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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)

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.

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

2014-05-01

2

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

PubMed Central

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.

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

2012-01-01

3

MSME Innovation Performance: erformance: erformance: erformance: erformance: The Role of Absorptive Capacity The Role of Absorptive Capacity The Role of Absorptive Capacity The Role of Absorptive Capacity The Role of Absorptive Capacity  

Microsoft Academic Search

A conceptual framework is proposed in this article showing how the social capital of a community shapes the innovation performance of micro, small and medium enterprises (MSMEs) through the exercise of absorptive capacity as the mediating phenomenon between the two. Its significance stems from the unprecedented effort of explaining how community social capital matters in the innovation performance of MSMEs,

Banjo Roxas

4

Analyzing Water's Optical Absorption  

NASA Technical Reports Server (NTRS)

A cooperative agreement between World Precision Instruments (WPI), Inc., and Stennis Space Center has led the UltraPath(TM) device, which provides a more efficient method for analyzing the optical absorption of water samples at sea. UltraPath is a unique, high-performance absorbance spectrophotometer with user-selectable light path lengths. It is an ideal tool for any study requiring precise and highly sensitive spectroscopic determination of analytes, either in the laboratory or the field. As a low-cost, rugged, and portable system capable of high- sensitivity measurements in widely divergent waters, UltraPath will help scientists examine the role that coastal ocean environments play in the global carbon cycle. UltraPath(TM) is a trademark of World Precision Instruments, Inc. LWCC(TM) is a trademark of World Precision Instruments, Inc.

2002-01-01

5

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

Microsoft Academic Search

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

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

2004-01-01

6

The Zone of Inertia: Absorptive Capacity and Organizational Change  

ERIC Educational Resources Information Center

Purpose: The purpose of this paper is to describe how interruptions in organizational learning effect institutional absorptive capacity and contribute to organizational inertia. Design/methodology/approach: An exploratory model is presented as a heuristic to describe how interruptions in organizational learning affect absorptive capacity.…

Godkin, Lynn

2010-01-01

7

Assessing Water System Managerial Capacity.  

National Technical Information Service (NTIS)

In September 2010, the U.S. Environmental Protection Agency (EPA) hosted the National Capacity Development/Operator Certification Workshop in Dallas, Texas, with 150 participants representing EPA Headquarters and Regions, states, third-party technical ass...

2012-01-01

8

Comparison of absorption rates and absorption capacity of ammonia solvents with MEA and MDEA aqueous blends for CO 2 capture  

Microsoft Academic Search

In this work we present the experimental results of absorption rates and absorption capacity for the CO2 absorption by ammonia (NH3) aqueous solutions. Experiments are carried out in a thermoregulated Lewis-type cell reactor and are achieved in temperature and concentration ranges of 278–303K and 2–5wt.% NH3 respectively. The obtained values for absorption kinetic rates and absorption capacity are compared with

Rodrigo Rivera-Tinoco; Chakib Bouallou

2010-01-01

9

Absorption Capacities and Limits of Stability for Hybrid CES  

NASA Astrophysics Data System (ADS)

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

Rygalov, V.; Carras, G.

10

Water retention capacity of tissue cultured plants  

Microsoft Academic Search

Leaves rapidly close their stomata after detachment resulting in a strong reduction of water loss. It has been reported that detached leaves of in vitro produced plants show continuous water loss indicating that they are unable to close the stomata properly and\\/or that their cuticle is malfunctioning. We examined the water retention capacity (WRC) of detached primary leaves of in

Klerk de G. J. M; F. Wijnhoven

2005-01-01

11

Isochoric Heat Capacity of Water and Steam.  

National Technical Information Service (NTIS)

Contents: Short review of the methods of determination of (C sub v); Method of experimental determination of heat capacity (C sub v) in the case of high parameters; Results of experimental investigations of isochoric heat capacity of water and steam; Heat...

K. I. Amirkhanov G. V. Stepanov B. G. Alibekov

1974-01-01

12

Protective Capacity and Absorptive Capacity: Managing the Balance between Retention and Creation of Knowledge-Based Resources  

ERIC Educational Resources Information Center

Purpose: In order to understand the pros and cons of an open organization regarding the flow of knowledge between firms, this paper introduces the concept of "protective capacity". The purpose of the paper is to elaborate the concept of "protective capacity" especially in relation to absorptive capacity, by presenting a number of propositions.…

Andersen, Jim

2012-01-01

13

Water storage capacity, stemflow and water funneling in Mediterranean shrubs  

NASA Astrophysics Data System (ADS)

SummaryTo predict water losses and other hydrological and ecological features of a given vegetation, its water storage capacity and stemflow need to be accurately determined. Vast areas of the Mediterranean region are occupied by shrublands yet there is scarce data available on their rainwater interception capacity. In this study, simulated rainfall tests were conducted in controlled conditions on nine Mediterranean shrubs of varying anatomic and morphological features to determine water storage capacity, stemflow and the funneling ratio. After assessing correlations between these hydrological variables and the biometric characteristics of the shrubs, we compared two methods of determining storage capacity: rainfall simulation and immersion. Mean water storage capacity was 1.02 mm (0.35-3.24 mm), stemflow was 16% (3.8-26.4%) and the funneling ratio was 104 (30-260). Per unit biomass, mean storage capacity was 0.66 ml g -1 and ranged from 0.23 ml g -1 for Cistus ladanifer to 2.26 ml g -1 for Lavandula latifolia. Despite their small size, shrubs may generate high water losses to the atmosphere when they form dense communities and this can have a significant impact in regions where water is scarce. When considered the whole shrubs in absolute terms (ml per plant), water storage capacity and stemflow were correlated to biomass and the dendrometric characteristics of the shrubs, yet in relative terms (expressed per surface area unit or as %), anatomic features such as pubescence, branch rigidity or leaf insertion angle emerged as determining factors. The use of a simple procedure to assess storage capacity was inefficient. The immersion method underestimated storage capacity to a different extent for each species. Some shrubs returned high stemflow values typical of their adaptation to the semiarid climate. In contrast, other shrubs seem to have structures that promote stemflow yet have developed other drought-adaptation mechanisms. In this report, we discuss the ecological and hydrological significance of stemflow and the funneling ratio.

Garcia-Estringana, P.; Alonso-Blázquez, N.; Alegre, J.

2010-08-01

14

Paracellular absorption in laboratory mice: Molecule size-dependent but low capacity.  

PubMed

Water-soluble nutrients are absorbed by the small intestine via transcellular and paracellular processes. The capacity for paracellular absorption seems lower in nonfliers than in fliers, although that conclusion rests largely on a comparison of relatively larger nonflying mammals (>155g) and relatively smaller flying birds (<155g). We report on paracellular absorption in laboratory mice, the smallest nonflying mammal species studied to date. Using a standard pharmacokinetic technique, we measured the extent of absorption (fractional absorption=f) of inert carbohydrate probes: L-arabinose (M(r)=150.13Da) and cellobiose (342.3) that are absorbed exclusively by the paracellular route, and 3-O-methyl D-glucose (3OMD-glucose) (M(r)=194) absorbed both paracellularly and transcellularly. f was measured accurately in urine collection trials of 5-10h duration. Absorption of 3OMD-glucose by mice was essentially complete (f=0.95±0.07) and much higher than that for L-arabinose (f=0.21±0.02), indicating that in mice, like other nonflying mammals, >80% of glucose is absorbed by mediated process(es) rather than the passive, paracellular route. As in all other vertebrates, absorption of cellobiose (f=0.13±0.02) was even lower than that for L-arabinose, suggesting an equivalent molecular size cut-off for flying and nonflying animals and thus a comparable effective TJ aperture. An important ecological implication is that smaller water-soluble plant secondary metabolites that have been shown to be absorbed by the paracellular path in cell culture, such as phenolics and alkaloids, might be absorbed in substantial amounts by bats and small birds relative to nonflying mammals such as mice. PMID:23000883

Fasulo, Verónica; Zhang, ZhiQiang; Price, Edwin R; Chediack, Juan G; Karasov, William H; Caviedes-Vidal, Enrique

2013-01-01

15

Modified calcium carbonate coatings with rapid absorption and extensive liquid uptake capacity  

Microsoft Academic Search

Special rapidly absorbing coatings with high absorption capacity are demonstrated based on new modified calcium carbonates which have been designed based on the absorption behaviour predicted by a combination of previous modelling using discrete pore and throat size distributions [Colloids Surf. A: Physicochem. Eng. Aspects 206 (2002) 217]. Firstly, the absorption driving force is determined by the proportion of fine

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

2004-01-01

16

Anomalous heat capacities of supercooled water and heavy water.  

PubMed

Emulsification makes it possible to supercool water to the homogeneous nucleation temperature. Accordingly, the heat capacities of water and deuterium oxide have been determined from the respective equilibrium melting points to -38 degrees and to -34 degrees C, respectively. Two methods, drift calorimetry and differential scanning calorimetry, have been used. Both methods reveal a striking rise in the constant-pressure heat capacity below -20 degrees C. This indication of an apparently cooperative behavior should serve to test current theories of water, most notably perhaps, the pair potential model of Ben-Naim and Stillinger. Some implications of possible meteorological significance are mentioned. PMID:17832030

Angell, C A; Tucker, J C

1973-07-27

17

High temperature measurement of water vapor absorption  

NASA Technical Reports Server (NTRS)

An investigation was undertaken to measure the absorption coefficient, at a wavelength of 10.6 microns, for mixtures of water vapor and a diluent gas at high temperature and pressure. The experimental concept was to create the desired conditions of temperature and pressure in a laser absorption wave, similar to that which would be created in a laser propulsion system. A simplified numerical model was developed to predict the characteristics of the absorption wave and to estimate the laser intensity threshold for initiation. A non-intrusive method for temperature measurement utilizing optical laser-beam deflection (OLD) and optical spark breakdown produced by an excimer laser, was thoroughly investigated and found suitable for the non-equilibrium conditions expected in the wave. Experiments were performed to verify the temperature measurement technique, to screen possible materials for surface initiation of the laser absorption wave and to attempt to initiate an absorption wave using the 1.5 kW carbon dioxide laser. The OLD technique was proven for air and for argon, but spark breakdown could not be produced in helium. It was not possible to initiate a laser absorption wave in mixtures of water and helium or water and argon using the 1.5 kW laser, a result which was consistent with the model prediction.

Keefer, Dennis; Lewis, J. W. L.; Eskridge, Richard

1985-01-01

18

Vitamin B12 absorption capacity in healthy children  

SciTech Connect

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%).

Hjelt, K.; Krasilnikoff, P.A.

1986-03-01

19

Absorption Capacities as a Basis of Stability for Closed Ecological Systems  

NASA Astrophysics Data System (ADS)

Growing plants in highly closed ecological systems (CES) will ultimately require conservation and recycling of plant essential elements to reduce system costs. One method for rapid recycling of elements would be incineration of residual, inedible biomass. The paper attempts to analyze the impact of biomass incineration for mineral recycling in a CES. Depending on system constraints, each CES will have its own range of steady-state operation, and this range becomes narrower as recycling rates increase. The paper presents a metric for CES stability, with the numerical estimates linked to carbon cycling rates. Along w th retrieving somei plant-essential elements, incineration of waste biomass would also release carbon dioxide, water, and other volatile compounds, depending on flue gas handling. Toxic products such as SO2 could damage or disrupt CES stability at high recycling rates. If such toxic species are not neutralized, the system tolerance would then be proportional to CES buffering or absorption capacity, and would be a non-linear function of the tolerance of the biota. We developed formulas to evaluate absorption capacities required for a stable CES by assessing different rates of material turnover. Numerical estimates of system stabilities in relation to carbon cycling rates were calculated for several examples of CES, including the Earth's Biosphere, the BIOS-3 project in Krasnoyarsk, Russia, and the Biosphere-2 project in Tucson, Arizona, USA.

Rygalov, V.; Pechurkin, N.; Wheeler, R.; Fowler, P.

20

Water Environmental Capacity Calculation Based on Unascertained Information  

Microsoft Academic Search

Hydrologic system is an unascertained system. For design discharge calculation according to design criterion , different results are likely to be gained if using different methods or different samples . Design water environmental capacity of river reach also has unascertained characteristics. On the basis of unascertained characteristics of water environmental capacity, a new calculation method for water environmental capacity of

Xiu-ling Sun; Bao-quan Wang

2010-01-01

21

Hitherto Unidentified Absorption Bands of Water Vapour  

Microsoft Academic Search

IN 1912-13, F. E. Fowle1 made studies of the absorption of infra-red radiation by water-vapour at 0.93mu, 1.13mu and 1.47mu, in order to determine spectroscopically the total water-vapour content of the atmosphere. The first two wave-lengths are at the centres of the rho and varphi bands; the last is about 450 cm.-1 from the Psi-band centre.

T. G. Cowling

1943-01-01

22

Bovine colostrum supplementation does not affect nutrient absorptive capacity in healthy young men  

Microsoft Academic Search

Bovine colostrum (BC) contains bioactive components that have been shown to enhance gastrointestinal development and increase nutrient absorptive capacity in neonatal animals. Recent studies in adult humans have shown that BC increases lean body mass and improves exercise performance and a number of authors have suggested that BC may elicit these effects by enhancing intestinal nutrient absorption. The purpose of

Grant D Brinkworth; Jonathan D Buckley

2003-01-01

23

Vacuum Ultraviolet Absorption of Supercritical Water  

NASA Astrophysics Data System (ADS)

The first continuum X&˜circ;->A&˜circ; peak in the gas phase absorption spectrum of H2O (maximum at 7.4 eV) , is ascribed to promotion of a nonbonding valence electron to a dissociative excited state which is an admixture of antibonding sigma and 3s Rydberg orbitals. Due to the large spatial extent of this orbital theX&˜circ;->A&˜circ; transition is strongly perturbed by the local environment. In liquid water, this peak is notably broadened and shifted to the blue, with an absorption maximum of 8.3 eV at room temperature. An obvious question is how this transition changes as a function of the water density in the supercritical regime as the system transitions from liquid to gas. As density decreases, most water molecules will be located at an interface between large clusters and voids. We will describe an experiment to measure the VUV absorption of the X&˜circ;->A&˜circ; transition in supercritical water (T>374 C, P>220 bar ) where the density can be tuned continuously. Experimentally this requires over six orders of magnitude detector dynamic range in the vacuum UV and a short path (ca. 1 micron) high temperature/pressure cell with sapphire windows. This has not been accomplished in any previous experiment. Results will be discussed in the light of recent ab initio calculations of the spectrum in large and small clusters.

Bartels, David; Janik, Ireneusz; Marin, Timothy

2009-03-01

24

Water absorption in horizontal corrugated boards under water sprays  

Microsoft Academic Search

Experiments were performed to determine the water absorption propensity of four different corrugated boards oriented horizontally and exposed to vertical water sprays from above. The corrugated samples used in the experiments were taken from cartons and partition boards from the FM Global Standard Plastic Commodity and from the inner and outer cartons of the FM Global Class II Commodity. These

T. M. Jayaweera; H.-Z. Yu

2006-01-01

25

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

Microsoft Academic Search

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

B. Mansoori

2010-01-01

26

Absorption  

NSDL National Science Digital Library

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.

Katie Hale (CSUF;)

2002-09-26

27

Absorptive capacity of iron-based magnetic carriers for blood detoxification  

NASA Astrophysics Data System (ADS)

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.

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

2001-01-01

28

Absorptive Capacity in R&D Project Teams: A Conceptualization and Empirical Test  

Microsoft Academic Search

The purpose of this study is to answer a call for the rejuvenation of the absorptive capacity (ACAP) construct by offering a novel conceptualization and empirical test of a multidimensional model of R&D project team ACAP that portrays it as a capability distinct from prior knowledge, specifies each dimension's level of analysis, distinguishes between individual and collective assimilation, and considers

Louise A. Nemanich; Robert T. Keller; Dusya Vera; Wynne W. Chin

2010-01-01

29

THE REIFICATION OF ABSORPTIVE CAPACITY: A CRITICAL REVIEW AND REJUVENATION OF THE CONSTRUCT  

Microsoft Academic Search

We conduct a detailed analysis of 289 absorptive capacity papers from 14 journals to assess how the construct has been utilized, examine the key papers in the field, and identify the substantive contributions to the broader literature using a thematic analysis. We argue that research in this area is fundamentally driven by five critical assumptions that we conclude have led

BALAJI R. KOKA; SEEMANTINI PATHAK

2006-01-01

30

Functional loading augments the initial tensile strength and energy absorption capacity of regenerating rabbit Achilles tendons.  

PubMed

The biomechanical effect of functional loading was studied in surgically tenotomized, repaired and immobilized right Achilles tendons of 34 rabbits. Beginning from the 5th day after surgery, loading was initiated by removing the immobilization casts of the animals to permit unrestricted weight-bearing to tolerance. At each of 12, 18 and 21 days after surgery, functionally loaded tendons and their corresponding nonloaded controls were excised and compared for differences in tensile strength, tensile stress and energy absorption capacity. Functional loading induced a twofold increase in the tensile strength (P less than 0.05) and energy absorption capacity (P less than 0.05) of the tendons, at both 12 and 18 days after surgery. No statistically significant differences were observed in the tensile strength and energy absorption capacity of the tendons at 21 days after surgery. Statistically significant differences in tensile stress were not observed at any time period throughout the study. These findings demonstrate that functional loading augments the tensile strength and energy absorption capacity of experimentally tenotomized tendons without promoting re-rupture, but only during the very early stages of healing. Even though the healing process of rabbit tendons may differ from healing of human tendons, these results suggest that similar beneficial effects may be attained if repaired human Achilles tendon ruptures are carefully loaded during the very early rather than later stages of healing. PMID:1739442

Enwemeka, C S

1992-02-01

31

Water holding capacities of fly ashes: Effect of size fractionation  

SciTech Connect

Water holding capacities of fly ashes from different thermal power plants in Eastern India have been compared. Moreover, the effect of size fractionation (sieving) on the water holding capacities has also been determined. The desorption rate of water held by the fly ash fractions at ambient temperature (25-30{sup o}C) has been investigated. The effect of mixing various size fractions of fly ash in increasing the water holding capacities of fly ash has been studied. It is observed that the fly ash obtained from a thermal power plant working on stoker-fired combustor has the highest water holding capacity, followed by the one that works on pulverized fuel combustor. Fly ash collected from super thermal power plant has the least water holding capacity (40.7%). The coarser size fractions of fly ashes in general have higher water holding capacities than the finer ones. An attempt has been made to correlate the results obtained, with the potential use in agriculture.

Sarkar, A.; Rano, R. [Indian School of Mines, Dhanbad (India). Dept. of Applied Chemistry

2007-07-01

32

Heavy metal complexation capacity of the South China Sea water  

Microsoft Academic Search

The seawater complexation capacity for heavy metals (copper, lead and cadmium) in the South China Sea was determined by anodic\\u000a voltammetry and the conditional stability constants of these complexes were calculated. The data showed that the complexation\\u000a capacity of the South China Sea water was greater than that of seawater in the Huanghe Estuary and the coast water of Qingdao.

Manping Zhang; Boshu Guo; Zhengbin Zhang; Liansheng Liu

1990-01-01

33

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

SciTech Connect

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)

El Mallakh, R

1980-01-01

34

Relationships between macroscopic paper structure and water absorption behavior  

Microsoft Academic Search

Macroscopic structure of paper influences how paper behaves in many ways. In this research, the relationship between macroscopic paper structure and water absorption behavior was investigated. The structure of the handsheets made from commercial hardwood pulp was modified by varying basis weight, beating levels and wet press levels. The structural properties as well as the water absorption properties were measured.

Kuntinee Suvarnakich; Toshiharu Enomae; Akira Isogai

35

Determination of the Complexing Capacity of Natural Water.  

National Technical Information Service (NTIS)

An analytical procedure for chemically measuring the complexing capacity (ability of a water to complex metal ions) of natural water is developed and tested. The procedure can be used in evaluating the role of natural complexing agents in the transport, t...

K. W. Hanck J. W. Dillard

1973-01-01

36

Estimating canopy water storage capacity: What do we really know?  

NASA Astrophysics Data System (ADS)

The canopy water storage capacity - the amount of water which is retained in the canopy - is an important parameter of many interception models. Furthermore, recent research indicates that even continental-scale hydrological models can be sensitive to this parameter. Surprisingly, however, there is no standard method to estimate the canopy capacity. Instead, several methods coexist and the multitude of individual decisions involved in their application suggests that the calculation of the canopy capacity might be associated with substantial uncertainty. This problem motivated us to systematically assess several methods for the estimation of the canopy capacity for two forest stands: a 5-year old and a more than 130-year old secondary forest. Both forests differ greatly with respect to canopy structure and we can expect that these differences are reflected in the estimates of canopy capacities. In our analyses we compare the results of four different canopy capacity estimation methods and explore the consequences of several common decisions involved in calculating canopy capacities. We base our calculations on event-based throughfall and rainfall data. For each rain event and at each forest site we use data from 200 throughfall sampling points which were distributed randomly over a 1 ha area. Our preliminary results seem to corroborate the supposition that canopy capacities vary widely depending on the applied method. Given the application of high-quality throughfall datasets, the tested methods permitted the detection of differences in canopy capacities between the two contrasting forest stands. Yet, results of individual methods varied so widely that comparisons of canopy capacity estimates obtained with different methods seem to be problematic. Our results further indicate that some methods cannot cope with data containing drip points, which points at their limited physical basis.

Wietzke, Luzie M.; Zimmermann, Alexander

2014-05-01

37

Measured performance of a 3-ton LiBr absorption water chiller and its effect on cooling system operation  

NASA Technical Reports Server (NTRS)

A 3-ton lithium bromide absorption water chiller was tested for a number of conditions involving hot-water input, chilled water, and the cooling water. The primary influences on chiller capacity were the hot water inlet temperature and the cooling water inlet temperature. One combination of these two parameters extended the output to as much as 125% of design capacity, but no combination could lower the capacity to below 60% of design. A cooling system was conceptually designed so that it could provide several modes of operation. Such flexibility is needed for any solar cooling system to be able to accommodate the varying solar energy collection and the varying building demand. It is concluded that a 3-ton absorption water chiller with the kind of performance that was measured can be incorporated into a cooling system such as that proposed, to provide efficient cooling over the specified ranges of operating conditions.

Namkoong, D.

1976-01-01

38

Measured performance of a 3 ton LiBr absorption water chiller and its effect on cooling system operation  

NASA Technical Reports Server (NTRS)

A three ton lithium bromide absorption water chiller was tested for a number of conditions involving hot water input, chilled water, and the cooling water. The primary influences on chiller capacity were the hot water inlet temperature and the cooling water inlet temperature. One combination of these two parameters extended the output to as much as 125% of design capacity, but no combination could lower the capacity to below 60% of design. A cooling system was conceptually designed so that it could provide several modes of operation. Such flexibility is needed for any solar cooling system to be able to accommodate the varying solar energy collection and the varying building demand. It was concluded that a three-ton absorption water chiller with the kind of performance that was measured can be incorporated into a cooling system such as that proposed, to provide efficient cooling over the specified ranges of operating conditions.

Namkoong, D.

1976-01-01

39

Trace metal complexing capacity of natural waters: A review  

Microsoft Academic Search

The theoretical basis of trace metal complexing capacity of natural waters and the analytical methods used to measure it are reviewed. The current literature on this subject is also reviewed, in an attempt to draw out the most important features relating to the validity of the methods used and the nature of the metal?binding ligands and complexes formed.

Barry T. Hart

1981-01-01

40

Energy absorption probes control oily-water discharges  

Microsoft Academic Search

Energy absorption instrumentation is rapidly emerging as the preferred method of interface control for separation processes. This high-frequency electromagnetic measurement technique accurately senses volume percentages (not level) in phase separations such as water and oil. Instead of searching for or assuming a clean interface, the instruments monitor percentages of water at points in the system, and can measure either water

G. Agar; P. Clewis; C. Spencer

1993-01-01

41

Distillation column configurations in ammonia–water absorption refrigeration systems  

Microsoft Academic Search

In ammonia–water absorption refrigeration systems a purification process to reduce the water content in the vapour leaving the generator is required. During this process the water content in the vapour must be reduced to a minimum, otherwise it tends to accumulate in the evaporator and strongly deteriorates the efficiency of the system. The vapour purification can be carried out by

José Fernández-Seara; Jaime Sieres; Manuel Vázquez

2003-01-01

42

Depressed gut absorptive capacity early after trauma-hemorrhagic shock. Restoration with diltiazem treatment.  

PubMed Central

Although bacterial translocation occurs after trauma-hemorrhage, it is unknown whether gut absorptive capacity (GAC) is altered under those conditions. The aim of this study, therefore, was to determine this and also whether diltiazem (DZ) has any effect on GAC after hemorrhage. Rats (n = 12; 270 to 300 g) were lightly anesthetized with ether and a 6-cm midline laparotomy performed (i.e., trauma induced). A nasogastric tube was inserted, cannulation of a carotid and femoral artery and a jugular and the portal veins performed, and the animals allowed to recover from anesthesia. They were then bled to a mean blood pressure of 40 mm Hg within 10 minutes and maintained at this pressure by further bleeding or return of fluid (lactated Ringer's solution [LRS] ) until 40% of the shed blood volume (SBV) had been returned in the form of LRS (end of hemorrhage, EH; time from onset of hemorrhage to EH = 93.4 +/- 4.4 minutes). The rats then were resuscitated with LRS, 3 times the SBV over 45 minutes, followed by 2x over 60 minutes. One group received 400 micrograms/kg DZ, and another group received saline, with the 2x LRS. Sham animals were not hemorrhaged. Gut absorptive capacity was determined by the 1-hour D-xylose absorption test at 2 and 4 hours after EH. Results demonstrate that GAC is significantly depressed after hemorrhage and resuscitation. Administration of diltiazem restored GAC to normal levels. Thus DZ is a useful adjuvant to treatment after trauma-hemorrhagic shock, because it restores GAC to normal and allows for early enteral nutrition.

Singh, G; Chaudry, K I; Chudler, L C; Chaudry, I H

1991-01-01

43

Absorption of water and lubricating oils into porous nylon  

NASA Technical Reports Server (NTRS)

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.

Bertrand, P. A.

1995-01-01

44

Measurement of atmospheric precipitable water using a solar radiometer. [water vapor absorption effects  

NASA Technical Reports Server (NTRS)

A technique is described and tested that allows the determination of atmospheric precipitable water from two measurements of solar intensity: one in a water-vapor absorption band and another in a nearby spectral region unaffected by water vapor.

Pitts, D. E.; Dillinger, A. E.; Mcallum, W. E.

1974-01-01

45

A polydimethylsiloxane (PDMS) sponge for the selective absorption of oil from water.  

PubMed

We present a sugar-templated polydimethylsiloxane (PDMS) sponge for the selective absorption of oil from water. The process for fabricating the PDMS sponge does not require any intricate synthesis processes or equipment and it is not environmentally hazardous, thus promoting potential in environmental applications. The proposed PDMS sponge can be elastically deformed into any shape, and it can be compressed repeatedly in air or liquids without collapsing. Therefore, absorbed oils and organic solvents can be readily removed and reused by simply squeezing the PDMS sponge, enabling excellent recyclability. Furthermore, through appropriately combining various sugar particles, the absorption capacity of the PDMS sponge is favorably optimized. PMID:22077378

Choi, Sung-Jin; Kwon, Tae-Hong; Im, Hwon; Moon, Dong-Il; Baek, David J; Seol, Myeong-Lok; Duarte, Juan P; Choi, Yang-Kyu

2011-12-01

46

Experimental studies on R134a-DMAC hot water based vapour absorption refrigeration systems  

Microsoft Academic Search

The objective of this paper is to present an experimental study on environment friendly vapour absorption refrigeration system of 1 kW capacity using R134a-DMAC as the working fluids. The system is designed and tested for various operating conditions using hot water as heat source. In this paper, performance of the fabricated system are outlined with respect to various operating parameters

V. Muthu; R. Saravanan; S. Renganarayanan

2008-01-01

47

Comprehensive evaluation on water environmental carrying capacity of Qiantang River watershed based on index system  

Microsoft Academic Search

Water environmental carrying capacity was related to economy,society,resource, environment, technology and management. Three indicators and fifteen variables were selected as the evaluation index, the three indicators including sustainable capacity of resource, assimilative capacity of environment and optimal allocation capacity of social economy. A comprehensive evaluation model of water environmental carrying capacity of Qiantang River watershed was developed. On the basis

Xiaobo Fang; Jianying Zhang; Chengxiao Mei; Song Li; Yingxu Chen

2011-01-01

48

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

NASA Astrophysics Data System (ADS)

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.

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

49

Oxygen absorption into moving water and tenside solutions  

Microsoft Academic Search

Oxygen absorption into water and waste water is an important process taking place with both natural and technical means, and a tool for a theoretical determination of the oxygen transfer coefficient, KL, is desirable.The objective of this investigation was to study the environment at and near the liquid side of a gas–liquid interface in order to present a model for

Tom Pedersen

2000-01-01

50

Optimum hot water temperature for absorption solar cooling  

Microsoft Academic Search

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

A. Lecuona; R. Ventas; M. Venegas; A. Zacarías; R. Salgado

2009-01-01

51

Gastrointestinal Absorption of Soluble Uranium from Drinking Water.  

National Technical Information Service (NTIS)

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...

M. E. Wrenn N. P. Singh H. Ruth D. Burleigh

1988-01-01

52

Dynamic viscoelastic properties, water absorption, and solubility of home reliners.  

PubMed

Scant rheological information is available regarding home reliners (liner type denture adhesives). We evaluated 6 different home reliners in regard to their viscoelastic properties, water absorption and solubility. Dynamic viscoelastic properties and changes over time were determined using a dynamic viscoelastometer, while weight changes, absorption, and solubility during immersion in water were also investigated. We found that the dynamic viscoelasticity of the tested home reliners was sensitive to changes in frequency, while the materials used had nearly no elasticity and exhibited viscous behaviors. They showed a dramatic change in viscoelastic properties and increase in weight after approximately 1 day of water immersion. A considerably high percentage of water absorption was also observed. From the viewpoint of dynamic viscoelastic properties and durability, our results indicate that the tested home reliners would not be suitable for improvement of ill-fitting dentures. PMID:20733263

Murata, Hiroshi; Hong, Guang; Yamakado, Chiaki; Kurogi, Tadafumi; Kano, Hiroshi; Hamada, Taizo

2010-10-01

53

Ground water applications of the heat capacity mapping mission  

NASA Technical Reports Server (NTRS)

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.

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

1981-01-01

54

Absorptive Capacity as a Guiding Concept for Effective Public Sector Management and Conservation of Freshwater Ecosystems  

NASA Astrophysics Data System (ADS)

The ability of an organisation to recognise the value of new external information, acquire it, assimilate it, transform, and exploit it, namely its absorptive capacity (AC), has been much researched in the context of commercial organisations and even applied to national innovation. This paper considers four key AC-related concepts and their relevance to public sector organisations with mandates to manage and conserve freshwater ecosystems for the common good. The concepts are the importance of in-house prior related knowledge, the importance of informal knowledge transfer, the need for motivation and intensity of effort, and the importance of gatekeepers. These concepts are used to synthesise guidance for a way forward in respect of such freshwater management and conservation, using the imminent release of a specific scientific conservation planning and management tool in South Africa as a case study. The tool comprises a comprehensive series of maps that depict national freshwater ecosystem priority areas for South Africa. Insights for implementing agencies relate to maintaining an internal science, rather than research capacity; making unpublished and especially tacit knowledge available through informal knowledge transfer; not underestimating the importance of intensity of effort required to create AC, driven by focussed motivation; and the potential use of a gatekeeper at national level (external to the implementing organisations), possibly playing a more general `bridging' role, and multiple internal (organisational) gatekeepers playing the more limited role of `knowledge translators'. The role of AC as a unifying framework is also proposed.

Murray, K.; Roux, D. J.; Nel, J. L.; Driver, A.; Freimund, W.

2011-05-01

55

Thermodynamic modeling of an ammonia–water absorption chiller  

Microsoft Academic Search

This article develops a general thermodynamic framework for the modeling of an irreversible absorption chiller at the design point, with application to a single-stage ammonia–water absorption chiller. Component models of the chiller have been assembled so as to quantify the internal entropy production and thermal conductance (UA) in a thermodynamically rigorous formalism, which is in agreement with the simultaneous heat-and-mass

H. T. Chua; H. K. Toh; K. C. Ng

2002-01-01

56

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

Microsoft Academic Search

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

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

2006-01-01

57

Atmospheric Precorrected Differential Absorption technique to retrieve columnar water vapor  

SciTech Connect

Differential absorption techniques are suitable to retrieve the total column water vapor contents from imaging spectroscopy data. A technique called Atmospheric Precorrected Differential Absorption (APDA) is derived directly from simplified radiative transfer equations. It combines a partial atmospheric correction with a differential absorption technique. The atmospheric path radiance term is iteratively corrected during the retrieval of water vapor. This improves the results especially over low background albedos. The error of the method for various ground reflectance spectra is below 7% for most of the spectra. The channel combinations for two test cases are then defined, using a quantitative procedure, which is based on MODTRAN simulations and the image itself. An error analysis indicates that the influence of aerosols and channel calibration is minimal. The APDA technique is then applied to two AVIRIS images acquired in 1991 and 1995. The accuracy of the measured water vapor columns is within a range of {+-}5% compared to ground truth radiosonde data.

Schlaepfer, D.; Itten, K.I. [Univ. of Zuerich (Switzerland). Dept. of Geography] [Univ. of Zuerich (Switzerland). Dept. of Geography; Borel, C.C. [Los Alamos National Lab., NM (United States)] [Los Alamos National Lab., NM (United States); Keller, J. [Paul Scherrer Inst., Villigen (Switzerland)] [Paul Scherrer Inst., Villigen (Switzerland)

1998-09-01

58

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

PubMed

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

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

2013-09-15

59

A Data Analysis of the Index System of Assessment Water Environmental Carrying Capacity  

Microsoft Academic Search

It is a key problem of making the environment and economy sustainable development plan to analyze and appraise the state of water environmental carrying capacity objectively. This paper, based on the water environmental carrying capacity definition, from eco-efficiency angle of the water resource and environment, put forward the index system of assessing water environmental carrying capacity. In order to prove

Yu Zhuang; Meiru Ji; Lifang Wang

2008-01-01

60

Determination of fixed water in rocks by infrared absorption  

USGS Publications Warehouse

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%.

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

1969-01-01

61

Numerical analysis of falling film absorption with ammonia–water in magnetic field  

Microsoft Academic Search

Absorption strengthen is an effective way to improve the coefficient of performance (COP) of ammonia–water absorption refrigeration system. A mathematical absorption model for ammonia–water falling film absorption in magnetic field was built in this paper to study the influence of magnetic field on the absorption process. Macroscopic magnetic field force was introduced to the mathematical model. Changes in physical properties

Niu Xiaofeng; Du Kai; Du Shunxiang

2007-01-01

62

Light scattering and absorption caused by bacterial activity in water.  

PubMed

There is a growing class of elementary particle detectors, large-water ?erenkov detectors, that have a body of water (thousands of tons) as a sensitive medium. Particles are detected when they interact with the water and produce ?erenkov light, so detection efficiency relies on the transparency of the water. These detectors are active typically for many years, so biological activity (primarily bacterial growth) is one of the means by which the transparency of the water may be reduced. We present the results of a measurement of light scattering and absorption from a population of Escherichia coli in water, which is used as a model for bacteria in general. One can separate the scattering and absorption by varying the refractive index of the medium by using a solute of high molecular weight. We show that the results can be understood simply in terms of light scattering from small spheres (radius ? wavelength) with an effective refractive index, n(b), plus a small amount of absorption in the ultraviolet. We compare his scattering with Rayleigh scattering in pure water. PMID:20941320

Waltham, C; Boyle, J; Ramey, B; Smit, J

1994-11-01

63

Ammonia-Water Absorption-Heat-Pump Cycle.  

National Technical Information Service (NTIS)

The state-of-art in ammonia-water absorption cooling has been applied to an air-source heating-only heat-pump cycle which delivers its heat indoors via circulating liquid. The cycle is described, differences from the cooling application noted, and test re...

D. Kuhlenschmidt R. H. Merrick

1983-01-01

64

Investigation of a Ammonia-Water Absorption Chiller Performance  

Microsoft Academic Search

An experimental prototype of a single stage ammonia-water absorption chiller was designed, built and tested. The thermodynamic models of the components, based on the First and Second Laws, have been assembled so as to quantify the simultaneous heat and mass transfer processes occurring within the exchangers. Calculated results were compared with experimental data. The results show that the cooling effect

Dingfeng Kong; Jianhua Liu; Liang Zhang; Zhiyun Fang

2010-01-01

65

Lambert Absorption Coefficients of Water in the Infrared.  

National Technical Information Service (NTIS)

By use of a wedge-shaped cell providing an absorbing layer tapering in thickness from less than one wavelength of visible light at one end to approximately 20 micrometers at the other end, the Lambert absorption coefficient for water in the spectral regio...

C. W. Robertson D. Williams

1971-01-01

66

Water Absorption Tests for Measuring Permeability of Field Concrete.  

National Technical Information Service (NTIS)

The research results from CFIRE Project 04-06 were communicated to engineers and researchers in this project. Specifically, the water absorption of concrete samples (i.e., 2-in. thick, 4-in. diameter discs cut from concrete cylinders) was found strongly r...

H. Tabatabai J. Zhao

2013-01-01

67

An experimental-finite element analysis on the kinetic energy absorption capacity of polyvinyl alcohol sponge.  

PubMed

Polyvinyl alcohol (PVA) sponge is in widespread use for biomedical and tissue engineering applications owing to its biocompatibility, availability, relative cheapness, and excellent mechanical properties. This study reports a novel concept of design in energy absorbing materials which consist in the use of PVA sponge as an alternative reinforcement material to enhance the energy loss of impact loads. An experimental study is carried out to measure the mechanical properties of the PVA sponge under uniaxial loading. The kinetic energy absorption capacity of the PVA sponge is computed by a hexahedral finite element (FE) model of the steel ball and bullet through the LS-DYNA code under impact load at three different thicknesses (5, 10, 15mm). The results show that a higher sponge thickness invokes a higher energy loss of the steel ball and bullet. The highest energy loss of the steel ball and bullet is observed for the thickest sponge with 160 and 35J, respectively. The most common type of traumatic brain injury in which the head subject to impact load causes the brain to move within the skull and consequently brain hemorrhaging. These results suggest the application of the PVA sponge as a great kinetic energy absorber material compared to commonly used expanded polystyrene foams (EPS) to absorb most of the impact energy and reduces the transmitted load. The results might have implications not only for understanding of the mechanical properties of PVA sponge but also for use as an alternative reinforcement material in helmet and packaging material design. PMID:24863223

Karimi, Alireza; Navidbakhsh, Mahdi; Razaghi, Reza

2014-06-01

68

A comparison between ammonia-water and water-lithium bromide solutions in vapor absorption refrigeration systems  

SciTech Connect

A Vapor Absorption Refrigeration (VAR) System is similar to a Vapor Compression Refrigeration (VCR) System. In both systems the required refrigeration is provided by refrigerants vaporizing in the evaporator. However, in the VAR System, a physico-chemical process replaces the mechanical process of the VCR system and heat rather than a mechanical and electrical energy is used. The advantages of this system lie in the possibility of utilizing of waste energy from industrial plants as well as of using solar energy. The study included an investigation to analyze the Vapor Absorption Refrigeration systems using ammonia-water and water-lithium bromide solutions. A fundamental VAR system is described and the operating sequence is explained. Since the most common VAR systems use ammonia-water solution with ammonia as the refrigerant and water-lithium bromide solution with water as the refrigerant, the comparison of the two is presented in respect of the coefficient of performance (COP), the cooling capacity and the maximum and minimum system pressures. It is concluded that the VAR system using water-lithium bromide solution provided better performance than the system using ammonia-water solution. However, there are some points to be considered such as: the danger of crystallization and impossibility of operating in very low temperatures because of the use of water as the refrigerant.

Horuz, I. [Univ. of Uludag, Bursa (Turkey)] [Univ. of Uludag, Bursa (Turkey)

1998-07-01

69

21 CFR 130.12 - General methods for water capacity and fill of containers.  

Code of Federal Regulations, 2012 CFR

...2014-04-01 false General methods for water capacity and fill of containers. 130...Provisions § 130.12 General methods for water capacity and fill of containers. For...act: (a) The term general method for water capacity of containers means the...

2014-04-01

70

Evaluating Beijing's human carrying capacity from the perspective of water resource constraints  

Microsoft Academic Search

As the demands on limited water resources intensify, concerns are being raised about the human carrying capacity of these resources. However, few researchers have studied the carrying capacity of regional water resources. Beijing, the second-largest city in China, faces a critical water shortage that will limit the city's future development. We developed a method to quantify the carrying capacity of

Yingxuan Zhang; Min Chen; Wenhua Zhou; Changwei Zhuang; Zhiyun Ouyang

2010-01-01

71

Estimation of Water Environment Capacity:Example as Four Basin in Shandong Province, China  

Microsoft Academic Search

Estimating of the water environment capacity is an important content of the assessment of regional environmental impact. This article estimates the environmental capacity of surface water of the Yellow River basin, Haihe River basin, Huaihe River basin, Jiaodong Peninsula rivers basin in Shandong based on discussing the concept of water environmental capacity and estimation methods. This article selects the appropriate

Han Mei; Mu Jinbo; Sun Fangling; Chengli; Hao Zhen

2010-01-01

72

Water storage capacity, stemflow and water funneling in Mediterranean shrubs: biotic and abiotic factors  

Microsoft Academic Search

Many lands of the Mediterranean basin of European Union have been abandoned in the last decades and consequently vegetation type changes too. This modifies hydrologic processes, changing the volume and the way in which the rainfall reaches the soil. To predict water losses and other hydrological and ecological features of vegetation, its water storage capacity and stemflow need to be

Pablo Garcia-Estringana; Jesús Alegre

2010-01-01

73

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

NASA Astrophysics Data System (ADS)

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.

Saxena, Pradeep

74

Effect of pressure on mass absorption in an ammonia-water absorption system  

NASA Astrophysics Data System (ADS)

Absorption phenomenon of ammonia vapor into ammonia water solution has been investigated experimentally, by inserting superheated ammonia vapor into a test cell containing a stagnant pool of ammonia water solution. Before commencing the experiment, the pressure in the test cell corresponds to the equilibrium vapor of the ammonia-water system at room temperature. When the valve is opened, mechanical equilibrium is established quickly and the pressure in the test cell becomes equal to that of the ammonia vapor cylinder. The difference between the initial pressure in the vapor cylinder and the initial pressure in the test cell is found to have a major influence on the absorption rate. The main objective of this study is to investigate the effect of this initial pressure difference on the absorption rate of ammonia vapor. A correlation which gives the total absorbed mass of ammonia as a function of the initial concentration, the initial pressure difference and time is derived. In addition the absorbed mass at no pressure difference could be estimated from the absorbed mass at initial pressure difference.

Mustafa, Hatem; Monde, Masanori

2007-11-01

75

Near-ultraviolet absorption cross sections of nitrophenols and their potential influence on tropospheric oxidation capacity.  

PubMed

Nitrophenols and methylnitrophenols have been identified as photolytic precursors of nitrous acid, HONO, but their gas-phase absorption has not previously been reported. In this study, the absorption cross sections of 2-nitrophenol, 3-methyl-2-nitrophenol, and 4-methyl-2-nitrophenol were measured from 320 to 450 nm using incoherent broad-band cavity-enhanced absorption spectroscopy (IBBCEAS). The benzaldehyde absorption spectrum was measured to validate the approach and was in good agreement with literature spectra. The nitrophenol absorption cross sections are large (ca. 10(-17) cm(2) molecule(-1)) and blue-shifted about 20 nm compared to previously measured solution spectra. Besides forming HONO, nitrophenol absorption influences other photochemistry by reducing the available actinic flux. The magnitudes of both effects are evaluated as a function of solar zenith angle, and nitrophenol absorption is shown to lower the photolysis rates of O(3) and NO(2). PMID:21958133

Chen, Jun; Wenger, John C; Venables, Dean S

2011-11-10

76

An Exergy Analysis of LiBr-Water Absorption Refrigerators  

NASA Astrophysics Data System (ADS)

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.

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

77

A Study of the Influence of Organizational Knowledge Ability and Knowledge Absorptive Capacity on Organization Performance in Taiwan`s Hi-Tech Enterprises  

NASA Astrophysics Data System (ADS)

In recent years, business operation tends to be internationalized and the production cost increases day by day, the technology promotion of Taiwan`s hi-tech enterprises met its bottleneck; lots of industries have introduced Knowledge Management (KM) and emphasized the knowledge absorptive capacity of the employees to promote the organizational business performance under this competition environment. This research studied the influence of organizational knowledge ability and knowledge absorptive capacity on organization performance in Taiwan`s hi-tech enterprises. The research found that: the industry with strong organizational knowledge ability has positive influence on organization performance; the industry with strong organizational knowledge ability has positive influence on knowledge absorptive capacity and the industry with strong knowledge absorptive capacity has positive influence on organization performance. Therefore, the organizational knowledge ability and knowledge absorption capacity of Taiwan`s high-tech enterprises have positive influence on the promotion of their organization performance.

Chen, Ching-Piao; Liu, Pang-Lo; Tsai, Chih-Hung

78

Theoretical modeling and experimental research on load capacity of supporting legs of water strider robot  

Microsoft Academic Search

Water strider can stay and move quickly on water surface by surface tension. Water strider robot inspired by such small aquatic insect would have a wide variety of applications in military reconnaissance, environmental monitoring, and pipeline inspection. However load capacity of the robot is a big challenge for its practicality. Under this situation research on load capacity of water strider

Lan Wang; Tiehong Gao; Feng Gao; Jianling Zhao; Junnan Wu

2010-01-01

79

Study on threshold expansion of the carrying capacity in desert grassland within the environmental capacity of grass and water resources  

Microsoft Academic Search

The life quality of livestock population in different time and space is determined by the limitations of water and grass resources and by the fixed position of resource. Carrying capacity is a variable which is closely related to the resource that the prairie can supply. Based on the systematic analysis on the grassland resources, water resources in Damaoqi desert steppe

Jingli He; Ende Xing; JianYing Guo; Wei Cui; Dan Shan

2011-01-01

80

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

Microsoft Academic Search

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

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

2004-01-01

81

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

Microsoft Academic Search

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

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

2004-01-01

82

Human intestinal water absorption: direct vs. indirect measurements.  

PubMed

Distilled water, a carbohydrate-electrolyte (CE; 4% sucrose, 2% glucose, 17.2 meq/l NaCl, and 2.8 meq/l KCl) solution, or a 10% glucose solution, all containing the nonabsorbed indicator polyethylene glycol (PEG) and deuterium oxide (D2O, 30 ppm), were infused (15 ml/min) into the duodenojejunum of seven men by using the triple lumen technique. Net water absorption was determined directly from the change in PEG concentration and was calculated from plasma D2O derived from D2O in the perfusion solutions. The protocol included a 45-min equilibration period followed by a 90-min test period. Intestinal samples were drawn at 10-min intervals from 15 to 45 min and at 15-min intervals thereafter. Blood was drawn at 45, 50, 55, 60, 75, 90, 105, 120, and 135 min. Intestinal samples were analyzed for D2O, Na+, K+, osmolality, PEG, and glucose; blood was analyzed for D2O. Results (+/- SE; positive values secretion, negative values absorption) showed net fluid absorption from distilled water (-9.40 +/- 1.28 ml.h-1.cm-1) and the CE (-13.30 +/- 1.22 ml.h-1.cm-1) solution, but net secretion (4.40 +/- 1.25 ml.h-1.cm-1) from the 10% glucose solution. All values were significantly (P less than 0.05) different from each other. Perfusing the CE solution caused net Na+ and K+ absorption, whereas perfusing the 10% dextrose solution caused net electrolyte secretion. Rates of D2O accumulation in the plasma were independent of the solutions perfused.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2305887

Gisolfi, C V; Summers, R W; Schedl, H P; Bleiler, T L; Oppliger, R A

1990-02-01

83

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

NASA Astrophysics Data System (ADS)

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.

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

2013-05-01

84

Absorptive Capacity for R&D: The Identification of Different Firm Profiles  

Microsoft Academic Search

Being competitive requires continuously performing product and process innovations nowadays. Because of this reason, the absorption of externally generated R&D is increasingly important for companies. It is well known that companies differ regarding their aptitude for knowledge absorption. This paper aims at the identification of different firm profiles by means of the identification and valuation of drivers that support the

Arturo Rodríguez-Castellanos; Markus Hagemeister; Stanislav Ranguelov

2010-01-01

85

SUITABILITY OF LOW RESOLUTION NUCLEAR MAGNETIC RESONANCE TO ASSESS WATER HOLDING CAPACITY OF RABBIT MEAT  

Microsoft Academic Search

SUMMARY - Water holding capacity has been studied on Longissimus dorsi muscles of growing rabbits reared in intensive system. The research work has been conducted on 48 carcasses) 48 h post mortem, by performing the same analyses which have been found useful for the assessment of water holding capacity in pork meat. Two different water compartments are detected by Low

F. Capozzi; C. Cavani; F. Luzi; L. Maertens

86

Phase Composition of Frozen Montmorillonite-Water Mixtures from Heat Capacity Measurements.  

National Technical Information Service (NTIS)

Equations are presented which form the basis of a method for determining the unfrozen water content of frozen clay-water mixtures from heat capacity measurements. The heat capacity of frozen sodium-montmorillonite water mixtures was determined at -4.7 and...

D. M. Anderson

1967-01-01

87

Analysis of the carrying capacity of water resources in Sheshui River watershed, China  

Microsoft Academic Search

A risk assessment for water shortage is constructed to analyze the carrying capacity of water resources in Sheshui River watershed, China. It is based on the information of present economic development. There are several serious environmental problems which might cripple the development potential in Sheshui River watershed. Risk assessment results are used to analyze the carrying capacity of water resources

Xuying Yuan; Yijin Wu; Min Zhang

2010-01-01

88

Water storage capacity, stemflow and water funneling in Mediterranean shrubs: biotic and abiotic factors  

NASA Astrophysics Data System (ADS)

Many lands of the Mediterranean basin of European Union have been abandoned in the last decades and consequently vegetation type changes too. This modifies hydrologic processes, changing the volume and the way in which the rainfall reaches the soil. To predict water losses and other hydrological and ecological features of vegetation, its water storage capacity and stemflow need to be accurately determined. Vast areas of the Mediterranean region are occupied by shrublands yet there is scarce data available on their rainwater interception capacity. Only 11% of publications have addressed this issue in shrubs. A technique for measuring in countryside interception loss, throughfall and stemflow in shrubs is reported. It allows expressing the results in relation to rainfall characteristics and environmental conditions for low intensity events. Simulated rainfall tests were also conducted in controlled conditions on 9 Mediterranean shrubs in order to assess the influence of varying anatomic and morphological features. Mean water storage capacity was 1.02 mm (0.35 mm to 3.24 mm), stemflow was 16% (3.8 % to 26.4%) and the funneling ratio was 104 (30 to 260). Despite their small size, shrubs may generate high water losses when they form dense communities and this can have a significant impact in regions where water is scarce. In this report, we discuss the ecological and hydrological significance of stemflow and the funneling ratio.

Garcia-Estringana, Pablo; Alegre, Jesús

2010-05-01

89

Calculation and Analysis the Water Environment Capacity for Taizi River Basin  

Microsoft Academic Search

According to the one-dimensional and two-dimensional water quality model, establish the model of water environmental capacity. Based on the comprehensive analysis of the Taizi River's water quality conditions, pollution sources and the characteristics of pollutants, selected one-dimensional model to calculate the water environmental capacity of the Taizi River. Basis of the river function zoning case, combined the various water quality

Xu Chen-guang; Zhang Fan; Xu Jian-xin; Zhao Mai-huan

2010-01-01

90

Energy analysis of an ammonia-water absorption refrigeration system  

SciTech Connect

Absorption refrigeration systems (ARSs) are run on heat-operated cycles. In these systems a secondary fluid (i.e., absorbent) is used to absorb the primary fluid (i.e., refrigerant) vaporized in the evaporator. ARSs for industrial and domestic applications have been attracting increasing interest throughout the world. A simple energy analysis technique for ammonia-water refrigeration systems is presented and verified with actual experimental data taken from the literature. Comparison was made in terms of the coefficient of performance, and very good agreement was found.

Dincer, I.; Dost, S. [Univ. of Victoria, British Columbia (Canada). Dept. of Mechanical Engineering

1996-09-01

91

The Effect of Broiler Breast Meat Color on pH, Moisture, Water-Holding Capacity, and Emulsification Capacity  

Microsoft Academic Search

The relationship between broiler breast meat color and pH, moisture content, water-holding ca- pacity (WHC), and emulsification capacity (EC) was in- vestigated. In each of three replicate trials, fillets were collected from three different commercial processing plants according to breast meat lightness (L*) values as follows: lighter than normal (light, L* > 53), normal (48 < L* < 53), and

M. Qiao; D. L. Fletcher; D. P. Smith; J. K. Northcutt

92

Dynamic of Water Teansport in Napiergrass (Pennisetum purpureum Schumach) Plant - Relationship between Water Transport Regulation and Water Storage Capacity in the Diurnal Water Balance  

Microsoft Academic Search

The characteristics of economical water transport in napiergrass were investigated with respect to water transport regulation by the nodal stem and a water storage capacity (WSC), partly compensation for transpiration wlth water in the plant. Changes in leaf photosynthesis after plant excisions suggested that water transport to the leaves was mainly regulated by the nodal stem in the morning and

Kiyoshi NAGASUGA

93

A nonisothermal emissivity and absorptivity formulation for water vapor  

NASA Technical Reports Server (NTRS)

An emissivity approach is taken to modeling fluxes and cooling rates in the atmosphere. The nonisothermal water vapor long wave radiation emissivity and absorptivity model that is developed satisfies the requirements of defining a monochromatic transfer equation for predicting water vapor emissions. Predictions made with the model compare favorably with fluxes predicted by a radiation model for narrow-band emissions in 5 kayser intervals. The spectral resolution assumed in narrow-band models is shown to be an arbitrary parameter and, if a far wing continuum-type opacity is included in the emissivity scheme presented, results can be obtained which are as accurate as predictions made with state of the art line-by-line (LBL) calculations.

Ramanathan, V.; Downey, P.

1986-01-01

94

Capacity of Water-Based Recreation Systems. Part II. A Systems Approach to Capacity Analysis.  

National Technical Information Service (NTIS)

The reports are designed to develop methods, models and guidelines useful to lake managers as they seek to measure or predict capacity as a step toward optimizing the recreational output of lake systems. Systems concepts are applied to the problem of anal...

G. A. Hammon H. K. Cordell L. W. Moncrief M. R. Warren R. A. Crysdale

1974-01-01

95

Theoretical and Experimental Analysis of a Single Stage Ammonia-Water Absorption Chiller Performance  

Microsoft Academic Search

The ammonia-water absorption chillers are thermally driven devices producing a cooling effect. It can be operated without any use of electrical or mechanical energy. The advantage of absorption chillers is precisely that they can utilize low grade energy. An experimental prototype of a single stage ammonia-water absorption chiller with complete condensation was designed, built and tested. The thermodynamic models of

Kong Dingfeng; Liu Jianhua; Zhang Liang; Fang Zhiyun; Zheng Guangping

2009-01-01

96

Polystichum munitum (Dryopteridaceae) varies geographically in its capacity to absorb fog water by foliar uptake within the redwood forest ecosystem.  

PubMed

• Premise of the study: Fog provides a critical water resource to plants around the world. In the redwood forest ecosystem of northern California, plants depend on fog absorbed through foliar uptake to stay hydrated during the rainless summer. In this study, we identified regions within the redwood ecosystem where the fern Polystichum munitum canopy most effectively absorbs fog drip that reaches the forest floor. • Methods: We measured the foliar uptake capacity of P. munitum fronds at seven sites along 700 km of the redwood forest ecosystem. We quantified the canopy cover of P. munitum at each site and estimated how much water the fern canopy can acquire aboveground through fog interception and absorption. • Key results: Throughout the ecosystem, nocturnal foliar uptake increased the leaf water content of P. munitum by 7.2%, and we estimated that the P. munitum canopy can absorb 5 ± 3% (mean ± SE) of intercepted fog precipitation. Strikingly, P. munitum had the highest foliar uptake capacity in the center of the ecosystem and may absorb 10% more of the fog its canopy intercepts in this region relative to other regions studied. Conversely, P. munitum had no foliar uptake capacity in the southern end of the ecosystem. • Conclusions: This study shows the first evidence that foliar uptake varies within species at the landscape scale. Our findings suggest that the P. munitum at the southern tip of the redwood ecosystem may suffer most from low summertime water availability because it had no potential to acquire fog as an aboveground water subsidy. PMID:21616864

Limm, Emily B; Dawson, Todd E

2010-07-01

97

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

PubMed

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

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

2013-01-01

98

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

PubMed Central

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.

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

2013-01-01

99

Comparison of Two Models for Calculating Water Environment Capacity of Songhua River  

Microsoft Academic Search

\\u000a Water environment capacity is an important conception in environmental science. As a basic theory applied in EIA (Environmental\\u000a Impact Assessment), water environmental capacity is also an indispensable factor in making District Environmental Planning\\u000a and total water pollutant control. With the statistic monitoring data of 17 water quality indexes from 2001 to 2005 of six\\u000a monitor sections offered by Harbin Environmental

Shihu Shu; Huan Ma

2010-01-01

100

Institutional Capacity Building within the Water Resources Sector of Developing Countries  

Microsoft Academic Search

Part 1 of this paper analyzes the concepts of institutional capacity building and of integrated water resources management, on the basis of recent publications. The authors, building on the work of others, combine this into a conceptual framework for institutional capacity building in the water resources sector. A matrix approach is developed that allows the analysis of project activities, projects

Gljsberth Lamoree; Joakim Harlin

2002-01-01

101

Contribution of H-bond vibrations to heat capacity of water  

Microsoft Academic Search

The origin of the anomalously large value of the heat capacity of liquid water is discussed. Comparing the temperature dependence of the heat capacities for water with those for argon and hydrogen sulfide, we separate contributions of the translational and rotational degrees of freedom. The residual part is considered as being caused by the specific contributions of the transversal vibrations

Sergey V. Lishchuk; Nikolay P. Malomuzh; Pavel V. Makhlaichuk

2011-01-01

102

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

Microsoft Academic Search

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

Thomas F. Garrity; Daniel R. Wilkins

1993-01-01

103

A theoretical calculation model for the acidification capacity of natural waters  

Microsoft Academic Search

The acidification capacity model is mainly used for the classification and the regional partitioning of the acidification sensitivity of natural waters. The theoretical calculation system of the acidification capacity from the conventional monitoring items, such as alkalinity, chemical oxygen demand and pH value, is established by simulating the acidification process of natural waters. In this study, the contributions of the

Jinhui Li; Hongxiao Tang

1998-01-01

104

Terahertz absorption spectrum of para and ortho water vapors at different humidities at room temperature  

Microsoft Academic Search

Terahertz time-domain spectroscopy has been used to measure the absorption of water vapor in 0.2-2.4 THz range from low to high humidity at room temperature. The observed absorption lines are due to the water molecular rotations in the ground vibrational state. We find that the absorption strength of para transitions increases as humidity increases, while the absorption strength of ortho

X. Xin; H. Altan; A. Saint; D. Matten; R. R. Alfano

2006-01-01

105

An experimental study on the energy absorption capacity of thin-walled castings  

Microsoft Academic Search

The energy absorption potential of high-pressure die cast (HPDC) components made of magnesium alloys AM20, AM50, AM60, AZ91 and the aluminium alloy A356 is investigated using a shear–bolt principle. Both quasi-static and dynamic tests have been performed. In addition, single cast plates of AM60 and A356 alloy with different thickness have been tested in order to investigate the effect of

Cato Dørum; Odd Sture Hopperstad; Odd-Geir Lademo; Magnus Langseth

2006-01-01

106

Impact of a lowered water table on water holding capacity of high elevation meadow soils  

NASA Astrophysics Data System (ADS)

Meadow degradation, as a product of overgrazing or disruption of hydrologic regime, is a critical problem facing a variety of environments, including high elevation ecosystems of the Sierra Nevada, California and has become a focus of major research and restoration efforts. Within the historic range of water level in a meadow, it is hypothesized that a meadow will retain its water holding capacity and resiliency. However, if the water table drops below a historic level, due to climate change and/or management practices, the process of soil consolidation will influence the resiliency of the meadow through the irreversible plastic deformation of the soil pores. The subsequent change in soil structure results in decreased porosity, increased bulk density, and a reduction in permeability of the meadow. Such changes can adversely impact the overall water holding capacity of the meadow. This study utilizes a modified triaxial system combined with a multiphysics modeling approach to quantify the historic limit of dryness experienced in a high elevation meadow and degree of consolidation the meadow would experience if that limit was exceeded.

Arnold, C. L.

2011-12-01

107

Estimation of the CO absorption capacities in aqueous 2-(2-aminoethylamino)ethanol and its blends with MDEA and TEA in the presence of SO  

Microsoft Academic Search

A study of carbon dioxide (CO) and sulfur dioxide (SO)\\/CO mixtures absorption has been carried out in aqueous 2-(2-aminoethylamino)ethanol (AEE) solution and its blends with N-methyldiethanolamine (MDEA) and triethanolamine (TEA) to estimate the influence of SO, MDEA, and TEA on the CO absorption capacity of the AEE. The CO absorption loading has been estimated in 15 wt % AEE alone

D. Bonenfant; M. Minleault; R. Hausler

2007-01-01

108

In-situ X-ray absorption spectroscopy analysis of capacity fade in nanoscale-LiCoO2  

NASA Astrophysics Data System (ADS)

The local structure of nanoscale (˜10-40 nm) LiCoO2 is monitored during electrochemical cycling utilizing in-situ X-ray absorption spectroscopy (XAS). The high surface area of the LiCoO2 nanoparticles not only enhances capacity fade, but also provides a large signal from the particle surface relative to the bulk. Changes in the nanoscale LiCoO2 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 LiCoO2 as a likely factor in the capacity fade and irreversible losses in practical, microscale LiCoO2.

Patridge, Christopher J.; Love, Corey T.; Swider-Lyons, Karen E.; Twigg, Mark E.; Ramaker, David E.

2013-07-01

109

Research on the water environmental features and environmental capacity of Enshi river reach of Qingjiang river  

Microsoft Academic Search

Based on the five years' ?ƒ 2003-2007?? monitoring data of two water quality monitoring sections at the upstream and downstream of Enshi river reach of Qingjiang river, the water quality status was analyzed and the water environmental capacity was calculated. The results show that at the upstream section, Ammonia nitrogen and Contain fecal coliform are overweight, and water environmental status

Zhu Junlin; Cai Chongfa; Deng Kun

2011-01-01

110

Water absorption length measurement with the ANTARES optical beacon system  

NASA Astrophysics Data System (ADS)

ANTARES is a neutrino telescope located in the Mediterranean Sea with the aim of detecting high energy neutrinos of extra-terrestrial origin. It consists of a three dimensional array on 12 detection lines of photomultiplier tubes (PMTs) able to detect the Cherenkov light induced by muons produced in the interaction of neutrinos with the surrounding water and seabed. To reach the best angular resolution, good time and positioning calibrations are required. The propagation of Cherenkov photons strongly depends on the optical properties of the sea water, which has an impact on the reconstruction efficiency. The determination of the optical parameters, as the absorption and scattering lengths, is crucial to calculate properly the effective area and the angular resolution of the detector. The ANTARES optical beacon system consists of pulsed and fast, well controlled light sources distributed throughout the detector to carry out in situ the relative time calibration of the detector components. In this contribution we show some results on the sea water optical properties and their stability measured with the optical beacon system.

Yepes-Ramirez, Harold; ANTARES Collaboration

2011-01-01

111

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

Microsoft Academic Search

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

Lihua H. Feng; Xingcai Zhang; Gaoyuan Luo

2009-01-01

112

EVALUATING CAPACITIES OF GAC PRELOADED WITH NATURAL WATER  

EPA Science Inventory

Adsorption studies are conducted to determine how preloading a natural groundwater onto GAC affects the adsorption of cis-1,2-dichloroexthene in small-scale and pilot-scale columns. Capacities are determined from batch-isotherm tests, microcolumns, and pilot columns, which are p...

113

Micropulse water vapor differential absorption lidar: transmitter design and performance.  

PubMed

An all diode-laser-based micropulse differential absorption lidar (DIAL) laser transmitter for tropospheric water vapor and aerosol profiling is presented. The micropulse DIAL (MPD) transmitter utilizes two continuous wave (cw) external cavity diode lasers (ECDL) to seed an actively pulsed, overdriven tapered semiconductor optical amplifier (TSOA). The MPD laser produces up to 7 watts of peak power over a 1 µs pulse duration (7 µJ) and a 10 kHz pulse repetition frequency. Spectral switching between the online and offline seed lasers is achieved on a 1Hz basis using a fiber optic switch to allow for more accurate sampling of the atmospheric volume between the online and offline laser shots. The high laser spectral purity of greater than 0.9996 coupled with the broad tunability of the laser transmitter will allow for accurate measurements of tropospheric water vapor in a wide range of geographic locations under varying atmospheric conditions. This paper describes the design and performance characteristics of a third generation MPD laser transmitter with enhanced laser performance over the previous generation DIAL system. PMID:23187280

Nehrir, Amin R; Repasky, Kevin S; Carlsten, John L

2012-10-22

114

Atmospheric absorption of near infrared and visible solar radiation by the hydrogen bonded water dimer  

Microsoft Academic Search

Summary Based on the physico-chemical properties of water dimers, we calculated their near infrared and visible absorption of solar radiation in the Earth's atmosphere. Our calculation has used equilibrium constants determined by statistical mechanics and a vibrational absorption spectrum determined by a coupled oscillator quantum mechanics model and ab-initio quantum chemistry. The resulting total atmospheric absorption was calculated using a

V. Vaida; J. S. Daniel; H. G. Kjaergaard; L. M. Goss; A. F. Tuck

2001-01-01

115

GEOGRAPHIC PATTERNS OF SOIL WATER-HOLDING CAPACITY IN THE CONTIGUOUS UNITED STATES  

EPA Science Inventory

The geographic patterns of soil water-holding capacity are important for studying the response of vegetation and water supply to climate change. his study was conducted to evaluate which dataset to use for national-scale water balance modeling. patial databases of soil properties...

116

Parameter determination to calculate water environmental capacity in Zhangweinan Canal Subbasin in China  

Microsoft Academic Search

Zhangweinan canal sub-basin (ZWN) has the most serious water resource shortage and water pollution problems in north of China. To calculate the water environmental capacity in ZWN, determination methods for design flow rates and degradation coeffcients were discussed in this study. Results showed that 90% and 50% hydrological guarantee flow rates were suitable to be the design flow rates for

Yingxia Li; Ruzhi Qiu; Zhifeng Yang; Chunhui Li; Jingshan Yu

2010-01-01

117

Copper complexation capacity in surface waters of the Venice Lagoon  

Microsoft Academic Search

Total copper (CuT), copper ion activity (pCu) and the copper complexation capacity (CuCC) were determined in samples of seawater collected in July 2003 from the Venice Lagoon. CuT and CuCC showed considerable spatial variability: CuT ranged from 1.8 to 70.0nM, whereas the CuCC varied from 195 to 573nM. pCu values varied from 11.6 to 12.6 and are consistent with those

Francisco Delgadillo-Hinojosa; Alberto Zirino; Cristina Nasci

2008-01-01

118

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.

119

A New Method for Regional Water Environmental Capacity Estimation Based on Natural-Social Water Cycle Analysis  

Microsoft Academic Search

Human's social-economic activities have significantly interrupted the natural water cycle, particularly in urban area. The so-called binary natural-social water cycle issue has highly increased the complexity of urban water system. Traditional method to calculate water environmental capacity (WEC) depending on water quality model and long time series of monitoring data is sometimes not practical, especially at the planning stage or

Pan Li; Siyu Zeng; Jining Chen

2010-01-01

120

Experimentally determined water storage capacity in the Earth's upper mantle  

NASA Astrophysics Data System (ADS)

Trace amounts of hydrogen dissolved as defects in nominally anhydrous minerals (NAMs) in the mantle are believed to play a key role in physical and chemical processes in the Earth’s upper mantle. Hence, the estimation of water storage in mantle phases and solubility mechanisms are important in order to better understand the effect of water. Experimental data on water solubility in NAMs are available for upper mantle minerals such as olivine, pyroxenes and garnet. However, the majority of studies are based on the study of single phases, and at temperatures or pressures that are too low for the Earth’s upper mantle. The aim of this study is to constrain the combined effects of pressure, temperature and composition on water solubility in olivine and orthopyroxene under upper mantle conditions. The solubility of water in coexisting orthopyroxene and olivine was investigated by simultaneously synthesizing the two phases at high pressure and high temperature in a multi-anvil press. Experiments were performed under water-saturated conditions in the MSH systems with Fe and Al at 2.5, 5, 7.5 and 9 GPa and temperatures between 1175 and 1400°C. Integrated OH absorbances were determined using polarized infrared spectroscopy on doubly polished thin sections of randomly oriented crystals. Water solubility in olivine increases with pressure and decreases with temperature as has been described previously (Bali et al., 2008). The aluminum content strongly decreases in olivine with pressure from 0.09 wt% at 2.5 GPa and 1250°C to 0.04 wt% at 9 GPa and 1175°C. The incorporation of this trivalent cation in the system enhances water solubility in olivine even if present in trace amounts, however this behavior appears to reverse at high pressure. The effect of temperature on water solubility follows a bell-shaped curve with a maximum solubility in olivine and orthopyroxene at 1250°C. Aluminum is incorporated in orthopyroxene following the Tschermak substitution and strongly decreases as pressure increases. Water partitioning between orthopyroxene and olivine is always lower than 1 except at low pressure. However, it increases with the incorporation of aluminum wich results in water contents in olivine 5 times greater that in orthopyroxene at 7.5 GPa, despite aluminum preferentially entering into orthopyroxene. Finally, water partitioning between orthopyroxene and olivine decreases with pressure in the Al-free and -bearing system. The effect of temperature is more variable with pressure. The present data allows constructing a model of water solubility in olivine at all pressures and temperatures in the MFASH system. Combining this model with the presently measured partitioning of water between olivine and orthopyroxene, as well as previous data on solubility in clinopyroxene and garnet we are able to build a model of water saturation curve in the upper mantle. References Bali, E., Bolfan-Casanova, N., Koga, K.T., 2008. Pressure and temperature dependence of H solubility in forsterite : an implication to water activity in the Earth interior. Earth Planet. Sci. Lett. 268, 354-363.

Ferot, A.; Bolfan-Casanova, N.

2010-12-01

121

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

Microsoft Academic Search

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

SERAPHIN A. SULLIVAN

1963-01-01

122

Near-infrared diode laser absorption diagnostic for temperature and water vapor in a scramjet combustor  

Microsoft Academic Search

Tunable diode laser absorption measurements of gas temperature and water concentration were made at the exit of a model scramjet combustor fueled on JP-7. Multiplexed, fiber-coupled, near-infrared distributed feedback lasers were used to probe three water vapor absorption features in the 1.34 1.47 mum spectral region (2v1 and v1+v3 overtone bands). Ratio thermometry was performed using direct-absorption wavelength scans of

Jonathan T. C. Liu; Gregory B. Rieker; Jay B. Jeffries; Mark R. Gruber; Campbell D. Carter; Tarun Mathur; Ronald K. Hanson

2005-01-01

123

Near-infrared diode laser absorption diagnostic for temperature and water vapor in a scramjet combustor  

Microsoft Academic Search

Tunable diode laser absorption measurements of gas temperature and water concentration were made at the exit of a model scramjet combustor fueled on JP-7. Multiplexed, fiber-coupled, near-infrared distributed feedback lasers were used to probe three water vapor absorption features in the 1.34-1.47 μm spectral region (2v1and v1+ v3overtone bands). Ratio thermometry was performed using direct-absorption wavelength scans of isolated features

Tarun Mathur

2005-01-01

124

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

National Technical Information Service (NTIS)

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 he...

D. L. Dietrich F. A. Williams M. C. Hicks V. Nayagam

2012-01-01

125

Modeling, simulation and optimization of a solar collector driven water heating and absorption cooling plant  

Microsoft Academic Search

A cogeneration system consisting of a solar collector, a gas burner, a thermal storage reservoir, a hot water heat exchanger, and an absorption refrigerator is devised to simultaneously produce heating (hot water heat exchanger) 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.

J. V. C. Vargas; J. C. Ordonez; E. Dilay; J. A. R. Parise

2009-01-01

126

Water absorption by secondary organic aerosol and its effect on inorganic aerosol behavior  

Microsoft Academic Search

The hygroscopic nature of atmospheric aerosol has generally been associated with its inorganic fraction. In this study, a group contribution method is used to predict the water absorption of secondary organic aerosol (SOA). Compared against growth measurements of mixed inorganic-organic particles, this method appears to provide a first-order approximation in predicting SOA water absorption. The growth of common SOA species

Asif S. Ansari; Spyros N. Pandis

2000-01-01

127

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

PubMed

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

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

2013-01-01

128

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

NASA Technical Reports Server (NTRS)

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.

Ma, Qiancheng

2014-01-01

129

Conformational Contribution to the Heat Capacity of Starch and Starch-Water  

NASA Astrophysics Data System (ADS)

The heat capacities of starch and starch-water have been measured using adiabatic calorimetry, and standard differential scanning calorimetry (DSC) and are reported from 5 K to 510 K. The amorphous starch containing 10 wt water shows a glass transition around 350 K. The heat capacities of the solid of amorphous, dry starch is linked to an approximate group vibrational spectrum, and the Tarasov equation is used to estimate the heat capacity contribution due to skeletal vibrations ( theta1 = 830 K and theta2 = 85 K theta3 = 85 K, Nskeletal = 17). The calculated and experimental heat capacities agree to better than ±3between 5 and 250 K. The experimental heat capacities of starch-water and dry starch are compared over the whole range of temperatures. Above the glass transition the differences are interpreted as contributions of different conformational heat capacities from interacting chain of carbohydrate with water. The conformational part is evaluated from a fit of the experimental Cp of starch-water, decreased by the vibrational and the external Cp to a one-dimensional Ising model with two discrete states and stiffness, cooperativity, and degeneracy parameters. NSF, Polymers Program, DMR-9703692, and the Div. of Mat. Sci., BES, DOE at ORNL, managed by Lockheed Martin Energy Research Corp., DE-AC05-96OR22464.

Pyda, Marek; Wunderlich, Bernhard

2000-03-01

130

Effects of sodium polyacrylate on water retention and infiltration capacity of a sandy soil.  

PubMed

Based on the laboratory study, the effects of sodium polyacrylate (SP) was investigated at 5 rates of 0, 0.08, 0.2, 0.5, and 1%, on water retention, saturated hydraulic conductivity(Ks), infiltration characteristic and water distribution profiles of a sandy soil. The results showed that water retention and available water capacity effectively increased with increasing SP rate. The Ks and the rate of wetting front advance and infiltration under certain pond infiltration was significantly reduced by increasing SP rate, which effectively reduced water in a sandy soil leaking to a deeper layer under the plough layer. The effect of SP on water distribution was obviously to the up layer and very little to the following deeper layers. Considering both the effects on water retention and infiltration capacity, it is suggested that SP be used to the sandy soil at concentrations ranging from 0.2 to 0.5%. PMID:24701379

Zhuang, Wenhua; Li, Longguo; Liu, Chao

2013-01-01

131

Terahertz absorption spectrum of para and ortho water vapors at different humidities at room temperature  

NASA Astrophysics Data System (ADS)

Terahertz time-domain spectroscopy has been used to measure the absorption of water vapor in 0.2-2.4 THz range from low to high humidity at room temperature. The observed absorption lines are due to the water molecular rotations in the ground vibrational state. We find that the absorption strength of para transitions increases as humidity increases, while the absorption strength of ortho transitions increases and then decreases in intensity with increasing humidity. We explain this difference based on the nuclear spin statistics based ratio of ortho to para water monomer populations at room temperature. The preferential adsorption on the solid surfaces of para water leads to an ortho dominated vapor cloud whose monomer rotational absorption intensity decreases due to the effects of dimerization, molecular collisions, clustering, and interactions with liquid droplets at high concentrations.

Xin, X.; Altan, H.; Saint, A.; Matten, D.; Alfano, R. R.

2006-11-01

132

EFFECT OF POLYMER ADSORPTION ON CELLULOSE NANOFIBRIL WATER BINDING CAPACITY AND AGGREGATION  

Microsoft Academic Search

Polymer adsorption on cellulose nanofibrils and the effect on nanofibril water binding capacity were studied using cellulose nanofibril films together with quartz crystal microbalance with dissipation (QCM-D) and surface plasmon resonance (SPR). The experiments were performed in the immersed state, and special attention was paid to the effect of polymer properties on the water content and viscoelastic properties of the

Susanna Ahola; Petri Myllytie; Monika Österberg; Tuija Teerinen; Janne Lainea

133

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...

134

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

PubMed

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 100g of motor oil, while it only picks up less than 0.1g 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

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

2014-07-15

135

MEASUREMENT OF THE ABSORPTION CHARACTERISTICS OF SUPERSATURATED WATER VAPOR  

Microsoft Academic Search

the atmosphere by as much as 40 Wm-2. This enhanced absorption, which was recognised by comparing model calculations with satellite-borne radiometric measurements, remains to be explained. Controversial explanations of this newly discovered fact have been offered and debated. A school of thought suggests that the enhanced absorption of the incoming short-wave solar radiation is due to erroneous depiction of the

Prasad Varanasi; B. Ranganayakamma; S. Mathur; T. Refaat; C. R. Prasad

136

Absorption cold and warm water system utilizing solar heat  

SciTech Connect

An absorbtion cold and warm water system utilizing solar heat is disclosed. Heat source water is obtained by heating water by the solar heat and a main heating source. The system is selectively made to function as a warm water system, a first heat pump and a second heat pump in accordance with temperature conditions associated with the heat source water.

Hibino, Y.; Kamejima, K.; Nara, Y.

1985-02-12

137

Capacity for digestive hydrolysis and amino acid absorption in Atlantic salmon ( Salmo salar) fed diets with soybean meal or inulin with or without addition of antibiotics  

Microsoft Academic Search

This experiment was done to study the effects of dietary soybean meal (SBM) and inulin (a prebiotic) on the capacity for digestive hydrolysis and amino acid absorption by Atlantic salmon, and how a dietary supplement of the broad-spectrum antibiotic oxytetracycline (OTC) modulated these responses. A control diet (FM) was made from fish meal, fish oil and extruded wheat. Two similar

Ståle Refstie; Anne Marie Bakke-McKellep; Michael H. Penn; Anne Sundby; Karl D. Shearer; Åshild Krogdahl

2006-01-01

138

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

PubMed Central

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.

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

2012-01-01

139

A parameterization for the absorption of solar radiation by water vapor in the earth's atmosphere  

NASA Technical Reports Server (NTRS)

A parameterization for the absorption of solar radiation as a function of the amount of water vapor in the earth's atmosphere is obtained. Absorption computations are based on the Goody band model and the near-infrared absorption band data of Ludwig et al. A two-parameter Curtis-Godson approximation is used to treat the inhomogeneous atmosphere. Heating rates based on a frequently used one-parameter pressure-scaling approximation are also discussed and compared with the present parameterization.

Wang, W.-C.

1976-01-01

140

Water and tissue equivalency of some gel dosimeters for photon energy absorption.  

PubMed

The mass energy absorption coefficients,, effective atomic numbers for photon energy absorption, ZPEAeff, and effective electron numbers for photon-energy absorption, NPEAeff, is calculated for 14 polymer gel dosimeter, five gel dosimeter, soft tissue and water, in the energy range from 1 keV to 20 MeV. The ZPEAeff(Gel)/ZPEAeff(Tissue) and NPEAeff(Gel)/NPEAeff (Tissue) are used to evaluate the tissue equivalency. PMID:24080343

Un, Adem

2013-12-01

141

Absorption  

NSDL National Science Digital Library

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 SocietyÃÂs 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.

Katherine M Knudson (Polson Middle School)

1998-04-01

142

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

Microsoft Academic Search

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

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

2007-01-01

143

Modeling water resources as a constraint in electricity capacity expansion models  

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

144

Drinking Spring Water and Lithium Absorption: A Preliminary Study  

Microsoft Academic Search

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

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

145

Solvation thermodynamics and heat capacity of polar and charged solutes in water.  

PubMed

The solvation thermodynamics and in particular the solvation heat capacity of polar and charged solutes in water is studied using atomistic molecular dynamics simulations. As ionic solutes we consider a F(-) and a Na(+) ion, as an example for a polar molecule with vanishing net charge we take a SPC/E water molecule. The partial charges of all three solutes are varied in a wide range by a scaling factor. Using a recently introduced method for the accurate determination of the solvation free energy of polar solutes, we determine the free energy, entropy, enthalpy, and heat capacity of the three different solutes as a function of temperature and partial solute charge. We find that the sum of the solvation heat capacities of the Na(+) and F(-) ions is negative, in agreement with experimental observations, but our results uncover a pronounced difference in the heat capacity between positively and negatively charged groups. While the solvation heat capacity ?C(p) stays positive and even increases slightly upon charging the Na(+) ion, it decreases upon charging the F(-) ion and becomes negative beyond an ion charge of q = -0.3e. On the other hand, the heat capacity of the overall charge-neutral polar solute derived from a SPC/E water molecule is positive for all charge scaling factors considered by us. This means that the heat capacity of a wide class of polar solutes with vanishing net charge is positive. The common ascription of negative heat capacities to polar chemical groups might arise from the neglect of non-additive interaction effects between polar and apolar groups. The reason behind this non-additivity is suggested to be related to the second solvation shell that significantly affects the solvation thermodynamics and due to its large spatial extent induces quite long-ranged interactions between solvated molecular parts and groups. PMID:23534665

Sedlmeier, Felix; Netz, Roland R

2013-03-21

146

Solvation thermodynamics and heat capacity of polar and charged solutes in water  

SciTech Connect

The solvation thermodynamics and in particular the solvation heat capacity of polar and charged solutes in water is studied using atomistic molecular dynamics simulations. As ionic solutes we consider a F{sup -} and a Na{sup +} ion, as an example for a polar molecule with vanishing net charge we take a SPC/E water molecule. The partial charges of all three solutes are varied in a wide range by a scaling factor. Using a recently introduced method for the accurate determination of the solvation free energy of polar solutes, we determine the free energy, entropy, enthalpy, and heat capacity of the three different solutes as a function of temperature and partial solute charge. We find that the sum of the solvation heat capacities of the Na{sup +} and F{sup -} ions is negative, in agreement with experimental observations, but our results uncover a pronounced difference in the heat capacity between positively and negatively charged groups. While the solvation heat capacity {Delta}C{sub p} stays positive and even increases slightly upon charging the Na{sup +} ion, it decreases upon charging the F{sup -} ion and becomes negative beyond an ion charge of q=-0.3e. On the other hand, the heat capacity of the overall charge-neutral polar solute derived from a SPC/E water molecule is positive for all charge scaling factors considered by us. This means that the heat capacity of a wide class of polar solutes with vanishing net charge is positive. The common ascription of negative heat capacities to polar chemical groups might arise from the neglect of non-additive interaction effects between polar and apolar groups. The reason behind this non-additivity is suggested to be related to the second solvation shell that significantly affects the solvation thermodynamics and due to its large spatial extent induces quite long-ranged interactions between solvated molecular parts and groups.

Sedlmeier, Felix; Netz, Roland R. [Fachbereich Physik, Freie Universitaet Berlin, 14195 Berlin (Germany)

2013-03-21

147

The effect of water absorption on the dielectric properties of epoxy nanocomposites  

Microsoft Academic Search

In this research, the influence of water absorption on the dielectric properties of epoxy resin and epoxy micro-composites and nano-composites filled with silica has been studied. Nanocomposites were found to absorb significantly more water than unfilled epoxy. However, the microcomposite absorbed less water than unfilled epoxy: corresponding to the reduced proportion of the epoxy in this composite. The glass transition

Chen Zou; J. C. Fothergill; S. W. Rowe

2008-01-01

148

Characteristics of the membrane utilized in a compact absorber for lithium bromide–water absorption chillers  

Microsoft Academic Search

This study aims at investigating experimentally and analytically the characteristics and properties of a membrane utilized to design compact absorbers for lithium bromide–water absorption chillers. The main focus of this study are the factors that influence the water vapor transfer flux into a lithium bromide–water solution in confined narrow channels under vacuum conditions, as well as the properties limits for

Ahmed Hamza H. Ali; Peter Schwerdt

2009-01-01

149

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

National Technical Information Service (NTIS)

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 inst...

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

1995-01-01

150

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

NASA Technical Reports Server (NTRS)

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.

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

1976-01-01

151

Terahertz absorption spectrum of water vapor at different humidity at room temperature  

NASA Astrophysics Data System (ADS)

We measured the absorption spectrum of water vapor in 0.2-2.4THz range at different humidity from 17% to 98% at room temperature using Er: doped fiber laser (IMRA America Inc.) based terahertz time-domain spectroscopy. The experiments were performed in a nitrogen-purged cage at atmosphere environment to obtain the reference and water absorption information. The seventeen absorption lines were observed due to water molecular rotations in the ground vibration state. The first three absorption lines at low frequencies increase with humidity, following the Beer-Lambert Law, while some of high frequency lines were found to decrease with humidity. These effects will be discussed. The observed line broadening is due to collisions occurring among water and nitrogen molecules.

Xin, Xuying; Altan, Hakan; Matten, David; Saint, Angelamaria; Alfano, Robert

2006-03-01

152

A method to evaluate capacity and efficiency of water soluble antioxidants as peroxyl radical scavengers  

Microsoft Academic Search

In this paper, we report on a method to evaluate the activity of water soluble and H-atom donor antioxidants as peroxyl radical scavengers in a micelle system reproducing the conditions occurring in the upper small intestine in humans, during digestion and absorption of lipids. This method, which overcomes some of the problems of the total radical trapping antioxidant parameter (TRAP)

Lucio Zennaro; Monica Rossetto; Paola Vanzani; Veronica De Marco; Marina Scarpa; Leontino Battistin; Adelio Rigo

2007-01-01

153

Absorption refrigeration method with alternative water-ammonia solution circulation system for microelectronics cooling  

Microsoft Academic Search

The study develops an analytical model of an optimized small scale absorption ammonia\\/water refrigeration system, designed to fit smaller scale power electronics, using a pump to circulate the binary ammonia-water solution cooling agent in the proposed miniaturized system. This continues the authors' previous study of a refrigeration absorption system, by replacing the thermo-siphon and gravitational based circulation of the compensatory

Victor Chiriac; Florea Chiriac

2010-01-01

154

RF Design, Power Handling, and Hot Switching of Waveguide Water-Based Absorptive Switches  

Microsoft Academic Search

This paper presents the first complete water-based waveguide absorptive switch from 25-40 GHz integrated with commercially available micropumps. The design exploits the absorptive properties of water in the microwave and millimeter-wave bands along with innovative techniques to achieve an optimized performance in both switching states. Besides its static RF performance, the hot-switching response is also experimentally characterized. Successful hot-switching measurements

Chung-Hao Chen; Dimitrios Peroulis

2009-01-01

155

Water absorption by secondary organic aerosol and its effect on inorganic aerosol behavior  

SciTech Connect

The hygroscopic nature of atmospheric aerosol has generally been associated with its inorganic fraction. In this study, a group contribution method is used to predict the water absorption of secondary organic aerosol (SOA). Compared against growth measurements of mixed inorganic-organic particles, this method appears to provide a first-order approximation in predicting SOA water absorption. The growth of common SOA species is predicted to be significantly less than common atmospheric inorganic salts such as (NH{sub 4}){sub 2}SO{sub 4} and NaCl. Using this group contribution method as a tool in predicting SOA water absorption, an integrated modeling approach is developed combining available SOA and inorganic aerosol models to predict overall aerosol behavior. The effect of SOA on water absorption and nitrate partitioning between the gas and aerosol phases is determined. On average, it appears that SOA accounts for approximately 7% of total aerosol water and increases aerosol nitrate concentrations by approximately 10%. At high relative humidity and low SOA mass fractions, the role of SOA in nitrate partitioning and its contribution to total aerosol water is negligible. However, the water absorption of SOA appears to be less sensitive to changes in relative humidity than that of inorganic species, and thus at low relative humidity and high SOA mass fraction concentrations, SOA is predicted to account for approximately 20% of total aerosol water and a 50% increase in aerosol nitrate concentrations. These findings could improve the results of modeling studies where aerosol nitrate has often been underpredicted.

Ansari, A.S.; Pandis, S.N.

2000-01-01

156

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...

157

Determination of the water vapor continuum absorption by THz-TDS and Molecular Response Theory.  

PubMed

Determination of the water vapor continuum absorption from 0.35 to 1 THz is reported. The THz pulses propagate though a 137 m long humidity-controlled chamber and are measured by THz time-domain spectroscopy (THz-TDS). The average relative humidity along the entire THz path is precisely obtained by measuring the difference between transit times of the sample and reference THz pulses to an accuracy of 0.1 ps. Using the measured total absorption and the calculated resonance line absorption with the Molecular Response Theory lineshape, based on physical principles and measurements, an accurate continuum absorption is obtained within four THz absorption windows, that agrees well with the empirical theory. The absorption is significantly smaller than that obtained using the van Vleck-Weisskopf lineshape with a 750 GHz cut-off. PMID:24663762

Yang, Yihong; Mandehgar, Mahboubeh; Grischkowsky, D

2014-02-24

158

Study on Carrying Capacity of Water Resources in the Beibu Gulf Economy Zone Guangxi Based on Environmental Requirements  

Microsoft Academic Search

For the purpose of maintaining a good ecological environment, this paper has analyzed available capacity of water resources and the water demand for human survival and development in the Beibu Gulf Economy Zone (Guangxi, China). The paper has also evaluated the population carrying capacity in the condition of rational and limit states of water exploitation and utilization in different level

Chong-Xun Mo; De-Suo Cai; Qun-Chao Du; Xin-Yi Fan

2010-01-01

159

Investigation of the Capacity of Underground Water Pumping Using Wind Energy in Dhahran  

Microsoft Academic Search

The capacity of pumping ground water with wind energy conversion systems in Dhahran, Saudi Arabia was statistically analyzed.\\u000a Experimental data of half-hourly wind energy measurements made for a period of 5 years (1995–2000) were used in the analysis.\\u000a Seven horizontal-axis wind turbines with different power ratings were considered in the study. Eight water pumps with different\\u000a power ratings to be powered

Ahmet Z. Sahin; Ahmet Bolat; Abdulrahman Al-Ahmari

160

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

Microsoft Academic Search

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

Zhang Zhanping; Ding Minglei; Li Yongle; Zhao Rongqin

2011-01-01

161

Copper complexing capacity of waters in the magela creek system, Northern Australia  

Microsoft Academic Search

The copper?binding ligand concentration (complexing capacity) and conditional formation constants were determined in water samples collected during the 1979 dry season from five Magela Creek billabongs (waterholes) by using an amperometric titration technique at pH 6.0. In filtered water the ligand concentrations ranged from’ 0.07 ? 0.46 ?M, and the log formation constants from 7.5–8.3. The mean values were little

Barry T. Hart; Simon H. R. Davies

1981-01-01

162

Effects of Osmosis on Water-Holding Capacity of Stratum corneum and Skin Hydration  

Microsoft Academic Search

The stratum corneum (SC) is characterized by highly hydrophilic compounds exhibiting osmotic properties. The role of osmosis in iontophoretic transdermal drug delivery has been a subject in numerous studies. However, the effects of osmosis on the water-holding capacity (WHC) of SC and skin hydration need to be clarified. In the present study, the WHC and skin hydration were found to

Fabrice Pirot; Bénédicte Morel; Géraldine Peyrot; Tiphaine Vuillet; Vincent Faivre; Christine Bodeau; Françoise Falson

2003-01-01

163

Evaluation of the purification capacity of nine portable, small-scale water purification devices.  

PubMed

A test was performed to evaluate the microbial and chemical purification capacity of nine portable, small-scale water purification filter devices with production capacity less than 100 L/h. The devices were tested for simultaneous removal capacity of bacteria (cultured Escherichia coli, Clostridium perfringens, Klebsiella pneumoniae and Enterobacter cloacae), enteric protozoans (formalin-stored Cryptosporidium parvum oocysts), viral markers (F-RNA bacteriophages) and microcystins produced by toxic cyanobacterial cultures. In general, the devices tested were able to remove bacterial contaminants by 3.6-6.9 log10 units from raw water. Those devices based only on filtration through pores 0.2-0.4 microm or larger failed in viral and chemical purification. Only one device, based on reverse osmosis, was capable of removing F-RNA phages at concentrations under the detection limit and microcystins by 2.5 log10. The present study emphasised the need for evaluation tests of water purification devices from the public safety and HACCP (Hazard Analysis and Critical Control Point) points of view. Simultaneous testing for various pathogenic/indicator microbes and microcystins was shown to be a useful and practical way to obtain essential data on actual purification capacity of commercial small-scale drinking-water filters. PMID:15318506

Hörman, A; Rimhanen-Finne, R; Maunula, L; von Bonsdorff, C H; Rapala, J; Lahti, K; Hänninen, M L

2004-01-01

164

Estimation and Allocation Water Environmental Capacity of Dadu River of Luding Segment  

Microsoft Academic Search

Environmental capacity of the water basin was often used as the basis of total amount control of pollutants, which was concerned by environmental workers for a long time. However, with the governance of the on point source pollution, the non-point source (NPS) pollution drew people's close attention day by day. This article was selected to the main non-point source pollution

Yingjun Wang; Jie Xia; Minghao Fan; Yan Chen

2010-01-01

165

An algal assay method for determination of copper complexation capacities of natural waters  

Microsoft Academic Search

Summary and conclusion The complexation capacities determined for natural waters by the Davey and the biological titration methods were statistically the same. However, these two methods differ in an important way. For Davey's method only those data in the vicinity of the equivalence point are used. For the biological titration all data can be used if the complex is strong.

Herbert E. Allen; Carol Blatchley; Thomas D. Brisbin

1983-01-01

166

Simulation of water environmental capacity and pollution load reduction using QUAL2K for water environmental management.  

PubMed

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 COD(Cr) NH(3)-N, TN, and TP were 17.51 t, 1.52 t, 2.74 t and 0.37 t, respectively. The results showed that the NH(3)-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

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

2012-12-01

167

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

PubMed Central

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.

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

2012-01-01

168

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

PubMed Central

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.

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

2014-01-01

169

Leaf photosynthetic rate of tropical ferns is evolutionarily linked to water transport capacity.  

PubMed

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

Zhang, Shi-Bao; Sun, Mei; Cao, Kun-Fang; Hu, Hong; Zhang, Jiao-Lin

2014-01-01

170

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

PubMed

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

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

2011-12-01

171

Interrelation between the crystallinity of polysaccharides and water absorption  

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

172

Water absorption in polyethylene under external electric fields.  

PubMed

Monte Carlo simulations of the solubility and structure of water in polyethylene in thermodynamic equilibrium with liquid water were performed in external fields ranging from 2 x 10(5) to 4 x 10(9) V/m. For a given equilibrium temperature and pressure, the water solubility decreases at higher fields. This occurs since it is energetically favorable for water molecules to be in the pure water phase than in the polyethylene matrix at high field strengths, and results in an increased density in the water phase. However, fields relevant to high voltage conduction (in the absence of defects that can lead to large local field strengths) do not change the solubility. In addition, at large fields the number of water clusters decreases for all cluster sizes. The rate of decrease is highest for large clusters, and a larger fraction of water molecules exist as monomers in the polyethylene matrix at high fields. Large fields also cause alignment of the water molecules, which leads to more clusters with linear topologies and hence an increase in the cluster radius of gyration. PMID:17640146

Johansson, E; Bolton, K; Ahlström, P

2007-07-14

173

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

NASA Astrophysics Data System (ADS)

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

Abdullaev, Iskandar; Rakhmatullaev, Shavkat

2014-05-01

174

Performance Evaluation of a 4.5 kW (1.3 Refrigeration Tons) Air-Cooled Lithium Bromide/Water Solar Powered (Hot-Water-Fired) Absorption Unit  

SciTech Connect

During the summer months, air-conditioning (cooling) is the single largest use of electricity in both residential and commercial buildings with the major impact on peak electric demand. Improved air-conditioning technology has by far the greatest potential impact on the electric industry compared to any other technology that uses electricity. Thermally activated absorption air-conditioning (absorption chillers) can provide overall peak load reduction and electric grid relief for summer peak demand. This innovative absorption technology is based on integrated rotating heat exchangers to enhance heat and mass transfer resulting in a potential reduction of size, cost, and weight of the "next generation" absorption units. Rotartica Absorption Chiller (RAC) is a 4.5 kW (1.3 refrigeration tons or RT) air-cooled lithium bromide (LiBr)/water unit powered by hot water generated using the solar energy and/or waste heat. Typically LiBr/water absorption chillers are water-cooled units which use a cooling tower to reject heat. Cooling towers require a large amount of space, increase start-up and maintenance costs. However, RAC is an air-cooled absorption chiller (no cooling tower). The purpose of this evaluation is to verify RAC performance by comparing the Coefficient of Performance (COP or ratio of cooling capacity to energy input) and the cooling capacity results with those of the manufacturer. The performance of the RAC was tested at Oak Ridge National Laboratory (ORNL) in a controlled environment at various hot and chilled water flow rates, air handler flow rates, and ambient temperatures. Temperature probes, mass flow meters, rotational speed measuring device, pressure transducers, and a web camera mounted inside the unit were used to monitor the RAC via a web control-based data acquisition system using Automated Logic Controller (ALC). Results showed a COP and cooling capacity of approximately 0.58 and 3.7 kW respectively at 35 C (95 F) design condition for ambient temperature with 40 C (104 F) cooling water temperature. This is in close agreement with the manufacturer data of 0.60 for COP and 3.9 kW for cooling capacity. This study resulted in a complete performance map of RAC which will be used to evaluate the potential benefits of rotating heat exchangers in making the "next-generation" absorption chillers more compact and cost effective without any significant degradation in the performance. In addition, the feasibility of using rotating heat exchangers in other applications will be evaluated.

Zaltash, Abdolreza [ORNL; Petrov, Andrei Y [ORNL; Linkous, Randall Lee [ORNL; Vineyard, Edward Allan [ORNL

2007-01-01

175

Calculation of heat capacities of light and heavy water by path-integral molecular dynamics  

NASA Astrophysics Data System (ADS)

As an application of atomistic simulation methods to heat capacities, path-integral molecular dynamics has been used to calculate the constant-volume heat capacities of light and heavy water in the gas, liquid, and solid phases. While the classical simulation based on conventional molecular dynamics has estimated the heat capacities too high, the quantum simulation based on path-integral molecular dynamics has given reasonable results based on the simple point-charge/flexible potential model. The calculated heat capacities (divided by the Boltzmann constant) in the quantum simulation are 3.1 in the vapor H2O at 300 K, 6.9 in the liquid H2O at 300 K, and 4.1 in the ice Ih H2O at 250 K, respectively, which are comparable to the experimental data of 3.04, 8.9, and 4.1, respectively. The quantum simulation also reproduces the isotope effect. The heat capacity in the liquid D2O has been calculated to be 10% higher than that of H2O, while it is 13% higher in the experiment. The results demonstrate that the path-integral simulation is a promising approach to quantitatively evaluate the heat capacities for molecular systems, taking account of quantum-mechanical vibrations as well as strongly anharmonic motions.

Shiga, Motoyuki; Shinoda, Wataru

2005-10-01

176

Calculation of heat capacities of light and heavy water by path-integral molecular dynamics.  

PubMed

As an application of atomistic simulation methods to heat capacities, path-integral molecular dynamics has been used to calculate the constant-volume heat capacities of light and heavy water in the gas, liquid, and solid phases. While the classical simulation based on conventional molecular dynamics has estimated the heat capacities too high, the quantum simulation based on path-integral molecular dynamics has given reasonable results based on the simple point-charge/flexible potential model. The calculated heat capacities (divided by the Boltzmann constant) in the quantum simulation are 3.1 in the vapor H2O at 300 K, 6.9 in the liquid H2O at 300 K, and 4.1 in the ice Ih H2O at 250 K, respectively, which are comparable to the experimental data of 3.04, 8.9, and 4.1, respectively. The quantum simulation also reproduces the isotope effect. The heat capacity in the liquid D2O has been calculated to be 10% higher than that of H2O, while it is 13% higher in the experiment. The results demonstrate that the path-integral simulation is a promising approach to quantitatively evaluate the heat capacities for molecular systems, taking account of quantum-mechanical vibrations as well as strongly anharmonic motions. PMID:16223309

Shiga, Motoyuki; Shinoda, Wataru

2005-10-01

177

Changes in the water holding capacity of psoriatic stratum corneum in vivo.  

PubMed

This study investigated the functional capacity of the stratum corneum of psoriatic skin to bind water in vivo during a relatively long period of time (water holding capacity--WHC). An electrical capacitance test was applied to the psoriatic skin on the elbows, perilesional skin and apparently normal skin of 11 patients and the elbows of 10 controls. Measurements of electrical capacitance were performed using a Corneometer Schwarzhaupt for 25 min. The WHC levels were calculated for this period. Our results demonstrate that the WHC of psoriatic stratum corneum does not differ from controls in the first 10 min. Only after the 20th min do the WHCs differ significantly (p less than 0.02). Despite the biochemical keratin changes in psoriatic plaque, the latter is highly hygroscopic, in particular in the first minute after bathing. Perilesional skin binds water like the stratum corneum of controls, though not beyond the 20th minute after bathing. PMID:2609866

Borroni, G; Vignati, G; Brazzelli, V; Vignoli, G P; Gabba, P; Gatti, M; Berardesca, E; Cosseta, A; Rabbiosi, G

1989-01-01

178

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

USGS Publications Warehouse

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.

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

1983-01-01

179

Absorption\\/desorption of NO x process on perovskites: impact of SO 2 on the storage capacity of BaSnO 3 and strategy to develop thioresistance  

Microsoft Academic Search

The formation of species when BaSnO3 is exposed to SO2 under a variety of conditions is reported and discussed. Direct contact with 25ppm SO2 during 15 cycles of Lean–Burn operation leads to the complete loss of NOx absorption capacity owing to the formation of stable and irreversible bulk-like sulphates identified by FT-IR (990, 1060, 1125 and 1190cm?1) and TGA–MS. When

S. Hodjati; C. Petit; V. Pitchon; A. Kiennemann

2001-01-01

180

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

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

181

The importance of the ammonia purification process in ammonia–water absorption systems  

Microsoft Academic Search

Practical experience in working with ammonia–water absorption systems shows that the ammonia purification process is a crucial issue in order to obtain an efficient and reliable system. In this paper, the detrimental effects of the residual water content in the vapour refrigerant are described and quantified based on the system design variables that determine the effectiveness of the purification process.

José Fernández-Seara; Jaime Sieres

2006-01-01

182

Methods for analysis of selected metals in water by atomic absorption  

USGS Publications Warehouse

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.

Fishman, Marvin J.; Downs, Sanford C.

1966-01-01

183

Computer simulation and optimization of ammonia-water absorption refrigeration systems  

SciTech Connect

The ammonia-water absorption refrigeration system is attracting increasing research interests, since the system can be powered by waste thermal energy, thus avoiding using ozone-depletion refrigerants and reducing demand on electricity supply. In the article, a mathematical model coupled with detailed equations for thermodynamic properties of an ammonia-water mixture is described. A computer simulation software based on the model is developed. With the software, the performance characteristics of ammonia-water absorption refrigeration systems are analyzed, and detailed optimum operation maps for the systems are presented. These maps can be used as guides in choosing operating conditions for designing such systems or for existing systems.

Sun, D.W. [National Univ. of Ireland, Dublin (Ireland)

1997-08-01

184

Energy Analysis of an Ammonia-Water Absorption Refrigeration System  

Microsoft Academic Search

A simple energy analysis technique for ammonia-water refrigeration systems is presented and verified with actual experimental data taken from the literature. Comparison was made in terms of the coefficient of performance, and very good agreement was found.

IBRAHIM DINCER; SADIK DOST

1996-01-01

185

Intestinal absorption of water-soluble vitamins in health and disease  

PubMed Central

Our knowledge of the mechanisms and regulation of intestinal absorption of water-soluble vitamins under normal physiological conditions, and of the factors/conditions that affect and interfere with theses processes has been significantly expanded in recent years as a result of the availability of a host of valuable molecular/cellular tools. Although structurally and functionally unrelated, the water-soluble vitamins share the feature of being essential for normal cellular functions, growth and development, and that their deficiency leads to a variety of clinical abnormalities that range from anaemia to growth retardation and neurological disorders. Humans cannot synthesize water-soluble vitamins (with the exception of some endogenous synthesis of niacin) and must obtain these micronutrients from exogenous sources. Thus body homoeostasis of these micronutrients depends on their normal absorption in the intestine. Interference with absorption, which occurs in a variety of conditions (e.g. congenital defects in the digestive or absorptive system, intestinal disease/resection, drug interaction and chronic alcohol use), leads to the development of deficiency (and sub-optimal status) and results in clinical abnormalities. It is well established now that intestinal absorption of the water-soluble vitamins ascorbate, biotin, folate, niacin, pantothenic acid, pyridoxine, riboflavin and thiamin is via specific carrier-mediated processes. These processes are regulated by a variety of factors and conditions, and the regulation involves transcriptional and/or post-transcriptional mechanisms. Also well recognized now is the fact that the large intestine possesses specific and efficient uptake systems to absorb a number of water-soluble vitamins that are synthesized by the normal microflora. This source may contribute to total body vitamin nutrition, and especially towards the cellular nutrition and health of the local colonocytes. The present review aims to outline our current understanding of the mechanisms involved in intestinal absorption of water-soluble vitamins, their regulation, the cell biology of the carriers involved and the factors that negatively affect these absorptive events.

Said, Hamid M.

2014-01-01

186

Functional, water-soluble binders for improved capacity and stability of lithium-sulfur batteries  

NASA Astrophysics Data System (ADS)

Binders based on mixtures of poly(ethylene oxide) (PEO) and poly(vinylpyrrolidone) (PVP) are here shown to significantly improve the reversible capacity and capacity retention of lithium- sulfur batteries compared to conventional binders. This mixed binder formulation combines the local improvement to the solvent system offered by PEO and the lithium (poly)sulfide-stabilising effect of PVP. Cells with cathodes made of simple mixtures of sulfur powder and carbon black with a binder of 4:1 PEO:PVP exhibited a reversible capacity of over 1000 mAh g-1 at C/5 after 50 cycles and 800 mAh g-1 at 1C after 200 cycles. Furthermore, these materials are water soluble, environmentally friendly and widely available, making them particularly interesting for large-scale production and applications in, for example, electric vehicles.

Lacey, Matthew J.; Jeschull, Fabian; Edström, Kristina; Brandell, Daniel

2014-10-01

187

Water absorption of poly(methyl methacrylate) containing 4-methacryloxyethyl trimellitic anhydride.  

PubMed

The amount of water absorption of poly(methyl methacrylate) (PMMA) containing 0, 1, 3 and 5 wt% of an adhesive monomer, 4-methacryloxyethyl trimellitic anhydride (4-META), was measured at 7 degrees C, 37 degrees C and 60 degrees C. After the water uptake reached equilibrium in specimens, they were desorbed to obtain a constant value and the absorption process was repeated. Mass changes in the second desorption were recorded for the storage temperatures of 37 degrees C and 60 degrees C. Multiple regression analyses were conducted on three independent variables, 4-META concentration, storage temperature and absorption-desorption cycle. A statistically significant relationship was found between the maximum water uptake and 4-META concentration, while there was no relationship between the maximum water uptake and diffusion coefficient obtained using the Fick's law. The negative relationship in the latter did not support the free space theory. The significant and positive relationship between the maximum water uptake and 4-META concentration demonstrates that water molecules diffuse through the formation of a hydrogen bond at polar sites. The maximum water uptake was not influenced by temperature, while the diffusion coefficient increased with the rise in temperature. The activation energy was 41-47 and 50-53 kJ/mol in the first and second absorption tests, respectively. PMID:12527279

Unemori, Masako; Matsuya, Yoko; Matsuya, Shigeki; Akashi, Akane; Akamine, Akifumi

2003-04-01

188

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

189

Assessment of an ammonia-water type absorption system as a heat pump  

Microsoft Academic Search

Traditionally, the application of an absorption system for use as a heat pump has been the adaptation of an existing cooling unit to function in the heating mode. The thermodynamic behavior of an ammonia-water type absorption system specifically designed to function as an air-to-air heater is discussed. The fluid flow pattern selected attempts to be consistent with actual machines. System

W. F. Rush; S. A. Weil

1976-01-01

190

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

PubMed

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

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

2012-06-13

191

NASA's Contribution to Water Research, Applications and Capacity Building in the America's  

NASA Astrophysics Data System (ADS)

NASA's water research, applications and capacity building activities use satellites and models to contribute to regional water information and solutions for the Americas. Free and open exchange of Earth data observations and products helps engage and improve integrated observation networks and enables national and multi-national regional water cycle research and applications. NASA satellite and modeling products provide a huge volume of valuable data extending back over 50 years across a broad range of spatial (local to global) and temporal (hourly to decadal) scales and include many products that are available in near real time (see earthdata.nasa.gov). In addition, NASA's work in hydrologic predictions are valuable for: 1) short-term and hourly data that is critical for flood and landslide warnings; 2) mid-term predictions of days to weeks useful for reservoir planning and water allocation, and 3) long term seasonal to decadal forecasts helpful for agricultural and irrigation planning, land use planning, and water infrastructure development and planning. To further accomplish these objectives NASA works to actively partner with public and private groups (e.g. federal agencies, universities, NGO's, and industry) in the U.S. and internationally to ensure the broadest use of its satellites and related information and products and to collaborate with regional end users who know the regions and their needs best. Through these data, policy and partnering activities, NASA addresses numerous water issues including water scarcity, the extreme events of drought and floods, and water quality so critical to the Americas. This presentation will outline and describe NASA's water related research, applications and capacity building programs' efforts to address the Americas' critical water challenges. This will specifically include water activities in NASA's programs in Terrestrial Hydrology (e.g., land-atmosphere feedbacks and improved stream flow estimation), Water Resources (e.g., drought, snow-pack and agriculture projects), and Disasters (e.g., flooding and landslides), and Capacity Building (e.g., 'SERVIR' science visualizations and environmental monitoring). The presentation will also demonstrate how NASA is a major contributor to water tasks and activities in GEOSS (Global Earth Observing System of Systems) in the Americas as well as USGEO and the international GEO (Group on Earth Observations) activities and to global environmental change research.

Toll, D. L.; Searby, N. D.; Doorn, B.; Lawford, R. G.; Entin, J. K.; Mohr, K. I.; Lee, C.; NASA International Water Team

2013-05-01

192

The variation in apparent trace metal complexing capacity of natural waters with plating potential using anodic stripping voltammetry  

Microsoft Academic Search

The measurement of the copper complexing capacity of natural waters by anodic stripping voltammeting (ASV) has been shown to be dependent on the plating potential used to measure the concentration of electroactive copper in solution. Results are presented for the complexing capacities and conditional stability constants of 3 Papua New Guinean lake waters at pH 6.0 measured at the plating

J. H. Kyle

1987-01-01

193

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

PubMed Central

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.

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

2014-01-01

194

Effects of thinning intensities on soil infiltration and water storage capacity in a chinese pine-oak mixed forest.  

PubMed

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

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

2014-01-01

195

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

SciTech Connect

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.

Nordlund, D

2012-02-14

196

Development of an Integrating Cavity Absorption Meter to Measure Optical Absorption of Pure Waters and Suspended Particulates.  

National Technical Information Service (NTIS)

The Integrating Cavity Absorption Meter (ICAM) provides an instrument capable of measuring optical absorption independent of scattering effects. The measurement of optical absorption has always been complicated by scattering effects. The most common and p...

R. M. Pope

1990-01-01

197

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

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

198

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

SciTech Connect

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.

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

2011-11-30

199

Heat Capacity of the Silk-Water System Based on Vibrational-Motions of Poly(amino acid)s and Water.  

NASA Astrophysics Data System (ADS)

The experimental heat capacities of B. Mori silk-water system are presented based on measurements by standard differential scanning calorimetry. Effect of plasticizing of silk by molecules of water leads to lowering of Tg of amorphous silk fibroin in the presence of water. The calculated heat capacities of silk fibroin with water were determined based on the vibrational motions of poly(amino acid)s and water, using the Advanced Thermal Analysis System (ATHAS) Data Bank. The heat capacities, Cp, of silk-water were linked to their vibrational spectra based on the group and skeletal vibration contributions. The heat capacity of the solid silk-water system, below Tg, was estimated from a sum of linear combinations of the molar fractions of the vibrational heat capacities of dry silk and glassy water. The vibration heat capacity of dry silk was constructed using a sum of vibrational heat capacity of poly(amino acid)s components. Calculations are compared to experimental data obtained from calorimetric methods, using hermetic and non-hermetic pans. The approach presented allows one to predict the low temperature vibrational heat capacity for the silk-water system down to zero kelvin, and, together with an extension to higher temperatures, above Tg. This can be used as a reference baseline for quantitative thermal analysis of this biomaterial with water.

Pyda, Marek; Hu, Xiao; Cebe, Peggy

2009-03-01

200

Pure sponge-like membranes bearing both high water permeability and high retention capacity  

Microsoft Academic Search

Porous poly(vinylidene fluoride) (PVDF) membranes were prepared using phase inversion method. It was found that three pure sponge-like membranes could be generated using composite additive such as ferrous chloride\\/nano-silica, calcium chloride\\/nano-silica, and ferrous chloride\\/hydroxylamine hydrochloride. The generated sponge-like membranes all bear obviously higher water permeability and higher or little lower retention capacity compared with their counterpart macrovoid membranes, which were

Zhenghui Wang; Jun Ma; Qianliang Liu

2011-01-01

201

Foliar Nitrogen Uptake from Wet Deposition and the Relation with Leaf Wettability and Water Storage Capacity  

Microsoft Academic Search

This study assessed the foliar uptake of 15N-labelled nitrogen (N) originating from wet deposition along with leaf surface conditions, measured by wettability and water\\u000a storage capacity. Foliar 15N uptake was measured on saplings of silver birch, European beech, pedunculate oak and Scots pine and the effect of nitrogen\\u000a form (NH4+ or NO3?), NH4+ to NO3? ratio and leaf phenology on

Sandy Adriaenssens; Jeroen Staelens; Karen Wuyts; An de Schrijver; Shari Van Wittenberghe; Tatiana Wuytack; Fatemeh Kardel; Kris Verheyen; Roeland Samson; Pascal Boeckx

2011-01-01

202

How to choose capacity of storage tank to utilize water on windless days  

SciTech Connect

As wind flow is not constant throughout the month or year and varies from season to season and from time to time in a day, a storage tank (or reservoir) is essential to supplement water to the field on calm days. In this paper the storage capacity required at two places, namely, Veeraval and Jamnagar in Gujarat State is discussed. The first prerequisite to know the suitability of the windmill size at particular place is the diameter of the windmill which should match the monthly required energy for lifting water.

Jugadeesh, A.

1983-12-01

203

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

USGS Publications Warehouse

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.

Huizinga, Richard J.

2014-01-01

204

Aggregating available soil water holding capacity data for crop yield models  

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

205

The Effect of Heat on Structural Characteristics and Water Absorption Behavior of Agave Fibers  

NASA Astrophysics Data System (ADS)

The structural characteristics and water absorptions behavior agave fibers were investigated over a range of temperature by using XRD, IR, TG and gravimetric methods. Three distinct thermal processes were observed during heating the fiber in the temperature range 310-760 K in air, oxygen and nitrogen invariably. The cellulose structures of the fibers were unaffected on heating up to 450 K. The samples showed thermal decomposition processes beyond 500 K. Fibers displayed a two-stage diffusion behavior. The structural parameters and kinetic of water absorption of the fibers at specific temperatures were analyzed.

Saikia, Dip

2008-04-01

206

Research of the water environmental capacity and the sewage control amount in Shaanxi reach of the Weihe River  

Microsoft Academic Search

According to the information of water quality, hydrology data and the discharge points' distribution, this paper chooses COD for main control factor. Based on the 1-D steady- state water quality model, water environmental capacity for Weihe River in Shaanxi is calculated using two methods in dry year, normal-water year and wet year. Results indicate that middle reaches of the Weihe

Ying Wang; Ru-bin Jia

2011-01-01

207

Trend Forecast for the Influence of the Three Gorges Project on the Water Environmental Capacity of Dongting Lake  

Microsoft Academic Search

Based on a series of research works on water environment monitoring and water resources protection in Dongting lake, this paper discusses the strategy of sustainable development about the requirements of water function and protection objectives, and quantitatively analyzes the variation trend of water environmental capacity of major pollutants before and after the running of the three Gorges project. It is

Shijun Yang; Haiying Hu; Zhenchun Hao

2009-01-01

208

Ab initio calculation of the electronic absorption spectrum of liquid water  

NASA Astrophysics Data System (ADS)

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.

Martiniano, Hugo F. M. C.; Galamba, Nuno; Cabral, Benedito J. Costa

2014-04-01

209

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

PubMed

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. PMID:24784291

Martiniano, Hugo F M C; Galamba, Nuno; Cabral, Benedito J Costa

2014-04-28

210

Environmental Impacts on Surface Water and Groundwater for Expanding Urban Water Supply Capacity Using Stone Quarries  

Microsoft Academic Search

Global climate change and its related impacts on water supply are universally recognized. In the past few years, drought impacts affecting big metropolitan water supplies alone have plagued Maryland and the Chesapeake Bay in 2001 through 2002, Lake Mead in Las Vegas in 2000 through 2004, the Peace River and Lake Okeechobee in South Florida in 2006, and Lake Lanier

Xing Fang; Ni-Bin Chang; Ming-Kuo Lee; Lorraine Wolf

211

Near-infrared diode laser absorption diagnostic for temperature and water vapor in a scramjet combustor  

NASA Astrophysics Data System (ADS)

Tunable diode laser absorption measurements of gas temperature and water concentration were made at the exit of a model scramjet combustor fueled on JP-7. Multiplexed, fiber-coupled, near-infrared distributed feedback lasers were used to probe three water vapor absorption features in the 1.34 1.47 ?m spectral region (2v1 and v1+v3 overtone bands). Ratio thermometry was performed using direct-absorption wavelength scans of isolated features at a 4-kHz repetition rate, as well as 2f wavelength modulation scans at a 2-kHz scan rate. Large signal-to-noise ratios demonstrate the ability of the optimally engineered optical hardware to reject beam steering and vibration noise. Successful measurements were made at full combustion conditions for a variety of fuel/air equivalence ratios and at eight vertical positions in the duct to investigate spatial uniformity. The use of three water vapor absorption features allowed for preliminary estimates of temperature distributions along the line of sight. The improved signal quality afforded by 2f measurements, in the case of weak absorption, demonstrates the utility of a scanned wavelength modulation strategy in such situations.

Liu, Jonathan T. C.; Rieker, Gregory B.; Jeffries, Jay B.; Gruber, Mark R.; Carter, Campbell D.; Mathur, Tarun; Hanson, Ronald K.

2005-11-01

212

Near-infrared diode laser absorption diagnostic for temperature and water vapor in a scramjet combustor.  

PubMed

Tunable diode laser absorption measurements of gas temperature and water concentration were made at the exit of a model scramjet combustor fueled on JP-7. Multiplexed, fiber-coupled, near-infrared distributed feedback lasers were used to probe three water vapor absorption features in the 1.34-1.47 microm spectral region (2v1 and vl + v3 overtone bands). Ratio thermometry was performed using direct-absorption wavelength scans of isolated features at a 4-kHz repetition rate, as well as 2f wavelength modulation scans at a 2-kHz scan rate. Large signal-to-noise ratios demonstrate the ability of the optimally engineered optical hardware to reject beam steering and vibration noise. Successful measurements were made at full combustion conditions for a variety of fuel/air equivalence ratios and at eight vertical positions in the duct to investigate spatial uniformity. The use of three water vapor absorption features allowed for preliminary estimates of temperature distributions along the line of sight. The improved signal quality afforded by 2f measurements, in the case of weak absorption, demonstrates the utility of a scanned wavelength modulation strategy in such situations. PMID:16270559

Liu, Jonathan T C; Rieker, Gregory B; Jeffries, Jay B; Gruber, Mark R; Carter, Campbell D; Mathur, Tarun; Hanson, Ronald K

2005-11-01

213

Near-infrared diode laser absorption diagnostic for temperature and water vapor in a scramjet combustor  

SciTech Connect

Tunable diode laser absorption measurements of gas temperature and water concentration were made at the exit of a model scramjet combustor fueled on JP-7. Multiplexed, fiber-coupled, near-infrared distributed feedback lasers were used to probe three water vapor absorption features in the 1.34-1.47 {mu}m spectral region (2v1and v1+ v3overtone bands). Ratio thermometry was performed using direct-absorption wavelength scans of isolated features at a 4-kHz repetition rate, as well as 2f wavelength modulation scans at a 2-kHz scan rate. Large signal-to-noise ratios demonstrate the ability of the optimally engineered optical hardware to reject beam steering and vibration noise. Successful measurements were made at full combustion conditions for a variety of fuel/air equivalence ratios and at eight vertical positions in the duct to investigate spatial uniformity. The use of three water vapor absorption features allowed for preliminary estimates of temperature distributions along the line of sight. The improved signal quality afforded by 2f measurements, in the case of weak absorption, demonstrates the utility of a scanned wavelength modulation strategy in such situations.

Liu, Jonathan T.C.; Rieker, Gregory B.; Jeffries, Jay B.; Gruber, Mark R.; Carter, Campbell D.; Mathur, Tarun; Hanson, Ronald K

2005-11-01

214

Liquid water absorption and scattering effects in DOAS retrievals over oceans  

NASA Astrophysics Data System (ADS)

It is well-known that spectral effects of liquid water are present in absorption (DOAS) measurements above the ocean and insufficiently removed liquid water structures may interfere with trace gas absorptions leading to wrong (sometimes even non-physical) results. Currently available literature cross-sections of liquid water absorption are provided in coarser resolution than hyperspectral DOAS applications require and Vibrational Raman Scattering (VRS) is mostly unconsidered or compensated for using simulated pseudo cross-sections from radiative transfer modelling. During the ship-based TransBrom campaign across the western Pacific in October 2009, MAX-DOAS measurements were performed into very clear natural waters achieving underwater light paths of up to 50 m. From these measurements, the retrieval of a residual (H2Ores) spectrum is presented compensating simultaneously for insufficiencies of the liquid water absorption cross-section and broad-banded VRS structures. Small-banded (Ring) structures caused by VRS were found to be very efficiently compensated for by the intensity offset (straylight) correction included in the DOAS fit. In the MAX-DOAS tropospheric NO2 retrieval, this method was able to compensate entirely for all liquid water effects that decrease the fit quality. This was not achieved using a liquid water cross-section in combination with a simulated VRS spectrum. Typical values of improvement depend on the measurement's contamination with liquid water structures and range from ? 30% for measurements slightly towards the water surface to several percent in small angles above the horizon. Furthermore, the H2Ores spectrum was found to prevent misfits of NO2 slant columns especially for very low NO2 scenarios and thus increase the reliability of the fit. In test fits on OMI satellite data, the H2Ores spectrum was found selectively above ocean surfaces where it leads to fit quality improvements of up to 6-18%.

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

2014-05-01

215

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

NASA Astrophysics Data System (ADS)

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.

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

216

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

217

Water and NaCl absorption by the intestine of the tilapia Sarotherodon mossambicus adapted to fresh water or seawater and the possible role of prolactin and cortisol  

Microsoft Academic Search

Rates of intestinal water, sodium and chloride absorption in tilapia, adapted to fresh water (FW) and seawater (SW), were measured in vitro, using noneverted sacs made from the anterior, middle and posterior intestinal regions. The anterior intestine from SW fish showed considerably less water, sodium and chloride absorption compared with that seen in FW fish. The middle intestine showed either

James R. Mainoya

1982-01-01

218

Absorption removal of sulfur dioxide by falling water droplets in the presence of inert solid particles  

NASA Astrophysics Data System (ADS)

An experimental analysis of the absorption removal of sulfur dioxide by the free falling water droplets containing the inert solid particles is presented. The wheat flour powder is introduced as the inert solid particles. Tests with and without the flour powder in the water droplets are examined. The mass fluxes and mass transfer coefficients of SO 2 for the cases with and without the flour powder are compared to elucidate the effects of the inert solid particles contained in the water droplets on the gas absorption. The results indicate aignificant difference between the two cases for the concentrations of the flour powder in the absorbent droplets ( Cs) within the ranges of the experimental conditions, namely 0.1 to 10 wt% flour powder in the absorbent droplets. In general, the inert solid particles of the flour powder as the impurities in the water droplets tend to decrease the SO 2 absorption rate for the experimental absorption system under investigation. Various values of Cs cause various levels of the interfacial resistance and affect the gas absorption rate. The interfacial resistance is recognized by introducing an interfacial mass transfer coefficient ks with its reciprocal being proportional to the magnitude of the interfacial resistance. The values of 1/ ks may be computed by the use of the equation 1/ ks=(1/ KOLs-1/ KOL), where KOLs and KOL are the overall liquid-phase mass transfer coefficients with and without the inert solid particles, respectively. The values of ks with Cs of 0.1 to 10 wt% are about 0.295-0.032 cms -1 for absorbing 1000-3000 ppmv SO 2 with the water droplets. This kind of information is useful for the SO 2 removal and the information of acid rain that the impurities of the inert solid particles contaminate the water droplets.

Liu, I.-Hung; Chang, Ching-Yuan; Liu, Su-Chin; Chang, I.-Cheng; Shih, Shin-Min

219

Predicting inhomogeneous water absorption in an ionic diblock polymer membrane  

NASA Astrophysics Data System (ADS)

Fuel cells convert fuel directly into electrical power. Their performance depends on a permeable (yet strong) membrane to allow ion conduction (while preventing combustion). Anion-exchange membrane fuel-cells are especially economical to produce, but technological hurdles currently limit durability and OH^- conductivity of the membrane. One solution to these problems is a diblock morphology. Layers of stiff hydrophobic polymer provide structure, while interspersed layers of polyelectrolyte provide avenues for conduction. Previously, little was known about the structure within the conducting layer. We adapted Scheutjens-Fleer polymer-brush theory to a lamellar geometry. The calculation tells where the polyelectrolytes congregate within a lamella, and hence how conduction occurs. This talk focuses on a new diblock material, PMB-PVBTMA. We show how the features of the material determine the intra-lamellar structure. We conclude that at low humidity, the bulkiness of PVBTMA causes it to adopt a near-uniform distribution within the conducting block. At high humidity, however, a phase separation may induce abrupt water channels. Understanding the architecture within the conducting layer will help guide research into better anion-exchange membranes materials.

Herbst, Daniel; Witten, Thomas

2013-03-01

220

The effects of a water environment on anomalous absorption behavior in graphite\\/epoxy composites  

Microsoft Academic Search

The effects of a water environment on moisture (H2O) absorption characteristics of a unidirectional T300\\/934 graphite\\/epoxy composite material have been investigated by the measurement and analysis of weight change, hygrothermal induced expansion, surface crack formation, and surface mass loss. Specimens were immersed in distilled water at 45, 60, 75, and 90 °C for more than 8000 h. Weight-change profiles for

Jiming Zhou; James P. Lucas

1995-01-01

221

Computer Simulation and Optimization of Ammonia-Water Absorption Refrigeration Systems  

Microsoft Academic Search

The ammonia-water absorption refrigeration system is attracting increasing research interests, since the system can be powered by waste thermal energy, thus avoiding using ozone-depletion refrigerants and reducing demand on electricity supply. In the article, a mathematical model coupled with detailed equations for thermodynamic properties of an ammonia-water mixture is described A computer simulation software based on the model is developed.

DA-WEN SUN

1997-01-01

222

AMMONIA-WATER ABSORPTION CYCLE FOR TRANSPORTATION OF LOW GRADE THERMAL ENERGY OVER LONG DISTANCE  

Microsoft Academic Search

This paper presents the thermodynamic and hydrodynamic feasibility of the application of the ammonia-water absorption system for transportation of low-grade thermal energy over long distance. A model is built and analyzed, and it shows satisfactory and attractive results. When a steam heat source at the temperature of 1200C is available, the user site can get hot water output at about

Qiang MA; Lingai LUO; Ruzhu WANG

223

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

Microsoft Academic Search

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

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

2004-01-01

224

Performance analysis and evaluation of a commercial absorption–refrigeration water–ammonia (ARWA) system  

Microsoft Academic Search

The Robur absorption–refrigeration water–ammonia (ARWA) system is analyzed using Aspen Plus flowsheet simulator. The results are compared with experimental and some manufacturer data reported in the open literature. Among performance parameters analyzed are coefficient of performance (COP), heat duties of the evaporator, absorber, and the condenser, refrigerant concentration in the weak and strong solution, and flow rates of the weak

N. A. Darwish; S. H. Al-Hashimi; A. S. Al-Mansoori

2008-01-01

225

Effect of water vapor absorption on integrating sphere output radiance and consequences for instrument calibration  

Microsoft Academic Search

Multiple photon scatterings inside an integrating sphere can result in significant path lengths compared with line-of- sight sources. In strong water vapor absorption channels, such as those on MODIS and the MODIS airborne simulator, these internal path lengths can result in a significant reduction in sphere output radiance. Path length probability distributions for photons exiting a sphere are determined using

Steven E. Platnick; Peter Abel; Michael D. King

1996-01-01

226

Radiation modification of water absorption of cassava starch by acrylic acid/acrylamide  

NASA Astrophysics Data System (ADS)

Graft copolymerizations of acrylamide and/or acrylic acid onto cassava starch by a simultaneous irradiation technique using gamma-rays as the initiator were studied with regard to various parameters of importance: the monomer-to-cassava starch ratio, total dose (kGy), dose rate (kGy h -1), acrylamide-to-acrylic acid ratio, and the addition of nitric acid and maleic acid as the additives. Grafting parameters were determined in relation to the water absorption of the saponified graft copolymer. The water absorption of the saponified graft copolymer in salt and buffer solutions of different ionic strengths was also measured, from which the superabsorbent properties are found to be pH sensitive. The starch graft copolymers of acrylamide and acrylic acid give higher water absorption than the starch graft copolymers of either acrylamide or acrylic acid alone. The porosity of the saponified starch graft copolymers prepared by the acrylamide/acrylic acid ratios of 70:30 and 50:50 was much higher than the porosity of copolymers in terms of fine networks. Ionic strength and multi-oxidation states of the saline and buffer solutions markedly decreased the water absorption of the saponified cassava starch grafted superabsorbent polymers.

Kiatkamjornwong, Suda; Chomsaksakul, Wararuk; Sonsuk, Manit

2000-10-01

227

Finite time thermodynamics study and exergetic analysis of ammonia–water absorption systems  

Microsoft Academic Search

This paper presents an optimization study of a single stage absorption machine operating with an ammonia–water mixture under steady state conditions. The power in the evaporator, the temperatures of the external fluids entering the four external heat exchangers as well as the effectiveness of these heat exchangers and the efficiency of the pump are assumed fixed. The results include the

Brice Le Lostec; Jocelyn Millette; Nicolas Galanis

2010-01-01

228

Water absorption and structural morphology in VC:VAc copolymer and VC:VAc:VA terpolymer  

Microsoft Academic Search

Water absorption in organic polymers is of considerable practical importance because it increases the electrical conductivity and power factor of the material and results in an enhancement of the electrochemical deterioration [1]. The structural morphology of polyvinyl chloride [2, 3] shows that there is a structural change in the growth of PVC films prepared in different solvents under different conditions.

V. S. Panwar; Ramadhar Singh; G. L. Malhotra; S. K. Sharma; P. C. Mehendru; N. P. Gupta

1988-01-01

229

Simulation of solar lithium bromide–water absorption cooling system with parabolic trough collector  

Microsoft Academic Search

Ahwaz is one of the sweltering cities in Iran where an enormous amount of energy is being consumed to cool residential places in a year. The aim of this research is to simulate a solar single effect lithium bromide–water absorption cooling system in Ahwaz. The solar energy is absorbed by a horizontal N–S parabolic trough collector and stored in an

M. Mazloumi; M. Naghashzadegan; K. Javaherdeh

2008-01-01

230

Simultaneous optimization of linear firing shrinkage and water absorption of triaxial ceramic bodies using experiments design  

Microsoft Academic Search

In the development and manufacture stages of floor and wall ceramic tiles, firing shrinkage and water absorption are basically determined by the combination of raw materials and frequently used as quality control parameters. This configures the ideal scenario to apply the techniques of experiments design, often used in various other areas, to model those properties of such ceramics bodies. In

S. L Correia; D Hotza; A. M Segadães

2004-01-01

231

Design and construction of a LiBr–water absorption machine  

Microsoft Academic Search

The objective of this paper is to present a method to evaluate the characteristics and performance of a single stage lithium bromide (LiBr)–water absorption machine. The necessary heat and mass transfer equations and appropriate equations describing the properties of the working fluids are specified. These equations are employed in a computer program, and a sensitivity analysis is performed. The difference

G. A. Florides; S. A. Kalogirou; S. A. Tassou; L. C. Wrobel

2003-01-01

232

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...

233

Relation of Water Absorption to Duration of Application in Furrow Irrigation.  

National Technical Information Service (NTIS)

This study sought to relate the rate of absorption and depth of penetration of water for several durations of application and soil types with a constant head supply. The study utilized moveable, metal panels that were formed into a bottomless container 1....

J. C. McWhorter

1978-01-01

234

Electromagnetic energy absorption potential and microwave heating capacity of SiC thin films in the 1-16 GHz frequency range  

NASA Astrophysics Data System (ADS)

We report on the electromagnetic (EM) absorption potential and microwave heating capacity of amorphous hydrogenated silicon carbide thin films (a-SiC:H) in the 1-16 GHz frequency domain. a-SiC:H thin films with typical thickness of 1 ?m were deposited by plasma enhanced chemical vapor deposition on [1 0 0] undoped silicon substrates, and exhibit a deep EM absorption - up to 96% of the total EM energy irradiation - which is systematically converted into heat. Two-wavelength pyrometer tests show that temperatures exceeding 2000 K can be reached in a very short time, less than 100 s exposure to microwaves, showing a promising potential for specific microwave heating applications.

Aïssa, B.; Tabet, N.; Nedil, M.; Therriault, D.; Rosei, F.; Nechache, R.

2012-05-01

235

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

PubMed

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

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

2014-11-01

236

In vivo hydration and water-retention capacity of stratum corneum in clinically uninvolved skin in atopic and psoriatic patients.  

PubMed

Hydration and the water-retention capacity of stratum corneum have been investigated in uninvolved psoriatic and atopic skin and compared with that of healthy controls. Thirty-three subjects of either sex and matched for age entered the study. The subjects were free from all signs of skin disease and skin dryness. Hydration was evaluated by means of transepidermal water loss and skin capacitance measurements. Water-retention capacity was investigated using the plastic occlusion stress test. Atopic skin differed significantly from uninvolved psoriatic and control skin which had a reduced water content and an increased transepidermal water loss. Furthermore, the skin surface water loss profile representing the stratum corneum water-retention capacity was significantly lower in normal atopic skin. The data suggest that clinically normal skin may be functionally abnormal, resulting in a defective barrier that could lead to higher risk of irritant or contact dermatitis. PMID:1980973

Berardesca, E; Fideli, D; Borroni, G; Rabbiosi, G; Maibach, H

1990-01-01

237

Functional evaluation of the field capacity concept for water balance analysis under climatic seasonality conditions  

NASA Astrophysics Data System (ADS)

Some types of hydrologic models, such as the bucket model, rely on the concept of field water capacity, ?FWC. In this study, the techniques traditionally proposed for determining this parameter have been critically analyzed in terms of their effectiveness in computing soil water budget. Two basic aspects of the problem will be presented: (i) to set up techniques for a suitable parameterization of hydrologic models, (ii) to implement simulation models that describe the various processes with different levels of complexity and compare their results. The following models are considered: the Richards equation based model and the simplified bucket-type model. Soil water content at the condition of field capacity has been determined for both uniform and layered soil profiles by using the numerical model developed by Romano et al. (1998) and verified by Brunone et al. (2003). This model solves the Richards equation with the Crank-Nicolson finite difference technique and uses a numerical algorithm specifically designed in case of layered soils for calculating the hydraulic conductivity at the layer interface. For layered soil profiles, which actually represent the rule rather than an exception, soil layer sequence and the reciprocal differences in the soil hydraulic properties (soil water retention and hydraulic conductivity functions) strongly influence the attainment of the field capacity condition. Simulations of soil water balance using the Richards-based model or the bucket-type model have been compared. It is shown that climatic seasonality typical of the Mediterranean environments exerts some influence on the dynamics of surficial water contents in soil and this influence can be kept only in part by the bucket model if not parameterized adequately. Rainfall variability during the vegetative season and that one evolving during the quiescent phase is responsible for different transpiration conditions and for evolutions of the water content in the soil characterized by specific trends. During the vegetative season, major controlling factors are the transpiration trend with respect to rainfall which assumes low values. During the quiescent season, on the other hand, the main controlling factor is rainfall trend.

Ceres, Francesca; Battista Chirico, Giovanni; Romano, Nunzio

2010-05-01

238

Responses to water stress of apoplastic water fraction and bulk modulus of elasticity in sunflower ( Helianthus annuus L.) genotypes of contrasting capacity for osmotic adjustment  

Microsoft Academic Search

The responses to water stress of the bulk modulus of elasticity (?) and the apoplastic water fraction were examined using six sunflower cultivars of differing capacity for osmotic adjustment (OA). Water stress did not affect the partitioning of water between apoplastic (ca. 20%) and symplastic fractions in leaves which expanded during the exposure to stress in any genotype. Hence, no

C. A. Chimenti; A. J. Hall

1994-01-01

239

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

NASA Astrophysics Data System (ADS)

Two measuring methods of wide absorption spectrum by DFB-LDs are presented in detecting water vapor absorption line. One is subsection scanning method, it takes advantage of wide spectrum tuning range by 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 corresponding to specific temperature of DFB-LD, and scanning every section by current modulation for hundreds times and average the data to raise SNR, 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 absorption line-shape function, the absorption line can be described by fitting with partial measured data. The fitting absorption line is fitted well with the measured data, and the square of correlation coefficient (R-square) is no less than 0.99.

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.

2013-09-01

240

Heat and Mass Diffusions in the Absorption of Water Vapor by Aqueous Solution of Lithium Bromide  

NASA Astrophysics Data System (ADS)

The recent development of absorption-type heat pump is highly essential from the viewpoint of extracting the effective energy from waste heat or solar energy. To increase the efficiency of energy conversion, it is important to improve the performance of absorbers. The objective of this paper is to obtain an increased understanding of the fine mechanisms of vapor absorption. A system combining holographic interferometry wity thermometry is adopted to observe the progress of one-dimensional water vapor absorption by aqueous solution of lithium bromide (LiBr) and also to measure the unsteady temperature and concentration distributions in the absorption process. The experiments are carried out under the condition that the solution surface is exposed to the saturated water vapor at reduced pressure, and the effects of LiBr mass concentration on absorption mechanism are examined in the concentration range 20-60 mass%. The interference fringes are analyzed to distinguish between the layers of heat conduction and mass diffusion. The temperature and concentration distributions thus determined experimentally are compared with numerical solutions obtained by the equations for unsteady heat conduction and mass diffusion taking into consideration the effect of heat by dilution, to give reasonable values of mass diffusivity hitherto remaining unknown. Especially in the range of 40-60 mass%, the mass diffusivity decreases extremely with the increase of mass concentration of LiBr and it falls down to 0.7-0.8×10-9 m2/s in case of 60 mass% solution.

Kashiwagi, Takao; Kurosaki, Yasuo; Nikai, Isao

241

The impact of water flow configuration on crystallisation in LiBr/H2O absorption water heater  

SciTech Connect

Lithium Bromide (LiBr) strong solution entering the absorber tends to crystallise when the absorber temperature is increased for a fixed evaporating pressure. This is considered the key technical barrier for the development of a LiBr absorption heat pump water heater. There are several approaches to avoid the crystallisation problem, such as chemical crystallisation inhibitors, heat and mass transfer enhancement and thermodynamic cycle modification. This paper investigates and compares two flow configurations of LiBr absorption heat pump water heater to evaluate the allowable operating conditions for each. The simulation results indicated that introducing the process water through the absorber first results in lower absorber temperature and hence less tendency for crystallisation.

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

2011-03-01

242

Core Knowledge Employee Creativity and Firm Performance: The Moderating Role of Riskiness Orientation, Firm Size, and Realized Absorptive Capacity  

ERIC Educational Resources Information Center

In this study, we examine when creativity is positively or negatively related to firm performance. Building on the creation-implementation tension theorized in the literature and the attention capacity perspective, we argue that the relationship between creativity and firm performance is contingent on riskiness orientation, firm size, and realized…

Gong, Yaping; Zhou, Jing; Chang, Song

2013-01-01

243

Trait correlated expression combined with expression QTL analysis reveals biological pathways and candidate genes affecting water holding capacity of muscle  

Microsoft Academic Search

BACKGROUND: Leakage of water and ions and soluble proteins from muscle cells occurs during prolonged exercise due to ischemia causing muscle damage. Also post mortem anoxia during conversion of muscle to meat is marked by loss of water and soluble components from the muscle cell. There is considerable variation in the water holding capacity of meat affecting economy of meat

Siriluck Ponsuksili; Elisabeth Jonas; Eduard Murani; Chirawath Phatsara; Tiranun Srikanchai; Christina Walz; Manfred Schwerin; Karl Schellander; Klaus Wimmers

2008-01-01

244

Assessing effects of aerobic and anaerobic conditions on phosphorus sorption and retention capacity of water treatment residuals  

Microsoft Academic Search

Water treatment residuals (WTRs) are the by-products of drinking water clarification processes, whereby chemical flocculants such as alum or ferric chloride are added to raw water to remove suspended clay particles, organic matter and other materials and impurities. Previous studies have identified a strong phosphorus (P) fixing capacity of WTRs which has led to experimentation with their use as P-sorbing

Ian W. Oliver; Cameron D. Grant; Robert S. Murray

2011-01-01

245

Water Quality Evaluation of Songhua River and Water Environment Capacity Calculation in Harbin  

Microsoft Academic Search

On basis of monitoring data from 2001 to 2005 of Songhua River's dry season in Harbin by Harbin Environmental Protection Administration, this paper applicated Radial Basis Function Neural Network (RBFNN) model based on Hybrid Hierarchy Genetic Algorithm (HHGA)and taked water quality evalucation of six monitoring sections: Zhushun tun, Ashe internal estuary, lower Ashe estuary, Hulan internal estuary, lower Hulan estuary

Sun Nan; Ma Lixin; Fu Qiang

2009-01-01

246

Capacity of stem water conductivity for two eucalyptus ( Eucalyptus urophylla ) plantations in South China  

Microsoft Academic Search

The sap flux density (SFD) was used as a measure of water capacity through stems of eucalyptus in this paper. It was found that daily SFD increased with daily vapor pressure deficit (VPD) in nonlinear regression Y=AX\\u000a 3+BX\\u000a 2+CX+D (R\\u000a 2=0.702 1, n=135, p=0.01) at both sites (Hetou and Jijia) in the Leizhou Peninsula, Guangdong Province, China, where Y was

Guangcai Yin; Guoyi Zhou; Morris Jim; Xu Wang; Zhihong Huang; Guowei Chu

2004-01-01

247

Control of water absorption and its effect on interlaminar shear strength of CFRC with Al 2O 3 dispersion  

Microsoft Academic Search

In this study the effect of water absorption on interlaminar shear strength (ILSS) of carbon fiber reinforced epoxy composites (CFRC) and micro or nano sized Al2O3 particle dispersed carbon fiber hybrid reinforced composites (CFHRC) was investigated. Different weight change profiles were observed depending on experimental temperature and water absorption time. A clear drop of interlaminar shear strength was confirmed due

Manwar Hussain; Koichi Niihara

1999-01-01

248

Measurement methods in trace water vapor concentration detection system based on direct absorption spectroscopy  

NASA Astrophysics Data System (ADS)

In trace water vapor direct absorption spectroscopy, the absorption signal is buried in noise and up and downs of the light intensity, an effective signal extraction method is vital. In the basis of double-beam differential absorption, division method in voltage and an approach based on balanced ratiometer detection (BRD) were studied. Voltage division has an excellent stability to temperature variation, mechanical extrusion and fiber bend loss. As to the BRD method, it has an outstanding self-adjusting capability and it can also avoid an excess phase difference caused by current-to-voltage converting circuit, thus this method has a high sensitivity. Furthermore, a so called dual-peak method based on the differential value of two adjacent absorption lines is introduced, the differential value proved has a linear relation with water vapor concentration, and this method provides a way to measure the concentration at high pressure. In addition, the influence of water vapor inside the optical components has been discussed.

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

2013-09-01

249

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

PubMed Central

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

Ammon, Helmut V.; Phillips, Sidney F.

1974-01-01

250

Cloud point extraction of aluminum (III) in water samples and determination by electrothermal atomic absorption spectrometry, flame atomic absorption spectrometry and UV-visible spectrophotometry  

Microsoft Academic Search

Cloud point extraction was applied as a preconcentration step for the determination of trace level of Al(III) in water samples with electrothermal atomic absorption spectrometry (ETAAS), flame atomic absorption spectrometry (FAAS) and UV-visible spectrophotometry. The aluminum was extracted as aluminum-Eriochrome Cyanine R (ECR) complex, at pH 6 by micelles of the non-ionic surfactant octylphenoxypolyethoxyethanol (Triton X-114). The investigations showed that

Nuray ?at?ro?lu; ?lknur Tokgöz

2010-01-01

251

Diesel driven low capacity heat pump for heating and hot water production  

NASA Astrophysics Data System (ADS)

Heat pumps that reduce primary energy consumption for heating needs when they are driven by an internal combustion motor were studied. The heat produced as well from the heat pump as from the combustion in the diesel motor was used for home heating and hot water preparation. The objective was a 25kW capacity for a one familiy house. Material used should be standard, so a special design diesel motor or heat pump was not considered. An air/water cooled type diesel motor was coupled to a 12kW capacity heat pump for an outdoor temperature of 3 C using R12 freon as refrigerant. Description of all elements is given. Tests were in the laboratory and in a one family house. The expected efficiency factor of 1.34 could not be confirmed and an average annual value of only 1.05 is assumed. The diesel driven heat pump can not produce the energy savings hoped for.

Hoefler, P.

1982-08-01

252

The effect of tannic acid and polyethylene glycol on the absorption capacity of chicken intestine for d-xylose and ?-carotene.  

PubMed

In an experiment, the possible influence of tannic acid (TA) and polyethylene glycol (PEG) on the absorption capacity of intestine for d-xylose and ?-carotene in broiler chicken was investigated. Four groups of nine 28-day-old broiler cockerels received d-xylose (500 mg) and ?-carotene (52 ?g) solutions (Group 1 to 4) with TA (1 g, Group 2 to 4) and PEG (500 mg Group 3 and 1 g Group 4), orally. One blood sample prior to, and four others after the administration of test materials, were collected from wing vein on 40 min basis, for 160 min and the concentration of plasma d-xylose was determined. The concentration of ?-carotene was also measured in plasma of blood samples taken prior to and 160 min post-administration of the test materials. Plasma d-xylose concentration of all groups showed quadratic correlations with time (p < 0.001, r(2) = 0.84, 0.60, 0.70 and 0.74 for Group 1 to 4, respectively). Administration of TA reduced the plasma concentration of d-xylose in Group 2. However, feeding PEG after TA raised the concentration of d-xylose in Group 4 to the level that there was no difference in that variable between this group and Group 1. Although the plasma concentration of ?-carotene was increased in 160 min post-ingestion of the test material, no difference was found in that variable among the experimental groups. In conclusion, TA and its interaction with PEG have impacts on the absorption capacity of intestine for d-xylose and highly likely other simple sugars, but TA or PEG have no influence on the absorption of ?-carotene and most probably other fat soluble vitamins. PMID:21244522

Mansoori, B; Modirsanei, M

2012-02-01

253

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

NASA Astrophysics Data System (ADS)

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.

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

2014-06-01

254

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

SciTech Connect

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.

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

1995-05-01

255

Water solubilization capacity and mean emulsion size of phospholipid-based isooctane-alcohol W\\/O microemulsion  

Microsoft Academic Search

The water solubilization capacity and mean droplet size of water in oil (W\\/O) microemulsion formed by phospholipids was investigated to understand the role of water content and additive alcohol as a co-solvent. Isooctane (C8*) was employed as the main solvent. The solubilized water content in the W\\/O microemulsion H2Osoln [mol] was strictly defined in order to compare it with the

Keiju Yamazaki; Masanao Imai; Isao Suzuki

2007-01-01

256

Surface relaxation in liquid water and methanol studied by x-ray absorption spectroscopy  

NASA Astrophysics Data System (ADS)

X-ray absorption spectroscopy is a powerful probe of local electronic structure in disordered media. By employing extended x-ray absorption fine structure spectroscopy of liquid microjets, the intermolecular O-O distance has been observed to undergo a 5.9% expansion at the liquid water interface, in contrast to liquid methanol for which there is a 4.6% surface contraction. Despite the similar properties of liquid water and methanol (e.g., abnormal heats of vaporization, boiling points, dipole moments, etc.), this result implies dramatic differences in the surface hydrogen bond structure, which is evidenced by the difference in surface tension of these liquids. This result is consistent with surface vibrational spectroscopy, which indicates both stronger hydrogen bonding and polar ordering at the methanol surface as a consequence of "hydrophobic packing" of the methyl group.

Wilson, Kevin R.; Schaller, R. D.; Co, D. T.; Saykally, R. J.; Rude, Bruce S.; Catalano, T.; Bozek, J. D.

2002-10-01

257

Temperature imaging of water in a microchannel using thermal sensitivity of near-infrared absorption.  

PubMed

This paper presents a remote and preparation-free method of temperature imaging of aqueous solutions in microchannels of microfluidic chips. The principle of this method is based on the temperature dependency of the near-infrared (NIR) absorption band (?(2) + ?(3) band) of water. Temperature images were constructed from absorbances in a narrow wavelength range including 1908 nm, the most sensitive to temperature in the band, measured by using an NIR camera and an optical narrow-bandpass filter. Calculation and calibration results demonstrated a linear relationship between the absorption coefficient and temperature with a temperature coefficient of 1.5 × 10(-2) K(-1) mm(-1). Temperature images of 50 ?m thick water in a Y-shaped PDMS microchannel locally heated by a neighboring hot wire were obtained, in which thermal diffusion processes in the microchip were visualized. Temperature resolution was estimated to be approximately 0.2 K according to the temperature coefficient and noise level. PMID:21869986

Kakuta, Naoto; Fukuhara, Yuko; Kondo, Katsuya; Arimoto, Hidenobu; Yamada, Yukio

2011-10-21

258

Tunable diode laser absorption technique for detection of water vapor in aerodynamic flows  

NASA Astrophysics Data System (ADS)

A tunable diode laser diagnostic based on spectrally resolved laser absorption has been developed to detect water vapor. The system uses a distributed feedback InGaAsP diode laser, emitting around 1.38 mm. The diode laser is tuned in wavelength by modulating the current, resulting in 1.3/cm tuning at 80 Hz repetition rate. Temperature and concentrations are inferred from the directly measured absorption spectra. The technique has been demonstrated, at low and high temperatures, to detect the water vapor present in laboratory room air and in the postflame gases above a methane-air flat flame burner. The results agree well with calculated values and independent measurements.

Arroyo, M. P.; Hanson, R. K.

1992-01-01

259

Measurement of Rn-222 in water by absorption in polycarbonates and liquid scintillation counting  

NASA Astrophysics Data System (ADS)

This work presents a new technique for measurement of activity concentrations of Rn-222 in water which is based on liquid scintillation counting (LSC) of polycarbonates exposed in the water. The polycarbonate material has high absorption ability to radon and when exposed in a radon-containing environment (air or water), it absorbs and concentrates radon in its volume. This property of the polycarbonate material is used for sampling 222Rn from the water. The main new element in this work is that it proposes the LSC technique for measurement of the radiation, emitted from the polycarbonate material. This radiation is due to the decay of the absorbed 222Rn and its progeny. Experimental results of LSC of polycarbonate granules and thin foils exposed in water with different activity concentrations of Rn-222 are presented. In all cases a very good linear correlation between the LS counting rate and the activity concentration of the water is found. The LSC of polycarbonates shows similar or even higher sensitivity in comparison to that of LSC of water. The estimated radon-in-water minimal detectable activity concentrations of the proposed method are similar or lower than those of the LSC and lower than those obtained by gamma spectrometry. The proposed method is simple, robust, inexpensive and avoids the need of taking water samples for laboratory analysis. It facilitates studies of the spatial distribution of 222Rn in water basins by exposure of polycarbonate specimens at different spots or depths and subsequent liquid scintillation counting.

Mitev, K.; Dimitrova, I.; Zhivkova, V.; Georgiev, S.; Gerganov, G.; Pressyanov, D.; Boshkova, T.

2012-06-01

260

Water-absorptivity and mechanical behaviors of PTFE\\/PA6 and PTFE\\/PA66 blends  

Microsoft Academic Search

The effects of polytetrafluoroethylene (PTFE) content on water-absorptivity, tensile strength, fiexural strength, and notched impact strength of polytctrafiuoroethylene\\/polyamide 6 (PTFE\\/PA6) and polytetrafluoroethylene\\/polyamide 66 (PTFE\\/PA66) blends were investigated by water immersion test, uniaxial tensile test, three-point test, and Charpy impact fracture test. The water-absorptivity in the blend decreases with increasing PTFE content, which indicates that the PTFE phase restrains the polyamide

Rong-guo ZHAO; Wen-bo LUO; Hua-ming XIAO; Guo-zhong WU

2006-01-01

261

X-Ray Absorption Signatures of the Molecular Environment in Water and Ice  

Microsoft Academic Search

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 effects of temperature change in the liquid, are reproduced from 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

Wei Chen; Xifan Wu; Roberto Car

2010-01-01

262

[Water absorption and resistance to wear of 2 newly invented composite resins].  

PubMed

Two recently built composites, one for posterior teeth, and the other for general employ, were evaluated in relation to their water absorption and resistance to wear by means of the "scratch test". Critical loads and attrition of the two materials were also evaluated, with statistical analysis. The results supported the good qualities of the two composites, which are to be considered very advanced in the field of esthetic reconstruction materials. PMID:2529421

Beltrame, A; Passi, P; Guzman, L; Miotti, F; Casale, C

1989-07-01

263

Ammonia-water absorption machines for refrigeration: theoretical and real performances  

Microsoft Academic Search

In principle, absorption chillers of the ammonia-water type could work at temperatures well below the usual air-conditioning temperatures, arriving at the range 250–260 K, which can be useful for refrigeration applications. This possibility is studied for an air-cooled machine, comparing the results with the experimental data supplied by a manufacturer that recently commercialized such a refrigerator. The prediction is fair,

G. A Longo

1996-01-01

264

Transportation of low-grade thermal energy over long distance by ammonia-water absorption  

Microsoft Academic Search

This paper presents the importance and the cycle choice for long-distance transportation of low-grade thermal energy, and\\u000a the thermodynamic and hydrodynamic feasibility of single-effect ammonia-water absorption system for heat or cold transportation\\u000a over long distance are also involved. A model of a long-distance thermal energy transportation system is built and analyzed,\\u000a which shows satisfactory and attractive results. When a steam

Qiang Ma; RuZhu Wang; LinGai Luo; ZaiZhong Xia; Peng Lin

2009-01-01

265

Investigation of the impact of water absorption on retinal OCT imaging in the 1060 nm range  

PubMed Central

Recently, the wavelength range around 1060 nm has become attractive for retinal imaging with optical coherence tomography (OCT), promising deep penetration into the retina and the choroid. The adjacent water absorption bands limit the useful bandwidth of broadband light sources, but until now, the actual limitation has not been quantified in detail. We have numerically investigated the impact of water absorption on the axial resolution and signal amplitude for a wide range of light source bandwidths and center wavelengths. Furthermore, we have calculated the sensitivity penalty for maintaining the optimal resolution by spectral shaping. As our results show, with currently available semiconductor-based light sources with up to 100–120 nm bandwidth centered close to 1060 nm, the resolution degradation caused by the water absorption spectrum is smaller than 10%, and it can be compensated by spectral shaping with negligible sensitivity penalty. With increasing bandwidth, the resolution degradation and signal attenuation become stronger, and the optimal operating point shifts towards shorter wavelengths. These relationships are important to take into account for the development of new broadband light sources for OCT.

Marschall, Sebastian; Pedersen, Christian; Andersen, Peter E.

2012-01-01

266

Aging of Toughened Polylactic Acid Nanocomposites: Water Absorption, Hygrothermal Degradation and Soil Burial Analysis  

Microsoft Academic Search

The environmental aging behaviour of montmorillonite (MMT) filled polylactic acid (PLA) nanocomposites (PLA\\/MMT) and linear\\u000a low density polyethylene (LLDPE)-toughened PLA (PLA\\/LLDPE ratio = 90\\/10) nanocomposites (PLA\\/LLDPE\\/MMT) were investigated\\u000a in this study. The nanocomposites were subjected to water absorption, hygrothermal degradation and soil burial analysis. Both\\u000a PLA\\/MMT and PLA\\/LLDPE\\/MMT nanocomposites were immersed in distilled water at three different temperatures (room temperature,\\u000a 60, and

Harintharavimal Balakrishnan; Azman Hassan; Muhammad Imran; Mat Uzir Wahit

267

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

USGS Publications Warehouse

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.

Fishman, M.

1977-01-01

268

Heat Capacity Anomaly Near the Lower Critical Consolute Point of Triethylamine-Water  

NASA Technical Reports Server (NTRS)

The heat capacity of the binary liquid mixture triethylamine-water has been measured near its lower critical consolute point using a scanning, adiabatic calorimeter. Two data runs are analyzed to provide heat capacity and enthalpy data that are fitted by equations with background terms and a critical term that includes correction to scaling. The critical exponent a was determined to be 0.107 +/- 0.006, consistent with theoretical predictions. When alpha was fixed at 0.11 to determine various amplitudes consistently, our values of A(+) and A(-) agreed with a previous heat capacity measurement, but the value of A(-) was inconsistent with values determined by density or refractive index measurements. While our value for the amplitude ratio A(+)/ A(-) = 0.56 +/- 0.02 was consistent with other recent experimental determinations in binary liquid mixtures, it was slightly larger than either theoretical predictions or recent experimental values in liquid-vapor systems. The correction to scaling amplitude ratio D(+)/D(-) = 0.5 +/- 0.1 was half of that predicted. As a result of several more precise theoretical calculations and experimental determinations, the two-scale-factor universality ratio X, which we found to be 0.019 +/- 0.003, now is consistent among experiments and theories. A new 'universal' amplitude ratio R(sup +/-)(sub Bcr) involving the amplitudes for the specific heat was tested. Our determination of R(sup +/-)(sub Bcr) = -0.5 +/- 0.1 and R(sup -)(sub Bcr) = 1.1 +/- 0.1 is smaller in magnitude than predicted and is the first such determination in a binary fluid mixture.

Flewelling, Anne C.; DeFonseka, Rohan J.; Khaleeli, Nikfar; Partee, J.; Jacobs, D. T.

1996-01-01

269

Ammonium nutrition increases water absorption in rice seedlings ( Oryza sativa L.) under water stress  

Microsoft Academic Search

Water stress is a primary limitation on plant growth. In previous studies, it has been found that ammonium enhances the tolerance\\u000a of rice plants to water stress, but how water is related to nitrogen form and water stress remains unknown. To study the effects\\u000a of nitrogen form (NH4+, NO3?, and a mixture of NH4+ and NO3?) on the growth and

Yingxu Gao; Yong Li; Xiuxia Yang; Haijun Li; Qirong Shen; Shiwei Guo

2010-01-01

270

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

PubMed

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

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

2012-06-01

271

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

PubMed Central

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.

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

2012-01-01

272

Effect of carboxymethylation conditions on the water-binding capacity of chitosan-based superabsorbents.  

PubMed

A superabsorbent polymer (SAP) from chitosan was provided via carboxymethylation of chitosan, followed by cross-linking with glutaraldehyde and freeze-drying. This work was focused on an investigation of the effects of monochloroacetic acid (MCAA), sodium hydroxide, and reaction time on preparation of carboxymethyl chitosan (CMCS). The CMCS products were characterized using FTIR spectroscopy, and their degrees of substitution (DS) were measured using conductimetry and FTIR analysis. The highest DS value was obtained when the carboxymethylation reaction was carried out using 1.75g MCAA and 1.75g NaOH per g of chitosan in 4h. The water solubilities of the CMCS products at various pHs were also evaluated, and the results indicated a significant impact of the reaction parameters on the solubility of CMCS. The CMCSs with the highest DS value resulted in SAPs having the highest water-binding capacity (WBC). The WBC of the best SAP measured after 10min exposure in distilled water, 0.9% NaCl solution, synthetic urine, and artificial blood was 104, 33, 30, and 57g/g, respectively. The WBC of this SAP at pH 2-9 passed a maximum at pH 6. PMID:20971451

Bidgoli, Hosein; Zamani, Akram; Taherzadeh, Mohammad J

2010-12-10

273

In vitro percutaneous absorption of cadmium from water and soil into human skin  

SciTech Connect

The objective was to determine percutaneous absorption of cadmium as the chloride salt from water and soil into and through human skin. Soil (Yolo County 65-California-57-8) was passed through 10-, 20-, and 48-mesh sieves. Soil retained by 80 mesh was mixed with radioactive cadmium-109 at 13 ppb. Water solutions of cadmium-109 at 116 ppb were prepared for comparative analysis. Human cadaver skin was dermatomed to 500-microns, and used in glass diffusion cells with human plasma as the receptor fluid (3 ml/hr flow rate) for a 16-hr skin application time. Cadmium in water (5 microliters/cm2) penetrated skin to concentrations of 8.8 +/- 0.6 and 12.7 +/- 11.7% of the applied dose from two human skin sources. Percentage doses absorbed into plasma were 0.5 +/- 0.2 and 0.6 +/- 0.6%, respectively. Cadmium from soil (0.04 g soil/cm2) penetrated skin at concentrations of 0.06 +/- 0.02 and 0.13 +/- 0.05% for the two human skin sources. Amounts absorbed into plasma were 0.01 +/- 0.01 and 0.07 +/- 0.03%. Most of the nonabsorbed cadmium was recovered in the soap and water skin surface wash. Binding of cadmium from water to soil was greater than binding from water to powdered human stratum corneum, supporting the lower absorption from soil than from water. Short-term exposure of cadmium in water to human skin for 30 min (bath or swim) resulted in skin uptake, which upon further perfusion (48 hr), absorbed into the plasma receptor fluid (systemic). Cadmium in soil was increased from 6.5 to 65 ppb.(ABSTRACT TRUNCATED AT 250 WORDS)

Wester, R.C.; Maibach, H.I.; Sedik, L.; Melendres, J.; DiZio, S.; Wade, M. (Department of Dermatology, University of California School of Medicine, San Francisco (United States))

1992-07-01

274

State-of-the-art review on crystallization control technologies for water\\/LiBr absorption heat pumps  

Microsoft Academic Search

The key technical barrier to using water\\/lithium bromide (LiBr) as the working fluid in air-cooled 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

Kai Wang; Omar Abdelaziz; Padmaja Kisari; Edward Allan Vineyard

2011-01-01

275

A comparison of methods for the measurement of the absorption coefficient in natural waters  

NASA Technical Reports Server (NTRS)

In the spring of 1992 an optical closure experiment was conducted at Lake Pend Orielle, Idaho. A primary objective of the experiment was to compare techniques for the measurement of the spectral absorption coefficent and other inherent optical properties of natural waters. Daily averages of absorption coefficents measured using six methods are compared at wavelengths of 456, 488, and 532 nm. Overall agreement was within 40% at 456 nm and improved with increasing wavelength to 25% at 532 nm. These absorption measurements were distributed over the final 9 days of the experiement, when bio-optical conditions in Lake Pend Oreille (as indexed by the beam attenuation coefficent c(sub p)(660) and chlorophyll a fluorescence profiles) were representative of those observed throughout the experiment. However, profiles of stimulated chlorophyll a fluorescence and beam transmission showed that bio-optical properties in the lake varied strongly on all time and space scales. Therefore environmental variabilty contributed significantly to deviations between daily mean absorption coefficients measured using the different techniques.

Pegau, W. Scott; Cleveland, Joan S.; Doss, W.; Kennedy, C. Dan; Maffione, Robert A.; Mueller, James L.; Stone, R.; Trees, Charles C.; Weidemann, Alan D.; Wells, Willard H.

1995-01-01

276

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

NASA Technical Reports Server (NTRS)

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.

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

277

NOTE: Effects of water light absorption properties of a radiographic film  

NASA Astrophysics Data System (ADS)

Photon beam dosimetry using Kodak extended dose range (EDR2) radiographic film can provide accurate and high spatial resolution information especially for areas such as IMRT dosimetry where a higher dose level (100-400 cGy) is often required to be delivered for verification. For such dosimetry checks, it may sometimes be useful to place the film in a tank filled with water during irradiation. The effects of water on the film when packaged and when removed from the packaging have been examined. Results have shown that the EDR2 film when supplied in the ready pack form is provided in water proof packages and no significant absorption effects are observed or measured on the film even after 48 h of soaking in a water bath. When the film is removed from the ready packs and exposed to water directly, various effects are seen. In the visible spectrum region, small variations (up to 3%) in recorded optical density (OD) are recorded using a fluorescent light densitometer. These effects become much larger in the infrared region (e.g. 7.5% at 900 nm and 12.5% at 1000 nm) and are wavelength dependent. The changes produced by the water are relatively independent of the exposure time to water from 5 s up to 1 h or whether the water exposure occurred.

Cheung, Tsang; Butson, Martin J.; Yu, Peter K. N.; Metcalfe, Peter

2002-10-01

278

Gravity factor of the formation of the field and capillary water capacities in soils and artificial layered soil-like bodies  

Microsoft Academic Search

The water retention capacity of soils characterizes a quasiequilibrium between the forces retaining and removing the soil water. It has been studied under field and laboratory conditions. It is shown that the gravity factor, as well as the soil particle-size distribution and structure, has an important role in determining the soil water capacity after the outflow of gravitational water. Our

A. V. Smagin; G. M. Khakimova; D. A. Khineeva; N. B. Sadovnikova

2008-01-01

279

The Measurement of Heat Capacity Differences Due to the Change of Water Structure in Aqueous Solutions of Organic Compounds  

Microsoft Academic Search

In order to observe more directly the structural organization of water molecules around a non-polar molecule in an aqueous\\u000a solution, heat capacity differences between two kinds of solutions (solution I and II) of quaternary ammonium salts were measured.\\u000a In the solution I stable water structure was retained as much as possible and in the solution II water structure was destroyed

H. Nakayama; K. Aida

1999-01-01

280

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

NASA Astrophysics Data System (ADS)

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.

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

281

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

SciTech Connect

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.

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

2009-06-03

282

Atmospheric Pre-Corrected Differential Absorption Techniques to Retrieve Columnar Water Vapor: Theory and Simulations  

NASA Technical Reports Server (NTRS)

Two different approaches exist to retrieve columnar water vapor from imaging spectrometer data: (1) Differential absorption techniques based on: (a) Narrow-Wide (N/W) ratio between overlapping spectrally wide and narrow channels; (b) Continuum Interpolated Band Ratio (CIBR) between a measurement channel and the weighted sum of two reference channels. (2) Non-linear fitting techniques which are based on spectral radiative transfer calculations. The advantage of the first approach is computational speed and of the second, improved retrieval accuracy. Our goal was to improve the accuracy of the first technique using physics based on radiative transfer. Using a modified version of the Duntley equation, we derived an "Atmospheric Pre-corrected Differential Absorption" (APDA) technique and described an iterative scheme to retrieve water vapor on a pixel-by-pixel basis. Next we compared both, the CIBR and the APDA using the Duntley equation for MODTRAN3 computed irradiances, transmissions and path radiance (using the DISORT option). This simulation showed that the CIBR is very sensitive to reflectance effects and that the APDA performs much better. An extensive data set was created with the radiative transfer code 6S over 379 different ground reflectance spectra. The calculated relative water vapor error was reduced significantly for the APDA. The APDA technique had about 8% (vs. over 35% for the CIBR) of the 379 spectra with a relative water vapor error of greater than +5%. The APDA has been applied to 1991 and 1995 AVIRIS scenes which visually demonstrate the improvement over the CIBR technique.

Borel, Christoph C.; Schlaepfer, Daniel

1996-01-01

283

Photochemistry of tetrasulphonated magnesium phthalocyanine in water and DMSO solutions by Raman, femtosecond transient absorption, and stationary absorption spectroscopies  

Microsoft Academic Search

Photochemical and photophysical behavior of the tetrasulphonated magnesium phthalocyanine MgPcS4 has been studied by Raman spectroscopy, femtosecond transient absorption, and stationary UV–VIS absorption spectroscopies. It has been shown also that the dimerization equilibrium constant K for the tetrasulfonated magnesium phthalocyanine is strongly shifted towards monomeric form in DMSO solutions compared to aqueous systems. The Raman and emission spectra recorded in

W. Czajkowski; M. Kurczewska; H. Abramczyk

2008-01-01

284

Near-Infrared Studies of Glucose and Sucrose in Aqueous Solutions: Water Displacement Effect and Red Shift in Water Absorption from Water-Solute Interaction  

NASA Astrophysics Data System (ADS)

We use near infrared spectroscopy to obtain concentration dependent glucose absorption spectra in their aqueous solutions in the near-infrared range (3800 - 7500 cm^{-1}). We introduce a new method to obtain reliable glucose absorption bands from aqueous glucose solutions without measuring the water displacement coefficients of glucose separately. Additionally, we are able to extract the water displacement coefficients of glucose, and this may give a new general method using spectroscopy techniques applicable to other water soluble materials. We also observe red shifts in the absorption bands of water in the hydration shell around solute molecules, which comes from contribution of the interacting water molecules around the glucose molecules in solutions. The intensity of the red shift get larger as the concentration increases, which indicates that as the concentration increases more water molecules are involved in the interaction. However, the red shift in frequency does not seem to depend significantly on the concentration up to our highest concentration. We also performed the same measurements and analysis with sucrose instead of glucose as solute and compare.

Jung, Youngeui; Hwang, Jungseek

2013-02-01

285

Graphical expression of thermodynamic characteristics of absorption process in ammonia-water system  

NASA Astrophysics Data System (ADS)

The adiabatic sorption is very interesting phenomenon that occurs when vapor of refrigerant is in contact with unsaturated liquid absorbent-refrigerant mixture and exchange of heat is forbid between the system and an environment. This contribution introduces new auxiliary lines that enable correct position determination of the adiabatic sorption process in the p-T-x diagram of ammoniawater system. The presented auxiliary lines were obtained from common functions for fast calculation of water-ammonia system properties. Absorption cycles designers often utilize p-t-x diagrams of working mixtures for first suggestion of new absorption cycles. The p-t-x diagrams enable fast correct determination of saturate states of liquid (and gaseous) mixtures of refrigerants and absorbents. The working mixture isn't only at saturated state during a real working cycle. If we know pressure and temperature of an unsaturated mixture, exact position determination is possible in the p-t-x diagrams too.

Pospíšil, Ji?í; Fortelný, Zden?k

2012-04-01

286

Theoretical analysis of ammonia-water absorption cycles for refrigeration and space conditioning systems  

NASA Astrophysics Data System (ADS)

A numerical model for the performance of an ammonia-water absorption cycle in solar air conditioning, refrigeration, and heat pump systems are presented. The configurations comprise a solar driven generator, a rectifier, condenser, evaporator, absorber, preheater, and a subcooler. Cooling modes involve supplying heat to the evaporator from the space to be cooled and transferring the heat to the ambient environment by way of the rectifier, absorber, and condenser. In a heat pump, the same equipment is used with the heat being dispersed into the space to be heated. Block diagrams are provided of the basic absorption cycle and a model is constructed from heat and mass balance equations and the equations of state for a NH3-H2O cycle system. System simulation then consists of the simultaneous solution of a set of algebraic nonlinear equations and using the Newton-Raphson method to iterate for implicit solutions in each operational mode.

Kaushik, S. C.; Bhardwaj, S. C.

1982-09-01

287

Investigation of the Influence of Cooling Water Inlet Temperature on Characteristics and Ammonia Charging Quantity of Ammonia-Water Absorption Refrigerator  

NASA Astrophysics Data System (ADS)

For purposes such as freezing and ice accumulation which require temperatures below 0 degrees, ammonia-water absorption refrigerator is being looked at once again. If used for these purpose, it is usually driven all through the year. In this case, cooling water inlet temperature which greatly influences absorption cycle changes very widely. So in such conditions, it is hoped to be driven high efficiently. And ammonia's charging quantity is required as small as possible on account of poisonous. But when it driven all through the year, ammonia charging quantity influences the efficiency greatly. So this research aims to clarify the ammonia charging quantity with which ammonia-water absorption refrigerator can be driven high efficiently. So static simulation model was made. By using this tool, we investigated the influence of cooling water inlet temperature on COP, solution concentration. As a result, minimum ammonia charging quantity with which ammonia water absorption refrigerator can be driven was obtained.

Takei, Toshitaka; Saito, Kiyoshi; Kawai, Sunao

288

Robust superhydrophobic/superoleophilic sponge for effective continuous absorption and expulsion of oil pollutants from water.  

PubMed

With the growth of oil production and transportation, there is greater potential for accidental oil spills. Here we fabricated a robust superhydrophobic and superoleophilic carbon nanotube/poly(dimethylsiloxane)-coated polyurethane sponge for the continuous absorption and expulsion of oils and organic solvents from water surfaces. When applied in conjunction with a vacuum system, this sponge could separate great amounts of oils-up to 35000 times its own weight-from water in a one-step process and could also separate surfactant-free water-in-oil emulsions with high efficiency (oil purity: >99.97 wt %), making it a promising candidate material for use in oil-spill cleanups. PMID:24032484

Wang, Chih-Feng; Lin, Sheng-Jhih

2013-09-25

289

Modeling of water absorption induced cracks in resin-based composite supported ceramic layer structures.  

PubMed

Cracking patterns in the top ceramic layers of the modeled dental multilayers with polymer foundation are observed when they are immersed in water. This article developed a model to understand this cracking mechanism. When water diffuses into the polymer foundation of dental restorations, the foundation will expand; as a result, the stress will build up in the top ceramic layer because of the bending and stretching. A finite element model based on this mechanism is built to predict the stress build-up and the slow crack growth in the top ceramic layers during the water absorption. Our simulations show that the stress build-up by this mechanism is high enough to cause the cracking in the top ceramic layers and the cracking patterns predicted by our model are well consistent with those observed in experiments on glass/epoxy/polymer multilayers. The model is then used to discuss the life prediction of different dental ceramics. PMID:17497681

Huang, Min; Thompson, V P; Rekow, E D; Soboyejo, W O

2008-01-01

290

WVR-GPS comparison measurements and calibration of the 20-32 GHz tropospheric water vapor absorption model  

Microsoft Academic Search

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

S. J. Keihm; Yoaz Bar-Sever; James C. Liljegren

2002-01-01

291

Influence of hot water dip on fruit quality, phenolic compounds and antioxidant capacity of Satsuma mandarin during storage.  

PubMed

The influence of hot water dips (50, 52 and 54? for 3?min) on fruit quality, phenolic compounds and antioxidant capacity of Satsuma mandarin during 60 days' storage at 10? was investigated. Hot water dips did not affect fruit quality attributes as well as ascorbic acid content, and 50? treatment significantly reduced fruit weight loss. Significant increases of flavonoids were found in all hot water treated fruit from after treatments till 15 days of storage, whereas phenolic acids were not greatly affected. Hot water dipping at 50? significantly increased total phenolics and antioxidant capacity of Satsuma mandarin immediately after treatment and maintained similar levels with control during storage, while 52 and 54? treatments showed relatively lower levels. The results suggested that hot water dipping at 50? for 3?min can be a promising way to retain functional quality of storing Satsuma mandarin. PMID:23733808

Shen, Yan; Zhong, Liezhou; Sun, Yujing; Chen, Jianchu; Liu, Donghong; Ye, Xingqian

2013-12-01

292

The impact of regional water resources capacity building: Citations of the published proceedings of the annual WaterNet\\/WARFSA\\/GWP-SA symposia in Southern Africa, 2001 2005  

Microsoft Academic Search

This paper measures the scientific impact of two regional water resources capacity building programmes in Southern Africa: WaterNet and WARFSA. The articles emanating from the annual symposia organised jointly by both programmes during the period 2001 2005 and published in special issues of Physics and Chemistry of the Earth were analysed in terms of numbers and citations. The paper concludes

Pieter van der Zaag

2007-01-01

293

Fibrous membranes electrospinning from acrylonitrile-based polymers: specific absorption behaviors and states of water.  

PubMed

Fibrous membranes with a fiber diameter ranging from 80 to 800 nm are prepared from polyacrylonitrile and poly[acrylonitrile-co-(N-vinyl-2-pyrrolidone)] by the electrospinning process. The parameters can be controlled to fabricate fibrous membranes with similar fiber diameters (between 600 and 800 nm) for further studies on the swelling behaviors and water states. Water swelling experiments indicate that the fibrous membrane has a great capacity for water sorption, which reaches a maximum in a few minutes because of its extremely high porosity. Furthermore, a remarkable overshoot occurs as a result of polymer chain relaxation and the non-compact structure of the fibrous membranes. Contrary to the dense membrane, the equilibrium water content in the fibrous membrane decreases with the content of hydrophilic NVP though the maximum is almost the same. Results from DSC experiments demonstrate that only non-freezable bound water and free water can be distinguished in the fibrous membrane. On the basis of the results of water swelling and DSC experiments, it is concluded that the specific behaviors of the fibrous membranes are induced by the non-compact and pore-fiber discontinuous structure, which is different from either dense membranes or hydrogels. [GRAPHS: SEE TEXT] DSC curves of fully swollen electrospun fibrous membranes and of fully swollen dense membranes with different NVP contents. PMID:16680807

Wan, Ling-Shu; Xu, Zhi-Kang; Jiang, Hong-Liang

2006-05-23

294

A simple two-band semi-analytical model for retrieval of specific absorption coefficients in coastal waters  

NASA Astrophysics Data System (ADS)

A non-linear iterative method is used to replace the traditional spectral slope technique in initializing the total absorption decomposition model. Based on comparison of absorption coefficient by QAA and two-band semi-analytical model (TSAA) models with field measurements collected from the West Florida Shelf waters and Bohai Sea, it is shown that both models are effective in estimating absorption coefficients from the West Florida Shelf waters, but the TSAA model is superior to the QAA model. Use of the TSAA model in estimating absorption coefficient in the West Florida Shelf and Bohai Sea decreases the uncertainty of estimation by 1.3–74.7% from the QAA model. The TSAA model's sensitivity to the input parameters was evaluated by varying one parameter and keeping the others fixed at their default values. Our results indicate that the TSAA model has quite a strong noise tolerance to addressing the field data of the total absorption coefficient.

Chen, Jun; Cui, Tingwei; Qiu, Zhongfeng; Lin, Changsong

2014-05-01

295

A new device for acquiring ground truth on the absorption of light by turbid waters  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. A new device, called a Spectral Attenuation Board, has been designed and tested, which enables ERTS-1 sea truth collection teams to monitor the attenuation depths of three colors continuously, as the board is being towed behind a boat. The device consists of a 1.2 x 1.2 meter flat board held below the surface of the water at a fixed angle to the surface of the water. A camera mounted above the water takes photographs of the board. The resulting film image is analyzed by a micro-densitometer trace along the descending portion of the board. This yields information on the rate of attenuation of light penetrating the water column and the Secchi depth. Red and green stripes were painted on the white board to approximate band 4 and band 5 of the ERTS MSS so that information on the rate of light absorption by the water column of light in these regions of the visible spectrum could be concurrently measured. It was found that information from a red, green, and white stripe may serve to fingerprint the composition of the water mass. A number of these devices, when automated, could also be distributed over a large region to provide a cheap method of obtaining valuable satellite ground truth data at present time intervals.

Klemas, V. (principal investigator); Srna, R.; Treasure, W.

1974-01-01

296

Improved energy efficiency in absorption heat pump through process modification. Part II: Thermodynamic potential of liquid-liquid extraction of ammonia-water mixtures  

Microsoft Academic Search

Extraction-system-attached (ESA) ammonia-water absorption heat pumps were derived from the conventional system as a strategy to improve the energy efficiency of the conventional ammonia-water absorption heat pump. The ESA absorption heat pumps were obtained by attaching a liquid-liquid extraction unit in the conventional system. Theoretical thermodynamic simulation of the ESA and conventional ammonia-water absorption heat pumps showed that a higher

A. S. Olawale; S. S. Adefila

1998-01-01

297

Water Absorption Behavior of Different Types of Organophilic Montmorillonite-Filled Polyamide 6\\/Polypropylene Nanocomposites  

Microsoft Academic Search

The water absorption behavior of different types of orga- nophilic montmorillonite (OMMT)-filled polyamide 6\\/poly- propylene nanocomposites with and without compatibil- izers (maleated PP or PP-g-MA and maleated styrene- ethylene\\/butylene-styrene or SEBS-g-MA) was evaluated. Four different types of OMMT, i.e., dodecylamine-modified MMT (D-MMT), 12 aminolauric acid-modified MMT (A- MMT), stearylamine-modified MMT (S-MMT), and commercial organo-MMT (C-MMT) were used as rein- forcement.

Z. A. Mohd Ishak; W. S. Chow; T. Takeichi

2010-01-01

298

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

NASA Technical Reports Server (NTRS)

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.

Miao, D.

1978-01-01

299

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

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

300

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

PubMed

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

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

2011-12-01

301

Differential sound absorption technique and effect of ion-pairing and pressure on sound absorption in sea water and aqueous mixtures of magnesium sulfate and sodium chloride  

NASA Astrophysics Data System (ADS)

Sound absorption in the ocean between 5 kHz and 350 kHz is principally due to the relaxation process associated with a pressure dependent chemical reaction of MgSO4. This research has resolved two conflicts regarding the effect of pressure on sound absorption and relaxation frequency due to MgSO4 in sea water and the reduction of sound absorption by the addition of up to 0.6 M NaCl to low concentration (0.02M) solution of NaCl. The reduction of absorption in MgSO4 solution upon the addition of NaCl can be accounted for theoretically by Debye-Huckel theory and by formation of MgCl(+) and NaSO4 ion-pairs. The measured reduction is less than that observed by Kurtze and Tamm, however. At this concentration of MgSO4, the effects of ionic strength and ion-pairing are about equal. The results are consistent with disassociation constants of 0.0062, 0.1, 0.178 for the MgSO4, NaSO4(-) and MgCl(+) ion-pairs, respectively up to 0.12 M NaCl addition. For 0.6M NaCl additions to 0.02 M MgSO4, the absorption results cannot be explained by either simple Debye-Huckel theory, the Johnson and Pytkowicz model of ion-pairing nor the Pitzer approach. The values of maximum absorption per wavelength were determined to an absolute accuracy of about 1% from .000080 to .000016. For the differential absorption measurements in MgSO4 and NaCl mixtures, the measurement accuracy is sufficient for quantitative studies of ion-pairing in electrolyte mixtures, particularly for unsymmetrical salts.

Hsu, C. C.

1981-11-01

302

Estimation of canopy water storage capacity from sap flow measurements in a Bornean tropical rainforest  

NASA Astrophysics Data System (ADS)

SummaryCanopy water storage capacity (Sc) is a key parameter for estimations of rainfall interception using a big-leaf model (BLM). This study proposes a simple method for estimating Sc. The crucial factor in this method is the canopy drying time (or wet canopy duration) after rainfall. The time can be estimated from sap flow measurements in accordance with an earlier study of ours in a Bornean tropical rainforest. By using the estimated canopy drying time to calibrate a BLM for rainfall interception, we derived Sc. This method could also provide aerodynamic resistance (Ra). To validate our estimations, the derived parameters Sc and Ra were compared to Sc and Ra determined independently by a method based on net rainfall measurements on an event basis and on wind profile measurements, respectively. The parameters in our method (Sc = 0.7 mm, Ra = 14 s m -1) were shown to correspond well to the values determined by independent methods. Furthermore, the method proposed in this study is applicable to tropical forests where short canopy drying times can be expected after rainfall; that is, if the cloudy weather after rainfall becomes sunny within 250 min.

Kume, Tomonori; Manfroi, Odair J.; Kuraji, Koichiro; Tanaka, Nobuaki; Horiuchi, Toshinobu; Suzuki, Masakazu; Kumagai, Tomo'omi

2008-05-01

303

Dynamic registration of the absorption spectrum of water in the SiO2 nanopores in high-frequency range  

NASA Astrophysics Data System (ADS)

The high-frequency region was used to record the absorption spectrum of water in nanoscale pores during vacuum pumping or injection of water. The wide spectral range, which included the vibration overtones, allowed to resolve the structure of the absorption bands with variation of water concentration in the pores of SiO2. The absorption bands of water clusters in the 4570-5400 cm-1 range consist of well-resolved sub-bands with interpeak intervals of up to 580 cm-1. When the pore diameter is decreased from 11.8 to 2.6 nm, the absorption bands of clusters in this frequency range are shifted by 530 cm-1 in the direction of the water monomer which indicates an increase of hydrogen bond strength in confined water with an increase of the pore diameter. The spectrum recorded during water pumping is extremely variable in time, and the cluster dynamics in large pores (11.8 nm) differs greatly from the dynamics in small pores (2.6 nm). While all types of water clusters are removed from small pores uniformly, in the case of large pores, the water clusters relating to strong hydrogen bonds are removed from the sample at the beginning of the vacuum pumping and the loosely coupled clusters are removed later. The rate of this process is not steady and varies throughout pumping.

Sinitsa, L. N.; Lugovskoy, A. A.

2010-11-01

304

Biological Processing Capacities and Biomass Growth in Waste Water Treatment by Infiltration On two Kinds of Sand  

Microsoft Academic Search

In this article, work is presented which highlights the biological processing capacities of urban waste water within porous media of different textures. A comparative study on the growth of biomass coupled with the general mechanisms for gas transfer through two biological beds is undertaken. Infiltration-percolation beds are simulated using columns filled with sands of different origins and structures. These are

Adrien Wanko; Robert Mose; Christian Beck

2005-01-01

305

Development of minimum efficiency standards for large capacity air conditioners, and commercial water heaters, refrigerators, and freezers. Final report  

Microsoft Academic Search

The California Energy Resources Conservation and Development Commission has promulgated appliance energy efficiency standards and energy conservation standards for new construction with the objective of reducing energy consumption in the State of California. The following appliance categories are specifically addressed: large capacity air conditioners; commercial water heaters; and commercial refrigerators and freezers. The tasks that have been performed include: an

P. S. Merrill; R. J. Rettberg; R. C. Erickson; J. S. Toor

1980-01-01

306

Atmospheric pre-corrected differential absorption techniques to retrieve columnar water vapor: Theory and simulations  

SciTech Connect

Two different approaches exist to retrieve columnar water vapor from imaging spectrometer data: (1) Differential absorption techniques based on: (a) Narrow-Wide (N/W) ratio between overlapping spectrally wide and narrow channels (b) Continuum Interpolated Band Ratio (CIBR) between a measurement channel and the weighted sum of two reference channels; and (2) Non-linear fitting techniques which are based on spectral radiative transfer calculations. The advantage of the first approach is computational speed and of the second, improved retrieval accuracy. Our goal was to improve the accuracy of the first technique using physics based on radiative transfer. Using a modified version of the Duntley equation, we derived an {open_quote}Atmospheric Pre-corrected Differential Absorption{close_quote} (APDA) technique and described an iterative scheme to retrieve water vapor on a pixel-by-pixel basis. Next we compared both, the CIBR and the APDA using the Duntley equation for MODTRAN3 computed irradiances, transmissions and path radiance (using the DISORT option). This simulation showed that the CIBR is very sensitive to reflectance effects and that the APDA performs much better. An extensive data set was created with the radiative transfer code 6S over 379 different ground reflectance spectra. The calculated relative water vapor error was reduced significantly for the APDA. The APDA technique had about 8% (vs. over 35% for the CIBR) of the 379 spectra with a relative water vapor error of greater than {+-}5%. The APDA has been applied to 1991 and 1995 AVIRIS scenes which visually demonstrate the improvement over the CIBR technique.

Borel, C.C.; Schlaepfer, D.

1996-03-01

307

Enhancing the intestinal absorption of poorly water-soluble weak-acidic compound by controlling local pH.  

PubMed

Recently, the number of poorly water-soluble drug candidates has increased and has hindered the rapid improvement of new drugs with low intestinal absorption; however, the intestinal absorption of pH-dependent poorly water-soluble compounds is expected to be markedly improved by changing the pH in the vicinity of the absorption site. The aim of this study is to clarify the effect of local pH change in the intestinal tract by magnesium oxide on the intestinal absorption of hydrochlorothiazide, a model poorly water-soluble weak-acid compound. The application of hydrochlorothiazide granule containing magnesium oxide to the rat intestinal loop increased the pH in the vicinity of the dosing site to more than 8.5 for 90?min without any mucosal damage. As a result, absorption of hydrochlorothiazide increased by the addition of magnesium oxide to the granule. Intraintestinal administration of a suspension prepared from hydrochlorothiazide granules with magnesium oxide increased the intestinal absorption and the AUC value was 3-fold higher than that without magnesium oxide. To further increase the intestinal absorption of hydrochlorothiazide, we prepared granules containing magnesium oxide and chitosan as a mucoadhesive and tight junction opening material. Chitosan showed a marked increase of intestinal absorption, and the AUC value after the administration of suspensions of chitosan granules was more than 5-fold higher than that of granules containing hydrochlorothiazide alone, respectively. In summary, it has been clarified that the intestinal absorption of weak-acidic poorly water-soluble compound can be enhanced by increasing local pH, mucoadhesion and opening tight junction. PMID:22443480

Iwanaga, Kazunori; Kato, Shino; Miyazaki, Makoto; Kakemi, Masawo

2013-12-01

308

Solar cooling with the absorption principle: first and Second Law analysis of an ammonia—water double-generator absorption chiller  

Microsoft Academic Search

This article deals with the modelling, thermodynamic simulation and Second Law analysis of an ammonia—water double-effect, double-generator absorption chiller. The analysis of the unit established a simulation thermodynamic model as well as the limits of the operating conditions. Computer simulation was carried out in order to determine its stream properties and the amount of heat and work exchanged with the

N. Ben Ezzine; M. Barhoumi; Kh. Mejbri; S. Chemkhi; A. Bellagi

2004-01-01

309

X-ray absorption and infrared spectra of water and ice: A first-principles electronic structure study  

Microsoft Academic Search

Water is of essential importance for chemistry and biology, yet the physics concerning many of its distinctive properties is not well known. In this thesis we present a theoretical study of the x-ray absorption (XA) and infrared (IR) spectra of water in liquid and solid phase. Our theoretical tools are the density functional theory (DFT), Car-Parrinello (CP) molecular dynamics (MD),

Wei Chen

2009-01-01

310

Determination of soluble cadmium, lead, silver, and indium in rainwater and stream water with the use of flameless atomic absorption  

Microsoft Academic Search

Stream water and rain water were analyzed for trace metals using flameless atomic absorption. Interferences were found in the direct determination of cadmium, lead, silver, and indium. The techniques used to overcome there interferences are described. 12 references, 2 figures, 4 tables.

Rattonnetti

1974-01-01

311

Water Absorption from Line-of-Sight Clouds toward W49A  

NASA Astrophysics Data System (ADS)

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.

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

312

THz absorption spectra and stability of Fe water complexes calculated by density functional theory  

NASA Astrophysics Data System (ADS)

Monitoring of water contaminants implies a need for determining their dielectric response properties with re- spect to electromagnetic wave excitation at various frequencies. Iron is a naturally occurring water contaminant resulting from decaying vegetation, which is at much higher concentrations than any other metal contaminant. The present study uses density functional theory (DFT) for the calculation of ground state resonance struc- ture and molecular stability analysis for Fe water complexes. The calculations presented are for excitation by electromagnetic waves at frequencies within the THz range. Dielectric response functions calculated by DFT can be used for the analysis of water contaminants. These functions provide quantitative initial estimates of spectral response features for subsequent adjustment with respect to additional information such as laboratory measurements and other types of theory based calculations. In addition, with respect to qualitative analysis, DFT calculated absorption spectra provide for molecular level interpretation of response structure. The DFT software GAUSSIAN was used for the calculations of ground state resonance structure presented here.

Huang, L.; Lambrakos, S. G.; Shabaev, A.; Massa, L.; Yapijakis, C.

2013-05-01

313

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

Microsoft Academic Search

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

Roger S. Cheng; Sergio Verdú

1993-01-01

314

The effect of decaying leaves on the ph and buffer capacity of waters  

Microsoft Academic Search

Acid rain has become a significant environmental problem in the United States. The survival of aquatic life depends on the ability of the aquatic's system to withstand acidic rainwater. This in turn is very dependant on the buffer capacity of the system. Understanding the factors that effect buffer capacity would be very valuable in formulating solutions for the protection of

Paula M. Deano; J. W. Robinson

1985-01-01

315

Selection of heat storage materials for ammonia–water and lithium bromide solar-powered absorption heat pump systems  

Microsoft Academic Search

A procedure for incorporating phase-change thermal storage materials in ammonia–water and lithium bromide absorption heat pumps systems is explored. Performance evaluation of the systems is presented and results are used as a guide in selecting appropriate phase-change materials (PCMs) for the absorption heat systems. Evaluation of the system indicates that there is a minimum generator temperature for each configuration of

S. N. Mumah

2008-01-01

316

Surfactant\\/oil\\/water system for the determination of selenium in eggs by graphite furnace atomic absorption spectrometry  

Microsoft Academic Search

An oil-in-water formulation has been optimized to determine trace levels of selenium in whole hen eggs by graphite furnace atomic absorption spectrometry. This method is simpler and requires fewer reagents when compared with other sample pre-treatment procedures. Graphite furnace atomic absorption spectrometric (GF AAS) measurement was carried out using standard addition calibration and Pd as a modifier. The precision, expressed

C. V. S. Ieggli; D. Bohrer; S. Noremberg; P. C. do Nascimento; L. M. de Carvalho; S. L. Vieira; R. N. Reis

2009-01-01

317

Reliability, validity, and applicability of isolated and combined sport-specific tests of conditioning capacities in top-level junior water polo athletes.  

PubMed

Uljevic, O, Esco, MR, and Sekulic, D. Reliability, validity and applicability of isolated and combined sport-specific tests of conditioning capacities in top-level junior water polo athletes. J Strength Cond Res 28(6): 1595-1605, 2014-Standard testing procedures are of limited applicability in water sports, such as water polo. The aim of this investigation was to construct and validate methods for determining water polo-specific conditioning capacities. We constructed 4 combined-capacity tests that were designed to mimic real-game water polo performances: sprint swimming performance, shooting performance, jumping performance, and precision performance. In all cases, combined-capacity tests included a period of standardized exhaustion followed by the performance of the targeted quality (swimming, shooting, jumping, and precision). In the first part of the study, single-capacity tests (sprint swim, in-water jump, drive shoot, and precision performance) were tested and later included in the combined-capacity tests. Study subjects consisted of 54 young male water polo players (15-18 years of age, 185.6 ± 6.7 cm, and 83.1 ± 9.9 kg). Most of the tests evaluated were found to be reliable with Cronbach alpha values ranging from 0.83 to 0.96 and coefficients of variation from 21 to 2% (for the single-capacity tests) and 0.75 to 0.93 test-retest correlation (intraclass correlation coefficients) with Bland-Altman tight limits of agreement (for combined-capacity tests). The combined-capacity tests discriminated qualitative groups of junior water polo players (national squad vs. team athletes) more effectively than single-capacity tests. This is most likely because combined-capacity tests more closely represent the complex fitness capacities required in real game situations. Strength and conditioning practitioners and coaches working with water polo athletes should consider incorporating these validated tests into their assessment protocols. PMID:24169473

Uljevic, Ognjen; Esco, Michael R; Sekulic, Damir

2014-06-01

318

Absorption and fluorescence spectroscopic investigations of PAC/humic substance-interactions in water  

NASA Astrophysics Data System (ADS)

Time-resolved emission spectra of humic substances of different origin have been recorded in order to extend our previous spectroscopic characterization of humic and fulvic acids in aqueous solution with stationary UV/Vis-absorption and fluorescence measurements. Instead of applying a fitting procedure, decay times are introduced as simple and robust experimental parameters for the quantitative description of fluorescence decays. The analysis of time-resolved emission spectra indicates a wavelength dependence of the fluorescence investigations of the interactions between pyrene and various humic substances in water. For all humic substances the quenching of pyrene fluorescence is dominated by a static quenching process, i.e. by a ground-state complexation. A significant influence of pH on the fluorescence quenching efficiencies is found, whereas no long-term changes of the interaction between pyrene and a humic substance are discernible. Time-resolved triplet- triplet absorption measurements reveal a decrease of chrysene triplet lifetime due to the presence of humic substances.

Zimmermann, Ute; Loehmannsroeben, Hans-Gerd; Skrivanek, Thomas

1997-05-01

319

Revisiting the total ion yield x-ray absorption spectra of liquid water microjets  

SciTech Connect

Measurements of the total ion yield (TIY) x-ray absorption spectrum (XAS) of liquid water by Wilson et al. (2002 J. Phys.: Condens. Matter 14 L221 and 2001 J. Phys. Chem. B 105 3346) have been revisited in light of new experimental and theoretical efforts by our group. Previously, the TIY spectrum was interpreted as a distinct measure of the electronic structure of the liquid water surface. However, our new results indicate that the previously obtained spectrum may have suffered from as yet unidentified experimental artifacts. Although computational results indicate that the liquid water surface should exhibit a TIY-XAS that is fundamentally distinguishable from the bulk liquid XAS, the new experimental results suggest that the observable TIY-XAS is actually nearly identical in appearance to the total electron yield (TEY-)XAS, which is a bulk probe. This surprising similarity between the observed TIY-XAS and TEY-XAS likely results from large contributions from x-ray induced electron stimulated desorption of ions, and does not necessarily indicate that the electronic structure of the bulk liquid and liquid surface are identical.

Saykally, Richard J; Cappa, Chris D.; Smith, Jared D.; Wilson, Kevin R.; Saykally, Richard J.

2008-02-16

320

Diffusion coefficients of water and leachables in methacrylate-based crosslinked polymers using absorption experiments.  

PubMed

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) cm(2)/sec (co-monomer TMTMA) to 3.15 × 10(-8) cm(2)/sec (co-monomer T4EGDMA). Correlation of the diffusion coefficients with crosslink density and hydrophilicity showed an inverse trend (R(2) = 0.41). The correlation of diffusion coefficient with crosslink density and hydrophilicity are closer for molecules differing by simple repeat units (R(2) = 0.95). These differences in the trends reveal mechanisms of interaction of the diffusing water with the polymer structure. PMID:22430592

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

2012-05-01

321

Ground-based differential absorption lidar for water-vapor and temperature profiling: methodology.  

PubMed

A comprehensive formulation of the differential absorption lidar (DIAL) methodology is presented that explicitly includes details of the spectral distributions of both the transmitted and the backscattered light. The method is important for high-accuracy water-vapor retrievals and in particular for temperature measurements. Probability estimates of the error that is due to Doppler-broadened Rayleigh scattering based on an extended experimental data set are presented, as is an analytical treatment of errors that are due to averaging in the nonlinear retrieval scheme. System performance requirements are derived that show that water-vapor retrievals with an accuracy of better than 5% and temperature retrievals with an accuracy of better than 1 K in the entire troposphere are feasible if the error that results from Rayleigh-Doppler correction can be avoided. A modification of the DIAL technique, high-spectral-resolution DIAL avoids errors that are due to Doppler-broadened Rayleigh backscatter and permits simultaneous water-vapor and wind measurements with the same system. PMID:18273353

Bösenberg, J

1998-06-20

322

Determination of aromatic compounds in water by solid phase microextraction and ultraviolet absorption spectroscopy. 1. Methodology  

SciTech Connect

A simple method is described for determining aromatic compounds (i.e., benzene, toluene, ethylbenzene, etc.) in water that combines solid phase microextraction (SPME) and ultraviolet (UV) absorption spectroscopy. The extraction medium consists of a small `chip` of poly(dimethylsiloxane) (total volume of nearly 80 {mu}L) that is immersed in a water sample contaminated with an aromatic compound. Equilibrium is first allowed to establish between the analyte in the water and the extraction medium, and the concentration of the aromatic compound is then determined directly in the sorbent chip by UV spectroscopy. Calibration information on this new method was obtained for 11 aromatic compounds commonly found in unleaded gasoline (e.g., benzene, toluene, naphthalene, etc). It was found that equilibrium is established in the range of 30-50 min, with the exception of 1-methylnaphthalene and naphthalene, which equilibrated within 100 min. Detection limits for the aromatic compounds at their equilibration times range from 0.40 to 12 ppb except for benzene (97 ppb). Relative standard deviations of the SPME-UV measurements are 3-12%. 17 refs., 3 figs., 5 tabs.

Wittkamp, B.L.; Hawthorne, S.B.; Tilotta, D.C. [Univ. of North Dakota, Grand Forks, ND (United States)] [Univ. of North Dakota, Grand Forks, ND (United States)

1997-03-15

323

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

PubMed

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

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

2012-08-01

324

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

NASA Technical Reports Server (NTRS)

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.

Kenimer, R. L.

1988-01-01

325

Water absorption characteristics and cytotoxic and biological evaluation of bone cements formulated with a novel activator.  

PubMed

A novel activator, N,N,Dimethylamino 4-benzyl laurate (DML) was used in the curing of acrylic bone cements, based on poly(methylmethacrylate). The water absorption characteristics were studied, and the behavior was found to be similar to commercial bone cements. The net amount of solubles were also in the same range as obtained for commercial cements cured with conventional activators. Biocompatibility tests were conducted on the neat activator (DML) and cured cements. The present study indicated that there were no toxic effects; furthermore, osteoblast-like cells were seen to proliferate and differentiate more readily on DML containing cements. The analysis of the effect of leachables from cements into the media showed continued cell proliferation and cell viability. PMID:10490688

Deb, S; Silvio, L D; Vazquez, B; San Roman, J

1999-01-01

326

First CRDS-measurements of water vapour continuum in the 940 nm absorption band  

Microsoft Academic Search

Measurements of near-infrared water vapour continuum using continuous wave cavity ring down spectroscopy (cw-CRDS) have been performed at around 10611.6 and 10685.2cm-1. The continuum absorption coefficients for N2-broadening have been determined to be CF296K=(1.0±0.2)×10-24cm2mol-1atm-1 and CF278K=(1.8±0.4)×10-24cm2mol-1atm-1 at 10611.6cm-1, and CF296K=(1.6±0.5)×10-24cm2mol-1atm-1 and CF278K=(2.1±0.4)×10-24cm2mol-1atm-1 at 10685.2cm-1, respectively.These results represent the first near-IR continuum laboratory data determined within the complex spectral environment in

L. Reichert; M. D. Andrés Hernández; J. P. Burrows; A. B. Tikhomirov; K. M. Firsov; I. V. Ptashnik

2007-01-01

327

Comparison of path integral molecular dynamics methods for the infrared absorption spectrum of liquid water.  

PubMed

The ring polymer molecular dynamics (RPMD) and partially adiabatic centroid molecular dynamics (PA-CMD) methods are compared and contrasted in an application to the infrared absorption spectrum of a recently parametrized flexible, polarizable, Thole-type potential energy model for liquid water. Both methods predict very similar spectra in the low-frequency librational and intramolecular bending region at wavenumbers below 2500 cm(-1). However, the RPMD spectrum is contaminated in the high-frequency O-H stretching region by contributions from the internal vibrational modes of the ring polymer. This problem is avoided in the PA-CMD method, which adjusts the elements of the Parrinello-Rahman mass matrix so as to shift the frequencies of these vibrational modes beyond the spectral range of interest. PA-CMD does not require any more computational effort than RPMD and it is clearly the better of the two methods for simulating vibrational spectra. PMID:19044777

Habershon, Scott; Fanourgakis, George S; Manolopoulos, David E

2008-08-21

328

Comparison of path integral molecular dynamics methods for the infrared absorption spectrum of liquid water  

NASA Astrophysics Data System (ADS)

The ring polymer molecular dynamics (RPMD) and partially adiabatic centroid molecular dynamics (PA-CMD) methods are compared and contrasted in an application to the infrared absorption spectrum of a recently parametrized flexible, polarizable, Thole-type potential energy model for liquid water. Both methods predict very similar spectra in the low-frequency librational and intramolecular bending region at wavenumbers below 2500 cm-1. However, the RPMD spectrum is contaminated in the high-frequency O-H stretching region by contributions from the internal vibrational modes of the ring polymer. This problem is avoided in the PA-CMD method, which adjusts the elements of the Parrinello-Rahman mass matrix so as to shift the frequencies of these vibrational modes beyond the spectral range of interest. PA-CMD does not require any more computational effort than RPMD and it is clearly the better of the two methods for simulating vibrational spectra.

Habershon, Scott; Fanourgakis, George S.; Manolopoulos, David E.

2008-08-01

329

Removal of Heavy Metals from Water: An Environmentally Significant Atomic Absorption Spectrometry Experiment  

NASA Astrophysics Data System (ADS)

A laboratory experiment that combines the environmentally significant topic of wastewater treatment with atomic absorption spectrometry (AAS) is described. In the first portion of the laboratory project, students perform treatment studies on simulated wastewater samples that contain heavy metal contaminants common to the effluent of the metal finishing industry. Following pretreatment reduction of Cr(VI) to Cr(III), sparingly soluble metal hydroxides are produced by pH adjustment and removed by filtration with the aid of a polyacrylamide flocculant. In the second portion of the experiment, AAS is used to determine metal concentrations in treated and untreated water samples, thus enabling the students to determine the effectiveness of the treatment process. Details of how this experiment integrates topics such as the pH-dependent solubility of metal hydroxides, complex equilibria, matrix interference, and polymers in the context of an environmentally important analysis are presented.

Buffin, Brian P.

1999-12-01

330

Gravity factor of the formation of the field and capillary water capacities in soils and artificial layered soil-like bodies  

Microsoft Academic Search

The water retention capacity of soils characterizes a quasiequilibrium between the forces retaining and removing the soil\\u000a water. It has been studied under field and laboratory conditions. It is shown that the gravity factor, as well as the soil\\u000a particle-size distribution and structure, has an important role in determining the soil water capacity after the outflow of\\u000a gravitational water. Our

A. V. Smagin; G. M. Khakimova; D. A. Khineeva; N. B. Sadovnikova

2008-01-01

331

2008 Upper Arkansas Water Conservancy District Temporary Excess Capacity Contract, Fryingpan-Arkansas Project. Environmental Assessment.  

National Technical Information Service (NTIS)

In general, the purpose of the issuance of excess storage capacity contracts is to maximize the use of existing infrastructure to support entities with temporary municipal, industrial, irrigation, fishery, and recreation needs in their response to increas...

2008-01-01

332

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

NASA Technical Reports Server (NTRS)

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.

Rall, Jonathan A. R.

1994-01-01

333

Forest structure and biomass estimates derived from red edge and water absorption geometry using AVIRIS data  

NASA Astrophysics Data System (ADS)

Geometric analysis of spectral signatures collected from known forest sites using narrow spectral bands in the red-edge and five water absorption regions are the basis for developing ratios to estimate forest biomass and canopy structure. The study area used to test the methodology was located within Congaree Swamp National Monument in central South Carolina. This is one of the oldest stands of hardwood bottomland forest preserved in the United States. Low altitude-high spatial resolution AVIRIS data collected at 3,800-meter altitude, that produced a 3.8 meter spatial resolution, were associated with USGS-NPS National Vegetation Inventory data in order to develop narrow band spectral analysis. Ratios were developed based on geometric properties of spectral signatures associated with biomass and canopy categories identified during spectral analysis and used as input data for a series of high dimensional unsupervised classifications. The ratios were developed from the four best performing spectral intervals: the red edge and three water absorption regions. Classification results were compared to test sites for accuracy assessment. The ratios produced from selected spectral bands in the regions between 707 and 754 nm, 918 and 994 nm, 1448 and 1480nm, and 1963 and 1993 nm showed significant spectral discrimination of vegetation features associated with the three categories of biomass and canopy. The research indicates that the limited areal coverage provided by ground truth data prevented a good correlation between image processing results and vegetation inventory data. Nonetheless, results of spectral analyses showed that biomass and canopy attributes could be identified using band ratios based on geometric properties of electromagnetic responses in the spectral regions selected. It is recommended that further research should be based on more extensive ground truth in order to evaluate forest feature detection ability of the ratios proposed. This methodology can be applied to other forest areas with minor adjustments.

Dias, Nelson Wellausen

334

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

SciTech Connect

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.

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

335

Variability of Water and Oxygen Absorption Bands in the Disk-integrated Spectra of Earth  

NASA Astrophysics Data System (ADS)

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 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 data. A difference in the diurnal variability patterns of H2O and O2 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 H2O 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.

Fujii, Yuka; Turner, Edwin L.; Suto, Yasushi

2013-03-01

336

Changes in water?soluble and exchangeable ions, cation exchange capacity, and phosphorusmax in soils under alternating waterlogged and drying conditions  

Microsoft Academic Search

The effects of waterlogging and subsequent drying on pH, Eh, dissolved oxygen (DO), water soluble ions, exchangeable cations, cation exchange capacity (CEC), and phosphorus sorption capacity (Pmax) in three soils were studied (krasnozem, sandy loam, and highly organic material from a Melaleuca wetland). Fifty grams of each soil were mixed with 75 mL of distilled water, and left in a

I. R. Phillips; M. Greenway

1998-01-01

337

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

338

Muscle water control in crustaceans and fishes as a function of habitat, osmoregulatory capacity, and degree of euryhalinity.  

PubMed

This study aimed at detecting possible patterns in the relationship between Anisosmotic Extracellular Regulation (AER) and Isosmotic Intracellular Regulation (IIR) in crustaceans and teleost fish from different habitats and evolutionary histories in fresh water (FW), thus different osmoregulatory capabilities, and degrees of euryhalinity. Crustaceans used were the hololimnetic FW Aegla schmitti, and Macrobrachium potiuna, the diadromous FW Macrobrachium acanthurus, the estuarine Palaemon pandaliformis and the marine Hepatus pudibundus; fishes used were the FW Corydoras ehrhardti, Mimagoniates microlepis, and Geophagus brasiliensis, and the marine-estuarine Diapterus auratus. The capacity for IIR was assessed in vitro following wet weight changes of isolated muscle slices incubated in anisosmotic saline (~50% change). M. potiuna was the crustacean with the highest capacity for IIR; the euryhaline perciforms G. brasiliensis and D. auratus displayed total capacity for IIR. It is proposed that a high capacity for IIR is required for invading a new habitat, but that it is later lost after a long time of evolution in a stable habitat, such as in the FW anomuran crab A. schmitti, and the Ostariophysian fishes C. ehrhardti and M. microlepis. More recent FW invaders such as the palaemonid shrimps (M. potiuna and M. acanthurus) and the cichlid G. brasiliensis are euryhaline and still display a high capacity for IIR. PMID:18325804

Freire, Carolina A; Amado, Enelise M; Souza, Luciana R; Veiga, Marcos P T; Vitule, Jean R S; Souza, Marta M; Prodocimo, Viviane

2008-04-01

339

Assessing water resources adaptive capacity to climate change impacts in the Pacific Northwest Region of North America  

NASA Astrophysics Data System (ADS)

Climate change impacts in Pacific Northwest Region of North America (PNW) are projected to include increasing temperatures and changes in the seasonality of precipitation (increasing precipitation in winter, decreasing precipitation in summer). Changes in precipitation are also spatially varying, with the northwestern parts of the region generally experiencing greater increases in cool season precipitation than the southeastern parts. These changes in climate are projected to cause loss of snowpack and associated streamflow timing shifts which will increase cool season (October-March) flows and decrease warm season (April-September) flows and water availability. Hydrologic extremes such as the 100 yr flood and extreme low flows are also expected to change, although these impacts are not spatially homogeneous and vary with mid-winter temperatures and other factors. These changes have important implications for natural ecosystems affected by water, and for human systems. The PNW is endowed with extensive water resources infrastructure and well-established and well-funded management agencies responsible for ensuring that water resources objectives (such as water supply, water quality, flood control, hydropower production, environmental services, etc.) are met. Likewise, access to observed hydrological, meteorological, and climatic data and forecasts is in general exceptionally good in the United States and Canada, and is often supported by federally funded programs that ensure that these resources are freely available to water resources practitioners, policy makers, and the general public. Access to these extensive resources support the argument that at a technical level the PNW has high capacity to deal with the potential impacts of natural climate variability on water resources. To the extent that climate change will manifest itself as moderate changes in variability or extremes, we argue that existing water resources infrastructure and institutional arrangements provide a reasonably solid foundation for coping with climate change impacts, and that the mandates of existing water resources policy and water resources management institutions are at least consistent with the fundamental objectives of climate change adaptation. A deeper inquiry into the underlying nature of PNW water resources systems, however, reveals significant and persistent obstacles to climate change adaptation, which will need to be overcome if effective use of the region's extensive water resources management capacity can be brought to bear on this problem. Primary obstacles include assumptions of stationarity as the fundamental basis of water resources system design, entrenched use of historical records as the sole basis for planning, problems related to the relatively short time scale of planning, lack of familiarity with climate science and models, downscaling procedures, and hydrologic models, limited access to climate change scenarios and hydrologic products for specific water systems, and rigid water allocation and water resources operating rules that effectively block adaptive response. Institutional barriers include systematic loss of technical capacity in many water resources agencies following the dam building era, jurisdictional fragmentation affecting response to drought, disconnections between water policy and practice, and entrenched bureaucratic resistance to change in many water management agencies. These factors, combined with a federal agenda to block climate change policy in the US during the Bush administration have (with some exceptions) contributed to widespread institutional "gridlock" in the PNW over the last decade or so despite a growing awareness of climate change as a significant threat to water management. In the last several years, however, significant progress has been made in surmounting some of these obstacles, and the region's water resources agencies at all levels of governance are making progress in addressing the fundamental challenges inherent in adapting to climate change.

Hamlet, A. F.

2011-05-01

340

The room temperature annealing peak in ionomers: Ionic crystallites or water absorption  

SciTech Connect

A quaternized diol, 3-(trimethylammonio)-1,2-propanediol neutralized with either bromine or iodine, was used to produce a polyurethane cationomer with a poly(tetramethylene oxide) soft segment and a 4,4[prime]-diphenylmethane diisocyanate hard segment. If those cationomers were annealed at room temperature for a period of approximately 1 month in a desiccator filled with dry CaSO[sub 4], differential scanning calorimetry (DSC) studies showed an endotherm centered near 70 C which was not present in the unannealed polymer and did not reappear upon subsequent cooling and heating cycles in the DSC. Some authors have suggested that a very similar endotherm found in other ionomers, most notably ethylene-methacrylic acid (E-MAA) copolymer ionomers, was due to an order-disorder transition within the ionic aggregates, i.e. ionic crystallite melting. In order to isolate the origin of this endotherm, the local environment around the anion in compression molded bromine neutralized samples was measured using the extended X-ray absorption fine-structure (EXAFS) technique. By measuring the change in the local environment over the temperature range corresponding to the DSC endotherm, it has been shown that this endotherm corresponds to water leaving the bromine coordination shell, rather than ionic crystallite melting. Other studies which include thoroughly drying the material in a vacuum oven below the transition temperature to remove the water suggest that the endotherm is due to the energetic change associated with water leaving the coordination environment of the anion in combination with water vaporization.

Goddard, R.J.; Grady, B.P.; Cooper, S.L. (Univ. of Wisconsin, Madison, WI (United States). Dept. of Chemical Engineering)

1994-03-28

341

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

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

342

Conditional stability constants and binding capacities for copper (II) by ultrafilterable material isolated from six surface waters of Wyoming, USA  

Microsoft Academic Search

Ultrafilterable material < 0.15 µm was collected from six Wyoming surface waters, for which the chemical limnology had also been determined. The material was separated into four nominal size-fractions and the binding capacity of each for copper was determined by a hyperbolic, site-saturation model. The conditional, overall, thermodynamic stability constants (K') for binding of copper were determined by two discrete

John P. Giesy; James J. Alberts

1989-01-01

343

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

NASA Technical Reports Server (NTRS)

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.

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

1982-01-01

344

Research on the accuracy of spectral calibration using atmospheric absorption features with different water vapor contents  

NASA Astrophysics Data System (ADS)

Nowadays, spectrometers are being increasingly used in the remote sensing of the earth system processes and they can be well conducted field spectral calibrated by using absorption features of atmospheric profile. The spectral calibration accuracy of an ASD spectrometer in different atmospheric conditions is analyzed in this paper. First of all, set the atsensor spectral radiance spectrum as the reference spectral curve, which is generated by the MODTRAN5 radiative transfer model outputs convolved with the spectral response function of each channel. The results can be totally different when input different water vapor contents. Meanwhile, under the same atmospheric conditions (the same observation target, the sun elevation angle, azimuth, aerosol distribution, composition and concentration distribution of atmosphere..etc. ), the diffuser whiteboard is measured by the ASD spectrometer to acquire observed spectral curve. The best spectral matching algorithm is used to compare the observed spectrum with the reference one. Central wavelength of the ASD is obtained by calculating the results of matching spectrum shifts within feature spectrum range. Finally, quantitative analysis and calculation about the effect on the accuracy of instrument spectral calibration with different water vapor contents is presented.

Li, Lin; Hu, Yong; Gong, Cailan; Wang, Yueming; Ding, Xuezhuan; He, Huaying; Zhu, Lingya

2012-10-01

345

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

NASA Astrophysics Data System (ADS)

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.

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

2013-08-01

346

A direct, evaporatively cooled, three-ton lithium bromide-water absorption chiller for solar application  

SciTech Connect

Lithium bromide absorption machines first appeared commercially circa 1940. In all designs marketed, absorber/condenser heat has been rejected from the cycle through shell-and-tube exchangers to circulating water that is then processed in contact with the ambient air through a cooling tower. In mechanical refrigeration technology, evaporative condensing products have been an available alternative to water-cooled condensers with separate cooling towers. Lithium bromide machines have not been available with this alternative, mainly because of the difficulty of managing internal and external heat transfer processes through a common surface configuration that would meet all the needs satisfactorily. The main focus of this paper is the development of a direct, evaporatively cooled absorber/condenser. Other features of the chiller already displayed in the past or presently available hardware on the market will not be a part of this discussion. A second objective is to establish the significance of evaporative cooling for active solar-cooling devices and, in particular, as an alternative to dry-air cooling as the means of heat rejection for solarcooling equipment.

Merrick, R.H.

1982-01-01

347

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

PubMed Central

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.

Pabari, RM; Ramtoola, Z

2012-01-01

348

Light tracking through ice and water—Scattering and absorption in heterogeneous media with PHOTONICS  

NASA Astrophysics Data System (ADS)

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.

Lundberg, J.; Mio?inovi?, P.; Woschnagg, K.; Burgess, T.; Adams, J.; Hundertmark, S.; Desiati, P.; Niessen, P.

2007-11-01

349

Theoretical study of negative thermal expansion in Y2Mo3O12: effect of water absorption  

NASA Astrophysics Data System (ADS)

Y2Mo3O12 exhibits negative thermal expansion (NTE) in a large temperature range (473 ˜ 1173 K). However, the material strongly absorb water and form a stable trihydrate structure, where the NTE disappears. Raman spectra revealed that some vibrational modes were missing in the hydrated structure. By DFT calculations, absorption of water in Y2Mo3O12 has been studied. Our results showed that water can strongly absorb in Y2Mo3O12 with O end of the water binding to Y cation, while one hydrogen approaches to the bridge O, which shared by polyhedrons YO6 and MoO4, and forms hydrogen bond. The absorption of water leads the angle of Y-O-Mo reduced, decreasing Y-Mo distance and consequently the volume of the material contracted. Calculated phonon spectra showed that the transverse vibration of Y-O-Mo is restricted due to water absorption. As a result, the NTE, originated from the vibrational mode, is hindered. Our MD simulations also revealed that water can easily diffuse and cross different channels in the material with the aid of Y cations. [4pt] [1] S. Sumithra, A. M. Umarji, Solid State Sci. 8, 1453(2006).[0pt] [2] E. J. Liang, H. L. Huo, J. P. Wang, M. J. Chao, J. Phys. C. 112, 6577(2008).

Sun, Qiang; Wu, Mingyi; Wang, Lei; Jia, Yu

2013-03-01

350

Design And Implementation Of A Water-Quality Monitoring Program In Support Of Establishing User Capacities In Yosemite National Park  

NASA Astrophysics Data System (ADS)

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.

Peavler, R. S.; Clow, D. W.; Panorska, A. K.

2008-12-01

351

In Situ Intestinal Absorption of a Poorly Water-Soluble Drug From Mixed Micellar Solutions of Bile Salt and Lipolysis Products in Rats  

Microsoft Academic Search

The role of a bile salt (sodium taurocholate) and lipolysis products (monoglyceride and fatty acid) in the intestinal absorption of a poorly water-soluble drug, diazepam, was investigated. Absorption rates and bioavailabilities were determined with the in situ rat gut technique of Doluisio et al. and analyzing the diazepam concentrations in the luminal solution, intestinal membrane, blood and lymph. The absorption

A. T. M. Serajuddin; M. Rosoff; A. H. Goldberg

1985-01-01

352

Specific absorption and backscattering coefficients of the main water constituents in Poyang Lake, China.  

PubMed

Obtaining and analyzing the specific inherent optical properties (SIOPs) of water bodies is necessary for bio-optical model development and remote sensing-based water quality retrievals and, further, for related ecological studies of aquatic ecosystems. This study aimed to measure and analyze the specific absorption and backscattering coefficients of the main water constituents in Poyang Lake, China. The specific absorption and/or backscattering coefficients of the main water constituents at 85 sampling sites (47 in 2010 and 38 in 2011) were measured and analyzed as follows: (1) the concentrations of chlorophyll a (C(CHL)), 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)), and non-pigment particulate (a(d)) were measured in the laboratory; (2) the total backscattering coefficients at six wavelengths of 420, 442, 470, 510, 590, and 700 nm, including the contribution of pure water, were measured in the field with a HydroScat-6 backscattering sensor, and 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; (3) the specific absorption coefficients of total particulate (a*(p)), phytoplankton (a(ph)*), and non-pigment particulate (a*(d)) were calculated by dividing a(p), a(ph), and ad by C(SPM), C(CHL), and C(SPIM), respectively, while the specific backscattering coefficients of total suspended particulate matter (b*(b)) were calculated by dividing b(b) by CSPM; and (4) the a(ph)*, a*(d), a*(p) and b*(b) of the remaining samples (46 in 2010 and 36 in 2011) were visualized and analyzed, and their relations to CCHL, CSPIM or CSPM were studied, respectively. The main results are summarized as follows: (1) the a(ph)* values at 440 nm were 0.0367-0.7203 m(2) mg(-1) with a mean of 0.1623 ± 0.1426 m(2) mg(-1) in 2010 and 0.0319-0.7735 m(2) mg(-1) with a mean of 0.3145 ± 0.1961 m(2) mg(-1) in 2011; there existed significant, negative, and moderate correlations between a(ph)* and C(CHL) at 400-700 nm in 2010 and 2011 (p<0.05); (2) The a*(d) values at 440 nm were 0.0672-0.2043 m(2) g(-1) with a mean of 0.1022 ± 0.0326 m(2) g-1) in 2010 and 0.0559-0.1347 m(2) g(-1) with a mean of 0.0953 ± 0.0196 m(2) g(-1) in 2011; there existed negative correlations between a*(d) and C(SPIM), while the correlations showed overall decreasing and increasing trends before and after around 575 nm with increasing wavelengths, respectively; (3) The a*(p) values at 440 nm were 0.0690-0.1929 m(2) g(-1) with a mean of 0.1036 ± 0.0298 m(2) g(-1) in 2010 and 0.0571-0.1321 m(2) g(-1) with a mean of 0.1014 ± 0.0191 m(2) g(-1) in 2011, and the negative correlations between a*(p) and C(SPM) were found in both years; (4) The b*(b) at the six wavelengths generally decreased with increasing wavelengths, while the b*(b) values at 420 nm were lower than those at 442 nm for some samples; the correlation between b*(b) and C(SPM) increased with increasing wavelength. Such results can only represent the SIOPs during the sampling time periods, and more measurements and analyses considering different seasons need to be carried out in the future to comprehensively understand the SIOPs of Poyang Lake. PMID:22976118

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

2013-05-01

353

Parameterization of light absorption by components of seawater in optically complex coastal waters of the Crimea Peninsula (Black Sea).  

PubMed

The absorption of sunlight by oceanic constituents significantly contributes to the spectral distribution of the water-leaving radiance. Here it is shown that current parameterizations of absorption coefficients do not apply to the optically complex waters of the Crimea Peninsula. Based on in situ measurements, parameterizations of phytoplankton, nonalgal, and total particulate absorption coefficients are proposed. Their performance is evaluated using a log-log regression combined with a low-pass filter and the nonlinear least-square method. Statistical significance of the estimated parameters is verified using the bootstrap method. The parameterizations are relevant for chlorophyll a concentrations ranging from 0.45 up to 2 mg/m(3). PMID:19252624

Dmitriev, Egor V; Khomenko, Georges; Chami, Malik; Sokolov, Anton A; Churilova, Tatyana Y; Korotaev, Gennady K

2009-03-01

354

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

NASA Astrophysics Data System (ADS)

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.

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

2005-12-01

355

Ponding-test procedure for assessing the infiltration capacity of storm-water basins, Nassau County, New York  

USGS Publications Warehouse

A procedure to obtain field data for assessing performance of storm-water basins having high infiltration rates is described. The basin selected is divided into test plots, and treated municipal water from a fire hydrant is ponded to the desired depth so that infiltration rates and flow patterns in the unsaturated zone can be determined by standard methods. The study was made at a storm-water basin excavated in glacial outwash deposits in Nassau County, Long Island, N.Y. in 1971-72. The types of interpretations and evaluations that can be made from test data are described, and applications of the procedure as well as guidelines for developing a similar testing program are given. Observations of special significance were: (1) Infiltration rate of the basin at low water stage is about 1.5 feet per hour but increases with increased water level; (2) flow through the unsaturated zone is essentially vertical; (3) infiltration rate is controlled by a surface stratum --in this case a gravelly, sandy loam; and (4) the position of the water table has little effect on infiltration rate provided it is below the lower boundary of the controlling zone. These observations can be used in evaluating a storm-water basin's suitability for supplemental recharge with treated wastewater, in comparing procedures for increasing a basin's infiltration capacity, or in the design of new storm-water basin systems.

Prill, Robert C.; Aronson, David A.

1978-01-01

356

Seed ultrastructure and water absorption pathway of the root-parasitic plant Phelipanche aegyptiaca (Orobanchaceae)  

PubMed Central

Background and Aims Obligate root parasitic plants of the Orobanchaceae do not germinate unless they chemically detect a host plant nearby. Members of this family, like Orobanche, Phelipanche and Striga, are noxious weeds that cause heavy damage to agriculture. In spite of their economic impact, only a few light microscopical studies of their minute seeds have been published, and there is no knowledge of their ultrastructure and of the role each tissue plays during the steps preceding germination. This paper describes the ultrastructure of Phelipanche seeds and contributes to our understanding of seed tissue function. Methods Seeds of P. aegyptiaca were examined under light, scanning electron, transmission electron and fluorescence microscopy following various fixations and staining protocols. The results were interpreted with physiological data regarding mode of water absorption and germination stimulation. Key Results and Conclusions The endothelium, which is the inner layer of the testa, rapidly absorbs water. Its interconnected cells are filled with mucilage and contain labyrinthine walls, facilitating water accumulation for germination that starts after receiving germination stimuli. Swelling of the endothelium leads to opening of the micropyle. The perisperm cells underneath this opening mediate between the rhizosphere and the embryo and are likely to be the location for the receptors of germination stimuli. The other perisperm cells are loaded with lipids and protein bodies, as are the endosperm and parts of the embryo. In the endosperm, the oil bodies fuse with each other while they are intact in the embryo and perisperm. Plasmodesmata connect the perisperm cells to each other, and the cells near the micropyle tightly surround the emerging seedling. These perisperm cells, and also the proximal embryo cells, have dense cytoplasmic contents, and they seem to represent the two seed components that are actively involved in transfer of reserve nutrients to the developing seedling during germination.

Joel, Daniel M.; Bar, Hilla; Mayer, Alfred M.; Plakhine, Dina; Ziadne, Hammam; Westwood, James H.; Welbaum, Gregory E.

2012-01-01

357

Infrared Reflection Absorption Spectroscopy of Amphipathic Model Peptides at the Air/Water Interface  

PubMed Central

The linear sequence KLAL (KLALKLALKALKAALKLA-NH2) and its corresponding d,l-isomers k9a10-KLAL (KLALKLALkaLKAALKLA-NH2) and l11k12-KLAL (KLALKLALKAlkAALKLA-NH2) are model compounds for potentially amphipathic ?-helical peptides which are able to bind to membranes and to increase the membrane permeability in a structure- and target-dependent manner (Dathe and Wieprecht, 1999) We first studied the secondary structure of KLAL and its analogs bound to the air/water using infrared reflection absorption spectroscopy. For the peptide films the shape and position of the amide I and amide II bands indicate that the KLAL adopts at large areas per molecule an ?-helical secondary structure, whereas at higher surface pressures or smaller areas it converts into a ?-sheet structure. This transition could be observed in the compression isotherm as well as during the adsorption at the air/water interface from the subphase as a function of time. The secondary structures are essentially orientated parallel to the air/water interface. The analogs with d-amino acids in two different positions of the sequence, k9a10-KLAL and l11k12-KLAL, form only ?-sheet structures at all surface pressures. The observed results are interpreted using a comparison of hydrophobic moments calculated for ?-helices and ?-sheets. The differences between the hydrophobic moments calculated using the consensus scale are not large. Using the optimal matching hydrophobicity scale or the whole-residue hydrophobicity scale the ?-sheet even has the larger hydrophobic moment.

Kerth, Andreas; Erbe, Andreas; Dathe, Margitta; Blume, Alfred

2004-01-01

358

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

SciTech Connect

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.

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

359

Trace Metals In Seawater: Chelation Capacities, Conditional Stability Constants, And Water Sampler Evaluations (copper, Zinc, Lead)  

Microsoft Academic Search

In this study, the use of anodic stripping voltammetry and copper titrations for the determination of complexation capacity and conditional stability constants for copper-organic complexes in seawater has been evaluated. Pseudopolarogram studies showed that there were two separate polarographic waves corresponding to the reduction of inorganic copper complexes and to the reduction of organic forms of copper. An equation for

Mary Jo Spencer

1984-01-01

360

Fuzzy Matter Element Model for Evaluating Environmental Carrying Capacity of Ground Water  

Microsoft Academic Search

Groundwater is important for people to live, environmental carrying capacity of groundwater is more important for industry and agriculture and people and the earth to exist and develop. On basis of the matter element theory, the fuzzy-matter element model based on informational entropy (FM-IE) is built by combining informational entropy and fuzzy theory and matter element & extension set; it

Baohui Men

2009-01-01

361

Analysis on the exploitable potentiality and carrying capacity of water resources in Inner Mongolia  

Microsoft Academic Search

With the development of society and economy, more and more people have concerned increasingly about water problem, which affect people's life and regional sustainable development. In this study, by using the model of load factors of water resources, taking population development as weigh factor, to water requirement per city in different situation as change factor, to evaluate exploitable potentiality and

Xing Li; Yong Wang; Mangmang Gou

2011-01-01

362

URBAN MANAGEMENT MODELCONCERNING THE ATTENDING CAPACITY OF THE WATER SUPPLY SYSTEM  

Microsoft Academic Search

The worldwide production of potable water represents a without cease enormous challenge. Each year 80 million new persons seek their rights for aqueous resources over the earth surface. Unhappily almost three billion new inhabitants for the next fifty years will be born in lands where scarcity of water is already nowadays present. Brazilians seem not worried with their water reserves

L. H. A. Lopes; C. Loch; H.-P. Bähr; WG VII

363

Atmospheric pre-corrected differential absorption techniques to retrieve columnar water vapor: Application to AVIRIS 91/95 data  

SciTech Connect

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 run resolution. This data includes 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 rationing 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, spectral transmittance and radiance are calculated by MODTRAN3 simulations with the new DISORT option. This work testS the best performing differential absorption techniques for imaging spectrometry of tropospheric water vapor.

Schlaepfer, D. [Univ. of Zuerich (Switzerland). Dept. of Geography; Borel, C.C. [Los Alamos National Lab., NM (United States); Keller, J. [Paul Scherrer Institut, Villigen (Switzerland)] [and others

1996-03-01

364

Optical absorption spectra of waters from the Orinoco River outflow: Terrestrial input of colored organic matter to the Caribbean  

Microsoft Academic Search

An extensive series of optical absorption spectra were recorded for waters in the eastern Caribbean Sea, the Gulf of Paria, and the Orinoco River Estuary during the high-flow period of the Orinoco River in the Fall of 1988. Evidence for high levels of dissolved, colored organic matter (COM) was found throughout the eastern Caribbean, with these levels increasing substantially at

N. V. Blough; O. C. Zafiriou; J. Bonilla

1993-01-01

365

Light absorption and fluorescence properties of chromophoric dissolved organic matter (CDOM), in the St. Lawrence Estuary (Case 2 waters)  

Microsoft Academic Search

The absorption coefficient and the fluorescence emission of chromophoric (coloured) dissolved organic matter (CDOM) were determined along a 1200 km transect in the Estuary and Gulf of St. Lawrence. Fluorescence spectra were spectrally corrected against a reference standard and normalized to the water Raman signal to provide results in Raman units. Because CDOM originates mainly from freshwater river runoff in

B. Nieke; R. Reuter; R. Heuermann; H. Wang; M. Babin; J. C. Therriault

1997-01-01

366

Gum arabic promotes rat jejunal sodium and water absorption from oral rehydration solutions in two models of diarrhea  

Microsoft Academic Search

BACKGROUND & AIMS: We have shown that addition of gum arabic (GA) to a 90 mmol\\/L sodium-111 mmol\\/L glucose oral rehydration solution (ORS) enhances its effectiveness for water and electrolyte absorption in normal rats. The present study extends these observations on GA in ORS to two rat models of diarrheal disease. METHODS: Juvenile rats were either treated for 1 week

RA Wapnir; MA Wingertzahn; J Moyse; S Teichberg

1997-01-01

367

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

Microsoft Academic Search

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

José Fernández-Seara; Jaime Sieres; Manuel Vázquez

2003-01-01

368

Attempt of integration of a small commercial ammonia-water absorption refrigerator with a solar concentrator: Experience and results  

Microsoft Academic Search

The integration of a small commercial ammonia-water absorption refrigerator with a solar concentrator as heat source was analyzed theoretically and experimentally. Operation parameters of the fridge were determined by parametric fitting experimental data using a thermodynamic model of the cycle leading to a working pressure of 25 bar, weak and strong solution concentrations of 15% and 30% respectively and a COP

A. Busso; J. Franco; N. Sogari; M. Cáceres

2011-01-01

369

Heat transfer coefficients in two phase flow for the water\\/lithium bromide mixture used in solar absorption refrigeration systems  

Microsoft Academic Search

This paper describes the experimental results obtained from the heat transfer in saturated nucleate boiling for the water\\/lithium bromide mixture flowing upward in a uniformly heated vertical tube, which is the generator of a solar absorption refrigeration system. The concentration range for the mixture was from 48 to 56wt.% Plots of local and average heat transfer coefficients are shown against

W. Rivera; A. Xicale

2001-01-01

370

Retrieval of Upper Precipitable Water Profile Based on MOS-1/VTIR H2O Absorption Channel Data.  

National Technical Information Service (NTIS)

An attempt is made to retrieve precipitable water profile within the range from top of the atmosphere down to the level of 500 mb based on MOS-1 (Marine Observation Satellite-1) VTIR (Visible and Thermal Infrared Radiometer) H2O absorption channel data. T...

M. Matsumoto S. Takasaki K. Tsuchiya

1990-01-01

371

The effect of clinker and limestone quality on the gas permeability, water absorption and pore structure of limestone cement concrete  

Microsoft Academic Search

In this paper the effect of clinker and limestone quality on the air permeability, water absorption and pore structure of limestone cement concrete is investigated. Portland limestone cements of different fineness and limestone content have been produced by intergrinding clinker, gypsum and limestone. Two clinkers with different chemical composition, mineralogical composition and strength development as well as three limestones, differing

S. Tsivilis; E. Chaniotakis; G. Batis; C. Meletiou; V. Kasselouri; G. Kakali; A. Sakellariou; G. Pavlakis; C. Psimadas

1999-01-01

372

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

NASA Astrophysics Data System (ADS)

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.

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

2014-02-01

373

Effect of intravenous ranitidine and omeprazole on intestinal absorption of water, sodium, and macronutrients in patients with intestinal resection  

PubMed Central

Background—H2 receptor blockers and proton pump inhibitors reduce intestinal output in patients with short bowel syndrome. ?Aims—To evaluate the effect of intravenous omeprazole and ranitidine on water, electrolyte, macronutrient, and energy absorption in patients with intestinal resection. ?Methods—Thirteen patients with a faecal weight above 1.5 kg/day (range 1.7-5.7 kg/day and a median small bowel length of 100cm were studied. Omeprazole 40 mg twice daily or ranitidine 150mg twice daily were administered for five days in a randomised, double blind, crossover design followed by a three day control period with no treatment. Two patients with a segment of colon in continuation were excluded from analysis which, however, had no influence on the results. ?Results—Omeprazole increased median intestinal wet weight absorption compared with no treatment and ranitidine (p<0.03). The effect of ranitidine was not significant. Four patients with faecal volumes below 2.6 kg/day did not respond to omeprazole; in two absorption increased by 0.5-1 kg/day; and in five absorption increased by 1?2 kg/day. Absorption of sodium, calcium, magnesium, nitrogen, carbohydrate, fat, and total energy was unchanged. Four high responders continued on omeprazole for 12-15 months, but none could be weaned from parenteral nutrition. ?Conclusion—Omeprazole increased water absorption in patients with faecal output above 2.50 kg/day. The effect varied significantly and was greater in patients with a high output, but did not allow parenteral nutrition to be discontinued. Absorption of energy, macronutrients, electrolytes, and divalent cations was not improved. The effect of ranitidine was not significant, possibly because the dose was too low. ?? Keywords: short bowel syndrome; human; diarrhoea; ranitidine; omeprazole

Jeppesen, P; Staun, M; Tjellesen, L; Mortensen, P

1998-01-01

374

Sorption-capacity limited retardation of radionuclides transport in water-saturated packing materials  

SciTech Connect

Radionuclides breakthrough times as calculated through constant retardation factors obtained in dilute solutions are non-conservative. The constant retardation approach regards the solid as having infinite sorption capacity throughout the solid. However, as the solid becomes locally saturated, such as in the proximity of the waste form-packing materials interface, it will exhibit no retardation properties, and transport will take place as if the radionuclides were locally non-reactive. The magnitude of the effect of finite sorption capacity of the packing materials on radionuclide transport is discussed with reference to high-level waste package performance. An example based on literature sorption data indicates that the breakthrough time may be overpredicted by orders of magnitude using a constant retardation factor as compared to using the entire sorption isotherm to obtain a concentration-dependent retardation factor. 8 references, 3 figures, 3 tables.

Pescatore, C.; Sullivan, T.

1984-01-01

375

Adsorption Kinetics and Capacity of Fatty Acid-Modified Banana Trunk Fibers for Oil in Water  

Microsoft Academic Search

Oil spill leaves detrimental effects to environment, living organisms, and economy. As such, it is of considerable interest\\u000a to find an effective, simple, and inexpensive method to treat this calamity. This work reports the use of banana trunk fibers\\u000a (BTF) modified with oleic acid, stearic acid, castor oil, and palm oil for oil spill recovery. The maximum sorption capacity,\\u000a effect

Kathiresan Sathasivam; Mas Rosemal Hakim Mas Haris

2010-01-01

376

The apparent solubilizing capacity of simulated intestinal fluids for poorly water-soluble drugs.  

PubMed

Drug solubility testing in biorelevant media has become an indispensable tool in pharmaceutical development. Despite this importance, there is still an incomplete understanding of how poorly soluble compounds interact with these media. The aim of this study was to apply the concept of the apparent solubilization capacity to fasted and fed state simulated intestinal fluid (FaSSIF and FeSSIF, respectively). A set of non-ionized poorly soluble compounds was studied in biorelevant media prepared from an instantly dissolving complex (SIF(™) Powder) at 37°C. The values of the solubilization capacity were different between FaSSIF and FeSSIF but correlated. Drug inclusion into the mixed micelles was highly specific for a given compound. The ratio of the FeSSIF to FaSSIF solubility was in particular considered and discussed in terms of the apparent solubilizing capacity. The apparent solubilization concept appears to be useful for the interpretation of biorelevant solubility tests. Further studies are needed to explore acidic and basic drugs. PMID:20214530

Schwebel, Hervé J; van Hoogevest, Peter; Leigh, Mathew L S; Kuentz, Martin

2011-06-01

377

Influence of a surfactant additive on absorption heat pump performance  

NASA Astrophysics Data System (ADS)

Surfactant additives have been known for some time to influence the boiling characteristics of water and water-salt solutions. An enhancement of boiling transfer coefficients can be obtained by a proper choice of additives. When the capacity of an absorption heat pump is limited by its generator capacity and the generator is of the boiling-pool type, it is possible to increase the machine capacity by means of surfactant addition. In this paper, the preliminary experiments leading to the selection of a surfactant for a lithium bromide-water absorption heat pump are described. Minimum foaming was the most important consideration in this selection process. The measured machine performance shows that the generator capacity may be increased by values ranging from 5% to 10% of the original capacity. The actual value depends on the operating conditions as given by solution concentration, flow rate, and temperatures.

Michel, J. W.; Perez-Blanco, H.

1985-06-01

378

Water storage capacity in olivine and pyroxene to 14 GPa: Implications for the water content of the Earth's upper mantle and nature of seismic discontinuities  

NASA Astrophysics Data System (ADS)

Experiments were performed under water-saturated conditions in the MFSH (MgO-FeO-SiO2-H2O) and MFASH (MgO-FeO-Al2O3-SiO2-H2O) systems at 2.5, 5, 7.5 and 9 GPa, at temperatures from 1175 to 1400 °C and H2O initial abundance of 0.5-5 wt%. One experiment was performed at 13.5 GPa at a temperature of 1400 °C in the MFSH system. Water contents were analyzed by Fourier transform infrared spectroscopy. Results show that Al contents in olivine and pyroxene in equilibrium with an aluminous phase decrease significantly with increasing pressure and decreasing temperature. The incorporation of Al enhances water incorporation in olivine and pyroxene, but only at pressures of 2.5 and 5 GPa. At 7.5 GPa (i.e. 225 km depth) the pyroxene is monoclinic, indicating that in a hydrous mantle the orthoenstatite to clinoenstatite phase transition occurs at shallower depths than previously thought, which is more consistent with the Lehmann discontinuity than with the X discontinuity. The partitioning of water between pyroxene and olivine in the MFASH system decreases from a value of 2 at 2.5 GPa (80 km depth) to 0.9 at 9 GPa (270 km depth). At 13.5 GPa and 1400 °C, the water content of olivine is 1700±300 ppm wt H2O. The water partition coefficient between coexisting wadsleyite and olivine equals 4.7±0.7. We conclude that the water storage capacity of the upper mantle just above the 410 km discontinuity is of 1500±300 ppm wt H2O. If we assume that the Low Velocity Layer observed near 350 km is due to mantle melting, we can constrain the water content of the mantle at that depth to be ˜850±150 ppm wt H2O. This new value is four times higher than previous estimates for the mantle source of Mid Oceanic Ridge Basalts. Finally, comparison of the depth ranges of the L and X seismic discontinuities and the water storage capacity of the upper mantle suggests that the L-discontinuity (180-240 km) is concomitant with a kink in the water storage due to the orthorhombic to monoclinic phase transition in enstatite, while the X-discontinuity (240-340 km) coincides with a kink in the water storage capacity due to dehydration of garnet.

Férot, Anaïs; Bolfan-Casanova, Nathalie

2012-10-01

379

Measurement of the spectral absorption of liquid water in melting snow with an imaging spectrometer  

NASA Technical Reports Server (NTRS)

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.

Green, Robert O.; Dozier, Jeff

1995-01-01

380

Profiling tropospheric water vapour with a coherent infrared differential absorption lidar: a sensitivity analysis  

NASA Astrophysics Data System (ADS)

In the last decade the precision of coherent Doppler differential absorption lidar (DIAL) has been greatly improved in near and middle infra-red domains for measuring greenhouse gases such as CO2, CH4 and winds. The National Institute of Information and Communications Technology (NICT, Japan) has developed and is operating a CO2 and wind measuring ground-based coherent DIAL at 2.05 ?m (4878 cm-1). The application of this technology from space is now considered. In this analysis we study the use of the NICT DIAL for profiling tropospheric water vapour from space. We present the methodology to select the spectral lines and summarized the results of the selected lines between 4000 and 7000 cm-1. The choice of the frequency offset, the pulse energy and repetition frequency are discussed. Retrieval simulations from the line at 4580 cm-1 (2.18 ?m) suitable for the boundary layer and the stronger one at 5621 cm-1 (1.78 ?m) for sounding the boundary layer and the middle troposphere, are shown.

Baron, Philippe; Ishii, Shoken; Mizutani, Kohei; Itabe, Toshikazu; Yasui, Motoaki

2012-11-01

381

How to remove the influence of trace water from the absorption spectra of SWNTs dispersed in ionic liquids  

PubMed Central

Summary Single-walled carbon nanotubes (SWNTs) can be efficiently dispersed in the imidazolium-based ionic liquids (ILs), at relatively high concentration, with their intrinsic structure and properties retained. Due to the hygroscopicity of the ILs, water bands may be introduced in the absorption spectra of IL-dispersed SWNTs and cause problems in spectral deconvolution and further analysis. In order to remove this influence, a quantitative characterization of the trace water in [BMIM]+[PF6]? and [BMIM]+[BF4]? was carried out by means of UV–vis-NIR absorption spectroscopy. A simple yet effective method involving spectral subtraction of the water bands was utilized, and almost no difference was found between the spectra of the dry IL-dispersed SWNT samples treated under vacuum for 10 hours and the spectra of the untreated samples with subtraction of the pure water spectrum. This result makes it more convenient to characterize SWNTs with absorption spectra in the IL-dispersion system, even in the presence of trace amount of water.

Zhang, Daqi

2011-01-01

382

The dynamic viscoelasticity and water absorption characteristics of soft acrylic resin materials containing adipates and a maleate plasticizer.  

PubMed

The purpose of this study was to investigate the use of different plasticizers in soft acrylic resin materials to reduce leaching of the plasticizer and thus increase the durability of tissue conditioners. Samples were prepared containing different combinations of three types of polymer/copolymer powder and four types of plasticizer liquid (DEHM, DIBA, DAA and DINA). The dynamic viscoelasticity of each sample was measured after water immersion using a dynamic mechanical analyzer. Water absorption, solubility and weight change were also measured. A significant difference was found among the materials regarding dynamic viscoelasticity, water absorption and solubility. The samples containing P-n-BMA had the most stable G' and G'' scores throughout the immersion. P-n-BMA is the most suitable powder together with DEHM as the most suitable liquid component for a tissue conditioner. These results suggest that it is possible to improve the durability of tissue conditioners by combining different polymers and plasticizers. PMID:22277618

Hong, Guang; Tsuka, Hiroki; Maeda, Takeshi; Akagawa, Yasumasa; Sasaki, Keiichi

2012-02-01

383

Effect of fibre and coupling agent contents on water absorption and flexural modulus of wood fibre polyethylene composites  

NASA Astrophysics Data System (ADS)

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.

Tissandier, C.; Zhang, Y.; Rodrigue, D.

2014-05-01

384

Absorption of solar radiation by water vapor, oxygen, and related collision pairs in the Earth's atmosphere  

Microsoft Academic Search

Absorption of solar radiation by collision pairs of oxygen is a small but significant part of the total budget of incoming shortwave radiation. It is shown that the 1.26-mum band of O4 and O2.N2 is likely to contribute 0.64-1.55Wm-2 to the total atmospheric absorption for overhead Sun, clear sky conditions, bringing the total estimated absorption by all collision pairs of

S. Solomon; R. W. Portmann; R. W. Sanders; J. S. Daniel

1998-01-01

385

A far wing line shape theory and its application to the foreign-broadened water continuum absorption. III  

NASA Technical Reports Server (NTRS)

The far wing line shape theory developed previously and applied to the calculation of the continuum absorption of pure water vapor is extended to foreign-broadened continua. Explicit results are presented for H2O-N2 and H2O-CO2 in the frequency range from 0 to 10,000/cm. For H2O-N2 the positive and negative resonant frequency average line shape functions and absorption coefficients are computed for a number of temperatures between 296 and 430 K for comparison with available laboratory data. In general the agreement is very good.

Ma, Q.; Tipping, R. H.

1992-01-01

386

Weak water absorption lines around 1.455 and 1.66 ?m by CW-CRDS  

Microsoft Academic Search

The absorption spectra of water vapor near 1.455 and 1.66?m have been recorded with a typical absorption sensitivity of 5×10?10cm?1 by using CW-cavity ring down spectroscopy. A series of 18 distributed feed-back (DFB) lasers was used as sources and allowed for the coverage of the 5911.0–5922.5, 5926–5941.8, 5957.0–6121.6, and 6745–7015.6cm?1 spectral regions. These regions extend to lower and higher energies

Semen N. Mikhailenko; Wang Le; Samir Kassi; Alain Campargue

2007-01-01

387

Exploring the capacity of radar remote sensing to estimate wetland marshes water storage  

Microsoft Academic Search

This paper focuses on the use of radar remote sensing for water storage estimation in wetland marshes of the Paraná River Delta in Argentina. The approach followed is based on the analysis of a temporal set of ENVISAT ASAR data which includes images acquired under different polarizations and incidence angles as well as different environmental conditions (water level, precipitation, and

F. Grings; M. Salvia; H. Karszenbaum; P. Ferrazzoli; P. Kandus; P. Perna

2009-01-01

388

Preliminary Studies of Exercise Capacity in Combat Swimmers after Cold Water Training Operations.  

National Technical Information Service (NTIS)

Four special warfare combat swimmers performed exercise before and after open water training exercises in swimmer delivery vehicles. The divers wore standard issue dry suits. The water temperature was 7-9 C. The resting heart rate values were higher in th...

T. J. Doubt R. P. Weinberg C. D. Baker E. T. Flynn

1985-01-01

389

Thermodynamic Modeling of an Ammonia-Water Absorption System Associated with a Microturbine  

Microsoft Academic Search

Thermodynamic modeling and Second Law analysis of a small-scale cogeneration system consisting of a 5 refrigerant ton absorption chiller connected by a thermosyphon heat exchanger to a 28 kWe natural gas microturbine are presented. The proposed configuration changes the heat source of the absorption chiller, replacing the original natural gas burning system. A computational algorithm was programmed to analyze the

Janilson Arcangelo Rossa; Edson Bazzo

2009-01-01

390

Estimating Water Storage Capacity of Existing and Potentially Restorable Wetland Depressions in a Subbasin of the Red River of the North.  

National Technical Information Service (NTIS)

The goals of this study were to (1) develop and improve methodologies for estimating and spatially depicting wetland storage volumes and interceptions areas and (2) develop models and approaches for estimating/simulating the water storage capacity of pote...

B. A. Tangen K. E. Kermes M. K. Laubhan N. H. Euliss R. A. Gleason

2007-01-01

391

Development Document for Best Technology Available for the Location, Design, Construction and Capacity of Cooling Water Intake Structures for Minimizing Adverse Environmental Impact.  

National Technical Information Service (NTIS)

The document presents the findings of an extensive study of the available technology for the location, design construction and capacity of cooling water intake structures for minimizing adverse environmental impact, in compliance with and to implement Sec...

D. Barnes

1976-01-01

392

Validation of phenol red versus gravimetric method for water reabsorption correction and study of gender differences in Doluisio's absorption technique.  

PubMed

The aim of the present study was to develop a method for water flux reabsorption measurement in Doluisio's Perfusion Technique based on the use of phenol red as a non-absorbable marker and to validate it by comparison with gravimetric procedure. The compounds selected for the study were metoprolol, atenolol, cimetidine and cefadroxil in order to include low, intermediate and high permeability drugs absorbed by passive diffusion and by carrier mediated mechanism. The intestinal permeabilities (Peff) of the drugs were obtained in male and female Wistar rats and calculated using both methods of water flux correction. The absorption rate coefficients of all the assayed compounds did not show statistically significant differences between male and female rats consequently all the individual values were combined to compare between reabsorption methods. The absorption rate coefficients and permeability values did not show statistically significant differences between the two strategies of concentration correction. The apparent zero order water absorption coefficients were also similar in both correction procedures. In conclusion gravimetric and phenol red method for water reabsorption correction are accurate and interchangeable for permeability estimation in closed loop perfusion method. PMID:24887261

Tu?cu-Demiröz, Fatmanur; Gonzalez-Alvarez, Isabel; Gonzalez-Alvarez, Marta; Bermejo, Marival

2014-10-01

393

Assessment of capacity sensors for monitoring soil water content in ecological orchards  

NASA Astrophysics Data System (ADS)

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.

Patrícia Prazeres Marques, Karina; Horcajo, Daniel; Rodriguez-Sinobas, Leonor

2014-05-01

394

WVR-GPS comparison measurements and calibration of the 20-32 GHz tropospheric water vapor absorption model.  

SciTech Connect

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.

Keihm, S. J.; Bar-Server, Y.; Liljegren, J. C.; Environmental Research; NASA

2002-06-01

395

Radiation effects in water ice: A near-edge x-ray absorption fine structure study  

NASA Astrophysics Data System (ADS)

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 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 50 K the irradiated p-ASW ice. This phase is stable up to 90 K and partially transforms into crystalline ice at 150 K.

Laffon, C.; Lacombe, S.; Bournel, F.; Parent, Ph.

2006-11-01

396

Profiling of carotenoids and antioxidant capacity of microalgae from subtropical coastal and brackish waters.  

PubMed

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 4.68-6.88mg/g dry weight (DW) were Dunaliella salina, Tetraselmis suecica, Isochrysis galbana, and Pavlova salina. TPC was low, with D. salina possessing the highest TPC (1.54mg 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

Ahmed, Faruq; Fanning, Kent; Netzel, Michael; Turner, Warwick; Li, Yan; Schenk, Peer M

2014-12-15

397

Analysis of chickpea soaking by simultaneous water transfer and water–starch reaction  

Microsoft Academic Search

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

Sedat Sayar; Mahir Turhan; Sundaram Gunasekaran

2001-01-01

398

Design, Fabrication, and Testing of High Capacity High-Temperature Monel\\/Water Heat Pipes  

Microsoft Academic Search

A development program was completed to demonstrate key technologies required for the JIMO Heat Pipe Radiator. Part of this work included the design, assembly, and performance testing of two favorable wick designs in full length water heat pipes. A parametric study identified CP-2 titanium and Monel K-500 alloys as favorable envelope materials. The design effort also identified two promising wick

John H. Rosenfeld; Bruce L. Drolen; Cheng-Yi Lu

2006-01-01

399

A Simple Approach for Demonstrating Soil Water Retention and Field Capacity  

ERIC Educational Resources Information Center

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…

Howard, A.; Heitman, J. L.; Bowman, D.

2010-01-01

400

Capacity Expansion Model of Water Resource Facilities for a Major River System.  

National Technical Information Service (NTIS)

The objective has been to develop a practical and effective strategy for the optional expansion of a complex water resources system. Certain linear and non-linear programming techniques have been combined and extended so that they can serve as tools to im...

D. M. Himmelblau W. G. Lesso

1975-01-01

401

Institutional Capacity on Water Pollution Control of the Pearl River in Guangzhou, China  

Microsoft Academic Search

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

Yuan Yu; Dieudonné-Guy Ohandja; J. Nigel B. Bell

2012-01-01

402

The study of total load allocation of water environmental capacity in Yuanhe River, China  

Microsoft Academic Search

Yuanhe River is a branch of the middle and lower reaches of Ganjiang River in Jiangxi Province. The Yuanhe River is a major source of drinking, irrigation, industrial, hydropower generation, and recreational water. And it flows through some heavy industry cities. So the allocation of wastewater discharge permit is a challenge in total mass control due to the conflicts between

Maolan Wang; Bin Luo; Wenbin Zhou; Yun Huang; Lei Liu

2011-01-01

403

Application of system dynamics in analyzing the carrying capacity of water resources in Yiwu City, China  

Microsoft Academic Search

A risk assessment model for water shortage is constructed using a risk analysis method based on the information diffusion theory. The application of this model is demonstrated in the city of Yiwu in Zhejiang Province, China. Based on the analytical results from a small sample, this study indicates that the present model is more stable and effective than the traditional

Li-hua Feng; Xing-cai Zhang; Gao-yuan Luo

2008-01-01

404

INCREASING THE PHOSPHORUS SORPTION CAPACITY OF SOUTHEASTERN COASTAL PLAIN SOILS USING WATER TREATMENT RESIDUALS  

Microsoft Academic Search

Long-term animal manure applications to many sandy Coastal Plain soils has resulted in the accumulation of excess soil phosphorus (P). When soils contain excessive P concentrations, dissolved phosphorus (DP) can be des- orbed with water and transported into streams and rivers via runoff and leaching. The addition of DP into nutrient-sensitive Coastal aquatic ecosys- tems can then stimulate aquatic weed

J. M. Novak; D. W. Watts

2004-01-01

405

Determination of zinc in water samples by flame atomic absorption spectrometry after homogeneous liquid-liquid extraction  

Microsoft Academic Search

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

Sh. Dehghan Abkenar; Z. Dahaghin; H. Bagheri Sadeghi; M. Hosseini; M. Salavati-Niasari

2011-01-01

406

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

Microsoft Academic Search

This paper presents a general differential mathematical model to analyze the simultaneous heat and mass transfer processes\\u000a that occur in different components of an ammonia–water absorption system: absorber, desorber, rectifier, distillation column,\\u000a condenser and evaporator. Heat and mass transfer equations are considered, taking into account the heat and mass transfer\\u000a resistances in the liquid and vapour phases. The model considers

Jaime Sieres; José Fernández-Seara

2007-01-01

407

Building capacity of the Baltic States to meet the EU Water Framework Directive through watershed demonstration projects.  

PubMed

The Ohio River Valley Water Sanitation Commission (ORSANCO), in cooperation with the United States EPA, is completing it role in assisting the Baltic Countries of Estonia, Latvia, Lithuania and Kaliningrad Oblast, Russia with watershed management capacity building demonstration projects under the Great Lakes/Baltic Sea Partnership Program. The Countries of Estonia, Latvia and Lithuania view the skills gained through this program as important to their objective of complying with the European Union's Water Framework Directive and thus facilitating accession into the European Union. The program also addressed Kaliningrad's desire to work cooperatively with their neighboring countries concerning shared waters. Three watershed demonstration projects were designed and implemented, two of which involved joint country efforts: Parnu River (Estonia) modeling for nutrients and bacteria survey; river basin assessment and management planning for the Lielupe Basin (Latvia and Lithuania); and data base development and cooperative water quality survey and analysis for the Sesupe River (Lithuania and Kaliningrad). The benefits of the projects include enhancing the country's technical skills and the forging of relationships, without which achieving effective watershed management will be difficult to achieve. PMID:15137146

Vicory, A; Staniskis, J; Heath, J; Davenport, T

2003-01-01

408

Development of minimum efficiency standards for large capacity air conditioners, and commercial water heaters, refrigerators, and freezers. Final report  

SciTech Connect

The California Energy Resources Conservation and Development Commission has promulgated appliance energy efficiency standards and energy conservation standards for new construction with the objective of reducing energy consumption in the State of California. The following appliance categories are specifically addressed: large capacity air conditioners; commercial water heaters; and commercial refrigerators and freezers. The tasks that have been performed include: an energy use pattern study for the subject equipment; an examination of the size distribution of commercial air conditioning equipment; an examination of the different types of commercial air conditioning systems; an evaluation of the effectiveness of economizers in reducing commercial air conditioning system energy consumption in California; an examination of the effects of oversizing commercial air conditioners; a detailed study of supermarket refrigeration and air conditioning equipment; an evaluation of the economic feasibility of utilizing air conditioner waste heat to heat water; an assessment of the applicability of existing test procedures for small water heaters to large water heaters; and a brief investigation of the marketing and distribution systems for air conditioning and refrigeration equipment. Results of the efforts are described.

Merrill, P.S.; Rettberg, R.J.; Erickson, R.C.; Toor, J.S.

1980-05-01

409

Photo-acoustic measurements of water vapor absorption coefficient in UV spectral region  

Microsoft Academic Search

Data on the absorption coefficient of H2O in binary mixture with N2 in UV region of spectra are presented. With the use of the high sensitivity photoacoustic spectrometer, the following values of the absorption coefficient were found: 2.3 × 10-9 cm-1 · Pa-1 (? = 255 nm), 0.9 × 10-9 cm-1 · Pa-1 (? = 271 nm), and 1.6 ×

B. A. Tikhomirov; V. O. Troitskii; V. A. Kapitanov; G. S. Evtushenko; Y. N. Ponomarev

1998-01-01

410

Photo-acoustic measurements of water vapor absorption coefficient in UV spectral region  

Microsoft Academic Search

Data on the absorption coefficient of H2O in binary mixture with N2 in UV region of spectra are presented. With the use of the high sensitivity photoacoustic spectrometer, the following values of the absorption coefficient were found: 2.3 × 10-9 cm-1 · Pa-1 (lambda = 255 nm), 0.9 × 10-9 cm-1 · Pa-1 (lambda = 271 nm), and 1.6 ×

B. A. Tikhomirov; V. O. Troitskii; V. A. Kapitanov; G. S. Evtushenko; Y. N. Ponomarev

1998-01-01

411

Probing the collective vibrational dynamics of a protein in liquid water by terahertz absorption spectroscopy  

Microsoft Academic Search

Biological polymers are expected to exhibit functionally relevant, global, and subglobal collective modes in the terahertz (THz) frequency range (i.e., picosecond timescale). In an effort to monitor these collective motions, we have experimentally determined the absorption spectrum of solvated bovine serum albumin (BSA) from 0.3 to 3.72 THz (10-124 cm? 1). We successfully extract the terahertz molar absorption of the

Jing Xu; Kevin W. Plaxco; S. James Allen

2006-01-01

412

Spatiotemporal distribution of water environmental capacity-a case study on the western areas of Taihu Lake in Jiangsu Province, China.  

PubMed

Currently, the poor water quality in Taihu Lake is a major problem in China, so pollution control in the upstream areas has become a government priority. In Jiangsu Province, pollution emissions around the western areas of Taihu Lake, including Changzhou Municipality and Yixing City, need to be highly restricted, and calculating the water environmental capacity is important if pollution is to be reduced. In this study, 19 control units in these areas were established, and a 0-D mathematical model was used to calculate the water environmental capacity. For three important control units with important cross sections, a 1-D model was established to redress the results. Finally, the total maximum monthly loads of each control unit were obtained using temporal allocation principles. The results suggested that (1) the total pollution control of chemical oxygen demand was 58,894.2 tonnes per annum (t a(-1)), with ammonia nitrogen, total nitrogen, and total phosphorus amounting to 3,808, 6,054.6, and 386.6 t a(-1), respectively; (2) water environmental capacity per unit water area in the ambient control units was smaller than that in the middle control units; and (3) the largest water environmental capacity was in June, and the smallest capacity was in December. The study provides important information for local governments, which will enable them to implement pollution control strategies that will improve the water quality in Taihu Lake. PMID:24399075

Xie, Rongrong; Pang, Yong; Bao, Kun

2014-04-01

413

Sunflower Protein Concentrates and Isolates Prepared from Oil Cakes Have High Water Solubility and Antioxidant Capacity  

Microsoft Academic Search

Increasing the applications of industrial by-products is of great interest. Therefore, in the present study, sunflower oil\\u000a cake from a local oil manufacturing company was used to obtain soluble protein concentrates and isolates with different content\\u000a of phenolic compounds. All the extraction procedures evaluated resulted in concentrates and isolates with water solubility\\u000a higher than 75% but with different chemical composition,

Pablo R. Salgado; Sara E. Molina Ortiz; Silvana Petruccelli; Adriana N. Mauri

2011-01-01

414

The Cooling Capacity of Mosses: Controls on Water and Energy Fluxes in a Siberian Tundra Site  

Microsoft Academic Search

Arctic tundra vegetation composition is expected to undergo rapid changes during the coming decades because of changes in\\u000a climate. Higher air temperatures generally favor growth of deciduous shrubs, often at the cost of moss growth. Mosses are\\u000a considered to be very important to critical tundra ecosystem processes involved in water and energy exchange, but very little\\u000a empirical data are available.

D. Blok; M. M. P. D. Heijmans; G. Schaepman-Strub; J. van Ruijven; F. J. W. Parmentier; T. C. Maximov; F. Berendse

2011-01-01

415

Influence of DMPS on the water retention capacity of electroporated stratum corneum: ATR-FTIR study.  

PubMed

Anionic lipids like phosphatidylserine are known to significantly enhance electroporation mediated transepidermal transport of polar solutes of molecular weights up to 10kDa. The underlying mechanism of the effect of anionic lipids on transdermal transport is not fully understood. The main barrier to transdermal transport lies within the intercellular lipid matrix (ILM) of the stratum corneum (SC) and our previous studies indicate that dimyristoyl phosphatidylserine (DMPS) can perturb the packing of this lipid matrix. Here we report on our investigation on water retention in the SC following electroporation in the presence and the absence of DMPS. The water content in the outer most layers of the SC of full thickness porcine skin was determined using ATR-FTIR-spectroscopy. The results show that in the presence of DMPS, the SC remains in a state of enhanced hydration for longer periods after electroporation. This increase in water retention in the SC by DMPS is likely to play an important role in trans-epidermal transport, since improved hydration of the skin barrier can be expected to increase the partitioning of polar solutes and possibly the permeability. PMID:17931807

Sckolnick, Maria; Hui, Sek-Wen; Sen, Arindam

2008-02-28

416

Solar absorption cooling plant in Seville  

Microsoft Academic Search

A solar\\/gas cooling plant at the Engineering School of Seville (Spain) was tested during the period 2008–2009. The system is composed of a double-effect LiBr+water absorption chiller of 174kW nominal cooling capacity, powered by: (1) a pressurized hot water flow delivered by mean of a 352m2 solar field of a linear concentrating Fresnel collector and (2) a direct-fired natural gas

Pablo Bermejo; Francisco Javier Pino; Felipe Rosa

2010-01-01

417

Impact of Dam Construction on Water Quality and Water Self-Purification Capacity of the Lancang River, China  

Microsoft Academic Search

Along with the sequent completion of Manwan and Dachaoshan Dam, the river continuum of the middle and lower reaches of the\\u000a Lancang River was separated into three types of segments: reservoir, below-dam segment and downstream flowing segment. The\\u000a long-term series of water quality and river flow data over 20 years were analyzed in order to study the impact of dam construction

GuoLiang Wei; ZhiFeng Yang; BaoShan Cui; Bing Li; He Chen; JunHong Bai; ShiKui Dong

2009-01-01

418

Vitamin Enhanced Waters and Polyphenol Rich Beverages Analyzed for Antioxidant Capacity and Antioxidants/Calorie  

PubMed Central

The purpose of this study was to analyze polyphenol rich beverages (vitamin enhanced waters (VEWs), fruit juices and berry juices) to determine free polyphenol concentrations and free polyphenols per Calorie based on a serving size. The Folin–Ciocalteu reagent was used in a colorimetric assay based on a catechin standard. Fruit and berry juices contained, on average, more than eight-times the concentration of free polyphenols when compared to VEWs. When Calories per serving were taken into consideration, fruit and berry juices contained more than twice the free polyphenols per Calorie.

Donnelly, Patrick E.; Churilla, Thomas M.; Coco, Michael G.; Vinson, Joe A.

2010-01-01

419

Coordination between water-transport efficiency and photosynthetic capacity in canopy tree species at different growth irradiances.  

PubMed

Plasticity in hydraulic architecture of five dominant Atlantic forest species differing in light requirements and growth rates was evaluated in saplings grown at different irradiances to determine if hydraulic architecture changes in coordination with photosynthetic capacity. Saplings were grown in shade-houses at 10, 30, 45 and 65% of full solar irradiance for 4 months. In four of the five species, maximum relative growth rates were observed at intermediate irradiances (30 and 40% of full sun). Slow-growing species had lower maximum electron transport rates (ETR(max)) than fast-growing species. A positive correlation between ETR(max) and maximum leaf hydraulic conductivity (K(L)) was found across species, suggesting that species-specific stem hydraulic capacity and photosynthetic capacity were linked. Species with relatively high growth rates, such as Cedrela fissilis Vell., Patagonula americana L. and Cordia trichotoma (Vell.) Arrab. Ex Stend, exhibited increased K(L) and specific hydraulic conductivity (K(S)) with increased growth irradiance. In contrast, K(S) and K(L) did not vary with irradiance in the slower-growing and more shade-tolerant species Balfourodendron riedelianum (Engl.) Engl. and Lonchocarpus leucanthus Burkart, despite a relatively large irradiance-induced variation in ETR(max). A correlation between K(S) and ETR(max) was observed in fast-growing species in different light regimes, suggesting that they are capable of plastic changes in hydraulic architecture and increased water-transport efficiency in response to changes in light availability resulting from the creation of canopy gaps, which makes them more competitive in gaps and open habitats. PMID:17938117

Campanello, Paula I; Gatti, M Genoveva; Goldstein, Guillermo

2008-01-01

420

Development document for best technology available for the location, design, construction, and capacity of cooling water intake structures for minimizing adverse environmental impact  

Microsoft Academic Search

This document presents the findings of an extensive study of the available technology for the location, design construction and capacity of cooling water intake structures for minimizing adverse environmental impact, in compliance with and to implement Section 316(b) of the Federal Water Pollution Control Act Amendments of 1972.

R. E. Train; A. W. Breidenbach; E. P. Hall; D. Barnes

1976-01-01

421

Building Capacity to Integrate NASA Earth Science into Water Resources Management Applications in the Context of a Changing Climate  

NASA Astrophysics Data System (ADS)

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.

Prados, A. I.; Mehta, A. V.

2011-12-01

422

An empirical ocean color algorithm for estimating the contribution of chromophoric dissolved organic matter to total light absorption in optically complex waters  

Microsoft Academic Search

To estimate the depth-integrated rate of photochemical processes involving chromophoric dissolved organic matter (CDOM) in coastal waters, the contribution of CDOM to the total absorption coefficient must be known from UV to green. At 307 sites sampled in various coastal marine environments, the ratio between CDOM and the total absorption coefficient ([a CDOM \\/a t ]) at 412 nm was

Simon Bélanger; Marcel Babin; Pierre Larouche

2008-01-01

423

Detection and quantification of montmorillonite nanoclay in water-ethanol solutions by graphite furnace atomic absorption spectrometry.  

PubMed

Organo-modified montmorillonite (O-MMT) was detected in various water-ethanol solutions by using graphite furnace atomic absorption spectrometry, based on the simultaneous elemental analysis of silicon (Si) and aluminium (Al). The quantification limits of the method were 0.03 mg L(-1) for Si and 0.01 mg L(-1) for Al, but can be improved to 8 ?g L(-1) for Si and 3 ?g L(-1) by using the concentration function of the instrument. A stability test of O-MMT in suspension was conducted by considering the solvent type (i.e., water and/or ethanol) and a surfactant. A good dispersion of O-MMT was achieved in suspensions with water and ethanol at 1:2 (v/v) or with pure ethanol, while the addition of a surfactant improved the dispersion of O-MMT in water. The Si and Al concentrations in the suspensions were correlated with O-MMT concentrations. The Si and Al contents in the O-MMT were determined by using graphite furnace atomic absorption spectrometry to be 22% ± 1.1% and 9.3% ± 0.5% wt/wt, respectively, which was in agreement with values obtained by X-ray fluorescence spectrometry method performed in this study. PMID:24215494

Yining, Xia; Rubino, Maria; Auras, Rafael

2013-01-01

424

Ontogeny of the digestive capacity of Senegalese sole ( Solea senegalensis ), with respect to digestion, absorption and metabolism of amino acids from Artemia  

Microsoft Academic Search

Ontogenetic changes in the capacity of Senegalese sole ( Solea senegalensis Kaup, 1858) larvae to digest and metabolise Artemia protein and amino acids (AA) were studied using 12, 22 and 35 days after hatching (DAH) larvae that were fed Artemia metanauplii radiolabelled with a [U- 14C] protein hydrolysate. About 82% and 18% of the label was incorporated into the Artemia trichloroacetic

S. Morais; M. Lacuisse; L. E. C. Conceição; M. T. Dinis; I. Rønnestad

2004-01-01

425

Relation of sound absorption and shallow water modal attenuation to plane wave attenuation.  

PubMed

Prediction of attenuation of acoustic fields in weakly absorbing media often uses the substitution of (omega/c)-->(omega/c)+ialpha(pw) into the idealized equations for constant frequency, with alpha(pw) representing the local plane wave attenuation coefficient. This assumption is flawed whenever the local absorption of sound is proportional to the square of the gradient of the acoustic pressure, as is the case when the absorption is caused by fluid velocity relaxation. A realistic analysis yields an improved weighting function over depth for determination of guided mode attenuation coefficients. PMID:19894791

Pierce, Allan D

2009-11-01

426

Nutrient Absorption by the Submerged Macrophyte Egeria densa Planch.: Effect of Ammonium and Phosphorus Availability in the Water Column on Growth and Nutrient Uptake  

Microsoft Academic Search

The relative importance of phosphorus and nitrogen absorption fkom water and sediments by Egeria densa Planch. (Hydrocharitaceae), a subinerged macropliyte very common in Pampean streams in Argentina, was experiiiientally assesced. Two experiments were performed to determine the importance of water as opposed to sediment cource of phosphorus, and to investigate the effect oftype of nitrogenouc ion dissolved in water on

Claudia Feijoó; María Eugenia García; Fernando Momo; Julia Toja

427

Design, Fabrication, and Testing of High Capacity High-Temperature Monel/Water Heat Pipes  

NASA Astrophysics Data System (ADS)

A development program was completed to demonstrate key technologies required for the JIMO Heat Pipe Radiator. Part of this work included the design, assembly, and performance testing of two favorable wick designs in full length water heat pipes. A parametric study identified CP-2 titanium and Monel K-500 alloys as favorable envelope materials. The design effort also identified two promising wick designs Based on porous-walled axially grooves. Several heat pipes of each design were assembled and tested. The heat pipes were tested at temperatures up to 300 °C under several tilt conditions. A sintered groove evaporator design operated at up to 1500 W against gravity at temperatures between 280 °C and 300 °C, and an inverted meniscus evaporator designs operated at up to 1200 W at similar temperature and tilt conditions. Based on the test results, the sintered groove wick design is recommended for further development. One of the heat pipes was also subjected to a startup from an initially frozen condition. A neon inert gas charge of 16 cc was added to the devices to promote successful frozen startup. A favorable response observed from this test provides confidence that the design will survive and operate under a frozen startup condition.

Rosenfeld, John H.; Drolen, Bruce L.; Lu, Cheng-Yi

2006-01-01

428

Borehole geophysical methods for analyzing specific capacity of multiaquifer wells : ground-water hydraulics  

USGS Publications Warehouse

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.

Bennett, Gordon D.; Patten, Eugene P., Jr.

1960-01-01

429

Spectral light attenuation and the absorption of UV and blue light in natural waters  

Microsoft Academic Search

The spectral pattern of light attenuation in the ultraviolet (UV) and blue region (360-500 nm) was analyzed for seven high Arctic lakes. The best description of Kd versus wavelength was obtained with an exponential model similar to the model used for absorption by chromophoric dissolved organic compounds (CDOM), but with an additional parameter (Kback) that accounts for background scattering: S(l

Stiig Markager; Warwick F. Vincent

2000-01-01

430

Determination of Trace Silver in Water Samples by Online Column Preconcentration Flame Atomic Absorption Spectrometry Using Termite Digestion Product  

PubMed Central

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.

Bianchin, Joyce Nunes; Martendal, Edmar; Carasek, Eduardo

2011-01-01

431

Monitoring water stable isotope composition in soils using gas-permeable tubing and infrared laser absorption spectroscopy  

NASA Astrophysics Data System (ADS)

The water stable isotopologues 1H2H16O and 1H218O are powerful tracers of processes occurring in nature. Their slightly different masses as compared to the most abundant water isotopologue (1H216O) affect their thermodynamic (e.g. during chemical equilibrium reactions or physical phase transitions with equilibration) and kinetic (liquid and vapor phases transport processes and chemical reactions without equilibration) properties. This results in measurable differences of the isotopic composition of water within or between the different terrestrial ecosystem compartments (i.e. sub-soil, soil, surface waters, plant, and atmosphere). These differences can help addressing a number of issues, among them water balance closure and flux partitioning from the soil-plant-atmosphere continuum at the field to regional scales. In soils particularly, the isotopic composition of water (?2H and ?18O) provides qualitative information about whether water has only infiltrated or already been re-evaporated since the last rainfall event or about the location of the evaporation front. From water stable isotope composition profiles measured in soils, it is also possible, under certain hypotheses, to derive quantitative information such as soil evaporation flux and the identification of root water uptake depths. In addition, water stable isotopologues have been well implemented into physically based Soil-Vegetation-Atmosphere Transfer models (e.g. SiSPAT-Isotope; Soil-Litter iso; TOUGHREACT) and have demonstrated their potential. However, the main disadvantage of the isotope methodology is that, contrary to other soil state variables that can be monitored over long time periods, ?2H and ?18O are typically analyzed following destructive sampling. Here, we present a non-destructive method for monitoring soil liquid water ?2H and ?18O over a wide range of water availability conditions and temperatures by sampling and measuring water vapor equilibrated with soil water using gas-permeable polypropylene tubing and a cavity ring-down laser absorption spectrometer. By analyzing water vapor ?2H and ?18O sampled with the tubing from a fine sand for temperatures ranging between 8-24° C, we demonstrate that (i) our new method is capa