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1

Nuclear driven water decomposition plant for hydrogen production  

Microsoft Academic Search

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

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

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

Are fire, soil fertility and toxicity, water availability, plant functional diversity, and litter decomposition related in a Neotropical savanna?  

PubMed

Understanding how biodiversity and ecosystem functioning respond to changes in the environment is fundamental to the maintenance of ecosystem function. In realistic scenarios, the biodiversity-ecosystem functioning path may account for only a small share of all factors determining ecosystem function. Here, we investigated the strength to which variations in environmental characteristics in a Neotropical savanna affected functional diversity and decomposition. We sought an integrative approach, testing a number of pairwise hypotheses about how the environment, biodiversity, and functioning were linked. We used structural equation modelling to connect fire frequency, soil fertility, exchangeable Al, water availability, functional diversity of woody plants, tree density, tree height, and litter decomposition rates in a causal chain. We found significant effects of soil nutrients, water availability, and Al on functional diversity and litter decomposition. Fire did not have a significant direct effect on functional diversity or litter decomposition. However, fire was connected to both variables through soil fertility. Functional diversity did not influence rates of litter decomposition. The mediated effects that emerged from pairwise interactions are encouraging not only for predicting the functional consequences of changes in environmental variables and biodiversity, but also to caution against predictions based on only environmental or only biodiversity change. PMID:24748157

Carvalho, Gustavo Henrique; Batalha, Marco Antônio; Silva, Igor Aurélio; Cianciaruso, Marcus Vinicius; Petchey, Owen L

2014-07-01

4

Decomposition of Aquatic Plants in Lakes.  

National Technical Information Service (NTIS)

This study was carried out to systematically determine the effects of temperature and oxygen concentration, two environmental parameters crucial to lake metabolism in general, on decomposition of five species of aquatic vascular plants of three growth for...

G. L. Godshalk

1977-01-01

5

Decomposition of water behind reflected shock waves  

Microsoft Academic Search

Water was introduced into a shock tube via two reactions: Dâ + Oâ and Dâ + COâ. The decomposition was measured in an Ar--Kr diluent by recording the infrared emission from DâO through an interference filter centered at 3.8 ..mu..m. The resulting intensity--time profiles were fit to a first-order decay equation. The apparent decomposition rate constants derived from both sets

J. M. Bopp; R. D. Kern; T. Niki

1978-01-01

6

Hydrogen Production by the Decomposition of Water.  

National Technical Information Service (NTIS)

A process is described for the production of hydrogen from water by a sulfuric acid process employing electrolysis and thermo-chemical decomposition. The water containing SO sub 2 is electrolyzed to produce H sub 2 at the cathode and to oxidize the SO sub...

C. M. Hollabaugh M. G. Bowman

1979-01-01

7

Decomposition of water hyacinth detritus in eutrophic lake water  

Microsoft Academic Search

A study was conducted to determine the seasonal production of detritus by water hyacinths [Eichhornia crassipes (Mart.) Sohns] cultured in eutrophic Lake Apopka water, and the decomposition of detritus in situ and under laboratory conditions. Annual averages for C, N and P deposited through detritus production at the sediment-water interface were 2870, 176 and 19 kg ha-1 yr-1, respectively.

K. R. Reddy; W. F. DeBusk

1991-01-01

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

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

10

MASCOT - A bench-scale plant for producing hydrogen by the UT3 thermochemical decomposition cycle  

Microsoft Academic Search

A bench-scale plant for producing hydrogen has been constructed on the basis of the thermochemical water-decomposition process, UT-3, consisting of Br, Ca and Fe compounds. This plant is named MASCOT (Model Apparatus for Studying Cyclic Operation in Tokyo) and is designed to be capable of producing 3 1\\/h of gaseous hydrogen at standard conditions. During several test runs, the continuous

T. Nakayama; H. Yoshioka; H. Furutani; H. Kameyama; K. Yoshida

1984-01-01

11

The Decomposition of Petroleum Products in Our Natural Waters.  

National Technical Information Service (NTIS)

The overall objective of this investigation was to study the decomposition of crude and refined petroleum products in our natural waters. More specifically, the aims of this proposal were (1) to investigate the physical, chemical, and microbiological chan...

L. R. Brown R. G. Tischer

1969-01-01

12

Decomposition of tetrafluoromethane by water plasma generated under atmospheric pressure  

Microsoft Academic Search

Tetrafluoromethane (CF4) decomposition by water plasma generated under atmospheric pressure was investigated by means of thermodynamic analyses and experiments. Thermodynamic equilibrium calculations were performed between 300 and 6000K at atmospheric pressure. Experimental results indicated that CF4 was completely decomposed by water plasma, and recovery of fluorine can be achieved more than 99%. Influence of factors such as arc current and

Narengerile; Hironori Saito; Takayuki Watanabe

2009-01-01

13

Hydrogen peroxide deposition and decomposition in rain and dew waters  

NASA Astrophysics Data System (ADS)

Peroxides and hydrogen peroxide were determined by a fluorometric method in dew and rain collected in the atmosphere of Santiago of Chile city. The measured peroxides comprise hydrogen peroxide (the main component) and peroxides not decomposed by catalase. The collected natural peroxides readily decompose in the natural matrix, rendering difficult an estimation of the values present in real-time. In order to establish the kinetics of the process and the factors that condition their decomposition, the kinetics of the decay at several pHs and/or the presence of metal chelators were followed. The kinetics of hydrogen peroxide decomposition in the water matrix was evaluated employing the natural peroxides or hydrogen peroxide externally added. First-order kinetics was followed, with half decay times ranging from 80 to 2300 min. The addition of Fe(II) in the micromolar range increases the decomposition rate, while lowering the pH (<3) notably reduces the rate of the process. The contribution of metals to the decomposition of the peroxides in the natural waters was confirmed by the reduction in decomposition rate elicited by its treatment with Chelex-100. Dew and rain waters were collected in pre-acidified collectors, rendering values considerably higher than those measured in non-treated collectors. This indicates that acidification can be proposed as an easy procedure to stabilize the samples, reducing its decomposition during collection time and the time elapsed between collection and analysis. The weighted average concentration for total peroxides measured in pre-treated collectors was 5.4 ?M in rains and 2.2 ?M in dews.

Ortiz, Vicky; Angélica Rubio, M.; Lissi, Eduardo A.

14

Kinetics of the pyrolytic and hydrothermal decomposition of water hyacinth.  

PubMed

The kinetics of water hyacinth decomposition using pyrolysis and hydrothermal treatment was compared. With pyrolysis, initial vaporization occurred at 453 K as determined by thermogravimetric analysis, while initial solubilisation occurred at 433 K with subcritical hydrothermal treatment. The "kinetic triplet" was determined for the ranges of 423-483 K (range I) and 473-553 K (range II) using the Coats-Redfern method for both treatments. The calculated activation energies for ranges I and II were 110 and 116 kJ/mol for conventional pyrolysis and 145 and 90 kJ/mol for hydrothermal treatment. The similar activation energies for the two temperature ranges observed for pyrolysis implied that only hemicellulose decomposition occurred. For hydrothermal treatment, both hemicellulose and cellulose decomposition occurred in temperature range II, in which a notable lower activation energy was observed. This implied hydrothermal treatment was more suitable for conversion lignocellulosic biomass under these conditions. PMID:21558054

Luo, Guang'en; Strong, P James; Wang, Hailong; Ni, Wuzhong; Shi, Weiyong

2011-07-01

15

Black carbon decomposition under varying water regimes  

Microsoft Academic Search

The stability of biomass-derived black carbon (BC) or biochar as a slow cycling pool in the global C cycle is an important property and is likely governed by environmental conditions. This study investigated the effects of water regimes (saturated, unsaturated and alternating saturated–unsaturated conditions) and differences in BC materials, produced by carbonizing corn residues and oak wood at two temperatures

Binh Thanh Nguyen; Johannes Lehmann

2009-01-01

16

Hydrogen Production from Thermal Decomposition of Water.  

National Technical Information Service (NTIS)

Conclusions concerning this research are summarized below: (1) The dual membrane approach is based on the use of a metal membrane (such as Mo) for decomposing water at its heated surface and simultaneous permeation of hydrogen. This approach had to be dis...

H. H. G. Jellinek H. Kachi Y. Kitamura K. Juznic

1982-01-01

17

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

18

Decomposition and Terapascal Phases of Water Ice  

NASA Astrophysics Data System (ADS)

Computational searches for stable and metastable structures of water ice and other H:O compositions at TPa pressures have led us to predict that H2O decomposes into H2O2 and a hydrogen-rich phase at pressures of a little over 5 TPa. The hydrogen-rich phase is stable over a wide range of hydrogen contents, and it might play a role in the erosion of the icy component of the cores of gas giants as H2O comes into contact with hydrogen. Metallization of H2O is predicted at a higher pressure of just over 6 TPa, and therefore H2O does not have a thermodynamically stable low-temperature metallic form. We have also found a new and rich mineralogy of complicated water ice phases that are more stable in the pressure range 0.8-2 TPa than any predicted previously.

Pickard, Chris J.; Martinez-Canales, Miguel; Needs, Richard J.

2013-06-01

19

Effects of hydrology on short term plant decomposition and nutrient content in a re-created Everglades wetland  

NASA Astrophysics Data System (ADS)

The effect of water depth and flow on tissue nutrients and decomposition rates of marsh plant species, and soil chemistry in vegetated plots was measured in the Loxahatchee Impoundment Landscape Assessment (LILA) facility in Boynton Beach, Florida, USA. The LILA facility consists of replicated wetland macrocosms that mimic Everglades ridge-and-slough landscape features. The experiments were conducted in two macrocosms that each had three habitats at different water depths (ridge, shallow slough and deep slough) but differed in flow. Decomposition rates of three common Everglades species, Cladium jamaicense (sawgrass), Eleocharis cellulosa (spikerush), and Nymphaea odorata (white water lily), were measured using litter bags incubated during both a wet and dry condition. Litter bag losses were more pronounced under wet conditions, and decomposition rates were not affected by the hydrologic conditions in this experiment, but rather by litter nutrient content and species. Litter nutrient (TC, TN, TP) concentrations varied over time. Species rich in the limiting nutrient (P) in the ecosystem decomposed faster. Therefore, N. odorata decomposed faster than C. jamaicense and E. cellulosa, confirming the importance of P availability in controlling microbial processes in the Everglades. Planted species had no effect on soil nutrient content over the 3 yrs period of plant growth in these plots. Our results have contributed to defining potential flow targets for restoration in Florida's Everglades by showing that average water velocities of 0.5 cm s-1 may not be sufficient to drive ecosystem changes in decomposition rates for the native species and soil chemistry.

Serna, A.; Richards, J.; Scinto, L.

2012-12-01

20

Decomposition methods for water resources optimization models with fixed costs  

NASA Astrophysics Data System (ADS)

This paper illustrates the application of two decomposition algorithms, generalized Benders decomposition (GBD) and outer approximation (OA), to water resources problems involving cost functions with both discrete and nonlinear terms. Each algorithm involves the solution of an alternating finite sequence of nonlinear programming subproblems and relaxed versions of a mixed-integer linear programming master problem. Three example models, involving capacity expansion of a conjunctively managed surface and groundwater system, are formulated and solved to demonstrate the performance of the algorithms. The results show that OA obtains solutions in far fewer iterations than GBD, but OA requires more computational resources per iteration. As a result, depending on the mixed-integer programming and nonlinear programming solvers available, GBD may be better suited for solving larger planning problems.

Watkins, David W.; McKinney, Daene C.

21

PCB decomposition and formation in thermal treatment plant equipment.  

PubMed

In this study we investigated both the decomposition and unintentional formation of polychlorinated biphenyl congeners during combustion experiments of refuse-derived fuel (RDF) and automobile shredder residue (ASR) at several stages in thermal treatment plant equipment composed of a primary combustion chamber, a secondary combustion chamber, and other equipments for flue gas treatment. In both experiments, the unintentional formation of PCB occurred in the primary combustion chamber at the same time as the decomposition of PCB in input samples. By combusting RDF, non-ortho-PCB predominantly formed, whereas ortho-PCB and symmetric chlorinated biphenyls (e.g., #52/69, #87/108, and #151) tended to be decomposed. ASR formed the higher chlorinated biphenyls more than RDF. These by-products from ASR had no structural relation with ortho-chlorine. Lower chlorinated biphenyls appeared as predominant homologues at the final exit site, while all congeners from lower to higher chlorinated PCB were unintentionally formed as by-products in the primary combustion chamber. This result showed that the flue gas treatment equipments effectively removed higher chlorinated PCB. Input marker congeners of RDF were #11, #39, and #68, while those for ASR were #11, #101, #110/120, and #118. Otherwise, combustion marker congeners of RDF were #13/12, #35, #77, and #126, while those for ASR were #170, #194, #206, and #209. While the concentration of PCB increased significantly in the primary combustion chamber, the value of toxicity equivalency quantity for dioxin-like PCB decreased in the secondary combustion chamber and the flue gas treatment equipments. PMID:17134732

Ishikawa, Yukari; Noma, Yukio; Yamamoto, Takashi; Mori, Yoshihito; Sakai, Shin-ichi

2007-04-01

22

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

23

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

24

Additive Effect of Water on the Decomposition of VOCs in Nonthermal Plasma  

Microsoft Academic Search

In the removal of volatile organic compounds (VOCs) with nonthermal plasma (NTP), the additive effect of water on VOC decomposition is an important issue to be solved since water is contained in VOC exhausts. Although there have been disputed discussions on the additive effect of water on the decomposition of VOCs in NTP, a unified mechanism has not been established

Masami Sugasawa; Tomoyuki Terasawa; Shigeru Futamura

2010-01-01

25

Laboratory and Plant Investigations on Decomposition Products of Morpholine in the Secondary System of French PWR.  

National Technical Information Service (NTIS)

Laboratory and plant tests have been carried out on French PWR operating with morpholine treatment. Morpholine decomposition products are one significant origin (but not the only one) of organic acids in the secondary system. Acetic and formic acids are r...

V. Dauvois I. Lambert D. Desmoulins F. Nordmann

1986-01-01

26

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

27

Atmospheric water vapor as driver of litter decomposition during rainless seasons  

NASA Astrophysics Data System (ADS)

Litter production in many drought-affected ecosystems coincides with the beginning of an extended season of no or limited rainfall. Because of lack of moisture litter decomposition during such periods has been largely ignored so far, despite potential importance for the overall decay process in such ecosystems. To determine drivers and extent of litter decay in rainless periods a litterbag study was conducted in Mediterranean shrublands, dwarf shrublands and grasslands. Heterogeneous local and common straw litter was left to decompose in open and shaded patches of various field sites in two study regions. Fresh local litter lost 4-18% of its initial mass over about 4 months without rainfall, which amounted to 15-50% of total annual decomposition. Lab incubations and changes in chemical composition suggested that litter was degraded by microbial activity, enabled by absorption of water vapor from the atmosphere. High mean relative humidity of 85% was measured during 8-9 h of most nights, but the possibility of fog deposition or dew formation at the soil surface was excluded. Over 95% of the variation in mass loss and changes in litter nitrogen were explained by characteristics of water-vapor uptake by litter. Photodegradation induced by the intense solar radiation was an additional mechanism of litter decomposition as indicated by lignin dynamics. Lignin loss from litter increased with exposure to ultraviolet radiation and with initial lignin concentration, together explaining 90-97% of the variation in lignin mass change. Results indicate that water vapor is a driver of litter decay which has been ignored so far. Water-vapor absorption presumably enables microbial degradation, which, together with solar radiation and litter quality, controls decomposition and changes in litter chemistry during rainless seasons. Warmer and drier conditions as a consequence of climate change will result in enhanced drying of litter layers also outside currently classified drylands. In addition, land-use change, e.g. logging, and fire open up plant canopies and significantly enhance dehydration of litter. With a large part of the land area affected by climate change, land-use change and/or fire, drying of litter layers is probably already a common phenomenon and might be more so in the future. Therefore, absorption of water vapor might play a role in decomposition and nutrient cycling in an increasing number of ecosystems.

Dirks, I.; Navon, Y.; Kanas, D.; Dumbur, R.; Grünzweig, José

2010-05-01

28

The liquid hydrogen iodide decomposition process step for water-splitting applications  

NASA Astrophysics Data System (ADS)

The reported studies are concerned with the optimization of the sulfur-iodine cycle used to obtain hydrogen from water. According to this cycle, sulfur dioxide reacts with iodine and water to form sulfuric acid and hydrogen iodide. Hydrogen and iodine are obtained as a result of the decomposition of HI. The homogeneous decomposition of HI could be used directly in a thermochemical process to split water. However, the temperature required would be relatively high. Catalyst utilization allows substantial temperature reduction for the same conversion rate. The decomposition of liquid HI is studied as another approach for enhancing HI conversion. A process step for liquid HI decomposition employing HI-I2 distillation is considered along with a process step for liquid HI decomposition employing I2 precipitation. The theoretical investigations were supplemented by precursory experimental studies to establish more fully the engineering viability of liquid HI decomposition.

Okeefe, D. R.; Norman, J. H.

29

[Characteristics of the biochemical composition of plant litter at different stages of decomposition (according to thermal analysis data)].  

PubMed

The composition of samples of needles, leaves, sheaved cottongrass (Eriophorum vaginatum) tissues, and the L horizon of the forest floor of different degree of decomposition, isolated from the plant litter in southern taiga ecosystems, was studied by thermal analysis. It was established that plant litter decomposition is accompanied by structural changes in celluloses and that the decomposition rates of hemicellulose and structured cellulose vary at different stages of decomposition. The structural specificity and incongruent thermal decomposition of grass lignocellulose were observed in all samples of plant material. The rates at which the content of components of the plant litter decreased depended on the type and stage of decomposition of plant material. The decomposition rate of biochemical components tended to increase in better drained soils. PMID:18491564

Kosheleva, Iu P; Trofimov, S Ia

2008-01-01

30

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

31

Manganese Cycling in a Long-term Plant Litter Decomposition Time Series  

NASA Astrophysics Data System (ADS)

Climate change is predicted to affect the chemical composition of plant litter, and global warming may increase microbial and enzymatic activity, with uncertain consequences for litter decomposition rates in soils. This uncertainty has highlighted the need to better understand the controls on litter decomposition rates and pathways. A key controlling processes that is poorly understood is the coupling between decomposition pathways and the inorganic resources available in fresh litter or the underlying soil. For example, a strong correlation was established between the concentration of manganese (Mn) in needle litter and the degradation of litter lignocellulose across boreal forest ecosystems, suggesting that litter decomposition proceeds more efficiently in the presence of Mn. There is good reason to assume that this is due to the critical role of Mn(III)-ligand complexes acting as potent oxidizers in the fungal decomposition of lignocellulose. Here we investigated how litter decomposing organisms redistribute and repurpose the Mn inherently present in fresh plant litter in order to enhance decomposition. For this purpose, we used two 7-year litter decomposition time series collected at sites at the H.J. Andrews Experimental Forest with widely differing decomposition rates. Spatially-resolved X-ray absorption spectroscopy and wet-chemical extractions were used to track pathways of microbially-mediated Mn transport and associated changes in its speciation in each annual litter layer. The cycling of Mn and other metal cations (e.g., Ca and Fe) was then related to changes in the litter chemistry as documented by 13C TMAH and FTIR. Our results show that, as litter decomposition progresses, reduced Mn in the vascular system of fresh needles is transformed into oxidized forms concentrated in Mn oxide precipitates. This transformation of Mn into more reactive forms proceeds faster at the site of greater decomposition. Our imaging data suggests that during this process Mn is redistributed from the vascular system of fresh needles towards lignocellulose-rich cell walls that are being decomposed by fungi.

Keiluweit, M.; Nico, P. S.; Kleber, M.; Bougoure, J.; Harmon, M. E.; Pett-Ridge, J.

2012-12-01

32

Emissions of volatile organic compounds during the decomposition of plant litter  

NASA Astrophysics Data System (ADS)

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 analyzed VOCs emitted by microbes or by abiotic mechanisms during the decomposition of litter from 12 plant species in a laboratory experiment using proton transfer reaction mass spectrometry (PTR-MS). Net emissions from litter with active microbial populations (non-sterile litters) were between 0 and 11 times higher than emissions from sterile controls over a 20-d incubation period, suggesting that abiotic sources of VOCs are generally less important than biotic sources. In all cases, the sterile and non-sterile litter treatments emitted different types of VOCs, with methanol being the dominant VOC emitted from litters during microbial decomposition, accounting for 78 to 99% of the net emissions. We also found that the types of VOCs released during biotic decomposition differed in a predictable manner among litter types with VOC profiles also changing as decomposition progressed over time. These results show the importance of incorporating both the biotic decomposition of litter and the species-dependent differences in terrestrial vegetation into global VOC emission models.

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

2010-09-01

33

Decomposition Trends of Five Plant Litter Types in Mitigated and Reference Wetlands in West Virginia, USA  

Microsoft Academic Search

Decomposition of organic matter in wetlands is linked to numerous wetland processes, making it a useful metric to assess wetland\\u000a function. We measured plant litter decomposition rates in three mitigated and three reference wetlands located in the Allegheny\\u000a Mountains of West Virginia, from 2007 to 2009. Four common wetland species were used: broadleaf cattail (Typha latifolia L.), common rush (Juncus

R. Tristan Gingerich; James T. Anderson

34

[Decomposition of different plant litters in Loess Plateau of Northwest China].  

PubMed

Taking the litters of species Hippophae rhamnoides, Medicago sativa, Populus simonii, Robinia pseudoacaci, Salix psammophila, and Stipa bungeana in the Loess Plateau of Northeast China as test objects, and by using mesh bags, this paper studied the dynamic changes of the litters mass, carbon, and nitrogen during decomposition after buried in the field in semiarid region. The litters buried were from one, two, or three of the plant species, and mixed thoroughly with equal proportion of masses. During decomposition, the mass loss rate, total carbon and nitrogen release rates, and total soluble carbon and nitrogen contents of different litters were higher at the early than at the later decomposition stage. After 412 d decomposition, the average mass loss rate of the litters was in the order of mixed litters of three plant species > mixed litters of two plant species > one plant species litter. By the end of this experiment, the average release rates of the litter total carbon and nitrogen ranked as one plant species litter > mixed litters of two plant species > mixed litters of three plant species, the litter soluble organic carbon content was mixed litters of two plant species > mixed litters of three plant species > one plant species litter, while the litter soluble total nitrogen content was mixed litters of three plant species > mixed litters of two plant species > one plant species litter. Correlation analysis showed that the litter mass loss rate had definite correlation with the litter soluble organic matter, especially soluble organic carbon. From the viewpoint of mass loss rate, the mixture of the litters of P. simonii, H. rhamnoide, and M. sativa was the optimum. It was suggested that in the process of returning farmland into forestland and grassland in the gully and valley region of Loess Plateau, it would be required to rationally increase plant species diversity to improve soil fertility. PMID:23479871

Li, Yun; Zhou, Jian-Bin; Dong, Yan-Jie; Xia, Zhi-Min; Chen, Zhu-Juin

2012-12-01

35

Stability of supported platinum sulfuric acid decomposition catalysts for use in thermochemical water splitting cycles  

Microsoft Academic Search

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 (96wt%) at atmospheric pressure at temperatures between 800 and 850?C and a weight hour space

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

2007-01-01

36

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

37

Experimental sets for process monitoring of water-oil emulsion decomposition during microwave heating  

Microsoft Academic Search

The question of experimental set construction for research of water-oil emulsion decomposition processes under influence of microwave electromagnetic field are considered. Metrological characteristics of sets are given and the prospects of application are determined.

N. V. Dorogov; M. R. Galimov; R. G. Galimov; Y. A. Korpatchev; O. G. Morozov; G. A. Morozov; Y. E. Sedeinikov

2000-01-01

38

Linking Predation Risk, Herbivore Physiological Stress and Microbial Decomposition of Plant Litter  

PubMed Central

The quantity and quality of detritus entering the soil determines the rate of decomposition by microbial communities as well as recycle rates of nitrogen (N) and carbon (C) sequestration1,2. Plant litter comprises the majority of detritus3, and so it is assumed that decomposition is only marginally influenced by biomass inputs from animals such as herbivores and carnivores4,5. However, carnivores may influence microbial decomposition of plant litter via a chain of interactions in which predation risk alters the physiology of their herbivore prey that in turn alters soil microbial functioning when the herbivore carcasses are decomposed6. A physiological stress response by herbivores to the risk of predation can change the C:N elemental composition of herbivore biomass7,8,9 because stress from predation risk increases herbivore basal energy demands that in nutrient-limited systems forces herbivores to shift their consumption from N-rich resources to support growth and reproduction to C-rich carbohydrate resources to support heightened metabolism6. Herbivores have limited ability to store excess nutrients, so stressed herbivores excrete N as they increase carbohydrate-C consumption7. Ultimately, prey stressed by predation risk increase their body C:N ratio7,10, making them poorer quality resources for the soil microbial pool likely due to lower availability of labile N for microbial enzyme production6. Thus, decomposition of carcasses of stressed herbivores has a priming effect on the functioning of microbial communities that decreases subsequent ability to of microbes to decompose plant litter6,10,11. We present the methodology to evaluate linkages between predation risk and litter decomposition by soil microbes. We describe how to: induce stress in herbivores from predation risk; measure those stress responses, and measure the consequences on microbial decomposition. We use insights from a model grassland ecosystem comprising the hunting spider predator (Pisuarina mira), a dominant grasshopper herbivore (Melanoplus femurrubrum),and a variety of grass and forb plants9.

Schmitz, Oswald J.; Bradford, Mark A.; Strickland, Michael S.; Hawlena, Dror

2013-01-01

39

Dry Season Decomposition of Leaf Litter from Five Common Plant Species of West Africa  

Microsoft Academic Search

The rates of decomposition of litter from five plant species common to West Africa namely: Chromolaena odorata (Siam weed), Anacardium occidentale (cashew), Acioa batteri, Imperata cylindrica (spear grass) and Pentaclethra macrophylla (oil bean) were investigated in the laboratory and the field during the dry season using respiration and litter bag techniques.There were significant differences (P< 0.05) amongst the species in

N. N. Agbim

1987-01-01

40

Power Plant Water Intake Assessment.  

ERIC Educational Resources Information Center

In order to adequately assess the impact of power plant cooling water intake on an aquatic ecosystem, total ecosystem effects must be considered, rather than merely numbers of impinged or entrained organisms. (Author/RE)

Zeitoun, Ibrahim H.; And Others

1980-01-01

41

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.

42

A Modal Decomposition of the Rotating Shallow Water Equations  

NASA Astrophysics Data System (ADS)

The dynamics of the atmosphere and oceans are complicated because of the vast range of length and time scales involved. Understanding how energy cascades from the large to small scales is an outstanding problem in the field and of great interest. In any attempt to do this it is always necessary to specify the physical structure of the basis functions. Perhaps the most popular choice are Fourier modes, which are desirable because they 1) can form a complete basis; 2) are well understood because of the richness of Fourier analysis; and 3) are a basis for high-order spectral methods. This is a convenient choice but numerous other possibilities exist, such as polynomials and wavelets. All of these choices are generic in that they do not arise from the underlying physics of the waves and can usually be applied to virtually any problem. The motivation for this work stems from the idea that a better choice for basis functions should be dictated by the model equations. One relatively simple model that has often been used to looked at energy transfers between different length and time scales is the Rotating Shallow Water model (RSW). It is restrictive in that it only describes homogeneous fluids, however, because it can contain both fast gravity and slow Rossby waves it is a useful paradigm to study energy transfers between waves with vastly different scales. The pioneering work of Leith (1980) investigated the decomposition of the RSW into its linear modes and subsequently others have built on this to understand the modal structure of stratified flows. In these works the emphasis has been on f-plane and therefore the slow component was a vortical mode that does not propagate. In his original paper Leith points out that it would be interesting to extend his methodology to a beta-plane and in this talk we present results from our preliminary work to do just that. This is done numerically using spectral methods to find the most accurate solutions possible for a given number of degrees of freedom. First, we determine the structure of the linear RSW modes on a beta-plane in meridional channel. In the continuous limit these waves form a complete basis and are a natural set of basis functions to study in this model and have extensions in other models. Second, we present results from a series of numerical experiments of both freely-evolving and forced flows, to address how energy is transferred between the linear waves. This will consist of wave-wave interactions as well as geostrophic turbulent flows.

Poulin, Francis; Waite, Michael; Greig, Daniel

2013-04-01

43

FTIR Studies of Water and Ammonia Decomposition on Silicon Surfaces.  

National Technical Information Service (NTIS)

Fourier transform infrared (FTIR) transmission spectroscopy was used to monitor the decomposition of H2O(D2O) and NH3 (ND3) on silicon surfaces. Experiments were performed in-situ in an ultra-high vacuum (UHV) chamber using high surface area porous-silico...

A. C. Dillon P. Gupta M. B. Robinson A. S. Bracker S. M. George

1991-01-01

44

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

45

Dual role of lignin in plant litter decomposition in terrestrial ecosystems  

PubMed Central

Plant litter decomposition is a critical step in the formation of soil organic matter, the mineralization of organic nutrients, and the carbon balance in terrestrial ecosystems. Biotic decomposition in mesic ecosystems is generally negatively correlated with the concentration of lignin, a group of complex aromatic polymers present in plant cell walls that is recalcitrant to enzymatic degradation and serves as a structural barrier impeding microbial access to labile carbon compounds. Although photochemical mineralization of carbon has recently been shown to be important in semiarid ecosystems, litter chemistry controls on photodegradative losses are not understood. We evaluated the importance of litter chemistry on photodegradation of grass litter and cellulose substrates with varying levels of lignin [cellulose-lignin (CL) substrates] under field conditions. Using wavelength-specific light attenuation filters, we found that light-driven mass loss was promoted by both UV and visible radiation. The spectral dependence of photodegradation correlated with the absorption spectrum of lignin but not of cellulose. Field incubations demonstrated that increasing lignin concentration reduced biotic decomposition, as expected, but linearly increased photodegradation. In addition, lignin content in CL substrates consistently decreased in photodegradative incubations. We conclude that lignin has a dual role affecting litter decomposition, depending on the dominant driver (biotic or abiotic) controlling carbon turnover. Under photodegradative conditions, lignin is preferentially degraded because it acts as an effective light-absorbing compound over a wide range of wavelengths. This mechanistic understanding of the role of lignin in plant litter decomposition will allow for more accurate predictions of carbon dynamics in terrestrial ecosystems.

Austin, Amy T.; Ballare, Carlos L.

2010-01-01

46

Effect of Water Vapor Pressure on the Thermal Decomposition of 2-Chloroethylphosphonic Acid 1  

PubMed Central

Decomposition of 2-chloroethylphosphonic acid (Ethephon) was studied in dried films at various water vapor pressures (0.6 to 86.9 millimeters Hg, 3.2 to 93.9% relative humidity) and temperatures (20, 30, 40, and 50 C) at pH 6.3 and 7.0. The rate of decomposition could be determined equally well by [14C]Ethephon or ethylene measurements. The rate increases at increasing water vapor pressures at a constant temperature and pH, up to an optimum. The optimum vapor pressure for decomposition approximately doubles for each 10 C increase. The activation energy for the decomposition reaction in water vapor pressures of 3.2 to 12 millimeters Hg is 8.7 and 14.3 kilocalories per mole at pH 6.3 and 7.0, respectively. Decomposition of Ethephon is inhibited above an optimum vapor pressure. The inhibition is stronger at lower temperatures and at pH 6.3 than at pH 7.0. The rate of decomposition and the inhibition observed at a low temperature (20 C) was found to be similar on various surfaces, including olive leaves. Failure to induce olive (Olea europaea L.) fruit abscission under certain environmental conditions can be readily attributed to rapid breakdown of Ethephon at elevated temperatures and low relative humidities.

Klein, Isaac; Lavee, Shimon; Ben-Tal, Yosel

1979-01-01

47

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

48

Connecting plant–microbial interactions above and belowground: a fungal endophyte affects decomposition  

Microsoft Academic Search

Mutualisms can strongly affect the structure of communities, but their influence on ecosystem processes is not well resolved.\\u000a Here we show that a plant–microbial mutualism affects the rate of leaf litter decomposition using the widespread interaction\\u000a between tall fescue grass (Lolium arundinaceum) and the fungal endophyte Neotyphodium coenophialum. In grasses, fungal endophytes live symbiotically in the aboveground tissues, where the

Alisha Lemons; Keith Clay; Jennifer A. Rudgers

2005-01-01

49

Variation in decomposition rates in the fynbos biome, South Africa: the role of plant species and plant stoichiometry  

PubMed Central

Previous studies in the fynbos biome of the Western Cape, South Africa, have suggested that biological decomposition rates in the fynbos vegetation type, on poor soils, may be so low that fire is the main factor contributing to litter breakdown and nutrient release. However, the fynbos biome also comprises vegetation types on more fertile soils, such as the renosterveld. The latter is defined by the shrub Elytropappus rhinocerotis, while the shrub Galenia africana may become dominant in overgrazed areas. We examined decomposition of litter of these two species and the geophyte Watsonia borbonica in patches of renosterveld in an agricultural landscape. In particular, we sought to understand how plant species identity affects litter decomposition rates, especially through variation in litter stoichiometry. Decomposition (organic matter mass loss) varied greatly among the species, and was related to litter N and P content. G. africana, with highest nutrient content, lost 65% of its original mass after 180 days, while E. rhinocerotis had lost ca. 30%, and the very nutrient poor W. borbonica <10%. Litter placed under G. africana decomposed slightly faster than when placed under E. rhinocerotis. Over the course of the experiment, G. africana and E. rhinocerotis lost N and P, while W. borbonica showed strong accumulation of these elements. Decomposition rates of G. africana and E. rhinocerotis were substantially higher than those previously reported from fynbos vegetation, and variation among the species investigated was considerable. Our results suggest that fire may not always be the main factor contributing to litter breakdown and nutrient release in the fynbos biome. Thus, biological decomposition has likely been underestimated and, along with small-scale variation in ecosystem processes, would repay further study. Electronic supplementary material The online version of this article (doi:10.1007/s00442-010-1753-7) contains supplementary material, which is available to authorized users.

Janion, Charlene; Chown, Steven L.; Leinaas, Hans Petter

2010-01-01

50

Novel Catalytic Behavior of Water in High Explosive Decomposition  

Microsoft Academic Search

Water under conditions of extremely high pressure and temperature is known to exhibit fascinating physical behaviors. Its remarkable structural and phase complexity strongly suggests that its chemical properties, which are largely unstudied, may be unusual as well. Detonations of high explosives containing oxygen and hydrogen provide unique systems for exploring the chemistry of ``extreme water,'' because detonations form water at

Laurence Fried; Christine Wu; Lin Yang; Nir Goldman; Sorin Bastea

2009-01-01

51

Carbon isotopic fractionation during decomposition of plant materials of different quality  

NASA Astrophysics Data System (ADS)

Changes in isotopic 13C composition of solid residues and CO2 evolved during decomposition of C3 and C4 plant materials were monitored over 10 months to determine carbon isotopic fractionation at successive stages of biodegradation. We selected plant materials of different chemical quality, e.g., Zea mays (leaves, stems, coarse roots, and fine roots), Lolium perenne (leaves and roots), Pinus pinaster (needles), and Cocos nucifera (coconut shell) and also characterized these by solid-state 13C NMR. Roots were more lignified than aerial parts of the same species. Lignin was always depleted in 13C (up to 5.2‰) as compared with cellulose from the same sample. Proteins were enriched in 13C in C3 plants but depleted in maize. Cumulative CO2 evolved fitted a double-exponential model with two C pools of different lability. During early stages of decomposition, the CO2-C released was usually 13C depleted as compared with the initial substrate but enriched at posterior stages. Consequently, with ongoing decomposition, the solid residue became 13C depleted, which could only partly be explained by an accumulation of lignin-C. The extension of the initial 13C depleted CO2-C phase was significantly correlated with the labile substrate C content, acid-detergent soluble fraction, and total N, pointing to a direct influence of plant quality on C isotopic dynamics during early stages of biodegradation. This isotopic fractionation can also lead to an underestimation of the contribution of plant residues to CO2-C when incubated in soils. We discuss possible implications of these mechanisms of 13C fractionation in ecosystems.

Fernandez, I.; Mahieu, N.; Cadisch, G.

2003-09-01

52

Short communication Do plant species encourage soil biota that specialise in the rapid decomposition of their litter?  

Microsoft Academic Search

Plants are often nutrient limited and soil organisms are important in mediating nutrient availability to plants. Thus, there may be a selective advantage to plants that alter the soil community in ways that enhance the decomposition of their litter and, hence, their ability to access nutrients. We incubated litter from three tree species (Fagus sylvatica, Acer pseudoplatanus and Picea sitchensis)

Edward Ayres; Karsten M. Dromph; Richard D. Bardgett

53

Dynamics of the Methanogenic Archaeal Community during Plant Residue Decomposition in an Anoxic Rice Field Soil ?  

PubMed Central

Incorporation of plant residues strongly enhances the methane production and emission from flooded rice fields. Temperature and residue type are important factors that regulate residue decomposition and CH4 production. However, the response of the methanogenic archaeal community to these factors in rice field soil is not well understood. In the present experiment, the structure of the archaeal community was determined during the decomposition of rice root and straw residues in anoxic rice field soil incubated at three temperatures (15°C, 30°C, and 45°C). More CH4 was produced in the straw treatment than root treatment. Increasing the temperature from 15°C to 45°C enhanced CH4 production. Terminal restriction fragment length polymorphism analyses in combination with cloning and sequencing of 16S rRNA genes showed that Methanosarcinaceae developed early in the incubations, whereas Methanosaetaceae became more abundant in the later stages. Methanosarcinaceae and Methanosaetaceae seemed to be better adapted at 15°C and 30°C, respectively, while the thermophilic Methanobacteriales and rice cluster I methanogens were significantly enhanced at 45°C. Straw residues promoted the growth of Methanosarcinaceae, whereas the root residues favored Methanosaetaceae. In conclusion, our study revealed a highly dynamic structure of the methanogenic archaeal community during plant residue decomposition. The in situ concentration of acetate (and possibly of H2) seems to be the key factor that regulates the shift of methanogenic community.

Peng, Jingjing; Lu, Zhe; Rui, Junpeng; Lu, Yahai

2008-01-01

54

(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

55

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

56

Decomposition kinetics of dimethyl methylphospate (chemical agent simulant) by supercritical water oxidation.  

PubMed

Supercritical water oxidation (SCWO) has been drawing much attention due to effectively destroy a large variety of high-risk wastes resulting from munitions demilitarization and complex industrial chemical. An important design consideration in the development of supercritical water oxidation is the information of decomposition rate. In this paper, the decomposition rate of dimethyl methylphosphonate (DMMP), which is similar to the nerve agent VX and GB (Sarin) in its structure, was investigated under SCWO conditions. The experiments were performed in an isothermal tubular reactor with a H2O2 as an oxidant. The reaction temperatures were ranged from 398 to 633 degrees C at a fixed pressure of 24 MPa. The conversion of DMMP was monitored by analyzing total organic carbon (TOC) on the liquid effluent samples. It is found that the oxidative decomposition of DMMP proceeded rapidly and a high TOC decomposition up to 99.99% was obtained within 11 s at 555 degrees C. On the basis of data derived from experiments, a global kinetic equation for the decomposition of DMMP was developed. The model predictions agreed well with the experimental data. PMID:20050541

Veriansyah, Bambang; Kim, Jae-Duck; Lee, Youn-Woo

2006-01-01

57

Decomposition of persistent materials using atmospheric pressure plasmas operated in processing water  

Microsoft Academic Search

Summary form only given. Water treatment by atmospheric oxygen plasma was examined for decomposing persistent materials such as dioxin. In the previous experiments the acetic acid (CH3COOH) as an alternative to the dioxin was successfully decomposed by the combination of fast oxygen flow and a DC driven micro hollow cathode discharge (MHCD). Meanwhile no decomposition was observed with ozone injection.

K. Yasuoka; A. Yamatake; S. Ishii

2006-01-01

58

A two-phase decomposition method for optimal design of looped water distribution networks  

Microsoft Academic Search

A two-phase decomposition method is proposed for the optimal design of new looped water distribution networks as well as for the parallel expansion of existing ones. The main feature of the method is that it generates a sequence of improving local optimal solutions. The first phase of the method takes a gradient approach with the flow distribution and pumping heads

Okitsugu Fujiwara; Do Ba Khang

1990-01-01

59

A Two-Phase Decomposition Method for Optimal Design of Looped Water Distribution Networks  

Microsoft Academic Search

A two-phase decomposition method is proposed for the optimal design of new looped water distribution networks as well as for the parallel expansion of existing ones. The main feature of the method is that it generates a sequence of improving local optimal solutions. The first phase of the method takes a gradient approach with the flow distribution and pumping heads

Okitsugu Fujiwara; Do Ba Khang

1990-01-01

60

Additive Effect of Water on the Decomposition of VOCs in Nonthermal Plasma  

Microsoft Academic Search

In the removal of volatile organic compounds (VOCs) with nonthermal plasma (NTP), gaseous oxygen is mandatory to oxidatively decompose VOCs. On the other hand, there have been disputed discussions on the additive effect of water in the decomposition of VOCs in NTP, but a unified mechanism has not been established yet. Both of VOC conversion and carbon balance can be

Masami Sugasawa; Tomoyuki Terasawa; Shigeru Futamura

2008-01-01

61

Soil-Plant-Water Environment Research.  

National Technical Information Service (NTIS)

A number of field observations were made within an actively growing crop environment. The observations included soil water movement, evapotranspiration rates, plant canopy temperatures, and water use predictions based on plant and meteorological condition...

M. L. Horton C. G. Carlson L. R. Stone

1973-01-01

62

Towards a fully 3D domain-decomposition strategy for water-on-deck phenomena  

Microsoft Academic Search

A numerical approach has been used to analyze the water shipping caused by head sea waves for a FPSO ship at rest. A 3D Domain-Decomposition (DD) strategy is used, where a linear potential-flow seakeeping analysis of the vessel is coupled with a local nonlinear rotational-flow investigation for the prediction of water-on-deck phenomena. The Navier-Stokes solver is applied in the region

Giuseppina Colicchio; Marilena Greco; Claudio Lugni; Odd Magnus Faltinsen

2010-01-01

63

Novel Catalytic Behavior of Water in High Explosive Decomposition  

NASA Astrophysics Data System (ADS)

Water under conditions of extremely high pressure and temperature is known to exhibit fascinating physical behaviors. Its remarkable structural and phase complexity strongly suggests that its chemical properties, which are largely unstudied, may be unusual as well. Detonations of high explosives containing oxygen and hydrogen provide unique systems for exploring the chemistry of ``extreme water,'' because detonations form water at conditions similar to those of giant planetary interiors. Contrary to the current view of water as a stable final product, we show here that water plays an unexpected role in catalyzing complex explosive reactions. From first-principles atomistic simulations of the high explosive pentaerythritol tetranitrate (PETN), we discovered that H2O (source), H (reducer) and OH (oxidizer) act as a dynamic team that transports oxygen between reactive centers. Our finding suggests that H2O may catalyze reactions in other explosives and in planetary interiors. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Fried, Laurence; Wu, Christine; Yang, Lin; Goldman, Nir; Bastea, Sorin

2009-06-01

64

Early diagenesis of vascular plant tissues: Lignin and cutin decomposition and biogeochemical implications  

NASA Astrophysics Data System (ADS)

Long-term subaqueous decomposition patterns of five different vascular plant tissues including mangrove leaves and wood ( Avicennia germinans), cypress needles and wood ( Taxodium distichum) and smooth cordgrass ( Spartina alternifora) were followed for a period of 4.0 years, representing the longest litter bag decomposition study to date. All tissues decomposed under identical conditions and final mass losses were 97, 68, 86, 39, and 93%, respectively. Analysis of the lignin component of herbaceous tissues using alkaline CuO oxidation was complicated by the presence of a substantial ester-bound phenol component composed primarily of cinnamyl phenols. To overcome this problem, we introduce a new parameter to represent lignin, ?6. ?6 is comprised only of the six syringyl and vanillyl phenols and was found to be much less sensitive to diagenetic variation than the commonly used parameter ?, which includes the cinnamyl phenols. Patterns of change in lignin content were strongly dependent on tissue type, ranging from 77% enrichment in smooth cordgrass to 6% depletion in cypress needles. In contrast, depletion of cutin was extensive (65-99%) in all herbaceous tissues. Despite these differences in the overall reactivity of lignin and cutin, both macromolecules were extensively degraded during the decomposition period. The long-term decomposition series also provided very useful information about the compositional parameters which are derived from the specific oxidation products of both lignin and cutin. The relative lability of ester-bound cinnamyl phenols compromised their use in parameters to distinguish woody from herbaceous plant debris. The dimer to monomer ratios of lignin-derived phenols indicated that most intermonomeric linkages in lignin degraded at similar rates. Acid to aldehyde ratios of vanillyl and syringyl phenols became elevated, particularly during the latter stages of decomposition supporting the use of these parameters as indicators of diagenetic alteration. Given the observation that cutin-derived source indicator parameters were generally more sensitive to diagenetic alteration than those of lignin, we suggest the distributional patterns of cutin-derived acids and their associated positional isomers may be most useful for tissue-specific distinctions complementing the general categorical information obtained from lignin phenol analysis alone.

Opsahl, Stephen; Benner, Ronald

1995-12-01

65

Carbon availability triggers the decomposition of plant litter and assimilation of nitrogen by an ectomycorrhizal fungus.  

PubMed

The majority of nitrogen in forest soils is found in organic matter-protein complexes. Ectomycorrhizal fungi (EMF) are thought to have a key role in decomposing and mobilizing nitrogen from such complexes. However, little is known about the mechanisms governing these processes, how they are regulated by the carbon in the host plant and the availability of more easily available forms of nitrogen sources. Here we used spectroscopic analyses and transcriptome profiling to examine how the presence or absence of glucose and/or ammonium regulates decomposition of litter material and nitrogen mobilization by the ectomycorrhizal fungus Paxillus involutus. We found that the assimilation of nitrogen and the decomposition of the litter material are triggered by the addition of glucose. Glucose addition also resulted in upregulation of the expression of genes encoding enzymes involved in oxidative degradation of polysaccharides and polyphenols, peptidases, nitrogen transporters and enzymes in pathways of the nitrogen and carbon metabolism. In contrast, the addition of ammonium to organic matter had relatively minor effects on the expression of transcripts and the decomposition of litter material, occurring only when glucose was present. On the basis of spectroscopic analyses, three major types of chemical modifications of the litter material were observed, each correlated with the expression of specific sets of genes encoding extracellular enzymes. Our data suggest that the expression of the decomposition and nitrogen assimilation processes of EMF can be tightly regulated by the host carbon supply and that the availability of inorganic nitrogen as such has limited effects on saprotrophic activities. PMID:23788332

Rineau, F; Shah, F; Smits, M M; Persson, P; Johansson, T; Carleer, R; Troein, C; Tunlid, A

2013-10-01

66

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 ...

67

Decomposition dynamics and structural plant components of genetically modified Bt maize leaves do not differ from leaves of conventional hybrids.  

PubMed

The cultivation of genetically modified Bt maize has raised environmental concerns, as large amounts of plant residues remain in the field and may negatively impact the soil ecosystem. In a field experiment, decomposition of leaf residues from three genetically modified (two expressing the Cry1Ab, one the Cry3Bb1 protein) and six non-transgenic hybrids (the three corresponding non-transformed near-isolines and three conventional hybrids) was investigated using litterbags. To elucidate the mechanisms that cause differences in plant decomposition, structural plant components (i.e., C:N ratio, lignin, cellulose, hemicellulose) were examined. Furthermore, Cry1Ab and Cry3Bb1 protein concentrations in maize leaf residues were measured from harvest to the next growing season. While leaf residue decomposition in transgenic and non-transgenic plants was similar, differences among conventional cultivars were evident. Similarly, plant components among conventional hybrids differed more than between transgenic and non-transgenic hybrids. Moreover, differences in senescent plant material collected directly from plants were larger than after exposure to soil for 5 months. While the concentration of Cry3Bb1 was higher in senescent maize leaves than that of Cry1Ab, degradation was faster, indicating that Cry3Bb1 has a shorter persistence in plant residues. As decomposition patterns of Bt-transgenic maize were shown to be well within the range of common conventional hybrids, there is no indication of ecologically relevant, adverse effects on the activity of the decomposer community. PMID:19609704

Zurbrügg, Corinne; Hönemann, Linda; Meissle, Michael; Romeis, Jörg; Nentwig, Wolfgang

2010-04-01

68

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

69

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

70

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.

71

Water for Power Plant Cooling.  

National Technical Information Service (NTIS)

Future demands for cooling water needed for the production of electrical energy; possible sources of cooling water, including agricultural and municipal waste water, brackish and saline interior water, geothermal water, ground water, and fresh surface wat...

1977-01-01

72

DRINKING WATER TREATMENT PLANT ADVISOR - USER DOCUMENTATION  

EPA Science Inventory

The Drinking Water Treatment Plant (DWTP) Advisor is a software application which has been designed to provide assistance in the evaluation of drinking water treatment plants. Specifically, this program, which is based on the source document Interim Handbook Optimizing Water Trea...

73

Response of plants to water stress.  

PubMed

Water stress adversely impacts many aspects of the physiology of plants, especially photosynthetic capacity. If the stress is prolonged, plant growth, and productivity are severely diminished. Plants have evolved complex physiological and biochemical adaptations to adjust and adapt to a variety of environmental stresses. The molecular and physiological mechanisms associated with water-stress tolerance and water-use efficiency have been extensively studied. The systems that regulate plant adaptation to water stress through a sophisticated regulatory network are the subject of the current review. Molecular mechanisms that plants use to increase stress tolerance, maintain appropriate hormone homeostasis and responses and prevent excess light damage, are also discussed. An understanding of how these systems are regulated and ameliorate the impact of water stress on plant productivity will provide the information needed to improve plant stress tolerance using biotechnology, while maintaining the yield and quality of crops. PMID:24659993

Osakabe, Yuriko; Osakabe, Keishi; Shinozaki, Kazuo; Tran, Lam-Son P

2014-01-01

74

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

75

Photocatalytic water decomposition and water-gas shift reactions over NaOH-coated, platinized TiOâ  

Microsoft Academic Search

The photocatalytic decomposition of gaseous water takes place over platinized TiOâ coated with NaOH (more than 7 wt %). The quantum efficiency of Hâ and Oâ production reaches about 7% (20 ..mu..mole Hâ\\/h) at the beginning of the reaction but declines with accumulation of the products due to the thermal back reaction over Pt. The effect of the back reaction

S. Sato; J. M. White

1981-01-01

76

Thermal decomposition of zirconium-yttrium citric complexes prepared in ethylene glycol and water media  

SciTech Connect

The thermal decomposition of Y-Zr citric complexes prepared in ethylene glycol or in water medium is studied. The compositions of 'aqueous' Y-, Zr- and YZr complexes are determined and the corresponding IR spectra are analyzed. Proofs are put in concerning the mixed-metal nature of the complexes. Based on TG, DTG and DTA analyses as well as on some intermediates identified, certain schemes are proposed concerning the processes involved in the thermal decomposition of the complexes studied. The crystal structure, crystallites size, specific surface area and the morphology of the final yttria stabilized zirconia are determined; the influences of the preparation mode and of the precursors calcination temperature on the characteristics mentioned are studied.

Petrova, Nikolina [University of Sofia, Faculty of Chemistry, 1, J. Bourchier Blvd., Sofia 1164 (Bulgaria)]. E-mail: nhnp@wmail.chem.uni-sofia.bg; Todorovsky, Dimitar [University of Sofia, Faculty of Chemistry, 1, J. Bourchier Blvd., Sofia 1164 (Bulgaria)

2006-03-09

77

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

78

Find Out How Plants Use Water  

NSDL National Science Digital Library

In this activity, learners investigate how plants use water. By making the flowers change color, learners see how water moves up the stem to the leaves and the flowers. Use this activity to discuss the structure of plants and the nutrients they need to survive. Safety note: young learners should get an adult to help them trim the stems of the flowers.

Dynamo

2012-01-01

79

Water reuse in oil shale plants  

SciTech Connect

Because oil shale development is centered in arid regions, water supply is a problem. The significant amounts of wastewater from shale oil extraction must also be dealt with. Surface retorting and in situ retorting of/shale oil are defined. Wastewater production varies with the retorter, type of shale, and site of plant. Mine water, off-gas condensate, retort water, and internal process waters are defined and analyzed. An integrated approach to all waters results in a simplified water management scheme, as shown. Basic reuse options include: steam generation, spent shale moisturization, flue gas scrubber, evaporative cooling, and refinery/upgrader plant. Another objective is selecting a suitable wastewater treatment operation.

Rosain, R.M.

1982-06-01

80

Dynamics of microbial communities during decomposition of litter from pioneering plants in initial soil ecosystems  

NASA Astrophysics Data System (ADS)

In initial ecosystems concentrations of all macro- and micronutrients can be considered as extremely low. Plant litter therefore strongly influences the development of a degraders' food web and is an important source for C and N input into soil in such ecosystems. In the present study, a 13C litter decomposition field experiment was performed for 30 weeks in initial soils from a post-mining area near the city of Cottbus (Germany). Two of this regions' dominant but contrasting pioneering plant species (Lotus corniculatus L. and Calamagrostis epigejos L.) were chosen to investigate the effects of litter quality on the litter decomposing microbial food web in initially nutrient-poor substrates. The results clearly indicate the importance of litter quality, mainly the amount of N stored in the litter material and its bioavailability for the degradation process and the development of microbial communities in the detritusphere and bulk soil. Whereas the degradation process of the L. corniculatus litter which had a low C/N ratio was fast and most pronounced changes in the microbial community structure were observed 1-4 weeks after litter addition, the degradation of the C. epigejos litter material was slow and microbial community changes mainly occurred at between 4 and 30 weeks after litter addition to the soil. However for both litter materials a clear indication for the importance of fungi for the degradation process was observed both on the abundance level as well as on the level of 13C incorporation (activity).

Esperschütz, J.; Zimmermann, C.; Dümig, A.; Welzl, G.; Buegger, F.; Elmer, M.; Munch, J. C.; Schloter, M.

2012-10-01

81

Search for memory effects in methane hydrate: structure of water before hydrate formation and after hydrate decomposition.  

PubMed

Neutron diffraction with HD isotope substitution has been used to study the formation and decomposition of the methane clathrate hydrate. Using this atomistic technique coupled with simultaneous gas consumption measurements, we have successfully tracked the formation of the sI methane hydrate from a water/gas mixture and then the subsequent decomposition of the hydrate from initiation to completion. These studies demonstrate that the application of neutron diffraction with simultaneous gas consumption measurements provides a powerful method for studying the clathrate hydrate crystal growth and decomposition. We have also used neutron diffraction to examine the water structure before the hydrate growth and after the hydrate decomposition. From the neutron-scattering curves and the empirical potential structure refinement analysis of the data, we find that there is no significant difference between the structure of water before the hydrate formation and the structure of water after the hydrate decomposition. Nor is there any significant change to the methane hydration shell. These results are discussed in the context of widely held views on the existence of memory effects after the hydrate decomposition. PMID:16268712

Buchanan, Piers; Soper, Alan K; Thompson, Helen; Westacott, Robin E; Creek, Jefferson L; Hobson, Greg; Koh, Carolyn A

2005-10-22

82

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.

83

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

84

Water reuse in oil shale plants  

Microsoft Academic Search

Because oil shale development is centered in arid regions, water supply is a problem. The significant amounts of wastewater from shale oil extraction must also be dealt with. Surface retorting and in situ retorting of\\/shale oil are defined. Wastewater production varies with the retorter, type of shale, and site of plant. Mine water, off-gas condensate, retort water, and internal process

Rosain

1982-01-01

85

Water retention capacity of tissue cultured plants  

Microsoft Academic Search

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

Klerk de G. J. M; F. Wijnhoven

2005-01-01

86

Effects of Acid on Plant Litter Decomposition in an Arctic Lake  

PubMed Central

The effects of acid on the microbial decomposition of the dominant aquatic macrophyte (Carex sp.) in Toolik Lake, Alaska were studied in microcosms during the ice-free season of 1980. Toolik Lake is slightly buffered, deep, and very oligotrophic. Microbial activities, as determined by 14C-acetate incorporation into extractable lipids, associated with Carex litter were significantly (P < 0.01) reduced within 2 days at pHs of 3.0 and 4.0, but not 5.0, 5.5, or 6.0, as compared with ambient controls (pH 7.4). ATP levels were significantly reduced at pH 3.0, but not at the other pHs tested. After 18 days, microbial activity significantly correlated with weight loss (P < 0.05), nitrogen content (P < 0.01), and C/N ratios (P < 0.01) of the litter, but did not correlate with ATP levels. Scanning electron microscopy of the litter surface revealed that the fungi present at ambient pH did not become dominant at pHs below 5.5, diatoms were absent below pH 4.0, and bacterial numbers and extracellular slime were greatly reduced at pH 4.0 and below. Mineralization of Carex14C-lignin-labeled or 14C-cellulose-labeled lignocellulose was reduced at pH 2.0, but not at pH 4.0, 5.0, or 6.0, compared with controls (pH 7). We concluded that if the pH of the water from this slightly buffered lake was sufficiently reduced, rates of litter decomposition would be significantly reduced. Images

McKinley, Vicky L.; Vestal, J. Robie

1982-01-01

87

Effects of acid on plant litter decomposition in an arctic lake. [Carex aquatilis  

SciTech Connect

The effects of acid on the microbial decomposition of the dominant aquatic macrophyte (Carex sp.) in Toolik Lake, Alaska were studied in microcosms during the ice-free season of 1980. Toolik Lake is slightly buffered, deep, and very oligotrophic. Microbial activities, as determined by /sup 14/C-acetate incorporation into extractable lipids, associated with Carex litter were signficantly (P < 0.01) reduced within 2 days at pHs of 3.0 and 4.0, but not 5.0, 5.5 or 6.0, as compared with ambient controls (pH 7.4). ATP levels were signficantly reduced at pH 3.0 but not at the other pHs tested. After 18 days, microbial activity signficantly correlated with weight loss (P < 0.05), nitrogen content (P < 0.01), and C/N ratios (P < 0.01) of the liter, but did not correlate with ATP levels. Scanning electron microscopy of the litter surface revealed that the fungi present at ambient pH did not become domimant at pHs below 5.5, diatoms were absent below pH 4.0, and bacterial numbers and extracellular slime were greatly reduced at pH 4.0 and below. Mineralization of Carex /sup 14/C-lignin-labeled or /sup 14/C-cellulose-labeled ligno-cellulose was reduced at pH 2.0, but not at pH 4.0, 5.0, or 6.0, compared with controls (pH '). We concluded that if the pH of the water from this slightly buffered lake was sufficiently reduced, rates of litter decomposition would be significantly reduced.

McKinley, V.L.; Vestal, J.R.

1982-05-01

88

Effects of polyacrylamide, biopolymer, and biochar on decomposition of soil organic matter and 14C-labeled plant residues as determined by enzyme activities  

NASA Astrophysics Data System (ADS)

Application of polymers for the improvement of aggregate structure and reduction of soil erosion may alter the availability and decomposition of plant residues. In this study, we assessed the effects of anionic polyacrylamide (PAM), synthesized biopolymer (BP), and biochar (BC) on the decomposition of 14C-labeled maize residue in sandy and sandy loam soils. Specifically, PAM and BP with or without 14C-labeled plant residue were applied at 400 kg ha-1, whereas BC was applied at 5000 kg ha-1, after which the soils were incubated for 80 days at 22 oC. Initially, plant residue decomposition was much higher in untreated sandy loam soil than in sandy soil. Nevertheless, the stimulating effects of BP and BC on the decomposition of plant residue were more pronounced in sandy soil, where it accounted for 13.4% and 23.4% of 14C input, respectively, whereas in sandy loam soil, the acceleration of plant residue decomposition by BP and BC did not exceed 2.6% and 14.1%, respectively, compared to untreated soil with plant residue. The stimulating effects of BP and BC on the decomposition of plant residue were confirmed based on activities of ?-cellobiohydrolase, ?-glucosidase, and chitinase in both soils. In contrast to BC and BP, PAM did not increase the decomposition of native or added C in both soils.

Mahmoud Awad, Yasser; Ok, Young Sik; Kuzyakov, Yakov

2014-05-01

89

Aquatic Plant Water Quality Criteria  

EPA Science Inventory

The USEPA, as stated in the Clean Water Act, is tasked with developing numerical Aquatic Life Critiera for various pollutants found in the waters of the United States. These criteria serve as guidance for States and Tribes to use in developing their water quality standards. The G...

90

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

PubMed Central

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 contribution consists of two components: (1) a background-masked Markov Random Field (MRF) energy model to formulate the local smoothness of field inhomogeneity; (2) a new Iterated Conditional Modes (ICM) algorithm accounting for high-performance optimization of the MRF energy model. The MRF energy model is integrated with background masking to prevent error propagation of background estimates as well as improve efficiency. The central component of our new ICM algorithm is the Stability Tracking (ST) mechanism intended to dynamically track iterative stability on pixels so that computation per iteration is performed only on instable pixels. The ST mechanism significantly improves the efficiency of ICM. We also develop a median-based initialization algorithm to provide good initial guesses for ICM iterations, and an adaptive gradient-based scheme for parametric configuration of the MRF model. We evaluate the robust of our approach with high-resolution mouse datasets acquired from 7-Tesla MRI.

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

2013-01-01

91

A Study of Water Plant Isolation from Contamination.  

National Technical Information Service (NTIS)

The scope of the report includes a determination of the potential of radioactive contamination of product water from a multistage flash desalination plant when water plant is connected to a nuclear power plant. Data from existing nuclear power plants was ...

F. E. Crever C. Wong E. N. Sieder

1969-01-01

92

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

93

Internal Water Status of Plants.  

National Technical Information Service (NTIS)

Sorghum (Sorghum bicolor (L.) Moench) is a crop known for its ability to persist under heat and moisture stress and often to make productive economic recovery once stresses are alleviated. The mechanisms permitting sorghum and other plants to exist under ...

J. D. Eastin C. Y. Sullivan E. J. Kinbacher

1969-01-01

94

Waste-Water Treatment Plant Control.  

National Technical Information Service (NTIS)

The Carrousel is a waste-water treatment plant based on the functioning of the activated sludge process. in this biochemical process, ammonium and nitrate and/or nitrite are broken down by living biomass. The main contribution to plant operation costs is ...

K. van Schagen R. Banning A. M. J. Veersma

1996-01-01

95

Responses of succulents to plant water stress.  

PubMed

Experiments were performed to test the hypothesis that succulents "shift" their method of photosynthetic metabolism in response to environmental change. Our data showed that there were at least three different responses of succulents to plant water status. When plant water status of Portulacaria afra (L.) Jacq. was lowered either by withholding water or by irrigating with 2% NaCl, a change from C(3)-photosynthesis to Crassulacean acid metabolism (CAM) occurred. Fluctuation of titratable acidity and nocturnal CO(2) uptake was induced in the stressed plants. Stressed Peperomia obtusifolia A. Dietr. plants showed a change from C(3)-photosynthesis to internal cycling of CO(2). Acid fluctuation commenced in response to stress but exogenous CO(2) uptake did not occur. Zygocactus truncatus Haworth plants showed a pattern of acid fluctuation and nocturnal CO(2) uptake typical of CAM even when well irrigated. The cacti converted from CAM to an internal CO(2) cycle similar to Peperomia when plants were water-stressed. Reverse phase gas exchange in succulents results in low water loss to carbon gain. Water is conserved and low levels of metabolic activity are maintained during drought periods by complete stomatal closure and continual fluctuation of organic acids. PMID:16660285

Hanscom, Z; Ting, I P

1978-03-01

96

Phase transition and chemical decomposition of hydrogen peroxide and its water mixtures under high pressures  

NASA Astrophysics Data System (ADS)

We have studied the pressure-induced phase transition and chemical decomposition of hydrogen peroxide and its mixtures with water to 50 GPa, using confocal micro-Raman and synchrotron x-ray diffractions. The x-ray results indicate that pure hydrogen peroxide crystallizes into a tetragonal structure (P41212), the same structure previously found in 82.7% H2O2 at high pressures and in pure H2O2 at low temperatures. The tetragonal phase (H2O2-I) is stable to 15 GPa, above which transforms into an orthorhombic structure (H2O2-II) over a relatively large pressure range between 13 and 18 GPa. Inferring from the splitting of the ?s(O-O) stretching mode, the phase I-to-II transition pressure decreases in diluted H2O2 to around 7 GPa for the 41.7% H2O2 and 3 GPa for the 9.5%. Above 18 GPa H2O2-II gradually decomposes to a mixture of H2O and O2, which completes at around 40 GPa for pure and 45 GPa for the 9.5% H2O2. Upon pressure unloading, H2O2 also decomposes to H2O and O2 mixtures across the melts, occurring at 2.5 GPa for pure and 1.5 GPa for the 9.5% mixture. At H2O2 concentrations below 20%, decomposed mixtures form oxygen hydrate clathrates at around 0.8 GPa-just after H2O melts. The compression data of pure H2O2 and the stability data of the mixtures seem to indicate that the high-pressure decomposition is likely due to the pressure-induced densification, whereas the low-pressure decomposition is related to the heterogeneous nucleation process associated with H2O2 melting.

Chen, Jing-Yin; Kim, Minseob; Yoo, Choong-Shik; Dattelbaum, Dana M.; Sheffield, Stephen

2010-06-01

97

Influence of water potential on decomposition of soil organic matter in high elevation meadows  

NASA Astrophysics Data System (ADS)

High elevation meadows of the Sierra Nevada, California are defined by the presence of a high water table throughout the growing season. This definition takes into account the natural drawdown of most meadow systems during the summer months to within a few feet of the surface. The cyclic drawdown/recharge of the meadow water table, as well as local hydrologic gradient that exists in most meadow systems (ranging from xeric to hydric) impose important controls on organic matter storage and decomposition in these systems. In this study we incubated soils from the xeric, mesic and hydric regions of a subalpine Sierra Nevada meadow at five different water potentials and measured the CO2 flux at intervals over one year. We found that the cumulative carbon mineralization was greatest at the lowest (0.1 bar) and highest (4 bar) water potentials, across all regions of the meadow, suggesting a microbial response threshold that is reached as the soil dries. Soils from the hydric meadow regions showed the largest response to extreme drying of the soil. These results highlight the importance of soil moisture in regulating soil respiration in these systems and different levels of microbial activity when these soils are wet vs. dry. While normal conditions in these systems keep water potentials low (< 0.2 bar), future drought conditions can potentially increase the level of dryness in the meadows to the point where rapid carbon loss can be expected.

Arnold, C. L.; Ghezzehei, T. A.; Berhe, A.

2013-12-01

98

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

99

Water relations in plants dominating phryganic ecosystems  

Microsoft Academic Search

The water potential and the osmotic potential in plants which dominate Greek phryganic ecosystems (Phlomis fruticosa, Sarcopoterium spinosum, Gistus sp.) were measured from April to Nowember. Water potential decreased considerably reaching a minimum in September. Higher\\u000a values of osmotic potential than that of water potential were found during dry period (i.e. negative values of pressure potential). This interesting fact was

N. S. Maegaris

1977-01-01

100

Water vapor recovery from plant growth chambers  

NASA Technical Reports Server (NTRS)

NASA is investigating the use of plant growth chambers (PGCs) for space missions and for bases on the moon and Mars. Key to successful development of PGCs is a system to recover and reuse the water vapor that is transpired from the leaves of the plants. A design is presented for a simple, reliable, membrane-based system that allows the recovery, purification, and reuse of the transpired water vapor through control of temperature and humidity levels in PGCs. The system is based on two membrane technologies: (1) dehumidification membrane modules to remove water vapor from the air, and (2) membrane contactors to return water vapor to the PGC (and, in doing so, to control the humidity and temperature within the PGC). The membrane-based system promises to provide an ideal, stable growth environment for a variety of plants, through a design that minimizes energy usage, volume, and mass, while maximizing simplicity and reliability.

Ray, R. J.; Newbold, D. D.; Colton, R. H.; Mccray, S. B.

1991-01-01

101

Spinodal decomposition of a three-component water-in-oil microemulsion system  

SciTech Connect

We have performed a series of spinodal decomposition measurements of a three-component microemulsion system made of a surfactant Aerosol OT, water, and decane. The measurements were made by a temperature jump from a one-phase droplet microemulsion to a two-phase droplet microemulsion along the critical isovolume fraction line (10%) using a time resolved light scattering intensity measurement technique. All three stages of the evolution were studied. Time evolution of intensities for the initial stage follows closely the linearized theory. On the other hand, time evolution of the characteristic wave vector, the maximum scattering intensity, and the intensity distributions in the intermediate and late stages are in good agreement with recent dynamic scaling theories.

Mallamace, F.; Micali, N.; Trusso, S.; Chen, S.H. [Department of Physics, University of Messina, Vill. S. Agata, C.P. 55, 98166 Messina (Italy)] [Department of Physics, University of Messina, Vill. S. Agata, C.P. 55, 98166 Messina (Italy); [Institute of Spectroscopic Techniques, Consiglio Nazionale delle Ricerche, Vill. S. Agata, Salita Sperone 31, 98166 Messina (Italy); [Department of Nuclear Engineering, 24-209, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

1995-06-01

102

Water treatment plants assessment at Talkha power plant.  

PubMed

Talkha power plant is the only power plant located in El-Mansoura. It generates electricity using two different methods by steam turbine and gas turbine. Both plants drew water from River Nile (208 m3 /h). The Nile raw water passes through different treatment processes to be suitable for drinking and operational uses. At Talkha power plant, there are two purification plants used for drinking water supply (100 m3/h) and for water demineralization supply (108 m3/h). This study aimed at studying the efficiency of the water purification plants. For drinking water purification plant, the annual River Nile water characterized by slightly alkaline pH (7.4-8), high annual mean values of turbidity (10.06 NTU), Standard Plate Count (SPC) (313.3 CFU/1 ml), total coliform (2717/100 ml), fecal coliform (0-2400/100 ml), and total algae (3 x 10(4) org/I). The dominant group of algae all over the study period was green algae. The blue green algae was abundant in Summer and Autumn seasons. The pH range, and the annual mean values of turbidity, TDS, total hardness, sulfates, chlorides, nitrates, nitrites, fluoride, and residual chlorine for purified water were in compliance with Egyptian drinking water standards. All the SPC recorded values with an annual mean value of 10.13 CFU/1 ml indicated that chlorine dose and contact time were not enough to kill the bacteria. However, they were in compliance with Egyptian decree (should not exceed 50 CFU/1 ml). Although the removal efficiency of the plant for total coliform and blue green algae was high (98.5% and 99.2%, respectively), the limits of the obtained results with an annual mean values of 40/100 ml and 15.6 org/l were not in compliance with the Egyptian decree (should be free from total coliform, fecal coliform and blue green algae). For water demineralization treatment plant, the raw water was characterized by slightly alkaline pH. The annual mean values of conductivity, turbidity, and TDS were 354.6 microS/cm, 10.84 NTU, and 214.6 mg/I, respectively. There was an increase in the results of conductivity, turbidity, total hardness, and TDS in carbon filter effluent which was attributed to the desorption of adsorbed ions on the carbon media. The removal efficiencies of turbidity, total hardness, and TDS indicated the high efficiency of the cationic filter. The annual removal efficiencies of conductivity, turbidity, chloride, and TDS proved the efficiency of the anionic filter for removing the dissolved and suspended ions. All of the recorded values of the pH, conductivity, turbidity, chlorides, hardness, and TDS of the mixed bed effluent indicated that the water at this stage was of high quality for boiler feed. The study recommended adjustment of coagulant and residual chlorine doses as well as contact time, and continuous monitoring and maintenance of the different units. PMID:17216967

El-Sebaie, Olfat D; Abd El-Kerim, Ghazy E; Ramadan, Mohamed H; Abd El-Atey, Magda M; Taha, Sahr Ahmed

2002-01-01

103

Seasonal colonization and decomposition of rat carrion in water and on land in an open field in South Carolina.  

PubMed

Decomposition and insect colonization of rat, Rattus rattus L., carrion on land and in water were compared during summer and winter in a plowed field in northwestern South Carolina. During winter, carcasses on land reached the dried-remains stage of decomposition, whereas carcasses in water reached the early-floating stage. During summer, carcasses in both habitats entered the final-remains stage of decomposition in 1-2 wk. Fewer than 30 species of carrion insects were recorded from the carcasses over the duration of the study, probably reflecting the small size of the carcasses and the depauperate fauna of the habitat. Three species of blow flies--Cynomyopsis cadaverina (Robineau-Desvoidy), Calliphora vicina Robineau-Desvoidy, and Lucilia illustris (Meigen)--colonized carrion on land during winter, but no insects colonized carrion in water during winter. Two species of blow flies, Cochliomyia macellaria (F.) and Phaenicia sericata (Meigen), and 1 species of flesh fly, Sarcophaga bullata Parker, colonized the carrion on land and in water during summer; the blow fly, Phormia regina (Meigen), colonized only the carrion on land. This study demonstrated seasonal variation in decomposition and colonization patterns of carrion in contrasting habitats, with important implications for forensic entomology. PMID:9775597

Tomberlin, J K; Adler, P H

1998-09-01

104

Process model-free analysis for thermodynamic efficiencies of sulfur–iodine processes for thermochemical water decomposition  

Microsoft Academic Search

Material, energy, and entropy balances, which depend only on stream conditions and flows entering and leaving a system, have been used to evaluate different scenarios for thermochemical decomposition of water to manufacture hydrogen using the Sulfur–Iodine cycle. Energy efficiencies have been found for idealized systems with variable stream amounts, as well as for a common flowsheet, to locate the greatest

John P. O'Connell; Parinya Narkprasert; Maximilian B. Gorensek

2009-01-01

105

Labile compounds in plant litter reduce the sensitivity of decomposition to warming and altered precipitation.  

PubMed

Together, climate and litter quality strongly regulate decomposition rates. Although these two factors and their interaction have been studied across species in continent-scale experiments, few researchers have studied how labile and recalcitrant compounds interact to influence decomposition, or the climate sensitivity of decomposition, within a litter type. Over a period of 3 yr, we studied the effects of warming and altered precipitation on mass loss and compound-specific decomposition using two litter types that possessed similar heteropolymer chemistry, but different proportions of labile and recalcitrant compounds. Climate treatments immediately affected the mass loss of the more recalcitrant litter, but affected the more labile litter only after 2 yr. After 3 yr, although both litter types had lost similar amounts of mass, warming (c. 4°C) and supplemental precipitation (150% of ambient) together accelerated the degradation of alkyl-carbon and lignin only in the more recalcitrant litter, highlighting the role of initial litter quality in determining whether the chemistry of litter residues converges or diverges under different climates. Our finding that labile compounds in litter reduce the climate sensitivity of mass loss and the decomposition of recalcitrant matrix is novel. Our results highlight the potential for litter quality to regulate the effect of climatic changes on the sequestration of litter-derived carbon. PMID:23822593

Suseela, Vidya; Tharayil, Nishanth; Xing, Baoshan; Dukes, Jeffrey S

2013-10-01

106

Presence of Pathogenic Microorganisms in Power Plant Cooling Waters.  

National Technical Information Service (NTIS)

Cooling waters from eleven geographically disparate power plants were tested for the presence of Naegleria fowleri and Legionella pneumophila (LDB). Control source waters for each plant were also tested for these pathogens. Water from two of the eleven pl...

R. L. Tyndall

1982-01-01

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

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...

109

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.

110

Fuzzy control of water desalination plants.  

National Technical Information Service (NTIS)

In this report we have chosen a sub-system of an MSF water desalination plant, the brine heater, for analysis, synthesis, and simulation. This system has been modelled and implemented on computer. A fuzzy logic controller (FLC) for the top brine temperatu...

A. Titli M. Jamshidi F. Olafsson

1995-01-01

111

Microbiological quality of drinking water at eight water treatment plants.  

PubMed

Eight drinking water treatment plants were sampled monthly during one year to evaluate the removal of bacterial indicators, new indicators and some pathogenic bacteria. Six plants are allocated along the Nile River at Cairo segment and the two others on Ismailia Canal. In this study many parameters were determined; the classical bacterial indicators (total bacterial counts at 22 and 37 degrees C, total coliforms, faecal coliforms and faecal streptococci) show the same trend in all plant intakes except faecal streptococci parameter. The numbers of faecal streptococci in plant intakes on the main stream of Nile River ranged from 8 to 250 MPN/100 ml, but the others ranged from 80 to 2700 MPN/100 ml. With regard to new indicators; total yeasts, Candida albicans, Aeromonas hydrophlia and total staphylococci ranged from 10(1) to 10(5), 10(2) to 10(5), 10(2) to 10(5) and 10(2) to 10(3) cfu/100 ml, respectively. In case of pathogens, salmonellae ranged between 10(2) and 10(3) cfu/100 ml, total vibrios varied between 10(2) and 10(4) and the Listeria group ranged from 10(2) to 10(5) cfu/100 ml from the intake samples. All tested samples from the outlet of water treatment plants, which produce drinking water, were free of classical bacterial indicators. So the produced water has a good quality from the bacteriological point, according to national and international regulations. On the other hand, the drinking water from some tested plants had one or more positive parameters of new indicators and pathogenic bacteria. PMID:11798415

El-Taweel, G E; Shaban, A M

2001-11-01

112

VIEW OF BUILDING 124, THE WATER TREATMENT PLANT, LOOKING NORTHEAST. ...  

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

VIEW OF BUILDING 124, THE WATER TREATMENT PLANT, LOOKING NORTHEAST. THE ROCKY FLATS PLANT WATER SUPPLY, TREATMENT, STORAGE, AND DISTRIBUTION SYSTEM HAS OPERATED CONTINUOUSLY SINCE 1953 - Rocky Flats Plant, Water Treatment Plant, West of Third Street, north of Cedar Avenue, Golden, Jefferson County, CO

113

Decomposition of litter produced under elevated CO 2 : Dependence on plant species and nutrient supply  

Microsoft Academic Search

We investigated the effect of CO2 concentration and soilnutrient availability during growth on the subsequent decomposition andnitrogen (N) release from litter of four annual grasses that differ inresource requirements and native habitat. Vulpia microstachys isa native grass found on California serpentine soils, whereas Avenafatua, Bromus hordaceus, and Lolium multiflorum areintroduced grasses restricted to more fertile sandstone soils (Hobbs & Mooney

VALERIE M. FRANCK; BRUCE A. HUNGATE; F. STUART CHAPIN; CHRISTOPHER B. FIELD

1997-01-01

114

Carbon allocation and decomposition of root-derived organic matter in a plant–soil system of Calluna vulgaris as affected by elevated CO 2  

Microsoft Academic Search

The effect of elevated CO2 on C allocation in plant and soil was assessed using soil cores planted with 1-y-old heather (Calluna vulgaris (L.) Hull). Plants were pulse-labeled with 14CO2 at ambient and elevated CO2 and two nitrogen regimes (low and high). After harvesting the plants, the soil was incubated to monitor total respiration and decomposition of 14C-labeled rhizodeposits. Total

P. S. J. Verburg; A. Gorissenand; W. J. Arp

1998-01-01

115

Experimental burial inhibits methanogenesis and anaerobic decomposition in water-saturated peats.  

PubMed

A mechanistic understanding of carbon (C) sequestration and methane (CH(4)) production is of great interest due to the importance of these processes for the global C budget. Here we demonstrate experimentally, by means of column experiments, that burial of water saturated, anoxic bog peat leads to inactivation of anaerobic respiration and methanogenesis. This effect can be related to the slowness of diffusive transport of solutes and evolving energetic constraints on anaerobic respiration. Burial lowered decomposition constants in homogenized peat sand mixtures from about 10(-5) to 10(-7) yr(-1), which is considerably slower than previously assumed, and methanogenesis slowed down in a similar manner. The latter effect could be related to acetoclastic methanogenesis approaching a minimum energy quantum of -25 kJ mol(-1) (CH(4)). Given the robustness of hydraulic properties that locate the oxic-anoxic boundary near the peatland surface and constrain solute transport deeper into the peat, this effect has likely been critical for building the peatland C store and will continue supporting long-term C sequestration in northern peatlands even under moderately changing climatic conditions. PMID:21958021

Blodau, Christian; Siems, Melanie; Beer, Julia

2011-12-01

116

Characteristics, Residue Decomposition, and Carbon Mineralization of Leguminous and Spontaneous Plants in Coffee Systems  

Microsoft Academic Search

We investigated the chemical and biochemical composition, residue decomposition, and mineralization rate of leguminous (Cajanus cajan, Crotalaria spectabilis, and Lablab purpureus) and spontaneous vegetation in two experimental coffee systems in southeast Brazil. The nitrogen (N) content of the shoot biomass varied from 19.3 to 45.7 g kg, and phosphorus (P) content ranged from 1.6 to 3.8 g kg. C. cajan

Eduardo da Silva Matos; Irene Maria Cardoso; Renata Lúcia Souto; Paulo César de Lima; Eduardo de Sá Mendonça

2011-01-01

117

Selective oxidative decomposition of ammonia in neutral water to nitrogen over titania-supported platinum or palladium catalyst  

Microsoft Academic Search

Selective oxidative decomposition of NH3 (1000ppm) in water to N2 (wet oxidation) was achieved with precious metal-supported catalysts at 433K under 8atm of O2 without alkalization of the solution. As a support for Pt, an anatase TiO2 (P-25) was superior in activity, while NO2? and NO3? were formed at concentrations of about 3 and 4ppm, respectively, at 6h. The activity

Junji Taguchi; Toshio Okuhara

2000-01-01

118

The effect of metal salts on the decomposition of sweet sorghum bagasse in flow-through liquid hot water  

Microsoft Academic Search

The impact of the metal salts NaCl, KCl, CaCl2, MgCl2, FeCl3, FeCl2, and CuCl2, particularly the latter, on the decomposition of hemicellulose and lignin from sweet sorghum bagasse in liquid hot water pretreatment processing was studied in an attempt to enhance the recovery of sugars. Transition metal chlorides significantly enhanced the hemicellulose removal compared to the alkaline earth metal chlorides

Qiang Yu; Xinshu Zhuang; Zhenhong Yuan; Wei Qi; Qiong Wang; Xuesong Tan

2011-01-01

119

Effects of irrigation water quality on loquat plant nutrition: Sensitivity of loquat plant to salinity  

Microsoft Academic Search

An investigation was conducted to study the possible use of municipal wastewater for watering loquat plants, and to determine the effects of this water on nutrient status of two?year?old loquat plants (Eriobotriae japonica L.) during two complete vegetative cycles. The plants, grafted on franco and Anger stocks, were planted on major soils of the area of La Marina Babea. Plants

1997-01-01

120

Barium and Radium in Water Treatment Plant Wastes.  

National Technical Information Service (NTIS)

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 ...

A. G. Myers C. K. Jongeward S. K. Richter V. L. Snoeyink

1985-01-01

121

Physiological Effects of Water Stress on Young Corn Plants.  

National Technical Information Service (NTIS)

Laboratory experiments were used to investigate the mechanism of plant response to water stress by determining the sensitivity of leaf elongation, photosynthesis and transpiration in young corn plants to a decrease in leaf water potential. The sensitivity...

E. W. R. Barlow

1974-01-01

122

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

123

Mass transfer in fuel cells. [electron microscopy of components, thermal decomposition of Teflon, water transport, and surface tension of KOH solutions  

NASA Technical Reports Server (NTRS)

Results of experiments on electron microscopy of fuel cell components, thermal decomposition of Teflon by thermogravimetry, surface area and pore size distribution measurements, water transport in fuel cells, and surface tension of KOH solutions are described.

Walker, R. D., Jr.

1973-01-01

124

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. Instead of focusing on WF from the perspective of administrative regions, we built a framework in which the input-output (IO) model, the structural decomposition analysis (SDA) model and the generating regional IO tables (GRIT) method are combined to implement decomposition analysis for WF in a river basin. This framework is illustrated in the WF in Haihe River basin (HRB) from 2002 to 2007, 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.

2014-05-01

125

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

126

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.

127

Decomposition and nutrient liberation rates of plant material in the Parana medio River (Argentina)  

Microsoft Academic Search

The degradation of plant material was studied in order to obtain degradation coefficients and nutrient release kinetics of the vegetation that will be submerged during the filling of the future Parana Medio man-made lake. A group of 13 plant species representative of the whole vegetation of the area were chosen.

M. Leguizamon; J. Hammerly; M. A. Maine; N. Sufie; M. J. Pizarro

1992-01-01

128

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

129

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

130

Water resource management planning guide for Savannah River Plant  

Microsoft Academic Search

The Water Resource Management Planning Guide provides an outline for the development of a Savannah River Plant Water Resource Management Plan (WRMP) to protect, manage, and monitor the site's water resources. The management plan is based on three principle elements: (1) protection of the water quality, (2) management of the water quantity, and (3) monitoring of the water quality and

J. E. Hubbard; D. E. Stephenson; J. L. Steele; D. E. Gordon

1988-01-01

131

Microbial Colonization of Beech and Spruce Litter—Influence of Decomposition Site and Plant Litter Species on the Diversity of Microbial Community  

Microsoft Academic Search

The present study was conducted to investigate the effect of decomposition site and plant litter species on the colonizing microbial communities. For this, litter bag technique using beech and spruce litter was combined with RNA-based fingerprinting and cloning. Litter bags were incubated for 2 and 8 weeks in the Ah horizon of beech and beech–spruce mixed forest sites. Although sugars

Manish Kumar Aneja; Shilpi Sharma; Frank Fleischmann; Susanne Stich; Werner Heller; Günther Bahnweg; Jean Charles Munch; Michael Schloter

2006-01-01

132

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 ...

133

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

134

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

135

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

136

Texas refiner starts up new waste water treatment plant  

Microsoft Academic Search

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

N. Al-Tell; R. Lueders

1994-01-01

137

Multipathway health risk assessment of power plant water discharges  

Microsoft Academic Search

The chemicals released with water discharges from a fossil-fueled power plant may present health risks through a variety of exposure pathways including ingestion of drinking water, fish consumption and dermal absorption while swimming. The Total Risk of Utility Emissions (TRUE) model provides a framework that allows one to assess the multipathway health risks associated with water discharges from power plants.

C. Seigneur; E. Constantinou; L. Levin

1996-01-01

138

Plant experience with temporary reverse osmosis makeup water systems  

Microsoft Academic Search

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

Polidoroff

1986-01-01

139

Preference of 'Mansonia uniformis' (Theob.) for Specific Water Hyacinth Plants.  

National Technical Information Service (NTIS)

Mansonia uniformis 4th instar larvae demonstrate a preference for attaching to live water hyacinth rather than dead ones and flowering rather than nonflowering plants. It is not clear whether the specific plants attract the mosquito immatures or the mosqu...

J. L. McDonald L. C. Lu

1973-01-01

140

Presence of Pathogenic Microorganisms in Power Plant Cooling Waters.  

National Technical Information Service (NTIS)

The content of Legionnaires' Disease Bacteria (LDB) in air discharged from industrial and power plant cooling towers was compared with the concentrations found in the cooling-tower basin water. Concentrates of the power plant air samples were also tested ...

R. L. Tyndall

1983-01-01

141

Microwave-hydrothermal decomposition of perfluorooctanoic acid in water by iron-activated persulfate oxidation  

Microsoft Academic Search

The microwave-hydrothermal decomposition of persistent and bioaccumulative perfluorooctanoic acid (PFOA) in aqueous solution using persulfate activated by zero-valent iron (ZVI) at 60 and 90°C was examined. The results of laboratory study reveal that when PFOA is treated with 5mM persulfate (PS) and ZVI at 90°C for 2h, 67.6% of PFOA is effectively decomposed to form shorter-chain perfluorinated carboxylic acids (PFCAs)

Yu-Chi Lee; Shang-Lien Lo; Pei-Te Chiueh; Yau-Hsuan Liou; Man-Li Chen

2010-01-01

142

Catalytic activities of cobalt, nickel and copper ferrospinels for sulfuric acid decomposition: The high temperature step in the sulfur based thermochemical water splitting cycles  

Microsoft Academic Search

The catalytic decomposition of sulfuric acid is the most endothermic step of the sulfur based water splitting thermochemical cycles, which are promising technologies for large scale hydrogen production in future. In the present study the catalytic activities of three ferrospinels AFe2O4 (A = Co, Ni, Cu) were evaluated for high temperature sulfuric acid decomposition reaction. Catalyst characterization by Mössbauer spectroscopy confirmed the

A. M. Banerjee; M. R. Pai; S. S. Meena; A. K. Tripathi; S. R. Bharadwaj

2011-01-01

143

Survival strategies of plants during water stress  

SciTech Connect

Fluorescence and gas exchange of bean, maize, sunflower and wooly foxglove were simultaneously measured at 250 {mu}mol quanta/m{sup 2}/s. Under severe water stresses conditions about 40% of the photochemical energy was converted to heat at PS II. This is interpreted as a protective mechanism against photoinhibitory damage when net CO{sub 2} uptake is reduced by about 70%. After {sup 14}CO{sub 2} gas exchange, only in bean was a homogeneous distribution of radioactivity over the leaf observed. In all other plants we found a patchy distribution of regions with either an intensive or a reduced gas exchange. We conclude that CO{sub 2}-recycling (photorespiration and reassimilation) behind closed stomata also contributed to energy dissipation under severe stress conditions.

Scheuermann, R.; Stuhlfauth, T.; Sueltemeyer, D.; Fock, H.

1989-04-01

144

SIMPLIFIED METHODS FOR ESTIMATING EMISSIONS FROM WASTE WATER TREATMENT PLANTS, BASED ON APPLICATION OF WATER9 TO MODEL PLANTS  

EPA Science Inventory

A set of model waste water treatment plant designs, estimates of their air emissions, and advice for selecting a model plant and scaling it up or down to represent a real plant. This will save much of the analytical work needed to fully model a particular plant using the complet...

145

Aquaporins: highly regulated channels controlling plant water relations.  

PubMed

Plant growth and development are dependent on tight regulation of water movement. Water diffusion across cell membranes is facilitated by aquaporins that provide plants with the means to rapidly and reversibly modify water permeability. This is done by changing aquaporin density and activity in the membrane, including posttranslational modifications and protein interaction that act on their trafficking and gating. At the whole organ level aquaporins modify water conductance and gradients at key "gatekeeper" cell layers that impact on whole plant water flow and plant water potential. In this way they may act in concert with stomatal regulation to determine the degree of isohydry/anisohydry. Molecular, physiological, and biophysical approaches have demonstrated that variations in root and leaf hydraulic conductivity can be accounted for by aquaporins but this must be integrated with anatomical considerations. This Update integrates these data and emphasizes the central role played by aquaporins in regulating plant water relations. PMID:24449709

Chaumont, François; Tyerman, Stephen D

2014-04-01

146

A theoretical study of water adsorption and decomposition on low-index spinel ZnGa2O4 surfaces: correlation between surface structure and photocatalytic properties.  

PubMed

Water adsorption and decomposition on stoichiometrically perfect and oxygen vacancy containing ZnGa2O4 (100), (110), and (111) surfaces were investigated through periodic density functional theory (DFT) calculations. The results demonstrated that water adsorption and decomposition are surface-structure-sensitive processes. On a stoichiometrically perfect surface, the most stable molecular adsorption that could take place involved the generation of hydrogen bonds. For dissociative adsorption, the adsorption energy of the (111) surface was more than 4 times the energies of the other two surfaces, indicating it to be the best surface for water decomposition. A detailed comparison of these three surfaces showed that the primary reason for this observation was the special electronic state of the (111) surface. When water dissociated on the (111) surface, the special Ga3c-4s and 4p hybridization states at the Fermi level had an obvious downshift to the lower energies. This large energy gain greatly promoted the dissociation of water. Because the generation of O(3c) vacancy defects on the (100) and (110) surfaces could increase the stability of the dissociative adsorption states with few changes to the energy barrier, this type of defect would make the decomposition of water molecules more favorable. However, for the (111) surface, the generation of vacancy defects could decrease the stability of the dissociative adsorption states and significantly increase their energy barriers. Therefore, the decomposition of water molecules on the oxygen vacancy defective (111) surface would be less favorable than the perfect (111) surface. These findings on the decomposition of H2O on the ZnGa2O4 surfaces can be used toward the synthesis of water-splitting catalysts. PMID:23682995

Jia, Chuanyi; Fan, Weiliu; Yang, Fei; Zhao, Xian; Sun, Honggang; Li, Pan; Liu, Li

2013-06-11

147

Research on Water Chemistry in a Nuclear Power Plant.  

National Technical Information Service (NTIS)

To prevent the corrosion problems on important components of nuclear power plants, the computerization methods of water chemistry and the analyses of corrosion failures were studied. A preliminary study on the computerization of water chemistry log-sheet ...

S. K. Chae K. R. Yang H. D. Kang J. H. Koo C. K. Hwang

1986-01-01

148

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

149

Decomposition of prepolymers and molding materials of phenol resin in subcritical and supercritical water under an Ar atmosphere  

SciTech Connect

Seven prepolymers of phenol resin were decomposed into their monomers such as phenol, cresols, and p-isopropylphenol by reactions at 523--703 K under an Ar atmosphere in subcritical and supercritical water. The total yield of identified products depended on the kind of prepolymers, and the maximum yield reached 78% in the reaction at 703 K for 0.5 h. The decomposition reactions were accelerated by the addition of Na{sub 2}CO{sub 3}, and the yields of identified monomers reached more than 90%. Two kinds of molding materials of phenol resin whose content of phenol resin was less than 50% were also decomposed mainly into phenol and cresols by the reaction in supercritical water.

Suzuki, Yuichi; Tagaya, Hideyuki; Kadokawa, Junichi; Chiba, Koji [Yamagata Univ., Yonezawa, Yamagata (Japan). Dept. of Materials Science and Engineering] [Yamagata Univ., Yonezawa, Yamagata (Japan). Dept. of Materials Science and Engineering; Asou, Tetsuo [Sumitomo Bakelite Co. Ltd., Fujieda, Shizuoka (Japan)] [Sumitomo Bakelite Co. Ltd., Fujieda, Shizuoka (Japan)

1999-04-01

150

Plants in water-controlled ecosystems: active role in hydrologic processes and response to water stress  

Microsoft Academic Search

The reduction of soil moisture content during droughts lowers the plant water potential and decreases transpiration; this in turn causes a reduction of cell turgor and relative water content which brings about a sequence of damages of increasing seriousness. A review of the literature on plant physiology and water stress shows that vegetation water stress can be assumed to start

A. Porporato; F. Laio; L. Ridolfi; I. Rodriguez-Iturbe

2001-01-01

151

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

152

EFFECTS OF WATER STRESS ON LEAF WATER RELATIONS OF YOUNG BEAN PLANTS ??????? ?? ?????? ????? ????? ?????????? ? ??????? ?? ????? ???????? ?????  

Microsoft Academic Search

The effects of water stress on water relations in the leaves of young common bean (Phaseolus vulgaris L.) plants were studied. Water stress was imposed 14 days after the emergency by withholding water until soil water potential reached -0.9 MPa. Water defi cit led to a noticeable decrease in both the osmotic potential at full hydration and turgor loss poin

Zlatko STOYANOV

153

Activity Concentration of Various Radionuclides in Tubificids Living in the Biobeds of a Sewage Treatment Plant.  

National Technical Information Service (NTIS)

Oligochaeta belonging to the family Tubificidae are used in the biobeds of waste water treatment plants in the decomposition process of organic matter. Waste water treatment plants also receive radionuclides in the form of radiopharmaceuticals. The most c...

A. Erlandsson B. Erlandsson S. Mattsson

1988-01-01

154

Detection of Plant Water Content with Needle-Type In-Situ Water Content Sensor  

NASA Astrophysics Data System (ADS)

A needle-type water content sensor with a polyethersulfone (PES) polymer membrane was developed for the low-invasive, direct in-situ measurement of plant water content (PWC) in prior work. In this paper we demonstrate a measurement of plant water stress that represents the demand for water of the plant and greatly affects its sweetness. We inserted the sensor into a stalk of strawberry (Fragaria×ananassa) and soil. The variation in both the plant and the soil water content were successfully detected, which revealed the delay between variation in the plant water stress and soil water content after irrigation. Such delay could only be detected by the proposed sensor that could directly measure the variation of PWC in situ and continuously. The experiments also showed the variation in the signals as a function of detection sites and suggested that the detection sites of plant water stress need to be considered when the sensor is applied to irrigation culture.

Katayanagi, Hitoshi; Miki, Norihisa

155

Oxidative decomposition of atrazine in water in the presence of hydrogen peroxide using an innovative microwave photochemical reactor.  

PubMed

The simultaneous application of microwave (MW) power and UV light leads to improved results in photochemical processes. This study investigates the oxidative decomposition of atrazine in water using an innovative MW and UV photochemical reactor, which activates a chemical reaction with MW and UV radiation using an immersed source without the need for a MW oven. We investigated the influence of reaction parameters such as initial H(2)O(2) concentrations, reaction temperatures and applied MW power and identified the optimal conditions for the oxidative decomposition of atrazine. Atrazine was completely degraded by MW/UV/H(2)O(2) in a very short time (i.e. t(1/2) = 1.1 min for 20.8 mg/L in optimal conditions). From the kinetic study, the disappearance rate of atrazine can be expressed as dX/dt = k(PH)[M](0)(b-X)(1-X), where b ? [H(2)O(2)](0)/[M](0)+k(OH)[·OH]/k(PH)[M](0), and X is the atrazine conversion, which correlates well with the experimental data. The kinetic analysis also showed that an indirect reaction of atrazine with an OH radical is dominant at low concentrations of H(2)O(2) and a direct reaction of atrazine with H(2)O(2) is dominant when the concentration of H(2)O(2) is more than 200 mg/L. PMID:21232855

Chen, Huilun; Bramanti, Emilia; Longo, Iginio; Onor, Massimo; Ferrari, Carlo

2011-02-28

156

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.

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

2013-01-01

157

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

158

Water resource management planning guide for Savannah River Plant  

SciTech Connect

The Water Resource Management Planning Guide provides an outline for the development of a Savannah River Plant Water Resource Management Plan (WRMP) to protect, manage, and monitor the site's water resources. The management plan is based on three principle elements: (1) protection of the water quality, (2) management of the water quantity, and (3) monitoring of the water quality and quantity. The plan will assure that changes in water quality and quantity are identified and that corrective action is implemented as needed. In addition, water management activities within and between Savannah River Plant (SRP) organizations and departments will be coordinated to ensure the proper management of water resources. This document is intended as a guide to suggest goals and objectives that will provide a basis for the development of a water resource plan for SRP. Planning should be flexible rather than rigid, and the plan outlines in this document was prepared to be modified or updated as conditions necessitate. 16 refs., 12 figs.

Hubbard, J.E.; Stephenson, D.E.; Steele, J.L. (Du Pont de Nemours (E.I.) and Co., Aiken, SC (USA). Savannah River Lab.); Gordon, D.E. (Du Pont de Nemours (E.I.) and Co., Aiken, SC (USA). Savannah River Plant)

1988-10-01

159

Visible light-induced decomposition of a fluorotelomer unsaturated carboxylic acid in water with a combination of tungsten trioxide and persulfate.  

PubMed

Photochemical decomposition of a fluorotelomer unsaturated carboxylic acid, C3F7CFCHCOOH (1), in the presence of WO3 and an electron acceptor (S2O8(2-) or H2O2) in water under visible-light irradiation was investigated. Under an O2 atmosphere, 1 was not decomposed either by TiO2 (P25) or WO3 alone. A combination of WO3 and H2O2 also resulted in almost no decomposition of 1. In contrast, irradiation in the presence of a combination of WO3 and S2O8(2-) (potassium salt) efficiently decomposed 1 to F(-), CO2, C3F7COOH, and C2F5COOH. The decomposition of 1 was affected by the counter cation of S2O8(2-): the decomposition extent was higher with K2S2O8 than with (NH4)2S2O8. The decomposition of 1 was further enhanced when the reaction in the presence of WO3 and K2S2O8 was carried out under an argon atmosphere. Under O2, the amount of H2O2 formed in the reaction solution was an order of magnitude higher than the amount formed under argon. This fact suggests that the decrease in the decomposition of 1 under O2 can be ascribed to the formation of H2O2, which consumed S2O8(2-) and SO4(-). PMID:24112660

Hori, Hisao; Ishiguro, Atsushi; Nakajima, Kohei; Sano, Taizo; Kutsuna, Shuzo; Koike, Kazuhide

2013-11-01

160

The potential of dual-energy computed tomography for quantitative decomposition of soft tissues to water, protein and lipid in brachytherapy  

NASA Astrophysics Data System (ADS)

Dosimetric accuracy of radiation treatment planning in brachytherapy depends on knowledge of tissue composition. It has been speculated that soft tissues can be decomposed to water, lipid and protein. The aim of our work is to evaluate the accuracy of such tissue decomposition. Selected abdominal soft tissues, whose average elemental compositions were taken from literature, were decomposed using dual energy computed tomography to water, lipid and protein via the three-material decomposition method. The quality of the decomposition was assessed using relative differences between (i) mass energy absorption and (ii) mass energy attenuation coefficients of the analyzed and approximated tissues. It was found that the relative differences were less than 2% for photon energies larger than 10 keV. The differences were notably smaller than the ones for water as the transport and dose scoring medium. The choice of the water, protein and lipid triplet resulted in negative elemental mass fractions for some analyzed tissues. As negative elemental mass fractions cannot be used in general purpose particle transport computer codes using the Monte Carlo method, other triplets should be used for the decomposition. These triplets may further improve the accuracy of the approximation as the differences were mainly caused by the lack of high-Z materials in the water, protein and lipid triplet.

Malusek, A.; Karlsson, M.; Magnusson, M.; Alm Carlsson, G.

2013-02-01

161

Integrating water by plant roots over spatially distributed soil salinity  

Microsoft Academic Search

In numerical simulation models dealing with water movement and solute transport in vadose zone, the water budget largely depends on uptake patterns by plant roots. In real field conditions, the uptake pattern largely changes in time and space. When dealing with soil and water salinity, most saline soils demonstrate spatially distributed osmotic head over the root zone. In order to

Mehdi Homaee; Urs Schmidhalter

2010-01-01

162

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...

163

Novel Catalytic Behavior of Dense Hot Water in PETN Decomposition Reactions  

Microsoft Academic Search

Under extreme conditions, water is known to exhibit fascinating physical behaviors. Its remarkable structural and phase complexity strongly suggests that its chemical properties may be unusual as well, which have remained largely unrevealed. Using ab inito molecular dynamics simulations, we have recently discovered that water plays an unexpected role in catalyzing complex reactions of a high explosive pentaerythritol tetranitrate (PETN).

Christine Wu; Laurence Fried; Lin Yang; Nir Goldman; Sorin Bastea

2009-01-01

164

Water Hammer in Nuclear Power Plants.  

National Technical Information Service (NTIS)

The staff reviewed information on water hammer events obtained primarily from Licensee Event Reports and information requests to licensees. Approximately 30 fluid systems in each of four light water reactor designs were also reviewed to determine the pote...

1979-01-01

165

Water use policies and power plant economics  

Microsoft Academic Search

This report ascertains the effect of various environmental policies relating to water use and water quality on: (1) the cost of generating electric power and (2) the demand for cooling water. The environmental policies tested include: a water withdrawal tax of from 0 to 2 cents\\/1000 gal; a heat-discharge tax of from 0 to 20 cents\\/million Btu; a temperature differential

K. Inoue; E. J. Henley; G. H. Otto; R. G. Thompson

1974-01-01

166

Novel Catalytic Behavior of Dense Hot Water in PETN Decomposition Reactions  

NASA Astrophysics Data System (ADS)

Under extreme conditions, water is known to exhibit fascinating physical behaviors. Its remarkable structural and phase complexity strongly suggests that its chemical properties may be unusual as well, which have remained largely unrevealed. Using ab inito molecular dynamics simulations, we have recently discovered that water plays an unexpected role in catalyzing complex reactions of a high explosive pentaerythritol tetranitrate (PETN). This finding is in contrary to the current view of water as a stable final product of high explosive reactions, and has possible implications in geochemistry, such as reactions in planetary interiors.

Wu, Christine; Fried, Laurence; Yang, Lin; Goldman, Nir; Bastea, Sorin

2009-03-01

167

Water Conservation with Urban Landscape Plants.  

National Technical Information Service (NTIS)

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 in the irrigation of l...

B. W. Hipp C. Giordano B. Simpson

1983-01-01

168

Municipal Waste Water as a Source of Cooling Water for California Electric Power Plants.  

National Technical Information Service (NTIS)

This report discusses sources of municipal waste water for potential use as cooling water in California power plants. It notes the major factors which affect this practice. Municipal treatment facilities in California with discharge volumes deemed adequat...

T. MacDonald

1980-01-01

169

Some Sensitivity Analyses of an Hourly Soil-Plant Water Relations Model.  

National Technical Information Service (NTIS)

Nineteen parameters representing landscape, plant, and soil characteristics were examined for their influence on midday plant water relations, daily fluxes and monthly water balance components predicted by a soil-plant-water relations model having hourly ...

R. J. Luxmoore J. L. Stolzy J. T. Holdeman

1976-01-01

170

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

171

Within- and Across-Species Responses of Plant Traits and Litter Decomposition to Elevation across Contrasting Vegetation Types in Subarctic Tundra  

PubMed Central

Elevational gradients are increasingly recognized as a valuable tool for understanding how community and ecosystem properties respond to climatic factors, but little is known about how plant traits and their effects on ecosystem processes respond to elevation. We studied the response of plant leaf and litter traits, and litter decomposability across a gradient of elevation, and thus temperature, in subarctic tundra in northern Sweden for each of two contrasting vegetation types, heath and meadow, dominated by dwarf shrubs and herbaceous plants respectively. This was done at each of three levels; across species, within individual species, and the plant community using a community weighted average approach. Several leaf and litter traits shifted with increasing elevation in a manner consistent with greater conservation of nutrients at all three levels, and the most consistent response was an increase in tissue N to P ratio. However, litter decomposition was less directly responsive to elevation because the leaf and litter traits which were most responsive to elevation were not necessarily those responsible for driving decomposition. At the community level, the response to elevation of foliar and litter traits, and decomposability, varied greatly among the two vegetation types, highlighting the importance of vegetation type in determining ecological responses to climatic factors such as temperature. Finally our results highlight how understanding the responses of leaf and litter characteristics of functionally distinct vegetation types, and the processes that they drive, to temperature helps provide insights about how future climate change could affect tundra ecosystems.

Sundqvist, Maja K.; Giesler, Reiner; Wardle, David A.

2011-01-01

172

Fluoride Analysis of Water-Treatment-Plant Sludges.  

National Technical Information Service (NTIS)

A method for fluoride analysis of sludges was developed and verified using laboratory-prepared alum sludge. The developed method was then used to measure fluoride concentrations in sludges from selected water treatment plants. Initially, three methods of ...

W. H. Duke

1974-01-01

173

COMPUTER COST MODELS FOR POTABLE WATER TREATMENT PLANTS  

EPA Science Inventory

A series of computer programs have been developed which calculate costs for specific unit treatment processes used in water treatment plants. The programs contained in this report are as follows: chlorination, chlorine dioxide, ozone, and granular activated carbon adsorption. Tab...

174

Survey of microbial enzymes in soil, water, and plant microenvironments.  

PubMed

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

175

MICROORGANISMS AND HIGHER PLANTS FOR WASTE WATER TREATMENT  

EPA Science Inventory

Batch experiments were conducted to compare the waste water treatment efficiencies of plant-free microbial filters with filters supporting the growth of reeds (Phragmites communis), cattail (Typha latifolia), rush (Juncus effusus), and bamboo (Bambusa multiplex). The experimental...

176

Cost Analysis of Light Water Reactor Power Plants.  

National Technical Information Service (NTIS)

This study centers on a statistical analysis of the licensing time, construction time, and capital cost of light water reactor power plants. The use of these econometric techniques allows the major cost driving variables to be identified through multivari...

W. E. Mooz

1980-01-01

177

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.

Alves, Priscila Divina Diniz; Siqueira, Flavia de Faria; Facchin, Susanne; Horta, Carolina Campolina Rebello; Victoria, Junia Maria Netto; Kalapothakis, Evanguedes

2014-01-01

178

Water Use by Coal-Fired Power Plants in 1975.  

National Technical Information Service (NTIS)

Steam electric generation plants require large quantities of water for dissipation of heat and waste disposal. Major systems in place are once-through, cooling tower, cooling ponds, and combination systems involving two or more of these systems. Cooling t...

N. L. Dalsted J. W. Green

1981-01-01

179

Investigation of sulfur based thermochemical cycles for hydrogen production by water decomposition. [Sulfur-based cycles  

Microsoft Academic Search

Preliminary screening of ten thermochemical cycles showed that only three cycles, all based on sulfur, had > 30% efficiency. A cost analysis of these cycles, assuming a high temperature nuclear reactor as primary energy source showed a production cost of $10.83\\/million Btu in a plant of 100,000 cu m\\/hr hydrogen capacity, which would have an investment cost of $207 to

Natarajan

1976-01-01

180

Nocturnal water storage in plants having Crassulacean acid metabolism  

Microsoft Academic Search

Measurements of water uptake and transpiration, during the dark period of plants having Crassulacean acid metabolism (CAM) allow calculation of leaf-volume changes (?V). Nocturnal leaf-volume changes of CAM plants have also been reported in the literature on the basis of waterdisplacement measurements. A third way of estimation is from measurements of turgor changes and cellular water-storage capacity using the pressure

U. Lfittge

1986-01-01

181

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 ...

182

Effects of Water Stress on the Photosynthetic Efficiency of Plants  

Microsoft Academic Search

The response of Photosystem II (PS II) activity to water deficit, as characterized by measurements of chlorophyll (Chi) a fluorescence, greatly differs among plant species. Only cyanobacteria and lower plants are capable of rapid restoration of\\u000a the PS II photochemical capacity following their rewetting after strong inhibition due to severe desiccation. In lower plants\\u000a kept in light and in the

Nikolai G Bukhov; Robert Carpentier

183

Gas exchange under water : acclimation of terrestrial plants to submergence  

Microsoft Academic Search

Gas exchange between the plant and the environment is severely hampered when plants are submerged, leading to oxygen and energy deficits. A straightforward way to reduce these shortages of oxygen and carbohydrates would be prolonged photosynthesis under water, but this has received only little attention. This thesis, therefore, aims to investigate in depth the effects of acclimation to submergence on

Liesje Mommer

2005-01-01

184

7. ONE OF THREE CIRCULATING WATER PUMPS FOR STEAM PLANT, ...  

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

7. ONE OF THREE CIRCULATING WATER PUMPS FOR STEAM PLANT, LOCATED ON FIRST FLOOR UNDER TURBINE DECK. VIEW OF PUMP LOCATED FARTHEST NORTH. November 13, 1990 - Crosscut Steam Plant, North side Salt River near Mill Avenue & Washington Street, Tempe, Maricopa County, AZ

185

Bacterial Diversity in a Mine Water Treatment Plant? †  

PubMed Central

We investigated the microbial community in a pilot plant for treatment of acid mine water by biological ferrous iron oxidation using clone library analysis and calculated statistical parameters for further characterization. The microbial community in the plant was conspicuously dominated by a group of Betaproteobacteria affiliated with “Ferribacter polymyxa”.

Heinzel, Elke; Hedrich, Sabrina; Janneck, Eberhard; Glombitza, Franz; Seifert, Jana; Schlomann, Michael

2009-01-01

186

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

Microsoft Academic Search

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

Kiyoshi NAGASUGA

187

Optical fluorescence biosensor for plant water stress detection  

NASA Astrophysics Data System (ADS)

Precision farming in arable agriculture and horticulture allows conservative use of resources that are applied according to plant needs. The growing concern for sustainability in crop production has accentuated the significance of our work to develop a rapid, sensitive and non-destructive spectroscopic method for real-time monitoring of plant water stress. Elucidation of crop water status before the onset of irreversible cellular damage is critical for effective water management to ensure maximum crop yield and profit margin. A two-component bio-sensing system comprising transgenic 'Indicator Plants' and a spectrometer-linked stereoscopic microscope was developed to detect early signs of water stress before the permanent wilting point is reached. The 'Indicator Plants' are transgenic Petunia hybrida genetically engineered with a drought-responsive promoter-linked enhanced green fluorescent protein marker gene (EGFP). No EGFP fluorescence was detected prior to induction of dehydration stress. Fluorescence emission intensity increased with dehydration period and was found mainly in the stems, leaf veins and leaf tips. While fluorescence emission above endogenous background was detectable after 2 hours of water stress treatment, the plants reached permanent wilting point after 6 hours, showing that our system was able to detect water stress prior to plant entry into the stage of irreversible damage. Future work will be geared towards overcoming biological and instrument-related difficulties encountered in our initial detection system.

Chong, Jenny P. C.; Liew, O. W.; Li, B. Q.; Asundi, A. K.

2007-06-01

188

Decomposition of polyethylene in radio-frequency nitrogen and water steam plasmas under reduced pressures  

Microsoft Academic Search

The possibility of radio-frequency (RF) nitrogen and water steam plasmas under reduced pressures for gasification of plastic waste as a thermal recycling method has been investigated in order to develop an innovative method for directly recycling plastic waste to hydrogen, synthesis gases or fuels. The products of pyrolysis were analyzed and classified into gaseous fraction and solid soot; and analytical

L. Tang; H. Huang

2007-01-01

189

The microwave influence on the electrolytic decomposition of KOH water solution  

Microsoft Academic Search

The effect of microwaves (MW) on the electrolytic process of 6M KOH water solutions was investigated in the temperature range from 291K to 337K. At lower temperatures, microwaves facilitated electrolytic process, whereas the effect is reversed at higher temperatures.

Dragomir R. Stanisavljev; Tomislav D. Grozdi?; Milica P. Mar?eta Kaninski; Antonije R. Djordjevi?; Dragica Lj. Stoji?

2007-01-01

190

Iowa's first electrodialysis reversal water treatment plant  

Microsoft Academic Search

In 1979 the City of Washington was notified by the Iowa Department of Natural Resources (IDNR) that the City was in violation of the radium standard for drinking water. The City of Washington authorized an engineering study to determine the most cost-effective and practical way to remove radium and, at the same time, improve overall water quality. Several possible treatment

John Hays

2000-01-01

191

Prediction of the effects of nutrient loadings from a power plant at Perryman on the water quality of the Bush River estuary. Final report  

SciTech Connect

A water-quality model consisting of a one-dimensional Hydraulic Module coupled with a Water Quality Module was used to assess the effects of increased nutrient loadings from the proposed Perryman Power Plant on the dissolved oxygen and chlorophyll-a concentrations in the Bush River estuary. The Hydraulic Module represented the longitudinal water movement (and physical transport of associated constituents) among 12 spatial segments. The Water Quality Module represented the biological processes affecting nitrogen, phosphorus, chlorophyll-a, and dissolved oxygen in each segment (e.g., photosynthesis, nutrient uptake, decomposition).

Rose, K.A.; Dwyer, R.L.; Turner, M.A.

1986-10-01

192

Occurrence of "mammalian" lignans in plant and water sources.  

PubMed

Enterolignans, also called "mammalian" lignans because they are formed in the intestine of mammals after ingestion of plant lignans, were identified for the first time in extracts of four tree species, i.e., in knot heartwood of the hardwood species Fagus sylvatica and in knot or stem heartwood of the softwood species Araucaria angustifolia, Picea smithiana, and Abies cilicia. They were also identified for the first time in grain extracts of cultivated plants, i.e., in 15 cereal species, in 3 nut species, and in sesame and linseeds. Furthermore, some plant lignans and enterolignans were identified in extracts of water from different sources, i.e., in sewage treatment plant influent and effluent and in humic water, and for the first time also in tap and seawater. They were present also in water processed through a water purification system (ultrapure water). As enterolignans seem to be abundant in the aquatic environment, the occurrence of enterolignans in plant sources is most likely due to uptake by the roots from the surrounding water. This uptake was also shown experimentally by treating wheat (Triticum aestivum ssp. vulgare) seeds with purified lignan-free water spiked with enterolactone (EL) during germination and growth. Both the remaining seeds and seedlings contained high EL levels, especially the roots. They also contained metabolites of EL, i.e., 7-hydroxy-EL and 7-oxo-EL. PMID:17497165

Smeds, Annika I; Willför, Stefan M; Pietarinen, Suvi P; Peltonen-Sainio, Pirjo; Reunanen, Markku H T

2007-08-01

193

Reduction of the CO sub 2 decomposition in the transversely excited atmospheric CO sub 2 laser discharge plasma by a very small amount of the water vapor  

SciTech Connect

Using a comprehensive theoretical model, we have theoretically clarified for the first time that the homogeneous catalytic reaction caused by a very small amount of water vapor ({lt}100 ppm) in the closed-cycle, transversely excited atmospheric (TEA) CO{sub 2} laser discharge plasma could considerably reduce the saturation value of the CO{sub 2} molecules decomposition. Effects of the water vapor at this concentration level have been overlooked in the previous investigations. A small concentration variation of the residual water vapor in the experimental laser chambers is thought to be one of the reasons for the considerable disagreements among the published data about the CO{sub 2} equilibrium decomposition level.

Hokazono, H.; Obara, M. (Department of Electrical Engineering, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223 (Japan))

1990-07-02

194

An anti-corrosive reactor for the decomposition of halogenated hydrocarbons with supercritical water oxidation  

Microsoft Academic Search

An anti-corrosive reactor was studied, which decomposes halogenated organic compounds by way of supercritical water oxidation (SCWO). Two different types of SCWO reactor were used: a floating type reactor using a non-porous ceramic tube and a transpiring wall-type SCWO reactor using a porous ceramic tube. Reactor configurations were evaluated to protect a SCWO system from corrosion, due to halogenated hydrocarbon

Hyeon-Cheol Lee; Jung-Hyun In; Sang-Young Lee; Jong-Hwa Kim; Chang-Ha Lee

2005-01-01

195

Presence of Pathogenic Amoebae in Power Plant Cooling Waters.  

National Technical Information Service (NTIS)

Cooling-water-associated algae and sediments from five northern and five southern or western electric power plants were tested for the presence of pathogenic amoebae. In addition, water algae and sediments from five northern and five southern/western site...

R. L. Tyndall E. Willaert A. R. Stevens

1981-01-01

196

ARSENIC REMOVAL FROM DRINKING WATER BY IRON REMOVAL PLANTS  

EPA Science Inventory

This report documents a long term performance study of two iron removal water treatment plants to remove arsenic from drinking water sources. Performance information was collected from one system located in midwest for one full year and at the second system located in the farwest...

197

Water use by coal-fired power plants in 1975  

Microsoft Academic Search

Steam electric generation plants require large quantities of water for dissipation of heat and waste disposal. Major systems in place are once-through, cooling tower, cooling ponds, and combination systems involving two or more of these systems. Cooling tower systems are becoming more prevalent as water withdrawal requirements are less and heat is released through evaporative techniques. But closed evaporative methods

N. L. Dalsted; J. W. Green

1981-01-01

198

The Effects of Water Stress on Plant Respiration  

Microsoft Academic Search

Plant growth can be limited by several factors, among which a lack of water is considered of major importance. Despite the vast knowledge of the effect of water stress on photosynthesis, there is much less known about its effect on respiration. Respiration, unlike photosynthesis, never halts, and it reflects the overall metabolism. However, the data available on the effect of

Jaume Flexas; Jeroni Galmes; Miquel Ribas-Carbo; Hipólito Medrano

199

DISPOSAL OF WASTES FROM WATER TREATMENT PLANTS—PART 4  

Microsoft Academic Search

The purpose of this report is to provide current information on the nature of the water treatment plant waste disposal problem, and to assist water utilities in solving the problem. The report describes technology presently available, defines new approaches to the problem, and suggests future directions for the coordination and dissemination of information.

R. I. Dick; R. B. Dean; D. D. Adrian; A. P. Black; R. N. Kinman; K. E. Shull; G. Tchobanoglous; W. K. Neubauer; D. P. Proudfit; W. W. Aultman; S. L. Bishop; P. W. Doe; J. C. Nebiker; W. H. Plautz; J. W. Krasauskas; Lee Streicher; C. M. Bach; H. Hartung; C. E. Johnson; H. R. Peters; J. C. Webber; J. C. Lamb III; E. C. Weber; J. B. Coulter; G. H. Eagle; Vern Fahy; Edgar Henry; H. B. Russelmann

1970-01-01

200

Water Treatment Plant Filter Backwash Optimization Study.  

National Technical Information Service (NTIS)

Filtration has been identified as the most important barrier for the removal of particles and microorganisms in drinking water treatment. The objective was to address the public demand for higher quality at lower costs and improved safeguards by optimizin...

1999-01-01

201

Plants for water recycling, oxygen regeneration and food production.  

PubMed

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. PMID:11537696

Bubenheim, D L

1991-10-01

202

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

203

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

204

Improving the water consumption system in industrial plants  

Microsoft Academic Search

The annual demand for watet by plants of this branch exceeds 450 million m 3. And, although during the last ten years the specific water demand has been reduced by 10-15%, the total amount of water needed has remained high, in connection with the considerable rise is man-made fibre production. Further assurance of water for the man-made fibre industry is

V. V. Shibalina; V. V. Shmatova

1989-01-01

205

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

206

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

207

Energy from fresh and brackish water aquatic plants  

SciTech Connect

Aquatic plants can achieve relatively high biomass productivities when compared to terrestrial plants because they need not be water-stressed and can be optimally supplied with nutrients. Based on literature reports, productivities in southern US regions of about 40 to 60 t/ha-yr (dry weight basis) can be predicted for green algae or marsh plants and about 80 t/ha-yr for water hyacinth. Higher productivities may be possible in exceptionally favorable locations by assuming development of advanced cultivation technologies and genetic selection of improved strains. The lack of established cultivation systems and low-cost harvesting processes imposes great uncertainties on the cost of biomass production by aquatic plants. Three potentially practical aquatic biomass energy systems are chemicals production from microalgae, alcohol production from marsh plants, and methane production from water hyacinths. At present, aquatic plants are not being used commercially as a fuel source any place in the world. Nevertheless, it is clear that aquatic plants have potentially high biomass productivities and, specifically for the case of microalgae, could produce a high-quality, high-value biomass suitable for conversion to fuels and extraction of other products. A list of the relative advantages and disadvantages of aquatic plant energy systems in comparison with the concepts of terrestrial tree or herbaceous plant energy farming is given. Three favorable aspects of aquatic plant biomass systems should be stressed - the relative short-term research and development effort that will be required to determine the practical feasibility of such systems, the continuous production nature of such systems, and the relative independence of aquatic biomass systems from soil characteristics and weather fluctuations. The fast generation times of most aquatic plants allow rapid data acquisition, as compared to even short-rotation trees.

Benemann, J.R.

1981-01-01

208

Uses of Ammonia Water in Catalytic DeNOx-Plants. Investigation Results from a Pilot Plant.  

National Technical Information Service (NTIS)

Ammonia is stored in power plants in pressurized liquid phase and used in gaseous phase for flue gas denitrification. Power plants, for which storage of ammonia in pressure liquefied phase poses problems, storage and use of ammonia water provide a safe al...

H. Katzer R. John

1989-01-01

209

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

210

Preliminary Design Experimental Water Treatment Plant.  

National Technical Information Service (NTIS)

On October 29, 1948, a report (ORNL 48-10-377) prepared by O.R. Placak and R.J. Morton appeared entitled 'Proposal For Evaluating The Impact of Water-Borne Radioactive Contaminants On Sanitary Engineering Facilities'. This report called attention to the n...

C. P. Straub

1973-01-01

211

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

212

Nuclear power plant with boiling water reactor  

Microsoft Academic Search

S>A system for cooling medium circulating pumps and high pressure ; coolant injection pumps is described. The circulating pumps are operated by a ; series of connected water turbines whose capacity is influenced by a series of ; regulating apparatuses. The arrangement of pumps and regulating parts are ; described. (GE);

Schill

1973-01-01

213

Performance of a hotel chilled water plant with cool storage  

SciTech Connect

A comprehensive monitoring suite was installed at a large convention hotel located in San Francisco, CA. The instrumentation was used for a research project to evaluate the effectiveness of electricity price based controls that automate response to real time pricing and to characterize the operation and performance of the hotel's chilled water plant that included a newly installed ice cool storage system. The hotel operates under real-time electricity rates. To date, over four years of data have been collected. Data included electricity use for all chillers, secondary coolant, chilled water, condenser pumps, and the cooling tower fans. Thermal flow data were also collected for the storage system, ice chiller, direct cooling chillers, and chilled water load loops. This paper (1) describes the chilled water plant, (2) defines the performance measurement objectives for the project, (3) discusses operational experience with the plant, focusing on the cool storage system, (4) analyzes chilled water plant and cool storage system operation by examining the charge/discharge heat flow data, and (5) evaluates how well the plant as a whole and the cool storage system specifically met cooling loads of the facility, and how this affected their use.

Gillespie, K.L.; Blanc, S.L.; Parker, S.

1999-07-01

214

Plant water uptake strategies to cope with stochastic rainfall  

NASA Astrophysics Data System (ADS)

We develop and compare two hydraulically-based schemes of the xylem structure of an individual plant. The dynamics of water uptake are analyzed under random conditions through the modeling of rainfall as a stochastic process. The two hydraulic schemes differ in the modeling of the root ability to cooperate, i.e., the capacity of roots to increase the water uptake from the wetter soil layers when other parts of the soil are dry (compensation effect) and to transfer water from moister into drier soil layers (water redistribution effect). Both compensation and water redistribution are direct consequences of the hydraulic structure of the root system, which is modeled here considering two contrasting cases corresponding to non-interacting uptake paths from different soil layers, and converging uptake paths. Only the latter hydraulic architecture allows for compensation and water redistribution. Another important difference between the hydraulic schemes is the stomatal response to soil dryness. When the soil water is unevenly distributed in the soil layers, the differences in the hydraulic schemes emerge. In semi-arid climates, plants characterized by a cooperative root system are shown to be less prone to water stress. In contrast, plants with non-interacting roots result to be better fit to humid climates, where the probability of droughts is small.

Tron, Stefania; Laio, Francesco; Ridolfi, Luca

2013-03-01

215

Macroscopic modeling of plant water uptake: soil and root resistances  

NASA Astrophysics Data System (ADS)

The macroscopic physically-based plant root water uptake (RWU) model, based on water-potential-gradient formulation (Vogel et al., 2013), was used to simulate the observed soil-plant-atmosphere interactions at a forest site located in a temperate humid climate of central Europe and to gain an improved insight into the mutual interplay of RWU parameters that affects the soil water distribution in the root zone. In the applied RWU model, the uptake rates are directly proportional to the potential gradient and indirectly proportional to the local soil and root resistances to water flow. The RWU algorithm is implemented in a one-dimensional dual-continuum model of soil water flow based on Richards' equation. The RWU model is defined by four parameters (root length density distribution, average active root radius, radial root resistance, and the threshold value of the root xylem potential). In addition, soil resistance to water extraction by roots is related to soil hydraulic conductivity function and actual soil water content. The RWU model is capable of simulating both the compensatory root water uptake, in situations when reduced uptake from dry layers is compensated by increased uptake from wetter layers, and the root-mediated hydraulic redistribution of soil water, contributing to more natural soil moisture distribution throughout the root zone. The present study focusses on the sensitivity analysis of the combined soil water flow and RWU model responses in respect to variations of RWU model parameters. Vogel T., M. Dohnal, J. Dusek, J. Votrubova, and M. Tesar. 2013. Macroscopic modeling of plant water uptake in a forest stand involving root-mediated soil-water redistribution. Vadose Zone Journal, 12, 10.2136/vzj2012.0154.

Vogel, Tomas; Votrubova, Jana; Dohnal, Michal; Dusek, Jaromir

2014-05-01

216

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

217

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

218

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.

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

2013-01-01

219

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

220

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

221

Water, plants, and early human habitats in eastern Africa.  

PubMed

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, C(4)-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

2013-01-22

222

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.

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

2013-01-01

223

Do rock fragments participate to plant water and mineral nutrition?  

NASA Astrophysics Data System (ADS)

Rock fragments modify soil properties, and can be a potential reservoir of water. Besides, recent studies showed that this coarse soil fraction is chemically active, release nutrients, and could therefore be involved in biogeochemical nutrient cycles. However, these studies carried out on rock fragments, crushed pebbles or mineral particles do not answer the question whether the coarse soil fraction has significant nutritive functions. Only a couple of studies were conducted on plants, one on grass and the other on coniferous seedlings. This present work attempted to assess if pebbles may act as water and nutrient sources for poplar saplings, a deciduous species. Remoulded soils were set up in 5 L-pots with three percentages of pebbles: 0, 20, and 40% in volume. We used, as substrate either fine earth or sand (quartz), and as rock fragments either calcareous or inert pebbles (quartz). Additional modalities were settled with sand mixed with 20 and 40% pebbles enriched with nutrients. Both fine earth and calcareous pebbles were collected from the Ap horizon of a calcareous lacustrine limestone silty soil located in the central region of France. After cleaning, all pebbles were mixed to reach a bulk density in pots of 1.1 g/cm3 for the fine earth and 1.5 g/cm3 for the sand. Ten replicates were settled per modality, and one cutting of Populus robusta was planted in each. The experiment was conducted under controlled conditions. All pots were saturated at the beginning of the experiment, then irrigated by capillarity and controlled to maintain a moderate water stress. Growth and evapotranspiration were followed regularly, while water stress status was measured by stomatal conductivity every day during two drying periods of 10 days. After three months, plants were collected, separated in below- and above-ground parts for biomass and cation analysis (Ca, Mg, K). Results showed that pebbles can participate to plant nutrition, but no reduction of water stress was observed. Indeed, plants' water stress increased along the drying periods but no significant difference of stomatal conductivity was measured between modalities. This indicates that water stored in the porosity of calcareous pebbles had no influence on the plant water status, suggesting that this reserve is either too low or not accessible for poplar saplings. Besides, the presence of pebbles reduced the growth (plant height and biomass), and even more the proportion of pebbles was high. This dilution effect was the main effect on plant development observed in this experiment. However at moderate pebbles proportion, mineralomass of plants grown with or without 20% calcareous pebbles were similar, and higher than that of modalities with quartz pebbles. In addition, plants had a biomass 16% higher when grown with calcareous pebbles than with quartz pebbles. These results indicate that plants access nutrients from pebbles and that growth conditions were significantly better in pots with calcareous compared to quartz pebbles at moderate proportion (20%). For modalities with 40% pebbles, no difference was found between calcareous and quartz pebbles when mixed with fine earth. However, plant biomass grown in sand were 2.5 to 3 times higher when mixed with 20 and 40% enriched pebbles respectively, than biomass of plants grown on sand only. These results suggest that plants access nutrients from pebbles, especially those adsorbed, but at higher proportion (40%) the detrimental effects of rock fragments (such as limitation of root development can mask their nutritional value. This study strengthen the hypothesis that coarse soil fraction may act as a nutrients source. The concept of an inert stone matrix that, from the plant point of view, only dilutes ecological functions of the soil, must be revised.

Korboulewsky, Nathalie; Tétégan, Marion; Besnault, Adeline; Cousin, Isabelle

2010-05-01

224

A one-dimensional model of water flow in soil-plant systems based on plant architecture  

Microsoft Academic Search

The estimation of root water uptake and water flow in plants is crucial to quantify transpiration and hence the water exchange\\u000a between land surface and atmosphere. In particular the soil water extraction by plant roots which provides the water supply\\u000a of plants is a highly dynamic and non-linear process interacting with soil transport processes that are mainly determined\\u000a by the

Michael Janott; Sebastian Gayler; Arthur Gessler; Mathieu Javaux; Christine Klier; Eckart Priesack

2011-01-01

225

Impact of plant water uptake strategy on soil moisture and evaporation dynamics during drydown  

Microsoft Academic Search

Experiments have shown that plants can compensate for water stress in the upper, more densely rooted, soil layers by increasing the water uptake from deeper layers. By adapting root water uptake to water availability, plants are able to extend the period of unstressed transpiration. This strategy conflicts with the approach in many land surface schemes, where plant water uptake is

Adriaan J. Teuling; Remko Uijlenhoet; François Hupet; Peter A. Troch

2006-01-01

226

77 FR 73056 - Initial Test Programs for Water-Cooled Nuclear Power Plants  

Federal Register 2010, 2011, 2012, 2013

...NRC-2012-0293] Initial Test Programs for Water-Cooled Nuclear Power Plants AGENCY...DG-1259, ``Initial Test Programs for Water-Cooled Nuclear Power Plants...entitled, ``Initial Test Programs for Water-Cooled Nuclear Power...

2012-12-07

227

Integrating water by plant roots over spatially distributed soil salinity  

NASA Astrophysics Data System (ADS)

In numerical simulation models dealing with water movement and solute transport in vadose zone, the water budget largely depends on uptake patterns by plant roots. In real field conditions, the uptake pattern largely changes in time and space. When dealing with soil and water salinity, most saline soils demonstrate spatially distributed osmotic head over the root zone. In order to quantify such processes, the major difficulty stems from lacking a sink term function that adequately accounts for the extraction term especially under variable soil water osmotic heads. The question of how plants integrate such space variable over its rooting depth remains as interesting issue for investigators. To move one step forward towards countering this concern, a well equipped experiment was conducted under heterogeneously distributed salinity over the root zone with alfalfa. The extraction rates of soil increments were calculated with the one dimensional form of Richards equation. The results indicated that the plant uptake rate under different mean soil salinities preliminary reacts to soil salinity, whereas at given water content and salinity the "evaporative demand" and "root activity" become more important to control the uptake patterns. Further analysis revealed that root activity is inconstant when imposed to variable soil salinity. It can be concluded that under heterogeneously distributed salinity, most water is taken from the less saline increment while the extraction from other root zone increments with higher salinities never stops.

Homaee, Mehdi; Schmidhalter, Urs

2010-05-01

228

Water transport by aquaporins in the extant plant Physcomitrella patens.  

PubMed

Although aquaporins (AQPs) have been shown to increase membrane water permeability in many cell types, the physiological role of this increase was not always obvious. In this report, we provide evidence that in the leafy stage of development (gametophore) of the moss Physcomitrella patens, AQPs help to replenish more rapidly the cell water that is lost by transpiration, at least if some water is in the direct vicinity of the moss plant. Three AQP genes were cloned in P. patens: PIP2;1, PIP2;2, and PIP2;3. The water permeability of the membrane was measured in protoplasts from leaves and protonema. A significant decrease was measured in protoplasts from leaves and protonema of PIP2;1 or PIP2;2 knockouts but not the PIP2;3 knockout. No phenotype was observed when knockout plants were grown in closed petri dishes with ample water supply. Gametophores isolated from the wild type and the pip2;3 mutant were not sensitive to moderate water stress, but pip2;1 or pip2;2 gametophores expressed a water stress phenotype. The knockout mutant leaves were more bent and twisted, apparently suffering from an important loss of cellular water. We propose a model to explain how the AQPs PIP2;1 and PIP2;2 delay leaf dessication in a drying atmosphere. We suggest that in ancestral land plants, some 400 million years ago, APQs were already used to facilitate the absorption of water. PMID:18184735

Liénard, David; Durambur, Gaëlle; Kiefer-Meyer, Marie-Christine; Nogué, Fabien; Menu-Bouaouiche, Laurence; Charlot, Florence; Gomord, Véronique; Lassalles, Jean-Paul

2008-03-01

229

[Methods for determining plant water source in thin soil region: a review].  

PubMed

Plant water source depends on the distribution of available water in the environment, and the capability of plants in capturing water. In dry season, the soil water in thin soil region cannot satisfy the demand of normal plant growth, and whether the plants can use the water stored in weathered bedrock is the key for them to maintain their normal water consumption. This paper reviewed the research methods for determining the plant water source in thin soil region, including investigating and analyzing the characteristics of root growth and distribution, monitoring the changes of water content at various depths below ground surface, monitoring and analyzing the seasonal variation of plant water status, and identifying the plant water source by stable isotope techniques. The advantages and disadvantages of these methods and their potential applications in tracing plant water source in karst region of Southwest China were discussed. PMID:21265170

Nie, Yun-peng; Chen, Hong-song; Wang, Ke-lin

2010-09-01

230

Low conductivity water plants -- Issues of process control  

SciTech Connect

The SSC Laboratory will require a large number of widely distributed low conductivity water (LCW) cooling systems to support accelerator operations. In addition to designing the physical plants, plans mustbe made for control/information systems and the human organization to run them. Initial considerations in these areas are presented.

Baritchi, L.; Haenni, D.

1993-04-01

231

STRATEGIES FOR WATER AND WASTE REDUCTION IN DAIRY FOOD PLANTS  

EPA Science Inventory

A study was undertaken to reduce water and waste discharges in a complex, multiproduct dairy food plant through management control and modifications of equipment and processes. The objectives were to develop approaches that would be broadly applicable throughout the dairy industr...

232

Factors Influencing Freezing of Supercooled Water in Tender Plants1  

Microsoft Academic Search

Seedlings of beans (Phaseolus vulgaris), corn (Zea mays), and tomatoes (Lycopersicon esculentum) were grown in the greenhouse and then exposed to controlled freezing conditions in a growth chamber. Variables were adjusted to determine the influence of plant water potential, freez- ing time, and external dew formation on the seedlings' susceptibility to frost injury. Freezing, detected visually and by release of

J. W. Cary

1970-01-01

233

POWER PLANT COOLING SYSTEM WATER CONSUMPTION AND NONWATER IMPACT REPORTS  

EPA Science Inventory

This study dealt with water evaporation and consumption of power plant cooling systems and evaluated six simple generic evaporation prediction models, one for cooling towers and five for cooling ponds/lakes using field data provided by twelve utilities. Also evaluated in the stud...

234

Measurement of plant water status by the pressure chamber technique  

Microsoft Academic Search

The pressure chamber has been widely used in the measurement of total water potential and pressure-volume relations of leaves, twigs and, to a lesser extent, roots. Some of the benefits and precautions in its use in these studies are reviewed and discussed. The pressure chamber has also been used to determine hydraulic resistances of plants, to collect xylem sap, to

Neil C. Turner

1988-01-01

235

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...

236

Solidification\\/Stabilization of Power Plants Wastes Potential Water Pollutants  

Microsoft Academic Search

The intensive firing of coal in power plants can harm the environment. The problems are caused by the emission of solid particles, sulphur oxides, nitrogen oxides, carbon monoxide, carbon dioxide to the atmosphere, as well as by pollution of the surrounding waters and the degradation of the land due to the disposition of the solid wastes: fly ash, bottom ash

Aleksandra Kosti?-Pulek; Svetlana Popov

237

Water extraction of plant tissues for analysis by ion chromatography  

Microsoft Academic Search

High pressure liquid chromatography (HPLC)?grade water was evaluated as an alternative extraction reagent to acid extraction of plant tissue. Green and red bell pepper fruit (Capsium annuum var. annuum L.), cultivar Pip; sweet corn internodes (Zea mays L.), cultivar Florida Staysweet; cabbage wrapper leaves (Brassica oleracea L. Capitata group), cultivar Solid Blue 770; peach leaves [Prunus persica (L.) Batsch], cultivar

V. M. Russo; S. V. Karmarkar

1998-01-01

238

Microbial colonization of beech and spruce litter--influence of decomposition site and plant litter species on the diversity of microbial community.  

PubMed

The present study was conducted to investigate the effect of decomposition site and plant litter species on the colonizing microbial communities. For this, litter bag technique using beech and spruce litter was combined with RNA-based fingerprinting and cloning. Litter bags were incubated for 2 and 8 weeks in the Ah horizon of beech and beech-spruce mixed forest sites. Although sugars and starch were rapidly lost, lignin content increased by more than 40% for beech and more than doubled for spruce litter at both soil sites at the end of the experiment. Denaturing gradient gel electrophoresis analysis of 16S and 18S rRNA RT-PCR products was used for screening of differences between bacterial and fungal communities colonizing the two litter types. Development of the microbial community over time was observed to be specific for each litter type and decomposition site. RT-PCR products from both litter types incubated in beech-spruce mixed forest site were also cloned to identify the bacterial and fungal colonizers. The 16S rRNA clone libraries of beech litter were dominated by gamma-proteobacterial members, whereas spruce libraries were mainly composed of alpha-, beta-, and gamma-proteobacterial members. Ascomycota members dominated the 18S rRNA clone libraries. Clones similar to Zygomycota were absent from spruce, whereas those similar to Basidiomycota and Glomeromycota were absent from beech libraries. Selective effects of litter quality were observed after 8 weeks. The study provides an insight into the bacterial and fungal communities colonizing beech and spruce litter, and the importance of litter quality and decomposition site as key factors in their development and succession. PMID:16691328

Aneja, Manish Kumar; Sharma, Shilpi; Fleischmann, Frank; Stich, Susanne; Heller, Werner; Bahnweg, Günther; Munch, Jean Charles; Schloter, Michael

2006-07-01

239

Effect of paste water content on APFBC plant efficiency  

SciTech Connect

In the search for a more efficient, less costly, and more environmentally responsible method for generating electrical power from coal, research and development has turned to advanced pressurized fluidized bed combustion (PFBC) and coal gasification technologies. A logical extension of this work is the second-generation PFBC plant, which incorporates key components of each of these technologies. In this new type of plant, coal is devolatilized/carbonized before it is injected into the PFB combustor bed, and the low-Btu fuel gas produced by this process is burned in a gas turbine topping combustor. By integrating coal carbonization with PFB coal/char combustion, gas turbine inlet temperatures of 1260{degrees}C (2300{degrees}F) and higher can be achieved. When operated with a dry coal-fed 871{degrees}C (1600{degrees}F) carbonizer and integrated with a conventional 16.5-MPa gage/538{degrees}C/538{degrees}C/8.5-kPa Hg (2400-psig/1000{degrees}F/1000{degrees}F/2.5-in. Hg) steam cycle, a plant electrical generating efficiency of 46.2 percent is predicted. Despite a loss in plant efficiency, first-generation PFB plants have been built with coal/water paste fuel systems because they offer advantages of simplicity and lower capital costs. The performance of second-generation PFB plants operating with coal paste water contents of 25 and 30 percent are presented in the paper.

Robertson, A. [Foster Wheeler Development Corp., Livingston, NJ (United States); Domeracki, W. [Westinghouse Electric Corp., Orlando, FL (United States). Power Generation Business Group; Horazak, [Gilbert/Commonwealth, Green Hills, PA (United States); Newby, R. [Westinghouse Electric Corp., Pittsburgh, PA (United States). Science and Technology Center; Rehmat, A. [Institute of Gas Technology, Chicago, IL (United States)

1994-06-01

240

Microbiological contamination in water filtration plants in islamabad.  

PubMed

Objective: To determine the frequency of microbiological contamination of water in different water filtration plants in Islamabad. Study Design: Descriptive cross-sectional study. Place and Duration of Study: Water Filtration Plants (WFP) in different sectors of Islamabad, from April to September 2012. Methodology: Water samples were collected in sterilized bottles according to the standard water sampling protocol from site and transported to Pakistan Council for Research in Water Resources (PCRWR) for analysis. Microbiological quality of water was determined in terms of total coliforms (< 2.0 MPN/100 ml) and Escherichia coli (< 2.0 MPN/100 ml). Microbiological contaminated water was defined the sample which had more than 2.0 MPN per 100 ml of either total coliforms or Escherichia (E.) coli. Results: Thirty two WFP were analyzed for microbiological contamination. E. coli was present in 8 (25.0%) water samples, while 24 (75.0%) water samples were free from it. Total coliforms were present in 13 (40.6%) of the samples of WFP, while 19 (59.3%) samples were free from total coliform. Faecal coliforms were present in 8 (25.0%) and absent in 24 (75.0%) samples. Both E. coli and total coliform were present in 8 (25.0%) samples. Nine (59.3) WFP were free from E. coli, total coliform and faecal coliform. Statistically, no significant association was found (p > 0.05) between microbiological contamination and the sectors. Conclusion: Less than half of the water samples of the WFP were contaminated while certain sectors showed more frequent contamination than others. PMID:24848394

Hisam, Aliya; Rahman, Mahmood Ur; Kadir, Ehsan; Tariq, Naseer Alam; Masood, Sumaira

2014-05-01

241

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

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 their overall research effort by evaluating water availability at power plants under drought conditions. While there are a number of competing demands on

T. A. Kimmell; J. A. Veil

2009-01-01

242

Ethylene plant steam strips waste water to recover benzene  

SciTech Connect

Du Pont's Sabine River Works' ethylene plant in Orange, Tex., has selected a steam stripping process to remove benzene from its waste water stream. Timely completion of the project plan diverted a possible cleanup cost in excess of $100 million. The Du Pont plant was constructed in 1967 to crack feedstocks ranging from 50% ethane/50% propane to purity ethane. The plant is currently cracking purity ethane in the presence of dilution steam to produce ethylene and various byproducts. The dilution steam is added to improve selectivity and reduce fouling in the heater coils. The cracked gas exists the heaters and goes to the quench tower, where the steam and a portion of the heavier hydrocarbons such as benzene, toulene, and styrene are condensed. After the cracked gas is cooled in the quench tower, it is compressed and then separated into the various products in the distillation train. The condensed steam and hydrocarbons are separated in the quench settler. The hydrocarbons are sent to the heavy aromatic distillate (HAD) storage for sale. The condensed steam, with dissolved hydrocarbons, combines with the effluent from the API separator and goes to the dissolved gas flotation (DGF) unit, which was installed in 1988. When the plant was started up, the quench water was recycled, to make dilution steam. However, this system was plagued by plugging problems, and the quench water was rerouted to the biponds. The API separator is the collection point for all of the oil and water blowdowns in the ethylene plant. In addition to the blowdowns, large quantities of rainwater go to the API separator. The hydrocarbons leaving the DGF go to HAD storage, and the water goes to the bioponds.

Taylor, M.A. (E.I. du Pont de Nemours and Co. Inc., Orange, TX (US))

1991-05-27

243

The importance of nutritional regulation of plant water flux.  

PubMed

Transpiration is generally considered a wasteful but unavoidable consequence of photosynthesis, occurring because water is lost when stomata open for CO(2) uptake. Additionally, transpiration has been ascribed the functions of cooling leaves, driving root to shoot xylem transport and mass flow of nutrients through the soil to the rhizosphere. As a consequence of the link between nutrient mass flow and transpiration, nutrient availability, particularly that of NO(3)(-), partially regulates plant water flux. Nutrient regulation of transpiration may function through the concerted regulation of: (1) root hydraulic conductance through control of aquaporins by NO(3)(-), (2) shoot stomatal conductance (g(s)) through NO production, and (3) pH and phytohormone regulation of g(s). These mechanisms result in biphasic responses of water flux to NO(3)(-) availability. The consequent trade-off between water and nutrient flux has important implications for understanding plant distributions, for production of water use-efficient crops and for understanding the consequences of global-change-linked CO(2) suppression of transpiration for plant nutrient acquisition. PMID:19449035

Cramer, Michael D; Hawkins, Heidi-Jayne; Verboom, G Anthony

2009-08-01

244

Dynamic modelling of water demand, water availability and adaptation strategies for power plants to global change  

Microsoft Academic Search

According to the latest IPCC reports, the frequency of hot and dry periods will increase in many regions of the world in the future. For power plant operators, the increasing possibility of water shortages is an important challenge that they have to face. Shortages of electricity due to water shortages could have an influence on industries as well as on

Hagen Koch; Stefan Vögele

2009-01-01

245

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

246

Perspectives on Pentaerythritol Tetranitrate (PETN) Decomposition  

Microsoft Academic Search

This report evaluates the large body of work involving the decomposition of PETN and identifies the major decomposition routes and byproducts. From these studies it becomes apparent that the PETN decomposition mechanisms and the resulting byproducts are primarily determined by the chemical environment. In the absence of water, PETN can decompose through the scission of the O-NO² bond resulting in

D Chambers; C Brackett; D O Sparkman

2002-01-01

247

Effects of ion exclusion and isotopic fractionation on pore water geochemistry during gas hydrate formation and decomposition  

Microsoft Academic Search

The effects of ion exclusion and isotopic fractionation associated with gas hydrate formation and decomposition in continental margin sediments are examined using simple mass balance calculations. In a closed system pore fluid salinity can be increased to brine levels and detectable changes in interstitial waterd18O can be caused by formation of significant amounts of interstitial gas hydrate. Time- and mass-dependent

W. Ussler; C. K. Paull

1995-01-01

248

Sector Decomposition  

Microsoft Academic Search

Sector decomposition is a constructive method to isolate divergences from parameter integrals occurring in perturbative quantum field theory. We explain the general algorithm in detail and review its application to multiloop Feynman parameter integrals as well as infrared divergent phase-space integrals over real radiation matrix elements.

Gudrun Heinrich

2008-01-01

249

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

250

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 Central

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.

Zeng, Lixiong; Huang, Zhilin; Lei, Jingpin; Zhou, Benzhi; Li, Maihe

2014-01-01

251

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

252

Nitrogen Removal from Eutrophicated Water by Aquatic Plants  

Microsoft Academic Search

\\u000a Increased N concentration in an aquatic ecosystem is one of important causes of eutrophication. Aquatic higher plants in eutrophic\\u000a water bodies can remove N by direct uptake and by being a carbon source and a surface substrate for microorganisms and algae,\\u000a which also use N as a nutrient and can transform N into gaseous forms that escape from the ecosystem.

Olga Babourina; Zed Rengel

253

Water reuse in a paper reprocessing plant. Final report  

Microsoft Academic Search

This project was undertaken to determine the feasibility of water reuse in a paper reprocessing plant with the goal being to 'close the loop' or to demonstrate zero discharge technology. Before the project began, Big Chief Roofing Company at Ardmore, OK, was discharging 7.89 1\\/sec (125 gpm). Normal operation is now zero discharge with approximately 0.76 1\\/sec (12 gpm) fresh

L. E. Streebin; G. W. Reid; P. Law; C. Hogan

1976-01-01

254

Benchmarking of municipal waste water treatment plants (an Austrian project).  

PubMed

An Austrian research project focused on the development of process indicators for treatment plants with different process and operation modes. The whole treatment scheme was subdivided into four processes, i.e. mechanical pretreatment (Process 1), mechanical-biological waste water treatment (Process 2), sludge thickening and stabilisation (Process 3) and further sludge treatment and disposal (Process 4). In order to get comparable process indicators it was necessary to subdivide the sample of 76 individual treatment plants all over Austria into five groups according to their mean organic load (COD) in the influent. The specific total yearly costs, the yearly operating costs and the yearly capital costs of the four processes have been related to the yearly average of the measured organic load expressed in COD (110 g COD/pe/d). The specific investment costs for the whole treatment plant and for Process 2 have been related to a calculated standard design capacity of the mechanical-biological part of the treatment plant expressed in COD. The capital costs of processes 1, 3 and 4 have been related to the design capacity of the treatment plant. For each group (related to the size of the plant) a benchmark band has been defined for the total yearly costs, the total yearly operational costs and the total yearly capital costs. For the operational costs of the Processes 1 to 4 one benchmark ([see symbol in text] per pe/year) has been defined for each group. In addition a theoretical cost reduction potential has been calculated. The cost efficiency in regard to water protection and some special sub-processes such as aeration and sludge dewatering has been analysed. PMID:15553485

Lindtner, S; Kroiss, H; Nowak, O

2004-01-01

255

Impact of Wastes from a Water Treatment Plant: Evaluative Procedures and Results.  

National Technical Information Service (NTIS)

This report summarized the procedures used and the results obtained in assessing the effects on a stream in Illinois of waste discharges from a water treatment plant that employs the clarification process. The water treatment plant serving Pontiac, Illino...

R. L. Evans D. H. Schnepper T. E. Hill

1979-01-01

256

Foliar pathogenesis and plant water relations: a review.  

PubMed

As the world population grows, there is a pressing need to improve productivity from water use in irrigated and rain-fed agriculture. Foliar diseases have been reported to decrease crop water-use efficiency (WUE) substantially, yet the effects of plant pathogens are seldom considered when methods to improve WUE are debated. We review the effects of foliar pathogens on plant water relations and the consequences for WUE. The effects reported vary between host and pathogen species and between host genotypes. Some general patterns emerge however. Higher fungi and oomycetes cause physical disruption to the cuticle and stomata, and also cause impairment of stomatal closing in the dark. Higher fungi and viruses are associated with impairment of stomatal opening in the light. A number of toxins produced by bacteria and higher fungi have been identified that impair stomatal function. Deleterious effects are not limited to compatible plant-pathogen interactions. Resistant and non-host interactions have been shown to result in stomatal impairment in light and dark conditions. Mitigation of these effects through selection of favourable resistance responses could be an important breeding target in the future. The challenges for researchers are to understand how the effects reported from work under controlled conditions translate to crops in the field, and to elucidate underlying mechanisms. PMID:22664583

Grimmer, Michael K; John Foulkes, M; Paveley, Neil D

2012-07-01

257

Over One-Year Operation of Lenox Water Treatment Plant. Part 1.  

National Technical Information Service (NTIS)

Lenox Water Treatment Plant is the first full-scale (1-MGD) potable flotation plant built in America. The treatment plant consisting of dissolved air flotation, automatic backwash filtration sludge lagoon, and flotation sludge thickener, has been serving ...

M. Krofta L. K. Wang

1983-01-01

258

Magnetic Resonance Imaging of Plants: Water Balance and Water Transport in Relation to Photosynthetic Activity  

Microsoft Academic Search

Nuclear magnetic resonance (NMR) and nuclear magnetic resonance imaging (MRI) techniques are described in relation to applications\\u000a on intact plants. These techniques are non-destructive and non-invasive and can be used to study the dynamics of plant water\\u000a relations and water transport, e.g., as a function of environmental (stress) conditions. Non-spatially resolved NMR as well\\u000a as two-dimensional or even three-dimensional imaging

Henk Van As; Carel W. Windt

2008-01-01

259

ARSENIC REMOVAL FROM DRINKING WATER BY COAGULATION/FILTRATION AND LIME SOFTENING PLANTS  

EPA Science Inventory

This report documents a long term performance (one year) study of 3 water treatment plants to remove arsenic from drinking water sources. The 3 plants consisted of 2 conventional coagulation/filtration plants and 1 lime softening plant. The study involved the collecting of weekly...

260

Analysis of Piping Systems for Life Extension of Heavy Water Plants in India  

Microsoft Academic Search

Heavy water production in India has achieved many milestones in the past. Two of the successfully running heavy water plants are on the verge of completion of their design life in the near future. One of these two plants, situated at Kota, is a hydrogen sulfide based plant and the other one at Tuticorin is an ammonia-based plant. Various exercises

Rajesh K. Mishra; R. S. Soni; H. S. Kushwaha; V. Venkat Raj

2002-01-01

261

Protecting against water loss: analysis of the barrier properties of plant cuticles  

Microsoft Academic Search

The cuticle is the major barrier against uncontrolled water loss from leaves, fruits and other primary parts of higher plants. More than 100 mean values for water permeabilities determined with isolated leaf and fruit cuticles from 61 plant species are compiled and discussed in relation to plant organ, natural habitat and morphology. The maximum barrier prop- erties of plant cuticles

Markus Riederer; Lukas Schreiber

2001-01-01

262

Mercury Bioaccumulation Potential from Wastewater Treatment Plants in Receiving Waters  

NASA Astrophysics Data System (ADS)

In early 2007, the Water Environment Research Foundation (WERF) mercury bioavailability project was initiated in response to the establishment of mercury Total Maximum Daily Load (TMDL) criteria around the country. While many TMDLs recognize that point sources typically constitute a small fraction of the mercury load to a water body, the question was raised concerning the relative bioavailablity of mercury coming from various sources. For instance, is the mercury discharged from a wastewater treatment plant more or less bioavailable than mercury contributed from other sources? This talk will focus on the results of a study investigating approaches to the estimation of bioavailability and potential bioaccumulation of mercury from wastewater treatment plants and other sources in receiving waters. From the outset, a working definition of bioavailability was developed which included not only methylmercury, the form that readily bioaccumulates in aquatic food chains, but also bioavailable inorganic mercury species that could be converted to methylmercury within a scientifically reasonable time frame. Factors that enhance or mitigate the transformation of inorganic mercury to methylmercury and its subsequent bioaccumulation were identified. Profiles were developed for various sources of mercury in watersheds, including wastewater treatment plants, with regard to methylmercury and inorganic bioavailable mercury, and the key factors that enhance or mitigate mercury bioavailability. Technologies that remove mercury from wastewater were reviewed and evaluated for their effect on bioavailability. A screening procedure was developed for making preliminary estimates of bioavailable mercury concentrations and fluxes in wastewater effluents and in fresh, estuarine and marine receiving waters. The procedure was validated using several diverse river and reservoir data sets. A "Bioavailability Tool" was developed which allows a user to estimate the bioavailability of an effluent and compare it to another, and to mix an effluent in a receiving water to estimate bioavailability in the near- and far-field. As part of this project, a study was undertaken to evaluate methylmercury and reactive mercury in wastewater effluents. Effluent samples from 7 municipal wastewater plants from around the Unites States were collected weekly over a ten week period from late June through August of 2008. These data represent the first comprehensive study of bioavailable mercury in wastewater effluents and have not been published elsewhere. Initial data suggest that bioavailable (methyl plus reactive) mercury is less than 30 percent of total unfiltered mercury. Reactive mercury percentages (relative to dissolved total mercury) are somewhat higher than were initially predicted from theoretical calculations. This presentation will overview the project as a whole with a focus on the bioavailability study of these 7 wastewater plants.

Dean, J. D.; Mason, R. P.

2008-12-01

263

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

PubMed

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 (r(2) >0.6-0.8) with leaf water potential (psi(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 (psi(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

2010-07-01

264

IRRIGATION WATER SALINITY EFFECTS ON SOME SOIL WATER CONSTANTS AND PLANT  

Microsoft Academic Search

Germination and pot experiment was conducted under green house conditions to study the influence of irrigation water salinity on yield and chemical composition of wheat (Triticum vulgare L. cv Sakha 8) plant grown in sandy and calcareous soil. Irrigation water salinity levels were, 0.43 (control), 4.85, 6.60 and 8.86 dS m-1, S1, S2, S3 and S4, respectively. Results concluded that,

A. A. M. M. Ragab; F. A. Hellal; M. Abd

2008-01-01

265

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

266

Interspecific differences in dead plant buffering capacity alter the impact of acid rain on decomposition rates in tidal marshes  

Microsoft Academic Search

Simulated acid rain did not alter respiration rates of microbial associations on dead Spartina alterniora from Delaware salt marshes or on dead Carex lyngbyei from Oregon brackish marshes. Since these dead plant-microbe associations have a strong buffering capacity for acid rain, the microbial associations did not experience a low pH. In contrast, Phragmites australis has a low buffering capacity and

John L. Gallagher; Lisa A. Donovan; Donna M. Grant; Debra M. Decker

1987-01-01

267

Organic halogens in unpolluted waters and large bodies of water receiving bleach plant effluents  

SciTech Connect

In this paper the authors review and update recently performed studies of organic halogens in unpolluted waters and two large bodies of water receiving bleach plant effluents---Lake Vattern in Sweden and the Baltic Sea. All water samples contained measurable amounts of adsorbable organic halogens (AOX); the highest concentrations (up to 200 {mu}g Cl/L) were observed in humic lakes not exposed to any industrial discharges. Analysis of chlorophenols revealed that there is a long-distance transport ({gt} 100 km) of chloroguaiacols from bleach plants to remote parts of receiving waters. However, there was no evidence of chlorinated organics from bleach plants accumulating over several years in the water phase. One chlorophenol, 2,4,6-trichlorophenol, and its methylated analogue, 2,4,6-trichloroanisole, were also detected in surface waters considered to be unpolluted. Mass balance calculations showed that different processes in terrestrial environments make large contributions of AOX; enzyme-mediated chlorination of humic substances is a plausible explanation to the widespread occurrence of organic halogens.

Grimvall, A.; Jonsson, S.; Karlsson, S.; Savenhed, R.; Boren, H. (Dept. of Water and Environmental Studies, Linkoping Univ., S-58183 Linkoping (SE))

1991-05-01

268

On the collective network of ionic liquid/water mixtures. III. Structural analysis of ionic liquids on the basis of Voronoi decomposition  

NASA Astrophysics Data System (ADS)

Three different mixtures of 1-butyl-3-methyl-imidazolium tetrafluoroborate with water have been studied by means of molecular dynamics simulations. Based on the classical Lopes-Padua force field trajectories of approximately 60 ns were computed. This is the third part of a series concerning the collective network of 1-butyl-3-methyl-imidazolium tetrafluoroborate/water mixtures. The first part [C. Schröder et al., J. Chem. Phys. 127, 234503 (2007)] dealt with the orientational structure and static dielectric constants. The second part [C. Schröder et al., J. Chem. Phys. 129, 184501 (2008)] was focused on the decomposition of the dielectric spectrum of these mixtures. In this work the focus lies on the characterization of the neighborhood of ionic liquids by means of the Voronoi decomposition. The Voronoi algorithm is a rational tool to uniquely decompose the space around a reference molecule without using any empirical parameters. Thus, neighborhood relations, direct and indirect ones, can be extracted and were used in combination with g-coefficients. These coefficients represent the generalization of the traditional radial distribution function in order to include the mutual positioning and orientation of anisotropic molecules. Furthermore, the Voronoi method provides, as a by-product, the mutual coordination numbers of molecular species.

Schröder, C.; Neumayr, G.; Steinhauser, O.

2009-05-01

269

Biotic vs. Abiotic Control of Decomposition: A Comparison of the Effects of Simulated Extinctions and Changes in Temperature  

PubMed Central

The loss of species is known to have significant effects on ecosystem functioning, but only recently has it been recognized that species loss might rival the effects of other forms of environmental change on ecosystem processes. There is a need for experimental studies that explicitly manipulate species richness and environmental factors concurrently to determine their relative impacts on key ecosystem processes such as plant litter decomposition. It is crucial to understand what factors affect the rate of plant litter decomposition and the relative magnitude of such effects because the rate at which plant litter is lost and transformed to other forms of organic and inorganic carbon determines the capacity for carbon storage in ecosystems and the rate at which greenhouse gasses such as carbon dioxide are outgassed. Here we compared how an increase in water temperature of 5°C and loss of detritivorous invertebrate and plant litter species affect decomposition rates in a laboratory experiment simulating stream conditions. Like some prior studies, we found that species identity, rather than species richness per se, is a key driver of decomposition, but additionally we showed that the loss of particular species can equal or exceed temperature change in its impact on decomposition. Our results indicate that the loss of particular species can be as important a driver of decomposition as substantial temperature change, but also that predicting the relative consequences of species loss and other forms of environmental change on decomposition requires knowledge of assemblages and their constituent species' ecology and ecophysiology.

Boyero, Luz; Cardinale, Bradley J.; Bastian, Mikis; Pearson, Richard G.

2014-01-01

270

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

271

Physiological Effects of 1-Methylcyclopropene on Well-Watered and Water-Stressed Cotton Plants  

Microsoft Academic Search

The current study investigated the effect of 1-methylcyclopropene (1-MCP), an ethylene inhibiting compound, in alleviating\\u000a the detrimental effect of drought on cotton plants. The experiment was conducted in a growth chamber in 2006 and 2007. Treatments\\u000a consisted of (T1) an untreated control well-watered, (T2) 1-MCP at 10 g ai\\/ha well-watered, (T3) an untreated control water-stressed,\\u000a and (T4) 1-MCP at 10 g ai\\/ha

Eduardo M. KawakamiDerrick; Derrick M. Oosterhuis; John L. Snider

2010-01-01

272

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

273

Removal of fluoride from water by five submerged plants.  

PubMed

Studies were conducted on the bioconcentration of fluoride (F(-)) in five submerged plants species. Ceratophyllum demersum, Hydrilla verticillata, Potamogeton malaianus, Myriophyllum verticillatum and Elodea nuttallii were all able to remove F(-) from water to some degree of efficiencies. At 5-20 mg F(-)/L culture solution, C. demersum had the best F(-)-removal performance, E. nuttallii had the poorest F(-)-removal performance among these plants. The relative growth rate (RGR) of the five species varied in different concentrations of F(-), of which C. demersum had the highest RGR. Its RGR decreased by 26.3 %, 63.2 % and 73.7 % from controls at 5, 10 and 20 mg F/L, respectively. PMID:22722597

Zhou, Jun; Gao, Jingqing; Liu, Yang; Ba, Kun; Chen, Shaohua; Zhang, Rinqin

2012-08-01

274

Life Cycle Assesment of Daugavgriva Waste Water Treatment Plant  

NASA Astrophysics Data System (ADS)

This paper presents the assessment of the environmental impacts caused by the treatment of Riga's waste water in the Daugavgriva plant with biogas energy cogeneration through the life cycle assessment (LCA). The LCA seems to be a good tool to assess and evaluate the most serious environmental impacts of a facility The results showed clearly that the impact category contributing the most to the total impact -eutrophicationcomes from the wastewater treatment stage. Climate change also seems to be a relevant impact coming from the wastewater treatment stage and the main contributor to the Climate change is N2O. The main environmental benefits, in terms of the percentages of the total impact, associated to the use of biogas instead of any other fossil fuel in the cogeneration plant are equal to: 3,11% for abiotic depletation, 1,48% for climate change, 0,51% for acidification and 0,12% for eutrophication.

Romagnoli, F.; Sampaio, F.; Blumberga, D.

2009-01-01

275

The impact of water use fees on dispatching and water requirements for water-cooled power plants in Texas.  

PubMed

We utilize a unit commitment and dispatch model to estimate how water use fees on power generators would affect dispatching and water requirements by the power sector in the Electric Reliability Council of Texas' (ERCOT) electric grid. Fees ranging from 10 to 1000 USD per acre-foot were separately applied to water withdrawals and consumption. Fees were chosen to be comparable in cost to a range of water supply projects proposed in the Texas Water Development Board's State Water Plan to meet demand through 2050. We found that these fees can reduce water withdrawals and consumption for cooling thermoelectric power plants in ERCOT by as much as 75% and 23%, respectively. To achieve these water savings, wholesale electricity generation costs might increase as much as 120% based on 2011 fuel costs and generation characteristics. We estimate that water saved through these fees is not as cost-effective as conventional long-term water supply projects. However, the electric grid offers short-term flexibility that conventional water supply projects do not. Furthermore, this manuscript discusses conditions under which the grid could be effective at "supplying" water, particularly during emergency drought conditions, by changing its operational conditions. PMID:24832169

Sanders, Kelly T; Blackhurst, Michael F; King, Carey W; Webber, Michael E

2014-06-17

276

Human pharmaceuticals, antioxidants, and plasticizers in wastewater treatment plant and water reclamation plant effluents.  

PubMed

The primary objective of this study was to determine the presence of unregulated organic chemicals in reclaimed water using complementary targeted and broad spectrum approaches. Eleven of 12 targeted human pharmaceuticals, antioxidants, and plasticizers, and 27 tentatively identified non-target organic chemicals, were present in secondary effluent entering tertiary treatment trains at a wastewater treatment plant and two water reclamation facilities. The removal of these compounds by three different tertiary treatment trains was investigated: coagulant-assisted granular media filtration (California Title-22 water, 22 CCR 60301-60357; Barclay [2006]), lime clarification/reverse osmosis (lime/ RO), and microfiltration-reverse osmosis (MF/RO). Carbamazepine, clofibric acid, gemfibrozil, ibuprofen, p-toluenesulfonamide, caffeine, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and N-butyl benzenesulfonamide (N-BBSA) were present at low to high nanogram-per-liter levels in Title 22 water. The lime/RO product waters contained lower concentrations of clofibric acid, ibuprofen, caffeine, BHA, and N-BBSA (<10 to 71 ng/L) than their Title 22 counterparts. The MF/RO treatment reduced concentrations to levels below their detection limits, although BHT was present in MF/RO product water from one facility. The presence of the target analytes in two surface waters used as raw drinking water sources and a recharged groundwater was also examined. Surface waters used as raw drinking water sources contained caffeine, BHA, BHT, and N-BBSA, while recharged groundwater contained BHT, BHA, and N-BBSA. Nontarget compounds in recharged groundwater appeared to be attenuated with increased residence time in the aquifer. PMID:17370841

Soliman, Mary A; Pedersen, Joel A; Park, Heesu; Castaneda-Jimenez, Angelica; Stenstrom, Michael K; Suffet, I H Mel

2007-02-01

277

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

278

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

279

18 CFR 420.51 - Hydroelectric power plant water use charges.  

Code of Federal Regulations, 2012 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

280

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

281

Plants reverse warming effect on ecosystem water balance.  

PubMed

Models predict that global warming may increase aridity in water-limited ecosystems by accelerating evapotranspiration. We show that interactions between warming and the dominant biota in a grassland ecosystem produced the reverse effect. In a 2-year field experiment, simulated warming increased spring soil moisture by 5-10% under both ambient and elevated CO2. Warming also accelerated the decline of canopy greenness (normalized difference vegetation index) each spring by 11-17% by inducing earlier plant senescence. Lower transpirational water losses resulting from this earlier senescence provide a mechanism for the unexpected rise in soil moisture. Our findings illustrate the potential for organism-environment interactions to modify the direction as well as the magnitude of global change effects on ecosystem functioning. PMID:12907704

Zavaleta, Erika S; Thomas, Brian D; Chiariello, Nona R; Asner, Gregory P; Shaw, M Rebecca; Field, Christopher B

2003-08-19

282

Numerical simulation of the thermal conditions in a sea bay water area used for water supply to nuclear power plants  

SciTech Connect

Consideration is given to the numerical simulation of the thermal conditions in sea water areas used for both water supply to and dissipation of low-grade heat from a nuclear power plant on the shore of a sea bay.

Sokolov, A. S. [JSC 'B. E. Vedeneev All-Russia Research Institute of Hydraulic Engineering (VNIIG)' (Russian Federation)] [JSC 'B. E. Vedeneev All-Russia Research Institute of Hydraulic Engineering (VNIIG)' (Russian Federation)

2013-07-15

283

Preliminary Study on the Supply of Industrial Water by Advanced Treatment of Waste Water Discharged from a Sewage Treatment Plant.  

National Technical Information Service (NTIS)

The reuse of waste water in closed circuit as industrial water after centralized treatment, but without passage through the soil, was studied for application in a newly developed industrial area which includes a sewage treatment plant. The quality of the ...

D. Wallisch

1981-01-01

284

Drinking Water Treatment Plant Residuals Management Technical Report: Summary of Residuals Generation, Treatment, and Disposal at Large Community Water Systems.  

National Technical Information Service (NTIS)

The purpose of this report is to summarize information EPA collected to assess drinking water treatment plant (WTP) discharges of treatment residuals to surface water. EPA identified WTPs for analysis in its 2004 Effluent Guidelines Program Plan based on ...

2011-01-01

285

Utilization of water hyacinths to upgrade heavily loaded waste-water treatment-plant effuents  

SciTech Connect

In recent years, considerable attention has been focused on the use of aquatic plants of various types to treat municipal wastewaters. While several species of plants have been found to be useful in this regard, water hyacinths appear to offer the most promise in areas where the climate is mild enough for them to flourish during most of the year. Accordingly, the primary purpose of this research was to test the acceptability of such systems for use in Southern States such as Alabama. A wastewater treatment plant located at Union Springs, Alabama was selected as the site for this study. The experimental water hyacinth system was configured as a set of two treatment trains with two growth channels in series for each train. One train was harvested and the other was not. Each growth channel was constructed of 3/4-inch marine plywood and was 8 feet wide, 2 feet deep and 32 feet long. The system was operated from May 1986 to October 1987. Observations from this study indicate that a water hyacinth treatment system can be a reliable method for upgrading secondary effluents to advance secondary levels in central Alabama. The reliable treatment period will extend from about May through December with no plant protection (possibly longer in Southern Alabama.)

McAnally, A.S.

1989-01-01

286

Macroinvertebrates Associated With Emergent Macrophyte Decomposition in a Constructed Wetland.  

NASA Astrophysics Data System (ADS)

This study took place at the San Jacinto constructed wetland in California. Wetland water is supplied to irrigators in this cooperative venture between Reclamation and the Eastern Municipal Water District. One of the problems at this highly productive site is that plant litter accumulates to where it needs to be managed by taking the wetland off-line, thus impacting O&M costs and water delivery schedules for extended periods. Information on decomposition rates and conditions needed to encourage invertebrate decomposers was required to improve wetland reliability and decrease biomass management costs. Standing dead culms of bulrush (Schoenoplectus) were collected and air-dried to constant weight. Twenty-gram culm packs were placed in the wetland and then collected at two month intervals. Comparisons between fine-mesh and coarse-mesh packs demonstrated that exclusion of aquatic invertebrates decreased processing. This was also demonstrated in laboratory studies. It also appeared that culm pack decomposition rate varied with the macroinvertebrate community, and that community distribution was influenced by water quality. Study results confirm the importance of vegetation management through water management and wetland design. Maintaining healthy, sustainable ecosystems will help to encourage natural decomposition processes and maintain better water quality.

Nelson, M.; Thullen, J.; Sartoris, J.

2005-05-01

287

Developments in high recovery brackish water desalination plants as part of the solution to water quantity problems  

Microsoft Academic Search

This paper reviews three ways in which existing brackish water reverse osmosis (BWRO) desalination plants can be modified to increase overall water recovery from the 70–75% range to the 90–95% range. The three techniques used to increase plant recovery are: (i) seawater reverse osmosis (SWRO) for water recovery on the BWRO brine stream; (ii) ZeeWeed® ultrafiltration immersed membranes for water

Asam Almulla; Mohamed Eid; Pierre Côté; John Coburn

2003-01-01

288

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

Microsoft Academic Search

Estimation of water uptake by plants and subsequent water stress are complicated by the need to resolve the soil-plant hydrodynamics at scales ranging from millimeters to meters. Using a simplified homogenization technique, the three-dimensional (3-D) soil water movement dynamics can be reduced to solving two 1-D coupled Richards' equations, one for the radial water movement toward rootlets (mesoscale, important for

Mario Siqueira; Gabriel Katul; Amilcare Porporato

2008-01-01

289

Climate and ET: Does Plant Water Requirements Increase during Droughts?  

NASA Astrophysics Data System (ADS)

With the expected rise in global warming and increased frequency of extreme climate variability in the coming decades, conservation and efficient use of water resources is essential and must make use of the most accurate and representative data available. Historically, governmental and private organizations have used estimates of plant water use estimated from a variety of methods for long-term water planning, for designing hydraulic structures, and for establishing regulatory guidance and conservation programs intended to reduce water waste. In recent years, there has been an expansion of agricultural weather station networks which report daily ETo (potential evapotranspiration) and commercial irrigation controllers with instrumentation which calculate real-time ETo from weather parameters. Efforts are underway to use this more precise information for regional water planning and ETo is routinely used for designing and implementing drought response programs. The year 2011 marked the driest year on record in the State of Texas. Compounding the lack of rainfall was record heat during the summer of 2011. In 2011, real-time ETo (reference evapotranspiration) data in Texas was 30 to 50% higher than historic averages. The implications are quite serious, as most current water planning and drought contingency plans do not take into consideration increases in ET during such periods, and irrigation planning and capacity sizing are based on historic averages of consumptive use. This paper examines the relationship between ET and climate during this extreme climatic event. While the solar radiation was near normal levels, temperature and wind was much higher and dew points much lower than norms. The variability and statistical difference between long term average ETo and ETo measurements (from 2006 to 2011) for selected weather stations of the Texas ET Network.

Fipps, G.; Bonaiti, G.; Swanson, C.

2012-04-01

290

EPR Study of Water Induced Decomposition of the SrCuO2 and Sr2CuO3 Ceramics Surface. The Role of Carbon Dioxide  

NASA Astrophysics Data System (ADS)

Processes of SrCuO_2 and Sr_2CuO_3 ceramics decomposition induced by contact with water and carbon dioxide were studied by EPR. The dominant signals in the spectra were found to originate from Sr_2Cu(OH)_6 (for Sr_2CuO_3) and SrCu(OH)_4·H_2O (for SrCuO_2) compounds. The thermally induced conversion of SrCu(OH)_4·H_2O into Sr_2Cu(OH)_6 was analysed, and its product CuO was found to exist in the nanocrystalline form. The presence of CO_2, reacting with Sr(OH)_2, was shown to modify the decomposition process leading to the appearance of SrCu(OH)_4·H_2O, some hydroxycarbonates and Cu(OH)_2 on the surface of ceramics studied. At temperatures higher than 300ºC CuO reacts back with Sr(OH)_2. For the samples being in contact with atmospheric moisture this compound, deposited on a surface of SrCuO_2, decomposes to Sr_2Cu(OH)_6. The presence of the antiferromagnetic compounds Cu(OH)_2, CuO, and Cu_2[(OH)_2CO_3] in the samples can influence the results of magnetic measurements of the studied ceramics.

Augustyniak-Jab?okow, M. A.; Yablokov, Yu. V.; Jacyna-Onyszkiewicz, I.; Ivanova, T. A.; Shustov, V. A.

2007-09-01

291

Effect of textile waste water on tomato plant, Lycopersicon esculentum.  

PubMed

In this study Sanganer town, Jaipur was selected as study area. The plants of Lycopersicon esculentum var. K 21(Tomato) treated with 20 and 30% textile wastewater were analyzed for metal accumulation, growth and biochemical parameters at per, peak and post flowering stages. Findings of the study revealed that chlorophyll content was most severely affected with the increase in metal concentration. Total chlorophyll content showed a reduction of 72.44% while carbohydrate, protein and nitrogen content showed a reduction of 46.83, 71.65 and 71.65% respectively. With the increase in waste water treatment the root and shoot length, root and shoot dry weight and total dry weight were reduced to 50.55, 52.06, 69.93, 72.42, 72.10% respectively. After crop harvesting, the fruit samples of the plants treated with highest concentration of textile waste water contained 2.570 mg g(-1)d.wt. of Zn, 0.800 mg g(-1) d.wt. Cu, 1.520 mg g(-1) d.wt. Cr and 2.010 mg g(-1) d.wt. Pb. PMID:23734449

Marwari, Richa; Khan, T I

2012-09-01

292

Accident source terms for light-water nuclear power plants  

SciTech Connect

This paper presents a discussion of current U.S. Nuclear Regulatory Commission (NRC) activities regarding the proposed revision of accident source terms for light-water nuclear power plants, particularly since the issuance of draft revised source terms in July 1992. The NRC's current reactor site criteria require that an accident fission product release within containment, or [open quotes]source term,[close quotes] be postulated to occur and that its radiological dose consequences be evaluated. The current source term, derived from a 1962 report 2 TID-14844, postulates the instantaneous appearance within containment of 10% of the core inventory of noble gases, 50% of the core inventory of iodine (with half of this assumed to plate out very rapidly on interior surfaces), and 10% of the remaining fission products. This source term has also been used to evaluate other important plant performance requirements, such as control room habitability, postaccident access, and sampling and equipment qualification, and consequently has played an important role in nuclear power plant licensing. Aspects of this source term have long been recognized as being inconsistent with a realistic understanding of severe accident behavior. Because NRC review of advanced reactor designs showed the need for a more realistic understanding of accident mitigation capability, it became clear that the current source term should be updated.

Soffer, L. (Nuclear Regulatory Commission, Washington, DC (United States))

1993-01-01

293

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

294

Growth stimulation of gram (Cicer arietinum) plant by water soluble carbon nanotubes  

NASA Astrophysics Data System (ADS)

Water soluble carbon nanotubes (wsCNTs) show enhancement of the growth rate of common gram (Cicer arietinum) plants. Treating plants with up to 6.0 ?g mL-1 of wsCNT shows an increased growth rate in every part of the plant including the roots, shoots and also in branching. The noticeable difference between the wsCNT treated and controlled gram is the water uptake; in the former it is dramatically enhanced, suggesting better water absorption and retention related to enhanced growth. This work shows that unlike CNTs, wsCNTs are non-toxic to plant cells that conserve water transport in plants.

Tripathi, Shweta; Sonkar, Sumit Kumar; Sarkar, Sabyasachi

2011-03-01

295

Does Ambient Water Quality Affect the Stringency of Regulations? Plant-Level Evidence of the Clean Water Act  

Microsoft Academic Search

This paper provides evidence that the Clean Water Act implemented through effluent limits responded to local water quality. We choose biological oxygen demand as the pollutant and dissolved oxygen as a water quality indicator. We use a panel of permits for 100 plants in Maryland, Virginia, and Pennsylvania for 1990 to 2004. We estimate that decline in water quality by

Lopamudra Chakraborti; Kenneth E. McConnell

2012-01-01

296

[Characteristics of dissolved organic carbon release under inundation from typical grass plants in the water-level fluctuation zone of the Three Gorges Reservoir area].  

PubMed

The water-level fluctuation zone of the Three Gorges Reservoir (TGR) exposes in spring and summer, then, green plants especially herbaceous plants grow vigorously. In the late of September, water-level fluctuation zone of TGR goes to inundation. Meanwhile, annually accumulated biomass of plant will be submerged for decaying, resulting in organism decomposition and release a large amount of dissolved organic carbon (DOC). This may lead to negative impacts on water environment of TGR. The typical herbaceous plants from water-level fluctuation zone were collected and inundated in the laboratory for dynamic measurements of DOC concentration of overlying water. According to the determination, the DOC release rates and fluxes have been calculated. Results showed that the release process of DOC variation fitted in a parabolic curve. The peak DOC concentrations emerge averagely in the 15th day of inundation, indicating that DOC released quickly with organism decay of herbaceous plant. The release process of DOC could be described by the logarithm equation. There are significant differences between the concentration of DOC (the maximum DOC concentration is 486.88 mg x L(-1) +/- 35.97 mg x L(-1) for Centaureapicris, the minimum is 4.18 mg x L(-1) +/- 1.07 mg x L(-1) for Echinochloacrusgalli) and the release amount of DOC (the maximum is 50.54 mg x g(-1) for Centaureapicris, the minimum is 6.51 mg x g(-1) for Polygonumhydropiper) due to different characteristics of plants, especially, the values of C/N of herbaceous plants. The cumulative DOC release quantities during the whole inundation period were significantly correlated with plants' C/N values in linear equations. PMID:24191546

Tan, Qiu-Xia; Zhu, Boi; Hua, Ke-Ke

2013-08-01

297

Growth and Water Relations in Mycorrhizal and Nonmycorrhizal Pinus Halepensis Plants in Response to Drought  

Microsoft Academic Search

Mycorrhizal and nonmycorrhizal Pinus halepensis plants were subjected to water stress by withholding irrigation for four months and then rehydrated for 30 d. Water stress affected plants growth and mycorrhizal association was unable to avoid the effects of drought on plant growth. However, when irrigation was re-established the increase in height, number of shoots, total dry mass, and chlorophyll content

A. Morte; G. Díaz; P. Rodríguez; J. J. Alarcón; M. J. Sánchez-Blanco

2001-01-01

298

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

299

Plant response to the soil environment: An analytical model integrating yield, water, soil type, and salinity  

Microsoft Academic Search

An accessible solution capable of reliably predicting plant-environmental interrelationships for variable species, climates, soils, and management options is a necessary tool for creating sustainable agriculture and environmental preservation. A mechanism-based analytical solution, the first of its kind that considers multiple environmental variables and their combined effects on plant response, was developed and tested. Water uptake by plants, water and salt

Uri Shani; Alon Ben-Gal; Effi Tripler; Lynn M. Dudley

2007-01-01

300

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

301

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

302

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

303

Determination of threshold value of soil water content for field and vegetable plants with lysimeter measurements  

Microsoft Academic Search

Both the potential water consumption of plants and their ability to withdraw soil water are necessary in order to estimate actual evapotranspiration and to predict irrigation timing and amount. In relating to root water uptake the threshold value at which plants reducing evapotranspiration is an important parameter. Since transpiration is linearly correlated to dry matter production, under the condition that

S. Knoblauch

2009-01-01

304

Prevention and Mitigation of Steam Generator Water Hammer Events in PWR Plants.  

National Technical Information Service (NTIS)

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:...

J. T. Han N. R. Anderson

1982-01-01

305

Desert shrub water relations with respect to soil characteristics and plant functional type  

Microsoft Academic Search

Summary 1. Soil characteristics influence plant communities in part through water relations. Hypothetically, finer textured soils in arid climates should be associated with more negative plant and soil water potentials during drought, greater resistance of xylem to cavitation, and shallower root systems than coarse soils. 2. These hypotheses were tested by comparing the water relations of Great Basin shrubs growing

J. S. Sperry; U. G. Hacke

2002-01-01

306

Heavy metals in water, sediments, fish and plants of river Hindon, U.P., India  

Microsoft Academic Search

We analysed the concentrations of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in the water, sediments, fish and plants of the River Hindon, U.P., India, at seven sampling stations, in the year 1982. Considerable variation in concentration between water, sediments, fish and plants were noted. The concentration in the water was in the order Fe > Zn

Mohammad Ajmal; Raziuddin; Ahsan Ullah Khan

1987-01-01

307

Plant performance and water use of peppermint treated with methanol and glycine  

Microsoft Academic Search

Methanol applied to foliage has been reported to reduce water use of C3 crops. Two field experiments on peppermint measured both plant performance and soil water depletion for methanol, glycine, and an untreated control. No differences were found in dry matter yield, oil yield, plant height, leaf weight, or water use. Preliminary phytotoxicity studies showed no toxicity or necrosis at

Alan R. Mitchell; Fred J. Crowe; Marvin D. Butler

1994-01-01

308

Bromoform in the effluents of a nuclear power plant: a potential tracer of coastal water masses  

Microsoft Academic Search

Bromoform (tribromomethane, CHBr3), one of the trihalomethanes, is a chlorination byproduct in cooling water of power plants and industrial complexes. We used the distribution of bromoform in seawater to monitor the movement of cooling water from the Youngkwang Nuclear Power Plant (YNPP) located on the West Coast of Korea. Bromoform concentrations were highest, 124 µg l-1, in surface water near

Jae Sam Yang

2001-01-01

309

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

310

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

311

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

312

Optimal Water Network with Zero Wastewater Discharge in an Alumina Plant  

Microsoft Academic Search

Zero wastewater discharge has been the ultimate goal of green water utilization in process industries. To make the water network with zero wastewater discharge economically beneficial, the system should be optimized. Alumina industry is a heavy water consumption industry, hence studying water re-use and zero wastewater discharge (ZWD) for water system in alumina plants is very important. This paper analyzes

CHUN DENG; XIAO FENG

2009-01-01

313

TOXICITY TESTS OF EFFLUENTS WITH MARSH PLANTS IN WATER AND SEDIMENT  

EPA Science Inventory

Methods are described for toxicity testing of water and sediment with the rooted marsh plants, Echinochloa crusgalli var. crusgalli and var. zelavensis (freshwater) and Spartina alterniflora (estuarine). ive industrial effluents, a sewage treatment plant effluent and a herbicide ...

314

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

315

Origin and decomposition of sinking particulate organic matter in the deep water column inferred from the vertical distributions of its ?15N, ?13 and ?14  

NASA Astrophysics Data System (ADS)

Sinking particles were analyzed for their nitrogen isotopic ratio ?15N) of total particulate nitrogen (PN), stable carbon isotopic ratio ( ?13C) and radioactive isotopic ratio ( ?14C) of total particulate organic carbon (POC), at three different latitudinal (temperate, subpolar and equatorial) and geomorphological (trench, proximal abyssal plain and distal abyssal plain) sites in the western North Pacific Ocean using year-long time series sediment trap systems, to clarify the common vertical trends of the isotopic signals in deep water columns. Although the ?15N and ?13C values of sinking particulate organic matter (POM) were partly affected by the resuspension of sedimentary POM from the sea floor, especially in the trench, the changes in ?15N and ?13C values owing to the resuspension could be corrected by calculation of the isotopic mass balance from ?14C of sinking POC. After this correction, common downward decreasing trends in ?15N and ?13C values were obtained in the deep water columns, irrespective of the latitudes and depths. These coincidental isotopic signals between ?15N and ?13C values provide new constraints for the decomposition process of sinking POM, such as the preferential degradation of 15N- and 13C-rich compounds and the successive re-formation of the sinking particles by higher trophic level organisms in the deep water column.

Nakatsuka, Takeshi; Handa, Nobuhiko; Harada, Naomi; Sugimoto, Tatsuhiro; Imaizumi, Shigemi

1997-12-01

316

Optimization of conventional water treatment plant using dynamic programming.  

PubMed

In this research, the mathematical models, indicating the capability of various units, such as rapid mixing, coagulation and flocculation, sedimentation, and the rapid sand filtration are used. Moreover, cost functions were used for the formulation of conventional water and wastewater treatment plant by applying Clark's formula (Clark, 1982). Also, by applying dynamic programming algorithm, it is easy to design a conventional treatment system with minimal cost. The application of the model for a case reduced the annual cost. This reduction was approximately in the range of 4.5-9.5% considering variable limitations. Sensitivity analysis and prediction of system's feedbacks were performed for different alterations in proportion from parameters optimized amounts. The results indicated (1) that the objective function is more sensitive to design flow rate (Q), (2) the variations in the alum dosage (A), and (3) the sand filter head loss (H). Increasing the inflow by 20%, the total annual cost would increase to about 12.6%, while 20% reduction in inflow leads to 15.2% decrease in the total annual cost. Similarly, 20% increase in alum dosage causes 7.1% increase in the total annual cost, while 20% decrease results in 7.9% decrease in the total annual cost. Furthermore, the pressure decrease causes 2.95 and 3.39% increase and decrease in total annual cost of treatment plants. PMID:23625909

Mostafa, Khezri Seyed; Bahareh, Ghafari; Elahe, Dadvar; Pegah, Dadras

2013-04-26

317

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

318

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

319

Belowground Water Dynamics Under Contrasting Annual and Perennial Plant Communities in an Agriculturally-Dominated Landscape  

NASA Astrophysics Data System (ADS)

The conversion from grasslands and forests to row-crops in the Midwest has affected soil water cycling because plant characteristics are one of the main parameters determining soil storage capacity, infiltration rates, and surface runoff. Little is known, however, about the extent of modification of soil water dynamics under different plant communities. To address this important issue, we are documenting soil water dynamics under contrasting perennial and annual plant communities in an agriculturally-dominated landscape. Measurements of soil moisture and depths of uptake of source water were obtained for six vegetative cover types (corn and soybean field, brome pasture, degraded savanna, restored savanna, and restored prairie) at the Neal Smith National Wildlife Refuge in Prairie City, Iowa. The depths of uptake of soil water were determined on the basis of oxygen isotope composition of soil water and stem water. Measurements were performed once a month during an entire growing season. Preliminary results indicate that soil water present under the different vegetation types show similar profiles with depth during the dry months. Soil water in the upper 5 cm is enriched in oxygen-18 by about 5 per mil relative to soil water at 100 cm. Our preliminary results also indicate that the isotopic composition of stem water from annual plants is typically higher by about 2 per mil relative to that of stem water from perennial plants during the dry period. Whereas the oxygen isotopic composition for corn stem water is -5.49 per mil, that for elm and oak stem water is -7.62 and -7.51 per mil, respectively. The higher isotope values for corn suggest that annual crop plants are withdrawing water from shallower soil horizons relative to perennial plants. Moreover, our preliminary data suggest lower moisture content in soil under annual plant cover. We propose that the presence of deeper roots in the perennial vegetation allows these plants to tap into deeper water sources when soil moisture is low at shallow depths.

Mora, G.; Asbjornsen, H.; Helmers, M. J.; Shepherd, G. W.

2005-12-01

320

Responses of Wetland Plants to Effluents in Water and Sediment.  

National Technical Information Service (NTIS)

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 germinat...

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

1991-01-01

321

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

322

Influence of water vapor and decomposition products on the positive- and negative-ion spectra of SF/sub 6/ corona  

SciTech Connect

We report on the positive- and negative-ion spectra obtained from in-situ mass spectrometric analyses of ions sampled from corona discharges in SF/sub 6/ at P = 6.7 kPa (50 Torr). In positive-ion spectra the presence of water vapor results in the formation of water cluster ions of the form H/sup +/(H/sub 2/O)/sub n/. The distribution of cluster sizes shifts to smaller clusters as the water vapor content decreases. In addition to the SF/sub 6/ fragment ions (SF/sub 5//sup +/, SF/sub 3//sup +/, and SF/sub 2//sup +/), which are observed under relatively dry conditions, the hydrated species SF/sub 5//sup +/(H/sub 2/O) is observed down to water additions of only 40 ppM, the lowest concentration studied. In addition, the ion detected at mass 197 is believed to be the complex SF/sub 3//sup +/(SF/sub 4/) where SF/sub 4/ is an important neutral by-product of SF/sub 6/ discharges. In negative-ion spectra, the influence of water vapor is manifested indirectly by the formation of HF clusters of the form F/sup /minus//(HF)/sub n/. Other clustered species observed include OH/sup /minus//(H/sub 2/O)/sub n/ and OH/sup /minus//(HF)/sub n/. The role of other decomposition by-products, such as SOF/sub 4/ and SO/sub 2/, of SF/sub 6/ corona on the positive- and negative-ion spectra will also be discussed. 11 refs., 6 figs., 1 tab.

Sauers, I.; Siddagangappa, M.C.; Harman, G.

1989-01-01

323

Manganese cluster in photosynthesis: Where plants oxidize water to dioxygen  

SciTech Connect

The essential involvement of manganese in photosynthetic water oxidation was implicit in the observation by Pirson in 1937 that plants and algae deprived of Mn in their growth medium lost the ability to evolve O{sub 2}. Addition of this essential element to the growth medium resulted in the restoration of water oxidation within 30 min. There is increased interest in the study of Mn in biological chemistry and dioxygen metabolism in the last two decades with the discovery of several Mn redox enzymes. The list of enzymes where Mn is required for redox activity includes a Mn superoxide dismutase, a binuclear Mn-containing catalase, a binuclear Mn-containing ribonucleotide reductase, a proposed binuclear Mn site in thiosulfate oxidase, a Mn peroxidase that is capable of oxidative degradation of lignin, and perhaps the most complex and important, the tetranuclear Mn-containing oxygen-evolving complex in photosystem II (Mn-OEC). Mn is well suited for the redox role with accessible oxidation states of II, III, and IV, and possibly V: oxidation states that have all been proposed to explain the mechanisms of the Mn redox enzymes.

Yachandra, V.K.; Klein, M.P. [Lawrence Berkeley National Lab., CA (United States). Structural Biology Div.] [Lawrence Berkeley National Lab., CA (United States). Structural Biology Div.; Sauer, K. [Lawrence Berkeley National Lab., CA (United States). Structural Biology Div.] [Lawrence Berkeley National Lab., CA (United States). Structural Biology Div.; [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry

1996-11-01

324

SOLAR CONVERSION AND ENERGY STORAGE BY THE CHLOROPHYLL A DIHYDRATE PHOTOCATALYTIC DECOMPOSITION OF WATER AND REDUCTION OF CARBON-DIOXIDE  

Microsoft Academic Search

In this work the photoconversion and storage of visible light energy based on the half-cell reactions of water photolysis by crystalline chlorophyll a dihydrate is described. The role of water on the photochemical activity of chlorophyll a is examined by a study of a photogalvanic cell consisting of a Pt\\/Chl a photocathode and a Chl a-free anode. The production of

DANIEL RAY FRUGE

1980-01-01

325

Evaluation of Sodium Aluminate as a Coagulant for Cost Savings at Water Treatment Plants.  

National Technical Information Service (NTIS)

The feasibility of using liquid sodium aluminate (SA) in a more cost effective way for maintaining or improving the finished water quality at water treatment plants was studied. Evaluation of all tests performed, together with calculations of theoretical ...

G. M. Huntley L. K. Wang W. Layer

1985-01-01

326

Changes in Resistance to Flow of Water through a Soil-Plant System.  

National Technical Information Service (NTIS)

A method employing the use of both a hanging water column and a field type thermocouple psychrometer was developed to control and measure water potential gradients in pepper plants with confined root systems. Small soil containers were constructed with Mi...

B. E. Janes G. W. Gee

1970-01-01

327

Feasibility Study for Upgrading of Potable Water Treatment Plants. Final Report.  

National Technical Information Service (NTIS)

The final report is intended to summarize findings from the project 'Feasibility Study for Upgrading of Potable Water Treatment Plants' conducted for the City of Istanbul Water and Sewer Administration (ISKI). The two-year project was initiated in October...

1999-01-01

328

Water Lily May Provide a "Missing Link" in the Evolution of Flowering Plants  

NSF Publications Database

... Erik Nilsen (703) 292-8421 enilsen@nsf.gov Water Lily May Provide a "Missing Link" in the Evolution ... discovered that the water lily may be a critical "missing link" in the evolution of flowering plants ...

329

Potential Usefulness of Antitranspirants for Increasing Water Use Efficiency in Plants.  

National Technical Information Service (NTIS)

Antitranspirants conserve water and maintain favorable plant water balances by reducing stomatal apertures, by forming a thin film over the leaves, or by reflecting excessive radiation. Under normal conditions, reductions in both transpiration and photosy...

R. M. Hagan D. C. Davenport

1970-01-01

330

Management regimes affect woody plant productivity and water use efficiency in an urban desert ecosystem  

Microsoft Academic Search

Woody plant productivity and water use were evaluated under various management regimes in the Central Arizona Phoenix Long\\u000a Term Ecological Research study area during 1999–2003. Management was defined as alteration of plant density, irrigation of\\u000a plants, and removal of plant biomass via pruning. In a ground survey of 204 randomly chosen sites woody plant canopy area\\u000a (CA) was higher in

L. Brooke Stabler

2008-01-01

331

Core and plant design of the power reactor cooled and moderated by supercritical light water with single tube water rods  

Microsoft Academic Search

A reactor cooled and moderated by supercritical light water with single tube water rods is designed. The plant system is a once-through direct cycle; the whole coolant which flows once through the core is fed to the turbine. This reactor is much simpler than the current light water reactors LWRs, which enhances its economy. The average outlet coolant temperature should

K. Dobashi; Y. Oka; S. Koshizuka

1997-01-01

332

Effects of climate change on water demand and water availability for power plants - examples for the German capital Berlin  

Microsoft Academic Search

Effects of climate change on water demand and water availability for power plants - examples for the German capital Berlin Stefan Vögelea, Hagen Kochb&c, Uwe Grünewaldb a Forschungszentrum Jülich, Institute of Energy Research - Systems Analysis and Technology Evaluation, D-52425 Jülich, Germany b Brandenburg University of Technology Cottbus, Chair Hydrology and Water Resources Management, P.O. Box. 101 344, D-03013 Cottbus,

Stefan Voegele; Hagen Koch; Uwe Grünewald

2010-01-01

333

[Purification effects of large-area planting water hyacinth on water environment of Zhushan Bay, Lake Taihu].  

PubMed

Using water hyacinth and other fast-growing and high biomass of floating plants to purify polluted water has become an efficient and effective ecological restoration method at present. Effects of nutrients adsorption and water purification of planting water hyacinth on water quality in Zhushan Bay were studied. The results indicated that no anoxia was observed in water hyacinth planting areas because of wave disturbance and strong water exchange. Concentrations of TN and TP in water hyacinth planting areas were higher than that in the outside of stocking area (the content ranged 3.03-7.45 mg/L and 0.15-0.38 mg/L, respectively), and the content changes ranged 3.37-8.02 mg/L and 0.15-0.36 mg/L,respectively. The higher concentration of TN and TP in water indicated the water body was heavily polluted. Water hyacinth roots have a strong ability to adsorb suspended solids and algae cells, the concentration of Chl-a in stocking areas was higher than that in stocking fringe and outside, the maximum Chlorophyll in the stocking region in August was 177.01 mg/m3, and at the same time the concentrations in planting fringe and outside were 101.53 mg/m3 and 76.96 mg/m, respectively. Higher Chl-a content on water hyacinth roots indicated that water hyacinth had strong blocking effects on algae cells, and demonstrated it had a great purification effects on eutrophicated water, and it also provides a basis for the larger polluted water bodies purification in using water hyacinth. PMID:21780583

Liu, Guo-feng; Zhang, Zhi-yong; Yan, Shao-hua; Zhang, Ying-ying; Liu, Hai-qin; Fan, Cheng-xin

2011-05-01

334

Comprehensive cooling water study annual report. Volume V: wetland plant communities, Savannah River Plant  

SciTech Connect

Wetlands cover approximately 4% of the entire Savannah River watershed. The SRP contains 15,885 ha of wetlands of which 12,722 ha are bottomland hardwood and cypress-tupelo forest, predominantly along streams and in the Savannah River floodplain. The most obvious effect of cooling water releases on wetland plant communities is canopy loss by wetland tree species. About 770 ha of wetland tree canopy exhibits degree of alteration as a result of cooling water releases. Canopy loss continues at a rate of 10.5 to 11 ha/yr in river swamp areas associated with streams that currently receive reactor effluents (Pen Branch and Four Mile Creek). Closed canopy forest is replaced by a mixture of algal mat, thermally tolerant herbaceous, and scrub-shrub communities in the thermal streams and deltas. Following cessation of reactor effluent discharges, stream and delta areas are recolonized by a variety of herbaceous and scrub-shrub species, including many species that occur in the thermal deltas. Successional processes in the post-thermal areas result in a shift from herb dominated to shrub dominated communities. Limited data on primary production indicate that community biomass production rates recover to predistribution levels much faster than community structural parameters. Bald cypress trees in the nonthermal swamp areas do not appear to be replacing themselves, while water tupelo appears to be experiencing adequate regeneration. 65 refs., 52 figs., 45 tabs.

Gladden, J.B.; Lower, M.W.; Mackey, H.E.; Specht, W.L.; Wilde, E.W.

1985-07-01

335

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

336

Spatial decomposition and assignment of infrared spectra of simple ions in water from mid-infrared to THz frequencies: Li+(aq) and F-(aq)  

NASA Astrophysics Data System (ADS)

Ionic hydration is of fundamental relevance from chemical reactivity in aqueous solution to biomolecular function at physiological conditions. Vibrational spectroscopy belongs to the most widely used experimental methods in studies of solvation phenomena. There is, however, still limited molecular understanding as to how the vibrational response of solutions is modulated by the presence of solvation shells around solutes, i.e., by interfacial water. Liquid-state THz spectroscopy has been demonstrated to be able to detect even small solute-induced changes of the hydrogen bond dynamics at the solute-water interface. In many cases it reveals rather long-ranged dynamical correlations around solutes, involving many solvent molecules, that can be tackled theoretically by analyzing vibrational spectra in a distance-resolved manner. Here, several spatial decomposition schemes for infrared spectra are used to reveal the distinct distance- and frequency-dependent contributions of the solvation shells to the spectral response in aqueous solutions of Li+ and F-. The importance of an explicit representation of the solute's electronic structure for the proper description of solute-solvent polarization effects is demonstrated. The solvent's response to the presence of the solute is systematically disentangled and reveals important differences between the spectral responses due to intra- and intermolecular motion as probed in the mid- and far-infrared spectral windows, respectively.

?miechowski, Maciej; Forbert, Harald; Marx, Dominik

2013-07-01

337

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

338

Monitoring and modeling of trihalomethanes (THMs) for a water treatment plant in Istanbul  

Microsoft Academic Search

Because of increasing concern for both microbial control and disinfection by-products (DBPs) formation, water utilities are strictly examining and optimizing disinfection practices. In this study, modeling of trihalomethanes (THMs) formation at processed water of the Kagithane water treatment plant in Istanbul City was conducted. Data for THMs and other water quality and operational parameters were generated through a 12-month sampling

V. Uyak; I. Toroz; S. Meriç

2005-01-01

339

Comparison of corn yield response to plant water stress caused by salinity and by drought  

Microsoft Academic Search

The effect of water stress on corn yield was studied in a salinity experiment and in a drought experiment. The plant water status was determined by measuring the pre-dawn leaf water potential regularly during the whole growing season and expressed by the water stress day index (WSDI). The yield response of corn did not differ under salinity and drought conditions.

N. Katerji; J. W. van Hoorn; A. Hamdy; M. Mastrorilli

2004-01-01

340

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

341

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

342

Water law constraints to siting and operating coal-fired electric generation plants in Kentucky  

SciTech Connect

The purpose of this study was to reveal possible constraints in the applicable laws to increased siting and continued operation of coal-fired power plants in Kentucky. This study includes not only the law of water availability, but some aspects of water quality as well. Kentucky's system of water resource allocation was reviewed to determine whether energy facilities, particularly steam-electric power plants, will be able to depend on a legally sustainable right to water which is physically available, especially during periods of low flow. A primary link between water quantity and quality is then discussed. Water consumption by cooling towers may limit the availability of water for use by additional power plants, other energy conversion systems, and other water users generally. This matter is largely governed by implementation of the section of the Clean Water Act dealing with discharge of thermal effluent.

Rosemarin, C.S.

1980-11-01

343

Membrane integrity — direct turbidity measurement of filtrate from MF membrane modules at an operating potable water treatment plant  

Microsoft Academic Search

The San Patricio Municipal Water District is a wholesale supplier of water to cities and industry in south Texas, USA, with nine municipal and six major industrial customers. It operates three water treatment plants. The newest, Plant “C”, is an MF plant rated at 7.8 mgd using Pall\\/Asahi PVDF membrane modules. The plant has been in continuous operation since January

James Naismith

2005-01-01

344

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

345

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

346

Seasonal progression of plant water relations in fynbos in the western Cape Province, South Africa  

Microsoft Academic Search

Plant xylem pressure potentials and leaf conductances to water loss were measured in the spring and summer at two sites in the western Cape Province, Republic of South Africa. The measurements were to test the hypothesis that the fynbos of South Africa was equivalent to the chaparral of California, therefore a period of plant water stress, similar to the period

P. C. Miller; J. M. Miller

1983-01-01

347

Degradation of oxadiazon in a bioreactor integrated in the water closed circuit of a plant nursery  

Microsoft Academic Search

Hardy ornamental nursery stock (HONS) use fertigation as a rational supply of nutrients all along the growth cycle of plants. Nevertheless, that frequency of irrigation increases the risks of nutrient and herbicide leaching and subsequent contamination of the waste water. Therefore, systems of water treatment are required in plant nurseries. Pseudomonas fluorescens strain CG5 cells were immobilized on a ceramic

Paloma Pinilla; Juan Ruiz; María Carmen Lobo; María José Martínez-Iñigo

2008-01-01

348

The Influence of Groundwater Depth and Nutrient Limitation on Plant Water Use in Owens Valley, California  

Microsoft Academic Search

While previous studies in Owens Valley have focused largely on the direct effects of groundwater depth on plant water stress as a control on plant community composition, particularly the abundance of grasses vs. shrubs, our results suggest that indirect effects of declining soil moisture on soil N availability are a key control. The interactions between water and N cycles may

Diane E. Pataki

349

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

350

One Mgd Ion Exchange Plant for Removal of Nitrate from Well Water.  

National Technical Information Service (NTIS)

A full scale 1 mgd demonstration plant, using ion exchange, for removal of nitrate from well water was built at McFarland, California. The plant has been performing satisfactorily in the semi-automatic mode since October 1983. Full automation of the plant...

R. P. Lauch G. A. Guter

1984-01-01

351

Acclimation of a terrestrial plant to submergence facilitates gas exchange under water  

Microsoft Academic Search

Flooding imposes stress upon terrestrial plants since it severely hampers gas exchange rates between the shoot and the environment. The resulting oxygen deficiency is considered to be the major problem for submerged plants. Oxygen microelectrode studies have, however, shown that aquatic plants maintain relatively high internal oxygen pressures under water, and even may release oxygen via the roots into the

L. Mommer; O. Pedersen; E. J. W. Visser

2004-01-01

352

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

PubMed

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

353

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.

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

2014-01-01

354

Newly observed several peroxides from the gas phase ozonolysis of isoprene using a flow tube reactor and the water vapor effect on their formation and decomposition  

NASA Astrophysics Data System (ADS)

In recent years, one has been paying more and more attention to the formation of hydrogen peroxide and organic peroxides in the oxidation of volatile organic compounds (VOCs) because peroxides play important roles, such as reservoir of OH, HO2 and RO2 radicals, intermediate of Criegee radical chemistry and contributor to secondary organic aerosol. However, to the best of our knowledge, in the reaction of ozone with VOCs, only several small peroxides such as hydrogen peroxide (H2O2), hydroxymethyl hydroperoxide (HMHP), and methyl hydroperoxide (MHP) were separately identified, and their yields varied widely between different studies. Moreover, the information on the formation mechanism of peroxides in the ozonolysis of VOCs was mostly from a speculation rather than experimental evidence. Notably, a static chamber was employed in most of the previous studies, potentially resulting in the decomposition and heterogeneous reaction of peroxides on the chamber walls within an experiment time of tens of minutes to several hours, and possibly missing the details about the generation of peroxides. In the present study, we have used a flow quartz tube reactor to investigate the formation of peroxides in the ozonolysis of isoprene at various relative humidities (RH). A variety of peroxides have been detected on the tens of seconds of time scale using an online high performance liquid chromatography coupled with post-column derivatization using p-hydroxyphenylacetic acid and fluorescence detection. Our experimental results show that in addition to the three peroxides mentioned previously, more four ones, those are peroxyacetic acid (PAA) and three unknown peroxides, have been found. Furthermore, the total yield of the three small peroxides (H2O2, HMHP and MHP) is found to be similar to the result of literature; while for PAA and three unknown peroxides, they highlight a combined molar yield, for example, ~ 40% at 5% RH, much higher than that of the three small peroxides. Opposite to the previous conclusion that the peroxide yield would be positively correlated with RH, the yields of PAA and three unknown peroxides detected in the present study decreased with the RH increase. We tentatively assign these unknown peroxides to be hydroxyl hydroperoxides, which are produced by the reaction of different Criegee radicals with water. We used a box model coupled with the MCM v3.2 mechanism to simulate the reaction processes of the ozone-initiated oxidation of isoprene, adding the reaction between the gaseous water (and water dimer) and Criegee radicals and the decomposition of water-assisted hydroxyl hydroperoxides. We find that this modified mechanism would better explain the variation of peroxides with the RH increase, implying that molecular water and water cluster should be involved in the production and removal of peroxides in the future model.

Huang, D.; Chen, Z.; Zhao, Y.

2012-12-01

355

POTENTIAL WATER QUANTITY AND WATER QUALITY IMPACTS OF POWER PLANT DEVELOPMENT SCENARIOS ON MAJOR RIVERS IN THE OHIO BASIN  

EPA Science Inventory

This report was prepared in support of the Ohio River Basin Energy Study (ORBES), a multidisciplinary policy research program supported by the Environmental Protection Agency. Water consumption levels associated with power plant cooling were estimated for different energy develop...

356

The role of SWRO Barcelona-Llobregat Plant in the water supply system of Barcelona Area  

Microsoft Academic Search

Barcelona-Llobregat Desalination Plant is actually the largest seawater desalination plant in Europe producing potable water from the seawater of the Mediterranean Sea. The plant is able to supply approximately the 20% of tap water of Barcelona Metropolitan area having a maximum capacity of 200,000?cubic meters per day. This project was developed by Aigües Ter-Llobregat, public company of the Catalonian Government

Miguel Angel Sanz; Carlos Miguel

2012-01-01

357

Evaluation of a System for the Imposition of Plant Water Stress 1  

PubMed Central

A system which imposes a range of water stress levels was developed and evaluated. Water stress was controlled by employing a screen to suspend roots above a water column of known height. Levels of water stress were imposed by changing water column height and/or hydraulic conductivity of the medium in the column. The system was evaluated in a series of growth chamber experiments in which sunflowers (Helianthus annuus L. cv NK894) were given three levels of water availability for a period of 3 weeks. Third leaf midday water potentials at the end of the trials ranged from ?0.73 ± 0.04 to ?2.35 ± 0.17 megapascals in waterstressed plants compared to ?0.40 ± 0.02 megapascals for control plants. Repetition of experiments showed no statistical differences in leaf water potentials, plant leaf areas, or plastochron indices between trials. During the experiments, the severity and pattern of water stress developments was related to both water column height and conductivity of the medium. Control plants exhibited normal diurnal water relations and transpirational behavior. Use of this system avoids many problems associated with other techniques and provides a means for subjecting plants to reproducible water stress levels for extended periods of time.

Snow, Michael D.; Tingey, David T.

1985-01-01

358

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...

359

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...

360

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

361

Aquifers as Processing Plants for the Modification of Injected Water.  

National Technical Information Service (NTIS)

Gulf Coast (Baton Rouge) Region aquifer systems offer potential for infested water storage and water composition modification. Study of natural processes on groundwater chemistry provides information on processes potentially influencing water composition ...

J. S. Hanor

1980-01-01

362

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.

2014-04-01

363

Closed-cycle hydrogen production via CO2 decomposition  

Microsoft Academic Search

Conversion of nuclear energy into chemical energy of hydrogen by water decomposition is examined on the basis of closed-cycle thermochemical and radiolytic decomposition of carbon dioxide. Particular attention is given to the decomposition of carbon dioxide by transition metal chlorides. The formation of carbon monoxide is analyzed for the reaction between carbon dioxide and dichlorides of manganese, iron, cobalt, and

S. Sato; Y. Ikezoe; M. Takehisa; R. Ueda

1975-01-01

364

[Effects of large-area planting water hyacinth on macro-benthos community structure and biomass].  

PubMed

The effects on macro-benthos and benthos environment of planting 200 hm2 water hyacinth (E. crassipens) in Zhushan Bay, Lake Taihu, were studied during 8-10 months consecutive surveys. Results indicated that average densities of mollusca (the main species were Bellamya aeruginosa) in far-planting, near-planting and planting area were 276.67, 371.11 and 440.00 ind/m2, respectively, and biomass were 373.15, 486.57 and 672.54 g/m2, respectively, showed that average density and biomass of planting area's were higher than those of others. However, the average density and biomass of Oligochaeta (the main species was Limodrilus hoffmeisteri) and Chironomidae in planting area were lower than that of outside planting area. The density and biomass of three dominant species of benthic animal increased quickly during 8-9 months, decreased quickly in October inside and outside water hyacinth planting area. The reason of this phenomenon could be possible that lots of cyanobacteria cells died and consumed dissolve oxygen in proceed decomposing. Algae cells released lots of phosphorus and nitrogen simultaneously, so macro-benthos died in this environment. The indexes of Shannon-Weaver and Simpson indicated that water environment was in moderate polluted state. On the basis of the survey results, the large-area and high-density planting water hyacinth haven't demonstrated a great impact on macrobenthos and benthos environment in short planting time (about 6 months planting time). PMID:21360881

Liu, Guo-Feng; Liu, Hai-Qin; Zhang, Zhi-Yong; Zhang, Ying-Ying; Yan, Shao-Hua; Zhong, Ji-Cheng; Fan, Cheng-Xin

2010-12-01

365

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

Microsoft Academic Search

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

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

1982-01-01

366

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

367

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

368

Thermoeconomic optimizarion of OC-OTEC electricity and water production plants. Final report  

SciTech Connect

The objectives of this yearlong project were to: (1) assess the economic and technical viability of open-cycle ocean thermal energy conversion of (OC-OTEC) for the production of electricity and/or fresh water based on the current state of the art; (2) develop conceptual designs of optimized OC-OTEC plants that produce electricity and/or fresh water for plant sizes that are economically attractive; and (3) identify the research issues that must be resolved before a commercial plant can be built. Oceanographic data for six potential sites were evaluated and generic site characteristics were developed. The generic site has a 20/sup 0/C temperature differential between the ocean surface and a depth of 1000 m. This temperature differential occurs at a distance of 5 km from shore. Current and projected prices and requirements for electricity and water at potential sites were obtained. The state of the art of components comprising the OC-OTEC plant was reviewed. Design options for each component were identified. The highest performing, least costly, and least technically uncertain design for each component was selected. Component cost and performance models were then developed and integrated into thermoeconomic system models for single- and double-stage OC-OTEC plants that produced electricity and/or fresh water. A computerized optimization procedure was developed to obtain optimal (minimum cost) plant configurations for the production of electricity and/or fresh water. All plant types - floating, moored, shelf-mounted, shallow-water and land-based plants - were evaluated. Based on the state-of-the-art and typical characteristics of potential sites, the primary thrust of the program was directed towards shallow-water and land-based plants. The shallow-water/land-based plant configurations selected had a 5-km long cold-water supply pipe and a 1-km long discharge pipe for the evaporator and condenser.

Block, D.L.; Girgis, M.A.; Huggins, J.C.; McCluney, R.; Rotundo, L.; Valenzuela, J.A.; Hutchings, B.J.; Stacy, W.D.; Sam, R.G.; Patel, B.R.

1984-09-01

369

WATER REUSE IN A WET PROCESS HARDBOARD MANUFACTURING PLANT  

EPA Science Inventory

Superior Fiber Products, Inc., a manufacturer of smooth on one side wet process hardboard, undertook a project to eliminate any discharge of process water through a program of increasing process water reuse. All but wash up water and some pump seal leak water discharges were elim...

370

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

371

Decomposition of water in the separate evolution of hydrogen and oxygen using visible light-responsive TiO 2 thin film photocatalysts: Effect of the work function of the substrates on the yield of the reaction  

Microsoft Academic Search

The development of visible light-responsive TiO2 thin films (vis-TiO2) was successfully carried out by applying a radio-frequency magnetron sputtering (RF-MS) deposition method. The Pt-loaded vis-TiO2 thin films clearly showed high potential for the decomposition of water into H2 and O2 by the evolution of H2 from methanol\\/water as well as O2 from a silver nitrate\\/water system under both UV and

Masaaki Kitano; Koichiro Tsujimaru; Masakazu Anpo

2006-01-01

372

Chemical Composition of Crop Biomass Impacts Its Decomposition  

Microsoft Academic Search

Abbreviations: AI, acid insoluble; AS, acid soluble; SOC, soil organic carbon; SOM, soil organic matter. Understanding the interaction between plant components and their subsequent decomposition provides insights on how plant quality differences may infl uence C sequestration within a given management system. Our hypothesis was that decomposition is a function of biochemical composi- tion when all other variables are constant

Jane M.-F. Johnson; Nancy W. Barbour; Sharon Lachnicht Weyers

2007-01-01

373

A novel modelling and decomposition strategy for overall refinery optimisation  

Microsoft Academic Search

In this paper, a novel decomposition strategy is presented to tackle large-scale overall refinery optimisation problems. This decomposition approach is derived from analysis of the mathematical structure of a general overall plant model, which contains common elements and independent elements. This understanding forms the basis for decomposing the overall plant model into two levels, namely a site level (master model),

N. Zhang; X. X. Zhu

2000-01-01

374

A method for controlling water content of small volumes of planted soil  

Microsoft Academic Search

A method is developed for growing plants in small volumes of soil under controlled and varying water regimes. Cylinders of uniformly packed soil are held on tension plates comprising glass-microfiber filter paper disks connected to hanging water columns. A fixed volume of water is added to the soil surface daily. With this system suctions up to the air-entry potential of

O. Huguenin-Elie; G. J. D. Kirk; E. Frossard

2002-01-01

375

Recovery of submerged plants from high water stress in a large subtropical lake in Florida, USA  

Microsoft Academic Search

The spatial and temporal dynamics of submerged plants were examined in a large subtropical lake in Florida, USA. The objective was to characterize succession of the community following a natural experiment in 2000–2001, when release of water from the lake, followed by a severe drought, reduced water levels by 2m, alleviating stress of multiple years of high water. A systematic

Karl E. Havens; Bruce Sharfstein; Mark A. Brady; Therese L. East; Matthew C. Harwell; Ryan P. Maki; Andrew J. Rodusky

2004-01-01

376

Assessment of cooling water supply in the United States. [Thermal power plants  

Microsoft Academic Search

Consistent with the Water Pollution Act of 1965 the Clear Water Restoration Act of 1966, and the Federal Water Pollution Act Amendment of 1972, and realizing the importance of long-range planning, studies were performed to examine the effect of the legislation on the methods of waste management for thermal power plants. Streams in eight major drainage areas in the United

D. E. Peterson; J. C. Jr. Sonnichsen

1977-01-01

377

Plant water relations as affected by heavy metal stress: A review  

SciTech Connect

Metal toxicity causes multiple direct and indirect effects in plants which concern practically all physiological functions. In this review the effects of excess heavy metals and aluminum on those functions which will alter plant water relations are considered. After a brief comment on the metal effects in cell walls and plasma-lemma, and their consequences for cell expansion growth, the influences of high meal availability on the factors which regulate water entry and water exit in plants are considered. Emphasis is placed on the importance of distinguishing between low water availability in mine and serpentine soils and toxicity effects in plants which may impair the ability of a plant to regulate water uptake. Examples on water relations of both plants grown on metalliferous soil and hydroponics are presented, and the effects of metal toxicity on root growth, water transport and transpiration are considered. It is concluded that future research has to focus on the mechanisms of metal-induced inhibition of both root elongation and morphogenetic processes within roots. In order to understand the relation between metal tolerance and drought resistance better, further studies into metal tolerance mechanisms at the cell wall, membrane and vacuolar level, as well as into the mechanisms of drought resistance of plants adapted to metalliferous soils are required. 135 refs., 7 figs., 6 tabs.

Barcelo, J.; Poschenrieder, C. (Barcelona Univ. (Spain))

1990-01-01

378

Hydrogen iodide decomposition  

DOEpatents

Liquid hydrogen iodide is decomposed to form hydrogen and iodine in the presence of water using a soluble catalyst. Decomposition is carried out at a temperature between about 350.degree. K. and about 525.degree. K. and at a corresponding pressure between about 25 and about 300 atmospheres in the presence of an aqueous solution which acts as a carrier for the homogeneous catalyst. Various halides of the platinum group metals, particularly Pd, Rh and Pt, are used, particularly the chlorides and iodides which exhibit good solubility. After separation of the H.sub.2, the stream from the decomposer is countercurrently extracted with nearly dry HI to remove I.sub.2. The wet phase contains most of the catalyst and is recycled directly to the decomposition step. The catalyst in the remaining almost dry HI-I.sub.2 phase is then extracted into a wet phase which is also recycled. The catalyst-free HI-I.sub.2 phase is finally distilled to separate the HI and I.sub.2. The HI is recycled to the reactor; the I.sub.2 is returned to a reactor operating in accordance with the Bunsen equation to create more HI.

O'Keefe, Dennis R. (San Diego, CA); Norman, John H. (San Diego, CA)

1983-01-01

379

Decomposition of Sodium Tetraphenylborate.  

National Technical Information Service (NTIS)

The chemical decomposition of aqueous alkaline solutions of sodium tetraphenylborate (NaTPB) has been investigated. The focus of the investigation is on the determination of additives and/or variables which influence NaTBP decomposition. This document des...

M. J. Barnes

1998-01-01

380

The incidence and implications of clouds for cloud forest plant water relations.  

PubMed

Although clouds are the most recognisable and defining feature of tropical montane cloud forests, little research has focussed on how clouds affect plant functioning. We used satellite and ground-based observations to study cloud and leaf wetting patterns in contrasting tropical montane and pre-montane cloud forests. We then studied the consequences of leaf wetting for the direct uptake of water accumulated on leaf surfaces into the leaves themselves. During the dry season, the montane forest experienced higher precipitation, cloud cover and leaf wetting events of longer duration than the pre-montane forest. Leaf wetting events resulted in foliar water uptake in all species studied. The capacity for foliar water uptake differed significantly between the montane and pre-montane forest plant communities, as well as among species within a forest. Our results indicate that foliar water uptake is common in these forest plants and improves plant water status during the dry season. PMID:23216898

Goldsmith, Gregory R; Matzke, Nicholas J; Dawson, Todd E

2013-03-01

381

Arsenic removal from waters by bioremediation with the aquatic plants Water Hyacinth ( Eichhornia crassipes) and Lesser Duckweed ( Lemna minor)  

Microsoft Academic Search

In this study the removal of arsenic by the Water Hyacinth (Eichhornia crassipes) and Lesser Duckweed (Lemna minor) was monitored under a concentration of 0.15mgL?1 of the element. Plant densities were 1kg\\/m2 for Lesser Duckweed and 4kg\\/m2 for Water Hyacinth on a wet basis. The arsenic was determined in foliar tissue and water samples by hydride generation atomic absorption spectroscopy.

Sandra Alvarado; Magdiel Guédez; Marcó P. Lué-Merú; Graterol Nelson; Anzalone Alvaro; Arroyo C. Jesús; Záray Gyula

2008-01-01

382

Alternative schemes for production of chilled water and cogeneration of electricity at Ashley Plant  

SciTech Connect

William Tao Associates, Inc. (TAO) evaluated alternative systems for the generation of Chilled Water at Ashley Plant. The generation of chilled water is necessary for several reason; initially as a source of revenue for St. Louis Thermal Energy Corporation (SLTEC), but more importantly as a necessary component of the Trash-to-Energy Plant proposed north of Ashley Plant. The chilled water system provides a base load for steam generated by the Trash-to-Energy Plant. The benefits include reduced tip-fees to the City of St. Louis, lower cost of energy to customers of both the district steam system and the proposed chilled water system, and will result in lower energy and operating costs for the system than if individual services are provided. This symbiotic relationship is main advantage of the Trash-to-Energy system. TAO provided preliminary engineering of the chilled water line route. The basic assumptions of an initial load of 10,000 tons with an ultimate load of 20,000 tons at a temperature difference of 16{degree}F remain. The findings of the pipeline study, although not incorporated into this document, remain valid. Assumptions include the following: An initial design load of 6000 tons which has the capability of growing to 20,000 tons; Incremental costs of steam generated by Ashley Plant and the Trash-to-Energy plant; The turbine room at Ashley Plant is suitable for gut rehab except for turbines No. 7 and No. 9 which should remain operational; and Daily chilled water flow and annual load profile. The paper describes the findings on 8 alternative chiller systems. Additional studies were performed on the following: chilled water storage; low-pressure absorption chiller for balancing plant steam loads; economizer cycle for chiller system; auxiliary equipment energy source; variable flow water pumps; and comparison to satellite chilled water plant study.

Not Available

1989-01-01

383

Transport Membrane Condenser for Water and Energy Recovery from Power Plant Flue Gas  

SciTech Connect

The new waste heat and water recovery technology based on a nanoporous ceramic membrane vapor separation mechanism has been developed for power plant flue gas application. The recovered water vapor and its latent heat from the flue gas can increase the power plant boiler efficiency and reduce water consumption. This report describes the development of the Transport Membrane Condenser (TMC) technology in details for power plant flue gas application. The two-stage TMC design can achieve maximum heat and water recovery based on practical power plant flue gas and cooling water stream conditions. And the report includes: Two-stage TMC water and heat recovery system design based on potential host power plant coal fired flue gas conditions; Membrane performance optimization process based on the flue gas conditions, heat sink conditions, and water and heat transport rate requirement; Pilot-Scale Unit design, fabrication and performance validation test results. Laboratory test results showed the TMC system can exact significant amount of vapor and heat from the flue gases. The recovered water has been tested and proved of good quality, and the impact of SO{sub 2} in the flue gas on the membrane has been evaluated. The TMC pilot-scale system has been field tested with a slip stream of flue gas in a power plant to prove its long term real world operation performance. A TMC scale-up design approach has been investigated and an economic analysis of applying the technology has been performed.

Dexin Wang

2012-03-31

384

Variations in water status, gas exchange, and growth in Rosmarinus officinalis plants infected with Glomus deserticola under drought conditions.  

PubMed

The influence of the arbuscular mycorrhizal fungus Glomus deserticola on the water relations, gas exchange parameters, and vegetative growth of Rosmarinus officinalis plants under water stress was studied. Plants were grown with and without the mycorrhizal fungus under glasshouse conditions and subjected to water stress by withholding irrigation water for 14 days. Along the experimental period, a significant effect of the fungus on the plant growth was observed, and under water stress, mycorrhizal plants showed an increase in aerial and root biomass compared to non-mycorrhizal plants. The decrease in the soil water potential generated a decrease in leaf water potential (psi(l)) and stem water potential (psi(x)) of mycorrhizal and non-mycorrhizal plants, with this decrease being lower in mycorrhizal water-stressed plants. Mycorrhization also had positive effects on the root hydraulic conductivity (Lp) of water stressed plants. Furthermore, mycorrhizal-stressed plants showed a more important decrease in osmotic potential at full turgor (psi(os)) than did non-mycorrhizal-stressed plants, indicating the capacity of osmotic adjustment. Mycorrhizal infection also improved photosynthetic activity (Pn) and stomatal conductance (g(s)) in plants under water stress compared to the non-mycorrhizal-stressed plants. A similar behaviour was observed in the photochemical efficiency of PSII (Fv/Fm) with this parameter being lower in non-mycorrhizal plants than in mycorrhizal plants under water stress conditions. In the same way, under water restriction, mycorrhizal plants showed higher values of chlorophyll content than did non-mycorrhizal plants. Thus, the results obtained indicated that the mycorrhizal symbiosis had a beneficial effect on the water status and growth of Rosmarinus officinalis plants under water-stress conditions. PMID:15266714

Sánchez-Blanco, Ma Jesús; Ferrández, Trinitario; Morales, Ma Angeles; Morte, Asunción; Alarcón, Juan José

2004-06-01

385

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

386

Plant water use efficiency over geological time--evolution of leaf stomata configurations affecting plant gas exchange.  

PubMed

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

387

[Coordination effect between vapor water loss through plant stomata and liquid water supply in soil-plant-atmosphere continuum (SPAC): a review].  

PubMed

Some important phenomena and behaviors concerned with the coordination effect between vapor water loss through plant stomata and liquid water supply in SPAC were discussed in this paper. A large amount of research results showed that plants show isohydric behavior when the plant hydraulic and chemical signals cooperate to promote the stomatal regulation of leaf water potential. The feedback response of stomata to the change of environmental humidity could be used to explain the midday depression of stomatal conductance and photosynthesis under drought condition, and also, to interpret the correlation between stomatal conductance and hydraulic conductance. The feed-forward response of stomata to the change of environmental humidity could be used to explain the hysteresis response of stomatal conductance to leaf-atmosphere vapor pressure deficit. The strategy for getting the most of xylem transport requires the rapid stomatal responses to avoid excess cavitation and the corresponding mechanisms for reversal of cavitation in short time. PMID:19102325

Liu, Li-Min; Qi, Hua; Luo, Xin-Lan; Zhang, Xuan

2008-09-01

388

Probability Matrix Decomposition Models.  

ERIC Educational Resources Information Center

Generalizing Boolean matrix decomposition to a larger class of matrix decomposition models is demonstrated, and probability matrix decomposition (PMD) models are introduced as a probabilistic version of the larger class. An algorithm is presented for the computation of maximum likelihood and maximum a posteriori estimates of the parameters of PMD…

Maris, Eric; And Others

1996-01-01

389

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

390

New coal plant technologies will demand more water  

SciTech Connect

Population shifts, growing electricity demand, and greater competition for water resources have heightened interest in the link between energy and water. The US Energy Information Administration projects a 22% increase in US installed generating capacity by 2030. Of the 259 GE of new capacity expected to have come on-line by then, more than 192 GW will be thermoelectric and thus require some water for cooling. Our challenge will become balancing people's needs for power and for water. 1 ref., 7 figs.

Peltier, R.; Shuster, E.; McNemar, A.; Stiegel, G.J.; Murphy, J.

2008-04-15

391

Reducing water freshwater consumption at coal-fired power plants : approaches used outside the United States.  

SciTech Connect

Coal-fired power plants consume huge quantities of water, and in some water-stressed areas, power plants compete with other users for limited supplies. Extensive use of coal to generate electricity is projected to continue for many years. Faced with increasing power demands and questionable future supplies, industries and governments are seeking ways to reduce freshwater consumption at coal-fired power plants. As the United States investigates various freshwater savings approaches (e.g., the use of alternative water sources), other countries are also researching and implementing approaches to address similar - and in many cases, more challenging - water supply and demand issues. Information about these non-U.S. approaches can be used to help direct near- and mid-term water-consumption research and development (R&D) activities in the United States. This report summarizes the research, development, and deployment (RD&D) status of several approaches used for reducing freshwater consumption by coal-fired power plants in other countries, many of which could be applied, or applied more aggressively, at coal-fired power plants in the United States. Information contained in this report is derived from literature and Internet searches, in some cases supplemented by communication with the researchers, authors, or equipment providers. Because there are few technical, peer-reviewed articles on this topic, much of the information in this report comes from the trade press and other non-peer-reviewed references. Reducing freshwater consumption at coal-fired power plants can occur directly or indirectly. Direct approaches are aimed specifically at reducing water consumption, and they include dry cooling, dry bottom ash handling, low-water-consuming emissions-control technologies, water metering and monitoring, reclaiming water from in-plant operations (e.g., recovery of cooling tower water for boiler makeup water, reclaiming water from flue gas desulfurization [FGD] systems), and desalination. Some of the direct approaches, such as dry air cooling, desalination, and recovery of cooling tower water for boiler makeup water, are costly and are deployed primarily in countries with severe water shortages, such as China, Australia, and South Africa. Table 1 shows drivers and approaches for reducing freshwater consumption in several countries outside the United States. Indirect approaches reduce water consumption while meeting other objectives, such as improving plant efficiency. Plants with higher efficiencies use less energy to produce electricity, and because the greater the energy production, the greater the cooling water needs, increased efficiency will help reduce water consumption. Approaches for improving efficiency (and for indirectly reducing water consumption) include increasing the operating steam parameters (temperature and pressure); using more efficient coal-fired technologies such as cogeneration, IGCC, and direct firing of gas turbines with coal; replacing or retrofitting existing inefficient plants to make them more efficient; installing high-performance monitoring and process controls; and coal drying. The motivations for increasing power plant efficiency outside the United States (and indirectly reducing water consumption) include the following: (1) countries that agreed to reduce carbon emissions (by ratifying the Kyoto protocol) find that one of the most effective ways to do so is to improve plant efficiency; (2) countries that import fuel (e.g., Japan) need highly efficient plants to compensate for higher coal costs; (3) countries with particularly large and growing energy demands, such as China and India, need large, efficient plants; (4) countries with large supplies of low-rank coals, such as Germany, need efficient processes to use such low-energy coals. Some countries have policies that encourage or mandate reduced water consumption - either directly or indirectly. For example, the European Union encourages increased efficiency through its cogeneration directive, which requires member states to assess their

Elcock, D. (Environmental Science Division)

2011-05-09

392

Management intensity alters decomposition via biological pathways  

Microsoft Academic Search

Current conceptual models predict that changes in plant litter chemistry during decomposition are primarily regulated by both\\u000a initial litter chemistry and the stage—or extent—of mass loss. Far less is known about how variations in decomposer community\\u000a structure (e.g., resulting from different ecosystem management types) could influence litter chemistry during decomposition.\\u000a Given the recent agricultural intensification occurring globally and the importance

Kyle WickingsA; A. Stuart Grandy; Sasha Reed; Cory Cleveland

2011-01-01

393

Ozonation at the 900 cfs Los Angeles Water Purification Plant  

Microsoft Academic Search

In 1979. the California Safe Drinking Water Act established a new turbidity limit of 0.5 turbidity unit for drinking waters. To meet this new standard at the Owens River Aqueductplantin Los Angelesi aprocessinvolvingpreozonation and direct filtration was tested and selected. In addition to providing water which meets the required turbidity standard, the ozone process reduces THM levels by about 50%,

Paul W. Prendiville

1986-01-01

394

Microbial As(III) Oxidation in Water Treatment Plant Filters  

EPA Science Inventory

Arsenic exists in two oxidation states in water - arsenite [As(III)] and arsenate [As(V)]. As(III) is relatively mobile in water and difficult to remove by arsenic-removal treatment processes. Source waters that contain As(III) must add a strong oxidant such as free chlorine or p...

395

Water treatment cuts deposition at oil and solvent recovery plant  

Microsoft Academic Search

To accommodate its process water needs, the Oil and Solvent Process Company (OSCO) of Azusa, CA uses city water containing over 69 ppm calcium (as CaCOâ) and over 15 ppm silica. The company requires a flow rate of 1800 gpm to cool its evaporative condensers. The previous water treatment program was unsatisfactory and, because of this, many of the cooling

N. Jr. Guevara; G. Weir; D. A. Toy

1985-01-01

396

Physiological, anatomical and leaf hydraulic effects on leaf water delta18O enrichment in different plant species  

Microsoft Academic Search

Stable oxygen isotope ratios (delta18O) of plant and source waters are valuable tools in the analysis of water and carbon fluxes at leaf, plant, and ecosystem scales. Recent improvements in mechanistic models have significantly advanced the understanding of isotopic leaf water enrichment, which is an important source of delta18O variability in plants and ecosystems. However, the marked variability in leaf

A. Kahmen; S. K. Arndt; T. E. Dawson

2007-01-01

397

Monitoring plant and soil water status: established and novel methods revisited and their relevance to studies of drought tolerance  

Microsoft Academic Search

In all studies of the effects of water deficits on plant functioning there is a need for an accurate and com- prehensive definition of treatments and their effects on plant water status. The various measures of water status used in plant and soil science are reviewed and their appropriateness for different purposes such as for studies of mechanistic effects of

Hamlyn G. Jones

2010-01-01

398

Impact of plant water uptake strategy on soil moisture and evapotranspiration dynamics during drydown  

NASA Astrophysics Data System (ADS)

Experiments have shown that plants can compensate for water stress in the upper, more densely rooted, soil layers by increasing the water uptake from deeper layers. By adapting root water uptake to water availability, plants are able to extend the period of unstressed transpiration. This strategy conflicts with the approach in many land surface schemes, where plant water uptake is treated as a static process. Here we derive expressions for the typical drydown trajectories of evapotranspiration and soil moisture for both strategies. We show that the maximum difference in evapotranspiration between the two strategies during drydown can exceed 50%. This in turn leads to a difference in root zone soil moisture of up to 25%. The results stress the importance of incorporating realistic root water uptake concepts in land surface schemes.

Teuling, Adriaan J.; Uijlenhoet, Remko; Hupet, François; Troch, Peter A.

2006-02-01

399

The Utility of Decomposition and Associated Microbial Parameters to Assess Changes in Stream Ecosystems due to Eutrophication  

NASA Astrophysics Data System (ADS)

Traditional approaches to assess stream ecosystem health rely on structural parameters, e.g. a variety of biotic indices. The goal of the Europe-wide RivFunction project is to develop methodology that uses functional parameters (e.g. plant litter decomposition) to this end. Here we report on decomposition experiments carried out in Portugal in five pairs of streams that differed in dissolved inorganic nutrients. On average, decomposition rates of alder and oak leaves were 2.8 and 1.4 times higher in high nutrient streams in coarse and fine mesh bags, respectively, than in corresponding reference streams. Breakdown rate correlated better with stream water SRP concentration rather than TIN. Fungal biomass and sporulation rates of aquatic hyphomycetes associated with decomposing leaves were stimulated by higher nutrient levels. Both fungal parameters measured at very early stages of decomposition (e.g. days 7-13) correlated well with overall decomposition rates. Eutrophication had no significant effect on shredder abundances in leaf bags but species richness was higher in disturbed streams. Decomposition is a key functional parameter in streams integrating many other variables and can be useful in assessing stream ecosystem health. We also argue that because decomposition is often controlled by fungal activity, microbial parameters can also be useful in bioassessment.

Gulis, V.; Ferreira, V. J.; Graca, M. A.

2005-05-01

400

Physiological, anatomical and leaf hydraulic effects on leaf water ?18O enrichment in different plant species  

NASA Astrophysics Data System (ADS)

Stable oxygen isotope ratios (?18O) of plant and source waters are valuable tools in the analysis of water and carbon fluxes at leaf, plant, and ecosystem scales. Recent improvements in mechanistic models have significantly advanced the understanding of isotopic leaf water enrichment, which is an important source of ?18O variability in plants and ecosystems. However, the marked variability in leaf water ?18O values that have been reported for different plant species hampers efforts to interpret and then apply data on leaf water ?18O values for studies conducted at the ecosystem scale. To improve the understanding and application of ?18O values in leaf water, we tested the interplay of physiological, morphological, anatomical and leaf hydraulic properties as drivers of leaf water ?18O values across 17 Eucalyptus species growing in a common garden. We observed large differences in leaf water ?18O across the 17 species. These differences were only partly driven by physiological and leaf morphological differences across species. A sensitivity analysis using state-of-the-art leaf water enrichment models showed that the parameter - effective path length - (L) is of critical importance for the variability of leaf water ?18O across different species. The data show that L can be related to a suite of leaf properties that include physiology, anatomy and hydraulics. Consequently, consideration of leaf properties will significantly improve the interpretation of ?18O values in leaf water across different plant species and will therefore help in the application of ?18O values in carbon and water cycle assessments at both the plant and the ecosystem scale.

Kahmen, A.; Arndt, S. K.; Dawson, T. E.

2007-12-01

401

Protection from corrosion and deposits for water-cooling systems in oil processing plants  

Microsoft Academic Search

Factors are noted that affect the formation of mineral and microbiological deposits in water circulation supply systems of\\u000a oil processing plants (OPP). The most widespread measures are considered for protection from biodeposits; chlorination using\\u000a hypochlorite; water treatment with copper sulfate; water treatment with organic biocides. Results are provided for a study\\u000a of protection of OPP water systems from corrosion using

Yu. I. Kuznetsov; G. V. Red’kina; A. A. Chirkunov

2008-01-01

402

Water use efficiency and carbon isotope composition of plants in a cold desert environment  

Microsoft Academic Search

The effects of the availabilities of water and nitrogen on water use efficiency (WUE) of plants were investigated in a sagebrush steppe. The four species studied wereArtemisia tridentata (shrub),Ceratoides lanata (suffrutescent shrub),Elymus lanceolatus (rhizomatous grass), andElymus elymoides (tussock grass). Water and nitrogen levels were manipulated in a two-by-two factorial design resulting in four treatments: control (no additions), added water, added

Nancee L. Toft; Jay E. Anderson; Robert S. Nowak

1989-01-01

403

Relationship between the oxygen isotope ratios of terrestrial plant cellulose, carbon dioxide, and water.  

PubMed

The ratios of oxygen-18 to oxygen-16 ( (18)O/(16)O) of cellulose purified from two sets of wheat plants grown under conditions similar in all respects except for a large difference in the (18)O/(16)O ratios of the carbon dioxide supplied to them differ by only a small amount. The difference in the (18)O/(16)O ratios of the cellulose is similar to that observed for the (18)O/(16)O ratios of the water present in the plants. These results indicate that the oxygen derived from carbon dioxide undergoes complete exchange with the oxygen of the water in the plant during the synthesis of cellulose and that the (18)O/(16)O ratio of the water inside the plant is the primary influence on the (18)O/(16)O ratio of cellulose in terrestrial plants. PMID:17816736

Deniro, M J; Epstein, S

1979-04-01

404

Two Legionnaires' disease cases associated with industrial waste water treatment plants: a case report  

PubMed Central

Background Finnish and Swedish waste water systems used by the forest industry were found to be exceptionally heavily contaminated with legionellae in 2005. Case presentation We report two cases of severe pneumonia in employees working at two separate mills in Finland in 2006. Legionella serological and urinary antigen tests were used to diagnose Legionnaires' disease in the symptomatic employees, who had worked at, or close to, waste water treatment plants. Since the findings indicated a Legionella infection, the waste water and home water systems were studied in more detail. The antibody response and Legionella urinary antigen finding of Case A indicated that the infection had been caused by Legionella pneumophila serogroup 1. Case A had been exposed to legionellae while installing a pump into a post-clarification basin at the waste water treatment plant of mill A. Both the water and sludge in the basin contained high concentrations of Legionella pneumophila serogroup 1, in addition to serogroups 3 and 13. Case B was working 200 meters downwind from a waste water treatment plant, which had an active sludge basin and cooling towers. The antibody response indicated that his disease was due to Legionella pneumophila serogroup 2. The cooling tower was the only site at the waste water treatment plant yielding that serogroup, though water in the active sludge basin yielded abundant growth of Legionella pneumophila serogroup 5 and Legionella rubrilucens. Both workers recovered from the disease. Conclusion These are the first reported cases of Legionnaires' disease in Finland associated with industrial waste water systems.

2010-01-01

405

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

406

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

407

Hydrogen production from water decomposition by redox of Fe{sub 2}O{sub 3} modified with single- or double-metal additives  

SciTech Connect

Iron oxide modified with single- or double-metal additives (Cr, Ni, Zr, Ag, Mo, Mo-Cr, Mo-Ni, Mo-Zr and Mo-Ag), which can store and supply pure hydrogen by reduction of iron oxide with hydrogen and subsequent oxidation of reduced iron oxide with steam (Fe{sub 3}O{sub 4} (initial Fe{sub 2}O{sub 3})+4H{sub 2}reversible3Fe+4H{sub 2}O), were prepared by impregnation. Effects of various metal additives in the samples on hydrogen production were investigated by the above-repeated redox. All the samples with Mo additive exhibited a better redox performance than those without Mo, and the Mo-Zr additive in iron oxide was the best effective one enhancing hydrogen production from water decomposition. For Fe{sub 2}O{sub 3}-Mo-Zr, the average H{sub 2} production temperature could be significantly decreased to 276 deg. C, the average H{sub 2} formation rate could be increased to 360.9-461.1 {mu}mol min{sup -1} Fe-g{sup -1} at operating temperature of 300 deg. C and the average storage capacity was up to 4.73 wt% in four cycles, an amount close to the IEA target. - Graphical abstract: Mo+Zr additive has the best modified effect on improving the redox performances of Fe{sub 2}O{sub 3}:H{sub 2} producing temperature of 276 deg. C and hydrogen storage capacity of 4.73 wt%.

Liu Xiaojie [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education), College of Chemistry and Materials Science, Northwest University, Xi'an 710069 (China); Wang Hui, E-mail: huiwang@nwu.edu.c [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education), College of Chemistry and Materials Science, Northwest University, Xi'an 710069 (China)

2010-05-15

408

Handbook: Optimizing Water Treatment Plant Performance Using the Composite Correction Program.  

National Technical Information Service (NTIS)

The handbook is an interim version of a source document for individuals responsible for improving the performance of existing surface water treatment plants using conventional and direct filtration unit processes to achieve compliance with the Surface Wat...

B. A. Hegg E. M. Bissonette H. Schultz J. H. Bender R. C. Renner

1991-01-01

409

Vertical or horizontal steam generators in nuclear power plants with pressurized water reactors  

Microsoft Academic Search

Based on some characteristics and funther reflections the advanteges and ; drawbacks of the two main versions of steam generators used in pressurized water ; reactor nuclear power plants are discussed. (9 references) (auth);

Sauermann

1973-01-01

410

Using Power Plant Discharge Water in Controlled Environment Greenhouses. Progress Report 2.  

National Technical Information Service (NTIS)

TVA's waste heat utilization program identifies potential uses of the low-grade energy contained in the condenser cooling water discharged from power plants and develops and demonstrates technology to utilize this energy in efficient agricultural and aqua...

E. R. Burns R. S. Pile C. E. Madewell J. B. Martin J. Carter

1976-01-01

411

To Examine Existing Water Quality Effect on Growth of Horticulture Plants.  

National Technical Information Service (NTIS)

The effects of the high soluble salt and high sodium concentrations found in South Dakota on horticultural enterprises, especially greenhouses, was investigated. Chysanthemum plants were grown in an aerated water culture and then with an automatic surface...

J. E. Klett M. Enevoldsen

1977-01-01

412

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 ...

413

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

414

Biological Purification of Waste Water from a Coking Plant.  

National Technical Information Service (NTIS)

Biological treatment of effluent, such as those from coking plants, is difficult. Phenols present in those effluents are less likely to influence the treatment than are associated inhibiting constituents such as cyanides, thiocyanates, sulphides and perha...

B. Boman J. Norrman

1981-01-01

415

New Strategy for Water Level Control at Hydro Power Plants.  

National Technical Information Service (NTIS)

This is the final report in a joint development project between Vattenfall (Swedish State Power Board, SSPB) and ASEA Generation. A new level control strategy has been developed, implemented and tested at the Bergeforsen hydro power plant reservoir, which...

G. Fabricius C. Jensen S. O. Lindstroem T. Ottosson

1987-01-01

416

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

417

A co-beneficial system using aquatic plants: bioethanol production from free-floating aquatic plants used for water purification.  

PubMed

A co-beneficial system using constructed wetlands (CWs) planted with aquatic plants is proposed for bioethanol production and nutrient removal from wastewater. The potential for bioethanol production from aquatic plant biomass was experimentally evaluated. Water hyacinth and water lettuce were selected because of their high growth rates and easy harvestability attributable to their free-floating vegetation form. The alkaline/oxidative pretreatment was selected for improving enzymatic hydrolysis of the aquatic plants. Ethanol was produced with yields of 0.14-0.17 g-ethanol/ g-biomass in a simultaneous saccharification and fermentation mode using a recombinant Escherichia coli strain or a typical yeast strain Saccharomyces cerevisiae. Subsequently, the combined benefits of the CWs planted with the aquatic plants for bioethanol production and nutrient removal were theoretically estimated. For treating domestic wastewater at 1,100 m(3)/d, it was inferred that the anoxic-oxic activated sludge process consumes energy at 3,200 MJ/d, whereas the conventional activated sludge process followed by the CW consumes only 1,800 MJ/d with ethanol production at 115 MJ/d. PMID:23752400

Soda, S; Mishima, D; Inoue, D; Ike, M

2013-01-01

418

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

419

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

420

Improvement of systems supplying process water to thermal and nuclear power plants  

Microsoft Academic Search

Scientific research in the field of systems supplying process water to thermal power plants began to evolve at the B. E. Vedeneyev All-Union Scientific-Research Institute of Hydraulic Engineering (AUSRIHE) in the 1940s. The problem of the substantiation of expedient systems for process-water supply for nuclear power plants arose at a later date. At the present time, developments in this field

I. I. Makarov; E. A. Sukhov; T. B. Ishchuk

1997-01-01

421

Review: mechanisms for boron deficiency-mediated changes in plant water relations.  

PubMed

Boron (B) is an essential microelement for plants and is constantly needed throughout the plant life due to its function as a structural element of the plant cell wall. B deficiency is a wide-spread problem in agricultural areas world-wide, and management of B nutrition is challenged by sudden occurrences of B deficiency or inconsistent effects of foliar B application. The effects of insufficient B supply on different structures relevant for the plant water status have been heavily researched, but the resulting conclusions are contradictory and no clear picture has so far emerged that fully explains the inconsistencies. B deficiency can affect water uptake by inhibition of root and shoot growth and by upregulation of water channels. Structural damage to xylem vessels can limit water transport to arial plant parts, while water loss can be altered by impaired barrier functions of leaf surfaces and reduced photosynthesis. In consequence of all these effects, transpiration is reduced in B-deficient plants under well-watered conditions. Under drought conditions, the responsiveness of stomata is impaired. Possible consequences of damaged vasculature for plant B nutrition include the reduced effectiveness of foliar B fertilization, especially in species with high B phloem mobility. Changes in leaf surface properties can further reduce B uptake after foliar application. In species with low B phloem mobility, weakened xylem vessels may not be able to supply sufficient B to arial parts under conditions of increased B demand, such as during bud development of trees. Since structural damage to vessels is hardly reversible, these effects could be permanent, even if B deficiency was only transient. Another consequence of reduced water status is the higher susceptibility of B-deficient plants to other abiotic stresses, which also impair water relations, especially drought. Since damage to vasculature can occur before visible symptoms of B deficiency appear in shoots, the importance to develop reliable diagnostic tools for detection of sub-acute B deficiency is highlighted. PMID:23415325

Wimmer, Monika A; Eichert, Thomas

2013-04-01

422

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

423

Catalytic links among the water–gas shift, water-assisted formic acid decomposition, and methanol steam reforming reactions over Pt-promoted thoria  

Microsoft Academic Search

Implied in the proposed water–gas shift (WGS) mechanisms for Pt\\/ceria and Pt\\/thoria catalysts is the presumption that reduced defect centers are formed on the surface. This X-ray absorption near-edge spectroscopy study provides direct results indicating that Pt facilitates reduction in the surface shell of thoria. Mechanistic arguments from in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) are provided suggesting

Gary Jacobs; Patricia M. Patterson; Uschi M. Graham; Adam C. Crawford; Alan Dozier; Burtron H. Davis

2005-01-01

424

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

425

Hydrogen production by high temperature, high pressure water electrolysis. III - Design and construction of test plant  

Microsoft Academic Search

The design and construction of a test plant of hydrogen capacity 4 cu Nm\\/hour based on high-temperature, high-pressure water electrolysis which was built to obtain technical data for the construction of a 20-cu Nm\\/hour pilot plant are outlined. The test plant is a forced circulation system comprised of an electrolyzer, electrolyte circulation line, gas-liquid separator, hydrogen\\/oxygen production gas line, measurement

Y. Kajiwara; S. Maezawa; K. Matsunaga

1981-01-01

426

Trends in water demand and water availability for power plants—scenario analyses for the German capital Berlin  

Microsoft Academic Search

The availability of electric power is an important prerequisite for the development or maintenance of high living standards.\\u000a Global change, including socio-economic change and climate change, is a challenge for those who have to deal with the long-term\\u000a management of thermoelectric power plants. Power plants have lifetimes of several decades. Their water demand changes with\\u000a climate parameters in the short

Hagen Koch; Stefan Vögele; Michael Kaltofen; Uwe Grünewald

2012-01-01

427

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 ...

428

The determination of boron in soil extracts, plant materials, composts, manures, water and nutrient solutions  

Microsoft Academic Search

A rapid colorimetric method for the determination of boron in soil extracts, plant materials, composts, manures, water and nutrient solution is proposed. The method is rapid, reliable and carried out in aqueous solution. A marked advantage is that boron can be determined in the same soil extract or plant material digest used for determination of other elements.

Benjamin Wolf

1971-01-01

429

Physiological parameters of desert truffle mycorrhizal Helianthemun almeriense plants cultivated in orchards under water deficit conditions  

Microsoft Academic Search

Physiological parameters of mycorrhizal symbiosis by Helianthemum almeriense and Terfezia claveryi in orchards were characterized under water deficit conditions. Our orchard included 40 mycorrhizal and 40 nonmycorrhizal plants. Only mycorrhizal plants survived at the beginning of the experimental period, indicating dependency on fungal symbionts in roots for survival. Drought stress significantly affected the mycorrhizal colonization percentage which was 70% in

Asunción Morte; Alfonso Navarro-Ródenas; Emilio Nicolás

2010-01-01

430

A model on optimal root–shoot allocation and water transport in clonal plants  

Microsoft Academic Search

Experimental studies have shown that interconnected ramets of clonal plants may exchange resources and adjust root–shoot allocation patterns when exposed to spatially heterogeneous habitats, thereby enhancing the efficiency of resource extraction from patchy environments. If ramets of a clonal plant are placed in conditions of high light and low water availability, and connected ramets are exposed to a low light

Josef F. Stuefer; Feike Schieving

1998-01-01

431

Development of GERT model for precommissioning\\/commissioning of water treatment plant  

Microsoft Academic Search

Since the introduction of GERT (graphical evaluation and review technique) many papers have been published to show its application in various fields of engineering, management and system study, etc. Application to the precommissioning\\/commissioning of different types of plant of a refinery has not yet been shown in the literature. In this paper its application to one such plant, a water

S. HASANUDDIN AHMAD; M. HANI ALDABBAGH

1996-01-01

432

Germination characteristics of lakeshore plants under an artificially stabilized water regime  

Microsoft Academic Search

To examine the possibility of the failure of lakeshore plants to germinate under an anthropogenically controlled water regime, we investigated physiological germination responses to temperature and inundation among 25 lakeshore plant species from Lake Kasumigaura, Japan. The requirement of low temperature for dormancy breakage, which is common in spring-germinators, was seen in 14 species. Eight species showed sensitivity to temperature

Jun Nishihiro; Sachiko Araki; Nobuo Fujiwara; Izumi Washitani

2004-01-01

433

78 FR 35330 - Initial Test Programs for Water-Cooled Nuclear Power Plants  

Federal Register 2010, 2011, 2012, 2013

...Regulatory Research, U.S. Nuclear Regulatory Commission...for light water cooled nuclear power plants. This...revised to address design qualification tests for new design...and Approvals for Nuclear Power Plants.'' This...for preoperational, fuel loading, initial...

2013-06-12

434

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