospheric fine particles and their ability to act as cloud condensation nuclei depend strongly upon their affinity for water. Laboratory experiments have shown that water-soluble sulfates and nitrates, which are major inorganic components of atmospheric fine particles, absorb water in an amount proportional to water vapor pressure. Analogous information about the interactions between water and organics is lacking. Moreover, the molecular composition of atmospheric particulate organics remains poorly characterized; information on the molecular composition of the water-soluble fraction is particularly sparse. Here we first analyze concurrent observations of particle chemical composition and water content from a continental nonurban (Grand Canyon) and an urban (Los Angeles) location to determine whether the water content of atmospheric particles is influenced by the presence of organics. We find that the aggregate hygroscopic properties of inorganic particles are altered substantially when organics are also present. For the nonurban location, organics enhance water absorption by inorganics. For the urban location, on the other hand, the net effect of organics is to diminish water absorption of the inorganics. Second, we identify specific compounds that are likely to contribute to the water-soluble fraction by juxtaposing published observations regarding the extraction characteristics and the molecular composition of atmospheric particulate organics with compound-specific solubility and condensibility for a wide variety of organics. We find that water-soluble organics, which constitute a substantial fraction of the total organic mass, include C2 to C7 multifunctional compounds (e.g. diacids, polyols, amino acids). Third, towards developing a simulation capability, we (1) synthesize published laboratory data to evaluate the water absorption behavior of multifunctional oxygenated organic compounds; and (2) test the reliability of the UNIFAC method for estimating water activities of aqueous organic solutions. Laboratory data show that multifunctional oxygenated compounds can absorb water over the entire range of relative humidities. For a wide variety of compounds (e.g., glycols, dicarboxylic acids, keto acids) and a wide range of solute concentrations (0 to over 90% by wt), we find that in most cases, water activities can be estimated within approximately 15% error.

  2. An Exergy Analysis of LiBr-Water Absorption Refrigerators

    NASA Astrophysics Data System (ADS)

    Asano, Hitoshi; Fujii, Terushige; Wang, Xiao; Origane, Takafumi; Katayama, Masatoshi; Inoue, Umeo

    Absorption refrigerators are very efficient as a heat recovery unit in a co-generation system.In order to design an absorption refrigerator for an arbitrary heat source properly, it is important to consider not only quantity but also quality of heat flow. The evaluation of exergy loss in each component is also effective for the improvement of system. This paper deals with the exergy analysis on a LiBr-water absorption refrigerator consisted of a single-and a double-effect cycle driven by the exhaust gas of the micro gas turbine with the output power of about 30 kW. Moreover, exergy loss in absorption process was eva1uated. As a result, it was shown that 80% of the exergy loss in an absorber was caused in absorption process, and the exergy loss decreased with decreasing the change in solution concentration in absorber. In these calculated results,the maximum cooling load of 77.8 kW was obtained from the exhaust gas with the temperature of 2900°C by utilizing both a single-and a double-effect cycles in combination. The energy and exergy efficiency of the system was 88.0% and 25.6%, respectively.

  3. Dynamics of absorption properties along a latitudinal gradient: sources of absorption in Australian inland waters

    NASA Astrophysics Data System (ADS)

    Hestir, E. L.; Campbell, G.; Malthus, T. J.; Dekker, A.; Botha, E.

    2013-12-01

    Australian inland waters are optically complex and vary spatially and temporally. Inversion of optical remote sensing data for the retrieval of optically active water quality constituents (chlorophyll, colored dissolved organic matter and total suspended solids) is impeded by the scarcity of inherent optical property (IOP) data sets. In 2012 a major measurement program commenced to improve understanding of IOPs in Australia. Seven large lakes were sampled along a latitudinal gradient in Eastern Australia; in situ observations were made of the absorption properties of the water quality during two epochs (wet and dry season). This study documents the seasonal, inter & intra lake variability of the absorption budget of Australian lakes. These data reveal the sources of biogeochemical constituents determining the light climate of lakes. Optically active water quality constituents (total suspended solids, chlorophyll-a, and colored dissolved organic matter) varied significantly between wet and dry season and between lakes. The primary contribution to the absorption budget was from non-algal particulate matter (NAP; 10-60%), followed by colored dissolved organic matter (CDOM; 20-80%). Absorption from phytoplankton contributed only 0-30% of the total budget. This indicates that these lakes are primarily light limited, though the limitation comes from multiple sources. The contribution of NAP to the total absorption budget showed the greatest amount of variance between wet and dry seasons. Examination of the organic matter and estimated phytoplankton biomass contributions to TSS reveal that chlorophyll is not the primary source of organic matter in Australian lakes: allochthonous inputs are the primary trophic driver. Finally, there is strong regional and seasonal variation in the IOPs of the lakes, with the exception of the slope of CDOM. The slope of CDOM was not significantly different between seasons (p=0.94). Non-parametric stepwise multiple comparisons showed the slope of CDOM was significantly different for only one lake, a mid-latitude, shallow, highly turbid diversion dam. The remaining IOP variability casts doubt on the suitability of a single parameterization for inland water remote sensing algorithms, with the possible exception of CDOM. IOP datasets representing the optical complexity and variability of geophysical and trophic conditions are needed for successful remote sensing application.

  4. Investigation of the Emission and Absorption Spectra of Water Vapor

    NASA Astrophysics Data System (ADS)

    Moskalenko, N. I.; Il'in, Yu. A.; Sadykov, M. S.

    2015-01-01

    Emission and absorption spectra of water vapor are measured and analyzed for temperatures 350-2500 K in the spectral range 0.57-25 ?m. Based on the developed mathematical model of radiative transfer, the parameters of spectral transmission functions of N2O vapors are obtained at different temperatures. Practical application of the obtained radiative characteristics is considered for solving problems of radiative heat exchange in high-temperature media and designing optoelectronic systems intended for monitoring of aero carriers.

  5. Airborne differential absorption lidar system for water vapor investigations

    NASA Technical Reports Server (NTRS)

    Browell, E. V.; Carter, A. F.; Wilkerson, T. D.

    1981-01-01

    Range-resolved water vapor measurements using the differential-absorption lidar (DIAL) technique is described in detail. The system uses two independently tunable optically pumped lasers operating in the near infrared with laser pulses of less than 100 microseconds separation, to minimize concentration errors caused by atmospheric scattering. Water vapor concentration profiles are calculated for each measurement by a minicomputer, in real time. The work is needed in the study of atmospheric motion and thermodynamics as well as in forestry and agriculture problems.

  6. Public water supplies of North Carolina : a summary of water sources, use, treatment, and capacity of water-supply systems

    USGS Publications Warehouse

    Mann, L.T., Jr.

    1978-01-01

    Data were collected during 1970-76 on 224 public water supply systems in North Carolina with 500 or more customers. This report summarizes these data that were previously published in five separate regional reports. The data are presented in order to Council of Government region, county, and water system name and include population served, average and maximum daily use, industrial use, water source, allowable draft of surface-water supplies, raw water pumping capacity, raw and finished water storage, type of water treatment, treatment plant capacity, and a summary of the chemical quality of finished water. Tables and maps provide cross references for system names, counties, Council of Government regions and water source.

  7. A Water Vapor Differential Absorption LIDAR Design for Unpiloted Aerial Vehicles

    NASA Technical Reports Server (NTRS)

    DeYoung, Russell J.; Mead, Patricia F.

    2004-01-01

    This system study proposes the deployment of a water vapor Differential Absorption LIDAR (DIAL) system on an Altair unmanned aerial vehicle (UAV) platform. The Altair offers improved payload weight and volume performance, and longer total flight time as compared to other commercial UAV's. This study has generated a preliminary design for an Altair based water vapor DIAL system. The design includes a proposed DIAL schematic, a review of mechanical challenges such as temperature and humidity stresses on UAV deployed DIAL systems, an assessment of the available capacity for additional instrumentation (based on the proposed design), and an overview of possible weight and volume improvements associated with the use of customized electronic and computer hardware, and through the integration of advanced fiber-optic and laser products. The results of the study show that less than 17% of the available weight, less than 19% of the volume capacity, and approximately 11% of the electrical capacity is utilized by the proposed water vapor DIAL system on the Altair UAV.

  8. Human skin binding and absorption of contaminants from ground and surface water during swimming and bathing

    SciTech Connect

    Wester, R.C.; Maibach, H.I. (California Univ., San Francisco (USA))

    1989-10-01

    Contaminants exist in ground and surface water. Human skin has the capacity to bind and then absorb these contaminants into the body during swimming and bathing. Powdered human stratum corneum will bind both lipid-soluble (alachlor, polychlorinated biphenyls (PCBs), benzene) and water-soluble (nitroaniline) chemicals. In vitro (Human skin) and in vivo (Rhesus monkey) studies show that these chemicals readily distribute into skin, and then some of the chemical is absorbed into the body. Linearity in binding and absorption exists for nitroaniline over a 10-fold concentration range. Multiple exposure to benzene is at least cumulative. Binding and adsorption can be significant for exposures as short as 30 minutes, and will increase with time. Adsorption with water dilution increased for alachlor, but not for dinoseb. Soap reversed the partitioning of alachlor between human stratum corneum and water. The PCBs could be removed from skin by soap and water for up to 3 hours and the decontamination potential decreased, due to continuing skin absorption. The model that in vitro and in vivo systems used should permit easy estimation of this area of extensive human exposure effect on risk assessment. 5 refs., 9 tabs.

  9. Community Capacity for Adaptation to Climate-Induced Water Shortages: Linking Institutional Complexity and Local Actors

    Microsoft Academic Search

    Janet L. Ivey; John Smithers; Rob C. de Loë; Reid D. Kreutzwiser

    2004-01-01

    There is growing concern for the capacity of urban and rural communities to manage current water shortages and to prepare for shortages that may accompany predicted changes in climate. In this paper, concepts relating to the notion of climate adaptation and particularly “capacity building” are used to elucidate several determinants of community-level capacity for water management. These concepts and criteria

  10. Absorption capacity of major urban afforestation species in northeastern China to heavy metal pollutants in the atmosphere

    Microsoft Academic Search

    Mu Li-qiang; Sun Hai-yan; Zhu Ning

    2004-01-01

    Totally 24 arbor tree species and 6 shrub species were measured on their absorption capacities to heavy metal Pb, Cd, Cr,\\u000a and Hg by collecting and analyzing the leaves of trees along different streets in Harbin city in Sept. to Oct. of 2003. The\\u000a results showed that all the measured species had certain absorbency to the pollutants (Pb, Cd, Cr

  11. Water vapor-nitrogen absorption at CO2 laser frequencies

    NASA Technical Reports Server (NTRS)

    Peterson, J. C.; Thomas, M. E.; Nordstrom, R. J.; Damon, E. K.; Long, R. K.

    1979-01-01

    The paper reports the results of a series of pressure-broadened water vapor absorption measurements at 27 CO2 laser frequencies between 935 and 1082 kaysers. Both multiple traversal cell and optoacoustic (spectrophone) techniques were utilized together with an electronically stabilized CW CO2 laser. Comparison of the results obtained by these two methods shows remarkable agreement, indicating a precision which has not been previously achieved in pressure-broadened studies of water vapor. The data of 10.59 microns substantiate the existence of the large (greater than 200) self-broadening coefficients determined in an earlier study by McCoy. In this work, the case of water vapor in N2 at a total pressure of 1 atm has been treated.

  12. Deformation behavior and energy absorption capacity of multi-cell aluminum profiles during quasi-static axial compression

    NASA Astrophysics Data System (ADS)

    Wang, Guan; Liu, Zhiwen; Xiang, Dong; Li, Luoxing

    2013-05-01

    The deformation behavior and energy absorption capacity of aluminum profiles under quasi-static axial compression were studied by quasi-static axial compression. The aluminum profiles were aged at temperature of 180 degrees from 30 min to 540 min before compression. The results indicated that the deformation mode of the aluminum extrusions was gradually changed from Diamond mode to Concertina mode and the energy absorption of the extrusions increased with increasing of aging time. The deformation mode of the aluminum sample aged for 540 min is completely concertina mode. Compared with the unaged sample, its energy absorption increased about 99%. Numerical simulation was used for accurately evaluating the load during compression deformation. The deformation behaviors were ideal and symmetrical, and the results were stable and repeatable in the simulation.

  13. The development of an integrating cavity absorption meter to measure optical absorption of pure waters and suspended particulates

    E-print Network

    Pope, Robin Merl

    1990-01-01

    -0. 34 4. 46 -0. 90 In initial cavity designs, the observed increase in absorption at high concentrations of scatterers was attributed to creation of an anisotropy of the Fo irradiance at the sample surface by the So detector Aber. Specifically... . . 20 13 (SI/SO) vs volume for fixed sainple absorption . 23 14 Observed absorption of water at 630 nm versus concentration of nonabsorbing scatterers in models II and V. . . . . . . . . . . 25 15 I&adiance vs distance from sample boundary . . 28...

  14. PURE WATER ABSORPTION COEFFICIENT AROUND 400NM: LAB MEASURED VERSUS FIELD OBSERVED

    E-print Network

    Lee, Zhongping

    PURE WATER ABSORPTION COEFFICIENT AROUND 400NM: LAB MEASURED VERSUS FIELD OBSERVED Zhongping Lee of the ratio of the backscattering coefficient to the absorption coefficient (or the sum of absorption]. In general, it has been found that reflectance can be well explained (or modeled) using known absorption

  15. Water vapour and greenhouse trapping: The role of far infrared absorption

    Microsoft Academic Search

    Ashok Sinha; John E. Harries

    1995-01-01

    Few observations have been made of atmospheric absorption across the far infrared. Yet water vapour absorption in this spectral region may significantly effect climate. The impact of far infrared absorption is assessed by calculating the spectral variation of the total and water vapour greenhouse effects, for the sub-arctic winter (SAW) and tropical (TRP) standard atmospheres. Although the calculated efficiency of

  16. The correlation between molecular motions and heat capacity in normal ice and water

    E-print Network

    Ke, Hai Bo; Wang, Wei Hua

    2011-01-01

    The heat capacities of ice and water at ambient pressure are reexamined to build an intrinsic correlation between H2O molecular motions and the heat capacity. Based on the evolution of H2O molecular motions, a satisfactory description of the heat capacity of ice and water is provided. The heat capacity of ice is related not only to H2O molecular vibrations, but also to the molecular rotations. In water, all H2O molecular vibrations, rotations and translations contribute to the heat capacity. The molecular translational motions are found to be the main contribution to the large heat capacity of water. The results provide a deep insight into the nature of water and ice at ambient pressure.

  17. Microclimate in ski boots--temperature, relative humidity, and water absorption.

    PubMed

    Hofer, Patrick; Hasler, Michael; Fauland, Gulnara; Bechtold, Thomas; Nachbauer, Werner

    2014-05-01

    Ski boot quality is determined by mechanical properties and comfort. Comfort is strongly affected by cold feet. The purpose of this study was to determine the microclimate in ski boots. Climate chamber tests with five male subjects and field tests with two male subjects were conducted. Temperature and relative humidity were measured using four sensors placed on the foot and one on the liner. Absorbed water in liners and socks was measured with a precision balance. The subjects gave subjective ratings for comfort. The toe sensor temperature dropped below 20 °C at an ambient temperature of 0 °C, -10 °C, and -20 °C. Relative humidity values at the foot were as high as 78% in the climate chamber and 93% in the field. Water absorption in socks and liners ranged from 4 to 10 g in the climate chamber and 19 to 45.5 g in the field. The results reveal the importance of keeping the feet and in particular the toes warm during skiing. One possible improvement may be to construct the liner so that sweat and melted snow are kept as far away as possible from the foot. Liner material with high water absorption capacity and hydrophobic socks were suggested to prevent wet feet. PMID:23932378

  18. Poor Diagnostic Accuracy of a Single Fasting Plasma Citrulline Concentration to Assess Intestinal Energy Absorption Capacity

    Microsoft Academic Search

    Job H. C. Peters; Nicolette J. Wierdsma; Tom Teerlink; Paul A. M. van Leeuwen; Chris J. J. Mulder; Ad A. van Bodegraven

    2007-01-01

    OBJECTIVES:Our aim was to explore the diagnostic value of fasting citrulline concentrations to detect decreased intestinal energy absorption in patients with recently diagnosed celiac disease (CeD), refractory celiac disease (RCeD), and short bowel syndrome (SBS). Decreased intestinal energy absorption is regarded a marker of intestinal failure.METHODS:Fasting plasma citrulline concentrations were determined by high performance liquid chromatography (HPLC) in a prospective

  19. Starch-based hydrogel loading with carbendazim for controlled-release and water absorption.

    PubMed

    Bai, Chan; Zhang, Sufen; Huang, Lei; Wang, Haiyan; Wang, Wei; Ye, Qingfu

    2015-07-10

    Starch, with properties of eco-friendliness and abundance, is one of the most important natural polymers. Starch-based hydrogels were investigated as carriers of carbendazim to combine controlled-release and water absorption (WA). Three carbendazim-loaded hydrogels (CLHs) with different WA capacities were prepared by solution polymerization. The CLHs were characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and liquid-chromatography mass-spectrometry (LC-MS/MS). Release kinetics of CLHs was investigated using (14)C-labeling method. The diffusion parameters of CLHs were 0.47, 0.57 and 0.81 in deionized H2O (ddH2O). WA affected release profile significantly, the release longevity reaching 240h when WA was 800g/g in ddH2O. Solution pH influenced release profiles and the lowest release rate occurred in the lowest pH. Addition of CLH (1.3g/kg soil) markedly increased water-holding capacity (WHC) of soil by 8.2%. The study indicated that starch-based CLH was a good controlled-release agent for carbendazim and water absorbent for soil. PMID:25857995

  20. Impact of the hydraulic capacity of plants on water and carbon fluxes in tropical South America

    E-print Network

    Boyce, C. Kevin

    capacity of angiosperms played a significant role in the expansion of tropical rain forest. Citation: LeeImpact of the hydraulic capacity of plants on water and carbon fluxes in tropical South America transpirational capacity of angiosperms plays a unique role in the maintenance of tropical rainforest

  1. A comparison of methods to estimate water-holding capacity in post-rigor porcine muscle.

    PubMed

    Kauffman, R G; Eikelenboom, G; van der Wal, P G; Engel, B; Zaar, M

    1986-01-01

    Water-holding capacity (WHC) of muscle is important because it affects both qualitative and quantitative aspects of meat and meat products. For assessment of WHC under field and laboratory conditions, there are several methods available, but they have not been compared in a single experiment to determine accuracy and repeatibility. The Longissimus dorsi from each of 28 porcine loins representing three distinct levels of WHC (DFD, PSE, normal) was separated into eighteen parts that were randomly assigned to individual methods. The following methods were compared: Grau-Hamm and Braunschweiger-Gerät filter paper press techniques using five approaches of evaluation for each method; transmission per cent; swelling due to added water; centrifugation; 48-h fresh and cooked shrink: imbibition of surface fluids, kapillar volumeter, permittivity; and score or weight of surface fluids accumulating on filter paper. Results indicated that most methods separated the three muscle types. However, the cooking loss tests failed to differentiate between PSE and normal samples, and the transmission, imbibition and pressed fluid methods did not always distinguish between DFD and normal. The tests that appeared to be most reliable included drip loss originating from size-standardized samples, swelling of homogenized samples by added water and absorption of surface fluids on filter paper. PMID:22055735

  2. Chlorophyll-specific absorption of phytoplankton in waters of Zhujiang River mouth, China

    NASA Astrophysics Data System (ADS)

    Yang, Dingtian; Cao, Wenxi; Mao, Zhihua; Pan, Delu

    2006-12-01

    Light absorption, chlorophyll-specific absorption and package effect of phytoplankton in Zhujiang River mouth was studied on the two cruises of "Shiyan 2". The vertical distribution of phytoplankton in waters can be simulated by Gaussian equation; light absorption of phytoplankton was made on 25 mm GF/F filter, maximum light absorption of phytoplankton was at the depth 5-10m underwater. The value of chlorophyll-specific absorption was negatively correlated with chlorophyll a concentration. Package effect index also had a negative relationship with chlorophyll concentration. These results indicated that the characteristics of light absorption by phytoplankton varied in different waters were properly related to the phytoplankton concentration.

  3. The role of R&D intensity, technical development and absorptive capacity in creating entrepreneurial wealth in high technology start-ups

    Microsoft Academic Search

    David L Deeds

    2001-01-01

    This study uses 80 newly public pharmaceutical biotechnology companies to explore the relationship between a high technology venture’s R&D intensity, technical capabilities and absorptive capacity and the amount of entrepreneurial wealth created by the venture. A novel measure of absorptive capacity based on co-citation analysis of a firm’s scientific publications is developed and several indicators of technical capabilities are used

  4. The nuclear option for US electrical generating capacity additions utilizing boiling water reactor technology

    Microsoft Academic Search

    Thomas F. Garrity; Daniel R. Wilkins

    1993-01-01

    The technology status of the advanced boiling water reactor (ABWR) and the simplified boiling water reactors (SBWR) is presented along with an analysis of the economic potential of advanced nuclear power generation systems based on BWR technology to meet the projected domestic electrical generating capacity need through 2005. The forecasted capacity needs are determined for each domestic North American Electric

  5. Factors Affecting the Water Holding Capacity of Red Meat Products: A Review of Recent Research Advances

    Microsoft Academic Search

    Qiaofen Cheng; Da-Wen Sun

    2008-01-01

    The water holding capacity of meat products is a very important quality attribute which has an influence on product yield, which in turn has economic implications, but is also important in terms of eating quality. A number of pre-and post-mortem factors influence the water holding capacity (WHC) of meat. During the growth and development of meat animals, genotype and animal

  6. The Impacts of Different Expansion Modes on Performance of Small Solar Energy Firms: Perspectives of Absorptive Capacity

    PubMed Central

    Chen, Hsing Hung; Shen, Tao; Xu, Xin-long; Ma, Chao

    2013-01-01

    The characteristics of firm's expansion by differentiated products and diversified products are quite different. However, the study employing absorptive capacity to examine the impacts of different modes of expansion on performance of small solar energy firms has never been discussed before. Then, a conceptual model to analyze the tension between strategies and corporate performance is proposed to filling the vacancy. After practical investigation, the results show that stronger organizational institutions help small solar energy firms expanded by differentiated products increase consistency between strategies and corporate performance; oppositely, stronger working attitudes with weak management controls help small solar energy firms expanded by diversified products reduce variance between strategies and corporate performance. PMID:24453837

  7. The impacts of different expansion modes on performance of small solar energy firms: perspectives of absorptive capacity.

    PubMed

    Chen, Hsing Hung; Shen, Tao; Xu, Xin-Long; Ma, Chao

    2013-01-01

    The characteristics of firm's expansion by differentiated products and diversified products are quite different. However, the study employing absorptive capacity to examine the impacts of different modes of expansion on performance of small solar energy firms has never been discussed before. Then, a conceptual model to analyze the tension between strategies and corporate performance is proposed to filling the vacancy. After practical investigation, the results show that stronger organizational institutions help small solar energy firms expanded by differentiated products increase consistency between strategies and corporate performance; oppositely, stronger working attitudes with weak management controls help small solar energy firms expanded by diversified products reduce variance between strategies and corporate performance. PMID:24453837

  8. Radiance irradiance inversion algorithm for estimating the absorption and backscattering coefficients of natural waters: homogeneous waters

    Microsoft Academic Search

    Howard R. Gordon; G. Chris Boynton

    1997-01-01

    A full multiple-scattering algorithm for inverting upwelling radiance ( L u ) or irradiance ( E u ) and downwelling irradiance ( E d ) profiles in homogeneous natural waters to obtain the absorption ( a ) and backscattering ( b b ) coefficients is described and tested with simulated data. An attractive feature of the algorithm is that it

  9. Improvement of the Performance for an Absorption Refrigeration System with Lithium bromide-water as Refrigerant by Increasing Absorption Pressure

    E-print Network

    Xie, G.; Sheng, G.; Li, G.; Pan, S.

    2006-01-01

    of the performance of an absorption refrigeration cycle using Lithium bromide-water as refrigerant. IIR-IHACE2006, 2006. (In Chinese) [2] Yuqing Zheng, Jinfa Wu, Double effects Chiller using Lithium-bromide with water solution as refrigerant and its application...

  10. Watching Hydrogen Bonds Break: A Transient Absorption Study of Water

    PubMed Central

    Steinel, Tobias; Asbury, John B.; Zheng, Junrong

    2008-01-01

    Ultrafast infrared transient absorption measurements of the complete hydroxyl OD stretching mode spectrum of HOD in water, from 100 fs to tens of picoseconds, observe hydrogen bond breaking and monitor the equilibration of the hydrogen bond network in water. In addition, the vibrational lifetime, the time constant for hydrogen bond breaking, and the rate of orientational relaxation are determined. The reactant and photoproduct spectra of the hydrogen bond breaking process are identified by decomposing the transient spectra into two components, the initial spectrum associated with vibrational excited states (reactants) and the long-time spectrum associated with broken hydrogen bonds (photoproducts). By properly taking into account the perturbation of the reactant spectrum decay by the growth of the photoproduct spectrum, it is found that the vibrational relaxation (1.45 ps) and orientational relaxation (1.53 ps) are wavelength independent and, therefore, independent of the degree of hydrogen bonding. Energy deposited into water by vibrational relaxation does not immediately break a hydrogen bond by predissociation nor produce a thermally equilibrated hydrogen bond distribution at an elevated temperature. Following deposition of energy by vibrational relaxation, the hydrogen bond breaking time is 800 fs, and there is a transient period of several picoseconds during which the hydrogen bond distribution is not in thermal equilibrium. PMID:19096727

  11. AN AMMONIA-WATER ABSORPTION-HIAT-PUMP CYCLE Donald Kuhlenschmidt, Member ASHRAE

    E-print Network

    Oak Ridge National Laboratory

    #12;AN AMMONIA-WATER ABSORPTION-HIAT-PUMP CYCLE BY Donald Kuhlenschmidt, Member ASHRAE Richard H and Research of Arkla Industries Inc., Evansville, Indiana. #12;INTRODUCTION The ammonia-water absorption cycle and the chilled water returns to the cycle at 12.8 0 C(55F). Several things became apparent at the outset: 1

  12. Effect of triggering on the energy absorption capacity of axially compressed aluminum tubes

    Microsoft Academic Search

    Sunghak Lee; Changsu Hahn; Meungho Rhee; Jae-Eung Oh

    1999-01-01

    The energy absorption performance of extruded aluminum tubing for space frames was evaluated using computer-simulated compressive tests and quasi-static compressive deformation tests. An experimental deformation test and its simulation were conducted for seven extruded tube specimens on which various types of triggering dents were introduced, and the test data were investigated via observation of deformation mode, maximum repulsive force, and

  13. Research on the Risk of Water Shortages and the Carrying Capacity of Water Resources in Yiwu, China

    Microsoft Academic Search

    Lihua H. Feng; Xingcai Zhang; Gaoyuan Luo

    2009-01-01

    The carrying capacity of water resources is defined as the maximum volume of water suitable for supporting human activity in certain stages of social development that can be borne by water resources under favorable ecological conditions. The results of other studies that have been performed in Yiwu City, China, indicate that water shortages in this city are not related to

  14. In-situ X-ray absorption spectroscopy analysis of capacity fade in nanoscale-LiCoO{sub 2}

    SciTech Connect

    Patridge, Christopher J. [NRC/NRL Cooperative Research Associate, U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Love, Corey T., E-mail: corey.love@nrl.navy.mil [Chemistry Division, Code 6113, U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Swider-Lyons, Karen E. [Chemistry Division, Code 6113, U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Twigg, Mark E. [Electronics Science and Technology Division, Code 6812, U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Ramaker, David E. [Chemistry Division, Code 6189, U.S. Naval Research laboratory, Washington, DC 20375 (United States)

    2013-07-15

    The local structure of nanoscale (?10–40 nm) LiCoO{sub 2} is monitored during electrochemical cycling utilizing in-situ X-ray absorption spectroscopy (XAS). The high surface area of the LiCoO{sub 2} nanoparticles not only enhances capacity fade, but also provides a large signal from the particle surface relative to the bulk. Changes in the nanoscale LiCoO{sub 2} metal-oxide bond lengths, structural disorder, and chemical state are tracked during cycling by adapting the delta mu (??) technique in complement with comprehensive extended X-ray absorption fine structure (EXAFS) modeling. For the first time, we use a ?? EXAFS method, and by comparison of the difference EXAFS spectra, extrapolate significant coordination changes and reduction of cobalt species with cycling. This combined approach suggests Li–Co site exchange at the surface of the nanoscale LiCoO{sub 2} as a likely factor in the capacity fade and irreversible losses in practical, microscale LiCoO{sub 2}. - Graphical abstract: Electrochemical cycling of Li-ion batteries has strong impact on the structure and integrity of the cathode active material particularly near the surface/electrolyte interface. In developing a new method, we have used in-situ X-ray absorption spectroscopy during electrochemical cycling of nanoscale LiCoO{sub 2} to track changes during charge and discharge and between subsequent cycles. Using difference spectra, several small changes in Co-O bond length, Co-O and Co-Co coordination, and site exchange between Co and Li sites can be tracked. These methods show promise as a new technique to better understand processes which lead to capacity fade and loss in Li-ion batteries. - Highlights: • A new method is developed to understand capacity fade in Li-ion battery cathodes. • Structural changes are tracked during Li intercalation/deintercalation of LiCoO{sub 2}. • Surface structural changes are emphasized using nanoscale-LiCoO{sub 2} and difference spectra. • Full multiple scattering calculations are used to support ?? analysis.

  15. Seasonal variability in the light absorption properties of western Arctic waters: Parameterization of the individual components of absorption for ocean color applications

    Microsoft Academic Search

    Atsushi Matsuoka; Victoria Hill; Yannick Huot; Marcel Babin; Annick Bricaud

    2011-01-01

    The light absorption properties of particulate and dissolved materials strongly influence the propagation of visible light in oceanic waters and therefore the accuracy of ocean color algorithms. While the general absorption properties of these materials have been reported for Arctic waters, their seasonal variability remains unknown. We investigated the light absorption coefficients of phytoplankton [a$\\\\varphi$(?)], nonalgal particles [aNAP(?)], and colored

  16. EXPERIMENTAL STUDY OF THE ABSORPTION IN DISTILLED WATER, ARTIFICIAL SEA WATER, AND HEAVY WATER IN THE VISIBLE REGION OF THE SPECTRUM

    Microsoft Academic Search

    SERAPHIN A. SULLIVAN

    1963-01-01

    The absorption of light in distilled water, artificial sea water, and ; heavy water was measured in the visible region. A Nielsen spectrometer with ; glass optics was used with a tungsten source and photomultiplier detector. Path ; lengths were 60.0 and 132.0 cm. The absorption in distilled and artificiai sea ; water differs little; maxima below 745 m mu

  17. Comparison of reflectance with backscatter and absorption parameters for turbid waters

    NASA Technical Reports Server (NTRS)

    Whitlock, C. H.; Poole, L. R.; Usry, J. W.; Houghton, W. M.; Witte, W. G.; Morris, W. D.; Gurganus, E. A.

    1981-01-01

    The relation of reflectance to backscatter and absorption parameters is investigated for waters more turbid than those of previous investigations. Experimental data are examined for river waters in which beam attenuation values range from 8.9 to 18.9 per m at 550 nm. Attenuation, absorption, backscatter, and irradiance reflectance spectral properties are presented for wavelengths between 450 and 800 nm. Comparisons of reflectance with backscatter to absorption ratio and backscatter with absorption plus backscatter ratio indicate that data for turbid waters do not fit linear or polynomial models which are presently available in the literature.

  18. Evaluating Some Empirical Models for Predicting Water Absorption in African Breadfruit (Treculia Africana) Seeds

    Microsoft Academic Search

    T. A. Shittu; S. O. Awonorin; A. O. Raji

    2004-01-01

    Water absorption process during soaking of African breadfruit (ABF) seeds was studied at five typical soaking temperatures, ranging between 30 and 70°C. The progress of water absorption by the seeds followed an exponential increase with increase in temperature. The experimental data were fitted to three empirical equations. All the equations were able to explain over 90% of the experimental data.

  19. Acid neutralizing capacity, alkalinity, and acid-base status of natural waters containing organic acids

    Microsoft Academic Search

    Harold F. Hemond

    1990-01-01

    The terms acid neutralizing capacity (ANC) and alkalinity (Alk) are extensively employed in the characterization of natural waters, including soft circumneutral or acidic waters. However, in the presence of organic acids, ANC measurements are inconsistent with many conceptual definitions of ANC or Alk and do not provide an adequate characterization of the acid-base chemistry of water. Knowledge of Gran ANC

  20. Investigation of Heat capacity and Specific Heat: Using Different Temperatures of Water and Solids

    NSDL National Science Digital Library

    This activity is a chemistry lab-based investigation where students apply observational skills and critical thinking skills to finding specific heat and heat capacity using different temperatures of water and solids. A final activity will assess students understanding of specific heat and heat capacity and promote data analysis skills, using real-life situations.

  1. A framework to assess adaptive capacity of the water resources system in Nepalese river basins

    Microsoft Academic Search

    Vishnu Prasad Pandey; Mukand S. Babel; Sangam Shrestha; Futaba Kazama

    2011-01-01

    This paper discusses an indicator-based framework – consisting of seven indicators, four parameters, and an index – to assess adaptive capacity of the water resources system in the Nepalese context and applies this framework to the Bagmati River Basin (BRB) in Nepal. With respect to the BRB, and Nepal in general, the study results show variations in adaptive capacity of

  2. Transparent hydrogel with enhanced water retention capacity by introducing highly hydratable salt

    E-print Network

    Suo, Zhigang

    Transparent hydrogel with enhanced water retention capacity by introducing highly hydratable salt 2014; published online 14 October 2014) Polyacrylamide hydrogels containing salt as electrolyte have of polyacrylamide hydrogel by introducing highly hydratable salts into the hydrogel. These hydrogels show enhanced

  3. Hydrogen capacity and absorption rate of the SAES St707 non-evaporable getter at various temperatures.

    SciTech Connect

    Hsu, Irving; Mills, Bernice E.

    2010-08-01

    A prototype of a tritium thermoelectric generator (TTG) is currently being developed at Sandia. In the TTG, a vacuum jacket reduces the amount of heat lost from the high temperature source via convection. However, outgassing presents challenges to maintaining a vacuum for many years. Getters are chemically active substances that scavenge residual gases in a vacuum system. In order to maintain the vacuum jacket at approximately 1.0 x 10{sup -4} torr for decades, nonevaporable getters that can operate from -55 C to 60 C are going to be used. This paper focuses on the hydrogen capacity and absorption rate of the St707{trademark} non-evaporable getter by SAES. Using a getter testing manifold, we have carried out experiments to test these characteristics of the getter over the temperature range of -77 C to 60 C. The results from this study can be used to size the getter appropriately.

  4. The high water-holding capacity of petrocalcic horizons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Petrocalcic soil horizons occur in most arid and semi-arid ecosystems around the world, often within the plant rooting zone. Little is known, however, about the water holding characteristic of soils indurated with calcium carbonate. We conducted a replicated experiment to define the soil-water relea...

  5. Temperature Dependences of Mechanisms Responsible for the Water-Vapor Continuum Absorption

    NASA Technical Reports Server (NTRS)

    Ma, Qiancheng

    2014-01-01

    The water-vapor continuum absorption plays an important role in the radiative balance in the Earth's atmosphere. It has been experimentally shown that for ambient atmospheric conditions, the continuum absorption scales quadratically with the H2O number density and has a strong, negative temperature dependence (T dependence). Over the years, there have been three different theoretical mechanisms postulated: far-wings of allowed transition lines, water dimers, and collision-induced absorption. The first mechanism proposed was the accumulation of absorptions from the far-wings of the strong allowed transition lines. Later, absorption by water dimers was proposed, and this mechanism provides a qualitative explanation for the continuum characters mentioned above. Despite the improvements in experimental data, at present there is no consensus on which mechanism is primarily responsible for the continuum absorption.

  6. Development of a UAV-based differential absorption lidar for measuring atmospheric water vapor

    Microsoft Academic Search

    Brian William Thomas

    2003-01-01

    Differential Absorption Lidar (DIAL) is a remote sensing technique useful for making range resolved measurements of chemical species. A water vapor DIAL system was developed for use on a high altitude unmanned air vehicle (UAV), in order to study water vapor distribution in hurricanes. The system uses a diode-pumped Cr:LiSAF laser to probe water vapor absorption lines at or near

  7. Carbon nanotube membranes with ultrahigh specific adsorption capacity for water desalination and purification.

    PubMed

    Yang, Hui Ying; Han, Zhao Jun; Yu, Siu Fung; Pey, Kin Leong; Ostrikov, Kostya; Karnik, Rohit

    2013-01-01

    Development of technologies for water desalination and purification is critical to meet the global challenges of insufficient water supply and inadequate sanitation, especially for point-of-use applications. Conventional desalination methods are energy and operationally intensive, whereas adsorption-based techniques are simple and easy to use for point-of-use water purification, yet their capacity to remove salts is limited. Here we report that plasma-modified ultralong carbon nanotubes exhibit ultrahigh specific adsorption capacity for salt (exceeding 400% by weight) that is two orders of magnitude higher than that found in the current state-of-the-art activated carbon-based water treatment systems. We exploit this adsorption capacity in ultralong carbon nanotube-based membranes that can remove salt, as well as organic and metal contaminants. These ultralong carbon nanotube-based membranes may lead to next-generation rechargeable, point-of-use potable water purification appliances with superior desalination, disinfection and filtration properties. PMID:23941894

  8. Analytical simulation of water system capacity reliability, 1. Modified frequency-duration analysis

    NASA Astrophysics Data System (ADS)

    Hobbs, Benjamin F.; Beim, Gina K.

    1988-09-01

    The problem addressed is the computation of the unavailability and expected unserved demand of a water supply system having random demand, finished water storage, and unreliable capacity components. Examples of such components include pumps, treatment plants, and aqueducts. Modified frequency-duration analysis estimates these reliability statistics by, first, calculating how often demand exceeds available capacity and, second, comparing the amount of water in storage with how long such capacity deficits last. This approach builds upon frequency-duration methods developed by the power industry for analyzing generation capacity deficits. Three versions of the frequency-duration approach are presented. Two yield bounds to system unavailability and unserved demand and the third gives an estimate of their true values between those bounds.

  9. The influence of water mixtures on the dermal absorption of glycol ethers

    SciTech Connect

    Traynor, Matthew J. [Toxicology Unit, Institute for Research on Environment and Sustainability and Medical School, University of Newcastle upon Tyne, Newcastle NE1 7RU (United Kingdom); Wilkinson, Simon C. [Toxicology Unit, Institute for Research on Environment and Sustainability and Medical School, University of Newcastle upon Tyne, Newcastle NE1 7RU (United Kingdom); Williams, Faith M. [Toxicology Unit, Institute for Research on Environment and Sustainability and Medical School, University of Newcastle upon Tyne, Newcastle NE1 7RU (United Kingdom)]. E-mail: F.M.Williams@ncl.ac.uk

    2007-01-15

    Glycol ethers are solvents widely used alone and as mixtures in industrial and household products. Some glycol ethers have been shown to have a range of toxic effects in humans following absorption and metabolism to their aldehyde and acid metabolites. This study assessed the influence of water mixtures on the dermal absorption of butoxyethanol and ethoxyethanol in vitro through human skin. Butoxyethanol penetrated human skin up to sixfold more rapidly from aqueous solution (50%, 450 mg/ml) than from the neat solvent. Similarly penetration of ethoxyethanol was increased threefold in the presence of water (50%, 697 mg/ml). There was a corresponding increase in apparent permeability coefficient as the glycol ether concentration in water decreased. The maximum penetration rate of water also increased in the presence of both glycol ethers. Absorption through a synthetic membrane obeyed Fick's Law and absorption through rat skin showed a similar profile to human skin but with a lesser effect. The mechanisms for this phenomenon involves disruption of the stratum corneum lipid bilayer by desiccation by neat glycol ether micelles, hydration with water mixtures and the physicochemical properties of the glycol ether-water mixtures. Full elucidation of the profile of absorption of glycol ethers from mixtures is required for risk assessment of dermal exposure. This work supports the view that risk assessments for dermal contact scenarios should ideally be based on absorption data obtained for the relevant formulation or mixture and exposure scenario and that absorption derived from permeability coefficients may be inappropriate for water-miscible solvents.

  10. Beyond peak reservoir storage? A global estimate of declining water storage capacity in large reservoirs

    NASA Astrophysics Data System (ADS)

    Wisser, Dominik; Frolking, Steve; Hagen, Stephen; Bierkens, Marc F. P.

    2013-09-01

    Water storage is an important way to cope with temporal variation in water supply and demand. The storage capacity and the lifetime of water storage reservoirs can be significantly reduced by the inflow of sediments. A global, spatially explicit assessment of reservoir storage loss in conjunction with vulnerability to storage loss has not been done. We estimated the loss in reservoir capacity for a global data set of large reservoirs from 1901 to 2010, using modeled sediment flux data. We use spatially explicit population data sets as a proxy for storage demand and calculate storage capacity for all river basins globally. Simulations suggest that the net reservoir capacity is declining as a result of sedimentation (˜5% compared to the installed capacity). Combined with increasing need for storage, these losses challenge the sustainable management of reservoir operation and water resources management in many regions. River basins that are most vulnerable include those with a strong seasonal flow pattern and high population growth rates such as the major river basins in India and China. Decreasing storage capacity globally suggests that the role of reservoir water storage in offsetting sea-level rise is likely weakening and may be changing sign.

  11. Modeling Climate-Water Impacts on Electricity Sector Capacity Expansion: Preprint

    SciTech Connect

    Cohen, S. M.; Macknick, J.; Averyt, K.; Meldrum, J.

    2014-05-01

    Climate change has the potential to exacerbate water availability concerns for thermal power plant cooling, which is responsible for 41% of U.S. water withdrawals. This analysis describes an initial link between climate, water, and electricity systems using the National Renewable Energy Laboratory (NREL) Regional Energy Deployment System (ReEDS) electricity system capacity expansion model. Average surface water projections from Coupled Model Intercomparison Project 3 (CMIP3) data are applied to surface water rights available to new generating capacity in ReEDS, and electric sector growth is compared with and without climate-influenced water rights. The mean climate projection has only a small impact on national or regional capacity growth and water use because most regions have sufficient unappropriated or previously retired water rights to offset climate impacts. Climate impacts are notable in southwestern states that purchase fewer water rights and obtain a greater share from wastewater and other higher-cost water resources. The electric sector climate impacts demonstrated herein establish a methodology to be later exercised with more extreme climate scenarios and a more rigorous representation of legal and physical water availability.

  12. INFLUENCE OF AQUEOUS ALUMINUM AND ORGANIC ACIDS ON MEASUREMENT OF ACID NEUTRALIZING CAPACITY IN SURFACE WATERS

    EPA Science Inventory

    Acid neutralizing capacity (ANC) is used to quantify the acid-base status of surface waters. Acidic waters have bean defined as having ANC values less than zero, and acidification is often quantified by decreases in ANC. Measured and calculated values of ANC generally agree, exce...

  13. Equilibrium structural model of liquid water: Evidence from heat capacity, spectra, density, and other properties

    Microsoft Academic Search

    Ralph C. Dougherty; Louis N. Howard

    1998-01-01

    Hydrogen bond strength depends on both temperature and pressure. The gradient for hydrogen bond strength with temperature, or pressure, depends upon the hydrogen bonded structure. These features create an intimate connection between quantum mechanics and thermodynamics in the structure of liquid water. The equilibrium structural model of liquid water developed from analysis of the heat capacity at constant pressure is

  14. Oil sorbents with high sorption capacity, oil/water selectivity and reusability for oil spill cleanup.

    PubMed

    Wu, Daxiong; Fang, Linlin; Qin, Yanmin; Wu, Wenjuan; Mao, Changming; Zhu, Haitao

    2014-07-15

    A sorbent for oil spill cleanup was prepared through a novel strategy by treating polyurethane sponges with silica sol and gasoline successively. The oil sorption capacity, oil/water selectivity, reusability and sorption mechanism of prepared sorbent were studied. The results showed that the prepared sorbent exhibited high sorption capacity and excellent oil/water selectivity. 1g of the prepared sorbent could adsorb more than 100 g of motor oil, while it only picks up less than 0.1 g of water from an oil-water interface under both static and dynamic conditions. More than 70% of the sorption capacity remained after 15 successive sorption-squeezing cycles, which suggests an extraordinary high reusability. The prepared sorbent is a better alternative of the commercial polypropylene sorbent which are being used nowadays. PMID:24856092

  15. Absorption spectrum (380–700 nm) of pure water. II. Integrating cavity measurements

    Microsoft Academic Search

    Robin M. Pope; Edward S. Fry

    1997-01-01

    Definitive data on the absorption spectrum of pure water from 380 to 700 nm have been obtained with an integrating cavity technique. The results are in good agreement with those recently obtained by our group with a completely independent photothermal technique. As before, we find that the absorption in the blue is significantly lower than had previously been generally believed

  16. Water Channel of Horseradish Peroxidase Studied by the Charge-Transfer Absorption Band of Ferric Heme

    E-print Network

    Sharp, Kim

    Water Channel of Horseradish Peroxidase Studied by the Charge-Transfer Absorption Band of Ferric The heme of horseradish peroxidase is buried in the protein, but a channel from the protein surface connects the aqueous solution to the heme site. Ferric horseradish peroxidase has an absorption band at 640

  17. Measurement of Water Vapor Concentration using Tunable Diode Laser Absorption Spectroscopy

    E-print Network

    Barrett, Alexander B.

    2010-07-14

    Tunable diode laser spectroscopy and the Beer-Lambert relation has been used to measure the absorption of water vapor both in an absorption cell and in a shock tube. The purpose of this thesis is to develop a laser diagnostic capable of determining...

  18. Potential Water Retention Capacity as a Factor in Silage Effluent Control: Experiments with High Moisture By-product Feedstuffs

    PubMed Central

    Razak, Okine Abdul; Masaaki, Hanada; Yimamu, Aibibula; Meiji, Okamoto

    2012-01-01

    The role of moisture absorptive capacity of pre-silage material and its relationship with silage effluent in high moisture by-product feedstuffs (HMBF) is assessed. The term water retention capacity which is sometimes used in explaining the rate of effluent control in ensilage may be inadequate, since it accounts exclusively for the capacity of an absorbent incorporated into a pre-silage material prior to ensiling, without consideration to how much the pre-silage material can release. A new terminology, ‘potential water retention capacity’ (PWRC), which attempts to address this shortcoming, is proposed. Data were pooled from a series of experiments conducted separately over a period of five years using laboratory silos with four categories of agro by-products (n = 27) with differing moisture contents (highest 96.9%, lowest 78.1% in fresh matter, respectively), and their silages (n = 81). These were from a vegetable source (Daikon, Raphanus sativus), a root tuber source (potato pulp), a fruit source (apple pomace) and a cereal source (brewer’s grain), respectively. The pre-silage materials were adjusted with dry in-silo absorbents consisting wheat straw, wheat or rice bran, beet pulp and bean stalks. The pooled mean for the moisture contents of all pre-silage materials was 78.3% (±10.3). Silage effluent decreased (p<0.01), with increase in PWRC of pre-silage material. The theoretical moisture content and PWRC of pre-silage material necessary to stem effluent flow completely in HMBF silage was 69.1% and 82.9 g/100 g in fresh matter, respectively. The high correlation (r = 0.76) between PWRC of ensiled material and silage effluent indicated that the latter is an important factor in silage-effluent relationship. PMID:25049587

  19. Water vapor microwave continuum absorption: A comparison of measurements and models

    Microsoft Academic Search

    Philip W. Rosenkranz

    1998-01-01

    Measurements, made in different laboratories, of absorption by water vapor in microwave windows are compared with models for the water vapor continuum. A reanalysis of some of these measurements leads to the conclusion that the laboratory data are best represented by a combination of Liebe's (1987) millimeter-wave propagation model (MPM) for the foreign-broadened component of the water continuum and the

  20. Absorption

    NSDL National Science Digital Library

    Katherine M Knudson (Polson Middle School)

    1998-04-01

    This activity can be used to allow students to explore the concept of absorption using a variety of materials. Extensions include exploring how Native Americans used absorbtion in a number of ways. This inquiry activity was developed by a K-12 science teacher in the American Physiological SocietyÂ?s 1998 Frontiers in Physiology Program. The NSES Standards addressed by this activity are current as of the year of development. For more information on the Frontiers in Physiology Program, please visit www.frontiersinphys.org.

  1. Drinking Spring Water and Lithium Absorption: A Preliminary Study

    Microsoft Academic Search

    Ippei Shiotsuki; Takeshi Terao; Hirochika Ogami; Nobuyoshi Ishii; Reiji Yoshimura; Jun Nakamura

    Background: In Japan, there are several resorts with cold springs that have mineral water containing relatively high levels of lithium compared to tap water. Visitors to such cold-spring resorts traditionally drink 2 to 4 L of mineral water for several hours in the early morning in the belief that the water has properties which maintain physical health. The present study

  2. Optoacoustic measurements of water vapor absorption at selected CO laser wavelengths in the 5-micron region

    NASA Technical Reports Server (NTRS)

    Menzies, R. T.; Shumate, M. S.

    1976-01-01

    Measurements of water vapor absorption were taken with a resonant optoacoustical detector (cylindrical pyrex detector, two BaF2 windows fitted into end plates at slight tilt to suppress Fabry-Perot resonances), for lack of confidence in existing spectral tabular data for the 5-7 micron region, as line shapes in the wing regions of water vapor lines are difficult to characterize. The measurements are required for air pollution studies using a CO laser, to find the differential absorption at the wavelengths in question due to atmospheric constituents other than water vapor. The design and performance of the optoacoustical detector are presented. Effects of absorption by ambient NO are considered, and the fixed-frequency discretely tunable CO laser is found suitable for monitoring urban NO concentrations in a fairly dry climate, using the water vapor absorption data obtained in the study.

  3. Derivation of water vapour absorption cross-sections in the red region

    NASA Technical Reports Server (NTRS)

    Lal, M.; Chakrabarty, D. K.

    1994-01-01

    Absorption spectrum in 436 to 448 nm wavelength region gives NO2 and O3 column densities. This spectrum can also give H2O column density. The spectrum in the range of 655 to 667 nm contains absorption due to NO3 and H2O. Combining the absorption spectra in the wavelength ranges of 436 to 448 and 655 to 667 nm, water vapor absorption cross-sections in this range comes out to be of the order of 2.0 x 10(exp -24) cm(exp -2).

  4. Modeling water resources as a constraint in electricity capacity expansion models

    NASA Astrophysics Data System (ADS)

    Newmark, R. L.; Macknick, J.; Cohen, S.; Tidwell, V. C.; Woldeyesus, T.; Martinez, A.

    2013-12-01

    In the United States, the electric power sector is the largest withdrawer of freshwater in the nation. The primary demand for water from the electricity sector is for thermoelectric power plant cooling. Areas likely to see the largest near-term growth in population and energy usage, the Southwest and the Southeast, are also facing freshwater scarcity and have experienced water-related power reliability issues in the past decade. Lack of water may become a barrier for new conventionally-cooled power plants, and alternative cooling systems will impact technology cost and performance. Although water is integral to electricity generation, it has long been neglected as a constraint in future electricity system projections. Assessing the impact of water resource scarcity on energy infrastructure development is critical, both for conventional and renewable energy technologies. Efficiently utilizing all water types, including wastewater and brackish sources, or utilizing dry-cooling technologies, will be essential for transitioning to a low-carbon electricity system. This work provides the first demonstration of a national electric system capacity expansion model that incorporates water resources as a constraint on the current and future U.S. electricity system. The Regional Electricity Deployment System (ReEDS) model was enhanced to represent multiple cooling technology types and limited water resource availability in its optimization of electricity sector capacity expansion to 2050. The ReEDS model has high geographic and temporal resolution, making it a suitable model for incorporating water resources, which are inherently seasonal and watershed-specific. Cooling system technologies were assigned varying costs (capital, operations and maintenance), and performance parameters, reflecting inherent tradeoffs in water impacts and operating characteristics. Water rights supply curves were developed for each of the power balancing regions in ReEDS. Supply curves include costs and availability of freshwater (surface and groundwater) and alternative water resources (municipal wastewater and brackish groundwater). In each region, a new power plant must secure sufficient water rights for operation before being built. Water rights constraints thus influence the type of power plant, cooling system, or location of new generating capacity. Results indicate that the aggregate national generating capacity by fuel type and associated carbon dioxide emissions change marginally with the inclusion of water rights. Water resource withdrawals and consumption, however, can vary considerably. Regional water resource dynamics indicate substantial differences in the location where power plant-cooling system technology combinations are built. These localized impacts highlight the importance of considering water resources as a constraint in the electricity sector when evaluating costs, transmission infrastructure needs, and externalities. Further scenario evaluations include assessments of how climate change could affect the availability of water resources, and thus the development of the electricity sector.

  5. A WATER VAPOR MONITOR USING DIFFERENTIAL INFRARED ABSORPTION

    EPA Science Inventory

    A water vapor monitor has been developed with adequate sensitivity and versatility for a variety of applications. Two applications for which the instrument has been designed are the continuous monitoring of water in ambient air and the measuring of the mass of water desorbed from...

  6. Influence of meal composition on canine jejunal water and electrolyte absorption.

    PubMed

    Bastidas, J A; Zinner, M J; Bastidas, J A; Orandle, M S; Yeo, C J

    1992-02-01

    The absorption of water and electrolytes from the proximal jejunal lumen increases immediately after a meal. This meal-induced jejunal absorption occurs in jejunal segments out of normal gastrointestinal continuity. This study was designed to characterize the jejunal absorptive response to a series of isovolumetric gavage-delivered stimuli. Twenty-five-centimeter canine proximal jejunal Thiry-Vella fistulas were constructed, and jejunal absorption studies (n = 66) were performed by luminal perfusion of the jejunal segments with an isotonic buffer containing 14C-labeled polyethylene glycol. Each study consisted of a 1-hour basal period, followed by a 3-hour experimental period. Nine groups were studied, each receiving one of the following isovolumetric stimuli delivered via the gavage route: water, 0.9% saline, mixed meal, protein, lipid, carbohydrate, and mannitol (150 mmol/L, 300 mmol/L, and 600 mmol/L). The water and 0.9% saline gavage groups showed no significant changes in integrated postprandial water and electrolyte absorption above basal. The isocaloric mixed meal, protein, lipid, carbohydrate, and mannitol groups all had significantly increased integrated postprandial jejunal water and electrolyte absorption above basal (P less than 0.05). These results indicate that a proabsorptive signal for meal-induced jejunal absorption originates from or distal to the stomach. Meal-induced jejunal absorption occurs in response to nutrients of diverse composition and is also responsive to nonnutritive solutes such as mannitol. These findings support a new role for gastric or intestinal chemo- or osmo-receptors in stimulating the neurohumoral mechanisms that mediate meal-induced jejunal absorption. PMID:1732119

  7. Determination of RW3-to-water mass-energy absorption coefficient ratio for absolute dosimetry.

    PubMed

    Seet, Katrina Y T; Hanlon, Peta M; Charles, Paul H

    2011-12-01

    The measurement of absorbed dose to water in a solid-phantom may require a conversion factor because it may not be radiologically equivalent to water. One phantom developed for the use of dosimetry is a solid water, RW3 white-polystyrene material by IBA. This has a lower mass-energy absorption coefficient than water due to high bremsstrahlung yield, which affects the accuracy of absolute dosimetry measurements. In this paper, we demonstrate the calculation of mass-energy absorption coefficient ratios, relative to water, from measurements in plastic water and RW3 with an Elekta Synergy linear accelerator (6 and 10 MV photon beams) as well as Monte Carlo modeling in BEAMnrc and DOSXYZnrc. From this, the solid-phantom-to-water correction factor was determined for plastic water and RW3. PMID:21960410

  8. Liquid water absorption and scattering effects in DOAS retrievals over oceans

    NASA Astrophysics Data System (ADS)

    Peters, E.; Wittrock, F.; Richter, A.; Alvarado, L. M. A.; Rozanov, V. V.; Burrows, J. P.

    2014-12-01

    Spectral effects of liquid water are present in absorption (differential optical absorption spectroscopy - DOAS) measurements above the ocean and, if insufficiently removed, may interfere with trace gas absorptions, leading to wrong results. Currently available literature cross sections of liquid water absorption are provided in coarser resolution than DOAS applications require, and vibrational Raman scattering (VRS) is mostly not considered, or is compensated for using simulated pseudo cross sections from radiative transfer modeling. During the ship-based TransBrom campaign across the western Pacific in October 2009, MAX-DOAS (Multi-AXis differential optical absorption spectroscopy) measurements of light penetrating very clear natural waters were performed, achieving average underwater light paths of up to 50 m. From these measurements, the retrieval of a correction spectrum (H2Ocorr) is presented, compensating simultaneously for insufficiencies in the liquid water absorption cross section and broad-banded VRS structures. Small-banded structures caused by VRS were found to be very efficiently compensated for by the intensity offset correction included in the DOAS fit. No interference between the H2Ocorr spectrum and phytoplankton absorption was found. In the MAX-DOAS tropospheric NO2 retrieval, this method was able to compensate entirely for all liquid water effects that decrease the fit quality, and performed better than using a liquid water cross section in combination with a simulated VRS spectrum. The decrease in the residual root mean square (rms) of the DOAS fit depends on the measurement's contamination with liquid water structures, and ranges from ? 30% for measurements slightly towards the water surface to several percent in small angles above the horizon. Furthermore, the H2Ocorr spectrum was found to prevent misfits of NO2 slant columns, especially for very low NO2 scenarios, and thus increases the reliability of the fit. In test fits on OMI satellite data, the H2Ocorr spectrum was found selectively above ocean surfaces, where it decreases the rms by up to ? 11 %.

  9. Interrelation between the crystallinity of polysaccharides and water absorption

    NASA Astrophysics Data System (ADS)

    Prusov, A. N.; Prusova, S. M.; Radugin, M. V.; Zakharov, A. G.

    2014-05-01

    The maximum sorption of water and its vapors is calculated using experimental data from calorimetric and effusion studies of flax, wood, and cotton cellulose. X-day diffraction is used to determine the crystallinity of cellulose samples. The equations relating crystallinity ( X) with maximum sorption and the enthalpy of interaction between cellulose and water are presented. Experimental results and the literature data on water sorption by chitin, chitosan and other polysaccharides show that our equations for calculating crystallinity are correct.

  10. Comparison of calcium absorptive and secretory capacities of segments of intact or functionally resected intestine during normo-, hypo-, and hyper-calcemia.

    PubMed

    Krishnamra, N; Angkanaporn, K; Deenoi, T

    1994-07-01

    Absorptive and secretory capacities of six in situ intestinal loops of equal length were compared under the same calcium load and calcemic condition. The highest rate of calcium absorption was found in duodenum, colon, and proximal jejunum when loops were filled with 0.3 mM calcium, and in duodenum and proximal jejunum when filled with 10 mM luminal calcium. Secretory rates were in the following order: duodenum, jejunum, proximal jejunum, cecum, ileum, and proximal colon. Absorption of 0.3 mM calcium was decreased in all but the cecum and colon during hypercalcemia, and in duodenum, proximal jejunum, and colon during thyroparathyroidectomy-induced hypocalcemia. In contrast, calcium secretion was directly related to plasma calcium concentration and the length of the intestine. Functional resection of any part met with a compensatory increase in calcium absorption by the remaining segments, with the exception of the resection of the distal ileum with the large bowel. In conclusion, proximal small intestine exhibited the highest rate of absorption and secretion, but functional resection of this or any part did not affect the overall calcium absorption if luminal calcium was 10 mM. Moreover, enhanced secretion and reduced absorption during hypercalcemia were beneficial with respect to plasma calcium regulation. PMID:7828084

  11. The influence of water mixtures on the dermal absorption of glycol ethers.

    PubMed

    Traynor, Matthew J; Wilkinson, Simon C; Williams, Faith M

    2007-01-15

    Glycol ethers are solvents widely used alone and as mixtures in industrial and household products. Some glycol ethers have been shown to have a range of toxic effects in humans following absorption and metabolism to their aldehyde and acid metabolites. This study assessed the influence of water mixtures on the dermal absorption of butoxyethanol and ethoxyethanol in vitro through human skin. Butoxyethanol penetrated human skin up to sixfold more rapidly from aqueous solution (50%, 450 mg/ml) than from the neat solvent. Similarly penetration of ethoxyethanol was increased threefold in the presence of water (50%, 697 mg/ml). There was a corresponding increase in apparent permeability coefficient as the glycol ether concentration in water decreased. The maximum penetration rate of water also increased in the presence of both glycol ethers. Absorption through a synthetic membrane obeyed Fick's Law and absorption through rat skin showed a similar profile to human skin but with a lesser effect. The mechanisms for this phenomenon involves disruption of the stratum corneum lipid bilayer by desiccation by neat glycol ether micelles, hydration with water mixtures and the physicochemical properties of the glycol ether-water mixtures. Full elucidation of the profile of absorption of glycol ethers from mixtures is required for risk assessment of dermal exposure. This work supports the view that risk assessments for dermal contact scenarios should ideally be based on absorption data obtained for the relevant formulation or mixture and exposure scenario and that absorption derived from permeability coefficients may be inappropriate for water-miscible solvents. PMID:17173944

  12. Simulation of Water Environmental Capacity and Pollution Load Reduction Using QUAL2K for Water Environmental Management

    PubMed Central

    Zhang, Ruibin; Qian, Xin; Yuan, Xingcheng; Ye, Rui; Xia, Bisheng; Wang, Yulei

    2012-01-01

    In recent years, water quality degradation associated with rapid socio-economic development in the Taihu Lake Basin, China, has attracted increasing attention from both the public and the Chinese government. The primary sources of pollution in Taihu Lake are its inflow rivers and their tributaries. Effective water environmental management strategies need to be implemented in these rivers to improve the water quality of Taihu Lake, and to ensure sustainable development in the region. The aim of this study was to provide a basis for water environmental management decision-making. In this study, the QUAL2K model for river and stream water quality was applied to predict the water quality and environmental capacity of the Hongqi River, which is a polluted tributary in the Taihu Lake Basin. The model parameters were calibrated by trial and error until the simulated results agreed well with the observed data. The calibrated QUAL2K model was used to calculate the water environmental capacity of the Hongqi River, and the water environmental capacities of CODCr NH3-N, TN, and TP were 17.51 t, 1.52 t, 2.74 t and 0.37 t, respectively. The results showed that the NH3-N, TN, and TP pollution loads of the studied river need to be reduced by 50.96%, 44.11%, and 22.92%, respectively to satisfy the water quality objectives. Thus, additional water pollution control measures are needed to control and reduce the pollution loads in the Hongqi River watershed. The method applied in this study should provide a basis for water environmental management decision-making. PMID:23222206

  13. Study on water environmental capacity and total content control of Jiaozuo section of Manghe River

    Microsoft Academic Search

    Zhang Zhanping; Ding Minglei; Li Yongle; Zhao Rongqin

    2011-01-01

    Water environmental capacity(WEC) of Jiaozuo section of Manghe River(JSMR) were calculated by using one-dimensional water quality model. And the projects of total content control of pollutants were determined. The results showed that WEC of CODcr and NH3-N are 3403.93 tons\\/yr and 88.70 tons\\/yr respectively, and are much smaller than the amount of CODcr and NH3-N discharged into the river, which

  14. An NMR microscopy study of water absorption in cork

    Microsoft Academic Search

    A. M. Gil; M. H. Lopes; C. Pascoal Neto; P. T. Callaghan

    2000-01-01

    NMR Microscopy is used to measure the imbibition of water into natural cork, extractives-free cork and desuberised cork. The results clearly indicate that suberin is the key constituent which determines the ability of cork to resist water uptake. Furthermore, a particular suberin with distinct spectral properties as viewed by 13C NMR is shown to be the component responsible for cork

  15. Dynamics of Water Absorption and Evaporation During Methanol Droplet Combustion in Microgravity

    NASA Technical Reports Server (NTRS)

    Hicks, Michael C.; Dietrich, Daniel L.; Nayagam, Vedha; Williams, Forman A.

    2012-01-01

    The combustion of methanol droplets is profoundly influenced by the absorption and evaporation of water, generated in the gas phase as a part of the combustion products. Initially there is a water-absorption period of combustion during which the latent heat of condensation of water vapor, released into the droplet, enhances its burning rate, whereas later there is a water-evaporation period, during which the water vapor reduces the flame temperature suffciently to extinguish the flame. Recent methanol droplet-combustion experiments in ambient environments diluted with carbon dioxide, conducted in the Combustion Integrated Rack on the International Space Station (ISS), as a part of the FLEX project, provided a method to delineate the water-absorption period from the water-evaporation period using video images of flame intensity. These were obtained using an ultra-violet camera that captures the OH* radical emission at 310 nm wavelength and a color camera that captures visible flame emission. These results are compared with results of ground-based tests in the Zero Gravity Facility at the NASA Glenn Research Center which employed smaller droplets in argon-diluted environments. A simplified theoretical model developed earlier correlates the transition time at which water absorption ends and evaporation starts. The model results are shown to agree reasonably well with experiment.

  16. Methods for analysis of selected metals in water by atomic absorption

    USGS Publications Warehouse

    Fishman, Marvin J.; Downs, Sanford C.

    1966-01-01

    This manual describes atomic-absorption-spectroscopy methods for determining calcium, copper, lithium, magnesium, manganese, potassium, sodium, strontium and zinc in atmospheric precipitation, fresh waters, and brines. The procedures are intended to be used by water quality laboratories of the Water Resources Division of the U.S. Geological Survey. Detailed procedures, calculations, and methods for the preparation of reagents are given for each element along with data on accuracy, precision, and sensitivity. Other topics discussed briefly are the principle of atomic absorption, instrumentation used, and special analytical techniques.

  17. Water holding capacity and evaporative loss from organic bedding materials used in livestock facilities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Physical and chemical characteristics of organic bedding materials determine how well they will absorb and retain moisture and may influence the environment in livestock facilities where bedding is used. The objective of this study was to determine water holding capacity (WHC) and rate of evaporativ...

  18. Visible/near-infrared spectroscopy to predict water holding capacity in broiler breast meat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Visible/Near-infrared spectroscopy (Vis/NIRS) was examined as a tool for rapidly determining water holding capacity (WHC) in broiler breast meat. Both partial least squares (PLS) and principal component analysis (PCA) models were developed to relate Vis/NIRS spectra of 85 broiler breast meat sample...

  19. Comparison of available soil water capacity estimated from topography and soil series information

    Microsoft Academic Search

    Daolan Zheng; E. R. Hunt; Steven W. Running

    1996-01-01

    We present a simple and generalized method to predict Available Soil Water Capacity (ASWC-TOP) for a given area using a topographic index, defined as ln(?\\/tan?), where ? is the upslope area draining past a certain point per unit width of slope, and ? is the local surface slope angle. The estimated results (ASWC-TOP) were then compared with the available soil

  20. Using lidar to estimate the capacity for storm water recycling and solar energy collection

    Microsoft Academic Search

    David Conway; Samsung Lim

    2010-01-01

    In this paper two lidar applications are addressed so that the data from large-scale airborne laser scanning of three New South Wales towns and the University of New South Wales can be used to estimate the capacity for storm water recycling and solar energy collection. The building outlines in each of these surveyed areas are extracted using the lidar point

  1. Landscape influences on soil nitrogen supply and water holding capacity for irrigated corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water and nitrogen (N) supply to a crop can interact throughout the growing season to influence yield potential. The increasing availability of variable rate irrigation systems to growers in irrigated regions, along with existing capacity for variable rate fertilization, provides the opportunity for...

  2. Effect of deboning time and cold storage on water-holding capacity of chicken breast meat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water-holding capacity (WHC) is a very important qualitative characteristic of meat and directly affects the yield of further processed meat and consumer acceptance of bagged pre-packaged fresh meat. Boneless skinless chicken breast meat for further processing and consumer usage is commonly deboned...

  3. Visible/near-infrared spectroscopy to predict pale broiler breast meat by measuring water holding capacity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Visible/Near-infrared spectroscopy (Vis/NIRS) was examined as a tool for rapidly determining water holding capacity (WHC) in broiler breast meat. Reflectance measurements for 85 breast filets were recorded over the 400 to 2498 nm wavelength range at 0.5 nm intervals and 32 scans. Chemometric analys...

  4. [Actinobacteria and their odor-producing capacities in a surface water in Shanghai].

    PubMed

    Chen, Jiao; Bai, Xiao-hui; Lu, Ning; Wang, Xian-yun; Zhang, Yong-hui; Wu, Pan-cheng; Guo, Xin-chi

    2014-10-01

    The odor in raw water is one of the main sources of odor in drinking water. The occurrence of actinobacteria and their odor producing capacities in a reservoir in.Shanghai were investigated. Gauze's medium and membrane filtration were used for actinobacteria isolation. Through combined methods of 16S rRNA sequencing, colony and hyphae morphology, carbon source utilization, physiological and biochemical characteristics, 40 strains of actinobacteria were identified from the reservoir. Results showed that there were 38 Streptomyces, an Aeromicrobium and a Pseudonocardia. Liquid culture medium and the real reservoir water were used to test the odor producing capacity of these 40 strains of actinobacteria, and headspace solid phase microextraction (HS-SPME) and high resolution gas chromatography mass spectroscopy (GC/MS) were used to analyze the odor compounds 2-methylisoborneol (2-MIB) and geosmin (GSM) in the fermentation liquor. The test results showed that, the odor-producing capacities of these actinobacteria in different fermentation media showed different variation trends, even within the genera Streptomyces. The odor-producing capacity of actinobacteria in the liquid culture medium could not represent their states in the reservoir water or their actual odor contribution to the aquatic environment. PMID:25693381

  5. Leaf Photosynthetic Rate of Tropical Ferns Is Evolutionarily Linked to Water Transport Capacity

    PubMed Central

    Cao, Kun-Fang; Hu, Hong; Zhang, Jiao-Lin

    2014-01-01

    Ferns usually have relatively lower photosynthetic potential than angiosperms. However, it is unclear whether low photosynthetic potential of ferns is linked to leaf water supply. We hypothesized that there is an evolutionary association of leaf water transport capacity with photosynthesis and stomatal density in ferns. In the present study, a series of functional traits relating to leaf anatomy, hydraulics and physiology were assessed in 19 terrestrial and 11 epiphytic ferns in a common garden, and analyzed by a comparative phylogenetics method. Compared with epiphytic ferns, terrestrial ferns had higher vein density (Dvein), stomatal density (SD), stomatal conductance (gs), and photosynthetic capacity (Amax), but lower values for lower epidermal thickness (LET) and leaf thickness (LT). Across species, all traits varied significantly, but only stomatal length (SL) showed strong phylogenetic conservatism. Amax was positively correlated with Dvein and gs with and without phylogenetic corrections. SD correlated positively with Amax, Dvein and gs, with the correlation between SD and Dvein being significant after phylogenetic correction. Leaf water content showed significant correlations with LET, LT, and mesophyll thickness. Our results provide evidence that Amax of the studied ferns is linked to leaf water transport capacity, and there was an evolutionary association between water supply and demand in ferns. These findings add new insights into the evolutionary correlations among traits involving carbon and water economy in ferns. PMID:24416265

  6. Water Vapour Absorption in the Clear Atmosphere of an exo-Neptune

    E-print Network

    Fraine, Jonathan; Benneke, Björn; Knutson, Heather; Jordán, Andrés; Espinoza, Néstor; Madhusudhan, Nikku; Wilkins, Ashlee; Todorov, Kamen

    2014-01-01

    Transmission spectroscopy to date has detected atomic and molecular absorption in Jupiter-sized exoplanets, but intense efforts to measure molecular absorption in the atmospheres of smaller (Neptune-sized) planets during transits have revealed only featureless spectra. From this it was concluded that the majority of small, warm planets evolve to sustain high mean molecular weights, opaque clouds, or scattering hazes in their atmospheres, obscuring our ability to observe the composition of these atmospheres. Here we report observations of the transmission spectrum of HAT-P-11b (~4 Earth radii) from the optical to the infrared. We detected water vapour absorption at 1.4 micrometre wavelength. The amplitude of the water absorption (approximately 250 parts-per- million) indicates that the planetary atmosphere is predominantly clear down to ~1 mbar, and sufficiently hydrogen-rich to exhibit a large scale height. The spectrum is indicative of a planetary atmosphere with an upper limit of ~700 times the abundance of...

  7. Effect of water on the physical properties and carbon dioxide capture capacities of liquid-like Nanoparticle Organic Hybrid Materials and their corresponding polymers.

    PubMed

    Petit, Camille; Bhatnagar, Sonali; Park, Ah-Hyung Alissa

    2013-10-01

    Binary systems composed of liquid-like Nanoparticle Organic Hybrid Materials (NOHMs) and the secondary fluid (i.e., water) were prepared, and their thermal stabilities, densities, viscosities, and CO2 absorption capacities were investigated. Recent work has suggested NOHMs as an alternative CO2 capture media with interesting chemical and physical tunability. Anhydrous CO2 capture solvents often degrade when they are exposed to water, while flue gas generally contains about 8-16% water. Thus, this study was conducted to investigate the effect of water on the NOHMs' properties relevant to CO2 capture as well as the chemical and thermal stabilities of H2O-loaded NOHMs. It was found that water acted as an antisolvent of NOHMs, and therefore, caused a decreased CO2 capture capacity. On the other hand, the results indicated that while water did not affect the NOHMs' thermal stability, it significantly helped lowering their density and viscosity. In order to investigate the effect of intermolecular interactions among two fluids on the density and viscosity, the excess volumes and viscosity deviations were calculated and correlated with Redlich-Kister equations. The trends revealed the existence of strong intermolecular interactions between water molecules and the poly(ethlyne glycol) component of NOHMs, which may have caused the drastic decrease in the NOHMs' viscosity with the addition of water. PMID:23842199

  8. Capacity building in water demand management as a key component for attaining millennium development goals

    NASA Astrophysics Data System (ADS)

    Gumbo, Bekithemba; Forster, Laura; Arntzen, Jaap

    Successful water demand management (WDM) implementation as a component of integrated water resource management (IWRM) can play a significant role in the alleviation of poverty through more efficient use of available water resources. The urban population in Southern African cities is characterised by so-called ‘water poor’ communities who typically expend a high percentage of their household income on poor quality water. Usually they have no access to an affordable alternative source. Although WDM as a component of IWRM is not a panacea for poverty, it can help alleviate poverty by facilitating water services management by municipal water supply agencies (MWSAs) in the region. WDM is a key strategy for achieving the millennium development goals (MDGs) and, as such, should be given due attention in the preparation of national IWRM and water efficiency plans. Various studies in the Southern African region have indicated that capacity building is necessary for nations to develop IWRM and water-use efficiency plans to meet the targets set out in the MDGs. WDM education and training of water professionals and end-users is particularly important in developing countries, which are resource and information-access poor. In response to these findings, The World Conservation Union (IUCN) and its consulting partners, the Training and Instructional Design Academy of South Africa (TIDASA), and Centre for Applied Research (CAR) designed, developed and presented a pilot WDM Guideline Training Module for MWSAs as part of Phase II of IUCN’s Southern Africa regional WDM project. Pilot training was conducted in July 2004 in Lusaka, Zambia for a group of 36 participants involved in municipal water supply from nine Southern African countries. This paper looks at the links between building the capacity of professionals, operational staff and other role-players in the municipal water supply chain to implement WDM as part of broader IWRM strategies, and the subsequent potential for poverty relief resulting from more effective, efficient and equitable use and allocation of municipal water supplies.

  9. Climate Change and Water Infrastructure in Central Asia: adaptation capacities and institutional challenges

    NASA Astrophysics Data System (ADS)

    Abdullaev, Iskandar; Rakhmatullaev, Shavkat

    2014-05-01

    The paper discusses vulnerability areas of water sector in arid Central Asia due to climate change projections with particular focus on adaptation to sustainable operation of physical infrastructure capacities (from legal, institutional and technical aspects). Two types of technical installations are the main focus of this paper, i.e., electrical lift irrigation systems and water reservoirs. The first set of electrical lift infrastructure is strategic for delivering water to water users via pumps, diversion structures, vertical drainage facilities and groundwater boreholes; on the other hand, the primarily task of second set of structures is to accumulate the water resources for sectors of economy. In Central Asia, approximately, 20-50% of irrigation water is lifted, yet major of lift structures are in very poor technical conditions coupled with ever increasing of electricity tariffs. Furthermore, useful volumes capacities of water reservoirs are being severely diminished due to bio-physical geomorphologic processes, improper operational regimes and chronic financing for special in-house sedimentation surveys. Most importantly, the key argument is that irrigation sector should internalize its adaptation efforts, i.e., integrate renewable energy technologies, energy audit programs and lastly design comprehensive investment prioritization processes and programs. Otherwise, water sector will be at great risk for continued provision of fundamental services to the public, food security and industry

  10. Water vapour foreign-continuum absorption in near-infrared windows from laboratory measurements.

    PubMed

    Ptashnik, Igor V; McPheat, Robert A; Shine, Keith P; Smith, Kevin M; Williams, R Gary

    2012-06-13

    For a long time, it has been believed that atmospheric absorption of radiation within wavelength regions of relatively high infrared transmittance (so-called 'windows') was dominated by the water vapour self-continuum, that is, spectrally smooth absorption caused by H(2)O--H(2)O pair interaction. Absorption due to the foreign continuum (i.e. caused mostly by H(2)O--N(2) bimolecular absorption in the Earth's atmosphere) was considered to be negligible in the windows. We report new retrievals of the water vapour foreign continuum from high-resolution laboratory measurements at temperatures between 350 and 430?K in four near-infrared windows between 1.1 and 5??m (9000-2000?cm(-1)). Our results indicate that the foreign continuum in these windows has a very weak temperature dependence and is typically between one and two orders of magnitude stronger than that given in representations of the continuum currently used in many climate and weather prediction models. This indicates that absorption owing to the foreign continuum may be comparable to the self-continuum under atmospheric conditions in the investigated windows. The calculated global-average clear-sky atmospheric absorption of solar radiation is increased by approximately 0.46?W?m(-2) (or 0.6% of the total clear-sky absorption) by using these new measurements when compared with calculations applying the widely used MTCKD (Mlawer-Tobin-Clough-Kneizys-Davies) foreign-continuum model. PMID:22547232

  11. Low-Dimensional Water on Ru(0001)Model System for X-ray Absorption Spectroscopy Studies of Liquid Water

    SciTech Connect

    Nordlund, D

    2012-02-14

    We present an x-ray absorption spectroscopy results for fully broken to a complete H-bond network of water molecules on Ru(0001) by varying the morphology from isolated water molecules via two-dimensional clusters to a fully covered monolayer as probed by scanning tunneling microscopy. The sensitivity of x-ray absorption to the symmetry of H-bonding is further elucidated for the amino (-NH{sub 2}) group in glycine adsorbed on Cu(110) where the E-vector is parallel either to the NH donating an H-bond or to the non-H-bonded NH. The results give further evidence for the interpretation of the various spectral features of liquid water and for the general applicability of x-ray absorption spectroscopy to analyze H-bonded systems.

  12. Low-Dimensional Water on Ru(0001); Model System for X-ray Absorption Spectroscopy Studies of Liquid Water

    SciTech Connect

    Nordlund, D.; Ogasawara, H.; Andersson, K.J.; Tatarkhanov, M.; Salmeron, M.; Pettersson, L. G. M.; Nilsson, A.

    2009-05-11

    We present an x-ray absorption spectroscopy results for fully broken to a complete H-bond network of water molecules on Ru(0001) by varying the morphology from isolated water molecules via two-dimensional clusters to a fully covered monolayer as probed by scanning tunneling microscopy. The sensitivity of x-ray absorption to the symmetry of H-bonding is further elucidated for the amino (-NH{sub 2}) group in glycine adsorbed on Cu(110) where the E-vector is parallel either to the NH donating an H-bond or to the non-H-bonded NH. The results give further evidence for the interpretation of the various spectral features of liquid water and for the general applicability of x-ray absorption spectroscopy to analyze H-bonded systems.

  13. Water governance: learning by developing adaptive capacity to incorporate climate variability and change.

    PubMed

    Kashyap, A

    2004-01-01

    There is increasing evidence that global climate variability and change is affecting the quality and availability of water supplies. Integrated water resources development, use, and management strategies, represent an effective approach to achieve sustainable development of water resources in a changing environment with competing demands. It is also a key to achieving the Millennium Development Goals. It is critical that integrated water management strategies must incorporate the impacts of climate variability and change to reduce vulnerability of the poor, strengthen sustainable livelihoods and support national sustainable development. UNDP's strategy focuses on developing adaptation in the water governance sector as an entry point within the framework of poverty reduction and national sustainable development. This strategy aims to strengthen the capacity of governments and civil society organizations to have access to early warning systems, ability to assess the impact of climate variability and change on integrated water resources management, and developing adaptation intervention through hands-on learning by undertaking pilot activities. PMID:15195430

  14. Characteristics of nutrient absorption and water purification in some plant species grown by floating culture system

    Microsoft Academic Search

    Akira Miyazaki; Teruo Takeuchi; Hitomi Nakamura; Yoshinori Yamamoto; Fumitake Kubota

    2004-01-01

    Nutrient absorption and water purification by rice (Oryza sativa L.), canna (Canna indica L.), reed (Phragmites communis Trin.), and umbrella plant (Cyperus alternifolius L.), grown by the floating culture system, were compared under different pH conditions in natural water. The pH of the rooting zone in natural water changed due to the increase in the CO2 concentration associated with root

  15. Impact of MIE-Resonances on the Atmospheric Absorption of Water Clouds

    NASA Technical Reports Server (NTRS)

    Wiscombe, W.; Kinne, S.; Nussenzveig, H.; Lau, William K. M. (Technical Monitor)

    2002-01-01

    Clouds strongly modulate radiative transfer processes in the Earth's atmosphere. Studies, which simulate bulk properties of clouds, such as absorption, require methods that accurately account for multiple scattering among individual cloud particles. Multiple scattering processes are well described by MIE-theory, if interacting particles have a spherical shape. This is a good assumption for water droplets. Thus, simulations for water clouds (especially for interactions with solar radiation) usually apply readily available MIE-codes. The presence of different drop-sizes, however, necessitates repetitive calculations for many sizes. The usual representation by a few sizes is likely to miss contributions from densely distributed, sharp resonances. Despite their usually narrow width, integrated over the entire size-spectrum of a cloud droplet distribution, the impact of missed resonances could add up. The consideration of these resonances tends to increase cloud extinction and cloud absorption. This mechanism for a larger (than by MIE-methods predicted) solar absorption has the potential to explain observational evidence of larger than predicted cloud absorption at solar wavelengths. The presentation will address the absorption impact of added resonances for typical properties of water clouds (e.g. drop size distributions, drop concentrations and cloud geometry). Special attention will be given to scenarios with observational evidence of law than simulated solar absorption; particularly if simultaneous measurements of cloud micro- and macrophysical properties are available.

  16. Nonlinear absorption of femtosecond laser pulses (800 nm) by atmospheric air and water vapour

    SciTech Connect

    Kiselev, A M; Ponomarev, Yu N; Stepanov, A N; Tikhomirov, A B; Tikhomirov, B A

    2011-11-30

    Quantitative data on the nonlinear absorption cross sections of femtosecond Ti : Sapphire laser pulses in air and water vapour have been obtained. A photoacoustic spectrometer calibrated based on the calculated value of linear absorption of laser pulses with a wavelength of 800 nm and a spectral width of 17.7 nm is used to find the nonlinear absorption cross sections of water vapour and air: {sigma}{sub 2}{sup w} = (2.6{+-}0.4) Multiplication-Sign 10{sup -55} cm{sup 4} s and {sigma}{sub 2}{sup a} = (8.7{+-}1.0) Multiplication-Sign 10{sup -56} cm{sup 4} s, respectively. Based on measuring the absorption of femtosecond Ti : Sapphire laser pulses with a photoacoustic detector calibrated with the known linear absorption of ruby laser radiation by water vapour in air, the air nonlinear absorption cross section is found to be (8.2{+-}0.9) Multiplication-Sign 10{sup -56} cm{sup 4} s.

  17. Magnesium absorption from mineral water decreases with increasing quantities of magnesium per serving in rats.

    PubMed

    Nakamura, Eri; Tai, Hideyuki; Uozumi, Yoshinobu; Nakagawa, Koji; Matsui, Tohru

    2012-01-01

    It is hypothesized that magnesium (Mg) absorption from mineral water is affected by the concentration of Mg in the water, the consumption pattern, and the volume consumed per serving. The present study examined the effect of serving volume and consumption pattern of artificial mineral water (AMW) and Mg concentration on Mg absorption in rats. Magnesium in AMW was labeled with magnesium-25 as a tracer. Each group consisted of 6 or 7 rats. In experiment 1, the rats received 1 mL of AMW containing 200 mg Mg/L at 4 times, 400 mg Mg/L twice, or 800 mg Mg/L at 1 time. In experiment 2, the rats received 1 mL of AMW containing 200 mg Mg/L or 0.25 mL of AMW containing 800 mg Mg/L at 4 times or 1 mL of AMW containing 800 mg Mg/L at 1 time. The absorption of Mg decreased with increasing Mg concentrations in the same serving volume of AMW with different serving frequencies. When the AMW containing 800 mg Mg/L was portioned into 4 servings, Mg absorption increased to the level of absorption in the group exposed to AMW containing 200 mg Mg/L served at the same frequency. These results suggest that the Mg concentration and the volume of AMW do not affect Mg absorption per se, but Mg absorption from AMW decreases when the amount of Mg in each serving is increased. Thus, frequent consumption is preferable for mineral water rich in Mg when the total consumption of mineral water is the same. PMID:22260865

  18. Water storage capacity of natural wetland depressions in the Devils Lake basin of North Dakota

    USGS Publications Warehouse

    Ludden, A.P.; Frink, D.L.; Johnson, D.H.

    1983-01-01

    Photogrammetric mapping techniques were used to derive the water storage capacities of natural wetland depressions other than lakes in the Devils Lake Basin of North Dakota. Results from sample quarter-section areas were expanded to the entire basin. Depressions in the Devils Lake Basin have a maximum storage capacity of nearly 811,000 cubic dekameters (657,000 acre-feet). The depressions store about 72 percent of the total runoff volume from a 2-year-frequency runoff and about 41 percent of the total runoff volume from a 100-year-frequency runoff.

  19. An Accurate Method for Computing the Absorption of Solar Radiation by Water Vapor

    NASA Technical Reports Server (NTRS)

    Chou, M. D.

    1980-01-01

    The method is based upon molecular line parameters and makes use of a far wing scaling approximation and k distribution approach previously applied to the computation of the infrared cooling rate due to water vapor. Taking into account the wave number dependence of the incident solar flux, the solar heating rate is computed for the entire water vapor spectrum and for individual absorption bands. The accuracy of the method is tested against line by line calculations. The method introduces a maximum error of 0.06 C/day. The method has the additional advantage over previous methods in that it can be applied to any portion of the spectral region containing the water vapor bands. The integrated absorptances and line intensities computed from the molecular line parameters were compared with laboratory measurements. The comparison reveals that, among the three different sources, absorptance is the largest for the laboratory measurements.

  20. [Study of high temperature water vapor concentration measurement method based on absorption spectroscopy].

    PubMed

    Chen, Jiu-ying; Liu, Jian-guo; He, Jun-feng; He, Ya-bai; Zhang, Guang-le; Xu, Zhen-yu; Gang, Qiang; Wang, Liao; Yao, Lu; Yuan, Song; Ruan, Jun; Dai, Yun-hai; Kan, Rui-feng

    2014-12-01

    Tunable diode laser absorption spectroscopy (TDLAS) has been developed to realize the real-time and dynamic measurement of the combustion temperature, gas component concentration, velocity and other flow parameters, owing to its high sensitivity, fast time response, non-invasive character and robust nature. In order to obtain accurate water vapor concentration at high temperature, several absorption spectra of water vapor near 1.39 ?m from 773 to 1273 K under ordinary pressure were recorded in a high temperature experiment setup using a narrow band diode laser. The absorbance of high temperature absorption spectra was calculated by combined multi-line nonlinear least squares fitting method. Two water vapor absorption lines near 7154.35 and 7157.73 cm(-1) were selected for measurement of water vapor at high temperature. A model method for high temperature water vapor concentration was first proposed. Water vapor concentration from the model method at high temperature is in accordance with theoretical reasoning, concentration measurement standard error is less than 0.2%, and the relative error is less than 6%. The feasibility of this measuring method is verified by experiment. PMID:25881402

  1. Modeling the current and future capacity of water resources to meet water demands in the Ebro basin

    NASA Astrophysics Data System (ADS)

    Milano, Marianne; Ruelland, Denis; Dezetter, Alain; Fabre, Julie; Ardoin-Bardin, Sandra; Servat, Eric

    2013-09-01

    Worldwide studies have shown that the Mediterranean region is one of the most vulnerable areas to water crisis. The region is characterized by limited and unequally distributed water resources and increasing water demands. The Ebro catchment (85,000 km2, Spain) is representative of this context. Since the late 1970s, a negative trend in river discharge has been observed, attributed to a decrease in mean precipitation, and a rise in mean temperature and in water consumption. Finally, over 230 storage dams regulate river discharge. In this context, an integrated water resources modeling framework was developed to evaluate the current and future capacity of water resources to meet domestic and agricultural water demands as well as environmental flow requirements. The approach was driven by a conceptual rainfall-runoff model generating water supplies and by a demand driven storage dam model. The approach defines current pressures on water resources and evaluates future changes in water allocation in the medium term under climatic and water use scenarios, considering changes in population and in irrigated areas. Currently, water demands in the Ebro catchment are satisfied. In 2050, water resources are projected to decrease by 15-35% during spring and summer, leading to growing competition among users and severe water shortages for irrigated agriculture. This study provides an original approach to identify the most vulnerable regions to water use conflicts. It also highlights the interest of integrated modeling for complete analysis of the ability of water resources to meet water demands in complex change scenarios as a support for decision making.

  2. Peculiar absorption of water by hydrophobized glass beads

    Microsoft Academic Search

    Laurent Forny; Isabelle Pezron; Kashayar Saleh; Pierre Guigon; Ljepsa Komunjer

    2005-01-01

    Hydrophobization of industrial powders is frequently used to avoid caking during transport and storage. Caking is induced by the formation of liquid bridges through capillary condensation at the contact point between particles. Liquid–solid contact angles are commonly determined through macroscopic experiments but the relationship between such observations and local water interaction with the microparticle is not straightforward. Here, model powders

  3. ABSORPTION OF LEAD FROM DRINKING WATER WITH VARYING MINERAL CONTENT

    EPA Science Inventory

    Lead (Pb) (200 ppm) was administered via drinking water to rats for nine weeks. In addition, the rats were grouped so that they received 75, 100, 150 and 250% of the minimum daily requirements (MDR) of calcium (Ca), iron (Fe), and magnesium (Mg) as required for normal growth. The...

  4. Effects of Thinning Intensities on Soil Infiltration and Water Storage Capacity in a Chinese Pine-Oak Mixed Forest

    PubMed Central

    Chen, Lili; Yuan, Zhiyou; Shao, Hongbo; Wang, Dexiang; Mu, Xingmin

    2014-01-01

    Thinning is a crucial practice in the forest ecosystem management. The soil infiltration rate and water storage capacity of pine-oak mixed forest under three different thinning intensity treatments (15%, 30%, and 60%) were studied in Qinling Mountains of China. The thinning operations had a significant influence on soil infiltration rate and water storage capacity. The soil infiltration rate and water storage capacity in different thinning treatments followed the order of control (nonthinning): <60%, <15%, and <30%. It demonstrated that thinning operation with 30% intensity can substantially improve soil infiltration rate and water storage capacity of pine-oak mixed forest in Qinling Mountains. The soil initial infiltration rate, stable infiltration rate, and average infiltration rate in thinning 30% treatment were significantly increased by 21.1%, 104.6%, and 60.9%, compared with the control. The soil maximal water storage capacity and noncapillary water storage capacity in thinning 30% treatment were significantly improved by 20.1% and 34.3% in contrast to the control. The soil infiltration rate and water storage capacity were significantly higher in the surface layer (0~20?cm) than in the deep layers (20~40?cm and 40~60?cm). We found that the soil property was closely related to soil infiltration rate and water storage capacity. PMID:24883372

  5. Water-controlled wealth of nations: Using Water Footprints to Estimate Nations Carrying Capacities and Demographic Sustainability

    NASA Astrophysics Data System (ADS)

    Suweis, Samir; Rinaldo, Andrea; Maritan, Amos; D'Odorico, Paolo

    2014-05-01

    Population growth is in general constrained by food production, which in turn depends on the access to water resources. At a country level, some populations use more water than they control because of their ability to import food and the virtual water required for its production. Here, we investigate the dependence of demographic growth on available water resources for exporting and importing nations. By quantifying the carrying capacity of nations based on calculations of the virtual water available through the food trade network, we point to the existence of a global water unbalance. We suggest that current export rates will not be maintained and consequently we question the long-run sustainability of the food trade system as a whole. Water rich regions are likely to soon reduce the amount of virtual water they export, thus leaving import-dependent regions without enough water to sustain their populations. We also investigate the potential impact of possible scenarios that might mitigate these effects through (1) cooperative interactions among nations whereby water rich countries maintain a tiny fraction of their food production available for export; (2) changes in consumption patterns; and (3) a positive feedback between demographic growth and technological innovations. We find that these strategies may indeed reduce the vulnerability of water-controlled societies.

  6. Thermodynamic optimization of a solar system for cogeneration of water heating/purification and absorption cooling

    NASA Astrophysics Data System (ADS)

    Hovsapian, Zohrob O.

    This dissertation presents a contribution to understanding the behavior of solar powered air conditioning and refrigeration systems with a view to determining the manner in which refrigeration rate; mass flows, heat transfer areas, and internal architecture are related. A cogeneration system consisting of a solar concentrator, a cavity-type receiver, a gas burner, and a thermal storage reservoir is devised to simultaneously produce water heating/purification and cooling (absorption refrigerator system). A simplified mathematical model, which combines fundamental and empirical correlations, and principles of classical thermodynamics, mass and heat transfer, is developed. An experimental setup was built to adjust and validate the numerical results obtained with the mathematical model. The proposed model is then utilized to simulate numerically the system transient and steady state response under different operating and design conditions. A system global optimization for maximum performance (or minimum exergy destruction) in the search for minimum pull-down and pull-up times, and maximum system second law efficiency is performed with low computational time. Appropriate dimensionless groups are identified and the results presented in normalized charts for general application. The numerical results show that the three way maximized system second law efficiency, etaII,max,max,max, occurs when three system characteristic mass flow rates are optimally selected in general terms as dimensionless heat capacity rates, i.e., (Psisps , Psiwxwx, PsiHs)opt ? (1.43, 0.17, 0.19). The minimum pull-down and pull-up times, and maximum second law efficiencies found with respect to the optimized operating parameters are sharp and, therefore important to be considered in actual design. As a result, the model is expected to be a useful tool for simulation, design, and optimization of solar energy systems in the context of distributed power generation.

  7. Water Absorption and Mechanical Properties of Silica Porous Glasses

    Microsoft Academic Search

    Ya. O. Roizin; S. A. Gevelyuk; L. P. Prokopovich; D. P. Savin; E. Rysiakiewicz-Pasek; K. Marczuk

    1997-01-01

    We have estimated the mechanical properties of silica porous glasses (SPG) using special two-layered structures consisting of a SPG layer on a solid glass substrate. These structures turned curved after keeping them in moist atmosphere. The linear dimensions of dry free-standing SPG wafers with the same pore size distribution increased significantly (up to 1.5%) after water vapour soaking. Bending angles

  8. Ab initio calculation of the electronic absorption spectrum of liquid water

    SciTech Connect

    Martiniano, Hugo F. M. C.; Galamba, Nuno [Grupo de Física Matemática da Universidade de Lisboa, Av. Professor Gama Pinto 2, 1649-003 Lisboa (Portugal)] [Grupo de Física Matemática da Universidade de Lisboa, Av. Professor Gama Pinto 2, 1649-003 Lisboa (Portugal); Cabral, Benedito J. Costa, E-mail: ben@cii.fc.ul.pt [Grupo de Física Matemática da Universidade de Lisboa, Av. Professor Gama Pinto 2, 1649-003 Lisboa (Portugal) [Grupo de Física Matemática da Universidade de Lisboa, Av. Professor Gama Pinto 2, 1649-003 Lisboa (Portugal); Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa (Portugal); Instituto de Física da Universidade de São Paulo, CP 66318, 05314-970 São Paulo, SP (Brazil)

    2014-04-28

    The electronic absorption spectrum of liquid water was investigated by coupling a one-body energy decomposition scheme to configurations generated by classical and Born-Oppenheimer Molecular Dynamics (BOMD). A Frenkel exciton Hamiltonian formalism was adopted and the excitation energies in the liquid phase were calculated with the equation of motion coupled cluster with single and double excitations method. Molecular dynamics configurations were generated by different approaches. Classical MD were carried out with the TIP4P-Ew and AMOEBA force fields. The BLYP and BLYP-D3 exchange-correlation functionals were used in BOMD. Theoretical and experimental results for the electronic absorption spectrum of liquid water are in good agreement. Emphasis is placed on the relationship between the structure of liquid water predicted by the different models and the electronic absorption spectrum. The theoretical gas to liquid phase blue-shift of the peak positions of the electronic absorption spectrum is in good agreement with experiment. The overall shift is determined by a competition between the O–H stretching of the water monomer in liquid water that leads to a red-shift and polarization effects that induce a blue-shift. The results illustrate the importance of coupling many-body energy decomposition schemes to molecular dynamics configurations to carry out ab initio calculations of the electronic properties in liquid phase.

  9. Spectral control of an alexandrite laser for an airborne water-vapor differential absorption lidar system

    NASA Technical Reports Server (NTRS)

    Ponsardin, Patrick; Grossmann, Benoist E.; Browell, Edward V.

    1994-01-01

    A narrow-linewidth pulsed alexandrite laser has been greatly modified for improved spectral stability in an aircraft environment, and its operation has been evaluated in the laboratory for making water-vapor differential absorption lidar measurements. An alignment technique is described to achieve the optimum free spectral range ratio for the two etalons inserted in the alexandrite laser cavity, and the sensitivity of this ratio is analyzed. This technique drastically decreases the occurrence of mode hopping, which is commonly observed in a tunable, two-intracavity-etalon laser system. High spectral purity (greater than 99.85%) at 730 nm is demonstrated by the use of a water-vapor absorption line as a notch filter. The effective cross sections of 760-nm oxygen and 730-nm water-vapor absorption lines are measured at different pressures by using this laser, which has a finite linewidth of 0.02 cm(exp -1) (FWHM). It is found that for water-vapor absorption linewidths greater than 0.04 cm(exp -1) (HWHM), or for altitudes below 10 km, the laser line can be considered monochromatic because the measured effective absorption cross section is within 1% of the calculated monochromatic cross section. An analysis of the environmental sensitivity of the two intracavity etalons is presented, and a closed-loop computer control for active stabilization of the two intracavity etalons in the alexandrite laser is described. Using a water-vapor absorption line as a wavelength reference, we measure a long-term frequency drift (approximately 1.5 h) of less than 0.7 pm in the laboratory.

  10. Spectral control of an alexandrite laser for an airborne water-vapor differential absorption lidar system.

    PubMed

    Ponsardin, P; Higdon, N S; Grossmann, B E; Browell, E V

    1994-09-20

    A narrow-linewidth pulsed alexandrite laser has been greatly modified for improved spectral stability in an aircraft environment, and its operation has been evaluated in the laboratory for making water-vapor differential absorption lidar measurements. An alignment technique is described to achieve the optimum free spectral range ratio for the two étalons inserted in the alexandrite laser cavity, and the sensitivity of this ratio is analyzed. This technique drastically decreases the occurrence of mode hopping, which is commonly observed in a tunable, two-intracavity-étalon laser system. High spectral purity (> 99.85%) at 730 nm is demonstrated by the use of a water-vapor absorption line as a notch filter. The effective cross sections of 760-nm oxygen and 730-nm water-vapor absorption lines are measured at different pressures by usingthis laser, which has a finite linewidth of 0.02 cm(-1) (FWHM). It is found that for water-vapor absorption linewidths greater than 0.04 cm(-1) (HWHM), or for altitudes below 10 km, the laser line can be considered monochromatic because the measured effective absorption cross section is within 1% of the calculated monochromatic cross section. An analysis of the environmental sensitivity of the two intracavity étalons is presented, and a closed-loop computer control for active stabilization of the two intracavity étalons in the alexandrite laser is described. Using a water-vapor absorption line as a wavelength reference, we measure a long-term frequency drift (? 1.5 h) of less than 0.7 pm in the laboratory. PMID:20941182

  11. Waste Feed Delivery Raw Water and Potable Water and Compressed Air Capacity Evaluation

    SciTech Connect

    MAY, T.H.

    2000-02-08

    This study evaluated the ability of the Raw Water, Potable Water, and Compressed Air systems to support safe storage as well as the first phase of the Waste Feed Delivery. Several recommendations are made to improve the system.

  12. Bathymetric surveys and area/capacity tables of water-supply reservoirs for the city of Cameron, Missouri, July 2013

    USGS Publications Warehouse

    Huizinga, Richard J.

    2014-01-01

    Years of sediment accumulation and dry conditions in recent years have led to the decline of water levels and capacities for many water-supply reservoirs in Missouri, and have caused renewed interest in modernizing outdated area/capacity tables for these reservoirs. The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, surveyed the bathymetry of the four water-supply reservoirs used by the city of Cameron, Missouri, in July 2013. The data were used to provide water managers with area/capacity tables and bathymetric maps of the reservoirs at the time of the surveys.

  13. Studies of Water Absorption Behavior of Plant Fibers at Different Temperatures

    NASA Astrophysics Data System (ADS)

    Saikia, Dip

    2010-05-01

    Moisture absorption of natural fiber plastic composites is one major concern in their outdoor applications. The absorbed moisture has many detrimental effects on the mechanical performance of these composites. A knowledge of the moisture diffusivity, permeability, and solubility is very much essential for the application of natural fibers as an excellent reinforcement in polymers. An effort has been made to study the water absorption behavior of some natural fibers such as bowstring hemp, okra, and betel nut at different temperatures to improve the long-term performance of composites reinforced with these fibers. The gain in moisture content in the fibers due to water absorption was measured as a function of exposure time at temperatures ranging from 300 K to 340 K. The thermodynamic parameters of the sorption process, such as diffusion coefficients and corresponding activation energies, were estimated.

  14. A procedure to determine the water-binding capacity of meat trimmings for cooked sausage formulation.

    PubMed

    Pouttu, Petri; Puolanne, Eero

    2004-02-01

    An attempt was made to determine the water-binding capacity of each individual trimming in a multicomponent system. Three types of experimental cooked sausages (finely chopped luncheon sausage, coarsely chopped sausage and ring sausage with potato starch) were made of five different meat trimmings: two pork trimmings and two beef trimmings, and one beef trimming used as a replacer. The water-binding was determined by the Tuominen-Honkavaara method by stepwise addition of water (basic formulation and four water additions) to the formulations and determining the firmness by a consistometer. The water-binding of each trimming was obtained by replacing the trimming by an additonal trimming. A total of 3 sausage types×5 meat trimmings×5 water levels giving 75 experimental batches of 5 kg each were made. The average water-binding values of the same meat trimming combination in each sausage type were practically the same, and therefore the total averages for the same meat trimming combinations of each of the three sausage types were used for the subsequent calculations. The determination of the water-binding values of the meat trimmings were solved by forming five equations with four unknowns each, and then solving the unknowns using Microsoft Excel's 'Solver' function. By this procedure it was possible to determine the water-binding of individual meat trimmings in sausage systems. This procedure can be used for the determination of the technological properties of meats for linear programming. PMID:22064135

  15. State-of-the-Art Review on Crystallization Control Technologies for water/LiBr Absorption Heat Pumps

    SciTech Connect

    Wang, Kai [ORNL; Abdelaziz, Omar [ORNL; Kisari, Padmaja [ORNL; Vineyard, Edward Allan [ORNL

    2011-01-01

    The key technical barrier to using water/lithium bromide (LiBr) as the working fluid in aircooled absorption chillers and absorption heat-pump systems is the risk of crystallization when the absorber temperature rises at fixed evaporating pressure. This article reviews various crystallization control technologies available to resolve this problem: chemical inhibitors, heat and mass transfer enhancement methods, thermodynamic cycle modifications, and absorption system-control strategies. Other approaches, such as boosting absorber pressure and J-tube technology, are reviewed as well. This review can help guide future efforts to develop water/LiBr air-cooled absorption chillers and absorption heatpump systems.

  16. Application of multiobjective optimization to scheduling capacity expansion of urban water resource systems

    NASA Astrophysics Data System (ADS)

    Mortazavi-Naeini, Mohammad; Kuczera, George; Cui, Lijie

    2014-06-01

    Significant population increase in urban areas is likely to result in a deterioration of drought security and level of service provided by urban water resource systems. One way to cope with this is to optimally schedule the expansion of system resources. However, the high capital costs and environmental impacts associated with expanding or building major water infrastructure warrant the investigation of scheduling system operational options such as reservoir operating rules, demand reduction policies, and drought contingency plans, as a way of delaying or avoiding the expansion of water supply infrastructure. Traditionally, minimizing cost has been considered the primary objective in scheduling capacity expansion problems. In this paper, we consider some of the drawbacks of this approach. It is shown that there is no guarantee that the social burden of coping with drought emergencies is shared equitably across planning stages. In addition, it is shown that previous approaches do not adequately exploit the benefits of joint optimization of operational and infrastructure options and do not adequately address the need for the high level of drought security expected for urban systems. To address these shortcomings, a new multiobjective optimization approach to scheduling capacity expansion in an urban water resource system is presented and illustrated in a case study involving the bulk water supply system for Canberra. The results show that the multiobjective approach can address the temporal equity issue of sharing the burden of drought emergencies and that joint optimization of operational and infrastructure options can provide solutions superior to those just involving infrastructure options.

  17. Aggregating available soil water holding capacity data for crop yield models

    NASA Technical Reports Server (NTRS)

    Seubert, C. E.; Daughtry, C. S. T.; Holt, D. A.; Baumgardner, M. F.

    1984-01-01

    The total amount of water available to plants that is held against gravity in a soil is usually estimated as the amount present at -0.03 MPa average water potential minus the amount present at -1.5 MPa water potential. This value, designated available water-holding capacity (AWHC), is a very important soil characteristic that is strongly and positively correlated to the inherent productivity of soils. In various applications, including assessing soil moisture status over large areas, it is necessary to group soil types or series as to their productivity. Current methods to classify AWHC of soils consider only total capacity of soil profiles and thus may group together soils which differ greatly in AWHC as a function of depth in the profile. A general approach for evaluating quantitatively the multidimensional nature of AWHC in soils is described. Data for 902 soil profiles, representing 184 soil series, in Indiana were obtained from the Soil Characterization Laboratory at Purdue University. The AWHC for each of ten 150-mm layers in each soil was established, based on soil texture and parent material. A multivariate clustering procedure was used to classify each soil profile into one of 4, 8, or 12 classes based upon ten-dimensional AWHC values. The optimum number of classes depends on the range of AWHC in the population of oil profiles analyzed and on the sensitivity of a crop to differences in distribution of water within the soil profile.

  18. Structural features and water holding capacities of pressed potato fibre polysaccharides.

    PubMed

    Ramaswamy, Urmila R; Kabel, Mirjam A; Schols, Henk A; Gruppen, Harry

    2013-04-01

    Pressed potato fibre (PPF) has a high water holding capacity (WHC) affecting its processing as an animal feed. The aim of this study was to characterize cell wall polysaccharides (CWPs) in PPF and investigate their WHC. This was done via sequential extractions. Half of all CWPs were recovered in the hot buffer soluble solids extract as pectins (uronic acid and rhamnose) and galactans wherein most pectins (76%) from PPF were water soluble. Most likely, the network of CWPs is loosened during processing of potatoes. PPF showed a WHC of 7.4 expressed as the amount of water held per g of dry matter (mL/g). Reconstituting hot buffer soluble solids with buffer insoluble solids in water gave a WHC comparable to that of PPF. Removal of alkali soluble solids, which mainly comprised xyloglucans, lowered the WHC of the final residue. The results indicated that interactions between CWPs could affect the WHC of PPF. PMID:23499100

  19. Application of Peleg model to study water absorption in chickpea during soaking

    Microsoft Academic Search

    Mahir Turhan; Sedat Sayar; Sundaram Gunasekaran

    2002-01-01

    Application of the Peleg model was investigated for predicting water absorption by five winter- and five spring-planted chickpea genotypes during soaking between temperature (T ) of 20 and 100 °C. The Peleg model can predict kinetics of the chickpea soaking till equilibrium using short-term data at the given conditions. Its specific form for infinite time may also be used to

  20. TPS/PCL composite reinforced with treated sisal fibers: property, biodegradation and water-absorption

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sisal fibers bleached with sodium-hydroxide followed by hydrogen peroxide treatment were incorporated in a thermoplastic starch;-polycaprolactone (TPS/PCL) blend via extrusion processing and examined for their property, biodegradability and water-absorption. Scanning electron microscopy revealed wel...

  1. DETERMINING BERYLLIUM IN DRINKING WATER BY GRAPHITE FURNACE ATOMIC ABSORPTION SPECTROSCOPY

    EPA Science Inventory

    A direct graphite furnace atomic absorption spectroscopy method for the analysis of beryllium in drinking water has been derived from a method for determining beryllium in urine. Ammonium phosphomolybdate and ascorbic acid were employed as matrix modifiers. The matrix modifiers s...

  2. LEO-LEO OCCULTATIONS MEASURING WATER VAPOR AND TEMPERATURE VIA ABSORPTION

    E-print Network

    LEO-LEO OCCULTATIONS MEASURING WATER VAPOR AND TEMPERATURE VIA ABSORPTION S. Syndergaard, B. M, future LEO-LEO occultation constella- tions will be able to provide profiles of temperature and moisture vapor and ozone profiles from active microwave occultation measurements. In Fujisada, H., Lurie, J. B

  3. Absorption\\/regeneration non-conventional system for water extraction from atmospheric air

    Microsoft Academic Search

    Ahmed Sultan

    2004-01-01

    The present work suggests a non-conventional method of water production from atmospheric air, on a 24-h basis using a compact system. The operation of the system is described and its efficiency is defined. The system performs under forced convection absorption and regeneration through a packed tower. The packed tower consists of two identical columns, each of them is packed with

  4. Determination of ionic alkyllead compounds in water by gas chromatography\\/atomic absorption spectrometry

    Microsoft Academic Search

    D. Chakraborti; W. R. A. De Jonghe; W. E. Van Mol; R. J. A. Van Cleuvenbergen; F. C. Adams

    1984-01-01

    Ionic alkyllead compounds are extracted from water samples into pentane by complexation with sodium diethyldithiocarbamate. Inorganic lead is complexed with EDTA. The organic phase is evaporated to dryness by vacuum distillation, after which butylation with n-butyl Grignard reagent is carried out in a microvolume of n-nonane. The analysis is performed by gas chromatography with atomic absorption spectrometric detection. The effects

  5. Performance evaluation of a monomethylamine–water solar absorption refrigeration system for milk cooling purposes

    Microsoft Academic Search

    I. Pilatowsky; W. Rivera; J. R. Romero

    2004-01-01

    This study reports the applicability and the theoretical thermodynamic simulation of a solar driven monomethylamine–water single-stage absorption refrigeration cycle for milk cooling purposes in the rural regions of Mexico. A solar heating system using evacuated tube collectors coupled with a conventional auxiliary heating system is proposed. The simulation of the yearly dynamic behaviour of the solar system is carried out

  6. Ammonia absorption from a bubble expanding at a submerged orifice into water

    Microsoft Academic Search

    Koichi Terasaka; Junko Oka; Hideki Tsuge

    2002-01-01

    To investigate the mechanism of gas absorption from a bubble containing soluble and insoluble components, a gaseous mixture of ammonia and nitrogen was bubbled into water. The growth curve, volume, surface area and shape of the growing bubbles were measured with parameters such as inlet gas composition, gas flow rate and gas chamber volume. The bubble volume decreased with the

  7. Estimating Available Water Capacity in the Lower Mekong River Basin by Integrating GRACE Observations into a Land Surface Model

    NASA Astrophysics Data System (ADS)

    Hung, C. J.; Bolten, J. D.; Lakshmi, V.; Wilson, R.; Strauch, K.; Doyle, T.; Habib, S.; Toll, D. L.; Srinivasan, R.

    2013-12-01

    The Gravity Recovery and Climate Experiment (GRACE) data has provided global monthly time series data on water storage change at one-degree resolution over the past decade (2003-2012). Available Water Capacity (AWC) of the soil in watersheds is useful for estimating potential groundwater recharge. The dynamics of Terrestrial Water Storage (TWS) are constrained by the Available Water Capacity, related to field capacity and wilting point, and reflect regional water dynamics. In the Lower Mekong River Basin, the Available Water Capacity map being applied by the Mekong River Commission (MRC) is in need of update. The goal of this study is to assimilate TWS from GRACE data using an Ensemble Kalman Smoother and the NASA Catchment Land Surface Model (CLSM) over a sub-basin of the Lower Mekong River Basin. In this way, the water holding capacity of the sub-basin is constrained. The calculated AWC is compared with AWC from MRC. Furthermore, the calculated AWC will be validated using the Soil and Water Assessment Tool (SWAT), which requires AWC as an adjusted parameter on discharge calibration. The implications of the available water capacity on watershed management will be discussed.

  8. Wide absorption spectrum measuring methods by DFB-LDs in water vapor detection system

    NASA Astrophysics Data System (ADS)

    Liu, Y. N.; Chang, J.; Lian, J.; Wang, Q.; Lv, G. P.; Wang, W. J.; Liu, Z.; Liu, X. Z.; Zhang, S. S.; Wang, Z. L.; Jiang, S.; Zhu, C. G.; Wei, W.; Sun, B. N.

    2014-09-01

    Two measuring methods of the wide absorption spectrum by distributed feedback laser diodes (DFB-LDs) are presented in detecting the water vapor absorption line. One is the subsection scanning method, and it takes advantage of the wide spectrum tuning range by the temperature modulation and fast spectrum tuning speed by current modulation. Specifically, this method is realized by dividing a target spectral region into several sections which correspond to the specific temperature of DFB-LD, scanning every section by current modulation for hundreds times, and averaging the data to raise the signal to noise ratio (SNR), then combining all sections to get the whole spectrum. An accuracy of 10 ppmv had been obtained in the measurement of water vapor with a 10-cm path length by this method. Another is data fitting method, based on the absorption line-shape function; the absorption line can be described by fitting with partial measured data. The fitting absorption line was fitted well with the measured data, and the square of correlation coefficient (R-square) was no less than 0.99.

  9. Fractional water allocation and reservoir capacity sharing concepts: An adaptation for the Komati Basin

    NASA Astrophysics Data System (ADS)

    Dlamini, Enoch M.; Dhlamini, Sidney; Mthimkhulu, Sindy

    This paper presents an adaptation of fractional water allocation and reservoir capacity sharing (FWARCS) concepts for application in the Komati Basin, a river system shared between South Africa, Swaziland and Mozambique. Many traditional methods for allocating water are based on volume-per-unit-time allocation that is supplied at some level of assurance and managed using priority-based reservoir and river system operating rules, as well as on the “use it or lose it” principle, which is considered exclusive by water users as it leaves them out of the management of their water allocations. In the Komati Basin, these traditional methods of water allocation led to frequent conflicts among users and with water managers. However, the introduction of the modified FWARCS, which assigns available water in the system to water users according to the proportions of their water entitlements and allows water to be banked in reservoirs, appears to be a solution to some of these problems. This method allows water users to decide when and how much of that entitlement they may use. Since the implementation of the modified FWARCS technique in the Komati Basin in 2002, the regulation, transparency and efficiency of operating the system improved and subsequently the number of disputes over water has declined. South Africa improved from an overuse of 8.2 Mm 3 in 2002/03 water year to realize a saving of 29.5 Mm 3 in 2005/06. Similarly, Swaziland improved from an overuse of 3.9 Mm 3 in 2002/03 to achieve a saving of 14.6 Mm 3 in 2005/06. Users have recognised and embraced the transparency and flexibility of the modified FWARCS. They choose, as the need and opportunity arise, when and how much water they utilise, whether to “bank” and/or “trade” the water they save subject to the conditions of their entitlements. The implementation of the modified FWARCS was also made successful by the existence of proper institutional structures, appropriate decision support tools, good water measurement infrastructure and reliable water accounting systems. The establishment, development and utilization of these elements of water management, as well as the challenges encountered in relation to the adoption of modified FWARCS in the Komati Basin are discussed in this paper.

  10. Accelerated Capacity Development in Water Resources Education: the experiences of the Ethiopian Institute of Water Resources

    NASA Astrophysics Data System (ADS)

    Alamirew, T.; Mekonnen, G.; Viglione, A.

    2012-04-01

    Ethiopia recently recognises that the water resources development is the major entry point in poverty alleviation and sustainable development. Water in Ethiopia plays a key role in the Water-Energy-Food-nexus. Over 98% of the electricity in the country is generated using hydropower and yet about 2000 MW has been developed. Out of the 3.5 Mha potentially irrigable land, only 0.25 Mha has been developed to date. Access to drinking water supply coverage is among the lowest in the world. One of the limiting factors in harnessing the resource base is the absence of water professionals to face the fast growing demand in education, research, development in the water sector. Recognising this, in collaboration with University of Connecticut of the United States, Addis Ababa University launched the Ethiopian Institute of Water Resources (EIWR) by enrolling 18 PhD and 24 MSc students. The program is unique in that much of the course instructors are coming from US and European Universities, but deliver courses together with Ethiopian collaborators. This is supposed to facilitate knowledge and experience transfer from the US/EU scientist to Ethiopian counterparts. The theses/dissertations are designed to focus on Ethiopia's immediate hydrological problems on selected basins, and will be coordinated by three advisors for each PhD - one from US/EU, one from Ethiopian Universities, and one water professional from the sector. We report here the lessons learned in setting up the EIWR institute and the education program.

  11. Effects of rainfall seasonality and soil moisture capacity on mean annual water balance for Australian catchments

    USGS Publications Warehouse

    Potter, N.J.; Zhang, L.; Milly, P.C.D.; McMahon, T.A.; Jakeman, A.J.

    2005-01-01

    An important factor controlling catchment-scale water balance is the seasonal variation of climate. The aim of this study is to investigate the effect of the seasonal distributions of water and energy, and their interactions with the soil moisture store, on mean annual water balance in Australia at catchment scales using a stochastic model of soil moisture balance with seasonally varying forcing. The rainfall regime at 262 catchments around Australia was modeled as a Poisson process with the mean storm arrival rate and the mean storm depth varying throughout the year as cosine curves with annual periods. The soil moisture dynamics were represented by use of a single, finite water store having infinite infiltration capacity, and the potential evapotranspiration rate was modeled as an annual cosine curve. The mean annual water budget was calculated numerically using a Monte Carlo simulation. The model predicted that for a given level of climatic aridity the ratio of mean annual evapotranspiration to rainfall was larger where the potential evapotranspiration and rainfall were in phase, that is, in summer-dominant rainfall catchments, than where they were out of phase. The observed mean annual evapotranspiration ratios have opposite results. As a result, estimates of mean annual evapotranspiration from the model compared poorly with observational data. Because the inclusion of seasonally varying forcing alone was not sufficient to explain variability in the mean annual water balance, other catchment properties may play a role. Further analysis showed that the water balance was highly sensitive to the catchment-scale soil moisture capacity. Calibrations of this parameter indicated that infiltration-excess runoff might be an important process, especially for the summer-dominant rainfall catchments; most similar studies have shown that modeling of infiltration-excess runoff is not required at the mean annual timescale. Copyright 2005 by the American Geophysical Union.

  12. Comparative Study of Water Absorption Behavior of Wood and Wood Plastic Composites of Simul Using Film Neutron Radiography

    Microsoft Academic Search

    M. N. Islam; M. A. Khan; M. A. Zaman

    2005-01-01

    The film neutron radiography method was adopted for a comparative study of water absorption behavior in wood and wood plastic composites (WPC) of Simul using the thermal neutron radiography facility of 3 MW TRIGA MARK-II research reactor at Atomic Energy Research Establishment, Savar Dhaka, Bangladesh. Variations of optical density values due to water absorption of these samples were measured from neutron

  13. Polder Effects on Sediment-to-Soil Conversion: Water Table, Residual Available Water Capacity, and Salt Stress Interdependence

    PubMed Central

    Radimy, Raymond Tojo; Dudoignon, Patrick; Hillaireau, Jean Michel; Deboute, Elise

    2013-01-01

    The French Atlantic marshlands, reclaimed since the Middle Age, have been successively used for extensive grazing and more recently for cereal cultivation from 1970. The soils have acquired specific properties which have been induced by the successive reclaiming and drainage works and by the response of the clay dominant primary sediments, that is, structure, moisture, and salinity profiles. Based on the whole survey of the Marais Poitevin and Marais de Rochefort and in order to explain the mechanisms of marsh soil behavior, the work focuses on two typical spots: an undrained grassland since at least 1964 and a drained cereal cultivated field. The structure-hydromechanical profiles relationships have been established thanks to the clay matrix shrinkage curve. They are confronted to the hydraulic functioning including the fresh-to-salt water transfers and to the recording of tensiometer profiles. The CE1/5 profiles supply the water geochemical and geophysical data by their better accuracy. Associated to the available water capacity calculation they allow the representation of the parallel evolution of the residual available water capacity profiles and salinity profiles according to the plant growing and rooting from the mesophile systems of grassland to the hygrophile systems of drained fields. PMID:23990758

  14. Finite element analysis and modeling of water absorption by date pits during a soaking process

    PubMed Central

    Waezi-Zadeh, Motahareh; Ghazanfari, Ahmad; Noorbakhsh, Shahin

    2010-01-01

    Date pits for feed preparation or oil extraction are soaked in water to soften before milling or extrusion. Knowledge of water absorption by the date pits helps in better managing the soaking duration. In this research, the process of water absorption by date pits was modeled and analyzed using Fick’s second law of diffusion, finite element approach, and Peleg model. The moisture content of the pits reached to its saturation level of 41.5% (wet basis) after 10 d. The estimated coefficient of diffusion was 9.89×10?12 m2/s. The finite element model with a proposed ellipsoid geometry for a single date pit and the analytical model fitted better to the experimental data with R 2 of 0.98. The former model slightly overestimated the moisture content of the pits during the initial stages of the soaking and the latter model generally underestimated this variable through the entire stages of soaking process. PMID:20593512

  15. Inhibition of Ileal Water Absorption by Intraluminal Fatty Acids INFLUENCE OF CHAIN LENGTH, HYDROXYLATION, AND CONJUGATION OF FATTY ACIDS

    PubMed Central

    Ammon, Helmut V.; Phillips, Sidney F.

    1974-01-01

    The influence of fatty acids on ileal absorption of water, electrolytes, glucose, and taurocholate was examined in Thirty-Vella fistulas in five mongrel dogs. Fatty acid absorption also was measured. Segments of terminal ileum were perfused at steady state with isotonic electrolyte solutions containing 11.2 mM glucose, 4.5 mM taurocholate, and 0.1-5.0 mM fatty acid. Three C18 fatty acids, oleic acid, 10(9)-hydroxystearic acid, and ricinoleic acid, completely inhibited water absorption at 5 mM. Sodium, chloride, and potassium absorptions were inhibited in parallel with absorption of water. Differences between the potencies of C18 fatty acids were apparent when lesser concentrations were perfused. Dodecanoic and decanoic acids were as effective as C18 fatty acids at 5 mM but octanoic and hexanoic acids were ineffective. The polar group of C18 fatty acids was modified by conjugating oleic and ricinoleic acids with taurine. When these compounds and a substituted C18 fatty acid, p-n-decylbenzenesulfonate, were perfused, water absorption was also inhibited. Short-chain fatty acids (C3 and C4) and their hydroxylated derivatives were ineffective at 5 mM. When water absorption was inhibited, absorption of glucose and taurocholate was decreased. We speculate that the phenomenon of inhibition of water and electrolyte absorption by fatty acids may be relevant to steatorrhea and diarrhea in man. Images PMID:4808636

  16. Low frequency sound absorption in sea water: A new chemical relaxation

    NASA Astrophysics Data System (ADS)

    Browning, D. G.; Mellen, R. H.; Simmons, V. P.

    1981-09-01

    This document presented the oral and visual presentation entitled 'Low Frequency Sound Absorption in Sea Water: A New Chemical Relaxation Mechanism?,' presented at the 101st Meeting of the Acoustical Society of America, 18-22 May 1981, in Ottawa, Ontario, Canada. Excess sound absorption in sea water arises mainly from chemical relaxations involving MgS04 and B(OH)3. The high-frequency (100 kHz) MgS04 relaxation has been identified as a multistep ion-pair process. The low frequency (1 kHz) and B(OH)3 relaxation apparently involves more complex interactions with other constituents. To investigate B(OH)3 interactions in a simpler system, we measured absorption in NH3 solution using the resonator method. We have found alpha max to be proportional to the product of NH(+) and B(OH)4(-) concentrations; however, the magnitude is much too large to be caused by the ion pair. The mechanism, probably similar to that in sea water, resembles catalysis, the absorption being governed by the large volume change of the faster NH3/NH4(+) equilibrium and the relaxation frequency by the slower B(OH)3/B(OH)4(-) equilibrium.

  17. The phase behavior and absorption spectra of the ternary system cobaltous chloride-water-acetonitrile

    E-print Network

    Bobbitt, Jeffrey Lovett

    1967-01-01

    . HE PHASZ BEHAVIOR ARD ABSORPTION SPECTRA. OF THE TER1MRY SYSTEN COBALTOUS CHLORIDE-WATER-AGZTOIJITRILE A Thesis by JEFFREY LOVZTT BOBBIT'1 Submitted to the Graduate College of the Texas A&N University in Partial fulfillment... of the recuirements tor the d. egrce of PlASTER OF SCIENCE Nay 1967 Najor Subject: GHENISTRY THE PHASE BIEIAVIOR Al'TD ABSORPTION SPZCTR4 OF TIIE TERNARY SYSTZNi COBAI, TOUS C&ILORIDZ-WATZR-ACZTONITRIIR A Thesis by JEFFREY I OVl'TT B013BITT APProved...

  18. A structural approach to understanding the interactions between colour, water-holding capacity and tenderness.

    PubMed

    Hughes, J M; Oiseth, S K; Purslow, P P; Warner, R D

    2014-11-01

    The colour, water-holding capacity (WHC) and tenderness of meat are primary determinants of visual and sensory appeal. Although there are many factors which influence these quality traits, the end-results of their influence is often through key changes to the structure of muscle proteins and their spatial arrangement. Water acts as a plasticiser of muscle proteins and water is lost from the myofibrillar lattice structure as a result of protein denaturation and consequent reductions in the muscle fibre volume with increasing cooking temperature. Changes in the myofilament lattice arrangement also impact the light scattering properties and the perceived paleness of the meat. Causes of variation in the quality traits of raw meat do not generally correspond to variations in cooked meat and the differences observed between the raw muscle and cooked or further processed meat are discussed. The review will also identify the gaps in our knowledge and where further investigation would beneficial. PMID:25034451

  19. Biodestruction of strongly swelling polymer hydrogels and its effect on the water retention capacity of soils

    NASA Astrophysics Data System (ADS)

    Smagin, A. V.; Sadovnikova, N. B.; Smagina, M. V.

    2014-06-01

    The biodestruction of strongly swelling polymer hydrogels (water adsorbing soil conditioners of the new generation) has been studied at the quantitative level using original mathematical models. In laboratory experiments, a relationship between the hydrogel degradation rate and the temperature has been obtained, and the effect of the biodestruction on the water retention curve of soil compositions with hydrogels (used as an index of their water retention capacity) has been assessed. From the automatic monitoring data of the temperature regime of soils, the potential biodestruction of hydrogels has been predicted for different climatic conditions. The loss of hydrogels during three months of the vegetation period because of destruction can exceed 30% of their initial content in irrigated agriculture under arid climatic conditions and more than 10% under humid climatic conditions. Thus, the biodestruction of hydrogels is one of the most important factors decreasing their efficiency under actual soil conditions.

  20. Determination of traces of silver in waters by anion exchange and atomic absorption spectrophotometry

    USGS Publications Warehouse

    Chao, T.T.; Fishman, M.J.; Ball, J.W.

    1969-01-01

    A method has been developed for the accurate determination of 0.1-1 ??g of silver per liter of water. The method permits stabilization of silver in water without loss to container walls. Optimum conditions have been established for the complete recovery of silver from water with an anion-exchange column, for quantitative elution of silver from the resin, and for measurement of silver by atomic absorption spectrophotometry after chelation with ammonium pyrrolidine dithiocarbamate and extraction of the chelate with MIBK. Silver in the 1-10 ??g 1 range can be determined by extraction without pre-concentration on an ion-exchange resin. ?? 1969.

  1. Complexing capacity of natural waters carrying a great amount of suspended matter.

    PubMed

    Minaberry, Yanina S; Gordillo, Gabriel J

    2007-11-01

    The cadmium binding properties of waters of the superior section of the Rio de la Plata estuarine were determined over a three-year period. Samples were collected at different hydrodynamic conditions. The complexing capacity was determined by square wave anodic stripping voltammetry (SWASV). Titration curve data were analyzed using a multivariable regression. Suspended particulate matter (SPM) was identified by XR diffraction and FTIR. These analyses showed that SPM principal components are clays (illite, montmorillonite and chlorite). The study was applied to the untreated, filtered and centrifuged fractions of each sample at the pH of the natural waters and at pH 1. The results show that the contribution of dissolved organic matter to the complexing capacity is negligible when compared with SPM. At natural pH, the complexing capacity of filtered and untreated fractions can be described by considering two kinds of binding sites. The associated conditional binding constants are independent of the concentration of suspended matter. Their average logarithms are ca. 6.5 and ca. 4.4. The total concentration of binding sites (S(T)) is in microM range, which is about three orders of magnitude higher than that reported for most of the studied estuaries. This difference is explained on the basis of the great amount of SPM. Hydrodynamic conditions produce variations in the concentration and composition of the SPM. At pH 1 samples still exhibit an important complexing capacity with only one binding site with log K(cond) ca. 5.4. These differences could be attributed to superficial modifications that take place at very low pH. PMID:17572474

  2. The water vapour self- and water-nitrogen continuum absorption in the 1000 and 2500 cm(-1) atmospheric windows.

    PubMed

    Baranov, Yu I; Lafferty, W J

    2012-06-13

    The pure water vapour and water-nitrogen continuum absorption in the 1000 and 2500?cm(-1) atmospheric windows has been studied using a 2?m base-length White-type multi-pass cell coupled with a BOMEM DA3-002 Fourier transform infrared spectrometer. The measurements were carried out at the National Institute of Standards and Technology (NIST, Gaithersburg, MD) over the course of several years (2004, 2006-2007, 2009). New data on the H(2)O:N(2) continuum in the 1000?cm(-1) window are presented and summarized along with the other experimental results and the continuum model. The experimental data reported on the water vapour continuum in these atmospheric windows basically agree with the most reliable laboratory data from the other sources. The MT_CKD (Mlawer-Tobin-Clough-Kneizys-Davies) continuum model significantly departs from the experimental data in both windows. The deviation observed includes the continuum magnitude, spectral behaviour and temperature dependence. In the 2500?cm(-1) region, the model does not allow for the nitrogen fundamental collision-induced absorption (CIA) band intensity enhancement caused by H(2)O:N(2) collisions and underestimates the actual absorption by over two orders of magnitude. The water vapour continuum interpretation as a typical CIA spectrum is reviewed and discussed. PMID:22547233

  3. Hydrogen-rich water enhances cadmium tolerance in Chinese cabbage by reducing cadmium uptake and increasing antioxidant capacities.

    PubMed

    Wu, Qi; Su, Nana; Cai, Jiangtao; Shen, Zhenguo; Cui, Jin

    2015-03-01

    The aim of the present paper was to understand the specific mechanism of hydrogen-rich water (HRW) in alleviating cadmium (Cd) toxicity in Chinese cabbage (Brassica campestris spp. chinensis L.). Our results showed that the addition of 50% saturation HRW significantly alleviated the Cd toxic symptoms, including the improvement of both root elongation and seedling growth inhibition. These responses were consistent with a significant decrease of Cd accumulation in roots and shoots, which was further confirmed by the histochemical staining. Molecular evidence illustrated that Cd-induced up-regulations of IRT1 and Nramp1 genes, responsible for Cd absorption, were blocked by HRW. By contrast, Cd-induced up-regulation of the HMA3 gene, which regulates Cd sequestration into the root vacuoles, was substantially strengthened by HRW. Furthermore, compared with those in Cd stress alone, the expressions of HMA2 and HMA4, which function in the transportation of Cd to xylem, were repressed by co-treatment with HRW. HRW enhanced the activities of antioxidant enzymes, including superoxide dismutase, guaiacol peroxidase, catalase and ascorbate peroxidase. These results were further confirmed by the alleviation of oxidative damage, as indicated by the decrease of thiobarbituric acid reactive substances (TBARS) and reactive oxygen species (ROS) production. Taken together, these results suggest that the improvement of Cd tolerance by HRW was associated with reduced Cd uptake and increased antioxidant defense capacities. Therefore, the application of HRW may be a promising strategy to improve Cd tolerance of Chinese cabbage. PMID:25543863

  4. Water holding capacity and collagen profile of bovine m. infraspinatus during postmortem ageing.

    PubMed

    Modzelewska-Kapitu?a, Monika; Kwiatkowska, Aleksandra; Jankowska, Barbara; D?browska, Ewa

    2015-02-01

    Changes in the water holding capacity (WHC) and collagen profile in bovine m. infraspinatus during ageing in avacuum at 3 °C up to 20 days were studied. Moisture, expressible water and total collagen content were determined in raw samples and muscles were then subjected to thermal treatment in steam. Moisture, collagen fractions(total, water-soluble, insoluble, acetic acid-soluble, total soluble) and cooking loss were determined in the cooked meat. Ageing time did not significantly influence WHC (expressible water content as a % of moisture), moisture content in raw and cooked meat or cooking loss. Between the 5th and 10th day of ageing a significant increase was noted in acetic acid-soluble collagen and total soluble collagen content along with a decrease in insoluble collagen content (p b 0.05). A significant negative relationship was found between the expressible water content and the water-soluble collagen. It was concluded that connective tissue ageing of bovine m. infraspinatus might be finished after 10 days. PMID:25460127

  5. Water solubilization capacity of pharmaceutical microemulsions based on Peceol®, lecithin and ethanol.

    PubMed

    Mouri, Abdelkader; Diat, Olivier; Lerner, Dan Alain; El Ghzaoui, Abdeslam; Ajovalasit, Alessia; Dorandeu, Christophe; Maurel, Jean-Claude; Devoisselle, Jean-Marie; Legrand, Philippe

    2014-11-20

    Biocompatible microemulsions composed of Peceol(®), lecithin, ethanol and water developed for encapsulation of hydrophilic drugs were investigated. The binary mixture Peceol(®)/ethanol was studied first. It was shown that the addition of ethanol to pure Peceol(®) has a significant fluidifying and disordering effect on the Peceol(®) supramolecular structure with an enhancement in water solubilization. The water solubilization capacity was improved by adding lecithin as a third component. It was then demonstrated that the ethanol/lecithin weight ratio played an important role in determining the optimal composition in term of water solubilization efficiency, a necessary property for a nutraceutical or pharmaceutical application. The optimal ethanol/lecithin weight ratio in the Peceol(®) rich region was found to be 40/60. Combination different techniques such as SAXS, fluorimetry, rheology and conductivity, we analyzed the water uptake within the microemulsion taking into account the partitioning of ethanol between polar and apolar domains. This ethanol distribution quantified along a water dilution line has a major effect on microemulsion properties. PMID:25034800

  6. Carrying Capacity

    NSDL National Science Digital Library

    2012-06-25

    This lesson helps students understand the notion of carrying capacity as it relates to ecosystems by considering an image of a bucket filled with water, and then filled with an "ecosystem." Students are asked to consider the factors on which carrying capacity is determined, and that a ecosystem's carrying capacity can change when certain variables are also changed.

  7. Effect of chitosan on gastrointestinal absorption of water-insoluble drugs following oral administration in rats.

    PubMed

    Nadai, Masayuki; Tajiri, Chiharu; Yoshizumi, Hideo; Suzuki, Yuji; Zhao, Ying Lan; Kimura, Masao; Tsunekawa, Yoshimi; Hasegawa, Takaaki

    2006-09-01

    Chitosan is widely used as a dietary weight-loss supplement in Japan. In the present study, we examined the effect of chitosan on the gastrointestinal absorption profiles of the water-insoluble drugs, indomethacin and griseofulvin, and the water-soluble drugs, acetaminophen and cephalexin, after oral administration in rats. Rats received oral administration of chitosan (5 mg/kg or 25 mg/kg) dissolved in 5% acetic acid or vehicle 15 min before oral administration of each drug. Chitosan at a dose of 25 mg/kg, but not 5 mg/kg, significantly decreased the plasma concentrations of indomethacin and griseofulvin after administration as a suspension with a significant delay of the time to reach maximum concentration compared to the corresponding control values (vehicle-pretreated rats). However, pretreatment of chitosan (25 mg/kg) did not change the pharmacokinetics of indomethacin administered as a solution. Further, the same dose of chitosan had no effect on the pharmacokinetics of acetaminophen. The gastrointestinal absorption profile of an amino-beta-lactam antibiotic, cephalexin, which is actively absorbed via carrier-mediated transport system, was also unchanged. The present findings at least suggest the possibility that chitosan at high dose reduces the gastrointestinal absorption of water-insoluble drugs such as indomethacin and griseofulvin, but not water-soluble drugs, by diminishing the surfactant-like effect of bile acids. PMID:16946514

  8. Direct relationship between osmotic and ionic conforming behavior and tissue water regulatory capacity in echinoids.

    PubMed

    Santos, Ivonete A; Castellano, Giovanna C; Freire, Carolina A

    2013-03-01

    Echinoderms are considered marine osmoconforming invertebrates. However, many are intertidal or live next to estuaries, tolerating salinity changes and showing extracellular gradients to dilute seawater. Three species of echinoids - Lytechinus variegatus, which can occur next to estuarine areas, the rocky intertidal Echinometra lucunter, and the mostly subtidal Arbacia lixula - were submitted to a protocol of stepwise (rate of 2-3 psu/h) dilution, down to 15 psu, or concentration, up to 45 psu, of control seawater (35 psu). Coelomic fluid samples were obtained every hour. The seawater dilution experiment lasted 8h, while the seawater concentration experiment lasted 6h. Significant gradients (40-90% above value in 15 psu seawater) for osmolality, sodium, magnesium, and potassium were shown by L. variegatus and E. lucunter. A. lixula showed the smallest gradients, displaying the strongest conforming behavior. The esophagus of the three species was challenged in vitro with 20 and 50% osmotic shocks (hypo- and hyperosmotic). A. lixula, the most "conforming" species, showed the highest capacity to avoid swelling of its tissues upon the -50% hyposmotic shock, and was also the species less affected by salinity changes concerning the observation of spines and ambulacral feet movement in the whole-animal experiments. Thus, the most conforming species (A. lixula) displayed the highest capacity to regulate tissue water/volume, and was also the most euryhaline among the three studied species. In addition, tissues from all three species swelled much more than they shrank under osmotic shocks of same magnitude. This distinct trend to gain water, despite the capacity to hold some gradients upon seawater dilution, helps to explain why echinoderms cannot be fully estuarine, or ever enter fresh water. PMID:23261991

  9. Estimating a Global Hydrological Carrying Capacity Using GRACE Observed Water Stress

    NASA Astrophysics Data System (ADS)

    An, K.; Reager, J. T.; Famiglietti, J. S.

    2013-12-01

    Global population is expected to reach 9 billion people by the year 2050, causing increased demands for water and potential threats to human security. This study attempts to frame the overpopulation problem through a hydrological resources lens by hypothesizing that observed groundwater trends should be directly attributed to human water consumption. This study analyzes the relationships between available blue water, population, and cropland area on a global scale. Using satellite data from NASA's Gravity Recovery and Climate Experiment (GRACE) along with land surface model data from the Global Land Data Assimilation System (GLDAS), a global groundwater depletion trend is isolated, the validity of which has been verified in many regional studies. By using the inherent distributions of these relationships, we estimate the regional populations that have exceeded their local hydrological carrying capacity. Globally, these populations sum to ~3.5 billion people that are living in presently water-stressed or potentially water-scarce regions, and we estimate total cropland is exceeding a sustainable threshold by about 80 million km^2. Key study areas such as the North China Plain, northwest India, and Mexico City were qualitatively chosen for further analysis of regional water resources and policies, based on our distributions of water stress. These case studies are used to verify the groundwater level changes seen in the GRACE trend . Tfor the many populous, arid regions of the world that have already begun to experience the strains of high water demand.he many populous, arid regions of the world have already begun to experience the strains of high water demand. It will take a global cooperative effort of improving domestic and agricultural use efficiency, and summoning a political will to prioritize environmental issues to adapt to a thirstier planet. Global Groundwater Depletion Trend (Mar 2003-Dec 2011)

  10. A yearlong study of water-soluble organic carbon in Beijing II: Light absorption properties

    NASA Astrophysics Data System (ADS)

    Du, Zhenyu; He, Kebin; Cheng, Yuan; Duan, Fengkui; Ma, Yongliang; Liu, Jiumeng; Zhang, Xiaolu; Zheng, Mei; Weber, Rodney

    2014-06-01

    Light absorption properties of water-soluble organic carbon (WSOC) in Beijing were investigated by 24 h-averaged fine particulate matter (PM2.5) samples collected from October 2010 to November 2011. The light absorption spectra of WSOC exhibited strong wavelength dependence such that the absorption Ångstrom exponent was approximately 7.5. The light absorption at 365 nm (Abs365), which is typically used as a proxy of water-soluble brown carbon, was found to correlate strongly with WSOC (R2 > 0.75, p < 0.01). Moreover, the correlation between Abs365 and levoglucosan (especially in fall and winter) indicated that biomass burning could contribute significantly to water-soluble brown carbon. Source apportionment with Positive Matrix Factorization (PMF) model showed that biomass burning and mixed sources contributed 58.0% and 20.8% to total Abs365, compared with 21.2% from WSOC associated with sulfate and oxalate. The mass absorption efficiency (MAE) of WSOC in Beijing showed distinct temporal variations (averaging 1.26 m2/g and 0.51 m2/g during winter and summer, respectively), and was approximately 2-3 times the values of that observed in the southeastern United States, but was substantially lower than the summertime results from Los Angeles. Influence factors responsible for the temporal and spatial variations of MAE were investigated. MAE were calculated for each PMF factor. It was found that the MAE for WSOC from biomass burning (1.19 m2/g) and mixed primary sources (2.89 m2/g) was much higher than that of WSOC associated with sulfate or oxalate (0.32-0.33 m2/g) in Beijing. In addition, it was concluded that differences in the precursors of WSOC might also be responsible for the observed variation of MAE such that WSOC associated with anthropogenic precursors are more light-absorbing compared with WSOC biogenic sources.

  11. Water vapour absorption in the clear atmosphere of a Neptune-sized exoplanet.

    PubMed

    Fraine, Jonathan; Deming, Drake; Benneke, Bjorn; Knutson, Heather; Jordán, Andrés; Espinoza, Néstor; Madhusudhan, Nikku; Wilkins, Ashlee; Todorov, Kamen

    2014-09-25

    Transmission spectroscopy has so far detected atomic and molecular absorption in Jupiter-sized exoplanets, but intense efforts to measure molecular absorption in the atmospheres of smaller (Neptune-sized) planets during transits have revealed only featureless spectra. From this it was concluded that the majority of small, warm planets evolve to sustain atmospheres with high mean molecular weights (little hydrogen), opaque clouds or scattering hazes, reducing our ability to observe the composition of these atmospheres. Here we report observations of the transmission spectrum of the exoplanet HAT-P-11b (which has a radius about four times that of Earth) from the optical wavelength range to the infrared. We detected water vapour absorption at a wavelength of 1.4 micrometres. The amplitude of the water absorption (approximately 250 parts per million) indicates that the planetary atmosphere is predominantly clear down to an altitude corresponding to about 1 millibar, and sufficiently rich in hydrogen to have a large scale height (over which the atmospheric pressure varies by a factor of e). The spectrum is indicative of a planetary atmosphere in which the abundance of heavy elements is no greater than about 700 times the solar value. This is in good agreement with the core-accretion theory of planet formation, in which a gas giant planet acquires its atmosphere by accreting hydrogen-rich gas directly from the protoplanetary nebula onto a large rocky or icy core. PMID:25254473

  12. Ammonia and ammonium hydroxide sensors for ammonia/water absorption machines: Literature review and data compilation

    SciTech Connect

    Anheier, N.C. Jr.; McDonald, C.E.; Cuta, J.M.; Cuta, F.M.; Olsen, K.B.

    1995-05-01

    This report describes an evaluation of various sensing techniques for determining the ammonia concentration in the working fluid of ammonia/water absorption cycle systems. The purpose of this work was to determine if any existing sensor technology or instrumentation could provide an accurate, reliable, and cost-effective continuous measure of ammonia concentration in water. The resulting information will be used for design optimization and cycle control in an ammonia-absorption heat pump. PNL researchers evaluated each sensing technology against a set of general requirements characterizing the potential operating conditions within the absorption cycle. The criteria included the physical constraints for in situ operation, sensor characteristics, and sensor application. PNL performed an extensive literature search, which uncovered several promising sensing technologies that might be applicable to this problem. Sixty-two references were investigated, and 33 commercial vendors were identified as having ammonia sensors. The technologies for ammonia sensing are acoustic wave, refractive index, electrode, thermal, ion-selective field-effect transistor (ISFET), electrical conductivity, pH/colormetric, and optical absorption. Based on information acquired in the literature search, PNL recommends that follow-on activities focus on ISFET devices and a fiber optic evanescent sensor with a colormetric indicator. The ISFET and fiber optic evanescent sensor are inherently microminiature and capable of in situ measurements. Further, both techniques have been demonstrated selective to the ammonium ion (NH{sub 4}{sup +}). The primary issue remaining is how to make the sensors sufficiently corrosion-resistant to be useful in practice.

  13. Water vapour absorption in the clear atmosphere of a Neptune-sized exoplanet

    NASA Astrophysics Data System (ADS)

    Fraine, Jonathan; Deming, Drake; Benneke, Bjorn; Knutson, Heather; Jordán, Andrés; Espinoza, Néstor; Madhusudhan, Nikku; Wilkins, Ashlee; Todorov, Kamen

    2014-09-01

    Transmission spectroscopy has so far detected atomic and molecular absorption in Jupiter-sized exoplanets, but intense efforts to measure molecular absorption in the atmospheres of smaller (Neptune-sized) planets during transits have revealed only featureless spectra. From this it was concluded that the majority of small, warm planets evolve to sustain atmospheres with high mean molecular weights (little hydrogen), opaque clouds or scattering hazes, reducing our ability to observe the composition of these atmospheres. Here we report observations of the transmission spectrum of the exoplanet HAT-P-11b (which has a radius about four times that of Earth) from the optical wavelength range to the infrared. We detected water vapour absorption at a wavelength of 1.4 micrometres. The amplitude of the water absorption (approximately 250 parts per million) indicates that the planetary atmosphere is predominantly clear down to an altitude corresponding to about 1 millibar, and sufficiently rich in hydrogen to have a large scale height (over which the atmospheric pressure varies by a factor of e). The spectrum is indicative of a planetary atmosphere in which the abundance of heavy elements is no greater than about 700 times the solar value. This is in good agreement with the core-accretion theory of planet formation, in which a gas giant planet acquires its atmosphere by accreting hydrogen-rich gas directly from the protoplanetary nebula onto a large rocky or icy core.

  14. Equilibrium phase diagrams and water absorption properties of aqueous mixtures of malonic acid and inorganic salts.

    NASA Astrophysics Data System (ADS)

    Salcedo, D.; Salgado-Olea, G.

    2006-12-01

    Tropospheric aerosols are usually complex mixtures of inorganic and organic components. Although the thermodynamic properties of inorganic aerosols have been widely studied, the effect of organics on such properties is still under discussion. Solubility in water, water activity of aqueous solutions, deliquescence relative humidity (DRH), eutonic composition, and eutonic DRH were determined for bulk mixtures of malonic acid with ammonium sulfate, ammonium bisulfate, and ammonium nitrate at 25oC over the full range of composition (from 0 wt% to the solubility limit of the mixture components). The data was used to construct equilibrium phase diagrams, which show the phase of the mixtures as a function of total composition, dry mixture composition, water content, and ambient relative humidity. Measured water activity of liquid solutions was compared with an extended Zdanovskii-Stokes-Robinson (ZSR) expression, which then was used to predict water absorption of the mixtures.

  15. 30 CFR 75.1107-7 - Water spray devices; capacity; water supply; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment...internal injection and inundation system on attended equipment the...injection or combination-type system, the amount of water discharged...required to be discharged by the system, however, such quantity...

  16. 30 CFR 75.1107-7 - Water spray devices; capacity; water supply; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment...internal injection and inundation system on attended equipment the...injection or combination-type system, the amount of water discharged...required to be discharged by the system, however, such quantity...

  17. 30 CFR 75.1107-7 - Water spray devices; capacity; water supply; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment...internal injection and inundation system on attended equipment the...injection or combination-type system, the amount of water discharged...required to be discharged by the system, however, such quantity...

  18. 30 CFR 75.1107-7 - Water spray devices; capacity; water supply; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment...internal injection and inundation system on attended equipment the...injection or combination-type system, the amount of water discharged...required to be discharged by the system, however, such quantity...

  19. Fluctuation of the water environmental carrying capacity in a huge river-connected lake.

    PubMed

    Wang, Hua; Zhou, Yiyi; Tang, Yang; Wu, Mengan; Deng, Yanqing

    2015-01-01

    A new method, with the non-fully mixed coefficient (NFMC) considered, was put forward to calculate the water environmental carrying capacity (WECC) for huge river-connected lakes, of which the hydrological conditions always vary widely during a year. Poyang Lake, the most typical river-connected lake and the largest freshwater lake in China, was selected as the research area. Based on field investigations and numerical simulation, the monthly pollutant degradation coefficients and non-fully mixed coefficients of different lake regions were determined to explore the WECCs of COD, TN and TP of Poyang Lake in a common water year. It was found that under the hydrological conditions of a common water year the total WECCs of COD, TN and TP in the lake were respectively 181.9 × 104 t, 33.3 × 104 t and 1.86 × 104 t. Due to the varied lake water volume and self-purification ability, an evident temporal fluctuation of WECCs in Poyang Lake was observed. The dry seasons were characterized by a higher NFMCs but lower WECCs owing to the lower water level and degradation ability. Variation coefficients of COD and TN WECC were close to each other, of which the average level was about 58.5%, a little higher than that of TP. PMID:25830284

  20. Calculation of the X-ray absorption spectrum of liquid water and ice

    Microsoft Academic Search

    Balazs Hetenyi; Paolo Giannozzi; Roberto Car

    2001-01-01

    We calculate the near-edge X-ray absorption fine structure (NEXAFS) spectrum of water in the gas liquid and solid (cubic) phases. We use density functional theory in the gas and solid phases and ab initio molecular dynamics to generate liquid phase configurations at a temperature of 300K. Subsequently, we calculate oscillator strengths between the 1s state of each oxygen atom and

  1. Relationship of Kernel Size to Flour Water Absorption for Canada Western Red Spring Wheat

    Microsoft Academic Search

    B. C. Morgan; J. E. Dexter; K. R. Preston

    2000-01-01

    Cereal Chem. 77(3):286-292 Canada Western Red Spring (CWRS) wheat exhibits consistent posi- tive relationships between kernel weight and farinograph and baking water absorption. These relationships are sufficiently robust to be statistically significant (P < 0.05) for historical Canadian Grain Commission harvest survey data generated one year apart for 17 years, and for historical data on individual cultivars in advanced Canadian

  2. Comparative simulation and investigation of ammonia-water: absorption cycles for heat pump applications

    Microsoft Academic Search

    M Engler; G Grossman; H.-M Hellmann

    1997-01-01

    Several recent programs in absorption research have focused on technology for domestic heating and cooling utilizing natural gas. In residential and small commercial size applications, ammonia-water cycles offer the possibility of a gas-fired heat pump for both winter heating and summer cooling, at better year-round COPS than currently available by various alternatives. Several cycles have been considered for this purpose,

  3. CO2 Absorption Rate and Solubility in Monoethanolamine\\/Piperazine\\/Water

    Microsoft Academic Search

    Gary T. Rochelle

    2003-01-01

    The solubility and absorption rate of carbon dioxide into monoethanolamine\\/ piperazine\\/water were measured in a wetted wall column at 40-60°C. The total amine concentration was varied from 1.0 M to 5.0 M with monoethanolamine blends containing 0 to 1.2 M piperazine. CO2 solubility and solution speciation were simulated by nine equilibrium reactions. Two of the equilibrium constants were adjusted to

  4. CO2 Absorption Rate and Solubility in Monoethanolamine\\/Piperazine\\/Water

    Microsoft Academic Search

    Hongyi Dang; Gary T. Rochelle

    2003-01-01

    The solubility and absorption rate of carbon dioxide into monoethanolamine\\/piperazine\\/water were measured in a wetted wall column at 40–60°C. The total amine concentration was varied from 1.0 M to 5.0 M, with monoethanolamine blends containing 0 to 1.2 M piperazine. CO2 solubility and solution speciation were simulated by nine equilibrium reactions. Two of the equilibrium constants were adjusted to match literature data. The

  5. Kinetics of absorption of carbon dioxide into solutions of N-methyldiethanolamine+water

    Microsoft Academic Search

    Jiun-Jie Ko; Meng-Hui Li

    2000-01-01

    Kinetics of the absorption of CO2 into N-methyldiethanolamine (MDEA)+water were investigated at 30, 35, and 40°C using a laboratory wetted wall column. Four systems of which 1.0, 1.5, 2.0, and 2.5kmolm?3 MDEA aqueous solutions were studied. The solubility and the diffusivity of N2O in amine systems were also studied. The N2O analogy was applied to estimate the solubility and the

  6. Assessment of underwater irradiance and absorption of solar radiation at water column from satellite data

    NASA Astrophysics Data System (ADS)

    Kopelevich, Oleg V.; Sheberstov, Sergey V.; Burenkov, Vladimir I.; Vazyulya, Svetlana V.; Likhacheva, Maria V.

    2007-04-01

    The volume absorption of solar radiation in water body determines important processes in the upper ocean such as primary bioproduction and heat balance. Assessment of penetration of solar radiation into water body can be performed with satellite data and the previous attempts in this direction were promising. This paper presents a package of the algorithms to compute the components of balance of photosynthetically available radiation (PAR) at sea level (incident, reflected from the rough sea surface, and water-leaving PAR) and to calculate the volume absorption of PAR in the upper layer from satellite ocean color data. Data measured by the SeaWiFS ocean color sensor and the ancillary data needed (such as ozone amount and wind speed) are used. Computations of the underwater irradiance are performed for the 0-25 m upper layer. The errors are estimated by direct comparison between the values of underwater irradiance and volume absorption derived by the algorithms developed and by the exact method. Monthly means of the components of PAR balance as well as the potential daily heating have been estimated in different regions.

  7. Automated atomic absorption spectrometric determination of total arsenic in water and streambed materials

    USGS Publications Warehouse

    Fishman, M.

    1977-01-01

    An automated method to determine both inorganic and organic forms of arsenic In water, water-suspended mixtures, and streambed materials Is described. Organic arsenic-containing compounds are decomposed by either ultraviolet radiation or by suHurlc acid-potassium persulfate digestion. The arsenic liberated, with Inorganic arsenic originally present, is reduced to arsine with sodium borohydrlde. The arable Is stripped from the solution with the aid of nitrogen and Is then decomposed In a tube furnace heated to 800 ??C which Is placed in the optical path of an atomic absorption spectrometer. Thirty samples per hour can be analyzed to levels of 1 ??g arsenic per liter.

  8. Determination of ionic alkyllead compounds in water by gas chromatography/atomic absorption spectrometry

    SciTech Connect

    Chakraborti, D.; De Jonghe, W.R.A.; Van Mol, W.E.; Van Cleuvenbergen, R.J.A.; Adams, F.C.

    1984-01-01

    Ionic alkyllead compounds are extracted from water samples into pentane by complexation with sodium diethyldithiocarbamate. Inorganic lead is complexed with EDTA. The organic phase is evaporated to dryness by vacuum distillation, after which butylation with n-butyl Grignard reagent is carried out in a microvolume of n-nonane. The analysis is performed by gas chromatography with atomic absorption spectrometric detection. The effects of various parameters on the analytical performance are discussed. With 500 mL of water, detection limits for individual species are situated at the ng.L/sup -1/ level.

  9. Differential absorption and Raman lidar for water vapor profile measurements - A review

    NASA Technical Reports Server (NTRS)

    Grant, William B.

    1991-01-01

    Differential absorption lidar and Raman lidar have been applied to the range-resolved measurements of water vapor density for more than 20 years. Results have been obtained using both lidar techniques that have led to improved understanding of water vapor distributions in the atmosphere. This paper reviews the theory of the measurements, including the sources of systematic and random error; the progress in lidar technology and techniques during that period, including a brief look at some of the lidar systems in development or proposed; and the steps being taken to improve such lidar systems.

  10. Water vapor absorption spectra of the upper atmosphere /45-185 per cm/

    NASA Technical Reports Server (NTRS)

    Augason, G. C.; Mord, A. J.; Witteborn, F. C.; Erickson, E. F.; Swift, C. D.; Caroff, L. J.; Kunz, L. W.

    1975-01-01

    The far IR nighttime absorption spectrum of the earth's atmosphere above 14 km is determined from observations of the bright moon. The spectra were obtained using a Michelson interferometer attached to a 30-cm telescope aboard a high-altitude jet aircraft. Comparison with a single-layer model atmosphere implies a vertical column of 3.4 plus or minus 0.4 microns of precipitable water on 30 August 1971 and 2.4 plus or minus 0.3 microns of precipitable water on 6 January 1972.-

  11. In-Line Capacitance Sensor for Real-Time Water Absorption Measurements

    NASA Technical Reports Server (NTRS)

    Nurge, Mark A.; Perusich, Stephen A.

    2010-01-01

    A capacitance/dielectric sensor was designed, constructed, and used to measure in real time the in-situ water concentration in a desiccant water bed. Measurements were carried out with two experimental setups: (1) passing nitrogen through a humidity generator and allowing the gas stream to become saturated at a measured temperature and pressure, and (2) injecting water via a syringe pump into a nitrogen stream. Both water vapor generating devices were attached to a downstream vertically-mounted water capture bed filled with 19.5 g of Moisture Gone desiccant. The sensor consisted of two electrodes: (1) a 1/8" dia stainless steel rod placed in the middle of the bed and (2) the outer shell of the stainless steel bed concentric with the rod. All phases of the water capture process (background, heating, absorption, desorption, and cooling) were monitored with capacitance. The measured capacitance was found to vary linearly with the water content in the bed at frequencies above 100 kHz indicating dipolar motion dominated the signal; below this frequency, ionic motion caused nonlinearities in the water concentration/capacitance relationship. The desiccant exhibited a dielectric relaxation whose activation energy was lowered upon addition of water indicating either a less hindered rotational motion or crystal reorientation.

  12. Protein-water network dynamics during metalloenzyme hydrolysis observed by kinetic THz absorption (KITA)

    NASA Astrophysics Data System (ADS)

    Born, Benjamin; Heyden, Matthias; Grossman, Moran; Sagi, Irit; Havenith, Martina

    2013-02-01

    For long, the contribution of water network motions to enzymatic reactions was enigmatic due to the complexity of biological systems and to experimental limitations. Thanks to the development of new powerful THz emitters and detectors in the last decades, it is now possible to probe dynamics on the timescale of the fast hydrogen bond rearrangements during biochemical reactions. For this purpose, we developed a kinetic terahertz absorption (KITA) spectrometer which combines the strength of THz radiation (~1012 Hz = 1 ps) to directly probe collective picosecond protein-water dynamics with the fast mixing properties of a stopped-flow apparatus which initializes a biochemical reaction within milliseconds. With KITA, we analyzed the collective water dynamics during substrate hydrolyses by a human matrix-metalloproteinase. In addition, we studied the reorganization and electrostatic changes at the catalytic zinc-ion from the enzyme active site and performed molecular dynamics simulations of the enzyme-substrate-water system. Our results revealed a systematic gradient of water network motions: From the active site to the bulk water hydrogen bond dynamics increased from 7 ps (active site) to 1ps (bulk water) prior to substrate binding and hydrolysis. The approaching substrate perturbs the dynamic water gradient resulting in an overshoot of KITA signal which then relaxes back during onset of substrate hydrolyses. Our findings suggest that collective water dynamics may contribute to effective substrate binding to enzyme active sites and could be induced by the charge of the catalytic zinc-ion residing at the active site.

  13. Inversion of the volume scattering function and spectral absorption in coastal waters with biogeochemical implications

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Huot, Y.; Gray, D. J.; Weidemann, A.; Rhea, W. J.

    2013-06-01

    In the aquatic environment, particles can be broadly separated into phytoplankton (PHY), non-algal particle (NAP) and dissolved (or very small particle, VSP) fractions. Typically, absorption spectra are inverted to quantify these fractions, but volume scattering functions (VSFs) can also be used. Both absorption spectra and VSFs were used to calculate particle fractions for an experiment in Chesapeake Bay. A complete set of water inherent optical properties was measured using a suite of commercial instruments and a prototype Multispectral Volume Scattering Meter (MVSM); the chlorophyll concentration, [Chl] was determined using the HPLC method. The total scattering coefficient (measured by an ac-s) and the VSF (at a few backward angles, measured by a HydroScat 6 and an ECO-VSF) agreed with the LISST and MVSM data within 5%, thus indicating inter-instrument consistency. The size distribution and scattering parameters for PHY, NAP and VSP were inverted from measured VSFs. For the absorption inversion, the "dissolved" absorption spectra were measured for filtrate passing through a 0.2 ?m filter, whereas [Chl] and NAP absorption spectra were inverted from the particulate fraction. Even though the total scattering coefficient showed no correlation with [Chl], estimates of [Chl] from the VSF-inversion agreed well with the HPLC measurements (r = 0.68, mean relative error s = -20%). The scattering associated with NAP and VSP both correlated well with the NAP and "dissolved" absorption coefficients, respectively. While NAP dominated forward, and hence total, scattering, our results also suggest that the scattering by VSP was far from negligible and dominated backscattering.

  14. Absorption of water and solute from glucose-electrolyte solutions in the human jejunum: effect of citrate or betaine.

    PubMed

    Leiper, J B; Maughan, R J

    1989-11-01

    The inclusion in oral rehydration solutions of solutes that are actively co-transported with sodium has been suggested as a means of increasing the effect of glucose on water absorption by the small intestine. Using a modified perfusion system we have examined water and solute absorption in the normal human intestine from two effervescent glucose-electrolyte solutions, containing either citrate or betaine hydrochloride, and compared the absorption rates with those from a commonly used bicarbonate-containing oral rehydration solution. Absorption of citrate (355 +/- 87 mumol/cm/h) and betaine (313 +/- 125 mumol/cm/h) occurred from the respective solutions. The inclusion of 46 mmol/l citrate or 36 mmol/l betaine in effervescent oral rehydration solutions had no effect on water or solute absorption. PMID:2595270

  15. Effect of water density on the absorption maximum of hydrated electrons in sub- and supercritical water up to 400 °C

    NASA Astrophysics Data System (ADS)

    Jay-Gerin, Jean-Paul; Lin, Mingzhang; Katsumura, Yosuke; He, Hui; Muroya, Yusa; Meesungnoen, Jintana

    2008-09-01

    The optical absorption spectra of the hydrated electron (eaq-) in supercritical (heavy) water (SCW) are measured by electron pulse radiolysis techniques as a function of water density at three temperatures of 380, 390, and 400 °C, and over the density range of ˜0.2-0.65 g/cm3. In agreement with previous work, the position of the eaq- absorption maximum (EAmax) is found to shift slightly to lower energies (spectral "redshift") with decreasing density. A comparison of the present EAmax-density data with other measurements already reported in the literature in subcritical (350 °C) and supercritical (375 °C) water reveals that at a fixed pressure, EAmax decreases monotonically with increasing temperature in passing through the phase transition at tc. By contrast, at constant density, EAmax exhibits a minimum as the water passes above the critical point into SCW. These behaviors are explained in terms of simple microscopic arguments based on the crucial role played by local density and configurational fluctuations (associated with criticality) in providing pre-existing polymeric clusters, which act as trapping sites for electrons.

  16. Airborne differential absorption lidar system for measurements of atmospheric water vapor and aerosols

    NASA Technical Reports Server (NTRS)

    Carter, Arlen F.; Allen, Robert J.; Mayo, M. Neale; Butler, Carolyn F.; Grossman, Benoist E.; Ismail, Syed; Grant, William B.; Browell, Edward V.; Higdon, Noah S.; Mayor, Shane D.; Ponsardin, Patrick; Hueser, Alene W.

    1994-01-01

    An airborne differential absorption lidar (DIAL) system has been developed at the NASA Langley Research Center for remote measurements of atmospheric water vapor (H2O) and aerosols. A solid-state alexandrite laser with a 1-pm linewidth and greater than 99.85% spectral purity was used as the on-line transmitter. Solid-state avalanche photodiode detector technology has replaced photomultiplier tubes in the receiver system, providing an average increase by a factor of 1.5-2.5 in the signal-to-noise ratio of the H2O measurement. By incorporating advanced diagnostic and data-acquisition instrumentation into other subsystems, we achieved additional improvements in system operational reliability and measurement accuracy. Laboratory spectroscopic measurements of H2O absorption-line parameters were performed to reduce the uncertainties in our knowledge of the absorption cross sections. Line-center H2O absorption cross sections were determined, with errors of 3-6%, for more than 120 lines in the 720-nm region. Flight tests of the system were conducted during 1989-1991 on the NASA Wallops Flight Facility Electra aircraft, and extensive intercomparison measurements were performed with dew-point hygrometers and H2O radiosondes. The H2O distributions measured with the DIAL system differed by less than 10% from the profiles determined with the in situ probes in a variety of atmospheric conditions.

  17. Airborne differential absorption lidar system for measurements of atmospheric water vapor and aerosols.

    PubMed

    Higdon, N S; Browell, E V; Ponsardin, P; Grossmann, B E; Butler, C F; Chyba, T H; Mayo, M N; Allen, R J; Heuser, A W; Grant, W B; Ismail, S; Mayor, S D; Carter, A F

    1994-09-20

    An airborne differential absorption lidar (DIAL) system has been developed at the NASA Langley Research Center for remote measurements of atmospheric water vapor (H(2)O) and aerosols. A solid-state alexandrite laser with a 1-pm linewidth and > 99.85% spectral purity was used as the on-line transmitter. Solid-state avalanche photodiode detector technology has replaced photomultiplier tubes in the receiver system, providing an average increase by a factor of 1.5-2.5 in the signal-to-noise ratio of the H(2)O measurement. By incorporating advanced diagnostic and data-acquisition instrumentation into other subsystems, we achieved additional improvements in system operational reliability and measurement accuracy. Laboratory spectroscopic measurements of H(2)O absorption-line parameters were perfo med to reduce the uncertainties in our knowledge of the absorption cross sections. Line-center H(2)O absorption cross sections were determined, with errors of 3-6%, for more than 120 lines in the 720-nm region. Flight tests of the system were conducted during 1989-1991 on the NASA Wallops Flight Facility Electra aircraft, and extensive intercomparison measurements were performed with dew-point hygrometers and H(2)O radiosondes. The H(2)O distributions measured with the DIAL system differed by ? 10% from the profiles determined with the in situ probes in a variety of atmospheric conditions. PMID:20941181

  18. Measurements of near-IR water vapor absorption at high pressure and temperature

    NASA Astrophysics Data System (ADS)

    Rieker, G. B.; Liu, X.; Li, H.; Jeffries, J. B.; Hanson, R. K.

    2007-03-01

    Tunable diode lasers (TDLs) are used to measure high resolution (0.1 cm-1), near-infrared (NIR) water vapor absorption spectra at 700 K and pressures up to 30 atm within a high-pressure and -temperature optical cell in a high-uniformity tube furnace. Both direct absorption and wavelength modulation with second harmonic detection (WMS-2f) spectra are obtained for 6 cm-1 regions near 7204 cm-1 and 7435 cm-1. Direct absorption measurements at 700 K and 10 atm are compared with simulations using spectral parameters from HITRAN and a hybrid database combining HITRAN with measured spectral constants for transitions in the two target spectral regions. The hybrid database reduces RMS error between the simulation and the measurements by 45% for the 7204 cm-1 region and 28% for the 7435 cm-1 region. At pressures above 10 atm, the breakdown of the impact approximation inherent to the Lorentzian line shape model becomes apparent in the direct absorption spectra, and measured results are in agreement with model results and trends at elevated temperatures reported in the literature. The wavelength-modulation spectra are shown to be less affected by the breakdown of the impact approximation and measurements agree well with the hybrid database predictions to higher pressures (30 atm).

  19. ICG 2000 Amsterdam Glass in the new Millennium Absorption Spectra of Iron and Water in Silicate Glasses

    E-print Network

    Glebov, Leon

    ]. This glass composition is similar to the standard float glass used in the glass industry, mol.%: 13Na2O-10Ca as sodium nitrate or oxygen was bubbled through the liquid glass in the furnace. Absorption spectra wereICG 2000 Amsterdam ­ Glass in the new Millennium Absorption Spectra of Iron and Water in Silicate

  20. Integrated modelling to assess long-term water supply capacity of a meso-scale Mediterranean catchment.

    PubMed

    Collet, Lila; Ruelland, Denis; Borrell-Estupina, Valérie; Dezetter, Alain; Servat, Eric

    2013-09-01

    Assessing water supply capacity is crucial to meet stakeholders' needs, notably in the Mediterranean region. This region has been identified as a climate change hot spot, and as a region where water demand is continuously increasing due to population growth and the expansion of irrigated areas. The Hérault River catchment (2500 km(2), France) is a typical example and a negative trend in discharge has been observed since the 1960s. In this context, local stakeholders need first to understand the processes controlling the evolution of water resources and demands in the past to latter evaluate future water supply capacity and anticipate the tensions users could be confronted to in the future. A modelling framework is proposed at a 10-day time step to assess whether water resources have been able to meet water demands over the last 50 years. Water supply was evaluated using hydrological modelling and a dam management model. Water demand dynamics were estimated for the domestic and agricultural sectors. A water supply capacity index is computed to assess the extent and the frequency to which water demand has been satisfied at the sub-basin scale. Simulated runoff dynamics were in good agreement with observations over the calibration and validation periods. Domestic water demand has increased considerably since the 1980s and is characterized by a seasonal peak in summer. Agricultural demand has increased in the downstream sub-basins and decreased upstream where irrigated areas have decreased. As a result, although most water demands were satisfied between 1961 and 1980, irrigation requirements in summer have sometimes not been satisfied since the 1980s. This work is the first step toward evaluating possible future changes in water allocation capacity in the catchment, using future climate change, dam management and water use scenarios. PMID:23756213

  1. Development of a Fluorescent Multiwell Assay for Evaluating the Capacity of the Ciliated Protozoan Tetrahymena for Bacterivory in Water Samples

    Microsoft Academic Search

    Mary E. Power; Dana Sotornik; Marcel D. O. Pinheiro; Vivian R. Dayeh; Barbara J. Butler; Robin Slawson; Lucy E. J. Lee; Denis H. Lynn; Niels C. Bols

    Bacterivory by ciliates in various water ecosystems, both natural and artificial, plays a significant role on the microbial popu- lation composition and consequently affects water quality. A convenient, rapid and inexpensive methodology to evaluate the capacity of the ciliate protozoan Tetrahymena thermophila for bacterivory was developed utilizing fluorescent protein expressing bacteria (FPEB) in a microtitre plate fluorimeter. Bacterivory was correlated

  2. Temperature sensitivity of differential absorption lidar measurements of water vapor in the 720-nm region

    NASA Technical Reports Server (NTRS)

    Browell, Edward V.; Ismail, Syed; Grossmann, Benoist E.

    1991-01-01

    Recently measured properties of water vapor (H2O) absorption lines have been used in calculations to evalute the temperature sensitivity of differential absorption lidar (Dial) H2O measurements. This paper estimates the temperature sensitivity of H2O lines in the 717-733-nm region for both H2O mixing ratio and number density measurements, and discusses the influence of the H2O line ground state energies E-double-prime, the H2O absorption linewidths, the linewidth temperature dependence parameter, and the atmospheric temperature and pressure variations with altitude and location on the temperature sensitivity calculations. Line parameters and temperature sensitivity calculations for 67 H2O lines in the 720-nm band are given which can be directly used in field experiments. Water vapor lines with E-double-prime values in the 100-300/cm range were found to be optimum for Dial measurements of H2O number densities, while E-double-prime values in the 250-500/cm range were found to be optimum for H2O mixing ratio measurements.

  3. WATER ABSORPTION FROM GAS VERY NEAR THE MASSIVE PROTOSTAR AFGL 2136 IRS 1

    SciTech Connect

    Indriolo, Nick; Neufeld, D. A. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Seifahrt, A. [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States); Richter, M. J. [Department of Physics, University of California Davis, Davis, CA 95616 (United States)

    2013-10-10

    We present ground-based observations of the ?{sub 1} and ?{sub 3} fundamental bands of H{sub 2}O toward the massive protostar AFGL 2136 IRS 1, identifying absorption features due to 47 different ro-vibrational transitions between 2.468 ?m and 2.561 ?m. Analysis of these features indicates the absorption arises in warm (T = 506 ± 25 K), very dense (n(H{sub 2}) > 5 × 10{sup 9} cm{sup –3}) gas, suggesting an origin close to the central protostar. The total column density of warm water is estimated to be N(H{sub 2}O) = (1.02 ± 0.02) × 10{sup 19} cm{sup –2}, giving a relative abundance of N(H{sub 2}O)/N(H{sub 2}) ? 10{sup –4}. Our study represents the first extensive use of water vapor absorption lines in the near infrared, and demonstrates the utility of such observations in deriving physical parameters.

  4. Atmospheric water vapor differential absorption measurements on vertical paths with a CO2 lidar.

    PubMed

    Baker, P W

    1983-08-01

    Ground based vertical path differential absorption measurements were obtained up to a height of 1.5 km with a CO2 lidar transmitting alternatively on the R(20) (10.247-microm) and R(18) (10.260-microm) lines during daylight in conditions of both strong and weak temperature inversions. The differential absorption between these lines for typical middle latitude lower atmosphere water vapor concentrations appears to be well suited to this type of measurement as the power loss on the more absorbed backscattered line [R(20)] is not too great as to unduly restrict the operating range, while the power differential is still sufficiently large to be readily measureable. In one set of measurements a strong temperature inversion at a height of 1 km resulted in a rapid vertical lapse in aerosol concentration with a consequent loss of SNR on the returns and severe distortion to the differential absorption profiles at this level. Water vapor profiles were derived from all measurements except in the region of the strong temperature inversion where the atmospheric backscattering cross section decayed rapidly. Reasonable results were obtained through the weak inversion region. The measurement capability of the lidar was found to be restricted by the length of the laser pulse tail and an inadequate signal-to-noise performance in regions of strong temperature inversions due to the associated decreases in aerosol concentration. PMID:18196122

  5. Surface Arsenic Speciation of a Drinking-Water Treatment Residual Using X-Ray Absorption Spectroscopy

    SciTech Connect

    Makris, K.C.; Sarkar, D.; Parsons, J.G.; Datta, R.; Gardea-Torresdey, J.L.

    2009-06-03

    Drinking-water treatment residuals (WTRs) present a low-cost geosorbent for As-contaminated waters and soils. Previous work has demonstrated the high affinity of WTRs for As, but data pertaining to the stability of sorbed As is missing. Sorption/desorption and X-ray absorption spectroscopy (XAS), both XANES (X-ray absorption near edge structure) and EXAFS (extended X-ray absorption fine structure) studies, were combined to determine the stability of As sorbed by an Fe-based WTR. Arsenic(V) and As(III) sorption kinetics were biphasic in nature, sorbing <90% of the initial added As (15,000 mg kg{sup -1}) after 48 h of reaction. Subsequent desorption experiments with a high P load (7500 mg kg{sup -1}) showed negligible As desorption for both As species, approximately <3.5% of sorbed As; the small amount of desorbed As was attributed to the abundance of sorption sites. XANES data showed that sorption kinetics for either As(III) or As(V) initially added to solution had no effect on the sorbed As oxidation state. EXAFS spectroscopy suggested that As added either as As(III) or as As(V) formed inner-sphere mononuclear, bidentate complexes, suggesting the stability of the sorbed As, which was further corroborated by the minimum As desorption from the Fe-WTR.

  6. Water Absorption from Gas Very near the Massive Protostar AFGL 2136 IRS 1

    NASA Astrophysics Data System (ADS)

    Indriolo, Nick; Neufeld, D. A.; Seifahrt, A.; Richter, M. J.

    2013-10-01

    We present ground-based observations of the ?1 and ?3 fundamental bands of H2O toward the massive protostar AFGL 2136 IRS 1, identifying absorption features due to 47 different ro-vibrational transitions between 2.468 ?m and 2.561 ?m. Analysis of these features indicates the absorption arises in warm (T = 506 ± 25 K), very dense (n(H2) > 5 × 109 cm-3) gas, suggesting an origin close to the central protostar. The total column density of warm water is estimated to be N(H2O) = (1.02 ± 0.02) × 1019 cm-2, giving a relative abundance of N(H2O)/N(H2) ? 10-4. Our study represents the first extensive use of water vapor absorption lines in the near infrared, and demonstrates the utility of such observations in deriving physical parameters. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile as part of program 089.C-0321

  7. Prediction of Mass Absorption of Ammonia Vapor into Ammonia Water Solution

    NASA Astrophysics Data System (ADS)

    Monde, Masanori; Mustafa, Hatem

    Mass absorption rate of ammonia vapor into ammonia water solution is investigated experimentally, by feeding a superheated ammonia vapor into a test cell to be absorbed into stagnant pool of ammonia water solution with an initial mass concentration of Ci = 0.0 to 0.63 kg/kg. The flowing of the ammonia vapor is due to a pressure difference of ?P = 50 to 300 kPa between the ammonia vapor cylinder and the pressure of the test cell. The main objectives are, to investigate the effect of initial pressure difference on the absorption rate of ammonia vapor and to develop an equation which predicts the total absorbed mass of ammonia with initial pressure difference, initial concentration and time. The experiment shows that the total absorbed mass of ammonia linearly increases with increasing initial pressure difference. A correlation can be proposed to yield the total absorbed mass of ammonia measured in the experiment. In addition, the absorbed mass at no pressure difference, namely free absorption, could be estimated from the absorbed mass at initial pressure difference.

  8. Absorption spectrum of deuterated water vapor enriched by 18O between 6000 and 9200 cm-1

    NASA Astrophysics Data System (ADS)

    Mikhailenko, S. N.; Naumenko, O. V.; Nikitin, A. V.; Vasilenko, I. A.; Liu, A.-W.; Song, K.-F.; Ni, H.-Y.; Hu, S.-M.

    2012-06-01

    The absorption spectrum of water vapor enriched by deuterium and oxygen-18 is analyzed in the 6000-9200 cm-1 region. The spectrum has been recorded at room temperature with a Bruker IFS 120 h Fourier transform spectrometer. More than 14,000 absorption lines were measured in the recorded spectrum. The vibration-rotation assignments were performed on the basis of previously published experimental energies and of variational calculations. Nine water species (H216O, HD16O, D216O, H218O, HD18O, D218O, H217O, HD17O and D217O) were found to contribute to the observed absorption. More than 3600 lines of 19 vibrational bands of D218O and about 4700 lines of 16 bands of HD18O with J as high as 19 and Ka as high as 11 were assigned. The main part of the HD18O and D218O lines and all lines of HD17O and D217O were observed in the laboratory for the first time. The obtained vibration-rotation energy levels are compared with previous experimental studies and the results of variational calculations.

  9. Multiplexed Selective Detection and Identification of TCE and Xylene in Water by On-Chip Absorption Spectroscopy

    E-print Network

    Chen, Ray

    Multiplexed Selective Detection and Identification of TCE and Xylene in Water by On-Chip Absorption spectroscopy. The signature of Trichloroethylene(TCE) and xylene in water enable multiplexed detection on one Volatile Organic Compounds (VOCs) in liquid and gaseous phases to detect xylene in water and methane

  10. Phase Transfer-Catalyzed Fast CO2 Absorption by MgO-Based Absorbents with High Cycling Capacity

    SciTech Connect

    Zhang, Keling; Li, Xiaohong S.; Li, Weizhen; Rohatgi, Aashish; Duan, Yuhua; Singh, Prabhakar; Li, Liyu; King, David L.

    2014-06-01

    CO2 capture from pre-combustion syngas in the temperature range of 250-400°C is highly desirable from an energy efficiency perspective. Thermodynamically, MgO is a promising material for CO2 capture, but the gas-solid reaction to produce MgCO3 is kinetically slow due to high lattice energy. We report here fast CO2 absorption over a solid MgO-molten nitrate/nitrite aggregate through phase transfer catalysis, in which the molten phase serves as both a catalyst and reaction medium. Reaction with CO2 at the gas-solid-liquid triple phase boundary results in formation of MgCO3 with significant reaction rate and a high conversion of MgO. This methodology is also applicable to other alkaline earth oxides, inspiring the design of absorbents which require activation of the bulk material.

  11. Chemical Characterization and Water Holding Capacity of Fibre-rich Feedstuffs Used for Pigs in Vietnam

    PubMed Central

    Ngoc, T. T. B.; Len, N. T.; Lindberg, J. E.

    2012-01-01

    During two years, four samples per year were collected in Vietnam from rice bran, cassava residue, brewer’s grain, tofu residue, soybean meal, coconut cake, sweet potato vines and water spinach for chemical analysis and assessment of water holding capacity (WHC). The selected feedstuffs represent fibre-rich plant sources and agro-industry co-products commonly used in pig feeding in Vietnam. The content (g/kg DM) of crude protein (CP), ether extract (EE) and non-starch polysaccharides (NSP) varied between feedstuffs and ranged from 21 to 506 for CP, from 14 to 118 for EE and from 197 to 572 for NSP. Cassava residue had a high starch content of 563 g/kg DM, while sweet potato vines, water spinach, coconut cake and soybean meal had a high content of sugars (63–71 g/kg DM). The content of individual neutral sugars varied between feed ingredients, with the highest content of arabinose, galactose and glucose in tofu residue, the highest content of xylose in brewer’s grain and the highest content of mannose in coconut cake. The content of uronic acid was high for cassava residue, tofu residue, sweet potato vines and water spinach (57–88 g/kg DM). The content of soluble non-cellulosic polysaccharides (S-NCP) was positively correlated (r2 = 0.82) to the WHC. The content (g/kg DM) of CP, NDF, neutral sugars, total NSP, total NCP, S-NCP and total dietary fibre in tofu residue, water spinach and coconut cake varied (p<0.05) between years. In conclusion, diet formulation to pigs can be improved if the variation in chemical composition of the fibre fraction and in WHC between potential feed ingredients is taken into account. PMID:25049638

  12. Chemical Characterization and Water Holding Capacity of Fibre-rich Feedstuffs Used for Pigs in Vietnam.

    PubMed

    Ngoc, T T B; Len, N T; Lindberg, J E

    2012-06-01

    During two years, four samples per year were collected in Vietnam from rice bran, cassava residue, brewer's grain, tofu residue, soybean meal, coconut cake, sweet potato vines and water spinach for chemical analysis and assessment of water holding capacity (WHC). The selected feedstuffs represent fibre-rich plant sources and agro-industry co-products commonly used in pig feeding in Vietnam. The content (g/kg DM) of crude protein (CP), ether extract (EE) and non-starch polysaccharides (NSP) varied between feedstuffs and ranged from 21 to 506 for CP, from 14 to 118 for EE and from 197 to 572 for NSP. Cassava residue had a high starch content of 563 g/kg DM, while sweet potato vines, water spinach, coconut cake and soybean meal had a high content of sugars (63-71 g/kg DM). The content of individual neutral sugars varied between feed ingredients, with the highest content of arabinose, galactose and glucose in tofu residue, the highest content of xylose in brewer's grain and the highest content of mannose in coconut cake. The content of uronic acid was high for cassava residue, tofu residue, sweet potato vines and water spinach (57-88 g/kg DM). The content of soluble non-cellulosic polysaccharides (S-NCP) was positively correlated (r(2) = 0.82) to the WHC. The content (g/kg DM) of CP, NDF, neutral sugars, total NSP, total NCP, S-NCP and total dietary fibre in tofu residue, water spinach and coconut cake varied (p<0.05) between years. In conclusion, diet formulation to pigs can be improved if the variation in chemical composition of the fibre fraction and in WHC between potential feed ingredients is taken into account. PMID:25049638

  13. Depth of cinder deposits and water-storage capacity at Cinder Lake, Coconino County, Arizona

    USGS Publications Warehouse

    Macy, Jamie P.; Amoroso, Lee; Kennedy, Jeff; Unema, Joel

    2012-01-01

    The 2010 Schultz fire northeast of Flagstaff, Arizona, burned more than 15,000 acres on the east side of San Francisco Mountain from June 20 to July 3. As a result, several drainages in the burn area are now more susceptible to increased frequency and volume of runoff, and downstream areas are more susceptible to flooding. Resultant flooding in areas downgradient of the burn has resulted in extensive damage to private lands and residences, municipal water lines, and roads. Coconino County, which encompasses Flagstaff, has responded by deepening and expanding a system of roadside ditches to move flood water away from communities and into an area of open U.S. Forest Service lands, known as Cinder Lake, where rapid infiltration can occur. Water that has been recently channeled into the Cinder Lake area has infiltrated into the volcanic cinders and could eventually migrate to the deep regional groundwater-flow system that underlies the area. How much water can potentially be diverted into Cinder Lake is unknown, and Coconino County is interested in determining how much storage is available. The U.S. Geological Survey conducted geophysical surveys and drilled four boreholes to determine the depth of the cinder beds and their potential for water storage capacity. Results from the geophysical surveys and boreholes indicate that interbedded cinders and alluvial deposits are underlain by basalt at about 30 feet below land surface. An average total porosity for the upper 30 feet of deposits was calculated at 43 percent for an area of 300 acres surrounding the boreholes, which yields a total potential subsurface storage for Cinder Lake of about 4,000 acre-feet. Ongoing monitoring of storage change in the Cinder Lake area was initiated using a network of gravity stations.

  14. Analyte induced water adsorbability in gas phase biosensors: the influence of ethinylestradiol on the water binding protein capacity.

    PubMed

    Snopok, Borys; Kruglenko, Ivanna

    2015-05-01

    An ultra-sensitive gas phase biosensor/tracer/bio-sniffer is an emerging technology platform designed to provide real-time information on air-borne analytes, or those in liquids, through classical headspace analysis. The desired bio-sniffer measures gaseous 17?- ethinylestradiol (ETED) as frequency changes on a quartz crystal microbalance (QCM), which is a result of the interactions of liquid sample components in the headspace (ETED and water) with a biorecognition layer. The latter was constructed by immobilization of polyclonal antiserum against a phenolic A-ring of estrogenic receptors through protein A. The QCM response exhibited stretched exponential kinetics of negative frequency shifts with reversible and "irreversible" components of mass uptake onto the sensor surface in static headspace conditions when exposed to water solutions of ETED over the sensor working range, from 10(-10) to 10(-17) g L(-1). It was shown that the variations in the QCM response characteristics are due to the change of the water-binding capacity of the sensing layer induced by protein transformations initiated by the binding of ETED molecules. This result is well correlated with the natural physiological function of estrogens in controlling the homeostasis of body fluids in living beings. PMID:25763411

  15. Performance of Generator of Absorption Refrigerating Machine Powered by Hot Water

    NASA Astrophysics Data System (ADS)

    Kunugi, Yoshifumi; Usui, Sanpei; Ouchi, Tomihisa; Fukuda, Tamio

    For 70 kW generator of absorption refrigerating machine powered by the hot water, lifted liquid rate of the bubble lift pump has a maximum value at some vapor flow rate of refrigerant and hot water inlet temperature. This is in agreement with results of small size bubble lift pump. Maximum lifted liquid rate G0 is correlated by the equation G0 = 5, 000?1.5, where ? is the degree of submergence. In this case, diameter of pump tube was 41.6mm, and length of it were 1,300 and 1,500mm. The range of hot water inlet temperature was 78 - 100°C. Multitube heat flux of first generator is about two times that of second generator at the same superheat.

  16. Combined effects of pre-cooling and water ingestion on thermoregulation and physical capacity during exercise in a hot environment

    Microsoft Academic Search

    Hiroshi Hasegawa; Tadashi Takatori; Takashi Komura; Masahiro Yamasaki

    2006-01-01

    The aim of the present study was to determine the combined effects of pre-cooling and water ingestion on thermoregulatory responses and exercise capacity at 32°C and 80% relative humidity. Nine untrained males exercised for 60 min on a cycle ergometer at 60% maximal oxygen uptake ([Vdot]O2max) (first exercise bout) under four separate conditions: No Water intake, Pre-cooling, Water ingestion, and a

  17. Impact of cooking formulation on flavor and hydrophilic oxygen radical absorption capacity values of whole grain pigmented rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whole grain rice is rich in healthful phenolic compounds that can impart flavors. Rice is prepared with water, salt, and/or oil. There is little opportunity to influence the flavor of plain rice during preparation. This research examines how cooking whole grain rice with salt, oil, or salt with o...

  18. High-resolution atmospheric water vapor measurements with a scanning differential absorption lidar

    NASA Astrophysics Data System (ADS)

    Späth, F.; Behrendt, A.; Muppa, S. K.; Metzendorf, S.; Riede, A.; Wulfmeyer, V.

    2014-11-01

    The scanning differential absorption lidar (DIAL) of the University of Hohenheim (UHOH) is presented. The UHOH DIAL is equipped with an injection-seeded frequency-stabilized high-power Ti:sapphire laser operated at 818 nm with a repetition rate of 250 Hz. A scanning transceiver unit with a 80 cm primary mirror receives the atmospheric backscatter signals. The system is capable of water vapor measurements with temporal resolutions of a few seconds and a range resolution between 30 and 300 m at daytime. It allows to investigate surface-vegetation-atmosphere exchange processes with high resolution. In this paper, we present the design of the instrument and illustrate its performance with recent water vapor measurements taken in Stuttgart-Hohenheim and in the frame of the HD(CP)2 Observational Prototype Experiment (HOPE). HOPE was located near research center Jülich, in western Germany, in spring 2013 as part of the project "High Definition of Clouds and Precipitation for advancing Climate Prediction" (HD(CP)2). Scanning measurements reveal the 3-dimensional structures of the water vapor field. The influence of uncertainties within the calculation of the absorption cross-section at wavelengths around 818 nm for the WV retrieval is discussed. Radiosonde intercomparisons show a very small bias between the instruments of only (-0.04 ± 0.11) g m-3 or (-1.0 ± 2.3) % in the height range of 0.5 to 3 km.

  19. Absorption of crystalline water ice in the far infrared at different temperatures

    NASA Astrophysics Data System (ADS)

    Reinert, C.; Mutschke, H.; Krivov, A. V.; Löhne, T.; Mohr, P.

    2015-01-01

    The optical properties of ice in the far infrared are important for models of protoplanetary and debris disks. In this report, we derive a new set of data for the absorption (represented by the imaginary part of the refractive index ?) of crystalline water ice in this spectral range. The study includes a detailed inspection of the temperature dependence, which has not been conducted in such detail before. We measured the transmission of three ice layers with different thicknesses at temperatures ? = 10...250 K and present data at wavelengths ? = 80...625 ?m. We found a change in the spectral dependence of ? at a wavelength of 175 ± 6 ?m. At shorter wavelengths, ? exhibits a constant flat slope and no significant temperature dependence. Long-ward of that wavelength, the slope gets steeper and has a clear, approximately linear temperature dependence. This change in behaviour is probably caused by a characteristic absorption band of water ice. The measured data were fitted by a power-law model that analytically describes the absorption behaviour at an arbitrary temperature. This model can readily be applied to any object of interest, for instance a protoplanetary or debris disk. To illustrate how the model works, we simulated the spectral energy distribution (SED) of the resolved, large debris disk around the nearby solar-type star HD 207129. Replacing our ice model by another, commonly used data set for water ice results in a different SED slope at longer wavelengths. This leads to changes in the characteristic model parameters of the disk, such as the inferred particle size distribution, and affects the interpretation of the underlying collisional physics of the disk.

  20. Simulation model of a single-stage lithium bromide-water absorption cooling unit

    NASA Technical Reports Server (NTRS)

    Miao, D.

    1978-01-01

    A computer model of a LiBr-H2O single-stage absorption machine was developed. The model, utilizing a given set of design data such as water-flow rates and inlet or outlet temperatures of these flow rates but without knowing the interior characteristics of the machine (heat transfer rates and surface areas), can be used to predict or simulate off-design performance. Results from 130 off-design cases for a given commercial machine agree with the published data within 2 percent.

  1. Evidence for direct water absorption by shallow-rooted desert plants in desert-oasis ecotone, Northwest China

    NASA Astrophysics Data System (ADS)

    Fang, Jing

    2014-05-01

    Besides the absorption by roots from the soil substrate, it has long been known that plants exhibit alternative water-absorption strategies, particularly in drought-prone environments. For many tropical epiphytic orchids, air moisture can be absorbed directly by aerial roots. Some conifers are also found to utilize air moisture by foliar absorption during the summer fog season. However, few studies have been carried out on the atmospheric water vapor absorption by shallow-rooted desert plants. We conducted experiments in desert-oasis ecotone and investigated the effects of dew absorbed by three kinds of shallow-rooted seedlings on net photosynthesis rate, as well as on other water relations variables. Three kinds of typical shallow-rooted desert species (Bassia dasyphylla, Salsola collina and Corispermum declinatum) have been chosen and potted. Each species were subjected to contrasting watering regimes (normal and deficient) and different air moisture conditions (having dew and having no dew) for 10 weeks. Net photosynthesis rate was measured on six occasions during the study. Other water relations variables (midday shoot water potential, relative water content, stomatal conductance) were also measured. Under the dew conditions, average net photosynthesis rate, shoot water potential, leaf relative water content and stomatal conductance increased, with greater responses observed for plants subjected to a deficient watering regime than for well-watered plants. These results indicated dew occurred in arid region could be utilized through foliar absorption by some shallow-rooted plants, and for the shallow-rooted plants, the presence of dew could significantly relieve the deficit of water in water-stressed regime.

  2. Absorption and backscattering coefficients and their relations to water constituents of Poyang Lake, China.

    PubMed

    Wu, Guofeng; Cui, Lijuan; Duan, Hongtao; Fei, Teng; Liu, Yaolin

    2011-12-01

    The measurement and analysis of inherent optical properties (IOPs) of the main water constituents are necessary for remote-sensing-based water quality estimation and other ecological studies of lakes. This study aimed to measure and analyze the absorption and backscattering coefficients of the main water constituents and, further, to analyze their relations to the water constituent concentrations in Poyang Lake, China. The concentrations and the absorption and backscattering coefficients of the main water constituents at 47 sampling sites were measured and analyzed as follows. (1) The concentrations of chlorophyll a (C(CHL)), dissolved organic carbon (C(DOC)), suspended particulate matter (C(SPM)), including suspended particulate inorganic matter (C(SPIM)) and suspended particulate organic matter (C(SPOM)), and the absorption coefficients of total particulate (a(p)), phytoplankton (a(ph)), nonpigment particulate (a(d)), and colored/chromophoric dissolved organic matter (a(g)) were measured in the laboratory. (2) The total backscattering coefficients, including the contribution of pure water at six wavelengths of 420, 442, 470, 510, 590, and 700 nm, were measured in the field with a HydroScat-6 backscattering sensor. (3) The backscattering coefficients without the contribution of pure water (b(b)) were then derived by subtracting the backscattering coefficients of pure water from the total backscattering coefficients. (4) The C(CHL), C(SPM), C(SPIM), C(SPOM), and C(DOC) of the 41 remaining water samples were statistically described and their correlations were analyzed. (5) The a(ph), a(d), a(p), a(g), and b(b) were visualized and analyzed, and their relations to C(CHL), C(SPM), C(SPIM), C(SPOM), or C(DOC) were studied. Results showed the following. (1) Poyang Lake was a suspended particulate inorganic matter dominant lake with low phytoplankton concentration. (2) One salient a(ph) absorption peak was found at 678 nm, and it explained 72% of the variation of C(CHL). (3) The a(d) and a(p) exponentially decreased with increasing wavelength, and they explained 74% of the variation of C(SPIM) and 71% variation of C(SPM), respectively, at a wavelength of 440 nm. (4) The a(g) also exponentially decreased with increasing wavelength, and it had no significant correlation to C(DOC) at a significance level of 0.05. (5) The b(b) decreased with increasing wavelength, and it had strong and positive correlations to C(SPM), C(SPIM) and C(SPOM), a strong and negative correlation to C(CHL), and no correlation to C(DOC) at a significance level of 0.05. Such results will be helpful for the understanding of the IOPs of Poyang Lake. They, however, only represented the IOPs during the sampling time period, and more measurements and analyses in different seasons need to be carried out in the future to ensure a comprehensive understanding of the IOPs of Poyang Lake. PMID:22192987

  3. A Preliminary Geomorphological Analysis of Water storage capacity: The Providence Watershed, California

    NASA Astrophysics Data System (ADS)

    Chamorro, A.; Giardino, J. R.; Vitek, J. D.

    2013-12-01

    The Critical Zone of Earth, as defined by NSF in 2007, is series of systems that extend from the top of the canopy to the bottom of the aquifer. The soil system has been used as the primary connection between the various systems. Knowledge of water storage capacity is essential for predicting water availability in the critical zone. Soil depth is one of the most important parameters used to study water storage capacity. Unfortunately, it is challenging to obtain an accurate representation of the degree of spatial variability of soil depth in a watershed. To obtain this data requires extensive and expensive surveys, which can be compounded in forested regions. We make the assumption that soil depth is a function of surface and subsurface geomorphological processes. The Providence Watershed, which is a Critical Zone Center (CZO) is located in the Southern Sierra Nevada of California. The Providence Watershed is ~ 2.8 km2. The general trend of the watershed is northeast and ranges in elevation from 1,700 m to 2,100 m. The dominant vegetation cover is coniferous. In this area, we compiled indices from LIDAR imagery and compared these to hand-auguring profiles collected along Ground Penetrating Radar (GPR) transects. Auguring profiles exist at a spacing of 123 m. The depths of these profiles varied from 0.5 to 7.0 m. We correlated the auguring data with nine indices. None of the correlations, which ranged from -0.50 to 0.21 (Pearson product-moment), were strong. The most significant finding of this study strengthens the important role that GPR can provide to capture the spatial heterogeneity present. GPR lines complimentary to geomorphological mapping can be used as an approach to obtain more accurate results in soil depth and bedrock topography mapping. The appropriate scale of work, however, depends on the understanding of the scale of processes controlling soil formation and erosion. This work is part of the collaborative effort of the Southern Sierra Critical Zone Observatory.

  4. Using the solvent retention capacity test when breeding wheat for diverse production environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The solvent retention capacity (SRC) test is used to predict commercial baking performance of soft wheat (Triticum aestivum L.) by measuring the capacity of flour to retain each of four sol- vents—water, Na 2CO3, sucrose, and lactic acid— to assess overall absorption capacity, starch damage, pentosa...

  5. Absorption spectra of liquid water and aqueous buffers between 0.3 and Department of Physics, University of California, Santa Barbara, California 93106

    E-print Network

    Xu, Jing

    Absorption spectra of liquid water and aqueous buffers between 0.3 and 3.72 THz Jing Xua Department-dependent terahertz absorption with attenuation lengths on the order of tens of micrometers. To access this spectral.5 THz, these studies provide a well- documented absorption spectrum for liquid water, at approxi- mately

  6. Differential Absorption Measurements of Atmospheric Water Vapor with a Coherent Lidar at 2050.532 nm

    NASA Technical Reports Server (NTRS)

    Koch, Grady J.; Dharamsi, Amin; Davis, Richard E.; Petros, Mulugeta; McCarthy, John C.

    1999-01-01

    Wind and water vapor are two major factors driving the Earth's atmospheric circulation, and direct measurement of these factors is needed for better understanding of basic atmospheric science, weather forecasting, and climate studies. Coherent lidar has proved to be a valuable tool for Doppler profiling of wind fields, and differential absorption lidar (DIAL) has shown its effectiveness in profiling water vapor. These two lidar techniques are generally considered distinctly different, but this paper explores an experimental combination of the Doppler and DIAL techniques for measuring both wind and water vapor with an eye-safe wavelength based on a solid-state laser material. Researchers have analyzed and demonstrated coherent DIAL water vapor measurements at 10 micrometers wavelength based on CO2 lasers. The hope of the research presented here is that the 2 gm wavelength in a holmium or thulium-based laser may offer smaller packaging and more rugged operation that the CO2-based approach. Researchers have extensively modeled 2 um coherent lasers for water vapor profiling, but no published demonstration is known. Studies have also been made, and results published on the Doppler portion, of a Nd:YAG-based coherent DIAL operating at 1.12 micrometers. Eye-safety of the 1.12 micrometer wavelength may be a concern, whereas the longer 2 micrometer and 10 micrometer systems allow a high level of eyesafety.

  7. X-ray absorption signatures of the molecular environment in water and ice

    E-print Network

    Wei Chen; Xifan Wu; Roberto Car

    2009-09-21

    The x-ray absorption spectra of water and ice are calculated with a many-body approach for electron-hole excitations. The experimental features, including the small effects of temperature change in the liquid, are quantitatively reproduced from molecular configurations generated by ab-initio molecular dynamics. The spectral difference between the solid and the liquid is due to two major short range order effects. One, due to breaking of hydrogen bonds, enhances the pre-edge intensity in the liquid. The other, due to a non-bonded molecular fraction in the first coordination shell, affects the main spectral edge in the conversion of ice to water. This effect may not involve hydrogen bond breaking as shown by experiment in high-density amorphous ice.

  8. Thermodynamic assessment of the effect of strongly swelling polymer hydrogels on the water retention capacity of model porous media

    NASA Astrophysics Data System (ADS)

    Sadovnikova, N. B.; Smagin, A. V.; Sidorova, M. A.

    2014-04-01

    The effect of different rates and fractions of strongly swelling polymer hydrogel (SSPH) based on radiation-grafted polyacrylamide on the water retention capacity and structural state of model porous media in the form of quartz sand fractions with different degrees of dispersion has been studied. The water retention curve (WRC) of sandy porous media obtained by the capillarimetric method has been used as a basic thermodynamic parameter. An original method has been proposed for the comparative study of the effect of SSPHs on the WRC based on the approximation of data by the nonlinear van Genuchten function followed by differential analysis. Equations are given for the calculation of capillary water capacity and structural curves of pore size distribution. SSPH concentrations in the range 0.05-0.2% of enclosing material weight reliably increase the water retention capacity of sandy fractions and the total, capillary, and field capacities (determined by the Voronin secant method) by 2-3 times; as well as the range of available water and the contents of fine macropores and mesopores. Factors limiting the swelling of SSPHs in model porous media have been revealed.

  9. Modeling of simultaneous heat and mass transfer processes in ammonia water absorption systems from general correlations

    NASA Astrophysics Data System (ADS)

    Sieres, Jaime; Fernández-Seara, José

    2007-11-01

    This paper presents a general differential mathematical model to analyze the simultaneous heat and mass transfer processes that occur in different components of an ammonia water absorption system: absorber, desorber, rectifier, distillation column, condenser and evaporator. Heat and mass transfer equations are considered, taking into account the heat and mass transfer resistances in the liquid and vapour phases. The model considers the different regions: vapour phase, liquid phase and an external heating or cooling medium. A finite difference numerical method has been considered to solve the resulting set of nonlinear differential equations and an iterative algorithm is proposed for its solution. A map of possible solutions of the mass transferred composition z is presented when varying the interface temperature, which enables to establish a robust implementation code. The analysis is focused on the processes presented in ammonia water absorption systems. The model is applied to analyze the ammonia purification process in an adiabatic packed rectification column and the numerical results show good agreement with experimental data.

  10. Light absorption and partitioning in Arctic Ocean surface waters: impact of multi year ice melting

    NASA Astrophysics Data System (ADS)

    Bélanger, S.; Cizmeli, S. A.; Ehn, J.; Matsuoka, A.; Doxaran, D.; Hooker, S.; Babin, M.

    2013-03-01

    Ice melting in the Arctic Ocean exposes the surface water to more radiative energy with poorly understood effects on photo-biogeochemical processes and heat deposition in the upper ocean. In August 2009, we documented the vertical variability of light absorbing components at 37 stations located in the southeastern Beaufort Sea including both Mackenzie river-influenced waters and polar mixed layer waters. We found that melting multi-year ice released significant amount of non-algal particulates (NAP) near the sea surface relative to sub-surface waters. NAP absorption coefficients at 440 nm (aNAP(440)) immediately below the sea surface (0-) were on average 3-fold (up to 10-fold) higher compared to sub-surface values measured at 2-3 m depth. The impact of this unusual feature on the light transmission and remote sensing reflectance (Rrs) was further examined using a radiative transfer model. A 10-fold particle enrichment homogeneously distributed in the first meter of the water column slightly reduced photosynthetically available and usable radiation (PAR and PUR) by ~6% and ~8%, respectively, relative to a fully homogenous water column with low particles concentration. In terms of Rrs, the particle enrichment significantly flattered the spectrum by reducing the Rrs by up to 20% in the blue-green spectral region (400-550 nm). These results highlight the impact of melt water on the concentration of particles at sea surface, and the need for considering nonuniform vertical distribution of particles in such systems when interpreting remotely sensed ocean color. Spectral slope of aNAP spectra calculated in the UV domain decreased with depth suggesting that this parameter is sensitive to detritus composition and/or diagenesis state (e.g., POM photobleaching).

  11. Water Absorption From Line-of-Sight Clouds Toward W49A

    E-print Network

    Rene Plume; Michael J. Kaufman; David A. Neufeld; Ronald L. Snell; David J. Hollenbach; Paul F. Goldsmith; John Howe; Edwin A. Bergin; Gary J. Melnick; Frank Bensch

    2004-01-22

    We have observed 6 clouds along the line-of-sight toward W49A using the Submillimeter Wave Astronomy Satellite (SWAS) and several ground-based observatories. The ortho-H2O 1-0 and OH (1665 and 1667 MHz) transitions are observed in absorption, whereas the low-J CO, 13CO, and C18O lines, as well as the [CI] 1-0 transition, are seen in emission. By using both the o-H218O and o-H2O absorption lines, we are able to constrain the column-averaged o-H_2O abundances in each line-of-sight cloud to within about an order of magnitude. Assuming the standard N(H2)/N(CO) ratio of 10^4, we find N(o-H2O)/N(H2) = 8.1 x 10^-8 - 4 x 10^-7 for three clouds with optically thin water lines. In three additional clouds, the H$_2$O lines are saturated so we have used observations of the H218O ground-state transition to find upper limits to the water abundance of 8.2x 10^-8 - 1.5x10^-6. We measure the OH abundance from the average of the 1665 and 1667 MHz observations and find N(OH)/N(H2) = 2.3x10^-7 - 1.1x10^-6. The o-H2O and OH abundances are similar to those determined for line-of-sight water absorption features towards W51 and Sgr B2 but are higher than those seen from water emission lines in molecular clouds. However, the clouds towards W49 have lower ratios of OH relative to H2O column densities than are predicted by simple models which assume that dissociative recombination is the primary formation pathway for OH and H2O. Building on the work of Neufeld et al. (2002), we present photo-chemistry models including additional chemical effects, which can also explain the observed OH and H2O column densities as well as the observed H2O/CO abundance ratios.

  12. Water Absorption from Line-of-Sight Clouds toward W49A

    NASA Astrophysics Data System (ADS)

    Plume, René; Kaufman, Michael J.; Neufeld, David A.; Snell, Ronald L.; Hollenbach, David J.; Goldsmith, Paul F.; Howe, John; Bergin, Edwin A.; Melnick, Gary J.; Bensch, Frank

    2004-04-01

    We have observed six clouds along the line of sight toward W49A using the Submillimeter Wave Astronomy Satellite and several ground-based observatories. The ortho-H2O 110-->101 and OH (1665 and 1667 MHz) transitions are observed in absorption, whereas the low-J CO, 13CO, and C18O lines, as well as the [C I] 3P1-3P0 transition, are seen in emission. The emission lines allow us to determine the gas density (n~1500-3000 cm-3) and CO column densities [N(CO)~7.9×1015-2.8×1017 cm-2] using a standard large velocity gradient analysis. By using both the o-H218O and o-H2O absorption lines, we are able to constrain the column-averaged o-H2O abundances in each line-of-sight cloud to within about an order of magnitude. Assuming the standard N(H2)/N(CO) ratio of 104, we find N(o-H2O)/N(H2)=8.1×10-8 to 4×10-7 for three clouds with optically thin water lines. In three additional clouds, the H2O lines are saturated, so we have used observations of the H218O ground-state transition to find upper limits to the water abundance of 8.2×10-8 to 1.5×10-6. We measure the OH abundance from the average of the 1665 and 1667 MHz observations and find N(OH)/N(H2)=2.3×10-7 to 1.1×10-6. The o-H2O and OH abundances are similar to those determined for line-of-sight water absorption features toward W51 and Sgr B2 but are higher than those seen from water emission lines in molecular clouds. However, the clouds toward W49 have lower ratios of OH relative to H2O column densities than are predicted by simple models, which assume that dissociative recombination is the primary formation pathway for OH and H2O. Building on the 2002 work of Neufeld and coworkers, we present photochemistry models including additional chemical effects, which can also explain the observed OH and H2O column densities, as well as the observed H2O/CO abundance ratios.

  13. K? absorption by locust gut and inhibition of ileal K? and water transport by FGLamide allatostatins.

    PubMed

    Robertson, Lisa; Donini, Andrew; Lange, Angela B

    2014-09-15

    The scanning ion-selective electrode technique (SIET) was utilized for the first time in Locusta migratoria to characterize K(+) transport along the digestive tract and to determine the effect of two locust FGLamide allatostatins (FGLa/ASTs) on K(+) transport: a previously sequenced FGLa/AST from Schistocerca gregaria (Scg-AST-6; ARPYSFGL-NH2) and a newly sequenced FGLa/AST from L. migratoria (Locmi-FGLa/AST-2; LPVYNFGL-NH2). Regional differences in K(+) fluxes along the gut were evident, where K(+) efflux in vitro (or absorption into the hemolymph in vivo) was greatest at the anterior ileum, and lowest at the colon. Ileal K(+) efflux was inhibited by both Scg-AST-6 and Locmi-FGLa/AST-2, with maximal inhibition at 10(-10) and 10(-11) mol l(-1), respectively. Both FGLa/ASTs also inhibited cAMP-stimulated K(+) efflux from the ileum. Locmi-FGLa/AST-2 also inhibited efflux of water across the ileum. Locusts are terrestrial insects living in dry climates, risking desiccation and making water conservation a necessity. The results suggest that FGLa/ASTs may be acting as diuretics by increasing K(+) excretion and therefore increasing water excretion. Thus it is likely that FGLa/ASTs are involved in the control of hemolymph water and ion levels during feeding and digestion, to help the locust deal with the excess K(+) load (and subsequently fluid) when the meal is processed. PMID:25013112

  14. Study of Water Absorption in Raffia vinifera Fibres from Bandjoun, Cameroon

    PubMed Central

    Sikame Tagne, N. R.; Njeugna, E.; Fogue, M.; Drean, J.-Y.; Nzeukou, A.; Fokwa, D.

    2014-01-01

    The study is focused on the water diffusion phenomenon through the Raffia vinifera fibre from the stem. The knowledge on the behavior of those fibres in presence of liquid during the realization of biocomposite, is necessary. The parameters like percentage of water gain at the point of saturation, modelling of the kinetic of water absorption, and the effective diffusion coefficient were the main objectives. Along a stem of raffia, twelve zones of sampling were defined. From Fick's 2nd law of diffusion, a new model was proposed and evaluated compared to four other models at a constant temperature of 23°C. From the proposed model, the effective diffusion coefficient was deduced. The percentage of water gain was in the range of 303–662%. The proposed model fitted better to the experimental data. The estimated diffusion coefficient was evaluated during the initial phase and at the final phase. In any cross section located along the stem of Raffia vinifera, it was found that the effective diffusion coefficient increases from the periphery to the centre during the initial and final phases. PMID:24592199

  15. The role of water in the performance of biofilters: parameterization of pressure drop and sorption capacities for common packing materials.

    PubMed

    Dorado, Antonio D; Lafuente, Javier; Gabriel, David; Gamisans, Xavier

    2010-08-15

    The presence of water in a biofilter is critical in keeping microorganisms active and abating pollutants. In addition, the amount of water retained in a biofilter may drastically affect the physical properties of packing materials and packed beds. In this study, the influence of water on the pressure drop and sorption capacities of 10 different packing materials were experimentally studied and compared. Pressure drop was characterized as a function of dynamic hold-up, porosity and gas flow rate. Experimental data were fitted to a mathematical expression based on a modified Ergun correlation. Sorption capacities for toluene were determined for both wet and dry materials to obtain information about the nature of interactions between the contaminant, the packing materials and the aqueous phase. The experimental sorption capacities of materials were fitted to different isotherm models for gas adsorption in porous materials. The corresponding confidence interval was determined by the Fisher information matrix. The results quantified the dynamic hold-up effect resulting from the significant increase in the pressure drop throughout the bed, i.e. the financial cost of driving air, and the negative effect of this air on the total amount of hydrophobic pollutant that can be adsorbed by the supports. Furthermore, the results provided equations for ascertaining water presence and sorption capacities that could be widely used in the mathematical modeling of biofilters. PMID:20483534

  16. UBXN1 polymorphism and its expression in porcine M. longissimus dorsi are associated with water holding capacity.

    PubMed

    Loan, Huynh Thi Phuong; Muráni, Eduard; Maak, Steffen; Ponsuksili, Siriluck; Wimmers, Klaus

    2014-03-01

    The UBX domain containing protein 1-like gene (UBXN1) promotes the protein degradation that affects meat quality, in particular traits related to water holding capacity. The aim of our study was to identify UBXN1 polymorphisms and to analyse their association with meat quality traits. Moreover, the relationship of UBXN1 polymorphisms and its transcript abundance as well as the link between UBXN1 expression and water holding capacity were addressed. Pigs of the breed German landrace (GL) and the commercial crossbreed of Pietrain × [German large white × GL] (PiF1) were used for this study. In GL, the novel SNP c.355 C > T showed significant association with conductivity and drip loss (P ? 0.05). Another SNP at nt 674 of the coding sequence [SNP c.674C>T (p.Thr225Ile)] was associated with drip loss (P ? 0.05) and pH1 (P ? 0.1). In PiF1, the SNP UBXN1 c.674C>T was associated with conductivity (P ? 0.01). Moreover, the haplotype combinations showed effects on conductivity within both commercial populations at P ? 0.1. In both populations, high expression of UBXN1 tended to decrease water holding capacity in the early post mortem period. The analysis of triangular relationship of UBXN1 polymorphism, transcript abundance, and water holding capacity evidences the existence of a causal polymorphism in cis-regulatory regions of UBXN1 that influences its expression. PMID:24407602

  17. Correlation of changes in pigment content with photosynthetic capacity of seaweeds as a function of water depth

    Microsoft Academic Search

    J. Ramus; S. I. Beale; D. Mauzerall

    1976-01-01

    We conducted a study of the relationship between changes in photosynthetic pigment content and photosynthetic capacity as a function of water depth in Great Harbor near Woods Hole, Massachusetts, USA, on the green algae Ulva lactuca and Codium fragile and the red algae Porphyra umbilicalis and Chondrus crispus. Seaweeds were attached to vertically buoyed lines at 0.5 and 10 m

  18. Sorption capacity of mesoporous metal oxides for the removal of MCPA from polluted waters.

    PubMed

    Addorisio, Veria; Esposito, Serena; Sannino, Filomena

    2010-04-28

    A study was performed to assess the sorption capacity of the phenoxy acid herbicide, MCPA, on two mesoporous oxides, Al(2)O(3) and Fe(2)O(3,) by using a batch equilibrium method. Effects of pH, contact time, initial concentration and sorbent dosage on the sorption of the herbicide were investigated. The collected data evidenced the greater sorption efficiency of Al(2)O(3) with respect to Fe(2)O(3). These results can be explained by considering the specific mesoporous structure of Al(2)O(3) together with the greater value of surface area. MCPA is assumed to be bound to Al(2)O(3) and Fe(2)O(3) by a combination of ionic and ion-dipole bonding. Both oxides present as sorbents for a fast and highly efficient removal of MCPA from contaminated waters. For the first time the possible use of mesoporous metal oxides to remove MCPA from contaminated wastewaters identifies these sorbents as suitable filters for the decontamination of point sources. PMID:20329794

  19. Estimating Dispersivity, Mass Recovery, and Water Hold Up in Field-Scale Leaching Studies by Use of a Capacity Model

    NASA Astrophysics Data System (ADS)

    Young, D. F.; Carleton, J. N.

    2012-12-01

    The USEPA uses field-scale tests (about 1 ha) to evaluate the leaching potential of pesticides used under realistic agricultural conditions. These tests include a bromide tracer to assess the hydrodynamics of the study site. We analyzed 21 of these bromide leaching studies to determine dispersivity, applied tracer mass recovery, and water retention in the vadose zone. Breakthrough curves were generated for various depths (typically 3 to 4 depths at 1-m intervals) at each of the 21 sites as functions of cumulative infiltration, using measured bromide pore water concentrations. Because the field sites were subjected to natural hydrologic conditions (i.e., evaporation, precipitation, and occasional irrigation), the leaching flow rate at each depth was not directly measurable, so leaching rates were estimated using a capacity model driven by measured daily rainfall, evaporation, and temperature. With the leaching rate thus estimated, the first moment of the bromide breakthrough at each depth was determined. Using the first moment, the effective soil-pore water volume was estimated, which allowed the fitting of a one-dimensional advection-dispersion model and optimization of a dispersion coefficient. Results showed indication of an increase in dispersivity with depth (e.g. dispersivity averaged about 10 cm at the 1-m depth, and around 35 cm at the 4-m depth). Peclet numbers ranged from 4 to 40, but averaged about 10 and varied little with depth. Using this method, apparent recovery of applied bromide varied widely from 8% to 250%, with an average of 60% (standard deviation also 60%) indicating the uncertainty involved in estimating breakthrough curves using field-scale data. Apparent water holdup was consistently greater than the reported field capacity, indicating that measured field capacity may provide low estimates of soil water for use in capacity models. It is important to note that the capacity model concept coupled to the advection dispersion model is the USEPA standard model (e.g., PRZM) used to assess pesticide leaching, and the work here will assist in properly parameterizing dispersivity and water holdup for that model. Plot showing that the capacity model's effective water requirements (y axis) are greater than field capacity (x axis). A 1:1 line also shown.

  20. Light absorption and partitioning in Arctic Ocean surface waters: impact of multiyear ice melting

    NASA Astrophysics Data System (ADS)

    Bélanger, S.; Cizmeli, S. A.; Ehn, J.; Matsuoka, A.; Doxaran, D.; Hooker, S.; Babin, M.

    2013-10-01

    Ice melting in the Arctic Ocean exposes the surface water to more radiative energy with poorly understood effects on photo-biogeochemical processes and heat deposition in the upper ocean. In August 2009, we documented the vertical variability of light absorbing components at 37 stations located in the southeastern Beaufort Sea including both Mackenzie River-influenced waters and polar mixed layer waters. We found that melting multiyear ice released significant amount of non-algal particulates (NAP) near the sea surface relative to subsurface waters. NAP absorption coefficients at 440 nm (aNAP(440)) immediately below the sea surface were on average 3-fold (up to 10-fold) higher compared to subsurface values measured at 2-3 m depth. The impact of this unusual feature on the light transmission and remote sensing reflectance (Rrs) was further examined using a radiative transfer model. A 10-fold particle enrichment homogeneously distributed in the first meter of the water column slightly reduced photosynthetically available and usable radiation (PAR and PUR) by ∼6 and ∼8%, respectively, relative to a fully homogenous water column with low particle concentration. In terms of Rrs, the particle enrichment significantly flattered the spectrum by reducing the Rrs by up to 20% in the blue-green spectral region (400-550 nm). These results highlight the impact of meltwater on the concentration of particles at sea surface, and the need for considering non-uniform vertical distribution of particles in such systems when interpreting remotely sensed ocean color. Spectral slope of aNAP spectra calculated in the UV (ultraviolet) domain decreased with depth suggesting that this parameter is sensitive to detritus composition and/or diagenesis state (e.g., POM (particulate organic matter) photobleaching).

  1. A far wing line shape theory and its application to the water continuum absorption in the infrared region. I

    NASA Technical Reports Server (NTRS)

    Ma, Q.; Tipping, R. H.

    1991-01-01

    The present theory for the continuous absorption that is due to the far-wing contribution of allowed lines is based on the quasistatic approximation for the far wing limit and the binary collision approximation of one absorber molecule and one bath molecule. The validity of the theory is discussed, and numerical results of the water-continuum absorption in the IR region are presented for comparison with experimental data. Good agreement is obtained for both the magnitude and temperature dependence of the absorption coefficients.

  2. Characterization of the aramid\\/epoxy interfacial properties by means of pull-out test and influence of water absorption

    Microsoft Academic Search

    Kazuto Tanaka; Kohji Minoshima; Witold Grela; Kenjiro Komai

    2002-01-01

    Single fiber pull-out tests were carried out to investigate the influence of water absorption on the interfacial properties of aramid\\/epoxy composite. The fiber\\/matrix interfacial strength was severely decreased between 4 and 7 week immersion time in deionized water at 80 °C, and thereafter showed a plateau. This change with immersion time did not correspond with that of the water gain of

  3. Absorption of insulin using water-in-oil-in-water emulsion from an enteral loop in rats.

    PubMed

    Matsuzawa, A; Morishita, M; Takayama, K; Nagai, T

    1995-12-01

    The present work was undertaken to prepare water-in-oil-in-water (W/O/W) emulsions as a carrier for insulin via the enteral route. The emulsions were prepared by a two-step procedure using a homogenizer. To avoid insulin escape from the inner aqueous phase, 3, 5, or 10% gelatin was added in the inner phase. The oily phase was composed of 5% lecithin, 20% Span 80 and 75% soybean oil. The purified water containing 3% Tween 80 was used for the outer aqueous phase. In addition, these emulsions were filtered with a membrane filter (0.45 micron) to obtain smaller emulsion particles. The stability of the emulsions was evaluated by a turbidity measurement method and photomicrographic observation. By the addition of gelatin to the inner aqueous phase and storage at 4 degrees C, the stability of the emulsions could be improved. The hypoglycemic effects of insulin after administration of emulsion to the stomach, the duodenum, the jejunum, the ileum and the colon were examined using an in situ loop method in rats. A significant hypoglycemic effect was observed at the ileum and colon loops after administration of the filtered emulsions containing 5% gelatin in the inner phase. These findings suggest that the W/O/W multiple emulsions stabilized by gelatin can improve ileal and colonic absorption of insulin. PMID:8787795

  4. Effect of liposomes on the absorption of water-soluble active pharmaceutical ingredients via oral administration.

    PubMed

    Yang, Zhijun; Lu, Aiping; Wong, Blenda Chi Kwan; Chen, Xiaoyu; Bian, Zhaoxiang; Zhao, Zhongzhen; Huang, Wenhua; Zhang, Ge; Chen, Hubiao; Xu, Min

    2013-01-01

    The objective of this study was to investigate the effect of liposomes on the absorption of water-soluble active pharmaceutical ingredients. Salbutamol sulfate (SBS) has been widely used for treatment of bronchospasm in conditions such as asthma. Using SBS as the model drug in this study, we developed SBS-loaded liposomes for oral administration and explored the relationship between their bioavailability and anti-asthmatic efficacy. SBS was entrapped in liposomes with encapsulation efficiency as high as 70%. The in vitro transport profile of SBS across a dialysis membrane for liposome suspension was compared with that for free SBS solution. Oral administration of liposomes labeled with the fluorescent dye 1,1'-dioctadecyltetramethyl indotricarbocyanine iodide (DiR) in a mouse model was assessed by a small animal imaging system. Pharmacokinetic and pharmacodynamic studies on SBS liposome suspension and free SBS solution were performed using animal models via oral administration. The results showed that liposomes could sustain the release of SBS in vitro and decrease the transport rate of SBS across the dialysis membrane. In vivo fluorescence imaging analysis demonstrated DiR liposome distribution in mouse stomach for at least 24 hr. The mean residence time of SBS from liposomes was found to be longer than that of free SBS, suggesting that the relative bioavailability of SBS was higher when liposome delivery was used. The pharmacokinetic data also showed that the drug absorption rate was relatively slower for treatment with liposomal SBS when compared to free SBS. Moreover, SBS liposome suspension was shown to give a prolonged anti-asthmatic effect after oral administration when compared to free SBS solution. Overall, this study demonstrated that use of liposomes as delivery vehicles for sustained drug release and controlled absorption could be a promising approach for improving the therapeutic potency of active pharmaceutical ingredients. PMID:23621538

  5. Laboratory Measurements of the 940, 1130, and 1370 nm Water Vapor Absorption Band Profiles

    NASA Technical Reports Server (NTRS)

    Giver, Lawrence P.; Gore, Warren J.; Pilewskie, P.; Freedman, R. S.; Chackerian, C., Jr.; Varanasi, P.

    2001-01-01

    We have used the solar spectral flux radiometer (SSFR) flight instrument with the Ames 25 meter base-path White cell to obtain about 20 moderate resolution (8 nm) pure water vapor spectra from 650 to 1650 nm, with absorbing paths from 806 to 1506 meters and pressures up to 14 torr. We also obtained a set at 806 meters with several different air-broadening pressures. Model simulations were made for the 940, 1130, and 1370 nm absorption bands for some of these laboratory conditions using the Rothman, et al HITRAN-2000 linelist. This new compilation of HITRAN includes new intensity measurements for the 940 nm region. We compared simulations for our spectra of this band using HITRAN-2000 with simulations using the prior HITRAN-1996. The simulations of the 1130 nm band show about 10% less absorption than we measured. There is some evidence that the total intensity of this band is about 38% stronger than the sum of the HITRAN line intensities in this region. In our laboratory conditions the absorption depends approximately on the square root of the intensity. Thus, our measurements agree that the band is stronger than tabulated in HITRAN, but by about 20%, substantially less than the published value. Significant differences have been shown between Doppler-limited resolution spectra of the 1370 nm band obtained at the Pacific Northwest National Laboratory and HITRAN simulations. Additional new intensity measurements in this region are continuing to be made. We expect the simulations of our SSFR lab data of this band will show the relative importance of improving the HITRAN line intensities of this band for atmospheric measurements.

  6. Effect of aminoalkyl methacrylate copolymer E/HCl on in vivo absorption of poorly water-soluble drug.

    PubMed

    Yoshida, Takatsune; Kurimoto, Ippei; Yoshihara, Keiichi; Umejima, Hiroyuki; Ito, Naoki; Watanabe, Shunsuke; Sako, Kazuhiro; Kikuchi, Akihiko

    2013-11-01

    This study aimed to investigate in vivo absorption of tacrolimus formulated as a solid dispersion using Eudragit E®/HCl (E-SD). E-SD is an aminoalkyl methacrylate copolymer that can be dissolved under neutral pH conditions. E-SD was used alone as a solid dispersion carrier and/or was mixed with tacrolimus primarily dispersed with hydroxypropylmethylcellulose (HPMC). Tacrolimus was formulated with E-SD at several different ratios. Formulations with tacrolimus/E-SD ratio of 1/3 showed higher in vivo absorption, compared to tacrolimus dispersed in the excipients (primarily HPMC) found in commercially available tacrolimus capsules, using a rat in situ closed loop method. Good correlation was observed between in vitro drug solubility and in vivo drug absorption. In vitro solubility tests and rat oral absorption studies of tacrolimus/HPMC solid dispersion formulations were also conducted after mixing the HPMC dispersion with several ratios of E-SD. E-SD/tacrolimus/HPMC formulations yielded high in vitro drug solubility but comparatively low in vivo absorption. Dog oral absorption studies were conducted using capsules containing a formulation of tacrolimus/E-SD at a ratio of 1/5. The E-SD formulation-containing capsule showed higher in vivo drug absorption than tacrolimus dispersed in the standard HPMC capsule. These studies report enhancement of the in vivo absorption of a poorly water-soluble drug following dispersion with E-SD when compared to formulation in HPMC. PMID:23062024

  7. Comparison of x-ray absorption spectra between water and ice: new ice data with low pre-edge absorption cross-section.

    PubMed

    Sellberg, Jonas A; Kaya, Sarp; Segtnan, Vegard H; Chen, Chen; Tyliszczak, Tolek; Ogasawara, Hirohito; Nordlund, Dennis; Pettersson, Lars G M; Nilsson, Anders

    2014-07-21

    The effect of crystal growth conditions on the O K-edge x-ray absorption spectra of ice is investigated through detailed analysis of the spectral features. The amount of ice defects is found to be minimized on hydrophobic surfaces, such as BaF2(111), with low concentration of nucleation centers. This is manifested through a reduction of the absorption cross-section at 535 eV, which is associated with distorted hydrogen bonds. Furthermore, a connection is made between the observed increase in spectral intensity between 544 and 548 eV and high-symmetry points in the electronic band structure, suggesting a more extended hydrogen-bond network as compared to ices prepared differently. The spectral differences for various ice preparations are compared to the temperature dependence of spectra of liquid water upon supercooling. A double-peak feature in the absorption cross-section between 540 and 543 eV is identified as a characteristic of the crystalline phase. The connection to the interpretation of the liquid phase O K-edge x-ray absorption spectrum is extensively discussed. PMID:25053326

  8. Development of a UAV-based differential absorption lidar for measuring atmospheric water vapor

    NASA Astrophysics Data System (ADS)

    Thomas, Brian William

    Differential Absorption Lidar (DIAL) is a remote sensing technique useful for making range resolved measurements of chemical species. A water vapor DIAL system was developed for use on a high altitude unmanned air vehicle (UAV), in order to study water vapor distribution in hurricanes. The system uses a diode-pumped Cr:LiSAF laser to probe water vapor absorption lines at or near 815 nm. The receiver is comprised of two detectors, an analog mode avalanche photodiode (APD), and a photon counting APD, which gives the receiver a dynamic range of 5 orders of magnitude. Data acquisition is done with a 12-bit digitizer and a separate digital counter for the photon counting APD. The data is stored locally for retrieval at the end of the mission. The system was designed for fully autonomous operation. The DIAL system was tested on the ground in a zenith looking configuration. The system demonstrated measurements of water vapor to a range of 1800 m, with a difference from local balloon sonde data of no more than 30--50% over that range. Tests showed that the system measurement uncertainty was dominated by limitations of the digitizer, which will not be a factor during airborne operation. Estimates of airborne performance suggest that, flying at an altitude of 20 km, the system is currently capable of measuring water vapor between 2 and 7.5 km with an uncertainty of <50%. This can be reduced to <10% uncertainty with a factor of 3 increase in return signal. Refinement of the system is therefore recommended with an emphasis on increasing laser pulse energy. This dissertation describes the development of the DIAL system including motivation for the research, computer modeling of the return signal, selection of system components, and the testing process at the component and system levels. The system design requirements and goals are presented and used as a basis for component selection. The test results are used to extrapolate an estimate of the airborne performance of the system, and recommendations for future development of the system are made based on these estimates.

  9. Intrinsic UV absorption spectrometry observed with a liquid core waveguide as a sensor technique for monitoring ozone in water.

    PubMed

    Le, Trang; Tao, Shiquan

    2011-08-21

    The industrial use of ozone as a sanitizing agent in water treatment and food processing in recent years calls for sensor technologies for monitoring ozone in water for process control. Ozone molecules absorb UV light with a peak absorption wavelength at 254 nm. This property has been used in this work to develop a simple sensor technology for online, real-time continuous monitoring of trace ozone in water. A Teflon AF2400 tube filled with pure water forms a liquid core waveguide (LCW), which is used as a long-path-length optical absorption cell. This pure water filled tube was deployed into a water sample. Ozone molecules dissolved in the water sample permeate through the Teflon AF2400 tube wall and dissolve in water filled in the tube. This prevents interference species from entering the LCW, and eliminates interferences. The optical absorption signal of the long-path-length cell at 254 nm measured by guiding light through the LCW is used as a sensing signal. This simple structured sensor does not involve any chemical reagent, is reversible, and has a response time <4.5 minutes. It can be used to detect ozone in water samples down to 3.6 × 10(-9) mol L(-1). PMID:21743914

  10. Variability of Water and Oxygen Absorption Bands in the Disk-Integrated Spectra of the Earth

    E-print Network

    Fujii, Yuka; Suto, Yasushi

    2013-01-01

    We study the variability of major atmospheric absorption features in the disk-integrated spectra of the Earth with future application to Earth-analogs in mind, concentrating on the diurnal timescale. We first analyze observations of the Earth provided by the EPOXI mission, and find 5-20% fractional variation of the absorption depths of H2O and O2 bands, two molecules that have major signatures in the observed range. From a correlation analysis with the cloud map data from the Earth Observing Satellite (EOS), we find that their variation pattern is primarily due to the uneven cloud cover distribution. In order to account for the observed variation quantitatively, we consider a simple opaque cloud model, which assumes that the clouds totally block the spectral influence of the atmosphere below the cloud layer, equivalent to assuming that the incident light is completely scattered at the cloud top level. The model is reasonably successful, and reproduces the EPOXI data from the pixel-level EOS cloud/water vapor ...

  11. Two-column ion-exchange method for the determination of copper-complexing capacity and conditional stability constants of copper complexes for ligands in natural waters.

    PubMed

    Liu, Y; Ingle, J D

    1989-01-01

    Sample solutions titrated with Cu(2+) ions are passed sequentially through two ion-exchange columns in an automated flow system. The first column is packed with Chelex-100 resin and retains Cu(2+) ions that are free or derived from copper complexes that dissociate in the column. The second column is packed with AG MP-1 anion-exchange resin and retains negatively charged Cu(II) complexes. The retained copper species are then eluted from the columns and determined on-line with a flame atomic-absorption spectrophotometer. It is necessary to correct for a small fraction of free Cu(2+) ions that pass through the first column and are retained by the second column. The Cu(II)-complexing capacity of sample solutions is determined from plots of the concentration ratio of free Cu(2+) ions to Cu(II) complexes vs. the concentration of free Cu(2+) ions. Conditional stability constants of the copper complexes are also estimated from these plots. The complexing capacity of sample solutions is also determined rapidly by measuring the concentration of complexed Cu(II) after spiking the sample with an excess of Cu(2+) ions. The sample solutions tested were 4.0muM NTA, 4.0-mg/l. humic acid, and a river water. PMID:18964688

  12. Differential absorption lidar measurements of atmospheric water vapor using a pseudonoise code modulated AlGaAs laser. Thesis

    NASA Technical Reports Server (NTRS)

    Rall, Jonathan A. R.

    1994-01-01

    Lidar measurements using pseudonoise code modulated AlGaAs lasers are reported. Horizontal path lidar measurements were made at night to terrestrial targets at ranges of 5 and 13 km with 35 mW of average power and integration times of one second. Cloud and aerosol lidar measurements were made to thin cirrus clouds at 13 km altitude with Rayleigh (molecular) backscatter evident up to 9 km. Average transmitter power was 35 mW and measurement integration time was 20 minutes. An AlGaAs laser was used to characterize spectral properties of water vapor absorption lines at 811.617, 816.024, and 815.769 nm in a multipass absorption cell using derivative spectroscopy techniques. Frequency locking of an AlGaAs laser to a water vapor absorption line was achieved with a laser center frequency stability measured to better than one-fifth of the water vapor Doppler linewidth over several minutes. Differential absorption lidar measurements of atmospheric water vapor were made in both integrated path and range-resolved modes using an externally modulated AlGaAs laser. Mean water vapor number density was estimated from both integrated path and range-resolved DIAL measurements and agreed with measured humidity values to within 6.5 percent and 20 percent, respectively. Error sources were identified and their effects on estimates of water vapor number density calculated.

  13. Evaluation of tropospheric water vapor profiling using eye-safe, infrared differential absorption lidar

    SciTech Connect

    Rye, B.J. [Colorado Univ., Boulder, CO (United States). Cooperative Inst. for Research in Environmental Sciences]|[National Oceanic and Atmospheric Administration, Boulder, CO (United States). Environmental Technology Lab.; Machol, J.L.; Grund, C.J.; Hardesty, R.M. [National Oceanic and Atmospheric Administration, Boulder, CO (United States). Environmental Technology Lab.

    1996-05-14

    Continuous, high quality profiles of water vapor, free of systematic bias, and of moderate temporal and spatial resolution are fundamental to the success of the ARM CART program. In addition, these should be acquired over long periods at low operational and maintenance cost. The development and verification of realistic climate model parameterizations for clouds and net radiation balance, and the correction of other CART site sensor observations for interferences due to the presence of water vapor are critically dependent on water vapor profile measurements. To date, application of profiles have been limited by vertical resolution and uniqueness and high operating cost, or diminished daytime performance, lack of eye-safety, and high maintenance cost. Recent developments in infrared laser and detector technology make possible compact IR differential absorption lidar (DIAL) systems at eye-safe wavelengths. In the studies reported here, we develop DIAL system performance models and examine the potential of solving some of the shortcomings of previous methods using parameters representative of current technologies. These simulations are also applied to determine the strengths and weaknesses unique to the DIAL method for this application.

  14. Diffusion Coefficients of Water and Leachables in Methacrylate-based Crosslinked Polymers using Absorption Experiments

    PubMed Central

    Parthasarathy, Ranganathan; Misra, Anil; Park, Jonggu; Ye, Qiang; Spencer, Paulette

    2012-01-01

    The diffusion of water into dentin adhesive polymers and leaching of unpolymerized monomer from the adhesive are linked to their mechanical softening and hydrolytic degradation. Therefore, diffusion coefficient data are critical for the mechanical design of these polymeric adhesives. In this study, diffusion coefficients of water and leachables were obtained for sixteen methacrylate-based crosslinked polymers using absorption experiments. The experimental mass change data was interpreted using numerical solution of the two-dimensional diffusion equations. The calculated diffusion coefficients varied from 1.05 × 10?8 cm2/sec (co-monomer TMTMA) to 3.15 × 10?8 cm2/sec (co-monomer T4EGDMA). Correlation of the diffusion coefficients with crosslink density and hydrophilicity showed an inverse trend (R2 = 0.41). The correlation of diffusion coefficient with crosslink density and hydrophilicity are closer for molecules differing by simple repeat units (R2 = 0.95). These differences in the trends reveal mechanisms of interaction of the diffusing water with the polymer structure. PMID:22430592

  15. A three-dimensional water quality model to evaluate the environmental capacity of nitrogen and phosphorus in Jiaozhou Bay, China.

    PubMed

    Li, Keqiang; Zhang, Li; Li, Yan; Zhang, Longjun; Wang, Xiulin

    2015-02-15

    Jiaozhou Bay has recently suffered from serious problems with pollution and eutrophication. Thus, land-based pollutant load must be reduced through a national control program. In this study, we developed a 3D water quality model to determine the environmental capacity of nitrogen and phosphorus in Jiaozhou Bay. A 3D hydrodynamic model (the estuarine, coastal, and ocean modeling system with sediments) was coupled with a water quality model, which was adapted from the dynamic model of nitrogen and phosphorus for a mesocosm near Jiaozhou Bay. The water quality model is divided into seven components: dissolved inorganic nitrogen, phosphate, phytoplankton, zooplankton, detritus, dissolved organic nitrogen, and dissolved organic phosphorus. Furthermore, it was calibrated based on data collected from Jiaozhou Bay in 2003. The proposed model effectively reproduced the spatiotemporal variability in nutrient concentration, thus suggesting that a reasonable numerical representation of the prototype system must be developed for further evaluation of environmental capacity. PMID:25549824

  16. Measurements of water vapour in the mesosphere with the spectral absorption line imager (SALI)

    NASA Astrophysics Data System (ADS)

    Shepherd, M. G.; Sargoytchev, S. I.; Brown, S.; Mullins, M.; Petersen, J.

    Water vapour concentration is one of the most important, yet one of the least known quantities of the mesosphere. Knowledge of water vapour concentration is the key to understanding many mesospheric processes, including the one that is primary focus of our investigation, Polar Mesospheric Clouds (PMC). The processes of formation and occurrence parameters of PMC constitute an interesting problem in their own right, but recent evidence had been provided which suggests that PMC are a critical indicator of climate change. In this context the feasibility of a low cost method of water vapour measurements using an instrument carried aloft by a sounding rocket has been examined and some of the results discussed. It is proposed to measure the strength of the 936nm water absorption line in a solar occultation configuration employing a CCD detector. This leads to the design of a small, low cost and low-mass instrument, which can be flown on a small rocket, of the type of the Orbital Sciences Corporation Viper 5. Alternatively the instrument can be flown as a "passenger" on larger rocket carrying other experiments. In either case flight costs are relatively low. Some performance simulations are presented showing that the instrument we have designed will be sufficiently sensitive to measure water vapor in concentrations that are expected at the summer mesopause, about 85 km height. Sufficient payload design work was carried out showing that the structural, thermal and electrical requirements for a flight on the Viper 5 rocket can be met and thus making the experiment feasible for a flight.

  17. Water absorption of poly(methyl methacrylate) measured by vertical interference microscopy.

    PubMed

    N'Diaye, Mambaye; Pascaretti-Grizon, Florence; Massin, Philippe; Baslé, Michel Felix; Chappard, Daniel

    2012-08-01

    PMMA (poly(methyl methacrylate)) is widely used to prepare orthopedic cements. They are in direct contact with cells and body fluids. PMMA, despite its hydrophobic nature, can absorb ~2% w/w water. We have evaluated by vertical interference microscopy if water absorption can produce a significant swelling in different types of PMMA blocks: pure, with a plasticizer, with a cross-linker, and in two types of commercial bone cements. Graphite rods which do not swell in water were used as internal standard. Hardness, indentation modulus, plastic, and elastic works were determined by nanoindentation under a 25mN fixed force. Vertical interference microscopy was used to image the polymer in the dry state and hydrated states (after 24 h in distilled water). On the surface of the polished polymers (before and after hydration), we measured roughness by the fractal dimension, the swelling in the vertical and the lateral directions. For each polymer block, four images were obtained and values were averaged. Comparison and standardization of the images in the dry and hydrated states were done with Matlab software. The average value measured on the graphite rod between the two images (dried and hydrated) was used for standardization of the images which were visualized in 3D. After grinding, a small retraction was noticeable between the surface of the rod and the polymers. A retraction ring was also visible around the graphite rod. After hydration, only the pure PMMA and bone cements had a significant swelling in the vertical direction. The presence of polymer beads in the cements limited the swelling in the lateral direction. Swelling parameters correlated with the nanoindentation data. PMMA can swell by absorbing a small amount of water and this induces a swelling that varies with the polymer composition and particle inclusions. PMID:22799564

  18. Application of a laser intracavity absorption detector to gas chromatography of trace organic pollutants in water

    NASA Astrophysics Data System (ADS)

    Green, R. B.

    1982-12-01

    A helium-neon (HeNe) laser operating simultaneously at 3.39 micrometers (infrared) and 0.63 micrometer (visible) were used as a selective detector for hydrocarbons in the effluent of a gas chromatography. The infrared and visible laser transitions originate at the same energy level and are competitive. In practice, the detector's selectivity for hydrocarbons is modified by various substituents. The detector responds to aliphatic and aromatic hydrocarbons with aliphatic side chains, except for those substituted with halogens. The HeNe laser intracavity absorption detector may be used without prior separation in some cases (e.g., methane in coal mines). This detector operates with nitrogen carrier gas without sacrifice of sensitivity and should be useful for monitoring organic pollutants since it does not respond to water or carbon dioxide. Also, it should be possible to manufacture this detector at competitive prices.

  19. Predictions of silicon avalanche photodiode detector performance in water vapor differential absorption lidar

    NASA Technical Reports Server (NTRS)

    Kenimer, R. L.

    1988-01-01

    Performance analyses are presented which establish that over most of the range of signals expected for a down-looking differential absorption lidar (DIAL) operated at 16 km the silicon avalanche photodiode (APD) is the preferred detector for DIAL measurements of atmospheric water vapor in the 730 nm spectral region. The higher quantum efficiency of the APD's, (0.8-0.9) compared to a photomultiplier's (0.04-0.18) more than offsets the higher noise of an APD receiver. In addition to offering lower noise and hence lower random error the APD's excellent linearity and impulse recovery minimize DIAL systematic errors attributable to the detector. Estimates of the effect of detector system parameters on overall random and systematic DIAL errors are presented, and performance predictions are supported by laboratory characterization data for an APD receiver system.

  20. Influence of wave and current flow on sediment-carrying capacity and sediment flux at the water-sediment interface.

    PubMed

    Zheng, Jun; Li, Ruijie; Yu, Yonghai; Suo, Anning

    2014-01-01

    In nearshore waters, spatial and temporal scales of waves, tidal currents, and circulation patterns vary greatly. It is, therefore, difficult to combine these factors' effects when trying to predict sediment transport processes. This paper proposes the concept of significant wave velocity, which combines the effects of waves, tides, and ocean currents using the horizontal kinetic energy superposition principle. Through a comparison of the relationship between shear stress at the water-sediment interface and sediment-carrying capacity, assuming equilibrium sediment flux, a new formula for sediment-carrying capacity, which incorporates the concept of significant wave velocities, is derived. Sediment-carrying capacity is a function of the critical velocity, which increases with water depth and decreases with increasing relative roughness of the sea bed. Finally, data from field observation stations and simulations are used to test the proposed formula. The results show that the new formula is in good agreement with both field and simulation data. This new formula for sediment-carrying capacity can be used to simulate nearshore sediment transport. PMID:25259499

  1. VARIABILITY OF WATER AND OXYGEN ABSORPTION BANDS IN THE DISK-INTEGRATED SPECTRA OF EARTH

    SciTech Connect

    Fujii, Yuka; Suto, Yasushi [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Turner, Edwin L., E-mail: yuka.fujii@utap.phys.s.u-tokyo.ac.jp [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

    2013-03-10

    We study the variability of major atmospheric absorption features in the disk-integrated spectra of Earth with future application to Earth-analogs in mind, concentrating on the diurnal timescale. We first analyze observations of Earth provided by the EPOXI mission, and find 5%-20% fractional variation of the absorption depths of H{sub 2}O and O{sub 2} bands, two molecules that have major signatures in the observed range. From a correlation analysis with the cloud map data from the Earth Observing Satellite (EOS), we find that their variation pattern is primarily due to the uneven cloud cover distribution. In order to account for the observed variation quantitatively, we consider a simple opaque cloud model, which assumes that the clouds totally block the spectral influence of the atmosphere below the cloud layer, equivalent to assuming that the incident light is completely scattered at the cloud top level. The model is reasonably successful, and reproduces the EPOXI data from the pixel-level EOS cloud/water vapor data. A difference in the diurnal variability patterns of H{sub 2}O and O{sub 2} bands is ascribed to the differing vertical and horizontal distribution of those molecular species in the atmosphere. On Earth, the inhomogeneous distribution of atmospheric water vapor is due to the existence of its exchange with liquid and solid phases of H{sub 2}O on the planet's surface on a timescale short compared with atmospheric mixing times. If such differences in variability patterns were detected in spectra of Earth-analogs, it would provide the information on the inhomogeneous composition of their atmospheres.

  2. The influence of water vapor on atmospheric exchange measurements with an ICOS* based Laser absorption analyzer

    NASA Astrophysics Data System (ADS)

    Bunk, Rüdiger; Quan, Zhi; Wandel, Matthias; Yi, Zhigang; Bozem, Heiko; Kesselmeier, Jürgen

    2014-05-01

    Carbonyl sulfide and carbon monoxide are both atmospheric trace gases of high interest. Recent advances in the field of spectroscopy have enabled instruments that measure the concentration of the above and other trace gases very fast and with good precision. Increasing the effective path length by reflecting the light between two mirrors in a cavity, these instruments reach impressive sensitivities. Often it is possible to measure the concentration of more than one trace gas at the same time. The OCS/CO2 Analyzer by LGR (Los Gatos Research, Inc.) measures the concentration of water vapor [H2O], carbonyl sulfide [COS], carbon dioxide [CO2] and carbon monoxide [CO] simultaneously. For that the cavity is saturated with light, than the attenuation of light is measured as in standard absorption spectroscopy. The instrument proved to be very fast with good precision and to be able to detect even very low concentrations, especially for COS (as low as 30ppt in the case of COS). However, we observed a rather strong cross sensitivity to water vapor. Altering the water vapor content of the sampled air with two different methods led to a change in the perceived concentration of COS, CO and CO2. This proved especially problematic for enclosure (cuvette) measurements, where the concentrations of one of the above species in an empty cuvette are compared to the concentration of another cuvette containing a plant whose exchange of trace gases with the atmosphere is of interest. There, the plants transpiration leads to a large difference in water vapor content between the cuvettes and that in turn produces artifacts in the concentration differences between the cuvettes for the other above mentioned trace gases. For CO, simultaneous measurement with a UV-Emission Analyzer (AL 5002, Aerolaser) and the COS/CO Analyzer showed good agreement of perceived concentrations as long as the sample gas was dry and an increasing difference in perceived concentration when the sample gas was humidified. The difference in perceived CO concentration showed a clear correlation to the water vapor content in the sample air. For COS we could show that changes in water vapor also impacted on the perceived COS concentrations; the raise of the water vapor concentration would lead to an increasing underestimation of the COS concentration. Drying the air using a Nafion Dryer before entering the COS/CO Analyzer eliminated any water vapor induced artifacts and showed no adverse effects on the quality of the conducted measurements. *Integrated cavity output spectroscopy

  3. Gaussian multiaccess channels with ISI: Capacity region and multiuser water-filling

    Microsoft Academic Search

    Roger S. Cheng; Sergio Verdú

    1993-01-01

    The capacity region of a two-user Gaussian multiac- cess channel with intersymbol interference (ISI), where the inputs pass through respective linear systems and are then superimposed before being corrupted by an additive Gaussian noise process, is found. A novel geometrical method is given to obtain the optimal input power spectral densities and the capacity region. This method can be viewed

  4. Worldwide Ozone Capacity for Treatment of Drinking Water and Wastewater: A Review

    Microsoft Academic Search

    Barry L. Loeb; Craig M. Thompson; Joseph Drago; Hirofumi Takahara; Sylvie Baig

    2012-01-01

    One question often raised when ozone professionals gather is “How much ozone capacity is installed?” Although the use of ozone for industrial purposes is growing, the largest use for ozone resides in the use of treatment of municipal drinking and wastewater. It is very difficult to summarize ozone capacity for industrial applications as much data are kept confidential. A number

  5. The Near Infrared Absorption Spectrum of Water by CRDS Between 1.26-1.70 µm:Complete Empirical Line List and Continuum Absorption

    NASA Astrophysics Data System (ADS)

    Mondelain, Didier; Campargue, Alain; Kassi, Samir; Mikhailenko, Semen

    2014-06-01

    Due to the increasing performances of Airborne- and ground-based spectrometers, a more and more accurate characterization of the water vapor absorption is required. This is especially true in the transparency windows, corresponding to low absorption spectral regions widely used for probing the Earth's atmosphere. State-of-the-art experimental developments are required to fulfill the needs in terms of accuracy of the spectroscopic data. For that purpose, we are using high-sensitivity Continuous Wave Cavity Ring Down Spectroscopy (CW-CRDS) allowing reproducing in laboratory conditions comparable to the atmospheric ones in terms of absorption path length (tens of kilometers), temperature and pressure. From extensive analysis of our CRDS spectra, we have constructed an empirical line list for "natural" water vapor at 296 K in the 5850 7920 cm-1 region including 38 318 transitions of four major water isotopologues (H2 16O, H218O, H217O and HD16O) with an intensity cut-off of 1·10-29 cm/molecule. The list is made mostly complete over the whole spectral region by including a large number of unobserved weak lines with positions calculated using experimentally determined energy levels and intensities obtained from variational calculations. In addition, we provide HD18O and HD 17O lists in the same region for transitions with intensities larger than 1·10-29 cm/molecule. The HD18O and HD17O lists (1 972 lines in total) were obtained using empirical energy levels available in the literature and variational intensities. The global list (40 290 transitions) including the contribution of the six major isotopologues has been adopted for the new edition of the GEISA database in the region. The advantages and drawbacks of our list will be discussed in comparison with the list provided for the same region in the 2012 edition of the HITRAN database. Separate experiments were dedicated to the measurement of the water vapor self-continuum crosssections in the 1.6 µm window by CW-CRDS at different temperatures (from room temperature to 340 K). Due to the weakness of the broadband absorption signal to be measured, very few measurements of the water vapor continuum are available in the NIR windows especially for temperature conditions relevant for our atmosphere. This is in particular the case for the 1.6 µm window where the very few available measurements show a large disagreement. The absorption cross-sections, Cs(?, T), were retrieved for different selected wave numbers from a fit of the absorption coefficients measured in real time during pressure ramps, after subtraction of the contributions of the local water monomer lines and of water adsorbed on the CRDS mirrors. The values measured between 5875 and 6665 cm-1 range between 1.5·10-25 and 2·10-24 cm2 molec-1 atm-1 with a minimum around 6300 cm-1. Overall, our measurements are found in strong disagreement with recent FTS measurements and in a good agreement with the values predicted by the MT CKD2.5 model, except for the temperature dependence in the center of the window which is found significantly smaller than predicted.

  6. Effects of nutritional modifications on the water-holding capacity of fresh pork: a review.

    PubMed

    Apple, J K

    2007-11-01

    Although genetics and preslaughter handling and management have the greatest impact on pork quality - especially water-holding capacity (WHC) - modifications to swine diets may offset the negative effects of genotype and/or pig handling on pork quality or improve quality attributes of pork from pigs with the genetic potential for good quality. There is little evidence that pork WHC is altered by the lysine or protein level (and source), cereal grain, or fat source used in growing-finishing diets. Yet, recent research indicates that feeding low-starch, high-fibre, high-fat, glycogen-reducing diets effectively improves the WHC of pork. Moreover, meta-analysis of the available information indicated that including 100, 200, or 400+ mg of alpha-tochopherol per kilogram of diet reduced pork drip losses by 10.1%, 30.5%, and 25.9%, respectively, whereas supplementing swine diets with magnesium for 1-2 days, 3-4 days, or 5-7 days reduced drip losses by 23.1%, 13.7%, or 15.9%, respectively. Some swine nutritionists have advocated the removal of vitamins and trace minerals from finishing diets; however, deletion of vitamin/trace mineral premixes actually reduced the WHC of pork, whereas drip losses were reduced by elevating the dietary inclusion levels of vitamins and trace minerals 150-250% of the recommended levels. Additionally, there is no evidence that feeding pigs ractopamine hydrochloride or injections of porcine somatotropin affect pork WHC. There may not be a single 'silver bullet' that will remedy poor quality genetics or poor animal management, but improvements in pork WHC can be achieved with some modifications to swine finishing diets. PMID:17988250

  7. Diode-laser-based water vapor differential absorption lidar (DIAL) profiler evaluation

    NASA Astrophysics Data System (ADS)

    Spuler, S.; Weckwerth, T.; Repasky, K. S.; Nehrir, A. R.; Carbone, R.

    2012-12-01

    We are in the process of evaluating the performance of an eye-safe, low-cost, diode-laser-based, water vapor differential absorption lidar (DIAL) profiler. This class of instrument may be capable of providing continuous water vapor and aerosol backscatter profiles at high vertical resolution in the atmospheric boundary layer (ABL) for periods of months to years. The technology potentially fills a national long term observing facility gap and could greatly benefit micro- and meso-meteorology, water cycle, carbon cycle and, more generally, biosphere-hydrosphere-atmosphere interaction research at both weather and climate variability time scales. For the evaluation, the Montana State University 3rd generation water vapor DIAL was modified to enable unattended operation for a period of several weeks. The performance of this V3.5 version DIAL was tested at MSU and NCAR in June and July of 2012. Further tests are currently in progress with Howard University at Beltsville, Maryland; and with the National Weather Service and Oklahoma University at Dallas/Fort Worth, Texas. The presentation will include a comparison of DIAL profiles against meteorological "truth" at the aforementioned locations including: radiosondes, Raman lidars, microwave and IR radiometers, AERONET and SUOMINET systems. Instrument reliability, uncertainty, systematic biases, detection height statistics, and environmental complications will be evaluated. Performance will be judged in the context of diverse scientific applications that range from operational weather prediction and seasonal climate variability, to more demanding climate system process studies at the land-canopy-ABL interface. Estimating the extent to which such research and operational applications can be satisfied with a low cost autonomous network of similar instruments is our principal objective.

  8. A theoretical investigation of gaseous absorption by water droplets from SO2-HNO3-NH3-CO2-HCl mixtures

    NASA Technical Reports Server (NTRS)

    Adewuyi, Y. G.; Carmichael, G. R.

    1982-01-01

    A physical-chemical model is developed and used to investigate gaseous absorption by water droplets from trace gas mixtures. The model is an extension of that of Carmichael and Peters (1979) and includes the simultaneous absorption of SO2, NH3, HNO3, CO2, and HCl. Gas phase depletion is also considered. Presented results demonstrate that the absorption behavior of raindrops is strongly dependent on drop size, fall distance, trace gas concentrations, and the chemical and physical properties of the constituents of the mixture. In addition, when gas phase depletion is considered, the absorption rates and equilibrium values are also dependent on the precipitation rate itself. Also, the trace constituents liquid phase concentrations may be a factor of six or more lower when gas depletion is considered then when the depletion is ignored. However, the hydrogen ion concentration may be insensitive to the gas phase depletion.

  9. Effect of a Disintegration Mechanism on Wetting, Water Absorption, and Disintegration Time of Orodispersible Tablets

    PubMed Central

    Pabari, RM; Ramtoola, Z

    2012-01-01

    The aim of this study was to evaluate the influence of disintegration mechanism of various types of disintegrants on the absorption ratio (AR), wetting time (WT), and disintegration time (DT) of orodispersible tablets (ODTs). ODTs were prepared by direct compression using mannitol as filler and disintegrants selected from a range of swellable, osmotic, and porous disintegrants. Tablets formed were characterized for their water AR, WT, and DT. The porosity and mechanical strength of the tablets were also measured. Results show that the DT of formulated ODTs was directly related to the WT and was a function of the disintegration mechanism of the disintegrant used. The lowest WT and DT were observed for tablets formulated using the osmotic disintegrant sodium citrate and these tablets also showed the lowest AR and porosity. The wetting and disintegration of tablets containing the highly swellable disintegrant, sodium starch glycollate, was slowest despite their high water AR and high tablet porosity. Rapid wetting and disintegration of ODTs were therefore not necessarily related to the porosity of the tablets. PMID:23112534

  10. Ultra reliable infrared absorption water vapor detection through the all-electronic feedback stabilization

    NASA Astrophysics Data System (ADS)

    Zhu, C. G.; Chang, J.; Wang, P. P.; Wang, Q.; Wei, W.; Tian, J. Q.; Chang, H. T.; Liu, X. Z.; Zhang, S. S.

    2014-03-01

    Single-beam balanced radiometric detection (BRD) system with all-electronic feedback stabilization has been proposed for high reliability water vapor detection under rough environmental conditions, which is insensitive to the fluctuation of transmission loss of light. The majority of photocurrent attenuation caused by the optical loss can be effectively compensated by automatically adjusting the splitting ratio of probe photocurrent. Based on the Ebers-Moll model, we present a theoretical analysis which can be suppressed the photocurrent attenuation caused by optical loss from 0.5552 dB to 0.0004 dB by using the all-electronic feedback stabilization. The deviation of the single-beam BRD system is below 0.29% with the bending loss of 0.31 dB in fiber, which is obviously lower than the dual-beam BRD system (5.96%) and subtraction system (11.3%). After averaging and filtering, the absorption sensitivity of water vapor at 1368.597 nm has been demonstrated, which is 7.368×10-6.

  11. Light tracking through ice and water -- Scattering and absorption in heterogeneous media with Photonics

    E-print Network

    J. Lundberg; P. Miocinovic; K. Woschnagg; T. Burgess; J. Adams; S. Hundertmark; P. Desiati; P. Niessen

    2007-08-29

    In the field of neutrino astronomy, large volumes of optically transparent matter like glacial ice, lake water, or deep ocean water are used as detector media. Elementary particle interactions are studied using in situ detectors recording time distributions and fluxes of the faint photon fields of Cherenkov radiation generated by ultra-relativistic charged particles, typically muons or electrons. The Photonics software package was developed to determine photon flux and time distributions throughout a volume containing a light source through Monte Carlo simulation. Photons are propagated and time distributions are recorded throughout a cellular grid constituting the simulation volume, and Mie scattering and absorption are realised using wavelength and position dependent parameterisations. The photon tracking results are stored in binary tables for transparent access through ANSI-C and C++ interfaces. For higher-level physics applications, like simulation or reconstruction of particle events, it is then possible to quickly acquire the light yield and time distributions for a pre-specified set of light source and detector properties and geometries without real-time photon propagation. In this paper the Photonics light propagation routines and methodology are presented and applied to the IceCube and Antares neutrino telescopes. The way in which inhomogeneities of the Antarctic glacial ice distort the signatures of elementary particle interactions, and how Photonics can be used to account for these effects, is described.

  12. Terahertz Absorption of Chemicals in Water: Ideal and Real Solutions and Mixtures

    NASA Astrophysics Data System (ADS)

    Funkner, Stefan; Niehues, Gudrun; Schmidt, Diedrich A.; Bründermann, Erik

    2013-08-01

    Complex biomolecules, such as proteins in liquids, show specific terahertz dynamics in reactions or in protein folding as measured by static or kinetic absorption. The complex nature of biomolecules requires investigating their frequency, space, and time characteristics via a multimodal approach that changes external parameters such as temperature, pressure, concentration, and solvents. Terahertz spectroscopy can add a new and deeper understanding to existing techniques in other spectral regions of the biological dynamics in the solvent of life, i.e. water. To understand more deeply complex liquids or macromolecules in water, it is essential to understand the building blocks of solutions, which may contain salts, or are components of larger molecules such as amino acids. Although this research mainly affects basic science, a few applications are in progress, some create interest in industry, and several pathways for new applications relevant to medical science are in view. In this article, we review THz spectroscopy of solutions and concentrate our description to liquids with small solutes such as salts and amino acids, and review the prerequisites for obtaining THz data from aqueous solutions.

  13. Solvent effect on the absorption spectra of coumarin 120 in water: A combined quantum mechanical and molecular mechanical study

    NASA Astrophysics Data System (ADS)

    Sakata, Tetsuya; Kawashima, Yukio; Nakano, Haruyuki

    2011-01-01

    The solvent effect on the absorption spectra of coumarin 120 (C120) in water was studied utilizing the combined quantum mechanical/molecular mechanical (QM/MM) method. In molecular dynamics (MD) simulation, a new sampling scheme was introduced to provide enough samples for both solute and solvent molecules to obtain the average physical properties of the molecules in solution. We sampled the structure of the solute and solvent molecules separately. First, we executed a QM/MM MD simulation, where we sampled the solute molecule in solution. Next, we chose random solute structures from this simulation and performed classical MD simulation for each chosen solute structure with its geometry fixed. This new scheme allowed us to sample the solute molecule quantum mechanically and sample many solvent structures classically. Excitation energy calculations using the selected samples were carried out by the generalized multiconfigurational perturbation theory. We succeeded in constructing the absorption spectra and realizing the red shift of the absorption spectra found in polar solvents. To understand the motion of C120 in water, we carried out principal component analysis and found that the motion of the methyl group made the largest contribution and the motion of the amino group the second largest. The solvent effect on the absorption spectrum was studied by decomposing it in two components: the effect from the distortion of the solute molecule and the field effect from the solvent molecules. The solvent effect from the solvent molecules shows large contribution to the solvent shift of the peak of the absorption spectrum, while the solvent effect from the solute molecule shows no contribution. The solvent effect from the solute molecule mainly contributes to the broadening of the absorption spectrum. In the solvent effect, the variation in C-C bond length has the largest contribution on the absorption spectrum from the solute molecule. For the solvent effect on the absorption spectrum from the solvent molecules, the solvent structure around the amino group of C120 plays the key role.

  14. Understanding enabling capacities for managing the 'wicked problem' of nonpoint source water pollution in catchments: a conceptual framework.

    PubMed

    Patterson, James J; Smith, Carl; Bellamy, Jennifer

    2013-10-15

    Nonpoint source (NPS) water pollution in catchments is a 'wicked' problem that threatens water quality, water security, ecosystem health and biodiversity, and thus the provision of ecosystem services that support human livelihoods and wellbeing from local to global scales. However, it is a difficult problem to manage because water catchments are linked human and natural systems that are complex, dynamic, multi-actor, and multi-scalar in nature. This in turn raises questions about understanding and influencing change across multiple levels of planning, decision-making and action. A key challenge in practice is enabling implementation of local management action, which can be influenced by a range of factors across multiple levels. This paper reviews and synthesises important 'enabling' capacities that can influence implementation of local management action, and develops a conceptual framework for understanding and analysing these in practice. Important enabling capacities identified include: history and contingency; institutional arrangements; collaboration; engagement; vision and strategy; knowledge building and brokerage; resourcing; entrepreneurship and leadership; and reflection and adaptation. Furthermore, local action is embedded within multi-scalar contexts and therefore, is highly contextual. The findings highlight the need for: (1) a systemic and integrative perspective for understanding and influencing change for managing the wicked problem of NPS water pollution; and (2) 'enabling' social and institutional arenas that support emergent and adaptive management structures, processes and innovations for addressing NPS water pollution in practice. These findings also have wider relevance to other 'wicked' natural resource management issues facing similar implementation challenges. PMID:23792915

  15. Water vapor concentration measurement in singlet oxygen generator by using emission spectroscopy method and absorption at 1392nm

    NASA Astrophysics Data System (ADS)

    Zhao, Weili; Wang, Zengqiang; Fang, Benjie; Li, Qingwei; Jin, Yuqi; Sang, Fengting

    2005-12-01

    By using emission spectroscopy method and absorption at 1392nm, partial water pressure at the exit of a square pipe-array jet-type singlet oxygen generator (SPJSOG) for chemical oxygen-iodine laser (COIL) was measured. The water vapor fraction was calculated from the partial water pressure in the diagnostic cell when we assumed the water vapor fraction in the diagnostic cell is the same as that in the generator. The results from the two methods showed that the water vapor concentration is less than 0.08 in this SPJSOG during normal operation. The water vapor fraction decreases with the increasing of the pressure in the generator and rises with the increasing of buffer gas flow rate and the basic hydrogen peroxide (BHP) temperature in the case of constant chlorine flow rate. Measurements showed that the change of water vapor fraction due to BHP temperature could be ignored during normal operation. It is indicated that the gas flow velocity is the main reason that affects on the water vapor fraction in COIL. It is proved that the emission spectroscopy method is one of the simple and convenient ways to measure the water vapor concentration in singlet oxygen generator (SOG), especially in real time measurements. But absorption spectroscopy method, as a direct measurement, can give the more factual results of the water concentration.

  16. Atmospheric Pre-Corrected Differential Absorption Techniques to Retrieve Columnar Water Vapor: Application to AVIRIS 91/95 Data

    NASA Technical Reports Server (NTRS)

    Schlaepfer, Daniel; Borel, Christoph C.; Keller, Johannes; Itten, Klaus I.

    1996-01-01

    Water vapor is one of the main forces for weather development as well as for mesoscale air transport processes. The monitoring of water vapor is therefore an important aim in remote sensing of the atmosphere. Current operational systems for water vapor detection use primarily the emission in the thermal infrared (AVHRR, GOES, ATSR, Meteosat) or in the microwave radiation bands (DMSP). The disadvantage of current satellite systems is either a coarse spatial (horizontal) resolution ranging from one to tens of kilometers or a limited insight into the lower atmosphere. Imaging spectrometry on the other hand measures total column water vapor contents at a high spatial horizontal resolution and has therefore the potential of filling these gaps. The sensors of the AVIRIS instrument are capable of acquiring hyperspectral data in 224 bands located in the visible and near infrared at 10 nm resolution. This data includes the information on constituents of the earth's surface as well as of the atmosphere. The optical measurement of water vapor can be performed using sensor channels located in bands or lines of the absorption spectrum. The AVIRIS sensor has been used to retrieve water vapor and with less accuracy carbon dioxide, oxygen and ozone. To retrieve the water vapor amount, the so called differential absorption technique has been applied. The goal of this technique is to eliminate background factors by taking a ratio between channels within the absorption band and others besides the band. Various ratioing methods on the basis of different channels and calculation techniques were developed. The influence of a trace gas of interest on the radiance at the sensor level is usually simulated by using radiative transfer codes. In this study, the spectral transmittance and radiance are calculated by MODTRAN3 simulations with the new DISORT option. The objective of this work is to test the best performing differential absorption techniques for imaging spectrometry of tropospheric water vapor.

  17. High frequency sound velocity and sound absorption in supercooled water and the thermodynamic singularity at 228°K

    Microsoft Academic Search

    Jacques Rouch; C. C. Lai; Sow-Hsin Chen

    1977-01-01

    The interpretation of our experimental results on the high frequency sound velocity and sound absorption in liquid and supercooled liquid water lends support to the existence of a thermodynamic singularity at about 228°K. We determine the respective critical exponents and find them in good agreement with those, whenever available, deduced from other techniques.

  18. Organic esters of plasticizers affecting the water absorption, adhesive property, glass transition temperature and plasticizer permanence of Eudragit acrylic films

    Microsoft Academic Search

    Shan-Yang Lin; Ko-Shao Chen; Liang Run-Chu

    2000-01-01

    The materials used in film coating technology are very important tools for pharmaceutical applications. The effects of four organic esters used as plasticizers (triacetin, diethyl phthalate (DEP), dibutyl phthalate (DBP) and tributyl citrate (TBC)) on the water absorption behavior and adhesive property of Eudragit films and on the glass transition temperature (Tg) and plasticizer permanence of Eudragit E film were

  19. Sources and light absorption of water-soluble organic carbon aerosols in the outflow from northern China

    NASA Astrophysics Data System (ADS)

    Kirillova, E. N.; Andersson, A.; Han, J.; Lee, M.; Gustafsson, Ö.

    2014-02-01

    High loadings of anthropogenic carbonaceous aerosols in Chinese air influence the air quality for over one billion people and impact the regional climate. A large fraction (17-80%) of this aerosol carbon is water-soluble, promoting cloud formation and thus climate cooling. Recent findings, however, suggest that water-soluble carbonaceous aerosols also absorb sunlight, bringing additional direct and indirect climate warming effects, yet the extent and nature of light absorption by this water-soluble "brown carbon" and its relation to sources is poorly understood. Here, we combine source estimates constrained by dual carbon isotopes with light-absorption measurements of water-soluble organic carbon (WSOC) for a March 2011 campaign at the Korea Climate Observatory at Gosan (KCOG), a receptor station in SE Yellow Sea for the outflow from northern China. The mass absorption cross section at 365 nm (MAC365) of WSOC for air masses from N. China were in general higher (0.8-1.1 m2 g-1), than from other source regions (0.3-0.8 m2 g-1). However, this effect corresponds to only 2-10% of the radiative forcing caused by light absorption by elemental carbon. Radiocarbon constraints show that the WSOC in Chinese outflow had significantly higher fraction fossil sources (30-50%) compared to previous findings in S. Asia, N. America and Europe. Stable carbon (?13C) measurements were consistent with aging during long-range air mass transport for this large fraction of carbonaceous aerosols.

  20. Laboratory methods for determining moisture absorption of thermal insulations III. Interlaboratory comparison of water intake of rigid thermal insulations

    Microsoft Academic Search

    M. Bomberg; R. F. Dillon

    1984-01-01

    A new test method for water absorption proposed for inclusion in the ASTM Book of Standards has been subjected to test series by seven laboratories using four rigid thermal insulating materials. This paper presents a statistical analysis and addresses general questions concerning evaluation of the test method uncertainties.

  1. Heat and mass transfer analysis of a helical coil rectifier in an ammonia–water absorption system

    Microsoft Academic Search

    José Fernández-Seara; Jaime Sieres; Manuel Vázquez

    2003-01-01

    This paper presents a detailed study on the ammonia–water vapour rectification process in absorption systems using a helical coil rectifier. A differential mathematical model has been developed on the basis of mass and energy balances and heat and mass transfer equations. The differential volume has been defined in each coil turn by a differential angle on the turn and a

  2. Feasibility of tropospheric water vapor profiling using infrared heterodyne differential absorption lidar

    SciTech Connect

    Grund, C.J.; Hardesty, R.M. [NOAA Environmental Technology Lab., Boulder, CO (United States); Rye, B.J. [Univ. of Colorado, Boulder, CO (United States). Cooperative Institute for Research in Environmental Sciences (CU/NOAA)

    1995-04-03

    Continuous, high quality profiles of water vapor, free of systematic bias, and of moderate temporal and spatial resolution, acquired over long periods at low operational and maintenance cost, are fundamental to the success of the ARM CART program. The development and verification of realistic climate model parameterizations for clouds and net radiation balance, and the correction of other CART site sensor observations for interferences due to the presence of water vapor are critically dependent on water vapor profile measurements. Application of profiles acquired with current techniques, have, to date, been limited by vertical resolution and uniqueness of solution [e.g. high resolution infrared (IR) Fourier transform radiometry], poor spatial and temporal coverage and high operating cost (e.g. radiosondes), or diminished daytime performance, lack of eye-safety, and high maintenance cost (e.g. Raman lidar). Recent developments in infrared laser and detector technology make possible compact IR differential absorption lidar (DIAL) systems at eye-safe wavelengths. In the study reported here, we develop DIAL system performance models and examine the potential of to solve some of the shortcomings of previous methods using parameterizations representative of current technologies. These models are also applied to diagnose and evaluate other strengths and weaknesses unique to the DIAL method for this application. This work is to continue in the direction of evaluating yet smaller and lower-cost laser diode-based systems for routine monitoring of the lower altitudes using photon counting detection methods. We regard the present report as interim in nature and will update and extend it as a final report at the end of the term of the contract.

  3. Water-holding capacity and structure of hydrocolloid-gels, WPC-gels and yogurts characterised by means of NMR

    Microsoft Academic Search

    R Hinrichs; J Götz; H Weisser

    2003-01-01

    The objective of this work is to illustrate the possibilities of NMR (nuclear magnetic resonance) for characterising gels. As model food systems, carrageenan-gels\\/solutions and whey protein gels are studied. The water-holding capacity of gels including sol-gel transitions is investigated. Pore systems of gels are characterised by analysed diffusion experiments. Yogurt is used as an example of a complex food, and

  4. An Assessment of Use, Need for, and Capacity to Integrate Climate Information Among Water Managers in Southeastern United States and the ACF Basin

    E-print Network

    Miami, University of

    An Assessment of Use, Need for, and Capacity to Integrate Climate Information Among Water Managers of the information use and needs of water resource managers in the region. Theoretical indicators of adaptive-year droughts, floods, and associated water management decisions have long concerned water managers in Western

  5. Water Retention Capacity in Root Segments Differing in the Degree of Exodermis Development

    Microsoft Academic Search

    E. TALEISNIK; G. PEYRANO; A. CÓRDOBA; C. ARIAS

    1999-01-01

    Water loss from roots back into drying soil is a problem of practical importance in plants growing under conditions of very low substrate water potential, such as dry or saline areas. Root exodermis is relatively impermeable and has been suggested to play a protective role against water loss. The relative water retention ability was compared in root segments from exodermal

  6. Design And Implementation Of A Water-Quality Monitoring Program In Support Of Establishing User Capacities In Yosemite National Park

    NASA Astrophysics Data System (ADS)

    Peavler, R. S.; Clow, D. W.; Panorska, A. K.

    2008-12-01

    Under the 1968 Wild and Scenic Rivers Act, the managing agency of the designated river is required to develop a comprehensive management plan that protects the characteristics of the river segment meriting special protection and that addresses user capacities. We analyzed water quality in the upper Merced and Tuolumne Rivers of Yosemite National Park, designated as Wild and Scenic, to provide baseline data in support of establishing park-specific water-quality standards as part of an adaptive management framework that addresses user capacities. Samples collected from 2004 to 2007 were analyzed for nitrate, total dissolved nitrogen, total dissolved phosphorus, and total phosphorus at all sites, and for E.coli, total petroleum hydrocarbons, and waste water compounds at a subset of sites. Water quality in the upper Merced and Tuolumne River basins was dilute, with concentrations in most samples falling near or below minimum detection limits for the constituents of concern. Results indicate that spatial and seasonal variability in nutrient concentrations is a function of local basin characteristics, particularly elevation. Generally, nitrate- plus-nitrite increased with elevation, while total dissolved nitrogen decreased with elevation. Anomalous high nitrate-plus-nitrite concentrations occurred during low flow at several sites, such as below Yosemite National Park's primary waste water treatment facility, making those sites good candidates for further investigation. Bootstrapping was used to characterize the distribution of concentrations at each site and to make inferences regarding background reference conditions, which could be used by the National Park Service to select anti- degradation water-quality standards and establish water-quality based user capacities. Results suggest that future monitoring efforts should emphasize storm-event sampling, which is necessary to capture infrequent elevated nutrient concentrations, and sampling in the head-waters of each basin where further data is needed to characterize possible impacts from atmospheric deposition of pollutants. Additional water-quality monitoring in Merced River tributaries throughout Yosemite Valley is needed to identify sources of nutrient inputs and to determine whether visitor use is contributing to the overall water quality.

  7. Absorption of glucose, sodium, and water by the human jejunum studied by intestinal perfusion with a proximal occluding balloon and at variable flow rates

    Microsoft Academic Search

    R. Modigliani; J. J. Bernier

    1971-01-01

    A perfusion technique with a proximal occluding balloon has been used to study the absorption of glucose, sodium, and water from the human jejunum at different rates of flow. The absorption of glucose and water was significantly higher with the balloon deflated than inflated, probably because of reflux of infused solution above the point of infusion. Above the inflated balloon

  8. Effect of fibre and coupling agent contents on water absorption and flexural modulus of wood fibre polyethylene composites

    NASA Astrophysics Data System (ADS)

    Tissandier, C.; Zhang, Y.; Rodrigue, D.

    2014-05-01

    In two previous studies, wood fiber-reinforced polymer composites (WPC) were prepared via melt processing. In particular, a response surface strategy of a 20 run optimal design for these three factors was adopted. It was found that for these WPC mixing torque, melt viscosity, Young's modulus and tensile stress at break were related to the type of wood used, as well as wood and coupling agent contents. In addition, thermal properties and strain at break were mainly affected by wood and coupling agent contents. Here, a more complete characterization of these WPC under extreme environmental conditions is performed. In particular, the effect of coupling agent content, wood fibre content and wood fibre type on water absorption and flexural modulus are reported under different water immersion time and temperature. The results show that water absorption is influenced by all the parameters studied, while flexural modulus is mainly influenced by wood content and immersion temperature.

  9. Cloud point extraction for speciation of chromium in water samples by electrothermal atomic absorption spectrometry.

    PubMed

    Zhu, Xiashi; Hu, Bin; Jiang, Zucheng; Li, Mingfang

    2005-02-01

    A new method based on the cloud point extraction (CPE) separation and electrothermal atomic absorption spectrometry (ETAAS) detection was proposed for the determination of chromium species. When the system temperature is higher than the cloud point extraction temperature (CPT) of selected surfactant p-octyl polyethyleneglycolphenyether (Triton X-100), the complex of Cr(VI) with dibromophenylfluorone (Br-PF) could enter surfactant-rich phase, whereas the Cr(III) remained in aqueous phase. Thus, an in situ separation of Cr(VI) and Cr(III) could be realized. Cr(VI) in surfactant-rich phase was analyzed by ETAAS and Cr(III) was calculated by subtracting of Cr(VI) from the total chromium which was directly determined by ETAAS. The main factors affecting the cloud point extraction, such as pH, concentration of Br-PF and Triton X-100, equilibration temperature and time, were investigated systematically. Under the optimized conditions, the quantitation limit for Cr(VI) as low as 0.01 microg/L was obtained by preconcentrating a 10 mL sample solution, and the relative standard deviation (n=6, c=2.0 microg/L) was 2.6%. The proposed method was applied to the speciation of chromium in different water samples and the recoveries in the range of 98.9-105.3% were obtained by spiking the real samples. In order to verify the accuracy of the method, a certified reference water sample was analyzed and the results obtained were in good agreement with the certified values. PMID:15707631

  10. Ultra Narrowband Optical Filters for Water Vapor Differential Absorption Lidar (DIAL) Atmospheric Measurements

    NASA Technical Reports Server (NTRS)

    Stenholm, Ingrid; DeYoung, Russell J.

    2001-01-01

    Differential absorption lidar (DIAL) systems are being deployed to make vertical profile measurements of atmospheric water vapor from ground and airborne platforms. One goal of this work is to improve the technology of such DIAL systems that they could be deployed on space-based platforms. Since background radiation reduces system performance, it is important to reduce it. One way to reduce it is to narrow the bandwidth of the optical receiver system. However, since the DIAL technique uses two or more wavelengths, in this case separated by 0.1 nm, a fixed-wavelength narrowband filter that would encompass both wavelengths would be broader than required for each line, approximately 0.02 nm. The approach employed in this project is to use a pair of tunable narrowband reflective fiber Bragg gratings. The Bragg gratings are germanium-doped silica core fiber that is exposed to ultraviolet radiation to produce index-of-refraction changes along the length of the fiber. The gratings can be tuned by stretching. The backscattered laser radiation is transmitted through an optical circulator to the gratings, reflected back to the optical circulator by one of the gratings, and then sent to a photodiode. The filter reflectivities were >90 percent, and the overall system efficiency was 30 percent.

  11. Measurement of the spectral absorption of liquid water in melting snow with an imaging spectrometer

    NASA Technical Reports Server (NTRS)

    Green, Robert O.; Dozier, Jeff

    1995-01-01

    Melting of the snowpack is a critical parameter that drives aspects of the hydrology in regions of the earth where snow accumulates seasonally. New techniques for measurement of snow melt over regional scales offer the potential to improve monitoring and modeling of snow-driven hydrological processes. We present the results of measuring the spectral absorption of liquid water in a melting snowpack with the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). AVIRIS data were acquired over Mammoth Mountain, in east central California on 21 May 1994 at 18:35 UTC. The air temperature at 2926 m on Mammoth Mountain at site A was measured at 15-minute intervals during the day preceding the AVIRIS data acquisition. At this elevation, the air temperature did not drop below freezing the night of May 20 and had risen to 6 degrees Celsius by the time of the overflight on May 21. These temperature conditions support the presence of melting snow at the surface as the AVIRIS data were acquired.

  12. Field-deployable diode-laser-based differential absorption lidar (DIAL) for profiling water vapor

    NASA Astrophysics Data System (ADS)

    Spuler, S. M.; Repasky, K. S.; Morley, B.; Moen, D.; Hayman, M.; Nehrir, A. R.

    2015-03-01

    A field-deployable water vapor profiling instrument that builds on the foundation of the preceding generations of diode-laser-based differential absorption lidar (DIAL) laboratory prototypes was constructed and tested. Significant advances are discussed, including a unique shared telescope design that allows expansion of the outgoing beam for eye-safe operation with optomechanical and thermal stability; multistage optical filtering enabling measurement during daytime bright-cloud conditions; rapid spectral switching between the online and offline wavelengths enabling measurements during changing atmospheric conditions; and enhanced performance at lower ranges by the introduction of a new filter design and the addition of a wide field-of-view channel. Performance modeling, testing, and intercomparisons are performed and discussed. In general, the instrument has a 150 m range resolution with a 10 min temporal resolution; 1 min temporal resolution in the lowest 2 km of the atmosphere is demonstrated. The instrument is shown capable of autonomous long-term field operation - 50 days with a > 95% uptime - under a broad set of atmospheric conditions and potentially forms the basis for a ground-based network of eye-safe autonomous instruments needed for the atmospheric sciences research and forecasting communities.

  13. Field deployable diode-laser-based differential absorption lidar (DIAL) for profiling water vapor

    NASA Astrophysics Data System (ADS)

    Spuler, S. M.; Repasky, K. S.; Morley, B.; Moen, D.; Hayman, M.; Nehrir, A. R.

    2014-11-01

    A field deployable water vapor profiling instrument that builds on the foundation of the preceding generations of diode-laser-based differential absorption lidar (DIAL) laboratory prototypes has been constructed and tested. Significant advances are discussed, including: a unique shared telescope design that allows expansion of the outgoing beam for eye-safe operation with opto-mechanical and thermal stability, multi-stage optical filtering enabling measurement during daytime bright-cloud conditions, rapid spectral switching between the online and offline wavelengths enabling measurements during changing atmospheric conditions, and enhanced performance at lower ranges by the introduction of a new filter design and the addition of a wide field-of-view channel. Performance modeling, testing and intercomparisons have been performed and are discussed. In general, the instrument has 150 m range resolution with 10 min temporal resolution - 1 min temporal resolution in the lowest 2 km of the atmosphere is demonstrated. The instrument was shown capable of autonomous long term field operation - 50 days with a >95% uptime - under a broad set of atmospheric conditions and potentially forms the basis for a ground-based network of eye-safe autonomous instruments needed for the atmospheric sciences research and forecasting communities.

  14. Monitoring the temperature of dilute aqueous solutions using near-infrared water absorption.

    PubMed

    Otal, Eugenio H; Iñón, Fernando A; Andrade, Francisco J

    2003-06-01

    An alternative spectroscopic approach for monitoring the temperature of aqueous solutions is presented. The method is based upon the temperature-induced spectral changes undergone by the second overtone (around 960 nm) of the near-infrared (NIR) water absorption band. Single and multilinear regression analysis are tested in order to evaluate the predictive ability of temperature. A linear dependence is found when measurements are performed at a single wavelength, but a lower prediction error is obtained when multilinear models are applied. No matrix effects produced by moderately concentrated common dissolved ions are found in a broad range of pH. A signal-to-noise ratio allows a precision of 0.5 degrees C for temperature monitoring. A prediction error of 0.77 degrees C (single linear regression) and 0.25 degrees C (multilinear approach) are achieved in a range from 15 to 90 degrees C. Advantages in terms of instrumentation and data analysis required are discussed. PMID:14658699

  15. Analysis of chickpea soaking by simultaneous water transfer and water–starch reaction

    Microsoft Academic Search

    Sedat Sayar; Mahir Turhan; Sundaram Gunasekaran

    2001-01-01

    The soaking process of five spring and five winter chickpea genotypes were investigated in water between 20°C and 100°C. Samples did not differ in initial water content (IWC), water absorption capacity (WAC), swelling capacity (SC), and seed coat thickness in terms of the growing season. While WAC decreased with increasing temperature, SC was not affected by temperature. The process was

  16. The seasonal variation in soil water acid neutralizing capacity in peaty podzols in Mid-Wales

    Microsoft Academic Search

    P. J. Chapman; B. Reynolds; H. S. Wheater

    1995-01-01

    Between 1985 and 1990, bulk precipitation and soil solution from the organic (Oh) and mineral (Bs) horizons of a well developed podzol were regularly sampled at a moorland catchment in Mid-Wales. Samples were analysed for pH, major cations, major anions, and dissolved organic carbon (DOC). Acid neutralizing capacity (ANC) was estimated by the charge balance method. Average monthly ANC of

  17. Geophysical imaging of watershed subsurface patterns and prediction of soil texture and water holding capacity

    Microsoft Academic Search

    H. Abdu; D. A. Robinson; M. Seyfried; S. B. Jones

    2008-01-01

    The spatial distribution of subsurface soil textural properties across the landscape is an important control on the hydrological and ecological function of a watershed. Traditional methods of mapping soils involving subjective assignment of soil boundaries are inadequate for studies requiring a quantitative assessment of the landscape and its subsurface connectivity and storage capacity. Geophysical methods such as electromagnetic induction (EMI)

  18. Heat capacities of freely evaporating charged water clusters A. E. K. Sundn,1

    E-print Network

    Hansen, Klavs

    clusters are studied in the laboratory. Although it is possible to thermalize cluster postproduction, most- tions that the clusters have evaporated a molecule at least once after production and entry into vacuum be inverted to give the heat capacity. II. EXPERIMENTAL SETUP AND PROCEDURE The experiment was carried out

  19. Improving estimations of field soil water capacity from laboratory-measured soil properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Different recommendations exist world-wide on which, if any, pressure heads should be used in laboratory measurements to approximate the 'field capacity' (FC) of the soil. Literature often deems any such pressure heads to be inadequate to approximate FC for soils of all textures. We used a data coll...

  20. USING AN ENERGY MODEL TO DESCRIBE THE CONTRIBUTION OF ORGANIC CARBON TO SOIL WATER HOLDING CAPACITY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A model of the water holding characteristics of soil is needed to develop a systematic method for valuing organic C in soil. Water is held in soil between two energy limits: hygroscopic water (-1500 kPa) and capillary rise (about -33 kPa). The General Energy Model for Limited Systems (GEMLS) was use...

  1. Integral energy of conventional available water, least limiting water range and integral water capacity for better characterization of water availability and soil physical quality

    Microsoft Academic Search

    H. Asgarzadeh; M. R. Mosaddeghi; A. A. Mahboubi; A. Nosrati; A. R. Dexter

    2011-01-01

    Different approaches have been proposed for quantification of soil water availability for plants but mostly they do not fully describe how water is released from the soil to be absorbed by the plant roots. A new concept of integral energy (EI) was suggested by Minasny and McBratney (Minasny, B., McBratney, A.B. 2003. Integral energy as a measure of soil-water availability.

  2. Non-isothermal effects on SO2 absorption by water droplets. I - Model development. II - Results and discussion

    NASA Technical Reports Server (NTRS)

    Reda, M.; Carmichael, G. R.

    1982-01-01

    An analytic model of SO2 absorption in a falling water droplet is developed and a simulation of SO2 washout is performed. Nonisothermic effects on drop growth, droplet physical parameters, reaction rates, and multicomponent diffusion are treated in the model. The gas-liquid interface is assumed to be at equilibrium, and interfacial resistance is negligible. Raindrops are simulated as falling from a 2 km height through an atmospheric region containing SO2. The droplets decrease in size from evaporation and cooling, and their slightly basic pH aids SO2 absorption. The simulation indicates higher SO2 absorption at higher altitudes, and desorption may occur at ground level. Isothermal effects are concluded to be significant, and quantification of effects will depend on further modelling.

  3. Pressurized water extraction of ?-glucan enriched fractions with bile acids-binding capacities obtained from edible mushrooms.

    PubMed

    Palanisamy, Marimuthu; Aldars-García, Laila; Gil-Ramírez, Alicia; Ruiz-Rodríguez, Alejandro; Marín, Francisco R; Reglero, Guillermo; Soler-Rivas, Cristina

    2014-01-01

    A pressurized water extraction (PWE) method was developed in order to extract ?-glucans with bile acids-binding capacities from cultivated mushrooms (Agaricus bisporus, Lentinula edodes, and Pleurotus ostreatus) to be used as supplements to design novel foods with hypocholesterolemic properties. Extraction yields were higher in individual than sequential extractions being the optimal extraction parameters: 200°C, 5 cycles of 5 min each at 10.3 MPa. The crude polysaccharide (PSC) fractions, isolated from the PWE extracts contained mainly ?-glucans (including chitooligosaccharides deriving from chitin hydrolysis), ?-glucans, and other PSCs (hetero-/proteo-glucans) depending on the extraction temperature and mushroom strain considered. The observed bile acids-binding capacities of some extracts were similar to a ?-glucan enriched fraction obtained from cereals. PMID:24399760

  4. The influence of recycled expanded polystyrene (EPS) on concrete properties: Influence on flexural strength, water absorption and shrinkage

    NASA Astrophysics Data System (ADS)

    Elsalah, Jamaleddin; Al-Sahli, Yosra; Akish, Ahmed; Saad, Omar; Hakemi, Abdurrahman

    2013-12-01

    Expanded polystyrene waste in a granular form was used as a lightweight aggregate in order to produce lightweight concretë Lightweight EPS concrete composites were produced by replacing the coarse aggregate, either partially or fully with equal volume of EPS aggregates. The coarse aggregate replacements levels used were 25, 50, 75, and 100%, which corresponded to (9.20, 18.40, 27.60, and 36.8%) from total volume. The investigation is directed towards the development and performance evaluation of the concrete composites containing EPS aggregates, without addition of either bonding additives, or super-plasticizers on some concrete properties such as flexure strength, water absorption and change in length (or shrinkage). Experimental results showed that a density reduction of 12% caused flexure strength to decrease by 25.3% at a replacement level of 25% EPS. However, the reduction percentage strongly depends upon the replacement level of EPS granules. Moreover, the lower strength concretes showed a higher water absorption values compared to higher strength concrete, i.e., increasing the volume percentage of EPS increases the water absorption as well as the negative strain (shrinkage). The negative strain was higher at concretes of lower density (containing a high amount of EPS aggregate). The water to cement ratio of EPS aggregate concrete is found to be slightly lower than that of conventional concrete.

  5. Supporting Information: Absorption spectra and photolysis of methyl peroxide in liquid and frozen water

    E-print Network

    Nizkorodov, Sergey

    Supporting Information: Absorption spectra and photolysis of methyl peroxide in liquid and frozen of an absorption temperature dependence. Fig. S3 A) liquid aqueous CH3OOH solution. B) Frozen CH3OOH solution. #12;Fig. S4 Predicted concentration of a dilute aqueous CH3OOH solution as a function of reaction time

  6. First-order equation worksheet Name: Problem 1. A container has the maximum capacity 100 L. Initially, 50 L of salt water (with con-

    E-print Network

    Oh, Seungly

    also) [This is not our typical problem. Note that the water level is changing with time.] (1) Let QFirst-order equation worksheet Name: Problem 1. A container has the maximum capacity 100 L. Initially, 50 L of salt water (with con- centration 2g/L) is in the container. Then, salt water (with

  7. WVR-GPS comparison measurements and calibration of the 20-32 GHz tropospheric water vapor absorption model.

    SciTech Connect

    Keihm, S. J.; Bar-Server, Y.; Liljegren, J. C.; Environmental Research; NASA

    2002-06-01

    Collocated measurements of opacity (from water vapor radiometer brightness temperatures) and wet path delay (from ground-based tracking of global positioning satellites) are used to constrain the model of atmospheric water vapor absorption in the 20-32 GHz band. A differential approach is presented in which the slope of opacity-versus-wet delay data is used as the absorption model constraint. This technique minimizes the effects of radiometric calibration errors and oxygen model uncertainties in the derivation of a best-fit vapor absorption model. A total of approximately five months of data was obtained from two experiment sites. At the Cloud and Radiation Testbed (CART) site near Lamont, Oklahoma, three independent water vapor radiometers (WVRs) provided near-continuous opacity measurements over the interval July-September 1998. At the NASA/Goldstone tracking station in the California desert two WVRs; obtained opacity data over the September-October 1997 interval. At both sites a Global Positioning Satellite (GPS) receiver and surface barometer obtained the data required for deriving the zenith wet delays over the same time frames. Measured values of the opacity-versus-wet delay slope parameter were obtained at four WVR frequencies (20.7, 22.2, 23.8, and 31.4 GHz) and compared with predictions of four candidate absorption models referenced in the literature. With one exception, all three models provide agreement within 5% of the opacity-versus-wet delay slope measurements at all WVR frequencies at both sites. One model provides agreement for all channels at both sites to the 2-3% level. This absorption model accuracy level represents a significant improvement over that attainable using radiosondes.

  8. Mn-Ce oxide as a high-capacity adsorbent for fluoride removal from water.

    PubMed

    Deng, Shubo; Liu, Han; Zhou, Wei; Huang, Jun; Yu, Gang

    2011-02-28

    A novel Mn-Ce oxide adsorbent with high sorption capacity for fluoride was prepared via co-precipitation method in this study, and the granular adsorbent was successfully prepared by calcining the mixture of the Mn-Ce powder and pseudo-boehmite. High-resolution transmission electron microscopy (TEM) image showed that the Mn-Ce adsorbent consisted of about 4.5 nm crystals, and X-ray diffraction (XRD) analysis indicated the formation of solid solution by Mn species entering CeO(2) lattices. The surface hydroxyl group density on the Mn-Ce adsorbent was determined to be as high as 15.3 mmol g(-1), mainly responsible for its high sorption capacity for fluoride. Sorption isotherms showed that the sorption capacities of fluoride on the powdered and granular adsorbent were 79.5 and 45.5 mg g(-1) respectively at the equilibrium fluoride concentration of 1 mg L(-1), much higher than all reported adsorbents. Additionally, the adsorption was fast within the initial 1 h. Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis revealed that the hydroxyl groups on the adsorbent surface were involved in the sorption of fluoride. Both anion exchange and electrostatic interaction were involved in the sorption of fluoride on the Mn-Ce oxide adsorbent. PMID:21208743

  9. Radiation effects in water ice: A near-edge x-ray absorption fine structure study

    SciTech Connect

    Laffon, C.; Lacombe, S.; Bournel, F.; Parent, Ph. [Laboratoire de Chimie-Physique, Matiere et Rayonnement, UMR 7614, Universite Pierre et Marie Curie et CNRS, 11 Rue Pierre et Marie Curie, 75231 Paris, Cedex 05 (France); Laboratoire des Collisions Atomiques et Moleculaires, UMR 8625, Universite Paris Sud 11, 91405 Orsay Cedex (France); Laboratoire de Chimie-Physique, Matiere et Rayonnement, UMR 7614, Universite Pierre et Marie Curie et CNRS, 11 Rue Pierre et Marie Curie, 75231 Paris, Cedex 05 (France)

    2006-11-28

    The changes in the structure and composition of vapor-deposited ice films irradiated at 20 K with soft x-ray photons (3-900 eV) and their subsequent evolution with temperatures between 20 and 150 K have been investigated by near-edge x-ray absorption fine structure spectroscopy (NEXAFS) at the oxygen K edge. We observe the hydroxyl OH, the atomic oxygen O, and the hydroperoxyl HO{sub 2} radicals, as well as the oxygen O{sub 2} and hydrogen peroxide H{sub 2}O{sub 2} molecules in irradiated porous amorphous solid water (p-ASW) and crystalline (I{sub cryst}) ice films. The evolution of their concentrations with the temperature indicates that HO{sub 2}, O{sub 2}, and H{sub 2}O{sub 2} result from a simple step reaction fuelled by OH, where O{sub 2} is a product of HO{sub 2} and HO{sub 2} a product of H{sub 2}O{sub 2}. The local order of ice is also modified, whatever the initial structure is. The crystalline ice I{sub cryst} becomes amorphous. The high-density amorphous phase (I{sub a}h) of ice is observed after irradiation of the p-ASW film, whose initial structure is the normal low-density form of the amorphous ice (I{sub a}l). The phase I{sub a}h is thus peculiar to irradiated ice and does not exist in the as-deposited ice films. A new 'very high density' amorphous phase--we call I{sub a}vh--is obtained after warming at 50 K the irradiated p-ASW ice. This phase is stable up to 90 K and partially transforms into crystalline ice at 150 K.

  10. Radiation effects in water ice: A near-edge x-ray absorption fine structure study

    NASA Astrophysics Data System (ADS)

    Laffon, C.; Lacombe, S.; Bournel, F.; Parent, Ph.

    2006-11-01

    The changes in the structure and composition of vapor-deposited ice films irradiated at 20K with soft x-ray photons (3-900eV) and their subsequent evolution with temperatures between 20 and 150K have been investigated by near-edge x-ray absorption fine structure spectroscopy (NEXAFS) at the oxygen K edge. We observe the hydroxyl OH, the atomic oxygen O, and the hydroperoxyl HO2 radicals, as well as the oxygen O2 and hydrogen peroxide H2O2 molecules in irradiated porous amorphous solid water (p-ASW) and crystalline (Icryst) ice films. The evolution of their concentrations with the temperature indicates that HO2, O2, and H2O2 result from a simple step reaction fuelled by OH, where O2 is a product of HO2 and HO2 a product of H2O2. The local order of ice is also modified, whatever the initial structure is. The crystalline ice Icryst becomes amorphous. The high-density amorphous phase (Iah ) of ice is observed after irradiation of the p-ASW film, whose initial structure is the normal low-density form of the amorphous ice (Ial). The phase Iah is thus peculiar to irradiated ice and does not exist in the as-deposited ice films. A new "very high density" amorphous phase—we call Iavh—is obtained after warming at 50K the irradiated p-ASW ice. This phase is stable up to 90K and partially transforms into crystalline ice at 150K.

  11. Variable Infiltration Capacity model (VIC) is a macro-scale energy and water balance

    E-print Network

    Cherkauer, Keith

    resulting from the fractional area topographic index curve that illustrates the baseflow from lake to upland by integrating topographic wetness index. This study will exam the larger watershed to analyze water table with topographic index, the spatial distribution of water table in large watersheds can be predicted. Syum

  12. LABORATORY CAPACITY NEEDS ASSESSMENT OF DRINKING WATER UTILITIES: A GLOBAL PERSPECTIVE

    EPA Science Inventory

    Fully-functioning analytical laboratories capable of producing quality data are essential components of well-run drinking water utilities. In Europe and the US, drinking water laboratory performance is closely monitored and regulated; this is not always the case in the less indu...

  13. Possibilistic approach for consideration of uncertainties to estimate structural capacity of ageing cast iron water mains

    Microsoft Academic Search

    Solomon Tesfamariam; Balvant Rajani; Rehan Sadiq

    2006-01-01

    Drinking water distribution networks form essential components of all urban centres. Water mains buried in the soil-backfill are exposed to different deleterious reactions, with the result being that the design factor of safety may significantly degrade, leading to structural failure. In particular, metallic distribution and trunk mains are subject to cor- rosion. Proactive pipeline management, which entails timely maintenance, repair,

  14. Capacity of Lemna gibba L. (Duckweed) for Uranium and Arsenic Phytoremediation in Mine Tailing Waters

    Microsoft Academic Search

    Martin Mkandawire; Barbara Taubert; E. Gert Dudel

    2004-01-01

    The potential of Lemna gibba L. to clean uranium and arsenic contamination from mine surface waters was investigated in wetlands of two former uranium mines in eastern Germany and in laboratory hydroponic culture. Water and plants were sampled and L. gibba growth and yield were monitored in tailing ponds from the field study sites. Contaminant accumulation, growth and yield experiments

  15. Effects of PE-g-MA on Tensile Properties, Morphology and Water Absorption of LDPE\\/Thermoplastic Sago Starch Blends

    Microsoft Academic Search

    R. Abdul Majid; H. Ismail; R. Mat Taib

    2009-01-01

    Effects of polyethylene-grafted maleic anhydride (PE-g-MA) on tensile properties, morphology and water absorption of LDPE\\/ Thermoplastic sago starch (TPSS) blends were studied. TPSS was prepared by mixing starch (65 wt. %) and glycerol (35 wt. %) and stored overnight at room temperature. The mixture then was melt-compounded using a heated 2 roll-mills at 150°C for 10 minutes. LDPE\\/TPSS blends with different TPSS

  16. Characterization of Bile Acid Absorption across the Unstirred Water Layer and Brush Border of the Rat Jejunum

    PubMed Central

    Wilson, Frederick A.; Dietschy, John M.

    1972-01-01

    We have examined the rate-limiting steps involved in bile acid absorption across the unstirred water layer and lipid cell membrane of the jejunal mucosa. Uptake of the polar bile acid taurocholate is limited solely by the cell membrane since this compound permeates the unstirred water layer more rapidly than the lipid cell membrane and stirring does not enhance uptake. With less polar bile acids which permeate the cell membrane relatively more rapidly, however, the unstirred water layer does exert resistance to mucosal uptake of these compounds. That the unstirred water layer is even more rate limiting to uptake from micellar solutions is indicated by the facts that the rate of bile acid absorption from such solutions is lower than from corresponding monomer solutions, stirring markedly enhances uptake from micellar solutions while increases in viscosity of the incubation media depress uptake and expansion of the micelle size further depresses absorption rates. We also have examined the important question of whether the micelle crosses the brush border intact once it reaches the aqueous-lipid interface. The observations that the calculated permeation rate of the micelle should be extremely low, the rate of mucosal cell uptake plateaus at a constant value when the critical micelle concentration is reached at the aqueous-lipid interface, and the different components of a mixed micelle are taken up at different rates indicate that uptake of the intact micelle does not occur; rather, bile acid absorption must be explained in terms of monomers in equilibrium with the micelle. Finally, after correction of the permeability coefficients of the various bile acids for the unstirred layer resistance the incremental partial molar free energy of solution of the hydroxyl group in the brush border membrane was calculated to equal ?6126 cal·mole?1 indicating that passive diffusion of these compounds occurs through a very polar region of the cell membrane. PMID:4674396

  17. Energy absorption buildup factor studies in water, air and concrete up to 100 mfp using GP fitting formula

    Microsoft Academic Search

    G. S. Brar; Karamjit Singh; Makhan Singh; Gurmel S. Mudahar

    1994-01-01

    The energy absorption buildup factors for water, air and concrete have been calculated up to a penetration depth of 100 mean free paths using 5-parameter Geometric Progression formula, in the energy range of 0.015-15.0 MeV. The results up to 40 mfp have been compared with the available standard data, whereas the buildup factors of these materials beyond 40 mfp and

  18. Determination of trace nickel in water samples by cloud point extraction preconcentration coupled with graphite furnace atomic absorption spectrometry

    Microsoft Academic Search

    Zhimei Sun; Pei Liang; Qiong Ding; Jing Cao

    2006-01-01

    A new method based on the cloud point extraction (CPE) preconcentration and graphite furnace atomic absorption spectrometry (GFAAS) detection was proposed for the determination of trace nickel in water samples. When the micelle solution temperature is higher than the cloud point of surfactant p-octylpolyethyleneglycolphenyether (Triton X-100), the complex of Ni2+ with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) could enter surfactant-rich phase and be concentrated,

  19. Application of a Micro Z-Arm Mixer to Characterize Mixing Properties and Water Absorption of Wheat Flour

    Microsoft Academic Search

    R. Haraszi; P. W. Gras; S. Tömösközi; A. Salgó; F. Békés

    2004-01-01

    Cereal Chem. 81(5):555-560 This study applied the use of a new small-scale apparatus, the micro Z- arm mixer, which has analogous mixing action to that of the traditional valorigraf and farinograph. A novel methodology has been developed for prediction of water absorption replacing the traditional titration method. The basis of this technique is a common characteristic of wheat flour samples:

  20. Application of Temperature-Dependent Fluorescent Dyes to the Measurement of Millimeter Wave Absorption in Water Applied to Biomedical Experiments

    PubMed Central

    Popenko, Oleksandr

    2014-01-01

    Temperature sensitivity of the fluorescence intensity of the organic dyes solutions was used for noncontact measurement of the electromagnetic millimeter wave absorption in water. By using two different dyes with opposite temperature effects, local temperature increase in the capillary that is placed inside a rectangular waveguide in which millimeter waves propagate was defined. The application of this noncontact temperature sensing is a simple and novel method to detect temperature change in small biological objects. PMID:25435859

  1. Determination of zinc in water samples by flame atomic absorption spectrometry after homogeneous liquid-liquid extraction

    Microsoft Academic Search

    Sh. Dehghan Abkenar; Z. Dahaghin; H. Bagheri Sadeghi; M. Hosseini; M. Salavati-Niasari

    2011-01-01

    In this study, a new and simple homogeneous liquid-liquid extraction (HLLE) method based on a pH-independent phase-separation process was developed using a ternary solvent system [water-tetrabutylammonium\\u000a ion (TBA\\u000a +)-chloroform] for the preconcentration of Zn2+ ions. A Schiff’s base ligand was used as the chelating agent prior to Zn2+ ions extraction. Flame atomic absorption spectrophotometry using acetylene-air flame was used for

  2. Spring carbonate chemistry dynamics of surface waters in the northern East China Sea: Water mixing, biological uptake of CO2, and chemical buffering capacity

    NASA Astrophysics Data System (ADS)

    Zhai, Wei-Dong; Chen, Jian-Fang; Jin, Hai-Yan; Li, Hong-Liang; Liu, Jin-Wen; He, Xian-Qiang; Bai, Yan

    2014-09-01

    We investigated sea surface total alkalinity (TAlk), dissolved inorganic carbon (DIC), dissolved oxygen (DO), and satellite-derived chlorophyll-a in the connection between the Yellow Sea and the East China Sea (ECS) during April to early May 2007. In spring, Changjiang dilution water (CDW), ECS offshore water, and together with Yellow Sea water (YSW) occupied the northern ECS. Using 16 day composite satellite-derived chlorophyll-a images, several algal blooms were identified in the CDW and ECS offshore water. Correspondingly, biological DIC drawdown of 73 ± 20 ?mol kg-1, oversaturated DO of 10-110 ?mol O2 kg-1, and low fugacity of CO2 of 181-304 ?atm were revealed in these two waters. YSW also showed CO2 uptake in spring, due to the very low temperature. However, its intrusion virtually counteracted CO2 uptake in the northern ECS. In the CDW and the ECS offshore water, Revelle factor was 9.3-11.7 and 8.9-10.6, respectively, while relatively high Revelle factor values of 11.4-13.0 were revealed in YSW. In the ECS offshore water, the observed relationship between DIC drawdown and oversaturated DO departed from the Redfield ratio, indicating an effect of chemical buffering capacity on the carbonate system during air-sea reequilibration. Given the fact that the chemical buffering capacity slows down the air-sea reequilibration of CO2, the early spring DIC drawdown may have durative effects on the sea surface carbonate system until early summer. Although our study is subject to limited temporal and spatial coverage of sampling, these insights are fundamental to understanding sea surface carbonate chemistry dynamics in this important ocean margin.

  3. Ultraviolet-visible absorption spectra of chromophoric dissolved organic matter (CDOM) in waters throughout the Kolyma River basin, East Siberia

    NASA Astrophysics Data System (ADS)

    Frey, K. E.; Bulygina, E. B.; Bunn, A. G.; Chandra, S.; Davydov, S.; Holmes, R. M.; Schade, J. D.; Sobczak, W. V.; Spektor, V. V.; Zimov, S. A.

    2009-12-01

    The Kolyma River in East Siberia is among the six largest Arctic rivers and drains a region underlain by vast deposits of Pleistocene loess known as yedoma, most of which are currently stored in ice-rich permafrost throughout the region. These yedoma deposits are important sources of dissolved organic matter to terrestrial waters that in turn play a significant role in the transport and ultimate mineralization of organic carbon to atmospheric CO2 and CH4. In order to determine the concentrations and characteristics of this dissolved organic matter, we measured the ultraviolet-visible absorption spectra (200-800 nm) of chromophoric dissolved organic matter (CDOM) from a broad collection of waters throughout a ~250 km transect of the northern Kolyma River basin. 124 samples were collected during July 2008 and 2009 and include soil pore waters, lakes, streams, rivers, and the Kolyma River mainstem. Absorbance values are highly positively correlated with dissolved organic carbon concentrations, with the highest values in soil pore waters and lowest values in the Kolyma River mainstem. Spectral slopes (at 275-295 nm and 350-400 nm, calculated within log-transformed absorption spectra) are also used to investigate contrasting water types and are found to be useful indicators of the bioavailability of dissolved organic matter. With ongoing and future permafrost degradation, yedoma deposits throughout the East Siberian region will become more hydrologically active and have the potential to be even greater sources of dissolved organic matter to soil pore waters, lakes, streams, rivers, and ultimately to the Arctic Ocean. As such, the ability to easily and comprehensively monitor the quantity and quality of dissolved organic matter across the landscape through methods such as ultraviolet-visible absorption is becoming critical for understanding the global significance of the Arctic carbon cycle.

  4. Graphite furnace atomic absorption spectrometric detection of vanadium in water and food samples after solid phase extraction on multiwalled carbon nanotubes.

    PubMed

    Wadhwa, Sham Kumar; Tuzen, Mustafa; Gul Kazi, Tasneem; Soylak, Mustafa

    2013-11-15

    Vanadium(V) ions as 8-hydroxyquinoline chelates were loaded on multiwalled carbon nanotubes (MWNTs) in a mini chromatographic column. Vanadium was determined by graphite furnace atomic absorption spectrometry (GFAAS). Various analytical parameters including pH of the working solutions, amounts of 8-hydroxyquinoline, eluent type, sample volume, and flow rates were investigated. The effects of matrix ions and some transition metals were also studied. The column can be reused 250 times without any loss in its sorption properties. The preconcentration factor was found as 100. Detection limit (3 s) and limit of quantification (10 s) for the vanadium in the optimal conditions were observed to be 0.012 µg L(-1) and 0.040 ?g L(-1), respectively. The capacity of adsorption was 9.6 mg g(-1). Relative standard deviation (RSD) was found to be 5%. The validation of the method was confirmed by using NIST SRM 1515 Apple leaves, NIST SRM 1570a Spinach leaves and GBW 07605 Tea certified reference materials. The procedure was applied to the determination of vanadium in tap water and bottled drinking water samples. The procedure was also successfully applied to microwave digested food samples including black tea, coffee, tomato, cabbage, zucchini, apple and chicken samples. PMID:24148394

  5. Effects of surface water on gas sorption capacities of gravimetric sensing layers analyzed by molecular descriptors of organic adsorbates.

    PubMed

    Sugimoto, Iwao; Mitsui, Kouta; Nakamura, Masayuki; Seyama, Michiko

    2011-02-01

    The gas sorption capacities of sputtered carbonaceous films are evaluated with quartz crystal resonators. These films are sensitive to 20 ppm organic vapors and exhibit structure-dependent responses. Films derived from synthetic polymers are hydrophobic, whereas films derived from biomaterials are amphiphilic or hydrophilic. Polyethylene (PE) film has an extremely high sorption capacity for a wide range of vapors. Transient sorption responses are investigated using a humidified carrier by employing carboxylic acid esters, whose aliphatic groups are systematically changed. Small esters with a higher affinity to water induce negative U-shaped responses from amphiphilic films derived from biomaterials. On the other hand, polymeric films exhibit positive exponential response curves. Even if the concentrations are decreased, the response intensities are enhanced with the incremental expansion of carbon chains of aliphatic groups. Only fluoropolymer film shows the opposite tendency. The modeling of quantitative structure property relationships has indicated that the sorption capacities of the PE film to the carboxylic acid esters are fundamentally governed by electrostatic interactions. The intermolecular attractive forces are basically attributable to interactions between the positively polarized sites in esters and the negatively polarized/charged sites in PE film. PMID:21165608

  6. Biogeochemical origins of particles obtained from the inversion of the volume scattering function and spectral absorption in coastal waters

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Huot, Y.; Gray, D. J.; Weidemann, A.; Rhea, W. J.

    2013-09-01

    In the aquatic environment, particles can be broadly separated into phytoplankton (PHY), non-algal particle (NAP) and dissolved (or very small particle, VSP) fractions. Typically, absorption spectra are inverted to quantify these fractions, but volume scattering functions (VSFs) can also be used. Both absorption spectra and VSFs were used to estimate particle fractions for an experiment in the Chesapeake Bay. A complete set of water inherent optical properties was measured using a suite of commercial instruments and a prototype Multispectral Volume Scattering Meter (MVSM); the chlorophyll concentration, [Chl] was determined using the HPLC method. The total scattering coefficient measured by an ac-s and the VSF at a few backward angles measured by a HydroScat-6 and an ECO-VSF agreed with the LISST and MVSM data within 5%, thus indicating inter-instrument consistency. The size distribution and scattering parameters for PHY, NAP and VSP were inverted from measured VSFs. For the absorption inversion, the "dissolved" absorption spectra were measured for filtrate passing through a 0.2 ?m filter, whereas [Chl] and NAP absorption spectra were inverted from the particulate fraction. Even though the total scattering coefficient showed no correlation with [Chl], estimates of [Chl] from the VSF-inversion agreed well with the HPLC measurements (r = 0.68, mean relative errors = -20%). The scattering associated with NAP and VSP both correlated well with the NAP and "dissolved" absorption coefficients, respectively. While NAP dominated forward, and hence total, scattering, our results also suggest that the scattering by VSP was far from negligible and dominated backscattering. Since the sizes of VSP range from 0.02 to 0.2 ?m, covering (a portion of) the operationally defined "dissolved" matter, the typical assumption that colored dissolved organic matter (i.e., CDOM) does not scatter may not hold, particularly in a coastal or estuarine environment.

  7. The self-cleaning capacity of surface waters after radioactive fallout. Evidence from European waters after Chernobyl, 1986-1988

    Microsoft Academic Search

    Peter H. Santschi; S. Bollhalder; S. Zingg; A. Lueck; K. Farrenkothen

    1990-01-01

    Radionuclide fallout from the burning Chernobyl reactor provided a pulsed input of ¹³⁷Cs to surface waters and watersheds of Europe. Radionuclide analyses of surface waters indicated that initial rates of decrease of ¹³⁷Cs concentrations in contaminated rivers were on the order of 0.125 day⁻¹, which was found to be consistent with the size of the mobile inventory in the watersheds

  8. Assessment of capacity sensors for monitoring soil water content in ecological orchards

    NASA Astrophysics Data System (ADS)

    Patrícia Prazeres Marques, Karina; Horcajo, Daniel; Rodriguez-Sinobas, Leonor

    2014-05-01

    Water is an important element for soil tillage and crop development. Its proper management is essential for the development of plants, by preventing excess or shortage in water application. Soil water content is affected by the soil-water-plant system and its monitoring is a required within a sustainable agriculture framework respectful with the natural environment. Thus, the aim of this study was to evaluate the performance of capacitive sensors in monitoring soil moisture from organic orchards. An experimental text was carried out at the Hydraulics Laboratory of the Agricultural Engineering School in the Polytechnic University of Madrid (Spain). Soil samples were collected within the 0-20 cm depth layers from the university organic orchard. The samples were air dried and subsequently sieved in a 2 mm mesh sieve, removing roots and coarse fractions and keeping the fine soil. The amount of fine soil was calculated from the soil density and the soil samples were compacted to obtain the relative volume that corresponded to their density. The measurements were carried out in dry and in saturated soil and, also in samples where soil was stirring with: 150 cm³, 300 cm³ and 450 cm³ of water. A 1890 ml container was used to hold the fine soil and the soil moisture sensor ECH2O, type 10 HS (Decagon Devices, Inc.) was placed horizontally at 5 cm depth. Soil water readings were recorded on a datalogger Em5b from the same manufacturer. The results showed that the capacitive sensor has a linear response to soil moisture content. Its value was overestimated in comparison to the volumetric values and the largest errors (about 8%) were observed in the soils with high moisture contents. Overall, these results point out that the ECH2O sensor, model 10 HS, could determine with sufficient accuracy the volumetric soil water content from organic orchards although it could be further improved by "in situ" calibration.

  9. Sources and light absorption of water-soluble brown carbon aerosols in the outflow from northern China

    NASA Astrophysics Data System (ADS)

    Kirillova, E. N.; Andersson, A.; Han, J.; Lee, M.; Gustafsson, Ö.

    2013-07-01

    High loadings of anthropogenic carbonaceous aerosols in Chinese air influence the air quality for over 1 billion people and impact the regional climate. A large fraction (17-80%) of this aerosol carbon is water soluble, promoting cloud formation and thus climate cooling. Recent findings, however, suggest that water-soluble carbonaceous aerosols also absorb sunlight, bringing additional direct and indirect climate warming effects, yet the extent and nature of light absorption by this water-soluble brown carbon (WS-BrC) and its relation to sources is poorly understood. Here, we combine source estimates constrained by dual-carbon-isotope with light absorption measurements of WS-BrC for a March 2011 campaign at the Korea Climate Observatory at Gosan (KCOG), a receptor station in SE Yellow Sea for the outflow from N. China. The mass absorption cross-section (MAC) of WS-BrC for air masses from N. China were in general higher (0.8-1.1 m2 g-1), than from other source regions (0.3-0.8 m2 g-1). We estimate that this effect corresponds to 13-49% of the radiative forcing caused by light absorption by black carbon. Radiocarbon constraints show that the WS-BrC in Chinese outflow had significantly higher amounts of fossil sources (30-50%) compared to previous findings in S. Asia, N. America and Europe. Stable carbon (?13C) measurements indicated influence of aging during air mass transport. These results indicate the importance of incorporating WS-BrC in climate models and the need to constrain climate effects by emission source sector.

  10. Profiling of carotenoids and antioxidant capacity of microalgae from subtropical coastal and brackish waters.

    PubMed

    Ahmed, Faruq; Fanning, Kent; Netzel, Michael; Turner, Warwick; Li, Yan; Schenk, Peer M

    2014-12-15

    Carotenoids are associated with various health benefits, such as prevention of age-related macular degeneration, cataract, certain cancers, rheumatoid arthritis, muscular dystrophy and cardiovascular problems. As microalgae contain considerable amounts of carotenoids, there is a need to find species with high carotenoid content. Out of hundreds of Australian isolates, 12 microalgal species were screened for carotenoid profiles, carotenoid productivity, and in vitro antioxidant capacity (total phenolic content (TPC) and ORAC). The top four carotenoid producers at 4.68-6.88 mg/g dry weight (DW) were Dunaliella salina, Tetraselmis suecica, Isochrysis galbana, and Pavlova salina. TPC was low, with D. salina possessing the highest TPC (1.54 mg Gallic Acid Equivalents/g DW) and ORAC (577 ?mol Trolox Equivalents/g DW). Results indicate that T. suecica, D. salina, P. salina and I. galbana could be further developed for commercial carotenoid production. PMID:25038679

  11. Influence of water depth on the carbon sequestration capacity of seagrasses

    NASA Astrophysics Data System (ADS)

    Serrano, Oscar; Lavery, Paul S.; Rozaimi, Mohammad; Mateo, Miguel Ángel

    2014-09-01

    The actual estimates of carbon stocks beneath seagrass meadows worldwide are derived from few data, resulting in a tendency to generalize global carbon stocks from a very limited number of seagrass habitats. We surveyed Posidonia oceanica and Posidonia sinuosa meadows along depth-induced gradients of light availability to assess the variability in their sedimentary organic carbon (Corg) stocks and accretion rates. This study showed a fourfold decrease in Corg stocks from 2-4 m to 6-8 m depth P. sinuosa meadows (averaging 7.0 and 1.8 kg m-2, respectively; top meter of sediment) and a fourteenfold to sixteenfold decrease from shallow (2 m) to deep (32 m) P. oceanica meadows (200 and 19 kg m-2 average, respectively; top 2.7 m of sediment). The average Corg accretion rates in shallow P. sinuosa meadows were higher (10.5 g m-2 yr-1) than in deeper meadows (2.1 g m-2 yr-1). The reduction of sedimentary Corg stocks and accretion rates along depth-related gradients of light reduction suggests that irradiance, controlling plant productivity, meadow density, and sediment accretion rates, is a key environmental factor affecting Corg storage potential of seagrasses. The results obtained highlighted the exceptional carbon storage capacity of P. oceanica meadows at Balearic Islands (Spain), containing the highest areal Corg stocks of all seagrasses (estimated in up to 691-770 kg m-2 in 8-13 m thick deposits). Seagrass communities are experiencing worldwide decline, and reduced irradiance (following e.g., eutrophication or sediment regime alterations) will lead to photoacclimation responses (i.e., reduced plant productivity and shoot density), which may impact the carbon sequestration capacity of seagrasses.

  12. Growth capacity and biochemical mechanisms involved in rhizobia tolerance to salinity and water deficit.

    PubMed

    Mhamdi, Rakia; Nouairi, Issam; Ben Hammouda, Thouraya; Mhamdi, Ridha; Mhadhbi, Haythem

    2015-04-01

    The aim of the present study was to evaluate abiotic stress tolerance of rhizobial strains belonging to Mesorhizobium, Sinorhizobium, and Rhizobium genera, as well as to investigate specie specific stress response mechanisms. Effect of NaCl and PEG on growth capacity, protein, lipid peroxydation (MDA), membrane fatty acid composition and antioxidant enzymes were investigated. Growth capacity and viability of overall rhizobia strains decreased proportionally to the increase of NaCl and PEG levels in the medium. Sinorhizobium strains appeared the most tolerant, where 4H41strain was able to grow at 800?mM NaCl and 40% PEG. On the other hand, growth of R. gallicum and M. mediterraneum was inhibited by 200?mM NaCl. The content of MDA was unchanged in Sinorhizobium strains under both stresses. For Mesorhizobium, only PEG treatment increased the content of MDA. Amount of the C19:0 cyclo fatty-acid was increased in both Sinorhizobium and Mesorhizobium tolerant strains. NaCl stress increased Superoxide dismutase (SOD) activity of overall species; especially the most tolerant strain 4H41. Both treatments increased catalase (CAT) activity in 4H41, TII7, and 835 strains. Obtained results suggest that major response of tolerant Sinorhizobium and Mesorhizobium strains to NaCl and PEG stresses is a preferential accumulation of the C19:0 cyclo fatty acid within bacterial membrane as mechanism to reduce fluidity and maintain integrity. Cell integrity and functioning is also assured by maintaining and/or increasing activity of SOD and CAT antioxidant enzymes for tolerant strains to omit structural and functional damages related to reactive oxygen species overproduced under stressful conditions. PMID:25546228

  13. Water vapor differential absorption lidar measurements using a diode-pumped all-solid-state laser at 935 nm

    NASA Astrophysics Data System (ADS)

    Fix, A.; Ehret, G.; Löhring, J.; Hoffmann, D.; Alpers, M.

    2011-03-01

    A diode-pumped, single-frequency laser system emitting at 935 nm has recently been developed to serve as the transmitter for water vapor differential absorption lidar (DIAL) measurements. This laser uses Nd:YGG (Y3Ga5O12) as the active medium and emits radiation directly at 935 nm without the need of additional frequency conversion processes. The system was diode-pumped at 806 nm and was built up in a master-oscillator-power-amplifier configuration. It generates more than 30 mJ of pulse energy at 100 Hz repetition rate with a beam quality ( M 2) of better than 1.4. Since water vapor DIAL demands for stringent requirements of the spectral properties those were carefully investigated in the scope of this paper. Single-frequency operation is achieved by injection seeding and active length control of the oscillator cavity. The range of continuously tunable single-frequency radiation extends to ˜0.4 nm centered around 935.31 nm. Values of the spectral purity of >99.996% were determined using long-pass absorption measurements in the atmosphere exceeding the requirements by a large margin. Finally, for the first time water vapor DIAL measurements were performed using a Nd:YGG laser. The reported results show much promise of these directly pumped lasers at 935 nm for future spaceborne but also airborne water vapor lidar systems.

  14. Institutional Capacity on Water Pollution Control of the Pearl River in Guangzhou, China

    Microsoft Academic Search

    Yuan Yu; Dieudonné-Guy Ohandja; J. Nigel B. Bell

    2012-01-01

    This paper analyzes the role of the prevalent formal and informal institutions in Guangzhou in alleviating deteriorating water quality in the Pearl River. In addition to the dominating role of the local government, it examines the influences of other relevant factors such as the role of environmental non-governmental organizations, the media, and the impact of social and cultural norms. It

  15. Geophysical imaging of watershed subsurface patterns and prediction of soil texture and water holding capacity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The extent to which soil resource availability, nutrients or moisture, contro1 the structure, function and diversity of plant communities has aroused considerableinterest in the past decade, and remains topical in light of global change. Numerous plant communities are controlled either by water or s...

  16. Influence of water vapor pressure on the apparent capacity for physiological thermoregulation in reptiles

    Microsoft Academic Search

    Wesley W. Weathers

    1972-01-01

    The rate of body temperature change was determined as lizards,Dipsosaurus dorsalis, were heated and cooled between 20 and 40 ° C, at various ambient water vapor pressures (WVP). While changes in WVP did not affect the rate of cooling, the rate of temperature change during heating increased exponentially with increasing WVP (Fig. 4). The ratio of the rate of body

  17. A Simple Approach for Demonstrating Soil Water Retention and Field Capacity

    ERIC Educational Resources Information Center

    Howard, A.; Heitman, J. L.; Bowman, D.

    2010-01-01

    It is difficult to demonstrate the soil water retention relationship and related concepts because the specialized equipment required for performing these measurements is unavailable in most classrooms. This article outlines a low-cost, easily visualized method by which these concepts can be demonstrated in most any classroom. Columns (62.5 cm…

  18. Flow-through PSICAM: a new approach for determining water constituents absorption continuously

    NASA Astrophysics Data System (ADS)

    Wollschläger, Jochen; Grunwald, Maik; Röttgers, Rüdiger; Petersen, Wilhelm

    2013-07-01

    Determination of spectral absorption coefficients in seawater is of interest for biologic oceanographers for various reasons, but faces also several problems, especially if continuous measurements are required. We introduce the flow-through point-source integrating cavity absorption meter (ft-PSICAM) as a new tool for the continuous measurement of spectral absorption coefficients in a range of 400-710 nm. A description of the system is given and its performance in comparison with a conventional PSICAM has been evaluated on two cruises in 2011 in the southern part of the North Sea (German Bight). Furthermore, factors influencing the measurement are discussed. When comparing the data of both systems, a good linear correlation has been found for all wavelengths ( r 2 > 0.91). Deviations between systems were different with respect to the wavelength examined with slopes of linear fits between 1.1 and 1.65 and offsets between -0.1 and 0.01, with the higher values at shorter wavelengths. They were caused mainly due to contamination of the flow-through system during operation by phytoplankton particles. Focus was also laid on the measurement of chlorophyll- a concentrations ([chl- a]) and total suspended matter concentrations ([TSM]) on the basis of absorption coefficient determination. For this, appropriate relationships were established and [chl- a] and [TSM] values were calculated from the relevant ft-PSICAM absorption coefficients. Their progression matches well with the progression of fluorescence and turbidity measurements made in parallel. In conclusion, the ft-PSICAM is successful in measuring spectral absorption coefficients continuously and resolving relative changes in seawater optical properties.

  19. Estimation of plant water content by spectral absorption features centered at 1,450 nm and 1,940 nm regions.

    PubMed

    Wang, Jie; Xu, Ruisong; Yang, Shilun

    2009-10-01

    Vegetation water content could possibly provide widespread utility in agriculture, forestry and hydrology. In this article, three species leaves were measured radiometrically in order to determine a relationship between leaf water status and the spectral feature centered at 1,450 and 1,940 nm where there are strong water absorptions. The first step of our research is to measure leaf spectra with a FieldSpec-FR. After the spectral analysis using the continuum removal technique, the spectral absorption feature parameters: absorption band depth (D (1450), D (1940)), the normalized band depth of absorption in 1,450 and 1,940 nm (BNA(1450), BNA(1940)), the ratio of the two reflectance of continuum line (R (1450i )/R (1940i )), the ratio of the two band depth (D (1450)/D (1940)) and the ratio of the two absorption areas (A (1450)/A (1940)) in the two wavebands were extracted from each leaf spectrum. The fuel moisture content (FMC), specific leaf weight (SLW), equivalent water thickness (EWT) were measured for each leaf sample. A correlation analysis was conducted between the spectral absorption feature parameters and corresponding FMC, SLW and EWT. In addition, some existing indices for assessing water status such as WI (water index), WI/NDVI (water index/normalized difference vegetation index), MSI (moisture stress index), NDWI (normalized difference water index)were calculated and the correlation between them and water status were analyzed too. The results by comparing the correlations indicated that the spectral absorption feature indices we proposed were better. The indexes BNA(1940), D (1450)/D (1940), and A (1450)/A (1940) were well correlated with FMC, and the correlation between the indexes D (1450,) D (1940), R (1450i )/R (1940i ) and EWT were strong. The index A (1450)/A (1940) was tested to be a good indictor for evaluating plant water content, because there was strongest positive correlation between it and FMC than other indices. PMID:18853268

  20. Determination of Trace Silver in Water Samples by Online Column Preconcentration Flame Atomic Absorption Spectrometry Using Termite Digestion Product

    PubMed Central

    Bianchin, Joyce Nunes; Martendal, Edmar; Carasek, Eduardo

    2011-01-01

    A new method for Ag determination in water samples using solid phase extraction (SPE) coupled to a flow injection system and flame atomic absorption spectrometry was developed. The sorbent used for Ag preconcentration and extraction was the termite digestion product. Flow and chemical variables of the system were optimized through a multivariate procedure. The factors selected were adsorbent mass, buffer type and concentration, sample pH, and sample flow rate. The detection limit and precision were 3.4??g?L?1 and 3.8% (n = 6, 15??g?L?1), respectively. The enrichment factor and the linear working range were, respectively, 21 and 10–50??g?L?1. Results for recovery tests using different water samples were between 96 and 107%. The proposed methodology was applied with success for the determination of Ag in water used to wash clothes impregnated with silver nanoparticles, supplied by a factory located in Santa Catarina, Brazil. PMID:21804766

  1. Determination of trace silver in water samples by online column preconcentration flame atomic absorption spectrometry using termite digestion product.

    PubMed

    Bianchin, Joyce Nunes; Martendal, Edmar; Carasek, Eduardo

    2011-01-01

    A new method for Ag determination in water samples using solid phase extraction (SPE) coupled to a flow injection system and flame atomic absorption spectrometry was developed. The sorbent used for Ag preconcentration and extraction was the termite digestion product. Flow and chemical variables of the system were optimized through a multivariate procedure. The factors selected were adsorbent mass, buffer type and concentration, sample pH, and sample flow rate. The detection limit and precision were 3.4??g?L(-1) and 3.8% (n = 6, 15??g?L(-1)), respectively. The enrichment factor and the linear working range were, respectively, 21 and 10-50??g?L(-1). Results for recovery tests using different water samples were between 96 and 107%. The proposed methodology was applied with success for the determination of Ag in water used to wash clothes impregnated with silver nanoparticles, supplied by a factory located in Santa Catarina, Brazil. PMID:21804766

  2. Globalland30 Mapping Capacity of Land Surface Water in Thessaly, Greece

    NASA Astrophysics Data System (ADS)

    Manakos, Ioannis; Chatzopoulos-Vouzoglanis, Konstantinos; Petrou, Zisis I.; Filchev, Lachezar; Apostolakis, Antonis

    2015-01-01

    The National Geomatics Center of China (NGCC) produced Global Land Cover (GlobalLand30) maps with 30 m spatial resolution for the years 2000 and 2009-2010, responding to the need for harmonized, accurate, and high-resolution global land cover data. This study aims to assess the mapping accuracy of the land surface water layer of GlobalLand30 for 2009-2010. A representative Mediterranean region, situated in Greece, is considered as the case study area, with 2009 as the reference year. The assessment is realized through an object-based comparison of the GlobalLand30 water layer with the ground truth and visually interpreted data from the Hellenic Cadastre fine spatial resolution (0.5 m) orthophoto map layer. GlobCover 2009, GlobCorine 2009, and GLCNMO 2008 corresponding thematic layers are utilized to show and quantify the progress brought along with the increment of the spatial resolution, from 500 m to 300 m and finally to 30 m with the newly produced GlobalLand30 maps. GlobalLand30 detected land surface water areas show a 91.9% overlap with the reference data, while the coarser resolution products are restricted to lower accuracies. Validation is extended to the drainage network elements, i.e., rivers and streams, where GlobalLand30 outperforms the other global map products, as well.

  3. Measurements of mesospheric water vapour, aerosols and temperatures with the Spectral Absorption Line Imager (SALI-AT)

    NASA Astrophysics Data System (ADS)

    Shepherd, M. G.; Mullins, M.; Brown, S.; Sargoytchev, S. I.

    2001-08-01

    Water vapour concentration is one of the most important, yet one of the least known quantities of the mesosphere. Knowledge of water vapour concentration is the key to understanding many mesospheric processes, including the one that is primary focus of our investigation, mesospheric clouds (MC). The processes of formation and occurrence parameters of MC constitute an interesting problem in their own right, but recently evidence has been provided which suggests that they are a critical indicator of atmospheric change. The aim of the SALI-AT experiment is to make simultaneous (although not strictly collocated) measurements of water vapour, aerosols and temperature in the mesosphere and the mesopause region under twilight condition in the presence of mesospheric clouds. The water vapour will be measured in the regime of solar occultation utilizing a water vapour absorption band at 936 nm wavelength employing the SALI (Spectral Absorption Line Imager) instrument concept. A three-channel zenith photometer, AT-3, with wavelengths of 385 nm, 525 nm, and 1040 nm will measure Mie and Rayleigh scattering giving both mesospheric temperature profiles and the particle size distribution. Both instruments are small, low cost and low mass. It is envisioned that the SALI-AT experiment be flown on a small rocket - the Improved Orion/Hotel payload configuration, from the Andoya Rocket range, Norway. Alternatively the instrument can be flown as a "passenger" on larger rocket carrying other experiments. In either case flight costs are relatively low. Some performance simulations are presented showing that the instrument we have designed will be sufficiently sensitive to measure water vapor in concentrations that are expected at the summer mesopause, about 85 km height.

  4. Improvement of the COP of the LiBr-Water Double-Effect Absorption Cycles

    NASA Astrophysics Data System (ADS)

    Shitara, Atsushi

    Prevention of the global warming has called for a great necessity for energy saving. This applies to the improvement of the COP of absorption chiller-heaters. We started the development of the high efficiency gas-fired double-effect absorption chiller-heater using LiBr-H2O to achieve target performance in short or middle term. To maintain marketability, the volume of the high efficiency machine has been set below the equal to the conventional machine. The absorption cycle technology for improving the COP and the element technology for downsizing the machine is necessary in this development. In this study, the former is investigated. In this report, first of all the target performance has been set at cooling COP of 1.35(on HHV), which is 0.35 higher than the COP of 1.0 for conventional machines in the market. This COP of 1.35 is practically close to the maximum limit achievable by double-effect absorption chiller-heater. Next, the design condition of each element to achieve the target performance and the effect of each mean to improve the COP are investigated. Moreover, as a result of comparing the various flows(series, parallel, reverse)to which the each mean is applied, it has been found the optimum cycle is the parallel flow.

  5. SOFIA/EXES Observations of Water Absorption in the Protostar AFGL 2591 at High Spectral Resolution

    NASA Astrophysics Data System (ADS)

    Indriolo, Nick; Neufeld, D. A.; DeWitt, C. N.; Richter, M. J.; Boogert, A. C. A.; Harper, G. M.; Jaffe, D. T.; Kulas, K. R.; McKelvey, M. E.; Ryde, N.; Vacca, W.

    2015-04-01

    We present high spectral resolution (˜3 km s-1) observations of the {{? }2} ro-vibrational band of H2O in the 6.086-6.135 ?m range toward the massive protostar AFGL 2591 using the Echelon-Cross-Echelle Spectrograph (EXES) on the Stratospheric Observatory for Infrared Astronomy (SOFIA). Ten absorption features are detected in total, with seven caused by transitions in the {{? }2} band of H2O, two by transitions in the first vibrationally excited {{? }2} band of H2O, and one by a transition in the {{? }2} band of H218O. Among the detected transitions is the {{? }2} 11,1-00,0 line that probes the lowest-lying rotational level of para-H2O. The stronger transitions appear to be optically thick, but reach maximum absorption at a depth of about 25%, suggesting that the background source is only partially covered by the absorbing gas or that the absorption arises within the 6 ?m emitting photosphere. Assuming a covering fraction of 25%, the H2O column density and rotational temperature that best fit the observed absorption lines are N({{H}2}O)=(1.3+/- 0.3)× {{10}19} cm-2 and T=640+/- 80 K.

  6. Estimation of the absorption and backscattering coefficients from in-water radiometric measurements

    Microsoft Academic Search

    Malgorzata Stramska; Dariusz Stramski; B. Greg Mitchell; Curtis D. Mobley

    2000-01-01

    Numerical simulations of radiative transfer within the ocean surface mixed layer have been used to derive a set of simple equations for estimating the absorption, a, and backscattering, bb, coefficients in the blue-green spectral region from measurements of downwelling irradiance, Ed, upwelling irradiance, Eu, and upwelling nadir radiance, Lu. Two relationships are used in this derivation: (i) irradiance reflectance, R

  7. Building Capacity to Integrate NASA Earth Science into Water Resources Management Applications in the Context of a Changing Climate

    NASA Astrophysics Data System (ADS)

    Prados, A. I.; Mehta, A. V.

    2011-12-01

    The NASA Applied Sciences program provides technical capacity building activities to enable decision-makers to integrate NASA Earth Science into environmental management activities. This includes workshops tailored to end-user needs by working directly with agencies to 1) identify environmental management activities that could benefit from NASA Earth Science and 2) conducting workshops that teach the NASA products and decision-support tools best suited to the identified application area. Building on a successful 3-year effort on air pollution monitoring for environmental applications, the project has expanded into water resources. Climate Change has dramatically increased demand for observational and predictive data in support of decision making activities related to water supply and demand. However, a gap remains between NASA products and applied research and the entities who stand to benefit from their utilization. To fill this gap, the project has developed short courses on 1) impacts of climate change on water resources 2) hands-on exercises on access and interpretation of NASA imagery relevant to water resources management via the use of decision-support web tools and software and 3) case studies on the application of NASA products in the field. The program is currently focused on two areas 1) precipitation products over the central and southern U.S. that help communities and agencies improve flooding forecasts and 2) snow and snow/water equivalent products over the western U.S and Latin America that can provide end-users with improved stream flow prediction in Spring within a framework of decreasing snow availability.

  8. Synthesis and water absorption transport mechanism of a pH-sensitive polymer network structured on vinyl-functionalized pectin.

    PubMed

    Guilherme, Marcos R; Moia, Thais A; Reis, Adriano V; Paulino, Alexandre T; Rubira, Adley F; Mattoso, Luiz H C; Muniz, Edvani C; Tambourgi, Elias B

    2009-01-12

    Polysaccharide-structured copolymer hydrogel having excellent pH-sensitivity was developed from N,N-dimethylacrylamide (DMAc) and vinyl-functionalized Pectin (Pec). The Pec was vinyl-functionalized by way of chemical reaction with glycidyl metacrylate (GMA) in water under acidic and thermal stimuli. 13C NMR, 1H NMR, and FT-IR spectra revealed that the vinyl groups coming from the GMA were attached onto backbone of the polysaccharide. The hydrogels were obtained by polymerization of the Pec-vinyl with the DMAc. 13C-CP/MAS NMR and FTIR spectra confirmed that the gelling process occurred by way of the vinyl groups attached on Pec-vinyl backbone. The values of apparent swelling rate constant (k) decreased appreciably for pH greater than 6, demonstrating the swelling process of the hydrogel becomes slower at more alkaline conditions. There was an increase of diffusional exponent (n) with increasing pH of the surrounding liquid. This means the water absorption profile becomes more dependent on the polymer relaxation in basified swelling media. In this condition, a longer water absorption half-time (t1/2) was verified, suggesting the polymer relaxation mechanism of the hydrogel would have a considerable effect on the t1/2. PMID:19133836

  9. Effect of water density on the absorption maximum of hydrated electrons in sub- and supercritical water up to 400 degrees C.

    PubMed

    Jay-Gerin, Jean-Paul; Lin, Mingzhang; Katsumura, Yosuke; He, Hui; Muroya, Yusa; Meesungnoen, Jintana

    2008-09-21

    The optical absorption spectra of the hydrated electron (e(aq) (-)) in supercritical (heavy) water (SCW) are measured by electron pulse radiolysis techniques as a function of water density at three temperatures of 380, 390, and 400 degrees C, and over the density range of approximately 0.2-0.65 g/cm(3). In agreement with previous work, the position of the e(aq) (-) absorption maximum (E(A(max) )) is found to shift slightly to lower energies (spectral "redshift") with decreasing density. A comparison of the present E(A(max) )-density data with other measurements already reported in the literature in subcritical (350 degrees C) and supercritical (375 degrees C) water reveals that at a fixed pressure, E(A(max) ) decreases monotonically with increasing temperature in passing through the phase transition at t(c). By contrast, at constant density, E(A(max) ) exhibits a minimum as the water passes above the critical point into SCW. These behaviors are explained in terms of simple microscopic arguments based on the crucial role played by local density and configurational fluctuations (associated with criticality) in providing pre-existing polymeric clusters, which act as trapping sites for electrons. PMID:19044973

  10. BREATH MEASUREMENT AND MODELS TO ASSESS VOC DERMAL ABSORPTION IN WATER

    EPA Science Inventory

    Dermal exposure to volatile organic compounds (VOCs) in water results from environmental contamination of surface, ground-, and drinking waters. This exposure occurs both in occupational and residential settings. Compartmental models incorporating body burden measurements have ...

  11. Mercury(II) and methyl mercury determinations in water and fish samples by using solid phase extraction and cold vapour atomic absorption spectrometry combination.

    PubMed

    Tuzen, Mustafa; Karaman, Isa; Citak, Demirhan; Soylak, Mustafa

    2009-07-01

    A method has been developed for mercury(II) and methyl mercury speciation on Staphylococcus aureus loaded Dowex Optipore V-493 micro-column in the presented work, by using cold vapour atomic absorption spectrometry. Selective and sequential elution with 0.1 molL(-1) HCl for methyl mercury and 2 molL(-1) HCl for mercury(II) were performed at the pH range of 2-6. Optimal analytical conditions including pH, amounts of biosorbent, sample volumes were investigated. The detection limits of the analytes were 2.5 ngL(-1) for Hg(II) and 1.7 ngL(-1) for methyl mercury. The capacity of biosorbent for mercury(II) and methyl mercury was 6.5 and 5.4 mgg(-1), respectively. The validation of the presented procedure is performed by the analysis of standard reference material. The speciation procedure established was successfully applied to the speciation of mercury(II) and methyl mercury in natural water and microwave digested fish samples. PMID:19394391

  12. Determination of trace lead in water samples by graphite furnace atomic absorption spectrometry after preconcentration with nanometer titanium dioxide immobilized on silica gel.

    PubMed

    Liu, Rui; Liang, Pei

    2008-03-21

    Nanometer titanium dioxide immobilized on silica gel (immobilized nanometer TiO2) was prepared by sol-gel method and characterized using X-ray diffraction (XRD) and scanning electron microscope (SEM). The adsorptive capability of immobilized nanometer TiO2 for lead was assessed in this work using column method. It was found that lead can be quantitatively retained by immobilized nanometer TiO2 in the pH range 4-7, then eluted completely with 1.0molL(-1) HCl. The adsorption capacity of immobilized nanometer TiO2 for Pb was found to be 3.16mgg(-1). A new method has been developed for the determination of trace lead based on preconcentration with a microcolumn packed with immobilized nanometer TiO2 prior to its determination by graphite furnace atomic absorption spectrometry (GFAAS). The detection limit of this method for Pb was 9.5ngL(-1) with an enrichment factor of 50, and the relative standard deviations (R.S.D.s) was 3.2% at the 10ngmL(-1) Pb level. The method was validated using a certified reference material, and was applied for the determination of trace lead in water samples. PMID:17681690

  13. Soluplus-coated colloidal silica nanomatrix system for enhanced supersaturation and oral absorption of poorly water-soluble drugs.

    PubMed

    Kim, Min-Soo

    2013-12-01

    In this study, a Soluplus-coated colloidal silica nanomatrix (SCCSN) formulation for the entrapment of poorly water-soluble drugs was devised. The maximum supersaturation of the drug-loaded nanomatrix was higher than that of a physical mixture as indicated by the results of in vitro kinetic solubility studies. For atorvastatin calcium, dutasteride, and sorafenib tosylate, there were 2.8-, 326-, and 46.4-fold increases in solubility, respectively. For dutasteride, a promising 4.7-fold increase for in vivo oral drug absorption in the entrapped nanomatrix was observed as compared to the free physical mixture, supported by statistical significance testing of pharmacokinetic parameters. PMID:23336707

  14. Effect of laser radiation absorption in water and blood on the optimal wavelength for endovenous obliteration of varicose veins

    SciTech Connect

    Zhilin, K M; Minaev, V P [IRE-Polyus Research and Technology Association, Fryazino, Moscow Region (Russian Federation); Sokolov, Aleksandr L [Medical Rehabilitation Centre, Federal Agency for Health Care and Social Development, Moscow (Russian Federation)

    2009-08-31

    This work examines laser radiation absorption in water and blood at the wavelengths that are used in endovenous laser treatment (EVLT): 0.81-1.06, 1.32, 1.47, 1.5 and 1.56 {mu}m. It is shown that the best EVLT conditions are ensured by 1.56-{mu}m radiation. Analysis of published data suggests that even higher EVLT efficacy may be achieved at wavelengths of 1.68 and 1.7 {mu}m. (laser medicine)

  15. X-ray absorption spectrum for guanosine- 5'-monophosphate in water solution in the vicinity of the nitrogen K-edge observed in free liquid jet in vacuum

    NASA Astrophysics Data System (ADS)

    Ukai, Masatoshi; Yokoya, Akinari; Fujii, Kentaro; Saitoh, Yuji

    2008-10-01

    A new spectroscopy for direct effect of radiation damage to nucleic acids such as DNA and RNA is underway using a liquid beam sample in vacuum combined with soft-X-ray synchrotron radiation. We show the X-ray absorption spectrum (XANES) of liquid phase water at X-ray photon energy in the vicinity of oxygen K-shell absorption edge obtained from total photoelectron yields ejected from a pure water beam. We confirm a "liquid sample in vacuum" for the present experiment by the measurements of the temperature dependence of the XANES spectrum for a liquid beam of pure water. Shown is the first measurement of the XANES spectrum for guanosine- 5'-monophosphate (GMP), which is one of the fundamental nucleotide unit for RNA, in water solution at X-ray photon energy in the vicinity of nitrogen K-shell absorption edge involved in the 'water-window' region, which corresponds to a selective excitation of guanine site.

  16. A new direct absorption measurement for high precision and accurate measurement of water vapor in the UT/LS

    NASA Astrophysics Data System (ADS)

    Sargent, M. R.; Sayres, D. S.; Smith, J. B.; Anderson, J.

    2011-12-01

    Highly accurate and precise water vapor measurements in the upper troposphere and lower stratosphere are critical to understanding the climate feedbacks of water vapor and clouds in that region. However, the continued disagreement among water vapor measurements (~1 - 2 ppmv) are too large to constrain the role of different hydration and dehydration mechanisms operating in the UT/LS, with model validation dependent upon which dataset is chosen. In response to these issues, we present a new instrument for measurement of water vapor in the UT/LS that was flown during the April 2011 MACPEX mission out of Houston, TX. The dual axis instrument combines the heritage and validated accuracy of the Harvard Lyman-alpha instrument with a newly designed direct IR absorption instrument, the Harvard Herriott Hygrometer (HHH). The Lyman-alpha detection axis has flown aboard NASA's WB-57 and ER2 aircraft since 1994, and provides a requisite link between the new HHH instrument and the long history of Harvard water vapor measurements. The instrument utilizes the highly sensitive Lyman-alpha photo-fragment fluorescence detection method; its accuracy has been demonstrated though rigorous laboratory calibrations and in situ diagnostic procedures. The Harvard Herriott Hygrometer employs a fiber coupled near-IR laser with state-of-the-art electronics to measure water vapor via direct absorption in a spherical Herriott cell of 10 cm length. The instrument demonstrated in-flight precision of 0.1 ppmv (1-sec, 1-sigma) at mixing ratios as low as 5 ppmv with accuracies of 10% based on careful laboratory calibrations and in-flight performance. We present a description of the measurement technique along with our methodology for calibration and details of the measurement uncertainties. The simultaneous utilization of radically different measurement techniques in a single duct in the new Harvard Water Vapor (HWV) instrument allows for the constraint of systematic errors inherent in each technique both in the laboratory and in flight. The HWV data set, in combination with the intercomparison of numerous water vapor instruments during MACPEX, constitutes a significant step toward resolving the controversy surrounding water vapor measurements in the tropopause region.

  17. Using GPR and Soil EC to Identify Spatial Variability of Water Holding Capacity for Precision Irrigation Management

    NASA Astrophysics Data System (ADS)

    Duncan, H. A.; Leib, B.

    2011-12-01

    Applying the appropriate amount of irrigation water is an especially critical part of irrigation management because both under and over irrigation can lead to reduced crop yield and loss of financial profit. Irrigation water soaks into and is stored in the soil moisture profile; the degree to which a soil can hold that moisture in the profile and prevent deep percolation is known as its water holding capacity (WHC). Because crops rely on the use of the water stored within the soil moisture profile, the WHC of the soil greatly influences the amount of applied irrigation water (AIW) required to optimize crop yield and resource management. Soil texture, which is a primary control of WHC, is known to vary spatially in many areas of agricultural production. Optimization of irrigation water use requires areas of different WHC to be irrigated differently; however, areas of differing WHC must be accurately identified for precision irrigation to be effective. Two methods were used on a research site known to contain soil texture variability to generate a geo-referenced map of soil texture differences in order to account for spatial WHC variability and optimize AIW. Ground penetrating radar (GPR) was used in conjunction with GPS and GIS systems to map the water content change found at the soil texture interfaces in the field. The second method was to produce a geo-referenced map of soil electrical conductivity (EC) using a Veris EC implement with similar GPS and GIS systems. The soil EC map is strongly related to soil texture and WHC under the consistent pH conditions that exist on the research site. The GPR and EC maps were then used to guide plot placement to block on soil WHC variation for a deficit irrigation study on upland cotton. The lint yield results from the irrigation study will provide insight into the effectiveness of the irrigation management zones identified by the two mapping methods. Lastly, soil cores will be taken from key areas identified in the GPR and EC results to ground-truth the readings and compare the accuracy of each mapping method.

  18. WATER ABSORPTION IN GALACTIC TRANSLUCENT CLOUDS: CONDITIONS AND HISTORY OF THE GAS DERIVED FROM HERSCHEL /HIFI PRISMAS OBSERVATIONS

    SciTech Connect

    Flagey, N.; Goldsmith, P. F. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)] [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Lis, D. C.; Monje, R.; Phillips, T. G. [California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States)] [California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Gerin, M.; De Luca, M.; Godard, B. [LERMA, UMR 8112 du CNRS, Observatoire de Paris, Ecole Normale Superieure, UPMC and UCP (France)] [LERMA, UMR 8112 du CNRS, Observatoire de Paris, Ecole Normale Superieure, UPMC and UCP (France); Neufeld, D. [Department of Physics and Astronomy, Johns Hopkins Univ. 3400 N. Charles St., Baltimore, MD 21218 (United States)] [Department of Physics and Astronomy, Johns Hopkins Univ. 3400 N. Charles St., Baltimore, MD 21218 (United States); Sonnentrucker, P. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)] [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Goicoechea, J. R., E-mail: nflagey@jpl.nasa.gov [Centro de Astrobiologia (CSIC-INTA), E-28850 Torrejon de Ardoz, Madrid (Spain)

    2013-01-01

    We present Herschel/HIFI observations of the three ground state transitions of H{sub 2}O (556, 1669, and 1113 GHz) and H{sub 2}{sup 18}O (547, 1655, and 1101 GHz)-as well as the first few excited transitions of H{sub 2}O (987, 752, and 1661 GHz)-toward six high-mass star-forming regions, obtained as part of the PRISMAS (PRobing InterStellar Molecules with Absorption line Studies) Guaranteed Time Key Program. Water vapor associated with the translucent clouds in Galactic arms is detected in absorption along every line of sight in all the ground state transitions. The continuum sources all exhibit broad water features in emission in the excited and ground state transitions. Strong absorption features associated with the source are also observed at all frequencies except 752 GHz. We model the background continuum and line emission to infer the optical depth of each translucent cloud along the lines of sight. We derive the column density of H{sub 2}O or H{sub 2}{sup 18}O for the lower energy level of each transition observed. The total column density of water in translucent clouds is usually about a few 10{sup 13} cm{sup -2}. We find that the abundance of water relative to hydrogen nuclei is 1 Multiplication-Sign 10{sup -8} in agreement with models for oxygen chemistry in which high cosmic ray ionization rates are assumed. Relative to molecular hydrogen, the abundance of water is remarkably constant through the Galactic plane with X(H{sub 2}O) =5 Multiplication-Sign 10{sup -8}, which makes water a good traced of H{sub 2} in translucent clouds. Observations of the excited transitions of H{sub 2}O enable us to constrain the abundance of water in excited levels to be at most 15%, implying that the excitation temperature, T {sub ex}, in the ground state transitions is below 10 K. Further analysis of the column densities derived from the two ortho ground state transitions indicates that T {sub ex} {approx_equal} 5 K and that the density n(H{sub 2}) in the translucent clouds is below 10{sup 4} cm{sup -3}. We derive the water ortho-to-para ratio for each absorption feature along the line of sight and find that most of the clouds show ratios consistent with the value of 3 expected in thermodynamic equilibrium in the high-temperature limit. However, two clouds with large column densities exhibit a ratio that is significantly below 3. This may argue that the history of water molecules includes a cold phase, either when the molecules were formed on cold grains in the well-shielded, low-temperature regions of the clouds, or when they later become at least partially thermalized with the cold gas ({approx}25 K) in those regions; evidently, they have not yet fully thermalized with the warmer ({approx}50 K) translucent portions of the clouds.

  19. A comparison of growth, photosynthetic capacity and water stress in Eucalyptus globulus coppice regrowth and seedlings during early development.

    PubMed

    Drake, Paul L; Mendham, Daniel S; White, Don A; Ogden, Gary N

    2009-05-01

    Eucalyptus globulus Labill., a globally significant plantation species, is grown commercially in a multiple rotation framework. Second and subsequent crops of E. globulus may be established either by allowing the cut stumps to resprout (commonly referred to as coppice) or by replanting a new crop of seedlings. Currently, long-term growth data comparing coppice and seedling productivity in second or later rotations in southern Australia is limited. The capacity to predict productivity using these tools is dependent on an understanding of the physiology of seedlings and coppice in response to light, water and nutrient supply. In this study, we compared the intrinsic (independent of the immediate environment) and native (dependent on the immediate environment) physiology of E. globulus coppice and second-generation seedlings during their early development in the field. Coppice not only grew more rapidly, but also used more water and drew on stored soil water to a depth of at least 4.5 m during the first 2 years of growth, whereas the seedlings only accessed the top 0.9 m of the soil profile. During the same period, there was no significant difference between coppice and seedlings in either their stomatal response to leaf-to-air vapour pressure difference (D) or intrinsic water-use efficiency; CO(2)- and light-saturated rates of photosynthesis were greater in seedlings than that in coppice as were the quantum yield of photosynthesis and total leaf chlorophyll content. Thus, at a leaf scale, seedlings are potentially more productive per unit leaf area than coppice during early development, but this is not realised under ambient conditions. The underlying cause of this inherent difference is discussed in the context of the allocation of resources to above- and below-ground organs during early development. PMID:19324701

  20. SOFIA/EXES Observations of Water Absorption in the Protostar AFGL 2591 at High Spectral Resolution

    E-print Network

    Indriolo, Nick; DeWitt, C N; Richter, M J; Boogert, A C A; Harper, G M; Jaffe, D T; Kulas, K R; McKelvey, M E; Ryde, N; Vacca, W

    2015-01-01

    We present high spectral resolution (~3 km/s) observations of the nu_2 ro-vibrational band of H2O in the 6.086--6.135 micron range toward the massive protostar AFGL 2591 using the Echelon-Cross-Echelle Spectrograph (EXES) on the Stratospheric Observatory for Infrared Astronomy (SOFIA). Ten absorption features are detected in total, with seven caused by transitions in the nu_2 band of H2O, two by transitions in the first vibrationally excited nu_2 band of H2O, and one by a transition in the nu_2 band of H2{18}O. Among the detected transitions is the nu_2 1(1,1)--0(0,0) line which probes the lowest lying rotational level of para-H2O. The stronger transitions appear to be optically thick, but reach maximum absorption at a depth of about 25%, suggesting that the background source is only partially covered by the absorbing gas, or that the absorption arises within the 6 micron emitting photosphere. Assuming a covering fraction of 25%, the H2O column density and rotational temperature that best fit the observed abs...

  1. Borehole geophysical methods for analyzing specific capacity of multiaquifer wells : ground-water hydraulics

    USGS Publications Warehouse

    Bennett, Gordon D.; Patten, Eugene P., Jr.

    1960-01-01

    Conventional well-logging techniques, combined with measurements of flow velocity in the borehole, can provide information on the discharge-drawdown characteriBtic8 of the several aquifers penetrated by a well. The information is most conveniently presented in a graph showing aquifer discharges as functions of the water level in the well at a particular time. To determine the discharge-drawdown characteristics, a well is pumped at a steady rate for a certain length of time. While the well is being pumped, measurements are made of drawdown and of the discharge rates of the individual aquifers within the well. Discharge rates and drawdowns ,are usually recorded as functions of time, and their values for any given time during the test are obtained by interpolation. The procedure is repeated for several different rates of total well discharge. The well may be allowed to recover after each step, or discharge may be changed from one rate to another, and changes in discharge and drawdown may be measured by extrapolation. The flow measurements within the well may be made by use of a subsurface flowmeter or by one of several techniques involving the injection of electrolytic or radioactive tracers. The method was tested on a well in Mercer County, Pa., and provided much useful information on aquifer yields, 'thieving,' and hydrostatic heads of the individual zones.

  2. Heat accumulation and storage capacity of the water-filled mines at Ely, Minnesota

    NASA Astrophysics Data System (ADS)

    Walton, M.; McSwiggen, P.

    1982-12-01

    The iron mines at Ely occupy a doubly plunging isoclinal syncline with a nearly vertical axial plane, forming an irregular, canoe-shaped structure, striking about N.70 E., enclosed within massive Archean greenstone pillow lavas. A reasonably complete collection of mine maps and sections has been assembled from several sources to provide, at least for the present an adequate picture of the as-built configuration of the underground workings. No topographic data have been found to show the contour of the ground over the mines before subsidence, but it is clear that most of the depression occupied by Miners Lake is due to subsidence, and only a minor amount is due to open-pit mining at the western end of the deposit. Acoustic profiles of the lake, the U.S. Geological Survey 7-1/2-minute topographic map prepared before the water in the mines rose into the subsidence area, and enlarged aerial photographs taken at different dates during the filling of the mines are being studied to evaluate the subsidence of the mine and filling of the lake since 1965.

  3. Water absorption in Galactic translucent clouds: conditions and history of the gas derived from Herschel/HIFI PRISMAS observations

    E-print Network

    Flagey, N; Lis, D C; Gerin, M; Neufeld, D; Sonnentrucker, P; De Luca, M; Godard, B; Goicoechea, J R; Monje, R; Phillips, T G

    2012-01-01

    We present Herschel/HIFI observations of nine transitions of \\hho and \\hheo towards six high-mass star-forming regions, obtained as part of the PRISMAS Key Program. Water vapor in translucent clouds is detected in absorption along every sightline. We derive the column density of \\hho or \\hheo for the lower energy level of each transition observed. The total water column density is about a few $10^{13} \\rm{cm^{-2}}$. We find that the abundance of water relative to hydrogen nuclei is $1\\times10^{-8}$ in agreement with models for oxygen chemistry with high cosmic ray ionization rates. Relative to \\hh, the abundance of water is remarkably constant at $5\\times10^{-8}$. The abundance of water in excited levels is at most 15%, implying that the excitation temperature $T_{ex}$ in the ground state transitions is below 10 K. The column densities derived from the two ortho ground state transitions indicates that $T_{ex}\\simeq5$ K and that the density $n($\\hh$)$ in the clouds is $\\le10^4 \\rm{cm^{-3}}$. For most clouds we...

  4. Water Absorption of Jute/Polylactic Acid Composite Intended for an Interior Application and Comparison with Wood-Based Panels

    NASA Astrophysics Data System (ADS)

    Zandvliet, C.; Bandyopadhyay, N. R.; Ray, D.

    2014-04-01

    Jute/polylactic acid (PLA) composite is of special interest because it is entirely from renewable resources with high mechanical properties. Thus, it could be a more eco-friendly alternative to the conventional wood-based panels made of formaldehyde resin which is asserted to be carcinogenic. Yet the water affinity of the natural fibres and susceptibility of polylactic acid towards hydrolysis raise a question about the water resistance of such composites in service condition. In this work, the water absorption behaviour of jute/PLA composites, jute/maleated polypropylene was investigated with regard to interior applications following the standard test method in accordance to ISO 16983:2003 `Wood-based panels—determination of swelling in thickness after immersion in water' and compared to standard of wood-based panels. Untreated and treated jute/PLA composites exhibited a superior water resistance property compared to particleboard, MDF and hardboard and they are by far, below the minimum requirement of the ISO standard 16983.

  5. Method and apparatus for simulating atomospheric absorption of solar energy due to water vapor and CO.sub.2

    DOEpatents

    Sopori, Bhushan L. (Denver, CO)

    1995-01-01

    A method and apparatus for improving the accuracy of the simulation of sunlight reaching the earth's surface includes a relatively small heated chamber having an optical inlet and an optical outlet, the chamber having a cavity that can be filled with a heated stream of CO.sub.2 and water vapor. A simulated beam comprising infrared and near infrared light can be directed through the chamber cavity containing the CO.sub.2 and water vapor, whereby the spectral characteristics of the beam are altered so that the output beam from the chamber contains wavelength bands that accurately replicate atmospheric absorption of solar energy due to atmospheric CO.sub.2 and moisture.

  6. Effect of O3 on Hydraulic Architecture in Pima Cotton (Biomass Allocation and Water Transport Capacity of Roots and Shoots)

    PubMed Central

    Grantz, D. A.; Yang, S.

    1996-01-01

    Pima cotton (Gossypium barbadense L. cv S-6) exhibits foliar injury and yield reduction at ambient concentrations of O3. We tested the hypotheses that O3 reduces the allocation of biomass to the root system, and that this disrupted carbohydrate allocation impairs root hydraulic capacity relative to transpiring leaf area. Both hypotheses are supported, even though leaf area development is itself reduced by O3. Seedlings were grown in pots in greenhouse fumigation chambers and exposed from planting to sinusoidal O3 profiles with peak concentrations of 0, 0.1, 0.2, and 0.3 [mu]L-1 (12-h averages of 0, 0.037, 0.074, and 0.111 [mu]L L-1). At 8 weeks after planting, stem basal diameter, leaf area, and total plant dry weight decreased by 61, 83, and 88%, whereas root/shoot dry weight ratio declined from 0.16 to 0.09 g/g. Hydraulic conductance decreased per plant by 85%, and per unit leaf area by 35%. Conductance of all organs declined per plant, but only root conductance declined per leaf area by 41%. Root resistance increased from 69 to 82% of whole plant resistance, a functional consequence of reduced carbon allocation to roots. Stomatal conductance declined with root hydraulic conductance, protecting short-term leaf water status. Reduced root hydraulic efficiency may mediate O3 injury to whole plants by reducing shoot gas exchange and biomass productivity through the inhibition of water and nutrient acquisition.

  7. Efficient tissue ablation using a laser tunable in the water absorption band at 3 microns with little collateral damage

    NASA Astrophysics Data System (ADS)

    Nierlich, Alexandra; Chuchumishev, Danail; Nagel, Elizabeth; Marinova, Kristiana; Philipov, Stanislav; Fiebig, Torsten; Buchvarov, Ivan; Richter, Claus-Peter

    2014-03-01

    Lasers can significantly advance medical diagnostics and treatment. At high power, they are typically used as cutting tools during surgery. For lasers that are used as knifes, radiation wavelengths in the far ultraviolet and in the near infrared spectral regions are favored because tissue has high contents of collagen and water. Collagen has an absorption peak around 190 nm, while water is in the near infrared around 3,000 nm. Changing the wavelength across the absorption peak will result in significant differences in laser tissue interactions. Tunable lasers in the infrared that could optimize the laser tissue interaction for ablation and/or coagulation are not available until now besides the Free Electron Laser (FEL). Here we demonstrate efficient tissue ablation using a table-top mid-IR laser tunable between 3,000 to 3,500 nm. A detailed study of the ablation has been conducted in different tissues. Little collateral thermal damage has been found at a distance above 10-20 microns from the ablated surface. Furthermore, little mechanical damage could be seen in conventional histology and by examination of birefringent activity of the samples using a pair of cross polarizing filters.

  8. Determination of Telluric Water Vapour using Absorption Measurements of Lunar Irradiance

    E-print Network

    Naylor, David A.

    and space-based platforms. Keywords: Radiometer, Precipitable Water Vapour, Infrared, Astronomy 1 applications in ground-based infrared astronomy and by extension in space-based terrestrial remote sensing is the largest source of opacity in the infrared and severely limits ground- based infrared astronomy. Water

  9. Equilibrium phase diagrams and water absorption properties of aqueous mixtures of malonic acid and inorganic salts

    Microsoft Academic Search

    D. Salcedo; G. Salgado-Olea

    2006-01-01

    Tropospheric aerosols are usually complex mixtures of inorganic and organic components. Although the thermodynamic properties of inorganic aerosols have been widely studied, the effect of organics on such properties is still under discussion. Solubility in water, water activity of aqueous solutions, deliquescence relative humidity (DRH), eutonic composition, and eutonic DRH were determined for bulk mixtures of malonic acid with ammonium

  10. Metal-and hydrogen-bonding competition during water absorption on Pd(111) and Ru(0001)

    SciTech Connect

    Tatarkhanov, Mouslim; Ogletree, D. Frank; Rose, Franck; Mitsui, Toshiyuki; Fomin, Evgeny; Rose, Mark; Cerda, Jorge I.; Salmeron, Miquel

    2009-09-03

    The initial stages of water adsorption on the Pd(111) and Ru(0001) surfaces have been investigated experimentally by Scanning Tunneling Microscopy in the temperature range between 40 K and 130 K, and theoretically with Density Functional Theory (DFT) total energy calculations and STM image simulations. Below 125 K water dissociation does not occur at any appreciable rate and only molecular films are formed. Film growth starts by the formation of flat hexamer clusters where the molecules bind to the metal substrate through the O-lone pair while making H-bonds with neighboring molecules. As coverage increases, larger networks of linked hexagons are formed with a honeycomb structure, which requires a fraction of the water molecules to have their molecular plane perpendicular to the metal surface with reduced water-metal interaction. Energy minimization favors the growth of networks with limited width. As additional water molecules adsorb on the surface they attach to the periphery of existing islands, where they interact only weakly with the metal substrate. These molecules hop along the periphery of the clusters at intermediate temperatures. At higher temperatures they bind to the metal to continue the honeycomb growth. The water-Ru interaction is significantly stronger than the water-Pd interaction, which is consistent with the greater degree of hydrogen-bonded network formation and reduced water-metal bonding observed on Pd relative to Ru.

  11. Significance of active ion transport in transalveolar water absorption: a study on isolated rat lung.

    PubMed Central

    Basset, G; Crone, C; Saumon, G

    1987-01-01

    1. Experiments were performed on isolated rat lungs perfused with Ringer solutions containing red cells. The goal was to clarify the role of active transport of Na+ for the absorption of fluid across the alveolar membrane, and to characterize active and passive pathways. 2. Partially degassed lungs were filled with 5 ml of an isotonic Ringer solution containing 125I-labelled albumin in order to calculate the fluid movement, and 22Na+ or 36Cl- for measurement of ion fluxes. Passive non-electrolyte permeability was determined in all experiments using [3H]mannitol. 3. The average rate of fluid absorption in phosphate-buffered instillates was 134 nl/s (S.E., 18.5; n = 14). With ouabain (10(-4) M) in the perfusate the fluid absorption rate fell to 57 nl/s (S.E., 8.2; n = 18). Amiloride (10(-3)-10(-4) M) in the instillate reduced the absorption to 75 nl/s (S.E., 8.6; n = 16). These results show that fluid absorption depends on transcellular transport of Na+ and that alveolar epithelial cells have a Na+ entry system in the luminal membrane and a Na+-K+ pump in the abluminal membrane. 4. The transcellular ion transport operates in parallel with a paracellular, passive leak that allows mannitol to pass with a permeability surface area product of 1.2 X 10(-4) ml/s, corresponding to a permeability coefficient of 2.4 X 10(-8) cm/s, assuming an alveolar surface area of 5000 cm2. 5. The passive fluxes of Na+ were 9.4 pmol/(cm2s) (S.E., 1.3; n = 25) in the direction from alveoli to perfusate and 8.0 pmol/(cm2s) (S.E., 0.86; n = 6) from perfusate to plasma. The passive fluxes of Cl- in the two directions were not significantly different either. Thus the transalveolar electrical potential difference is too small to affect ion movements measurably. 6. The passive permeability to Na+ was 6.7 X 10(-8) cm/s and to Cl- was 10.2 X 10(-8) cm/s (alveolar surface area assumed to be 5000 cm2). The ratio of the permeabilities is close to the ratio of the diffusion coefficients in free solution, suggesting a neutral or weakly charged paracellular channel. 7. We conclude that the alveolar epithelium performs solute-coupled fluid transport from alveoli to plasma, and that it shows many features that are common to other fluid-transporting epithelia; with an approximate surface area of 100 m2 in humans it constitutes one of the largest epithelial surfaces in the body.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3656149

  12. Design of Advanced Atmospheric Water Vapor Differential Absorption Lidar (DIAL) Detection System

    NASA Technical Reports Server (NTRS)

    Refaat, Tamer F.; Luck, William S., Jr.; DeYoung, Russell J.

    1999-01-01

    The measurement of atmospheric water vapor is very important for understanding the Earth's climate and water cycle. The lidar atmospheric sensing experiment (LASE) is an instrument designed and operated by the Langley Research Center for high precision water vapor measurements. The design details of a new water vapor lidar detection system that improves the measurement sensitivity of the LASE instrument by a factor of 10 are discussed. The new system consists of an advanced, very low noise, avalanche photodiode (APD) and a state-of-the-art signal processing circuit. The new low-power system is also compact and lightweight so that it would be suitable for space flight and unpiloted atmospheric vehicles (UAV) applications. The whole system is contained on one small printed circuit board (9 x 15 sq cm). The detection system is mounted at the focal plane of a lidar receiver telescope, and the digital output is read by a personal computer with a digital data acquisition card.

  13. Interlayer design for the graphite-like carbon film with high load-bearing capacity under sliding-friction condition in water

    NASA Astrophysics Data System (ADS)

    Wang, Yongxin; Pu, Jibin; Wang, Jiafan; Li, Jinlong; Chen, Jianmin; Xue, Qunji

    2014-08-01

    GLC films with single Ti interlayer, single Cr interlayer, thickness gradient Cr/C interlayer and composition gradient Cr/C interlayer were fabricated by magnetron sputtering technique. The microstructures, mechanical properties and tribological performance under sliding friction in distilled water and seawater of the as-deposited GLC films were investigated. Results showed that the adhesion strength and the load-bearing capacity under sliding-friction condition in water of GLC film could be improved effectively by interlayer design. GLC film with composition gradient Cr/C interlayer exhibited highest adhesion strength and load-bearing capacity under sliding-friction conditions in water, which was closely related to nano-interlocked microstructure and hard carbide phase formations inside the interlayer. The adhesion strength in scratch test and the critical bearing load under sliding-friction in water of the GLC film with composition gradient Cr/C interlayer exceeded 50 N and 2.73 GPa, respectively.

  14. Variations of light absorption by suspended particles with chlorophyll a concentration in oceanic (case 1) waters: Analysis and implications for bio-optical models

    Microsoft Academic Search

    Annick Bricaud; André Morel; Marcel Babin; Karima Allali; Hervé Claustre

    1998-01-01

    Spectral absorption coefficients of total particulate matter ap(lambda) were determined using the in vitro filter technique. The present analysis deals with a set of 1166 spectra, determined in various oceanic (case 1) waters, with field chl a concentrations () spanning 3 orders of magnitude (0.02-25 mgm-3). As previously shown [Bricaud et al., 1995] for the absorption coefficients of living phytoplankton

  15. Light absorption properties of colored dissolved organic matter (CDOM) in adjacent waters of the Changjiang Estuary during a flood season: implication for DOC estimation

    NASA Astrophysics Data System (ADS)

    Liu, Yangyang; Shen, Fang; Li, Xiuzhen

    2014-11-01

    Light absorption properties of colored dissolved organic matter (CDOM) in adjacent waters of the Changjiang Estuary were investigated during the summer of 2013. CDOM absorption showed a substantial portion of the total absorption and clearly dominant among most investigation stations. It generally decreased from the northwest to the southeast, which controlled by physical mixing of fresh water and seawater as was indicated by a conservative behaviour of CDOM. CDOM absorption sharply increased during phytoplankton blooms. Similarly, dissolved organic carbon (DOC) also peaked during blooms period. However, DOC exhibited a more complex behavior relative to a simple conservative mixing, possibly attributed to multiple origins of DOC. CDOM absorption and DOC co-varied to some degree, implying a potential way of DOC estimation from CDOM absorption. However, more detailed information such as CDOM and DOC composition and more validation data were required to obtain a stable CDOM - DOC pattern. Lastly, empirical algorithms with limited data were developed to retrieve CDOM absorption. Further validation of the algorithms were needed when they were to be commonly applied.

  16. Water-holding capacity of a floating peat mat determines the survival and growth of Menyanthes trifoliata L (bog bean) in an oligotrophic lake

    Microsoft Academic Search

    Miehie Han; Jae Geun Kim

    2006-01-01

    Menyanthes trifoliata is a threatened and endangered species in Korea and USA. To assess the important ecological characteristics for its conservation\\u000a and restoration, we measured the level of soluble reactive phosphorus (SRP) in the water, total N and C contents in the plants,\\u000a and the water-holding capacity of the surrounding floating peat mat. These factors, which limit the success of

  17. Effect of water vapor on sound absorption in nitrogen at low frequency/pressure ratios

    NASA Technical Reports Server (NTRS)

    Zuckerwar, A. J.; Griffin, W. A.

    1981-01-01

    Sound absorption measurements were made in N2-H2O binary mixtures at 297 K over the frequency/pressure range f/P of 0.1-2500 Hz/atm to investigate the vibrational relaxation peak of N2 and its location on f/P axis as a function of humidity. At low humidities the best fit to a linear relationship between the f/P(max) and humidity yields an intercept of 0.013 Hz/atm and a slope of 20,000 Hz/atm-mole fraction. The reaction rate constants derived from this model are lower than those obtained from the extrapolation of previous high-temperature data.

  18. Development of High-speed Water Vapor Absorption Thermometry in Harsh

    NASA Astrophysics Data System (ADS)

    Whitney, Jean M.

    This work aimed to improve near IR, direct absorption spectroscopy measurements of H2O vapor for thermometry purposes by focusing on spectroscopic light source systems and post-processing techniques. A survey was conducted of available near IR spectroscopic light source systems, and the 2-VCSEL system was chosen as the focus of this research. The 2-VCSEL system developed and constructed utilizes two, time-division multiplexed, injection-current tuned, vertical-cavity surface-emitting lasers (VCSELs) to measure high-resolution spectra at a rate of 10 kHz. Post-processing techniques were improved by developing a method to simultaneously fit baseline, temperature, and broadening variables when comparing measured spectra to simulated database spectra. This new post-processing also improved the consistency of output temperature data thereby enabling a study of the sources of error in H2O vapor absorption temperature measurements. Two of the largest sources of temperature error discussed are inaccuracies in the H2O line list database (e.g., line positions, linestrengths, and lower state energies), and inaccurate broadening models. A method for minimizing temperature error due to broadening inaccuracies is presented and tested. The 2-VCSEL system was used to take experimental data in a constant volume combustion chamber and in a single-cylinder research engine. The data was analyzed using the post-processing techniques and broadening models developed in this research in order to determine line-of-sight average temperature. The measured spectra were matched to database simulations with low residuals, and good agreement was found between optically measured and theoretically predicted temperatures.

  19. Water relations and photosynthetic capacity of two species of Calotropis in a tropical semi-arid ecosystem

    PubMed Central

    Tezara, Wilmer; Colombo, Rita; Coronel, Ilsa; Marín, Oranys

    2011-01-01

    Background and Aims Calotropis procera and Calotropis gigantea, originally from warm parts of Africa and Asia, are now pan-tropical and in ecological terms considered an indicator of overgrazed, disturbed lands; they grow successfully in dry areas. Variations in water relations, morphology and photosynthesis of the two species growing in the same habitat were studied to assess possible mechanisms of tolerance to drought and how these relate to their ecophysiological success. Also the hypothesis that their photosynthetic rate (A) under drought would be affected by stomatal and non-stomatal limitations was tested. Methods Water relations, gas exchange, water use efficiency (WUE), fluorescence parameters, pubescence and specific leaf area (SLA) of Calotropis procera and C. gigantea plants growing in the field were evaluated during the wet (WS) and dry (DS) seasons. Results The xylem water potential (?) was similar in both species during the WS and DS; drought caused a 28 % decrease of ?. In C. procera, A, stomatal conductance (gs) and carboxylation efficiency (CE) were higher in the WS with half the values of those during the DS, this species being more affected by drought than C. gigantea. A high ?13C of C. gigantea (–26·2 ‰) in the WS indicated a higher integrated WUE, in agreement with its lower gs. Leaves of C. gigantea were more pubescent than C. procera. Relative stomatal and non-stomatal limitation of A increased with drought in both species; no changes in maximum quantum yield of photosystem II (PSII; Fv/Fm) were observed. The decrease in the relative quantum yield of PSII (?PSII) and in the photochemical quenching coefficient (qP) was more pronounced in C. procera than in C. gigantea. Conclusions The photosynthetic capacity of C. procera was higher than that of C. gigantea. During the DS, A was regulated by stomatal and non-stomatal factors in a coordinated manner and drought did not cause chronic photoinhibition. A higher density of trichomes and leaf angle in C. gigantea may contribute to the maintenance of A and confer more efficient protection of photochemical activity in the DS. Ecophysiological traits such as high photosynthetic rate throughout the year even during the DS, and high WUE, highly pubescent leaves and low SLA observed in both species contribute to the establishment and growth of Calotropis in dry conditions. PMID:21149276

  20. Water absorption behavior and its effect on tensile properties of ethylene–propylene–diene–terpolymer\\/polypropylene\\/filler ternary composites: a preliminary study

    Microsoft Academic Search

    S. Siriwardena; H. Ismail

    2002-01-01

    The water absorption behavior of white rice husk ash (WRHA) and silica filled ethylene-propylene-diene-terpolymer\\/polypropylene (EPDM\\/PP) ternary composites was studied with special reference to filler type, test specimen preparation (die cut or molded), and dynamic vulcanization of elastomer phase. The water uptake of composites was recorded as a function of them over 40 days of immersion period in distilled water. The

  1. Measurement of water-holding capacity in raw and freeze-dried broiler breast meat with visible and near-infrared spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The feasibility of using visible/near-infrared spectroscopy (vis/NIR) to segregate broiler breast fillets by water-holding capacity (WHC) was determined. Broiler breast fillets (n = 72) were selected from a commercial deboning line based on visual color assessment. Meat color (L*a*b*), pH (2 and 2...

  2. A Bayesian Belief Network Approach to Explore Alternative Decisions for Sediment Control and water Storage Capacity at Lago Lucchetti, Puerto Rico

    EPA Science Inventory

    A Bayesian belief network (BBN) was developed to characterize the effects of sediment accumulation on the water storage capacity of Lago Lucchetti (located in southwest Puerto Rico) and to forecast the life expectancy (usefulness) of the reservoir under different management scena...

  3. Postmortem aging can significantly enhance water-holding capacity of broiler pectoralis major muscle measured by the salt-induced swelling/centrifuge method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water-holding capacity (WHC) is one of the most important functional properties of fresh meat and can be significantly affected by postmortem muscle changes. Two experiments were carried out to evaluate the effects of postmortem aging on WHC of broiler pectoralis (p.) major muscle indicated with % s...

  4. Characterization of Muscles from Boars, Barrows, and Gilts Slaughtered at 100 or 110 Kilograms: Differences in Fat, Moisture, Color, Water-Holding Capacity, and Collagen 1

    Microsoft Academic Search

    R. A. Nold; J. R. Romans; W. J. Costello; G. W. Libal

    2010-01-01

    For characterization of ether-extrac- table fat content (EE), L*, a*, and b* color, and water-holding capacity (WHC), 12 muscles or muscle groups were dissected from 48 pork carcasses of boars, barrows, or gilts that were fed diets either at minimum (LO) or 1% above (HI) their protein requirements and slaughtered in two separate trials at 100 or 110 kg. In

  5. Quantification of the dynamic changes in the absorption coefficient of liquid water at erbium:YAG and carbon dioxide laser wavelengths

    NASA Astrophysics Data System (ADS)

    Shori, Ramesh K.

    The interaction of high-intensity, short-pulsed radiation with liquid water results in dynamic changes in the optical absorption coefficient of water. These changes and their implications, as related to mid-infrared laser ablation of tissue, were not investigated until the late 1980's and early 1990's. Classical models of absorption and heating do not explain the dynamic, non-linear changes in water. The objective of the present work was to quantify the dynamic changes in the absorption coefficient of liquid water as a function of incident energy at three clinically relevant infrared wavelengths (? = 2.94, 9.6, 10.6 ?m). To investigate the changes in the absorption spectrum of water in the 3-?m band, a stable, high-energy Q- switched Er:YAG laser emitting 2.94-?m radiation in a near-perfect TEMoo spatial beam profile was developed. Key to the development of this laser was careful attention to the gain medium, optical pump system, system optics, and the thermal system. The final system design was capable of emitting 110 mJ/pulse at of 2-4 Hz with a lamp lifetime exceeding 12 million pulses The laser was used in two sets of experiments in order to quantify the above changes. First, the laser was used to measure the velocity of the shock front produced by vaporizing a gelatin-based tissue phantom. The measured shock velocity was related to the optical energy absorbed by the tissue phantom and the absorption coefficient, based on the pressure relationships derived using a 1-D piston model for an expanding plume. The shock front velocity measurements indicate that the absorption coefficient is constant for incident fluences less than 20 J/cm2, a result consistent with transmission data. For higher fluences, the data indicate a decrease in the absorption coefficient, which is again consistent with transmission data. Quantification of the absorption coefficient can, however, not be made without violating assumptions that form the basis for the 1-D piston model. Second, the laser was used to measure the optical transmission across water layers of known thicknesses. The data were used to develop a Dynamic Saturable Absorption (DSA) model to predict the dynamic changes in the absorption coefficient of water as a function of incident energy. The DSA model, based in part upon the homogeneous broadening of an atomic transition in a laser gain medium, accurately predicts the absorption coefficient of water over a wide range of incident fluences. One sees saturation of the absorption at both high and low fluence with a monotonic decrease in absorption with increasing fluence. Transmission measurements were also made at 9.6 and 10.6 ?m using a TEA CO2 laser. The data show essentially no change in the absorption coefficient as the fluence is varied. The results from the experiments make a significant contribution towards an understanding of the relationship among the dynamic optical properties of water and clinically relevant properties such as ablation rate and residual thermal damage.

  6. First-Order Phase Transition in Liquid Water in Terms of the Mode Structure of Absorption Spectrum in the Near-IR Range

    NASA Astrophysics Data System (ADS)

    Sinitsa, L. N.; Lugovskoy, A. A.; Sukhov, A. B.; Poplavskii, Yu. A.

    2015-01-01

    Absorption spectra of liquid water H2O are investigated in the region 4500-5600 cm-1 at temperatures from -53.0 to +20.3°C. The absorption band is decomposed into component modes at (I) 4700, (II) 4890, (III) 5080, and (IV) 5200 cm-1 whose centers are shifted slightly with temperature. Modes (II), (III), and (IV) are present in the spectrum of liquid water, whereas modes (I), (II), and (III) are registered in the spectrum of ice. The appearance of the ordered crystalline lattice is characterized by the occurrence of low-frequency mode (I) and by the disappearance of high-frequency component (IV) of the water absorption band in the region 4500-5600 cm-1. The spectral regions and temperature ranges in which the structure is changed during phase transition are determined.

  7. Emission from Water Vapor and Absorption from Other Gases at 5-7.5 ?m in Spitzer-IRS Spectra of Protoplanetary Disks

    NASA Astrophysics Data System (ADS)

    Sargent, B. A.; Forrest, W.; Watson, Dan M.; D'Alessio, P.; Calvet, N.; Furlan, E.; Kim, K. H.; Green, J.; Pontoppidan, K.; Richter, I.; Tayrien, C.

    2014-09-01

    We present spectra of 13 T Tauri stars in the Taurus-Auriga star-forming region showing emission in Spitzer Space Telescope Infrared Spectrograph 5-7.5 ?m spectra from water vapor and absorption from other gases in these stars' protoplanetary disks. Seven stars' spectra show an emission feature at 6.6 ?m due to the ?2 = 1-0 bending mode of water vapor, with the shape of the spectrum suggesting water vapor temperatures >500 K, though some of these spectra also show indications of an absorption band, likely from another molecule. This water vapor emission contrasts with the absorption from warm water vapor seen in the spectrum of the FU Orionis star V1057 Cyg. The other 6 of the 13 stars have spectra showing a strong absorption band, peaking in strength at 5.6-5.7 ?m, which for some is consistent with gaseous formaldehyde (H2CO) and for others is consistent with gaseous formic acid (HCOOH). There are indications that some of these six stars may also have weak water vapor emission. Modeling of these stars' spectra suggests these gases are present in the inner few AU of their host disks, consistent with recent studies of infrared spectra showing gas in protoplanetary disks.

  8. Coacervative extraction of trace lead from natural waters prior to its determination by electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Hagarová, Ingrid; Bujdoš, Marek; Matúš, Peter; Kubová, Jana

    2013-10-01

    In this work, a relatively simple and sensitive method for separation/preconcentration of trace lead from natural waters prior to its determination by electrothermal atomic absorption spectrometry has been proposed. The method is based on the extraction of Pb-dithizone chelate with coacervates made up of lauric acid in the presence of potassium ions and methanol. Several important factors affecting extraction efficiency such as pH, concentration of lauric acid and dithizone, ionic strength, incubation and centrifugation time were investigated and optimized. After separation of aqueous bulk solution from surfactant-rich phase, the final extract was redissolved by using 500 ?l of methanol acidified with 0.2 mol l- 1 HNO3. Under the optimized conditions (using initial sample volume of 10 ml), enrichment factor of 17.0, detection limit of 0.12 ?g l- 1, quantification limit of 0.38 ?g l- 1, relative standard deviation of 4.2% (for 2 ?g l- 1 of Pb; n = 26), linearity of the calibration graph in the range of 0.5-4.0 ?g l- 1 (with correlation coefficient better than 0.995) were achieved. The method was validated by the analysis of certified reference material (TMDA-61). Extraction recoveries for the CRM, spiked model solutions and spiked natural water samples were in the range of 91-96%. Finally, the method was applied to the separation/preconcentration and determination of trace lead in natural waters.

  9. Ultrasonic-assisted cloud point extraction for determination of nickel in water samples by flame atomic absorption spectrometry.

    PubMed

    Song, Jun; Zhen, Wei; Li, Zonghao; Lian, Yuanpei; Yang, Yaling

    2012-01-01

    A novel method for the determination of nickel was established by ultrasonic-assisted cloud point extraction (UA-CPE) prior to flame atomic absorption spectrometry (FAAS) analysis. The nickel reacted with N,N'-bis(salicylidene)-1,2-ethanediamine (BSE) to form hydrophobic chelates, which were extracted into the micelles of alpha-[3,5-dimethyl-1-(2-methylpropyl)hexyl]-omega- poly(oxy-2-ethanediyl) (Tergitol TMN-6). Tergitol TMN-6 was used as green nonionic surfactant. BSE was synthesized and checked by nuclear magnetic resonance (NMR) spectra. The phase diagrams of the binary system, water-surfactant (Tergitol TMN-6), and the ternary systems, water-surfactant-salt, were determined. The effects of experimental conditions including pH of sample solution, concentration of chelating agent and surfactant, ultrasonic power, equilibration temperature and incubation time were evaluated in order to enhance sensitivity of the method. Under the optimal conditions, the calibration graph was linear in the range of 10-500 ?g L(-1). The values obtained for the limit of detection and enrichment factor were 1.0 ?g L(-1) and 30, respectively. The method was successfully applied to the analysis of nickel in water samples. PMID:22766868

  10. Compressive Strength and Water Absorption of Pervious Concrete that Using the Fragments of Ceramics and Roof Tiles

    NASA Astrophysics Data System (ADS)

    Prahara, E.; Meilani

    2014-03-01

    Pervious concrete was introduced in America in 2003, popularized by Dan Brown and used as a rigid pavement in the open parking lot. Rigid pavement using pervious concrete can absorb water in the surface to go straight through the concrete to the ground below.This water flow is one of the benefit of using the pervious concrete. Using of wastes such as broken roof and ceramics tiles are not commonly used in Indonesia. Utilization these kind of wastes is predicted lower the compressive strength of pervious concrete as they are used as a substitute for coarse aggregate.In this research, pervious concrete is made using a mixture of the fragment of ceramics and roof tiles.This research using broken ceramics and roof tiles with a grain size that loose from 38 mm sieve, retained on 19 mm sieve and the coarse aggregate from crushed stone that loose 12.5 mm sieve, retained on 9.5 mm sieve. The water cement ratio is 0.3 and to assist the mixing process, the addition of addictive in pervious concrete is used.The size of coarse aggregate used in the mixture affects the strength of pervious concrete. The larger the size of aggregate, the obtained compressive strength becomes smaller. It also affects the density of pervious concrete. The using of mixture of ceramics and roof tiles only reduce 2 MPa of pervious concrete compressive strength so this mixture can be used as a substitute for coarse aggregate with a maximum portion of 30 %. The high porosity of the specimens causes the reduction of pervious concrete density that affect the compressive strength. This high level of porosity can be seen from the high level of water absorption that exceed the required limit of water infiltration.

  11. Evaluation of tropospheric water vapor profiling using eye-safe, infrared differential absorption lidar

    Microsoft Academic Search

    B. J. Rye; J. L. Machol; C. J. Grund; R. M. Hardesty

    1996-01-01

    Continuous, high quality profiles of water vapor, free of systematic bias, and of moderate temporal and spatial resolution are fundamental to the success of the ARM CART program. In addition, these should be acquired over long periods at low operational and maintenance cost. The development and verification of realistic climate model parameterizations for clouds and net radiation balance, and the

  12. PLASTICIZERS FOR ZEIN: THEIR EFFECT ON TENSILE PROPERTIES AND WATER ABSORPTION OF ZEIN FILMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zein will gain or lose moisture to reach equilibrium with ambient air. Cast zein films are brittle at room conditions so plasticizers are added to make them more flexible. The amount of water absorbed or lost in these films is known to be affected by relative humidity of the ambient air. However,...

  13. Method and apparatus for simulating atmospheric absorption of solar energy due to water vapor and COâ

    Microsoft Academic Search

    Sopori

    1995-01-01

    A method and apparatus for improving the accuracy of the simulation of sunlight reaching the earth`s surface includes a relatively small heated chamber having an optical inlet and an optical outlet, the chamber having a cavity that can be filled with a heated stream of COâ and water vapor. A simulated beam comprising infrared and near infrared light can be

  14. Calculation procedure to determine average mass transfer coefficients in packed columns from experimental data for ammonia water absorption refrigeration systems

    NASA Astrophysics Data System (ADS)

    Sieres, Jaime; Fernández-Seara, José

    2008-08-01

    The ammonia purification process is critical in ammonia water absorption refrigeration systems. In this paper, a detailed and a simplified analytical model are presented to characterize the performance of the ammonia rectification process in packed columns. The detailed model is based on mass and energy balances and simultaneous heat and mass transfer equations. The simplified model is derived and compared with the detailed model. The range of applicability of the simplified model is determined. A calculation procedure based on the simplified model is developed to determine the volumetric mass transfer coefficients in the vapour phase from experimental data. Finally, the proposed model and other simple calculation methods found in the general literature are compared.

  15. Absorption spectroscopy of oxygen, carbon dioxide and water species for applications in combustion diagnostics

    NASA Astrophysics Data System (ADS)

    Mei, Anhua

    Laser absorption spectroscopy has been a useful tool applied in combustion diagnostics because of its capability to measure the species' concentration, particularly to measure concentration, temperature, and pressure simultaneously. These measurements provide the necessary information for dynamic combustion control. Due to its advantages such as fast response, non-intrusive nature and applicability under harsh environment like high temperature and high pressure, absorption laser spectroscopy makes it possible to monitor combustion system on-line and in situ. Since its development for more than thirty years, laser spectroscopy has matured, and the novel and advanced laser sensors have pushed it to be applied fast. On the other hand, industry still needs cheaper and more operable spectroscopy, which becomes an important consideration in the development and application of modern laser spectroscopy. This study presents an instrumental structure including the algorithm of the spectrum computation and the hardware configuration. The algorithm applied the central maximum value of the spectrum to simplify the computation. The whole calculation was done extensively using Beer-Lambert theory and HITRAN database which makes it efficient and applicable. This research conducted the simulations of high temperature species, such as CO2, H2O to carry out the algorithm, which were compared with published data. Also, this research designed and performed the experiments of measuring oxygen and its mixture with Helium by using a 760 nm diode laser and a 655 nm Helium/Neon laser sensor with fixed wavelength structures. The results of this research also conclude the following: (1) extensive literature survey, field research and laboratory work; (2) studying the significant theories and experimental methods of the laser spectroscopy; (3) developing efficient and simplified algorithm for spectrum calculation; (4) simulating high temperature species H2O and CO2; (5) designing and building experiments for measuring species O2; (6) Numerical model of Abel Transform and analytical model for spatial distribution of concentration using line of sight data. The work in this research for the spectroscopy of H2O, CO 2 and O2 will help to construct an economic, operable and robust instrument.

  16. Vibrational absorption and vibrational circular dichroism spectra of leucine in water under different pH conditions: hydrogen-bonding interactions with water.

    PubMed

    Poopari, Mohammad Reza; Zhu, Peiyan; Dezhahang, Zahra; Xu, Yunjie

    2012-11-21

    Vibrational absorption (VA) and vibrational circular dichroism (VCD) spectroscopy have been used to study leucine, a flexible branched-chain amino acid, in aqueous solution. The VA spectra in the range of 1800-1250 cm(-1) of leucine in D(2)O under three representative pHs from strongly acidic (pH = 1), near neutral (pH = 6), to strongly basic (pH = 13), have been measured. The related VCD spectrum has been obtained under near neutral condition. Searches have been carried out to identify the most stable conformers of the Zwitterionic, protonated, and deprotonated forms of leucine in water. The geometry optimization, harmonic frequency calculations, and VA and VCD intensities have been computed at the B3LYP/6-311++G(d,p) level with the implicit polarizable continuum solvation model. While the observed VA spectra under three pHs can be well interpreted with the inclusion of the implicit solvation model, both implicit and explicit solvation models have been found to be crucial for the adequate interpretation of the complex VCD features observed. Molecular dynamics simulations and radial distribution functions have been used to aid the modeling of the leucine-(water)(N) clusters. It has been recognized that the insertion of a water molecule between the COO(-) and NH(3) (+) functional groups in the explicit solvated clusters is critical to reproduce the VCD signatures observed. Furthermore, the inclusion of the implicit bulk water environment has been found to be essential to lock water molecules, which are directly hydrogen bonded to leucine, into the positions expected in solution. The application of the explicit and implicit solvation models simultaneously allows new insights into the hydrogen bonding network surrounding leucine in aqueous solution and the role of the surrounding bulk water in stabilizing such hydrogen-bonding network. PMID:23181307

  17. Vibrational absorption and vibrational circular dichroism spectra of leucine in water under different pH conditions: Hydrogen-bonding interactions with water

    NASA Astrophysics Data System (ADS)

    Poopari, Mohammad Reza; Zhu, Peiyan; Dezhahang, Zahra; Xu, Yunjie

    2012-11-01

    Vibrational absorption (VA) and vibrational circular dichroism (VCD) spectroscopy have been used to study leucine, a flexible branched-chain amino acid, in aqueous solution. The VA spectra in the range of 1800-1250 cm-1 of leucine in D2O under three representative pHs from strongly acidic (pH = 1), near neutral (pH = 6), to strongly basic (pH = 13), have been measured. The related VCD spectrum has been obtained under near neutral condition. Searches have been carried out to identify the most stable conformers of the Zwitterionic, protonated, and deprotonated forms of leucine in water. The geometry optimization, harmonic frequency calculations, and VA and VCD intensities have been computed at the B3LYP/6-311++G(d,p) level with the implicit polarizable continuum solvation model. While the observed VA spectra under three pHs can be well interpreted with the inclusion of the implicit solvation model, both implicit and explicit solvation models have been found to be crucial for the adequate interpretation of the complex VCD features observed. Molecular dynamics simulations and radial distribution functions have been used to aid the modeling of the leucine-(water)N clusters. It has been recognized that the insertion of a water molecule between the COO- and NH3+ functional groups in the explicit solvated clusters is critical to reproduce the VCD signatures observed. Furthermore, the inclusion of the implicit bulk water environment has been found to be essential to lock water molecules, which are directly hydrogen bonded to leucine, into the positions expected in solution. The application of the explicit and implicit solvation models simultaneously allows new insights into the hydrogen bonding network surrounding leucine in aqueous solution and the role of the surrounding bulk water in stabilizing such hydrogen-bonding network.

  18. Nitrate Absorption by Barley

    PubMed Central

    Rao, K. Prasad; Rains, D. William

    1976-01-01

    The influence of protein synthesis and nitrate reductase activity on nitrate absorption by barley (Hordeum vulgare L.) was investigated. Cycloheximide decreased nitrate absorption. Pretreatment studies showed that cycloheximide affects either energy transfer or nitrate reductase activity or both. Illumination increased plant capacity for nitrate absorption, possibly through increased energy supply and/or increased nitrate reductase activity. There was a positive correlation between nitrate reductase activity and light. Inhibiting the development of nitrate reductase activity by tungstate decreased nitrate absorption. At least two nitrate transport systems are thus proposed in barley: one operating in the dark, with little nitrate reductase activity detectable; and one closely correlated with nitrate reductase activity. Total absorption is the sum of dark absorption and absorption facilitated by nitrate reductase. PMID:16659426

  19. A comparison of simultaneous plasma, atomic absorption, and iron colorimetric determinations of major and trace constituents in acid mine waters

    USGS Publications Warehouse

    Ball, J.W.; Nordstrom, D.K.

    1994-01-01

    Sixty-three water samples collected during June to October 1982 from the Leviathan/Bryant Creek drainage basin were originally analyzed by simultaneous multielement direct-current plasma (DCP) atomic-emission spectrometry, flame atomic-absorption spectrometry, graphite-furnace atomic-absorption spectrometry (GFAAS) (thallium only), ultraviolet-visible spectrometry, and hydride-generation atomic-absorption spectrometry.Determinations were made for the following metallic and semi-metallic constituents: AI, As, B, Ba, Be, Bi, Cd, Ca, Cr, Co, Cu, Fe(11), Fe(total), Li, Pb, Mg, Mn, Mo, Ni, K, Sb, Se, Si, Na, Sr, TI, V, and Zn. These samples were re-analyzed later by simultaneous multielement inductively coupled plasma (ICP) atomic-emission spectrometry and Zeeman-corrected GFAAS to determine the concentrations of many of the same constituents with improved accuracy, precision, and sensitivity. The result of this analysis has been the generation of comparative concentration values for a significant subset of the solute constituents. Many of the more recently determined values replace less-than-detection values for the trace metals; others constitute duplicate analyses for the major constituents. The multiple determinations have yielded a more complete, accurate, and precise set of analytical data. They also have resulted in an opportunity to compare the performance of the plasma-emission instruments operated in their respective simultaneous multielement modes. Flame atomic-absorption spectrometry was judged best for Na and K and hydride-generation atomic-absorption spectrometry was judged best for As because of their lower detection limit and relative freedom from interelement spectral effects. Colorimetric determination using ferrozine as the color agent was judged most accurate, precise, and sensitive for Fe. Cadmium, lead, and vanadium concentrations were too low in this set of samples to enable a determination of whether ICP or DCP is a more suitable technique. Of the remaining elements, Ba, Be, Ca, Cr, Mg, Mn, Sr, and Zn have roughly equivalent accuracy, precision, and detection limit by ICP and DCP. Cobalt and Ni were determined to be better analyzed by ICP, because of lower detection limits; B, Cu, Mo, and Si were determined to be better analyzed by DCP, because of relative freedom from interferences. The determination oral by DCP was far more sensitive, owing to the use of a more sensitive wavelength, compared with the ICP. However, there is a very serious potential interference from a strong Ca emission line near the 396.15 nanometer DCP wavelength. Thus, there is no clear choice between the plasma techniques tested, for the determination oral. The ICP and DCP detection limits are typically between 0.001 and 0.5 milligrams per liter in acid mine waters. For those metals best analyzed by ICP and/or DCP, but below these limits, GFAAS is the method of choice because of its relatively greater sensitivity and specificity. Six of the elements were not determined by DCP, ICP or Zeeman-corrected GFAAS, and are not discussed in this report. These elements are: Bi, Fe(11), Li, Sb, Se, and TI.

  20. Modelling absorption and dilution of unconfined releases of hazardous gases by water curtains or monitors

    SciTech Connect

    Fthenakis, V.M. [Brookhaven National Lab., Upton, NY (United States); Blewitt, D.N. [Amoco Production Co., Chicago, IL (United States); Hague, W.J. [Allied-Signal, Inc., Morristown, NJ (United States)

    1995-05-01

    OSHA Process Safety Management guidelines suggest that a facility operator investigate and document a plan for installing systems to detect, contain, or mitigate accidental releases if such systems are not already in place. In addition, proposed EPA 112(r) regulations would require such analysis. This paper illustrates how mathematical modelling can aid such an evaluation and describes some recent enhancements of the HGSPRAY model: (1) Adding algorithms for modeling NH{sub 3} and LNG mitigation; (2) Modeling spraying of releases with fire water monitors encircling the point of release; (3) Combining wind tunnel modeling with mathematical modeling; and (4) Linking HGSPRAY and BEGADAS. Case cases are presented as examples of how HGSPRAY can aid the design of water spray systems for initiation of toxic gases (e.g., BF, NH,) or dilution/dispersion of flammable vapors (e.g., LNG).

  1. Absorption of light and heavy water vapours in polyelectrolyte multilayer films

    Microsoft Academic Search

    Christophe Delajon; Thomas Gutberlet; Helmuth Möhwald; Rumen Krastev

    2009-01-01

    We studied the swelling and the uptake of water (H2O or D2O) vapours in polyelectrolyte (PE) multilayer (PEM) samples deposited on solid support (Si wafers) as a function of the isotope nature of the vapour and the charge of the last polymer layer. The samples were prepared with deuterated poly(sodium 4-styrenesulfonate) (dPSS) and poly(allylamine hydrochloride) (PAH). Two types of samples

  2. Multilayer Cloud Detection with the MODIS Near-Infrared Water Vapor Absorption Band

    NASA Technical Reports Server (NTRS)

    Wind, Galina; Platnick, Steven; King, Michael D.; Hubanks, Paul A,; Pavolonis, Michael J.; Heidinger, Andrew K.; Yang, Ping; Baum, Bryan A.

    2009-01-01

    Data Collection 5 processing for the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the NASA Earth Observing System EOS Terra and Aqua spacecraft includes an algorithm for detecting multilayered clouds in daytime. The main objective of this algorithm is to detect multilayered cloud scenes, specifically optically thin ice cloud overlying a lower-level water cloud, that presents difficulties for retrieving cloud effective radius using single layer plane-parallel cloud models. The algorithm uses the MODIS 0.94 micron water vapor band along with CO2 bands to obtain two above-cloud precipitable water retrievals, the difference of which, in conjunction with additional tests, provides a map of where multilayered clouds might potentially exist. The presence of a multilayered cloud results in a large difference in retrievals of above-cloud properties between the CO2 and the 0.94 micron methods. In this paper the MODIS multilayered cloud algorithm is described, results of using the algorithm over example scenes are shown, and global statistics for multilayered clouds as observed by MODIS are discussed. A theoretical study of the algorithm behavior for simulated multilayered clouds is also given. Results are compared to two other comparable passive imager methods. A set of standard cloudy atmospheric profiles developed during the course of this investigation is also presented. The results lead to the conclusion that the MODIS multilayer cloud detection algorithm has some skill in identifying multilayered clouds with different thermodynamic phases

  3. Application of multiwall carbon nanotubes impregnated with 5-dodecylsalicylaldoxime for on-line copper preconcentration and determination in water samples by flame atomic absorption spectrometry.

    PubMed

    Tobiasz, Anna; Walas, Stanis?aw; Soto Hernández, Arlene; Mrowiec, Halina

    2012-07-15

    The paper presents application of multiwall carbon nanotubes (MWCNTs) modified with 5-dodecylsalicylaldoxime to copper(II) flow-injection on-line preconcentration and flame atomic absorption spectrometric (FAAS) determination. Two new sorbents were obtained by impregnation of MWCNTs with Cu(II)-LIX 622(®) complex, however in the first case modification was preceded by carbon wall activation via oxidization (Cu-LIX-CNT-A sorbent), and in the second one no surface activation was performed (Cu-LIX-CNT sorbent). It was found that effective leaching of initially introduced copper and Cu(II) retained in preconcentration process could be realized with the use 7% and 5% (v/v) nitric acid, for particular sorbents. Testing the influence of loading solution pH and rate of loading on sorption it was found out that optimal range of loading solution pH was about 4.5-6.3 for activated and 6.15-6.25 for non-activated CNT. Investigation of sorption kinetics showed that the process can be described by pseudo-second order reaction model. Sorption equilibrium conditions (90% sorption) for LIX-CNT-A and LIX-CNT were obtained after 8-15min, respectively and maximum sorption capacity for the new sorbents amounted to 18.1mgg(-1) and 31.6mgg(-1), respectively. For the examined sorbents enrichment factors increased with extension of loading time up to 180s: linearly for activated and non-linearly for non-activated MWCNTs. Influence of potential interferents such as Cd(II), Zn(II), Fe(III), Mg(II) and Ca(II) ions on copper(II) sorption on the new CNT materials was examined individually and with the use of 2(5-2) factorial design. The study revealed significant interference from iron, magnesium and calcium ions at relatively high concentrations. Applicability of the proposed sorbents was tested for Cu(II) determination in various kinds of water samples and the results were compared with those obtained with the use of ICP MS as a reference technique. Copper(II) determination in two certified reference materials: waste water (EU-H-3) and ground (ES-H-2) water was performed in order to assess trueness of the evaluated preconcentration procedures. Satisfactory values of relative errors were obtained for both procedures. PMID:22817933

  4. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of chromium in water by graphite furnace atomic absorption spectrophotometry

    USGS Publications Warehouse

    McLain, B.J.

    1993-01-01

    Graphite furnace atomic absorption spectrophotometry is a sensitive, precise, and accurate method for the determination of chromium in natural water samples. The detection limit for this analytical method is 0.4 microg/L with a working linear limit of 25.0 microg/L. The precision at the detection limit ranges from 20 to 57 percent relative standard deviation (RSD) with an improvement to 4.6 percent RSD for concentrations more than 3 microg/L. Accuracy of this method was determined for a variety of reference standards that was representative of the analytical range. The results were within the established standard deviations. Samples were spiked with known concentrations of chromium with recoveries ranging from 84 to 122 percent. In addition, a comparison of data between graphite furnace atomic absorption spectrophotometry and direct-current plasma atomic emission spectrometry resulted in suitable agreement between the two methods, with an average deviation of +/- 2.0 microg/L throughout the analytical range.

  5. Optimization of a new resin, Amberlyst 36, as a solid-phase extractor and determination of copper(II) in drinking water and tea samples by flame atomic absorption spectrometry.

    PubMed

    Kendüzler, Erdal; Türker, Ali Rehber

    2005-11-01

    A new simple and reliable method has been developed to separate and preconcentrate trace copper ion in drinking water and tea samples for subsequent measurement by flame atomic absorption spectrometry (FAAS). The copper ions are adsorbed quantitatively during passage of aqueous solutions through Amberlyst 36 cation exchange resin. After the separation and preconcentration stage, the analyte was eluted with a potassium cyanide solution and determined by FAAS. Different factors including pH of sample solution, sample volume, amount of resin, flow rate of aqueous solution, volume and concentration of eluent, and matrix effects for preconcentration were examined. The analytical figures of merit for the determination of copper are as follows: analytical detection limit (3 sigma), 0.26 microg/L; precision (RSD), 3.1% for 100 microg/L; enrichment factor, 200 (using 1000 mL of sample solution and 5 mL of eluent); time of analysis, 3.5 h (for obtaining enrichment factor of 200); capacity of resin, 125 mg/g. The method was applied for copper determination by FAAS in tap water, commercial natural spring water, commercial treated drinking water, and commercial tea bag sample. The accuracy of the method is confirmed by analyzing tea leaves (GBW 07605). The results demonstrated good agreement with the certified values. PMID:16342801

  6. Curcumin/cellulose micro crystals/chitosan films: Water absorption behavior and in vitro cytotoxicity.

    PubMed

    Bajpai, S K; Chand, Navin; Ahuja, Sonam; Roy, M K

    2015-04-01

    A new technique, called vapor induced phase inversion (VIPI), has been employed to fabricate cellulose micro crystals (CMC)-loaded chitosan (Ch) films. The method involves immediate exposure of CMC-dispersed chitosan solution to NH3 gas. The films were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) analysis. The swelling ratio (SR) of films showed negative dependence on the cellulose content in the films. The dynamic water uptake data were interpreted by various kinetic models. Finally, the release of curcumin from the films was investigated. The CMC-loaded chitosan film showed slower release as compared to the plain chitosan film, suggesting that cellulose micro crystals acted as diffusion barrier. The films were non-cytotoxic, non-thrombogenic and non-hemolytic. PMID:25643996

  7. Detection of Carbon Monoxide and Water Absorption Lines in an Exoplanet Atmosphere

    NASA Astrophysics Data System (ADS)

    Konopacky, Quinn M.; Barman, Travis S.; Macintosh, Bruce A.; Marois, Christian

    2013-03-01

    Determining the atmospheric structure and chemical composition of an exoplanet remains a formidable goal. Fortunately, advancements in the study of exoplanets and their atmospheres have come in the form of direct imaging—spatially resolving the planet from its parent star—which enables high-resolution spectroscopy of self-luminous planets in jovian-like orbits. Here, we present a spectrum with numerous, well-resolved molecular lines from both water and carbon monoxide from a massive planet orbiting less than 40 astronomical units from the star HR 8799. These data reveal the planet’s chemical composition, atmospheric structure, and surface gravity, confirming that it is indeed a young planet. The spectral lines suggest an atmospheric carbon-to-oxygen ratio that is greater than that of the host star, providing hints about the planet’s formation.

  8. Detection of carbon monoxide and water absorption lines in an exoplanet atmosphere.

    PubMed

    Konopacky, Quinn M; Barman, Travis S; Macintosh, Bruce A; Marois, Christian

    2013-03-22

    Determining the atmospheric structure and chemical composition of an exoplanet remains a formidable goal. Fortunately, advancements in the study of exoplanets and their atmospheres have come in the form of direct imaging--spatially resolving the planet from its parent star--which enables high-resolution spectroscopy of self-luminous planets in jovian-like orbits. Here, we present a spectrum with numerous, well-resolved molecular lines from both water and carbon monoxide from a massive planet orbiting less than 40 astronomical units from the star HR 8799. These data reveal the planet's chemical composition, atmospheric structure, and surface gravity, confirming that it is indeed a young planet. The spectral lines suggest an atmospheric carbon-to-oxygen ratio that is greater than that of the host star, providing hints about the planet's formation. PMID:23493423

  9. Determination of ultra-trace gold in natural water by graphite furnace atomic absorption spectrophotometry after in situ enrichment with thiol cotton fiber

    Microsoft Academic Search

    Muqing Yu; Daowei Sun; Rui Huang; Wei Tian; Wanbin Shen; Hucheng Zhang; Ning Xu

    2003-01-01

    A simple method of determining ultra-trace Au in natural water was presented by using graphite furnace atomic absorption spectrophotometry (GFAAS) after in situ enrichment with thiol cotton fiber (TCF). The sample solution was adjusted to pH 1.5–2.0 with HCl, then the water sample was passed through a column packed with 0.10–0.20g TCF and the flow rate was controlled at 20–40mlmin?1.

  10. Determination of copper, cadmium and lead in seawater and mineral water by flame atomic absorption spectrometry after coprecipitation with aluminum hydroxide

    Microsoft Academic Search

    G. Doner; A. Ege

    2005-01-01

    An aluminum hydroxide coprecipitation method for the determination of cadmium, copper and lead by flame atomic absorption spectrometry in aqueous solutions, seawater and mineral water samples has been investigated. The coprecipitation conditions, such as the effect of the pH, the amount of carrier element, the effect of possible matrix ions and the time were examined in detail for the studied

  11. Electronic structure of liquid water from polarization-dependent two-photon absorption spectroscopy

    E-print Network

    Elles, Christopher G.; Rivera, Christopher A.; Zhang, Yuyuan; Pieniazek, Piotr A.; Bradforth, Stephen E.

    2009-02-26

    ;2PA, 12 #1;2PA = #7;#8;pump n #4; , #1;3#2; where #8;pump is the frequency of the pump pulse and n is the number density of water. The absolute cross section often is expressed in units of Goeppert–Mayer #1;1 GM =10?50 cm4 s molecule?1 photon?1....1#1;2.33#2; 49.3#1;1.09#2; 233.1#1;7.55#2; Liquid waterb Transition energy 8.09 eV 9.74 eV 10.01 eV 10.53 eVc 10.25 eVc 2PA cross section,a #1;para Degenerate pump/10?3 GM 4.0 0.1 43.1 0.6 64 1 35 1 110 2 a2PA cross-sectional units are Goeppert–Mayer #1;1 GM=10...

  12. Investigation of on-line coupling electrothermal atomic absorption spectrometry with flow injection sorption preconcentration using a knotted reactor for totally automatic determination of lead in water samples

    NASA Astrophysics Data System (ADS)

    Sperling, Michael; Yan, Xiu-ping; Welz, Bernhard

    1996-12-01

    A flow injection on-line sorption preconcentration electrothermal atomic absorption spectrometric system for fully automatic determination of lead in water was investigated. The discrete non-flow-through nature of ETAAS, the limited capacity of the graphite tube and the relatively large volume of the knotted reactor (KR) are obstacles to overcome for the on-line coupling of the KR sorption preconcentration system with ETAAS. A new FI manifold has been developed with the aim of reducing the eluate volume and minimizing dispersion. The lead diethyldithiocarbamate complex was adsorbed on the inner walls of a knotted reactor made of PTFE tubing (100 cm long, 0.5 mm i.d.). After that, an air flow was introduced to remove the residual solution from the KR and the eluate delivery tube, then the adsorbed analyte chelate was quantitatively eluted into a delivery tube with 50 ?l of ethanol. An air flow was used to propel the eluent from the eluent loop through the reactor and to introduce all the ethanolic eluate onto the platform of the transversely heated graphite tube atomizer, which was preheated to 80°C. With the use of the new FI manifold, the consumption of eluent was greatly reduced and dispersion was minimized. The adsorption efficiency was 58%, and the enhancement factor was 142 in the concentration range 0.01-0.05 ?g l -1 Pb at a sample loading rate of 6.8 ml min -1 with 60 s preconcentration time. For the range 0.1-2.0 ?g l -1 of Pb a loading rate of 3.0 ml min -1 and 30 s preconcentration time were chosen, resulting in an adsorption efficiency of 42% and an enhancement factor of 21, respectively. A detection limit (3?) of 2.2 ng l -1 of lead was obtained using a sample loading rate of 6.8 ml min -1 and 60 s preconcentration. The relative standard deviation of the entire procedure was 4.9% at the 0.01 ?g l -1 Pb level with a loading rate of 6.8 ml min -1 and 60 s preconcentration, and 2.9% at the 0.5 ?g l -1 Pb level with a 3.0 ml min -1 loading rate and 30 s preconcentration. Efficient washing of the matrix from the reactor was critical, requiring the use of the standard addition method for seawater samples. The analytical results obtained for seawater and river water standard reference materials were in good agreement with the certified values.

  13. Impact of future climate change on wheat production in relation to plant-available water capacity in a semiaridenvironment

    NASA Astrophysics Data System (ADS)

    Yang, Yanmin; Liu, De Li; Anwar, Muhuddin Rajin; Zuo, Heping; Yang, Yonghui

    2014-02-01

    Conceptions encompassing climate change are irreversible rise of atmospheric carbon dioxide (CO2) concentration, increased temperature, and changes in rainfall both in spatial- and temporal-scales worldwide. This will have a major impact on wheat production, particularly if crops are frequently exposed to a sequence, frequency, and intensity of specific weather events like high temperature during growth period. However, the process of wheat response to climate change is complex and compounded by interactions among atmospheric CO2 concentration, climate variables, soil, nutrition, and agronomic management. In this study, we use the Agricultural Production Systems sIMulator (APSIM)-wheat model, driven by statistically downscaled climate projections of 18 global circulation models (GCMs) under the 2007 Intergovernmental Panel on Climate Change (IPCC) Special Report on Emission Scenarios (SRES) A2 CO2 emission scenario to examine impact on future wheat yields across key wheat growing regions considering different soil types in New South Wales (NSW) of Australia. The response of wheat yield, yield components, and phenology vary across sites and soil types, but yield is closely related to plant available water capacity (PAWC). Results show a decreasing yield trend during the period of 2021-2040 compared to the baseline period of 1961-1990. Across different wheat-growing regions in NSW, grain yield difference in the future period (2021-2040) over the baseline (1961-1990) varies from +3.4 to -14.7 %, and in most sites, grain number is decreased, while grain size is increased in future climate. Reduction of wheat yield is mainly due to shorter growth duration, where average flowering and maturing time are advanced by an average of 11 and 12 days, respectively. In general, larger negative impacts of climate change are exhibited in those sites with higher PAWC. Current wheat cultivars with shorter growing season properties are viable in the future climate, but breading for early sowing wheat varieties with longer growing duration will be a desirable adaptation strategy for mitigating the impact of changing climate on wheat yield.

  14. Kinetic study of the scavenging reaction of the aroxyl radical by seven kinds of rice bran extracts in ethanol solution. Development of an aroxyl radical absorption capacity (ARAC) assay method.

    PubMed

    Mukai, Kazuo; Ouchi, Aya; Abe, Takumi; Murata, Kazumasa; Nakagawa, Kiyotaka; Miyazawa, Teruo

    2014-12-10

    Recently, a new assay method that can quantify the aroxyl radical (ArO•) absorption capacity (ARAC) of antioxidants (AOHs) was proposed. In the present work, the second-order rate constants (ks(Extract)) and ARAC values for the reaction of ArO• with seven kinds of rice bran extracts 1-7, which contain different concentrations of ?-, ?-, ?-, and ?-tocopherols and -tocotrienols (?-, ?-, ?-, and ?-Tocs and -Toc-3s) and ?-oryzanol, were measured in ethanol at 25 °C using stopped-flow spectrophotometry. The ks(Extract) value (1.26 × 10(-2) M(-1) s(-1)) of Nipponbare (extract 1) with the highest activity was 1.5 times larger than that (8.29 × 10(-3)) of Milyang-23 (extract 7) with the lowest activity. The concentrations (in mg/100 g) of ?-, ?-, ?-, and ?-Tocs and -Toc-3s and ?-oryzanol found in the seven extracts 1-7 were determined using HPLC-MS/MS and UV-vis absorption spectroscopy, respectively. From the results, it has been clarified that the ArO•-scavenging rates (ks(Extract)) (that is, the relative ARAC value) obtained for the seven extracts 1-7 may be approximately explained as the sum of the product {? ks(AOH-i) [AOH-i]/10(5)} of the rate constant (ks(AOH-i)) and the concentration ([AOH-i]/10(5)) of AOH-i (Tocs, Toc-3s, and ?-oryzanol) included in rice bran extracts. The contribution of ?-oryzanol to the ks(Extract) value was estimated to be between 3.0-4.7% for each extract. Taken together, these results suggest that the ARAC assay method is applicable to general food extracts. PMID:25393029

  15. Systematic trend of water vapour absorption in red giant atmospheres revealed by high resolution TEXES 12 ?m spectra

    NASA Astrophysics Data System (ADS)

    Ryde, N.; Lambert, J.; Farzone, M.; Richter, M. J.; Josselin, E.; Harper, G. M.; Eriksson, K.; Greathouse, T. K.

    2015-01-01

    Context. The structures of the outer atmospheres of red giants are very complex. Recent interpretations of a range of different observations have led to contradictory views of these regions. It is clear, however, that classical model photospheres are inadequate to describe the nature of the outer atmospheres. The notion of large optically thick molecular spheres around the stars (MOLspheres) has been invoked in order to explain spectro-interferometric observations and low- and high-resolution spectra. On the other hand high-resolution spectra in the mid-IR do not easily fit into this picture because they rule out any large sphere of water vapour in LTE surrounding red giants. Aims: In order to approach a unified scenario for these outer regions of red giants, more empirical evidence from different diagnostics are needed. Our aim here is to investigate high-resolution, mid-IR spectra for a range of red giants, spanning spectral types from early K to mid M. We want to study how the pure rotational lines of water vapour change with effective temperature, and whether we can find common properties that can put new constraints on the modelling of these regions, so that we can gain new insights. Methods: We have recorded mid-IR spectra at 12.2 - 12.4 ?m at high spectral resolution of ten well-studied bright red giants, with TEXES mounted on the IRTF on Mauna Kea. These stars span effective temperatures from 3450 K to 4850 K. Results: We find that all red giants in our study cooler than 4300 K, spanning a wide range of effective temperatures (down to 3450 K), show water absorption lines stronger than expected and none are detected in emission, in line with what has been previously observed for a few stars. The strengths of the lines vary smoothly with spectral type. We identify several spectral features in the wavelength region that are undoubtedly formed in the photosphere. From a study of water-line ratios of the stars, we find that the excitation temperatures, in the line-forming regions, are several hundred Kelvin lower than expected from a classical photospheric model. Conclusions: All stars in our sample show several photospheric features in their 12 ?m spectra, which can be modelled with a classical model photosphere. However, in all stars showing water-vapour lines (stars cooler than ~4300 K), the water lines are found to be much deeper than expected. The line ratios of these pure-rotational lines reveal low excitation temperatures. This could either be due to lower temperatures than expected in the outer regions of the photospheres caused by for example extra cooling, or due to non-LTE level populations, affecting the source function and line opacities, but this needs further investigation. We have demonstrated that these diagnostically interesting water lines are a general feature of red giants across spectral types, and we argue for a general explanation of their formation rather than explanations requiring specific properties, such as dust. Since the water lines are neither weak (filled in by emission) nor do they appear in emission, as predicted by LTE MOLsphere models in their simplest forms, the evidence of the existence of such large optically-thick, molecular spheres enshrouding the stars is weakened. It is still a challenge to find a unifying picture of the outer regions of the atmospheres of red giants, but we have presented new empirical evidence that needs to be taken into account and explained in any model of these regions. Table 4 is available in electronic form at http://www.aanda.org

  16. The effects of water acidification, temperature and salinity on the regenerative capacity of the polychaete Diopatra neapolitana.

    PubMed

    Pires, Adília; Figueira, Etelvina; Moreira, Anthony; Soares, Amadeu M V M; Freitas, Rosa

    2015-05-01

    Changes in seawater pH, temperature and salinity are expected to occur in the near future, which can be a threat to aquatic systems, mainly for marine coastal areas, and their inhabiting species. Hence, the present study proposes to evaluate the effects of temperature shifts, pH decrease and salinity changes in the tissue's regenerative capacity of the polychaete Diopatra neapolitana. This study evidenced that D. neapolitana individuals exposed to lower pH exhibited a significantly lower capacity to regenerate their body, while with the increase of temperature individuals showed a higher capacity to regenerate their tissues. Furthermore, the present work demonstrated that individuals exposed to salinities 28 and 35 did not present significant differences between them, while salinities 21 and 42 negatively influenced the regenerative capacity of D. neapolitana. At the end of regeneration, comparing all conditions, high salinity (42) seemed to have a greater impact on the regenerative capacity of individuals than the other factors, since under this condition individuals took longer to completely regenerate. Overall, this study demonstrated that variations in abiotic factors can strongly affect D. neapolitana's performance. PMID:25756899

  17. Recent Advances in Delivery Systems and Therapeutics of Cinnarizine: A Poorly Water Soluble Drug with Absorption Window in Stomach

    PubMed Central

    Pathak, Kamla

    2014-01-01

    Low solubility causing low dissolution in gastrointestinal tract is the major problem for drugs meant for systemic action after oral administration, like cinnarizine. Pharmaceutical products of cinnarizine are commercialized globally as immediate release preparations presenting low absorption with low and erratic bioavailability. Approaches to enhance bioavailability are widely cited in the literature. An attempt has been made to review the bioavailability complications and clinical therapeutics of poorly water soluble drug: cinnarizine. The interest of writing this paper is to summarize the pharmacokinetic limitations of drug with special focus on strategies to improvise bioavailability along with effectiveness of novel dosage forms to circumvent the obstacle. The paper provides insight to the approaches to overcome low and erratic bioavailability of cinnarizine by cyclodextrin complexes and novel dosage forms: self-nanoemulsifying systems and buoyant microparticulates. Nanoformulations need to systematically explored in future, for their new clinical role in prophylaxis of migraine attacks in children. Clinical reports have affirmed the role of cinnarizine in migraine prophylaxis. Research needs to be dedicated to develop dosage forms for efficacious bioavailability and drug directly to brain. PMID:25478230

  18. Determination of fluoride in sea-water by molecular absorption spectrometry of aluminium monofluoride after removal cation and anion interferences.

    PubMed

    Corvillo, M A; Gomez, M G; Rica, C C

    1990-07-01

    Three procedures are proposed for the determination of trace levels of fluoride in sea-water, based on the formation of aluminium monofluoride in an electrothermal graphite furnace, followed by measurement of its molecular absorption at 227.45 nm. They involve the use of dilution, a matrix modifier, or a matrix modifier and an ion-exchange resin, and are all acceptably sensitive and specific for fluoride. Interferences from cations and anions are removed by a simple 20-fold dilution of the sample. At 10-fold sample dilution, chloride interference can be removed by adding 0.3M ammonium nitrate together with 0.01M aluminium + 0.01M strontium as a matrix modifier. The same matrix modifier is valid for use with 5-fold sample dilution and a cation-exchange step to avoid matrix affects from cations and chloride. The detection limit is about 8-10 ng/ml fluoride and the determination limit is 20 ng/ml. The precision of peak-height measurement at 0.2 mug/ml is 5-7%. PMID:18965008

  19. Cloud point extraction-flame atomic absorption spectrometry method for preconcentration and determination of trace cadmium in water samples.

    PubMed

    Ning, Jinyan; Jiao, Yang; Zhao, Jiao; Meng, Lifen; Yang, Yaling

    2014-01-01

    A method based on cloud point extraction (CPE) separation/preconcentration of trace cadmium (Cd) as a prior step to its determination by flame atomic absorption spectrometry has been developed. Cadmium reacted with 8-hydroxyquinoline to form hydrophobic chelates, which were extracted into the micelles of nonionic surfactant oligoethylene glycol monoalkyl ether (Genapol X-080) in an alkaline medium. Octanol was used to depress the cloud point of Genapol X-080 in the extraction process. The chemical variables that affect the CPE, such as pH of complexation reaction, amount of chelating agent, Genapol X-080 and octanol were evaluated and optimized. Under optimized conditions, linearity was obeyed in the range of 10-500 ?g/L, with the correlation coefficient of 0.9993. For 5 mL of sample solution, the enhancement factor was about 20. The limit of detection and limit of quantification of the method were 0.21 and 0.63 ?g/L, respectively. The relative standard deviations (n = 6) was 3.2% for a solution containing 100 ?g/L of Cd. The accuracy of the preconcentration system was evaluated by recovery measurements on spiked water samples. Recoveries of spiked samples varied in the range of 94.1-103.8%. PMID:25116488

  20. Speciation of selenium in plant water extracts by ion exchange chromatography-hydride generation atomic absorption spectrometry.

    PubMed

    Zhang, Y; Frankenberger, W T

    2001-03-26

    Determination of selenium (Se) speciation in plants is important in studying the bioavailability and toxicity of Se in Se-contaminated soil/sediment. In this study, we used an anion exchange resin (Dowex 1-10X) to separate Se into non-amino acid organic Se, Se-amino acids, selenite (Se [IV]) and selenate (Se [VI]) in a plant (Stanleya pinnata) extract. The hydride generation atomic absorption spectrometry (HGAAS) was used to determine concentrations of these Se compounds in plant extracts. Results showed that Se compounds can be quantitatively separated by the resin column. Recovery of five spiked standard Se compounds (trimethylselenonium ion (TMSe+), dimethylselenoxide (DMSeO), selenomethionine (Semet), Se [IV] and Se [VII]) in the plant extract ranged from 92.9 to 103%. Water extractable Se accounted for 60.4-72.6% of the total Se in the plant. Among the soluble Se compounds in the plant extract, Se-amino acids were 73-85.5%, Se [VI] ranged from 7.5 to 19.5% and non-amino acid organic Se was less than 7%. Se [IV] in most samples was below the detection limit (1 microg/g). This study showed that considerable amounts of the accumulated Se [VI] in the plant was metabolized to Se-amino acids during growth of the plant. PMID:11305342

  1. On the influence of water on the electronic structure of firefly oxyluciferin anions from absorption spectroscopy of bare and monohydrated ions in vacuo.

    PubMed

    Støchkel, Kristian; Hansen, Christian Nygaard; Houmøller, Jørgen; Nielsen, Lisbeth Munksgaard; Anggara, Kelvin; Linares, Mathieu; Norman, Patrick; Nogueira, Fernando; Maltsev, Oleg V; Hintermann, Lukas; Brøndsted Nielsen, Steen; Naumov, Pan?e; Milne, Bruce F

    2013-05-01

    A complete understanding of the physics underlying the varied colors of firefly bioluminescence remains elusive because it is difficult to disentangle different enzyme-lumophore interactions. Experiments on isolated ions are useful to establish a proper reference when there are no microenvironmental perturbations. Here, we use action spectroscopy to compare the absorption by the firefly oxyluciferin lumophore isolated in vacuo and complexed with a single water molecule. While the process relevant to bioluminescence within the luciferase cavity is light emission, the absorption data presented here provide a unique insight into how the electronic states of oxyluciferin are altered by microenvironmental perturbations. For the bare ion we observe broad absorption with a maximum at 548 ± 10 nm, and addition of a water molecule is found to blue-shift the absorption by approximately 50 nm (0.23 eV). Test calculations at various levels of theory uniformly predict a blue-shift in absorption caused by a single water molecule, but are only qualitatively in agreement with experiment highlighting limitations in what can be expected from methods commonly used in studies on oxyluciferin. Combined molecular dynamics simulations and time-dependent density functional theory calculations closely reproduce the broad experimental peaks and also indicate that the preferred binding site for the water molecule is the phenolate oxygen of the anion. Predicting the effects of microenvironmental interactions on the electronic structure of the oxyluciferin anion with high accuracy is a nontrivial task for theory, and our experimental results therefore serve as important benchmarks for future calculations. PMID:23557511

  2. Effect of average flow and capacity utilization on effluent water quality from US municipal wastewater treatment facilities.

    PubMed

    Weirich, Scott R; Silverstein, Joann; Rajagopalan, Balaji

    2011-08-01

    There is increasing interest in decentralization of wastewater collection and treatment systems. However, there have been no systematic studies of the performance of small treatment facilities compared with larger plants. A statistical analysis of 4 years of discharge monthly report (DMR) data from 210 operating wastewater treatment facilities was conducted to determine the effect of average flow rate and capacity utilization on effluent biochemical oxygen demand (BOD), total suspended solids (TSS), ammonia, and fecal coliforms relative to permitted values. Relationships were quantified using generalized linear models (GLMs). Small facilities (40 m³/d) had violation rates greater than 10 times that of the largest facilities (400,000 m³/d) for BOD, TSS, and ammonia. For facilities with average flows less than 40,000 m³/d, increasing capacity utilization was correlated with increased effluent levels of BOD and TSS. Larger facilities tended to operate at flows closer to their design capacity while maintaining treatment suggesting greater efficiency. PMID:21704355

  3. Carrying Capacity

    NSDL National Science Digital Library

    2012-06-25

    This one-day activity challenges students to understand the ecological concept of carrying capacity through the physically-active process of role playing. Upon completion, students will be able to formulate and test hypotheses related to ecosystems and carrying capacity as well as describe the significance of carrying capacity.

  4. Heat Capacity Analysis Report

    SciTech Connect

    A. Findikakis

    2004-11-01

    The purpose of this report is to provide heat capacity values for the host and surrounding rock layers for the waste repository at Yucca Mountain. The heat capacity representations provided by this analysis are used in unsaturated zone (UZ) flow, transport, and coupled processes numerical modeling activities, and in thermal analyses as part of the design of the repository to support the license application. Among the reports that use the heat capacity values estimated in this report are the ''Multiscale Thermohydrologic Model'' report, the ''Drift Degradation Analysis'' report, the ''Ventilation Model and Analysis Report, the Igneous Intrusion Impacts on Waste Packages and Waste Forms'' report, the ''Dike/Drift Interactions report, the Drift-Scale Coupled Processes (DST and TH Seepage) Models'' report, and the ''In-Drift Natural Convection and Condensation'' report. The specific objective of this study is to determine the rock-grain and rock-mass heat capacities for the geologic stratigraphy identified in the ''Mineralogic Model (MM3.0) Report'' (BSC 2004 [DIRS 170031], Table 1-1). This report provides estimates of the heat capacity for all stratigraphic layers except the Paleozoic, for which the mineralogic abundance data required to estimate the heat capacity are not available. The temperature range of interest in this analysis is 25 C to 325 C. This interval is broken into three separate temperature sub-intervals: 25 C to 95 C, 95 C to 114 C, and 114 C to 325 C, which correspond to the preboiling, trans-boiling, and postboiling regimes. Heat capacity is defined as the amount of energy required to raise the temperature of a unit mass of material by one degree (Nimick and Connolly 1991 [DIRS 100690], p. 5). The rock-grain heat capacity is defined as the heat capacity of the rock solids (minerals), and does not include the effect of water that exists in the rock pores. By comparison, the rock-mass heat capacity considers the heat capacity of both solids and pore water. For temperatures in the trans-boiling regime (95 C to 114 C), the additional energy required to vaporize the pore water is accounted for in the rock-mass heat capacity. The rock-grain heat capacities are intended to be used in models and analyses that explicitly account for the thermodynamic effects of the water within the rock porosity. The rock-mass heat capacities are intended to be used in models and analyses that do not explicitly account for these thermodynamic effects, particularly boiling. The term specific heat is often used synonymously with heat capacity; however, the latter term is used throughout this document.

  5. 14 CFR 29.723 - Shock absorption tests.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2010-01-01 false Shock absorption tests. 29.723 Section 29...Landing Gear § 29.723 Shock absorption tests. The landing inertia load factor and the reserve energy absorption capacity of the landing gear...

  6. 14 CFR 27.723 - Shock absorption tests.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2010-01-01 false Shock absorption tests. 27.723 Section 27...Landing Gear § 27.723 Shock absorption tests. The landing inertia load factor and the reserve energy absorption capacity of the landing gear...

  7. 14 CFR 29.723 - Shock absorption tests.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 2011-01-01 false Shock absorption tests. 29.723 Section 29...Landing Gear § 29.723 Shock absorption tests. The landing inertia load factor and the reserve energy absorption capacity of the landing gear...

  8. 14 CFR 29.723 - Shock absorption tests.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 2013-01-01 false Shock absorption tests. 29.723 Section 29...Landing Gear § 29.723 Shock absorption tests. The landing inertia load factor and the reserve energy absorption capacity of the landing gear...

  9. 14 CFR 27.723 - Shock absorption tests.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 2013-01-01 false Shock absorption tests. 27.723 Section 27...Landing Gear § 27.723 Shock absorption tests. The landing inertia load factor and the reserve energy absorption capacity of the landing gear...

  10. 14 CFR 29.723 - Shock absorption tests.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 2012-01-01 false Shock absorption tests. 29.723 Section 29...Landing Gear § 29.723 Shock absorption tests. The landing inertia load factor and the reserve energy absorption capacity of the landing gear...

  11. 14 CFR 29.723 - Shock absorption tests.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 2014-01-01 false Shock absorption tests. 29.723 Section 29...Landing Gear § 29.723 Shock absorption tests. The landing inertia load factor and the reserve energy absorption capacity of the landing gear...

  12. 14 CFR 27.723 - Shock absorption tests.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 2014-01-01 false Shock absorption tests. 27.723 Section 27...Landing Gear § 27.723 Shock absorption tests. The landing inertia load factor and the reserve energy absorption capacity of the landing gear...

  13. 14 CFR 27.723 - Shock absorption tests.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 2011-01-01 false Shock absorption tests. 27.723 Section 27...Landing Gear § 27.723 Shock absorption tests. The landing inertia load factor and the reserve energy absorption capacity of the landing gear...

  14. 14 CFR 27.723 - Shock absorption tests.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 2012-01-01 false Shock absorption tests. 27.723 Section 27...Landing Gear § 27.723 Shock absorption tests. The landing inertia load factor and the reserve energy absorption capacity of the landing gear...

  15. Corrosion Problems in Absorption Chillers

    ERIC Educational Resources Information Center

    Stetson, Bruce

    1978-01-01

    Absorption chillers use a lithium bromide solution as the medium of absorption and water as the refrigerant. Discussed are corrosion and related problems, tests and remedies, and cleaning procedures. (Author/MLF)

  16. Network Position, Absorptive Capacity and Firm Success

    Microsoft Academic Search

    Uwe Cantner; Kristin Joel

    Interaction between firms or institutions in a regionally bounded area leads to a substructure conductive for innovative activities. In a vital regional innovation system the actors benefit from a multilayer network consisting of business relations, innovative cooperations and daily personal contacts by which they get access to external innovative impulses. We ask in this paper whether these knowledge flows and

  17. Comparison of the gravimetric, phenol red, and 14C-PEG-3350 methods to determine water absorption in the rat single-pass intestinal perfusion model.

    PubMed

    Sutton, S C; Rinaldi, M T; Vukovinsky, K E

    2001-01-01

    This study was undertaken to determine whether the gravimetric method provided an accurate measure of water flux correction and to compare the gravimetric method with methods that employ nonabsorbed markers (eg, phenol red and 14C-PEG-3350). Phenol red,14C-PEG-3350, and 4-[2-[[2-(6-amino-3-pyridinyl)-2-hydroxyethyl]amino]ethoxy]-, methyl ester, (R)-benzene acetic acid (Compound I) were co-perfused in situ through the jejunum of 9 anesthetized rats (single-pass intestinal perfusion [SPIP]). Water absorption was determined from the phenol red,14C-PEG-3350, and gravimetric methods. The absorption rate constant (ka) for Compound I was calculated. Both phenol red and 14C-PEG-3350 were appreciably absorbed, underestimating the extent of water flux in the SPIP model. The average +/- SD water flux microg/h/cm) for the 3 methods were 68.9 +/- 28.2 (gravimetric), 26.8 +/- 49.2 (phenol red), and 34.9 +/- 21.9 (14C-PEG-3350). The (average +/- SD) ka for Compound I (uncorrected for water flux) was 0.024 +/- 0.005 min(-1). For the corrected, gravimetric method, the average +/- SD was 0.031 +/- 0.001 min(-1). The gravimetric method for correcting water flux was as accurate as the 2 "nonabsorbed" marker methods. PMID:11741276

  18. Biodegradable plastic made from soybean products. II. Effects of cross-linking and cellulose incorporation on mechanical properties and water absorption

    Microsoft Academic Search

    I. Paetau; C.-Z. Chen; J. Jane

    1994-01-01

    Soy isolate was treated with formaldehyde and glyoxal at 1.0, 2.5, and 5.0% (w\\/w isolate) and with adipic and acetic anhydrides. The materials were then compression-molded into plastic tensile bars and tested for tensile and yield strength, percentage elongation, Young's modulus, and water absorption. Treatment with 5% formaldehyde increased the tensile strength significantly, to 4.9 kg\\/mm2, compared with the untreated

  19. Antimony in Drinking Water, Red Blood Cells, and Serum: Development of Analytical Methodology Using Transversely Heated Graphite Furnace Atomization-Atomic Absorption Spectrometry

    Microsoft Academic Search

    K. S. Subramanian; R. Poon; I. Chu; J. W. Connor

    1997-01-01

    .   An atomic absorption spectrometric (AAS) method has been developed for determining ?g\\/L levels of Sb in samples of water\\u000a and blood. The AAS method is based on the concept of stabilized temperature platform furnace atomization (STPF) realized through\\u000a the use of a transversely heated graphite atomizer (THGA) furnace, longitudinal Zeeman-effect background correction, and matrix\\u000a modification with palladium nitrate-magnesium nitrate-nitric

  20. Calculation of near-edge x-ray-absorption fine structure at finite temperatures: Spectral signatures of hydrogen bond breaking in liquid water

    Microsoft Academic Search

    Balázs Hetényi; Filippo de Angelis; Paolo Giannozzi; Roberto Car

    2004-01-01

    We calculate the near-edge x-ray-absorption fine structure of H2O in the gas, hexagonal ice, and liquid phases using heuristic density-functional based methods. We present a detailed comparison of our results with experiment. The differences between the ice and water spectra can be rationalized in terms of the breaking of hydrogen bonds around the absorbing molecule. In particular the increase in

  1. Off-line determination of trace silver in water samples and standard reference materials by cloud poin t extraction-atomic absorption spectrometry

    Microsoft Academic Search

    Ersin Kilinc; Viia Lepane; Bahattin Gumgum

    An off-line method for the determination of tr ace silver in water samples and certified reference materials by cl oud point extraction (CPE) followed by flame atomic absorption spectrometry (FAAS) has been worked out. Preconcentration of CPE was based on complex formation of silver with dithizone in the presence of non-ionic micelles of octylphenoxy polyethoxy ethanol (Triton X-114) at pH

  2. Computer-aided prediction of the Al 2 O 3 nanoparticles’ effects on tensile strength and percentage of water absorption of concrete specimens

    Microsoft Academic Search

    Ali Nazari; Shadi Riahi

    In the present paper, two models based on artificial neural networks and genetic programming for predicting split tensile\\u000a strength and percentage of water absorption of concretes containing Al2O3 nanoparticles have been developed at different ages of curing. For purpose of building these models, training and testing\\u000a using experimental results for 144 specimens produced with 16 different mixture proportions were conducted.

  3. Variable Infiltration Capacity model (VIC) is a macro-scale energy and water balance model with lake and wetland

    E-print Network

    Cherkauer, Keith

    ) Distributed water table resulting from the fractional area topographic index curve that illustrates landscape positions is represented by integrating the topographic index (TI) for different fractional areas

  4. Absorption and fluorescence properties of chromophoric dissolved organic matter: implications for the monitoring of water quality in a large subtropical reservoir.

    PubMed

    Liu, Xiaohan; Zhang, Yunlin; Shi, Kun; Zhu, Guangwei; Xu, Hai; Zhu, Mengyuan

    2014-12-01

    The development of techniques for real-time monitoring of water quality is of great importance for effectively managing inland water resources. In this study, we first analyzed the absorption and fluorescence properties in a large subtropical reservoir and then used a chromophoric dissolved organic matter (CDOM) fluorescence monitoring sensor to predict several water quality parameters including the total nitrogen (TN), total phosphorus (TP), chemical oxygen demand (COD), dissolved organic carbon (DOC), and CDOM fluorescence parallel factor analysis (PARAFAC) components in the reservoir. The CDOM absorption coefficient at 254 nm (a(254)), the humic-like component (C1), and the tryptophan-like component (C3) decreased significantly along a gradient from the northwest to the lake center, northeast, southwest, and southeast region in the reservoir. However, no significant spatial difference was found for the tyrosine-like component (C2), which contributed only four marked peaks. A highly significant linear correlation was found between the a(254) and CDOM concentration measured using the CDOM fluorescence sensor (r(2)?= 0.865, n = 76, p < 0.001), indicating that CDOM concentrations could act as a proxy for the CDOM absorption coefficient measured in the laboratory. Significant correlations were also found between the CDOM concentration and TN, TP, COD, DOC, and the maximum fluorescence intensity of C1, suggesting that the real-time monitoring of CDOM concentrations could be used to predict these water quality parameters and trace the humic-like fluorescence substance in clear aquatic ecosystems with DOC <2 mg/L and total suspended matter (TSM) concentrations <15 mg/L. These results demonstrate that the CDOM fluorescence sensor is a useful tool for on-line water quality monitoring if the empirical relationship between the CDOM concentration measured using the CDOM fluorescence sensor and the water quality parameters is calibrated and validated. PMID:25053284

  5. A new direct absorption tunable diode laser spectrometer for high precision measurement of water vapor in the upper troposphere and lower stratosphere.

    PubMed

    Sargent, M R; Sayres, D S; Smith, J B; Witinski, M; Allen, N T; Demusz, J N; Rivero, M; Tuozzolo, C; Anderson, J G

    2013-07-01

    We present a new instrument for the measurement of water vapor in the upper troposphere and lower stratosphere (UT?LS), the Harvard Herriott Hygrometer (HHH). HHH employs a tunable diode near-IR laser to measure water vapor via direct absorption in a Herriott cell. The direct absorption technique provides a direct link between the depth of the observed absorption line and the measured water vapor concentration, which is calculated based on spectroscopic parameters in the HITRAN database. While several other tunable diode laser (TDL) instruments have been used to measure water vapor in the UT?LS, HHH is set apart by its use of an optical cell an order of magnitude smaller than those of other direct absorption TDLs in operation, allowing for a more compact, lightweight instrument. HHH is also unique in its integration into a common duct with the Harvard Lyman-? hygrometer, an independent photo-fragment fluorescence instrument which has been thoroughly validated over 19 years of flight measurements. The instrument was flown for the first time in the Mid-latitude Airborne Cirrus Properties Experiment (MACPEX) on NASA's WB-57 aircraft in spring, 2011, during which it demonstrated in-flight precision of 0.1 ppmv (1 s) with 1-sigma uncertainty of 5% ± 0.7 ppmv. Since the campaign, changes to the instrument have lead to improved accuracy of 5% ± 0.2 ppmv as demonstrated in the laboratory. During MACPEX, HHH successfully measured water vapor at concentrations from 3.5 to 600 ppmv in the upper troposphere and lower stratosphere. HHH and Lyman-?, measuring independently but under the same sampling conditions, agreed on average to within 1% at water vapor mixing ratios above 20 ppmv and to within 0.3 ppmv at lower mixing ratios. HHH also agreed with a number of other in situ water vapor instruments on the WB-57 to within their stated uncertainties, and to within 0.7 ppmv at low water. This agreement constitutes a significant improvement over past in situ comparisons, in which differences of 1.5-2 ppmv were routinely observed, and demonstrates that the accuracy of HHH is consistent with other instruments which use a range of detection methods and sampling techniques. PMID:23902086

  6. A new direct absorption tunable diode laser spectrometer for high precision measurement of water vapor in the upper troposphere and lower stratosphere

    NASA Astrophysics Data System (ADS)

    Sargent, M. R.; Sayres, D. S.; Smith, J. B.; Witinski, M.; Allen, N. T.; Demusz, J. N.; Rivero, M.; Tuozzolo, C.; Anderson, J. G.

    2013-07-01

    We present a new instrument for the measurement of water vapor in the upper troposphere and lower stratosphere (UT/LS), the Harvard Herriott Hygrometer (HHH). HHH employs a tunable diode near-IR laser to measure water vapor via direct absorption in a Herriott cell. The direct absorption technique provides a direct link between the depth of the observed absorption line and the measured water vapor concentration, which is calculated based on spectroscopic parameters in the HITRAN database. While several other tunable diode laser (TDL) instruments have been used to measure water vapor in the UT/LS, HHH is set apart by its use of an optical cell an order of magnitude smaller than those of other direct absorption TDLs in operation, allowing for a more compact, lightweight instrument. HHH is also unique in its integration into a common duct with the Harvard Lyman-? hygrometer, an independent photo-fragment fluorescence instrument which has been thoroughly validated over 19 years of flight measurements. The instrument was flown for the first time in the Mid-latitude Airborne Cirrus Properties Experiment (MACPEX) on NASA's WB-57 aircraft in spring, 2011, during which it demonstrated in-flight precision of 0.1 ppmv (1 s) with 1-sigma uncertainty of 5% ± 0.7 ppmv. Since the campaign, changes to the instrument have lead to improved accuracy of 5% ± 0.2 ppmv as demonstrated in the laboratory. During MACPEX, HHH successfully measured water vapor at concentrations from 3.5 to 600 ppmv in the upper troposphere and lower stratosphere. HHH and Lyman-?, measuring independently but under the same sampling conditions, agreed on average to within 1% at water vapor mixing ratios above 20 ppmv and to within 0.3 ppmv at lower mixing ratios. HHH also agreed with a number of other in situ water vapor instruments on the WB-57 to within their stated uncertainties, and to within 0.7 ppmv at low water. This agreement constitutes a significant improvement over past in situ comparisons, in which differences of 1.5-2 ppmv were routinely observed, and demonstrates that the accuracy of HHH is consistent with other instruments which use a range of detection methods and sampling techniques.

  7. Nanofluid heat capacities

    NASA Astrophysics Data System (ADS)

    Starace, Anne K.; Gomez, Judith C.; Wang, Jun; Pradhan, Sulolit; Glatzmaier, Greg C.

    2011-12-01

    Significant increases in the heat capacity of heat transfer fluids are needed not only to reduce the costs of liquid heating and cooling processes, but also to bring clean energy producing technologies like concentrating solar power (CSP) to price parity with conventional energy generation. It has been postulated that nanofluids could have higher heat capacities than conventional fluids. In this work, nano- and micron-sized particles were added to five base fluids (poly-? olefin, mineral oil, ethylene glycol, a mixture of water and ethylene glycol, and calcium nitrate tetrahydrate), and the resulting heat capacities were measured and compared with those of the neat base fluids and the weighted average of the heat capacities of the components. The particles used were inert metals and metal oxides that did not undergo any phase transitions over the temperature range studied. In the nanofluids studied here, we found no increase in heat capacity upon the addition of the particles larger than the experimental error.

  8. Thermal conductivity, thermal effusivity, and specific heat capacity near the lower critical point of the binary liquid mixture n-butoxyethanol-water.

    PubMed

    Pittois, S; Van Roie, B; Glorieux, C; Thoen, J

    2004-07-22

    Experimental investigations on binary liquid mixtures near the critical mixing point are presently leading to a controversy about the anomaly in the thermal conductivity. A photopyroelectric technique is used to determine the thermal conductivity and the effusivity of the binary liquid mixture n-butoxyethanol-water at its critical concentration near the critical mixing point. It is proven that, contrary to previous reports, there is no critical enhancement in the thermal conductivity. The specific heat capacity is calculated from these results and compared with the results from measurements performed by adiabatic scanning calorimetry. PMID:15260737

  9. Influence of Anesthetic Regimens on Intestinal Absorption in Rats

    Microsoft Academic Search

    Hiroaki Yuasa; Kenji Matsuda; Jun Watanabe

    1993-01-01

    We compared the influence of anesthetic regimens using urethane (U), pentobarbital (P), ether (E), and ketamine\\/midazolam (K) on the intestinal absorption of several probes using a single-pass per-fusion technique in rats. The selected probes were D-glucose (1 mM) for the resistance of the unstirred water layer (UWL), D-glucose (100 mM) for the capacity of carrier-mediated D-glucose transport, L-glucose, and urea

  10. The Potential of Biochar produced from Eichhornia crassipes and Prosopis juliflora to Enhance Soil Water Holding Capacity of Drylands Soils 

    E-print Network

    Aller, Deborah

    2012-11-29

    Environmental degradation, agricultural productivity, food security, fresh water scarcity, and the adaptation to and mitigation of climate change are all significant concerns of the 21st century. Biochar is a highly porous, carbon rich material...

  11. Surface properties and water treatment capacity of surface engineered silica coated with 3-(2-aminoethyl) aminopropyltrimethoxysilane

    NASA Astrophysics Data System (ADS)

    Majewski, Peter; Keegan, Alexandra

    2012-01-01

    This study's focus was on the water-based, one-pot preparation and characterisation of silica particles coated with 3-(2-aminoethyl)aminopropyltrimethoxysilane (Diamo) and the efficiency of the material in removing the pathogens Escherichia coli, Pseudomonas aeruginosa, Mycobacterium immunogenum, Vibrio cholerae, poliovirus, and Cryptosporidium parvum. The water-based processing resulted in Diamo coated silica particles with significantly increased positive surface charge as determined by zeta potential measurements. In addition, X-ray photoelectron spectrometry of pure and Diamo coated silica confirmed the presence of Diamo on the surface of the particles. Thermogravimetric measurements and chemical analysis of the silica indicated a surface concentration of amine groups of about 1 mmol/g silica. Water treatment tests with the pathogens showed that a dose of about 10 g appeared to be sufficient to remove pathogens from pure water samples which were spiked with pathogen concentrations between about 10 2 and 10 4 cfu/mL.

  12. Impact of Land Use Change On Soil Water Holding Capacity and River Modelling of The Nakambe River In Burkina-faso

    NASA Astrophysics Data System (ADS)

    Mahe, G.; Paturel, J. E.; Conway, D.; Servat, E.; Ouedraogo, M.

    The annual hydrological regime of the Nakambe River shows substantial changes dur- ing the period 1955 to 1998 with a shift occurring around 1970. From 1970 to the mid- 1990s, despite a reduction in rainfall and an increase in the number of dams, runoff increased, including maximum daily discharges, and a delay of several weeks in the timing of peak flows occurred. To assess the impact of land use change on soil water holding capacity (WHC) during this period we compare the results of two monthly hydrological models using several different rainfall, potential evapotranspiration (PE ) and WHC data sets. Soil WHC values are modified over time using historical maps of land use, and compared with a constant value for WHC over time. There is a mod- erate improvement in flow simulation using the varying values of soil WHC which underlines how much it is important to take into account land use changes and its implications on water cycle.

  13. AquaPedia: Building Intellectual Capacity Through Shared Learning and Open Access Platform to Resolve Water Conflicts

    NASA Astrophysics Data System (ADS)

    Islam, S.; Akanda, A. S.; Jutla, A.; Lin, C.; Gao, Y.

    2009-04-01

    Water promises to be the resource that determines the wealth, welfare, and stability of many countries in the 21st century. With burgeoning population pressure and competing needs, water resources are increasingly overused, water quality is often sub-optimal, and ecological integrity is excessively taxed. This problem occurs at various levels within the frameworks created by society and are exacerbated at political, physical, cultural, and economic boundaries. A key difficulty in addressing existing and emerging water conflicts is the scale discrepancy between conflicts and policies in place. Although significant local knowledge exists for a range of water conflicts across the globe, it is neither readily accessible nor easily transferable to other regions. We suggest that the origin of many water conflicts can be understood as a dynamic consequence of competition, interconnections, and feedback among variables in the natural and societal systems (NSSs). Within the natural system, the triple constraints on water (quantity (Q), quality (P), and ecological functions, goods, and services (E)) and their interconnections may lead to conflicts. Within the societal system, interdependencies and feedback among societal values, norms, and customs (V), economic costs and benefits derived from water resources (C), and governance (G) create intractable contextual differences. We argue that water issues can be framed and formulated within the NSSs comprised of these six variables (Q, P, E and V, C, G) and their dynamic interactions and feedbacks. As both sides of NSSs are porous, coupled, and interactive, we cannot explain - much less predict - the behavior of these systems without treating both sides as endogenous. The knowledge needed to address and manage contemporary and emerging water problems need to go beyond scientific assessment in which societal factors (C, G, and V) are treated as exogenous or largely ignored, and social science and policy research that does not consider the impact of natural factors (E, P, and Q) and coupling among them. We recognize that uncertainties and incomplete information about interconnections, feedbacks, and complexities within and between societal and natural systems will continue to pose high barriers in finding an effective solution and reaching an agreement for a given water conflict. Sharing of knowledge across river basins can catalyze this learning process. Yet, each water problem or conflict is usually highly contextual and local with different patterns of interconnections and complexities within and between societal and natural system. A management intervention that works in one basin may not be applicable to another due to differences in social-economic context and natural settings. Consequently, we need a conceptual framework that can integrate knowledge as well as compare and contrast outcomes across different scales, boundaries, and river basins. Such a framework will allow us to share knowledge and speed up the learning process across scales and boundaries. Our proposed web-based, wiki-style, self-learning repository of interactive and searchable water case studies, AquaPedia, is a step in that direction. This repository of water information and collective wisdom will bring together various stakeholders across the globe on a common platform to discuss and craft possible solution(s) for a conflict through joint fact finding and interactive learning. An open access collaborative model is adopted in AquaPedia so that stakeholders can participate in the creation, collaboration, discussion, and modification of the content in a meaningful way. The goal is to encourage and combine multiple perspectives and explore negotiated solutions to water conflicts.

  14. Cationic reverse micelles create water with super hydrogen-bond-donor capacity for enzymatic catalysis: hydrolysis of 2-naphthyl acetate by alpha-chymotrypsin.

    PubMed

    Moyano, Fernando; Falcone, R Dario; Mejuto, J C; Silber, Juana J; Correa, N Mariano

    2010-08-01

    Reverse micelles (RMs) are very good nanoreactors because they can create a unique microenvironment for carrying out a variety of chemical and biochemical reactions. The aim of the present work is to determine the influence of different RM interfaces on the hydrolysis of 2-naphthyl acetate (2-NA) by alpha-chymotrypsin (alpha-CT). The reaction was studied in water/benzyl-n-hexadecyldimethylammonium chloride (BHDC)/benzene RMs and, its efficiency compared with that observed in pure water and in sodium 1,4-bis-2-ethylhexylsulfosuccinate (AOT) RMs. Thus, the hydrolysis rates of 2-NA catalyzed by alpha-CT were determined by spectroscopic measurements. In addition, the method used allows the joint evaluation of the substrate partition constant K(p) between the organic and the micellar pseudophase and the kinetic parameters: catalytic rate constant k(cat), and the Michaelis constant K(M) of the enzymatic reaction. The effect of the surfactant concentration on the kinetics parameters was determined at constant W(0)=[H(2)O]/[surfactant], and the variation of W(0) with surfactant constant concentration was investigated. The results show that the classical Michaelis-Menten mechanism is valid for alpha-CT in all of the RMs systems studied and that the reaction takes place at both RM interfaces. Moreover, the catalytic efficiency values k(cat)/K(M) obtained in the RMs systems are higher than that reported in water. Furthermore, there is a remarkable increase in alpha-CT efficiency in the cationic RMs in comparison with the anionic system, presumably due to the unique water properties found in these confined media. The results show that in cationic RMs the hydrogen-bond donor capacity of water is enhanced due to its interaction with the cationic interface. Hence, entrapped water can be converted into "super-water" for the enzymatic reaction studied in this work. PMID:20572177

  15. Method development for the determination of fluorine in water samples via the molecular absorption of strontium monofluoride formed in an electrothermal atomizer

    NASA Astrophysics Data System (ADS)

    Ozbek, Nil; Akman, Suleyman

    The presence of fluorine (F) was detected via the rotational molecular absorption line of diatomic strontium-monofluoride (SrF) generated in the gas phase at 651.187 nm using high-resolution continuum source electrothermal atomic absorption spectrometry. Upon the addition of excess strontium (Sr) as the nitrate, the fluorine in the sample was converted to SrF in the gas phase of a graphite furnace. The effects on the accuracy, precision and sensitivity of variables such as the SrF wavelength, graphite furnace program, amount of Sr, coating of the graphite tube and platform with Zr and Ir and the use of a modifier were investigated and optimized. It was determined that there was no need to use a modifier or to cover the platform/tubes with Zr or Ir. Fluorine concentrations in various water samples (certified waste water, tap water, drinking water and mineral water) were determined using 20 ?g of Sr as the molecule-forming reagent and applying a maximum pyrolysis temperature of 800 °C and a molecule-forming temperature of 2200 °C with a heating rate of 2000 °C s- 1. Good linearity was maintained up to 0.1 ?g of F. The accuracy and precision of the method were tested by analyzing certified reference wastewater. The results were in good agreement with certified values, and the precision was satisfactory (RSD < 10%). The limit of detection and the characteristic mass for the method were 0.36 ng and 0.55 ng, respectively. Finally, the fluorine concentrations in several drinking water and mineral water samples taken from the market were determined. The results were in good agreement with the values supplied by the producers. No significant differences were found between the results from the linear calibration and standard addition techniques. The method was determined to be simple, fast, accurate and sensitive.

  16. Reclaimed water as a main resource to enhance the adaptive capacity to climate change in semi-arid Mediterranean agricultural areas using Earth Observation products

    NASA Astrophysics Data System (ADS)

    Pavia Rico, Ana; Lopez-Baeza, Ernesto; Matieu, Pierre-Philippe; Hernandez Sancho, Francesc; Loarte, Edwin

    Lack of water is being a big problem in semi-arid areas to make agricultural profits. Most of Mediterranean countries like Spain, Italy, Greece or Cyprus and other countries like Morocco, the Arab United Emirates, South-American countries or China are starting to reuse wastewater as adaptation to climate change water scarcity. Drought areas are nowadays increasing, thus making fertile areas unproductive. For this reason, the European trend is to work on reusing wastewater as a solution to water scarcity in agriculture. Moreover, since population is growing fast, wastewater production is increasing as well as drinkable water demand, thus making reclaimed water as the water guarantee for irrigation and better agricultural management. This work represents a preliminary initiative to check, analyse and monitor the land by using remote sensing techniques to identify and determine the potential lands that used to be productive in the past, are now abandoned, and we want to recuperate to obtain socio-economic benefits. On top of this, this initiative will clearly enhance the adaption capacity of rural/agricultural lands to climate change. Alternatively to reclaimed water, greenhouses, desalination plants or transboarding water do not really eliminate the problem but only offer a temporary solution, make spending plenty of money and always provoking irreversible damages to the environment. The pilot area to first develop this research is the Valencia and Murcia Autonomous Communities located in the Spanish Mediterranean Coastline. An added value of this work will be to develop a methodology transferable to other potential countries with similar climatic characteristics and difficulties for irrigation, by using remote sensing methods and techniques. The remote sensing products obtained provide full information about the current state of the potential lands to grow crops. Potential areas are then being selected to carry out a socio-economic analysis leading to: (i) determining potential wastewater treatment plants to supply reclaimed water, based on pre-established criteria such as effluent quality, distance to the target land, existence of infrastructures to transport reclaimed water, etc. (ii) an analysis of the efficiency of the treatment plants selected taking into account that their possible inefficiency will probably derive into an increase in the cost of the reclaimed water. (iii) a feasibility analysis on cost (fixed and variable) and potential benefits (monetary and environmental). Monetary benefits will be estimated after analysing the most profitable crop type for each potential land

  17. Health status and bioremediation capacity of wild freshwater mussels (Diplodon chilensis) exposed to sewage water pollution in a glacial Patagonian lake.

    PubMed

    Bianchi, Virginia A; Castro, Juan M; Rocchetta, Iara; Bieczynski, Flavia; Luquet, Carlos M

    2014-04-01

    Deleterious effects on health and fitness are expected in mussels chronically exposed to sewage water pollution. Diplodon chilensis inhabiting SMA, an area affected by untreated and treated sewage water, shows increased hemocyte number and phagocytic activity, while bacteriolytic and phenoloxidase activities in plasma and reactive oxygen species production in hemocytes are lower compared to mussels from an unpolluted area (Yuco). There are not differences in cell viability, lysosomal membrane stability, lipid peroxidation and total oxygen scavenging capacity between SMA and Yuco mussels' hemocytes. Energetic reserves and digestive gland mass do not show differences between groups; although the condition factor is higher in SMA than in Yuco mussels. Gills of SMA mussels show an increase in mass and micronuclei frequency compared to those of Yuco. Mussels from both sites reduce bacterial loads in polluted water and sediments, improving their quality with similar feeding performance. These findings suggest that mussels exposed to sewage pollution modulate physiological responses by long-term exposure; although, gills are sensitive to these conditions and suffer chronic damage. Bioremediation potential found in D. chilensis widens the field of work for remediation of sewage bacterial pollution in water and sediments by filtering bivalves. PMID:24589503

  18. Magnetic, Durable, and Superhydrophobic Polyurethane@Fe3O4@SiO2@Fluoropolymer Sponges for Selective Oil Absorption and Oil/Water Separation.

    PubMed

    Wu, Lei; Li, Lingxiao; Li, Bucheng; Zhang, Junping; Wang, Aiqin

    2015-03-01

    Magnetic, durable, and superhydrophobic polyurethane (PU) sponges were fabricated by chemical vapor deposition (CVD) of tetraethoxysilane (TEOS) to bind the Fe3O4 nanoparticles tightly on the sponge and then dip-coating in a fluoropolymer (FP) aqueous solution. The sponges were characterized using scanning electron microscopy and other analytical techniques. The effects of CVD time of TEOS and FP concentration on wettability, mechanical properties, oil absorbency, and oil/water selectivity of the sponges were also investigated. The sponges exhibit fast magnetic responsivity and excellent superhydrophobicity/superoleophilicity (CAwater = 157° and CAoil ? 0°). The sponges also show very high efficiency in oil/water separation and could, driven by a magnet, quickly absorb floating oils on the water surface and heavy oils under water. Moreover, the PU@Fe3O4@SiO2@FP sponges could be used as membranes for oil/water separation and for continuous separation of large amounts of oil pollutants from the water surface with the help of a pump. The in turn binding of Fe3O4 nanoparticles, SiO2, and FP can also improve mechanical properties of the PU sponge. The sponges maintain the superhydrophobicity even when they are stretched with 200% strain or compressed with 50% strain. The sponges also show excellent mechanical stability, oil stability, and reusability in terms of superhydrophobicity and oil absorbency. The magnetic, durable, and superhydrophobic PU sponges are very promising materials for practical oil absorption and oil/water separation. PMID:25671386

  19. X-ray absorption spectra of nucleotides (AMP, GMP, and CMP) in liquid water solutions near the nitrogen K-edge

    NASA Astrophysics Data System (ADS)

    Ukai, Masatoshi; Yokoya, Akinari; Fujii, Kentaro; Saitoh, Yuji

    2010-07-01

    The X-ray absorption of nucleotides (adenosine-5'-monophosphate, guanosine 5'-monophosphate, and cytidine 5'-monophosphate) are measured in both water solutions and thin solid films at X-ray energies near the nitrogen K-edge in the 'water-window' region. Each spectrum corresponds to the selective excitation of a nucleobase site in a nucleotide, and thus has features similar to the spectrum of the corresponding nucleobase. An additional new peak in the energy region of the nitrogen 1s ? ?* resonance is observed for each nucleotide. No significant difference between the water solutions and thin solid films is found, which might be attributable to the hydrophobic properties of a nucleobase in a nucleotide.

  20. Coordination between water transport capacity, biomass growth, metabolic scaling and species stature in co-occurring shrub and tree species.

    PubMed

    Smith, Duncan D; Sperry, John S

    2014-12-01

    The significance of xylem function and metabolic scaling theory begins from the idea that water transport is strongly coupled to growth rate. At the same time, coordination of water transport and growth seemingly should differ between plant functional types. We evaluated the relationships between water transport, growth and species stature in six species of co-occurring trees and shrubs. Within species, a strong proportionality between plant hydraulic conductance (K), sap flow (Q) and shoot biomass growth (G) was generally supported. Across species, however, trees grew more for a given K or Q than shrubs, indicating greater growth-based water-use efficiency (WUE) in trees. Trees also showed slower decline in relative growth rate (RGR) than shrubs, equivalent to a steeper G by mass (M) scaling exponent in trees (0.77-0.98). The K and Q by M scaling exponents were common across all species (0.80, 0.82), suggesting that the steeper G scaling in trees reflects a size-dependent increase in their growth-based WUE. The common K and Q by M exponents were statistically consistent with the 0.75 of ideal scaling theory. A model based upon xylem anatomy and branching architecture consistently predicted the observed K by M scaling exponents but only when deviations from ideal symmetric branching were incorporated. PMID:25041417