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1

Nuclear driven water decomposition plant for hydrogen production  

NASA Technical Reports Server (NTRS)

The conceptual design of a hydrogen production plant using a very-high-temperature nuclear reactor (VHTR) to energize a hybrid electrolytic-thermochemical system for water decomposition has been prepared. A graphite-moderated helium-cooled VHTR is used to produce 1850 F gas for electric power generation and 1600 F process heat for the water-decomposition process which uses sulfur compounds and promises performance superior to normal water electrolysis or other published thermochemical processes. The combined cycle operates at an overall thermal efficiency in excess of 45%, and the overall economics of hydrogen production by this plant have been evaluated predicated on a consistent set of economic ground rules. The conceptual design and evaluation efforts have indicated that development of this type of nuclear-driven water-decomposition plant will permit large-scale economic generation of hydrogen in the 1990s.

Parker, G. H.; Brecher, L. E.; Farbman, G. H.

1976-01-01

2

The Conceptual Design of an Integrated Nuclearhydrogen Production Plant Using the Sulfur Cycle Water Decomposition System  

NASA Technical Reports Server (NTRS)

A hydrogen production plant was designed based on a hybrid electrolytic-thermochemical process for decomposing water. The sulfur cycle water decomposition system is driven by a very high temperature nuclear reactor that provides 1,283 K helium working gas. The plant is sized to approximately ten million standard cubic meters per day of electrolytically pure hydrogen and has an overall thermal efficiently of 45.2 percent. The economics of the plant were evaluated using ground rules which include a 1974 cost basis without escalation, financing structure and other economic factors. Taking into account capital, operation, maintenance and nuclear fuel cycle costs, the cost of product hydrogen was calculated at $5.96/std cu m for utility financing. These values are significantly lower than hydrogen costs from conventional water electrolysis plants and competitive with hydrogen from coal gasification plants.

Farbman, G. H.

1976-01-01

3

Thermochemical water decomposition processes  

NASA Technical Reports Server (NTRS)

Thermochemical processes which lead to the production of hydrogen and oxygen from water without the consumption of any other material have a number of advantages when compared to other processes such as water electrolysis. It is possible to operate a sequence of chemical steps with net work requirements equal to zero at temperatures well below the temperature required for water dissociation in a single step. Various types of procedures are discussed, giving attention to halide processes, reverse Deacon processes, iron oxide and carbon oxide processes, and metal and alkali metal processes. Economical questions are also considered.

Chao, R. E.

1974-01-01

4

Phlogopite Decomposition, Water, and Venus  

NASA Technical Reports Server (NTRS)

Venus is a hot and dry planet with a surface temperature of 660 to 740 K and 30 parts per million by volume (ppmv) water vapor in its lower atmosphere. In contrast Earth has an average surface temperature of 288 K and 1-4% water vapor in its troposphere. The hot and dry conditions on Venus led many to speculate that hydrous minerals on the surface of Venus would not be there today even though they might have formed in a potentially wetter past. Thermodynamic calculations predict that many hydrous minerals are unstable under current Venusian conditions. Thermodynamics predicts whether a particular mineral is stable or not, but we need experimental data on the decomposition rate of hydrous minerals to determine if they survive on Venus today. Previously, we determined the decomposition rate of the amphibole tremolite, and found that it could exist for billions of years at current surface conditions. Here, we present our initial results on the decomposition of phlogopite mica, another common hydrous mineral on Earth.

Johnson, N. M.; Fegley, B., Jr.

2005-01-01

5

Fast Construction of Plant Architectural Models Based on Substructure Decomposition  

Microsoft Academic Search

Plant structure, representing the physical link among different organs, includes many similar substructures. In this paper, a new method is presented to construct plant architectural models of most plant species. The plant structure is decomposed into a stem, a set of lateral substructures and a terminal substructure, which is called substructure decomposition; then based on substructure decomposition, the plant structures

Hongping Yan; Philippe De Reffye; Chunhong Pan; Bao-gang Hu

2003-01-01

6

Ozone decomposition in water solutions  

E-print Network

. . . . . . . . . . . . . 75 III. CBI. iiICAT, OXYGEN DEMAND TEST. . IV. OIONE DECOI'IPOSITION DATA. . . . . V. COD DATA FOH THE CONTINUOUS ABSOHBER- REACTION SYSTEM VITA 78 8$ LIST OF TABLES TABI E PAGE I. OZONE DECOMPOSITION IN MATER SOLUTIONS. . . g4 Il. REACTION.... The spectrophotometric method was used since ozone molecules whicn are dissolved in an aqueous solution will maintain approximately the same adsorption maximum as they have in the gas phase. The iodometric method was used to determine the total concentration...

Hewes, Cecil Grayson

2012-06-07

7

Plant Water Relations  

NSDL National Science Digital Library

Plant water relations are presented in this learning activity to help participants understand the components of water potential, explain how water moves through plants, provide examples of plant adaptations to water stress, and have a general understanding of how water potential can be measured.

Bidlack, Jim

8

Effect of water level drawdown on decomposition in boreal peatlands  

NASA Astrophysics Data System (ADS)

Plant litter production and decomposition are key processes in element cycling in most ecosystems. In peatlands, there has been a long-term imbalance between litter production and decay caused by high water levels (WL) and consequent anoxia. This has resulted in peatlands being a significant sink of carbon (C) from the atmosphere. However, peatlands are experiencing both "natural" (global climate change) and anthropogenic (ditching) changes that threaten their ability to retain this ecosystem identity and function. Many of these alterations can be traced back to WL drawdown, which can cause increased aeration, higher acidity, falling temperatures, and a greater probability of drought. Such changes are also associated with an increasing decomposition rate, and therefore a greater amount of C released back to the atmosphere. Yet studies about how the overall C balance of peatlands will be affected have come up with conflicting conclusions, demonstrating that the C store could increase, decrease, or remain static. A factor that has been largely overlooked is the change in litter type composition following persistent WL drawdown. It is the aim of our study, then, to help to resolve this issue. We studied the effects of short-term (ca. 4 years) and long-term (ca. 40 years) persistent WL drawdown on the decomposition of numerous types of above-ground and below-ground plant litters at three boreal peatland sites: bog, oligotrophic fen and mesotrophic fen. We thus believe that enough permutations have been created to obtain a good assessment of how each factor, site nutrient level, WL regime, and litter type composition, influences decomposition. We used the litter bag method to measure the decomposition rates: placed measured amounts of plant litter, or cellulose strips as a control, into closed mesh bags, and installed the bags in the natural environment for decomposition for each litter type for varying amounts of time. Following litter bag recovery, the litter was cleaned of excess debris and analyzed for changes in mass, enzyme activity, mesofauna presence, and microbial community composition, among other things. The experiment has a run-time of ten years, the results from the first two years are presented in the poster.

Straková, Petra; Penttilä, Timo; Laiho, Raija

2010-05-01

9

Tremolite Decomposition and Water on Venus  

NASA Technical Reports Server (NTRS)

We present experimental data showing that the decomposition rate of tremolite, a hydrous mineral, is sufficiently slow that it can survive thermal decomposition on Venus over geologic timescales at current and higher surface temperatures.

Johnson, N. M.; Fegley, B., Jr.

2000-01-01

10

Theoretical study of water cluster catalyzed decomposition of formic acid.  

PubMed

We have performed a number of quantum chemical simulations to examine water cluster catalyzed decomposition of formic acid. The decomposition of formic acid consists of two competing pathways, dehydration, and decarboxylation. We use the Gaussian 4 method of the Gaussian09 software to locate and optimize a transition state of the decomposition reaction and obtain the activation energy. The decomposition starts by transferring a proton of a formic acid to a water molecule. The de Broglie wavelength of a proton is similar to the width of the potential barrier of the decomposition reaction at low temperature. The tunneling, in which a proton penetrates the potential barrier, enhances the decomposition rate. Water molecules serve as the catalyst in the decomposition and reduce the activation energy. The relay of a proton from a water molecule to a neighboring water molecule is accomplished with little change of the geometry of a molecule, resulting in the reduction of the activation energy. Two water molecules are actively involved in the decomposition reaction to reduce the activation energy. We have also examined the effect of water clusters with three, four, and five water molecules on the decomposition reaction. The noncovalent distance between a hydrogen atom of a water molecule and an oxygen atom of a neighboring water molecule decreases in a water cluster due to the cooperative many-body interactions. A water molecule in a water cluster becomes a better proton donor as well as a better proton acceptor. The activation energy of the decomposition is further decreased by the catalytic effect of a water cluster. We calculate the reaction rate using the transition state theory corrected by the tunneling effect of a proton. The calculated reaction rate of the decarboxylation is smaller than that of the dehydration when less than three water molecules are included in the simulation. However, the major product of the decomposition of a formic acid becomes carbon dioxide and hydrogen molecule formed by the decarboxylation when a water cluster with more than four water molecules serves as catalyst in the decomposition of formic acid. PMID:24735438

Inaba, Satoshi

2014-04-24

11

Water Desalination Plant  

NSDL National Science Digital Library

Students use a thermal process approach to design, build and test a small-scale desalination plant that is capable of significantly removing the salt content from a saltwater solution. Students use a saltwater circuit to test the efficiency of their model desalination plant and learn how the water cycle is the basis for the thermal processes that drive their desalination plant.

Integrated Teaching and Learning Program,

12

Plant litter decomposition in a semi-arid ecosystem controlled by photodegradation.  

PubMed

The carbon balance in terrestrial ecosystems is determined by the difference between inputs from primary production and the return of carbon to the atmosphere through decomposition of organic matter. Our understanding of the factors that control carbon turnover in water-limited ecosystems is limited, however, as studies of litter decomposition have shown contradictory results and only a modest correlation with precipitation. Here we evaluate the influence of solar radiation, soil biotic activity and soil resource availability on litter decomposition in the semi-arid Patagonian steppe using the results of manipulative experiments carried out under ambient conditions of rainfall and temperature. We show that intercepted solar radiation was the only factor that had a significant effect on the decomposition of organic matter, with attenuation of ultraviolet-B and total radiation causing a 33 and 60 per cent reduction in decomposition, respectively. We conclude that photodegradation is a dominant control on above-ground litter decomposition in this semi-arid ecosystem. Losses through photochemical mineralization may represent a short-circuit in the carbon cycle, with a substantial fraction of carbon fixed in plant biomass being lost directly to the atmosphere without cycling through soil organic matter pools. Furthermore, future changes in radiation interception due to decreased cloudiness, increased stratospheric ozone depletion, or reduced vegetative cover may have a more significant effect on the carbon balance in these water-limited ecosystems than changes in temperature or precipitation. PMID:16885982

Austin, Amy T; Vivanco, Lucía

2006-08-01

13

Plant decomposition and soil respiration in terrestrial ecosystems  

Microsoft Academic Search

Summary  This review deals with methodological approaches, measured rates, and environmental control of two major interdependent processes\\u000a regulating the structure and function of terrestrial ecosystems, viz., plant decomposition and soil respiration.\\u000a \\u000a Both these processes have been evaluated through indirect assessments as well as through direct measurements under the field\\u000a conditions. The techniques used suffer in general from difficulties in creating conditions

J. S. Singh; S. R. Gupta

1977-01-01

14

Decomposition of Plant Debris by the Nematophagous Fungus ARF  

PubMed Central

In the study of the biological control of plant-parasitic nematodes, knowledge of the saprophytic ability of a nematophagous fungus is necessary to understand its establishment and survival in the soil. The objectives of this study were (i) to determine if the nematophagous fungus ARF (Arkansas Fungus) shows differential use of plant residues; and (ii) to determine if ARF still existed in the soil of a field in which ARF was found originally and in which the population level of Heterodera glycines had remained very low, despite 15 years of continuous, susceptible soybean. Laboratory studies of the decomposition of wheat straw or soybean root by ARF were conducted in two separate experiments, using a CO? collection apparatus, where CO?-free air was passed through sterilized cotton to remove the microorganisms in the air and then was passed over the samples, and evolved CO? was trapped by KOH. Milligrams of C as CO? was used to calculate the percentage decomposition of the plant debris by ARF. Data indicated ARF decomposed 11.7% of total organic carbon of the wheat straw and 20.1% of the soybean roots in 6 weeks. In the field soil study, 21 soil samples were taken randomly from the field. Only 3 months after the infestation of the soil with H. glycines, the percentage of parasitized eggs of H. glycines reached 64 ± 19%, and ARF was isolated from most parasitized eggs of H. glycines. Research results indicated ARF could use plant residues to survive. PMID:19262814

Wang, Kening; Riggs, R. D.; Crippen, Devany

2004-01-01

15

Metal-induced decomposition of perchlorate in pressurized hot water.  

PubMed

Decomposition of perchlorate (ClO(4)(-)) in pressurized hot water (PHW) was investigated. Although ClO(4)(-) demonstrated little reactivity in pure PHW up to 300°C, addition of zerovalent metals to the reaction system enhanced the decomposition of ClO(4)(-) to Cl(-) with an increasing order of activity of (no metal)?Al < Cu < Zn < Ni < Fe: the addition of iron powder led to the most efficient decomposition of ClO(4)(-). When the iron powder was added to an aqueous ClO(4)(-) solution (104 ?M) and the mixture was heated at 150°C, ClO(4)(-) concentration fell below 0.58 ?M (58 ?g L(-1), detection limit of ion chromatography) in 1 h, and Cl(-) was formed with the yield of 85% after 6 h. The decomposition was accompanied by transformation of the zerovalent iron to Fe(3)O(4). This method was successfully used in the decomposition of ClO(4)(-) in a water sample contaminated with this compound, following fireworks display at Albany, New York, USA. PMID:22840541

Hori, Hisao; Sakamoto, Takehiko; Tanabe, Takashi; Kasuya, Miu; Chino, Asako; Wu, Qian; Kannan, Kurunthachalam

2012-10-01

16

Earthworms and legumes control litter decomposition in a plant diversity gradient.  

PubMed

The role of species and functional group diversity of primary producers for decomposers and decomposition processes is little understood. We made use of the "Jena Biodiversity Experiment" and tested the hypothesis that increasing plant species (1, 4, and 16 species) and functional group diversity (1, 2, 3, and 4 groups) beneficially affects decomposer density and activity and therefore the decomposition of plant litter material. Furthermore, by manipulating the densities of decomposers (earthworms and springtails) within the plant diversity gradient we investigated how the interactions between plant diversity and decomposer densities affect the decomposition of litter belonging to different plant functional groups (grasses, herbs, and legumes). Positive effects of increasing plant species or functional group diversity on earthworms (biomass and density) and microbial biomass were mainly due to the increased incidence of legumes with increasing diversity. Neither plant species diversity nor functional group diversity affected litter decomposition, However, litter decomposition varied with decomposer and plant functional group identity (of both living plants and plant litter). While springtail removal generally had little effect on decomposition, increased earthworm density accelerated the decomposition of nitrogen-rich legume litter, and this was more pronounced at higher plant diversity. The results suggest that earthworms (Lumbricus terrestris L.) and legumes function as keystone organisms for grassland decomposition processes and presumably contribute to the recorded increase in primary productivity with increasing plant diversity. PMID:18705374

Milcu, Alexandru; Partsch, Stephan; Scherber, Christoph; Weisser, Wolfgang W; Scheu, Stefan

2008-07-01

17

Thermal decomposition of substituted phenols in supercritical water  

SciTech Connect

The thermal decomposition of cresols, hydroxybenzaldehydes, nitrophenols, and benzenediols was studied in dilute aqueous solutions and in the absence of oxygen at 460 C and 250 atm for residence times around 10 s. Thermolysis under these conditions produced conversions of less than 10% for o-, m-, and p-cresol, whereas hydroxybenzaldehydes and nitrophenols were much more reactive. Global rate expressions are reported for the thermolysis of each hydroxybenzaldehyde and nitrophenol isomer. Phenol was a major product from the decomposition of all of the substituted phenols studied. For a given substituent, ortho-substituted phenols reacted more rapidly than the other isomers. For a given substituted position, nitrophenols reacted more rapidly than hydroxybenzaldehydes, which in turn reacted more rapidly than cresols. These results demonstrate that the treatment of CHO- and NO{sub 2}-substituted phenols by oxidation in supercritical water will involve the oxidation of thermal decomposition products in addition to the oxidation of the original compounds.

Martino, C.J.; Savage, P.E. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Chemical Engineering] [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Chemical Engineering

1997-05-01

18

Plant traits are the predominant control on litter decomposition rates within biomes worldwide  

Microsoft Academic Search

Worldwide decomposition rates depend both on climate and the legacy of plant functional traits as litter quality. To quantify the degree to which functional differentiation among species affects their litter decomposition rates, we brought together leaf trait and litter mass loss data for 818 species from 66 decomposition experiments on six continents. We show that: (i) the magnitude of species-driven

William K. Cornwell; Johannes H. C. Cornelissen; K. Amatangalo; Ellen Dorrepaal; Valerie T. Eviner; Oscar Godoy; S. E. Hobbir; Bart Hoorens; Hiroko Kurokawa; N. Perez-Harguindeguy; Helen M. Quested; Louis S. Santiago; David A. Wardle; Ian J. Wright; Rien Aerts; Steven D. Allison; Bodegom van P. M; Victor Brovkin; Alex Chatain; Terry V. Callaghan; S. Diaz; Eric Garnier; Diego E. Gurvich; Elena Kazakou; Julia A. Klein; Jenny Read; Peter B. Reich; Nadejda A. Soudzilovskaia; M. Victoria Vaieretti; Mark Westoby

2008-01-01

19

Decomposition reaction of sesamin in supercritical water.  

PubMed

The methylenedioxyphenyl moiety in the structure of sesamin and episesamin was changed into the catechol moieties, (1R,2S,5R,6S)-6-(3,4-dihydroxyphenyl)-2-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3,3,0]octane, (1R,2R,5R,6S)-2-(3,4-dihydroxyphenyl)-6-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3,3,0]octane, (1R,2R,5R,6S)-6-(3,4-dihydroxyphenyl)-2-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3,3,0]octane, (1R,2S,5R,6S)-2,6-bis(3,4-dihydroxyphenyl)-3,7-dioxabicyclo[3,3,0]octane, and (1R,2R,5R,6S)-2,6-bis(3,4-dihydroxyphenyl)-3,7-dioxabicyclo[3,3,0]octane, in supercritical water. These products had same structures as the sesamin metabolites which act as antioxidants in the liver. These features suggested the direct preparation of antioxidants from sesamin by a one-step reaction using supercritical water. PMID:16717436

Nakai, Masaaki; Kageyama, Norihiko; Nakahara, Koichi; Miki, Wataru

2006-05-01

20

Water treatment plant  

SciTech Connect

A water treatment plant comprises a generally horizontal cylindrical tank and an upstanding cylindrical tank usually having a diameter less than the horizontal tank and being integrally attached to and intersecting an end wall portion thereof. The horizontal tank includes a transverse partition and a longitudinal partition which extends from an intermediate portion of the transverse partition to the upstanding tank and divides the first tank into an aeration chamber, a sludge holding chamber and a purifying or chlorine contact chamber. The second tank comprises a clarifying chamber including an upper portion having influent and effluent pipe means and skimming means and a bottom portion having a circular bottom surface, an outlet and scraper means for moving sediment into the outlet for recirculation either to the aeration chamber or to the sludge holding chamber.

Mixon, J.A.

1982-09-28

21

Adiabatic calorimetric decomposition studies of 50 wt.% hydroxylamine/water.  

PubMed

Calorimetric data can provide a basis for determining potential hazards in reactions, storage, and transportation of process chemicals. This work provides calorimetric data for the thermal decomposition behavior in air of 50wt.% hydroxylamine/water (HA), both with and without added stabilizers, which was measured in closed cells with an automatic pressure tracking adiabatic calorimeter (APTAC). Among the data provided are onset temperatures, reaction order, activation energies, pressures of noncondensable products, thermal stability at 100 degrees C, and the effect of HA storage time. Discussed also are the catalytic effects of carbon steel, stainless steel, stainless steel with silica coating, inconel, titanium, and titanium with silica coating on the reaction self-heat rates and onset temperatures. In borosilicate glass cells, HA was relatively stable at temperatures up to 133 degrees C, where the HA decomposition self-heat rate reached 0.05 degrees C/min. The added stabilizers appeared to reduce HA decomposition rates in glass cells and at ambient temperatures. The tested metals and metal surfaces coated with silica acted as catalysts to lower the onset temperatures and increase the self-heat rates. PMID:11165058

Cisneros, L O; Rogers, W J; Mannan, M S

2001-03-19

22

Decomposition of Glycerine by Water Plasmas at Atmospheric Pressure  

NASA Astrophysics Data System (ADS)

High concentration of aqueous glycerine was decomposed using a direct current (DC) plasma torch at atmospheric pressure. The torch can generate the plasma with water as the plasma-supporting gas in the absence of any additional gas supply system and cooling devices. The results indicated that 5 mol% glycerine was completely decomposed by water plasmas at arc powers of 0.55~1.05 kW. The major products in the effluent gas were H2 (68.9%~71.1%), CO2 (18.9%~23.0%), and CO (0.2%~0.6%). However, trace levels of formic acid (HCOOH) and formaldehyde (HCHO) were observed in the liquid effluent. The results indicated that the water plasma waste treatment process is capable of being an alternative green technology for organic waste decomposition.

Takayuki, Watanabe; Narengerile

2013-04-01

23

Decomposition of Volatile Organic Compounds and Environmental Hazardous Substances in Water using Discharge Plasma  

NASA Astrophysics Data System (ADS)

Recent works for the decomposition of gaseous volatile organic compounds (VOCs) and environmental hazardous substances in water using discharge plasma are encapsulated. The kinds of reactors used for the decomposition of VOCs, the decomposition characteristics of VOCs by the reactors and the effects of the discharge type, applied voltage, etc. on VOCs decomposition are briefly described. Further, the detailed investigation of by-products from benzene, toluene and xylene and the estimation of decomposition path of acetone by discharge plasma treatment are introduced as works which contribute to the design of VOC-decomposition reactors and to assuring the safety of VOCs decomposition by the discharge plasma. For the decomposition of environmental hazardous substances in water by discharge plasma, the treatment of aqueous phenol solution and organic dyes are focused. The effects of sparging gas, the conductivity of the solution, background-gas composition, etc. on phenol decomposition rate are described, and the mechanism that the species contributing phenol decomposition change with the background-gas composition is illustrated in detail. Recent works to clarify the by-products of phenol are also introduced. For the decomposition rate of organic dyes, the effects of pH of solution, background-gas composition, etc. on the decomposition rate and the species contributing the decomposition are shown. Further, the efficiency difference for organic-dye decomposition due to the kinds of discharge plasma reactor is introduced.

Satoh, Kohki

24

Elevated CO2 and plant species diversity interact to slow root decomposition  

SciTech Connect

Changes in plant species diversity can result in synergistic increases in decomposition rates, while elevated atmospheric CO2 can slow the decomposition rates; yet it remains unclear how diversity and changes in atmospheric CO2 may interact to alter root decomposition. To investigate how elevated CO2 interacts with changes in root-litter diversity to alter decomposition rates, we conducted a 120-day laboratory incubation. Roots from three species (Trifolium repens, Lespedeza cuneata, and Festuca pratense) grown under ambient or elevated CO2 were incubated individually or in combination in soils that were exposed to ambient or elevated CO2 for five years. Our experiment resulted in two main findings: (1) Roots from T. repens and L. cuneata, both nitrogen (N) fixers, grown under elevated CO2 treatments had significantly slower decomposition rates than similar roots grown under ambient CO2 treatments; but the decomposition rate of F. pratense roots (a non-N-fixing species) was similar regardless of CO2 treatment. (2) Roots of the three species grown under ambient CO2 and decomposed in combination with each other had faster decomposition rates than when they were decomposed as single species. However, roots of the three species grown under elevated CO2 had similar decomposition rates when they were incubated alone or in combination with other species. These data suggest that if elevated CO2 reduces the root decomposition rate of even a few species in the community, it may slow root decomposition of the entire plant community.

De Graaff, Marie-Anne [ORNL; Schadt, Christopher Warren [ORNL; Rula, Kelly L [ORNL; Six, Johan W U A [University of California, Davis; Schweitzer, Jennifer A [ORNL; Classen, Aimee T [University of Tennessee, Knoxville (UTK)

2011-01-01

25

Emissions of volatile organic compounds during the decomposition of plant litter  

Microsoft Academic Search

Volatile organic compounds (VOCs) are emitted during plant litter decomposition, and such VOCs can have wide-ranging impacts on atmospheric chemistry, terrestrial biogeochemistry, and soil ecology. However, we currently have a limited understanding of the relative importance of biotic versus abiotic sources of these VOCs and whether distinct types of litter emit different types and quantities of VOCs during decomposition. We

Christopher M. Gray; Russell K. Monson; Noah Fierer

2010-01-01

26

Water Filtration Using Plant Xylem  

PubMed Central

Effective point-of-use devices for providing safe drinking water are urgently needed to reduce the global burden of waterborne disease. Here we show that plant xylem from the sapwood of coniferous trees – a readily available, inexpensive, biodegradable, and disposable material – can remove bacteria from water by simple pressure-driven filtration. Approximately 3 cm3 of sapwood can filter water at the rate of several liters per day, sufficient to meet the clean drinking water needs of one person. The results demonstrate the potential of plant xylem to address the need for pathogen-free drinking water in developing countries and resource-limited settings. PMID:24587134

Chambers, Valerie; Venkatesh, Varsha; Karnik, Rohit

2014-01-01

27

On Assessing Decomposition Rates of Plant Debris and Standard Cellulose Samples in Tundra Communities  

Microsoft Academic Search

Interest in studies on the rate of plant debris decomposition (however labor-consuming they are) is maintained owing to the desire to comprehensively describe the structural and functional characteristics of the Earth’s biogeocenotic cover and to solve the problem of monitoring and long-term prognosis. Numerous attempts to use a simplified approach to the assessment of decomposition rates (substitution of plant samples

N. I. Andreyashkina; N. V. Peshkova

2001-01-01

28

Water Treatment Plant  

NSDL National Science Digital Library

In most parts of the United States, getting clean, safe water is as easy as turning on a faucet. Generally, this water comes from either groundwater or nearby streams and reservoirs. What most of us never see or have to worry about are the steps required to make this water drinkable. This video segment, adapted from a ZOOM television broadcast, shows how a water treatment facility in Cambridge, Massachusetts purifies its city's water. The segment is two minutes twenty seconds in length.

29

Water Filtration Using Plant Xylem  

E-print Network

Effective point-of-use devices for providing safe drinking water are urgently needed to reduce the global burden of waterborne disease. Here we show that plant xylem from the sapwood of coniferous trees – a readily available, ...

Boutilier, Michael Stephen Ha

30

Transpiration - Water Movement through Plants  

NSDL National Science Digital Library

This lesson and its animation follows the journey of water through a plant from its uptake by roots to its evaporation from the leaf surface. How this journey is altered by plant characteristics such as stomata and cuticles as well as by changes in the environment will be described.

31

Waste Water Plant Operators Manual.  

ERIC Educational Resources Information Center

This manual for sewage treatment plant operators was prepared by a committee of operators, educators, and engineers for use as a reference text and handbook and to serve as a training manual for short course and certification programs. Sewage treatment plant operators have a responsibility in water quality control; they are the principal actors in…

Washington State Coordinating Council for Occupational Education, Olympia.

32

Labile soil carbon inputs mediate the soil microbial community composition and plant residue decomposition rates  

SciTech Connect

Root carbon (C) inputs may regulate decomposition rates in soil, and in this study we ask: how do labile C inputs regulate decomposition of plant residues, and soil microbial communities? In a 14 d laboratory incubation, we added C compounds often found in root exudates in seven different concentrations (0, 0.7, 1.4, 3.6, 7.2, 14.4 and 21.7 mg C g{sup -1} soil) to soils amended with and without {sup 13}C-labeled plant residue. We measured CO{sub 2} respiration and shifts in relative fungal and bacterial rRNA gene copy numbers using quantitative polymerase chain reaction (qPCR). Increased labile C input enhanced total C respiration, but only addition of C at low concentrations (0.7 mg C g{sup -1}) stimulated plant residue decomposition (+2%). Intermediate concentrations (1.4, 3.6 mg C g{sup -1}) had no impact on plant residue decomposition, while greater concentrations of C (> 7.2 mg C g{sup -1}) reduced decomposition (-50%). Concurrently, high exudate concentrations (> 3.6 mg C g{sup -1}) increased fungal and bacterial gene copy numbers, whereas low exudate concentrations (< 3.6 mg C g{sup -1}) increased metabolic activity rather than gene copy numbers. These results underscore that labile soil C inputs can regulate decomposition of more recalcitrant soil C by controlling the activity and relative abundance of fungi and bacteria.

De Graaff, Marie-Anne [ORNL; Classen, Aimee T [University of Tennessee, Knoxville (UTK); Castro Gonzalez, Hector F [ORNL; Schadt, Christopher Warren [ORNL

2010-01-01

33

Transpiration: Water Movement Through Plants  

NSDL National Science Digital Library

Learn the basics of transpiration -- the transportation of water through plants from soil to leaves to atmosphere -- with this playful animation created by weed physiologist Tracy Sterling and animator Matt Byrnes. Interactive features allow you to explore the process including how changing environmental conditions can impact how fast water moves.

Tracy Sterling (New Mexico State University; )

2005-09-23

34

Algebraic decomposition of fat and water in MRI.  

PubMed

The decomposition of magnetic resonance imaging (MRI) data to generate water and fat images has several applications in medical imaging, including fat suppression and quantification of visceral fat. We introduce a novel algorithm to overcome some of the problems associated with current analytical and iterative decomposition schemes. In contrast to traditional analytical schemes, our approach is general enough to accommodate any uniform echo-shift pattern, any number of metabolites and signal samples. In contrast to region-growing method that use a smooth field-map initialization to resolve the ambiguities with the IDEAL algorithm, we propose to use an explicit smoothness constraint on the final field-map estimate. Towards this end, we estimate the number of feasible solutions at all the voxels, prior to the evaluation of the roots. This approach enables the algorithm to evaluate all the feasible roots, thus avoiding the convergence to the wrong solution. The estimation procedure is based on a modification of the harmonic retrieval (HR) framework to account for the chemical shift dependence in the frequencies. In contrast to the standard linear HR framework, we obtain the frequency shift as the common root of a set of quadratic equations. On most of the pixels with multiple feasible solutions, the correct solution can be identified by a simple sorting of the solutions. We use a region-merging algorithm to resolve the remaining ambiguity and phase-wrapping. Experimental results indicate that the proposed algebraic scheme eliminates most of the difficulties with the current schemes, without compromising the noise performance. Moreover, the proposed algorithm is also computationally more efficient. PMID:19188106

Jacob, Mathews; Sutton, Bradley P

2009-02-01

35

Interactions between decomposition of plant residues and nitrogen cycling in soil  

Microsoft Academic Search

The processes of N mineralization and immobilization which can occur in agricultural soils during decomposition of plant residues are briefly reviewed in this paper. Results from different incubation studies have indicated that the amounts of N immobilized can be very important and that the intensity and kinetics of N immobilization and subsequent remineralization depend on the nature of plant residues

B. Mary; S. Recous; D. Darwis; D. Robin

1996-01-01

36

What drives plant litter decomposition globally? Ecological Monographs?  

E-print Network

and plant environments. Plant evolution balances physiological adaptations to environment, phytochemical balances physiological adaptations to environment, phytochemical responses to herbivory and pathologens

Tennessee, University of

37

Enzyme activities during litter decomposition of two exotic and two native plant species in hardwood forests of New Jersey  

Microsoft Academic Search

Invasions by exotic plant species can alter ecosystem properties, including important soil functions and characteristics. As a result, decomposition of litter from the exotic, as well as native plants, can also be altered, leading to more profound changes in ecosystem functioning. We present here a study of eight enzyme activities during the decomposition of litter from four plant species, two

P. S Kourtev; J. G Ehrenfeld; W. Z Huang

2002-01-01

38

Interactions among fungal community structure, litter decomposition and depth of water table in a cutover peatland.  

PubMed

Peatlands are important reservoirs of carbon (C) but our understanding of C cycling on cutover peatlands is limited. We investigated the decomposition over 18 months of five types of plant litter (Calluna vulgaris, Eriophorum angustifolium, Eriophorum vaginatum, Picea sitchensis and Sphagnum auriculatum) at a cutover peatland in Scotland, at three water tables. We measured changes in C, nitrogen (N) and phosphorus (P) in the litter and used denaturing gradient gel electrophoresis to investigate changes in fungal community composition. The C content of S. auriculatum litter did not change throughout the incubation period whereas vascular plant litters lost 30-40% of their initial C. There were no differences in C losses between low and medium water tables, but losses were always significantly less at the high water table. Most litters accumulated N and E. angustifolium accumulated significant quantities of P. C, N and P were significant explanatory variables in determining changes in fungal community composition but explained <25% of the variation. Litter type was always a stronger factor than water table in determining either fungal community composition or turnover of C, N and P in litter. The results have implications for the ways restoration programmes and global climate change may impact upon nutrient cycling in cutover peatlands. PMID:18430005

Trinder, Clare J; Johnson, David; Artz, Rebekka R E

2008-06-01

39

Modeling water use at thermoelectric power plants  

E-print Network

The withdrawal and consumption of water at thermoelectric power plants affects regional ecology and supply security of both water and electricity. The existing field data on US power plant water use, however, is of limited ...

Rutberg, Michael J. (Michael Jacob)

2012-01-01

40

Detailed modeling of the evaporation and thermal decomposition of urea-water-solution in SCR systems  

E-print Network

Detailed modeling of the evaporation and thermal decomposition of urea-water-solution in SCRE Journal. Keywords: Multi-component, , evaporation, UWS, Adbue, urea decomposition, thermolysis SCR, kinetics Abstract This work aims to develop a multi-component evaporation model for droplets of urea

Boyer, Edmond

41

Changes in bacterial and eukaryotic communities during sewage decomposition in Mississippi River water  

EPA Science Inventory

Microbial decay processes are one of the mechanisms whereby sewage contamination is reduced in the environment. This decomposition process involves a highly complex array of bacterial and eukaryotic communities from both sewage and ambient waters. However, relatively little is kn...

42

Seasonal Plant Water Relationships in Acacia berlandieri  

Microsoft Academic Search

In order to assess how plant water potential is related to soil water availability and evaporative demand, determinations of diurnal and seasonal plant water potentials between 23 April 1997, and 22 September 1998, were studied in Acacia berlandieri Benth., a native shrub of the northeastern region of Mexico. Average plant water potentials during the wettest period ranged from-0.37 MPa (predawn,

H. González Rodríguez; I. Cantú Silva; M. V. Gómez Meza; W. R. Jordan

2000-01-01

43

LITTER DECOMPOSITION IN A SIERRA NEVADA RIPARIAN MEADOW AS A FUNCTION OF PLANT SPECIES, DISTANCE FROM STREAM EDGE, AND GRAZING  

Technology Transfer Automated Retrieval System (TEKTRAN)

A key process in nutrient cycling is decomposition of plant litter and the potential resulting increase in soil nutrient levels. We compare the decomposition rate (k-value yr-1) of four riparian graminoids as influenced by plant species, distance from stream edge (2.5, 20, and 50 m), and grazi...

44

A Fast Iterated Conditional Modes Algorithm for Water–Fat Decomposition in MRI  

Microsoft Academic Search

Decomposition of water and fat in magnetic resonance imaging (MRI) is important for biomedical research and clinical applications. In this paper, we propose a two-phased approach for the three-point water-fat decomposition problem. Our contribu- tion consists of two components: 1) a background-masked Markov random field (MRF) energy model to formulate the local smooth- ness of field inhomogeneity; 2) a new

Fangping Huang; Sreenath Narayan; David Wilson; David Johnson; Guo-Qiang Zhang

2011-01-01

45

PLANT WATER STATUS INFLUENCES OZONE SENSITIVITY OF BEAN PLANTS  

EPA Science Inventory

Studies were conducted in a controlled environment chamber to determine the association between plant water status and ozone sensitivity. Bean plants were subjected to various water stress regimes for 4 to 10 days using a semipermeable membrane system which controlled plant water...

46

A FULLY IMPLICIT DOMAIN DECOMPOSITION ALGORITHM FOR SHALLOW WATER EQUATIONS ON THE CUBED-SPHERE  

E-print Network

. Key words. Shallow water equations, cubed-sphere, fully implicit method, domain decomposi- tionA FULLY IMPLICIT DOMAIN DECOMPOSITION ALGORITHM FOR SHALLOW WATER EQUATIONS ON THE CUBED-SPHERE CHAO YANG, JIANWEN CAO, AND XIAO-CHUAN CAI§ Abstract. Popular approaches for solving the shallow water

Cai, Xiao-Chuan

47

Noise Decomposition in Boiling Water Reactors with Application to Stability Monitoring  

E-print Network

Noise Decomposition in Boiling Water Reactors with Application to Stability Monitoring J. Karlsson in boiling water reactor (BWR) noise measure- ments, based on flux factorization techniques (i.e., using reactors4 or flux oscillations in boiling water reactors5,6 ~BWRs!. In these cases the different modes have

Pázsit, Imre

48

(Plant growth with limited water)  

SciTech Connect

The work supported by DOE in the last year built on our earlier findings that stem growth in soybean subjected to limited water is inhibited first by a physical limitation followed in a few hours by metabolic changes that reduce the extensibility of the cell walls. With time, there is modest recovery in extensibility and a 28kD protein accumulates in the walls of the growth-affected cells. A 31kD protein that was 80% similar in amino acid sequence also was present but did not accumulate in the walls of the stem cells. Explorations of the mRNA for these proteins showed that the mRNA for the 28kD protein increased in the shoot in response to water deprivation but the mRNA for the 31kD protein did not accumulate. In contrast, the roots continued to grow and the mRNA for the 31kD protein accumulated but the mRNA for the 28kD protein was undetectable. We also explored how growth occurs in the absence of an external water supply. We found that, under these conditions, internal water is mobilized from surrounding nongrowing or slowly growing tissues and is used by rapidly growing cells. We showed that a low water potential is normally present in the enlarging tissues and is the likely force that extracts water from the surrounding tissues. We found that it involved a gradient in water potential that extended from the xylem to the outlying cells in the enlarging region and was not observed in the slowly growing basal tissue of the stems of the same plant. The gradient was measured directly with single cell determinations of turgor and osmotic potential in intact plants. The gradient may explain instances of growth inhibition with limited water when there is no change in the turgor of the enlarging cells. 17 refs.

Not Available

1991-01-01

49

Dantzig-Wolfe decomposition and plant-wide MPC coordination  

Microsoft Academic Search

Due to the enormous success of model predictive control (MPC) in industrial practice, the efforts to extend its application from unit-wide to plant-wide control are becoming more widespread. In general, industrial practice has tended toward a decentralized MPC architecture. Most existing MPC systems work independently of other MPC systems installed within the plant and pursue a unit\\/local optimal operation. Thus,

Ruoyu Cheng; J. Fraser Forbes; W. San Yip

2008-01-01

50

Plant diversity impacts decomposition and herbivory via changes in aboveground arthropods.  

PubMed

Loss of plant diversity influences essential ecosystem processes as aboveground productivity, and can have cascading effects on the arthropod communities in adjacent trophic levels. However, few studies have examined how those changes in arthropod communities can have additional impacts on ecosystem processes caused by them (e.g. pollination, bioturbation, predation, decomposition, herbivory). Therefore, including arthropod effects in predictions of the impact of plant diversity loss on such ecosystem processes is an important but little studied piece of information. In a grassland biodiversity experiment, we addressed this gap by assessing aboveground decomposer and herbivore communities and linking their abundance and diversity to rates of decomposition and herbivory. Path analyses showed that increasing plant diversity led to higher abundance and diversity of decomposing arthropods through higher plant biomass. Higher species richness of decomposers, in turn, enhanced decomposition. Similarly, species-rich plant communities hosted a higher abundance and diversity of herbivores through elevated plant biomass and C:N ratio, leading to higher herbivory rates. Integrating trophic interactions into the study of biodiversity effects is required to understand the multiple pathways by which biodiversity affects ecosystem functioning. PMID:25226237

Ebeling, Anne; Meyer, Sebastian T; Abbas, Maike; Eisenhauer, Nico; Hillebrand, Helmut; Lange, Markus; Scherber, Christoph; Vogel, Anja; Weigelt, Alexandra; Weisser, Wolfgang W

2014-01-01

51

Plant Diversity Impacts Decomposition and Herbivory via Changes in Aboveground Arthropods  

PubMed Central

Loss of plant diversity influences essential ecosystem processes as aboveground productivity, and can have cascading effects on the arthropod communities in adjacent trophic levels. However, few studies have examined how those changes in arthropod communities can have additional impacts on ecosystem processes caused by them (e.g. pollination, bioturbation, predation, decomposition, herbivory). Therefore, including arthropod effects in predictions of the impact of plant diversity loss on such ecosystem processes is an important but little studied piece of information. In a grassland biodiversity experiment, we addressed this gap by assessing aboveground decomposer and herbivore communities and linking their abundance and diversity to rates of decomposition and herbivory. Path analyses showed that increasing plant diversity led to higher abundance and diversity of decomposing arthropods through higher plant biomass. Higher species richness of decomposers, in turn, enhanced decomposition. Similarly, species-rich plant communities hosted a higher abundance and diversity of herbivores through elevated plant biomass and C:N ratio, leading to higher herbivory rates. Integrating trophic interactions into the study of biodiversity effects is required to understand the multiple pathways by which biodiversity affects ecosystem functioning. PMID:25226237

Ebeling, Anne; Meyer, Sebastian T.; Abbas, Maike; Eisenhauer, Nico; Hillebrand, Helmut; Lange, Markus; Scherber, Christoph; Vogel, Anja; Weigelt, Alexandra; Weisser, Wolfgang W.

2014-01-01

52

Decomposition and nutrient release from C 3 and C 4 plant litters in a natural grassland  

NASA Astrophysics Data System (ADS)

The rate of litter loss, and the release of N, P, K, Ca during litter decomposition of two C 4 plants ( Dichanthium ischaemum L. and Chrysopogon gryllus L.) and one C 3 plant ( Festuca ovina H.) were studied for 24 months. This was achieved by placing leaf and culm litter in nylon screen bags close to the soil surface, sampling every three months to mease the changes in litter weight and chemical composition during the experimental period. Litter decomposition was faster during the first 12 months for both leaves and culms of all species. The order was D. ischaemum > F. ovina > C. gryllus. The mean rate litter loss for the 12 and 24 month period was similar for leaf and culm litter. Nitrogen accumulation was observed during the entire experimental period for all species. Phosphorus release had occurred during the experimental period in the decreasing order: C. gryllus > D. ischaemum > F. ovina. Potassium release was observed after 12 and 24 months in the decreasing order D. ischaemum > C. gryllus > F. ovina, while calcium was accumulating. The decomposition rates were similar for C 4 and C 3 plants and their contribution to nutrient cycling depended on the release of the various elements during decomposition.

Koukoura, Zoi

1998-04-01

53

Water Treatment Technology - General Plant Operation.  

ERIC Educational Resources Information Center

One of twelve water treatment technology units, this student manual on general plant operations provides instructional materials for seven competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: water supply regulations, water plant…

Ross-Harrington, Melinda; Kincaid, G. David

54

MINI PILOT PLANT FOR DRINKING WATER RESEARCH  

EPA Science Inventory

The Water Supply & Water Resources Division (WSWRD) has constructed 2 mini-pilot plant systems used to conduct drinking water research. These two systems each have 2 parallel trains for comparative research. The mini-pilot plants are small conventional drinking water treatment ...

55

Temperature and plant species control over litter decomposition in Alaskan tundra  

SciTech Connect

This study compared effects of increased temperature and litter from different Alaskan tundra plant species on cycling of carbon and nitrogen through litter and soil in microcosms. Warming between 4{degrees} and 10{degrees}C significantly increased rates of soil and litter respiration, litter decomposition, litter nitrogen release, and soil net nitrogen mineralization. Thus, future warming will directly increase rates of carbon and nitrogen cycling through litter and soil in tundra. In addition, differences among species` litter in rates of decomposition, N release, and effects on soil net nitrogen mineralization were sometimes larger than differences between the two temperature treatments within a species. Thus, changes in plant community structure and composition associated with future warming will have important consequences for how elements cycle through litter and soil in tundra. In general, species within a growth form (graminoids, evergreen shrubs, deciduous shrubs, and mosses) were more similar in their effects on decomposition than were species belonging to different growth forms, with gramminoid litter having the fastest rate and litter of deciduous shrubs and mosses having the slowest rates. Differences in rates of litter decomposition were more related to carbon quality than to nitrogen concentration. Increased abundance of deciduous shrubs with future climate warming will promote carbon storage, because of their relatively large allocation to woody stems that decompose slowly. Changes in moss abundance will also have important consequences for future carbon and nitrogen cycling, since moss litter is extremely recalcitrant and has a low potential to immobilize nitrogen. 82 refs., 8 figs., 7 tabs.

Hobbie, S.E. [Univ. of California, Berkeley, CA (United States)

1996-11-01

56

Economic comparison of hydrogen production using sulfuric acid electrolysis and sulfur cycle water decomposition. Final report  

Microsoft Academic Search

An evaluation of the relative economics of hydrogen production using two advanced techniques was performed. The hydrogen production systems considered were the Westinghouse Sulfur Cycle Water Decomposition System and a water electrolysis system employing a sulfuric acid electrolyte. The former is a hybrid system in which hydrogen is produced in an electrolyzer which uses sulfur dioxide to depolarize the anode.

G. H. Farbman; B. R. Krasicki; C. C. Hardman; S. S. Lin; G. H. Parker

1978-01-01

57

Photogeneration of active formate decomposition catalysts to produce hydrogen from formate and water  

DOEpatents

A process for producing hydrogen from formate and water by photogenerating an active formate decomposition catalyst from transition metal carbonyl precursor catalysts at relatively low temperatures and otherwise mild conditions is disclosed. Additionally, this process may be expanded to include the generation of formate from carbon monoxide and hydroxide such that the result is the water gas shift reaction.

King, Jr., Allen D. (Athens, GA); King, Robert B. (Athens, GA); Sailers, III, Earl L. (Athens, GA)

1983-02-08

58

Phenolic control of plant nitrogen acquisition through the inhibition of soil microbial decomposition processes: a plant-microbe competition model.  

PubMed

Phenolics are a dominant class of plant secondary metabolites that have strong effects on various ecosystem processes. The ecological significance of these compounds, however, is still poorly understood. We hypothesized that the inhibitory effects of phenolics on microbial activity could enhance plant nitrogen acquisition by relaxing competition between plants and microbes. To test this hypothesis theoretically, we constructed a novel and simple mechanistic model by unifying two concepts: one is a new paradigm of nitrogen cycling which considers the uptake of organic nitrogen by plants, and the other is that phenolics can regulate nitrogen cycling by inhibiting microbial decomposition processes. Our plant-microbe competition model consists of five compartments (plants, soil microbes, debris, organic nitrogen and inorganic nitrogen) and incorporates the essential processes of nitrogen cycling: plant uptake of monomers, competition between plants and microbes, and the depolymerization process. Our analysis showed that plant nitrogen acquisition was maximized at intermediate levels of phenolics, but only when plants could utilize organic nitrogen. Furthermore, this pattern occurred over a broad range of parameter conditions. Our study successfully demonstrated the potential role of phenolics in plant nitrogen acquisition throughout natural environments. PMID:21566372

Ushio, Masayuki; Miki, Takeshi; Kitayama, Kanehiro

2009-01-01

59

Seasonal variation in carbon isotopic composition of bog plant litter during 3 years of field decomposition  

Microsoft Academic Search

In this study, we describe the seasonal variation in 13C abundance in the litter of two Sphagnum species and four vascular plant species during 3 years of field decomposition in an Italian alpine bog. Litter bags were\\u000a periodically retrieved at the end of summer and winter periods, and the ?13C in residual litter was related to mass loss, litter chemistry, and

Luca Bragazza; Paola Iacumin

2009-01-01

60

Seasonal variation in nitrogen isotopic composition of bog plant litter during 3 years of field decomposition  

Microsoft Academic Search

In this study, we describe the seasonal variation in 15N abundance in the litter of two Sphagnum species and four vascular plant species during 3 years of field decomposition in an Italian Alpine bog. Litter bags were\\u000a periodically retrieved at the end of summer and winter periods, and the ?15N in residual litter was related to mass loss, litter chemistry, and

Luca Bragazza; Paola Iacumin; Chiara Siffi; Renato Gerdol

2010-01-01

61

Water Balance in Terrestrial PlantsWater Balance in Terrestrial Plants Water Regulation on LandWater Regulation on Land --PlantsPlants WWipip= W= Wrr + W+ Waa --WWtt --WWss  

E-print Network

1 Water Balance in Terrestrial PlantsWater Balance in Terrestrial Plants Water Regulation on LandWater waters internal water WWrr =Roots=Roots WWaa = Air= Air WWtt = Transpiration= Transpiration WWss = Secretions= Secretions Water Regulation on Land - Plants Water Balance in Terrestrial PlantsWater Balance

Cochran-Stafira, D. Liane

62

Root water potential in polycormon plants  

Microsoft Academic Search

Water potential of roots was measured by thermocouple psyohometers in a series of two or more plants ofCynodon dactylon (L.)Pers. interconnected by overground stolons and thus forming one s.c. polycormon. Root water potential was lowest (most negative)\\u000a in the oldest “mother” plant and increased in younger individua to highest walues in the youngest “doughter” plants. This\\u000a gradient of root water

Ji?ina Slavíková

1973-01-01

63

[Influence of decomposition of Cladophora sp. on phosphorus concentrations and forms in the overlying water].  

PubMed

Sediments were sampled in the dominated zone of Cladophora sp. in Rongcheng Swan Lake, and cultivated with algae in the laboratory to reveal the influence of Cladophora decomposition on concentrations and forms of phosphorus in the overlying water. Concentrations of total phosphorus (TP), dissolved total phosphorus (DTP), soluble reactive phosphorus (SRP), particulate phosphorus (PP) and dissolved organic phosphorus (DOP) in overlying water were investigated, and some physicochemical parameters, such as dissolved oxygen (DO), pH and conductivity were monitored during the experiment. In addition, the influence of algae decomposition on P release from sediments was analyzed. Due to the decomposition of Cladophora, DO concentration in the overlying water declined remarkably and reached the anoxic condition (0-0.17 mg x L(-1)). The pH value of different treatments also decreased, and treatments with algae reduced by about 1 unit. Concentrations of TP and different P forms all increased obviously, and the increasing extent was larger with the adding algae amount. TP concentrations of different treatments varied from 0.04 mg x L(-1) to 1.34 mg x L(-1). DOP and PP were the main P forms in the overlying water in algae without sediments treatments, but SRP concentrations became much higher in algae with sediments treatments. The result showed that P forms released from decomposing Cladophora were mainly DOP and PP, and the Cladophora decomposition could also promote the sediments to release P into the overlying water. PMID:23947031

Hou, Jin-Zhi; Wei, Quan; Gao, Li; Sun, Wei-Ming

2013-06-01

64

Algebraic decomposition of fat and water in MRI Mathews Jacob, Member, IEEE, and Bradley P. Sutton, Member, IEEE  

E-print Network

several applications in medical imaging, including fat suppression and quantification of visceral fat. We1 Algebraic decomposition of fat and water in MRI Mathews Jacob, Member, IEEE, and Bradley P. Sutton, Member, IEEE Abstract-- The decomposition of MRI data to generate water and fat images has

Jacob, Mathews

65

Reconciling Phylogeny and Function During Plant Litter Decomposition by High-Throughput Functional Metagenomics  

NASA Astrophysics Data System (ADS)

Integrating information on microbial diversity and functionality with ecosystem processes may be critical to predicting how ecosystems respond to environmental change. While theoretical models can be used to link microbial processes to environmental responses and rates, accurate predictions of ecosystem functioning would benefit from detailed information on microbial community composition and function. In this study, our aim was to identify functional traits involved in plant litter decomposition, a model process for carbon cycling, from decomposing plant litter. The overall goal is then to link these traits with individual microbial taxa and use this information to build predictive trait-based models of ecosystem responses to global change. In order to identify activities involved in plant litter decomposition we used automated high-throughput assays for functional screening of metagenomic fosmid libraries prepared from decomposing plant litter. Litter was collected over 15 month period from a global change field experiment undergoing rainfall and nitrogen manipulations. We identified over 600 cellulose, hemicellulose, chitin and starch hydrolyzing clones following screening of over 300,000 clones. The frequency of positive clones was ten times lower during dry season but no significant differences in hit rates were observed between different treatments. The positive clones were shotgun sequenced on the Illumina sequencing platform and the identified hydrolytic genes were shown to represent variety bacterial taxonomic groups including Proteobacteria and Bacteroidetes.

Nyyssonen, M.; Weihe, C.; Goulden, M.; Treseder, K. K.; Martiny, J.; Martiny, A.; Allison, S. D.; Brodie, E. L.

2012-12-01

66

WATER DECOMPOSITION BY FISSION FRAGMENT RECOIL ENERGY IN AN AQUEOUS SLURRY OF URANIUM-THORIUM OXIDES  

Microsoft Academic Search

Measurements of the rate of decomposition of water as a function of ; particle size and concentration of a slurry of fissionable and fertile fuel were ; made. Irradiations of 10 cc samples of slurry, kept in suspension by a ; mechanical stirrer, were carried out in a nuclear reactor. By passing N through ; the slurry during the irradiation,

Steele

1962-01-01

67

Hydrogen-oxygen closed cycle MHD power generation system based upon thermochemical decomposition of water  

Microsoft Academic Search

A new closed cycle energy conversion system in which an MHD generator operates on hydrogen and oxygen produced from water by means of multi-step thermochemical decomposition processes is proposed. It is shown that the MHD generator and the thermochemical decomposer can be combined effectively in the power generation process and that the conversion of nuclear heat available from already existing

T. Nakamura; W. Riedmueller

1975-01-01

68

Plant-driven variation in decomposition rates improves projections of global litter stock distribution  

NASA Astrophysics Data System (ADS)

Plant litter stocks are critical, regionally for their role in fueling fire regimes and controlling soil fertility, and globally through their feedback to atmospheric CO2 and climate. Here we employ two global databases linking plant functional types to decomposition rates of wood and leaf litter (Cornwell et al., 2008; Weedon et al., 2009) to improve future projections of climate and carbon cycle using an intermediate complexity Earth system model. Implementing separate wood and leaf litter decomposabilities and their temperature sensitivities for a range of plant functional types yielded a more realistic distribution of litter stocks in all present biomes with except of boreal forests and projects a strong increase in global litter stocks and a concomitant small decrease in atmospheric CO2 by the end of this century. Despite a relatively strong increase in litter stocks, the modified parameterization results in less elevated wildfire emissions because of litter redistribution towards more humid regions.

Brovkin, V.; van Bodegom, P. M.; Kleinen, T.; Wirth, C.; Cornwell, W.; Cornelissen, J. H. C.; Kattge, J.

2011-08-01

69

Plant-driven variation in decomposition rates improves projections of global litter stock distribution  

NASA Astrophysics Data System (ADS)

Plant litter stocks are critical, regionally for their role in fueling fire regimes and controlling soil fertility, and globally through their feedback to atmospheric CO2 and climate. Here we employ two global databases linking plant functional types to decomposition rates of wood and leaf litter (Cornwell et al., 2008; Weedon et al., 2009) to improve future projections of climate and carbon cycle using an intermediate complexity Earth System model. Implementing separate wood and leaf litter decomposabilities and their temperature sensitivities for a range of plant functional types yielded a more realistic distribution of litter stocks in all present biomes with the exception of boreal forests and projects a strong increase in global litter stocks by 35 Gt C and a concomitant small decrease in atmospheric CO2 by 3 ppm by the end of this century. Despite a relatively strong increase in litter stocks, the modified parameterization results in less elevated wildfire emissions because of a litter redistribution towards more humid regions.

Brovkin, V.; van Bodegom, P. M.; Kleinen, T.; Wirth, C.; Cornwell, W. K.; Cornelissen, J. H. C.; Kattge, J.

2012-01-01

70

Regulation of Water in Plant Cells  

ERIC Educational Resources Information Center

Cell water relationships are important topics to be included in cell biology courses. Differences exist in the control of water relationships in plant cells relative to control in animal cells. One important reason for these differences is that turgor pressure is a consideration in plant cells. Diffusion and osmosis are the underlying factors…

Kowles, Richard V.

2010-01-01

71

Theoretical study of the decomposition of formamide in the presence of water molecules.  

PubMed

Formamide (NH2CHO, FM) has been considered an active key precursor in prebiotic chemistry on early Earth. Under certain conditions such as dry lagoons, FM can decompose to produce reactants that lead to formation of more complex biomolecules. Specifically, FM decomposition follows many reactive channels producing small molecules such as H2, CO, H2O, HCN, HNC, NH3, and HNCO with comparable energy barriers in the range of 73-82 kcal/mol. Due to the likely presence of water on prebiotic Earth and the intrinsic presence of water following FM decomposition, we explore the effects of water oligomers, (H2O)n with n = 1-3, on its dehydration, dehydrogenation, and decarbonylation reactions using quantum chemical computations. Geometries are optimized using MP2/aug-cc-pVxZ calculations (x = D,T), and relative energies are evaluated using coupled-cluster theory CCSD(T) with the aug-cc-pVxZ basis sets (x = D, T, Q). Where possible the coupled-cluster energies are extrapolated to the complete basis set limit (CBS). Water classically acts as an efficient bifunctional catalyst for decomposition. With the presence of one water molecule, the dehydration pathway leading to HCN is favored. When two and three water molecules are involved, dehydration remains energetically favored over other channels and attains an energy barrier of ~30 kcal/mol. PMID:23461351

Nguyen, Vinh Son; Orlando, Thomas M; Leszczynski, Jerzy; Nguyen, Minh Tho

2013-03-28

72

Daily water level forecasting using wavelet decomposition and artificial intelligence techniques  

NASA Astrophysics Data System (ADS)

Reliable water level forecasting for reservoir inflow is essential for reservoir operation. The objective of this paper is to develop and apply two hybrid models for daily water level forecasting and investigate their accuracy. These two hybrid models are wavelet-based artificial neural network (WANN) and wavelet-based adaptive neuro-fuzzy inference system (WANFIS). Wavelet decomposition is employed to decompose an input time series into approximation and detail components. The decomposed time series are used as inputs to artificial neural networks (ANN) and adaptive neuro-fuzzy inference system (ANFIS) for WANN and WANFIS models, respectively. Based on statistical performance indexes, the WANN and WANFIS models are found to produce better efficiency than the ANN and ANFIS models. WANFIS7-sym10 yields the best performance among all other models. It is found that wavelet decomposition improves the accuracy of ANN and ANFIS. This study evaluates the accuracy of the WANN and WANFIS models for different mother wavelets, including Daubechies, Symmlet and Coiflet wavelets. It is found that the model performance is dependent on input sets and mother wavelets, and the wavelet decomposition using mother wavelet, db10, can further improve the efficiency of ANN and ANFIS models. Results obtained from this study indicate that the conjunction of wavelet decomposition and artificial intelligence models can be a useful tool for accurate forecasting daily water level and can yield better efficiency than the conventional forecasting models.

Seo, Youngmin; Kim, Sungwon; Kisi, Ozgur; Singh, Vijay P.

2015-01-01

73

Complementary symbiont contributions to plant decomposition in a fungus-farming termite.  

PubMed

Termites normally rely on gut symbionts to decompose organic matter but the Macrotermitinae domesticated Termitomyces fungi to produce their own food. This transition was accompanied by a shift in the composition of the gut microbiota, but the complementary roles of these bacteria in the symbiosis have remained enigmatic. We obtained high-quality annotated draft genomes of the termite Macrotermes natalensis, its Termitomyces symbiont, and gut metagenomes from workers, soldiers, and a queen. We show that members from 111 of the 128 known glycoside hydrolase families are represented in the symbiosis, that Termitomyces has the genomic capacity to handle complex carbohydrates, and that worker gut microbes primarily contribute enzymes for final digestion of oligosaccharides. This apparent division of labor is consistent with the Macrotermes gut microbes being most important during the second passage of comb material through the termite gut, after a first gut passage where the crude plant substrate is inoculated with Termitomyces asexual spores so that initial fungal growth and polysaccharide decomposition can proceed with high efficiency. Complex conversion of biomass in termite mounds thus appears to be mainly accomplished by complementary cooperation between a domesticated fungal monoculture and a specialized bacterial community. In sharp contrast, the gut microbiota of the queen had highly reduced plant decomposition potential, suggesting that mature reproductives digest fungal material provided by workers rather than plant substrate. PMID:25246537

Poulsen, Michael; Hu, Haofu; Li, Cai; Chen, Zhensheng; Xu, Luohao; Otani, Saria; Nygaard, Sanne; Nobre, Tania; Klaubauf, Sylvia; Schindler, Philipp M; Hauser, Frank; Pan, Hailin; Yang, Zhikai; Sonnenberg, Anton S M; de Beer, Z Wilhelm; Zhang, Yong; Wingfield, Michael J; Grimmelikhuijzen, Cornelis J P; de Vries, Ronald P; Korb, Judith; Aanen, Duur K; Wang, Jun; Boomsma, Jacobus J; Zhang, Guojie

2014-10-01

74

Evaluation of water hammer events in light water reactor plants  

SciTech Connect

This document presents the results of an evaluation of water hammer events in LWR power plants. The evaluation was based upon reports of actual events, typical plant design drawings and operating procedures. Included in this report are design and operating recommendations for the prevention or mitigation of water hammer occurrence.

Uffer, R.A.; Banerjee, S.; Buckholz, F.B.; Frankel, M.; Kasahara, M.; Miller, L.C.; Silvester, A.G.

1982-07-01

75

Thermal decomposition of hydrogen peroxide and its effect on reactor water monitoring of boiling water reactors  

Microsoft Academic Search

The thermal decomposition rate of hydrogen peroxide (HâOâ) was measured in the aqueous phase at an elevated temperature. It was shown that the reaction follows first-order kinetics, and the rate constant was determined as a function of temperature. The mechanism of the aqueous phase decomposition is discussed, particularly in relation to the activation energy of the reaction. Calculations were carried

J. Takagi; K. Ishigure

1985-01-01

76

Role of Plants in Water Filtration  

NSDL National Science Digital Library

This experiment will help students to understand the role of plants in filtering the water moving through a watershed. Students will discover that soil and plants have something of a dual role in this process and, depending on whether materials are dissolved or suspended in the water, soils and plant roots can remove some or all of this material as the water moves down through soil. They also learn that most suspended materials will adhere to the soil and these may then be broken down and used as food by the plants. This experiment is a very simplified way to show whether plants will take up certain kinds of materials from water moving relatively quickly through their root systems.

77

A Trip to the Water Plant.  

ERIC Educational Resources Information Center

Produced for primary and intermediate grades, this student booklet provides a study of where water comes from, how we get clean water, and the operations of a water treatment plant. Photographs, a few line drawings, a minimum of narrative, and a glossary of terms make up its content. A related document is the teacher's guide, SE 016 490. This work…

Laskey, Marilyn

78

Influence of soil temperature and water tension on the decomposition rate of ¹⁴Ca labeled herbage  

Microsoft Academic Search

The relation of decomposition rate of carbon-14 labeled blue grama (Bouteloua gracilis) to soil water content and temperature was examined in laboratory studies. Soil samples amended with ground herbage were incubated at various temperatures (3, 10, 25, 40, 50, and 60°C and water contents (.009, .03, .06, .60, 5.8, and 113 atm water tension). The oxygen concentrations in the decomposition

J. W. NYHAN

1976-01-01

79

Species-specific effects of elevated ozone on wetland plants and decomposition processes.  

PubMed

Seven species from two contrasting wetlands, an upland bog and a lowland rich fen in North Wales, UK, were exposed to elevated ozone (150 ppb for 5 days and 20 ppb for 2 days per week) or low ozone (20 ppb) for four weeks in solardomes. The rich fen species were: Molinia caerulea, Juncus subnodulosus, Potentilla erecta and Hydrocotyle vulgaris and the bog species were: Carex echinata, Potentilla erecta and Festuca rubra. Senescence significantly increased under elevated ozone in all seven species but only Molinia caerulea showed a reduction in biomass under elevated ozone. Decomposition rates of plants exposed to elevated ozone, as measured by carbon dioxide efflux from dried plant material inoculated with peat slurry, increased for Potentilla erecta with higher hydrolytic enzyme activities. In contrast, a decrease in enzyme activities and a non-significant decrease in carbon dioxide efflux occurred in the grasses, sedge and rush species. PMID:20185216

Williamson, Jennifer; Mills, Gina; Freeman, Chris

2010-05-01

80

Stage efficiency in the analysis of thermochemical water decomposition processes  

NASA Technical Reports Server (NTRS)

The procedure for analyzing thermochemical water-splitting processes using the figure of merit is expanded to include individual stage efficiencies and loss coefficients. The use of these quantities to establish the thermodynamic insufficiencies of each stage is shown. A number of processes are used to illustrate these concepts and procedures and to demonstrate the facility with which process steps contributing most to the cycle efficiency are found. The procedure allows attention to be directed to those steps of the process where the greatest increase in total cycle efficiency can be obtained.

Conger, W. L.; Funk, J. E.; Carty, R. H.; Soliman, M. A.; Cox, K. E.

1976-01-01

81

Method of generating hydrogen by catalytic decomposition of water  

DOEpatents

A method for producing hydrogen includes providing a feed stream comprising water; contacting at least one proton conducting membrane adapted to interact with the feed stream; splitting the water into hydrogen and oxygen at a predetermined temperature; and separating the hydrogen from the oxygen. Preferably the proton conducting membrane comprises a proton conductor and a second phase material. Preferable proton conductors suitable for use in a proton conducting membrane include a lanthanide element, a Group VIA element and a Group IA or Group IIA element such as barium, strontium, or combinations of these elements. More preferred proton conductors include yttrium. Preferable second phase materials include platinum, palladium, nickel, cobalt, chromium, manganese, vanadium, silver, gold, copper, rhodium, ruthenium, niobium, zirconium, tantalum, and combinations of these. More preferably second phase materials suitable for use in a proton conducting membrane include nickel, palladium, and combinations of these. The method for generating hydrogen is preferably preformed in the range between about 600.degree. C. and 1,700.degree. C.

Balachandran, Uthamalingam (Hinsdale, IL); Dorris, Stephen E. (LaGrange Park, IL); Bose, Arun C. (Pittsburgh, PA); Stiegel, Gary J. (Library, PA); Lee, Tae-Hyun (Naperville, IL)

2002-01-01

82

Drinking Water Plant Lecture-Demonstration.  

ERIC Educational Resources Information Center

Describes a simple way to demonstrate the principles involved in a drinking water plant. This demonstration developed for a general public lecture can be used in chemistry and biology courses for an ecological and environmental emphasis. (HM)

Vestling, Martha M.

1977-01-01

83

Water/Wastewater Treatment Plant Operator Qualifications.  

ERIC Educational Resources Information Center

This article summarizes in tabular form the U.S. and Canadian programs for classification of water and wastewater treatment plant personnel. Included are main characteristics of the programs, educational and experience requirements, and indications of requirement substitutions. (CS)

Water and Sewage Works, 1979

1979-01-01

84

Photoassisted decomposition of water over doped rutile electrodes  

NASA Astrophysics Data System (ADS)

The photoelectrolysis of water on a series of doped TiO2 semiconductors is presented. The TiO2 electrodes are prepared from 1 mm thick laminae of titanium, oxidized in an oven at 700 C for 4 h, and repeatedly impregnated in aqueous or acid (HCL) solutions containing equimolar (1M) quantities of TiCl3 and nitrates (or chlorides) of the dopant metal. The electrode current-voltage characteristics are measured in a one-compartment cell, using a 1 m Na 2SO4 solution. A 400 W medium pressure mercury lamp, emitting in the 310 to 1000 nm range, is used as a light source. Cell potentials are measured with an electrometer. An expression is derived for the energy conversion efficiency, which is strongly influenced by the preparation procedure. Pt-doping has the most marked positive influence and results in an energy conversion of 2.8 percent at 1 sun concentration, vs. 0.5 percent for an undoped sample. It is suggested that the best dopants, such as Pt, act through a reduction of the surface, thereby decreasing its acidity and increasing n-typeness.

Giordano, N.; Antonucci, V.; Cavallaro, S.; Lembo, R.; Bart, J. C. J.

85

Water-induced granular decomposition and its effects on geotechnical properties of crushed soft rocks  

NASA Astrophysics Data System (ADS)

The widespread availability of soft rocks and their increasing use as cheap rockfill material is adding more to geotechnical hazards because time-dependent granular decomposition causes significant damage to their mechanical properties. An experimental study was conducted through monotonic torsional shear tests on crushed soft rocks under fully saturated and dry conditions and compared with analogous tests on standard Toyoura sand. Due to the sensitivity of material to disintegration upon submergence, saturated conditions accelerated granular decomposition and, hence, simulated loss of strength with time, whereas, dry test condition represented the response of the soil with intact grains. A degradation index, in relation to gradation analyses after each test, was defined to quantify the degree of granular decomposition. Possible correlations of this index, with strength and deformation characteristics of granular soils, were explored. Enormous volumetric compression during consolidation and monotonic loading of saturated specimens and drastic loss of strength parameters upon submergence were revealed. It is revealed that the observed soil behaviour can be critical for embankments constructed with such rockfill materials. Moreover, the enhanced ability of existing soil mechanics models to predict time-dependent behaviour by incorporating water-induced granular decomposition can simplify several in situ geotechnical problems.

Aziz, M.; Towhata, I.; Yamada, S.; Qureshi, M. U.; Kawano, K.

2010-06-01

86

Decomposition of ethylene, a flower-senescence hormone, with electrolyzed anode water.  

PubMed

Electrolyzed anode water (EAW) markedly extended the vase life of cut carnation flowers. Therefore, a flower-senescence hormone involving ethylene decomposition by EAW with potassium chloride as an electrolyte was investigated. Ethylene was added externally to EAW, and the reaction between ethylen and the available chlorine in EAW was examined. EAW had a low pH value (2.5), a high concentration of dissolved oxygen, and extremely high redox potential (19.2 mg/l and 1323 mV, respectively) when available chlorine was at a concentration of about 620 microns. The addition of ethylene to EAW led to ethylene decomposition, and an equimolar amount of ethylene chlorohydrine with available chlorine was produced. The ethylene chlorohydrine production was greatly affected by the pH value (pH 2.5, 5.0 and 10.0 were tested), and was faster in an acidic solution. Ethylene chlorohydrine was not produced after ethylene had been added to EAW at pH 2.6 when available chlorine was absent, but was produced after potassium hypochlorite had been added to such EAW. The effect of the pH value of EAW on the vase life of cut carnations was compatible with the decomposition rate of ethylene in EAW of the same pH value. These results suggest that the effect of EAW on the vase life of cut carnations was due to the decomposition of ethylene to ethylene chlorohydrine by chlorine from chlorine compounds. PMID:12784619

Harada, Kazuo; Yasui, Keiko

2003-04-01

87

Water management and productivity in planted forests  

NASA Astrophysics Data System (ADS)

As climate variability endangers water security in many parts of the world, maximizing the carbon balance of plantation forestry is of global importance. High plant water use efficiency is generally associated with lower plant productivity, so an explicit balance in resources is necessary to optimize water yield and tree growth. This balance requires predicting plant water use under different soil, climate, and planting conditions, as well as a mechanism to account for trade-offs in ecosystem services. Several strategies for reducing the water use of forests have been published but there is little research tying these to operational forestry. Using data from silvicultural and biofuel feedstock research in pine plantation ownership in the southeastern USA, proposed water management tools were evaluated against known treatment responses to estimate water yield, forest productivity, and economic outcomes. Ecosystem impacts were considered qualitatively and related to water use metrics. This work is an attempt to measure and compare important variables to make sound decisions about plantations and water use.

Nettles, J. E.

2014-09-01

88

Pt\\/TiO 2 (rutile) catalysts for sulfuric acid decomposition in sulfur-based thermochemical water-splitting cycles  

Microsoft Academic Search

Thermochemical cycles consist of a series of chemical reactions to produce hydrogen from water at lower temperatures than by direct thermal decomposition. All the sulfur-based cycles for water splitting employ the sulfuric acid decomposition reaction. This work reports the studies performed on 1wt% Pt\\/TiO2 (rutile) catalysts submitted to flowing concentrated sulfuric acid at 1123K and atmospheric pressure for different times

L. M. Petkovic; D. M. Ginosar; H. W. Rollins; K. C. Burch; P. J. Pinhero; H. H. Farrell

2008-01-01

89

Combined cycle power plants - water chemistry  

SciTech Connect

Water chemistry guidelines are provided for combined cycle power plants. These plants utilize a gas and steam turbine to generate electric power. The gas turbine exhaust is passed through a heat recovery steam generator to produce steam. The steam is then expanded through a steam turbine for added power generation. This cycle comprises key features such as low feedwater temperature, large makeup water requirements, and low exhaust steam pressure. The steam purity and water chemistry guidelines address these features to provide a protective cycle chemistry environment.

Gabrielli, F. [Combustion Engineering, Inc., Windsor, CT (United States); Sandmann, H.; Svoboda, R. [ABB Kraftwerke AG, Baden (Switzerland)

1995-01-01

90

North City Water Reclamation Plant  

E-print Network

#12;#12;Magnitudes and Costs Location: San Diego, CA Near Interstate 805 Facility Size: 16 acres Courses Agricultural Irrigation #12;Economic & Environmental Benefits Self Sustaining Facility On-Site Cogeneration Methane Power Plant Methane piped in from: Miramar LandfillMiramar Landfill Metropolitan Biosolids

Prevedouros, Panos D.

91

Plant litter quality influences the contribution of soil fauna to litter decomposition in humid tropical forests, southwestern China  

Microsoft Academic Search

The aim of this field experiment was to quantify the contribution of soil fauna to plant litter decomposition in three forest sites differing in C\\/N ratio under natural conditions in Xishuangbanna, southwestern China. We conducted a survey of soil fauna communities, the forest floor litter and investigated mass loss of mixed tree species leaf litter for two years in a

Xiaodong Yang; Jin Chen

2009-01-01

92

7. Water treatment plant, view to E, berm in foreground ...  

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

7. Water treatment plant, view to E, berm in foreground covering settling tank - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

93

5. Water treatment plant, view to N, berm in foreground ...  

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

5. Water treatment plant, view to N, berm in foreground - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

94

10. Water treatment plant, view to S. 1965 addition is ...  

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

10. Water treatment plant, view to S. 1965 addition is in the foreground - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

95

3. Water treatment plant, view to W, detail of door ...  

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

3. Water treatment plant, view to W, detail of door area - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

96

13. Water treatment plant interior view of tanks in control ...  

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

13. Water treatment plant interior view of tanks in control room. View to SW - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

97

8. Water treatment plant, view to SE, berm in foreground ...  

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

8. Water treatment plant, view to SE, berm in foreground covering settling tank - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

98

4. Water treatment plant, view to NW, berm in foreground ...  

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

4. Water treatment plant, view to NW, berm in foreground - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

99

6. Water treatment plant, view NE, berm in foreground ...  

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

6. Water treatment plant, view NE, berm in foreground - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

100

2. Water treatment plant entrance, view to W Fort ...  

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

2. Water treatment plant entrance, view to W - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

101

14. Water treatment plant interior view of chlorination room. View ...  

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

14. Water treatment plant interior view of chlorination room. View to N - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

102

The Water Circuit of the Plants - Do Plants have Hearts ?  

E-print Network

There is a correspondence between the circulation of blood in all higher animals and the circulation of sap in all higher plants - up to heights h of 140 m - through the xylem and phloem vessels. Plants suck in water from the soil, osmotically through the roothair zone, and subsequently lift it osmotically again, and by capillary suction (via their buds, leaves, and fruits) into their crowns. In between happens a reverse osmosis - the endodermis jump - realized by two layers of subcellular mechanical pumps in the endodermis walls which are powered by ATP, or in addition by two analogous layers of such pumps in the exodermis. The thus established root pressure helps forcing the absorbed ground water upward, through the whole plant, and often out again, in the form of guttation, or exudation.

Wolfgang Kundt; Eva Gruber

2006-03-17

103

[Purification of eutrophicated water by aquatic plant].  

PubMed

In this study, aquatic plants were used to control the pollution of eutrophicated water. The results showed that aquatic plants had a higher ability to remove total nitrogen (TN), total phosphorus (TP) and nitrate nitrogen. Among them, foxtail alga (Myriophyllum verticillatum) and grain leaf pondweed (Potamogeton maackianus) could effectively remove TN (83.84% and 77.54%), TP (91.3%) and nitrate nitrogen (95.85% and 90.65%), but had no significant effect on removing ammonia nitrogen (only 14% to 70%). Sediment shielded by plastic could prolong the release of the nutrients from it for 15 to 20 days, and show the compensation effect later. The results also showed that aquatic plants could greatly improve the transparency of water, but could not improve the COD and DO of water effectively. PMID:15574005

Tong, Chanhua; Yang, Xiao'e; Pu, Peimin

2004-08-01

104

Adaptive phenotypic plasticity and plant water use  

Microsoft Academic Search

The emergence of new techniques in plant science, including molecular and phenomic tools, presents a novel opportunitytore-evaluatethewayweexaminethephenotype.Ourincreasingcapacityforphenotypingmeansthatnotonly canweconsiderincreasingnumbersofspeciesorvarieties,butalsothatwecaneffectivelyquantifythephenotypesofthese differentgenotypesunderarangeofenvironmentalconditions.Thephenotypicplasticityofagivengenotype,ortherangeof phenotypes, that can be expressed dependent upon environment becomes something we can feasibly assess. Of particular importance is phenotypic variation that increases fitness or survival - adaptive phenotypic plasticity. Here, we examine the case of adaptive phenotypic plasticity in plant water

Adrienne B. NicotraA; Amy DavidsonA

2010-01-01

105

Changes in bacterial and eukaryotic communities during sewage decomposition in Mississippi river water.  

PubMed

Microbial decay processes are one of the mechanisms whereby sewage contamination is reduced in the environment. This decomposition process involves a highly complex array of bacterial and eukaryotic communities from both sewage and ambient waters. However, relatively little is known about how these communities change due to mixing and subsequent decomposition of the sewage contaminant. We investigated decay of sewage in upper Mississippi River using Illumina sequencing of 16S and 18S rRNA gene hypervariable regions and qPCR for human-associated and general fecal Bacteroidales indicators. Mixtures of primary treated sewage and river water were placed in dialysis bags and incubated in situ under ambient conditions for seven days. We assessed changes in microbial community composition under two treatments in a replicated factorial design: sunlight exposure versus shaded and presence versus absence of native river microbiota. Initial diversity was higher in sewage compared to river water for 16S sequences, but the reverse was observed for 18S sequences. Both treatments significantly shifted community composition for eukaryotes and bacteria (P < 0.05). Data indicated that the presence of native river microbiota, rather than exposure to sunlight, accounted for the majority of variation between treatments for both 16S (R = 0.50; P > 0.001) and 18S (R = 0.91; P = 0.001) communities. A comparison of 16S sequence data and fecal indicator qPCR measurements indicated that the latter was a good predictor of overall bacterial community change over time (rho: 0.804-0.814, P = 0.001). These findings suggest that biotic interactions, such as predation by bacterivorous protozoa, can be critical factors in the decomposition of sewage in freshwater habitats and support the use of Bacteroidales genetic markers as indicators of fecal pollution. PMID:25463929

Korajkic, Asja; Parfrey, Laura Wegener; McMinn, Brian R; Baeza, Yoshiki Vazquez; VanTeuren, Will; Knight, Rob; Shanks, Orin C

2014-11-13

106

Water relations of riparian plants from warm desert regions  

Microsoft Academic Search

Riparian plants have been classified as “drought avoiders” due to their access to an abundant subsurface water supply. Recent\\u000a water-relations research that tracks water sources of riparian plants using the stable isotopes of water suggests that many\\u000a plants of the riparian zone use ground water rather than stream water, and not all riparian plants are obligate phreatophytes\\u000a (dependent on ground

Stanley D. Smith; Dale A. Devitt; Anna Sala; James R. Cleverly; David E. Busch

1998-01-01

107

regulating plant water status by stomatal control  

Microsoft Academic Search

The regulation of gas exchange at the leaf level is a key factor for plant survival under a fluctuating environment (Buckley,\\u000a 2005). In this context, control of stomatal opening and closure is the evolutionary solution to balance water loss with CO2 uptake and yield. A decrease in leaf\\/root water potential resulting from soil drought is typically accompanied by an elevated

Laury Chaerle; DOMINIQUE VAN DER STRAETEN

108

Plant water uptake in drying soils.  

PubMed

Over the last decade, investigations on root water uptake have evolved toward a deeper integration of the soil and roots compartment properties, with the goal of improving our understanding of water acquisition from drying soils. This evolution parallels the increasing attention of agronomists to suboptimal crop production environments. Recent results have led to the description of root system architectures that might contribute to deep-water extraction or to water-saving strategies. In addition, the manipulation of root hydraulic properties would provide further opportunities to improve water uptake. However, modeling studies highlight the role of soil hydraulics in the control of water uptake in drying soil and call for integrative soil-plant system approaches. PMID:24515834

Lobet, Guillaume; Couvreur, Valentin; Meunier, Félicien; Javaux, Mathieu; Draye, Xavier

2014-04-01

109

Water Movement in Vascular Plants: A Primer  

E-print Network

The origin of land plants was one of the most important events in evolutionary history of earth in terms of its broad impact on metazoan life and the biotic environment. Because vascular tissues enabled land plants to meet the challenges of terrestrial life, it is important to understand the mechanistic basis of water transport through these tissues from soil to the canopy of trees, in some cases almost 100 meters high. The answers to these questions involve not only the biology of plant vasculature, but also the physical properties of water that enable such transport. Although early researchers proposed the hypothesis of cohesion-tension of water as the likely mechanism for sap ascent, the exact mechanism of transport continues to be a hotly debated topic in the field of plant physiology. This debate continues to be enriched with several sophisticated studies on plants of various morphologies growing in diverse habitats. Although a wealth of evidence has upheld the cohesion-tension theory as being fundamenta...

Sane, Sanjay P

2011-01-01

110

RECYCLING OF WATER IN POULTRY PROCESSING PLANTS  

EPA Science Inventory

Studies were conducted on recycling chiller water in a poultry processing plant. The recycling system must be provided with the capability of removing solids and controlling the microbial population. UV was used to control the microbial population. For this control to be effectiv...

111

Effects of Water Pollution on Plants  

NSDL National Science Digital Library

This is an inquiry activity that, while based on a local area (the San Francisco Bay), could be adapted to the teacher's/student's local area. Students perform an experiment in which they observe how water pollution is absorbed into plants. The site contains a teacher's guide and printable student worksheet.

112

Plant traits and decomposition: are the relationships for roots comparable to those for leaves?  

PubMed Central

Background and Aims Fine root decomposition is an important determinant of nutrient and carbon cycling in grasslands; however, little is known about the factors controlling root decomposition among species. Our aim was to investigate whether interspecific variation in the potential decomposition rate of fine roots could be accounted for by root chemical and morphological traits, life history and taxonomic affiliation. We also investigated the co-ordinated variation in root and leaf traits and potential decomposition rates. Methods We analysed potential decomposition rates and the chemical and morphological traits of fine roots on 18 Mediterranean herbaceous species grown in controlled conditions. The results were compared with those obtained for leaves in a previous study conducted on similar species. Key Results Differences in the potential decomposition rates of fine roots between species were accounted for by root chemical composition, but not by morphological traits. The root potential decomposition rate varied with taxonomy, but not with life history. Poaceae, with high cellulose concentration and low concentrations of soluble compounds and phosphorus, decomposed more slowly than Asteraceae and Fabaceae. Patterns of root traits, including decomposition rate, mirrored those of leaf traits, resulting in a similar species clustering. Conclusions The highly co-ordinated variation of roots and leaves in terms of traits and potential decomposition rate suggests that changes in the functional composition of communities in response to anthropogenic changes will strongly affect biogeochemical cycles at the ecosystem level. PMID:22143881

Birouste, Marine; Kazakou, Elena; Blanchard, Alain; Roumet, Catherine

2012-01-01

113

Effects of natural water constituents on the photo-decomposition of methylmercury and the role of hydroxyl radical.  

PubMed

Photo-decomposition of methylmercury (MeHg) in surface water is thought to be an important process that reduces the bioavailability of mercury (Hg) to aquatic organisms. In this study, photo-initiated decomposition of MeHg was investigated under UVA irradiation in the presence of natural water constituents including NO3(-), Fe(3+), and HCO3(-) ions, and dissolved organic matter such as humic and fulvic acid. MeHg degradation followed the pseudo-first-order kinetics; the rate constant increased with increasing UVA intensity (0.3 to 3.0 mW cm(-2)). In the presence of NO3(-), Fe(3+), and fulvic acid, the decomposition rate of MeHg increased significantly due to photosensitization by reactive species such as hydroxyl radical. The presence of humic acid and HCO3(-) ions lowered the degradation rate through a radical scavenging effect. Increasing the pH of the solution increased the degradation rate constant by enhancing the generation of hydroxyl radicals. Hydroxyl radicals play an important role in the photo-decomposition of MeHg in water, and natural constituents in water can affect the photo-decomposition of MeHg by changing radical production and inhibition. PMID:23416204

Kim, Moon-Kyung; Zoh, Kyung-Duk

2013-04-01

114

Decomposition of roots of black alder and hybrid poplar in short-rotation plantings: Nitrogen and lignin control  

Microsoft Academic Search

The decomposition of the roots (0–2 mm, 2–5 mm and 5–10 mm) of black alder (Alnus glutinosa (L.) Gaertn.) and hybrid poplar (Populus nigra L. X Populus trichocarpa Torr & Gray) was followed over a 462-day period in pure and mixed plantings in southern Quebec. Small roots of alder had the highest initial concentrations of nitrogen and lignin, and lost

C. Camiré; B. Côté; S. Brulotte

1991-01-01

115

A decomposition approach for the scheduling of a steel plant production  

Microsoft Academic Search

In this paper we present a decomposition strategy for solving large scheduling problems using mathematical programming methods. Instead of formulating one huge and unsolvable MILP problem, we propose a decomposition scheme that generates smaller programs that can often be solved to global optimality. The original problem is split into subproblems in a natural way using the special features of steel

Iiro Harjunkoski; Ignacio E. Grossmann

2001-01-01

116

Stability of Supported Platinum Sulfuric Acid Decomposition Catalysts for use in Thermochemical Water Splitting Cycles  

SciTech Connect

The activity and stability of several metal oxide supported platinum catalysts were explored for the sulfuric acid decomposition reaction. The acid decomposition reaction is common to several sulfur based thermochemical water splitting cycles. Reactions were carried out using a feed of concentrated liquid sulfuric acid (96 wt%) at atmospheric pressure at temperatures between 800 and 850 °C and a weight hour space velocity of 52 g acid/g catalyst/hr. Reactions were run at these high space velocities such that variations in kinetics were not masked by surplus catalyst. The influence of exposure to reaction conditions was explored for three catalysts; 0.1-0.2 wt% Pt supported on alumina, zirconia and titania. The higher surface area Pt/Al2O3 and Pt/ZrO2 catalysts were found to have the highest activity but deactivated rapidly. A low surface area Pt/TiO2 catalyst was found to have good stability in short term tests, but slowly lost activity for over 200 hours of continuous operation.

Daniel M. Ginosar; Lucia M. Petkovic; Anne W. Glenn; Kyle C. Burch

2007-03-01

117

Decomposition of environmentally persistent trifluoroacetic acid to fluoride ions by a homogeneous photocatalyst in water.  

PubMed

Decomposition of trifluoroacetic acid (TFA) was achieved with a tungstic heteropolyacid photocatalyst H3PW12O40*6H2O in order to develop a technique for measures against TFA stationary sources. This is the first example of C-F bond cleavage in an environmentally harmful perfluoromethyl-group-containing compound using a homogeneous photocatalyst. The catalytic reaction proceeds in water at room temperature under UV-visible light irradiation in the presence of oxygen. The system produces only F- ions and CO2; the (mole of formed F-)/(mole of decomposed TFA) and (mole of formed CO2)/(mole of decomposed TFA) ratios were 2.91 and 2.09, respectively. GC/MS measurements showed no trace of other species such as environmentally undesirable CF4, which is the most stable perfluorocarbon and has a very high global warming potential. When the (initial TFA)/(initial catalyst) molar ratio was 20:1, the turnover number of TFA decomposition reached 5.58 by 72 h of irradiation, accompanying with no catalyst degradation. The catalytic reaction mechanism can be explained by a redox reaction between the catalyst and TFA, involving a photo-Kolbe process. PMID:12564917

Hori, Hisao; Takano, Yuko; Koike, Kazuhide; Takeuchi, Koji; Einaga, Hisahiro

2003-01-15

118

Succession of Phylogeny and Function During Plant Litter Decomposition (2013 DOE JGI Genomics of Energy and Environment 8th Annual User Meeting)  

SciTech Connect

Eoin Brodie of Berkeley Lab on "Succession of phylogeny and function during plant litter decomposition" at the 8th Annual Genomics of Energy & Environment Meeting on March 27, 2013 in Walnut Creek, Calif.

Brodie, Eoin [Berkeley Lab

2013-03-01

119

Hydraulic lift and water use by plants: implications for water balance, performance and plant-plant interactions  

Microsoft Academic Search

During drought periods, sugar maple (Acer saccharum) demonstrates “hydraulic lift”; nocturnal uptake of water by roots from deep soil layers that is released from shallow roots into upper soil layers. Using standard water relations methods and stable hydrogen isotope analysis of both source-water and plant-water, I investigated (1) the magnitude and radial extent of hydraulic lift by mature, relatively open-grown

Todd E. Dawson

1993-01-01

120

CHROMOPHORIC DISSOLVED ORGANIC MATTER (CDOM) DERIVED FROM DECOMPOSITION OF VARIOUS VASCULAR PLANT AND ALGAL SOURCES  

EPA Science Inventory

Chromophoric dissolved organic (CDOM) in aquatic environments is derived from the microbial decomposition of terrestrial and microbial organic matter. Here we present results of studies of the spectral properties and photoreactivity of the CDOM derived from several organic matter...

121

Capacitance Level Gauge for Pressurizers of Pressurized Water Reactor Plants  

Microsoft Academic Search

The pressure of a pressurized water nuclear power plant is maintained by heating water to saturation temperature in a vessel partially filled with water. The water level in this vessel, the pressurizer, must be monitored for safe plant operation. This paper describes the application of a well-known principle of liquid level measurement to this problem. The unusual operating conditions made

William Gernert

1958-01-01

122

Performance of small water treatment plants: The case study of Mutshedzi Water Treatment Plant  

NASA Astrophysics Data System (ADS)

The performance of small water treatment plants (SWTPs) was evaluated using Mutshedzi WTP as a case study. The majority of SWTPs in South Africa (SA) that supply water to rural villages face problems of cost recovery, water wastages, limited size and semi-skilled labour. The raw and final water quality analyses and their compliance were used to assess the performance of the Mutshedzi WTP. Electrical conductivity (EC), p? and turbidity were measured in the field using a portable multimeter and a turbidity meter respectively. Atomic Absorption Spectrometry and Ion Chromatography were used to analyse metals and non-metals respectively. The results were compared with the Department of Water Affairs (DWA) guidelines for domestic use. The turbidity levels partially exceeded the recommended guidelines for domestic water use of 1 NTU. The concentrations of chemical parameters in final water were within the DWA guidelines for domestic water use except for fluoride, which exceeded the maximum allowable guideline of 1.5 mg/L in August 2009. Mutshedzi WTP had computed compliance for raw and final water analyses ranging from 79% to 93% and 86% to 93% throughout the sampling period, respectively. The results from earlier studies showed that the microbiological quality of final water in Mutshedzi WTP complied with the recommended guidelines, eliminating the slight chance of adverse aesthetic effects and infectious disease transmission associated with the turbidity values between 1 and 5 NTU. The study concluded that Mutshedzi WTP, though moving towards compliance, is still not producing adequate quality of water. Other studies also indicated that the quantity of water produced from Mutshedzi WTP was inadequate. The findings of the study indicate that lack of monitoring of quantity of water supplied to each village, dosage of treatment chemicals, the treatment capacity of the WTP and monitoring the quality of water treated are some of the factors that limit the performance of Mutshedzi WTP. These have been confirmed in literature to be widespread in similar WTPs in SA. It is recommended that water meters be provided and the community be advised to subsidise the cost of water supply. The study recommended that the treatments of turbidity and fluoride should form critical functions of the plant to ensure that final water for domestic use is always safe from any harmful substances or disease causing pathogens. The study concluded that the WTP only needs minor improvement to boost its efficiency with regard to the treatment of raw water. This will also ensure that the plant achieves 100% compliance for final water.

Makungo, R.; Odiyo, J. O.; Tshidzumba, N.

123

Problems of Terminology in the Teaching of Plant Water Relations  

ERIC Educational Resources Information Center

Recommends use by teachers of new terminology regarding plant water relations. Includes definitions and Greek symbols for the following terms: water potential, water potential of cell, osmotic potential, matric potential, and pressure potential. (CS)

Bradbeer, Philip A.; And Others

1976-01-01

124

Photocatalytic decomposition of gaseous water over TiO 2 and TiO 2—RuO 2 surfaces  

NASA Astrophysics Data System (ADS)

Hg-lamp irradiation of TiO 2 powders mixed with RuO 2 leads to the continuous production of hydrogen and oxygen from gaseous water at room temperature. The rate of hydrogen evolution per 100 mg TiO 2—RuO 2 and 20 h was 11 ?mole at a steady state. A mechanism of water decomposition over TiO 2 is proposed from the dependence of the reactivity on the surface treatments.

Kawai, Tomoji; Sakata, Tadayoshi

1980-05-01

125

WSU-TFREC Orchard Calculator: Estimating Water Use by Plants  

NSDL National Science Digital Library

The Washington State University Tree Fruit Research and Extension Center provides a calculator for estimating water use by plants or pET (potential evapotranspiration). Water use varies widely from plant to plant, so estimates are usually first derived for a single situation, such as grass, and then adapted for other plants. The calculator uses the Penman method to estimate daily pET in inches of water. It requires average daily values of four measurements: sunlight, wind, temperature, and humidity.

1996-05-29

126

DECOMPOSITION OF TRIHALOACETIC ACIDS AND FORMATION OF THE CORRESPONDING TRIHALOMETHANES IN DRINKING WATER. (R826834)  

EPA Science Inventory

The decomposition of trihaloacetic acids [bromodichloroacetic acid (BDCAA), dibromochloroacetic acid (DBCAA), tribromoacetic acid (TBAA)], and the formation of the corresponding trihalomethanes [bromodichloromethane (BDCM), dibromochloromethane (DBCM), tribromomethane (TBM)] w...

127

12. Water treatment plant interior view of pipes and pump ...  

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

12. Water treatment plant interior view of pipes and pump in heater room. View to W - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

128

11. Water treatment plant interior view of pipes, stairs, and ...  

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

11. Water treatment plant interior view of pipes, stairs, and pump in pump room. View to SW - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

129

BARIUM AND RADIUM IN WATER TREATMENT PLANT WASTES  

EPA Science Inventory

Water treatment plants at nine locations (10 plants) in Illinois and Iowa were studied to determine the characteristics and disposal practices for the sludge, brine, and backwash water containing radium (Ra) and/or barium (Ba). The treatment processes in these ten plants include ...

130

Plants reverse warming effect on ecosystem water balance  

E-print Network

Plants reverse warming effect on ecosystem water balance Erika S. Zavaleta* , Brian D. Thomas the relatively brief time when plants are exposed. For the snow-free majority of ecosystems in which vegetation in mediating water balance. In particular, warming effects on plant production or phenology could influence

Zavaleta, Erika

131

Does pre-dawn water potential reflect conditions of equilibrium in plant and soil water status?  

Microsoft Academic Search

Variation in base water potential (?b, a daily maximum level of plant water potential, which is presumed to correspond to the equilibrium between soil and plant water potentials) was examined in shoots of Picea abies and Vaccinium myrtillus with respect to soil (available water storage, water potential, temperature) and atmospheric (temperature, relative humidity, vapour pressure deficit) conditions. The available soil

Arne Sellin

1999-01-01

132

Onset of water stress, hysteresis in plant conductance, and hydraulic lift: Scaling soil water dynamics  

E-print Network

effective is dictated by soil hydraulic properties and surrogates for atmospheric water vapor demandOnset of water stress, hysteresis in plant conductance, and hydraulic lift: Scaling soil water] Estimation of water uptake by plants and subsequent water stress are complicated by the need to resolve

Katul, Gabriel

133

Plant water uptake and water use efficiency of greenhouse tomato cultivars irrigated with saline water  

Microsoft Academic Search

Effects of salinity on tomato (Lycopersicon esculentum Mill.) fruit yield, plant water uptake and water use efficiency (WUE) have been quantified in experiments carried out under greenhouse and soil-less cultivation with four cultivars (Floradade, L1, L5 and L9) and four salinity levels (0, 25, 50, and 75mM NaCl). Fruit represented 70% of plant fresh weight while leaves and stems represented

A. Reina-Sánchez; R. Romero-Aranda; J. Cuartero

2005-01-01

134

Beneath the Arctic Green: Have recent increases in plant production been offset by increases in soil decomposition?  

NASA Astrophysics Data System (ADS)

Observational and modeling studies suggest that boreal vegetation has undergone an increase in plant production and C uptake in recent decades, coincident with increases in regional air temperatures, atmospheric CO2 concentration, and fire/successional dynamics. In the North American boreal forest, wildfires have increased in extent, season length, and depth of burn, driving higher C emission from black spruce ecosystems. Meanwhile, responses in soil systems that dictate the net ecosystem carbon (C) balance are less well known, in part owing to problems with elucidating the relatively small signals of organic matter decomposition from the large C fluxes of gross primary production and ecosystem respiration. Here, we measured net C accumulation in soils from Interior Alaska using radiocarbon (14C), lead isotopes (210Pb), cesium isotopes (137Cs), and time sequences of forest regeneration (fire and thaw chronosequences). We use soil 14C and non-steady-state models to estimate turnover times for soil organic C. Over the past century, rates of soil C uptake based on upland chronosequences ranged from -20 to -30 g C/m2/yr, but regionally likely shifted toward a reduced sink or source of - 20 to + 10 g C/m2/yr in recent decades due to increased combustion losses and deep C mobilization associated with permafrost thaw. C accumulation rates in lowland thermokarst chronosequences suggest a mixed sink/source effect, with post-thaw increases in surface accumulation potentially offset by decomposition at depth, or enhanced initial decomposition of C from previously frozen soils, followed by long-term net uptake of post-thaw peat. Large uncertainties remain regarding the turnover of soil organic C in boreal soil, yet enhanced decomposition has likely offset the increase in NPP, resulting in a reduced sink activity relative to pre1960s.

Harden, J. W.; O'Donnell, J.; Fuller, C.; Sierra, C. A.; Johnson, K. D.; Manies, K.; Jorgenson, T.; Jones, M.; Ewing, S. A.; Yue, C.; Turetsky, M.

2013-12-01

135

Plant Pathogens in Irrigation Water: Challenges and Opportunities  

Microsoft Academic Search

Plant pathogens in irrigation water were recognized early in the last century as a significant crop health issue. This issue has increased greatly in scope and degree of impact since that time and it will continue to be a problem as agriculture increasingly depends on the use of recycled water. Plant pathogens detected from water resources include 17 species of

C. X. Hong; G. W. Moorman

2005-01-01

136

Numerical Simulation of Cooling Water of Yangluo Power Plant  

Microsoft Academic Search

The thermal pollution due to the cooling water project of the phase IV expansion project of Yangluo power plant is studied using a 2-D horizontal mathematical model, to predict the flow and temperature fields of the warm water outflow from the power plant. Based on the calculated area of thermal pollution of this cooling water project, proposals to reduce the

Wenqian Qu; Xiaofeng Zhang; Xinhua Lu

2009-01-01

137

Decomposition of root mixtures from high arctic plants: a microcosm study  

Microsoft Academic Search

Fine roots (<1 mm dia.) of Dryas octopetala L., Carex rupestris All., Saxifraga oppositifolia L. and Salix polaris Wahlenb. were decomposed as single species, and in mixtures with fine roots of D. octopetala, under laboratory conditions. Decomposition was measured as carbon dioxide release and mass loss over 556 d at 6°C. There was no relationship between cumulative CO2 release and

C. H. Robinson; J. B. Kirkham; R. Littlewood

1999-01-01

138

Nonadditive effects of litter mixtures on decomposition and correlation with initial litter N and P concentrations in grassland plant species of northern China  

Microsoft Academic Search

We studied the occurrence of nonadditive effects of litter mixtures on the decomposition (the deviation of decomposition rate\\u000a of litter mixtures from the expected values based on the arithmetic means of individual litter types) of litters from three\\u000a plant species (i.e., Stipa krylovii Roshev., Artemisia frigida Willd., and Allium bidentatum Fisch. ex Prokh. & Ikonn.-Gal.) endemic to the grassland ecosystems

Ping Liu; Osbert J. Sun; Jianhui Huang; Linghao Li; Xingguo Han

2007-01-01

139

Design of inter-plant water network with central and decentralized water mains  

Microsoft Academic Search

This paper presents a mathematical model for the inter-plant water integration of an industrial complex that consists of a number of process plants. Opportunities for water reuse\\/recycle across plants are exploited. In particular, a novel integration scheme is proposed, where central and decentralized water mains are placed to interconnect the water-using units of the individual plants. The principal advantage of

Cheng-Liang Chen; Szu-Wen Hung; Jui-Yuan Lee

2010-01-01

140

Diagenetic processes near the sediment-water interface of Long Island Sound. I. Decomposition and nutrient element geochemistry (S,N,P)  

SciTech Connect

Selected early diagenetic reactions associated with the decomposition of organic matter in estuarine deposits of Long Island Sound are examined with particular emphasis on undstanding the role of benthic macroorganisms together with the depositional environment in controlling the decomposition of surface sediments and in determining the flux of solutes between sediment and overlying water.

Aller, R.C.

1980-12-01

141

Diagenetic Processes Near the Sediment-Water Interface of Long Island Sound.I. Decomposition and Nutrient Element Geochemistry (S, N, P)  

Microsoft Academic Search

Selected early diagenetic reactions associated with the decomposition of organic matter in estuarine deposits of Long Island Sound are examined with particular emphasis on undstanding the role of benthic macroorganisms together with the depositional environment in controlling the decomposition of surface sediments and in determining the flux of solutes between sediment and overlying water.

Robert C. Aller

1980-01-01

142

Outdoor Water Use Conservation through Native Plants Shapiro, Chan, Carson, Tayag Outdoor Water Use Conservation through Native Plants  

E-print Network

for regular turfgrass and buffalo grass (developed by UC Davis as a water efficient alternative to turfgrassOutdoor Water Use Conservation through Native Plants Shapiro, Chan, Carson, Tayag Outdoor Water Use, the front lawn is one of the greatest consumers of outdoor water use. Because of population growth, water

Pasternack, Gregory B.

143

Atomic decomposition of the protein solvation free energy and its application to amyloid-beta protein in water  

NASA Astrophysics Data System (ADS)

We report the development of an atomic decomposition method of the protein solvation free energy in water, which ascribes global change in the solvation free energy to local changes in protein conformation as well as in hydration structure. So far, empirical decomposition analyses based on simple continuum solvation models have prevailed in the study of protein-protein interactions, protein-ligand interactions, as well as in developing scoring functions for computer-aided drug design. However, the use of continuum solvation model suffers serious drawbacks since it yields the protein free energy landscape which is quite different from that of the explicit solvent model and since it does not properly account for the non-polar hydrophobic effects which play a crucial role in biological processes in water. Herein, we develop an exact and general decomposition method of the solvation free energy that overcomes these hindrances. We then apply this method to elucidate the molecular origin for the solvation free energy change upon the conformational transitions of 42-residue amyloid-beta protein (A?42) in water, whose aggregation has been implicated as a primary cause of Alzheimer's disease. We address why A?42 protein exhibits a great propensity to aggregate when transferred from organic phase to aqueous phase.

Chong, Song-Ho; Ham, Sihyun

2011-07-01

144

Decomposition of atrazine traces in water by combination of non-thermal electrical discharge and adsorption on nanofiber membrane.  

PubMed

In recent decades, several types of persistent substances are detected in the aquatic environment at very low concentrations. Unfortunately, conventional water treatment processes are not able to remove these micropollutants. As such, advanced treatment methods are required to meet both current and anticipated maximally allowed concentrations. Plasma discharge in contact with water is a promising new technology, since it produces a wide spectrum of oxidizing species. In this study, a new type of reactor is tested, in which decomposition by atmospheric pulsed direct barrier discharge (pDBD) plasma is combined with micropollutant adsorption on a nanofiber polyamide membrane. Atrazine is chosen as model micropollutant with an initial concentration of 30 ?g/L. While the H2O2 and O3 production in the reactor is not influenced by the presence of the membrane, there is a significant increase in atrazine decomposition when the membrane is added. With membrane, 85% atrazine removal can be obtained in comparison to only 61% removal without membrane, at the same experimental parameters. The by-products of atrazine decomposition identified by HPLC-MS are deethylatrazine and ammelide. Formation of these by-products is more pronounced when the membrane is added. These results indicate the synergetic effect of plasma discharge and pollutant adsorption, which is attractive for future applications of water treatment. PMID:25482844

Vanraes, Patrick; Willems, Gert; Daels, Nele; Van Hulle, Stijn W H; De Clerck, Karen; Surmont, Pieter; Lynen, Frederic; Vandamme, Jeroen; Van Durme, Jim; Nikiforov, Anton; Leys, Christophe

2014-11-20

145

Carbon Assimilation Pathways, Water Relationships and Plant Ecology.  

ERIC Educational Resources Information Center

Discusses between-species variation in adaptation of the photosynthetic mechanism to cope with wide fluctuations of environmental water regime. Describes models for water conservation in plants and the role of photorespiration in the evolution of the different pathways. (CW)

Etherington, John R.

1988-01-01

146

Nuclear magnetic resonance imaging of water motion in plants  

Microsoft Academic Search

This Thesis treats one of the new techniques in plant science i.e. nuclear magnetic resonance imaging (NMRi) applied to water motion in plants. It is a challenge, however, to measure this motion in intact plants quantitatively, because plants impose specific problems when studied using NMRi. At high magnetic field strength air-filled intercellular spaces in the plant tissue cause susceptibility-related local

T. W. J. Scheenen

2001-01-01

147

Further evidence for the importance of residual leaf protein complexes in litter decomposition and the supply of nitrogen for plant growth  

Microsoft Academic Search

Summary The nitrogen absorbed by birch seedlings grown in sand culture has been used as a measure of the resistance to decomposition of complexes formed in vitro by interaction between protein and water-extractable leaf constituents ofCalluna vulgaris, Chamaenerion angustifolium andCircaea lutetiana. The resistance to decomposition of these complexes measured in this way isCalluna vulgaris >Chamaenerion angustifolium >Circaea lutetiana. This result

W. R. C. Handley

1961-01-01

148

A new conceptual model on the fate and controls of fresh and pyrolized plant litter decomposition  

Technology Transfer Automated Retrieval System (TEKTRAN)

The leaching of dissolved organic matter (DOM) from fresh and pyrolyzed aboveground plant inputs to the soil is a major pathway by which decomposing aboveground plant material contributes to soil organic matter formation. Understanding how aboveground plant input chemical traits control the partiti...

149

A micropump based on water potential difference in plants  

Microsoft Academic Search

In land plants, water vapor diffuses into the air through the stomata. The loss of water vapor creates a water potential difference\\u000a between the leaf and the soil, which draws the water upward. Quantitatively, the water potential difference is 1–2 MPa which\\u000a can support a water column of 100–200 m. Here we present the design and operation of a biomimetic micropump. The

Jing Min Li; Chong Liu; Kai Ping Zhang; Xue Ke; Zheng Xu; Chun Yu Li; Li Ding Wang

150

A hydrologic retention system and water quality monitoring program for a human decomposition research facility: concept and design.  

PubMed

Forensic taphonomy is an essential research field; however, the decomposition of human cadavers at forensic science facilities may lead to nutrient loading and the introduction of unique biological compounds to adjacent areas. The infrastructure of a water retention system may provide a mechanism for the biogeochemical processing and retention of nutrients and compounds, ensuring the control of runoff from forensic facilities. This work provides a proof of concept for a hydrologic retention system and an autonomous water quality monitoring program designed to mitigate runoff from The Southeast Texas Applied Forensic Science (STAFS) Facility. Water samples collected along a sample transect were analyzed for total phosphorous, total nitrogen, NO3-, NO2-, NH4 , F(-) , and Cl(-) . Preliminary water quality analyses confirm the overall effectiveness of the water retention system. These results are discussed with relation to how this infrastructure can be expanded upon to monitor additional, more novel, byproducts of forensic science research facilities. PMID:25041409

Wozniak, Jeffrey R; Thies, Monte L; Bytheway, Joan A; Lutterschmidt, William I

2015-01-01

151

Simulation of Water Transport in the Soil-Plant - System.  

NASA Astrophysics Data System (ADS)

The objective of this dissertation is to develop a mechanistic model of water transport in the soil-plant -atmosphere system that describes the plant's physical expression of water stress to study the effects of environmental factors, and plant hydraulic and physical properties on plant water transport. The model includes soil moisture uptake, soil heat and water transfer, evapotranspiration, and energy partitioning in the canopy and at the soil surface. The model inputs are: daily weather data (air temperature, dew point temperature, wind speed, and solar radiation); initial soil moisture and temperature profiles; plant characteristics; root density; and soil hydraulic properties. The model user may select from a number of outputs. Principal outputs include: leaf resistance, leaf temperature, soil moisture profile and evapotranspiration rate. The model describes a feedback mechanism by which transpiration controls leaf water potential, leaf water potential influences leaf resistance, and leaf resistance which, in turn, controls transpiration. The simulation runs represented the energy partitioning in the canopy and at the soil surface, and the diurnal variation of temperatures and vapor pressures of the leaf, the canopy air, and the soil surface. The relationships of leaf water potential to soil water potential, leaf resistance and transpiration were also presented. In addition, results show that root water extraction is related to the root length density profile and the soil moisture profile. The model mechanistically describes the water transport in the soil-plant-atmosphere system. The results of model validation indicated that the model is capable of simulating plant water transport under natural conditions with reasonable accuracy. Results show that the model simulates the basic features of the system including feedback processes. The sensitivity studies show that the model may be used to study plant water response to environmental factors and plant properties. The model is also useful for estimating evapotranspiration and the soil moisture profile and may provide information for irrigation and soil water management. (Abstract shortened with permission of author.).

Guo, Yimei

1992-01-01

152

Plant water relations and control of cell elongation at low water potentials  

Microsoft Academic Search

Recent developments in water status measurement techniques using the psychrometer, the pressure probe, the osmometer and pressure\\u000a chamber are reviewed, and the process of cell elongation from the viewpoint of plant-water relations is discussed for plants\\u000a subjected to various environmental stress conditions. Under water-deficient conditions, cell elongation of higher plants can\\u000a be inhibited by interruption of water flow from the

Hiroshi Nonami

1998-01-01

153

Air-cooled condensers eliminate plant water use  

SciTech Connect

River or ocean water has been the mainstay for condensing turbine exhaust steam since the first steam turbine began generating electricity. A primary challenge facing today's plant developers, especially in drought-prone regions, is incorporating processes that reduce plant water use and consumption. One solution is to shed the conventional mindset that once-through cooling is the only option and adopt dry cooling technologies that reduce plant water use from a flood to a few sips. A case study at the Astoria Energy plant, New York City is described. 14 figs.

Wurtz, W.; Peltier, R. [SPX Cooling Technologies Inc. (United States)

2008-09-15

154

Pt/TiO2 (Rutile) Catalysts for Sulfuric Acid Decomposition in Sulfur-Based Thermochemical Water-Splitting Cycles  

SciTech Connect

Thermochemical cycles consist of a series of chemical reactions to produce hydrogen from water at lower temperatures than by direct thermal decomposition. All the sulfur-based cycles for water splitting employ the sulfuric acid decomposition reaction. This work reports the studies performed on platinum supported on titania (rutile) catalysts to investigate the causes of catalyst deactivation under sulfuric acid decomposition reaction conditions. Samples of 1 wt% Pt/TiO2 (rutile) catalysts were submitted to flowing concentrated sulfuric acid at 1123 K and atmospheric pressure for different times on stream (TOS) between 0 and 548 h. Post-operation analyses of the spent catalyst samples showed that Pt oxidation and sintering occurred under reaction conditions and some Pt was lost by volatilization. Pt loss rate was higher at initial times but total loss appeared to be independent of the gaseous environment. Catalyst activity showed an initial decrease that lasted for about 66 h, followed by a slight recovery of activity between 66 and 102 h TOS, and a period of slower deactivation after 102 h TOS. Catalyst sulfation did not seem to be detrimental to catalyst activity and the activity profile suggested that a complex dynamical situation involving platinum sintering, volatilization, and oxidation, along with TiO2 morphological changes affected catalyst activity in a non-monotonic way.

L. M. Petkovic; D. M. Ginosar; H. W. Rollins; K. C. Burch; P. J. Pinhero; H. H. Farrell

2008-04-01

155

Litter stoichiometric traits of plant species of high-latitude ecosystems show high responsiveness to global change without causing strong variation in litter decomposition.  

PubMed

• High-latitude ecosystems are important carbon accumulators, mainly as a result of low decomposition rates of litter and soil organic matter. We investigated whether global change impacts on litter decomposition rates are constrained by litter stoichiometry. • Thereto, we investigated the interspecific natural variation in litter stoichiometric traits (LSTs) in high-latitude ecosystems, and compared it with climate change-induced LST variation measured in the Meeting of Litters (MOL) experiment. This experiment includes leaf litters originating from 33 circumpolar and high-altitude global change experiments. Two-year decomposition rates of litters from these experiments were measured earlier in two common litter beds in sub-Arctic Sweden. • Response ratios of LSTs in plants of high-latitude ecosystems in the global change treatments showed a three-fold variation, and this was in the same range as the natural variation among species. However, response ratios of decomposition were about an order of magnitude lower than those of litter carbon/nitrogen ratios. • This implies that litter stoichiometry does not constrain the response of plant litter decomposition to global change. We suggest that responsiveness is rather constrained by the less responsive traits of the Plant Economics Spectrum of litter decomposability, such as lignin and dry matter content and specific leaf area. PMID:22889103

Aerts, R; van Bodegom, P M; Cornelissen, J H C

2012-10-01

156

A class-information-based penalized matrix decomposition for identifying plants core genes responding to abiotic stresses.  

PubMed

In terms of making genes expression data more interpretable and comprehensible, there exists a significant superiority on sparse methods. Many sparse methods, such as penalized matrix decomposition (PMD) and sparse principal component analysis (SPCA), have been applied to extract plants core genes. Supervised algorithms, especially the support vector machine-recursive feature elimination (SVM-RFE) method, always have good performance in gene selection. In this paper, we draw into class information via the total scatter matrix and put forward a class-information-based penalized matrix decomposition (CIPMD) method to improve the gene identification performance of PMD-based method. Firstly, the total scatter matrix is obtained based on different samples of the gene expression data. Secondly, a new data matrix is constructed by decomposing the total scatter matrix. Thirdly, the new data matrix is decomposed by PMD to obtain the sparse eigensamples. Finally, the core genes are identified according to the nonzero entries in eigensamples. The results on simulation data show that CIPMD method can reach higher identification accuracies than the conventional gene identification methods. Moreover, the results on real gene expression data demonstrate that CIPMD method can identify more core genes closely related to the abiotic stresses than the other methods. PMID:25180509

Liu, Jin-Xing; Liu, Jian; Gao, Ying-Lian; Mi, Jian-Xun; Ma, Chun-Xia; Wang, Dong

2014-01-01

157

A Class-Information-Based Penalized Matrix Decomposition for Identifying Plants Core Genes Responding to Abiotic Stresses  

PubMed Central

In terms of making genes expression data more interpretable and comprehensible, there exists a significant superiority on sparse methods. Many sparse methods, such as penalized matrix decomposition (PMD) and sparse principal component analysis (SPCA), have been applied to extract plants core genes. Supervised algorithms, especially the support vector machine-recursive feature elimination (SVM-RFE) method, always have good performance in gene selection. In this paper, we draw into class information via the total scatter matrix and put forward a class-information-based penalized matrix decomposition (CIPMD) method to improve the gene identification performance of PMD-based method. Firstly, the total scatter matrix is obtained based on different samples of the gene expression data. Secondly, a new data matrix is constructed by decomposing the total scatter matrix. Thirdly, the new data matrix is decomposed by PMD to obtain the sparse eigensamples. Finally, the core genes are identified according to the nonzero entries in eigensamples. The results on simulation data show that CIPMD method can reach higher identification accuracies than the conventional gene identification methods. Moreover, the results on real gene expression data demonstrate that CIPMD method can identify more core genes closely related to the abiotic stresses than the other methods. PMID:25180509

Liu, Jin-Xing; Liu, Jian; Gao, Ying-Lian; Mi, Jian-Xun; Ma, Chun-Xia; Wang, Dong

2014-01-01

158

Diurnal Pattern of Water Potential in Woody Plants  

PubMed Central

The dynamic relationship between the rates of water loss and uptake controls plant water status. Marked diurnal variations in water potential of both leaves and fruit occurred in all plants studied. Variations in water status during the day were most clearly related to changes in evaporative demand of the air and were different for the east and west sides of a tree. At night, the plant water potential reflected the soil moisture status. Changes in the water potential of pear fruit were correlated with changes in fruit diameter. Since water loss from fruit occurred mostly through the pedicel into the xylem of the tree, the fruit could be used as a crude gauge of xylem water potential, which also showed dramatic changes during the day. PMID:16656992

Klepper, Betty

1968-01-01

159

Plant experience with temporary reverse osmosis makeup water systems  

SciTech Connect

Pacific Gas and Electric (PG and E) Company's Diablo Canyon Power Plant (DCPP), which is located on California's central coast, has access to three sources of raw water: creek water, well water, and seawater. Creek and well water are DCPP's primary sources of raw water; however, because their supply is limited, these sources are supplemented with seawater. The purpose of this paper is to discuss the temporary, rental, reverse osmosis systems used by PG and E to process DCPP's raw water into water suitable for plant makeup. This paper addresses the following issues: the selection of reverse osmosis over alternative water processing technologies; the decision to use vendor-operated temporary, rental, reverse osmosis equipment versus permanent PG and E-owned and -operated equipment; the performance of DCPP's rental reverse osmosis systems; and, the lessons learned from DCPP's reverse osmosis system rental experience that might be useful to other plants considering renting similar equipment.

Polidoroff, C.

1986-01-01

160

The impact of uranium mine contamination of soils on plant litter decomposition.  

PubMed

As part of a tier 3 risk assessment performed for a uranium mining area, the ability of soils with different degrees of metal contamination to degrade organic matter was assessed using litter bags filled with leaves of Quercus robur, Pinus pinaster, Salix atrocinerea, or a mixture of the three species. Litter bags were exposed at different sites within the mine area and at a reference area for 3, 6, 9, and 12 months. Biomass loss, nitrogen (N), phosphorus (P), carbon (C) and total fatty acid, total phenolic, and ergosterol contents were assessed for each litter bag retrieved from the field. The decomposition of litter at each site seemed to be governed by a complex interaction of many different factors. After 12 months of exposure, leaves from the most contaminated sites were distinguishable from those from the reference site. In the reference site, the greatest percentages of biomass loss were attained by Q. robur and P. pinaster leaves. These species displayed the second highest and the lowest C-to-N ratios, respectively. In addition, the high P content of the litter from these two species may have favored microbial colonization. The results suggest that the decomposition of P. pinaster and Q. robur leaves may have been favored at the reference site by the high abundance of both species at this site and the subsequent adaptation of the microbial community to their litter. Our study shows that different species of leaf litter should be used to discriminate between contaminated sites with different levels of contamination. PMID:24823679

Freitas, Ana C; Rodrigues, Dina; Rocha-Santos, Teresa A P; Gonçalves, Fernando; Duarte, Armando C; Pereira, Ruth

2014-11-01

161

Water Conservation with Urban Landscape Plants  

E-print Network

Water shortages are a common problem in much of the southwest. Increasing urbanization and increasing population places greater demands on dwindling water supplies. Over half of the water used in urban areas of the southwest is used...

Hip, B. W.; Giordano, C.; Simpson, B.

162

Interactions of earthworms ( Octolasion lacteum), millipedes ( Glomeris marginata) and plants ( Hordelymus europaeus) in a beechwood on a basalt hill: implications for litter decomposition and soil formation  

Microsoft Academic Search

Effects of endogeic earthworms (Octolasion lacteum) and millipedes (Glomeris marginata) on litter decomposition and soil formation were investigated in field microcosms with and without plants (Hordelymus europaeus). Microcosms in a beechwood on a basalt hill in northern Hesse (Germany) were exposed for 21 weeks during the vegetation period. Previous studies had shown that anecic earthworm species were almost absent and

Michael Bonkowski; Stefan Scheu; Matthias Schaefer

1998-01-01

163

The crystallization water of gypsum rocks is a relevant water source for plants.  

PubMed

Some minerals, like gypsum, hold water in their crystalline structure. Although still unexplored, the use of such crystallization water by organisms would point to a completely new water source for life, critical under dry conditions. Here we use the fact that the isotopic composition of free water differs from gypsum crystallization water to show that plants can use crystallization water from the gypsum structure. The composition of the xylem sap of gypsum plants during summer shows closer values to gypsum crystallization water than to free soil water. Crystallization water represents a significant water source for organisms growing on gypsum, especially during summer, when it accounts for 70-90% of the water used by shallow-rooted plants. Given the widespread occurrence of gypsum in dry lands throughout the Earth and in Mars, these results may have important implications for arid land reclamation and exobiology. PMID:25130772

Palacio, Sara; Azorín, José; Montserrat-Martí, Gabriel; Ferrio, Juan Pedro

2014-01-01

164

Localized corrosion of 316L stainless steel in tritiated water containing aggressive radiolytic and decomposition products at different temperatures  

NASA Astrophysics Data System (ADS)

Tritium is one of the more important radionuclides used in nuclear industry as plutonium and uranium. The tritium in tritiated water always causes difficulties in nuclear installations, including equipment corrosion. Moreover, with tritiated water there are, in addition, the radiolytic and decomposition products such as hydrogen peroxide formed during decay, chloride ions produced by degradation of organic seals and oils used for tightness and pumping, and acid pH produced by excitation of nitrogen in air by the ? - particle. Highly concentrated tritiated water releases energy and its temperature is about 80 °C, moreover heating is necessary in the tritium processes. These conditions highly facilitate the corrosion of stainless steels by pitting and crevice attack. Corrosion tests were performed by electrochemical analysis methods and by visual inspection of the surface of stainless steel.

Bellanger, G.

2008-02-01

165

Water use, productivity and interactions among desert plants  

SciTech Connect

Water plays a central role affecting all aspects of the dynamics in aridland ecosystems. Productivity, stability, and competitive interactions among ecosystem components within aridlands are key processes related directly to water in deserts. The ecological studies in this project revolve around one fundamental premise: that integrated aspects of plant metabolism provide insight into the structure and function of plant communities and ecosystems. While it is difficult to extrapolate from instantaneous physiological observations to higher scales, such as whole plant performance or to interactions between plants as components of ecosystems, several key aspects of plant metabolism are scalable. Analyses of stable isotopic composition in plant tissues at natural abundance levels provide a useful tool that can provide insight into the consequences of physiological processes over temporal and spatial scales. Some plant processes continuously fractionate among light and heavy stable isotopic forms of an element; over time this results in integrated measures of plant metabolism. For example, carbon isotope fractionation during photosynthesis results in leaf carbon isotopic composition that is a measure of the set-point for photosynthetic metabolism and of water-use efficiency. Thus it provides information on the temporal scaling of a key physiological process. In contrast, hydrogen is not fractionated during water uptake through the root. Soil water availability in shallow, deep, and/or groundwater layers vary spatially; therefore hydrogen isotope ratios of xylem sap provide a direct measure of the water source currently used by a plant. The longer-term record of carbon and hydrogen isotope ratios is recorded annually in xylem tissues (tree rings). The research in this project addresses variation in stable isotopic composition of aridland plants and its consequences for plant performance and community-level interactions.

Ehleringer, J.R.

1992-11-17

166

Decomposition analysis of water footprint changes in a water-limited river basin: a case study of the Haihe River Basin, China  

NASA Astrophysics Data System (ADS)

Decomposition analysis of water footprint (WF) changes, or assessing the changes in WF and identifying the contributions of factors leading to the changes, is important to water resource management. However, conventional studies focus on WF from the perspective of administrative region rather than river basin. Decomposition analysis of WF changes from the perspective of the river basin is more scientific. To address this perspective, we built a framework in which the input-output (IO) model and the Structural Decomposition Analysis (SDA) model for WF could be implemented in a river basin by computing IO data for the river basin with the Generating Regional IO Tables (GRIT) method. This framework is illustrated in the Haihe River Basin (HRB), which is a typical water-limited river basin. It shows that the total WF in the HRB increased from 4.3 × 1010 m3 in 2002 to 5.6 × 1010 m3 in 2007, and the agriculture sector makes the dominant contribution to the increase. Both the WF of domestic products (internal) and the WF of imported products (external) increased, and the proportion of external WF rose from 29.1% to 34.4%. The technological effect was the dominant contributor to offsetting the increase of WF; however, the growth of WF caused by the economic structural effect and the scale effect was greater, so the total WF increased. This study provides insights about water challenges in the HRB and proposes possible strategies for the future, and serves as a reference for WF management and policy making in other water-limited river basins.

Zhi, Y.; Yang, Z. F.; Yin, X. A.

2013-12-01

167

Water recovery using waste heat from coal fired power plants.  

SciTech Connect

The potential to treat non-traditional water sources using power plant waste heat in conjunction with membrane distillation is assessed. Researchers and power plant designers continue to search for ways to use that waste heat from Rankine cycle power plants to recover water thereby reducing water net water consumption. Unfortunately, waste heat from a power plant is of poor quality. Membrane distillation (MD) systems may be a technology that can use the low temperature waste heat (<100 F) to treat water. By their nature, they operate at low temperature and usually low pressure. This study investigates the use of MD to recover water from typical power plants. It looks at recovery from three heat producing locations (boiler blow down, steam diverted from bleed streams, and the cooling water system) within a power plant, providing process sketches, heat and material balances and equipment sizing for recovery schemes using MD for each of these locations. It also provides insight into life cycle cost tradeoffs between power production and incremental capital costs.

Webb, Stephen W.; Morrow, Charles W.; Altman, Susan Jeanne; Dwyer, Brian P.

2011-01-01

168

Use of reclaimed water for power plant cooling.  

SciTech Connect

Freshwater demands are steadily increasing throughout the United States. As its population increases, more water is needed for domestic use (drinking, cooking, cleaning, etc.) and to supply power and food. In arid parts of the country, existing freshwater supplies are not able to meet the increasing demands for water. New water users are often forced to look to alternative sources of water to meet their needs. Over the past few years, utilities in many locations, including parts of the country not traditionally water-poor (e.g., Georgia, Maryland, Massachusetts, New York, and North Carolina) have needed to reevaluate the availability of water to meet their cooling needs. This trend will only become more extreme with time. Other trends are likely to increase pressure on freshwater supplies, too. For example, as populations increase, they will require more food. This in turn will likely increase demands for water by the agricultural sector. Another example is the recent increased interest in producing biofuels. Additional water will be required to grow more crops to serve as the raw materials for biofuels and to process the raw materials into biofuels. This report provides information about an opportunity to reuse an abundant water source -- treated municipal wastewater, also known as 'reclaimed water' -- for cooling and process water in electric generating facilities. The report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL) Innovations for Existing Plants research program (Feeley 2005). This program initiated an energy-water research effort in 2003 that includes the availability and use of 'nontraditional sources' of water for use at power plants. This report represents a unique reference for information on the use of reclaimed water for power plant cooling. In particular, the database of reclaimed water user facilities described in Chapter 2 is the first comprehensive national effort to identify and catalog those plants that are using reclaimed water for cooling.

Veil, J. A.; Environmental Science Division

2007-10-16

169

2. VIEW NORTHEAST OF CONDENSER WATER INTAKE (LEFT), GENERATING PLANT ...  

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

2. VIEW NORTHEAST OF CONDENSER WATER INTAKE (LEFT), GENERATING PLANT AND STACK (CENTER), AND VIADUCT (EXTREME RIGHT) - Turners Falls Power & Electric Company, Hampden Station, East bank of Connecticut River, Chicopee, Hampden County, MA

170

Sacramento River Water Treatment Plant Intake Pier & Access Bridge, ...  

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

Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

171

Survey of Microbial Enzymes in Soil, Water, and Plant Microenvironments  

PubMed Central

Detection of microbial enzymes in natural environments is important to understand biochemical activities and to verify the biotechnological potential of the microorganisms. In the present report, 346 isolates from soil, water, and plants were screened for enzyme production (caseinase, gelatinase, amylase, carboxymethyl cellulase, and esterase). Our results showed that 89.6% of isolates produced at least one tested enzyme. A predominance of amylase in soil samples, carboxymethyl cellulase in plants, as well as esterase and gelatinase in water was observed. Interesting enzymatic profiles were found in some microenvironments, suggesting specificity of available nutrients and/or natural selection. This study revealed the potential of microorganisms present in water, soil, and plant to produce important enzymes for biotechnological exploration. A predominance of certain enzymes was found, depending on the type of environmental sample. The distribution of microbial enzymes in soil, water and plants has been little exploited in previous reports. PMID:24847390

Alves, Priscila Divina Diniz; Siqueira, Flávia de Faria; Facchin, Susanne; Horta, Carolina Campolina Rebello; Victória, Júnia Maria Netto; Kalapothakis, Evanguedes

2014-01-01

172

OZONATION AND BIOLOGICAL STABILITY OF WATER IN AN OPERATING WATER TREATMENT PLANT  

EPA Science Inventory

Ozonation of drinking water may adversely affect the biological stability of the inished water. his study was designed assess the effect of ozone as a preoxidant on the nutrient status of water treated in a full-scale water treatment plant. he study was conducted over a ten week ...

173

A new look at water transport regulation in plants.  

PubMed

Plant function requires effective mechanisms to regulate water transport at a variety of scales. Here, we develop a new theoretical framework describing plant responses to drying soil, based on the relationship between midday and predawn leaf water potentials. The intercept of the relationship (?) characterizes the maximum transpiration rate per unit of hydraulic transport capacity, whereas the slope (?) measures the relative sensitivity of the transpiration rate and plant hydraulic conductance to declining water availability. This framework was applied to a newly compiled global database of leaf water potentials to estimate the values of ? and ? for 102 plant species. Our results show that our characterization of drought responses is largely consistent within species, and that the parameters ? and ? show meaningful associations with climate across species. Parameter ? was ?1 in most species, indicating a tight coordination between the gas and liquid phases of water transport, in which canopy transpiration tended to decline faster than hydraulic conductance during drought, thus reducing the pressure drop through the plant. The quantitative framework presented here offers a new way of characterizing water transport regulation in plants that can be used to assess their vulnerability to drought under current and future climatic conditions. PMID:24985503

Martínez-Vilalta, Jordi; Poyatos, Rafael; Aguadé, David; Retana, Javier; Mencuccini, Maurizio

2014-10-01

174

Surface water pollution by herbicides from effluents of waste water treatment plants  

Microsoft Academic Search

Herbicide loads of urban and rural waste water treatment plant effluents were calculated over a one-year period by measuring the herbicide concentrations in 14-day mixed samples. More than three quarters of the total herbicide load of the effluent of the rural waste water treatment plant consists of isoproturon. Particularly large amounts of this substance contribute to the total herbicide load

Walter Schüssler

1998-01-01

175

The importance of native and exotic plant identity and dominance on decomposition patterns in mountain woodlands of central Argentina  

NASA Astrophysics Data System (ADS)

Exotic species can have a strong influence on ecosystem processes, especially when exotic invaders differ from natives in key morpho-functional features. We explored whether exotic species, especially those forming monospecific patches in Chaco montane woodlands, differ from natives in leaf attributes and decomposability. We then evaluated how exotic monospecific patches in that region alter litter decomposability, by weighting leaf trait values and decomposability by species abundance in the communities. In general, native and exotic species from Córdoba Chaco montane woodlands did not differ in leaf attributes (specific leaf area, leaf toughness, and leaf water content), or decomposability. Because of similar trait values and decomposability, we expected to find no differences in litter decomposability between plots dominated by exotic species and those of Native woodland. However, individual species decomposability weighted by species abundance in the communities showed that litter from exotic monospecific plots had slower decomposition than native ones. This pattern was confirmed by the higher decomposability and higher quality of the naturally mixed litter collected from native plots, compared to those collected from exotic plots. Despite the general similarities between most native and exotic species inhabiting Chaco montane woodlands, the overwhelming dominance of some exotic invaders in monospecific stands (and the consequent weight of their attributes on the litter each woodland produces) might be driving differences in decomposition patterns between woodland types. Our results indicate that when estimating the impact of exotic species on ecosystem processes, we should include their relative abundance in the community, as well as the relevance of the traits influencing those processes. Otherwise, we may draw erroneous conclusions.

Furey, Carolina; Tecco, Paula A.; Perez-Harguindeguy, Natalia; Giorgis, Melisa A.; Grossi, Mariana

2014-01-01

176

South Florida ornamental plant grower perspectives: water conservation management practices 1  

E-print Network

ABE 369 South Florida ornamental plant grower perspectives: water conservation management practices ornamental plant grower perspectives: water conservation management.... 2 water quantity and quality historically experienced periods of extended droughts which threaten production capabilities thus making water

Migliaccio, Kati White

177

On-line performance monitoring for boiling water reactor plants  

SciTech Connect

While fossil plants have utilized on-line performance monitoring for reducing heat rate, nuclear plants have traditionally employed off-line tools to improve plant efficiency. However, any increase in plant output while maintaining reactor heat input is easily justified. Thus on-line performance monitoring on boiling water reactor (BWR) plants to locate power losses in the cycle is useful in maximizing the capacity of the plant. In addition, it is quite valuable to use an off-line predictive model to perform what-if analyses and to retrieve and display plant data in a variety of formats. This paper presents an overview of the unique software product jointly developed by GE Nuclear Energy and Black and Veatch, including a description of the software capabilities, sample screens and reports, and typical applications of the product.

Josyula, R. [General Electric Nuclear Energy, San Jose, CA (United States); Gross, R.; Jonas, T.; Logback, F. [Black and Veatch, Kansas City, MO (United States)

1995-10-01

178

Efficient decomposition of a new fluorochemical surfactant: Perfluoroalkane disulfonate to fluoride ions in subcritical and supercritical water.  

PubMed

Decomposition of (-)O3SC3F6SO3(-) in subcritical and supercritical water was investigated, and the results were compared with the results for C3F7SO3(-). This is the first report on the decomposition of perfluoroalkane disulfonates, which are being introduced in electronics industry as greener alternatives to environmentally persistent and bioaccumulative perfluoroalkyl surfactants. Addition of zerovalent iron to the reaction system dramatically increased the yield of F(-) in the reaction solution: when the reaction of (-)O3SC3F6SO3(-) was carried out in subcritical water at 350°C for 6h, the F(-) yield was 70%, which was 23times the yield without zerovalent iron. Prolonged reaction increased the F(-) formation: after 18h, the F(-) yield from the reaction of (-)O3SC3F6SO3(-) reached 81%, which was 2.1times the F(-) yield from the reaction of C3F7SO3(-). Although the reactivity of FeO toward these substrates was lower than zerovalent iron in subcritical water, the reactivity was enhanced when the reaction temperature was elevated to supercritical state, at which temperature FeO underwent in situ disproportionation to form zerovalent iron, which acted as the reducing agent. When the reaction of (-)O3SC3F6SO3(-) was carried out in the presence of FeO in supercritical water at 380°C for 18h, the F(-) yield reached 92%, which was the highest yield among tested. PMID:25015226

Hori, Hisao; Saito, Hiroki; Sakai, Hidenori; Kitahara, Toshiyuki; Sakamoto, Takehiko

2014-07-01

179

INORGANIC CHEMICAL CHARACTERIZATION OF WATER TREATMENT PLANT RESIDUALS  

EPA Science Inventory

The study obtained field data on the inorganic contaminants and constituents in residuals produced by Water Treatment Plants (WTPs). Eight WTPs were studied based on treatment technology, contamination or suspected contamination of raw water, and efficiency in the removal of cont...

180

Multibubble plasma production and solvent decomposition in water by slot-excited microwave discharge  

SciTech Connect

Intense microwaves are injected from a slot antenna into water partly filling a metal vessel. When the vessel is evacuated to saturated vapor pressure ({approx}5x10{sup 3} Pa) of water, microwave breakdown gives rise to plasmas in many bubbles in the boiling water. Gas bubbling technique enables production of multibubble plasmas in water even at atmospheric pressure. Optical emissions from the exited species are investigated to identify radical species in water. In order to demonstrate application to purification of polluted water, methylene blue and trichlorethylene solution in 8 l water were observed to rapidly decrease with multibubble plasma treatment.

Ishijima, T.; Hotta, H.; Sugai, H.; Sato, M. [Plasma Nanotechnology Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Honda Electronics Corporation, 20 Oyamazuka, Oiwa-cho, Toyohashi 441-3193 (Japan)

2007-09-17

181

Texas refiner starts up new waste water treatment plant  

SciTech Connect

Chevron Corp. has started up a new waste water treatment plant at its Port Arthur, Tex., refinery. The new facility has an hydraulic capacity of 10,000 gpm and will treat process waste water, cooling tower blowdown, and contaminated storm water. The plant includes: A process unit for removing free and emulsified oil; and equalization facility; a biological system for organics biodegradation; and a volatile organic compounds (VOC) control system. The paper describes predesign studies, the preliminary design and VOC control, the final design, cost savings, process control, and construction.

Al-Tell, N. (Bechtel Corp., Houston, TX (United States)); Lueders, R. (Chevron Corp., Port Arthur, TX (United States))

1994-03-21

182

Partitioning of polycyclic aromatic hydrocarbons between plant roots and water  

Microsoft Academic Search

Partition of phenanthrene between water and roots was determined for 13 plant species using a batch equilibration technique.\\u000a Partition coefficients (K\\u000a rt) from 734 to 2,564 L\\/kg were measured. A simple model to estimate the partition of organic contaminants between roots and\\u000a water was developed based on the composition of plant roots and the 1-octanol\\/water partitioning coefficient. The estimates\\u000a were close

Yanzheng Gao; Wei Xiong; Wanting Ling; Hua Wang; Lili Ren; Zhenya Yang

2008-01-01

183

Investigating water transport through the xylem network in vascular plants.  

PubMed

Our understanding of physical and physiological mechanisms depends on the development of advanced technologies and tools to prove or re-evaluate established theories, and test new hypotheses. Water flow in land plants is a fascinating phenomenon, a vital component of the water cycle, and essential for life on Earth. The cohesion-tension theory (CTT), formulated more than a century ago and based on the physical properties of water, laid the foundation for our understanding of water transport in vascular plants. Numerous experimental tools have since been developed to evaluate various aspects of the CTT, such as the existence of negative hydrostatic pressure. This review focuses on the evolution of the experimental methods used to study water transport in plants, and summarizes the different ways to investigate the diversity of the xylem network structure and sap flow dynamics in various species. As water transport is documented at different scales, from the level of single conduits to entire plants, it is critical that new results be subjected to systematic cross-validation and that findings based on different organs be integrated at the whole-plant level. We also discuss the functional trade-offs between optimizing hydraulic efficiency and maintaining the safety of the entire transport system. Furthermore, we evaluate future directions in sap flow research and highlight the importance of integrating the combined effects of various levels of hydraulic regulation. PMID:24609652

Kim, Hae Koo; Park, Joonghyuk; Hwang, Ildoo

2014-04-01

184

Plants for water recycling, oxygen regeneration and food production  

NASA Technical Reports Server (NTRS)

During long-duration space missions that require recycling and regeneration of life support materials the major human wastes to be converted to usable forms are CO2, hygiene water, urine and feces. A Controlled Ecological Life Support System (CELSS) relies on the air revitalization, water purification and food production capabilities of higher plants to rejuvenate human wastes and replenish the life support materials. The key processes in such a system are photosynthesis, whereby green plants utilize light energy to produce food and oxygen while removing CO2 from the atmosphere, and transpiration, the evaporation of water from the plant. CELSS research has emphasized the food production capacity and efforts to minimize the area/volume of higher plants required to satisfy all human life support needs. Plants are a dynamic system capable of being manipulated to favour the supply of individual products as desired. The size and energy required for a CELSS that provides virtually all human needs are determined by the food production capacity. Growing conditions maximizing food production do not maximize transpiration of water; conditions favoring transpiration and scaling to recycle only water significantly reduces the area, volume, and energy inputs per person. Likewise, system size can be adjusted to satisfy the air regeneration needs. Requirements of a waste management system supplying inputs to maintain maximum plant productivity are clear. The ability of plants to play an active role in waste processing and the consequence in terms of degraded plant performance are not well characterized. Plant-based life support systems represent the only potential for self sufficiency and food production in an extra-terrestrial habitat.

Bubenheim, D. L.

1991-01-01

185

DOSE CONTROLLER FOR AGUACLARA WATER TREATMENT PLANTS  

EPA Science Inventory

The expected results include a proven design for a gravity powered dose controller that works for calcium hypochlorite or aluminum sulfate solutions. The dose controller will be coupled with plant flow rate measuring systems that have compatible relationships between flow rate...

186

Plant physiology Seasonal patterns of water relationships,  

E-print Network

(Hayward) and 6-yr-old staminate (Tomuri) cultivars of kiwifruit grown under Mediterranean climate'élasticité / pertes d'eau foliaire * Correspondence and reprints #12;INTRODUCTION Although kiwifruit (Actinidia, the presence of staminate and pistillate plants is essential in a kiwifruit orchard to guarantee adequate

Paris-Sud XI, Université de

187

USE of mine pool water for power plant cooling.  

SciTech Connect

Water and energy production issues intersect in numerous ways. Water is produced along with oil and gas, water runs off of or accumulates in coal mines, and water is needed to operate steam electric power plants and hydropower generating facilities. However, water and energy are often not in the proper balance. For example, even if water is available in sufficient quantities, it may not have the physical and chemical characteristics suitable for energy or other uses. This report provides preliminary information about an opportunity to reuse an overabundant water source--ground water accumulated in underground coal mines--for cooling and process water in electric generating facilities. The report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL), which has implemented a water/energy research program (Feeley and Ramezan 2003). Among the topics studied under that program is the availability and use of ''non-traditional sources'' of water for use at power plants. This report supports NETL's water/energy research program.

Veil, J. A.; Kupar, J. M .; Puder, M. G.

2006-11-27

188

Water vulnerabilities for existing coal-fired power plants.  

SciTech Connect

This report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL) Existing Plants Research Program, which has an energy-water research effort that focuses on water use at power plants. This study complements the Existing Plants Research Program's overall research effort by evaluating water issues that could impact power plants. Water consumption by all users in the United States over the 2005-2030 time period is projected to increase by about 7% (from about 108 billion gallons per day [bgd] to about 115 bgd) (Elcock 2010). By contrast, water consumption by coal-fired power plants over this period is projected to increase by about 21% (from about 2.4 to about 2.9 bgd) (NETL 2009b). The high projected demand for water by power plants, which is expected to increase even further as carbon-capture equipment is installed, combined with decreasing freshwater supplies in many areas, suggests that certain coal-fired plants may be particularly vulnerable to potential water demand-supply conflicts. If not addressed, these conflicts could limit power generation and lead to power disruptions or increased consumer costs. The identification of existing coal-fired plants that are vulnerable to water demand and supply concerns, along with an analysis of information about their cooling systems and related characteristics, provides information to help focus future research and development (R&D) efforts to help ensure that coal-fired generation demands are met in a cost-effective manner that supports sustainable water use. This study identified coal-fired power plants that are considered vulnerable to water demand and supply issues by using a geographical information system (GIS) that facilitated the analysis of plant-specific data for more than 500 plants in the NETL's Coal Power Plant Database (CPPDB) (NETL 2007a) simultaneously with 18 indicators of water demand and supply. Two types of demand indicators were evaluated. The first type consisted of geographical areas where specific conditions can generate demand vulnerabilities. These conditions include high projected future water consumption by thermoelectric power plants, high projected future water consumption by all users, high rates of water withdrawal per square mile (mi{sup 2}), high projected population increases, and areas projected to be in a water crisis or conflict by 2025. The second type of demand indicator was plant specific. These indicators were developed for each plant and include annual water consumption and withdrawal rates and intensities, net annual power generation, and carbon dioxide (CO{sub 2}) emissions. The supply indictors, which are also area based, include areas with low precipitation, high temperatures, low streamflow, and drought. The indicator data, which were in various formats (e.g., maps, tables, raw numbers) were converted to a GIS format and stored, along with the individual plant data from the CPPDB, in a single GIS database. The GIS database allowed the indicator data and plant data to be analyzed and visualized in any combination. To determine the extent to which a plant would be considered 'vulnerable' to a given demand or supply concern (i.e., that the plant's operations could be affected by water shortages represented by a potential demand or supply indicator), criteria were developed to categorize vulnerability according to one of three types: major, moderate, or not vulnerable. Plants with at least two major demand indicator values and/or at least four moderate demand indicator values were considered vulnerable to demand concerns. By using this approach, 144 plants were identified as being subject to demand concerns only. Plants with at least one major supply indicator value and/or at least two moderate supply indicator values were considered vulnerable to supply concerns. By using this approach, 64 plants were identified as being subject to supply concerns only. In addition, 139 plants were identified as subject to both demand and supply concerns. Therefore, a total of 347 plants were considere

Elcock, D.; Kuiper, J.; Environmental Science Division

2010-08-19

189

Non-Additive Effects on Decomposition from Mixing Litter of the Invasive Mikania micrantha H.B.K. with Native Plants  

PubMed Central

A common hypothesis to explain the effect of litter mixing is based on the difference in litter N content between mixed species. Although many studies have shown that litter of invasive non-native plants typically has higher N content than that of native plants in the communities they invade, there has been surprisingly little study of mixing effects during plant invasions. We address this question in south China where Mikania micrantha H.B.K., a non-native vine, with high litter N content, has invaded many forested ecosystems. We were specifically interested in whether this invader accelerated decomposition and how the strength of the litter mixing effect changes with the degree of invasion and over time during litter decomposition. Using litterbags, we evaluated the effect of mixing litter of M. micrantha with the litter of 7 native resident plants, at 3 ratios: M1 (1?4,?=?exotic:native litter), M2 (1?1) and M3 (4?1,?=?exotic:native litter) over three incubation periods. We compared mixed litter with unmixed litter of the native species to identify if a non-additive effect of mixing litter existed. We found that there were positive significant non-additive effects of litter mixing on both mass loss and nutrient release. These effects changed with native species identity, mixture ratio and decay times. Overall the greatest accelerations of mixture decay and N release tended to be in the highest degree of invasion (mix ratio M3) and during the middle and final measured stages of decomposition. Contrary to expectations, the initial difference in litter N did not explain species differences in the effect of mixing but overall it appears that invasion by M. micrantha is accelerating the decomposition of native species litter. This effect on a fundamental ecosystem process could contribute to higher rates of nutrient turnover in invaded ecosystems. PMID:23840435

Chen, Bao-Ming; Peng, Shao-Lin; D’Antonio, Carla M.; Li, Dai-Jiang; Ren, Wen-Tao

2013-01-01

190

Plants Clean Air and Water for Indoor Environments  

NASA Technical Reports Server (NTRS)

Wolverton Environmental Services Inc., founded by longtime government environmental scientist B.C. "Bill" Wolverton, is an environmental consulting firm that gives customers access to the results of his decades of cutting-edge bioremediation research. Findings about how to use plants to improve indoor air quality have been published in dozens of NASA technical papers and in the book, "How to Grow Fresh Air: 50 Houseplants That Purify Your Home or Office." The book has now been translated into 12 languages and has been on the shelves of bookstores for nearly 10 years. A companion book, "Growing Clean Water: Nature's Solution to Water Pollution," explains how plants can clean waste water. Other discoveries include that the more air that is allowed to circulate through the roots of the plants, the more effective they are at cleaning polluted air; and that plants play a psychological role in welfare in that people recover from illness faster in the presence of plants. Wolverton Environmental is also working in partnership with Syracuse University, to engineer systems consisting of modular wicking filters tied into duct work and water supplies, essentially tying plant-based filters into heating, ventilation, and air conditioning (HVAC) systems. Also, the company has recently begun to assess the ability of the EcoPlanter to remove formaldehyde from interior environments. Wolverton Environmental is also in talks with designers of the new Stennis Visitor's Center, who are interested in using its designs for indoor air-quality filters

2007-01-01

191

Institutional impediments to using alternative water sources in thermoelectric power plants  

Microsoft Academic Search

This report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL) Existing Plants Research Program, which has an energy-water research effort that focuses on water use at power plants. This study complements the Existing Plants Research Program's overall research effort by evaluating water issues that could impact power plants. Obtaining adequate water supplies for cooling

Elcock

2011-01-01

192

Wetlands: Water, Wildlife, Plants, and People.  

ERIC Educational Resources Information Center

Describes wetlands and explains their importance to man and ecology. Delineates the role of water in wetlands. Describes how wetlands are classified: estuarine, riverine, lacustrine, palustrine, and marine. Accompanying article is a large, color poster on wetlands. Describes an activity where metaphors are used to explore the functions of…

Vandas, Steve

1992-01-01

193

Predawn plant water potential does not necessarily equilibrate with soil water potential under well-watered conditions  

Microsoft Academic Search

Predawn leaf water potential (Ow) and xylem pressure potential (Op) are expected to be in equilibrium with the soil water potential (soil Ow) around roots of well-watered plants. We surveyed 21 plant species (desert, chaparral, and coastal salt marsh species, as well as two temperate tree and two crop species) for departures from this expectation and for two potential mechanisms

L. A. Donovan; M. J. Linton; J. H. Richards

2001-01-01

194

Plant Response to Differential Soil Water Content and Salinity  

NASA Astrophysics Data System (ADS)

Root-zone soil water content is extremely dynamic, governed by complex and coupled processes such as root uptake, irrigation, evaporation, and leaching. Root uptake of water and nutrients is influenced by these conditions and the processes involved. Plant roots are living and functioning in a dynamic environment that is subjected to extreme changes over relatively short time and small distances. In order to better manage our agricultural resources and cope with increasing constraints of water limitation, environmental concerns and climate change, it is vital to understand plants responses to these changes in their environment. We grew chick pea (Cicer arietinum) plants, in boxes of 30 x 25 x 1 cm dimensions filled with fine sand. Layers of coarse sand (1.5 cm thick) were embedded in the fine-sand media to divide the root growth environment into sections that were hydraulically disconnected from each other. This way, each section could be independently treated with differential levels of water and salinity. The root growth and distribution in the soil was monitored on daily bases using neutron radiography. Daily water uptake was measured by weighing the containers. Changes of soil water content in each section of the containers were calculated from the neutron radiographs. Plants that part of their root system was stressed with drought or salinity showed no change in their daily water uptake rate. The roots in the stressed sections stayed turgid during the stress period and looked healthy in the neutron images. However the uptake rate was severely affected when the soil in the non-stressed section started to dry. The plants were then fully irrigated with water and the water uptake rate recovered to its initial rate shortly after irrigation. The neutron radiographs clearly illustrated the shrinkage and recovery of the roots under stress and the subsequent relief. This cycle was repeated a few times and the same trend could be reproduced. Our results show that plants' response to water- or salinity-stress ranges from full compensation to severe reduction in transpiration, depending on the availability of water in their surrounding soil. Results of applying different treatments of salinity and drought will be shown. Available models of root water uptake will be employed to simulate the obtained results.

Moradi, A. B.; Dara, A.; Kamai, T.; Ngo, A.; Walker, R.; Hopmans, J. W.

2011-12-01

195

The role of planted forests in urban water budgets (Invited)  

NASA Astrophysics Data System (ADS)

In arid regions which are not naturally forested, urban trees are sustained through the redistribution of water resources as irrigation. Assessments of outdoor water use in Southwestern US cities have shown that not only is 30-75% of residential water use expended on outdoor landscapes, but that irrigation is frequently in excess of estimated plant demand. Thus, there is a need to understand the factors which influence the magnitude and variability of water use of urban trees. A complicating factor in assessing urban tree water use is the widely recognized heterogeneity of urban environments. Human choices and decision-making result in a landscape with significant variability in water and nutrient inputs, microclimate, biotic inputs and vegetation composition. In order to quantify urban tree water use and explain variation in water use resulting from variability in resource availability and species composition, we have conducted a combination of sapflux, growth and isotopic studies on more than 35 common (primarily non-native) tree species in the Los Angeles basin. The objective of these studies was to determine how much variability in water use and water use efficiency exists within and between commonly planted urban tree species, and what factors explain or can be used to predict this variability. Through these studies we have found considerable differences (up to two fold) in tree transpiration within a given species, attributable to differences in water and nutrient availability and tree planting density. Additionally, we have found substantial variation in the water use of different species: at typical urban planting densities, peak transpiration rates can be more than ten times greater for high transpiring trees than low transpiring trees. Finally, we found whole tree water use efficiency to vary across species by a factor of up to a hundred, explained to a large degree by the climate conditions (especially vapor pressure deficit) in the native ranges of these non-native trees. On the scale of the entire city of Los Angeles, we estimate that the urban forest could use as much as 50% of the total municipal water use. Overall, we have found that urban trees can use substantial quantities of water, and that species choice matters greatly in determining urban landscape water use.

McCarthy, H. R.; Pataki, D. E.; Litvak, E.

2009-12-01

196

Singular Value Decomposition Proper Orthogonal Decomposition  

E-print Network

Singular Value Decomposition Proper Orthogonal Decomposition Model Order Reduction Techniques SVD;Singular Value Decomposition Proper Orthogonal Decomposition Singulärwerte und -vektoren Eigenschaften / 24 #12;Singular Value Decomposition Proper Orthogonal Decomposition Singulärwerte und -vektoren

197

Water relations and alleviation of drought stress in mycorrhizal plants  

Microsoft Academic Search

\\u000a Changes in water relations and increased mineral uptake have been the two major reported effects of arbuscular mycorrhizal\\u000a infection on host plants (Cooper, 1984; Safir, 1987). Some authors have suggested that mycorrhizas may be even more important to plant growth under dry conditions than when\\u000a soil moisture is plentiful (Allen and Allen, 1986; Nelsen, 1987; Sánchez-Díaz et al., 1990). However,

M. Sánchez-Díaz; M. Honrubia

198

Response of floodplain grassland plant communities to altered water regimes  

Microsoft Academic Search

Floodplain grasslands are often composed of a mosaic of plant communities controlled by hydrological regime. This article\\u000a examines the sensitivity of floodplain grassland plant communities to water regime using reciprocal transplantation of an\\u000a inundation grassland and a flood-meadow within an English floodplain. Experimental treatments comprised control, transplanted\\u000a and lifted plots; the last treatment, in order to elucidate any disturbance effects

Sarah E. Toogood; Chris B. Joyce; Stephen Waite

2008-01-01

199

Water, plants, and early human habitats in eastern Africa  

PubMed Central

Water and its influence on plants likely exerted strong adaptive pressures in human evolution. Understanding relationships among water, plants, and early humans is limited both by incomplete terrestrial records of environmental change and by indirect proxy data for water availability. Here we present a continuous record of stable hydrogen-isotope compositions (expressed as ?D values) for lipid biomarkers preserved in lake sediments from an early Pleistocene archaeological site in eastern Africa—Olduvai Gorge. We convert sedimentary leaf- and algal-lipid ?D values into estimates for ancient source-water ?D values by accounting for biochemical, physiological, and environmental influences on isotopic fractionation via published water–lipid enrichment factors for living plants, algae, and recent sediments. Reconstructed precipitation and lake-water ?D values, respectively, are consistent with modern isotopic hydrology and reveal that dramatic fluctuations in water availability accompanied ecosystem changes. Drier conditions, indicated by less negative ?D values, occur in association with stable carbon-isotopic evidence for open, C4-dominated grassland ecosystems. Wetter conditions, indicated by lower ?D values, are associated with expanded woody cover across the ancient landscape. Estimates for ancient precipitation amounts, based on reconstructed precipitation ?D values, range between approximately 250 and 700 mm·y?1 and are consistent with modern precipitation data for eastern Africa. We conclude that freshwater availability exerted a substantial influence on eastern African ecosystems and, by extension, was central to early human proliferation during periods of rapid climate change. PMID:23267102

Magill, Clayton R.; Ashley, Gail M.; Freeman, Katherine H.

2013-01-01

200

Plant metabolomics: resolution and quantification of elusive peaks in liquid chromatography-mass spectrometry profiles of complex plant extracts using multi-way decomposition methods.  

PubMed

Previous studies on LC-MS metabolomic profiling of 127 F2 Barbarea vulgaris plants derived from a cross of parental glabrous (G) and pubescent (P) type, revealed four triterpenoid saponins (hederagenin cellobioside, oleanolic acid cellobioside, epihederagenin cellobioside, and gypsogenin cellobioside) that correlated with resistance of plants against the insect herbivore, Phyllotreta nemorum. In this study, for the first time, we demonstrate the efficiency of the multi-way decomposition method PARAllel FACtor analysis 2 (PARAFAC2) for exploring complex LC-MS data. PARAFAC2 enabled automated resolution and quantification of several elusive chromatographic peaks (e.g. overlapped, elution time shifted and low s/n ratio), which could not be detected and quantified by conventional chromatographic data analysis. Raw LC-MS data of 127 F2 B. vulgaris plants were arranged in a three-way array (elution time point×mass spectra×samples), divided into 17 different chromatographic intervals and each interval were individually modeled by PARAFAC2. Three main outputs of the PARAFAC2 models described: (1) elution time profile, (2) relative abundance, and (3) pure mass spectra of the resolved peaks modeled from each interval of the chromatographic data. PARAFAC2 scores corresponding to relative abundances of the resolved peaks were extracted and further used for correlation and partial least squares (PLS) analysis. A total of 71 PARAFAC2 components (which correspond to actual peaks, baselines and tails of neighboring peaks) were modeled from 17 different chromatographic retention time intervals of the LC-MS data. In addition to four previously known saponins, correlation- and PLS-analysis resolved five unknown saponin-like compounds that were significantly correlated with insect resistance. The method also enabled a good separation between resistant and susceptible F2 plants. PARAFAC2 spectral loadings corresponding to the pure mass spectra of chromatographic peaks matched well with experimentally recorded mass spectra (correlation based similarity >95%). This enabled to extract pure mass spectra of highly overlapped and low s/n ratio peaks. PMID:23107118

Khakimov, Bekzod; Amigo, José Manuel; Bak, Søren; Engelsen, Søren Balling

2012-11-30

201

Combined plant for electricity generation and water production  

SciTech Connect

Combined plants for the production of electricity and water are becoming quite common in the Gulf area; different possible configuration are as follows: (a) conventional boilers plant with steam turbine and backpressure feeding to the desalination units; and (b) gas turbine plants with intermediate Heat Recovery Steam Generator (HRSG) with and without steam turbine. In particular the latter scheme has been widely used and a particular application shall be described in some detail hereinafter. Also some discussion about the basic cycle thermodynamics shall be given in some detail.

Lazzeri, L. [Ansaldo Energia, Genova (Italy)

1996-11-01

202

Water uptake in green roof microcosms: Effects of plant species and water availability  

Microsoft Academic Search

Green roofs are engineered ecosystems that rely on vegetation to provide services such as reduction of roof temperatures. Drought resistance is critical for plant survival on shallow-substrate green roofs, but potential trade-offs exist between water-use efficiency and ecosystem functions like transpirative cooling. Water loss from simulated green roof systems (microcosms) each containing 1 of 14 plant species belonging to 4

Derek Wolf; Jeremy T. Lundholm

2008-01-01

203

Mathematics for Water and Wastewater Treatment Plant Operators. Water and Wastewater Training Program.  

ERIC Educational Resources Information Center

This booklet is intended to aid the prospective waste treatment plant operator or drinking water plant operator in learning to solve mathematical problems, which is necessary for Class I certification. It deals with the basic mathematics which a Class I operator may require in accomplishing day-to-day tasks. The book also progresses into problems…

South Dakota Dept. of Environmental Protection, Pierre.

204

Integrated operation of drinking water treatment plant at Amsterdam water supply  

Microsoft Academic Search

Water treatment plants are in general robust and designs are based on the performance of individual processes with pre-set boundary conditions. It is assumed that an integral approach of the entire treatment plant can lead to more efficient operation. Taking into account the developments in sensoring, automation and computation, it is a challenge to improve quality and reliability of the

G. J. Bosklopper; L. C. Rietveld; R. Babuska; B. Smaal; J. Timmer

205

Stomatal Behavior and Water Relations of Waterlogged Tomato Plants  

PubMed Central

The effects of waterlogging the soil on leaf water potential, leaf epidermal conductance, transpiration, root conductance to water flow, and petiole epinasty have been examined in the tomato (Lycopersicon esculentum Mill.). Stomatal conductance and transpiration are reduced by 30% to 40% after approximately 24 hours of soil flooding. This is not due to a transient water deficit, as leaf water potential is unchanged, even though root conductance is decreased by the stress. The stomatal response apparently prevents any reduction in leaf water potential. Experiments with varied time of flooding, root excision, and stem girdling provide indirect evidence for an influence of roots in maintaining stomatal opening potential. This root-effect cannot be entirely accounted for by alterations in source-sink relationships. Although 1-aminocyclopropane-1-carboxylic acid, the immediate precursor of ethylene, is transported from the roots to the shoots of waterlogged tomato plants, it has no direct effect on stomatal conductance. Ethylene-induced petiole epinasty develops coincident with partial stomatal closure in waterlogged plants. Leaf epinasty may have beneficial effects on plant water balance by reducing light interception. PMID:16662706

Bradford, Kent J.; Hsiao, Theodore C.

1982-01-01

206

Optimal plant water-use strategies under stochastic rainfall  

NASA Astrophysics Data System (ADS)

hydraulic traits have been conjectured to be coordinated, thereby providing plants with a balanced hydraulic system that protects them from cavitation while allowing an efficient transport of water necessary for photosynthesis. In particular, observations suggest correlations between the water potentials at which xylem cavitation impairs water movement and the one at stomatal closure, and between maximum xylem and stomatal conductances, begging the question as to whether such coordination emerges as an optimal water-use strategy under unpredictable rainfall. Here mean transpiration is used as a proxy for long-term plant fitness and its variations as a function of the water potentials at 50% loss of stem conductivity due to cavitation and at 90% stomatal closure are explored. It is shown that coordination between these hydraulic traits is necessary to maximize , with rainfall patterns altering the optimal range of trait values. In contrast, coordination between ecosystem-level conductances appears not necessary to maximize . The optimal trait ranges are wider under drier than under mesic conditions, suggesting that in semiarid systems different water use strategies may be equally successful. Comparison with observations across species from a range of ecosystems confirms model predictions, indicating that the coordinated functioning of plant organs might indeed emerge from an optimal response to rainfall variability.

Manzoni, Stefano; Vico, Giulia; Katul, Gabriel; Palmroth, Sari; Porporato, Amilcare

2014-07-01

207

PHOTOREACTIVITY OF CHROMOPHORIC DISSOLVED ORGANIC MATTER (CDOM) DERIVED FROM DECOMPOSITION OF VARIOUS VASCULAR PLANT AND ALGAL SOURCES  

EPA Science Inventory

Chromophoric dissolved organic matter (CDOM) in aquatic environments is derived from the microbial decomposition of terrestrial and microbial organic matter. Here we present results of studies of the spectral properties and photoreactivity of the CDOM derived from several organi...

208

PILOT PLANT PROJECT FOR REMOVING ORGANIC SUBSTANCES FROM DRINKING WATER  

EPA Science Inventory

This report describes research on the European practice of preozonation of water to modify naturally occurring organics, followed by bacteria activated carbon (BAC) adsorption to remove trihalomethane precursors. A 100-gal/min pilot plant was designed, constructed and operated to...

209

Classroom Techniques to Illustrate Water Transport in Plants  

ERIC Educational Resources Information Center

The transport of water in plants is among the most difficult and challenging concepts to explain to students. It is even more difficult for students enrolled in an introductory general biology course. An easy approach is needed to demonstrate this complex concept. I describe visual and pedagogical examples that can be performed quickly and easily…

Lakrim, Mohamed

2013-01-01

210

Current focuses in woody plant water relations and drought resistance  

E-print Network

Current focuses in woody plant water relations and drought resistance T.M. Hinckley1 R. Ceulemans2, such as drought, affects physio- logical processes and is the result of one or a combination of environmental and experimental relevance. Drought stress may be induced by environmental (e.g., low precipitation, low humidity

Boyer, Edmond

211

SEMIPERMEABLE MEMBRANE SYSTEM FOR SUBJECTING PLANTS TO WATER STRESS  

EPA Science Inventory

A system was evaluated for growing plants at reproducible levels of water stress. Beans (Phaseolus vulgaris L.) were grown in vermiculite, transferred to a semipermeable membrane system that encased the root vermiculate mass, and then placed into nutrient solutions to which vario...

212

Phosphorus recovery from centralised municipal water recycling plants  

Microsoft Academic Search

Depletion of world phosphorus reserves is driving research into options to recover and recycle this essential, non-renewable resource. Phosphate (PO43?) recovery at centralised wastewater treatment plants can be achieved through biosolids reuse or sidestream precipitation though the PO43? levels are low compared with decentralised systems based on source separation. However, the recent growth in membrane based water recycling projects, where

Zenah Bradford-Hartke; Paul Lant; Gregory Leslie

213

ENERGY AND WATER OPTIMIZATION IN BIOFUEL PLANTS Ignacio E. Grossmann*  

E-print Network

alternative energy resources that are inexpensive, renewable, without significant environmental impact simultaneously. Therefore, attention is being placed upon a variety of energy sources including solar, wind1 ENERGY AND WATER OPTIMIZATION IN BIOFUEL PLANTS Ignacio E. Grossmann* , Mariano Martín Center

Grossmann, Ignacio E.

214

STUDY OF MICROBIAL AEROSOLS EMITTED FROM A WATER RECLAMATION PLANT  

EPA Science Inventory

The purpose of this investigation was to determine the occurrence of selected microorganisms in the air in the vicinity of the O'Hare Water Reclamation Plant (OWRP), Des Plaines, Illinois. The contribution of the OWRP to ambient microbial aerosols was determined by comparing base...

215

TANNINS IN BACCHARIS DRACUNCULIFOLIA (ASTERACEAE): EFFECTS OF SEASONALITY, WATER AVAILABILITY AND PLANT SEX  

Microsoft Academic Search

Tannins in Baccharjs dracunculifolja (Asteraceae): effects of seasonality, water availability and plant sex). Several ecological. genetic, and environmental factors are known to influence tannin concentration in plant tissues. In this study, the effects of seasonality, water availability. and sex of the plant on tannin concentration in the dioecious shrub Baccharjs dracunculifolja were assessed. Tbe effects of water availability on plant

Mário M. Espírito-Santo; G. Wilson Femandes; Luciana R. Allainl; Ticiana R. F. Reif

1999-01-01

216

Plant Morphological and Biochemical Responses to Field Water Deficits  

PubMed Central

Activity of glutathione reductase has been related to stress tolerance; however, these enzyme assays are generally conducted at 25°C. Foliage temperature varies greatly in the field in response to soil water availability and ambient conditions and this may affect enzyme response. This study was conducted to determine the effect of changing foliage temperature on glutathione reductase activity of wheat under field conditions. Wheat leaf glutathione reductase was purified and the temperature response of the enzyme was determined at 2.5°C intervals between 12.5 and 45°C. These data, in conjunction with continuous measurements of field-grown wheat foliage temperatures, were used to compare the temperature-related changes in potential glutathione reductase activities in water stressed and control plants. Assuming saturating substrate levels, the results indicate that early in the season the daily potential enzyme activity of the irrigated and stressed plants could never have reached the daily activity predicted from the 25°C (room temperature) measurements. Later in the season, the daily potential activity of the irrigated plants was lower, and the daily potential activity of the stressed plants was higher, than the activities predicted from the 25°C determinations. These results suggest that a better understanding of the regulation of plant metabolism will be obtained by linking continuous temperature measurements of plant foliage with enzyme responses to temperature. PMID:16665639

Burke, John J.; Hatfield, Jerry L.

1987-01-01

217

REGULAR ARTICLE Small-scale variability in water storage and plant available  

E-print Network

variability in soil properties by roots foraging for water. Keywords Karst . Soil water storage capacity. RootREGULAR ARTICLE Small-scale variability in water storage and plant available water in shallow in water storage and plant access to water in the rocky soils of a karst savanna dominated by Ashe juniper

Schwinning, Susan - Department of Biology, Texas State University

218

Application of spectral decomposition algorithm for mapping water quality in a turbid lake (Lake Kasumigaura, Japan) from Landsat TM data  

NASA Astrophysics Data System (ADS)

The remote sensing of Case 2 water has been far less successful than that of Case 1 water, due mainly to the complex interactions among optically active substances (e.g., phytoplankton, suspended sediments, colored dissolved organic matter, and water) in the former. To address this problem, we developed a spectral decomposition algorithm (SDA), based on a spectral linear mixture modeling approach. Through a tank experiment, we found that the SDA-based models were superior to conventional empirical models (e.g. using single band, band ratio, or arithmetic calculation of band) for accurate estimates of water quality parameters. In this paper, we develop a method for applying the SDA to Landsat-5 TM data on Lake Kasumigaura, a eutrophic lake in Japan characterized by high concentrations of suspended sediment, for mapping chlorophyll-a (Chl-a) and non-phytoplankton suspended sediment (NPSS) distributions. The results show that the SDA-based estimation model can be obtained by a tank experiment. Moreover, by combining this estimation model with satellite-SRSs (standard reflectance spectra: i.e., spectral end-members) derived from bio-optical modeling, we can directly apply the model to a satellite image. The same SDA-based estimation model for Chl-a concentration was applied to two Landsat-5 TM images, one acquired in April 1994 and the other in February 2006. The average Chl-a estimation error between the two was 9.9%, a result that indicates the potential robustness of the SDA-based estimation model. The average estimation error of NPSS concentration from the 2006 Landsat-5 TM image was 15.9%. The key point for successfully applying the SDA-based estimation model to satellite data is the method used to obtain a suitable satellite-SRS for each end-member.

Oyama, Youichi; Matsushita, Bunkei; Fukushima, Takehiko; Matsushige, Kazuo; Imai, Akio

219

On the collective network of ionic liquid/water mixtures. II. Decomposition and interpretation of dielectric spectra  

NASA Astrophysics Data System (ADS)

This study deals with the dielectric spectra of mixtures of the ionic liquid 1-butyl-3-methyl-imidazolium (BMIM+) tetrafluoroborate with water at three selected mole fractions 0.767?xH2O?0.967. The focus lies on the comparison of experimental and computational data. On the one hand, a computational analysis permits a complete decomposition of spectra, both with respect to dynamical behavior (translation and rotation) as well as to composition of the mixture (cation, anion, and water). Thereby, not only the peak assignment in experimental spectra is enabled but one can also learn more about solvation properties. Of particular importance is the interplay of the dielectric constant and the conductivity representing a measure of collective rotational and translational motion. On the other hand, the comparison with experimental spectra is essential for the validation of the force fields used in simulation. The satisfying agreement between corresponding peaks in the dielectric spectra confirms not only computed dielectric relaxation times but also other collective dynamical properties such as the viscosity. Nevertheless, the detailed fine structure of the conductivity regime reveals specific ion-pair effects not covered by the simulation. A possible confinement of dynamical heterogeneity as a consequence of a system size effect is also indicated.

Schröder, C.; Hunger, J.; Stoppa, A.; Buchner, R.; Steinhauser, O.

2008-11-01

220

Water Extraction from Coal-Fired Power Plant Flue Gas  

SciTech Connect

The overall objective of this program was to develop a liquid disiccant-based flue gas dehydration process technology to reduce water consumption in coal-fired power plants. The specific objective of the program was to generate sufficient subscale test data and conceptual commercial power plant evaluations to assess process feasibility and merits for commercialization. Currently, coal-fired power plants require access to water sources outside the power plant for several aspects of their operation in addition to steam cycle condensation and process cooling needs. At the present time, there is no practiced method of extracting the usually abundant water found in the power plant stack gas. This project demonstrated the feasibility and merits of a liquid desiccant-based process that can efficiently and economically remove water vapor from the flue gas of fossil fuel-fired power plants to be recycled for in-plant use or exported for clean water conservation. After an extensive literature review, a survey of the available physical and chemical property information on desiccants in conjunction with a weighting scheme developed for this application, three desiccants were selected and tested in a bench-scale system at the Energy and Environmental Research Center (EERC). System performance at the bench scale aided in determining which desiccant was best suited for further evaluation. The results of the bench-scale tests along with further review of the available property data for each of the desiccants resulted in the selection of calcium chloride as the desiccant for testing at the pilot-scale level. Two weeks of testing utilizing natural gas in Test Series I and coal in Test Series II for production of flue gas was conducted with the liquid desiccant dehumidification system (LDDS) designed and built for this study. In general, it was found that the LDDS operated well and could be placed in an automode in which the process would operate with no operator intervention or adjustment. Water produced from this process should require little processing for use, depending on the end application. Test Series II water quality was not as good as that obtained in Test Series I; however, this was believed to be due to a system upset that contaminated the product water system during Test Series II. The amount of water that can be recovered from flue gas with the LDDS is a function of several variables, including desiccant temperature, L/G in the absorber, flash drum pressure, liquid-gas contact method, and desiccant concentration. Corrosion will be an issue with the use of calcium chloride as expected but can be largely mitigated through proper material selection. Integration of the LDDS with either low-grade waste heat and or ground-source heating and cooling can affect the parasitic power draw the LDDS will have on a power plant. Depending on the amount of water to be removed from the flue gas, the system can be designed with no parasitic power draw on the power plant other than pumping loads. This can be accomplished in one scenario by taking advantage of the heat of absorption and the heat of vaporization to provide the necessary temperature changes in the desiccant with the flue gas and precipitates that may form and how to handle them. These questions must be addressed in subsequent testing before scale-up of the process can be confidently completed.

Bruce C. Folkedahl; Greg F. Weber; Michael E. Collings

2006-06-30

221

Study on the TOC concentration in raw water and HAAs in Tehran's water treatment plant outlet.  

PubMed

A sampling has been undertaken to investigate the variation of haloacetic acids formation and nature organic matter through 81 samples were collected from three water treatment plant and three major rivers of Tehran Iran. Changes in the total organic matter (TOC), ultraviolet absorbance (UV254), specific ultraviolet absorbance (SUVA) were measured in raw water samples. Haloacetic acids concentrations were monitored using a new static headspace GC-ECD method without a manual pre-concentration in three water treatment plants. The average concentration of TOC and HAAs in three rivers and three water treatment plants in spring, summer and fall, were 4, 2.41 and 4.03 mg/L and 48.75, 43.79 and 51.07 ?g/L respectively. Seasonal variation indicated that HAAs levels were much higher in spring and fall. PMID:24283403

Ghoochani, Mahboobeh; Rastkari, Noushin; Nabizadeh Nodehi, Ramin; Mahvi, Amir Hossein; Nasseri, Simin; Nazmara, Shahrokh

2013-01-01

222

Plant Water Use Efficiency over Geological Time – Evolution of Leaf Stomata Configurations Affecting Plant Gas Exchange  

PubMed Central

Plant gas exchange is a key process shaping global hydrological and carbon cycles and is often characterized by plant water use efficiency (WUE - the ratio of CO2 gain to water vapor loss). Plant fossil record suggests that plant adaptation to changing atmospheric CO2 involved correlated evolution of stomata density (d) and size (s), and related maximal aperture, amax. We interpreted the fossil record of s and d correlated evolution during the Phanerozoic to quantify impacts on gas conductance affecting plant transpiration, E, and CO2 uptake, A, independently, and consequently, on plant WUE. A shift in stomata configuration from large s-low d to small s-high d in response to decreasing atmospheric CO2 resulted in large changes in plant gas exchange characteristics. The relationships between gas conductance, gws, A and E and maximal relative transpiring leaf area, (amax?d), exhibited hysteretic-like behavior. The new WUE trend derived from independent estimates of A and E differs from established WUE-CO2 trends for atmospheric CO2 concentrations exceeding 1,200 ppm. In contrast with a nearly-linear decrease in WUE with decreasing CO2 obtained by standard methods, the newly estimated WUE trend exhibits remarkably stable values for an extended geologic period during which atmospheric CO2 dropped from 3,500 to 1,200 ppm. Pending additional tests, the findings may affect projected impacts of increased atmospheric CO2 on components of the global hydrological cycle. PMID:23844085

Assouline, Shmuel; Or, Dani

2013-01-01

223

Photochemical water decomposition in the troposphere: DFT study with a symmetrized Kohn-Sham formalism.  

PubMed

Photochemical reaction of the electronically excited NO(2)* species with the water molecule is studied in terms of a new version of density functional theory by selecting the specific (2)A'' symmetry of the whole system, which is different from the ground-state pattern. The excited C(2)A(2) state of the NO(2) molecule is found to be distorted to the equilibrium structure O=N-O(.), which poses the (2)A'' symmetry in the C(s) point group. With the B3LYP functional it is shown that such an electronically excited NO(2)* molecule, generated by visible light (?=420 nm), can react with water vapor to produce OH+HONO species, an important source of tropospheric hydroxyl radicals. This photochemical process can be considered as a possible mechanism of atmosphere self-cleaning. PMID:21080398

Minaev, Boris F; Zakharov, Ivan I; Zakharova, Olga I; Tselishtev, Alexei B; Filonchook, Anton V; Shevchenko, Alexandr V

2010-12-17

224

Reduced-order optimal control of water flooding using proper orthogonal decomposition  

Microsoft Academic Search

Model-based optimal control of water flooding generally involves multiple reservoir simulations, which makes it into a time-consuming\\u000a process. Furthermore, if the optimization is combined with inversion, i.e., with updating of the reservoir model using production\\u000a data, some form of regularization is required to cope with the ill-posedness of the inversion problem. A potential way to\\u000a address these issues is through

Jorn F. M. van Doren; Renato Markovinovi?; Jan-Dirk Jansen

2006-01-01

225

Application of 2D-Nonlinear Shallow Water Model of Tsunami by using Adomian Decomposition Method  

Microsoft Academic Search

One of the most important questions in tsunami modeling is the estimation of tsunami run-up heights at different points along a coastline. Methods for numerical simulation of tsunami wave propagation in deep and shallow seas are well developed and have been widely used by many scientists (2001-2008). In this paper, we consider a two-dimensional nonlinear shallow water model of tsunami

Sribudh Waewcharoen; Supachai Boonyapibanwong; Sanoe Koonprasert

2008-01-01

226

Effect of Electrolytes on the Decomposition of Dye by Pulsed Discharge in Air Spraying Water Droplets  

NASA Astrophysics Data System (ADS)

Effect of electrolytes on the decolorization of indigo carmine and on the production of H2O2 by pulsed discharge in air spraying water droplets was performed in sodium chloride and magnesium sulfate solutions. Peak voltage of the discharge decreased with increasing solution conductivity, but peak current and discharge energy increased. Decolorization rate and decolorization efficiency of indigo carmine and the yield of H2O2 decreased with increasing chloride and sulfate ion concentrations. It was found that the decolorization of indigo carmine and the production of H2O2 are affected by the ion concentration even in the case of discharge in air spraying water droplets. However it was less effective than that of discharge in water. Chloride ion was more effective than sulfate ion regarding the decrease of decolorization rate and the production of H2O2. Decolorization rate of indigo carmine was strongly related to the production of H2O2. These results also indicated that decolorization of indigo carmine depends on the production of hydroxyl radical.

Nose, Taisuke; Yokoyama, Yuzo; Minamitani, Yasushi

227

Changes in water quality in the Owabi water treatment plant in Ghana  

NASA Astrophysics Data System (ADS)

The study was conducted on the status of the quality of water from the Owabi water treatment plant that supplies drinking water to Kumasi, a major city in Ghana, to ascertain the change in quality of water from source to point-of-use. Physico-chemical, bacteriological water quality parameters and trace metal concentration of water samples from five different treatment points from the Owabi water treatment plant were investigated. The raw water was moderately hard with high turbidity and colour that exceeds the WHO guideline limits. Nutrient concentrations were of the following order: NH3 < NO2 - < NO3 - < PO4 3- < SO4 2- and were all below WHO permissible level for drinking water in all the samples at different stages of treatment. Trace metal concentrations of the reservoir were all below WHO limit except chromium (0.06 mg/L) and copper (0.24 mg/L). The bacteriological study showed that the raw water had total coliform (1,766 cfu/100 mL) and faecal coliform (257 cfu/100 mL) that exceeded the WHO standard limits, rendering it unsafe for domestic purposes without treatment. Colour showed strong positive correlation with turbidity (r = 0.730), TSS (r ? 0.922) and alkalinity (0.564) significant at p < 0.01. The quality of the treated water indicates that colour, turbidity, Cr and Cu levels reduced and fall within the WHO permissible limit for drinking water. Treatment process at the water treatment plant is adjudged to be good.

Akoto, Osei; Gyamfi, Opoku; Darko, Godfred; Barnes, Victor Rex

2014-09-01

228

Significance of Plant Root Microorganisms in Reclaiming Water in CELSS  

NASA Technical Reports Server (NTRS)

Since many microorganisms demonstrate the ability to quickly break down complex mixtures of waste and environmental contaminants, examining their potential use for water recycling in a closed environment is appealing. Water contributes approximately 90 percent of the life sustaining provisions in a human space habitat. Nearly half of the daily water requirements will be used for personal hygiene and dish washing. The primary contaminants of the used "gray" water will be the cleansing agents or soaps used to carry out these functions. Reclaiming water from the gray water waste streams is one goal of the NASA program, Controlled Ecological Life Support Systems (CELSS). The microorganisms of plane roots are well documented to be of a beneficial effect to promote plant growth. Most plants exhibit a range of bacteria and fungi which can be highly plant-specific. In our investigations with lettuce grown in hydroponic culture, we identified a microflora of normal rhizosphere. When the roots were exposed to an anionic surfactant, the species diversity changed, based on morphological characteristics, with the numbers of species being reduced from 7 to 2 after 48 hours of exposure. In addition, the species that became dominant in the presence of the anionic surfactant also demonstrated a dramatic increase in population density which corresponded to the degradation of the surfactant in the root zone. The potential for using these or other rhizosphere bacteria as a primary or secondary waste processor is promising, but a number of issues still warrant investigation; these include but are not limited to: (1) the full identification of the microbes, (2) the classes of surfactants the microbes will degrade, (3) the environmental conditions required for optimal processing efficiency and (4) the ability of transferring the microbes to a non-living solid matrix such as a bioreactor.

Bubenheim, David L.; Greene, Catherine; Wignarajah, Kanapathipillai; Kliss, Mark H. (Technical Monitor)

1996-01-01

229

Hydraulic redistribution may stimulate decomposition  

Microsoft Academic Search

Roots influence root litter decomposition through multiple belowground processes. Hydraulic lift or redistribution (HR) by\\u000a plants is one such process that creates diel drying–rewetting cycles in soil. However, it is unclear if this phenomenon influences\\u000a decomposition. Since decomposition in deserts is constrained by low soil moisture and is stimulated when dry soils are rewetted,\\u000a we hypothesized that diel drying–rewetting, via

Zachary T. Aanderud; James H. Richards

2009-01-01

230

INNOVATIVE FRESH WATER PRODUCTION PROCESS FOR FOSSIL FUEL PLANTS  

SciTech Connect

An innovative Diffusion Driven Desalination (DDD) process was recently described where evaporation of mineralized water is driven by diffusion within a packed bed. The energy source to drive the process is derived from low pressure condensing steam within the main condenser of a steam power generating plant. Since waste heat is used to drive the process, the main cost of fresh water production is attributed to the energy cost of pumping air and water through the packed bed. This report describes the annual progress made in the development and analysis of a Diffusion Driven Desalination (DDD) system. A combined thermodynamic and dynamic analysis demonstrates that the DDD process can yield a fresh water production of 1.03 million gallon/day by utilizing waste heat from a 100 MW steam power plant based on a condensing steam pressure of only 3'' Hg. Throughout the past year, the main focus of the desalination process has been on the diffusion tower and direct contact condenser. Detailed heat and mass transfer analyses required to size and analyze these heat and mass transfer devices are described. An experimental DDD facility has been fabricated, and temperature and humidity data have been collected over a range of flow and thermal conditions. The analyses agree quite well with the current data and the information available in the literature. Direct contact condensers with and without packing have been investigated. It has been experimentally observed that the fresh water production rate is significantly enhanced when packing is added to the direct contact condensers.

James F. Klausner; Renwei Mei; Yi Li; Jessica Knight

2004-09-01

231

Hot water geothermal development: opportunities and pilot plant results  

SciTech Connect

It has been projected that up to 11,000 MW of geothermal electric capacity may be on line in the United States by the year 2000. The majority of this capacity will come from hot water geothermal plants, as dry steam resources are limited. Currently, no commercial hot water geothermal capacity exists in the U.S., although, substantial capacity does exist in other countries. Large hot, high temperature resources exist in Southern California's Imperial Valley. Early research work has led to the technical success of a 10 MW unit at Brawley, and to the construction of second generation pilot unit at the Salton Sea resource.

Crane, G.K.

1982-08-01

232

Modeling Halophytic Plants in APEX for Sustainable Water and Agriculture  

NASA Astrophysics Data System (ADS)

A major problem for irrigated agricultural production is soil salinization, which can occur naturally or can be human-induced. Human-induced, or secondary salinization, is particularly a problem in arid and semi-arid regions, especially in irrigated areas. Irrigated land has more than twice the production of rainfed land, and accounts for about one third of the world's food, but nearly 20% of irrigated lands are salt-affected. Many farmers worldwide currently seasonally leach their land to reduce the soil salt content. These practices, however, create further problems such as a raised groundwater table, and salt, fertilizer, and pesticide pollution of nearby lakes and groundwater. In Uzbekistan, a combination of these management practices and a propensity to cultivate 'thirsty' crops such as cotton has also contributed to the Aral Sea shrinking nearly 90% by volume since the 1950s. Most common agricultural crops are glycophytes that have reduced yields when subjected to salt-stress. Some plants, however, are known as halophytic or 'salt-loving' plants and are capable of completing their life-cycle in higher saline soil or water environments. Halophytes may be useful for human consumption, livestock fodder, or biofuel, and may also be able to reduce or maintain salt levels in soil and water. To assess the potential for these halophytes to assist with salinity management, we are developing a model that is capable of tracking salinity under different management practices in agricultural environments. This model is interdisciplinary as it combines fields such as plant ecology, hydrology, and soil science. The US Department of Agriculture (USDA) model, Agricultural Policy/Environmental Extender (APEX), is being augmented with a salinity module that tracks salinity as separate ions across the soil-plant-water interface. The halophytes Atriplex nitens, Climacoptera lanata, and Salicornia europaea are being parameterized and added into the APEX model database. Field sites in the Central Kyzylkum and Khorezm regions of Uzbekistan are being characterized in the model, where halophytes are being grown and plant, soil, and water data are being collected for model verification. This presentation will discuss the plant and site parameterizations as well as preliminary progress on developing and applying the APEX salinity module for modeling the salt cycle through soil, water, and halophytes under different management practices.

DeRuyter, T.; Saito, L.; Nowak, B.; Rossi, C.; Toderich, K.

2013-12-01

233

Planted floating bed performance in treatment of eutrophic river water.  

PubMed

The objective of the study was to treat eutrophic river water using floating beds and to identify ideal plant species for design of floating beds. Four parallel pilot-scale units were established and vegetated with Canna indica (U1), Accords calamus (U2), Cyperus alternifolius (U3), and Vetiveria zizanioides (U4), respectively, to treat eutrophic river water. The floating bed was made of polyethylene foam, and plants were vegetated on it. Results suggest that the floating bed is a viable alternative for treating eutrophic river water, especially for inhibiting algae growth. When the influent chemical oxygen demand (COD) varied from 6.53 to 18.45 mg/L, total nitrogen (TN) from 6.82 to 12.25 mg/L, total phosphorus (TP) from 0.65 to 1.64 mg/L, and Chla from 6.22 to 66.46 g/m(3), the removal of COD, TN, TP, and Chla was 15.3%-38.4%, 25.4%-48.4%, 16.1%-42.1%, and 29.9 %-88.1%, respectively. Ranked by removal performance, U1 was best, followed by U2, U3, and U4. In the floating bed, more than 60% TN and TP were removed by sedimentation; plant uptake was quantitatively of low importance with an average removal of 20.2% of TN and 29.4% of TP removed. The loss of TN (TP) was of the least importance. Compared with the other three, U1 exhibited better dissolved oxygen (DO) gradient distributions, higher DO levels, higher hydraulic efficiency, and a higher percentage of nutrient removal attributable to plant uptake; in addition, plant development and the volume of nutrient storage in the C. indica tissues outperformed the other three species. C. indica thus could be selected when designing floating beds for the Three Gorges Reservoir region of P. R. China. PMID:23737127

Bu, Faping; Xu, Xiaoyi

2013-11-01

234

CHANGES IN MASS AND CHEMISTRY OF PLANT ROOTS DURING LONG-TERM DECOMPOSITION ON A CHIHUAHUAN DESERT WATERSHED  

EPA Science Inventory

We studied the spatial and temporal patterns of decomposition of roots of a desert sub-shrub, a herbaceous annual, and four species of perennial grasses at several locations on nitrogen fertilized and unfertilized transects on a Chihuahuan Desert watershed for 3.5 years. There we...

235

Co-variations in litter decomposition, leaf traits and plant growth in species from a Mediterranean old-field succession  

Microsoft Academic Search

Summary 1. A growing consensus is developing that the impact of species on ecosystem properties is mediated, at least partially, by the traits of their component species. A previous study demonstrated that the field decomposition of complex litters produced by different communities of a Mediterranean successional sere was related to the average trait value of these communities. Here we scale

E. KAZAKOU; D. VILE; B. SHIPLEY; C. GALLET; E. GARNIER

2006-01-01

236

Plant litter decomposition and nutrient cycling in north Queensland tropical rain-forest communities of differing successional status  

Microsoft Academic Search

Soil processes are essential in enabling forest regeneration in disturbed landscapes. Little is known about whether litterfall from dominating pioneer species in secondary rain forest is functionally equivalent to that of mixed rain-forest litter in terms of contribution to soil processes. This study used the litterbag technique to quantify the decomposition and nutrient dynamics of leaf litter characteristic of three

Scott A. Parsons; Robert A. Congdon

2008-01-01

237

Water treatment plant simulation program, version 1. 21, user's manual  

SciTech Connect

The User's Manual for Version 1.21 of the Water Treatment Plant Simulation Program has been prepared to provide a basic understanding of (1) how to operate the program, and (2) the underlying assumptions and equations that are used to calculate the removal of natural organic matter and the formation of disinfection by-products. The manual represents the first public release of the program.

Not Available

1992-06-01

238

Enhanced photocatalytic activity of TiO 2 nanofibers and their flexible composite films: Decomposition of organic dyes and efficient H 2 generation from ethanol-water mixtures  

Microsoft Academic Search

TiO2 nanofibers decorated with Pt and Pd nanoparticles have been synthesized and studied in various photocatalytic processes.\\u000a Excellent photocatalytic behavior in the decomposition of organic dyes in water, degradation of organic stains on the surface\\u000a of flexible freestanding cellulose\\/catalyst composite films and in generation of hydrogen from ethanol using both suspended\\u000a and immobilized catalysts are demonstrated. The performance of the

Ming-Chung Wu; András Sápi; Anna Avila; Mária Szabó; Jussi Hiltunen; Mika Huuhtanen; Géza Tóth; Ákos Kukovecz; Zoltán Kónya; Riitta Keiski; Wei-Fang Su; Heli Jantunen; Krisztián Kordás

2011-01-01

239

Innovative Fresh Water Production Process for Fossil Fuel Plants  

SciTech Connect

This project concerns a diffusion driven desalination (DDD) process where warm water is evaporated into a low humidity air stream, and the vapor is condensed out to produce distilled water. Although the process has a low fresh water to feed water conversion efficiency, it has been demonstrated that this process can potentially produce low cost distilled water when driven by low grade waste heat. This report describes the annual progress made in the development and analysis of a Diffusion Driven Desalination (DDD) system. A dynamic analysis of heat and mass transfer demonstrates that the DDD process can yield a fresh water production of 1.03 million gallon/day by utilizing waste heat from a 100 MW steam power plant based on a condensing steam pressure of only 3 Hg. The optimum operating condition for the DDD process with a high temperature of 50 C and sink temperature of 25 C has an air mass flux of 1.5 kg/m{sup 2}-s, air to feed water mass flow ratio of 1 in the diffusion tower, and a fresh water to air mass flow ratio of 2 in the condenser. Operating at these conditions yields a fresh water production efficiency (m{sub fW}/m{sub L}) of 0.031 and electric energy consumption rate of 0.0023 kW-hr/kg{sub fW}. Throughout the past year, the main focus of the desalination process has been on the direct contact condenser. Detailed heat and mass transfer analyses required to size and analyze these heat and mass transfer devices are described. The analyses agree quite well with the current data. Recently, it has been recognized that the fresh water production efficiency can be significantly enhanced with air heating. This type of configuration is well suited for power plants utilizing air-cooled condensers. The experimental DDD facility has been modified with an air heating section, and temperature and humidity data have been collected over a range of flow and thermal conditions. It has been experimentally observed that the fresh water production rate is enhanced when air is heated prior to entering the diffusion tower. Further analytical analysis is required to predict the thermal and mass transport with the air heating configuration.

James F. Klausner; Renwei Mei; Yi Li; Jessica Knight; Venugopal Jogi

2005-09-01

240

Soil Water Sensor Needs for the Evaluation of Hydraulic Lift in Crop Plants  

Technology Transfer Automated Retrieval System (TEKTRAN)

Hydraulic lift (HL) in plants is defined as the process by which water is redistributed from wet soil zones to drier soil zones through the plant root system in response to gradients in water potential. Water is released into the dry soil when plant transpiration is low (night) and reabsorbed by th...

241

Association of water spectral indices with plant and soil water relations in contrasting wheat genotypes  

PubMed Central

Spectral reflectance indices can be used to estimate the water status of plants in a rapid, non-destructive manner. Water spectral indices were measured on wheat under a range of water-deficit conditions in field-based yield trials to establish their relationship with water relations parameters as well as available volumetric soil water (AVSW) to indicate soil water extraction patterns. Three types of wheat germplasm were studied which showed a range of drought adaptation; near-isomorphic sister lines from an elite/elite cross, advanced breeding lines, and lines derived from interspecific hybridization with wild relatives (synthetic derivative lines). Five water spectral indices (one water index and four normalized water indices) based on near infrared wavelengths were determined under field conditions between the booting and grain-filling stages of crop development. Among all water spectral indices, one in particular, which was denominated as NWI-3, showed the most consistent associations with water relations parameters and demonstrated the strongest associations in all three germplasm sets. NWI-3 showed a strong linear relationship (r2 >0.6–0.8) with leaf water potential (?leaf) across a broad range of values (–2.0 to –4.0 MPa) that were determined by natural variation in the environment associated with intra- and inter-seasonal affects. Association observed between NWI-3 and canopy temperature (CT) was consistent with the idea that genotypes with a better hydration status have a larger water flux (increased stomatal conductance) during the day. NWI-3 was also related to soil water potential (?soil) and AVSW, indicating that drought-adapted lines could extract more water from deeper soil profiles to maintain favourable water relations. NWI-3 was sufficiently sensitive to detect genotypic differences (indicated by phenotypic and genetic correlations) in water status at the canopy and soil levels indicating its potential application in precision phenotyping. PMID:20639342

Gutierrez, Mario; Reynolds, Matthew P.; Klatt, Arthur R.

2010-01-01

242

Stable isotopes in plant physiology: using water isotopes to study water fluxes in a temperate forest  

NASA Astrophysics Data System (ADS)

Drought has profound consequences on vegetation, including decreases in instantaneous carbon uptake; damage that limits future uptake for the life of the plant; mortality that can lead to large sources of carbon to the atmosphere; and shifts in biogeography that alter future potential for carbon uptake and capacitance. These processes are largely absent from global models, for lack of understanding in how co-occurring plants compete for water, weak understanding of how plant hydraulics is coordinated to minimize risk of drought, and few empirical data to constrain superior models of these processes. Here we present the results of a large-scale field experiment at Silas Little Experimental Forest (NJ), where rainwater was diverted from a 10m^2 area around selected trees from two different species (either oak or pine trees) and either re-injected (control plots), discarded (drought plots) or replaced by isotopically labeled water (isotope plots). We sampled heavily the drought plots and collected valuable information on tree hydraulics under drought conditions, such as water potentials of soil, leaf and stem, photosynthetic rate or sap flow. At the isotope plots, we followed the injected water within the injection trees and the surrounding ones. In particular, using an innovative setup for in-situ measurement paired with a laser spectrometer, we studied the isotopes effects within the tree xylem, which gave us a better understanding of water uptake by the roots and its transport to the leaves. By tracking the labeled water in the surrounding trees, we were also able to quantify the importance of plant competition for water availability below ground. We show here the importance of understanding all the phases of the water transport in the biosphere to help constraining climate models.

Gerlein, C.; Wolf, A.; Caylor, K. K.

2013-12-01

243

Spatial and temporal variability of soil water in drylands: plant water potential as a diagnostic tool  

Microsoft Academic Search

Arid and semi-arid regions are characterized by low rainfall and high potential evaporative demand. Here, water is the major\\u000a limiting factor for plant growth and productivity. Soil and surface hydrology properties (e.g. field capacity, infiltration\\u000a rates) effectively control the water re-distribution in the ecosystem, a fact that is aggravated in arid environments. Information\\u000a of the spatial and temporal accessibility of

Maik Veste; Markus Staudinger; Manfred Küppers

2008-01-01

244

Passive cooling means for water cooled nuclear reactor plants  

SciTech Connect

This patent describes a water cooled, nuclear fission reactor plant having an improved auxiliary passive cooling system for dissipating heat produced during periods of other than normal operation, the nuclear fission reactor plant. It comprises the combination of: a reactor pressure vessel containing a core of heat producing fissionable fuel material provided with reciprocally removable fission control rods and having external steam and hot coolant water conduits extending out therefrom including a circulation loop passing through a heat exchanger comprising a steam driven turbine, the reactor pressure vessel and adjacent components being housed within an enclosing, substantially gas impermeable containment structure for retaining a gaseous atmosphere enveloping the reactor pressure vessel and adjacent components; a container retaining a pool of cooling water isolated from the atmosphere of the containment structure and positioned at a level within the containment structure above the reactor pressure vessel, the isolation container including a heat exchanger unit submerged in the retained pool of cooling water having an inlet which is in optional fluid communication with the interior of the reactor pressure vessel and with the atmosphere of the containment structure enveloping the pressure vessel; a suppression pool chamber containing a pool of cooling water for condensing steam positioned adjacent to the reactor pressure vessel and having a horizontal vent passing to an adjoining area which is in open communication to the atmosphere of the containment structure; a vent duct extending from an outlet of the heat exchanger unit submerged in the isolation container pool downward into the suppression pool chamber with its open end terminating below the surface of the cooling water pool and above the level of the horizontal vent passing an adjoining area.

Gluntz, D.M.; Oosterkamp, W.J.; van Kuijk, R.M.

1992-04-07

245

Mixing Effects of Understory Plant Litter on Decomposition and Nutrient Release of Tree Litter in Two Plantations in Northeast China  

PubMed Central

Understory vegetation plays a crucial role in carbon and nutrient cycling in forest ecosystems; however, it is not clear how understory species affect tree litter decomposition and nutrient dynamics. In this study, we examined the impacts of understory litter on the decomposition and nutrient release of tree litter both in a pine (Pinus sylvestris var. mongolica) and a poplar (Populus × xiaozhuanica) plantation in Northeast China. Leaf litter of tree species, and senesced aboveground materials from two dominant understory species, Artemisia scoparia and Setaria viridis in the pine stand and Elymus villifer and A. sieversiana in the poplar stand, were collected. Mass loss and N and P fluxes of single-species litter and three-species mixtures in each of the two forests were quantified. Data from single-species litterbags were used to generate predicted mass loss and N and P fluxes for the mixed-species litterbags. In the mixture from the pine stand, the observed mass loss and N release did not differ from the predicted value, whereas the observed P release was greater than the predicted value. However, the presence of understory litter decelerated the mass loss and did not affect N and P releases from the pine litter. In the poplar stand, litter mixture presented a positive non-additive effect on litter mass loss and P release, but an addition effect on N release. The presence of understory species accelerated only N release of poplar litter. Moreover, the responses of mass loss and N and P releases of understory litter in the mixtures varied with species in both pine and poplar plantations. Our results suggest that the effects of understory species on tree litter decomposition vary with tree species, and also highlight the importance of understory species in litter decomposition and nutrient cycles in forest ecosystems. PMID:24143184

Zhao, Lei; Hu, Ya-Lin; Lin, Gui-Gang; Gao, Yong-chao; Fang, Yun-Ting; Zeng, De-Hui

2013-01-01

246

Mixing effects of understory plant litter on decomposition and nutrient release of tree litter in two plantations in Northeast China.  

PubMed

Understory vegetation plays a crucial role in carbon and nutrient cycling in forest ecosystems; however, it is not clear how understory species affect tree litter decomposition and nutrient dynamics. In this study, we examined the impacts of understory litter on the decomposition and nutrient release of tree litter both in a pine (Pinus sylvestris var. mongolica) and a poplar (Populus × xiaozhuanica) plantation in Northeast China. Leaf litter of tree species, and senesced aboveground materials from two dominant understory species, Artemisia scoparia and Setaria viridis in the pine stand and Elymus villifer and A. sieversiana in the poplar stand, were collected. Mass loss and N and P fluxes of single-species litter and three-species mixtures in each of the two forests were quantified. Data from single-species litterbags were used to generate predicted mass loss and N and P fluxes for the mixed-species litterbags. In the mixture from the pine stand, the observed mass loss and N release did not differ from the predicted value, whereas the observed P release was greater than the predicted value. However, the presence of understory litter decelerated the mass loss and did not affect N and P releases from the pine litter. In the poplar stand, litter mixture presented a positive non-additive effect on litter mass loss and P release, but an addition effect on N release. The presence of understory species accelerated only N release of poplar litter. Moreover, the responses of mass loss and N and P releases of understory litter in the mixtures varied with species in both pine and poplar plantations. Our results suggest that the effects of understory species on tree litter decomposition vary with tree species, and also highlight the importance of understory species in litter decomposition and nutrient cycles in forest ecosystems. PMID:24143184

Zhao, Lei; Hu, Ya-Lin; Lin, Gui-Gang; Gao, Yong-chao; Fang, Yun-Ting; Zeng, De-Hui

2013-01-01

247

Influence of decomposition on chemical properties of plant- and manure-derived dissolved organic matter and sorption to goethite.  

PubMed

Sorption of dissolved organic matter (DOM) plays an important role in maintaining the fertility and quality of soils in agricultural ecosystems. Few studies have examined the effects of decomposition on DOM sorption and chemical characteristics. This study investigated the sorption to goethite (alpha-FeOOH) of fresh and decomposed hydrophilic (HPL) and hydrophobic (HPB) DOM fractions extracted from the shoots and roots of crimson clover (Trifolium incarnatum L.), corn (Zea mays L.), soybean [Glycine max (L.) Merr.], hairy vetch (Vicia villosa L.), and dairy and poultry manures. Sorption was positively related to apparent molecular weight (MWAP), aromaticity as measured by absorptivity at 280 nm, and phenolic acid content. A 10-d laboratory microbial decomposition of the source organic matter generally increased the sorption of the extracted DOM onto goethite. The decomposition effect on sorption was greater for the HPL fractions than for the HPB fractions. There was a decrease in the MWAP values of the DOM samples following sorption to goethite. In many cases the reduction in MWAP was large, indicating a strong preference by goethite for the higher MWAP DOM fractions. The results of this laboratory-based research demonstrate that microbial processes affect the chemical characteristics of DOM which may affect the distribution of soil organic C pools. PMID:17215221

Hunt, James F; Ohno, Tsutomu; He, Zhongqi; Honeycutt, C Wayne; Dail, D Bryan

2007-01-01

248

Introduction to Chemistry for Water and Wastewater Treatment Plant Operators. Water and Wastewater Training Program.  

ERIC Educational Resources Information Center

Presented are basic concepts of chemistry necessary for operators who manage drinking water treatment plants and wastewater facilities. It includes discussions of chemical terms and concepts, laboratory procedures for basic analyses of interest to operators, and discussions of appropriate chemical calculations. Exercises are included and answer…

South Dakota Dept. of Environmental Protection, Pierre.

249

Soil water content and water supply of plants in the southern Crimea  

NASA Astrophysics Data System (ADS)

In cinnamonic soils of the Nikitsky Botanical Garden (Crimea), the average productive water reserves (WR) under different plants in 1981-1990 exhibited close correlation with the field water capacity (FC) and the productive moisture range, which is equal to the difference between the FC and the permanent wilting point (WP). The soil water content (SWC) regularly increased with the depth. An 8-year-long variation cycle of the meteorological conditions and the WR was revealed. A correlation between the WR and the precipitation was noted. The relationship of the occurrence frequencies of the FC and WR with their values was analogous to the Maxwell distribution close to the normal (Gaussian) distribution.

Sudnitsyn, I. I.

2008-01-01

250

Photosynthesis, plant growth and dry matter distribution in kiwifruit as influenced by water deficits  

Microsoft Academic Search

The effects of water deficits on photosynthesis, plant growth and dry matter accumulation and distribution in the kiwifruit, cv Hayward, grown under controlled conditions in the glasshouse were studied. Water stress was imposed by irrigating the plants with 100%, 85%, 65% and 40% of water needed to reach pot capacity in the soil. Water deficits reduced the rate of photosynthesis

K. Chartzoulakis; B. Noitsakis; I. Therios

1993-01-01

251

The movement of materials into plants Part I. Osmosis and the movement of water into plants  

Microsoft Academic Search

Summary  The fundamental principles of osmosis are reviewed. A scheme is presented for mathematically dealing with the osmotic quantities,\\u000a expressed as osmotic specific free energies, and graphically representing the same in a diagram with appropriate coordinates.\\u000a Theoretical cases are introduced, utilizing various osmotic action capacities which possibly control water movement between\\u000a the plant and its environment. Four typical sets of data

T. C. Broyer

1947-01-01

252

18 CFR 420.51 - Hydroelectric power plant water use charges.  

Code of Federal Regulations, 2011 CFR

18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false Hydroelectric power plant water use charges. 420.51 Section 420.51 Conservation of Power and Water Resources DELAWARE RIVER BASIN...

2011-04-01

253

18 CFR 420.51 - Hydroelectric power plant water use charges.  

Code of Federal Regulations, 2013 CFR

18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true Hydroelectric power plant water use charges. 420.51 Section 420.51 Conservation of Power and Water Resources DELAWARE RIVER BASIN...

2013-04-01

254

18 CFR 420.51 - Hydroelectric power plant water use charges.  

Code of Federal Regulations, 2014 CFR

18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false Hydroelectric power plant water use charges. 420.51 Section 420.51 Conservation of Power and Water Resources DELAWARE RIVER BASIN...

2014-04-01

255

18 CFR 420.51 - Hydroelectric power plant water use charges.  

Code of Federal Regulations, 2012 CFR

18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false Hydroelectric power plant water use charges. 420.51 Section 420.51 Conservation of Power and Water Resources DELAWARE RIVER BASIN...

2012-04-01

256

18 CFR 420.51 - Hydroelectric power plant water use charges.  

Code of Federal Regulations, 2010 CFR

18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Hydroelectric power plant water use charges. 420.51 Section 420.51 Conservation of Power and Water Resources DELAWARE RIVER BASIN...

2010-04-01

257

(Metabolic mechanisms of plant growth at low water potentials)  

SciTech Connect

The work supported by DOE showed that water-limitation inhibits plant growth first by imposing a physical limitation that is followed in a few h by metabolic changes leading to reduced wall extensibility in the enlarging cells. After the wall extensibility decreased, a 28kD protein accumulated particularly in the walls of the growth-affected cells. Antibodies were used to identify cDNA for the protein. The base sequence of the cDNA was typical of an enzyme rather than known structural components of walls. The sequence was identical to one published by another laboratory at the same time and encoding a protein that accumulates in vacuoles of depodded soybean plants.

Not Available

1990-01-01

258

Rapid In Situ Identification of Source Water and Leaf Water in a Variety of Plant Species and Functional Types  

NASA Astrophysics Data System (ADS)

Plant rooting distributions and use of soil water resources are important determinants of ecological and hydrological function. The isotope composition of plant xylem water can be used to infer soil water source variations, in particular differences among species and plant functional types. We report here on dynamics in the oxygen and hydrogen isotope composition of plant and soil water pools and fluxes within the Manitou Experimental Forest in the Colorado Rockies. For this work, we used multiple in situ laser-based spectroscopic analyzers to collect isotope data on soil water, leaf water, stem water, transpiration water, and canopy vapor from multiple heights in the canopy. Using an Induction Module - Cavity Ring-Down Spectroscopy system, which extracts and analyzes soil and plant samples in a few minutes, we measured soil and plant water isotopic composition from multiple soil depths and plant species at several points throughout the growing season. Stem (source) water isotopic composition varied greatly among the various plant species and functional types (pine trees, shrubs, forbs, grasses), broadly in agreement with expected plant rooting depths. The steady-state isotopic composition of leaf transpiration, another proxy of source water, was also consistent with this variation by plant functional type and rooting depth. Leaf water generally followed these patterns, but pine needles exhibited dramatic isotopic gradients along the needle length, with hydrogen isotope gradients of close to 100 per mil from leaf base to tip. We also introduced an isotopic label in two pines of different sizes (that were previously instrumented with sapflow probes and dendrometers) to further identify the pathways and pace of water flow though the trees. These results demonstrate the complex interactions between multiple source and fluxes of water, and that simple ecosystem isotope models, while generally valid, require careful evaluation as high-frequency and in situ isotopic data become more widely available.

Still, C. J.; Hu, J.; Berkelhammer, M. B.; Barnard, H. R.; Rahn, T.; Hsiao, G.; Raudzens Bailey, A.; Noone, D. C.

2011-12-01

259

Functional Differences in Soil Water Pools: a New Perspective on Plant Water Use in Water-Limited Ecosystems  

Microsoft Academic Search

\\u000a Arid and semi-arid ecosystems cover roughly half of the earth's surface. Significant changes in vegetation cover combined\\u000a with climate change have increased concern over the future of these lands, which have considerable economic importance. Much\\u000a research has focused on plant—soil water relations in these systems, yet many mechanisms and significance of water use patterns\\u000a are not well under-stood. Here we

Ronald J. Ryel; Carolyn Y. Ivans; Michael S. Peek; A. Joshua Leffler

260

Dual-fluid-hybrid power plant co-powered by low-temperature geothermal water  

Microsoft Academic Search

Three variants of power plants fuelled or co-fuelled by geothermal water have been assessed, with the aim of making the best use of the energy contained in a stream of 80–120°C geothermal water. Heat-flow calculations for three power plant types, namely an Organic Rankine Cycle (ORC) power plant, a dual-fluid-hybrid power plant and a single-fluid hybrid-fuelled power plant, are presented.

Aleksandra Borsukiewicz-Gozdur

2010-01-01

261

Has the plant genetic variability any role in models of water transfer in the soil-plant-atmosphere continuum ?  

NASA Astrophysics Data System (ADS)

Water transfer in the SPAC is essentially linked to environmental conditions such as evaporative demand or soil water potential, and physical parameters such as soil hydraulic capacity or hydraulic conductivity. Models used in soil science most often represent the plant via a small number of variables such as the water flux that crosses the base of the stem or the root length (or area) in each soil layer. Because there is an increasing demand for computer simulations of plants that would perform better under water deficit, models of SPA water transfer are needed that could better take into account the genetic variability of traits involved in plant hydraulics. (i) The water flux through the plant is essentially limited by stomata, which present a much higher resistance to water flow than those in the soil - root continuum. This can lead to unexpected relations between flux, leaf water potential and root hydraulic conductance. (ii) A large genetic variability exists within and between species for stomatal control, with important consequences for the minimum soil water potential that is accessible to the plant. In particular, isohydric plants that maintain leaf water potential in a narrow range via stomatal control have a higher (nearer to 0) 'wilting point' than anisohydric plants that allow leaf water potential to reach very low values. (iii) The conductivity for water transfer in roots and shoots is controlled by plants via aquaporins. It largely varies with time of the day, water and nutrient status, in particular via plant hormones and circadian rhythms. Models of SPA water transfer with a time definition of minutes to hour should probably not ignore this, while those with longer time steps are probably less sensitive to changes in plant hydraulic conductivity. (iv) The "dogma" that dense root systems provide tolerance to water deficit is profoundly affected when the balance "H2O gain vs C investment" is taken into account. At least three programmes of recurrent selection for drought tolerance have resulted in a decrease in root biomass. Overall, it is now crucial to take into account the rapid progress in plant hydraulics in SPA models of water transfer. Several projects aim at this objective, in particular the EU project DROPS that gathers geneticists, plant modellers and soil modellers.

Tardieu, F.

2012-04-01

262

Study of the dynamics of Zn, Fe, and Cu in the soil-plant system during leaf litter decomposition using isotopic compositions  

NASA Astrophysics Data System (ADS)

Litter decomposition is a key process in the cycle of the elements in the soil-plant system. We have investigated the dynamics of three essential micronutrients (Zn, Fe, and Cu) in the vegetal cover, litter, organic horizons, and upper soil horizon (0-2 and 5-10 cm) using both element concentrations and isotopic compositions. The study was conducted on the O3HP (Oak Observatory at the Haute-Provence Observatory) experimental field site in southern France. O3HP is located far from pollution sources. It has been a fallow land for 70 years with the tree cover represented mainly by oak trees (Quercus pubescens). The soil is a thin layer of Calcisol developed under Mediterranean climate. The area has been subdivided in four zones as a function of plant cover. The results for two of these zones, dominated by respectively Poaceae and Genista hispanica, are reported here. We found that the concentrations of the three elements increase from the Ol to the Of horizon. Copper concentration in the Of horizon is close to that of the soil, whereas it is lower for Fe and Zn. For isotopic compositions, the behavior of the three elements is, however, different, which suggests different processes of redistribution for these elements. An enrichment in light Fe isotopes was observed from the Ol to the Of horizon, the latter having an isotopic composition similar to that of the soil. Zinc isotopic compositions are also similar in the Of horizon and the soil but they are isotopically heavier than in the Ol horizon. For Cu, the O horizons are isotopically heavier than the soil, with Of being the heaviest horizon. In addition, for Cu and Zn, the profiles in the O-horizons in the Poaceae-dominated and Genista hispanica-dominated areas are similar but their values are offset, suggesting an influence of the vegetal cover. The increase in concentration for Cu, Zn and Fe with age/depth in the O horizons is in agreement with what is commonly observed in litter-bag experiments, e.g. 1,2. Two mechanisms have been invoked to explain this phenomenon: 1) addition of metals by aerial dust and wet deposition or 2) absorption of metals from the soil by organisms that develop on the litter. Our vertical profiles of isotopic compositions in the O horizons show that the first hypothesis is unlikely. Instead, they suggest a downward transfer of isotopically light metals from the fresh litter to the base of the O horizon. In addition, the assumption of an upward transfer of isopically heavy Cu and Zn from the upper soil horizon to the Of horizon is needed to fully explain the profiles we observed. 1 Lomander and Johansson (2001) Water, Air, and Soil Pollut. 132, 165-184 2 Scheid et al. (2009) Eur. J. Soil Sci. 60, 613-621

Pichat, S.; Fekiacova, Z.

2013-12-01

263

A partition-limited model for the plant uptake of organic contaminants from soil and water  

USGS Publications Warehouse

In dealing with the passive transport of organic contaminants from soils to plants (including crops), a partition-limited model is proposed in which (i) the maximum (equilibrium) concentration of a contaminant in any location in the plant is determined by partition equilibrium with its concentration in the soil interstitial water, which in turn is determined essentially by the concentration in the soil organic matter (SOM) and (ii) the extent of approach to partition equilibrium, as measured by the ratio of the contaminant concentrations in plant water and soil interstitial water, ??pt (??? 1), depends on the transport rate of the contaminant in soil water into the plant and the volume of soil water solution that is required for the plant contaminant level to reach equilibrium with the external soil-water phase. Through reasonable estimates of plant organic-water compositions and of contaminant partition coefficients with various plant components, the model accounts for calculated values of ??pt in several published crop-contamination studies, including near-equilibrium values (i.e., ??pt ??? 1) for relatively water-soluble contaminants and lower values for much less soluble contaminants; the differences are attributed to the much higher partition coefficients of the less soluble compounds between plant lipids and plant water, which necessitates much larger volumes of the plant water transport for achieving the equilibrium capacities. The model analysis indicates that for plants with high water contents the plant-water phase acts as the major reservoir for highly water-soluble contaminants. By contrast, the lipid in a plant, even at small amounts, is usually the major reservoir for highly water-insoluble contaminants.

Chiou, C.T.; Sheng, G.; Manes, M.

2001-01-01

264

Water treatment plant sludge disposal into stabilization ponds.  

PubMed

Researchers have paid particular attention to the disposal of sludge produced in water treatment plants (WTPs) into wastewater treatment plants (WWTPs) for further processing, mainly because it is considered an attractive alternative for the treatment of waste generated in water production processes. This study evaluated the effects of flow equalization and disposal of sludge, from a conventional WTP, into a WWTP system that includes an anaerobic stabilization pond followed by a facultative pond. During the period of sludge discharge from the WTP into the wastewater system, the influent to the WWTP presented an increase of 17% (from 171 to 200 mg L(-1)) of total suspended solids (TSS) and a 7.0% flow rate increase, without showing adverse effects on the organic load, TSS and nutrients removal. The most significant impact observed in the WWTP was the increase of solids accumulation rate in the anaerobic pond, with a value of 141 mm/year during the sludge discharge period. The operating time, before the dredging and desludging cycles required for this specific anaerobic pond, decreased from 12.7 to 10.4 years, which is consistent with previous studies in literature. Thus, based on the observed parameters of this study, it is viable to release solids from a WTP effluent into a WWTP that includes anaerobic stabilization ponds followed by a facultative pond. Indeed, this process scheme becomes a viable technical, environmental, and economical alternative for small to medium WWTPs. PMID:23416593

Filho, Sidney Seckler Ferreira; Piveli, Roque Passos; Cutolo, Silvana Audrá; de Oliveira, Alexandre Alves

2013-01-01

265

Effect of Sequoyah Nuclear Plant discharges on Chickamauga Lake water temperatures  

Microsoft Academic Search

The near-field effect of Sequoyah Nuclear Plant thermal discharges on Chickamauga Lake water temperatures is discussed. A description and performance characteristics of the plant's heat dispersal facilities, including the cooling water intake, discharge diffuser and cooling towers, are given. The use of the various facilities is described for open, helper and closed mode cooling of the plant. The expected temperature

C. D. Ungate; K. A. Howerton

1978-01-01

266

Water and Plant Cells: Notes on a Teaching Scheme for O-Level.  

ERIC Educational Resources Information Center

Offers suggestions for teaching some aspects of water economy in plants. These include diffusion/osmosis, water transport, the part played by turgor in structural support, and its implications for plant organs or whole plants. Several practical demonstrations/experiments are also described. (JN)

Grenville, H. W.

1983-01-01

267

Biogeochemistry of Decomposition and Detrital Processing  

NASA Astrophysics Data System (ADS)

Decomposition is a key ecological process that roughly balances net primary production in terrestrial ecosystems and is an essential process in resupplying nutrients to the plant community. Decomposition consists of three concurrent processes: communition or fragmentation, leaching of water-soluble compounds, and microbial catabolism. Decomposition can also be viewed as a sequential process, what Eijsackers and Zehnder (1990) compare to a Russian matriochka doll. Soil macrofauna fragment and partially solubilize plant residues, facilitating establishment of a community of decomposer microorganisms. This decomposer community will gradually shift as the most easily degraded plant compounds are utilized and the more recalcitrant materials begin to accumulate. Given enough time and the proper environmental conditions, most naturally occurring compounds can completely be mineralized to inorganic forms. Simultaneously with mineralization, the process of humification acts to transform a fraction of the plant residues into stable soil organic matter (SOM) or humus. For reference, Schlesinger (1990) estimated that only ˜0.7% of detritus eventually becomes stabilized into humus.Decomposition plays a key role in the cycling of most plant macro- and micronutrients and in the formation of humus. Figure 1 places the roles of detrital processing and mineralization within the context of the biogeochemical cycling of essential plant nutrients. Chapin (1991) found that while the atmosphere supplied 4% and mineral weathering supplied no nitrogen and <1% of phosphorus, internal nutrient recycling is the source for >95% of all the nitrogen and phosphorus uptake by tundra species in Barrow, Alaska. In a cool temperate forest, nutrient recycling accounted for 93%, 89%, 88%, and 65% of total sources for nitrogen, phosphorus, potassium, and calcium, respectively ( Chapin, 1991). (13K)Figure 1. A decomposition-centric biogeochemical model of nutrient cycling. Although there is significant external input (1) and output (2) from neighboring ecosystems (such as erosion), weathering of primary minerals (3), loss of secondary minerals (4), atmospheric deposition and N-fixation (5) and volatilization (6), the majority of plant-available nutrients are supplied by internal recycling through decomposition. Nutrients that are taken up by plants (7) are either consumed by fauna (8) and returned to the soil through defecation and mortality (10) or returned to the soil through litterfall and mortality (9). Detritus and humus can be immobilized into microbial biomass (11 and 13). Humus is formed by the transformation and stabilization of detrital (12) and microbial (14) compounds. During these transformations, SOM is being continually mineralized by the microorganisms (15) replenishing the inorganic nutrient pool (after Swift et al., 1979). The second major ecosystem role of decomposition is in the formation and stabilization of humus. The cycling and stabilization of SOM in the litter-soil system is presented in a conceptual model in Figure 2. Parallel with litterfall and most root turnover, detrital processing is concentrated at or near the soil surface. As labile SOM is preferentially degraded, there is a progressive shift from labile to passive SOM with increasing depth. There are three basic mechanisms for SOM accumulation in the mineral soil: bioturbation or physical mixing of the soil by burrowing animals (e.g., earthworms, gophers, etc.), in situ decomposition of roots and root exudates, and the leaching of soluble organic compounds. In the absence of bioturbation, distinct litter layers often accumulate above the mineral soil. In grasslands where the majority of net primary productivity (NPP) is allocated belowground, root inputs will dominate. In sandy soils with ample rainfall, leaching may be the major process incorporating carbon into the soil. (11K)Figure 2. Conceptual model of carbon cycling in the litter-soil system. In each horizon or depth increment, SOM is represented by three pools: labile SOM, slow SOM, and passive SOM. Inputs inc

Sanderman, J.; Amundson, R.

2003-12-01

268

Efficient taste and odour removal by water treatment plants around the Han River water supply system.  

PubMed

Seven major water treatment plants in Seoul Metropolitan Area, which are under Korea Water Resources Corporation (KOWACO)'s management, take water from the Paldang Reservoir in the Han River System for drinking water supply. There are taste and odour (T&O) problems in the finished water because the conventional treatment processes do not efficiently remove the T&O compounds. This study evaluated T&O removal by ozonation, granular activated carbon (GAC) treatment, powder activated carbon (PAC) and an advanced oxidation process in a pilot-scale treatment plant and bench-scale laboratory experiments. During T&O episodes, PAC alone was not adequate, but as a pretreatment together with GAC it could be a useful option. The optimal range of ozone dose was 1 to 2 mg/L at a contact time of 10 min. However, with ozone alone it was difficult to meet the T&O target of 3 TON and 15 ng/L of MIB or geosmin. The GAC adsorption capacity for DOC in the three GAC systems (F/A, GAC and O3 + GAC) at an EBCT of 14 min is mostly exhausted after 9 months. However, substantial TON removal continued for more than 2 years (>90,000 bed volumes). GAC was found to be effective for T&O control and the main removal mechanisms were adsorption capacity and biodegradation. PMID:17489399

Ahn, H; Chae, S; Kim, S; Wang, C; Summers, R S

2007-01-01

269

Genotoxicity of drinking water disinfectants in plant bioassays.  

PubMed

The genotoxicity of two widely used drinking water disinfectants, sodium hypochlorite (NaClO) and chlorine dioxide (ClO(2)), and a new disinfectant, peracetic acid (PAA, CH(3)-CO-COOH), was evaluated in three short-term plant tests: (1) induction of anaphase chromosome aberrations in the root cells of Allium cepa, (2) micronucleus induction in the root cells of Vicia faba, and (3) micronucleus induction in Tradescantia pollen cells. The study was carried out in the laboratory by directly exposing the plants to several concentrations of the disinfectants in redistilled water at unadjusted (acid) and adjusted (neutral) pHs. Both 0.1 and 0.2 mg/l NaClO induced chromosome aberrations in the Allium cepa test at acid pH, but concentrations up to 0.5 mg/l of all the disinfectants were negative at neutral pH. Concentrations ranging from 0.1 to 0.5 mg/l NaClO, ClO(2,) and PAA induced micronuclei in Vicia faba at acid pH, while 1-2 mg/l NaClO and ClO(2) and 0.5-2 mg/l PAA gave positive responses at neutral pH. Most of concentrations of ClO(2) produced positive responses in the Tradescantia micronucleus test. In general, the highest levels of genotoxicity were observed under acid conditions; at acid pH, significant effects were induced by low concentrations of ClO(2) and PAA. Since the test concentrations of disinfectants are typical of those encountered in the biocidal treatment of tap water and similar concentrations are consumed daily by a large number of people, the genotoxicity of these compounds may constitute a significant public health concern. PMID:15880733

Monarca, Silvano; Feretti, Donatella; Zani, Claudia; Rizzoni, Marco; Casarella, Silvia; Gustavino, Bianca

2005-08-01

270

Impact of drought on U.S. steam electric power plant cooling water intakes and related water resource management issues.  

SciTech Connect

This report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL) Existing Plants Research Program, which has an energy-water research effort that focuses on water use at power plants. This study complements their overall research effort by evaluating water availability at power plants under drought conditions. While there are a number of competing demands on water uses, particularly during drought conditions, this report focuses solely on impacts to the U.S. steam electric power plant fleet. Included are both fossil-fuel and nuclear power plants. One plant examined also uses biomass as a fuel. The purpose of this project is to estimate the impact on generation capacity of a drop in water level at U.S. steam electric power plants due to climatic or other conditions. While, as indicated above, the temperature of the water can impact decisions to halt or curtail power plant operations, this report specifically examines impacts as a result of a drop in water levels below power plant submerged cooling water intakes. Impacts due to the combined effects of excessive temperatures of the returned cooling water and elevated temperatures of receiving waters (due to high ambient temperatures associated with drought) may be examined in a subsequent study. For this study, the sources of cooling water used by the U.S. steam electric power plant fleet were examined. This effort entailed development of a database of power plants and cooling water intake locations and depths for those plants that use surface water as a source of cooling water. Development of the database and its general characteristics are described in Chapter 2 of this report. Examination of the database gives an indication of how low water levels can drop before cooling water intakes cease to function. Water level drops are evaluated against a number of different power plant characteristics, such as the nature of the water source (river vs. lake or reservoir) and type of plant (nuclear vs. fossil fuel). This is accomplished in Chapter 3. In Chapter 4, the nature of any compacts or agreements that give priority to users (i.e., which users must stop withdrawing water first) is examined. This is examined on a regional or watershed basis, specifically for western water rights, and also as a function of federal and state water management programs. Chapter 5 presents the findings and conclusions of this study. In addition to the above, a related intent of this study is to conduct preliminary modeling of how lowered surface water levels could affect generating capacity and other factors at different regional power plants. If utility managers are forced to take some units out of service or reduce plant outputs, the fuel mix at the remaining plants and the resulting carbon dioxide emissions may change. Electricity costs and other factors may also be impacted. Argonne has conducted some modeling based on the information presented in the database described in Chapter 2 of this report. A separate report of the modeling effort has been prepared (Poch et al. 2009). In addition to the U.S. steam electric power plant fleet, this modeling also includes an evaluation of power production of hydroelectric facilities. The focus of this modeling is on those power plants located in the western United States.

Kimmell, T. A.; Veil, J. A.; Environmental Science Division

2009-04-03

271

Water Quality Improvements with the Use of Ozone at the Los Angeles Water Treatment Plant  

Microsoft Academic Search

At 600 mgd (2,270 ML\\/day), the recently completed Los Angeles Aqueduct Filtration Plant (LAAFP) is one of the world's largest water' treatment facilities utilizing ozone for pretreatment. The treatment process features direct filtration at rates of up to 13.5 gpm\\/ft (33 m\\/h). Under the optimized full-scale operation, preozonation has resulted in significantly reduced THM levels and very low effluent turbidity

Duane L. Georgeson; Ali A. Karimi

1988-01-01

272

Mechanisms underlying plant resilience to water deficits: prospects for water-saving agriculture.  

PubMed

Drought is one of the greatest limitations to crop expansion outside the present-day agricultural areas. It will become increasingly important in regions of the globe where, in the past, the problem was negligible, due to the recognized changes in global climate. Today the concern is with improving cultural practices and crop genotypes for drought-prone areas; therefore, understanding the mechanisms behind drought resistance and the efficient use of water by the plants is fundamental for the achievement of those goals. In this paper, the major constraints to carbon assimilation and the metabolic regulations that play a role in plant responses to water deficits, acting in isolation or in conjunction with other stresses, is reviewed. The effects on carbon assimilation include increased resistance to diffusion by stomata and the mesophyll, as well as biochemical and photochemical adjustments. Oxidative stress is critical for crops that experience drought episodes. The role of detoxifying systems in preventing irreversible damage to photosynthetic machinery and of redox molecules as local or systemic signals is revised. Plant capacity to avoid or repair membrane damage during dehydration and rehydration processes is pivotal for the maintenance of membrane integrity, especially for those that embed functional proteins. Among such proteins are water transporters, whose role in the regulation of plant water status and transport of other metabolites is the subject of intense investigation. Long-distance chemical signalling, as an early response to drought, started to be unravelled more than a decade ago. The effects of those signals on carbon assimilation and partitioning of assimilates between reproductive and non-reproductive structures are revised and discussed in the context of novel management techniques. These applications are designed to combine increased crop water-use efficiency with sustained yield and improved quality of the products. Through an understanding of the mechanisms leading to successful adaptation to dehydration and rehydration, it has already been possible to identify key genes able to alter metabolism and increase plant tolerance to drought. An overview of the most important data on this topic, including engineering for osmotic adjustment or protection, water transporters, and C4 traits is presented in this paper. Emphasis is given to the most successful or promising cases of genetic engineering in crops, using functional or regulatory genes. as well as to promising technologies, such as the transfer of transcription factors. PMID:15475377

Chaves, M M; Oliveira, M M

2004-11-01

273

Predawn disequilibrium between plant and soil water potentials in two cold-desert shrubs  

Microsoft Academic Search

Classical water relations theory predicts that predawn plant water potential should be in equilibrium with soil water potential\\u000a (soil ?w) around roots, and many interpretations of plant water status in natural populations are based on this expectation. We examined\\u000a this expectation for two salt-tolerant, cold-desert shrub species in glasshouse experiments where frequent watering assured\\u000a homogeneity in soil ?w and soil-root

L. A. Donovan; D. J. Grisé; J. B. West; R. A. Pappert; N. N. Alder; J. H. Richards

1999-01-01

274

Natural selection on the plant-water relations of Cleome serrulata growing along natural moisture gradients  

Microsoft Academic Search

I investigated the extent and adaptive importance of genetically-based variation in plant water relations in two populations of the annual plant Cleome serrulata found growing along relatively short (Plant in May and June of 1984; differences up to 0.9 MPa were seen along the gradients. Seeds were collected from maternal plants growing along the moisture gradients and then grown under

M. A. Farris

1987-01-01

275

2006 Nature Publishing Group Plants are a rich source of nutrients and water for  

E-print Network

© 2006 Nature Publishing Group Plants are a rich source of nutrients and water for microbes, insects or cultivation practices. They enter plant tissues either by wounds or through natural openings plant tissues or the xylem. Plant-pathogenic members of the Proteobacteria cause diverse disease

Pawlowski, Wojtek

276

Studies on water-steam Rankine-cycle solar central receiver power plants. Final report  

Microsoft Academic Search

Cost estimates are provided for four 150 MWe solar hybrid central receiver power plants, based on the updating of conceptual designs developed in a previous EPRI solar hybrid power plant cost study, Water\\/Steam Rankine Cycle Solar Central Receiver Power Plant Cost Estimates. The power plants are hybrid in that main steam is generated in a central receiver and a conventional

J. R. Darnell; R. L. Lessley; J. A. Paffenbarger; A. A. Agur

1985-01-01

277

Prevention and mitigation of steam-generator water-hammer events in PWR plants  

Microsoft Academic Search

Water hammer in nuclear power plants is an unresolved safety issue under study at the NRC (USI A-1). One of the identified safety concerns is steam generator water hammer (SGWH) in pressurized-water reactor (PWR) plants. This report presents a summary of: (1) the causes of SGWH; (2) various fixes employed to prevent or mitigate SGWH; and (3) the nature and

J. T. Han; N. Anderson

1982-01-01

278

A Beginner's Guide to Water Management--Aquatic Plants in Florida Lakes1  

E-print Network

CIR 111 A Beginner's Guide to Water Management--Aquatic Plants in Florida Lakes1 Florida LAKEWATCH2 volunteers to collect monthly water samples, algae samples, and water clarity information from a lake/IFAS Extension. Aquatic Plants in Florida Lakes Information Circular 111 UF/IFAS Florida LAKEWATCH UF

Watson, Craig A.

279

Decomposition of ozone in water in the presence of organic solutes acting as promoters and inhibitors of radical chain reactions  

Microsoft Academic Search

The decomposition of aqueous ozone is generally due to a chain reaction involving .OH radicals. Many organic solutes (impurities) can react with .OH to yield .Oâ⁻ upon addition of Oâ. .Oâ⁻ transfers its electron to a further ozone molecule in a rather selective reaction. The ozonide anion (.Oâ⁻) formed immediately decomposes into a further .OH radical. Compounds that convert .OH

Johannes Staehelin; Juerg Hoigne

1985-01-01

280

Small-scale Geothermal Power Plants Using Hot Spring Water  

NASA Astrophysics Data System (ADS)

The installed capacity of the geothermal power plants has been summed up to be about 515MW in Japan. However, the electricity generated by the geothermal resources only contributes to 0.2% of the whole electricity supply. After the catastrophic earthquake and tsunami devastated the Pacific coast of north-eastern Japan on Friday, March 11, 2011, the Japanese government is encouraging the increase of the renewable energy supply including the geothermal. It needs, however, more than 10 years to construct the geothermal power plant with more than 10MW capacity since the commencement of the development. Adding the problem of the long lead time, high temperature fluid is mainly observed in the national parks and the high quality of the geothermal resources is limited. On the other hand hot springs are often found. The utilisation of the low temperature hot water becomes worthy of notice. The low temperature hot water is traditionally used for bathing and there are many hot springs in Japan. Some of the springs have enough temperature and enthalpy to turn the geothermal turbine but a new technology of the binary power generation makes the lower temp fluid to generate electricity. Large power generators with the binary technology are already installed in many geothermal fields in the world. In the recent days small-scale geothermal binary generators with several tens to hundreds kW capacity are developed, which are originally used by the waste heat energy in an iron factory and so on. The newly developed binary unit is compact suitable for the installation in a Japanese inn but there are the restrictions for the temperature of the hot water and the working fluid. The binary power unit using alternatives for chlorofluorocarbon as the working fluid is relatively free from the restriction. KOBELCO, a company of the Kobe Steel Group, designed and developed the binary power unit with an alternative for chlorofluorocarbon. The unit has a 70 MW class electric generator. Three units have been installed in Obama Hot Spring area, Nagasaki Prefecture, where about 15,000 tonnes of hot water are produced in a day and more than 35% of the hot water flow directly to the sea. Another demonstration experiments are also conducted in several hot spring areas. In this study we will review several examples to utilise low temperature hot springs in Japan. Binary Power Unit at Obama (Fujino, 2013)

Tosha, T.; Osato, K.; Kiuchi, T.; Miida, H.; Okumura, T.; Nakashima, H.

2013-12-01

281

Techniques and experimental approaches for the measurement of plant water status  

Microsoft Academic Search

Living cells need to be more or less saturated with water to function normally, but they are usually incomplete in this desirable condition. The two basic parameters which describe the degree of unsaturation, i.e. the plant water deficit are (i) the water content and (ii) the energy status of the water in the cell. The water content is usually expressed

Neil C. Turner

1981-01-01

282

Rates of litter decomposition and soil respiration in relation to soil temperature and water in different-aged Pinus massoniana forests in the Three Gorges Reservoir Area, China.  

PubMed

To better understand the soil carbon dynamics and cycling in terrestrial ecosystems in response to environmental changes, we studied soil respiration, litter decomposition, and their relations to soil temperature and soil water content for 18-months (Aug. 2010-Jan. 2012) in three different-aged Pinus massoniana forests in the Three Gorges Reservoir Area, China. Across the experimental period, the mean total soil respiration and litter respiration were 1.94 and 0.81, 2.00 and 0.60, 2.19 and 0.71 µmol CO2 m(-2) s(-1), and the litter dry mass remaining was 57.6%, 56.2% and 61.3% in the 20-, 30-, and 46-year-old forests, respectively. We found that the temporal variations of soil respiration and litter decomposition rates can be well explained by soil temperature at 5 cm depth. Both the total soil respiration and litter respiration were significantly positively correlated with the litter decomposition rates. The mean contribution of the litter respiration to the total soil respiration was 31.0%-45.9% for the three different-aged forests. The present study found that the total soil respiration was not significantly affected by forest age when P. masonniana stands exceed a certain age (e.g. >20 years old), but it increased significantly with increased soil temperature. Hence, forest management strategies need to protect the understory vegetation to limit soil warming, in order to reduce the CO2 emission under the currently rapid global warming. The contribution of litter decomposition to the total soil respiration varies across spatial and temporal scales. This indicates the need for separate consideration of soil and litter respiration when assessing the climate impacts on forest carbon cycling. PMID:25004164

Xiao, Wenfa; Ge, Xiaogai; Zeng, Lixiong; Huang, Zhilin; Lei, Jingpin; Zhou, Benzhi; Li, Maihe

2014-01-01

283

Mathematical modelling of plant water and nutrient uptake  

NASA Astrophysics Data System (ADS)

In this presentation I will describe a model of plant water and nutrient uptake and how to translate this model and experimental data from the single root scale to the root branching structure scale. The model starts at the single root scale and describes the water and nutrient movement in the soil using Richards' equation (water uptake) and diffusion-convection equation (nutrient uptake). The water and nutrient uptake in the single root scale model is represented by boundary conditions. In the case of nutrient uptake this has the form of a non-linear Michaelis-Menten uptake law and in the case of water this is given by a soil-xylem pressure difference boundary condition. The flow of water in the xylem is modeled as Poiseuille flow. We solve the single root scale models using the analytic approximate technique of asymptotic expansions similar to Oseen expansions known from fluid dynamics. We will then discuss how to use the analytic expression to estimate the water and nutrient uptake by growing root branching systems. We model the growth of the root system using a dynamic population model to describe the branching and elongation of roots in the branching system. This root branching population model results in a hyperbolic equation similar to age dependent population models and it can be solved fully analytically using the method of characteristics. Thus we have a fully analytic description of the root branching system evolution. We use this branching model to estimate the nutrient uptake in a scenario when the competition between subbranches is small, i.e., as it is in the case of phosphate, potassium and arsenic. We compare our approximate analytic model to a full 3d simulation of the root system phosphate uptake and find that the analytic model almost perfectly reproduces the 3d numerical model. In addition the analytic model can be included in larger field/catchment/climate scale models something which is not practically possible with the numerical simulations due to their high computational burden. As a further development of the analytic model we extend it to take into account more details about the root morphology, such as the branching angle between roots, to calculate the evolution of the soil moisture and nutrient concentration profiles due to surface fertilisation and rainfall events. Using this model we are able to determine the relationship between the rainfall events and fertiliser movement into the soil profile. We find that there is a critical rate of rainfall below which the fertilizer (or pollutant) movement into the deeper layers of the soil is impeded due to the development of a slowly varying fluid saturation profile.

Roose, Tiina

2010-05-01

284

Heat and Mass Transfer in Quenching the Reaction of Thermal Decomposition of a Forest Combustible Material with a Group of Water Drops  

NASA Astrophysics Data System (ADS)

We have carried out computational investigations of the processes of heat and mass transfer in quenching the reaction of thermal decomposition of the typical forest combustible materials (birch leaves and pine and fir needles) with a group of water drops. It has been established that the termination time of pyrolysis is influenced by the integral parameter characterizing the relative position of drops and the temperature of the vapor-gas mixture over the forest combustible material. The thicknesses of layers providing termination of pyrolysis of evaporated liquid materials for a group of drops have been determined.

Kuznetsov, G. V.; Strizhak, P. A.

2014-05-01

285

Plant response to environmental conditions: assessing potential production, water demand, and negative effects of water deficit  

PubMed Central

This paper reviews methods for analyzing plant performance and its genetic variability under a range of environmental conditions. Biomass accumulation is linked every day to available light in the photosynthetically active radiation (PAR) domain, multiplied by the proportion of light intercepted by plants and by the radiation use efficiency. Total biomass is cumulated over the duration of the considered phase (e.g., plant cycle or vegetative phase). These durations are essentially constant for a given genotype provided that time is corrected for temperature (thermal time). Several ways of expressing thermal time are reviewed. Two alternative equations are presented, based either on the effect of transpiration, or on yield components. Their comparative interests and drawbacks are discussed. The genetic variability of each term of considered equations affects yield under water deficit, via mechanisms at different scales of plant organization and time. The effect of any physiological mechanism on yield of stressed plants acts via one of these terms, although the link is not always straightforward. Finally, I propose practical ways to compare the productivity of genotypes in field environments, and a “minimum dataset” of environmental data and traits that should be recorded for that. PMID:23423357

Tardieu, François

2013-01-01

286

Effect of transpiration rate on internal plant resistance to water flow  

E-print Network

Transport in the Soil-Plant Atmosphere System Mathematical models have been developed by Philip (1957 ). Gardner (1960)i and Cowan ( 1965 ) for water trans- port in the soil-plant-atmosphere system. Gardner (1960) quantitatively evaluated...- ciently dense that the transpiration demands can be met without excess soil water potential gradients ~ Cowan (1945 ) presented an approximate solution to the differential equation describing water movement in un- saturated soils toward plants...

Hailey, James Lester

1971-01-01

287

Basic Study on Estimating Water Stress of a Plant Using Vibration Measurement of Leaf  

NASA Astrophysics Data System (ADS)

A new noninvasive method for estimating the water stress of a plant was proposed. In order to investigate this method, we first examined the characteristic frequency of an individual leaf picked from the plant, and obtained the result that its characteristic frequency decreased in proportion to the reduction in the water content of the leaf. Next, we applied this method to a leaf on a branch and confirmed the same tendency when the water stress was increased by stopping the water supply of a plant cultured in water. From these results, it was suggested that the water stress of the plant could be estimated from the vibration measurement of the leaf. Lastly, the relationship between the water potential of the leaf and its elastic constant was discussed with the soil-plant-atmosphere-continuum model (SPAC model), and Young's modulus of a tomato leaf was roughly estimated.

Sano, Motoaki; Sugimoto, Tsuneyoshi; Hosoya, Hiroshi; Ohaba, Motoyoshi; Shibusawa, Sakae

2013-07-01

288

Dynamic aspects of soil water availability for isohydric plants: Focus on root hydraulic resistances  

NASA Astrophysics Data System (ADS)

water availability for plant transpiration is a key concept in agronomy. The objective of this study is to revisit this concept and discuss how it may be affected by processes locally influencing root hydraulic properties. A physical limitation to soil water availability in terms of maximal flow rate available to plant leaves (Qavail) is defined. It is expressed for isohydric plants, in terms of plant-centered variables and properties (the equivalent soil water potential sensed by the plant, ?s eq; the root system equivalent conductance, Krs; and a threshold leaf water potential, ?leaf lim). The resulting limitation to plant transpiration is compared to commonly used empirical stress functions. Similarities suggest that the slope of empirical functions might correspond to the ratio of Krs to the plant potential transpiration rate. The sensitivity of Qavail to local changes of root hydraulic conductances in response to soil matric potential is investigated using model simulations. A decrease of radial conductances when the soil dries induces earlier water stress, but allows maintaining higher night plant water potentials and higher Qavail during the last week of a simulated 1 month drought. In opposition, an increase of radial conductances during soil drying provokes an increase of hydraulic redistribution and Qavail at short term. This study offers a first insight on the effect of dynamic local root hydraulic properties on soil water availability. By better understanding complex interactions between hydraulic processes involved in soil-plant hydrodynamics, better prospects on how root hydraulic traits mitigate plant water stress might be achieved.

Couvreur, V.; Vanderborght, J.; Draye, X.; Javaux, M.

2014-11-01

289

Water quality investigation of Kingston Fossil Plant dry ash stacking  

SciTech Connect

Changing to a dry ash disposal systems at Kingston Fossil Plant (KFP) raises several water quality issues. The first is that removing the fly ash from the ash pond could alter the characteristics of the ash pond discharge to the river. The second concerns proper disposal of the runoff and possibly leachate from the dry ash stack. The third is that dry ash stacking might change the potential for groundwater contamination at the KFP. This report addresses each of these issues. The effects on the ash pond and its discharge are described first. The report is intended to provide reference material to TVA staff in preparation of environmental review documents for new ash disposal areas at Kingston. Although the investigation was directed toward analysis of dry stacking, considerations for other disposal options are also discussed. This report was reviewed in draft form under the title Assessment of Kingston Fossil Plant Dry Ash Stacking on the Ash Pond and Groundwater Quality.'' 11 refs., 3 figs., 18 tabs.

Bohac, C.E.

1990-04-01

290

Engineering the use of green plants to reduce produced water disposal volume.  

SciTech Connect

In 1990, the Laboratory began an investigation into biological approaches for the reduction of water produced from oil and gas wells. In the spring of 1995, the Company began an on-site experiment at an oil/gas lease in Oklahoma using one of these approaches. The process, known as phytoremediation, utilizes the ability of certain salt tolerant plants to draw the produced water through their roots, transpire the water from their leaves, and thereby reduce overall water disposal volumes and costs. At the Company experimental site, produced water flows through a trough where green plants (primarily cordgrass) have been planted in pea gravel. The produced water is drawn into the plant through its roots, evapotranspirates and deposits a salt residue on the plant leaves. The plant leaves are then harvested and used by a local rancher as cattle feed. The produced water is tested to assure it contains nothing harmful to cattle. In 1996, the Company set up another trough to compare evaporation rates using plants versus using an open container without plants. Data taken during all four seasons (water flow rate, temperature, pH, and conductivity) have shown that using plants to evapotranspirate produced water is safe, more cost effective than traditional methods and is environmentally sound.

Hinchman, R.; Mollock, G. N.; Negri, M. C.; Settle, T.

1998-01-29

291

Optimal Thermolysis Conditions for Soil Carbon Storage on Plant Residue Burning: Modeling the Trade-Off between Thermal Decomposition and Subsequent Biodegradation.  

PubMed

Field burning of plant biomass is a widespread practice that provides charred materials to soils. Its impact on soil C sequestration remains unclear due to the heterogeneity of burning products and difficulty in monitoring the material's biodegradation in fields. Basic information is needed on the relationship between burning conditions and the resulting quantity/quality of residue-derived C altered by thermal decomposition and biodegradation. In this study, we thermolyzed residues (rice straw and husk) at different temperatures (200-600°C) under two oxygen availability conditions and measured thermal mass loss, C compositional change by solid-state C NMR spectroscopy, and biodegradability of the thermally altered residues by laboratory aerobic incubation. A trade-off existed between thermal and microbial decomposition: when burned at higher temperatures, residues experience a greater mass loss but become more recalcitrant via carbonization. When an empirical model accounting for the observed trade-off was projected over 10 to 10 yr, we identified the threshold temperature range (330-400°C) above and below which remaining residue C is strongly reduced. This temperature range corresponded to the major loss of O-alkyl C and increase in aromatic C. The O/C molar ratios of the resultant residues decreased to 0.2 to 0.4, comparable to those of chars in fire-prone field soils reported previously. Although the negative impacts of biomass burning need to be accounted for, the observed relationship may help to assess the long-term fate of burning-derived C and to enhance soil C sequestration. PMID:25602338

Kajiura, Masako; Wagai, Rota; Hayashi, Kentaro

2015-01-01

292

Rangeland - plant responses to elevated CO{sub 2}. Final report, October 1988--October 1993  

SciTech Connect

Research is described on plant (tallgrass) response to elevated carbon dioxide. Variables addressed include biomass production, as well as water use efficiency, photosynthetic capacity, decomposition, nutrient cycling, and forage quality.

NONE

1997-05-01

293

Plants water status of the shelterbelt along the Tarim Desert Highway  

Microsoft Academic Search

The plant water consumption and irrigation management are the core issue of the sustainable growing of the Tarim Desert Highway\\u000a shelterbelt in the hyperaride Taklimakan Desert. The stem sap flow, water status and water consumption of shelterbelt plants\\u000a were studied, then, the issue of the water save in the process of shelterbelt irrigation management was discussed by measuring\\u000a the sap

Hao Xu; XiMing Zhang; HaiLong Yan; ShaoMin Liang; LiShan Shan

2008-01-01

294

Coupled Oxygen and Hydrogen Isotope Analysis of Water Along the Soil-Plant- Atmosphere Continuum  

NASA Astrophysics Data System (ADS)

The oxygen and hydrogen isotope compositions of water within a plant vary with transpiration rates and the isotopic composition of soil water. Both of these parameters are affected by temperature and relative humidity. A controlled-temperature, growth-chamber experiment was conducted to determine the relationships among temperature, relative humidity, soil water evaporation and plant-water isotope composition in cattails and horsetails. Typha, a cattail species that grows in wetland conditions, and Equisetum, a horsetail species that prefers dry soils, were each grown in four chambers at 15, 20, 25 and 30 degrees Celsius. The oxygen and hydrogen isotope compositions of watering water, soil water, vapour in the growth chambers and plant water from the leaves and stems were analyzed throughout the eight-month long artificial growing season. Although the oxygen isotope composition of the watering water remained constant, the soil water, atmospheric vapour and plant water were progressively enriched in oxygen-18 and deuterium in each of the four chambers from low to high temperatures as a result of increasing evaporation. The oxygen isotope composition of plant water along the length of a single stem or leaf was increasingly enriched in the heavier isotopes towards the apex. There was no significant difference in the magnitude of this trend between species. These results indicate that the isotopic composition of plant water is primarily controlled by environmental conditions. The oxygen isotope composition of the water vapour in the growing chamber increased with temperature, consistent with equilibration between the vapour and the oxygen-18 enriched soil and plant water reservoirs. The magnitude and interaction of these variables, as measured for these modern samples of cattails and horsetails, should be useful in calibrating paleoclimate proxies based on fossilized plant materials (e.g., cellulose, phytoliths).

Huang, Z.; Webb, E. A.; Longstaffe, F. J.

2008-12-01

295

Dioecy Impacts on Plant Water Fluxes in Riparian Ecosystems  

NASA Astrophysics Data System (ADS)

Dioecious plants are frequently associated with different spatial distributions of the two sexes across resource gradients. Segregation between sexes might be expected to occur if the cost of reproduction is greater in females than in males. If so, females would be under stronger selection to increase rates of resource uptake. Acer negundo is a dioecious riparian tree species that show spatial segregation among sexes: females are typically more common along streamside (high resource) environments than males. The spatial segregation of the sexes leads to the hypothesis that male and female individuals have varying influence on ecohydrological processes. To address this, we measured sap flux, water relations and hydraulic architecture of mature streamside (less than 1 m from stream channel) male and female Acer negundo trees occurring near Salt Lake City, Utah, USA during the 2004 growing season. Despite similar predawn and midday leaf water potentials, sap flux density ( Js) was 40 percent higher in female trees than in male trees during the 2004 growing season (n = 42 days, F = 73.56, P < 0.0001). Both genders showed a similar relationship between conducting sapwood area to stem diameter ratio suggesting that differences in Js scale to the whole tree level. Sap flux data from Acer negundo trees was compared to five other co-occurring riparian tree species. Female Acer negundo trees showed the highest Js among all species while Js in male Acer negundo trees was lower than all other species except one ( Acer grandidentatum). These data demonstrate that individual female Acer negundo trees have the capacity remove water at higher rates than males in high resource environments. The spatial segregation of the sexes along streamside environments may therefore have profound impacts on ecohydrological processes such as stream discharge, groundwater recharge, and nutrient cycling.

Hultine, K. R.; Bush, S. E.; West, A. G.; Ehleringer, J. R.

2005-12-01

296

Simulated acid rain alters litter decomposition and enhances the allelopathic potential of the invasive plant Wedelia trilobata (Creeping Daisy)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Invasive species and acid rain cause global environmental problems. Limited information exists, however, concerning the effects of acid rain on the invasiveness of these plants. For example, creeping daisy, an invasive exotic allelopathic weed, has caused great damage in southern China where acid ra...

297

[Pilot-scale study on riparian mixed plant zones treating polluted river water].  

PubMed

The polluted river water is treated with pilot-scale riparian zones of no aquatic plant, Vetiveria zizanioides + submerged plants, and weed+ Typha angustifolia L. + Phragmites communis. It is shown that the vegetation water zones are better than the no vegetation water zone and Vetiveria zizanioides + submerged plants zone is the best in improving water quality. The average removals of the Vetiveria zizanioides + submerged plant zone is 43.5% COD, 71.1% ammonia and 69.3% total phosphorus respectively. The dissolved oxygen (DO) and temperature of effluents from the three water zones are also investigated. It shows that DO of effluent from the vegetation zones are more stable than that of effluent from the no vegetation zone, and the temperature of the effluent from the vegetation zones are lower than that from the no vegetation zones. The submerged plants have special role in water quality improvement, and should be studied further. PMID:16767981

Li, Rui-hua; Guan, Yun-tao; He, Miao; Hu, Hong-yin; Jiang, Zhan-peng

2006-04-01

298

Water use at pulverized coal power plants with postcombustion carbon capture and storage.  

PubMed

Coal-fired power plants account for nearly 50% of U.S. electricity supply and about a third of U.S. emissions of CO(2), the major greenhouse gas (GHG) associated with global climate change. Thermal power plants also account for 39% of all freshwater withdrawals in the U.S. To reduce GHG emissions from coal-fired plants, postcombustion carbon capture and storage (CCS) systems are receiving considerable attention. Current commercial amine-based capture systems require water for cooling and other operations that add to power plant water requirements. This paper characterizes and quantifies water use at coal-burning power plants with and without CCS and investigates key parameters that influence water consumption. Analytical models are presented to quantify water use for major unit operations. Case study results show that, for power plants with conventional wet cooling towers, approximately 80% of total plant water withdrawals and 86% of plant water consumption is for cooling. The addition of an amine-based CCS system would approximately double the consumptive water use of the plant. Replacing wet towers with air-cooled condensers for dry cooling would reduce plant water use by about 80% (without CCS) to about 40% (with CCS). However, the cooling system capital cost would approximately triple, although costs are highly dependent on site-specific characteristics. The potential for water use reductions with CCS is explored via sensitivity analyses of plant efficiency and other key design parameters that affect water resource management for the electric power industry. PMID:21329343

Zhai, Haibo; Rubin, Edward S; Versteeg, Peter L

2011-03-15

299

Practical Application of Iterative Decomposition of Water and Fat with Echo Asymmetry and Least-Squares Estimation (IDEAL) Imaging in Minimizing Metallic Artifacts  

PubMed Central

Iterative decomposition of water and fat with echo asymmetry and the least-squares estimation (IDEAL) is a recently developed method for robust separation of fat and water with very high signal-to-noise-ratio (SNR) efficiency. In contrast to conventional fat-saturation methods, IDEAL is insensitive to magnetic field (B0 and B1) inhomogeneity. The aim of this study was to illustrate the practical application of the IDEAL technique in reducing metallic artifacts in postoperative patients with metallic hardware. The IDEAL technique can help musculoskeletal radiologists make an accurate diagnosis particularly in musculoskeletal imaging by reducing metallic artifacts, enabling the use of contrast enhancement, improving SNR performance, and providing various modes of MR images with one scan parameter. PMID:22563271

Hong, Hyun Sook; Park, Jai Soung; Paik, Sang Hyun; Lee, Hae Kyung

2012-01-01

300

Improvement of chemical control in the water-steam cycle of thermal power plants  

Microsoft Academic Search

A more effective chemical control in the water-steam cycle (WSC) of thermal power plants (TPP) is proposed in this paper. Minimization of corrosion effects by the production of ultra pure water and its strict control is the basis of all the investigated processes. The research involved the analysis of water samples in the WSC through key water quality parameters and

Vladana N. Rajakovi?-Ognjanovi?; Dragana Z. Živojinovic; Branimir N. Grgur; Ljubinka V. Rajakovi?

2011-01-01

301

Importance of permafrost as a source of water for plants in east Siberian taiga  

Microsoft Academic Search

Stable oxygen isotope ratios of plant water (sap water) were observed at Spasskaya Pad experimental forest near Yakutsk, Russia in 1997–1999. The ? 18O of sap water in larch trees ( Larix gmelinii) decreased soon after leaf unfolding every year, indicating that snowmelt water was used in the beginning of summer. During mid to late summer, a clear difference in

Atsuko Sugimoto; Nao Yanagisawa; Daisuke Naito; Noboru Fujita; Trofim C. Maximov

2002-01-01

302

Water relations of four perennial plant species at the southern periphery of the Taklimakan desert  

Microsoft Academic Search

The investigations started from the assumption that perennial plants in the foreland of river oases in the Taklimakan desert are able to take up water from soils of low water content and low water potential during long drought periods. In order to check this assumption, P-V curves were established and selected water relation parameters were derived. Alhagi sparsifolia, Calligonum caput-medusae,

XiangYi Li; LiSha Lin; FanJiang Zeng; XiMing Zhang

2011-01-01

303

Competition for nitrogen during decomposition of plant residues in soil: Effect of spatial placement of N-rich and N-poor plant residues  

Microsoft Academic Search

The distance between “hot spots” for N-mineralization (N-rich clover residues) and for N-immobilization (high C-to-N straw) in soil was experimentally manipulated to investigate its effect on the competition between plant roots and microorganisms for mineralized N. The experiment demonstrated that plant roots were reasonably competitive, resulting in deprivation of the N-supply to the microorganisms growing on the straw material, but

Wang Jingguo; Lars R. Bakken

1997-01-01

304

Trade-Offs in Resource Allocation Among Moss Species Control Decomposition in Boreal Peatlands  

SciTech Connect

We separated the effects of plant species controls on decomposition rates from environmental controls in northern peatlands using a full factorial, reciprocal transplant experiment of eight dominant bryophytes in four distinct peatland types in boreal Alberta, Canada. Standard fractionation techniques as well as compound-specific pyrolysis molecular beam mass spectrometry were used to identify a biochemical mechanism underlying any interspecific differences in decomposition rates. We found that over a 3-year field incubation, individual moss species and not micro-environmental conditions controlled early stages of decomposition. Across species, Sphagnum mosses exhibited a trade-off in resource partitioning into metabolic and structural carbohydrates, a pattern that served as a strong predictor of litter decomposition. Decomposition rates showed a negative co-variation between species and their microtopographic position, as species that live in hummocks decomposed slowly but hummock microhabitats themselves corresponded to rapid decomposition rates. By forming litter that degrades slowly, hummock mosses appear to promote the maintenance of macropore structure in surface peat hummocks that aid in water retention. Many northern regions are experiencing rapid climate warming that is expected to accelerate the decomposition of large soil carbon pools stored within peatlands. However, our results suggest that some common peatland moss species form tissue that resists decomposition across a range of peatland environments, suggesting that moss resource allocation could stabilize peatland carbon losses under a changing climate.

Turetsky, M. R.; Crow, S. E.; Evans, R. J.; Vitt, D. H.; Wieder, R. K.

2008-01-01

305

Evaluation of coal-gasification - combustion-turbine power plants emphasizing low water consumption  

SciTech Connect

A cost and performance study was made of several integrated power plants using coal gasification technology now in advanced development and combustion turbines for power generation. The principal emphasis was placed on studying plants using air cooling and comparing costs and performance of those plants with water-cooled coal gasification-combined-cycle (GCC) and conventional coal-fired power plants. The major objective was to determine whether cost and performance penalties would be prohibitive for air-cooled plants that use yet-to-be-developed coal gasifiers and commercially available combustion turbines for topping cycle power. The results indicate the following: air-cooled GCC plants using conceptual designs of either the Texaco or the British Gas Corporation (BGC) slaging gasifier could have coal-to-net electric power efficiencies equivalent to that of a water-cooled conventional coal-fired plant; the air-cooled GCC plants could produce electricity at busbar cost 1 to 3 mills per kWh (1980 dollars) less than busbar cost in a water-cooled conventional plant and only up to 2 mills per kWh higher than busbar cost in a water-cooled Texaco GCC plant; and even a simple-cycle regenerative combustion turbine plant fueled with gas from the BGC gasifier could have a coal-to-net electric power efficiency of over 30% and a busbar cost competitive with that in a water cooled conventional plant. The principal reason that air-cooled power plants using combustion turbines could be competitive with conventional water-cooled, coal-fired steam plants is that a majority of net power is produced by the combustion turbines, which require no cooling water. This, in turn, leads to a reduced cost and performance penalty when bottoming steam-cycle condensers are air-cooled.

Cavazo, R.; Clemmer, A.B.; de la Mora, J.A.; Grisso, J.R.; Klumpe, H.W.; Meissner, R.E.; Musso, A.; Roszkowski, T.R.

1982-01-01

306

Geographic, technologic, and economic analysis of using reclaimed water for thermoelectric power plant cooling.  

PubMed

Use of reclaimed water-municipal wastewater treatment plant effluent-in nonpotable applications can be a sustainable and efficient water management strategy. One such nonpotable application is at thermoelectric power plants since these facilities require cooling, often using large volumes of freshwater. To evaluate the geographic, technologic, and economic feasibility of using reclaimed water to cool thermoelectric power plants, we developed a spatially resolved model of existing power plants. Our model integrates data on power plant and municipal wastewater treatment plant operations into a combined geographic information systems and optimization approach to evaluate the feasibility of cooling system retrofits. We applied this broadly applicable methodology to 125 power plants in Texas as a test case. Results show that sufficient reclaimed water resources exist within 25 miles of 92 power plants (representing 61% of capacity and 50% of generation in our sample), with most of these facilities meeting both short-term and long-term water conservation cost goals. This retrofit analysis indicates that reclaimed water could be a suitable cooling water source for thermoelectric power plants, thereby mitigating some of the freshwater impacts of electricity generation. PMID:24625241

Stillwell, Ashlynn S; Webber, Michael E

2014-04-15

307

A series RCL circuit theory for analyzing non-steady-state water uptake of maize plants.  

PubMed

Understanding water uptake and transport through the soil-plant continuum is vital for ecosystem management and agricultural water use. Plant water uptake under natural conditions is a non-steady transient flow controlled by root distribution, plant configuration, soil hydraulics, and climatic conditions. Despite significant progress in model development, a mechanistic description of transient water uptake has not been developed or remains incomplete. Here, based on advanced electrical network theory (RLC circuit theory), we developed a non-steady state biophysical model to mechanistically analyze the fluctuations of uptake rates in response to water stress. We found that the non-steady-state model captures the nature of instantaneity and hysteresis of plant water uptake due to the considerations of water storage in plant xylem and coarse roots (capacitance effect), hydraulic architecture of leaf system (inductance effect), and soil-root contact (fuse effect). The model provides insights into the important role of plant configuration and hydraulic heterogeneity in helping plants survive an adverse environment. Our tests against field data suggest that the non-steady-state model has great potential for being used to interpret the smart water strategy of plants, which is intrinsically determined by stem size, leaf size/thickness and distribution, root system architecture, and the ratio of fine-to-coarse root lengths. PMID:25335512

Zhuang, Jie; Yu, Gui-Rui; Nakayama, Keiichi

2014-01-01

308

Improvement of growth rate of plants by bubble discharge in water  

NASA Astrophysics Data System (ADS)

The effect of bubble discharge in water on the growth rate of plants was investigated experimentally for application to plant cultivation systems. Spinach (Spinacia oleracea), radish (Raphanus sativus var. sativus), and strawberry (Fragaria × ananassa) were used as specimens to clarify the effect of the discharge treatment on edible parts of the plants. The specimens were cultivated in pots filled with artificial soil, which included chicken manure charcoal. Distilled water was sprayed on the artificial soil and drained through a hole in the pots to a water storage tank. The water was circulated from the water storage tank to the cultivation pots after 15 or 30 min discharge treatment on alternate days. A magnetic compression-type pulsed power generator was used to produce the bubble discharge with a repetition rate of 250 pps. The plant height in the growth phase and the dry weight of the harvested plants were improved markedly by the discharge treatment in water. The soil and plant analyzer development (SPAD) value of the plants also improved in the growth phase of the plants. The concentration of nitrate nitrogen, which mainly contributed to the improvement of the growth rate, in the water increased with the discharge treatment. The Brix value of edible parts of Fragaria × ananassa increased with the discharge treatment. The inactivation of bacteria in the water was also confirmed with the discharge treatment.

Takahata, Junichiro; Takaki, Koichi; Satta, Naoya; Takahashi, Katsuyuki; Fujio, Takuya; Sasaki, Yuji

2015-01-01

309

Study on precision water-saving irrigation automatic control system by plant physiology  

Microsoft Academic Search

Olympic games in 2008 is not only a world sports event, but also a great opportunity to show our current level of economic development and modern science and technology strength. Precision water-saving irrigation automatic control system by plant physiology this paper described is one of the Olympic games facilities projects, which takes standards of water plant physiologically need and soil

Yandong Zhao; Junfu Zhang; Jinfeng Guan; Weilun Yin

2009-01-01

310

Soil and plant water relations in a crested wheatgrass pasture: response to spring grazing by cattle  

Microsoft Academic Search

Few field studies have attempted to relate effects of actual livestock grazing on soil and plant water status. The present study was initiated to determine the effects of periodic defoliations by cattle during spring on soil moisture and plant water status in a crested wheatgrass (Agropyron cristatum (L.) Gaertn. and A. desertorum (Fisch. ex Link) Schult.) pasture in central Utah.

J. M. Wraith; D. A. Johnson; R. J. Hanks; D. V. Sisson

1987-01-01

311

Ground performance of air conditioning and water recycle system for a space plant box  

NASA Astrophysics Data System (ADS)

Researchers from 5 Japanese universities have developed a plant growth facility (Space Plant Box) for seed to seed experiments under microgravity. The breadboard model of the Space Plant Box was fabricated by assembling subsystems developed for microgravity. The subsystems include air conditioning and water recycle system, air circulation system, water and nutrient delivery system, lighting system and plant monitoring system. The air conditioning and water recycle system is simply composed of a single heat exchanger, two fans and hydrophilic fibrous strings. The strings allow water movement from the cooler fin in the Cooling Box to root supporting materials in the Plant Growth Chamber driven by water potential deficit. Relative humidity in the Plant Growth Chamber can be changed over a wide range by controlling the ratio of latent heat exchange to sensible heat exchange on the cooling fin of the heat exchanger. The transpiration rate was successfully measured by circulating air inside the Plant Growth Chamber only. Most water was recycled and a small amount of water needed to be added from the outside. The simple, air conditioning and water recycle system for the Space Plant Box showed good performance through a barley ( Hordeum vulgare L.) growth experiment.

Tani, A.; Okuma, T.; Goto, E.; Kitaya, Y.; Saito, T.; Takahashi, H.

312

A Series RCL Circuit Theory for Analyzing Non-Steady-State Water Uptake of Maize Plants  

PubMed Central

Understanding water uptake and transport through the soil-plant continuum is vital for ecosystem management and agricultural water use. Plant water uptake under natural conditions is a non-steady transient flow controlled by root distribution, plant configuration, soil hydraulics, and climatic conditions. Despite significant progress in model development, a mechanistic description of transient water uptake has not been developed or remains incomplete. Here, based on advanced electrical network theory (RLC circuit theory), we developed a non-steady state biophysical model to mechanistically analyze the fluctuations of uptake rates in response to water stress. We found that the non-steady-state model captures the nature of instantaneity and hysteresis of plant water uptake due to the considerations of water storage in plant xylem and coarse roots (capacitance effect), hydraulic architecture of leaf system (inductance effect), and soil-root contact (fuse effect). The model provides insights into the important role of plant configuration and hydraulic heterogeneity in helping plants survive an adverse environment. Our tests against field data suggest that the non-steady-state model has great potential for being used to interpret the smart water strategy of plants, which is intrinsically determined by stem size, leaf size/thickness and distribution, root system architecture, and the ratio of fine-to-coarse root lengths. PMID:25335512

Zhuang, Jie; Yu, Gui-Rui; Nakayama, Keiichi

2014-01-01

313

The search for optimum condenser cooling water flow rate in a thermal power plant  

Microsoft Academic Search

Heat losses from the thermal power plant cycle are due mainly to heat rejection through the condenser. Operating the condenser at optimum circulation water flowrate is essentially important to ensure maximum efficiency and minimum operating cost of the plant. In this study, computer program codes were developed in Microsoft Excel macros for simulation of a thermal plant at various circulation

A. N. Anozie; O. J. Odejobi

2011-01-01

314

Effects of Static versus Flowing Water on Aquatic Plant Preferences of Triploid Grass Carp  

Microsoft Academic Search

Triploid grass carp Ctenopharyngodon idella were presented with three aquatic plant species (sago pondweed Potamogeton pectinatus, Eurasian watermilfoil Myriophyllum spicatum, and American pondweed P. nodosus) in outdoor canals with static and flowing water in winter, spring, and summer. Plant consumption by triploid grass carp in winter was low but increased dramatically in spring and summer. Based on plant shoot lengths,

Robert T. Pine; Lars W. J. Anderson; Silas S. O. Hung

1989-01-01

315

Carbohydrate partitioning in relation to whole plant production and water use of Vigna unguiculata (L.) Walp  

Microsoft Academic Search

Increases in plant biomass are mainly a balance between growth of new leaves and growth of new roots, the new leaves having positive feedback upon the production process and the new roots having positive feedback upon the plant water status. Control of both opposing processes with respect to biomass production may be considered optimal whenever biomass of the plant reaches

E. D. Schulze; K. Schilling; S. Nagarajah

1983-01-01

316

MAGNITUDE AND MECHANISMS OF DISEQUILIBRIUM BETWEEN PREDAWN PLANT AND SOIL WATER POTENTIALS  

Microsoft Academic Search

Predawn plant water potential (Cw, measured with leaf psychrometers) and surrogate measurements made with the pressure chamber (termed Cpc here) are used to infer comparative ecological performance, based on the expectation that these plant po- tentials reflect the wettest soil Cw accessed by roots. There is growing evidence, however, that some species exhibit substantial predawn disequilibrium (PDD), defined as plant

Lisa A. Donovan; James H. Richards; Matthew J. Linton

2003-01-01

317

Plant nitrogen uptake drives responses of productivity to nitrogen and water addition in a grassland  

PubMed Central

Increased atmospheric nitrogen (N) deposition and altered precipitation regimes have profound impacts on ecosystem functioning in semiarid grasslands. The interactions between those two factors remain largely unknown. A field experiment with N and water additions was conducted in a semiarid grassland in northern China. We examined the responses of aboveground net primary production (ANPP) and plant N use during two contrasting hydrological growing seasons. Nitrogen addition had no impact on ANPP, which may be accounted for by the offset between enhanced plant N uptake and decreased plant nitrogen use efficiency (NUE). Water addition significantly enhanced ANPP, which was largely due to enhanced plant aboveground N uptake. Nitrogen and water additions significantly interacted to affect ANPP, plant N uptake and N concentrations at the community level. Our observations highlight the important role of plant N uptake and use in mediating the effects of N and water addition on ANPP. PMID:24769508

Lü, Xiao-Tao; Dijkstra, Feike A.; Kong, De-Liang; Wang, Zheng-Wen; Han, Xing-Guo

2014-01-01

318

Evaluation of Effectiveness Technological Process of Water Purification Exemplified on Modernized Water Treatment Plant at Otoczna  

NASA Astrophysics Data System (ADS)

The article presents the work of the Water Treatment Plant in the town of Otoczna, located in the Wielkopolska province, before and after the modernization of the technological line. It includes the quality characteristics of the raw water and treated water with particular emphasis on changes in the quality indicators in the period 2002 -2012 in relation to the physicochemical parameters: the content of total iron and total manganese, the ammonium ion as well as organoleptic parameters(colour and turbidity). The efficiency of technological processes was analysed, including the processes of bed start up with chalcedonic sand to remove total iron and manganese and ammonium ion. Based on the survey, it was found that the applied modernization helped solve the problem of water quality, especially the removal of excessive concentrations of iron, manganese and ammonium nitrogen from groundwater. It has been shown that one year after modernization of the technological line there was a high reduction degree of most parameters, respectively for the general iron content -99%, general manganese - 93% ammonia - 93%, turbidity - 94%. It has been proved, that chalcedonic turned out to be better filter material than quartz sand previously used till 2008. The studies have confirmed that the stage of modernization was soon followed by bed start-up for removing general iron from the groundwater. The stage of manganese removal required more time, about eight months for bed start-up. Furthermore, the technological modernization contributed to the improvement of the efficiency of the nitrification process.

Jordanowska, Joanna; Jakubus, Monika

2014-12-01

319

Coxiella burnetii in sewage water at sewage water treatment plants in a Q fever epidemic area.  

PubMed

During 2007-2010, over 4000 persons in The Netherlands contracted Q-fever, a zoonosis caused by the bacterium Coxiella burnetii. Goats and sheep are the main reservoir of C. burnetti and infected animals shed the bacterium with their urine, faeces and birth products. Human infections may occur through direct contact with infected animals, or through inhalation of contaminated dust particles or aerosols. Discharge of waste water from Q fever contaminated goat farms may result in the presence of C. burnetii in sewage water and aerosols at sewage water treatment plants (SWTPs) which may pose a health risk for workers or neighbouring residents. The objectives of this study were to determine the presence of C. burnetii at SWTPs and to optimize available detection methods. In March-July 2011, sewage influent and aeration tank samples from four SWTPs receiving discharge from Q fever positive goat farms were examined by using a multiplex real-time PCR detecting C. burnetii DNA by targeting IS1111 and com1 genes. Influent (44%; n=16/36) and active sludge (36%; n=13/36) samples were positive with low C. burnetii DNA content. Percentage positive samples per SWTP were 28-61%. Positive samples were most frequent in March 2011 and least frequent in May 2011. The presence of C. burnetii DNA in sewage water samples suggests that SWTPs receiving waste water from Q fever contaminated goat farms may contribute to the spread of C. burnetii to the environment. The low levels of C. burnetii DNA in sewage water during the decline of the Q fever outbreak in The Netherlands in 2011 indicate a low health risk for SWTP workers and residents. PMID:23347968

Schets, F M; de Heer, L; de Roda Husman, A M

2013-11-01

320

Water uptake, water use efficiency, plant growth and ionic balance of wheat, barley, canola and chickpea plants on a sodic vertosol with variable subsoil NaCl salinity  

Microsoft Academic Search

Salinity in topsoil and subsoil is one of the major abiotic environmental stresses to crop production. To investigate the comparative tolerance ability of wheat, barley, canola and chickpea to subsoil NaCl salinity and its impact on water uptake, water use efficiency, plant growth and ionic balance, a pot experiment was conducted on a heavy texture soil (sodic vertosol) having 20

Harsharn Singh Grewal

2010-01-01

321

Prevention and mitigation of steam-generator water-hammer events in PWR plants  

SciTech Connect

Water hammer in nuclear power plants is an unresolved safety issue under study at the NRC (USI A-1). One of the identified safety concerns is steam generator water hammer (SGWH) in pressurized-water reactor (PWR) plants. This report presents a summary of: (1) the causes of SGWH; (2) various fixes employed to prevent or mitigate SGWH; and (3) the nature and status of modifications that have been made at each operating PWR plant. The NRC staff considers that the issue of SGWH in top feedring designs has been technically resolved. This report does not address technical findings relevant to water hammer in preheat type steam generators. 10 figures, 2 tables.

Han, J.T.; Anderson, N.

1982-11-01

322

Optimization under Uncertainty for Water Consumption in a Pulverized Coal Power Plant  

SciTech Connect

Pulverized coal (PC) power plants are widely recognized as major water consumers whose operability has started to be affected by drought conditions across some regions of the country. Water availability will further restrict the retrofitting of existing PC plants with water-expensive carbon capture technologies. Therefore, national efforts to reduce water withdrawal and consumption have been intensified. Water consumption in PC plants is strongly associated to losses from the cooling water cycle, particularly water evaporation from cooling towers. Accurate estimation of these water losses requires realistic cooling tower models, as well as the inclusion of uncertainties arising from atmospheric conditions. In this work, the cooling tower for a supercritical PC power plant was modeled as a humidification operation and used for optimization under uncertainty. Characterization of the uncertainty (air temperature and humidity) was based on available weather data. Process characteristics including boiler conditions, reactant ratios, and pressure ratios in turbines were calculated to obtain the minimum water consumption under the above mentioned uncertainties. In this study, the calculated conditions predicted up to 12% in reduction in the average water consumption for a 548 MW supercritical PC power plant simulated using Aspen Plus. Optimization under uncertainty for these large-scale PC plants cannot be solved with conventional stochastic programming algorithms because of the computational expenses involved. In this work, we discuss the use of a novel better optimization of nonlinear uncertain systems (BONUS) algorithm which dramatically decreases the computational requirements of the stochastic optimization.

Juan M. Salazar; Stephen E. Zitney; Urmila Diwekar

2009-01-01

323

Optimization Under Uncertainty for Water Consumption in a Pulverized Coal Power Plant  

SciTech Connect

Pulverized coal (PC) power plants are widely recognized as major water consumers whose operability has started to be affected by drought conditions across some regions of the country. Water availability will further restrict the retrofitting of existing PC plants with water-expensive carbon capture technologies. Therefore, national efforts to reduce water withdrawal and consumption have been intensified. Water consumption in PC plants is strongly associated to losses from the cooling water cycle, particularly water evaporation from cooling towers. Accurate estimation of these water losses requires realistic cooling tower models, as well as the inclusion of uncertainties arising from atmospheric conditions. In this work, the cooling tower for a supercritical PC power plant was modeled as a humidification operation and used for optimization under uncertainty. Characterization of the uncertainty (air temperature and humidity) was based on available weather data. Process characteristics including boiler conditions, reactant ratios, and pressure ratios in turbines were calculated to obtain the minimum water consumption under the above mentioned uncertainties. In this study, the calculated conditions predicted up to 12% in reduction in the average water consumption for a 548 MW supercritical PC power plant simulated using Aspen Plus. Optimization under uncertainty for these large-scale PC plants cannot be solved with conventional stochastic programming algorithms because of the computational expenses involved. In this work, we discuss the use of a novel better optimization of nonlinear uncertain systems (BONUS) algorithm which dramatically decreases the computational requirements of the stochastic optimization.

Juan M. Salazara; Stephen E. Zitney; Urmila M. Diwekara

2009-01-01

324

Optimal plant water use across temporal scales: bridging eco-hydrological theories and plant eco-physiological responses  

NASA Astrophysics Data System (ADS)

In terrestrial ecosystems, plant photosynthesis occurs at the expense of water losses through stomata, thus creating an inherent hydrologic constrain to carbon (C) gains and productivity. While such a constraint cannot be overcome, evolution has led to a number of adaptations that allow plants to thrive under highly variable and often limiting water availability. It may be hypothesized that these adaptations are optimal and allow maximum C gain for a given water availability. A corollary hypothesis is that these adaptations manifest themselves as coordination between the leaf photosynthetic machinery and the plant hydraulic system. This coordination leads to functional relations between the mean hydrologic state, plant hydraulic traits, and photosynthetic parameters that can be used as bridge across temporal scales. Here, optimality theories describing the behavior of stomata and plant morphological features in a fluctuating soil moisture environment are proposed. The overarching goal is to explain observed global patterns of plant water use and their ecological and biogeochemical consequences. The problem is initially framed as an optimal control problem of stomatal closure during drought of a given duration, where maximizing the total photosynthesis under limited and diminishing water availability is the objective function. Analytical solutions show that commonly used transpiration models (in which stomatal conductance is assumed to depend on soil moisture) are particular solutions emerging from the optimal control problem. Relations between stomatal conductance, vapor pressure deficit, and atmospheric CO2 are also obtained without any a priori assumptions under this framework. Second, the temporal scales of the model are expanded by explicitly considering the stochasticity of rainfall. In this context, the optimal control problem becomes a maximization problem for the mean photosynthetic rate. Results show that to achieve maximum C gains under these unpredictable rainfall conditions, plant hydraulic traits (xylem and stomatal response to water availability) and morphological features (leaf and sapwood areas) must be coordinated - thus providing an ecohydrological interpretation of observed coordination (or homeostasis) among hydraulic traits. Moreover, the combinations of hydraulic traits and responses to drought that are optimal are found to depend on both total rainfall and its distribution during the growing season. Both drier conditions and more intense rainfall events interspaced by longer dry periods favor plants with high resistance to cavitation and delayed stomatal closure as soils dry. In contrast, plants in mesic conditions benefit from cavitation prevention through earlier stomatal closure. The proposed ecohydrological optimality criteria can be used as analytical tools to interpret variability in plant water use and predict trends in plant productivity and species composition under future climates.

Manzoni, S.; Vico, G.; Palmroth, S.; Katul, G. G.; Porporato, A. M.

2013-12-01

325

Beyond hypoxia: occurrence and characteristics of black blooms due to the decomposition of the submerged plant Potamogeton crispus in a shallow lake.  

PubMed

Organic matter-induced black blooms (hypoxia and an offensive odor) are a serious ecosystem disasters that have occurred in some large eutrophic shallow lakes in China. In this study, we investigated two separate black blooms that were induced by Potamogeton crispus in Lake Taihu, China. The main physical and chemical characteristics, including color- and odor-related substances, of the black blooms were analyzed. The black blooms were characterized by low dissolved oxygen concentration (close to 0 mg/L), low oxidation-reduction potential, and relatively low pH of overlying water. Notably higher Fe2+ and sigmaS(2-) were found in the black-bloom waters than in waters not affected by black blooms. The black color of the water may be attributable to the high concentration of these elements, as black FeS was considered to be the main substance causing the black color of blooms in freshwater lakes. Volatile organic sulfur compounds, including dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide, were very abundant in the black-bloom waters. The massive anoxic degradation of dead Potamogeton crispus plants released dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide, which were the main odor-causing compounds in the black blooms. The black blooms also induced an increase in ammonium nitrogen and soluble reactive phosphorus levels in the overlying waters. This extreme phenomenon not only heavily influenced the original lake ecosystem but also greatly changed the cycling of Fe, S, and nutrients in the water column. PMID:25076519

Shen, Qiushi; Zhou, Qilin; Shang, Jingge; Shao, Shiguang; Zhang, Lei; Fan, Chengxin

2014-02-01

326

Decomposition of white clover ( Trifolium repens) and ryegrass ( Lolium perenne) components: C and N dynamics simulated with the DAISY soil organic matter submodel  

Microsoft Academic Search

Using data from a decomposition study, we aimed to test the parameterisation of the soil organic matter module of the DAISY model, and link measurable plant litter fractions (lignin, water-soluble) with the model defined plant litter pools. Shoot and root material from perennial ryegrass and white clover was incubated in a sandy loam soil at 9 °C for 94 days.

Andreas de Neergaard; Henrik Hauggaard-Nielsen; Lars Stoumann Jensen; Jakob Magid

2002-01-01

327

POWER PLANT COOLING WATER CHLORINATION IN NORTHERN CALIFORNIA  

EPA Science Inventory

A survey was conducted of chlorination practices at five power plants owned and operated by the Pacific Gas and Electric Company. Frequency and duration of chlorination varied significantly from plant to plant and was controlled analytically by the orthotolidine and/or amperometr...

328

RESPONSES OF WETLAND PLANTS TO EFFLUENTS IN WATER & SEDIMENT  

EPA Science Inventory

Responses of two wetland vascular plants, Echinochloa crusgalli and Sesbania macrocarpa, exposed to effluents from a coke plant, a pulp mill, a wastewater treatment plant, and the herbicide, hexazinone, were measured in three types of tests: seed germination and early growth, see...

329

Ameliorative Effect of Calcium Nitrate on Cucumber and Melon Plants Drip Irrigated with Saline Water  

Microsoft Academic Search

Cucumber (Cucumis sativus cv. Orlando) and melon (Cucumis melo cv. Ananas) were field grown to investigate the effects of supplementary calcium nitrate applied to irrigation water on plant growth and fruit yield of salt stressed and unstressed cucumber and melon plants. Treatments were (1) control: normal irrigation water (C); (2) normal irrigation water plus supplementary 5 mM Ca(NO3)2 added to the

Cengiz Kaya; David Higgs; Halil Kirnak; Ismail Tas

2003-01-01

330

Study of the ionome and uptake fluxes in cherry tomato plants under moderate water stress conditions  

Microsoft Academic Search

Nutritional imbalance under water-deficit conditions depresses plant growth by affecting nutrient uptake, transport, and distribution.\\u000a The present work analyses the variations in the foliar concentrations of macro- and micronutrients as well as the transport\\u000a of these nutrients in five cherry tomato cultivars under well-watered and moderately water-stressed conditions with the aim\\u000a of establishing whether the ionome of the plants is

Eva Sánchez-Rodríguez; Maria del Mar Rubio-Wilhelmi; Luis Miguel Cervilla; Begoña Blasco; Juan Jose Rios; Rocio Leyva; Luis Romero; Juan Manuel Ruiz

2010-01-01

331

Combined production of electrical power and desalinated water by nuclear power plants  

Microsoft Academic Search

Processes suitable for dual-purpose nuclear power plants generating electric power and fresh water supplies via desalination of sea water are described. Fresh water resources and demands are graphed for Italian regions (central-north, south, islands). Desalination processes are described and compared (multiple flash, thermocompression, multiple-effect evaporator, electrodialysis, ion exchange, back-osmosis, brine recycling, solvent extraction, freezing), and flowsheets of some dual-purpose plants

M. Marena; M. Nordio; R. Senis

1976-01-01

332

A biomarker based on gene expression indicates plant water status in controlled and natural environments.  

PubMed

Plant or soil water status is required in many scientific fields to understand plant responses to drought. Because the transcriptomic response to abiotic conditions, such as water deficit, reflects plant water status, genomic tools could be used to develop a new type of molecular biomarker. Using the sunflower (Helianthus annuus L.) as a model species to study the transcriptomic response to water deficit both in greenhouse and field conditions, we specifically identified three genes that showed an expression pattern highly correlated to plant water status as estimated by the pre-dawn leaf water potential, fraction of transpirable soil water, soil water content or fraction of total soil water in controlled conditions. We developed a generalized linear model to estimate these classical water status indicators from the expression levels of the three selected genes under controlled conditions. This estimation was independent of the four tested genotypes and the stage (pre- or post-flowering) of the plant. We further validated this gene expression biomarker under field conditions for four genotypes in three different trials, over a large range of water status, and we were able to correct their expression values for a large diurnal sampling period. PMID:23639099

Marchand, Gwenaëlle; Mayjonade, Baptiste; Varès, Didier; Blanchet, Nicolas; Boniface, Marie-Claude; Maury, Pierre; Nambinina Andrianasolo, Fety; Nambinina, Fety Andrianasolo; Burger, Philippe; Debaeke, Philippe; Casadebaig, Pierre; Vincourt, Patrick; Langlade, Nicolas B

2013-12-01

333

[Genotoxicity of surface water treated with different disinfectants using in situ plant tests].  

PubMed

Disinfection of surface drinking water, in particular water chlorination, produces many by-products with genotoxic and/or carcinogenic activity. The aim of this research was to evaluate the genotoxicity of surface water after treatment with different disinfectants by means of in situ plant genotoxicity assays. The study was carried out in a pilot plant using lake water after sedimentation and filtration, which supplied four stainless steel basins: three basins were disinfected with sodium hypochlorite, chlorine dioxide and peracetic acid, respectively, and the fourth basin contained untreated lake water and was used as a control. The study was carried out using water collected in different seasons over a period of about one year in order to assess the treatments under different physical and chemical lake water conditions. Plant genotoxicity tests were performed by exposing plant bioindicators directly to raw and disinfected water. The Tradescantia micronucleus test in pollen cells of the flowers of an hybrid of Tradescantia and the Allium cepa test, a chromosome aberration test in root cells of Allium cepa, showed genotoxic effects only in some disinfected samples and revealed genotoxicity also in raw water in one experiment. The Vicia faba test, a micronucleus test in root cells of Vicia faba, revealed genotoxicity in many samples of disinfected water. The results of the study indicated that the Vicia faba/MCN test was the most sensitive plant assay for disinfected water, and that peracetic acid disinfection produced lower genotoxicity than sodium hypochlorite or chlorine dioxide treatment. PMID:15049553

Alberti, A; Tizzoni, M; Zani, C; Feretti, D; Gustavino, B; Zerbini, I; Nardi, G; Monarca, S

2003-01-01

334

Combined treatment of coke-plant waste water and blast furnace blowdown water in a coupled biological fluidized bed system  

Microsoft Academic Search

The technical and economic feasibility of treating a combined stream of coke plant waste water and blast furnace blowdown water in a coupled fluidised bed process, operated in the denitrification-denitrification flow mode, was evaluated. More than 90% removal of total nitrogen was achieved at a total system hydraulic retention time of 4.5 h. Removal of other conventional contaminants, including filtered

Melcer

1984-01-01

335

Plant Anatomy and Reproduction Plants have three main parts Absorb water  

E-print Network

division, delay aging, and help direct plant organ growth Abscisic acid initiates dormancy, closes stomata. Angiosperm Seeds Seeds open to the outside Seeds NOT open to outside #12;6 Plant Growth Primary Growth Secondary Growth Plant Responses #12;7 Gravitropism above; phototropism to the right Plant Hormones Many

Brown, Christopher A.

336

Withdrawal and consumption of water by thermoelectric power plants in the United States, 2010  

USGS Publications Warehouse

An analysis of 2005 and 2010 EIA-reported water use indicated that withdrawal and consumption declined 18 percent and 34 percent, respectively. Alternative water types (types other than freshwater) accounted for approximately 25 percent of all withdrawals in 2010, most of which occurred at plants with once-through cooling systems using saline and brackish tidal waters. Differences among withdrawal and consumption coefficients based on EIA-reported water use for 2005 and 2010 and heat-budget model results for 2010 reveal opportunities for improving consistency and accuracy of reporting of water-use information at the plant scale.

Diehl, Timothy H.; Harris, Melissa A.

2014-01-01

337

Water impacts of CO2 emission performance standards for fossil fuel-fired power plants.  

PubMed

We employ an integrated systems modeling tool to assess the water impacts of the new source performance standards recently proposed by the U.S. Environmental Protection Agency for limiting CO2 emissions from coal- and gas-fired power plants. The implementation of amine-based carbon capture and storage (CCS) for 40% CO2 capture to meet the current proposal will increase plant water use by roughly 30% in supercritical pulverized coal-fired power plants. The specific amount of added water use varies with power plant and CCS designs. More stringent emission standards than the current proposal would require CO2 emission reductions for natural gas combined-cycle (NGCC) plants via CCS, which would also increase plant water use. When examined over a range of possible future emission standards from 1100 to 300 lb CO2/MWh gross, new baseload NGCC plants consume roughly 60-70% less water than coal-fired plants. A series of adaptation approaches to secure low-carbon energy production and improve the electric power industry's water management in the face of future policy constraints are discussed both quantitatively and qualitatively. PMID:25229670

Talati, Shuchi; Zhai, Haibo; Morgan, M Granger

2014-10-21

338

Impacts of oil sands process water on fen plants: implications for plant selection in required reclamation projects.  

PubMed

Fen plant growth in peat contaminated with groundwater discharges of oil sands process water (OSPW) was assessed in a greenhouse over two growing seasons. Three treatments (non-diluted OSPW, diluted OSPW and rainwater) were tested on five vascular plants and four mosses. All vascular plants tested can grow in salinity and naphthenic acids levels currently produced by oil sands activity in northwestern Canada. No stress sign was observed after both seasons. Because of plant characteristics, Carex species (C. atherodes and C. utriculata) and Triglochin maritima would be more useful for rapidly restoring vegetation and creating a new peat-accumulating system. Groundwater discharge of OSPW proved detrimental to mosses under dry conditions and ensuring adequate water levels would be crucial in fen creation following oil sands exploitation. Campylium stellatum would be the best choice to grow in contaminated areas and Bryum pseudotriquetrum might be interesting as it has spontaneously regenerated in all treatments. PMID:22575093

Pouliot, Rémy; Rochefort, Line; Graf, Martha D

2012-08-01

339

Comparing actual evapotranspiration and plant water potential on a vineyard  

Microsoft Academic Search

Agricultural water requirement in arid and semi-arid environments represents an important fraction of the total water consumption, suggesting the need of appropriate water management practices to sparingly use the resource. Furthermore the quality and quantity of some crops products, such as grape, is improved under a controlled amount of water stress. The latter is related, on a side to actual

Antonino Maltese; Carmelo Cammalleri; Fulvio Capodici; Giuseppe Ciraolo; Francesco Colletti; Goffredo La Loggia; Tanino Santangelo

2011-01-01

340

Coupled Soil-Plant Water Dynamics During Drought-Rewetting Transitions  

NASA Astrophysics Data System (ADS)

The predicted climate and land-use changes could have dramatic effects on the water balance of the soil-vegetation system, particularly under frequent drought and subsequent rewetting conditions. Yet, estimation of these effects and associated consequences for the structure and functioning of ecosystems, groundwater recharge, drinking water availability, and the water cycle is currently impeded by gaps in our understanding of the spatiotemporal dynamics of soil water in the rooted soil horizons, the dynamics and driving physiological processes of plant water acquisition, and the transpiration from plant leaves under changing environmental conditions. Combining approaches from the disciplines of plant ecophysiology and soil and isotope hydrology, this work aims to fill this gap by quantitatively characterizing the interaction between plant water use - as affected by rooting patterns and ecophysiology of different plant functional groups - and the water balance of variably complex ecosystems with emphasis on drought and rewetting phases. Results from artificial drought and subsequent rewetting in field experiments using isotopically and dye (Brilliant Blue FCF) labeled water conducted on plots of various surface cover (bare soil, grass, beech, oak, vine) established on luvisol on loess in southwestern Germany are presented. Detailed spatiotemporal insights into the coupled short-term (hours to days) dynamics of soil and plant water during the experiments is facilitated by the application of newly developed techniques for high-frequency in-situ monitoring of stable isotope signatures in both pore water and transpired water using commercial laser-based spectrometers in conjunction with plant ecophysiological, soil physical state, and dye staining observations. On the one hand, the spatiotemporal patterns of plant water uptake are assessed and related to morphological and physiological traits driving plant water uptake, functional adaptations of plants to changes of soil water availability, and intra- and interspecies competition for water resources access. On the other hand, the effects of vegetation cover on infiltration, preferential flow paths characteristics, and soil water storage in the rooted soil horizons are investigated. The results of the experiments and the developed methodology will contribute to an improved understanding of ecosystem response and adaptation to drought and short-term changes in environmental conditions.

Volkmann, T. H.; Haberer, K.; Gessler, A.; Weiler, M.

2013-12-01

341

POTASSIUM SULFATE IMPROVES WATER DEFICIT TOLERANCE IN MELON PLANTS GROWN UNDER GLASSHOUSE CONDITIONS  

Microsoft Academic Search

Interactive effects of water stress and potassium (K) on some physiological attributes and nutritional status of melon (Cucumis melo L. cv. ‘Tempo F1’) plants were assessed in a pot experiment. Treatments used were: (1) control or well-watered (WW) + K1, (2) WW + K2, (3) WW + K3, (4) water stress (WS) + K1, (5) WS + K2, and (6)

A. Levent Tuna; Cengiz Kaya; Muhammad Ashraf

2010-01-01

342

Continuous measurement of plant and soil water status for irrigation scheduling in plum  

Microsoft Academic Search

The usefulness of continuous measurement of soil and plant water status for automated irrigation scheduling was studied in a drip-irrigation experiment on plum ( Prunus salicina Black Gold). Two levels of water restriction were imposed at different phenological periods (from pit-hardening to harvest, post-harvest) and compared with a well irrigated control treatment. Soil matrix water potential ( ? soil) was

D. S. Intrigliolo; J. R. Castel

2004-01-01

343

A simulation model of plant water relations and production in the alpine tundra, Colorado  

Microsoft Academic Search

A model to predict the daily courses of leaf resistance, leaf water potential, transpiration, leaf temperature and net photosynthesis based on soil-plant-atmosphere continuum and energy budget concepts is presented. The principle water relations parameters required by the model are the minimum leaf resistance, the response curves of leaf resistance to light, temperature, and leaf water potential, and the relationship between

James R. Ehleringer; Philip C. Miller

1975-01-01

344

DESCRIPTION OF THE FRESH AND SALT WATER SUPPLY AND PUMPING PLANTS USED FOR THE AQUARIUM.  

E-print Network

DESCRIPTION OF THE FRESH AND SALT WATER SUPPLY AND PUMPING PLANTS USED FOR THE AQUARIUM. BY I. S. K was supplied from one of the water mains under the aquarium building at an average pressure of about 60 pounds per square inch, and before passing into the supply pipes erected over the aquarium this water

345

Bacteriological Changes Associated with Granular Activated Carbon in a Pilot Water Treatment Plant  

Microsoft Academic Search

Bacteriological analysis were performed on collected water samples from a conventional water treatment pilot plant in Cincinnati, Ohio in which granular activated carbon (GAC) has been used as the final process to assess the impact of GAC on the bacteriological quality and incidence of antibiotic resistant bacteria in water produced. Heterotrophic bacterial counts (HPC) at 20 °C was stabilized at

Helmy Tawfik El-Zanfaly; Donald J. Reasoner; Edwin E. Geldreich

1998-01-01

346

All insects and plants depend on epicuticular lipids for water balance, protection from pathogens and environmental  

E-print Network

All insects and plants depend on epicuticular lipids for water balance, protection from pathogens, and their hydrophobic properties contribute significantly to water retention and water balance (Hadley, 1984; Gibbs of the butterfly Calpodes ethlius oenocytes are also found in the hemocoel (Jackson and Locke, 1989

347

Identifying Critical Thresholds for Acute Response of Plants and Ecosystems to Water Stress (TARP)  

E-print Network

1 Identifying Critical Thresholds for Acute Response of Plants and Ecosystems to Water Stress (TARP Experimental approach 4 Experimental performance 5 Whole-tree water use 8 Storage carbohydrates 8 Canopy and seedling physiology 9 Tree growth 10 Modeling water stress propagation 11 A new manipulation 12 #12;2 First

348

Water deficit stress - host plant nutrient accumulations and associations with phytophagous arthropods  

Technology Transfer Automated Retrieval System (TEKTRAN)

In addition to making otherwise arable regions less, or nonarable, from lack of life-sustaining water, water deficit also affects the extent to which crops are afflicted by arthropod pests. This chapter focuses on the effects of water deficit stress on physical and nutritional aspects of host plants...

349

Development of a Water Treatment Plant Operation Manual Using an Algorithmic Approach.  

ERIC Educational Resources Information Center

This document describes the steps to be followed in the development of a prescription manual for training of water treatment plant operators. Suggestions on how to prepare both flow and narrative prescriptions are provided for a variety of water treatment systems, including: raw water, flocculation, rapid sand filter, caustic soda feed, alum feed,…

Counts, Cary A.

350

Influence of paclobutrazol on water consumption and plant performance of Arbutus unedo seedlings  

Microsoft Academic Search

The purpose of this study was to examine the effect of paclobutrazol on the water consumption, plant water relations, gas exchange and development of strawberry tree seedlings (Arbutus unedo L.), to evaluate water resource management. Seedlings (8cm in height) were subjected to a single drench of 60 or 100mg of paclobutrazol and pot-grown in a greenhouse for 4 months. Untreated

Alejandra Navarro; M Sánchez-Blanco; Sebastián Bañon

2007-01-01

351

Models of Water Transport in the Soil-Plant System: A Review  

NASA Astrophysics Data System (ADS)

Although the study of plants (botany) is one of the oldest sciences, relatively detailed quantitative theories of water transport in plant tissue have lagged behind those describing water transport in soils and other geologic materials which constitute the saturated and unsaturated zones. Many existing texts deal with various aspects of water transport in these earth materials, but little or nothing is devoted to the analogous transport of water in plant roots and tissue at a similar quantitative level. Yet the soil-root-stem water pathway is a major component of the subsurface hydrologic system. Evidently there is a need for both engineering and agricultural hydrologists to further develop their quantitative understanding of water movement in plant and soil-plant systems. Modern quantitative theories of water transport in plants can be traced to concepts developed and disseminated effectively in landmark papers by Gradmann and van den Honert in 1928 and 1948 respectively. The material reviewed in this paper, while more advanced, is based on these concepts. Emphasis is placed on water movement in soil containing roots and on a general approach to water transport in living plant tissue. Detailed quantitative studies of water extraction by plant roots date back to studies by Gardner published in 1960. Many contemporary models are built around extraction functions in the Darcy-Richards equation. Several such functions are listed in a table, and their applications, relative advantages, and limitations are discussed in the text. In a series of papers published in 1958, Philip developed the first detailed quantitative description of water transport in plant tissue. His approach resulted in a diffusion equation which could be written with water potential as the dependent variable. Philip's derivation assumed that water movement was primarily from vacuole to vacuole. Subsequent workers have refined and extended Philip's development to include water movement in cell walls and plasmodesmata. The development, interpretation, and application of these models over the past decade is presented in some detail. It can be argued that contemporary models of water transport in plant tissue are oversimplified. However, they have been subjected to some successful testing and they provide a framework within which to devise experiments. Moreover, the recent development of sophisticated experimental techniques should result in more detailed model testing during the 1980's.

Molz, Fred J.

1981-10-01

352

Water uptake efficiency of a maize plant - A simulation case study  

NASA Astrophysics Data System (ADS)

Water uptake by plant roots is a complex mechanism controlled by biological and physical properties of the soil-plant-atmosphere system and affects a major component of the water cycle, transpiration. This uptake of water by plants is one of the major factors of plant development. Since water uptake occurs at the roots, root architecture and hydraulic properties both play a crucial role in plant productivity. A fundamental understanding of the main processes of water uptake will enable better breeding of drought resistant plants and the improvement of irrigation strategies. In this work we analyzed the differences of root water uptake between idealized genotypes of a plant using mathematical modelling The numerical simulations were performed by the R-SWMS software (Javaux et al., 2008). The model describes 3-D water movement in soil by solving Richard's equation with a sink term representing root uptake. Water flow within the root xylem network and between soil and root is modelled based on water pressure gradients and calculated according to Doussan's model. The sink term is calculated by integration of local uptakes within rooted representative elementary volumes of soil. The plant water demand is described by a boundary condition at the base of the shoot. We compare the water uptake efficiency of three types of root system architectures of a maize plant. Two are actual architectures from genotypes showing significant differences regarding the internodal distance, the root growth rate and the insertion angle of their primary roots. The third one is an ideotype according to Lynch of the maize plant designed to perform better in one dry environment. We generated with RootBox five repetitions of these three root systems with the same total root volume and simulated two drought scenarios at the flowering stage (lack of water at the top or at the bottom of the soil domain). We did these simulations for two distinct distributions of local conductivities of root segments based on literature values. This numerical experiment shows significantly different behaviors of the root systems in terms of dynamics of the water uptake, duration of the water stress or cumulative transpiration. The ranking of the maize architectures varied according to the considered drought scenario. The performance of a root system depends on the environment and on its hydraulic architecture suggesting that we always need to take the genotype-environment interaction into account for recommending breeding options. This study also shows that an ideotype must be built for one specific environment: the one we created experienced difficulties to transpire when placed in different conditions it has been designed for. By mathematical simulation we increased the understanding of the most important underlying processes governing water uptake in a root system.

Meunier, Félicien; Leitner, Daniel; Bodner, Gernot; Javaux, Mathieu; Schnepf, Andrea

2014-05-01

353

Genotoxicity of surface water treated with different disinfectants using in situ plant tests.  

PubMed

Disinfection of surface drinking water, in particular water chlorination, results in many by-products with potential genotoxic and/or carcinogenic activity. In the present study, we evaluated the genotoxicity of surface water after treatment with different disinfectants by means of in situ plant genotoxicity assays (micronucleus and chromosomal aberration tests) which can detect both clastogenic and aneugenic effects. The study was carried out at a pilot plant using lake water after sedimentation and filtration. This water supplied four stainless steel basins: three basins were disinfected with sodium hypochlorite, chlorine dioxide, and peracetic acid and the fourth basin containing untreated lake water was used as a control. Plants were exposed in situ in the basins. The study was carried out using water collected in different seasons over a period of about 1 year in order to assess the treatments in different physical and chemical lake water conditions. The micronucleus test in root cells of Vicia faba (Vicia faba/MCN test) revealed genotoxicity in many samples of disinfected water. The micronucleus test in Tradescantia pollen cells and the chromosome aberration test in root cells of Allium cepa showed genotoxic effects only in some disinfected samples, but also revealed genotoxicity in raw water. The results of the study indicated that the Vicia faba/MCN test was the most sensitive plant assay for disinfected water and that peracetic acid disinfection produced similar or lower genotoxicity than sodium hypochlorite or chlorine dioxide treatment. PMID:12802806

Monarca, S; Rizzoni, M; Gustavino, B; Zani, C; Alberti, A; Feretti, D; Zerbini, I

2003-01-01

354

Influence of Solar Radiation and Biotic Interactions on Bacterial and Eukaryotic Communities Associated with Sewage Decomposition in Ambient Water - Poster  

EPA Science Inventory

Sewage and ambient water both consist of a highly complex array of bacteria and eukaryotic microbes. When these communities are mixed, the persistence of sewage-derived pathogens in environmental waters can represent a significant public health concern. Solar radiation and biotic...

355

Influence of solar radiation and biotic interactions on bacterial and eukaryotic communities associated with sewage decomposition in ambient water  

EPA Science Inventory

Sewage and ambient water both consist of a highly complex array of bacteria and eukaryotic microbes. When these communities are mixed, the persistence of sewage-derived pathogens in environmental waters can represent a significant public health concern. Solar radiation and biot...

356

Interpreting the metabolic responses of plants to water stress  

SciTech Connect

Biological adaptation by-plants to drying (dessication) or drought-prone environments is analyzed. The metabolic components of adaptation and the metabolic symptoms of stress injury are reviewed. Breeding programs for selection of drought-resistance in plants are suggested.

Hanson, A.D.

1980-10-01

357

Water balance altered in cucumber plants infected with Fusarium oxysporum f. sp. cucumerinum  

PubMed Central

Fusarium wilt is caused by the infection and growth of the fungus Fusarium oxysporum in the xylem of host plants. The physiological responses of cucumbers that are infected with Fusarium oxysporum f. sp. cucumerinum (FOC) was studied in pot and hydroponic experiments in a greenhouse. The results showed that although water absorption and stem hydraulic conductance decreased markedly in infected plants, large amounts of red ink accumulated in the leaves of infected cucumber plants. The transpiration rate (E) and stomatal conductance (gs) of the infected plants were significantly reduced, but the E/gs was higher than healthy plants. We further found that there was a positive correlation between leaf membrane injury and E/gs, indicating that the leaf cell membrane injury increased the non-stomatal water loss from infected plants. The fusaric acid (FA), which was detected in the infected plant, resulted in damage to the leaf cell membranes and an increase in E/gs, suggesting that FA plays an important role in non-stomatal water loss. In conclusion, leaf cell membrane injury in the soil-borne Fusarium wilt of cucumber plants induced uncontrolled water loss from damaged cells. FA plays a critical role in accelerating the development of Fusarium wilt in cucumber plants. PMID:25579504

Wang, Min; Sun, Yuming; Sun, Guomei; Liu, Xiaokang; Zhai, Luchong; Shen, Qirong; Guo, Shiwei

2015-01-01

358

Water balance altered in cucumber plants infected with Fusarium oxysporum f. sp. cucumerinum.  

PubMed

Fusarium wilt is caused by the infection and growth of the fungus Fusarium oxysporum in the xylem of host plants. The physiological responses of cucumbers that are infected with Fusarium oxysporum f. sp. cucumerinum (FOC) was studied in pot and hydroponic experiments in a greenhouse. The results showed that although water absorption and stem hydraulic conductance decreased markedly in infected plants, large amounts of red ink accumulated in the leaves of infected cucumber plants. The transpiration rate (E) and stomatal conductance (gs) of the infected plants were significantly reduced, but the E/gs was higher than healthy plants. We further found that there was a positive correlation between leaf membrane injury and E/gs, indicating that the leaf cell membrane injury increased the non-stomatal water loss from infected plants. The fusaric acid (FA), which was detected in the infected plant, resulted in damage to the leaf cell membranes and an increase in E/gs, suggesting that FA plays an important role in non-stomatal water loss. In conclusion, leaf cell membrane injury in the soil-borne Fusarium wilt of cucumber plants induced uncontrolled water loss from damaged cells. FA plays a critical role in accelerating the development of Fusarium wilt in cucumber plants. PMID:25579504

Wang, Min; Sun, Yuming; Sun, Guomei; Liu, Xiaokang; Zhai, Luchong; Shen, Qirong; Guo, Shiwei

2015-01-01

359

Optimization of Water Consumption in Second Generation Bioethanol Plants  

E-print Network

of these resources have focused on energy sources like crude oil, carbon and natural gas1 . Water has been overlooked of Tuzla, 75000 Tuzla, Bosnia and Herzegovina Abstract In this work we address the water consumption. In order to optimize the water consumption a three stage method is used. First, energy consumption

Grossmann, Ignacio E.

360

PACKAGE WATER TREATMENT PLANTS. VOLUME 1. A PERFORMANCE EVALUATION  

EPA Science Inventory

Many small and rural water systems have both cost and quality problems. Their unit costs tend to be higher because of the small number of connections they service. As shown by the Community Water Supply Survey of 1969 many small systems have trouble meeting minimal drinking water...

361

Toxicity tests of effluents with marsh plants in water and sediment  

SciTech Connect

Methods are described for toxicity testing of water and sediment with two varieties of the freshwater marsh plant Echinochloa crusgalli (Linneaus) Palisot de Beauvois (Poaceae), and complex effluents. Two tests are described: a seed germination and early seedling growth test in water, and a survival and seedling growth test in natural and synthetic sediments. Effects of effluents from a sewage treatment plant, tannery, textile mill, pulp and paper mill, coking plant and sewage treatment plant included inhibition of germination, chlorophyll synthesis and growth. The tests with rooted marsh plants were sensitive to pollutants and detected toxicity of a range of pollutants in water and sediment. Synthetic sediments similar to natural sediments allowed toxicity tests to be done under carefully controlled conditions of particle size distribution, organic content, pH, electrode potential (Eh) and cation exchange capacity (CEC).

Walsh, G.E.; Weber, D.E.; Simon, T.L.; Brashers, L.K.

1991-01-01

362

Water management requirements for animal and plant maintenance on the Space Station  

NASA Technical Reports Server (NTRS)

Long-duration Space Station experiments that use animals and plants as test specimens will require increased automation and advanced technologies for water management in order to free scientist-astronauts from routine but time-consuming housekeeping tasks. The three areas that have been identified as requiring water management and that are discusseed are: (1) drinking water and humidity condensate of the animals, (2) nutrient solution and transpired water of the plants, and (3) habitat cleaning methods. Automation potential, technology assessment, crew time savings, and resupply penalties are also discussed.

Johnson, C. C.; Rasmussen, D.; Curran, G.

1987-01-01

363

Seismicity and seismic response of the Soviet-designed VVER (Water-cooled, Water moderated Energy Reactor) reactor plants  

SciTech Connect

On March 4, 1977, a strong earthquake occurred at Vrancea, Romania, about 350 km from the Kozloduy plant in Bulgaria. Subsequent to this event, construction of the unit 2 of the Armenia plant was delayed over two years while seismic features were added. On December 7, 1988, another strong earthquake struck northwest Armenia about 90 km north of the Armenia plant. Extensive damage of residential and industrial facilities occurred in the vicinity of the epicenter. The earthquake did not damage the Armenia plant. Following this event, the Soviet government announced that the plant would be shutdown permanently by March 18, 1989, and the station converted to a fossil-fired plant. This paper presents the results of the seismic analyses of the Soviet-designed VVER (Water-cooled, Water moderated Energy Reactor) plants. Also presented is the information concerning seismicity in the regions where VVERs are located and information on seismic design of VVERs. The reference units are the VVER-440 model V230 (similar to the two units of the Armenia plant) and the VVER-1000 model V320 units at Kozloduy in Bulgaria. This document provides an initial basis for understanding the seismicity and seismic response of VVERs under seismic events. 1 ref., 9 figs., 3 tabs.

Ma, D.C.; Gvildys, J.; Wang, C.Y.; Spencer, B.W.; Sienicki, J.J.; Seidensticker, R.W.; Purvis, E.E. III

1989-01-01

364

Detritus Quality Controls Macrophyte Decomposition under Different Nutrient Concentrations in a Eutrophic Shallow Lake, North China  

PubMed Central

Macrophyte decomposition is important for carbon and nutrient cycling in lake ecosystems. Currently, little is known about how this process responds to detritus quality and water nutrient conditions in eutrophic shallow lakes in which incomplete decomposition of detritus accelerates the lake terrestrialization process. In this study, we investigated the effects of detritus quality and water nutrient concentrations on macrophyte decomposition in Lake Baiyangdian, China, by analyzing the decomposition of three major aquatic plants at three sites with different pollution intensities (low, medium, and high pollution sites). Detritus quality refers to detritus nutrient contents as well as C?N, C?P, and N?P mass ratios in this study. Effects of detritus mixtures were tested by combining pairs of representative macrophytes at ratios of 75?25, 50?50 and 25?75 (mass basis). The results indicate that the influence of species types on decomposition was stronger than that of site conditions. Correlation analysis showed that mass losses at the end of the experimental period were significantly controlled by initial detritus chemistry, especially by the initial phosphorus (P) content, carbon to nitrogen (C?N), and carbon to phosphorus (C?P) mass ratios in the detritus. The decomposition processes were also influenced by water chemistry. The NO3-N and NH4-N concentrations in the lake water retarded detritus mass loss at the low and high pollution sites, respectively. Net P mineralization in detritus was observed at all sites and detritus P release at the high pollution site was slower than at the other two sites. Nonadditive effects of mixtures tended to be species specific due to the different nutrient contents in each species. Results suggest that the nonadditive effects varied significantly among different sites, indicating that interactions between the detritus quality in species mixtures and site water chemistry may be another driver controlling decomposition in eutrophic shallow lakes. PMID:22848699

Li, Xia; Cui, Baoshan; Yang, Qichun; Tian, Hanqin; Lan, Yan; Wang, Tingting; Han, Zhen

2012-01-01

365

Computers and Chemical Engineering 26 (2002) 5979 Energy efficient water utilization systems in process plants  

E-print Network

deliver wastewater, which may contain several contaminants. Therefore, wastewater treatment constitutes a primary concern in most industrial sites. Wastewater treatment has al- ways focused on end. Keywords: Water utilization networks; Process plants; Energy minimization; Wastewater minimization

Savelski, Mariano J.

366

COMETABOLISM OF TRIHALOMETHANES BY NITRIFYING BIOFILTERS UNDER DRINKING WATER TREATMENT PLANT CONDITIONS  

EPA Science Inventory

EPA Identifier: FP916412 Title: Cometabolism of Trihalomethanes by Nitrifying Biofilters Under Drinking Water Treatment Plant Conditions Fellow (Principal Investigator): David G. Wahman Institution: University of Texas at Austin EPA ...

367

Water Treatment Plant Sludges--An Update of the State of the Art: Part 2.  

ERIC Educational Resources Information Center

This report outlines the state of the art with respect to nonmechanical and mechanical methods of dewatering water treatment plant sludge, ultimate solids disposal, and research and development needs. (CS)

American Water Works Association Journal, 1978

1978-01-01

368

Plant-wide Control for Better De-oiling of Produced Water in Offshore Oil & Gas  

E-print Network

Plant-wide Control for Better De-oiling of Produced Water in Offshore Oil & Gas Production Zhenyu into the reservoirs so as to maintain the reservoir pressure (Robinson (2007)). After separation, de-oiling and de

Yang, Zhenyu

369

Institutional impediments to using alternative water sources in thermoelectric power plants.  

SciTech Connect

This report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL) Existing Plants Research Program, which has an energy-water research effort that focuses on water use at power plants. This study complements the Existing Plants Research Program's overall research effort by evaluating water issues that could impact power plants. Obtaining adequate water supplies for cooling and other operations at a reasonable cost is a key factor in siting new and maintaining existing thermoelectric power plant operations. One way to reduce freshwater consumption is to use alternative water sources such as reclaimed (or recycled) water, mine pool water, and other nontraditional sources. The use of these alternative sources can pose institutional challenges that can cause schedule delays, increase costs, or even require plants to abandon their plans to use alternative sources. This report identifies and describes a variety of institutional challenges experienced by power plant owners and operators across the country, and for many of these challenges it identifies potential mitigating approaches. The information comes from publically available sources and from conversations with power plant owners/operators familiar with using alternative sources. Institutional challenges identified in this investigation include, but are not limited to, the following: (1) Institutional actions and decisions that are beyond the control of the power plant. Such actions can include changes in local administrative policies that can affect the use of reclaimed water, inaccurate growth projections regarding the amount of water that will be available when needed, and agency workloads and other priorities that can cause delays in the permitting and approval processes. (2) Developing, cultivating, and maintaining institutional relationships with the purveyor(s) of the alternative water source, typically a municipal wastewater treatment plant (WWTP), and with the local political organizations that can influence decisions regarding the use of the alternative source. Often a plan to use reclaimed water will work only if local politics and power plant goals converge. Even then, lengthy negotiations are often needed for the plans to come to fruition. (3) Regulatory requirements for planning and developing associated infrastructure such as pipelines, storage facilities, and back-up supplies that can require numerous approvals, permits, and public participation, all of which can create delays and increased costs. (4) Permitting requirements that may be difficult to meet, such as load-based discharge limits for wastewater or air emissions limitations for particulate matter (which will be in the mist of cooling towers that use reclaimed water high in dissolved solids). (5) Finding discharge options for cooling tower blowdown of reclaimed water that are acceptable to permitting authorities. Constituents in this wastewater can limit options for discharge. For example, discharge to rivers requires National Pollutant Discharge Elimination System (NPDES) permits whose limits may be difficult to meet, and underground injection can be limited because many potential injection sites have already been claimed for disposal of produced waters from oil and gas wells or waters associated with gas shale extraction. (6) Potential liabilities associated with using alternative sources. A power plant can be liable for damages associated with leaks from reclaimed water conveyance systems or storage areas, or with mine water that has been contaminated by unscrupulous drillers that is subsequently discharged by the power plant. (7) Community concerns that include, but are not limited to, increased saltwater drift on farmers fields; the possibility that the reclaimed water will contaminate local drinking water aquifers; determining the 'best' use of WWTP effluent; and potential health concerns associated with emissions from the cooling towers that use recycled water. (8) Interveners that raise public concerns about the potential for emissions of emergi

Elcock, D. (Environmental Science Division)

2011-08-03

370

The impact of extreme precipitation on plant growth and water relations  

NASA Astrophysics Data System (ADS)

Background The global hydrological cycle is predicted to become more intense, or extreme in future climates, with both larger precipitation events and longer times between events. The resulting wide fluctuations in soil water content (long droughts followed by flooding) may dramatically affect terrestrial ecosystems. Although effects of drought are well studied, tree responses to changed timing of precipitation are mostly unknown. Further, in future extreme precipitation is likely to occur in conjunction with elevated atmospheric CO2 concentrations [CO2]. We tested the impact of extreme precipitation and elevated [CO2] on plant growth and water relations. Methods/results Ten Acacia auriculiformis and Eucalyptus tetradonta saplings were grown in glasshouses, with ambient (380 p.p.m.) and elevated (600 p.p.m.) [CO2] and subject to ambient (1L weekly) and extreme (2L fortnightly) watering conditions (four treatments). We tested whether: (1) plants would show differential water stress and growth under extreme precipitation compared with ambient water treatments; and (2) plants would show differential water stress and growth responses under elevated compared with ambient [CO2] treatments. We found that the extreme precipitation, compared to ambient precipitation, lead to more water stressed plants, with more negative leaf water potential and lower stomatal conductance in both species. Further, plants experiencing extreme precipitation had a higher proportion of root volume at depth within the Eucalyptus. In contrast, the root depth of Acacia was similar across all treatments. Leaf area was smaller in extreme precipitation compared with ambient for Acacias, whereas leaf area was comparable across watering treatments in Eucalypts. Elevated CO2 had no impact on leaf water potential, stomatal conductance during the day or proportion of root depth. The Acacia, from tropical dry forest ecosystems, showed more signs of water stress (more negative leaf water potential and lower stomatal conductance) than the Eucalyptus, from savanna ecosystems. This suggests Eucalyptus saplings may tolerate water stress imposed by extreme precipitation better than Acacias, perhaps influencing community structure in tropical ecosystems.

Zeppel, M.; Lehmann, C.; Lewis, J. D.; Medlyn, B. E.

2012-12-01

371

Electrophysiological assessment of water stress in fruit-bearing woody plants.  

PubMed

Development and evaluation of a real-time plant water stress sensor, based on the electrophysiological behavior of fruit-bearing woody plants is presented. Continuous electric potentials are measured in tree trunks for different irrigation schedules, inducing variable water stress conditions; results are discussed in relation to soil water content and micro-atmospheric evaporative demand, determined continuously by conventional sensors, correlating this information with tree electric potential measurements. Systematic and differentiable patterns of electric potentials for water-stressed and no-stressed trees in 2 fruit species are presented. Early detection and recovery dynamics of water stress conditions can also be monitored with these electrophysiology sensors, which enable continuous and non-destructive measurements for efficient irrigation scheduling throughout the year. The experiment is developed under controlled conditions, in Faraday cages located at a greenhouse area, both in Persea americana and Prunus domestica plants. Soil moisture evolution is controlled using capacitance sensors and solar radiation, temperature, relative humidity, wind intensity and direction are continuously registered with accurate weather sensors, in a micro-agrometeorological automatic station located at the experimental site. The electrophysiological sensor has two stainless steel electrodes (measuring/reference), inserted on the stem; a high precision Keithley 2701 digital multimeter is used to measure plant electrical signals; an algorithm written in MatLab(®), allows correlating the signal to environmental variables. An electric cyclic behavior is observed (circadian cycle) in the experimental plants. For non-irrigated plants, the electrical signal shows a time positive slope and then, a negative slope after restarting irrigation throughout a rather extended recovery process, before reaching a stable electrical signal with zero slope. Well-watered plants presented a continuous signal with daily maximum and a minimum EP of similar magnitude in time, with zero slope. This plant electrical behavior is proposed for the development of a sensor measuring real-time plant water status. PMID:24877671

Ríos-Rojas, Liliana; Tapia, Franco; Gurovich, Luis A

2014-06-15

372

IMPACTS OF COAL-FIRED POWER PLANTS ON LOCAL GROUND-WATER SYSTEMS: WISCONSIN POWER PLANT IMPACT STUDY  

EPA Science Inventory

Quantitative techniques for simulating the impacts of a coal-fired power plant on the ground-water system of a river flood-plain wetland were developed and tested. Effects related to the construction and operation of the cooling lake and ashpit had the greatest impact. Ground-wat...

373

Plant nutrients in a degraded soil treated with water treatment sludge and cultivated with grasses and leguminous plants  

Microsoft Academic Search

The objective of this work was to evaluate rates for applications of water treatment sludge (WTS) as a nutrient source for grasses and leguminous plants cropped in a soil degraded by tin mining in the Amazon Region (Natural Forest of Jamari, Rondonia State, Brazil). The treatments consisted of three rates of nitrogen supplied by WTS (100, 150 and 200mgkg?1 soil),

Sandra Tereza Teixeira; Wanderley José de Melo; Érica Tomé Silva

2007-01-01

374

Does Water Deficit Stress Promote Ethylene Synthesis by Intact Plants? 1  

PubMed Central

The effect of plant water deficit on ethylene production by intact plants was tested in three species, beans (Phaseolus vulgaris L.), cotton (Gossypium hirsutum L.) and miniature rose (Rosa hybrida L., cv Bluesette). Compressed air was passed through glass, plant-containing cuvettes, ethylene collected on chilled columns, and subsequently assayed by gas chromatography. The usual result was that low water potential did not promote ethylene production. When plants were subjected to cessation of irrigation, ethylene production decreased on a per plant or dry weight basis of calculation. No significant promotion of ethylene production above control levels was detected when water deficit-treated bean or cotton plants were rewatered. The one exception to this was for cotton subjected to a range of water deficits, plants subjected to deficits of ?1.4 to ?1.6 MPa exhibited a transient increase of ethylene production of 40 to 50% above control levels at 24 or 48 hours. Ethylene was collected from intact leaves while plants developed a water deficit stress of ?2.9 megapascals after rewatering, and no significant promotion of ethylene production was detected. The shoots of fruited, flowering cotton plants produced less ethylene when subjected to cessation of irrigation. In contrast, the ability of bench drying of detached leaves to increase ethylene production several-fold was verified for both beans and cotton. The data indicate that detached leaves react differently to rapid drying than intact plants react to drying of the soil with regard to ethylene production. This result suggests the need for additional attention to ethylene as a complicating factor in experiments employing excised plant parts and the need to verify the relevance of shock stresses in model systems. PMID:16667895

Morgan, Page W.; He, Chuan-Jin; De Greef, Jan A.; De Proft, Maurice P.

1990-01-01

375

COOLING WATER ISSUES AND OPPORTUNITIES AT U.S. NUCLEAR POWER PLANTS  

SciTech Connect

This report has been prepared for the Department of Energy, Office of Nuclear Energy (DOE-NE), for the purpose of providing a status report on the challenges and opportunities facing the U.S. commercial nuclear energy industry in the area of plant cooling water supply. The report was prompted in part by recent Second Circuit and Supreme Court decisions regarding cooling water system designs at existing thermo-electric power generating facilities in the U.S. (primarily fossil and nuclear plants). At issue in the courts have been Environmental Protection Agency regulations that define what constitutes “Best Technology Available” for intake structures that withdraw cooling water that is used to transfer and reject heat from the plant’s steam turbine via cooling water systems, while minimizing environmental impacts on aquatic life in nearby water bodies used to supply that cooling water. The report was also prompted by a growing recognition that cooling water availability and societal use conflicts are emerging as strategic energy and environmental issues, and that research and development (R&D) solutions to emerging water shortage issues are needed. In particular, cooling water availability is an important consideration in siting decisions for new nuclear power plants, and is an under-acknowledged issue in evaluating the pros and cons of retrofitting cooling towers at existing nuclear plants. Because of the significant ongoing research on water issues already being performed by industry, the national laboratories and other entities, this report relies heavily on ongoing work. In particular, this report has relied on collaboration with the Electric Power Research Institute (EPRI), including its recent work in the area of EPA regulations governing intake structures in thermoelectric cooling water systems.

Gary Vine

2010-12-01

376

Total energy concept at the joint water pollution control plant. [Carson, CA  

Microsoft Academic Search

The proposed total-energy facilities at the Joint Water Pollution Control Plant (Carson, Calif.) are designed to maximize electrical power production to meet significant increases in demands resulting from secondary treatment, and to minimize dependence on public utilities for natural gas and water by reusing waste heat and plant effluent. The generator prime-mover selection process includes analyses of reciprocating engines, simple-cycle

G. M. Adams; J. D. Eppich; W. E. Garrison; J. C. Gratteau

1980-01-01

377

Improvement of water treatment pilot plant with Moringa oleifera extract as flocculant agent  

Microsoft Academic Search

Moringa oleifera extract is a high?capacity flocculant agent for turbidity removal in surface water treatment. A complete study of a pilot?plant installation has been carried out. Because of flocculent sedimentability of treated water, a residual turbidity occured in the pilot plant (around 30 NTU), which could not be reduced just by a coagulation?flocculation?sedimentation process. Because of this limitation, the pilot

2009-01-01

378

COMMUNITY RESPIRATION OF DECOMPOSING PLANTS IN OREGON ESTUARINE MARSHES  

EPA Science Inventory

Community respiration rates in air and water were measured as indicators of the decomposition rate of dead plant tissue from nine stands of plants in two Oregon estuarine marshes. Respiration rates were low and relatively constant from November to February; during warmer periods ...

379

Responses of wetland plants to effluents in water and sediment  

SciTech Connect

Responses of two wetland vascular plants, Echinochloa crusgalli and Sesbania macrocarpa, exposed to effluents from a coke plant, a pulp mill, a wastewater treatment plant, and the herbicide, hexazinone, were measured in three types of tests: seed germination and early growth, seedling survival and growth in hydroponic culture, and seedling survival and growth in sand and synthetic sediments with clay, silt, and sand, 3, 5, 7.5, or 10% organic contents. There was no effect of effluents or herbicide on germination and survival was affected only by the herbicide. When compared to controls, growth rates were reduced significantly in all tests except for E. crusgalli exposed to effluent from a wastewater treatment plant. There, the effluent stimulated growth in sediments. Increasing concentrations of organic matter in sediments had little effect on toxicity of effluents, but did cause reduced effects of hexazinone.

Walsh, G.E.; Weber, D.E.; Nguyen, M.T.; Esry, L.K.

1991-01-01

380

Plant growth enhancement by elevated CO2 eliminated by joint water and nitrogen limitation  

NASA Astrophysics Data System (ADS)

Rising atmospheric CO2 concentrations can fertilize plant growth. The resulting increased plant uptake of CO2 could, in turn, slow increases in atmospheric CO2 levels and associated climate warming. CO2 fertilization effects may be enhanced when water availability is low, because elevated CO2 also leads to improved plant water-use efficiency. However, CO2 fertilization effects may be weaker when plant growth is limited by nutrient availability. How variation in soil nutrients and water may act together to influence CO2 fertilization is unresolved. Here we report plant biomass levels from a five-year, open-air experiment in a perennial grassland under two contrasting levels of atmospheric CO2, soil nitrogen and summer rainfall, respectively. We find that the presence of a CO2 fertilization effect depends on the amount of available nitrogen and water. Specifically, elevated CO2 levels led to an increase in plant biomass of more than 33% when summer rainfall, nitrogen supply, or both were at the higher levels (ambient for rainfall and elevated for soil nitrogen). But elevated CO2 concentrations did not increase plant biomass when both rainfall and nitrogen were at their lower level. We conclude that given widespread, simultaneous limitation by water and nutrients, large stimulation of biomass by rising atmospheric CO2 concentrations may not be ubiquitous.

Reich, Peter B.; Hobbie, Sarah E.; Lee, Tali D.

2014-12-01

381

Hydrogen production by high temperature, high pressure water electrolysis. I - Plant development  

Microsoft Academic Search

The development of a test plant with a hydrogen-production capacity of 4 cu Nm\\/hour based on a high-temperature, high-pressure water electrolyzer is discussed, and results of corrosion tests on metallic materials for plant construction are presented. The test plant electrolyzer was designed and constructed on the basis of the construction and testing of a series of bench-scale electrolyzers operating at

I. Abe; T. Fujimaki; Y. Kajiwara; Y. Yokoo

1981-01-01

382

Enterococcus faecalis Gene Transfer under Natural Conditions in Municipal Sewage Water Treatment Plants  

Microsoft Academic Search

Received 2 October 1997\\/Accepted 12 November 1997 The ability of Enterococcus faecalis to transfer various genetic elements under natural conditions was tested in two municipal sewage water treatment plants. Experiments in activated sludge basins of the plants were performed in a microcosm which allowed us to work under sterile conditions; experiments in anoxic sludge digestors were performed in dialysis bags.

HERBERT MARCINEK; REINHARD WIRTH; ALBRECHT MUSCHOLL-SILBERHORN; MATTHIAS GAUER

1998-01-01

383

Plant responses, climate pivot points, and trade-offs in water-limited ecosystems  

USGS Publications Warehouse

Plant species in dryland ecosystems are limited by water availability and may be vulnerable to increases in aridity. Methods are needed to monitor and assess the rate of change in plant abundance and composition in relation to climate, understand the potential for degradation in dryland ecosystems, and forecast future changes in plant species assemblages. I employ nearly a century of vegetation monitoring data from three North American deserts to demonstrate an approach to determine plant species responses to climate and critical points over a range of climatic conditions at which plant species shift from increases to decreases in abundance (climate pivot points). I assess these metrics from a site to regional scale and highlight how these indicators of plant performance can be modified by the physical and biotic environment. For example, shrubs were more responsive to drought and high temperatures on shallow soils with limited capacity to store water and fine-textured soils with slow percolation rates, whereas perennial grasses were more responsive to precipitation in sparse shrublands than in relatively dense grasslands and shrublands, where competition for water is likely more intense. The responses and associated climate pivot points of plant species aligned with their lifespan and structural characteristics, and the relationship between responses and climate pivot points provides evidence of the trade-off between the capacity of a plant species to increase in abundance when water is available and its drought resistance.

Munson, Seth M.

2013-01-01

384

INFLUENCE OF PEROXYACETYL NITRATE (PAN) ON WATER STRESS IN BEAN PLANTS  

EPA Science Inventory

Bean plants (Phaseolus vulgaris) were exposed to 395 micrograms/cu m (0.08 ppm) peroxyacetyl nitrate (PAN) for 0.5 hr and subjected to drought stress following exposure. PAN influenced the plant water potential of PAN-sensitive 'Provider' resulting in visible wilting and reduced ...

385

Heavy Metals In Water, Suspended Particles, Sediments And Aquatic Plants Of Habbaniya Lake, Iraq  

Microsoft Academic Search

Seasonal samples were taken from four selected stations on the Habbaniya lake, middle of Iraq during 1997, to study six heavy metals (Cu, Cd, Pb, Ni, Mn, and Zn), in water suspended particles, sediments and aquatic plants. Five plant species were collected, represented the most dominant in the lake, namely Myriophyllum verticillatum, Potamogeton crispus, P. pectinatus, Ceratophyllum demersum and Vallisnaria

Hussain A. Al-Saadi; Ali A. Al-Lami; Falih A. Hassan; Amer A. Al-Dulymi

2002-01-01

386

Investigation of an automatic control system of an atomic energy plant with boiling-water reactor  

Microsoft Academic Search

Conclusions The experimental investigations of the dynamics of the atomic electric power plant with boiling water vessel reactor and natural circulation and automatic control system have shown that:-1)The pressure and level in the reactor, the level in the steam generators, and the preturbine pressure must be regarded as the main regulated parameters of the plant.2)When changes are made in the

V. I. Gritskov; V. A. Afanas'ev; G. A. Sankovskii; R. A. Shugam; I. N. Sokolov; Yu. A. Solov'ev

1968-01-01

387

Effects of environment on source water for desalination plants on the eastern coast of Saudi Arabia  

Microsoft Academic Search

A study was carried out in the sea adjacent to a major MSF plant where a new 24MGD SWRO plant is being commissioned. Data were collected on the topographical feature of the marine basin, water quality and plankton of the intake zone. The incidents of planktonic bloom, influx of invasive organisms like jellyfish and macrofouling organisms and ingress of marine

P. K. Abdul Azis; Ibrahim Al-Tisan; Mohammad Al-Daili; Troy N. Green; Abdul Ghani I. Dalvi; M. A. Javeed

2000-01-01

388

Water Use Efficiency in Plant Growth and Ambient Carbon Dioxide Level  

E-print Network

and carbon dioxide balance of plant leaves was made in the form of a computer program based upon known physiological facts. It predicts significant increases in water use efficiency by plants as CO is enriched, the size of the increase depending upon...

van Bavel, C. H. M.

389

Effects of water pulsing on individual performance and competitive hierarchies in plants  

E-print Network

Effects of water pulsing on individual performance and competitive hierarchies in plants and there were significant hierarchies of competitive ability. Under frequent pulses, the fast-growing species plants and ability to tolerate the presence of neighbors. However, under infrequent pulses, the slowest

Novoplansky, Ariel

390

Plant hormones regulate fast shoot elongation under water: From genes to communities  

Microsoft Academic Search

Flooding affects the abundance and distribution of plant species worldwide. Many plants are damaged or even killed by flooding events, due to the associated oxygen deprivation in cells. Stimulated shoot elongation is an important adaptive mode that can restore contact of leaves with the atmosphere above the water surface. This strongly improves inward diffusion of oxygen and the rate of

L. A. C. J. Voesenek; J. H. G. M. Rijnders; A. J. M. Peeters; H. M. V. van de Steeg; J. C. J. M. de Kroon

2004-01-01

391

Influence of temperature and process technology on the occurrence of Aeromonas species and hygienic indicator organisms in drinking water production plants.  

PubMed

The occurrence of Aeromonas spp. and hygienic indicator organisms in raw and treated waters of five drinking water production plants in Flanders (Belgium) was surveyed over a period of 17 months. Aeromonads were isolated on ampicillin-dextrin agar (ADA) and further identified by gas-liquid chromatographic analysis of their cellular fatty acid methyl ester (FAME) content. ADA medium was found to be highly specific for the enumeration of Aeromonas spp. In general, Aeromonas counts were very low in untreated groundwater but numbered 10(4)-10(6) colony-forming units per liter in open storage reservoirs for surface water. Aeromonas spp. were seasonally distributed with maximal densities occurring during the summer. The ecology of Aeromonas in the different waters was studied in relation to the physical, chemical, and microbiological water characteristics. Strongly positive correlations were observed between Aeromonas densities and heterotrophic plate counts, whereas a clearly negative relationship was found with dissolved oxygen. On average, 99.7% of the aeromonads were removed by flocculation-decantation followed by breakpoint chlorination, whereas 98.9% were removed by slow sand filtration. Flocculation-decantation without breakpoint chlorination did not reduce the microbial numbers. At three of four drinking water production plants tested, rapid sand filtration decreased the number of aeromonads and hygienic indicator organisms. At one plant, however, the numbers of Aeromonas and hygienic indicator organisms were high in the sand filter effluents. Increased numbers of aeromonads were also counted in the effluent of the activated carbon filters. Hence, inactivation of Aeromonas spp. by the current process technology appears not sufficient to exclude postchlorination. The survival of aeromonads in certain filter systems may be due to the growth of these bacteria on biodegradable organic material, provided by the decomposition from bacteria, algae, or other sources. PMID:24185486

Kersters, I; Van Vooren, L; Huys, G; Janssen, P; Kersters, K; Verstraet, W

1995-09-01

392

Occurrence and elimination of cyanobacterial toxins in drinking water treatment plants  

SciTech Connect

Toxin-producing cyanobacteria (blue-green algae) are abundant in surface waters used as drinking water resources. The toxicity of one group of these toxins, the microcystins, and their presence in surface waters used for drinking water production has prompted the World Health Organization (WHO) to publish a provisional guideline value of 1.0 {mu}g microcystin (MC)-LR/l drinking water. To verify the efficiency of two different water treatment systems with respect to reduction of cyanobacterial toxins, the concentrations of MC in water samples from surface waters and their associated water treatment plants in Switzerland and Germany were investigated. Toxin concentrations in samples from drinking water treatment plants ranged from below 1.0 {mu}g MC-LR equiv./l to more than 8.0 {mu}g/l in raw water and were distinctly below 1.0 {mu}g/l after treatment. In addition, data to the worldwide occurrence of cyanobacteria in raw and final water of water works and the corresponding guidelines for cyanobacterial toxins in drinking water worldwide are summarized.

Hoeger, Stefan J.; Hitzfeld, Bettina C.; Dietrich, Daniel R

2005-03-15

393

Green roofs for a drier world: effects of hydrogel amendment on substrate and plant water status.  

PubMed

Climate features of the Mediterranean area make plant survival over green roofs challenging, thus calling for research work to improve water holding capacities of green roof systems. We assessed the effects of polymer hydrogel amendment on the water holding capacity of a green roof substrate, as well as on water status and growth of Salvia officinalis. Plants were grown in green roof experimental modules containing 8 cm or 12 cm deep substrate (control) or substrate mixed with hydrogel at two different concentrations: 0.3 or 0.6%. Hydrogel significantly increased the substrate's water content at saturation, as well as water available to vegetation. Plants grown in 8 cm deep substrate mixed with 0.6% of hydrogel showed the best performance in terms of water status and membrane integrity under drought stress, associated to the lowest above-ground biomass. Our results provide experimental evidence that polymer hydrogel amendments enhance water supply to vegetation at the establishment phase of a green roof. In particular, the water status of plants is most effectively improved when reduced substrate depths are used to limit the biomass accumulation during early growth stages. A significant loss of water holding capacity of substrate-hydrogel blends was observed after 5 months from establishment of the experimental modules. We suggest that cross-optimization of physical-chemical characteristics of hydrogels and green roof substrates is needed to improve long term effectiveness of polymer-hydrogel blends. PMID:24867709

Savi, Tadeja; Marin, Maria; Boldrin, David; Incerti, Guido; Andri, Sergio; Nardini, Andrea

2014-08-15

394

Plant water use in a greenhouse: theory and measurements  

E-print Network

glasshouse were both highly correlated, on a daily basis and an hourly basis, with water loss (ET) measured with a weighing lysimeter. The fraction of incident solar radiation within the greenhouse (irradiance) used for ET was quite constant for a given... water use, which is of interest for both practical growers and theoretical analysts as well, a special effort was made to study this parameter by Heathman (1981). He compared the water use as measured directly with weighable lysimeters...

Shaer, Yacoub Adib

2012-06-07

395

Supercritical water oxidation of polyvinyl alcohol and desizing wastewater: influence of NaOH on the organic decomposition.  

PubMed

Polyvinyl alcohol is a refractory compound widely used in industry. Here we report supercritical water oxidation of polyvinyl alcohol solution and desizing wastewater with and without sodium hydroxide addition. However, it is difficult to implement complete degradation of organics even though polyvinyl alcohol can readily crack under supercritical water treatment. Sodium hydroxide had a significant catalytic effect during the supercritical water oxidation of polyvinyl alcohol. It appears that the OH- ion participated in the C-C bond cleavage of polyvinyl alcohol molecules, the CO2-capture reaction and the neutralization of intermediate organic acids, promoting the overall reactions moving in the forward direction. Acetaldehyde was a typical intermediate product during reaction. For supercritical water oxidation of desizing wastewater, a high destruction rate (98.25%) based on total organic carbon was achieved. In addition, cases where initial wastewater was alkaline were favorable for supercritical water oxidation treatment, but salt precipitation and blockage issues arising during the process need to be taken into account seriously. PMID:24520696

Zhang, Jie; Wang, Shuzhong; Guo, Yang; Xu, Donghai; Gong, Yanmeng; Tang, Xingying

2013-08-01

396

No Evidence of Complementary Water Use along a Plant Species Richness Gradient in Temperate Experimental Grasslands.  

PubMed

Niche complementarity in resource use has been proposed as a key mechanism to explain the positive effects of increasing plant species richness on ecosystem processes, in particular on primary productivity. Since hardly any information is available for niche complementarity in water use, we tested the effects of plant diversity on spatial and temporal complementarity in water uptake in experimental grasslands by using stable water isotopes. We hypothesized that water uptake from deeper soil depths increases in more diverse compared to low diverse plant species mixtures. We labeled soil water in 8 cm (with 18O) and 28 cm depth (with ²H) three times during the 2011 growing season in 40 temperate grassland communities of varying species richness (2, 4, 8 and 16 species) and functional group number and composition (legumes, grasses, tall herbs, small herbs). Stable isotope analyses of xylem and soil water allowed identifying the preferential depth of water uptake. Higher enrichment in 18O of xylem water than in ²H suggested that the main water uptake was in the upper soil layer. Furthermore, our results revealed no differences in root water uptake among communities with different species richness, different number of functional groups or with time. Thus, our results do not support the hypothesis of increased complementarity in water use in more diverse than in less diverse communities of temperate grassland species. PMID:25587998

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

2015-01-01

397

No Evidence of Complementary Water Use along a Plant Species Richness Gradient in Temperate Experimental Grasslands  

PubMed Central

Niche complementarity in resource use has been proposed as a key mechanism to explain the positive effects of increasing plant species richness on ecosystem processes, in particular on primary productivity. Since hardly any information is available for niche complementarity in water use, we tested the effects of plant diversity on spatial and temporal complementarity in water uptake in experimental grasslands by using stable water isotopes. We hypothesized that water uptake from deeper soil depths increases in more diverse compared to low diverse plant species mixtures. We labeled soil water in 8 cm (with 18O) and 28 cm depth (with ²H) three times during the 2011 growing season in 40 temperate grassland communities of varying species richness (2, 4, 8 and 16 species) and functional group number and composition (legumes, grasses, tall herbs, small herbs). Stable isotope analyses of xylem and soil water allowed identifying the preferential depth of water uptake. Higher enrichment in 18O of xylem water than in ²H suggested that the main water uptake was in the upper soil layer. Furthermore, our results revealed no differences in root water uptake among communities with different species richness, different number of functional groups or with time. Thus, our results do not support the hypothesis of increased complementarity in water use in more diverse than in less diverse communities of temperate grassland species. PMID:25587998

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

2015-01-01

398

Water and temperature dynamics in a clay soil under winter wheat: influence on straw decomposition and N immobilization  

Microsoft Academic Search

Winter wheat grown on a clay soil was subjected to one of four treatments. The control was not irrigated; the drought treatment had screens to divert rainwater; the irrigation and irrigation\\/fertilization treatments were irrigated using a drip-tube system with liquid fertilizer (200 kg N ha-1 year-1) applied daily in the irrigation\\/fertilization treatment according to predicted plant uptake. All other treatments

Olof Andrén; Kfilmfin Rajkai; Thomas Kiitterer

1993-01-01

399

Mechanism, decomposition pathway and new evidence for self-healing of manganese oxides as efficient water oxidizing catalysts: new insights.  

PubMed

The electrochemical water-oxidation reaction usually requires a catalyst to reduce the overpotential and Earth-abundant catalysts, like MnO2, are attracting much attention. Here we use chemometric analysis, EPR and UV-Vis spectroscopies to track Mn(II) and MnO4(-) byproducts to the reaction of a MnO2 film in the presence of cerium(IV) ammonium nitrate. Permanganate ion is involved in at least two key reactions: it may oxidize water to O2 or can combine with Mn(II) to remake MnO2 solid. We propose mechanisms for water oxidation and present a self-healing process for this reaction. PMID:23982587

Najafpour, Mohammad Mahdi; Kompany-Zareh, Mohsen; Zahraei, Ali; Jafarian Sedigh, Davood; Jaccard, Hugues; Khoshkam, Maryam; Britt, R David; Casey, William H

2013-10-28

400

A Qualitative Survey of Five Antibiotics in a Water Treatment Plant in Central Plateau of Iran  

PubMed Central

Introduction. This study aimed to survey a total of five common human and veterinary antibiotics based on SPE-LC-MS-MS technology in a water treatment plant at central plateau of Iran. Also two sampling techniques, passive and grab samplings, were compared in the detection of selected antibiotics. Materials and Methods. In January to March 2012, grab and passive samples were taken from the influent and effluent of a water treatment plant. The samples were prepared using solid-phase extraction (SPE), and extracts were analyzed by liquid chromatography tandem mass spectrometry (LC-MS-MS). Results. The results showed that enrofloxacin, oxytetracycline, and tylosin were not detected in none of the samples. However, ampicillin was detected in the grab and passive samples taken from the influent (source water) of the plant, and ciprofloxacin was detected in passive samples taken from the influent and effluent (finished water) of the plant. Conclusion. The results imply that passive sampling is a better approach than grab sampling for the investigation of antibiotics in aquatic environments. The presence of ampicillin and ciprofloxacin in source water and finished water of the water treatment plant may lead to potential emergence of resistant bacteria that should be considered in future studies. PMID:23690801

Heidari, Mohsen; Kazemipour, Maryam; Bina, Bijan; Ansari, Mehdi; Ghasemian, Mohammad; Amin, Mohammad Mehdi

2013-01-01

401

Influence of arbuscular mycorrhizae on photosynthesis and water status of maize plants under salt stress.  

PubMed

The influence of arbuscular mycorrhizal (AM) fungus Glomus mosseae on characteristics of the growth, water status, chlorophyll concentration, gas exchange, and chlorophyll fluorescence of maize plants under salt stress was studied in the greenhouse. Maize plants were grown in sand and soil mixture with five NaCl levels (0, 0.5, 1.0, 1.5, and 2.0 g/kg dry substrate) for 55 days, following 15 days of non-saline pretreatment. Under salt stress, mycorrhizal maize plants had higher dry weight of shoot and root, higher relative chlorophyll content, better water status (decreased water saturation deficit, increased water use efficiency, and relative water content), higher gas exchange capacity (increased photosynthetic rate, stomatal conductance and transpiration rate, and decreased intercellular CO(2) concentration), higher non-photochemistry efficiency [increased non-photochemical quenching values (NPQ)], and higher photochemistry efficiency [increased the maximum quantum yield in the dark-adapted state (Fv/Fm), the maximum quantum yield in the light-adapted sate (Fv'/Fm'), the actual quantum yield in the light-adapted steady state (phiPSII) and the photochemical quenching values (qP)], compared with non-mycorrhizal maize plants. In addition, AM symbiosis could trigger the regulation of the energy biturcation between photochemical and non-photochemical events reflected in the deexcitation rate constants (kN, kN', kP, and kP'). All the results show that G. mosseae alleviates the deleterious effect of salt stress on plant growth, through improving plant water status, chlorophyll concentration, and photosynthetic capacity, while the influence of AM symbiosis on photosynthetic capacity of maize plants can be indirectly affected by soil salinity and mycorrhizae-mediated enhancement of water status, but not by the mycorrhizae-mediated enhancement of chlorophyll concentration and plant biomass. PMID:18584217

Sheng, Min; Tang, Ming; Chen, Hui; Yang, Baowei; Zhang, Fengfeng; Huang, Yanhui

2008-09-01

402

Optimization of energy parks with biomass plants and water desalination  

Microsoft Academic Search

This paper shows a possibility of the combination of renewable energy sources and water desalination in a self-contained installation. There is a chance to combine both aspects to save our climate and to solve the problem of water shortage in many countries, especially in countries with a high sun radiation, like in Africa as well in northern industrial countries with

D. Buschert; B. Bitzer

2008-01-01

403

PACKAGE WATER TREATMENT PLANTS. VOLUME 2. A COST EVALUATION  

EPA Science Inventory

Many small and rural systems have both cost and quality problems. Their unit costs tend to be higher because of the small number of connections they service. As shown by the Community Water Supply Survey of 1969, many small systems have trouble meeting minimal drinking water stan...

404

Responses of wetland plants to ammonia and water level  

Microsoft Academic Search

Constructed wetland systems receiving animal wastewater may enhance water quality when designed, operated, and maintained properly. In the case of wetlands designed to treat animal waste, system effectiveness may be limited by high ammonia concentrations and inundation, conditions that can adversely affect macrophytic vegetation. We conducted a 4-month greenhouse experiment to assess the impact of ammonia concentration and water level

Ernest Clarke; Andrew H. Baldwin

2002-01-01

405

Reflectance of vegetation, soil, and water. [effects of measurable plant parameters on multispectral signal variations  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. Reflectance of crop residues, that are important in reducing wind and water erosion, was more often different from bare soil in band 4 than in bands 5, 6, or 7. The plant parameters leaf area index, plant population, plant cover, and plant height explained 95.9 percent of the variation in band 7 (reflective infrared) digital counts for cotton and 78.2 percent of the variation in digital counts for the combined crops sorghum and corn; hence, measurable plant parameters explain most of the signal variation recorded for corpland. Leaf area index and plant population are both highly correlated with crop yields; since plant population can be readily measured (or possibly inferred from seeding rates), it is useful measurement for calibrating ERTS-type MSS digital data in terms of yield.

Wiegand, C. L. (principal investigator)

1974-01-01

406

Decomposition of Persistent Organics in Water Using a Gas–Liquid Two-Phase Flow Plasma Reactor  

Microsoft Academic Search

Pulsed dielectric barrier discharges (DBDs) generated inside inert gas bubbles were studied to decompose persistent organic materials in water. Two glass tubes were coaxially mounted, and metal electrodes were attached at the inner and outer surfaces of the tubes that acted as dielectric barriers. A 10-ppm acetic acid solution filled the gap between the tubes and acted as the persistent

Hiroshi Katayama; Hiroyuki Honma; Naoyuki Nakagawara; Koichi Yasuoka

2009-01-01

407

A MultiChannel Continuous Water Toxicity Monitoring System: Its Evaluation and Application to Water Discharged from a Power Plant  

Microsoft Academic Search

A multi-channel continuous water toxicity monitoring system was, after confirming the systems' performance, implemented to samples of water discharged from power plants to detect and classify their toxicity using several recombinant bioluminescent bacteria. Each channel of the system is composed of a series of two mini-bioreactors to enable a continuous operation, i.e., without system interruption due to highly toxic samples.

Byoung Chan Kim; Man Bock Gu

2005-01-01

408

Water use in four model tropical plant associations established in the lowlands of Costa Rica.  

PubMed

We examined soil water use patterns of four model plant associations established in the North Caribbean lowlands of Costa Rica by comparing the stable hydrogen isotope composition, deltaD, in xylem sap and in soil water at different depths, under rainy and dry conditions. Four 5-year-old model plant associations composed of 2 tree species (Hyeronima alchorneoides and Cedrela odorata) having different architecture and phenology were studied. Average tree height was 8.9 and 7.6 m, respectively. Each tree species was grown in monoculture and in polyculture with 2 perennial monocotyledons (Euterpe oleracea and Heliconia imbricata). Maximum rooting depth at the time of 6D determination was approximately 2 m for almost all species. Most roots of all species were concentrated in the upper soil layers. Stomatal conductance to water vapor (gS) was higher in the deciduous C. odorata than in the evergreen H. alchorneoides; within each species, g, did not differ when the trees were grown in mono or in polyculture. During the rainy season, gradients in soil water 6D were not observed. Average rainy season xylem sap deltaD did not differ among members of the plant combinations tested (-30% per thousand), and was more similar to deltaD values of shallow soil water. Under dry conditions, volumetric soil water content declined from 50 to approximately 35%, and modest gradients in soil water deltaD were observed. Xylem sap deltaD obtained during dry conditions was significantly lower than rainy season values. Xylem sap deltaD of plants growing in the four associations varied between -9 and -22% per hundred, indicating that shallow water was predominantly absorbed during the dry period too. Differences in xylem sap deltaD of trees and monocots were also detected, but no significant patterns emerged. The results suggest that: (a) the plant associations examined extracted water predominantly from shallow soil layers (<1 m), (b) the natural isotopic variation in soil and plant water at the study site was low, and (c) the plant mixes obtain water from more than a single soil layer simultaneously. Temporal factors were important in determining the competition and complementary relations observed among the trees and the perennial monocots. Under the prevailing environmental conditions, water use in these plant associations was determined largely by species-specific attributes such as biomass allocation to fine roots, phenology, and canopy architecture, and to a lesser extent by water limitations. PMID:19419093

Gutiérrez-Soto, Marco V; Ewel, John J

2008-12-01

409

Plant growth, leaf water potential, nitrogenase activity and nodule anatomy in Leucaena leucocephala as affected by water stress and nitrogen availability  

Microsoft Academic Search

The effects of water stress and nitrogen availability on leaf water potential, nitrogenase activity, and growth was studied\\u000a in a pot experiment with Leucaena leucocephala seedlings. Water stress was imposed on fertilized and unfertilized plants after inoculation with Rhizobium. Non-inoculated seedlings were used as control plants. Water stress lowered leaf water potential in all seedlings after 14\\u000a days of treatment.

A. F. Mrema; U. Granhall; L. Sennerby-Forsse

1997-01-01

410

A dynamic mathematical model of a direct expansion (DX) water-cooled air-conditioning plant  

Microsoft Academic Search

A dynamic mathematical model for a direct expansion water-cooled air-conditioning plant typical to many actual installations in buildings has been developed. The system components modelled are a compressor, a thermostatic expansion valve, a water cooled condenser and a direct expansion evaporator which is also the cooling and dehumidifying coil in the air side. The evaporator (cooling coil) model consists of

Deng Shiming

2000-01-01

411

Interactions Among Water, Carbon, And Nutrient Cycles With Woody Plant Encroachment Into Grasslands  

Microsoft Academic Search

The expansion of woody plants into deserts, grasslands, and savannas alters water and nutrient cycling, affecting some one-fifth of the world's population. In this talk, research along precipitation gradients in North and South America will be used to examine interactions among water, carbon and nutrients in the southwestern U.S. and in grasslands of Argentina and Uruguay. Those interactions include groundwater

R. B. Jackson; V. Engel; E. G. Jobbagy; A. J. McElrone; W. T. Pockman

2003-01-01

412

Health Risk Assessment of Fluoride Exposure in Soil, Plants, and Water at Isfahan, Iran  

Microsoft Academic Search

Fluoride is a potentially toxic element, with a narrow range of tolerable amounts taken up via food or drinking water. To evaluate F content in surface soils, 255 topsoil samples (0–20 cm) in an area of 6800 km in Isfahan province of central Iran were collected. Crop plants and randomly sampled water samples from wells were evaluated during the spring

E. Chavoshi; M. Afyuni; M. A. Hajabbasi; A. H. Khoshgoftarmanesh; K. C. Abbaspour; H. Shariatmadari; N. Mirghafari

2011-01-01

413

Ground-based RGB imaging to determine the leaf water potential of potato plants  

Microsoft Academic Search

The determination of plant water status from leaf water potential (Psi L) data obtained by conventional methods is impractical for meeting real time irrigation monitoring requirements. This research, undertaken first, in a greenhouse and then in the field, examined the use of artificial neural network (ANN) modeling of RGB (red green blue) images, captured by a ground-based, five mega pixel

Robert F. Zakaluk

2008-01-01

414

(Metabolic mechanisms of plant growth at low-water potentials): Progress report  

Microsoft Academic Search

We used soybean seedlings grown in vermiculite in a dark, humid environment because they are convenient to grow, undergo most of the physiological changes induced by low water potentials in large plants, and have exposed growing regions. We studied how growth-induced water potentials originate; which of the parameters regulating cell enlargement are the cause of the decreased rate of stem

1988-01-01

415

[Water physiological characteristics of four perennial plant species around Cele Oasis in Xinjiang].  

PubMed

The water physiological characteristics of four perennial plant species (Populus euphratica, Tamarix ramosissima, Calligonum caput-medusae, and Alhagi sparsifolia) around Cele Oasis in Xinjiang were studied through their vegetation growth period. No signs of serious drought stress were observed in any of the test perennial species during their vegetation growth, and irrigation had little effects on the water status of the plants (P > 0.05). The seasonal variation characteristics of water physiological parameters differed with the plants. A. sparsifolia had the highest predawn water potential (PWP) and daily mean sap flow, but the lowest mean water use efficiency (WUE); C. caput-medusae had the highest mean WUE, and its PWP and sap flow were stable and had less seasonal change; T. ramosissima had the lowest PWP during its growth, and had better adaptation ability to the environment; and P. euphratica had relatively stable water physiological characteristics during its growth. The four perennial plant species had deep root systems to access underground water to satisfy their large demands for water, and thus, well adapted to the harsh environmental conditions around Cele Oasis. PMID:20135993

Zeng, Fan-Jiang; Li, Xiang-Yi; Zhaneg, Xi-Ming; Foetzki, A; Arndt, S K

2009-11-01

416

Simulated Soil Water Content Effects On Plant Nitrogen Uptake and Export for Watershed Management  

Technology Transfer Automated Retrieval System (TEKTRAN)

In watershed nutrient management for water quality assessment, it is important to understand the critical pathways of nutrient cycles and nutrient transport processes from lands to the receiving water bodies. Soil moisture content influences plant nitrogen uptake significantly. This paper discussed...

417

Water Treatment Plant Operation. Volume I. A Field Study Training Program.  

ERIC Educational Resources Information Center

The purpose of this water treatment field study training program is to: (1) develop new qualified water treatment plant operators; (2) expand the abilities of existing operators, permitting better service both to employers and public; and (3) prepare operators for civil service and certification examinations (examinations administered by…

California State Univ., Sacramento. School of Engineering.

418

Evaluation of the impact of membrane change at a membrane softening water treatment plant  

Microsoft Academic Search

At the water treatment plant in Dunedin, Florida, reverse osmosis membranes remove the hardness from groundwater sources. Reverse osmosis membranes remove salts, pathogens, and organics from the feed water but can create an aggressive permeate. The membranes strip most ions in the process and the resulting permeate, if not subjected to blending on post treatment, has a tendency to leach

Michael Keen

2009-01-01

419

Water chemistry analysis of an industrial selective flocculation dispersion hematite ore concentrator plant  

Microsoft Academic Search

Hematite ore selective flocculation-dispersion process water is a complex system of ions and reagents working together to produce a concentrated iron oxide product. The purpose of this study was to determine the process water concentrations of the important ionic species in a selective flocculation–dispersion hematite ore concentrating plant while process conditions were stable. This information was used to provide a

Howard J. Haselhuhn; Joshua J. Carlson; S. Komar Kawatra

420

SEATTLE DISTRIBUTION SYSTEM CORROSION CONTROL STUDY. VOLUME 2. TOLT RIVER WATER PILOT PLANT STUDY  

EPA Science Inventory

For 6 months, the Seattle Water Department conducted a corrosion treatment pilot plant study, obtaining data on the treatment of Tolt River water with lime/sodium carbonate, lime/sodium bicarbonate, and lime/bicarbonate/silicate. Continuous-flow pipe coupon tests were conducted t...

421

Corrosion behavior of Ni-base alloys for advanced high temperature water-cooled nuclear plants  

Microsoft Academic Search

Due to the projected requirement for highly enhanced efficiency in power generation, the environment in advanced high temperature water-cooled nuclear systems becomes more rigorous compared to conventional fossil and nuclear power plants. The corrosion behavior of candidate alloys Inconel 617, 625, and 718 exposed to supercritical water was studied by a variety of analytical techniques. Grain boundary engineering (GBE) was

L. Tan; X. Ren; K. Sridharan; T. R. Allen

2008-01-01

422

Numerical Simulation of Turbulent Flow in Recycled Water Pump Intake Sump of Thermal Power Plant  

Microsoft Academic Search

The numerical simulation of flow in recycled water pump intake sump of thermal power plant is carried out by k-epsiv turbulence model. According to the results of numerical simulation, the influence of different sump sizes combination on the flow flied is valuated. On the basis of ensuring the water flowing in the sump with a good flow pattern, the optimal

Zhou Longcai; Li Xiaoyi; Song Yuansheng

2009-01-01

423

Water Treatment Plant Operation Volume 2. A Field Study Training Program. Revised.  

ERIC Educational Resources Information Center

The purpose of this water treatment field study training program is to: (1) develop new qualified water treatment plant operators; (2) expand the abilities of existing operators, permitting better service both to employers and public; and (3) prepare operators for civil service and certification examinations (examinations administered by…

California State Univ., Sacramento. School of Engineering.

424

Water Treatment Plant Operation. Volume II. A Field Study Training Program.  

ERIC Educational Resources Information Center

The purpose of this water treatment field study training program is to: (1) develop new qualified water treatment plant operators; (2) expand the abilities of existing operators, permitting better service both to employers and public; and (3) prepare operators for civil service and certification examinations (examinations administered by…

California State Univ., Sacramento. School of Engineering.

425

The photovoltaic-powered water desalination plant 'SORO' design, start up, operating experience  

NASA Astrophysics Data System (ADS)

Design features, operational parameters, and test results of a year of operation of the SORO prototype photovoltaic (PV) reverse osmosis salt water desalinization plant are described. Chemicals are added to the salt water to control the pH, prevent formation of compounds which could plug the flow system, and kill bacteria and slime which might grow in the solution. The water is pressurized and forced into contact with membranes which separate the fresh water from the brackish or sea water. The flow rate in the project was 180 l/h, with the main electrical energy load being the high pressure pump and the well pump. Batteries are charged before current is switched to power the desalinization system. The plant yielded 1.50 cu of fresh water/day and is concluded to be a viable design for scale-up to larger production figures, besides being economically competitive with solar desalinization installations where the salt content is 2000 ppm.

Neuhaeusser, G.; Mohn, J.; Petersen, G.

426

Coupling of copper–chloride hybrid thermochemical water splitting cycle with a desalination plant for hydrogen production from nuclear energy  

Microsoft Academic Search

Energy and environmental concerns have motivated research on clean energy resources. Nuclear energy has the potential to provide a significant share of energy supply without contributing to environmental emissions and climate change. Nuclear energy has been used mainly for electric power generation, but hydrogen production via thermochemical water decomposition provides another pathway for the utilization of nuclear thermal energy. One

Mehmet F. Orhan; Ibrahim Dincer; Greg F. Naterer; Marc A. Rosen

2010-01-01

427

Measurement of changes in water thickness in plant materials using very low-energy neutron radiography  

NASA Astrophysics Data System (ADS)

Low-energy neutron radiographic images of Hedera leaves were obtained using the very cold neutron (VCN) beam at Institut Laue-Langevin, France. A change in hydrogen concentration measured in a short period by means of neutron radiography indicates a change in water concentration in the plant. A regression model was evaluated to estimate changes in water thickness of the leaves and, the resolution of this method was smaller than 5 ?m. The method was effective to measure small changes in water thickness of thin plant leaves.

Matsushima, U.; Kawabata, Y.; Hino, M.; Geltenbort, P.; Nicolaï, B. M.

2005-04-01

428

Dioecy Impacts on Plant Water Fluxes in Riparian Ecosystems  

Microsoft Academic Search

Dioecious plants are frequently associated with different spatial distributions of the two sexes across resource gradients. Segregation between sexes might be expected to occur if the cost of reproduction is greater in females than in males. If so, females would be under stronger selection to increase rates of resource uptake. Acer negundo is a dioecious riparian tree species that show

K. R. Hultine; S. E. Bush; A. G. West; J. R. Ehleringer

2005-01-01

429

Soil water status influences plant nitrogen use: a case study  

Microsoft Academic Search

We studied differences in nitrogen use efficiency (NUE) among six species [Calamagrostis epigejos (L.) Roth., Carex duriuscula C.A. Mey., Phragmites communis (L.) Trin., Salix gordejevii Y.L. Chang, Salix cheilophila Schneid., and Typha minima Funk.] growing in two contrasting habitat types, i.e., a riverine wetland with high water supply and a riparian zone with\\u000a low water supply. The two sites were

Zhi-You Yuan; Ling-Hao Li

2007-01-01

430

Characterization of plutonium in ground water near the idaho chemical processing plant  

USGS Publications Warehouse

Plutonium is present in very low concentrations in ground water near the disposal well at the Idaho Chemical Processing Plant but was not detected in waters at greater distances. Because of the absence of strong complexing agents, the plutonium is present as an uncomplexed (perhaps hydrolyzed) tetravalent species, which is readily precipitated or sorbed by basalt or sediments along the ground-water flow path.

Cleveland, J.M.

1982-01-01

431

A comparison of two water potential predictors for use in plant and soil thermocouple psychrometry  

Microsoft Academic Search

Summary A linear and a non-linear equation for predicting soil and plant water potentials as measured by thermocouple psychrometric techniques were compared. The non-linear predictor was often just as accurate as the linear predictor. The non-linear predictor did not predict positive water potentials. The non-linear predictor was most accurate in the range of zero to 10 negative bars water potential

H. M. Rauscher; D. W. Smith

1978-01-01

432

The interaction of water flow and nutrients on aquatic plant growth  

Microsoft Academic Search

A long-term experiment was conducted to compare the effects of flowing and still water on growth, and the relationship between water flow and nutrients, in Aponogeton elongatus, a submerged aquatic macrophyte. A. elongatus plants were grown for 23 weeks with three levels of nutrition (0, 0.5 and 1g Osmocote Plus® fertiliser pot-1) in aquaria containing stirred or unstirred water. Fertilized

Mark N. Crossley; William C. Dennison; Richard R. Williams; Alan H. Wearing

2002-01-01

433

Compilation of data concerning know and suspected water hammer events in nuclear power plants, CY 1969  

SciTech Connect

This report compiles data concerning known and suspected water hammer events reported by BWR and PWR power plants in the United States from January 1, 1969, to May 1, 1981. This information is summarized for each event and is tabulated for all events by plant, plant type, year of occurrence, type of water hammer, system affected, basis/cause for the event, and damage incurred. Information is also included from other events not specifically identified as water hammer related. These other events involved vibration and/or system components similar to those involved in the water hammer events. The other events are included to ensure completeness of the report, but are not used to point out particular facts or trends. This report does not evaluate findings abstracted from the data.

Chapman, R.L.; Christensen, D.D.; Dafoe, R.E.; Hanner, O.M.; Wells, M.E.

1981-05-01

434

A consecutive decomposition–sintering dilatometer method to study the effect of limestone impurities on lime microstructure and its water reactivity  

Microsoft Academic Search

In this paper we develop a consecutive decomposition–sintering dilatometer method (CDSD) to study the effect of limestone impurities on lime microstructure features that are formed during the limestone decomposition. Two experimental parameters, the changing in slope of the dilatometer traces (??) and the total shrinkage of the produced lime (?) in the subsequent sintering stage, have been shown to be

D. T. Beruto; R. Botter; R. Cabella; A. Lagazzo

2010-01-01

435

Interactive effects of elevated CO{sub 2}, drought and high temperature on plant water use efficiency  

SciTech Connect

Water use efficiency (WUE) by plants is a key determinant of productivity and survival of plants under water limiting or drought conditions. The aim of this project was to develop a mechanistic basis for predicting WUE without the prohibitive task of studying every plant species under a range of environmental conditions.

Theodore C. Hsiao

1998-08-01

436

PRODUCTION AND RELEASE OF PLANT MATERIAL IN BRACKISH AND FRESHWATER WETLANDS  

EPA Science Inventory

Production, decomposition, and transport of detritus were investigated in the fresh-water and brackish water wetlands of the Altamaha River Delta, Georgia from April 17, 1978-April 1979. Maximum live standing crop biomass of Spartina cynosuroides, a brackish water marsh plant, wa...

437

[Organohalogen contamination of a dialysis-water treatment plant].  

PubMed

On March 2001 the regular quality control test of the water used for dialysis in an urban centre using a reverse osmosis system revealed a high level of organo-halogenated contamination. The compounds implicated were: trichloroethylene (trielene) [M.Wt. 131 D], tetrachloroethylene, trichloromethane (chloroform) [M.Wt. 121 D], chlorodibromomethane. The dialysis unit was closed. Water samples were analysed in duplicate. The table shows the values (in ppm or microgram/l) obtained for chloroform at the given times: March 8th, altered sample; March 12th, confirmation sample; March 16th, after osmosis membranes change; March 22nd, after carbon filtration replacement; March 26th, after softener resins substitution. The AAMI doesn't recommend any value for organo-halogenated compounds in dialysis water. In the past, the European Pharmacopoeia and the Italian Health Ministry released some reference values for tap water, values which were extended to water used for dialysis. The values are 1 ppm as reference value, 30 ppm as maximum accepted value for the sum of all organo-halogenated compounds, and 10 ppm as the recommended value. In conclusion, the problem was solved by progressive replacement of the components of the water treatment system, even though the real cause remained undetermined. No clinical symptom was recorded and no level of chloroform or trielene was detected in patients' sera despite the low molecular weight and low protein binding of the compounds. A strict control of the water quality and a more comprehensive and updated reference guide are needed for better and safer dialysis delivery. PMID:12369053

Formica, M; Vallero, A; Forneris, G; Cesano, G; Pozzato, M; Borca, M; Iadarola, G M; Quarello, F

2002-01-01

438

Water Status of Arctic Tundra Plants During the Winter-Spring Transition  

NASA Astrophysics Data System (ADS)

The arctic winter-spring transition when full snow cover rapidly changes to snow-free conditions potentially represents a time of physiological stress for tundra plants. Plants that have been subjected to freezing temperatures for several months over winter are suddenly exposed to high radiation loads from clear skies and reflection from unmelted snow. Water uptake at this time may be limited by low stem temperatures and cold or even frozen soils. Because of these potential stresses it may be advantageous for plants to delay photosynthetic activity and water loss until soils are warmer. However, given the short length of the growing season, the optimal strategy for plants may be to maximize carbon uptake and begin photosynthesis and growth as soon as possible after snowmelt. Some tundra evergreens even photosynthesize under snow cover. To test the hypothesis that plant water stress increases immediately following loss of snow cover, we investigated xylem and leaf osmotic potentials of evergreen tundra species before and immediately after snowmelt. We also compared these measurements with summer and winter measurements. Our study was conducted in moist acidic tundra near Toolik Field Station in the northern foothills of the Brooks Range, Alaska. Xylem water potentials were measured by Scholander pressure chamber and osmotic potentials by psychrometry of cell sap expressed from frozen (-80 °C) leaf tissue. Xylem water potentials under snow were generally higher than those of plants recently released from snow. Osmotic potentials measured before and after snowmelt did not show evidence of strong changes. Some species, such as Ledum palustre, maintained high water potentials both under snow and shortly after snow melt. With only a few exceptions, water potentials just after melt out were generally higher than those after soils had warmed and plants had greened up. Low water potentials (< -3 MPa) were most commonly found in Cassiope tetragona, a snowbed-associated species that showed noticeable shoot mortality in two of the three sample years. Winter measurements revealed low water potentials in some samples of Cassiope tetragona, Empetrum nigrum, and Vaccinium vitis-ideae. However, considerable variation in water potentials was found under both snow-covered and snow-free conditions and among the three sample years, likely as a result of differences in winter temperature regimes and snow cover properties. Changes in winter temperature and snow cover regimes will likely have important consequences for plant water status and shoot mortality during winter and the spring thaw.

Oberbauer, S. F.; Olivas, P. C.; Moser, J.; Starr, G.; Mortazavi, B.

2012-12-01

439

Comparison of Austenite Decomposition Models During Finite Element Simulation of Water Quenching and Air Cooling of AISI 4140 Steel  

NASA Astrophysics Data System (ADS)

An indigenous, non-linear, and coupled finite element (FE) program has been developed to predict the temperature field and phase evolution during heat treatment of steels. The diffusional transformations during continuous cooling of steels were modeled using Johnson-Mehl-Avrami-Komogorov equation, and the non-diffusion transformation was modeled using Koistinen-Marburger equation. Cylindrical quench probes made of AISI 4140 steel of 20-mm diameter and 50-mm long were heated to 1123 K (850 °C), quenched in water, and cooled in air. The temperature history during continuous cooling was recorded at the selected interior locations of the quench probes. The probes were then sectioned at the mid plane and resultant microstructures were observed. The process of water quenching and air cooling of AISI 4140 steel probes was simulated with the heat flux boundary condition in the FE program. The heat flux for air cooling process was calculated through the inverse heat conduction method using the cooling curve measured during air cooling of a stainless steel 304L probe as an input. The heat flux for the water quenching process was calculated from a surface heat flux model proposed for quenching simulations. The isothermal transformation start and finish times of different phases were taken from the published TTT data and were also calculated using Kirkaldy model and Li model and used in the FE program. The simulated cooling curves and phases using the published TTT data had a good agreement with the experimentally measured values. The computation results revealed that the use of published TTT data was more reliable in predicting the phase transformation during heat treatment of low alloy steels than the use of the Kirkaldy or Li model.

Babu, K.; Prasanna Kumar, T. S.

2014-08-01

440

Determination of the ?2H and ?18O of soil water and water in plant matter; RSIL lab code 1700  

USGS Publications Warehouse

The purpose of the Reston Stable Isotope Laboratory lab code 1700 is to determine the ?2H/1H), abbreviated as ?2H, and the ?18O/16O), abbreviated as ?18O, of soil water and water in plant matter. This method is based on the observation that water and toluene form an azeotropic mixture at 84.1 °C. This temperature is substantially lower than the boiling points of water (100 °C) and toluene (110 °C), but water and toluene are immiscible at ambient temperature. The water content of a soil or plant is determined by weighing, drying, and reweighing a small amount of sample. Sufficient sample to collect 3 to 5 milliliters of water after distillation is loaded into a distillation flask. Sufficient toluene is added so that the sample is immersed throughout the entire distillation to minimize evaporation of water, which would affect the ?2H and ?18O values. The mixture of sample and toluene is heated in a flask to its boiling point (84.1 °C) so that water from the sample and toluene can distill together into a specially designed collection funnel. The temperature of 84.1 °C is maintained until the water has been quantitatively transferred to the collection funnel, at which time the temperature is raised to the boiling point of the remaining component (toluene, 110 °C). The collection funnel is maintained at ambient temperature so that the sample water and toluene can be separated physically. After separation, the sample water is purified by addition of paraffin wax to the container with the sample water, capping the container, and heating to approximately 60 °C to melt the wax. Trace amounts of toluene will dissolve in the wax, purifying the sample water for isotopic analysis. The isotopic composition of the purified water is then determined by equilibration with gaseous hydrogen or carbon dioxide, followed by dual-inlet isotope-ratio mass spectrometry. Because laser-absorption spectrometry is sensitive to organic compounds, such as trace toluene remaining in water samples, water samples should be analyzed for isotopic composition only by mass spectrometry and not by laser-absorption spectrometry.

Revesz, Kinga M.; Buck, Bryan; Coplen, Tyler B.

2012-01-01

441

Water Relations of Cotton Plants under Nitrogen Deficiency  

PubMed Central

Suboptimal N nutrition increased the water potential for stomatal closure in water stressed cotton (Gossypium hirsutum L.) leaves. This increased sensitivity to water stress had two components, increased accumulation of abscisic acid (ABA) and increased apparent stomatal sensitivity to ABA. Low N increased the threshold water potentials for stomatal closure and ABA accumulation by about 4 bars and 2 bars, respectively. Low N also greatly increased stomatal response to low concentrations of exogenous ABA applied to excised leaves through the transpiration stream. In low N leaves, kinetin decreased stomatal response to ABA to the level observed with high N leaves. Kinetin by itself had little effect on stomata, nor did it alter stomatal response to ABA in high N leaves. The results suggest a cytokinin-ABA balance which is altered by suboptimal N nutrition to favor stomatal closure during stress. Ambient temperature and N nutrition interacted to alter stomatal response to water stress. Stress-induced ABA accumulation and apparent stomatal sensitivity to ABA were independently affected. The effects of each treatment, and their interaction, could be explained as the net result of changes in both accumulation and apparent sensitivity. Although the results document environmental control of stomatal response to ABA, either altered partitioning of ABA between active and inactive pools, or altered sensitivity of the guard cells, could account for the data. PMID:16662614

Radin, John W.; Parker, Linda L.; Guinn, Gene

1982-01-01

442

A three step approach for removing organic matter from South African water sources and treatment plants  

NASA Astrophysics Data System (ADS)

The high variability in the levels and composition of natural organic matter (NOM) in South-African water sources in different regions means that no single treatment process can be prescribed for each water treatment plant operating in the country. In order to remove NOM from water in a water treatment train, the composition of the NOM in the source water must be taken into account, especially as it may not necessarily be uniform since the composition is dependent on local environmental situation. The primary objective of this study was to characterise the NOM present in South African source waters through an extensive sampling of representative water types across the country and then develop a rapid NOM characterisation protocol. Water samples were thus collected from eight different water treatment plants located throughout the country at different sites of their water treatment trains. Raw water samples, the intermediate samples before filtration and water samples before disinfection were collected at these drinking water treatment plants. The fluorescence excitation-emission matrices (FEEMs), biodegradable dissolved organic carbon (BDOC), ultraviolet (UV) characterisation (200-900 nm) and dissolved organic carbon (DOC) analysis were used to characterise the NOM in the water samples. The FEEM and UV results revealed that the samples were composed mainly of humic substances with a high UV-254 absorbance, while some samples had marine humic substances and non-humic substances. The sample’s DOC results were within the range of 3.25-21.44 mg C/L, which was indicative of the varying nature of the NOM composition in the regions where samples were obtained. The BDOC fraction of the NOM, on the other hand, ranged from 20% to 65%, depending on the geographical location of the sampling site. It is evident from the results obtained that the NOM composition varied per sampling site which would eventually have a bearing on its treatability. The various water treatment processes employed at the different treatment plants were able to effectively reduce NOM, as evidenced by a percentage DOC removal of between 11% and 85%. The highest DOC removal was achieved at the treatment plants that had highly humic and coloured raw water sources.

Nkambule, T. I.; Krause, R. W. M.; Haarhoff, J.; Mamba, B. B.

443

Worldwide assessment of steam-generator problems in pressurized-water-reactor nuclear power plants  

SciTech Connect

Objective is to assess the reliability of steam generators of pressurized water reactor (PWR) power plants in the United States and abroad. The assessment is based on operation experience of both domestic and foreign PWR plants. The approach taken is to collect and review papers and reports available from the literature as well as information obtained by contacting research institutes both here and abroad. This report presents the results of the assessment. It contains a general background of PWR plant operations, plant types, and materials used in PWR plants. A review of the worldwide distribution of PWR plants is also given. The report describes in detail the degradation problems discovered in PWR steam generators: their causes, their impacts on the performance of steam generators, and the actions to mitigate and avoid them. One chapter is devoted to operating experience of PWR steam generators in foreign countries. Another discusses the improvements in future steam generator design.

Woo, H.H.; Lu, S.C.

1981-09-15

444

76 FR 66779 - Endangered and Threatened Wildlife and Plants; Removal of the Concho Water Snake From the Federal...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Wildlife and Plants; Removal of the Concho Water Snake From the Federal List of Endangered...Wildlife and Plants; Removal of the Concho Water Snake From the Federal List of Endangered...commercial data indicate that the Concho water snake (Nerodia paucimaculata), a...

2011-10-27

445