Science.gov

Sample records for center water distribution

  1. Distributed Active Archive Center

    NASA Technical Reports Server (NTRS)

    Bodden, Lee; Pease, Phil; Bedet, Jean-Jacques; Rosen, Wayne

    1993-01-01

    The Goddard Space Flight Center Version 0 Distributed Active Archive Center (GSFC V0 DAAC) is being developed to enhance and improve scientific research and productivity by consolidating access to remote sensor earth science data in the pre-EOS time frame. In cooperation with scientists from the science labs at GSFC, other NASA facilities, universities, and other government agencies, the DAAC will support data acquisition, validation, archive and distribution. The DAAC is being developed in response to EOSDIS Project Functional Requirements as well as from requirements originating from individual science projects such as SeaWiFS, Meteor3/TOMS2, AVHRR Pathfinder, TOVS Pathfinder, and UARS. The GSFC V0 DAAC has begun operational support for the AVHRR Pathfinder (as of April, 1993), TOVS Pathfinder (as of July, 1993) and the UARS (September, 1993) Projects, and is preparing to provide operational support for SeaWiFS (August, 1994) data. The GSFC V0 DAAC has also incorporated the existing data, services, and functionality of the DAAC/Climate, DAAC/Land, and the Coastal Zone Color Scanner (CZCS) Systems.

  2. Technical Support to the Drinking Water Distribution System Simulator Research Center - Biofilm Test Loop

    EPA Science Inventory

    This project will utilize the distribution system simulator (DSS) designed and fabricated by the U.S. Environmental Protection Agency (EPA) to simulate continuous flow conditions observed in a typical distribution system. The experimental studies performed through this project a...

  3. International Water Center

    NASA Astrophysics Data System (ADS)

    The urban district of Nancy and the Town of Nancy, France, have taken the initiative of creating an International Center of Water (Centre International de l'Eau à Nancy—NAN.C.I.E.) in association with two universities, six engineering colleges, the Research Centers of Nancy, the Rhine-Meuse Basin Agency, and the Chamber of Commerce and Industry. The aim of this center is to promote research and technology transfer in the areas of water and sanitation. In 1985 it will initiate a research program drawing on the experience of 350 researchers and engineers of various disciplines who have already been assigned to research in these fields. The research themes, the majority of which will be multidisciplinary, concern aspects of hygiene and health, the engineering of industrial processes, water resources, and the environment and agriculture. A specialist training program offering five types of training aimed at university graduates, graduates of engineering colleges, or experts, will start in October 1984.

  4. GROUND WATER TECHNICAL SUPPORT CENTER

    EPA Science Inventory

    EPA's Office of Research and Development operates a Ground Water Technical Support Center (GWTSC). The Center provides support on issues regarding subsurface contamination, contaminant fluxes to other media (e.g., surface water or air), and ecosystem restoration. The GWTSC creat...

  5. Cooling water distribution system

    DOEpatents

    Orr, Richard

    1994-01-01

    A passive containment cooling system for a nuclear reactor containment vessel. Disclosed is a cooling water distribution system for introducing cooling water by gravity uniformly over the outer surface of a steel containment vessel using an interconnected series of radial guide elements, a plurality of circumferential collector elements and collector boxes to collect and feed the cooling water into distribution channels extending along the curved surface of the steel containment vessel. The cooling water is uniformly distributed over the curved surface by a plurality of weirs in the distribution channels.

  6. The Hydrologic Cycle Distributed Active Archive Center

    NASA Technical Reports Server (NTRS)

    Hardin, Danny M.; Goodman, H. Michael

    1995-01-01

    The Marshall Space Flight Center Distributed Active Archive Center in Huntsville, Alabama supports the acquisition, production, archival and dissemination of data relevant to the study of the global hydrologic cycle. This paper describes the Hydrologic Cycle DAAC, surveys its principle data holdings, addresses future growth, and gives information for accessing the data sets.

  7. Managing Returns in a Catalog Distribution Center

    ERIC Educational Resources Information Center

    Gates, Joyce; Stuart, Julie Ann; Bonawi-tan, Winston; Loehr, Sarah

    2004-01-01

    The research team of the Purdue University in the United States developed an algorithm that considers several different factors, in addition to cost, to help catalog distribution centers process their returns more efficiently. A case study to teach the students important concepts involved in developing a solution to the returns disposition problem…

  8. Water--The New Fitness Center!

    ERIC Educational Resources Information Center

    Spannuth, John

    1989-01-01

    This article presents an explanation of the benefits of exercises done in the water and describes several water fitness programs implemented by an Oklahoma YMCA center. Water walking is described, and guidelines and cautions are given to maximize the benefits and minimize the risks of this form of exercise. (IAH)

  9. Water Treatment Technology - Distribution Systems.

    ERIC Educational Resources Information Center

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on distribution systems provides instructional materials for six competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: types of pipe for distribution systems, types…

  10. GROUND-WATER TECHNICAL SUPPORT CENTER

    EPA Science Inventory

    This flyer describes the objectives and activities of the Ground-Water Technical Support Center, which is part of the Ground Water and Ecosystems Restoration Division. It is directed toward technical audiences (EPA Regions and State regulators within the Regions) and will be use...

  11. Modeled ground water age distributions

    USGS Publications Warehouse

    Woolfenden, Linda R.; Ginn, Timothy R.

    2009-01-01

    The age of ground water in any given sample is a distributed quantity representing distributed provenance (in space and time) of the water. Conventional analysis of tracers such as unstable isotopes or anthropogenic chemical species gives discrete or binary measures of the presence of water of a given age. Modeled ground water age distributions provide a continuous measure of contributions from different recharge sources to aquifers. A numerical solution of the ground water age equation of Ginn (1999) was tested both on a hypothetical simplified one-dimensional flow system and under real world conditions. Results from these simulations yield the first continuous distributions of ground water age using this model. Complete age distributions as a function of one and two space dimensions were obtained from both numerical experiments. Simulations in the test problem produced mean ages that were consistent with the expected value at the end of the model domain for all dispersivity values tested, although the mean ages for the two highest dispersivity values deviated slightly from the expected value. Mean ages in the dispersionless case also were consistent with the expected mean ages throughout the physical model domain. Simulations under real world conditions for three dispersivity values resulted in decreasing mean age with increasing dispersivity. This likely is a consequence of an edge effect. However, simulations for all three dispersivity values tested were mass balanced and stable demonstrating that the solution of the ground water age equation can provide estimates of water mass density distributions over age under real world conditions.

  12. EPA'S GROUND WATER TECHNICAL SUPPORT CENTER

    EPA Science Inventory

    The purpose and the services provided by EPA's Ground Water Technical Support Center (GWTSC) will be presented. In 1987 the Office of Solid Waste and Emergency Response, Regional Waste Management Offices, and ORD established the Technical Support Project (TSP)

    The purpos...

  13. Water Distribution and Removal Model

    SciTech Connect

    Y. Deng; N. Chipman; E.L. Hardin

    2005-08-26

    The design of the Yucca Mountain high level radioactive waste repository depends on the performance of the engineered barrier system (EBS). To support the total system performance assessment (TSPA), the Engineered Barrier System Degradation, Flow, and Transport Process Model Report (EBS PMR) is developed to describe the thermal, mechanical, chemical, hydrological, biological, and radionuclide transport processes within the emplacement drifts, which includes the following major analysis/model reports (AMRs): (1) EBS Water Distribution and Removal (WD&R) Model; (2) EBS Physical and Chemical Environment (P&CE) Model; (3) EBS Radionuclide Transport (EBS RNT) Model; and (4) EBS Multiscale Thermohydrologic (TH) Model. Technical information, including data, analyses, models, software, and supporting documents will be provided to defend the applicability of these models for their intended purpose of evaluating the postclosure performance of the Yucca Mountain repository system. The WD&R model ARM is important to the site recommendation. Water distribution and removal represents one component of the overall EBS. Under some conditions, liquid water will seep into emplacement drifts through fractures in the host rock and move generally downward, potentially contacting waste packages. After waste packages are breached by corrosion, some of this seepage water will contact the waste, dissolve or suspend radionuclides, and ultimately carry radionuclides through the EBS to the near-field host rock. Lateral diversion of liquid water within the drift will occur at the inner drift surface, and more significantly from the operation of engineered structures such as drip shields and the outer surface of waste packages. If most of the seepage flux can be diverted laterally and removed from the drifts before contacting the wastes, the release of radionuclides from the EBS can be controlled, resulting in a proportional reduction in dose release at the accessible environment. The purposes

  14. BIOFILM IN DRINKING WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Throughout the world there are millions of miles of water distribution pipe lines which provide potable water for use by individuals and industry. Some of these water distribution systems have been in service well over one hundred years. Treated water moving through a distributio...

  15. STANDARDIZED COSTS FOR WATER SUPPLY DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Presented within the report are cost data for construction and operation/maintenance of domestic water distribution and transmission pipelines, domestic water pumping stations, and domestic water storage reservoirs. To allow comparison of new construction with rehabilitation of e...

  16. 2. WATER PUMPS IN THE BASEMENT OF THE VISITORS CENTER, ...

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

    2. WATER PUMPS IN THE BASEMENT OF THE VISITORS CENTER, LOOKING WEST. - Hot Springs National Park, Bathhouse Row, Visitor's Center, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

  17. 3. WATER PUMPS IN THE BASEMENT OF THE VISITORS CENTER, ...

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

    3. WATER PUMPS IN THE BASEMENT OF THE VISITORS CENTER, LOOKING EAST. - Hot Springs National Park, Bathhouse Row, Visitor's Center, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

  18. Silver disinfection in water distribution systems

    NASA Astrophysics Data System (ADS)

    Silvestry Rodriguez, Nadia

    Silver was evaluated as disinfectant to maintain water quality in water distribution system. It was used to inhibit growth of two opportunistic bacteria in planktonik form and in biofilm formation in Robbins devices with stainless steel and PVC surfaces. The results of this work show that silver is a potential secondary disinfectant to be used in water distribution systems.

  19. Effects of graded distribution of scattering centers on ballistic transport

    SciTech Connect

    Mitran, T. L.; Nemnes, G. A.; Ion, L.; Dragoman, Daniela

    2014-09-28

    The transmission coefficient of a two dimensional scattering region connected to ideal leads was calculated for the case of electrons interacting with an inhomogeneous distribution of repulsive or attractive scattering centers. The scattering centers with Gaussian profiles were positioned at regular intervals perpendicular to the transport direction, but were spaced according to a power law along this direction. The transmission function was obtained using a scattering formalism based on the R-matrix method. The simulations revealed that although, overall, the transmission coefficient decreases and becomes almost monotonously dependent on energy as the inhomogeneity of both attractive and repulsive scattering centers increases, the redistribution of transmission between open channels depends on the type of scattering centers.

  20. Transparent exopolymer particle removal in different drinking water production centers.

    PubMed

    Van Nevel, Sam; Hennebel, Tom; De Beuf, Kristof; Du Laing, Gijs; Verstraete, Willy; Boon, Nico

    2012-07-01

    Transparent exopolymer particles (TEP) have recently gained interest in relation to membrane fouling. These sticky, gel-like particles consist of acidic polysaccharides excreted by bacteria and algae. The concentrations, expressed as xanthan gum equivalents L⁻¹ (μg X(eq) L⁻¹), usually reach hundred up to thousands μg X(eq) L⁻¹ in natural waters. However, very few research was performed on the occurrence and fate of TEP in drinking water, this far. This study examined three different drinking water production centers, taking in effluent of a sewage treatment plant (STP), surface water and groundwater, respectively. Each treatment step was evaluated on TEP removal and on 13 other chemical and biological parameters. An assessment on TEP removal efficiency of a diverse range of water treatment methods and on correlations between TEP and other parameters was performed. Significant correlations between particulate TEP (>0.4 μm) and viable cell concentrations were found, as well as between colloidal TEP (0.05-0.4 μm) and total COD, TOC, total cell or viable cell concentrations. TEP concentrations were very dependent on the raw water source; no TEP was detected in groundwater but the STP effluent contained 1572 μg X(eq) L⁻¹ and the surface water 699 μg X(eq) L⁻¹. Over 94% of total TEP in both plants was colloidal TEP, a fraction neglected in nearly every other TEP study. The combination of coagulation and sand filtration was effective to decrease the TEP levels by 67%, while the combination of ultrafiltration and reverse osmosis provided a total TEP removal. Finally, in none of the installations TEP reached the final drinking water distribution system at significant concentrations. Overall, this study described the presence and removal of TEP in drinking water systems.

  1. Passive containment cooling water distribution device

    DOEpatents

    Conway, Lawrence E.; Fanto, Susan V.

    1994-01-01

    A passive containment cooling system for a nuclear reactor containment vessel. Disclosed is a cooling water distribution system for introducing cooling water by gravity uniformly over the outer surface of a steel containment vessel using a series of radial guide elements and cascading weir boxes to collect and then distribute the cooling water into a series of distribution areas through a plurality of cascading weirs. The cooling water is then uniformly distributed over the curved surface by a plurality of weir notches in the face plate of the weir box.

  2. Water sample-collection and distribution system

    NASA Technical Reports Server (NTRS)

    Brooks, R. R.

    1978-01-01

    Collection and distribution system samples water from six designated stations, filtered if desired, and delivers it to various analytical sensors. System may be controlled by Water Monitoring Data Acquisition System or operated manually.

  3. Energy optimization of water distribution systems

    SciTech Connect

    1994-09-01

    Energy costs associated with pumping treated water into the distribution system and boosting water pressures where necessary is one of the largest expenditures in the operating budget of a municipality. Due to the size and complexity of Detroit`s water transmission system, an energy optimization project has been developed to better manage the flow of water in the distribution system in an attempt to reduce these costs.

  4. PERFORMANCE VERIFICATION OF CONTINUOUS MULTI-PARAMETER WATER MONITORS FOR DISTRIBUTION SYSTEMS

    EPA Science Inventory

    The Environmental Technology Verification (ETV) Program's Advanced Monitoring Systems (AMS) Center has been charged by EPA to verify the performance of commercially available monitoring technologies for air, water, soil. Multi-parameter water monitors for distributions systems we...

  5. JPL Physical Oceanography Distributed Active Archive Center (PO.DAAC) data availability, version 1-94

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The Physical Oceanography Distributed Active Archive Center (PO.DAAC) archive at the Jet Propulsion Laboratory (JPL) includes satellite data sets for the ocean sciences and global-change research to facilitate multidisciplinary use of satellite ocean data. Parameters include sea-surface height, surface-wind vector, sea-surface temperature, atmospheric liquid water, and integrated water vapor. The JPL PO.DAAC is an element of the Earth Observing System Data and Information System (EOSDIS) and is the United States distribution site for Ocean Topography Experiment (TOPEX)/POSEIDON data and metadata.

  6. Saturn's Stratospheric Water Vapor Distribution

    NASA Astrophysics Data System (ADS)

    Hesman, Brigette E.; Bjoraker, Gordon L.; Achterberg, Richard K.; Romani, Paul N.; Irwin, Patrick G. J.

    2015-11-01

    Water is a sought after commodity in the solar system. It is used as an indication of life, planetary formation timescales, and signatures of past cometary impacts. In Saturn’s atmosphere there are two sources of water: an internal primordial reservoir that is confined to the troposphere, and an external source of unknown origin that delivers water to the stratosphere. Potential sources of stratospheric water include: Saturn’s main rings (via neutral infall and/or ions transported along magnetic field lines - “Ring Rain”), interplanetary dust particles, and the E-ring that is supplied with water from the plumes of Enceladus. Measuring the latitudinal and seasonal variation of H2O on Saturn will constrain the source of Saturn’s stratospheric water.Cassini’s Composite InfraRed Spectrometer (CIRS) has detected emission lines of H2O on Saturn at wavelengths of 40 and 50 microns. CIRS also retrieves the temperature of the stratosphere using CH4 lines at 7.7 microns. Using our retrieved temperatures, we derive the mole fraction of H2O at the 0.5-5 mbar level for comparison with water-source models. The latitudinal variation of stratospheric water vapor will be presented as a first step in understanding the external source of water on Saturn. The observed local maximum near Saturn’s equator supports either a neutral infall from the rings or a source in the E-ring. We will look for secondary maxima at mid-latitudes to determine whether “Ring Rain” also contributes to the inventory of water in Saturn’s upper atmosphere.

  7. Saturn's Stratospheric Water Vapor Distribution

    NASA Astrophysics Data System (ADS)

    Hesman, B. E.

    2015-12-01

    Water is a sought after commodity in the solar system. It is used as an indication of life, planetary formation timescales, and signatures of past cometary impacts. In Saturn's atmosphere there are two sources of water: an internal primordial reservoir that is confined to the troposphere, and an external source of unknown origin that delivers water to the stratosphere. Potential sources of stratospheric water include: Saturn's main rings (via neutral infall and/or ions transported along magnetic field lines - "Ring Rain"), interplanetary dust particles, and the E-ring that is supplied with water from the plumes of Enceladus. Measuring the latitudinal and seasonal variation of H2O on Saturn will constrain the source of Saturn's stratospheric water. Cassini's Composite InfraRed Spectrometer (CIRS) has detected emission lines of H2O on Saturn at wavelengths of 40 and 50 microns. CIRS also retrieves the temperature of the stratosphere using CH4 lines at 7.7 microns. Using our retrieved temperatures, we derive the mole fraction of H2O at the 0.5-5 mbar level for comparison with water-source models. The latitudinal variation of stratospheric water vapor between 2004-2009 will be presented as a first step in understanding the external source of water on Saturn. The observed local maximum near Saturn's equator supports either a neutral infall from the rings or a source in the E-ring. We will look for secondary maxima at mid-latitudes to determine whether "Ring Rain" also contributes to the inventory of water in Saturn's upper atmosphere.

  8. Mercury in waters, soils, and sediments of the New Jersey Coastal Plain: A comparison of regional distribution and mobility with the mercury contamination at the William J. Hughes Technical Center, Atlantic County, New Jersey

    USGS Publications Warehouse

    Barringer, Julia L.; Szabo, Zoltan; Reilly, Pamela A.

    2012-01-01

    Mercury in soils, surface water, and groundwater at the William J. Hughes Technical Center , Atlantic County, New Jersey, has been found at levels that exceed established background concentrations in Coastal Plain waters, and, in some cases, New Jersey State standards for mercury in various media. As of 2012, it is not known whether this mercury is part of regional mercury contamination or whether it is related to former military activities. Regionally, groundwater supplying about 700 domestic wells in the New Jersey Coastal Plain is contaminated with mercury that appears to be derived from anthropogenic inputs, such as agricultural pesticide use and atmospheric deposition. High levels of mercury occasionally are found in Coastal Plain soils, but disturbance during residential development on former agricultural land is thought to have mobilized any mercury applied during farming, a hypothesis borne out by experiments leaching mercury from soils. In the unsewered residential areas with mercury-contaminated groundwater, septic-system effluent is believed to create reducing conditions in which mercury sorbed to subsoils is mobilized to groundwater. In comparing the levels of mercury found in soils, sediments, streamwater, and groundwater at the William J. Hughes Technical Center site with those found regionally, mercury concentrations in groundwater in the region are, in some cases, substantially higher than those found in groundwater at the William J. Hughes Technical Center site. Nevertheless, concentrations of mercury in streamwater at the site are, in some instances, higher than most found regionally. The mercury contents in soils and sediment at the William J. Hughes Technical Center site are substantially higher than those found to date (2012) in the region, indicating that a source other than regional sources may be present at the site.

  9. The Land Processes Distributed Active Archive Center (LP DAAC)

    USGS Publications Warehouse

    Golon, Danielle K.

    2016-10-03

    The Land Processes Distributed Active Archive Center (LP DAAC) operates as a partnership with the U.S. Geological Survey and is 1 of 12 DAACs within the National Aeronautics and Space Administration (NASA) Earth Observing System Data and Information System (EOSDIS). The LP DAAC ingests, archives, processes, and distributes NASA Earth science remote sensing data. These data are provided to the public at no charge. Data distributed by the LP DAAC provide information about Earth’s surface from daily to yearly intervals and at 15 to 5,600 meter spatial resolution. Data provided by the LP DAAC can be used to study changes in agriculture, vegetation, ecosystems, elevation, and much more. The LP DAAC provides several ways to access, process, and interact with these data. In addition, the LP DAAC is actively archiving new datasets to provide users with a variety of data to study the Earth.

  10. Water vapor distribution in protoplanetary disks

    SciTech Connect

    Du, Fujun; Bergin, Edwin A.

    2014-09-01

    Water vapor has been detected in protoplanetary disks. In this work, we model the distribution of water vapor in protoplanetary disks with a thermo-chemical code. For a set of parameterized disk models, we calculate the distribution of dust temperature and radiation field of the disk with a Monte Carlo method, and then solve the gas temperature distribution and chemical composition. The radiative transfer includes detailed treatment of scattering by atomic hydrogen and absorption by water of Lyα photons, since the Lyα line dominates the UV spectrum of accreting young stars. In a fiducial model, we find that warm water vapor with temperature around 300 K is mainly distributed in a small and well-confined region in the inner disk. The inner boundary of the warm water region is where the shielding of UV field due to dust and water itself become significant. The outer boundary is where the dust temperature drops below the water condensation temperature. A more luminous central star leads to a more extended distribution of warm water vapor, while dust growth and settling tends to reduce the amount of warm water vapor. Based on typical assumptions regarding the elemental oxygen abundance and the water chemistry, the column density of warm water vapor can be as high as 10{sup 22} cm{sup –2}. A small amount of hot water vapor with temperature higher than ∼300 K exists in a more extended region in the upper atmosphere of the disk. Cold water vapor with temperature lower than 100 K is distributed over the entire disk, produced by photodesorption of the water ice.

  11. Land processes distributed active archive center product lifecycle plan

    USGS Publications Warehouse

    Daucsavage, John C.; Bennett, Stacie D.

    2014-01-01

    The U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center and the National Aeronautics and Space Administration (NASA) Earth Science Data System Program worked together to establish, develop, and operate the Land Processes (LP) Distributed Active Archive Center (DAAC) to provide stewardship for NASA’s land processes science data. These data are critical science assets that serve the land processes science community with potential value beyond any immediate research use, and therefore need to be accounted for and properly managed throughout their lifecycle. A fundamental LP DAAC objective is to enable permanent preservation of these data and information products. The LP DAAC accomplishes this by bridging data producers and permanent archival resources while providing intermediate archive services for data and information products.

  12. Architecture and evolution of Goddard Space Flight Center Distributed Active Archive Center

    NASA Technical Reports Server (NTRS)

    Bedet, Jean-Jacques; Bodden, Lee; Rosen, Wayne; Sherman, Mark; Pease, Phil

    1994-01-01

    The Goddard Space Flight Center (GSFC) Distributed Active Archive Center (DAAC) has been developed to enhance Earth Science research by improved access to remote sensor earth science data. Building and operating an archive, even one of a moderate size (a few Terabytes), is a challenging task. One of the critical components of this system is Unitree, the Hierarchical File Storage Management System. Unitree, selected two years ago as the best available solution, requires constant system administrative support. It is not always suitable as an archive and distribution data center, and has moderate performance. The Data Archive and Distribution System (DADS) software developed to monitor, manage, and automate the ingestion, archive, and distribution functions turned out to be more challenging than anticipated. Having the software and tools is not sufficient to succeed. Human interaction within the system must be fully understood to improve efficiency to improve efficiency and ensure that the right tools are developed. One of the lessons learned is that the operability, reliability, and performance aspects should be thoroughly addressed in the initial design. However, the GSFC DAAC has demonstrated that it is capable of distributing over 40 GB per day. A backup system to archive a second copy of all data ingested is under development. This backup system will be used not only for disaster recovery but will also replace the main archive when it is unavailable during maintenance or hardware replacement. The GSFC DAAC has put a strong emphasis on quality at all level of its organization. A Quality team has also been formed to identify quality issues and to propose improvements. The DAAC has conducted numerous tests to benchmark the performance of the system. These tests proved to be extremely useful in identifying bottlenecks and deficiencies in operational procedures.

  13. Characterization of Cloud Water-Content Distribution

    NASA Technical Reports Server (NTRS)

    Lee, Seungwon

    2010-01-01

    The development of realistic cloud parameterizations for climate models requires accurate characterizations of subgrid distributions of thermodynamic variables. To this end, a software tool was developed to characterize cloud water-content distributions in climate-model sub-grid scales. This software characterizes distributions of cloud water content with respect to cloud phase, cloud type, precipitation occurrence, and geo-location using CloudSat radar measurements. It uses a statistical method called maximum likelihood estimation to estimate the probability density function of the cloud water content.

  14. Optimal irrigation water allocation for a center pivot using remotely sensed data

    NASA Astrophysics Data System (ADS)

    Hassan Esfahani, L.; McKee, M.

    2013-12-01

    Efficient irrigation can help avoid crop water stress, undesirable leaching of nutrients, and yield reduction due to water shortage, and runoff and soil erosion due to over irrigation. Gains in water use efficiency can be achieved when water application is precisely matched to the spatially distributed crop water demand. This is important to produce high quality crops and otherwise conserve water for greatest efficiency of use. Irrigation efficiency is a term which defines irrigation performance based on indicators such as irrigation uniformity, crop production, economic return and water resources sustainability. The present paper introduces a modeling approach for optimal water allocation to a center pivot irrigation unit in consideration of these types of indicators. Landsat images, weather data and field measurements were used to develop a soil water balance model using Artificial Neural Networks (ANN). The model includes two main modules, one for soil water forecasting and one for optimization of water allocation. The optimization module uses Genetic Algorithms (GA) to identify optimal crop water application rates based on the crop type, growing stage and sensitivity to water stress. The forecasting module allocates water through time across the area covered by the center pivot considering the results from the previous period of irrigation and the operational limitations of the center pivot irrigation system. The model was tested for a farm equipped with a modern sprinkler irrigation system in Scipio, Utah. The solution obtained from the model used up to 30 percent less water without reducing the benefits realized by the irrigator than traditional operating procedures.

  15. 76 FR 2711 - Cinram Distribution, LLC, a Subsidiary of Cinram International, Simi Valley Distribution Center...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-14

    ... Southwest, Inc., and Select Remedy Staffing Services, Simi Valley, California. The notice was published in the Federal Register on September 15, 2010 (75 FR 51643). At the request of a petitioner, the... Valley Distribution Center, Including On-Site Leased Workers From Labor Ready Southwest, Inc. and...

  16. Constraint based scheduling for the Goddard Space Flight Center distributed Active Archive Center's data archive and distribution system

    NASA Technical Reports Server (NTRS)

    Short, Nick, Jr.; Bedet, Jean-Jacques; Bodden, Lee; Boddy, Mark; White, Jim; Beane, John

    1994-01-01

    The Goddard Space Flight Center (GSFC) Distributed Active Archive Center (DAAC) has been operational since October 1, 1993. Its mission is to support the Earth Observing System (EOS) by providing rapid access to EOS data and analysis products, and to test Earth Observing System Data and Information System (EOSDIS) design concepts. One of the challenges is to ensure quick and easy retrieval of any data archived within the DAAC's Data Archive and Distributed System (DADS). Over the 15-year life of EOS project, an estimated several Petabytes (10(exp 15)) of data will be permanently stored. Accessing that amount of information is a formidable task that will require innovative approaches. As a precursor of the full EOS system, the GSFC DAAC with a few Terabits of storage, has implemented a prototype of a constraint-based task and resource scheduler to improve the performance of the DADS. This Honeywell Task and Resource Scheduler (HTRS), developed by Honeywell Technology Center in cooperation the Information Science and Technology Branch/935, the Code X Operations Technology Program, and the GSFC DAAC, makes better use of limited resources, prevents backlog of data, provides information about resources bottlenecks and performance characteristics. The prototype which is developed concurrently with the GSFC Version 0 (V0) DADS, models DADS activities such as ingestion and distribution with priority, precedence, resource requirements (disk and network bandwidth) and temporal constraints. HTRS supports schedule updates, insertions, and retrieval of task information via an Application Program Interface (API). The prototype has demonstrated with a few examples, the substantial advantages of using HTRS over scheduling algorithms such as a First In First Out (FIFO) queue. The kernel scheduling engine for HTRS, called Kronos, has been successfully applied to several other domains such as space shuttle mission scheduling, demand flow manufacturing, and avionics communications

  17. Impact of RO-desalted water on distribution water qualities.

    PubMed

    Taylor, J; Dietz, J; Randall, A; Hong, S

    2005-01-01

    A large-scale pilot distribution study was conducted to investigate the impacts of blending different source waters on distribution water qualities, with an emphasis on metal release (i.e. corrosion). The principal source waters investigated were conventionally treated ground water (G1), surface water processed by enhanced treatment (S1), and desalted seawater by reverse osmosis membranes (RO). Due to the nature of raw water quality and associated treatment processes, G1 water had high alkalinity, while S1 and RO sources were characterized as high sulfate and high chloride waters, respectively. The blending ratio of different treated waters determined the quality of finished waters. Iron release from aged cast iron pipes increased significantly when exposed to RO and S1 waters: that is, the greater iron release was experienced with alkalinity reduced below the background of G1 water. Copper release to drinking water, however, increased with increasing alkalinity and decreasing pH. Lead release, on the other hand, increased with increasing chloride and decreasing sulfate. The effect of pH and alkalinity on lead release was not clearly observed from pilot blending study. The flat and compact corrosion scales observed for lead surface exposed to S1 water may be attributable to lead concentration less than that of RO water blends.

  18. BIOFILMS IN DRINKING WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Virtually anywhere a surface comes into contact with the water in a distribution system, one can find biofilms. Biofilms are formed in distribution system pipelines when microbial cells attach to pipe surfaces and multiply to form a film or slime layer on the pipe. Probably withi...

  19. GHRC: NASAs Hazardous Weather Distributed Active Archive Center

    NASA Technical Reports Server (NTRS)

    Ramachandran, Rahul; Bugbee, Kaylin

    2016-01-01

    The Global Hydrology Resource Center (GHRC; ghrc.nsstc.nasa.gov) is one of NASA's twelve Distributed Active Archive Centers responsible for providing access to NASA's Earth science data to users worldwide. Each of NASA's twelve DAACs focuses on a specific science discipline within Earth science, provides data stewardship services and supports its research community's needs. Established in 1991 as the Marshall Space Flight Center DAAC and renamed GHRC in 1997, the data center's original mission focused on the global hydrologic cycle. However, over the years, data holdings, tools and expertise of GHRC have gradually shifted. In 2014, a User Working Group (UWG) was established to review GHRC capabilities and provide recommendations to make GHRC more responsive to the research community's evolving needs. The UWG recommended an update to the GHRC mission, as well as a strategic plan to move in the new direction. After a careful and detailed analysis of GHRC's capabilities, research community needs and the existing data landscape, a new mission statement for GHRC has been crafted: to provide a comprehensive active archive of both data and knowledge augmentation services with a focus on hazardous weather, its governing dynamical and physical processes, and associated applications. Within this broad mandate, GHRC will focus on lightning, tropical cyclones and storm-induced hazards through integrated collections of satellite, airborne, and in-situ data sets. The new mission was adopted at the recent 2015 UWG meeting. GHRC will retain its current name until such time as it has built substantial data holdings aligned with the new mission.

  20. Legacy data center integration into distributed data federations: The World Data Center for Climate (WDCC) experience

    NASA Astrophysics Data System (ADS)

    Kindermann, Stephan; Berger, Katharina; Toussaint, Frank

    2014-05-01

    The integration of well-established legacy data centers into newly developed data federation infrastructures is a key requirement to enhance climate data access based on widely agreed interfaces. We present the approach taken to integrate the ICSU World Data Center for Climate (WDCC) located in Hamburg, Germany into the European ENES climate data Federation which is part of the international ESGF data federation. The ENES / ESGF data federation hosts petabytes of climate model data and provides scalable data search and access services across the worldwide distributed data centers. Parts of the data provided by the ENES / ESGF data federation is also long term archived and curated at the WDCC data archive, allowing e.g. for DOI based data citation. An integration of the WDCC into the ENES / ESGF federation allows end users to search and access WDCC data using consistent interfaces worldwide. We will summarize the integration approach we have taken for WDCC legacy system and ESGF infrastructure integration. On the technical side we describe the provisioning of ESGF consistent metadata and data interfaces as well as the security infrastructure adoption. On the non-technical side we describe our experiences in integrating a long-term archival center with costly quality assurance procedures with an integrated distributed data federation putting emphasis on providing early and consistent data search and access services to scientists. The experiences were gained in the process of curating ESGF hosted CMIP5 data at the WDCC. Approximately one petabyte of CMIP5 data which was used for the IPCC climate report is being replicated and archived at the WDCC.

  1. Contents of the JPL Distributed Active Archive Center (DAAC) archive, version 2-91

    NASA Technical Reports Server (NTRS)

    Smith, Elizabeth A. (Editor); Lassanyi, Ruby A. (Editor)

    1991-01-01

    The Distributed Active Archive Center (DAAC) archive at the Jet Propulsion Laboratory (JPL) includes satellite data sets for the ocean sciences and global change research to facilitate multidisciplinary use of satellite ocean data. Parameters include sea surface height, surface wind vector, sea surface temperature, atmospheric liquid water, and surface pigment concentration. The Jet Propulsion Laboratory DAAC is an element of the Earth Observing System Data and Information System (EOSDIS) and will be the United States distribution site for the Ocean Topography Experiment (TOPEX)/POSEIDON data and metadata.

  2. Surface-Water Quality-Assurance Plan for the USGS Wisconsin Water Science Center

    USGS Publications Warehouse

    Garn, H.S.

    2007-01-01

    This surface-water quality-assurance plan documents the standards, policies, and procedures used by the Wisconsin Water Science Center of the U.S. Geological Survey, Water Resources Discipline, for activities related to the collection, processing, storage, analysis, management, and publication of surface-water data. The roles and responsibilities of Water Science Center personnel in following these policies and procedures including those related to safety and training are presented.

  3. Water losses dynamic modelling in water distribution networks

    NASA Astrophysics Data System (ADS)

    Puleo, Valeria; Milici, Barbara

    2015-12-01

    In the last decades, one of the main concerns of the water system managers have been the minimisation of water losses, that frequently reach values of 30% or even 70% of the volume supplying the water distribution network. The economic and social costs associated with water losses in modern water supply systems are rapidly rising to unacceptably high levels. Furthermore, the problem of the water losses assumes more and more importance mainly when periods of water scarcity occur or when not sufficient water supply takes part in areas with fast growth. In the present analysis, a dynamic model was used for estimating real and apparent losses of a real case study. A specific nodal demand model reflecting the user's tank installation and a specific apparent losses module were implemented. The results from the dynamic model were compared with the modelling estimation based on a steady-state approach.

  4. Quality-Assurance Plan for Water-Quality Activities in the USGS Ohio Water Science Center

    USGS Publications Warehouse

    Francy, Donna S.; Shaffer, Kimberly H.

    2008-01-01

    In accordance with guidelines set forth by the Office of Water Quality in the Water Resources Discipline of the U.S. Geological Survey, a quality-assurance plan has been written for use by the Ohio Water Science Center in conducting water-quality activities. This quality-assurance plan documents the standards, policies, and procedures used by the Ohio Water Science Center for activities related to the collection, processing, storage, analysis, and publication of water-quality data. The policies and procedures documented in this quality-assurance plan for water-quality activities are meant to complement the Ohio Water Science Center quality-assurance plans for water-quality monitors, the microbiology laboratory, and surface-water and ground-water activities.

  5. Microbial ecology of drinking water distribution systems.

    PubMed

    Berry, David; Xi, Chuanwu; Raskin, Lutgarde

    2006-06-01

    The supply of clean drinking water is a major, and relatively recent, public health milestone. Control of microbial growth in drinking water distribution systems, often achieved through the addition of disinfectants, is essential to limiting waterborne illness, particularly in immunocompromised subpopulations. Recent inquiries into the microbial ecology of distribution systems have found that pathogen resistance to chlorination is affected by microbial community diversity and interspecies relationships. Research indicates that multispecies biofilms are generally more resistant to disinfection than single-species biofilms. Other recent findings are the increased survival of the bacterial pathogen Legionella pneumophila when present inside its protozoan host Hartmannella vermiformis and the depletion of chloramine disinfectant residuals by nitrifying bacteria, leading to increased overall microbial growth. Interactions such as these are unaccounted for in current disinfection models. An understanding of the microbial ecology of distribution systems is necessary to design innovative and effective control strategies that will ensure safe and high-quality drinking water. PMID:16701992

  6. Surface water quality-assurance plan, U.S. Geological Survey, Kentucky Water Science Center, water year 2006

    USGS Publications Warehouse

    Griffin, Michael S.

    2006-01-01

    This Surface Water Quality-Assurance Plan documents the standards, policies, and procedures used by the Kentucky Water Science Center for activities related to the collection, processing, storage, analysis, and publication of surface-water data.

  7. Disinfection of water distribution systems for Legionella.

    PubMed

    Lin, Y S; Stout, J E; Yu, V L; Vidic, R D

    1998-06-01

    Hospital-acquired legionnaires' disease arises from the presence of Legionella in hospital water systems. Legionella not only persists in hot water tanks but is also found in the biofilm throughout the entire water distribution system. Conditions within water systems that promote Legionella colonization include water temperature, configuration and age of the hot water tank, physicochemical constituents of the water, plumbing materials, and commensal microflora. Hospital-acquired legionnaires' disease has been prevented by instituting control measures directed at the water distribution system. These include superheat-and-flush, copper/silver ionization, ultraviolet light, instantaneous heating systems, and hyperchlorination. Each of the above disinfection methods has been proven to be effective in the short-term, but long-term efficacy has been difficult due to limitations associated with each method. The complexities of Legionella disinfection, including advantages and disadvantages of each method, are reviewed. A successful Legionella prevention program requires cooperation and communication among hospital administrative personnel, engineers, and infection control staff. Routine environmental surveillance cultures for Legionella are the critical component for successful long-term disinfection. Culture results document the efficacy of the disinfection method and alert the hospital staff to consider Legionella in hospitalized patients with pneumonia. PMID:9643393

  8. Data Information for Global Change Studies: NASA's Distributed Active Archive Centers and Cooperating Data Centers

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The Earth Observing System (EOS) is an integral part of the National Aeronautics and Space Administration's (NASA's) Earth Science Enterprise (ESE). ESE is a long-term global change research program designed to improve our understanding of the Earth's interrelated processes involving the atmosphere, oceans, land surfaces, and polar regions. Data from EOS instruments and other Earth science measurement systems are useful in understanding the causes and processes of global climate change and the consequences of human activities. The EOS Data and Information System (EOSDIS) provides a structure for data management and user services for products derived from EOS satellite instruments and other NASA Earth science data. Within the EOSDIS framework, the Distributed Active Archive Centers (DAACs) have been established to provide expertise in one or more Earth science disciplines. The DAACs and cooperating data centers provide data and information services to support the global change research community. Much of the development of the DAACs has been in anticipation of the enormous amount of data expected from EOS instruments to be launched within the next two decades. Terra, the EOS flagship launched in December 1999, is the first of a series of EOS satellites to carry several instruments with multispectral capabilities. Some data products from these instruments are now available from several of the DAACs. These and other data products can be ordered through the EOS Data Gateway (EDG) and DAAC-specific online ordering systems.

  9. Data catalog for JPL Physical Oceanography Distributed Active Archive Center (PO.DAAC)

    NASA Technical Reports Server (NTRS)

    Digby, Susan

    1995-01-01

    The Physical Oceanography Distributed Active Archive Center (PO.DAAC) archive at the Jet Propulsion Laboratory contains satellite data sets and ancillary in-situ data for the ocean sciences and global-change research to facilitate multidisciplinary use of satellite ocean data. Geophysical parameters available from the archive include sea-surface height, surface-wind vector, surface-wind speed, surface-wind stress vector, sea-surface temperature, atmospheric liquid water, integrated water vapor, phytoplankton pigment concentration, heat flux, and in-situ data. PO.DAAC is an element of the Earth Observing System Data and Information System and is the United States distribution site for TOPEX/POSEIDON data and metadata.

  10. Distilled Water Distribution Systems. Laboratory Design Notes.

    ERIC Educational Resources Information Center

    Sell, J.C.

    Factors concerning water distribution systems, including an evaluation of materials and a recommendation of materials best suited for service in typical facilities are discussed. Several installations are discussed in an effort to bring out typical features in selected applications. The following system types are included--(1) industrial…

  11. COST FOR WATER SUPPLY DISTRIBUTION SYSTEM REHABILITATION

    EPA Science Inventory

    A major challenge for the society in the twenty-first century will be design, rehabilitation, replacement, and optimal management of drinking water distribution systems. A recent survey conducted by the USEPA found that $138B will be needed to maintain and replace existing drinki...

  12. Development of Secondary Archive System at Goddard Space Flight Center Version 0 Distributed Active Archive Center

    NASA Technical Reports Server (NTRS)

    Sherman, Mark; Kodis, John; Bedet, Jean-Jacques; Wacker, Chris; Woytek, Joanne; Lynnes, Chris

    1996-01-01

    The Goddard Space Flight Center (GSFC) version 0 Distributed Active Archive Center (DAAC) has been developed to support existing and pre Earth Observing System (EOS) Earth science datasets, facilitate the scientific research, and test EOS data and information system (EOSDIS) concepts. To ensure that no data is ever lost, each product received at GSFC DAAC is archived on two different media, VHS and digital linear tape (DLT). The first copy is made on VHS tape and is under the control of UniTree. The second and third copies are made to DLT and VHS media under a custom built software package named 'Archer'. While Archer provides only a subset of the functions available with commercial software like UniTree, it supports migration between near-line and off-line media and offers much greater performance and flexibility to satisfy the specific needs of a data center. Archer is specifically designed to maximize total system throughput, rather than focusing on the turn-around time for individual files. The commercial off the shelf software (COTS) hierarchical storage management (HSM) products evaluated were mainly concerned with transparent, interactive, file access to the end-user, rather than a batch-orientated, optimizable (based on known data file characteristics) data archive and retrieval system. This is critical to the distribution requirements of the GSFC DAAC where orders for 5000 or more files at a time are received. Archer has the ability to queue many thousands of file requests and to sort these requests into internal processing schedules that optimize overall throughput. Specifically, mount and dismount, tape load and unload cycles, and tape motion are minimized. This feature did not seem to be available in many COTS pacages. Archer also uses a generic tar tape format that allows tapes to be read by many different systems rather than the proprietary format found in most COTS packages. This paper discusses some of the specific requirements at GSFC DAAC, the

  13. 14 CFR 25.1519 - Weight, center of gravity, and weight distribution.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Weight, center of gravity, and weight... Information Operating Limitations § 25.1519 Weight, center of gravity, and weight distribution. The airplane weight, center of gravity, and weight distribution limitations determined under §§ 25.23 through...

  14. 14 CFR 25.1519 - Weight, center of gravity, and weight distribution.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Weight, center of gravity, and weight... Information Operating Limitations § 25.1519 Weight, center of gravity, and weight distribution. The airplane weight, center of gravity, and weight distribution limitations determined under §§ 25.23 through...

  15. 14 CFR 25.1519 - Weight, center of gravity, and weight distribution.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Weight, center of gravity, and weight... Information Operating Limitations § 25.1519 Weight, center of gravity, and weight distribution. The airplane weight, center of gravity, and weight distribution limitations determined under §§ 25.23 through...

  16. 14 CFR 25.1519 - Weight, center of gravity, and weight distribution.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Weight, center of gravity, and weight... Information Operating Limitations § 25.1519 Weight, center of gravity, and weight distribution. The airplane weight, center of gravity, and weight distribution limitations determined under §§ 25.23 through...

  17. 14 CFR 25.1519 - Weight, center of gravity, and weight distribution.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Weight, center of gravity, and weight... Information Operating Limitations § 25.1519 Weight, center of gravity, and weight distribution. The airplane weight, center of gravity, and weight distribution limitations determined under §§ 25.23 through...

  18. 75 FR 9343 - Nomenclature Change Relating to the Network Distribution Center Transition

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-02

    ... 111 and 121 Nomenclature Change Relating to the Network Distribution Center Transition AGENCY: Postal... to the ongoing transition of USPS bulk mail centers (BMC) to network distribution centers (NDC), by... Gambhir at 202-268-6256. SUPPLEMENTARY INFORMATION: Background: The BMC network was established in...

  19. AVIRIS and TIMS data processing and distribution at the land processes distributed active archive center

    NASA Technical Reports Server (NTRS)

    Mah, G. R.; Myers, J.

    1993-01-01

    The U.S. Government has initiated the Global Change Research program, a systematic study of the Earth as a complete system. NASA's contribution of the Global Change Research Program is the Earth Observing System (EOS), a series of orbital sensor platforms and an associated data processing and distribution system. The EOS Data and Information System (EOSDIS) is the archiving, production, and distribution system for data collected by the EOS space segment and uses a multilayer architecture for processing, archiving, and distributing EOS data. The first layer consists of the spacecraft ground stations and processing facilities that receive the raw data from the orbiting platforms and then separate the data by individual sensors. The second layer consists of Distributed Active Archive Centers (DAAC) that process, distribute, and archive the sensor data. The third layer consists of a user science processing network. The EOSDIS is being developed in a phased implementation. The initial phase, Version 0, is a prototype of the operational system. Version 0 activities are based upon existing systems and are designed to provide an EOSDIS-like capability for information management and distribution. An important science support task is the creation of simulated data sets for EOS instruments from precursor aircraft or satellite data. The Land Processes DAAC, at the EROS Data Center (EDC), is responsible for archiving and processing EOS precursor data from airborne instruments such as the Thermal Infrared Multispectral Scanner (TIMS), the Thematic Mapper Simulator (TMS), and Airborne Visible and Infrared Imaging Spectrometer (AVIRIS). AVIRIS, TIMS, and TMS are flown by the NASA-Ames Research Center ARC) on an ER-2. The ER-2 flies at 65000 feet and can carry up to three sensors simultaneously. Most jointly collected data sets are somewhat boresighted and roughly registered. The instrument data are being used to construct data sets that simulate the spectral and spatial

  20. Atrial natriuretic factor and body water distribution.

    PubMed

    Vidal, N A; Arranz, C T; Mones Sias, M C; Herrmann, A P; Martinez Seeber, A

    1987-11-01

    In the rat, the effects of an atrial natriuretic factor (ANF) (Rat, 8-33 Peninsula Lab) on body water distribution have been evaluated. The ANF administration to nephrectomized animals produced a decrease in plasma volume and a slight increase in haematocrit and in plasma albumin concentration. No modifications were observed in total and intracellular water. The fluid efflux from the capillaries appeared to be located in the interstitial space. These results suggest that ANF could regulate plasma volume and systemic blood pressure, concurrently with its other known effects.

  1. DISTRIBUTION OF WATER VAPOR IN MOLECULAR CLOUDS

    SciTech Connect

    Melnick, Gary J.; Tolls, Volker; Snell, Ronald L.; Bergin, Edwin A.; Hollenbach, David J.; Kaufman, Michael J.; Li Di; Neufeld, David A. E-mail: vtolls@cfa.harvard.edu E-mail: ebergin@umich.edu E-mail: mkaufman@email.sjsu.edu E-mail: neufeld@pha.jhu.edu

    2011-01-20

    We report the results of a large-area study of water vapor along the Orion Molecular Cloud ridge, the purpose of which was to determine the depth-dependent distribution of gas-phase water in dense molecular clouds. We find that the water vapor measured toward 77 spatial positions along the face-on Orion ridge, excluding positions surrounding the outflow associated with BN/KL and IRc2, display integrated intensities that correlate strongly with known cloud surface tracers such as CN, C{sub 2}H, {sup 13}CO J = 5-4, and HCN, and less well with the volume tracer N{sub 2}H{sup +}. Moreover, at total column densities corresponding to A{sub V}< 15 mag, the ratio of H{sub 2}O to C{sup 18}O integrated intensities shows a clear rise approaching the cloud surface. We show that this behavior cannot be accounted for by either optical depth or excitation effects, but suggests that gas-phase water abundances fall at large A{sub V}. These results are important as they affect measures of the true water-vapor abundance in molecular clouds by highlighting the limitations of comparing measured water-vapor column densities with such traditional cloud tracers as {sup 13}CO or C{sup 18}O. These results also support cloud models that incorporate freeze out of molecules as a critical component in determining the depth-dependent abundance of water vapor.

  2. Cyber Graph Queries for Geographically Distributed Data Centers

    SciTech Connect

    Berry, Jonathan W.; Collins, Michael; Kearns, Aaron; Phillips, Cynthia A.; Saia, Jared

    2015-05-01

    We present new algorithms for a distributed model for graph computations motivated by limited information sharing we first discussed in [20]. Two or more independent entities have collected large social graphs. They wish to compute the result of running graph algorithms on the entire set of relationships. Because the information is sensitive or economically valuable, they do not wish to simply combine the information in a single location. We consider two models for computing the solution to graph algorithms in this setting: 1) limited-sharing: the two entities can share only a polylogarithmic size subgraph; 2) low-trust: the entities must not reveal any information beyond the query answer, assuming they are all honest but curious. We believe this model captures realistic constraints on cooperating autonomous data centers. We have algorithms in both setting for s - t connectivity in both models. We also give an algorithm in the low-communication model for finding a planted clique. This is an anomaly- detection problem, finding a subgraph that is larger and denser than expected. For both the low- communication algorithms, we exploit structural properties of social networks to prove perfor- mance bounds better than what is possible for general graphs. For s - t connectivity, we use known properties. For planted clique, we propose a new property: bounded number of triangles per node. This property is based upon evidence from the social science literature. We found that classic examples of social networks do not have the bounded-triangles property. This is because many social networks contain elements that are non-human, such as accounts for a business, or other automated accounts. We describe some initial attempts to distinguish human nodes from automated nodes in social networks based only on topological properties.

  3. Energy optimization of water distribution system

    SciTech Connect

    Not Available

    1993-02-01

    In order to analyze pump operating scenarios for the system with the computer model, information on existing pumping equipment and the distribution system was collected. The information includes the following: component description and design criteria for line booster stations, booster stations with reservoirs, and high lift pumps at the water treatment plants; daily operations data for 1988; annual reports from fiscal year 1987/1988 to fiscal year 1991/1992; and a 1985 calibrated KYPIPE computer model of DWSD`s water distribution system which included input data for the maximum hour and average day demands on the system for that year. This information has been used to produce the inventory database of the system and will be used to develop the computer program to analyze the system.

  4. GPR-Based Water Leak Models in Water Distribution Systems

    PubMed Central

    Ayala-Cabrera, David; Herrera, Manuel; Izquierdo, Joaquín; Ocaña-Levario, Silvia J.; Pérez-García, Rafael

    2013-01-01

    This paper addresses the problem of leakage in water distribution systems through the use of ground penetrating radar (GPR) as a nondestructive method. Laboratory tests are performed to extract features of water leakage from the obtained GPR images. Moreover, a test in a real-world urban system under real conditions is performed. Feature extraction is performed by interpreting GPR images with the support of a pre-processing methodology based on an appropriate combination of statistical methods and multi-agent systems. The results of these tests are presented, interpreted, analyzed and discussed in this paper.

  5. Epidemiology of urban water distribution systems

    NASA Astrophysics Data System (ADS)

    Bardet, Jean-Pierre; Little, Richard

    2014-08-01

    Urban water distribution systems worldwide contain numerous old and fragile pipes that inevitably break, flood streets and damage property, and disrupt economic and social activities. Such breaks often present dramatically in temporal clusters as occurred in Los Angeles during 2009. These clustered pipe breaks share many characteristics with human mortality observed during extreme climatological events such as heat waves or air pollution. Drawing from research and empirical studies in human epidemiology, a framework is introduced to analyze the time variations of disruptive pipe breaks that can help water agencies better understand clustered pipe failures and institute measures to minimize the disruptions caused by them. It is posited that at any time, a cohort of the pipes comprising the water distribution system will be in a weakened state due to fatigue and corrosion. This frail cohort becomes vulnerable during normal operations and ultimately breaks due to rapid increase in crack lengths induced by abnormal stressors. The epidemiological harvesting model developed in this paper simulates an observed time series of monthly pipe breaks and has both explanatory and predictive power. It also demonstrates that models from nonengineering disciplines such as medicine can provide improved insights into the performance of infrastructure systems.

  6. Water distribution characteristics of spray nozzles in a cooling tower

    NASA Astrophysics Data System (ADS)

    Vitkovic, Pavol

    2015-05-01

    Water distribution characteristics of spray nozzles with spray plates used to distribute cooling water to the cooling fills in a cooling tower is one of the important parameters for the selection of nozzles. Water distribution characteristic describes the distribution of water from the axis of the nozzle along a fill. One of the parameters affecting the water distribution characteristic of the nozzle is airflow velocity of counter flow airstream. Water distribution characteristics are commonly measured using by a set of containers. The problem with this method of the measurement of characteristics is block of the airflow with collections of containers. Therefore, this work is using the visualization method.

  7. Hydrology and tree-distribution patterns of karst wetlands at Arnold Engineering Development Center, Tennessee

    USGS Publications Warehouse

    Wolfe, W.J.

    1996-01-01

    Flooding regimes, ground-water interactions, and tree distribution patterns were determined in seasonally flooded sinkhole wetlands at Arnold Engineering Development Center near Manchester, Tennessee. The wetlands are ecologically significant because they support coastal-plain plants and animals far from their typical ranges. Surface-water stage, ground-water levels, rainfall, and streamflow were monitored at or near five wetland sites. Sinking Pond, Willow Oak Swamp, and Westall Swamp are compound sinks with depths greater than 2.5 meters, visible internal drains, and complex bottom topography dominated by coalesced sinkholes and connecting channels. Tupelo Swamp and Goose Pond are karst pans with depths less than 1.5 meters, flat bottoms, and without visible internal drains. Stage rose and fell abruptly in the compound sinks. Maximum water depths ranged from 2.6 meters in Westall Swamp to 3.5 meters in Sinking Pond. Water levels in wells adjacent to Sinking Pond and Westall Swamp rose and fell abruptly, corresponding closely to surface-water stage throughout periods of high water. The two karst pans filled and drained more gradually, but remained flooded longer than the compound sinks. The maximum recorded water depths were 1.1 meters in Tupelo Swamp and 0.7 meter in Goose Pond. Water levels in nearby wells remained lower than the stage in the pans throughout the study period. Tree species were identified and the elevations and diameters of individual trees were measured along 10 transects. Two transects crossed Sinking Pond, two crossed Tupelo Swamp, and one crossed Willow Oak Swamp. The remaining five transects crossed intermittent drainageways that carry flow into or out of Sinking Pond. Transects through ponds had fewer trees but more basal area per unit area of land surface than did transects through channels. Water tupelo (Nyssa aquatica L.) dominated the interior of Tupelo Swamp and had minimal overlap in terms of elevation and flooding duration with other

  8. 30 CFR 71.602 - Drinking water; distribution.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Drinking water; distribution. 71.602 Section 71... Drinking Water § 71.602 Drinking water; distribution. (a) Water shall be piped or transported in sanitary containers. Water systems and appurtenances thereto shall be constructed and maintained in accordance...

  9. 30 CFR 71.602 - Drinking water; distribution.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Drinking water; distribution. 71.602 Section 71... Drinking Water § 71.602 Drinking water; distribution. (a) Water shall be piped or transported in sanitary containers. Water systems and appurtenances thereto shall be constructed and maintained in accordance...

  10. 30 CFR 71.602 - Drinking water; distribution.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Drinking water; distribution. 71.602 Section 71... Drinking Water § 71.602 Drinking water; distribution. (a) Water shall be piped or transported in sanitary containers. Water systems and appurtenances thereto shall be constructed and maintained in accordance...

  11. 30 CFR 71.602 - Drinking water; distribution.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drinking water; distribution. 71.602 Section 71... Drinking Water § 71.602 Drinking water; distribution. (a) Water shall be piped or transported in sanitary containers. Water systems and appurtenances thereto shall be constructed and maintained in accordance...

  12. 30 CFR 71.602 - Drinking water; distribution.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Drinking water; distribution. 71.602 Section 71... Drinking Water § 71.602 Drinking water; distribution. (a) Water shall be piped or transported in sanitary containers. Water systems and appurtenances thereto shall be constructed and maintained in accordance...

  13. The Impact of Wireless Technology on Order Selection Audits at an Auto Parts Distribution Center

    ERIC Educational Resources Information Center

    Goomas, David T.

    2012-01-01

    Audits of store order pallets or totes performed by auditors at five distribution centers (two experimental and three comparison distribution centers) were used to check for picking accuracy prior to being loaded onto a truck for store delivery. Replacing the paper audits with wireless handheld computers that included immediate auditory and visual…

  14. Water group ion distributions in the midcometosheath of comet Halley

    NASA Technical Reports Server (NTRS)

    Huddleston, D. E.; Neugebauer, M.; Goldstein, Bruce E.

    1993-01-01

    In the midcometosheath of comet Halley (1 x 10(exp 5) to 2 x 10(exp 5) km from the nucleus) the center-of-mass plasma frame is approximately the bulk flow velocity of the cometary ions, and the Alfven wave speed is an appreciable fraction of the flow speed. Here, the peaks of the water group ion distributions observed by the Giotto ion mass spectrometer are at velocities consistently below the expected pickup speed. It is shown that this effect is consistent with the scattering of the new pickup ions onto a bispherical shell distribution. The model does not fit the data inside approximately 1.2 x 10(exp 5) km, however, possibly as a result of the growing importance of collisions or the presence of other processes such as scattering on obliquely propagating magnetosonic waves.

  15. [Third World cities: points of accumulation, centers of distribution].

    PubMed

    Armstrong, W R; Mcgee, T G

    1985-01-01

    Attention was called over 3 decades ago to the very rapid growth of Third World cities and the significance of the differences between their patterns of urbanization and those of industrialized countries. Their demographic growth occurred much faster and depended much more heavily on high fertility, their economies were geared more to export of raw materials than to manufacturing and were unable to create massive numbers of jobs to absorb the growing labor force except in the unproductive tertiary sector, and it appeared unlikely that they would be able to produce entrepreneurial classes of their own. Several economic developments during the 1970s affected the world economy and the patterns of urbanization of the Third World: the decline of the principal capitalist economies and the multiple increases in the price of oil, the floating exchange rate, the considerable increase in consumer goods, and the increasing costs of labor in industrialized countries, among others, created new conditions. World economic interdependence, international control of investment and exchange, and volume and mobility of capital increased at a time of rapid economic growth in some Third World countries, especially those whose governments took an aggressive role in promoting growth and investment. Some Third World cities now seem to be developing according to a more western model, but the same cannot be said of all Third World countries, and international economic evolution appears to have led to increasing polarization between countries as well as within them. The 1 domain where a certain convergence has occurred is consumption, beginning with the privileged classes and filtering to the lower income groups. Consumption of collective and individual consumer goods, which is concentrated in the largest cities, increases dependence on imports, technology, knowledge, and usually debt. The modern productive sector and its distribution activities become implanted in the cities to such a degree

  16. Evaluation of potential human health risk and investigation of drinking water quality in Isparta city center (Turkey).

    PubMed

    Varol, Simge; Davraz, Aysen

    2016-06-01

    Isparta city center is selected as a work area in this study because the public believes that the tap water is dirty and harmful. In this study, the city's drinking water in the distribution system and other spring waters which are used as drinking water in this region were investigated from the point of water quality and health risk assessment. Water samples were collected from major drinking water springs, tap waters, treatment plants and dam pond in the Isparta province center. Ca-Mg-HCO3, Mg-Ca-HCO3, Ca-Na-HCO3, Ca-HCO3, Ca-HCO3-SO4 and Ca-Mg-HCO3-SO4 are dominant water types. When compared to drinking water guidelines established by World Health Organization and Turkey, much greater attention should be paid to As, Br, Fe, F, NH4, PO4 through varied chemicals above the critical values. The increases of As, Fe, F, NH4 and PO4 are related to water-rock interaction. In tap waters, the increases of As and Fe are due to corrosion of pipes in drinking water distribution systems. The major toxic and carcinogenic chemicals within drinking water are As and Br for both tap water and spring water. Also, F is the non-carcinogenic chemical for only spring waters in the study area.

  17. Evaluation of potential human health risk and investigation of drinking water quality in Isparta city center (Turkey).

    PubMed

    Varol, Simge; Davraz, Aysen

    2016-06-01

    Isparta city center is selected as a work area in this study because the public believes that the tap water is dirty and harmful. In this study, the city's drinking water in the distribution system and other spring waters which are used as drinking water in this region were investigated from the point of water quality and health risk assessment. Water samples were collected from major drinking water springs, tap waters, treatment plants and dam pond in the Isparta province center. Ca-Mg-HCO3, Mg-Ca-HCO3, Ca-Na-HCO3, Ca-HCO3, Ca-HCO3-SO4 and Ca-Mg-HCO3-SO4 are dominant water types. When compared to drinking water guidelines established by World Health Organization and Turkey, much greater attention should be paid to As, Br, Fe, F, NH4, PO4 through varied chemicals above the critical values. The increases of As, Fe, F, NH4 and PO4 are related to water-rock interaction. In tap waters, the increases of As and Fe are due to corrosion of pipes in drinking water distribution systems. The major toxic and carcinogenic chemicals within drinking water are As and Br for both tap water and spring water. Also, F is the non-carcinogenic chemical for only spring waters in the study area. PMID:27280612

  18. Evaluating Center Pivot Distribution Uniformity from Catch Can Tests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Center pivot irrigation is an important irrigation method in Missouri. However, only about half of the pivots in Missouri are the “typical”, full-circle, seven-span pivots. The other half are partial circles and/or have shorter or longer span lengths. Both items significantly impact the economics...

  19. Failure monitoring in water distribution networks.

    PubMed

    Misiunas, D; Vítkovský, J; Olsson, G; Lambert, M; Simpson, A

    2006-01-01

    An algorithm for the burst detection and location in water distribution networks based on the continuous monitoring of the flow rate at the entry point of the network and the pressure at a number of points within the network is presented. The approach is designed for medium to large bursts with opening times in the order of a few minutes and is suitable for networks of relatively small size, such as district metered areas (DMAs). The burst-induced increase in the inlet flow rate is detected using the modified cumulative sum (CUSUM) change detection test. Based on parameters obtained from the CUSUM test, the burst is simulated at a number of burst candidate locations. The calculated changes in pressure at the pressure monitoring points are then compared to the measured values and the location resulting in the best fit is selected as the burst location. The EPANET steady-state hydraulic solver is utilised to simulate the flows and pressures in the network. A sensitivity-based sampling design procedure is introduced to find the optimal positions for pressure monitoring points. The proposed algorithm is tested on a case study example network and shows potential for burst detection and location in real water distribution systems.

  20. Water-Pressure Distribution on Seaplane Float

    NASA Technical Reports Server (NTRS)

    Thompson, F L

    1929-01-01

    The investigation presented in this report was conducted for the purpose of determining the distribution and magnitude of water pressures likely to be experienced on seaplane hulls in service. It consisted of the development and construction of apparatus for recording water pressures lasting one one-hundredth second or longer and of flight tests to determine the water pressures on a UO-1 seaplane float under various conditions of taxiing, taking off, and landing. The apparatus developed was found to operate with satisfactory accuracy and is suitable for flight tests on other seaplanes. The tests on the UO-1 showed that maximum pressures of about 6.5 pounds per square inch occur at the step for the full width of the float bottom. Proceeding forward from the step the maximum pressures decrease in magnitude uniformly toward the bow, and the region of highest pressures narrows toward the keel. Immediately abaft the step the maximum pressures are very small, but increase in magnitude toward the stern and there once reached a value of about 5 pounds per square inch. (author)

  1. 24 CFR 3280.609 - Water distribution systems.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 5 2013-04-01 2013-04-01 false Water distribution systems. 3280....609 Water distribution systems. (a) Water supply—(1) Supply piping. Piping systems shall be sized to provide an adequate quantity of water to each plumbing fixture at a flow rate sufficient to keep...

  2. 24 CFR 3280.609 - Water distribution systems.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Water distribution systems. 3280....609 Water distribution systems. Link to an amendment published at 78 FR 73986, Dec. 9, 2013. (a) Water supply—(1) Supply piping. Piping systems shall be sized to provide an adequate quantity of water to...

  3. EQUITY EVALUATION OF PADDY IRRIGATION WATER DISTRIBUTION BY SOCIETY-JUSTICE-WATER DISTRIBUTION RULE HYPOTHESIS

    NASA Astrophysics Data System (ADS)

    Tanji, Hajime; Kiri, Hirohide; Kobayashi, Shintaro

    When total supply is smaller than total demand, it is difficult to apply the paddy irrigation water distribution rule. The gap must be narrowed by decreasing demand. Historically, the upstream served rule, rotation schedule, or central schedule weight to irrigated area was adopted. This paper proposes the hypothesis that these rules are dependent on social justice, a hypothesis called the "Society-Justice-Water Distribution Rule Hypothesis". Justice, which means a balance of efficiency and equity of distribution, is discussed under the political philosophy of utilitarianism, liberalism (Rawls), libertarianism, and communitarianism. The upstream served rule can be derived from libertarianism. The rotation schedule and central schedule can be derived from communitarianism. Liberalism can provide arranged schedule to adjust supply and demand based on "the Difference Principle". The authors conclude that to achieve efficiency and equity, liberalism may provide the best solution after modernization.

  4. SWAG: Survey of Water and Ammonia in the Galactic Center

    NASA Astrophysics Data System (ADS)

    Ott, Juergen; Meier, David; Mills, Elizabeth

    2015-08-01

    We present a new survey of the Galactic Center: SWAG (Survey of Water and Ammonia in the Galactic Center). The survey region spans the entire ~400pc Central Molecular Zone of the Milky Way and will produce maps of ~42 spectral lines at ~1cm wavelength at ~1pc resolution. In addition, we will obtain a deep continuum (produced by synchrotron, free-free, and dust) and polarization map for the region. To date, ~1/2 of the survey has been completed with the Australia Telescope Compact Array in the compact H75 configuration. The data are a good compromise between spatial resolution and sensitivity to large angular scale emission. The spectral lines include many transitions of the temperature tracer ammonia, which allows us to construct maps of molecular gas temperature, opacity and gas formation temperature. Water masers reveal the sites of active star formation and other molecules are good tracers for density, radiation field, shocks, and ionization. This extremely rich survey will allow us to construct maps of physical parameters in this extreme environment, and we will present results from our pilot survey.

  5. Survey of Water and Ammonia in the Galactic Center (SWAG)

    NASA Astrophysics Data System (ADS)

    Ott, Juergen; Jones, Paul; Staveley-Smith, Lister; Weiss, Axel; Henkel, Christian; Edwards, Philip; Burton, Michael; Menten, Karl; Schilke, Peter; Zhang, Qizhou; Longmore, Steven; Yusef-Zadeh, Farhad; Meier, David; Miller-Jones, James; Walsh, Andrew; Morris, Mark; Lang, Cornelia; Beuther, Henrik; Contreras, Yanett; Goldsmith, Paul; Crocker, Roland Murley; Corby, Joanna`; Anderson, Crystal; Ginsburg, Adam; Bally, John; Battersby, Cara; Mills, Elisabeth; Rosolowsky, Erik; Kruijssen, Diederik; Bihr, Simon; Morabito, Leah

    2014-04-01

    The Galactic Center contains 10% of all Galactic molecular gas (in the Central Molecular Zone; CMZ), material that is potentially converted into stars. The CMZ is an extreme environment. Many physical phenomena can be observed that shape the gas properties such as strong shocks, cosmic rays, high energy photons, turbulence, strong magnetic and tidal fields. We propose to perform the "Survey of Water and Ammonia in the Galactic Center (SWAG)'', a Large ATCA survey to cover the CMZ in the line-rich K-band to study the gas parameters that ultimately control the ability to cool, collapse and form stars. We ask to observe molecular species and continuum that will be used to (1) map the structure and kinematics of the gas at 1pc resolution; (2) obtain a large scale temperature map, accurate up to hundreds of K; (3) derive a map of opacity; (4) obtain an "archaeological" map of gas formation temperatures; (5) collate a water maser survey to trace actual star formation; (6) obtain maps of shock and photon-dominated region tracers; (7) derive maps of radio recombination lines to mark ionizing sources; (8) compute maps of continuum, spectral index and curvature; (9) derive a molecular clump catalog with properties for ~10000 objects. Together these data will allow us to disentangle the processes that control the state of the gas and capability to form stars. SWAG will serve as a benchmark for galactic nucleus physics at all cosmic epochs.

  6. Fuzzy probabilistic design of water distribution networks

    NASA Astrophysics Data System (ADS)

    Fu, Guangtao; Kapelan, Zoran

    2011-05-01

    The primary aim of this paper is to present a fuzzy probabilistic approach for optimal design and rehabilitation of water distribution systems, combining aleatoric and epistemic uncertainties in a unified framework. The randomness and imprecision in future water consumption are characterized using fuzzy random variables whose realizations are not real but fuzzy numbers, and the nodal head requirements are represented by fuzzy sets, reflecting the imprecision in customers' requirements. The optimal design problem is formulated as a two-objective optimization problem, with minimization of total design cost and maximization of system performance as objectives. The system performance is measured by the fuzzy random reliability, defined as the probability that the fuzzy head requirements are satisfied across all network nodes. The satisfactory degree is represented by necessity measure or belief measure in the sense of the Dempster-Shafer theory of evidence. An efficient algorithm is proposed, within a Monte Carlo procedure, to calculate the fuzzy random system reliability and is effectively combined with the nondominated sorting genetic algorithm II (NSGAII) to derive the Pareto optimal design solutions. The newly proposed methodology is demonstrated with two case studies: the New York tunnels network and Hanoi network. The results from both cases indicate that the new methodology can effectively accommodate and handle various aleatoric and epistemic uncertainty sources arising from the design process and can provide optimal design solutions that are not only cost-effective but also have higher reliability to cope with severe future uncertainties.

  7. Manganese deposition in drinking water distribution systems.

    PubMed

    Gerke, Tammie L; Little, Brenda J; Barry Maynard, J

    2016-01-15

    This study provides a physicochemical assessment of manganese deposits on brass and lead components from two fully operational drinking water distributions systems. One of the systems was maintained with chlorine; the other, with secondary chloramine disinfection. Synchrotron-based in-situ micro X-ray adsorption near edge structure was used to assess the mineralogy. In-situ micro X-ray fluorescence mapping was used to demonstrate the spatial relationships between manganese and potentially toxic adsorbed metal ions. The Mn deposits ranged in thickness from 0.01 to 400 μm. They were composed primarily of Mn oxides/oxhydroxides, birnessite (Mn(3+) and Mn(4+)) and hollandite (Mn(2+) and Mn(4+)), and a Mn silicate, braunite (Mn(2+) and Mn(4+)), in varying proportions. Iron, chromium, and strontium, in addition to the alloying elements lead and copper, were co-located within manganese deposits. With the exception of iron, all are related to specific health issues and are of concern to the U.S. Environmental Protection Agency (U.S. EPA). The specific properties of Mn deposits, i.e., adsorption of metals ions, oxidation of metal ions and resuspension are discussed with respect to their influence on drinking water quality.

  8. Self-Powered WSN for Distributed Data Center Monitoring

    PubMed Central

    Brunelli, Davide; Passerone, Roberto; Rizzon, Luca; Rossi, Maurizio; Sartori, Davide

    2016-01-01

    Monitoring environmental parameters in data centers is gathering nowadays increasing attention from industry, due to the need of high energy efficiency of cloud services. We present the design and the characterization of an energy neutral embedded wireless system, prototyped to monitor perpetually environmental parameters in servers and racks. It is powered by an energy harvesting module based on Thermoelectric Generators, which converts the heat dissipation from the servers. Starting from the empirical characterization of the energy harvester, we present a power conditioning circuit optimized for the specific application. The whole system has been enhanced with several sensors. An ultra-low-power micro-controller stacked over the energy harvesting provides an efficient power management. Performance have been assessed and compared with the analytical model for validation. PMID:26729135

  9. Self-Powered WSN for Distributed Data Center Monitoring.

    PubMed

    Brunelli, Davide; Passerone, Roberto; Rizzon, Luca; Rossi, Maurizio; Sartori, Davide

    2016-01-01

    Monitoring environmental parameters in data centers is gathering nowadays increasing attention from industry, due to the need of high energy efficiency of cloud services. We present the design and the characterization of an energy neutral embedded wireless system, prototyped to monitor perpetually environmental parameters in servers and racks. It is powered by an energy harvesting module based on Thermoelectric Generators, which converts the heat dissipation from the servers. Starting from the empirical characterization of the energy harvester, we present a power conditioning circuit optimized for the specific application. The whole system has been enhanced with several sensors. An ultra-low-power micro-controller stacked over the energy harvesting provides an efficient power management. Performance have been assessed and compared with the analytical model for validation. PMID:26729135

  10. Self-Powered WSN for Distributed Data Center Monitoring.

    PubMed

    Brunelli, Davide; Passerone, Roberto; Rizzon, Luca; Rossi, Maurizio; Sartori, Davide

    2016-01-02

    Monitoring environmental parameters in data centers is gathering nowadays increasing attention from industry, due to the need of high energy efficiency of cloud services. We present the design and the characterization of an energy neutral embedded wireless system, prototyped to monitor perpetually environmental parameters in servers and racks. It is powered by an energy harvesting module based on Thermoelectric Generators, which converts the heat dissipation from the servers. Starting from the empirical characterization of the energy harvester, we present a power conditioning circuit optimized for the specific application. The whole system has been enhanced with several sensors. An ultra-low-power micro-controller stacked over the energy harvesting provides an efficient power management. Performance have been assessed and compared with the analytical model for validation.

  11. Evolution of the dark matter distribution at the galactic center.

    PubMed

    Merritt, David

    2004-05-21

    Annihilation radiation from neutralino dark matter at the Galactic center (GC) would be greatly enhanced if the dark matter were strongly clustered around the supermassive black hole (SBH). The existence of a dark matter "spike" is made plausible by the observed, steeply rising stellar density near the GC SBH. Here the time-dependent equations describing gravitational interaction of the dark matter with the stars are solved. Scattering of dark matter particles by stars would substantially lower the dark matter density near the GC SBH over 10 Gyr, due both to kinetic heating and to capture of dark matter particles by the SBH. This evolution implies a decrease by several orders of magnitude in the observable flux of annihilation products compared with models that associate a steep, dark matter spike with the SBH.

  12. NASA Langley Research Center's distributed mass storage system

    NASA Technical Reports Server (NTRS)

    Pao, Juliet Z.; Humes, D. Creig

    1993-01-01

    There is a trend in institutions with high performance computing and data management requirements to explore mass storage systems with peripherals directly attached to a high speed network. The Distributed Mass Storage System (DMSS) Project at NASA LaRC is building such a system and expects to put it into production use by the end of 1993. This paper presents the design of the DMSS, some experiences in its development and use, and a performance analysis of its capabilities. The special features of this system are: (1) workstation class file servers running UniTree software; (2) third party I/O; (3) HIPPI network; (4) HIPPI/IPI3 disk array systems; (5) Storage Technology Corporation (STK) ACS 4400 automatic cartridge system; (6) CRAY Research Incorporated (CRI) CRAY Y-MP and CRAY-2 clients; (7) file server redundancy provision; and (8) a transition mechanism from the existent mass storage system to the DMSS.

  13. Distribution of characteristics of LWR [light water reactor] spent fuel

    SciTech Connect

    Reich, W.J.; Notz, K.J.; Moore, R.S.

    1991-01-01

    The purpose of this report is to develop a collective description of the entire spent fuel inventory in terms of various fuel properties relevant to Approved Testing Materials (ATMs) using information available from the Characteristics Data Base (CBD), which is sponsored by the US Department of Energy`s (DOE`s) Office of Civilian Radioactive Waste Management. A number of light-water reactor (LWR) characteristics were analyzed including assembly class representation, fuel burnup, enrichment, fuel fabrication data, defective fuel quantities, and, at PNL`s specific request, linear heat generation rate (LHGR) and the utilization of burnable poisons. A quantitative relationships was developed between burnup and enrichment for BWRs and PWRs. The relationship shows that the existing BWR ATM is near the center of the burnup-enrichment distribution, while the four PWR ATMs bracket the center of the burnup range but are on the low side of the enrichment range. Fuel fabrication data are based on vendor specifications for new fuel. Defective fuel distributions were analyzed in terms of assembly class and vendor design. LHGR values were calculated from utility data on burnup and effective full-power days; these calculations incorporate some unavoidable assumptions which may compromise the value of the results. Only a limited amount of data are available on burnable poisons at this time. Based on this distribution study, suggestions for additional ATMs are made. These are based on the class and design concepts and include BWR/2,3 barrier fuel, and the WE 17 {times} 17 class with integral burnable poison. Both should be at relatively high burnups. 16 refs., 5 figs., 15 tabs.

  14. The NASA Lewis Research Center Water Tunnel Facility

    NASA Technical Reports Server (NTRS)

    Wasserbauer, Charles A.

    1997-01-01

    A water tunnel facility specifically designed to investigate internal fluid duct flows has been built at the NASA Research Center. It is built in a modular fashion so that a variety of internal flow test hardware can be installed in the facility with minimal facility reconfiguration. The facility and test hardware interfaces are discussed along with design constraints for future test hardware. The inlet chamber flow conditioning approach is also detailed. Instrumentation and data acquisition capabilities are discussed. The incoming flow quality has been documented for about one quarter of the current facility operating range. At that range, there is some scatter in the data in the turbulent boundary layer which approaches 10 percent of the duct radius leading to a uniform core.

  15. Distributed information system (water fact sheet)

    USGS Publications Warehouse

    Harbaugh, A.W.

    1986-01-01

    During 1982-85, the Water Resources Division (WRD) of the U.S. Geological Survey (USGS) installed over 70 large minicomputers in offices across the country to support its mission in the science of hydrology. These computers are connected by a communications network that allows information to be shared among computers in each office. The computers and network together are known as the Distributed Information System (DIS). The computers are accessed through the use of more than 1500 terminals and minicomputers. The WRD has three fundamentally different needs for computing: data management; hydrologic analysis; and administration. Data management accounts for 50% of the computational workload of WRD because hydrologic data are collected in all 50 states, Puerto Rico, and the Pacific trust territories. Hydrologic analysis consists of 40% of the computational workload of WRD. Cost accounting, payroll, personnel records, and planning for WRD programs occupies an estimated 10% of the computer workload. The DIS communications network is shown on a map. (Lantz-PTT)

  16. Science center capabilities to monitor and investigate Michigan’s water resources, 2016

    USGS Publications Warehouse

    Giesen, Julia A.; Givens, Carrie E.

    2016-09-06

    Michigan faces many challenges related to water resources, including flooding, drought, water-quality degradation and impairment, varying water availability, watershed-management issues, stormwater management, aquatic-ecosystem impairment, and invasive species. Michigan’s water resources include approximately 36,000 miles of streams, over 11,000 inland lakes, 3,000 miles of shoreline along the Great Lakes (MDEQ, 2016), and groundwater aquifers throughout the State.The U.S. Geological Survey (USGS) works in cooperation with local, State, and other Federal agencies, as well as tribes and universities, to provide scientific information used to manage the water resources of Michigan. To effectively assess water resources, the USGS uses standardized methods to operate streamgages, water-quality stations, and groundwater stations. The USGS also monitors water quality in lakes and reservoirs, makes periodic measurements along rivers and streams, and maintains all monitoring data in a national, quality-assured, hydrologic database.The USGS in Michigan investigates the occurrence, distribution, quantity, movement, and chemical and biological quality of surface water and groundwater statewide. Water-resource monitoring and scientific investigations are conducted statewide by USGS hydrologists, hydrologic technicians, biologists, and microbiologists who have expertise in data collection as well as various scientific specialties. A support staff consisting of computer-operations and administrative personnel provides the USGS the functionality to move science forward. Funding for USGS activities in Michigan comes from local and State agencies, other Federal agencies, direct Federal appropriations, and through the USGS Cooperative Matching Funds, which allows the USGS to partially match funding provided by local and State partners.This fact sheet provides an overview of the USGS current (2016) capabilities to monitor and study Michigan’s vast water resources. More

  17. [Influence of water source switching on water quality in drinking water distribution system].

    PubMed

    Wang, Yang; Niu, Zhang-bin; Zhang, Xiao-jian; Chen, Chao; He, Wen-jie; Han, Hong-da

    2007-10-01

    This study investigates the regularity of the change on the physical and chemical water qualities in the distribution system during the process of water source switching in A city. Due to the water source switching, the water quality is chemical-astable. Because of the differences between the two water sources, pH reduced from 7.54 to 7.18, alkalinity reduced from 188 mg x L(-1) to 117 mg x L(-1), chloride (Cl(-)) reduced from 310 mg x L(-1) to 132 mg x L(-1), conductance reduced from 0.176 S x m(-1) to 0.087 S x m(-1) and the ions of calcium and magnesium reduced to 15 mg x L(-1) and 11 mg x L(-1) respectively. Residual chlorine changed while the increase of the chlorine demand and the water quantity decreasing at night, and the changes of pH, alkalinity and residual chlorine brought the iron increased to 0.4 mg x L(-1) at the tiptop, which was over the standard. The influence of the change of the water parameters on the water chemical-stability in the drinking water distribution system is analyzed, and the controlling countermeasure is advanced: increasing pH, using phosphate and enhancing the quality of the water in distribution system especially the residual chlorine.

  18. Vertical Water Vapor Distribution at Phoenix

    NASA Astrophysics Data System (ADS)

    Tamppari, L. K.; Lemmon, M. T.

    2016-09-01

    The Phoenix SSI camera data along with radiative transfer modeling are used to retrieve the vertical water vapor profile. Preliminary results indicate that water vapor is often confined near the surface.

  19. Prevent infection linked to the dialysis water in a hemodialysis center in Fez city (Morocco)

    PubMed Central

    Oumokhtar, Bouchra; Lalami, Abdelhakim El Ouali; Mahmoud, Mustapha; Berrada, Sanae; Arrayhani, Mohammed; Houssaini, Tarik Squalli

    2013-01-01

    Background Water treatment systems are a critical variable in dialysis therapy. Rigorous control of hemodialysis water quality is particularly important in order to guarantee a better quality of life of the hemodialysis patients. The objective of the study was to evaluate the chemical, microbiological quality and antimicrobial resistance of bacteria isolated from water and dialysate in a public HD center. Methods Fifty five samples of water and dialysate were collected weekly over a period of 4 months. The samples were collected from 4 points in the distribution loop. The microbiological and chemical analyses were performed according to our national standards. Antimicrobial susceptibilities patterns of isolated bacteria were determined by disk diffusion method. Results The chemical and microbiological parameters in all dialysis water and dialysate samples are in accordance with national standards. However, 70 Gram-negative bacteria were identified: Pseudomonas sp, Ochrobactrum antropi and Burkholderia cepacia, isolated at 52.8%, 12.8% and 17% simultaneously. Fourteen per cent of the isolates were resistant to three or more antibiotics. All resistant bacteria belong to the genus of Pseudomonas, 80% were resistant to tetracycline and to co-trimoxazole, 30% to ceftazidime. No colistin and imipenem resistance was observed. Conclusion To avoid a health risk due to bacterial contamination, an adequate system for water treatment, disinfection of the hemodialysis system and microbiological monitoring of the water and dialysate are necessary. PMID:24839530

  20. THE EPANET WATER DISTRIBUTION SYSTEM MODEL

    EPA Science Inventory

    EPANET is a Windows program that performs extended period simulation of hydraulic and water-quality behavior within pressurized pipe networks. It tracks the flow of water in each pipe, the pressure at each node, the height of water in each tank, and the concentration of a chemica...

  1. Vertical Distribution of Water at Phoenix

    NASA Technical Reports Server (NTRS)

    Tamppari, L. K.; Lemmon, M. T.

    2011-01-01

    Phoenix results, combined with coordinated observations from the Mars Reconnaissance Orbiter of the Phoenix lander site, indicate that the water vapor is nonuniform (i.e., not well mixed) up to a calculated cloud condensation level. It is important to understand the mixing profile of water vapor because (a) the assumption of a well-mixed atmosphere up to a cloud condensation level is common in retrievals of column water abundances which are in turn used to understand the seasonal and interannual behavior of water, (b) there is a long history of observations and modeling that conclude both that water vapor is and is not well-mixed, and some studies indicate that the water vapor vertical mixing profile may, in fact, change with season and location, (c) the water vapor in the lowest part of the atmosphere is the reservoir that can exchange with the regolith and higher amounts may have an impact on the surface chemistry, and (d) greater water vapor abundances close to the surface may enhance surface exchange thereby reducing regional transport, which in turn has implications to the net transport of water vapor over seasonal and annual timescales.

  2. GROWTH OF HETROTROPHIC BIOFILMS IN A WATER DISTRIBUTION SYSTEM SIMULATOR

    EPA Science Inventory

    The U.S. EPA has designed and constructed a distribution system simulator (DSS) to evaluate factors which influence water quality within water distribution systems. Six individual 25 meter lengths of 15 cm diameter ductile iron pipe are arranged into loop configurations. Each lo...

  3. Analysis Model for Domestic Hot Water Distribution Systems: Preprint

    SciTech Connect

    Maguire, J.; Krarti, M.; Fang, X.

    2011-11-01

    A thermal model was developed to estimate the energy losses from prototypical domestic hot water (DHW) distribution systems for homes. The developed model, using the TRNSYS simulation software, allows researchers and designers to better evaluate the performance of hot water distribution systems in homes. Modeling results were compared with past experimental study results and showed good agreement.

  4. MEASURING AND MODELING VARIATIONS IN DISTRIBUTION SYSTEM WATER QUALITY

    EPA Science Inventory

    The authors describe a field study that examined the effects of hydraulic mixing on water quality variations in a distribution system. Conducted at the North Penn Water Authority (average production of 5 mgd and 225 mi of distribution pipe), the study incorporated a field samplin...

  5. National Space Transportation System telemetry distribution and processing, NASA-JFK Space Center/Cape Canaveral

    NASA Technical Reports Server (NTRS)

    Jenkins, George

    1986-01-01

    Prelaunch, launch, mission, and landing distribution of RF and hardline uplink/downlink information between Space Shuttle Orbiter/cargo elements, tracking antennas, and control centers at JSC, KSC, MSFC, GSFC, ESMC/RCC, and Sunnyvale are presented as functional block diagrams. Typical mismatch problems encountered during spacecraft-to-project control center telemetry transmissions are listed along with new items for future support enhancement.

  6. National Space Transportation System telemetry distribution and processing, NASA-JFK Space Center/Cape Canaveral

    NASA Astrophysics Data System (ADS)

    Jenkins, George

    Prelaunch, launch, mission, and landing distribution of RF and hardline uplink/downlink information between Space Shuttle Orbiter/cargo elements, tracking antennas, and control centers at JSC, KSC, MSFC, GSFC, ESMC/RCC, and Sunnyvale are presented as functional block diagrams. Typical mismatch problems encountered during spacecraft-to-project control center telemetry transmissions are listed along with new items for future support enhancement.

  7. Quality-assurance plan for ground-water activities, U.S. Geological Survey, Washington Water Science Center

    USGS Publications Warehouse

    Drost, B. W.

    2005-01-01

    This quality-assurance plan documents the standards, policies, and procedures used by the U.S. Geological Survey's Washington Water Science Center, for activities related to the collection, processing, storage, analysis, and publication of ground-water data. This plan serves as a guide to all Washington Water Science Center personnel involved in ground-water activities, and changes as the needs and requirements of the Washington Water Science Center and Discipline change. Regular updates to this plan represent an integral part of the quality-assurance process.

  8. Residential hot water distribution systems: Roundtablesession

    SciTech Connect

    Lutz, James D.; Klein, Gary; Springer, David; Howard, Bion D.

    2002-08-01

    Residential building practice currently ignores the lossesof energy and water caused by the poor design of hot water systems. Theselosses include: combustion and standby losses from water heaters, thewaste of water (and energy) while waiting for hot water to get to thepoint of use; the wasted heat as water cools down in the distributionsystem after a draw; heat losses from recirculation systems and thediscarded warmth of waste water as it runs down the drain. Severaltechnologies are available that save energy (and water) by reducing theselosses or by passively recovering heat from wastewater streams and othersources. Energy savings from some individual technologies are reported tobe as much as 30 percent. Savings calculations of prototype systemsincluding bundles of technologies have been reported above 50 percent.This roundtable session will describe the current practices, summarizethe results of past and ongoing studies, discuss ways to think about hotwater system efficiency, and point to areas of future study. We will alsorecommend further steps to reduce unnecessary losses from hot waterdistribution systems.

  9. Spatial distribution and alignments of volcanic centers: Clues to the formation of monogenetic volcanic fields

    NASA Astrophysics Data System (ADS)

    Le Corvec, Nicolas; Spörli, K. Bernhard; Rowland, Julie; Lindsay, Jan

    2013-09-01

    Monogenetic basaltic volcanic fields occur worldwide in tectonic environments ranging from extensional to convergent. Understanding similarities and differences between these fields may help to characterize key controls on their generation. Such volcanic fields consist of numerous volcanic centers, each of which represents a pathway of magma from its source to the surface. We analyzed the spatial distribution of volcanic centers in 37 monogenetic volcanic fields, and assuming that the distribution of volcanic centers relative to each other is matched by a similar source pattern within the mantle, applied the following methods for each: (1) the Poisson Nearest Neighbor (PNN) analysis, representing the degree to which the distribution of the volcanic centers departs from a predicted Poisson distribution, and (2) a volcanic alignment analysis to ascertain the preferential pathways, if any, used by the magma to reach the surface. This is the first comprehensive global comparison of such analyses. Magma pathways within the brittle upper crust are influenced to various degrees by two end-member situations: (1) formation of new extension fractures perpendicular to the least compressive stress (σ3) and (2) re-activation of pre-existing fractures that are near-parallel to the maximum principal stress (σ1). The results of the PNN analysis show that, independently of the tectonic environment, most volcanic fields display a clustered distribution of their volcanic centers. Alignment analysis shows that either the ambient tectonic environment exerts a strong influence on the preferential orientations of the volcanic alignments, or that it is in competition with other factors (e.g., pre-existing structures, local stress changes due to older intrusions). Overall, these results indicate that the propagation of the magma (and therefore the spatial distribution of the volcanic centers within volcanic fields) is the product of an interplay between deep level influences (i

  10. WATER QUALITY IN SOURCE WATER, TREATMENT, AND DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Most drinking water utilities practice the multiple-barrier concept as the guiding principle for providing safe water. This chapter discusses multiple barriers as they relate to the basic criteria for selecting and protecting source waters, including known and potential sources ...

  11. OPTIMAL SCHEDULING OF BOOSTER DISINFECTION IN WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Booster disinfection is the addition of disinfectant at locations distributed throughout a water distribution system. Such a strategy can reduce the mass of disinfectant required to maintain a detectable residual at points of consumption in the distribution system, which may lea...

  12. EVALUATION OF WATER MONITORING INSTRUMENTATION AT EPA'S WATER AWARENESS TECHNOLOGY EVALUATION RESEARCH SECURITY CENTER

    EPA Science Inventory

    The safety and security of distribution systems has come under reassessment in the past year. Several chemical and biological agents have been identified that might constitute a credible threat against water supply systems. There have also been a few reported threats against wate...

  13. Shallow ground-water quality beneath a major urban center: Denver, Colorado, USA

    USGS Publications Warehouse

    Bruce, B.W.; McMahon, P.B.

    1996-01-01

    A survey of the chemical quality of ground water in the unconsolidated alluvial aquifer beneath a major urban center (Denver, Colorado, USA) was performed in 1993 with the objective of characterizing the quality of shallow ground-water in the urban area and relating water quality to land use. Thirty randomly selected alluvial wells were each sampled once for a broad range of dissolved constituents. The urban land use at each well site was sub- classified into one of three land-use settings: residential, commercial, and industrial. Shallow ground-water quality was highly variable in the urban area and the variability could be related to these land-use setting classifications. Sulfate (SO4) was the predominant anion in most samples from the residential and commercial land-use settings, whereas bicarbonate (HCO3) was the predominant anion in samples from the industrial land-use setting, indicating a possible shift in redox conditions associated with land use. Only three of 30 samples had nitrate concentrations that exceeded the US national drinking-water standard of 10 mg l-1 as nitrogen, indicating that nitrate contamination of shallow ground water may not be a serious problem in this urban area. However, the highest median nitrate concentration (4.2 mg l-1) was in samples from the residential setting, where fertilizer application is assumed to be most intense. Twenty-seven of 30 samples had detectable pesticides and nine of 82 analyzed pesticide compounds were detected at low concentrations, indicating that pesticides are widely distributed in shallow ground water in this urban area. Although the highest median total pesticide concentration (0.17 ??g l-1) was in the commercial setting, the herbicides prometon and atrazine were found in each land-use setting. Similarly, 25 of 29 samples analyzed had detectable volatile organic compounds (VOCs) indicating these compounds are also widely distributed in this urban area. The total VOC concentrations in sampled wells

  14. Cumulus convection and the terrestrial water-vapor distribution

    NASA Technical Reports Server (NTRS)

    Donner, Leo J.

    1988-01-01

    Cumulus convection plays a significant role in determining the structure of the terrestrial water vapor field. Cumulus convection acts directly on the moisture field by condensing and precipitating water vapor and by redistributing water vapor through cumulus induced eddy circulations. The mechanisms by which cumulus convection influences the terrestrial water vapor distribution is outlined. Calculations using a theory due to Kuo is used to illustrate the mechanisms by which cumulus convection works. Understanding of these processes greatly aids the ability of researchers to interpret the seasonal and spatial distribution of atmospheric water vapor by providing information on the nature of sources and sinks and the global circulation.

  15. ANIMATION AND VISUALIZATION OF WATER QUALITY IN DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Water may undergo a number of changes in the distribution system, making the quality of the water at the customer's tap different from the quality of the water that leaves the treatment plant. Such changes in quality may be caused by chemical or biological variations or by a loss...

  16. Microflora of drinking water distributed through decentralized supply systems (Tomsk)

    NASA Astrophysics Data System (ADS)

    Khvaschevskaya, A. A.; Nalivaiko, N. G.; Shestakova, A. V.

    2016-03-01

    The paper considers microbiological quality of waters from decentralized water supply systems in Tomsk. It has been proved that there are numerous microbial contaminants of different types. The authors claim that the water distributed through decentralized supply systems is not safe to drink without preliminary treatment.

  17. 24 CFR 3280.609 - Water distribution systems.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...-free (as defined in section 109(c)(2) of the Safe Drinking Water Act Amendments of 1986) with solders... screw piping shall be less than 1/2 inch iron pipe size. (2) Sizing procedure. Both hot and cold water... 24 Housing and Urban Development 5 2012-04-01 2012-04-01 false Water distribution systems....

  18. WATER DISTRIBUTION SYSTEM ANALYSIS: FIELD STUDIES, MODELING AND MANAGEMENT

    EPA Science Inventory

    The user‘s guide entitled “Water Distribution System Analysis: Field Studies, Modeling and Management” is a reference guide for water utilities and an extensive summarization of information designed to provide drinking water utility personnel (and related consultants and research...

  19. Particulate Arsenic Release in a Drinking Water Distribution System

    EPA Science Inventory

    Trace contaminants, such as arsenic, have been shown to accumulate in solids found in drinking water distribution systems. The obvious concern is that the contaminants in these solids could be released back into the water resulting in elevated levels in a consumer’s tap water. Th...

  20. Water distribution in dentin matrices: bound vs. unbound water

    PubMed Central

    Agee, Kelli A.; Prakki, Anuradha; Abu-Haimed, Tariq; Naguib, Ghada H.; Nawareg, Manar Abu; Tezvergil-Mutluay, Arzu; Scheffel, Debora L.S.; Chen, Chen; Jang, Seung Soon; Hwang, Hyea; Brackett, Martha; Grégoire, Geneviéve; Tay, Franklin R.; Breschi, Lorenzo; Pashley, David H.

    2015-01-01

    Objectives This work measured the amount of bound versus unbound water in completely-demineralized dentin. Methods Dentin beams prepared from extracted human teeth were completely demineralized, rinsed and dried to constant mass. They were rehydrated in 41% relative humidity (RH), while gravimetrically measuring their mass increase until the first plateau was reached at 0.064 (vacuum) or 0.116 g H2O/g dry mass (Drierite). The specimens were then exposed to 60% RH until attaining the second plateau at 0.220 (vacuum) or 0.191 g H2O/g dry mass (Drierite), and subsequently exposed to 99% RH until attaining the third plateau at 0.493 (vacuum) or 0.401 g H2O/g dry mass (Drierite). Results Exposure of the first layer of bound water to 0% RH for 5 min produced a −0.3% loss of bound water; in the second layer of bound water it caused a −3.3% loss of bound water; in the third layer it caused a −6% loss of bound water. Immersion in 100% ethanol or acetone for 5 min produced a 2.8 and 1.9% loss of bound water from the first layer, respectively; it caused a −4 and −7% loss of bound water in the second layer, respectively; and a −17 and −23% loss of bound water in the third layer.. Bound water represented 21–25% of total dentin water. Chemical dehydration of water-saturated dentin with ethanol/acetone for 1 min only removed between 25 to 35% of unbound water, respectively. Significance Attempts to remove bound water by evaporation were not very successful. Chemical dehydration with 100% acetone was more successful than 100% ethanol especially the third layer of bound water. Since unbound water represents between 75–79% of total matrix water, the more such water can be removed, the more resin can be infiltrated. PMID:25612786

  1. Iron and copper release in drinking-water distribution systems.

    PubMed

    Shi, Baoyou; Taylor, James S

    2007-09-01

    A large-scale pilot study was carried out to evaluate the impacts of changes in water source and treatment process on iron and copper release in water distribution systems. Finished surface waters, groundwaters, and desalinated waters were produced with seven different treatment systems and supplied to 18 pipe distribution systems (PDSs). The major water treatment processes included lime softening, ferric sulfate coagulation, reverse osmosis, nanofiltration, and integrated membrane systems. PDSs were constructed from PVC, lined cast iron, unlined cast iron, and galvanized pipes. Copper pipe loops were set up for corrosion monitoring. Results showed that surface water after ferric sulfate coagulation had low alkalinity and high sulfates, and consequently caused the highest iron release. Finished groundwater treated by conventional method produced the lowest iron release but the highest copper release. The iron release of desalinated water was relatively high because of the water's high chloride level and low alkalinity. Both iron and copper release behaviors were influenced by temperature.

  2. Designing a Knowledge Management System for Distributed Activities: A Human Centered Approach

    PubMed Central

    Rinkus, Susan; Johnson-Throop, Kathy A.; Zhang, Jiajie

    2003-01-01

    In this study we use the principles of distributed cognition and the methodology of human-centered distributed information design to analyze a complex distributed human-computer system, identify its problems, and generate design requirements and implementation specifications of a replacement prototype for effective organizational memory and knowledge management. We argue that a distributed human-computer information system has unique properties, structures and processes that are best described in the language of distributed cognition. Distributed cognition provides researchers a richer theoretical understanding of human-computer interactions and enables researchers to capture the phenomenon that emerges in social interactions as well as the interactions between people and structures in their environment. PMID:14728235

  3. Designing a knowledge management system for distributed activities: a human centered approach.

    PubMed

    Rinkus, Susan; Johnson-Throop, Kathy A; Zhang, Jiajie

    2003-01-01

    In this study we use the principles of distributed cognition and the methodology of human-centered distributed information design to analyze a complex distributed human-computer system, identify its problems, and generate design requirements and implementation specifications of a replacement prototype for effective organizational memory and knowledge management. We argue that a distributed human-computer information system has unique properties, structures and processes that are best described in the language of distributed cognition. Distributed cognition provides researchers a richer theoretical understanding of human-computer interactions and enables re-searchers to capture the phenomenon that emerges in social interactions as well as the interactions between people and structures in their environment.

  4. Final technical report for CENTER FOR ENABLING DISTRIBUTED SCIENCE (CEDS) project

    SciTech Connect

    Livny, Miron

    2004-04-10

    An overview of the main activities performed by the UW-Madison in support of the CENTER FOR ENABLING DISTRIBUTED SCIENCE (CEDS). The main contribution of the team were in the area of storage management support for GridFTP, integartion of Globus online services with Condor and using NetLogger to record events about Condor jobs.

  5. Seismic Fragility of the LANL Fire Water Distribution System

    SciTech Connect

    Greg Mertz Jason Cardon Mike Salmon

    2007-03-30

    The purpose of this report is to present the results of a site-wide system fragility assessment. This assessment focuses solely on the performance of the water distribution systems that supply Chemical and Metallurgy Research (CMR), Weapons Engineering and Tritium Facility (WETF), Radioactive Liquid Waste Treatment Facility (RLWTF), Waste Characterization, Reduction, Repackaging Facility (WCRRF), and Transuranic Waste Inspectable Storage Project (TWISP). The analysis methodology is based on the American Lifelines Alliance seismic fragility formulations for water systems. System fragilities are convolved with the 1995 LANL seismic hazards to develop failure frequencies. Acceptance is determined by comparing the failure frequencies to the DOE-1020 Performance Goals. This study concludes that: (1) If a significant number of existing isolation valves in the water distribution system are closed to dedicate the entire water system to fighting fires in specific nuclear facilities; (2) Then, the water distribution systems for WETF, RLWTF, WCRRF, and TWISP meet the PC-2 performance goal and the water distribution system for CMR is capable of surviving a 0.06g earthquake. A parametric study of the WETF water distribution system demonstrates that: (1) If a significant number of valves in the water distribution system are NOT closed to dedicate the entire water system to fighting fires in WETF; (2) Then, the water distribution system for WETF has an annual probability of failure on the order of 4 x 10{sup -3} that does not meet the PC-2 performance goal. Similar conclusions are expected for CMR, RLWTF, WCRRF, and TWISP. It is important to note that some of the assumptions made in deriving the results should be verified by personnel in the safety-basis office and may need to be incorporated in technical surveillance requirements in the existing authorization basis documentation if credit for availability of fire protection water is taken at the PC-2 level earthquake levels

  6. ARSENIC DESORPTION FROM DRINKING WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    The U.S. Environmental Protection Agency (USEPA) has recently lowered the maximum contaminant level (MCL) for arsenic from 0.050 mg/L to 0.010 mg/L for all community and non-community water sources. The new MCL for arsenic must be met by January 2006. Recent studies have found th...

  7. LOCATING MONITORING STATIONS IN WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Water undergoes changes in quality between the time it leaves the treatment plant and the time it reaches the customer's tap, making it important to select monitoring stations that will adequately monitor these changers. But because there is no uniform schedule or framework for ...

  8. Distribution of dissolved silver in marine waters

    NASA Astrophysics Data System (ADS)

    Barriada, J. L.; Achterberg, E. P.; Tappin, A.; Truscott, J.

    2003-04-01

    Silver is one of the most toxic heavy metals, surpassed only by mercury [1-3]. Monitoring of dissolved silver concentrations in natural waters is therefore of great importance. The determination of dissolved silver in waters is not without challenges, because of its low (picomolar) concentrations. Consequently, there are only a few reported studies in marine waters, which have been performed in USA [4-6] and Japan [7]. The analytical techniques used in the reported studies for the determination of silver in seawater were Graphite Furnace Atomic Absorption Spectroscopy (GFAAS) after solvent extraction [2,4,5], and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) after solvent extraction or solid phase extraction [7,8]. In this contribution, we will present an optimised Magnetic Sector (MS) ICP-MS technique for the determination of dissolved silver in marine waters. The MS-ICP-MS method used anion exchange column to preconcentrate silver from saline waters, and to remove the saline matrix. The ICP-MS method has been used successfully to determine total dissolved silver in estuarine and oceanic samples. Bibliography 1. H. T. Ratte, Environ. Toxicol. Chem. 1999, 18: p. 89-108. 2. R. T. Herrin, A. W. Andren and D. E. Armstrong, Environ. Sci. Technol. 2001, 35: 1953-1958. 3. D. E. Schildkraut, P. T. Dao, J. P. Twist, A. T. Davis and K. A. Robillard, Environ. Toxicol. Chem. 1998, 17: 642-649. 4. E. Breuer, S. A. Sanudo-Wilhelmy and R. C. Aller, Estuaries. 1999, 22:603-615. 5. A. R. Flegal, S. A. Sanudowilhelmy and G. M. Scelfo, Mar. Chem. 1995, 49: 315-320. 6. S. N. Luoma, Y. B. Ho and G. W. Bryan, Mar. Pollut. Bull. 1995, 31: 44-54. 7. Y. Zhang, H. Amakawa and Y. Nozaki, Mar. Chem. 2001, 75: 151-163. 8. L. Yang and R. E. Sturgeon, J. Anal. At. Spectrom. 2002, 17: 88-93.

  9. Ground Water Technical Support Center (GWTSC) Annual Report FY 2012: October 2011 – September 2012

    EPA Science Inventory

    The Ground Water Technical Support Center (GWTSC) is part of the Ground Water and Ecosystems Restoration Division (GWERD), which is based in the Robert S. Kerr Environmental Research Center in Ada, Oklahoma. The GWERD is a research division of U.S. EPA's National Risk Management...

  10. Data and spatial studies of the USGS Texas Water Science Center

    USGS Publications Warehouse

    Burley, Thomas E.

    2014-01-01

    Hydrologists, geographers, geophysicists, and geologists with the U.S. Geological Survey (USGS) Texas Water Science Center (TXWSC) work in the USGS Water Mission Area on a diverse range of projects built on a foundation of spatial data. The TXWSC has developed sophisticated data and spatial-studies-related capabilities that are an integral part of the projects undertaken by the Center.

  11. Ground Water Technical Support Center (GWTSC) Annual Report Fiscal Year 2014 (FY14)

    EPA Science Inventory

    The Ground Water Technical Support Center (GWTSC) is part of the Ground Water and Ecosystems Restoration Division (GWERD), which is based in the Robert S. Kerr Environmental Research Center in Ada, Oklahoma. The GWERD is a research division of U.S. EPA's National Risk Management...

  12. Adapting to climate change: water distribution in BBA City, Algeria

    NASA Astrophysics Data System (ADS)

    Zeroual, A.; Meddi, M.; Assani, A. A.

    2015-04-01

    For over 20 years, the eastern Algeria region has had significant rainfall deficits that resulted in severe droughts, which seriously affected the availability of water for drinking. Owing to considerations of affordability, drinking water is systematically underpriced because water is essential for life. Such a low price results in water being used inefficiently. This research presents the impact that a high leakage level in the water distribution network has on the water service price in BBA (Bordj Bou Arréridj) city and expected future water resources management scenarios in BBA watersheds by taking into account to the river flow simulated by GR2M using the outputs of climate models with emissions scenarios A1 and A1B. The analysis of the results shows a large economy can be made with regard to water losses, reaching up to 47% saving of the produced water volume; also, BBA city is expected to experience water stress before 2030.

  13. Spatially distributed control netowork for flow proportional chemical injection with center pivot irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The agricultural production practice of injecting a chemical into an operating irrigation system and applying it to the field area with the water is known as chemigation. Chemigation is a widely adopted practice with center pivot irrigation because it is relatively easy and is usually the least exp...

  14. Earth Science Data Archive and Access at the NASA/Goddard Space Flight Center Distributed Active Archive Center (DAAC)

    NASA Technical Reports Server (NTRS)

    Leptoukh, Gregory

    1999-01-01

    The Goddard Distributed Active Archive Center (DAAC), as an integral part of the Earth Observing System Data and Information System (EOSDIS), is the official source of data for several important earth remote sensing missions. These include the Sea-viewing Wide-Field-of-view Sensor (SeaWiFS) launched in August 1997, the Tropical Rainfall Measuring Mission (TRMM) launched in November 1997, and the Moderate Resolution Imaging Spectroradiometer (MODIS) scheduled for launch in mid 1999 as part of the EOS AM-1 instrumentation package. The data generated from these missions supports a host of users in the hydrological, land biosphere and oceanographic research and applications communities. The volume and nature of the data present unique challenges to an Earth science data archive and distribution system such as the DAAC. The DAAC system receives, archives and distributes a large number of standard data products on a daily basis, including data files that have been reprocessed with updated calibration data or improved analytical algorithms. A World Wide Web interface is provided allowing interactive data selection and automatic data subscriptions as distribution options. The DAAC also creates customized and value-added data products, which allow additional user flexibility and reduced data volume. Another significant part of our overall mission is to provide ancillary data support services and archive support for worldwide field campaigns designed to validate the results from the various satellite-derived measurements. In addition to direct data services, accompanying documentation, WWW links to related resources, support for EOSDIS data formats, and informed response to inquiries are routinely provided to users. The current GDAAC WWW search and order system is being restructured to provide users with a simplified, hierarchical access to data. Data Browsers have been developed for several data sets to aid users in ordering data. These Browsers allow users to specify

  15. Spatial Distribution of Small Water Body Types across Indiana Ecoregions

    EPA Science Inventory

    Due to their large numbers and biogeochemical activity, small water bodies (SWB), such as ponds and wetlands, can have substantial cumulative effects on hydrologic, biogeochemical, and biological processes; yet the spatial distributions of various SWB types are often unknown. Usi...

  16. Spatial Distribution of Small Water Body Types in Indiana Ecoregions

    EPA Science Inventory

    Due to their large numbers and biogeochemical activity, small water bodies (SWBs), such as ponds and wetlands, can have substantial cumulative effects on hydrologic and biogeochemical processes. Using updated National Wetland Inventory data, we describe the spatial distribution o...

  17. MICROBIOLOGICAL CHARACTERIZATION OF BACTERIA INHABITING A WATER DISTRIBUTION SYSTEM SIMULATOR

    EPA Science Inventory

    The impact of chlorination and chloramination treatments on heterotrophic bacteria (HB) and ammonia oxidizing bacteria (AOB) inhabiting a water distribution system simulator was investigated. Notable changes in bacterial densities were observed during this monitoring study. For e...

  18. Hot Water Distribution System Model Enhancements

    SciTech Connect

    Hoeschele, M.; Weitzel, E.

    2012-11-01

    This project involves enhancement of the HWSIM distribution system model to more accurately model pipe heat transfer. Recent laboratory testing efforts have indicated that the modeling of radiant heat transfer effects is needed to accurately characterize piping heat loss. An analytical methodology for integrating radiant heat transfer was implemented with HWSIM. Laboratory test data collected in another project was then used to validate the model for a variety of uninsulated and insulated pipe cases (copper, PEX, and CPVC). Results appear favorable, with typical deviations from lab results less than 8%.

  19. The distribution of water frost on Charon

    NASA Technical Reports Server (NTRS)

    Buie, Marc W.; Shriver, Scott K.

    1994-01-01

    We present high-spatial-resolution imaging observations of the Pluto-Charon system taken with ProtoCAM on the Infrared Telescope Facility (IRTF). Our dataset consists of measurements from eight nights at widely separated rotational longitudes and covering five wavelengths -- standard J, H, and K, plus two special narrow band filters at 1.5 and 1.75 microns. The relative flux contributions of Pluto and Charon were extracted, when possible, by fitting a two-source Gaussian image model to the observed images. At K, we find the Charon-Pluto magnitude difference to be on average 1.8 mag, somewhat less than the value of 2.2 mag found by Bosh et al. (1992). The average differential magnitude at 1.5 and 1.75 microns is 2.0 and 1.6, respectively. The larger magnitude difference at 1.5 microns is due to a water-frost absorption band on the surface of Charon. Our observations are consistent with a surface of Charon dominated by water frost at all longitudes.

  20. The CUAHSI Water Data Center: Empowering scientists to discover, use, store, and share water data

    NASA Astrophysics Data System (ADS)

    Couch, A. L.; Hooper, R. P.; Arrigo, J. S.

    2012-12-01

    The proposed CUAHSI Water Data Center (WDC) will provide production-quality water data resources based upon the successful large-scale data services prototype developed by the CUAHSI Hydrologic Information System (HIS) project. The WDC, using the HIS technology, concentrates on providing time series data collected at fixed points or on moving platforms from sensors primarily (but not exclusively) in the medium of water. The WDC's missions include providing simple and effective data discovery tools useful to researchers in a variety of water-related disciplines, and providing simple and cost-effective data publication mechanisms for projects that do not desire to run their own data servers. The WDC's activities will include: 1. Rigorous curation of the water data catalog already assembled during the CUAHSI HIS project, to ensure accuracy of records and existence of declared sources. 2. Data backup and failover services for "at risk" data sources. 3. Creation and support for ubiquitously accessible data discovery and access, web-based search and smartphone applications. 4. Partnerships with researchers to extend the state of the art in water data use. 5. Partnerships with industry to create plug-and-play data publishing from sensors, and to create domain-specific tools. The WDC will serve as a knowledge resource for researchers of water-related issues, and will interface with other data centers to make their data more accessible to water researchers. The WDC will serve as a vehicle for addressing some of the grand challenges of accessing and using water data, including: a. Cross-domain data discovery: different scientific domains refer to the same kind of water data using different terminologies, making discovery of data difficult for researchers outside the data provider's domain. b. Cross-validation of data sources: much water data comes from sources lacking rigorous quality control procedures; such sources can be compared against others with rigorous quality

  1. Distribution of Water in Synthetic Calcium Silicate Hydrates.

    PubMed

    Roosz, C; Gaboreau, S; Grangeon, S; Prêt, D; Montouillout, V; Maubec, N; Ory, S; Blanc, P; Vieillard, P; Henocq, P

    2016-07-12

    Understanding calcium silicate hydrates (CSHs) is of paramount importance for understanding the behavior of cement materials because they control most of the properties of these man-made materials. The atomic scale water content and structure have a major influence on their properties, as is analogous with clay minerals, and we should assess these. Here, we used a multiple analytical approach to quantify water distribution in CSH samples and to determine the relative proportions of water sorbed on external and internal (interlayer) surfaces. Water vapor isotherms were used to explain the water distribution in the CSH microstructure. As with many layered compounds, CSHs have external and internal (interlayer) surfaces displaying multilayer adsorption of water molecules on external surfaces owing to the hydrophilic surfaces. Interlayer water was also quantified from water vapor isotherm, X-ray diffraction (XRD), and thermal gravimetric analyses (TGA) data, displaying nonreversible swelling/shrinkage behavior in response to drying/rewetting cycles. From this quantification and balance of water distribution, we were able to explain most of the widely dispersed data already published according to the various relative humidity (RH) conditions and measurement techniques. Stoichiometric formulas were proposed for the different CSH samples analyzed (0.6 < Ca/Si < 1.6), considering the interlayer water contribution. PMID:27281114

  2. A Virtual Geophysical Network: Using Industry Standard Technology to Link Geographically Distributed Sensors and Data Centers

    NASA Astrophysics Data System (ADS)

    Ahern, T. K.; Benson, R. B.; Crotwell, H. P.

    2003-12-01

    The IRIS Data Management System has long supported distributed data centers as a method of providing scientific researchers access to data from seismological networks around the world. For nearly a decade, the NetDC system used email as the method through which users could access data centers located around the globe in a seamless fashion. More recently the IRIS DMC has partnered with the University of South Carolina to develop a new method through which a virtual data center can be created. The Common Object Request Broker Architecture (CORBA) technology is an industry standard distributed computing architecture. Traditionally used by major corporations, IRIS has developed a Data Handling Interface (DHI) system that is capable of connecting services at participating data centers (servers) to applications running on end-users computing platforms (clients). For seismology we have identified three services. 1) A network service that provides information about geophysical observatories around the world such as where the sensors exist, what types of information are recorded on the sensors, and calibration information that allows proper use of the data, 2) an event service that allows applications to access information about earthquakes and seismological events and 3) waveform services that allow users to gain access to seismograms or time series data from other geophysical sensors. Seismological Data Centers operate the servers thereby allowing a variety of client applications to directly access the information at these data centers. Currently IRIS, the U. of South Carolina, UC Berkeley, and a European Data Center (ORFEUS) have been involved in the DHI project. This talk will highlight some of the DHI enabled clients that allow geophysical information to be directly transferred to the clients. Since the data center servers appear with the same interface specification (Interface Definition Language) a client that can talk to one DHI server can talk to any DHI enabled

  3. Quality-Assurance Plan for Water-Quality Activities of the U.S. Geological Survey Montana Water Science Center

    USGS Publications Warehouse

    Lambing, John H.

    2006-01-01

    In accordance with guidelines set forth by the Office of Water Quality in the Water Resources Discipline of the U.S. Geological Survey (USGS), a quality-assurance plan has been created for use by the USGS Montana Water Science Center in conducting water-quality activities. This quality-assurance plan documents the standards, policies, and procedures used by the USGS Montana Water Science Center for activities related to the collection, processing, storage, analysis, and publication of water-quality data. The policies and procedures presented in this quality-assurance plan for water-quality activities complement the quality-assurance plans for surface-water and ground-water activities and suspended-sediment analysis.

  4. The Accumulation of Radioactive Contaminants in Drinking Water Distribution Systems

    EPA Science Inventory

    The accumulation of trace contaminants in drinking water distribution systems has been documented and the subsequent release of the contaminants back to the water is a potential exposure pathway. Radioactive contaminants are of particular concern because of their known health eff...

  5. Condition Assessment of Drinking Water Transmission and Distribution Systems

    EPA Science Inventory

    Condition assessment of water transmission and distribution mains is the collection of data and information through direct and/or indirect methods, followed by analysis of the data and information, to make a determination of the current and/or future structural, water quality, an...

  6. Condition Assessment Technologies for Water Transmission and Distribution Systems

    EPA Science Inventory

    As part of the U.S. Environmental Protection Agency’s (EPA’s) Aging Water Infrastructure Research Program, this research was conducted to identify and characterize the state of the technology for structural condition assessment of drinking water transmission and distribution syst...

  7. Corrosion manual for internal corrosion of water distribution systems

    SciTech Connect

    Singley, J.E.; Beaudet, B.A.; Markey, P.H.

    1984-04-01

    Corrosion of distribution piping and of home plumbing and fixtures has been estimated to cost the public water supply industry more than $700 million per year. Two toxic metals that occur in tap water, almost entirely because of corrosion, are lead and cadmium. Three other metals, usually present because of corrosion, cause staining of fixtures, or metallic taste, or both. These are copper (blue stains and metallic taste), iron (red-brown stains and metallic taste), and zinc (metallic taste). Since the Safe Drinking Water Act (P.L. 93-523) makes the supplying utility responsible for the water quality at the customer's tap, it is necessary to prevent these metals from getting into the water on the way to the tap. This manual was written to give the operators of potable water treatment plants and distribution systems an understanding of the causes and control of corrosion.

  8. Distribution of Fullerene Nanoparticles between Water and Solid Supported Lipid Membranes: Thermodynamics and Effects of Membrane Composition on Distribution.

    PubMed

    Ha, Yeonjeong; Katz, Lynn E; Liljestrand, Howard M

    2015-12-15

    The distribution coefficient (Klipw) of fullerene between solid supported lipid membranes (SSLMs) and water was examined using different lipid membrane compositions. Klipw of fullerene was significantly higher with a cationic lipid membrane compared to that with a zwitterionic or anionic lipid membrane, potentially due to the strong interactions between negative fullerene dispersions and positive lipid head groups. The higher Klipw for fullerene distribution to ternary lipid mixture membranes was attributed to an increase in the interfacial surface area of the lipid membrane resulting from phase separation. These results imply that lipid composition can be a critical factor that affects bioconcentration of fullerene. Distribution of fullerene into zwitterionic unsaturated lipid membranes was dominated by the entropy contribution (ΔS) and the process was endothermic (ΔH > 0). This result contrasts the partitioning thermodynamics of highly and moderately hydrophobic chemicals indicating that the lipid-water distribution mechanism of fullerene may be different from that of molecular level chemicals. Potential mechanisms for the distribution of fullerene that may explain these differences include adsorption on the lipid membrane surfaces and partitioning into the center of lipid membranes (i.e., absorption).

  9. The International Center for Integrated Water Resources Management (ICIWaRM): The United States' Contribution to UNESCO IHP's Global Network of Water Centers

    NASA Astrophysics Data System (ADS)

    Logan, W. S.

    2015-12-01

    The concept of a "category 2 center"—i.e., one that is closely affiliated with UNESCO, but not legally part of UNESCO—dates back many decades. However, only in the last decade has the concept been fully developed. Within UNESCO, the International Hydrological Programme (IHP) has led the way in creating a network of regional and global water-related centers.ICIWaRM—the International Center for Integrated Water Resources Management—is one member of this network. Approved by UNESCO's General Conference, the center has been operating since 2009. It was designed to fill a niche in the system for a center that was backed by an institution with on-the-ground water management experience, but that also had strong connections to academia, NGOs and other governmental agencies. Thus, ICIWaRM is hosted by the US Army Corps of Engineers' Institute for Water Resources (IWR), but established with an internal network of partner institutions. Three main factors have contributed to any success that ICIWaRM has achieved in its global work: A focus on practical science and technology which can be readily transferred. This includes the Corps' own methodologies and models for planning and water management, and those of our university and government partners. Collaboration with other UNESCO Centers on joint applied research, capacity-building and training. A network of centers needs to function as a network, and ICIWaRM has worked together with UNESCO-affiliated centers in Chile, Brazil, Paraguay, the Dominican Republic, Japan, China, and elsewhere. Partnering with and supporting existing UNESCO-IHP programs. ICIWaRM serves as the Global Technical Secretariat for IHP's Global Network on Water and Development Information in Arid Lands (G-WADI). In addition to directly supporting IHP, work through G-WADI helps the center to frame, prioritize and integrate its activities. With the recent release of the United Nation's 2030 Agenda for Sustainable Development, it is clear that

  10. Performance Monitoring of Residential Hot Water Distribution Systems

    SciTech Connect

    Liao, Anna; Lanzisera, Steven; Lutz, Jim; Fitting, Christian; Kloss, Margarita; Stiles, Christopher

    2014-08-11

    Current water distribution systems are designed such that users need to run the water for some time to achieve the desired temperature, wasting energy and water in the process. We developed a wireless sensor network for large-scale, long time-series monitoring of residential water end use. Our system consists of flow meters connected to wireless motes transmitting data to a central manager mote, which in turn posts data to our server via the internet. This project also demonstrates a reliable and flexible data collection system that could be configured for various other forms of end use metering in buildings. The purpose of this study was to determine water and energy use and waste in hot water distribution systems in California residences. We installed meters at every end use point and the water heater in 20 homes and collected 1s flow and temperature data over an 8 month period. For a typical shower and dishwasher events, approximately half the energy is wasted. This relatively low efficiency highlights the importance of further examining the energy and water waste in hot water distribution systems.

  11. Optimization and capacity expansion of a water distribution system

    NASA Astrophysics Data System (ADS)

    Hsu, Nien-Sheng; Cheng, Wei-Chen; Cheng, Wen-Ming; Wei, Chih-Chiang; Yeh, William W.-G.

    2008-05-01

    This paper develops an iterative procedure for capacity expansion studies for water distribution systems. We propose a methodology to analyze an existing water distribution system and identify the potential bottlenecks in the system. Based on the results, capacity expansion alternatives are proposed and evaluated for improving the efficiency of water supply. The methodology includes a network flow based optimization model, four evaluation indices, and a series of evaluation steps. We first use a directed graph to configure the water distribution system into a network. The network flow based model optimizes the water distribution in the system so that different expansion alternatives can be evaluated on a comparable basis. This model lends itself to linear programming (LP) and can be easily solved by a standard LP code. The results from the evaluation tool help to identify the bottlenecks in the water distribution system and provide capacity expansion alternatives. A useful complementary tool for decision making is composed of a series of evaluation steps with the bottleneck findings, capacity expansion alternatives, and the evaluation of results. We apply the proposed methodology to the Tou-Qian River Basin, located in the northern region of Taiwan, to demonstrate its applicability in optimization and capacity expansion studies.

  12. Implications of heterogeneous distributions of organisms on ballast water sampling.

    PubMed

    Costa, Eliardo G; Lopes, Rubens M; Singer, Julio M

    2015-02-15

    Ballast water sampling is one of the problems still needing investigation in order to enforce the D-2 Regulation of the International Convention for the Control and Management of Ship Ballast Water and Sediments. Although statistical "representativeness" of the sample is an issue usually discussed in the literature, neither a definition nor a clear description of its implications are presented. In this context, we relate it to the heterogeneity of the distribution of organisms in ballast water and show how to specify compliance tests under different models based on the Poisson and negative binomial distributions. We provide algorithms to obtain minimum sample volumes required to satisfy fixed limits on the probabilities of Type I and II errors. We show that when the sample consists of a large number of aliquots, the Poisson model may be employed even under moderate heterogeneity of the distribution of the organisms in the ballast water tank. PMID:25510550

  13. An Efficient Method to Calculate the Aggregated Isotopic Distribution and Exact Center-Masses

    NASA Astrophysics Data System (ADS)

    Claesen, Jürgen; Dittwald, Piotr; Burzykowski, Tomasz; Valkenborg, Dirk

    2012-04-01

    In this article, we present a computation- and memory-efficient method to calculate the probabilities of occurrence and exact center-masses of the aggregated isotopic distribution of a molecule. The method uses fundamental mathematical properties of polynomials given by the Newton-Girard theorem and Viete's formulae. The calculation is based on the atomic composition of the molecule and the natural abundances of the elemental isotopes in normal terrestrial matter. To evaluate the performance of the proposed method, which we named BRAIN, we compare it with the results obtained from five existing software packages ( IsoPro, Mercury, Emass, NeutronCluster, and IsoDalton) for 10 biomolecules. Additionally, we compare the computed mass centers with the results obtained by calculating, and subsequently aggregating, the fine isotopic distribution for two of the exemplary biomolecules. The algorithm will be made available as a Bioconductor package in R, and is also available upon request.

  14. Apoastron shift constraints on dark matter distribution at the Galactic Center

    NASA Astrophysics Data System (ADS)

    Zakharov, A. F.; Nucita, A. A.; de Paolis, F.; Ingrosso, G.

    2007-09-01

    The existence of dark matter (DM) at scales of a few parsecs down to ≃10-5pc around the centers of galaxies and, in particular, in the Galactic Center region has been considered in the literature. Under the assumption that such a DM clump, principally constituted by nonbaryonic matter (like weakly interacting massive particles) does exist at the center of our galaxy, the study of the γ-ray emission from the Galactic Center region allows us to constrain both the mass and the size of this DM sphere. Further constraints on the DM distribution parameters may be derived by observations of bright infrared stars around the Galactic Center. Hall and Gondolo [J. Hall and P. Gondolo, Phys. Rev. D 74, 063511 (2006)PRVDAQ0556-282110.1103/PhysRevD.74.063511] used estimates of the enclosed mass obtained in various ways and tabulated by Ghez et al. [A. M. Ghez , Astron. Nachr. 324, 527 (2003); ASNAAN0004-633710.1002/asna.200385103A. M. Ghez , Astrophys. J.ASJOAB0004-637X 620, 744 (2005)10.1086/427175]. Moreover, if a DM cusp does exist around the Galactic Center it could modify the trajectories of stars moving around it in a sensible way depending on the DM mass distribution. Here, we discuss the constraints that can be obtained with the orbit analysis of stars (as S2 and S16) moving inside the DM concentration with the present and next generations of large telescopes. In particular, consideration of the S2 star apoastron shift may allow improving limits on the DM mass and size.

  15. KDD Services at the Goddard Earth Sciences Distributed Active Archive Center

    NASA Technical Reports Server (NTRS)

    Lynnes, Christopher; Mack, Robert; Wharton, Stephen W. (Technical Monitor)

    2000-01-01

    NASA's Goddard Earth Sciences Distributed Active Archive Center (GES DAAC) processes, stores and distributes earth science data from a variety of remote sensing satellites. End users of the data range from instrument scientists to global change and climate researchers to federal agencies and foreign governments. Many of these users apply data mining techniques to large volumes of data (up to 1 TB) received from the GES DAAC. However, rapid advances in processing power are enabling increases in data processing that are outpacing tape drive performance and network capacity. As a result, the proportion of data that can be distributed to users continues to decrease. As mitigation, we are migrating more data mining and mining preparation activities into the data center in order to reduce the data volume that needs to be distributed and to offer the users a more useful and manageable product. This migration of activities faces a number of technical and human-factor challenges. As data reduction and mining algorithms are normally quite specific to the user's research needs, the user's algorithm must be integrated virtually unchanged into the archive environment. Also, the archive itself is busy with everyday data archive and distribution activities and cannot be dedicated to, or even impacted by, the mining activities. Therefore, we schedule KDD 'campaigns' (similar to reprocessing campaigns), during which we schedule a wholesale retrieval of specific data products, offering users the opportunity to extract information from the data being retrieved during the campaign.

  16. Description of the surface water filtration and ozone treatment system at the Northeast Fishery Center

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A water filtration and ozone disinfection system was installed at the U.S. Fish and Wildlife Service's Northeast Fishery Center in Lamar, Pennsylvania to treat a surface water supply that is used to culture sensitive and endangered fish. The treatment system first passes the surface water through dr...

  17. 41 CFR 102-41.230 - May SASPs pick up or store donated drug paraphernalia in their distribution centers?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false May SASPs pick up or store donated drug paraphernalia in their distribution centers? 102-41.230 Section 102-41.230 Public... SASPs pick up or store donated drug paraphernalia in their distribution centers? No, you must...

  18. 41 CFR 102-41.230 - May SASPs pick up or store donated drug paraphernalia in their distribution centers?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false May SASPs pick up or store donated drug paraphernalia in their distribution centers? 102-41.230 Section 102-41.230 Public... SASPs pick up or store donated drug paraphernalia in their distribution centers? No, you must...

  19. 41 CFR 102-41.230 - May SASPs pick up or store donated drug paraphernalia in their distribution centers?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false May SASPs pick up or store donated drug paraphernalia in their distribution centers? 102-41.230 Section 102-41.230 Public... SASPs pick up or store donated drug paraphernalia in their distribution centers? No, you must...

  20. 41 CFR 102-41.230 - May SASPs pick up or store donated drug paraphernalia in their distribution centers?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false May SASPs pick up or store donated drug paraphernalia in their distribution centers? 102-41.230 Section 102-41.230 Public... SASPs pick up or store donated drug paraphernalia in their distribution centers? No, you must...

  1. 41 CFR 102-41.230 - May SASPs pick up or store donated drug paraphernalia in their distribution centers?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false May SASPs pick up or store donated drug paraphernalia in their distribution centers? 102-41.230 Section 102-41.230 Public... SASPs pick up or store donated drug paraphernalia in their distribution centers? No, you must...

  2. Biological Instability in a Chlorinated Drinking Water Distribution Network

    PubMed Central

    Nescerecka, Alina; Rubulis, Janis; Vital, Marius; Juhna, Talis; Hammes, Frederik

    2014-01-01

    The purpose of a drinking water distribution system is to deliver drinking water to the consumer, preferably with the same quality as when it left the treatment plant. In this context, the maintenance of good microbiological quality is often referred to as biological stability, and the addition of sufficient chlorine residuals is regarded as one way to achieve this. The full-scale drinking water distribution system of Riga (Latvia) was investigated with respect to biological stability in chlorinated drinking water. Flow cytometric (FCM) intact cell concentrations, intracellular adenosine tri-phosphate (ATP), heterotrophic plate counts and residual chlorine measurements were performed to evaluate the drinking water quality and stability at 49 sampling points throughout the distribution network. Cell viability methods were compared and the importance of extracellular ATP measurements was examined as well. FCM intact cell concentrations varied from 5×103 cells mL−1 to 4.66×105 cells mL−1 in the network. While this parameter did not exceed 2.1×104 cells mL−1 in the effluent from any water treatment plant, 50% of all the network samples contained more than 1.06×105 cells mL−1. This indisputably demonstrates biological instability in this particular drinking water distribution system, which was ascribed to a loss of disinfectant residuals and concomitant bacterial growth. The study highlights the potential of using cultivation-independent methods for the assessment of chlorinated water samples. In addition, it underlines the complexity of full-scale drinking water distribution systems, and the resulting challenges to establish the causes of biological instability. PMID:24796923

  3. Biological instability in a chlorinated drinking water distribution network.

    PubMed

    Nescerecka, Alina; Rubulis, Janis; Vital, Marius; Juhna, Talis; Hammes, Frederik

    2014-01-01

    The purpose of a drinking water distribution system is to deliver drinking water to the consumer, preferably with the same quality as when it left the treatment plant. In this context, the maintenance of good microbiological quality is often referred to as biological stability, and the addition of sufficient chlorine residuals is regarded as one way to achieve this. The full-scale drinking water distribution system of Riga (Latvia) was investigated with respect to biological stability in chlorinated drinking water. Flow cytometric (FCM) intact cell concentrations, intracellular adenosine tri-phosphate (ATP), heterotrophic plate counts and residual chlorine measurements were performed to evaluate the drinking water quality and stability at 49 sampling points throughout the distribution network. Cell viability methods were compared and the importance of extracellular ATP measurements was examined as well. FCM intact cell concentrations varied from 5×10(3) cells mL(-1) to 4.66×10(5) cells mL(-1) in the network. While this parameter did not exceed 2.1×10(4) cells mL(-1) in the effluent from any water treatment plant, 50% of all the network samples contained more than 1.06×10(5) cells mL(-1). This indisputably demonstrates biological instability in this particular drinking water distribution system, which was ascribed to a loss of disinfectant residuals and concomitant bacterial growth. The study highlights the potential of using cultivation-independent methods for the assessment of chlorinated water samples. In addition, it underlines the complexity of full-scale drinking water distribution systems, and the resulting challenges to establish the causes of biological instability.

  4. Global Distribution of Outbreaks of Water-Associated Infectious Diseases

    PubMed Central

    Yang, Kun; LeJeune, Jeffrey; Alsdorf, Doug; Lu, Bo; Shum, C. K.; Liang, Song

    2012-01-01

    Background Water plays an important role in the transmission of many infectious diseases, which pose a great burden on global public health. However, the global distribution of these water-associated infectious diseases and underlying factors remain largely unexplored. Methods and Findings Based on the Global Infectious Disease and Epidemiology Network (GIDEON), a global database including water-associated pathogens and diseases was developed. In this study, reported outbreak events associated with corresponding water-associated infectious diseases from 1991 to 2008 were extracted from the database. The location of each reported outbreak event was identified and geocoded into a GIS database. Also collected in the GIS database included geo-referenced socio-environmental information including population density (2000), annual accumulated temperature, surface water area, and average annual precipitation. Poisson models with Bayesian inference were developed to explore the association between these socio-environmental factors and distribution of the reported outbreak events. Based on model predictions a global relative risk map was generated. A total of 1,428 reported outbreak events were retrieved from the database. The analysis suggested that outbreaks of water-associated diseases are significantly correlated with socio-environmental factors. Population density is a significant risk factor for all categories of reported outbreaks of water-associated diseases; water-related diseases (e.g., vector-borne diseases) are associated with accumulated temperature; water-washed diseases (e.g., conjunctivitis) are inversely related to surface water area; both water-borne and water-related diseases are inversely related to average annual rainfall. Based on the model predictions, “hotspots” of risks for all categories of water-associated diseases were explored. Conclusions At the global scale, water-associated infectious diseases are significantly correlated with socio

  5. Identification and characterization of steady and occluded water in drinking water distribution systems.

    PubMed

    Tong, Huiyan; Zhao, Peng; Zhang, Hongwei; Tian, Yimei; Chen, Xi; Zhao, Weigao; Li, Mei

    2015-01-01

    Deterioration and leakage of drinking water in distribution systems have been a major issue in the water industry for years, which are associated with corrosion. This paper discovers that occluded water in the scales of the pipes has an acidic environment and high concentration of iron, manganese, chloride, sulfate and nitrate, which aggravates many pipeline leakage accidents. Six types of water samples have been analyzed under the flowing and stagnant periods. Both the water in the exterior of the tubercles and stagnant water carry suspended iron particles, which explains the occurrence of "red water" when the system hydraulic conditions change. Nitrate is more concentrated in occluded water under flowing condition in comparison with that in flowing water. However, the concentration of nitrate in occluded water under stagnant condition is found to be less than that in stagnant water. A high concentration of manganese is found to exist in steady water, occluded water and stagnant water. These findings impact secondary pollution and the corrosion of pipes and containers used in drinking water distribution systems. The unique method that taking occluded water from tiny holes which were drilled from the pipes' exteriors carefully according to the positions of corrosion scales has an important contribution to research on corrosion in distribution systems. And this paper furthers our understanding and contributes to the growing body of knowledge regarding occluded environments in corrosion scales.

  6. Distribution of water quality parameters in Dhemaji district, Assam (India).

    PubMed

    Buragohain, Mridul; Bhuyan, Bhabajit; Sarma, H P

    2010-07-01

    The primary objective of this study is to present a statistically significant water quality database of Dhemaji district, Assam (India) with special reference to pH, fluoride, nitrate, arsenic, iron, sodium and potassium. 25 water samples collected from different locations of five development blocks in Dhemaji district have been studied separately. The implications presented are based on statistical analyses of the raw data. Normal distribution statistics and reliability analysis (correlation and covariance matrix) have been employed to find out the distribution pattern, localisation of data, and other related information. Statistical observations show that all the parameters under investigation exhibit non uniform distribution with a long asymmetric tail either on the right or left side of the median. The width of the third quartile was consistently found to be more than the second quartile for each parameter. Differences among mean, mode and median, significant skewness and kurtosis value indicate that the distribution of various water quality parameters in the study area is widely off normal. Thus, the intrinsic water quality is not encouraging due to unsymmetrical distribution of various water quality parameters in the study area.

  7. Vertical distributions of lightning sources and flashes over Kennedy Space Center, Florida

    NASA Astrophysics Data System (ADS)

    Hansen, Amanda E.; Fuelberg, Henry E.; Pickering, Kenneth E.

    2010-07-01

    Warm season vertical distributions of lightning sources and flash segments are presented using data from the lightning detection and ranging network at Kennedy Space Center, Fla. We emphasize the percentage of sources/flash segments at each level compared to the vertical total and present the distributions as a function of storm top above ground level (AGL). The vertical profiles of sources and flash segments are compared with each other and with those from previous studies. Results indicate that storms with tops higher than ˜10 km AGL often have a bimodal or multiple peak distribution of percentage sources and flash segments. However, distributions for storms with tops lower than ˜10 km AGL exhibit only a single dominant peak. Temporal variations in the vertical distributions of flash percentages are examined for four clusters of storms occurring on different days. Results reveal considerable storm-to-storm and intrastorm variability. However, two similarities are observed between the four cases: (1) maximum flash density (flash segments km-3) occurs as the maximum storm top is reached and (2) as the storms increase in intensity, both maximum flash density and flash segment percentage increase in altitude, and then both decrease in altitude as the storms decay. The distributions are useful for understanding lightning characteristics as a function of storm evolution, specifying the vertical distribution of lightning-produced nitrogen oxides in chemical transport models and verifying model-simulated lightning.

  8. Visualization of Water Distribution in the Facial Epidermal Layers of Skin Using High-Sensitivity Near-Infrared (NIR) Imaging.

    PubMed

    Egawa, Mariko; Yanai, Motohiro; Maruyama, Nao; Fukaya, Yukitaka; Hirao, Tetsuji

    2015-04-01

    Skin moisturization is an important function of cosmetics in dermatology, and acquisition of two-dimensional information about the water content of facial skin is of great interest. Near-infrared (NIR) imaging using the water OH band centered near 1460 nm has been applied to the evaluation of water in skin. However, detection of small changes in the water content of skin water is difficult using this band because of the low absorption coefficient of water at that wavelength and inadequate optical units. We developed a high-sensitivity water imaging system using strong water bands centered near 1920 nm. This system can be used for the entire face. With the water imaging system, time-dependent changes in the water content of moisturizer-treated skin and hair were visualized with high sensitivity. In this study, we performed a water distribution analysis, with the aim of understanding the water distribution in facial skin under different environmental conditions. The water imaging system combines a diffuse illumination unit and an extended-range indium-gallium arsenide NIR camera with a detection range of 1100-2200 nm. The skin water distributions for multiple subjects with different facial shapes and sizes were compared using averaged NIR image data and a mesh partition analysis using a developed algorithm. Changes in the facial skin water content with season and humidity were visualized by the algorithm. The water content decreased in autumn, especially near the eyes and upper-cheek. Compared to other areas on the face, the water content around the eyes decreased more during an 85 min stay in a room at 10% relative humidity. The proposed method for water distribution analysis provides a powerful tool for facial skin hydration research in dermatological and cosmetics fields.

  9. Quality-assurance and data-management plan for water-quality activities in the Kansas Water Science Center, 2014

    USGS Publications Warehouse

    Rasmussen, Teresa J.; Bennett, Trudy J.; Foster, Guy M.; Graham, Jennifer L.; Putnam, James E.

    2014-01-01

    As the Nation’s largest water, earth, and biological science and civilian mapping information agency, the U.S. Geological Survey is relied on to collect high-quality data, and produce factual and impartial interpretive reports. This quality-assurance and data-management plan provides guidance for water-quality activities conducted by the Kansas Water Science Center. Policies and procedures are documented for activities related to planning, collecting, storing, documenting, tracking, verifying, approving, archiving, and disseminating water-quality data. The policies and procedures described in this plan complement quality-assurance plans for continuous water-quality monitoring, surface-water, and groundwater activities in Kansas.

  10. The Distribution of Water in a Viscous Protoplanetary Disk

    NASA Technical Reports Server (NTRS)

    Ciesla, F. J.; Cuzzi, J. N.

    2005-01-01

    The distribution of water in the solar nebula is important to understand for a number of reasons. Firstly, in the inner regions of the solar nebula, the concentration of water vapor is expected to have played a major role in determining its oxidation state, and therefore would control which minerals would form there. Secondly, in the outer nebula, water would be a major condensable, making up nearly 50% of the mass of the solids and thus possibly playing a role in determining where giant planets formed. Lastly, liquid water is important for forming and sustaining life, and therefore understanding where and how water was transported to the habitable zone of a a star is critical to understanding how common life may be in the galaxy. Because of its importance, the distribution of water in the solar nebula has been studied by a number of authors. The main transport mechanisms which would determine the distribution of water would be diffusion and gas drag migration. Water vapor and small solids would diffuse in the nebula, moving away from areas of high concentrations. Larger bodies, while also subject to diffusion, though to a lesser extent, would experience gas drag migration, causing them to move inwards with time. The bodies most affected by this transport mechanism would be on the order of 1 meter in size. As objects continued to grow larger, their inertia would also grow, making them nearly immobile to gas drag. While efforts have been made to understand how water would be distributed in a protoplanetary disk, none of the published models simultaneously consider the effects of nebular evolution, transport of material throughout the nebula, and the existence of solids of various sizes at a given location of the nebula. We are currently developing a model which allows for these effects and is consistent with models for the accretion of bodies in the solar nebula.

  11. Analysis of residual chlorine in simple drinking water distribution system with intermittent water supply

    NASA Astrophysics Data System (ADS)

    Goyal, Roopali V.; Patel, H. M.

    2015-09-01

    Knowledge of residual chlorine concentration at various locations in drinking water distribution system is essential final check to the quality of water supplied to the consumers. This paper presents a methodology to find out the residual chlorine concentration at various locations in simple branch network by integrating the hydraulic and water quality model using first-order chlorine decay equation with booster chlorination nodes for intermittent water supply. The explicit equations are developed to compute the residual chlorine in network with a long distribution pipe line at critical nodes. These equations are applicable to Indian conditions where intermittent water supply is the most common system of water supply. It is observed that in intermittent water supply, the residual chlorine at farthest node is sensitive to water supply hours and travelling time of chlorine. Thus, the travelling time of chlorine can be considered to justify the requirement of booster chlorination for intermittent water supply.

  12. Fiscal Year 1990 program report: Wyoming Water Research Center

    SciTech Connect

    Gloss, S.P.

    1991-07-01

    Four research projects were directly funded under the FY90 program, as well as information transfer activities. Two research projects were funded through the WWRC state grants program as part of the matching contribution. These six research projects relate to important water issues in the region and the State of Wyoming. Reaction of CO2 under pressure in fly ash and spent oil shale waste materials was shown to lower the pH of the materials and effectively reduced the concentrations of toxic elements (As, B, F, Mn and Se) as well as increasing the native population of microbes. Movement of aldicarb through the unsaturated zone and in the groundwater of an agricultural area of Wyoming indicates that aldicarb itself is not persistent, but that the sulfoxide and sulfone metabolities of aldicarb may be quite persistent. A set of water education curriculum materials for elementary schools in Wyoming have been developed that will require intensive workshops and personnel with water knowledge.

  13. Improving levels of service through enhanced distribution techniques at Newark Beth Israel Medical Center.

    PubMed

    Faup, S A; Felix, M J

    1994-02-01

    In an effort to reduce cost and improve service, Materiels Management Distribution Services, in cooperation with a prime vendor, created a distribution method unique to the needs of Newark Beth Israel Medical Center. The project combined the vendor's expertise and ability to "deliver direct" to an internal hospital location by product group with the distribution staff's ability to complete the process and deliver the merchandise to the final destination in an expedited manner. This article provides a contract template that can be adapted for other collaborative efforts and highlights the components of a successful program: electronic data interchange, verification of usage and par, reconfiguration of space, direct pallet delivery, and some basic indicators of success. PMID:10131692

  14. Elevated Natural Source Water Ammonia and Nitrification in the Distribution Systems of Four Water Utilities

    EPA Science Inventory

    Nitrification in drinking water distribution systems is a concern of many drinking water systems. Although chloramination as a source of nitrification (i.e., addition of excess ammonia or breakdown of chloramines) has drawn the most attention, many source waters contain signific...

  15. Water Quality Modeling in the Dead End Sections of Drinking Water Distribution Networks -journal article

    EPA Science Inventory

    Dead-end sections of drinking water distribution networks are known to be problematic zones in terms of water quality degradation. Extended residence time due to water stagnation leads to rapid reduction of disinfectant residuals allowing the regrowth of microbial pathogens. Wate...

  16. Water Quality Modeling in the Dead End Sections of Drinking Water Distribution Networks

    EPA Science Inventory

    Dead-end sections of drinking water distribution networks are known to be problematic zones in terms of water quality degradation. Extended residence time due to water stagnation leads to rapid reduction of disinfectant residuals allowing the regrowth of microbial pathogens. Wate...

  17. Bacterial Composition in a Metropolitan Drinking Water Distribution System Utilizing Different Source Waters

    EPA Science Inventory

    The microbial community structure was investigated from bulk phase water samples of multiple collection sites from two service areas within the Cincinnati drinking water distribution system (DWDS). Each area is associated with a different primary source of water (i.e., groundwat...

  18. Shallow ground-water quality beneath a major urban center: Denver, Colorado, USA

    NASA Astrophysics Data System (ADS)

    Bruce, Breton W.; McMahon, Peter B.

    1996-11-01

    A survey of the chemical quality of ground water in the unconsolidated alluvial aquifer beneath a major urban center (Denver, Colorado, USA) was performed in 1993 with the objective of characterizing the quality of shallow ground-water in the urban area and relating water quality to land use. Thirty randomly selected alluvial wells were each sampled once for a broad range of dissolved constituents. The urban land use at each well site was sub-classified into one of three land-use settings: residential, commercial, and industrial. Shallow ground-water quality was highly variable in the urban area and the variability could be related to these land-use setting classifications. Sulfate (SO 4) was the predominant anion in most samples from the residential and commercial land-use settings, whereas bicarbonate (HCO 3) was the predominant anion in samples from the industrial land-use setting, indicating a possible shift in redox conditions associated with land use. Only three of 30 samples had nitrate concentrations that exceeded the US national drinking-water standard of 10 mg l -1 as nitrogen, indicating that nitrate contamination of shallow ground water may not be a serious problem in this urban area. However, the highest median nitrate concentration (4.2 mg l -1) was in samples from the residential setting, where fertilizer application is assumed to be most intense. Twenty-seven of 30 samples had detectable pesticides and nine of 82 analyzed pesticide compounds were detected at low concentrations, indicating that pesticides are widely distributed in shallow ground water in this urban area. Although the highest median total pesticide concentration (0.17 μg l -) was in the commercial setting, the herbicides prometon and atrazine were found in each land-use setting. Similarly, 25 of 29 samples analyzed had detectable volatile organic compounds (VOCs) indicating these compounds are also widely distributed in this urban area. The total VOC concentrations in sampled wells

  19. Bacterial communities associated with an occurrence of colored water in an urban drinking water distribution system.

    PubMed

    Wu, Hui Ting; Mi, Zi Long; Zhang, Jing Xu; Chen, Chao; Xie, Shu Guang

    2014-08-01

    This study aimed to investigate bacterial community in an urban drinking water distribution system (DWDS) during an occurrence of colored water. Variation in the bacterial community diversity and structure was observed among the different waters, with the predominance of Proteobacteria. While Verrucomicrobia was also a major phylum group in colored water. Limnobacter was the major genus group in colored water, but Undibacterium predominated in normal tap water. The coexistence of Limnobacter as well as Sediminibacterium and Aquabacterium might contribute to the formation of colored water.

  20. Dynamics of Biofilm Regrowth in Drinking Water Distribution Systems

    PubMed Central

    Husband, S.; Loza, V.; Boxall, J.

    2016-01-01

    ABSTRACT The majority of biomass within water distribution systems is in the form of attached biofilm. This is known to be central to drinking water quality degradation following treatment, yet little understanding of the dynamics of these highly heterogeneous communities exists. This paper presents original information on such dynamics, with findings demonstrating patterns of material accumulation, seasonality, and influential factors. Rigorous flushing operations repeated over a 1-year period on an operational chlorinated system in the United Kingdom are presented here. Intensive monitoring and sampling were undertaken, including time-series turbidity and detailed microbial analysis using 16S rRNA Illumina MiSeq sequencing. The results show that bacterial dynamics were influenced by differences in the supplied water and by the material remaining attached to the pipe wall following flushing. Turbidity, metals, and phosphate were the main factors correlated with the distribution of bacteria in the samples. Coupled with the lack of inhibition of biofilm development due to residual chlorine, this suggests that limiting inorganic nutrients, rather than organic carbon, might be a viable component in treatment strategies to manage biofilms. The research also showed that repeat flushing exerted beneficial selective pressure, giving another reason for flushing being a viable advantageous biofilm management option. This work advances our understanding of microbiological processes in drinking water distribution systems and helps inform strategies to optimize asset performance. IMPORTANCE This research provides novel information regarding the dynamics of biofilm formation in real drinking water distribution systems made of different materials. This new knowledge on microbiological process in water supply systems can be used to optimize the performance of the distribution network and to guarantee safe and good-quality drinking water to consumers. PMID:27208119

  1. Nonpoint source pollution: a distributed water quality modeling approach.

    PubMed

    León, L F; Soulis, E D; Kouwen, N; Farquhar, G J

    2001-03-01

    A distributed water quality model for nonpoint source pollution modeling in agricultural watersheds is described in this paper. A water quality component was developed for WATFLOOD (a flood forecast hydrological model) to deal with sediment and nutrient transport. The model uses a distributed group response unit approach for water quantity and quality modeling. Runoff, sediment yield and soluble nutrient concentrations are calculated separately for each land cover class, weighted by area and then routed downstream. With data extracted using Geographical Information Systems (GIS) technology for a local watershed, the model is calibrated for the hydrologic response and validated for the water quality component. The transferability of model parameters to other watersheds, especially those in remote areas without enough data for calibration, is a major problem in diffuse modeling. With the connection to GIS and the group response unit approach used in this paper, model portability increases substantially, which will improve nonpoint source modeling at the watershed-scale level.

  2. Modeling contaminant propagation in drinking-water distribution systems

    SciTech Connect

    Clark, R.M.; Grayman, W.M.; Males, R.M.; Hess, A.F.

    1993-01-01

    The Safe Drinking Water Act and its Amendments (SDWAA) will pose a massive challenge for the drinking-water industry in the United States. As the SDWAA regulations reach implementation, increasing effort will be devoted to understanding the factors causing deterioration of water quality between treatment and consumption. A cooperative study involving the U.S. EPA, the University of Michigan, and the South Central Connecticut Regional Water Authority (RWA) demonstrated and validated the use of modeling techniques in the RWA distribution system. Models are used to predict the propagation of chlorine residual in one portion of the RWA system. It is found that residuals varied widely both spatially and temporally. Long residence times in storage tanks caused residual disinfection concentrations to be low or nonexistent during discharge cycles. It was found that system operation has a significant effect on the distribution and concentration of chlorine residuals in the system.

  3. Metal contamination of drinking water from corrosion of distribution pipes.

    PubMed

    Alam, I A; Sadiq, M

    1989-01-01

    The objectives of this study were to evaluate metal contamination of drinking water resulting from the corrosion of distribution pipes and its significance to human health. A community in Dhahran, which is served from its own desalination facilities, was chosen for this study. About 150 drinking water samples were collected and analyzed for metal concentrations using an inductively coupled argon plasma analyzer. It was found that copper, iron and zinc in the drinking water increased during its transportation from the desalination plant to the consumers. This increase was related to the length and material of distribution pipes. Concentrations of copper and zinc were increased during overnight storage of water in the appliances. Metal concentrations found in this study are discussed with reference to human health.

  4. Metal contamination of drinking water from corrosion of distribution pipes.

    PubMed

    Alam, I A; Sadiq, M

    1989-01-01

    The objectives of this study were to evaluate metal contamination of drinking water resulting from the corrosion of distribution pipes and its significance to human health. A community in Dhahran, which is served from its own desalination facilities, was chosen for this study. About 150 drinking water samples were collected and analyzed for metal concentrations using an inductively coupled argon plasma analyzer. It was found that copper, iron and zinc in the drinking water increased during its transportation from the desalination plant to the consumers. This increase was related to the length and material of distribution pipes. Concentrations of copper and zinc were increased during overnight storage of water in the appliances. Metal concentrations found in this study are discussed with reference to human health. PMID:15092461

  5. Water masses and 129I distribution in the Nordic Seas

    NASA Astrophysics Data System (ADS)

    Alfimov, Vasily; Aldahan, Ala; Possnert, Göran

    2013-01-01

    The application of the radioactive isotope iodine-129 as a tracer of water circulation in the oceans has provided interesting information with respect to sources and mixing of different water masses. We here present results of 129I distribution in water profiles located in the Nordic Seas and use the isotope to fingerprint water masses in the region. The samples were collected by the US research vessel Knorr in May-June 2002. 129I signatures along the Norwegian Sea reflect a mixing of 129I-rich surface water along the Scandinavian continental slope and 129I-poor North Atlantic surface water. These two water masses become less segregated along the Fram Strait where apparent 129I enrichment penetrates the return Arctic flow into the East Greenland Current. The 129I data further suggest existence of a water mass that is not entirely labeled with respect to origin at the Denmark Strait bottom water. This water parcel probably originates from the Iceland Sea. 129I data also shed light on the major deep water outflow from the Nordic Seas located at the Faeroe Bank Channel.

  6. WASH (Water and Sanitation for Health) Rainwater Information Center.

    ERIC Educational Resources Information Center

    Campbell, D.

    1986-01-01

    Describes project funded by U.S. Agency for International Development to provide short-term technical assistance (general, technology transfer, institutional development and training, information support) to rural and urban fringe water supply and sanitation projects. Initial steps, special collection, and future components of rainwater network…

  7. Imaging of water distribution in thermally fractured granites by SPRITE.

    PubMed

    Yamaguchi, Makoto; Kobori, Kazuo; Suzuki, Kazunori; Ikeda, Yasuhisa; Altobelli, Stephen

    2005-02-01

    Water distribution in thermally fractured granite samples was visualized by using SPRITE sequences. Networks of intergranular fractures were observed in the coarse-grained Inada granite after heating at 873 K or above. On the other hand, bright spots were observed in the fine-grained Okazaki granite, which may be due to pore water in feldspar grains. D2O diffusion into samples saturated with H2O was also observed by 2D-projected SPRITE imaging.

  8. The accumulation of radioactive contaminants in drinking water distribution systems.

    PubMed

    Lytle, Darren A; Sorg, Thomas; Wang, Lili; Chen, Abe

    2014-03-01

    The accumulation of trace contaminants in drinking water distribution system sediment and scales has been documented, raising concerns that the subsequent release of the contaminants back to the water is a potential human exposure pathway. Radioactive contaminants are of concern because of their known health effects and because of their persistence within associated distribution system materials. The objective of this work was to measure the amount of a number of radioactive contaminants (radium, thorium, and uranium isotopes, and gross alpha and beta activity) in distribution solids collected from water systems in four states (Wisconsin, Illinois, Minnesota, and Texas). The water utilities chosen had measurable levels of radium in their source waters. In addition, 19 other elements in the solids were quantified. Water systems provided solids primarily collected during routine fire hydrant flushing. Iron was the dominant element in nearly all of the solids and was followed by calcium, phosphorus, magnesium, manganese, silicon, aluminum and barium in descending order. Gross alpha and beta radiation averaged 255 and 181 pCi/g, and were as high as 1602 and 1169 pCi/g, respectively. Total radium, thorium and uranium averaged 143, 40 and 6.4 pCi/g, respectively. Radium-226 and -228 averaged 74 and 69 pCi/g, and were as high as 250 and 351 pCi/g, respectively. PMID:24275108

  9. The accumulation of radioactive contaminants in drinking water distribution systems.

    PubMed

    Lytle, Darren A; Sorg, Thomas; Wang, Lili; Chen, Abe

    2014-03-01

    The accumulation of trace contaminants in drinking water distribution system sediment and scales has been documented, raising concerns that the subsequent release of the contaminants back to the water is a potential human exposure pathway. Radioactive contaminants are of concern because of their known health effects and because of their persistence within associated distribution system materials. The objective of this work was to measure the amount of a number of radioactive contaminants (radium, thorium, and uranium isotopes, and gross alpha and beta activity) in distribution solids collected from water systems in four states (Wisconsin, Illinois, Minnesota, and Texas). The water utilities chosen had measurable levels of radium in their source waters. In addition, 19 other elements in the solids were quantified. Water systems provided solids primarily collected during routine fire hydrant flushing. Iron was the dominant element in nearly all of the solids and was followed by calcium, phosphorus, magnesium, manganese, silicon, aluminum and barium in descending order. Gross alpha and beta radiation averaged 255 and 181 pCi/g, and were as high as 1602 and 1169 pCi/g, respectively. Total radium, thorium and uranium averaged 143, 40 and 6.4 pCi/g, respectively. Radium-226 and -228 averaged 74 and 69 pCi/g, and were as high as 250 and 351 pCi/g, respectively.

  10. Catchment travel time distributions and water flow in soils

    NASA Astrophysics Data System (ADS)

    Rinaldo, A.; Beven, K. J.; Bertuzzo, E.; Nicotina, L.; Davies, J.; Fiori, A.; Russo, D.; Botter, G.

    2011-07-01

    Many details about the flow of water in soils in a hillslope are unknowable given current technologies. One way of learning about the bulk effects of water velocity distributions on hillslopes is through the use of tracers. However, this paper will demonstrate that the interpretation of tracer information needs to become more sophisticated. The paper reviews, and complements with mathematical arguments and specific examples, theory and practice of the distribution(s) of the times water particles injected through rainfall spend traveling through a catchment up to a control section (i.e., "catchment" travel times). The relevance of the work is perceived to lie in the importance of the characterization of travel time distributions as fundamental descriptors of catchment water storage, flow pathway heterogeneity, sources of water in a catchment, and the chemistry of water flows through the control section. The paper aims to correct some common misconceptions used in analyses of travel time distributions. In particular, it stresses the conceptual and practical differences between the travel time distribution conditional on a given injection time (needed for rainfall-runoff transformations) and that conditional on a given sampling time at the outlet (as provided by isotopic dating techniques or tracer measurements), jointly with the differences of both with the residence time distributions of water particles in storage within the catchment at any time. These differences are defined precisely here, either through the results of different models or theoretically by using an extension of a classic theorem of dynamic controls. Specifically, we address different model results to highlight the features of travel times seen from different assumptions, in this case, exact solutions to a lumped model and numerical solutions of the 3-D flow and transport equations in variably saturated, physically heterogeneous catchment domains. Our results stress the individual characters of the

  11. Effect of the distribution system on drinking-water quality

    SciTech Connect

    Clark, R.M.; Goodrich, J.A.; Wymer, L.J.

    1993-01-01

    The Safe Drinking Water Act and its Amendments has focused interest on the factors that cause the deterioration of water between the treatment plant and the consumer. The distribution system itself can contribute to this deterioration. Numerous examples of waterborne disease outbreaks have demonstrated the importance of the distribution system in preventing disease. Water-quality propagation models can be used to study the factors that contribute to water quality deterioration. These models have been used in many locations to study contaminant propagation. The paper describes the application of contaminant propagation models in the South Central Connecticut Regional Water Authority (USA). The fluoride feed was cut off at the water treatment plant to calibrate the model and determine residence times in the system. An extensive simulation of the system was conducted to predict conservative contaminant propagation and chlorine decay. After completing the simulation study a sampling program was conducted to verify the results from the model. In general the field results verified the model predictions. Water quality varied widely over the service area. Long retention times in storage tanks and pipe wall demand, especially in dead end sections, caused significant losses in chlorine residuals.

  12. Impact of Arsenic Treatment Techniques on Distribution Water Quality

    EPA Science Inventory

    This presentation will summarize the results of the distribution water quality studies (arsenic, lead, and copper) of the demonstration program. The impact of the treatment systems by type of system (adsorptive media, coagulation/filtration, ion exchange, etc) will be shown by co...

  13. THE EPANET PROGRAMMER'S TOOLKIT FOR ANALYSIS OF WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    The EPANET Programmer's Toolkit is a collection of functions that helps simplify computer programming of water distribution network analyses. the functions can be used to read in a pipe network description file, modify selected component properties, run multiple hydraulic and wa...

  14. MODELING CHLORINE RESIDUALS IN DRINKING-WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    A mass-transfer-based model is developed for predicting chlorine decay in drinking-water distribution networks. The model considers first-order reactions of chlorine to occur both in the bulk flow and at the pipe wall. The overall rate of the wall reaction is a function of the ...

  15. Online Toxicity Monitors (OTM) for Distribution System Water Quality Monitoring

    EPA Science Inventory

    Drinking water distribution systems in the U.S. are vulnerable to episodic contamination events (both unintentional and intentional). The U.S. Environmental Protection Agency (EPA) is conducting research to investigate the use of broad-spectrum online toxicity monitors (OTMs) in ...

  16. EFFECT OF THE DISTRIBUTION SYSTEM ON DRINKING WATER QUALITY

    EPA Science Inventory

    The SDWA and its amendments has focused interest on the factors that cause the deterioration of water between the treatment plant and the consumer. The distribution system itself can contribute to this deterioration. Numerous examples of waterborne outbreaks have demonstrated the...

  17. Metagenomic Analysis of Water Distribution System Bacterial Communities

    EPA Science Inventory

    The microbial quality of drinking water is assessed using culture-based methods that are highly selective and that tend to underestimate the densities and diversity of microbial populations inhabiting distribution systems. In order to better understand the effect of different dis...

  18. Monitoring Design for Source Identification in Water Distribution Systems

    EPA Science Inventory

    The design of sensor networks for the purpose of monitoring for contaminants in water distribution systems is currently an active area of research. Much of the effort has been directed at the contamination detection problem and the expression of public health protection objective...

  19. URBAN DRINKING WATER DISTRIBUTION SYSTEMS: A U.S. PERSPECTIVE

    EPA Science Inventory

    This paper will examine several case studies that illustrate the critical role drinking water treatment and distribution systems play in protecting public health. It will also present a case study that documents the dramatic impact that the regulations promulgated under the Safe...

  20. Universal Distribution of Centers and Saddles in Two-Dimensional Turbulence

    NASA Astrophysics Data System (ADS)

    Wu, X. L.; Rivera, Michael; Yeung, Chuck

    2000-11-01

    Statistical distribution of topological structures of two-dimensional turbulence are investigated using freely suspended soap films. These local structures comprise of centers of rotation and saddle points in the flow and can be characterized by a Jacobian determinant Λ(x,y). Our central finding is that when Λ is properly normalized by its rms value, P(Λ) is a universal function, independent of turbulent intensity and the means that turbulence is created. Such a universality appears to result from the stream function being a Gaussian field with a finite spatial correlation.

  1. Voltage profile program for the Kennedy Space Center electric power distribution system

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The Kennedy Space Center voltage profile program computes voltages at all busses greater than 1 Kv in the network under various conditions of load. The computation is based upon power flow principles and utilizes a Newton-Raphson iterative load flow algorithm. Power flow conditions throughout the network are also provided. The computer program is designed for both steady state and transient operation. In the steady state mode, automatic tap changing of primary distribution transformers is incorporated. Under transient conditions, such as motor starts etc., it is assumed that tap changing is not accomplished so that transformer secondary voltage is allowed to sag.

  2. Non-Gaussian center-of-pressure velocity distribution during quiet stance

    NASA Astrophysics Data System (ADS)

    Santos, E. S. D.; Picoli, S.; Deprá, P. P.; Mendes, R. S.

    2015-02-01

    In the present study, we investigate patterns in the postural sway that characterize the static balance in human beings. To measure the postural sway, sixteen healthy young subjects performed quiet stance tasks providing the center-of-pressure (COP) trajectories. From these trajectories, we obtained the COP velocities. We verified that the velocity distributions exhibit non-normal behavior and can be approximated by generalized Gaussians with fat tails. We also discuss possible implications of modeling COP velocity by using generalized Fokker-Planck equations related to Tsallis statistics and Richardson anomalous diffusion.

  3. Better understanding of water quality evolution in water distribution networks using data clustering.

    PubMed

    Mandel, Pierre; Maurel, Marie; Chenu, Damien

    2015-12-15

    The complexity of water distribution networks raises challenges in managing, monitoring and understanding their behavior. This article proposes a novel methodology applying data clustering to the results of hydraulic simulation to define quality zones, i.e. zones with the same dynamic water origin. The methodology is presented on an existing Water Distribution Network; a large dataset of conductivity measurements measured by 32 probes validates the definition of the quality zones. The results show how quality zones help better understanding the network operation and how they can be used to analyze water quality events. Moreover, a statistical comparison with 158,230 conductivity measurements validates the definition of the quality zones.

  4. Distribution and Support of Aquarius/SAC-D Data through the Physical Oceanography Distributed Active Archive Center

    NASA Astrophysics Data System (ADS)

    Tsontos, V. M.; Vazquez, J.

    2012-12-01

    The Physical Oceanography Distributed Active Center (PO.DAAC) serves as the designated NASA repository and distribution node for all Aquarius/SAC-D data products in close collaboration with the project. Here we report on the status of Aquarius data holdings at PO.DAAC, observed patterns of usage of these datasets, and the range of data services and access tools that we provide in support of this mission. These currently include dataset discovery and access via the PO.DAAC web-portal, an interactive L3-browser tool for online visualization, and user services that span help-desk support, Aquarius user guide documentation, and reader software development. In anticipation of the release of the Aquarius science quality dataset by the end of 2012 and as the project transitions out of the current calibration/evaluation phase, additional PO.DAAC tools and services that will be leveraged for Aquarius are described. These range from OPeNDAP and THREDDS data access services, web-based visualization via PO.DAAC's SOTO tool and LAS, to our advanced L2 subsetting tool called HITIDE.

  5. From the orbit theory to a guiding center parametric equilibrium distribution function

    NASA Astrophysics Data System (ADS)

    Di Troia, C.

    2012-10-01

    This work proposes a parametric equilibrium distribution function F_eq to be applied to the gyrokinetic studies of the finite orbit width behavior of guiding centers representing several species encountered in axisymmetric tokamak plasmas, such as fusion products, thermal bulk and energetic particles from ion cyclotron radiation heating and negative neutral beam injections. F_eq can be used to fit experimental profiles and it could provide a useful tool for experimental and numerical data analysis. Moreover, it could help one to develop analytical computations for facilitating data interpretation in the light of theoretical models. This distribution function can be easily implemented in gyrokinetic codes, where it could be used to simulate plasma also in the presence of external heating sources.

  6. Quality-Assurance Plan for Water-Quality Activities in the U.S. Geological Survey Washington Water Science Center

    USGS Publications Warehouse

    Wagner, Richard J.; Kimbrough, Robert A.; Turney, Gary L.

    2007-01-01

    In accordance with guidelines set forth by the Office of Water Quality in the Water Resources Discipline of the U.S. Geological Survey (USGS), this quality-assurance plan has been created for use by the USGS Washington Water Science Center (WAWSC) in conducting water-quality activities. The plan documents the standards, policies, and procedures used by the personnel of the WAWSC for activities related to the collection, processing, storage, analysis, and publication of water-quality data. The policies and procedures that are documented in this quality-assurance plan for water-quality activities are meant to complement the WAWSC's quality-assurance plans for surface-water and ground-water activities and to supplement the WAWSC quality-assurance plan.

  7. Analysis of the access patterns at GSFC distributed active archive center

    NASA Technical Reports Server (NTRS)

    Johnson, Theodore; Bedet, Jean-Jacques

    1996-01-01

    The Goddard Space Flight Center (GSFC) Distributed Active Archive Center (DAAC) has been operational for more than two years. Its mission is to support existing and pre Earth Observing System (EOS) Earth science datasets, facilitate the scientific research, and test Earth Observing System Data and Information System (EOSDIS) concepts. Over 550,000 files and documents have been archived, and more than six Terabytes have been distributed to the scientific community. Information about user request and file access patterns, and their impact on system loading, is needed to optimize current operations and to plan for future archives. To facilitate the management of daily activities, the GSFC DAAC has developed a data base system to track correspondence, requests, ingestion and distribution. In addition, several log files which record transactions on Unitree are maintained and periodically examined. This study identifies some of the users' requests and file access patterns at the GSFC DAAC during 1995. The analysis is limited to the subset of orders for which the data files are under the control of the Hierarchical Storage Management (HSM) Unitree. The results show that most of the data volume ordered was for two data products. The volume was also mostly made up of level 3 and 4 data and most of the volume was distributed on 8 mm and 4 mm tapes. In addition, most of the volume ordered was for deliveries in North America although there was a significant world-wide use. There was a wide range of request sizes in terms of volume and number of files ordered. On an average 78.6 files were ordered per request. Using the data managed by Unitree, several caching algorithms have been evaluated for both hit rate and the overhead ('cost') associated with the movement of data from near-line devices to disks. The algorithm called LRU/2 bin was found to be the best for this workload, but the STbin algorithm also worked well.

  8. Predicting the Distribution of Yellowfin Tuna in Philippine Waters

    NASA Astrophysics Data System (ADS)

    Perez, G. J. P.; Leonardo, E. M.

    2015-12-01

    The Philippines is considered as a major tuna producer in the Western and Central Pacific Ocean, both for domestic consumption and on industrial scale. However, with the ever-increasing demand of growing population, it has always been a challenge to achieve sustainable fishing. The creation of satellite-derived potential fishing zone maps is a technology that has been adopted by advanced countries for almost three decades already and has led to reduction in search times by up to 40%. In this study, a Generalized Additive Model (GAM) is developed to predict the distribution of the Yellowfin tuna species in seas surrounding the Philippines based on the Catch-Per-Unit-Effort (CPUE) index. Level 3 gridded chlorophyll-a and sea surface temperature from the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Aqua satellite of the National Aeronautics and Space Administration (NASA) are the main input parameters of the model. Chlorophyll-a is linked with the presence of phytoplankton, which indicates primary productivity and suggests potential regions of fish aggregation. Fish also prefers to stay in regions where the temperature is stable, thus the sea surface temperature fronts serve as a guide to locate concentrations of fish school. Historical monthly tuna catch data from Western and Central Pacific Commissions (WCPFC) is used to train the model. The resulting predictions are converted to potential fishing zone maps and are evaluated within and beyond the historical time range of the training data used. Diagnostic tests involving adjusted R2 value, GAM residual plots and root mean square error value are used to assess the accuracy of the model. The generated maps were able to confirm locations of known tuna fishing grounds in Mindanao and other parts of the country, as well us detect their seasonality and interannual variability. To improve the performance of the model, ancillary data such as surface winds reanalysis from National Centers for

  9. Distribution system water age can create premise plumbing corrosion hotspots.

    PubMed

    Masters, Sheldon; Parks, Jeffrey; Atassi, Amrou; Edwards, Marc A

    2015-09-01

    Cumulative changes in chemical and biological properties associated with higher "water age" in distribution systems may impact water corrosivity and regulatory compliance with lead and copper action levels. The purpose of this study was to examine the effects of water age and chemistry on corrosivity of various downstream premise plumbing pipe materials and configurations using a combination of controlled laboratory studies and a field survey. Examination of lead pipe, copper pipe with lead solder, and leaded brass materials in a replicated lab rig simulating premise plumbing stagnation events indicated that lead or copper release could increase as much as ∼440 % or decrease as much as 98 % relative to water treatment plant effluent. In field studies at five utilities, trends in lead and copper release were highly dependent on circumstance; for example, lead release increased with water age in 13 % of cases and decreased with water age in 33 % of conditions tested. Levels of copper in the distribution system were up to 50 % lower and as much as 30 % higher relative to levels at the treatment plant. In many cases, high-risks of elevated lead and copper did not co-occur, demonstrating that these contaminants will have to be sampled separately to identify "worst case" conditions for human exposure and monitoring. PMID:26251058

  10. Distribution system water age can create premise plumbing corrosion hotspots.

    PubMed

    Masters, Sheldon; Parks, Jeffrey; Atassi, Amrou; Edwards, Marc A

    2015-09-01

    Cumulative changes in chemical and biological properties associated with higher "water age" in distribution systems may impact water corrosivity and regulatory compliance with lead and copper action levels. The purpose of this study was to examine the effects of water age and chemistry on corrosivity of various downstream premise plumbing pipe materials and configurations using a combination of controlled laboratory studies and a field survey. Examination of lead pipe, copper pipe with lead solder, and leaded brass materials in a replicated lab rig simulating premise plumbing stagnation events indicated that lead or copper release could increase as much as ∼440 % or decrease as much as 98 % relative to water treatment plant effluent. In field studies at five utilities, trends in lead and copper release were highly dependent on circumstance; for example, lead release increased with water age in 13 % of cases and decreased with water age in 33 % of conditions tested. Levels of copper in the distribution system were up to 50 % lower and as much as 30 % higher relative to levels at the treatment plant. In many cases, high-risks of elevated lead and copper did not co-occur, demonstrating that these contaminants will have to be sampled separately to identify "worst case" conditions for human exposure and monitoring.

  11. Water Distribution in the Continental and Oceanic Upper Mantle

    NASA Technical Reports Server (NTRS)

    Peslier, Anne H.

    2015-01-01

    Nominally anhydrous minerals such as olivine, pyroxene and garnet can accommodate tens to hundreds of ppm H2O in the form of hydrogen bonded to structural oxygen in lattice defects. Although in seemingly small amounts, this water can significantly alter chemical and physical properties of the minerals and rocks. Water in particular can modify their rheological properties and its distribution in the mantle derives from melting and metasomatic processes and lithology repartition (pyroxenite vs peridotite). These effects will be examined here using Fourier transform infrared spectrometry (FTIR) water analyses on minerals from mantle xenoliths from cratons, plume-influenced cratons and oceanic settings. In particular, our results on xenoliths from three different cratons will be compared. Each craton has a different water distribution and only the mantle root of Kaapvaal has evidence for dry olivine at its base. This challenges the link between olivine water content and survival of Archean cratonic mantle, and questions whether xenoliths are representative of the whole cratonic mantle. We will also present our latest data on Hawaii and Tanzanian craton xenoliths which both suggest the intriguing result that mantle lithosphere is not enriched in water when it interacts with melts from deep mantle upwellings (plumes).

  12. Performance characteristics of single effect lithium bromide/ water absorption chiller for small data centers

    NASA Astrophysics Data System (ADS)

    Mysore, Abhishek Arun Babu

    A medium data center consists of servers performing operations such as file sharing, collaboration and email. There are a large number of small and medium data centers across the world which consume more energy and are less efficient when compared to large data center facilities of companies such as GOOGLE, APPLE and FACEBOOK. Such companies are making their data center facilities more environmental friendly by employing renewable energy solutions such as wind and solar to power the data center or in data center cooling. This not only reduces the carbon footprint significantly but also decreases the costs incurred over a period of time. Cooling of data center play a vital role in proper functioning of the servers. It is found that cooling consumes about 50% of the total power consumed by the data center. Traditional method of cooling includes the use of mechanical compression chillers which consume lot of power and is not desirable. In order to eliminate the use of mechanical compressor chillers renewable energy resources such as solar and wind should be employed. One such technology is solar thermal cooling by means of absorption chiller which is powered by solar energy. The absorption chiller unit can be coupled with either flat plate or evacuated tube collectors in order to achieve the required inlet temperature for the generator of the absorption chiller unit. In this study a modular data center is considered having a cooling load requirement of 23kw. The performance characteristics of a single stage Lithium Bromide/ water refrigeration is presented in this study considering the cooling load of 23kw. Performance characteristics of each of the 4 heat exchangers within the unit is discussed which helps in customizing the unit according to the users' specific needs. This analysis helps in studying the importance of different properties such as the effect of inlet temperatures of hot water for generator, inlet temperatures of cooling water for absorber and

  13. Data Processing, Archiving and Distribution at the WISE Science Data Center

    NASA Astrophysics Data System (ADS)

    Cutri, Roc M.; Conrow, T.; Alles, R.; Brandenberg, H.; Evans, T.; Fowler, J.; Gelino, C.; Jarrett, T.; Kirkpatrick, J. D.; Marsh, K.; Masci, F.; McCallon, H.; Padgett, D.; Wheelock, S.; Yan, L.; Tholen, D.

    2009-01-01

    The Wide-Field Infrared Survey Explorer (WISE), scheduled for launch in November 2009, will conduct an imaging survey of the entire sky in the 3.3, 4.7, 12 and 23 micron bands. Each day during its six-month mission WISE will scan 4800 sq.deg. of the sky, and will downlink approximately 50GB of raw science imaging data and engineering telemetry. The Infrared Processing and Analysis Center is the WISE Science Data Center (WSDC) and is responsible for processing, archiving and distribution of WISE science data. We describe the five elements of the WISE Science Data (WSDS) that will carry out these functions: INGEST which receives and merges science and ancillary data from WISE Mission Operations Center and stages for processing; PIPELINES which performs image calibration, source extraction and calibration on both single-exposure and coadded WISE images; QA which performs automated science data quality assessment and scoring; ARCHIVE which provides storage of and access to raw and processed WISE data products and metadata; FPG which extracts the final WISE Image Atlas and Source Catalog from the "working databases" generated by the data processing system and prepares them for public release; and EXEC which manages job execution and compute and storage resources for the other WSDS elements.

  14. Sentinel-1 Data System at the Alaska Satellite Facility Distributed Active Archive Center

    NASA Astrophysics Data System (ADS)

    Wolf, V. G.

    2014-12-01

    The Alaska Satellite Facility Distributed Active Archive Center (ASF DAAC) has a long history of supporting international collaborations between NASA and foreign flight agencies to promote access to Synthetic Aperture Radar (SAR) data for US science research. Based on the agreement between the US and the EC, data from the Sentinel missions will be distributed by NASA through archives that mirror those established by ESA. The ASF DAAC is the designated archive and distributor for Sentinel-1 data. The data will be copied from the ESA archive to a rolling archive at the NASA Goddard center, and then pushed to a landing area at the ASF DAAC. The system at ASF DAAC will take the files as they arrive and put them through an ingest process. Ingest will populate the database with the information required to enable search and download of the data through Vertex, the ASF DAAC user interface. Metadata will be pushed to the NASA Common Metadata Repository, enabling data discovery through clients that utilize the repository. Visual metadata will be pushed to the NASA GIBS system for visualization through clients linked to that system. Data files will be archived in the DataDirect Networks (DDN) device that is the primary storage device for the ASF DAAC. A backup copy of the data will be placed in a second DDN device that serves as the disaster recovery solution for the ASF DAAC.

  15. Modeling contaminant concentration distributions in China's centralized source waters.

    PubMed

    Wu, Rui; Qian, Song S; Hao, Fanghua; Cheng, Hongguang; Zhu, Dangsheng; Zhang, Jianyong

    2011-07-15

    Characterizing contaminant occurrences in China's centralized source waters can provide an understanding of source water quality for stakeholders. The single-factor (i.e., worst contaminant) water-quality assessment method, commonly used in Chinese official analysis and publications, provides a qualitative summary of the country's water-quality status but does not specify the extent and degree of specific contaminant occurrences at the national level. Such information is needed for developing scientifically sound management strategies. This article presents a Bayesian hierarchical modeling approach for estimating contaminant concentration distributions in China's centralized source waters using arsenic and fluoride as examples. The data used are from the most recent national census of centralized source waters in 2006. The article uses three commonly used source water stratification methods to establish alternative hierarchical structures reflecting alternative model assumptions as well as competing management needs in characterizing pollutant occurrences. The results indicate that the probability of arsenic exceeding the standard of 0.05 mg/L is about 0.96-1.68% and the probability of fluoride exceeding 1 mg/L is about 9.56-9.96% nationally, both with strong spatial patterns. The article also discusses the use of the Bayesian approach for establishing a source water-quality information management system as well as other applications of our methods. PMID:21692445

  16. Modeling of heterotrophic bacteria counts in a water distribution system.

    PubMed

    Francisque, Alex; Rodriguez, Manuel J; Miranda-Moreno, Luis F; Sadiq, Rehan; Proulx, François

    2009-03-01

    Heterotrophic plate count (HPC) constitutes a common indicator for monitoring of microbiological water quality in distribution systems (DS). This paper aims to identify factors explaining the spatiotemporal distribution of heterotrophic bacteria and model their occurrence in the distribution system. The case under study is the DS of Quebec City, Canada. The study is based on a robust database resulting from a sampling campaign carried out in about 50 DS locations, monitored bi-weekly over a three-year period. Models for explaining and predicting HPC levels were based on both one-level and multi-level Poisson regression techniques. The latter take into account the nested structure of data, the possible spatiotemporal correlation among HPC observations and the fact that sampling points, months and/or distribution sub-systems may represent clusters. Models show that the best predictors for spatiotemporal occurrence of HPC in the DS are: free residual chlorine that has an inverse relation with the HPC levels, water temperature and water ultraviolet absorbance, both having a positive impact on HPC levels. A sensitivity analysis based on the best performing model (two-level model) allowed for the identification of seasonal-based strategies to reduce HPC levels.

  17. Pesticides in ground water: distribution, trends, and governing factors

    USGS Publications Warehouse

    Barbash, Jack; Resek, Elizabeth A.

    1997-01-01

    A comprehensive review of published information on the distribution and behavior of pesticides and their transformation products in ground water indicates that pesticides from every chemical class have been detected in ground waters of the United States. Many of these compounds are commonly present at low concentrations in ground water beneath agricultural land. Little information is available on their occurrence beneath non-agricultural land, although the intensity of their use in such areas (on lawns, golf courses, rights of way, timberlands, etc.) is often comparable to, or greater than agricultural use. Information on pesticides in ground water is not sufficient to provide either a statistically representative view of pesticide occurrence in ground water across the United States, or an indication of long-term trends or changes in the severity or extent of this contamination over the past three decades. This is largely due to wide variations in analytical detection limits, well selection procedures, and other design features among studies conducted in different areas or at different times. Past approaches have not been well suited for distinguishing "point source" from "nonpoint source" pesticide contamination. Among the variety of natural and anthropogenic factors examined, those that appear to be most strongly associated with the intensity of pesticide contamination of ground water are the depth, construction and age of the sampled wells, the amount of recharge (by precipitation or irrigation), and the depth of tillage. Approaches commonly employed for predicting pesticide distributions in the subsurface--including computer simulations, indicator solutes (e.g., nitrate or tritium), and ground-water vulnerability assessments--generally provide unreliable predictions of pesticide occurrence in ground water. Such difficulties may arise largely from a general failure to account for the preferential transport of pesticides in the subsurface. Significant

  18. Distribution of fluoride in ground water of West Virginia

    USGS Publications Warehouse

    Mathes, M.V.; Waldron, M.C.

    1993-01-01

    This report describes the results of a study by the U.S. Geological Survey, in cooperation with the West Virginia Geological and Economic Survey, to evaluate the distribution of fluoride in ground water of West Virginia. Fluoride is a natural chemical constituent in domestic and public water supplies in West Virginia. Fluoride concentrations of about 1.0 milligram per liter in drinking water are beneficial to dental health. Concentrations greater than 2.0 milligrams per liter, however, could harm teeth and bones. Fluoride concentra- tions in ground water of West Virginia range from less than 0.1 to 12 milligrams per liter. Fluoride concentrations that exceed 2.0 milligrams per liter are found in wells drilled to all depths, wells drilled in all topographic settings, and wells drilled into most geologic units. Most fluoride concentrations that exceed 2.0 milligrams per liter are located at sites clustered in the northwestern part of the State.

  19. Simulation of Ground-Water Flow in the Irwin Basin Aquifer System, Fort Irwin National Training Center, California

    USGS Publications Warehouse

    Densmore, Jill N.

    2003-01-01

    Ground-water pumping in the Irwin Basin at Fort Irwin National Training Center, California resulted in water-level declines of about 30 feet from 1941 to 1996. Since 1992, artificial recharge from wastewater-effluent infiltration and irrigation-return flow has stabilized water levels, but there is concern that future water demands associated with expansion of the base may cause a resumption of water-level declines. To address these concerns, a ground-water flow model of the Irwin Basin was developed to help better understand the aquifer system, assess the long-term availability and quality of ground water, and evaluate ground-water conditions owing to current pumping and to plan for future water needs at the base. Historical data show that ground-water-level declines in the Irwin Basin between 1941 and 1996, caused the formation of a pumping depression near the pumped wells, and that recharge from the wastewater-treatment facility and disposal area caused the formation of a recharge mound. There have been two periods of water-level recovery in the Irwin Basin since the development of ground water in this basin; these periods coincide with a period of decreased pumpage from the basin and a period of increased recharge of water imported from the Bicycle Basin beginning in 1967 and from the Langford Basin beginning in 1992. Since 1992, artificial recharge has exceeded pumpage in the Irwin Basin and has stabilized water-level declines. A two-layer ground-water flow model was developed to help better understand the aquifer system, assess the long-term availability and quality of ground water, and evaluate ground-water conditions owing to current pumping and to plan for future water needs at the base. Boundary conditions, hydraulic conductivity, altitude of the bottom of the layers, vertical conductance, storage coefficient, recharge, and discharge were determined using existing geohydrologic data. Rates and distribution of recharge and discharge were determined from

  20. Occurrence of Mycobacteria in Water Treatment Lines and in Water Distribution Systems

    PubMed Central

    Le Dantec, Corinne; Duguet, Jean-Pierre; Montiel, Antoine; Dumoutier, Nadine; Dubrou, Sylvie; Vincent, Véronique

    2002-01-01

    The frequency of recovery of atypical mycobacteria was estimated in two treatment plants providing drinking water to Paris, France, at some intermediate stages of treatment. The two plants use two different filtration processes, rapid and slow sand filtration. Our results suggest that slow sand filtration is more efficient for removing mycobacteria than rapid sand filtration. In addition, our results show that mycobacteria can colonize and grow on granular activated carbon and are able to enter distribution systems. We also investigated the frequency of recovery of mycobacteria in the water distribution system of Paris (outside buildings). The mycobacterial species isolated from the Paris drinking water distribution system are different from those isolated from the water leaving the treatment plants. Saprophytic mycobacteria (present in 41.3% of positive samples), potentially pathogenic mycobacteria (16.3%), and unidentifiable mycobacteria (54.8%) were isolated from 12 sites within the Paris water distribution system. Mycobacterium gordonae was preferentially recovered from treated surface water, whereas Mycobacterium nonchromogenicum was preferentially recovered from groundwater. No significant correlations were found among the presence of mycobacteria, the origin of water, and water temperature. PMID:12406720

  1. High-resolution subsurface water-ice distributions on Mars.

    PubMed

    Bandfield, Joshua L

    2007-05-01

    Theoretical models indicate that water ice is stable in the shallow subsurface (depths of <1-2 m) of Mars at high latitudes. These models have been mainly supported by the observed presence of large concentrations of hydrogen detected by the Gamma Ray Spectrometer suite of instruments on the Mars Odyssey spacecraft. The models and measurements are consistent with a water-ice table that steadily increases in depth with decreasing latitude. More detailed modelling has predicted that the depth at which water ice is stable can be highly variable, owing to local surface heterogeneities such as rocks and slopes, and the thermal inertia of the ground cover. Measurements have, however, been limited to the footprint (several hundred kilometres) of the Gamma Ray Spectrometer suite, preventing the observations from documenting more detailed water-ice distributions. Here I show that by observing the seasonal temperature response of the martian surface with the Thermal Emission Imaging System on the Mars Odyssey spacecraft, it is possible to observe such heterogeneities at subkilometre scale. These observations show significant regional and local water-ice depth variability, and, in some cases, support distributions in the subsurface predicted by atmospheric exchange and vapour diffusion models. The presence of water ice where it follows the depth of stability under current climatic conditions implies an active martian water cycle that responds to orbit-driven climate cycles. Several regions also have apparent deviations from the theoretical stability level, indicating that additional factors influence the ice-table depth. The high-resolution measurements show that the depth to the water-ice table is highly variable within the potential Phoenix spacecraft landing ellipses, and is likely to be variable at scales that may be sampled by the spacecraft.

  2. [Three-dimension temporal and spatial dynamics of soil water for the artificial vegetation in the center of Taklimakan desert under saline water drip-irrigation].

    PubMed

    Ding, Xin-yuan; Zhou, Zhi-bin; Xu, Xin-wen; Lei, Jia-qiang; Lu, Jing-jing; Ma, Xue-xi; Feng, Xiao

    2015-09-01

    Three-dimension temporal and spatial dynamics of the soil water characteristics during four irrigating cycles of months from April to July for the artificial vegetation in the center of Taklimakan Desert under saline water drip-irrigation had been analyzed by timely measuring the soil water content in horizontal and vertical distances 60 cm and 120 cm away from the irrigating drips, respectively. Periodic spatial and temporal variations of soil water content were observed. When the precipitation effect was not considered, there were no significant differences in the characteristics of soil water among the irrigation intervals in different months, while discrepancies were obvious in the temporal and spatial changes of soil moisture content under the conditions of rainfall and non-rainfall. When it referred to the temporal changes of soil water, it was a little higher in April but a bit lower in July, and the soil water content in June was the highest among four months because some remarkable events of precipitation happened in this month. However, as a whole, the content of soil moisture was reduced as months (from April to July) went on and it took a decreasing tendency along with days (1-15 d) following a power function. Meanwhile, the characteristics of soil water content displayed three changeable stages in an irrigation interval. When it referred to the spatial distributions of soil water, the average content of soil moisture was reduced along with the horizontal distance following a linear regression function, and varied with double peaks along with the vertical distance. In addition, the spatial distribution characteristics of the soil water were not influenced by the factors of precipitation and irrigating time but the physical properties of soil. PMID:26785539

  3. Thermodynamic characteristics of cyclohexanone distribution between extractants and water

    SciTech Connect

    Vozin, V.G.; Diyarov, I.N.; Gainullin, I.F.

    1986-01-10

    The authors have determined the thermodynamic characteristics of cyclohexanone distribution between extractants and water, making it possible to estimate the effectiveness of its separation by the extraction method. The extractants studied were hexane, heptane, octane, benzene, toluene, ethylbenzene, ethyl acetate, and butyl acetate. Analysis of the results shows that the partition ratio increases with increase of the equilibrium concentrations of cyclohexanone in the coexisting phases, indicating association of the molecules of the distributed substance in the extractant phase. The foregoing leads to the conclusion that aromatic hydrocarbons and acetate esters are superior to paraffins in extractive properties.

  4. Directory of assistance centers of the National Water Data Exchange (NAWDEX)

    USGS Publications Warehouse

    Blackwell, Cassandra D.

    1994-01-01

    The National Water Data Exchange (NAWDEX) is a nationwide program managed by the U.S. Geological Survey to assist users of water data or water- related data in identifying, locating, and acquiring needed data. NAWDEX is a confederation of water- oriented organizations working together to make their data more readily accessible and to facilitate a more efficient exchange of water data. NAWDEX services are available through a Program Office located at the U.S. Geological Survey's National Center in Reston, Virginia. A nationwide network of Assistance Centers has been established in 45 states, the District of Columbia and Puerto Rico to provide local and convenient access to NAWDEX facilities. This Directory provides the names of organizations and persons to contact, addresses, telephone numbers, and the various types of data and services available at each location.

  5. Desorption of arsenic from drinking water distribution system solids.

    PubMed

    Copeland, Rachel C; Lytle, Darren A; Dionysious, Dionysios D

    2007-04-01

    Previous work has shown that arsenic can accumulate in drinking water distribution system (DWDS) solids (Lytle et al., 2004) when arsenic is present in the water. The release of arsenic back into the water through particulate transport and/or chemical release (e.g. desorption, dissolution) could result in elevated arsenic levels at the consumers' tap. The primary objective of this work was to examine the impact of pH and orthophosphate on the chemical release (i.e. desorption) of arsenic from nine DWDS solids collected from utilities located in the Midwest. Arsenic release comparisons were based on the examination of arsenic and other water quality parameters in leach water after contact with the solids over the course of 168~hours. Results showed that arsenic was released from solids and suggested that arsenic release was a result of desorption rather than dissolution. Arsenic release generally increased with increasing initial arsenic concentration in the solid and increasing pH levels (in the test range of 7 to 9). Finally, orthophosphate (3 and 5 mg PO(4)/L) increased arsenic release at all pH values examined. Based on the study results, utilities with measurable levels of arsenic present in their water should be aware that some water quality changes can cause arsenic release in the DWDS potentially resulting in elevated levels at the consumer's tap.

  6. Heterotrophic bacteria in drinking water distribution system: a review.

    PubMed

    Chowdhury, Shakhawat

    2012-10-01

    The microbiological quality of drinking water in municipal water distribution systems (WDS) depends on several factors. Free residual chlorine and/or chloramines are typically used to minimize bacterial recontamination and/or regrowth in WDS. Despite such preventive measures, regrowth of heterotrophic (HPC) and opportunistic bacteria in bulk water and biofilms has yet to be controlled completely. No approach has shown complete success in eliminating biofilms or HPC bacteria from bulk water and pipe surfaces. Biofilms can provide shelter for pathogenic bacteria and protect these bacteria from disinfectants. Some HPC bacteria may be associated with aesthetic and non-life threatening diseases. Research to date has achieved important success in understanding occurrence and regrowth of bacteria in bulk water and biofilms in WDS. To achieve comprehensive understanding and to provide efficient control against bacteria regrowth, future research on bacteria regrowth dynamics and their implications is warranted. In this study, a review was performed on the literature published in this area. The findings and limitations of these papers are summarized. Occurrences of bacteria in WDS, factors affecting bacteria regrowth in bulk water and biofilms, bacteria control strategies, sources of nutrients, human health risks from bacterial exposure, modelling of bacteria regrowth and methods of bacteria sampling and detection and quantification are investigated. Advances to date are noted, and future research needs are identified. Finally, research directions are proposed to effectively control HPC and opportunistic bacteria in bulk water and biofilms in WDS.

  7. The DIAS/CEOS Water Portal, distributed system using brokering architecture

    NASA Astrophysics Data System (ADS)

    Miura, Satoko; Sekioka, Shinichi; Kuroiwa, Kaori; Kudo, Yoshiyuki

    2015-04-01

    The DIAS/CEOS Water Portal is a one of the DIAS (Data Integration and Analysis System, http://www.editoria.u-tokyo.ac.jp/projects/dias/?locale=en_US) systems for data distribution for users including, but not limited to, scientists, decision makers and officers like river administrators. This portal has two main functions; one is to search and access data and the other is to register and share use cases which use datasets provided via this portal. This presentation focuses on the first function, to search and access data. The Portal system is distributed in the sense that, while the portal system is located in Tokyo, the data is located in archive centers which are globally distributed. For example, some in-situ data is archived at the National Center for Atmospheric Research (NCAR) Earth Observing Laboratory in Boulder, Colorado, USA. The NWP station time series and global gridded model output data is archived at the Max Planck Institute for Meteorology (MPIM) in cooperation with the World Data Center for Climate in Hamburg, Germany. Part of satellite data is archived at DIAS storage at the University of Tokyo, Japan. This portal itself does not store data. Instead, according to requests made by users on the web page, it retrieves data from distributed data centers on-the-fly and lets them download and see rendered images/plots. Although some data centers have unique meta data format and/or data search protocols, our portal's brokering function enables users to search across various data centers at one time, like one-stop shopping. And this portal is also connected to other data brokering systems, including GEOSS DAB (Discovery and Access Broker). As a result, users can search over thousands of datasets, millions of files at one time. Our system mainly relies on the open source software GI-cat (http://essi-lab.eu/do/view/GIcat), Opensearch protocol and OPeNDAP protocol to enable the above functions. Details on how it works will be introduced during the

  8. Operational guidelines for assistance centers of the National Water Data Exchange

    USGS Publications Warehouse

    Edwards, Melvin D.; Thompson, Gerald L.

    1980-01-01

    The National Water Data Exchange (NAWDES) is a nationwide program managed by the U.S. Geological Survey to assist users of water data and water-related data in identifying, locating, and acquiring needed data. NAWDEX services are available through a program office located in the Geological Survey 's National Center in Reston, Va., and a network of assistance centers established in 45 States and in Puerto Rico to provide local and cnvenient access to NAWDEX facilities. This manual presents operational guidelines for the operation of these assistance centers to accomplish the expeditious flow of data from holder to user. These guildlines will be occasionally modified and supplemented to accomodate new concepts and techniques that may be needed. (USGS)

  9. Effect of water table fluctuations on phreatophytic root distribution.

    PubMed

    Tron, Stefania; Laio, Francesco; Ridolfi, Luca

    2014-11-01

    The vertical root distribution of riparian vegetation plays a relevant role in soil water balance, in the partition of water fluxes into evaporation and transpiration, in the biogeochemistry of hyporheic corridors, in river morphodynamics evolution, and in bioengineering applications. The aim of this work is to assess the effect of the stochastic variability of the river level on the root distribution of phreatophytic plants. A function describing the vertical root profile has been analytically obtained by coupling a white shot noise representation of the river level variability to a description of the dynamics of root growth and decay. The root profile depends on easily determined parameters, linked to stream dynamics, vegetation and soil characteristics. The riparian vegetation of a river characterized by a high variability turns out to have a rooting system spread over larger depths, but with shallower mean root depths. In contrast, a lower river variability determines root profiles with higher mean root depths. PMID:25014476

  10. The Challenge of Providing Safe Water with an Intermittently Supplied Piped Water Distribution System

    NASA Astrophysics Data System (ADS)

    Kumpel, E.; Nelson, K. L.

    2012-12-01

    An increasing number of urban residents in low- and middle-income countries have access to piped water; however, this water is often not available continuously. 84% of reporting utilities in low-income countries provide piped water for fewer than 24 hours per day (van den Berg and Danilenko, 2010), while no major city in India has continuous piped water supply. Intermittent water supply leaves pipes vulnerable to contamination and forces households to store water or rely on alternative unsafe sources, posing a health threat to consumers. In these systems, pipes are empty for long periods of time and experience low or negative pressure even when water is being supplied, leaving them susceptible to intrusion from sewage, soil, or groundwater. Households with a non-continuous supply must collect and store water, presenting more opportunities for recontamination. Upgrading to a continuous water supply, while an obvious solution to these challenges, is currently out of reach for many resource-constrained utilities. Despite its widespread prevalence, there are few data on the mechanisms causing contamination in an intermittent supply and the frequency with which it occurs. Understanding the impact of intermittent operation on water quality can lead to strategies to improve access to safe piped water for the millions of people currently served by these systems. We collected over 100 hours of continuous measurements of pressure and physico-chemical water quality indicators and tested over 1,000 grab samples for indicator bacteria over 14 months throughout the distribution system in Hubli-Dharwad, India. This data set is used to explore and explain the mechanisms influencing water quality when piped water is provided for a few hours every 3-5 days. These data indicate that contamination occurs along the distribution system as water travels from the treatment plant to reservoirs and through intermittently supplied pipes to household storage containers, while real

  11. Physical Modeling of Scaled Water Distribution System Networks.

    SciTech Connect

    O'Hern, Timothy J.; Hammond, Glenn Edward; Orear, Leslie ,; van Bloemen Waanders, Bart G.; Paul Molina; Ross Johnson

    2005-10-01

    Threats to water distribution systems include release of contaminants and Denial of Service (DoS) attacks. A better understanding, and validated computational models, of the flow in water distribution systems would enable determination of sensor placement in real water distribution networks, allow source identification, and guide mitigation/minimization efforts. Validation data are needed to evaluate numerical models of network operations. Some data can be acquired in real-world tests, but these are limited by 1) unknown demand, 2) lack of repeatability, 3) too many sources of uncertainty (demand, friction factors, etc.), and 4) expense. In addition, real-world tests have limited numbers of network access points. A scale-model water distribution system was fabricated, and validation data were acquired over a range of flow (demand) conditions. Standard operating variables included system layout, demand at various nodes in the system, and pressure drop across various pipe sections. In addition, the location of contaminant (salt or dye) introduction was varied. Measurements of pressure, flowrate, and concentration at a large number of points, and overall visualization of dye transport through the flow network were completed. Scale-up issues that that were incorporated in the experiment design include Reynolds number, pressure drop across nodes, and pipe friction and roughness. The scale was chosen to be 20:1, so the 10 inch main was modeled with a 0.5 inch pipe in the physical model. Controlled validation tracer tests were run to provide validation to flow and transport models, especially of the degree of mixing at pipe junctions. Results of the pipe mixing experiments showed large deviations from predicted behavior and these have a large impact on standard network operations models.3

  12. CLASSIFICATION OF THE MGR SUBSURFACE WATER DISTRIBUTION SYSTEM

    SciTech Connect

    R. Garrett

    1999-08-31

    The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) subsurface water distribution system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333P, ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998).

  13. Development of Distributed Research Center for monitoring and projecting regional climatic and environmental changes: first results

    NASA Astrophysics Data System (ADS)

    Gordov, Evgeny; Shiklomanov, Alexander; Okladinikov, Igor; Prusevich, Alex; Titov, Alexander

    2016-04-01

    Description and first results of the cooperative project "Development of Distributed Research Center for monitoring and projecting of regional climatic and environmental changes" recently started by SCERT IMCES and ESRC UNH are reported. The project is aimed at development of hardware and software platform prototype of Distributed Research Center (DRC) for monitoring and projecting regional climatic and environmental changes over the areas of mutual interest and demonstration the benefits of such collaboration that complements skills and regional knowledge across the northern extratropics. In the framework of the project, innovative approaches of "cloud" processing and analysis of large geospatial datasets will be developed on the technical platforms of two U.S. and Russian leading institutions involved in research of climate change and its consequences. Anticipated results will create a pathway for development and deployment of thematic international virtual research centers focused on interdisciplinary environmental studies by international research teams. DRC under development will comprise best features and functionality of earlier developed by the cooperating teams' information-computational systems RIMS (http://rims.unh.edu) and CLIMATE(http://climate.scert.ru/), which are widely used in Northern Eurasia environment studies. The project includes several major directions of research (Tasks) listed below. 1. Development of architecture and defining major hardware and software components of DRC for monitoring and projecting of regional environmental changes. 2. Development of an information database and computing software suite for distributed processing and analysis of large geospatial data hosted at ESRC and IMCES SB RAS. 3. Development of geoportal, thematic web client and web services providing international research teams with an access to "cloud" computing resources at DRC; two options will be executed: access through a basic graphical web browser and

  14. Contamination potential of drinking water distribution network biofilms.

    PubMed

    Wingender, J; Flemming, H C

    2004-01-01

    Drinking water distribution system biofilms were investigated for the presence of hygienically relevant microorganisms. Early biofilm formation was evaluated in biofilm reactors on stainless steel, copper, polyvinyl chloride (PVC) and polyethylene coupons exposed to unchlorinated drinking water. After 12 to 18 months, a plateau phase of biofilm development was reached. Surface colonization on the materials ranged between 4 x 10(6) and 3 x 10(7) cells/cm2, with heterotrophic plate count (HPC) bacteria between 9 x 10(3) and 7 x 10(5) colony-forming units (cfu)/cm2. Established biofilms were investigated in 18 pipe sections (2 to 99 years old) cut out from distribution pipelines. Materials included cast iron, galvanized steel, cement and PVC. Colonization ranged from 4 x 10(5) to 2 x 10(8) cells/cm2, HPC levels varied between 1 and 2 x 10(5) cfu/cm2. No correlation was found between extent of colonization and age of the pipes. Using cultural detection methods, coliform bacteria were rarely found, while Escherichia coli, Pseudomonas aeruginosa and Legionella spp. were not detected in the biofilms. In regular operation, distribution system biofilms do not seem to be common habitats for pathogens. However, nutrient-leaching materials like rubber-coated valves were observed with massive biofilms which harboured coliform bacteria contaminating drinking water.

  15. Optimization of water distribution systems in high-rise buildings

    SciTech Connect

    Loh, Han Tong; Chew, T.C.

    1994-12-31

    The scarcity of land in Singapore has led to a rapid escalation of land prices in recent years. This has resulted in developers building taller and taller buildings in order to maximize their return on building projects. Due to the height involved, the water distribution system in such buildings is a multi-stage one. Hence the problem of deciding the number of stages and the location of each stage arises. In this paper, we will describe the design decisions to be taken in the preliminary design of a multi-stage water distribution system in a high-rise building and pose it as an optimization problem to minimize the overall cost of implementation. The variable costcomponents are the cost of pumps, the floor space cost and the operational cost of the water distribution system. We will describe a study on a 66-story building and highlight the major findings. Interesting results are observed when the cost components are taken one at a time. The strategy for finding the optimum or near optimum for other high-rise buildings will be discussed.

  16. Contamination potential of drinking water distribution network biofilms.

    PubMed

    Wingender, J; Flemming, H C

    2004-01-01

    Drinking water distribution system biofilms were investigated for the presence of hygienically relevant microorganisms. Early biofilm formation was evaluated in biofilm reactors on stainless steel, copper, polyvinyl chloride (PVC) and polyethylene coupons exposed to unchlorinated drinking water. After 12 to 18 months, a plateau phase of biofilm development was reached. Surface colonization on the materials ranged between 4 x 10(6) and 3 x 10(7) cells/cm2, with heterotrophic plate count (HPC) bacteria between 9 x 10(3) and 7 x 10(5) colony-forming units (cfu)/cm2. Established biofilms were investigated in 18 pipe sections (2 to 99 years old) cut out from distribution pipelines. Materials included cast iron, galvanized steel, cement and PVC. Colonization ranged from 4 x 10(5) to 2 x 10(8) cells/cm2, HPC levels varied between 1 and 2 x 10(5) cfu/cm2. No correlation was found between extent of colonization and age of the pipes. Using cultural detection methods, coliform bacteria were rarely found, while Escherichia coli, Pseudomonas aeruginosa and Legionella spp. were not detected in the biofilms. In regular operation, distribution system biofilms do not seem to be common habitats for pathogens. However, nutrient-leaching materials like rubber-coated valves were observed with massive biofilms which harboured coliform bacteria contaminating drinking water. PMID:15303752

  17. Sampling and quantifying invertebrates from drinking water distribution mains.

    PubMed

    van Lieverloo, J Hein M; Bosboom, Dick W; Bakker, Geo L; Brouwer, Anke J; Voogt, Remko; De Roos, Josje E M

    2004-03-01

    Water utilities in the Netherlands aim at controlling the multiplication of (micro-) organisms by distributing biologically stable water through biologically stable materials. Disinfectant residuals are absent or very low. To be able to assess invertebrate abundance, methods for sampling and quantifying these animals from distribution mains were optimised and evaluated. The presented method for collecting invertebrates consists of unidirectionally flushing a mains section with a flow rate of 1 ms(-1) and filtering the flushed water in two separate flows with 500 microm and 100 microm mesh plankton gauze filters. Removal efficiency from mains was evaluated in nine experiments by collecting the invertebrates removed from the mains section by intensive cleaning immediately subsequent to sampling. Of 12 taxa distinguished, all except case-building Chironomidae larvae (2%) and Oligochaeta (30%) were removed well (51-75%). Retention of invertebrates in 100 microm filters was evaluated by filtering 39 filtrates using 30 microm filters. Except for flexible and small invertebrates such as Turbellaria (13%), Nematoda (11%) and Copepoda larvae (24%), most taxa were well retained in the 100 microm filters (53-100%). During sample processing, the method for taking sub-samples with a 10 ml pipette from the suspension of samples with high sediment concentrations was found to perform well in 75% of the samples. During a 2-year national survey in the Netherlands and consecutive investigations, the method appeared to be very suitable to assess the abundance of most invertebrate taxa in drinking water distribution systems and to be practicable for relatively inexperienced sampling and lab technicians. Although the numbers of small, less abundant or sessile taxa were not accurately assessed using the method, these taxa probably should not be the primary focus of monitoring by water utilities, as consumer complaints are not likely to be caused by these invertebrates. The accuracy of

  18. Global distribution of plant-extractable water capacity of soil

    USGS Publications Warehouse

    Dunne, K.A.; Willmott, C.J.

    1996-01-01

    Plant-extractable water capacity of soil is the amount of water that can be extracted from the soil to fulfill evapotranspiration demands. It is often assumed to be spatially invariant in large-scale computations of the soil-water balance. Empirical evidence, however, suggests that this assumption is incorrect. In this paper, we estimate the global distribution of the plant-extractable water capacity of soil. A representative soil profile, characterized by horizon (layer) particle size data and thickness, was created for each soil unit mapped by FAO (Food and Agriculture Organization of the United Nations)/Unesco. Soil organic matter was estimated empirically from climate data. Plant rooting depths and ground coverages were obtained from a vegetation characteristic data set. At each 0.5?? ?? 0.5?? grid cell where vegetation is present, unit available water capacity (cm water per cm soil) was estimated from the sand, clay, and organic content of each profile horizon, and integrated over horizon thickness. Summation of the integrated values over the lesser of profile depth and root depth produced an estimate of the plant-extractable water capacity of soil. The global average of the estimated plant-extractable water capacities of soil is 8??6 cm (Greenland, Antarctica and bare soil areas excluded). Estimates are less than 5, 10 and 15 cm - over approximately 30, 60, and 89 per cent of the area, respectively. Estimates reflect the combined effects of soil texture, soil organic content, and plant root depth or profile depth. The most influential and uncertain parameter is the depth over which the plant-extractable water capacity of soil is computed, which is usually limited by root depth. Soil texture exerts a lesser, but still substantial, influence. Organic content, except where concentrations are very high, has relatively little effect.

  19. Global Distribution of Plant-Extractable Water Capacity of Soil

    NASA Astrophysics Data System (ADS)

    Dunne, K. A.; Willmott, Cort J.

    1996-08-01

    Plant-extractable water capacity of soil is the amount of water that can be extracted from the soil to fulfill evapotranspiration demands. It is often assumed to be spatially invariant in large-scale computations of the soil-water balance. Empirical evidence, however, suggests that this assumption is incorrect. In this paper, we estimate the global distribution of the plant-extractable water capacity of soil.A representative soil profile, characterized by horizon (layer) particle size data and thickness, was created for each soil unit mapped by FAO (Food and Agriculture Organization of the United Nations)/Unesco. Soil organic matter was estimated empirically from climate data. Plant rooting depths and ground coverages were obtained from a vegetation characteristic data set. At each 0.5°×0.5° grid cell where vegetation is present, unit available water capacity (cm water per cm soil) was estimated from the sand, clay, and organic content of each profile horizon, and integrated over horizon thickness. Summation of the integrated values over the lesser of profile depth and root depth produced an estimate of the plant-extractable water capacity of soil.The global average of the estimated plant-extractable water capacities of soil is 86cm (Greenland, Antarctica and bare soil areas excluded). Estimates are less than 5, 10 and 15 cm - over approximately 30, 60, and 89 per cent of the area, respectively. Estimates reflect the combined effects of soil texture, soil organic content, and plant root depth or profile depth. The most influential and uncertain parameter is the depth over which the plant- extractable water capacity of soil is computed, which is usually limited by root depth. Soil texture exerts a lesser, but still substantial, influence. Organic content, except where concentrations are very high, has relatively little effect.

  20. Fiscal Year 1990 program report: New Hampshire Water Resources Research Center

    SciTech Connect

    Ballestero, T.P.

    1991-08-01

    The report covers the activities of the New Hampshire Water Resource Research Center for the period July 1, 1990 through June 30, 1991. The projects include: effects of the forest land application of municipal wastewater treatment plant sludge, the analysis of how contaminants attach to lake sediments, oil spill response plans on the Piscataqua River, literature review of motor boat and personal water craft on environmental quality, performance evaluation of point-of-entry treatment units for gasoline-contaminated ground waters and automation of a portable pressure filtration system for community water supplies.

  1. Surface-water quality-assurance plan for the U.S. Geological Survey Washington Water Science Center

    USGS Publications Warehouse

    Kresch, David L.; Tomlinson, Stewart A.

    2004-01-01

    This Surface-Water Quality-Assurance Plan documents the standards, policies, and procedures used by the U.S. Geological Survey's Washington District, Water Resources Discipline office, also known as the Washington Water Science Center, for activities related to the collection, processing, storage, analysis, and publication of surface-water data. This plan serves as a guide to all District personnel involved in surface-water data activities, and changes as the needs and requirements of the District and Discipline change. Regular updates to this Plan represent an integral part of the qualityassurance process. In the Washington District, direct oversight and responsibility by the hydrographer(s) assigned to a surface-water station, combined with team approaches in all work efforts, assure high-quality data, analyses, reviews, and reports for cooperating agencies and the public.

  2. Corrosion behaviour and biocorrosion of galvanized steel water distribution systems.

    PubMed

    Delaunois, F; Tosar, F; Vitry, V

    2014-06-01

    Galvanized steel tubes are a popular mean for water distribution systems but suffer from corrosion despite their zinc or zinc alloy coatings. First, the quality of hot-dip galvanized (HDG) coatings was studied. Their microstructure, defects, and common types of corrosion were observed. It was shown that many manufactured tubes do not reach European standard (NBN EN 10240), which is the cause of several corrosion problems. The average thickness of zinc layer was found at 41μm against 55μm prescribed by the European standard. However, lack of quality, together with the usual corrosion types known for HDG steel tubes was not sufficient to explain the high corrosion rate (reaching 20μm per year versus 10μm/y for common corrosion types). Electrochemical tests were also performed to understand the corrosion behaviours occurring in galvanized steel tubes. Results have shown that the limiting step was oxygen diffusion, favouring the growth of anaerobic bacteria in steel tubes. EDS analysis was carried out on corroded coatings and has shown the presence of sulphur inside deposits, suggesting the likely bacterial activity. Therefore biocorrosion effects have been investigated. Actually sulphate reducing bacteria (SRB) can reduce sulphate contained in water to hydrogen sulphide (H2S), causing the formation of metal sulphides. Although microbial corrosion is well-known in sea water, it is less investigated in supply water. Thus, an experimental water main was kept in operation for 6months. SRB were detected by BART tests in the test water main.

  3. System analysis for the Huntsville Operational Support Center distributed computer system

    NASA Technical Reports Server (NTRS)

    Ingels, F. M.; Mauldin, J.

    1984-01-01

    The Huntsville Operations Support Center (HOSC) is a distributed computer system used to provide real time data acquisition, analysis and display during NASA space missions and to perform simulation and study activities during non-mission times. The primary purpose is to provide a HOSC system simulation model that is used to investigate the effects of various HOSC system configurations. Such a model would be valuable in planning the future growth of HOSC and in ascertaining the effects of data rate variations, update table broadcasting and smart display terminal data requirements on the HOSC HYPERchannel network system. A simulation model was developed in PASCAL and results of the simulation model for various system configuraions were obtained. A tutorial of the model is presented and the results of simulation runs are presented. Some very high data rate situations were simulated to observe the effects of the HYPERchannel switch over from contention to priority mode under high channel loading.

  4. System analysis for the Huntsville Operation Support Center distributed computer system

    NASA Technical Reports Server (NTRS)

    Ingels, F. M.

    1986-01-01

    A simulation model of the NASA Huntsville Operational Support Center (HOSC) was developed. This simulation model emulates the HYPERchannel Local Area Network (LAN) that ties together the various computers of HOSC. The HOSC system is a large installation of mainframe computers such as the Perkin Elmer 3200 series and the Dec VAX series. A series of six simulation exercises of the HOSC model is described using data sets provided by NASA. The analytical analysis of the ETHERNET LAN and the video terminals (VTs) distribution system are presented. An interface analysis of the smart terminal network model which allows the data flow requirements due to VTs on the ETHERNET LAN to be estimated, is presented.

  5. System Analysis for the Huntsville Operation Support Center, Distributed Computer System

    NASA Technical Reports Server (NTRS)

    Ingels, F. M.; Massey, D.

    1985-01-01

    HOSC as a distributed computing system, is responsible for data acquisition and analysis during Space Shuttle operations. HOSC also provides computing services for Marshall Space Flight Center's nonmission activities. As mission and nonmission activities change, so do the support functions of HOSC change, demonstrating the need for some method of simulating activity at HOSC in various configurations. The simulation developed in this work primarily models the HYPERchannel network. The model simulates the activity of a steady state network, reporting statistics such as, transmitted bits, collision statistics, frame sequences transmitted, and average message delay. These statistics are used to evaluate such performance indicators as throughout, utilization, and delay. Thus the overall performance of the network is evaluated, as well as predicting possible overload conditions.

  6. Mass Spectrometry Data from the Biological MS Data and Software Distribution Center

    DOE Data Explorer

    Anderson, Gordon

    The mass spectrometry capabilities at Pacific Northwest National Laboratory (PNNL) are primarily applied to biological research, with an emphasis on proteomics and metabolomics. Many of these cutting-edge mass spectrometry capabilities and bioinformatics methods are housed in the Department of Energy's Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility operated by PNNL. These capabilities have been developed and acquired through cooperation between the EMSL national scientific user program and PNNL programmatic research. At the website of the Biological MS Data and Software Distribution Center, the following resources are made available: PNNL-developed software tools and source code, PNNL-generated raw data and processed results, links to publications that used the data and results available on this site, and tutorials and user manuals. [taken from http://omics.pnl.gov/

  7. Convective Cloud Ice Water Content Distribution in the Upper Tropical Troposphere

    NASA Astrophysics Data System (ADS)

    Avery, M. A.; Davis, S. M.; Vaughan, M. A.; Young, S. A.; Schoeberl, M. R.; Rosenlof, K. H.; Trepte, C. R.; Winker, D. M.

    2015-12-01

    The Cloud and Aerosol LIdar with Orthogonal Polarization (CALIOP) has been making backscatter measurements of cirrus clouds in the upper tropical troposphere and lowermost stratosphere for more than nine years. Using empirical relationships between backscatter and extinction coefficients, as well as cloud ice water content measured by aircraft, the lidar backscatter can be converted into cloud ice water content. A nine-year climatology of ice water content from CALIOP shows that the distribution of ice mass in the tropical UT/LS is dominated by convection over land, with a large longitudinal variation. There are four centers of activity for high altitude tropical convection, over South America, Africa, the Asian Monsoon region and in the tropical Western Pacific over the maritime continent. The distribution of cloud ice water content is very different from that of cloud fraction, which includes many thin cloud layers in the TTL that do not contain much ice, and that are locally and not convectively generated. These results suggest that approaches based on zonal means, or on cloud fraction do not give an accurate accounting of the total water budget of the UT/LS, and that a regional approach is needed. It is found that "overshooting" convection likely dominates the stratospheric moistening process in specific regions and at specific times of the year. Finally, upper tropical tropospheric cloud ice mass loading is correlated with the Asian monsoon and with climate cycles such as ENSO and the QBO.

  8. Soil Water Characteristics of Cores from Low- and High-Centered Polygons, Barrow, Alaska, 2012

    DOE Data Explorer

    Graham, David; Moon, Ji-Won

    2016-08-22

    This dataset includes soil water characteristic curves for soil and permafrost in two representative frozen cores collected from a high-center polygon (HCP) and a low-center polygon (LCP) from the Barrow Environmental Observatory. Data include soil water content and soil water potential measured using the simple evaporation method for hydrological and biogeochemical simulations and experimental data analysis. Data can be used to generate a soil moisture characteristic curve, which can be fit to a variety of hydrological functions to infer critical parameters for soil physics. Considering the measured the soil water properties, the van Genuchten model predicted well the HCP, in contrast, the Kosugi model well fitted LCP which had more saturated condition.

  9. Quality-assurance plan for groundwater activities, U.S. Geological Survey, Washington Water Science Center

    USGS Publications Warehouse

    Kozar, Mark D.; Kahle, Sue C.

    2013-01-01

    This report documents the standard procedures, policies, and field methods used by the U.S. Geological Survey’s (USGS) Washington Water Science Center staff for activities related to the collection, processing, analysis, storage, and publication of groundwater data. This groundwater quality-assurance plan changes through time to accommodate new methods and requirements developed by the Washington Water Science Center and the USGS Office of Groundwater. The plan is based largely on requirements and guidelines provided by the USGS Office of Groundwater, or the USGS Water Mission Area. Regular updates to this plan represent an integral part of the quality-assurance process. Because numerous policy memoranda have been issued by the Office of Groundwater since the previous groundwater quality assurance plan was written, this report is a substantial revision of the previous report, supplants it, and contains significant additional policies not covered in the previous report. This updated plan includes information related to the organization and responsibilities of USGS Washington Water Science Center staff, training, safety, project proposal development, project review procedures, data collection activities, data processing activities, report review procedures, and archiving of field data and interpretative information pertaining to groundwater flow models, borehole aquifer tests, and aquifer tests. Important updates from the previous groundwater quality assurance plan include: (1) procedures for documenting and archiving of groundwater flow models; (2) revisions to procedures and policies for the creation of sites in the Groundwater Site Inventory database; (3) adoption of new water-level forms to be used within the USGS Washington Water Science Center; (4) procedures for future creation of borehole geophysics, surface geophysics, and aquifer-test archives; and (5) use of the USGS Multi Optional Network Key Entry System software for entry of routine water-level data

  10. From Policy to Practice: Implementation of Water Policies in Child Care Centers in Connecticut

    ERIC Educational Resources Information Center

    Middleton, Ann E.; Henderson, Kathryn E.; Schwartz, Marlene B.

    2013-01-01

    Objective: Child care policies may contribute to healthy beverage consumption patterns. This study documented availability and accessibility of water and correspondence with state and federal policy and accreditation standards in child care centers. Design: One-day observations were conducted in a random sample of 40 Child and Adult Care Food…

  11. Surface-water quality-assurance plan for the U.S. Geological Survey Washington Water Science Center

    USGS Publications Warehouse

    Mastin, Mark C.

    2016-01-01

    This Surface-Water Quality-Assurance Plan documents the standards, policies, and procedures used by the U.S. Geological Survey Washington Water Science Center (WAWSC) for activities related to the collection, processing, storage, analysis, and publication of surface-water data. This plan serves as a guide to all WAWSC personnel involved in surface-water data activities, and changes as the needs and requirements of the WAWSC change. Regular updates to this plan represent an integral part of the quality-assurance process. In the WAWSC, direct oversight and responsibility by the hydrographer(s) assigned to a surface-water station, combined with team approaches in all work efforts, assure high-quality data, analyses, reviews, and reports for cooperating agencies and the public.

  12. Water Pressure Distribution on a Twin-Float Seaplane

    NASA Technical Reports Server (NTRS)

    Thompson, F L

    1930-01-01

    This is the second of a series of investigations to determine water pressure distribution on various types of seaplane floats and hulls, and was conducted on a twin-float seaplane. It consisted of measuring water pressures and accelerations on a TS-1 seaplane during numerous landing and taxiing maneuvers at various speeds and angles. The results show that water pressures as great as 10 lbs. per sq. in.may occur at the step in various maneuvers and that pressures of approximately the same magnitude occur at the stern and near the bow in hard pancake landings with the stern way down. At the other parts of the float the pressures are less and are usually zero or slightly negative for some distance abaft the step. A maximum negative pressure of 0.87 lb. Per square inch was measured immediately abaft the step. The maximum positive pressures have a duration of approximately one-twentieth to one-hundredth second at any given location and are distributed over a very limited area at any particular instant.

  13. Two and three-dimensional quantitative neutron imaging of the water distribution during ponded infiltration

    NASA Astrophysics Data System (ADS)

    Sacha, Jan; Snehota, Michal; Jelinkova, Vladimira

    2016-04-01

    sample. Tomography images were reconstructed from the both corrected and uncorrected water thickness maps to obtain the 3D spatial distribution of water content within the sample. Without the correction the beam hardening and scattering effects overestimated the water content values close to the sample perimeter and underestimated the values close to the center of the sample, however the total water content of whole sample was the same in both cases.

  14. Low-delay center-bridged and distributed combining schemes for multipoint videoconferencing

    NASA Astrophysics Data System (ADS)

    Chen, Ting-Chung; Wang, Wen-deh

    1994-09-01

    Multipoint videoconferencing is a natural evolution of two-point videoconferencing and can increase its value to users. Currently, ITU-T's SG8 and SG15 are working on multipoint control related issues; ANSI's T1A1.5 is also working in this area. The video coding and related communication standards of the upcoming MPEG4 and H.26P will all include multipoint communication capability. This paper investigates transport structures and the associated combining schemes that can be used to support multipoint videoconferencing. Since low delay is a major issue for multipoint interactive communications, a distributed structure which renders the lowest delay with many other system advantages is especially investigated. We first analyze the insertion delay of a QCIF combiner bridge which have been proposing for multipoint videoconferencing. Partial input-output pipelining has been used to reduce the delay. To reduce the insertion delay caused by unevenly distributed inputs, a parallel parsing scheme is proposed. This parallel parsing scheme allows low complexity inputs not to be held up by high complexity inputs and can reduce insertion delay significantly. An efficient delay- reduction algorithm using intraslice coding was also cited in a previous proposal. As a comparison, we describe low delay pel-domain transcoding schemes which have similar delay performance with coded-domain combining but have much higher complexities. We also describe a recent proposal which eliminates most of the insertion delay but which require major changes to existing standards and encoder and decoder implementations. The performance of a distributed transport structure in providing multipoint video services is then investigated. Using the face that bandwidth usage is an important factor in estimating network complexity, it is shown that a distributed transport structure saves 40 to 62.5% bandwidth for a 4-point conferencing and also renders the shortest delay when compared with other center

  15. Optimizing booster chlorination in water distribution networks: a water quality index approach.

    PubMed

    Islam, Nilufar; Sadiq, Rehan; Rodriguez, Manuel J

    2013-10-01

    The optimization of chlorine dosage and the number of booster locations is an important aspect of water quality management in distribution networks. Booster chlorination helps to maintain uniformity and adequacy of free residual chlorine concentration, essential for safeguarding against microbiological contamination. Higher chlorine dosages increase free residual chlorine concentration but generate harmful by-products, in addition to taste and odor complaints. It is possible to address these microbial, chemical, and aesthetic water quality issues through free residual chlorine concentration. Estimating a water quality index (WQI) based on regulatory chlorine thresholds for microbial, chemical, and aesthetics criteria can help engineers make intelligent decisions. An innovative scheme for maintaining adequate residual chlorine with optimal chlorine dosages and numbers of booster locations was established based on a proposed WQI. The City of Kelowna (BC, Canada) water distribution network served to demonstrate the application of the proposed scheme. Temporal free residual chlorine concentration predicted with EPANET software was used to estimate the WQI, later coupled with an optimization scheme. Preliminary temporal and spatial analyses identified critical zones (relatively poor water quality) in the distribution network. The model may also prove useful for small or rural communities where free residual chlorine is considered as the only water quality criterion.

  16. Distribution of binding energies of a water molecule in the water liquid-vapor interface

    SciTech Connect

    Chempath, Shaji; Pratt, Lawrence R

    2008-01-01

    Distributions of binding energies of a water molecule in the water liquid-vapor interface are obtained on the basis of molecular simulation with the SPC/E model of water. These binding energies together with the observed interfacial density profile are used to test a minimally conditioned Gaussian quasi-chemical statistical thermodynamic theory. Binding energy distributions for water molecules in that interfacial region clearly exhibit a composite structure. A minimally conditioned Gaussian quasi-chemical model that is accurate for the free energy of bulk liquid water breaks down for water molecules in the liquid-vapor interfacial region. This breakdown is associated with the fact that this minimally conditioned Gaussian model would be inaccurate for the statistical thermodynamics of a dilute gas. Aggressive conditioning greatly improves the performance of that Gaussian quasi-chemical model. The analogy between the Gaussian quasi-chemical model and dielectric models of hydration free energies suggests that naive dielectric models without the conditioning features of quasi-chemical theory will be unreliable for these interfacial problems. Multi-Gaussian models that address the composite nature of the binding energy distributions observed in the interfacial region might provide a mechanism for correcting dielectric models for practical applications.

  17. First experimental-based characterization of oxygen ion beam depth dose distributions at the Heidelberg Ion-Beam Therapy Center

    NASA Astrophysics Data System (ADS)

    Kurz, C.; Mairani, A.; Parodi, K.

    2012-08-01

    Over the last decades, the application of proton and heavy-ion beams to external beam radiotherapy has rapidly increased. Due to the favourable lateral and depth dose profile, the superposition of narrow ion pencil beams may enable a highly conformal dose delivery to the tumour, with better sparing of the surrounding healthy tissue in comparison to conventional radiation therapy with photons. To fully exploit the promised clinical advantages of ion beams, an accurate planning of the patient treatments is required. The clinical treatment planning system (TPS) at the Heidelberg Ion-Beam Therapy Center (HIT) is based on a fast performing analytical algorithm for dose calculation, relying, among others, on laterally integrated depth dose distributions (DDDs) simulated with the FLUKA Monte Carlo (MC) code. Important input parameters of these simulations need to be derived from a comparison of the simulated DDDs with measurements. In this work, the first measurements of 16O ion DDDs at HIT are presented with a focus on the determined Bragg peak positions and the understanding of factors influencing the shape of the distributions. The measurements are compared to different simulation approaches aiming to reproduce the acquired data at best. A simplified geometrical model is first used to optimize important input parameters, not known a priori, in the simulations. This method is then compared to a more realistic, but also more time-consuming simulation approach better accounting for the experimental set-up and the measuring process. The results of this work contributed to a pre-clinical oxygen ion beam database, which is currently used by a research TPS for corresponding radio-biological cell experiments. A future extension to a clinical database used by the clinical TPS at HIT is foreseen. As a side effect, the performed investigations showed that the typical water equivalent calibration approach of experimental data acquired with water column systems leads to slight

  18. Assessment of Nitrification in Distribution Systems of Waters with Elevated Ammonia Levels

    EPA Science Inventory

    The objective of this work is to monitor ammonia, nitrite, and nitrate in drinking water from the distribution systems of four drinking water utilities in Illinois. A monthly drinking water distribution system water quality monitoring protocol for each water utility in Illinois h...

  19. Distribution of guidance models for cardiac resynchronization therapy in the setting of multi-center clinical trials

    NASA Astrophysics Data System (ADS)

    Rajchl, Martin; Abhari, Kamyar; Stirrat, John; Ukwatta, Eranga; Cantor, Diego; Li, Feng P.; Peters, Terry M.; White, James A.

    2014-03-01

    Multi-center trials provide the unique ability to investigate novel techniques across a range of geographical sites with sufficient statistical power, the inclusion of multiple operators determining feasibility under a wider array of clinical environments and work-flows. For this purpose, we introduce a new means of distributing pre-procedural cardiac models for image-guided interventions across a large scale multi-center trial. In this method, a single core facility is responsible for image processing, employing a novel web-based interface for model visualization and distribution. The requirements for such an interface, being WebGL-based, are minimal and well within the realms of accessibility for participating centers. We then demonstrate the accuracy of our approach using a single-center pacemaker lead implantation trial with generic planning models.

  20. Water-Group Ion Distributions in the Mid-Cometosheath of Comet Halley

    NASA Technical Reports Server (NTRS)

    Huddleston, D. E.; Neugebauer, M.; Goldstein, B. E.

    1993-01-01

    In the mid-cometosheath of comet Halley (1-2x10^5 km from the nucleus) the center- of-mass plasma frame is approximately the bulk flow velocity of the cometary ions, and the Alfven wave speed is an appreciable fraction of the flow speed. Here, the peaks of the water-group ion distributions observed by the Giotto Ion Mass Spectrometer are at velocities consistently below the expected pickup speed. It is shown that this effect is consistent with the scattering of the new pickup ions onto a bispherical shell distribution. The model does not fit the data inside similar 1.2x10^5 km however, possibly as a result of the growing importance of collisions or the presence of other processes such as scattering on obliquely-propagating magnetosonic waves.

  1. Method for determining the droplet size distribution of emulsified water

    SciTech Connect

    Rzaev, A.G.

    1988-09-10

    Accelerating crude-oil processing requires estimation of the major parameters, including the droplet size distribution of the oil emulsion (OE) in the flow ahead of the settlers. This is handled here as follows. Under industrial conditions, samples are taken ahead of the settler into a calibrated vessel specially designed for the purpose and allowed to separate at a temperature equal to the flow temperature, where the amount of water deposited and the settling time are recorded. A hyperbolic relation applies quite closely to those data. The model expresses the droplet size as a function of the hydrodynamic parameters and can be used in optimizing dewatering and desalting oil.

  2. Signatures of present and past melt distribution along fast and intermediate spreading centers

    NASA Astrophysics Data System (ADS)

    Marjanovic, Milena

    The work presented in this dissertation depicts past and present signatures of melt distribution at fast and intermediate spreading centers. The primary goal of the studies included in this thesis is to provide better understanding of melt distribution and variation in melt physical properties within and at the base of oceanic crust formed at these spreading centers. Furthermore, this work examines effects that melt presence might have on formation and structural characteristics of oceanic crust. To explore the above we use geophysical data collected during two expeditions conducted along the Juan de Fuca Ridge (intermediate) and the East Pacific Rise (fast). The major part of the thesis is based on the work conducted on high resolution reflection seismic data that investigate present day intracrustal melt distribution along the East Pacific Rise (EPR) axis extending between 8°20' and 10°10'N. Here, the character of the melt reservoir is examined from different aspects and by using different seismic data analysis methods. By systematic analysis of the seismic reflection data, we show that the axial melt lens (AML) is segmented at different segment scales. Locations of the mapped disruptions in the AML correspond to previously identified tectonic discontinuities well expressed in the seafloor bathymetry. The above result corroborates genetic relationship between tectonic and magmatic segmentation. To examine melt distribution along the EPR, here for the first time we use amplitude variation with angle of incidence (AVA) crossplotting technique that was developed by oil and gas industry experts to look for presence of hydrocarbons. Further data examination for the first time for the mid-ocean ridges show presence of deeper lenses (lenses that are present below the AML). Presence of gaps in these sub-events and their collocation with what is believed to be the location of origin of the last documented eruption occurred in 2005--06, may shed light on the mechanisms

  3. Ground-water hydrology and water quality of Irwin Basin at Fort Irwin National Training Center, California

    USGS Publications Warehouse

    Densmore, Jill N.; Londquist, Clark J.

    1997-01-01

    Geohydrologic data were collected from Irwin Basin at Fort Irwin National Training Center in the Mojave Desert of southern California by the U.S. Geological Survey during 199296 to deter mine the quantity and quality of ground water available in this basin. In addition to data collected from existing wells and test holes, 17 monitoring sites were constructed in Irwin Basin to provide data on subsurface geology, ground-water levels, and ground-water quality. Eleven of these sites were multiple-well monitoring sites that were constructed to provide depth-dependent geohydrologic data in the aquifer system. The aquifer system of Irwin Basin, defined on the basis of hydrologic data collected from wells in Irwin Basin, consists of an upper and a lower aquifer. A 1994 water-table contour map shows that a cone of depression beneath Irwin Basin well field has developed as a result of ground-water development. Water-quality samples collected from Irwin Basin wells to determine potential sources of ground-water degradation indicate that water in three areas in the basin contains high nitrate and dissolved-solids concentrations. The stable isotopes of oxygen and hydrogen indicate that present-day precipitation is not a major source of recharge in this basin. Tritium and carbon-14 data indicate that most of the basin was recharged before 1953 and that this water may be more than 14,000 years old.

  4. Rapid detection of Naegleria fowleri in water distribution pipeline biofilms and drinking water samples.

    PubMed

    Puzon, Geoffrey J; Lancaster, James A; Wylie, Jason T; Plumb, Iason J

    2009-09-01

    Rapid detection of pathogenic Naegleria fowler in water distribution networks is critical for water utilities. Current detection methods rely on sampling drinking water followed by culturing and molecular identification of purified strains. This culture-based method takes an extended amount of time (days), detects both nonpathogenic and pathogenic species, and does not account for N. fowleri cells associated with pipe wall biofilms. In this study, a total DNA extraction technique coupled with a real-time PCR method using primers specific for N. fowleri was developed and validated. The method readily detected N. fowleri without preculturing with the lowest detection limit for N. fowleri cells spiked in biofilm being one cell (66% detection rate) and five cells (100% detection rate). For drinking water, the detection limit was five cells (66% detection rate) and 10 cells (100% detection rate). By comparison, culture-based methods were less sensitive for detection of cells spiked into both biofilm (66% detection for <10 cells) and drinking water (0% detection for <10 cells). In mixed cultures of N. fowleri and nonpathogenic Naegleria, the method identified N. fowleri in 100% of all replicates, whereastests with the current consensus primers detected N. fowleri in only 5% of all replicates. Application of the new method to drinking water and pipe wall biofilm samples obtained from a distribution network enabled the detection of N. fowleri in under 6 h, versus 3+ daysforthe culture based method. Further, comparison of the real-time PCR data from the field samples and the standard curves enabled an approximation of N. fowleri cells in the biofilm and drinking water. The use of such a method will further aid water utilities in detecting and managing the persistence of N. fowleri in water distribution networks.

  5. Climatic effects of atmospheric water vapor distribution through volcanic eruptions

    NASA Astrophysics Data System (ADS)

    Yim, W. W.

    2011-12-01

    Volcanic eruptions play an important role in changing the water vapor distribution of the atmosphere. In comparison with the emission of carbon dioxide released during the consumption of fossil fuel, water vapor's role in climate change has been grossly underestimated. Studies made of modern volcanic eruptions, including satellite images and meteorological records, have revealed climatic effects in different parts of the globe through the migration of volcanic clouds, depending mainly on their timing, location, Volcanic Explosivity Index (VEI) and composition. The climatic effects of volcanic eruptions include: (1) Reduction in solar heating because of the particulates discharged. (2) Interference with the 'normal' atmospheric circulation and/or oceanic circulation. (3) The ash particles and aerosols provide condensation nuclei for water. (4) The transfer from the troposphere into the stratosphere of water vapor which act as a greenhouse gas more important than carbon dioxide. (5) Variability in regional rainfall including the occurrence of droughts, floods, landslides salinization and crop failures. (6) Anomalous regional wind and rain storms. (7) Acid rain. Selected volcanic eruptions will be used as examples to illustrate the different climatic effects.

  6. Water-containing hydrogen-bonding network in the active center of channelrhodopsin.

    PubMed

    Ito, Shota; Kato, Hideaki E; Taniguchi, Reiya; Iwata, Tatsuya; Nureki, Osamu; Kandori, Hideki

    2014-03-01

    Channelrhodopsin (ChR) functions as a light-gated ion channel in Chlamydomonas reinhardtii. Passive transport of cations by ChR is fundamentally different from the active transport by light-driven ion pumps such as archaerhodopsin, bacteriorhodopsin, and halorhodopsin. These microbial rhodopsins are important tools for optogenetics, where ChR is used to activate neurons by light, while the ion pumps are used for neural silencing. Ion-transport functions by these rhodopsins strongly depend on the specific hydrogen-bonding networks containing water near the retinal chromophore. In this work, we measured protein-bound water molecules in a chimeric ChR protein of ChR1 (helices A to E) and ChR2 (helices F and G) of Chlamydomonas reinhardtii using low-temperature FTIR spectroscopy at 77 K. We found that the active center of ChR possesses more water molecules (9 water vibrations) than those of other microbial (2-6 water vibrations) and animal (6-8 water vibrations) rhodopsins. We conclude that the protonated retinal Schiff base interacts with the counterion (Glu162) directly, without the intervening water molecule found in proton-pumping microbial rhodopsins. The present FTIR results and the recent X-ray structure of ChR reveal a unique hydrogen-bonding network around the active center of this light-gated ion channel. PMID:24512107

  7. The inventory and distribution of water on Mars

    USGS Publications Warehouse

    Carr, M.H.

    1987-01-01

    Terrain softening, fretted channels, debris flows, and closed depressions indicate that at least the upper 2 km of the cratered uplands at high latitudes (>30??) contain ice in amounts that exceed the porosity, estimated to be 10-20 percent. Theoretical studies, and lack of these features in the cratered uplands at low latitudes, suggest that the upper 1 km of the uplands at low latitudes is ice poor. However, valley networks indicate that water was present near the surface early in the planet's history, although in amounts smaller than at high latitudes. On the basis of these observations, the entire upper 1 km, planet-wide is estimated to have contained 75-125 meters of water at the end of heavy bombardment. From the volume of water needed to cut the circum-Chryse channels, and assuming uniform planet-wide distribution of water, the deep megaregolith is estimated to have contained at least 350 meters of water at the end of heavy bombardment, thereby giving a total minimum inventory of 425-475 meters planet-wide. Most of the water lost from the low latitude uplands by diffusion and in cutting the valley networks is now believed to be in the polar layered terrains. Most of the water involved in cutting the outflow channels is in the low-lying northern plains where a variety of features that have been attributed to ground ice is present. Since the end of heavy bombardment, a large fraction of the planet's surface has been overplated with water-poor volcanics, of which we have samples in the SNC meteorites. The younger volcanics have reacted extensively with the old volatile-rich basement. Part of the 10-20 bars of CO2 and 0.1 to 0.3 bars of N2 outgassed with the water was lost during heavy bombardment by impact erosion of the atmosphere and other processes. The remaining was fixed carbonates and nitrates and folded deep into the megaregolith during heavy bombardment. ?? 1987.

  8. Hydrogeology and water quality of the shallow aquifer system at the Mainside, Naval Surface Warfare Center, Dahlgren Site, Dahlgren, Virginia

    USGS Publications Warehouse

    Harlow, G.E.; Bell, C.F.

    1996-01-01

    Lithologic and geophysical logs of boreholes at 29 sites show that the hydrogeologic framework of the Mainside of the Naval Surface Warfare Center, Dahlgren Site at Dahlgren, Virginia, consists of un-consolidated sedimentary deposits of gravel, sand, silt, and clay. The upper 220 feet of these sediments are divided into five hydrogeologic units, including the (1) Columbia (water-table) aquifer, (2) upper confining unit, (3) upper confined aquifer, (4) Nanjemoy-Marlboro confining unit, and (5) Aquia aquifer. The Columbia aquifer in the study area is a local system that is not affected by regional pumping. Ground-water recharge occurs at topographic highs in the northern part of the Mainside, and ground-water discharge occurs at topographic lows associated with adjacent surface-water bodies. Regionally, the direction of ground-water flow in the upper confined and Aquia aquifers is toward the southwest and southeast, respectively. A downward hydraulic gradient exists between the aquifers in the shallow system, and stresses on the Aquia aquifer are indicated by heads that range between 2 and 12 feet below sea level. The ratio of median horizontal hydraulic conductivity of the Columbia aquifer to median vertical hydraulic con-ductivity of the upper confining unit, however, is approximately 2,600:1; therefore, under natural- flow conditions, most water in the Columbia aquifer probably discharges to adjacent surface- water bodies. The composition and distribution of major ions vary in the Columbia aquifer. In general, water samples from wells located along the inland perimeter roads of the study area have chloride or a combination of chloride and sulfate as the dominant anions, and water samples from wells located in the interior of the study area have bicarbonate or a combination of bicarbonate and sulfate as the dominant anions. Sodium and calcium were the dominant cations in most samples. Dissolved solids and four inorganic constituents are present in water from the

  9. Modelling income distribution impacts of water sector projects in Bangladesh.

    PubMed

    Ahmed, C S; Jones, S

    1991-09-01

    Dynamic analysis was conducted to assess the long-term impacts of water sector projects on agricultural income distribution, and sensitivity analysis was conducted to check the robustness of the 5 assumptions in this study of income distribution and water sector projects in Bangladesh. 7 transitions are analyzed for mutually exclusive irrigation and flooding projects: Nonirrigation to 1) LLP irrigation, 2) STW irrigation, 3) DTW irrigation, 4) major gravity irrigation, and manually operated shallow tubewell irrigation (MOSTI) and Flood Control Projects (FCD) of 6) medium flooded to shallow flooded, and 7) deeply flooded to shallow flooded. 5 analytical stages are involved: 1) farm budgets are derived with and without project cropping patterns for each transition. 2) Estimates are generated for value added/hectare from each transition. 3) Assumptions are made about the number of social classes, distribution of land ownership between classes, extent of tenancy for each social class, term of tenancy contracts, and extent of hiring of labor for each social class. 4) Annual value added/hectare is distributed among social classes. 5) Using Gini coefficients and simple ratios, the distribution of income between classes is estimated for with and without transition. Assumption I is that there are 4 social classes defined by land acreage: large farmers (5 acres), medium farmers (1.5-5.0), small farmers, (.01-1.49), and landless. Assumption II is that land distribution follows the 1978 Land Occupancy Survey (LOS). Biases, if any, are indicated. Assumption III is that large farmers sharecrop out 15% of land to small farmers. Assumption IV is that landlords provide nonirrigated crop land and take 50% of the crop, and, under irrigation, provide 50% of the fertilizer, pesticide, and irrigation costs and take 50% of the crop. Assumption V is that hired and family labor is assumed to be 40% for small farmers, 60% for medium farmers, and 80% for large farmers. It is understood that

  10. Modelling income distribution impacts of water sector projects in Bangladesh.

    PubMed

    Ahmed, C S; Jones, S

    1991-09-01

    Dynamic analysis was conducted to assess the long-term impacts of water sector projects on agricultural income distribution, and sensitivity analysis was conducted to check the robustness of the 5 assumptions in this study of income distribution and water sector projects in Bangladesh. 7 transitions are analyzed for mutually exclusive irrigation and flooding projects: Nonirrigation to 1) LLP irrigation, 2) STW irrigation, 3) DTW irrigation, 4) major gravity irrigation, and manually operated shallow tubewell irrigation (MOSTI) and Flood Control Projects (FCD) of 6) medium flooded to shallow flooded, and 7) deeply flooded to shallow flooded. 5 analytical stages are involved: 1) farm budgets are derived with and without project cropping patterns for each transition. 2) Estimates are generated for value added/hectare from each transition. 3) Assumptions are made about the number of social classes, distribution of land ownership between classes, extent of tenancy for each social class, term of tenancy contracts, and extent of hiring of labor for each social class. 4) Annual value added/hectare is distributed among social classes. 5) Using Gini coefficients and simple ratios, the distribution of income between classes is estimated for with and without transition. Assumption I is that there are 4 social classes defined by land acreage: large farmers (5 acres), medium farmers (1.5-5.0), small farmers, (.01-1.49), and landless. Assumption II is that land distribution follows the 1978 Land Occupancy Survey (LOS). Biases, if any, are indicated. Assumption III is that large farmers sharecrop out 15% of land to small farmers. Assumption IV is that landlords provide nonirrigated crop land and take 50% of the crop, and, under irrigation, provide 50% of the fertilizer, pesticide, and irrigation costs and take 50% of the crop. Assumption V is that hired and family labor is assumed to be 40% for small farmers, 60% for medium farmers, and 80% for large farmers. It is understood that

  11. Methane Distribution In Plumes Of The South Mariana Back-arc Spreading Center

    NASA Astrophysics Data System (ADS)

    Toki, T.; Hirota, A.; Tsunogai, U.; Gamo, T.; Nakamura, K.; Noguchi, T.; Taira, N.; Oomori, T.; Ishibashi, J.; Utsumi, M.

    2004-12-01

    In the South Mariana Back-arc Spreading Center, two methane plumes were observed in water column based on analysis of methane in seawater samples collected during the R/V Thompson expeditions in 2003 around water depth of 2,700 m over the Fryer site on the ridge-axis seamount (12\\deg57.22N, 143\\deg37.16E, depth: 2,850 m). The estimated end-member isotopic compositions of methane in the two plumes are \\delta13C_{CH4} = -5‰ PDB and -50‰ PDB. These values indicated that the two plumes were originated from the different sources. During YK03-09 cruise using the submersible Shinkai 6500 from October to November in 2003, detailed seafloor observation discovered sulfide chimneys emitting black and clear hydrothermal fluid on the off-axis seamount at Pika site (12°55.15N, 143°36.96E, depth: 2,773 m). The result of analysis of isotopic composition of methane in the hydrothermal fluids recovered from the off-axis hydrothermal vents using WHATS (Water and Hydrothermal Atsuryoku Tight Sampler) was averaged value of -4‰ PDB (standard deviation = 1‰ PDB, n = 3). Hydrothermal fluids from the Fryer site were also sampled and were measured: average value = -6.7‰ PDB, standard deviation = 0.3‰ PDB, n = 3. During the R/V Thompson expeditions in March 2004 using ROV ROPOS, 11 ROPOS dives and CTD-RMS plume surveys were conducted, and newly discovered a huge hydrothermal structure with active fluid venting at Achaean site on the ridge skirt (12°56.37N, 143°37.92E, depth: 2,990 m). The δ ^{13}C_{CH4} value of the fluid sample from the site using ROCS (Rotary Clean Seawater sampler) was -14.7‰ PDB. Analysis of isotopic composition of methane in the plume samples collected using the CTD-hydrocast at water depth of 2,500 m over the Archaean site showed -45‰ PDB. Source of methane (δ ^{13}C_{CH4} = -50‰ PDB), however, in the two plumes of the South Mariana Back-arc Spreading Center has been missing. The δ ^{13}C of methane cannot be considered in sediment

  12. RELATIONSHIPS BETWEEN LEVELS OF HETEROTROPHIC BACTERIA AND WATER QUALITY PARAMETERS IN A DRINKING WATER DISTRIBUTION SYSTEM

    EPA Science Inventory

    Conventional plating methods were used to quantify heterotrophic bacteria from a drinking water distribution system. Three media, plate count agar (PCA), R2A agar and sheep blood agar (TSA-SB) were used to determine heterotrophic plate count (HPC) levels. Grab samples were collec...

  13. IMPACT ON WATER DISTRIBUTION SYSTEM BIOFILM DENSITIES FROM REVERSE OSMOSIS MEMBRANE TREATMENT OF SUPPLY WATER

    EPA Science Inventory

    The quality of potable water is such that the concentration of nutrients available for growth of microorganisms within distribution systems is limited. In such systems carbon is often the growth limiting nutrient. Research conducted in the Netherlands has indicated that low level...

  14. A Visual Insight into the Degradation of Metals Used in Drinking Water Distribution Systems Using AFM

    EPA Science Inventory

    Evaluating the fundamental corrosion and passivation of metallic copper used in drinking water distribution materials is important in understanding the overall mechanism of the corrosion process. Copper pipes are widely used for drinking water distribution systems and although it...

  15. Local Environment Distribution in Ab Initio Liquid Water

    NASA Astrophysics Data System (ADS)

    Santra, Biswajit; Distasio, Robert A., Jr.; Car, Roberto

    2013-03-01

    We have analyzed the distribution of local environments in liquid water at ambient conditions and its inherent potential energy surface (IPES) based on state-of-the-art ab initio molecular dynamics simulations performed on 128 molecules implementing hybrid PBE0 exchange [PRB 79, 085102 (2009)] and van der Waals (vdW) interactions [PRL 102, 073005 (2009)]. The local environments of molecules are characterized in terms of the local structure index (LSI) [JCP 104, 7671 (1996)] which is able to distinguish high- and low-density molecular environments. In agreement with simulations based on model potentials, we find that the distribution of LSI is unimodal at ambient conditions and bimodal in the IPES, consistent with the existence of polymorphism in amorphous phases of water. At ambient conditions spatial LSI fluctuations extend up to ~7 Å and their dynamical correlation decays on a time scale of ~3 ps, as found for density fluctuations in a recent study [PRL 106, 037801 (2011)]. DOE: DE-SC0008626, DOE: DE-SC0005180, NSF: CHE-0956500

  16. Web Services Implementations at Land Process and Goddard Earth Sciences Distributed Active Archive Centers

    NASA Astrophysics Data System (ADS)

    Cole, M.; Bambacus, M.; Lynnes, C.; Sauer, B.; Falke, S.; Yang, W.

    2007-12-01

    NASA's vast array of scientific data within its Distributed Active Archive Centers (DAACs) is especially valuable to both traditional research scientists as well as the emerging market of Earth Science Information Partners. For example, the air quality science and management communities are increasingly using satellite derived observations in their analyses and decision making. The Air Quality Cluster in the Federation of Earth Science Information Partners (ESIP) uses web infrastructures of interoperability, or Service Oriented Architecture (SOA), to extend data exploration, use, and analysis and provides a user environment for DAAC products. In an effort to continually offer these NASA data to the broadest research community audience, and reusing emerging technologies, both NASA's Goddard Earth Science (GES) and Land Process (LP) DAACs have engaged in a web services pilot project. Through these projects both GES and LP have exposed data through the Open Geospatial Consortiums (OGC) Web Services standards. Reusing several different existing applications and implementation techniques, GES and LP successfully exposed a variety data, through distributed systems to be ingested into multiple end-user systems. The results of this project will enable researchers world wide to access some of NASA's GES & LP DAAC data through OGC protocols. This functionality encourages inter-disciplinary research while increasing data use through advanced technologies. This paper will concentrate on the implementation and use of OGC Web Services, specifically Web Map and Web Coverage Services (WMS, WCS) at GES and LP DAACs, and the value of these services within scientific applications, including integration with the DataFed air quality web infrastructure and in the development of data analysis web applications.

  17. Evaluation of a distributed catchment scale water balance model

    NASA Technical Reports Server (NTRS)

    Troch, Peter A.; Mancini, Marco; Paniconi, Claudio; Wood, Eric F.

    1993-01-01

    The validity of some of the simplifying assumptions in a conceptual water balance model is investigated by comparing simulation results from the conceptual model with simulation results from a three-dimensional physically based numerical model and with field observations. We examine, in particular, assumptions and simplifications related to water table dynamics, vertical soil moisture and pressure head distributions, and subsurface flow contributions to stream discharge. The conceptual model relies on a topographic index to predict saturation excess runoff and on Philip's infiltration equation to predict infiltration excess runoff. The numerical model solves the three-dimensional Richards equation describing flow in variably saturated porous media, and handles seepage face boundaries, infiltration excess and saturation excess runoff production, and soil driven and atmosphere driven surface fluxes. The study catchments (a 7.2 sq km catchment and a 0.64 sq km subcatchment) are located in the North Appalachian ridge and valley region of eastern Pennsylvania. Hydrologic data collected during the MACHYDRO 90 field experiment are used to calibrate the models and to evaluate simulation results. It is found that water table dynamics as predicted by the conceptual model are close to the observations in a shallow water well and therefore, that a linear relationship between a topographic index and the local water table depth is found to be a reasonable assumption for catchment scale modeling. However, the hydraulic equilibrium assumption is not valid for the upper 100 cm layer of the unsaturated zone and a conceptual model that incorporates a root zone is suggested. Furthermore, theoretical subsurface flow characteristics from the conceptual model are found to be different from field observations, numerical simulation results, and theoretical baseflow recession characteristics based on Boussinesq's groundwater equation.

  18. Standards and guides of water treatment and water-distribution systems. Volume 2. Manual for 1987-1988

    SciTech Connect

    Wang, L.K.; Wang, M.H.S.

    1988-04-15

    The following 6 important documents are compiled for design of municipal water treatment facilities and water distribution systems: (1) Standards of the Construction of Public Community Water Systems; (2) Community System Design Standards; (3) Bottled Water, Bulk Water Hauling and Vending Machines; (4) Noncommunity System Design Standards; (5) Operation and Maintenance; and (6) Cross-Contamination Control.

  19. Water Vapour Abundance and Distribution in the Lower Venusian Atmosphere

    NASA Astrophysics Data System (ADS)

    Chamberlain, S.; Bailey, J.

    2012-04-01

    We present ground-based observations and modelling studies of water vapour abundance and distribution in the Venusian lower atmosphere through analysis of absorption band depths within the 1.18 μm window. The lower atmosphere of Venus is difficult to study by both in situ and remote instruments. This is due to the planet wide cloud cover that obscures visual wavelengths and surface pressures approaching 100 times that of the Earth. In 1984 ground based observations resulted in the discovery of atmospheric windows on the Venusian nightside (Allen and Crawford, 1984). Here, near infrared radiation originating at the surface and lower atmosphere, pass relatively unimpeded through the Venus clouds. This discovery enabled remote studies of the Venusian subcloud region. Determining the abundance and distribution of water vapour is key to understanding the development, maintenance and links between major radiative and dynamical features of the Venus atmosphere. Water vapour in the lower atmosphere plays an important role in heat transfer and is pertinent to the runaway greenhouse effect and dynamical superrotation observed on Venus. Detailed studies of water vapour abundance and distribution throughout the lower atmosphere of Venus are therefore needed in order to develop accurate chemical, radiative and dynamical models. Ground-based spatially resolved near infrared spectroscopic observations of the Venusian nightside have been obtained from Siding Spring Observatory at each inferior conjunction since 2002. Observations have been made using the IRIS2 instrument on the Anglo-Australian Telescope and CASPIR on the 2.3m ANU telescope. The model VSTAR (Bailey and Kedziora-Chudczer 2012) is used to simulate the observed Venus spectra as seen through the Earth's atmosphere and best fit water vapour abundances are found for approximately 300 locations across the Venus nightside disk. Recent improvements in ground-based near-infrared instruments allow a substantial improvement

  20. Factors controlling the regional distribution of vanadium in ground water

    USGS Publications Warehouse

    Wright, Michael T.; Belitz, Kenneth

    2010-01-01

    Although the ingestion of vanadium (V) in drinking water may have possible adverse health effects, there have been relatively few studies of V in groundwater. Given the importance of groundwater as a source of drinking water in many areas of the world, this study examines the potential sources and geochemical processes that control the distribution of V in groundwater on a regional scale. Potential sources of V to groundwater include dissolution of V rich rocks, and waste streams from industrial processes. Geochemical processes such as adsorption/desorption, precipitation/dissolution, and chemical transformations control V concentrations in groundwater. Based on thermodynamic data and laboratory studies, V concentrations are expected to be highest in samples collected from oxic and alkaline groundwater. However, the extent to which thermodynamic data and laboratory results apply to the actual distribution of V in groundwater is not well understood. More than 8400 groundwater samples collected in California were used in this study. Of these samples, high (> or = 50 μg/L) and moderate (25 to 49 μg/L) V concentrations were most frequently detected in regions where both source rock and favorable geochemical conditions occurred. The distribution of V concentrations in groundwater samples suggests that significant sources of V are mafic and andesitic rock. Anthropogenic activities do not appear to be a significant contributor of V to groundwater in this study. High V concentrations in groundwater samples analyzed in this study were almost always associated with oxic and alkaline groundwater conditions, which is consistent with predictions based on thermodynamic data.

  1. Stability and effectiveness of chlorine disinfectants in water distribution systems

    SciTech Connect

    Olivieri, V.P.; Snead, M.C.; Kruse, C.W.; Kawata, K.

    1986-11-01

    A test system for water distribution was used to evaluate the stability and effectiveness of three residual disinfectants - free chlorine, combined chlorine, and chlorine dioxide - when challenged with a sewage contaminant. The test distribution system consisted of the street main and internal plumbing for two barracks at Fort George G. Meade, MD. To the existing pipe network, 152 m (500 ft) of 13-mm (0.5 in.) copper pipe were added for sampling, and 60 m (200 ft) of 2.54-cm (1.0 in.) plastic pipe were added for circulation. The levels of residual disinfectants tested were 0.2 mg/L and 1.0 mg/L as available chlorine. In the absence of a disinfectant residual, microorganisms in the sewage contaminant were consistently recovered at high levels. The presence of any disinfectant residual reduced the microorganism level and frequency of occurrence at the consumer's tap. Free chlorine was the most effective residual disinfectant and may serve as a marker or flag in the distribution network. Free chlorine and chlorine dioxide were the least stable in the pipe network. The loss of disinfectant in the pipe network followed first-order kinetics. The half-life determined in static tests for free chlorine, chlorine dioxide, and combined chlorine was 140, 93, and 1680 min.

  2. Environmental Data from the ORNL Distributed Active Archive Center (DAAC) for Biogeochemical Dynamics

    DOE Data Explorer

    The Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC) is a NASA-sponsored source for biogeochemical and ecological data and models useful in environmental research. Data have been collected on the ground, by aircraft, by satellite, and from computer models. The extent of data and model products ranges from site specific to global, and durations range from days to years. Data products and models are free, but users must typically register. Major field campaigns with available data include: • The Boreal Ecosystem - Atmosphere Study (BOREAS) • The First ISLSCP (International Satellite Land Surface Climatology Project) Field Experiment (FIFE) Project) • The Large-Scale Biosphere - Atmosphere Experiment in Amazonia (LBA) • The North American Carbon Program (NACP) • Oregon Transect Ecosystem Research (OTTER) Project • The SAFARI 2000 (S2K) Project in Africa • Superior National Forest(SNF)Project Validation projects with available data include: • BigFoot • The Accelerated Canopy Chemistry Program (ACCP) • The EOS Land Validation Project • FLUXNET • MODIS • The Prototype Validation Exercise (PROVE) The ORNL DAAC also provides access to data for many regional and global projects and to a model archive. (Specialized Interface)(Registration Required)

  3. Spatial distribution of dissolved constituents in Icelandic river waters

    NASA Astrophysics Data System (ADS)

    Oskarsdottir, Sigrídur Magnea; Gislason, Sigurdur Reynir; Snorrason, Arni; Halldorsdottir, Stefanía Gudrún; Gisladottir, Gudrún

    2011-02-01

    SummaryIn this study we map the spatial distribution of selected dissolved constituents in Icelandic river waters using GIS methods to study and interpret the connection between river chemistry, bedrock, hydrology, vegetation and aquatic ecology. Five parameters were selected: alkalinity, SiO 2, Mo, F and the dissolved inorganic nitrogen and dissolved inorganic phosphorus mole ratio (DIN/DIP). The highest concentrations were found in rivers draining young rocks within the volcanic rift zone and especially those draining active central volcanoes. However, several catchments on the margins of the rift zone also had high values for these parameters, due to geothermal influence or wetlands within their catchment area. The DIN/DIP mole ratio was higher than 16 in rivers draining old rocks, but lowest in rivers within the volcanic rift zone. Thus primary production in the rivers is limited by fixed dissolved nitrogen within the rift zone, but dissolved phosphorus in the old Tertiary catchments. Nitrogen fixation within the rift zone can be enhanced by high dissolved molybdenum concentrations in the vicinity of volcanoes. The river catchments in this study were subdivided into several hydrological categories. Importantly, the variation in the hydrology of the catchments cannot alone explain the variation in dissolved constituents. The presence or absence of central volcanoes, young reactive rocks, geothermal systems and wetlands is important for the chemistry of the river waters. We used too many categories within several of the river catchments to be able to determine a statistically significant connection between the chemistry of the river waters and the hydrological categories. More data are needed from rivers draining one single hydrological category. The spatial dissolved constituent distribution clearly revealed the difference between the two extremes, the young rocks of the volcanic rift zone and the old Tertiary terrain.

  4. Nitric and nitrous oxide emissions and soil nitrate distribution in a center-pivot-irrigated cornfield

    SciTech Connect

    Guenzi, W.D.; Hutchinson, G.L.; Beard, W.E.

    1994-05-01

    Research on soil N loss mechanisms remains a high priority not only because of the need to increase agricultural N use efficiency, but also because of environmental concerns such as NO{sub 3}{sup -} contamination of groundwater and increasing N oxide concentrations in the atmosphere. We measured NO and N{sub 2}O emissions and downward movement of NO{sub 3}{sup -} in an eastern Colorado corn (Zea mays L.) field irrigated with a modified center-pivot system that applied water to alternate furrows. One hour after infiltration of the irrigation water, emission rates measured by an enclosure method ranged from 0 to 6 g N ha{sup -1} d{sup -1}for NO and 0 to 26 g N ha{sup -1} d{sup -1} for N{sub 2}O. The emission rates wine largest after the first irrigation and much smaller following subsequent irrigations. Greater N oxide evolution from nonirrigated furrows than adjacent irrigated furrows probably resulted from lateral transport of gases produced in the wet soil. Analyses of soil cores taken after planting and after harvest provided no evidence that NO{sub 3}{sup -} moved below the root zone during the growing season, despite the presence of substantially more inorganic N than required for maximum corn yield. These data suggest that when the size and frequency of irrigations are efficiently managed, use of a low energy precision application (LEPA) irrigation system results in no loss to groundwater and no economically significant gaseous N oxide loss to the atmosphere. 23 refs., 3 figs., 2 tabs.

  5. Distribution of diffuse flow megafauna in two sites on the Eastern Lau Spreading Center, Tonga

    NASA Astrophysics Data System (ADS)

    Podowski, Elizabeth L.; Moore, Tom S.; Zelnio, Kevin A.; Luther, George W., III; Fisher, Charles R.

    2009-11-01

    Hydrothermal vent environments are characterized by large gradients of toxic chemicals and high temperatures, which play a significant role in defining species' distributions. We used high-resolution imagery and spatially explicit in-situ physico-chemical measurements analyzed within a Geographic Information System (GIS) in order to characterize the spatial relations among different groups of megafauna, temperature, and chemistry within two discrete vent communities (40 and 50 m 2) on the Eastern Lau Spreading Center (ELSC). Chemical (sulfide and O 2 concentrations) and temperature data were obtained from approximately 75 different locations within each community using in-situ instruments. All data were integrated into a GIS, which served as a visualization tool and enabled the data to be analyzed in a spatial context. Our results confirm the importance of abiotic variables in defining the distributions of some fauna and elucidate several biological associations that are consistent between the two communities. The provannid snail, Alviniconcha spp., appears to actively avoid temperatures above 32-46 °C and/or sulfide concentrations exceeding approximately 260 μM. Slightly higher average sulfide concentrations and temperatures were measured among aggregations of Ifremeria nautilei compared to aggregations of the mussel Bathymodiolus brevior; however, the presence of mixed aggregations of the two species indicates an overlap in requirements. The brachyuran crab, Austinograea spp., was consistently observed directly on symbiont-containing species, particularly Alviniconcha spp. The solitary snail, Eosipho desbruyeresi, was rarely observed on biological substrata, but was often (60% of its population at the most active site) within 5 cm of symbiont-containing fauna, indicating a tolerance and preference for proximity to areas of high productivity. Densities and coverage of species differed substantially between the two communities despite high species overlap

  6. Water quality modeling in the dead end sections of drinking water distribution networks.

    PubMed

    Abokifa, Ahmed A; Yang, Y Jeffrey; Lo, Cynthia S; Biswas, Pratim

    2016-02-01

    Dead-end sections of drinking water distribution networks are known to be problematic zones in terms of water quality degradation. Extended residence time due to water stagnation leads to rapid reduction of disinfectant residuals allowing the regrowth of microbial pathogens. Water quality models developed so far apply spatial aggregation and temporal averaging techniques for hydraulic parameters by assigning hourly averaged water demands to the main nodes of the network. Although this practice has generally resulted in minimal loss of accuracy for the predicted disinfectant concentrations in main water transmission lines, this is not the case for the peripheries of the distribution network. This study proposes a new approach for simulating disinfectant residuals in dead end pipes while accounting for both spatial and temporal variability in hydraulic and transport parameters. A stochastic demand generator was developed to represent residential water pulses based on a non-homogenous Poisson process. Dispersive solute transport was considered using highly dynamic dispersion rates. A genetic algorithm was used to calibrate the axial hydraulic profile of the dead-end pipe based on the different demand shares of the withdrawal nodes. A parametric sensitivity analysis was done to assess the model performance under variation of different simulation parameters. A group of Monte-Carlo ensembles was carried out to investigate the influence of spatial and temporal variations in flow demands on the simulation accuracy. A set of three correction factors were analytically derived to adjust residence time, dispersion rate and wall demand to overcome simulation error caused by spatial aggregation approximation. The current model results show better agreement with field-measured concentrations of conservative fluoride tracer and free chlorine disinfectant than the simulations of recent advection dispersion reaction models published in the literature. Accuracy of the simulated

  7. Water quality modeling in the dead end sections of drinking water distribution networks.

    PubMed

    Abokifa, Ahmed A; Yang, Y Jeffrey; Lo, Cynthia S; Biswas, Pratim

    2016-02-01

    Dead-end sections of drinking water distribution networks are known to be problematic zones in terms of water quality degradation. Extended residence time due to water stagnation leads to rapid reduction of disinfectant residuals allowing the regrowth of microbial pathogens. Water quality models developed so far apply spatial aggregation and temporal averaging techniques for hydraulic parameters by assigning hourly averaged water demands to the main nodes of the network. Although this practice has generally resulted in minimal loss of accuracy for the predicted disinfectant concentrations in main water transmission lines, this is not the case for the peripheries of the distribution network. This study proposes a new approach for simulating disinfectant residuals in dead end pipes while accounting for both spatial and temporal variability in hydraulic and transport parameters. A stochastic demand generator was developed to represent residential water pulses based on a non-homogenous Poisson process. Dispersive solute transport was considered using highly dynamic dispersion rates. A genetic algorithm was used to calibrate the axial hydraulic profile of the dead-end pipe based on the different demand shares of the withdrawal nodes. A parametric sensitivity analysis was done to assess the model performance under variation of different simulation parameters. A group of Monte-Carlo ensembles was carried out to investigate the influence of spatial and temporal variations in flow demands on the simulation accuracy. A set of three correction factors were analytically derived to adjust residence time, dispersion rate and wall demand to overcome simulation error caused by spatial aggregation approximation. The current model results show better agreement with field-measured concentrations of conservative fluoride tracer and free chlorine disinfectant than the simulations of recent advection dispersion reaction models published in the literature. Accuracy of the simulated

  8. Streamflow, groundwater, and water-quality monitoring by USGS Nevada Water Science Center

    USGS Publications Warehouse

    Gipson, Marsha L.; Schmidt, Kurtiss

    2013-01-01

    The U.S. Geological Survey (USGS) has monitored and assessed the quantity and quality of our Nation's streams and aquifers since its inception in 1879. Today, the USGS provides hydrologic information to aid in the evaluation of the availability and suitability of water for public and domestic supply, agriculture, aquatic ecosystems, mining, and energy development. Although the USGS has no responsibility for the regulation of water resources, the USGS hydrologic data complement much of the data collected by state, county, and municipal agencies, tribal nations, U.S. District Court Water Masters, and other federal agencies such as the Environmental Protection Agency, which focuses on monitoring for regulatory compliance. The USGS continues its mission to provide timely and relevant water-resources data and information that are available to water-resource managers, non-profit organizations, industry, academia, and the public. Data collected by the USGS provide the science needed for informed decision-making related to resource management and restoration, assessment of flood and drought hazards, ecosystem health, and effects on water resources from land-use changes.

  9. Characterization of anthropogenic impacts in a large urban center by examining the spatial distribution of halogenated flame retardants.

    PubMed

    Wei, Yan-Li; Bao, Lian-Jun; Wu, Chen-Chou; Zeng, Eddy Y

    2016-08-01

    Anthropogenic impacts have continuously intensified in mega urban centers with increasing urbanization and growing population. The spatial distribution pattern of such impacts can be assessed with soil halogenated flame retardants (HFRs) as HFRs are mostly derived from the production and use of various consumer products. In the present study, soil samples were collected from the Pearl River Delta (PRD), a large urbanized region in southern China, and its surrounding areas and analyzed for a group of HFRs, i.e., polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane, bis(hexachlorocyclopentadieno)cyclooctane (DP) and hexabromobenzene. The sum concentrations of HFRs and PBDEs were in the ranges of 0.66-6500 and 0.37-5700 (mean: 290 and 250) ng g(-1) dry weight, respectively, around the middle level of the global range. BDE-209 was the predominant compound likely due to the huge amounts of usage and its persistence. The concentrations of HFRs were greater in the land-use types of residency, industry and landfill than in agriculture, forestry and drinking water source, and were also greater in the central PRD than in its surrounding areas. The concentrations of HFRs were moderately significantly (r(2) = 0.32-0.57; p < 0.05) correlated with urbanization levels, population densities and gross domestic productions in fifteen administrative districts. The spatial distribution of DP isomers appeared to be stereoselective as indicated by the similarity in the spatial patterns for the ratio of anti-DP versus the sum of DP isomers (fanti-DP) and DP concentrations. Finally, the concentrations of HFRs sharply decreased with increasing distance from an e-waste recycling site, indicating that e-waste derived HFRs largely remained in local soil. PMID:27203466

  10. Strategic plan for science-U.S. Geological Survey, Ohio Water Science Center, 2010-15

    USGS Publications Warehouse

    ,

    2010-01-01

    This Science Plan identifies specific scientific and technical programmatic issues of current importance to Ohio and the Nation. An examination of those issues yielded a set of five major focus areas with associated science goals and strategies that the Ohio Water Science Center will emphasize in its program during 2010-15. A primary goal of the Science Plan is to establish a relevant multidisciplinary scientific and technical program that generates high-quality products that meet or exceed the expectations of our partners while supporting the goals and initiatives of the U.S. Geological Survey. The Science Plan will be used to set the direction of new and existing programs and will influence future training and hiring decisions by the Ohio Water Science Center.

  11. Water quality in the proposed Prosperity Reservoir area, Center Creek Basin, Missouri

    USGS Publications Warehouse

    Barks, James H.; Berkas, Wayne R.

    1979-01-01

    Water in Center Creek basin, Mo., upstream from the proposed Prosperity Reservoir damsite is a calcium bicarbonate type that is moderately mineralized, hard, and slightly alkaline. Ammonia and organic nitrogen, phosphorus, total organic carbon, chemical oxygen demand, and bacteria increased considerably during storm runoff, probably due to livestock wastes. Nitrogen and phosphorus concentrations are probably high enough to cause the proposed lake to be eutrophic. Minor-element concentrations were at or near normal levels in Center and Jones Creeks. The only pesticides detected were 0.01 micrograms per liter of 2, 4, 5-T in one base-flow sample and 0.02 to 0.04 micrograms per liter of 2, 4, 5-T and 2, 4-D in all storm-runoff samples. Fecal coliform and fecal streptococcus densities ranged from 2 to 650 and 2 to 550 colonies per 100 milliliters, respectively, during base flow , but were 17,000 to 45,000 and 27,000 to 70,000 colonies per 100 milliliters, respectively, during storm runoff. Water in Center Creek about 2.5 miles downstream from the proposed damsite is similar in quality to that upstream from the damsite except for higher concentrations of sodium, sulfate, chloride, fluoride, nitrogen, and phosphorus. These higher concentrations are caused by fertilizer industry wastes that enter Center Creek about 1.0 mile downstream from the proposed damsite. (Woodard-USGS).

  12. Creatine Supplementation Increases Total Body Water Without Altering Fluid Distribution.

    PubMed

    Powers, Michael E.; Arnold, Brent L.; Weltman, Arthur L.; Perrin, David H.; Mistry, Dilawaar; Kahler, David M.; Kraemer, William; Volek, Jeff

    2003-03-01

    OBJECTIVE: To examine the effects of oral creatine (Cr) monohydrate supplementation on muscle Cr concentration, body mass, and total body water (TBW), extracellular water (ECW), and intracellular water (ICW) volumes. DESIGN AND SETTING: After an overnight fast, urinary Cr and creatinine concentrations, muscle Cr concentration, body mass, TBW, ECW, and ICW were measured, and subjects were randomly assigned to either a Cr or a placebo (P) group. The Cr group ingested 25 g/d of Cr for 7 days (loading phase) and 5 g/d for the remaining 21 days (maintenance phase), whereas the P group ingested a sucrose P using the same protocol. All the measures were reassessed immediately after the loading and maintenance phases. SUBJECTS: Sixteen men (age = 22.8 +/- 3.01 years, height = 179.8 +/- 7.1 cm, body mass = 84.8 +/- 11.2 kg) and 16 women (age = 21.8 +/- 2.51 years, height = 163.4 +/- 5.9 cm, body mass = 63.6 +/- 14.0 kg) involved in resistance training volunteered to participate in this study. MEASUREMENTS: Muscle Cr concentration was determined from the vastus lateralis muscle using a percutaneous needle-biopsy technique. Total body water, ECW, and ICW volumes were assessed using deuterium oxide and sodium bromide dilution analyses. RESULTS: The Cr group experienced a significant increase in muscle Cr concentration, body mass, and TBW. The P group experienced a small but significant increase in TBW only. CONCLUSIONS: The Cr supplementation protocol was effective for increasing muscle Cr concentrations, body mass, and TBW; however, fluid distribution was not changed.

  13. Creatine Supplementation Increases Total Body Water Without Altering Fluid Distribution

    PubMed Central

    Arnold, Brent L.; Weltman, Arthur L.; Perrin, David H.; Mistry, Dilawaar; Kahler, David M.; Kraemer, William; Volek, Jeff

    2003-01-01

    Objective: To examine the effects of oral creatine (Cr) monohydrate supplementation on muscle Cr concentration, body mass, and total body water (TBW), extracellular water (ECW), and intracellular water (ICW) volumes. Design and Setting: After an overnight fast, urinary Cr and creatinine concentrations, muscle Cr concentration, body mass, TBW, ECW, and ICW were measured, and subjects were randomly assigned to either a Cr or a placebo (P) group. The Cr group ingested 25 g/d of Cr for 7 days (loading phase) and 5 g/d for the remaining 21 days (maintenance phase), whereas the P group ingested a sucrose P using the same protocol. All the measures were reassessed immediately after the loading and maintenance phases. Subjects: Sixteen men (age = 22.8 ± 3.01 years, height = 179.8 ± 7.1 cm, body mass = 84.8 ± 11.2 kg) and 16 women (age = 21.8 ± 2.51 years, height = 163.4 ± 5.9 cm, body mass = 63.6 ± 14.0 kg) involved in resistance training volunteered to participate in this study. Measurements: Muscle Cr concentration was determined from the vastus lateralis muscle using a percutaneous needle-biopsy technique. Total body water, ECW, and ICW volumes were assessed using deuterium oxide and sodium bromide dilution analyses. Results: The Cr group experienced a significant increase in muscle Cr concentration, body mass, and TBW. The P group experienced a small but significant increase in TBW only. Conclusions: The Cr supplementation protocol was effective for increasing muscle Cr concentrations, body mass, and TBW; however, fluid distribution was not changed. PMID:12937471

  14. Spatial distributions and seasonal variations of organochlorine pesticides in water and soil samples in Bolu, Turkey.

    PubMed

    Karadeniz, Hatice; Yenisoy-Karakaş, Serpil

    2015-03-01

    In this study, a total of 75 water samples (38 groundwater and 37 surface water samples) and 54 surface soil samples were collected from the five districts of Bolu, which is located in the Western Black Sea Region of Turkey in the summer season of 2009. In the autumn season, 17 water samples (surface water and groundwater samples) and 17 soil samples were collected within the city center to observe the seasonal changes of organochlorine pesticides (OCPs). Groundwater and surface water samples were extracted using solid phase extraction. Soil samples were extracted ultrasonically. Sixteen OCP compounds in the standard solution were detected by a gas chromatography-electron capture detector (GC-ECD). Therefore, the method validation was performed for those 16 OCP compounds. However, 13 OCP compounds could be observed in the samples. The concentrations of most OCPs were higher in samples collected in the summer than those in the autumn. The most frequently observed pesticides were endosulfan sulfate and 4,4'-dichlorodiphenyltrichloroethane (DDT) in groundwater samples, α-HCH in surface water samples, and endosulfan sulfate in soil samples. The average concentration of endosulfan sulfate was the highest in water and soil samples. Compared to the literature values, the average concentrations in this study were lower values. Spatial distribution of OCPs was evaluated with the aid of contour maps for the five districts of Bolu. Generally, agricultural processes affected the water and soil quality in the region. However, non-agricultural areas were also affected by pesticides. The concentrations of pesticides were below the legal limits of European directives for each pesticide.

  15. NASA's Marshall Space Flight Center Saves Water With High-Efficiency Toilet and Urinal Program

    SciTech Connect

    2011-02-22

    The National Aeronautics and Space Administration’s (NASA) Marshall Space Flight Center (MSFC) has a longstanding, successful sustainability program that focuses on energy and water efficiency as well as environmental protection. Because MSFC was built in the 1960s, most of the buildings house outdated, inefficient restroom fixtures. The facility engineering team at MSFC developed an innovative efficiency model for replacing these older toilets and urinals.

  16. Water-Cooled Data Center Packs More Power Per Rack | Poster

    Cancer.gov

    By Frank Blanchard and Ken Michaels, Staff Writers Behind each tall, black computer rack in the data center at the Advanced Technology Research Facility (ATRF) is something both strangely familiar and oddly out of place: It looks like a radiator. The back door of each cabinet is gridded with the coils of the Liebert cooling system, which circulates chilled water to remove heat generated by the high-speed, high-capacity, fault-tolerant equipment.

  17. Magnetic anomalies on Io and their relationship to the spatial distribution of volcanic centers

    NASA Astrophysics Data System (ADS)

    Knicely, J.; Everett, M. E.; Sparks, D. W.

    2014-12-01

    The analysis of terrestrial magnetic anomalies has long proved useful for constraining crustal structure and dynamics. Here, we study Jupiter's moon, Io, using magnetics. We conduct forward modeling to make predictions of the crustal magnetic anomaly distribution on Io. Io is the most volcanic body in the solar system due to tidal heating from its Laplace resonance with Europa and Ganymede, causing extensive sulfur and silicate volcanism. We assume the magnetic susceptibility, which controls the measured magnetic signal, is controlled by temperature. Continuous overturn of the crust controls the vertical temperature profile, and local volcanic centers give the lateral temperature structure. As non-magnetic sulfur volcanism occurs at cool temperatures beneath the Curie point, it should not greatly affect the planetary magnetism and consequently is ignored in this paper. We assume that the average crustal temperatures are determined by a model of continuous burial by newly erupted material (O'Reilly and Davies 1981, Geophysical Research Letters), which put the Curie isotherm at great depth. We use a cylindrically symmetric model of the thermal evolution of the crust around an isolated volcanic center to obtain the local deviations in the thickness of the magnetizable layer. The crustal rocks are presumed to be mafic or ultramafic in composition, based on their spectral signatures, the temperature of the silicate volcanic eruptions, and their rheology as inferred from flow structures. Analysis of the 1997 Pillan eruption suggests a composition similar to lunar mare basalt or komatiite. The magnetic and thermal properties of lunar mare basalt have been well studied since the Apollo missions. Unaltered terrestrial ultramafics have been studied sufficiently to constrain their properties. A common technique of discretizing the magnetized material into prisms and summing the magnetic field of each prism as per Blakely (1995) was used to obtain an estimate of the crustal

  18. Photochemical control of the distribution of Venusian water

    NASA Astrophysics Data System (ADS)

    Parkinson, Christopher D.; Gao, Peter; Esposito, Larry; Yung, Yuk; Bougher, Stephen; Hirtzig, Mathieu

    2015-08-01

    We use the JPL/Caltech 1-D photochemical model to solve continuity diffusion equation for atmospheric constituent abundances and total number density as a function of radial distance from the planet Venus. Photochemistry of the Venus atmosphere from 58 to 112 km is modeled using an updated and expanded chemical scheme (Zhang et al., 2010, 2012), guided by the results of recent observations and we mainly follow these references in our choice of boundary conditions for 40 species. We model water between 10 and 35 ppm at our 58 km lower boundary using an SO2 mixing ratio of 25 ppm as our nominal reference value. We then vary the SO2 mixing ratio at the lower boundary between 5 and 75 ppm holding water mixing ratio of 18 ppm at the lower boundary and finding that it can control the water distribution at higher altitudes. SO2 and H2O can regulate each other via formation of H2SO4. In regions of high mixing ratios of SO2 there exists a "runaway effect" such that SO2 gets oxidized to SO3, which quickly soaks up H2O causing a major depletion of water between 70 and 100 km. Eddy diffusion sensitivity studies performed characterizing variability due to mixing that show less of an effect than varying the lower boundary mixing ratio value. However, calculations using our nominal eddy diffusion profile multiplied and divided by a factor of four can give an order of magnitude maximum difference in the SO2 mixing ratio and a factor of a few difference in the H2O mixing ratio when compared with the respective nominal mixing ratio for these two species. In addition to explaining some of the observed variability in SO2 and H2O on Venus, our work also sheds light on the observations of dark and bright contrasts at the Venus cloud tops observed in an ultraviolet spectrum. Our calculations produce results in agreement with the SOIR Venus Express results of 1 ppm at 70-90 km (Bertaux et al., 2007) by using an SO2 mixing ratio of 25 ppm SO2 and 18 ppm water as our nominal reference

  19. The Effects of Computerized Auditory Feedback on Electronic Article Surveillance Tag Placement in an Auto-Parts Distribution Center

    ERIC Educational Resources Information Center

    Goomas, David T.

    2008-01-01

    In this report from the field, computerized auditory feedback was used to inform order selectors and order selector auditors in a distribution center to add an electronic article surveillance (EAS) adhesive tag. This was done by programming handheld computers to emit a loud beep for high-priced items upon scanning the item's bar-coded Universal…

  20. Business Activity Monitoring: Real-Time Group Goals and Feedback Using an Overhead Scoreboard in a Distribution Center

    ERIC Educational Resources Information Center

    Goomas, David T.; Smith, Stuart M.; Ludwig, Timothy D.

    2011-01-01

    Companies operating large industrial settings often find delivering timely and accurate feedback to employees to be one of the toughest challenges they face in implementing performance management programs. In this report, an overhead scoreboard at a retailer's distribution center informed teams of order selectors as to how many tasks were…

  1. Immediate Feedback on Accuracy and Performance: The Effects of Wireless Technology on Food Safety Tracking at a Distribution Center

    ERIC Educational Resources Information Center

    Goomas, David T.

    2012-01-01

    The effects of wireless ring scanners, which provided immediate auditory and visual feedback, were evaluated to increase the performance and accuracy of order selectors at a meat distribution center. The scanners not only increased performance and accuracy compared to paper pick sheets, but were also instrumental in immediate and accurate data…

  2. Impacts of blending ground, surface, and saline waters on lead release in drinking water distribution systems.

    PubMed

    Tang, Zhijian; Hong, Seungkwan; Xiao, Weizhong; Taylor, James

    2006-03-01

    The impacts of distribution water quality changes caused by blending different source waters on lead release from corrosion loops containing small lead coupons were investigated in a pilot distribution study. The 1-year pilot study demonstrated that lead release to drinking water increased as chlorides increased and sulfates decreased. Silica and calcium inhibited lead release to a lesser degree than sulfates. An additional 3-month field study isolated and verified the effects of chlorides and sulfates on lead release. Lead release decreased with increasing pH and increasing alkalinity during the 1-year pilot study; however, the effects of pH and alkalinity on lead release, were not clearly elucidated due to confounding effects. A statistical model was developed using nonlinear regression, which showed that lead release increased with increasing chlorides, alkalinity and temperature, and decreased with increasing pH and sulfates. The model indicated that primary treatment processes such as enhanced coagulation and RO (reverse osmosis membrane) were related to lead release by water quality. Chlorides are high in RO-finished water and increase lead release, while sulfates are high following enhanced coagulation and decrease lead release.

  3. Joint physical and numerical modeling of water distribution networks.

    SciTech Connect

    Zimmerman, Adam; O'Hern, Timothy John; Orear, Leslie Jr.; Kajder, Karen C.; Webb, Stephen Walter; Cappelle, Malynda A.; Khalsa, Siri Sahib; Wright, Jerome L.; Sun, Amy Cha-Tien; Chwirka, J. Benjamin; Hartenberger, Joel David; McKenna, Sean Andrew; van Bloemen Waanders, Bart Gustaaf; McGrath, Lucas K.; Ho, Clifford Kuofei

    2009-01-01

    This report summarizes the experimental and modeling effort undertaken to understand solute mixing in a water distribution network conducted during the last year of a 3-year project. The experimental effort involves measurement of extent of mixing within different configurations of pipe networks, measurement of dynamic mixing in a single mixing tank, and measurement of dynamic solute mixing in a combined network-tank configuration. High resolution analysis of turbulence mixing is carried out via high speed photography as well as 3D finite-volume based Large Eddy Simulation turbulence models. Macroscopic mixing rules based on flow momentum balance are also explored, and in some cases, implemented in EPANET. A new version EPANET code was developed to yield better mixing predictions. The impact of a storage tank on pipe mixing in a combined pipe-tank network during diurnal fill-and-drain cycles is assessed. Preliminary comparison between dynamic pilot data and EPANET-BAM is also reported.

  4. Software-defined optical network for metro-scale geographically distributed data centers.

    PubMed

    Samadi, Payman; Wen, Ke; Xu, Junjie; Bergman, Keren

    2016-05-30

    The emergence of cloud computing and big data has rapidly increased the deployment of small and mid-sized data centers. Enterprises and cloud providers require an agile network among these data centers to empower application reliability and flexible scalability. We present a software-defined inter data center network to enable on-demand scale out of data centers on a metro-scale optical network. The architecture consists of a combined space/wavelength switching platform and a Software-Defined Networking (SDN) control plane equipped with a wavelength and routing assignment module. It enables establishing transparent and bandwidth-selective connections from L2/L3 switches, on-demand. The architecture is evaluated in a testbed consisting of 3 data centers, 5-25 km apart. We successfully demonstrated end-to-end bulk data transfer and Virtual Machine (VM) migrations across data centers with less than 100 ms connection setup time and close to full link capacity utilization.

  5. Determination of oil/water and octanol/water distribution coefficients from aqueous solutions from four fossil fuels. [MS thesis; in oil-water and octanol-water

    SciTech Connect

    Thomas, B.L.

    1984-07-01

    Liquid fossil fuels, both petroleum and synthetically derived oils, are exceedingly complex mixtures of thousands of components. The effect of many of these energy-related components on the environment is largely unknown. Octanol/water distribution coefficients relate both to toxicity and to the bioaccumulation potential of chemical components. Use of these partition data in conjunction with component concentrations in the oils in environmental models provides important information on the fate of fossil fuel components when released to the environment. Octanol/water distribution data are not available for many energy-related organic compounds, and those data that are available have been determined for individual components in simple, one-component octanol/water equilibrium mixtures. In this study, methods for determining many octanol/water distribution coefficients from aqueous extracts of oil products were developed. Sample aqueous mixtures were made by equilibrating liquid fossil fuels with distilled water. This approach has the advantage of detecting interactions between components of interest and other sample components. Compound types studied included phenols, nitrogen bases, hydrocarbons, sulfur heterocyclic compounds, and carboxylic acids. Octanol/water distribution coefficients that were determined in this study ranged from 9.12 for aniline to 67,600 for 1,2-dimethylnaphthalene. Within a compound type, distribution coefficients increased logarithmically with increasing alkyl substitution and molecular weight. Additionally, oil/water distribution data were determined for oil components. These data are useful in predicting maximum environmental concentrations in water columns. 96 references, 26 figures, and 40 tables.

  6. Evaluation of Current Water Treatment and Distribution System Optimization to Provide Safe Drinking Water from Various Source Water Types and Conditions (Deliverable 5.2.C.1)

    EPA Science Inventory

    Increasingly, drinking water treatment plants (DWTPs) are being challenged by changes in the quality of their source waters and by their aging treatment and distribution system infrastructure. Individually or in combination, factors such as shrinking water and financial resources...

  7. CO2 Data Distribution and Support from the Goddard Earth Science Data and Information Services Center (GES-DISC)

    NASA Technical Reports Server (NTRS)

    Hearty, Thomas; Savtchenko, Andrey; Vollmer, Bruce; Albayrak, Arif; Theobald, Mike; Esfandiari, Ed; Wei, Jennifer

    2015-01-01

    This talk will describe the support and distribution of CO2 data products from OCO-2, AIRS, and ACOS, that are archived and distributed from the Goddard Earth Sciences Data and Information Services Center. We will provide a brief summary of the current online archive and distribution metrics for the OCO-2 Level 1 products and plans for the Level 2 products. We will also describe collaborative data sets and services (e.g., matchups with other sensors) and solicit feedback for potential future services.

  8. Detection of Aeromonas hydrophila in a drinking-water distribution system: a field and pilot study.

    PubMed

    Chauret, C; Volk, C; Creason, R; Jarosh, J; Robinson, J; Warnes, C

    2001-08-01

    A 16-month study was conducted on the presence of Aeromonas hydrophila in drinking water in Indiana, U.S.A. Enumeration was conducted in source water, in various sites within a water treatment plant, and in the distribution system in both bulk water and biofilm, as well as in a simulated (annular reactors) drinking-water distribution system. Presumptive Aeromonas spp. counts on source waters regularly approached 10(3)-10(4) CFU/100 mL, during summer months and granular activated carbon - filtered water counts ranged from <1 to 490 CFU/100 mL. In source water, presumptive Aeromonas levels were related to water temperature. Aeromonas hydrophila was never detected in the treatment plant effluent or distributed bulk water, showing disinfectant efficiency on suspended bacteria; however, isolates of A. hydrophila were identified in 7.7% of the biofilm samples, indicating a potential for regrowth and contamination of drinking-water distribution systems.

  9. Electrical impedance imaging of water distribution in the root zone

    NASA Astrophysics Data System (ADS)

    Newill, P.; Karadaglić, D.; Podd, F.; Grieve, B. D.; York, T. A.

    2014-05-01

    The paper describes a technique that is proposed for imaging water transport in and around the root zone of plants using distributed measurements of electrical impedance. The technique has the potential to analyse sub-surface phenotypes, for instance drought tolerance traits in crop breeding programmes. The technical aim is to implement an automated, low cost, instrument for high-throughput screening. Ultimately the technique is targeted at in-field, on-line, measurements. For demonstration purposes the present work considers measurements on laboratory scale rhizotrons housing growing maize plants. Each rhizotron is fitted with 60 electrodes in a rectangular array. To reduce electrochemical effects the capacitively coupled contactless conductivity (C4D) electrodes have an insulating layer on the surface and the resistance of the bulk material is deduced from spectroscopic considerations. Electrical impedance is measured between pairs of electrodes to build up a two-dimensional map. A modified electrical model of such electrodes is proposed which includes the resistive and reactive components of both the insulating layer and the bulk material. Measurements taken on a parallel-plate test cell containing water confirm that the C4D technique is able to measure electrical impedance. The test cell has been used to explore the effects of water content, compaction and temperature on measurements in soil. Results confirm that electrical impedance measurements are very sensitive to moisture content. Impedance fraction changes up to 20% are observed due to compaction up to a pressure of 0.21 kg cm-2 and a temperature fraction sensitivity of about 2%/°C. The effects of compaction and temperature are most significant under dry conditions. Measurements on growing maize reveal the changes in impedance across the rhizotron over a period of several weeks. Results are compared to a control vessel housing only soil.

  10. Influence of water quality on nitrifier regrowth in two full-scale drinking water distribution systems.

    PubMed

    Scott, Daniel B; Van Dyke, Michele I; Anderson, William B; Huck, Peter M

    2015-12-01

    The potential for regrowth of nitrifying microorganisms was monitored in 2 full-scale chloraminated drinking water distribution systems in Ontario, Canada, over a 9-month period. Quantitative PCR was used to measure amoA genes from ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), and these values were compared with water quality parameters that can influence nitrifier survival and growth, including total chlorine, ammonia, temperature, pH, and organic carbon. Although there were no severe nitrification episodes, AOB and AOA were frequently detected at low concentrations in samples collected from both distribution systems. A culture-based presence-absence test confirmed the presence of viable nitrifiers. AOB were usually present in similar or greater numbers than AOA in both systems. As well, AOB showed higher regrowth potential compared with AOA in both systems. Statistically significant correlations were measured between several water quality parameters of relevance to nitrification. Total chlorine was negatively correlated with both nitrifiers and heterotrophic plate count (HPC) bacteria, and ammonia levels were positively correlated with nitrifiers. Of particular importance was the strong correlation between HPC and AOB, which reinforced the usefulness of HPC as an operational parameter to measure general microbiological conditions in distribution systems. PMID:26518069

  11. Influence of water quality on nitrifier regrowth in two full-scale drinking water distribution systems.

    PubMed

    Scott, Daniel B; Van Dyke, Michele I; Anderson, William B; Huck, Peter M

    2015-12-01

    The potential for regrowth of nitrifying microorganisms was monitored in 2 full-scale chloraminated drinking water distribution systems in Ontario, Canada, over a 9-month period. Quantitative PCR was used to measure amoA genes from ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), and these values were compared with water quality parameters that can influence nitrifier survival and growth, including total chlorine, ammonia, temperature, pH, and organic carbon. Although there were no severe nitrification episodes, AOB and AOA were frequently detected at low concentrations in samples collected from both distribution systems. A culture-based presence-absence test confirmed the presence of viable nitrifiers. AOB were usually present in similar or greater numbers than AOA in both systems. As well, AOB showed higher regrowth potential compared with AOA in both systems. Statistically significant correlations were measured between several water quality parameters of relevance to nitrification. Total chlorine was negatively correlated with both nitrifiers and heterotrophic plate count (HPC) bacteria, and ammonia levels were positively correlated with nitrifiers. Of particular importance was the strong correlation between HPC and AOB, which reinforced the usefulness of HPC as an operational parameter to measure general microbiological conditions in distribution systems.

  12. Bacterial composition in a metropolitan drinking water distribution system utilizing different source waters.

    PubMed

    Gomez-Alvarez, Vicente; Humrighouse, Ben W; Revetta, Randy P; Santo Domingo, Jorge W

    2015-03-01

    We investigated the bacterial composition of water samples from two service areas within a drinking water distribution system (DWDS), each associated with a different primary source of water (groundwater, GW; surface water, SW) and different treatment process. Community analysis based on 16S rRNA gene clone libraries indicated that Actinobacteria (Mycobacterium spp.) and α-Proteobacteria represented nearly 43 and 38% of the total sequences, respectively. Sequences closely related to Legionella, Pseudomonas, and Vibrio spp. were also identified. In spite of the high number of sequences (71%) shared in both areas, multivariable analysis revealed significant differences between the GW and SW areas. While the dominant phylotypes where not significantly contributing in the ordination of samples, the populations associated with the core of phylotypes (1-10% in each sample) significantly contributed to the differences between both service areas. Diversity indices indicate that the microbial community inhabiting the SW area is more diverse and contains more distantly related species coexisting with local assemblages as compared with the GW area. The bacterial community structure of SW and GW service areas were dissimilar, suggesting that their respective source water and/or water quality parameters shaped by the treatment processes may contribute to the differences in community structure observed.

  13. Effects of vertical distribution of water vapor and temperature on total column water vapor retrieval error

    NASA Technical Reports Server (NTRS)

    Sun, Jielun

    1993-01-01

    Results are presented of a test of the physically based total column water vapor retrieval algorithm of Wentz (1992) for sensitivity to realistic vertical distributions of temperature and water vapor. The ECMWF monthly averaged temperature and humidity fields are used to simulate the spatial pattern of systematic retrieval error of total column water vapor due to this sensitivity. The estimated systematic error is within 0.1 g/sq cm over about 70 percent of the global ocean area; systematic errors greater than 0.3 g/sq cm are expected to exist only over a few well-defined regions, about 3 percent of the global oceans, assuming that the global mean value is unbiased.

  14. Implications of organic carbon in the deterioration of water quality in reclaimed water distribution systems.

    PubMed

    Weinrich, Lauren A; Jjemba, Patrick K; Giraldo, Eugenio; LeChevallier, Mark W

    2010-10-01

    Changes in water quality in reclaimed water distribution systems are a major concern especially when considering the potential for growth of pathogenic microbes. A survey of 21 wastewater process configurations confirmed the high quality effluent produced using membrane bioreactor (MBR) technology, but suggests that other technologies can be operated to produce similar quality. Data from an intensive twelve-month sampling campaign in four reclaimed water utilities revealed the important trends for various organic carbon parameters including total organic carbon (TOC), biodegradable dissolved organic carbon (BDOC), and assimilable organic carbon (AOC). Of the four utilities, two were conventional wastewater treatment with open reservoir storage and two employed MBR technology with additional treatment including UV, ozone, and/or chlorine disinfection. Very high BDOC concentrations occurred in conventional systems, accounting for up to 50% of the TOC loading into the system. BDOC concentrations in two conventional plants averaged 1.4 and 6.3 mg/L and MBR plants averaged less than 0.6 mg/L BDOC. Although AOC showed wide variations, ranging from 100 to 2000 μg/L, the AOC concentrations in the conventional plants were typically 3-10 times higher than in the MBR systems. Pipe-loop studies designed to understand the impact of disinfection on the microbiology of reclaimed water in the distribution system revealed that chlorination will increase the level of biodegradable organic matter, thereby increasing the potential for microbial growth in the pipe network. This study concludes that biodegradable organic carbon is an important factor in the microbial quality and stability of reclaimed water and could impact the public health risk of reclaimed water at the point of use.

  15. Supporting users through integrated retrieval, processing, and distribution systems at the land processes distributed active archive center

    USGS Publications Warehouse

    Kalvelage, T.; Willems, Jennifer

    2003-01-01

    The design of the EOS Data and Information Systems (EOSDIS) to acquire, archive, manage and distribute Earth observation data to the broadest possible user community was discussed. A number of several integrated retrieval, processing and distribution capabilities have been explained. The value of these functions to the users were described and potential future improvements were laid out for the users. The users were interested in acquiring the retrieval, processing and archiving systems integrated so that they can get the data they want in the format and delivery mechanism of their choice.

  16. Supporting users through integrated retrieval, processing, and distribution systems at the Land Processes Distributed Active Archive Center

    USGS Publications Warehouse

    Kalvelage, Thomas A.; Willems, Jennifer

    2005-01-01

    The LP DAAC is the primary archive for the Landsat 7 Enhanced Thematic Mapper Plus (ETM+) data; it is the only facility in the United States that archives, processes, and distributes data from the Advanced Spaceborne Thermal Emission/Reflection Radiometer (ASTER) on NASA's Terra spacecraft; and it is responsible for the archive and distribution of “land products” generated from data acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra and Aqua satellites.

  17. The EGI-Engage EPOS Competence Center - Interoperating heterogeneous AAI mechanisms and Orchestrating distributed computational resources

    NASA Astrophysics Data System (ADS)

    Bailo, Daniele; Scardaci, Diego; Spinuso, Alessandro; Sterzel, Mariusz; Schwichtenberg, Horst; Gemuend, Andre

    2016-04-01

    The mission of EGI-Engage project [1] is to accelerate the implementation of the Open Science Commons vision, where researchers from all disciplines have easy and open access to the innovative digital services, data, knowledge and expertise they need for collaborative and excellent research. The Open Science Commons is grounded on three pillars: the e-Infrastructure Commons, an ecosystem of services that constitute the foundation layer of distributed infrastructures; the Open Data Commons, where observations, results and applications are increasingly available for scientific research and for anyone to use and reuse; and the Knowledge Commons, in which communities have shared ownership of knowledge, participate in the co-development of software and are technically supported to exploit state-of-the-art digital services. To develop the Knowledge Commons, EGI-Engage is supporting the work of a set of community-specific Competence Centres, with participants from user communities (scientific institutes), National Grid Initiatives (NGIs), technology and service providers. Competence Centres collect and analyse requirements, integrate community-specific applications into state-of-the-art services, foster interoperability across e-Infrastructures, and evolve services through a user-centric development model. One of these Competence Centres is focussed on the European Plate Observing System (EPOS) [2] as representative of the solid earth science communities. EPOS is a pan-European long-term plan to integrate data, software and services from the distributed (and already existing) Research Infrastructures all over Europe, in the domain of the solid earth science. EPOS will enable innovative multidisciplinary research for a better understanding of the Earth's physical and chemical processes that control earthquakes, volcanic eruptions, ground instability and tsunami as well as the processes driving tectonics and Earth's surface dynamics. EPOS will improve our ability to better

  18. Assessing microbiological water quality in drinking water distribution systems with disinfectant residual using flow cytometry.

    PubMed

    Gillespie, Simon; Lipphaus, Patrick; Green, James; Parsons, Simon; Weir, Paul; Juskowiak, Kes; Jefferson, Bruce; Jarvis, Peter; Nocker, Andreas

    2014-11-15

    Flow cytometry (FCM) as a diagnostic tool for enumeration and characterization of microorganisms is rapidly gaining popularity and is increasingly applied in the water industry. In this study we applied the method to obtain a better understanding of total and intact cell concentrations in three different drinking water distribution systems (one using chlorine and two using chloramines as secondary disinfectants). Chloramine tended to result in lower proportions of intact cells than chlorine over a wider residual range, in agreement with existing knowledge that chloramine suppresses regrowth more efficiently. For chlorinated systems, free chlorine concentrations above 0.5 mg L(-1) were found to be associated with relatively low proportions of intact cells, whereas lower disinfectant levels could result in substantially higher percentages of intact cells. The threshold for chlorinated systems is in good agreement with guidelines from the World Health Organization. The fact that the vast majority of samples failing the regulatory coliform standard also showed elevated proportions of intact cells suggests that this parameter might be useful for evaluating risk of failure. Another interesting parameter for judging the microbiological status of water, the biological regrowth potential, greatly varied among different finished waters providing potential help for investment decisions. For its measurement, a simple method was introduced that can easily be performed by water utilities with FCM capability.

  19. Biofilm bacterial communities in urban drinking water distribution systems transporting waters with different purification strategies.

    PubMed

    Wu, Huiting; Zhang, Jingxu; Mi, Zilong; Xie, Shuguang; Chen, Chao; Zhang, Xiaojian

    2015-02-01

    Biofilm formation in drinking water distribution systems (DWDS) has many adverse consequences. Knowledge of microbial community structure of DWDS biofilm can aid in the design of an effective control strategy. However, biofilm bacterial community in real DWDS and the impact of drinking water purification strategy remain unclear. The present study investigated the composition and diversity of biofilm bacterial community in real DWDSs transporting waters with different purification strategies (conventional treatment and integrated treatment). High-throughput Illumina MiSeq sequencing analysis illustrated a large shift in the diversity and structure of biofilm bacterial community in real DWDS. Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Nitrospirae, and Cyanobacteria were the major components of biofilm bacterial community. Proteobacteria (mainly Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria) predominated in each DWDS biofilm, but the compositions of the dominant proteobacterial classes and genera and their proportions varied among biofilm samples. Drinking water purification strategy could shape DWDS biofilm bacterial community. Moreover, Pearson's correlation analysis indicated that Actinobacteria was positively correlated with the levels of total alkalinity and dissolved organic carbon in tap water, while Firmicutes had a significant positive correlation with nitrite nitrogen.

  20. A Wireless Sensor Network approach for distributed in-line chemical analysis of water.

    PubMed

    Capella, J V; Bonastre, A; Ors, R; Peris, M

    2010-03-15

    In this work we propose the implementation of a distributed system based on a Wireless Sensor Network for the control of a chemical analysis system for fresh water. This implementation is presented by describing the nodes that form the distributed system, the communication system by wireless networks, control strategies, and so on. Nitrate, ammonium, and chloride are measured in-line using appropriate ion selective electrodes (ISEs), the results obtained being compared with those provided by the corresponding reference methods. Recovery analyses with ISEs and standard methods, study of interferences, and evaluation of major sensor features have also been carried out. The communication among the nodes that form the distributed system is implemented by means of the utilization of proprietary wireless networks, and secondary data transmission services (GSM or GPRS) provided by a mobile telephone operator. The information is processed, integrated and stored in a control center. These data can be retrieved--through the Internet--so as to know the real-time system status and its evolution. PMID:20152412

  1. Software-defined optical network for metro-scale geographically distributed data centers.

    PubMed

    Samadi, Payman; Wen, Ke; Xu, Junjie; Bergman, Keren

    2016-05-30

    The emergence of cloud computing and big data has rapidly increased the deployment of small and mid-sized data centers. Enterprises and cloud providers require an agile network among these data centers to empower application reliability and flexible scalability. We present a software-defined inter data center network to enable on-demand scale out of data centers on a metro-scale optical network. The architecture consists of a combined space/wavelength switching platform and a Software-Defined Networking (SDN) control plane equipped with a wavelength and routing assignment module. It enables establishing transparent and bandwidth-selective connections from L2/L3 switches, on-demand. The architecture is evaluated in a testbed consisting of 3 data centers, 5-25 km apart. We successfully demonstrated end-to-end bulk data transfer and Virtual Machine (VM) migrations across data centers with less than 100 ms connection setup time and close to full link capacity utilization. PMID:27410146

  2. Inhomogeneous distribution of water droplets in cloud turbulence.

    PubMed

    Fouxon, Itzhak; Park, Yongnam; Harduf, Roei; Lee, Changhoon

    2015-09-01

    We consider sedimentation of small particles in the turbulent flow where fluid accelerations are much smaller than acceleration of gravity g. The particles are dragged by the flow by linear friction force. We demonstrate that the pair-correlation function of particles' concentration diverges with decreasing separation as a power law with negative exponent. This manifests fractal distribution of particles in space. We find that the exponent is proportional to ratio of integral of energy spectrum of turbulence times the wave number over g. The proportionality coefficient is a universal number independent of particle size. We derive the spectrum of Lyapunov exponents that describes the evolution of small patches of particles. It is demonstrated that particles separate dominantly in the horizontal plane. This provides a theory for the recently observed vertical columns formed by the particles. We confirm the predictions by direct numerical simulations of Navier-Stokes turbulence. The predictions include conditions that hold for water droplets in warm clouds thus providing a tool for the prediction of rain formation.

  3. Dynamic simulation of multicomponent reaction transport in water distribution systems.

    PubMed

    Munavalli, G R; Mohan Kumar, M S M S

    2004-04-01

    Given the presence of nutrients, regrowth of bacteria within a distribution system is possible. The bacterial growth phenomena, which can be studied by developing a multicomponent (substrate, biomass and disinfectant) reaction transport model, is governed by its relationship with the substrate (organic carbon) and disinfectant (chlorine). The multicomponent reaction transport model developed in the present study utilizes the simplified expressions for the basic processes (in bulk flow and at pipe wall) such as bacterial growth and decay, attachment to and detachment from the surface, substrate utilization and disinfectant action involved in the model. The usefulness of the model is further enhanced by the incorporation of an expression for bulk reaction parameter relating it with the organic carbon. The model is validated and applied to study the sensitive behavior of the components using a hypothetical network. The developed model is able to simulate the biodegradable organic carbon threshold in accordance with the values reported in the literature. The spread of contaminant intruded into the system at any location can also be simulated by the model. The multicomponent model developed is useful for water supply authorities in identifying the locations with high substrate concentrations, bacterial growth and lower chlorine residuals. PMID:15087178

  4. Soil, Groundwater, Surface Water, and Sediments of Kennedy Space Center, Florida: Background Chemical and Physical Characteristics

    NASA Technical Reports Server (NTRS)

    Shmalzer, Paul A.; Hensley, Melissa A.; Mota, Mario; Hall, Carlton R.; Dunlevy, Colleen A.

    2000-01-01

    This study documented background chemical composition of soils, groundwater, surface; water, and sediments of Kennedy Space Center. Two hundred soil samples were collected, 20 each in 10 soil classes. Fifty-one groundwater wells were installed in 4 subaquifers of the Surficial Aquifer and sampled; there were 24 shallow, 16 intermediate, and 11 deep wells. Forty surface water and sediment samples were collected in major watershed basins. All samples were away from sites of known contamination. Samples were analyzed for organochlorine pesticides, aroclors, chlorinated herbicides, polycyclic aromatic hydrocarbons (PAH), total metals, and other parameters. All aroclors (6) were below detection in all media. Some organochlorine pesticides were detected at very low frequencies in soil, sediment, and surface water. Chlorinated herbicides were detected at very low frequencies in soil and sediments. PAH occurred in low frequencies in soiL, shallow groundwater, surface water, and sediments. Concentrations of some metals differed among soil classes, with subaquifers and depths, and among watershed basins for surface water but not sediments. Most of the variation in metal concentrations was natural, but agriculture had increased Cr, Cu, Mn, and Zn.

  5. CDC provides guidelines on suspect water supplies. Centers for Disease Control and Prevention.

    PubMed

    1995-08-01

    The Centers for Disease Control and Prevention (CDC) recommends that immunocompromised people avoid exposure to cryptosporidium in outbreak settings by drinking water that is boiled, filtered, or bottled. A parasite, cryptosporidium is spread when persons ingest infected feces of humans or animals, or eat raw or undercooked vegetables contaminated with an egg-like form of the parasite. Symptoms include watery diarrhea, headache, abdominal cramps, nausea, vomiting and low-grade fever; in immunocompromised patients infection often leads to weight loss, dehydration, and may become life-threatening. Drugs can treat the symptoms, although cryptosporidiosis is not curable and often recurs in severely immunocompromised patients. To prevent becoming infected; HIV-positive people should not drink water from lakes, rivers, and swimming pools; avoid unpasteurized milk or milk products; wash hands after contact with pets or with soil; and follow safe-sex guidelines. The CDC also recommends that in settings with an outbreak of cryptosporidium, individuals boil water for one minute to kill the parasite or use a filter for tap water that is capable of removing particles less than one micron in diameter. A third option is to use bottled water for drinking, although it is difficult to know which is safe since no organization regulates it.

  6. Centers for Water Research on National Priorities Related to a Systems View of Nutrient Management: Kickoff Workshop

    EPA Science Inventory

    The purpose of this presentation is to brief meeting participants on the "Centers for Water Research on National Priorities Related to a Systems View of Nutrient Management" solicitation's components, objectives and goals.

  7. ATRAZOME CHLORINATION TRANSFORMATION PRODUCTS UNDER DRINKING WATER DISTRIBUTION SYSTEM CONDITIONS

    EPA Science Inventory

    Chlorination is a commonly-used disinfectant step in drinking water treatment. Should free chlorine be added to water used as a drinking water source, it is widely understood that many biological species in the water, along with dissolved organic and inorganic chemicals, will rea...

  8. Investigation of sensitizer ions tunable-distribution in fluoride nanoparticles for efficient accretive three-center energy transfer

    SciTech Connect

    Guo, Hui; Yu, Hua Lao, Aiqing; Chang, Lifen; Gao, Shaohua; Zhang, Haoxiong; Zhou, Taojie; Zhao, Lijuan

    2014-09-14

    Cooperative upconversion luminescence of Yb³⁺-Yb³⁺ couples and three-center energy transfer mechanisms have been deeply investigated in Yb³⁺ doped and Yb³⁺-Tb³⁺ co-doped β-PbF₂ nanoparticles. As sensitizer ions, the distribution of Yb³⁺ ions, which is a key factor that affects the cooperative upconversion luminescence and three-center energy transfer processes, can be tuned by the structure of nanoparticles. Based on the three-center distributions in tetragonal PbYb{sub x}Tb{sub 1–x}F₅ nanoparticles, two different energy transfer models, Cooperative Energy Transfer (CET) and Accretive Energy Transfer (AET) mechanisms were established. Especially, AET model is observed and verified in this work for the first time. Experimental results obtained from photoluminescence spectroscopy study are in agreement with the theoretical calculations by applying rate equations in these models, strongly supporting the proposed three-center energy transfer mechanisms. The sensitization between Yb³⁺ ions only existing in AET process can greatly improve the energy transfer rates, further to enhance the quantum efficiency. The results that the calculated luminescence quantum efficiency in AET quantum cutting process is much higher than that in CET process (134% and 104%, respectively), can benefit for further increasing the conversion efficiency of c-Si solar cells.

  9. Geometrically centered region: a "wet" model of protein binding hot spots not excluding water molecules.

    PubMed

    Li, Zhenhua; Li, Jinyan

    2010-12-01

    A protein interface can be as "wet" as a protein surface in terms of the number of immobilized water molecules. This important water information has not been explicitly taken by computational methods to model and identify protein binding hot spots, overlooking the water role in forming interface hydrogen bonds and in filing cavities. Hot spot residues are usually clustered at the core of the protein binding interfaces. However, traditional machine learning methods often identify the hot spot residues individually, breaking the cooperativity of the energetic contribution. Our idea in this work is to explore the role of immobilized water and meanwhile to capture two essential properties of hot spots: the compactness in contact and the far distance from bulk solvent. Our model is named geometrically centered region (GCR). The detection of GCRs is based on novel tripartite graphs, and atom burial levels which are a concept more intuitive than SASA. Applying to a data set containing 355 mutations, we achieved an F measure of 0.6414 when ΔΔG ≥ 1.0 kcal/mol was used to define hot spots. This performance is better than Robetta, a benchmark method in the field. We found that all but only one of the GCRs contain water to a certain degree, and most of the outstanding hot spot residues have water-mediated contacts. If the water is excluded, the burial level values are poorly related to the ΔΔG, and the model loses its performance remarkably. We also presented a definition for the O-ring of a GCR as the set of immediate neighbors of the residues in the GCR. Comparative analysis between the O-rings and GCRs reveals that the newly defined O-ring is indeed energetically less important than the GCR hot spot, confirming a long-standing hypothesis. PMID:20818601

  10. Water security: continuous monitoring of water distribution systems for chemical agents by SERS

    NASA Astrophysics Data System (ADS)

    Inscore, Frank; Shende, Chetan; Sengupta, Atanu; Farquharson, Stuart

    2007-04-01

    Ensuring safe water supplies requires continuous monitoring for potential poisons and portable analyzers to map distribution in the event of an attack. In the case of chemical warfare agents (CWAs) analyzers are needed that have sufficient sensitivity (part-per-billion), selectivity (differentiate the CWA from its hydrolysis products), and speed (less than 10 minutes) to be of value. We have been investigating the ability of surface-enhanced Raman spectroscopy (SERS) to meet these requirements by detecting CWAs and their hydrolysis products in water. The expected success of SERS is based on reported detection of single molecules, the one-to-one relationship between a chemical and its Raman spectrum, and the minimal sample preparation requirements. Recently, we have developed a simple sampling device designed to optimize the interaction of the target molecules with the SERS-active material with the goal of increasing sensitivity and decreasing sampling times. This sampling device employs a syringe to draw the water sample containing the analyte into a capillary filled with the SERS-active material. Recently we used such SERS-active capillaries to measure 1 ppb cyanide in water. Here we extend these measurements to nerve agent hydrolysis products using a portable Raman analyzer.

  11. From honeybees to Internet servers: biomimicry for distributed management of Internet hosting centers.

    PubMed

    Nakrani, Sunil; Tovey, Craig

    2007-12-01

    An Internet hosting center hosts services on its server ensemble. The center must allocate servers dynamically amongst services to maximize revenue earned from hosting fees. The finite server ensemble, unpredictable request arrival behavior and server reallocation cost make server allocation optimization difficult. Server allocation closely resembles honeybee forager allocation amongst flower patches to optimize nectar influx. The resemblance inspires a honeybee biomimetic algorithm. This paper describes details of the honeybee self-organizing model in terms of information flow and feedback, analyzes the homology between the two problems and derives the resulting biomimetic algorithm for hosting centers. The algorithm is assessed for effectiveness and adaptiveness by comparative testing against benchmark and conventional algorithms. Computational results indicate that the new algorithm is highly adaptive to widely varying external environments and quite competitive against benchmark assessment algorithms. Other swarm intelligence applications are briefly surveyed, and some general speculations are offered regarding their various degrees of success. PMID:18037727

  12. From honeybees to Internet servers: biomimicry for distributed management of Internet hosting centers.

    PubMed

    Nakrani, Sunil; Tovey, Craig

    2007-12-01

    An Internet hosting center hosts services on its server ensemble. The center must allocate servers dynamically amongst services to maximize revenue earned from hosting fees. The finite server ensemble, unpredictable request arrival behavior and server reallocation cost make server allocation optimization difficult. Server allocation closely resembles honeybee forager allocation amongst flower patches to optimize nectar influx. The resemblance inspires a honeybee biomimetic algorithm. This paper describes details of the honeybee self-organizing model in terms of information flow and feedback, analyzes the homology between the two problems and derives the resulting biomimetic algorithm for hosting centers. The algorithm is assessed for effectiveness and adaptiveness by comparative testing against benchmark and conventional algorithms. Computational results indicate that the new algorithm is highly adaptive to widely varying external environments and quite competitive against benchmark assessment algorithms. Other swarm intelligence applications are briefly surveyed, and some general speculations are offered regarding their various degrees of success.

  13. Injection of Contaminants into a Simulated Water Distribution System Equipped with Continuous Multi-Parameter Water Monitors

    EPA Science Inventory

    The U.S. EPA’s Technology Testing and Evaluation Program has been charged by EPA to evaluate the performance of commercially available water security-related technologies. Multi-parameter water monitors for distributions systems have been evaluated as such a water security techn...

  14. Disinfectant Penetration into Nitrifying Drinking Water Distribution System Biofilm Using Microelectrodes

    EPA Science Inventory

    Nitrification within drinking water distribution systems reduces water quality, causes difficulties maintaining adequate disinfectant residual, and poses public health concerns including exposure to nitrite, nitrate, and opportunistic pathogenic microorganisms. Monochloramine is...

  15. GEOCHEMISTRY OF SULFUR IN IRON CORROSION SCALES FOUND IN DRINKING WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Iron-sulfur geochemistry is important in many natural and engineered environments, including drinking water systems. In the anaerobic environment beneath scales of corroding iron drinking water distribution system pipes, sulfate reducing bacteria (SRB) produce sulfide from natu...

  16. USE OF NETWORK MODELS FOR ESTIMATING EXPOSURE OF CONSUMERS TO CONTAMINANTS IN DRINKING WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    The presence of contaminants in a drinking water distribution system can result in exposure of consumers to contaminated water. Whether the contaminants result from waterborne outbreaks that accidentally enter the system or through purposeful acts, the movement of the resulting ...

  17. The production and spatial distribution of neutral and ionized water vapor in Comet P/Halley

    SciTech Connect

    Disanti, M.A.

    1989-01-01

    The problem of water vapor production and distribution in comet P/Halley is addressed. The data was acquired using the Lunar and Planetary Laboratory charge-coupled device (CCD) on the 154 cm Catalina telescope of the University of Arizona Observatories. The data acquisition system was employed in two modes. The long-slit spectroscopy mode covered the wavelength range 5200 to 10400 A. The narrow band filter imaging mode allowed two-dimensional mapping of selected cometary emission features. The 1986 March 5 long-slit spatial profiles showed a central dip in the water ion (H2O+) column density, of order 30 percent in the inner coma, which filled in farther tailward. Vega-1 spacecraft measurements (March 6) revealed a decrease in local ion density, of roughly 60 percent at closest approach R is approximate or equal to 9000 km sunward of the nucleus, relative to an inbound maximum R is approximate or equal to 12000 km. Our filter images (March 6), centered on the H2O+ 0, 8, 0 band, showed that the falloff in ions was relatively rapid sunward of the nucleus. In the anti-solar direction the decrease was much more gradual, due to the solar wind sweeping ions from the head of the comet into the plasma tail, whose width was of order 10(exp 5) km in the inner coma, diverging slowly and breaking up into a ray pattern farther tailward. The distribution of neutral water was mapped out using the O I wavelength 6300 emission as diagnostic probe. In contrast to the ions, the H2O molecules were confined mainly to the inner few x 10(exp 4) km of the coma.

  18. Assessment of a Bidirectional Reflectance Distribution Correction of Above-Water and Satellite Water-Leaving Radiance in Coastal Waters

    NASA Technical Reports Server (NTRS)

    Hlaing, Soe; Gilerson, Alexander; Harmal, Tristan; Tonizzo, Alberto; Weidemann, Alan; Arnone, Robert; Ahmed, Samir

    2012-01-01

    Water-leaving radiances, retrieved from in situ or satellite measurements, need to be corrected for the bidirectional properties of the measured light in order to standardize the data and make them comparable with each other. The current operational algorithm for the correction of bidirectional effects from the satellite ocean color data is optimized for typical oceanic waters. However, versions of bidirectional reflectance correction algorithms specifically tuned for typical coastal waters and other case 2 conditions are particularly needed to improve the overall quality of those data. In order to analyze the bidirectional reflectance distribution function (BRDF) of case 2 waters, a dataset of typical remote sensing reflectances was generated through radiative transfer simulations for a large range of viewing and illumination geometries. Based on this simulated dataset, a case 2 water focused remote sensing reflectance model is proposed to correct above-water and satellite water-leaving radiance data for bidirectional effects. The proposed model is first validated with a one year time series of in situ above-water measurements acquired by collocated multispectral and hyperspectral radiometers, which have different viewing geometries installed at the Long Island Sound Coastal Observatory (LISCO). Match-ups and intercomparisons performed on these concurrent measurements show that the proposed algorithm outperforms the algorithm currently in use at all wavelengths, with average improvement of 2.4% over the spectral range. LISCO's time series data have also been used to evaluate improvements in match-up comparisons of Moderate Resolution Imaging Spectroradiometer satellite data when the proposed BRDF correction is used in lieu of the current algorithm. It is shown that the discrepancies between coincident in-situ sea-based and satellite data decreased by 3.15% with the use of the proposed algorithm.

  19. 238U, 226Ra and 210Pb in some vent waters of the Galapagos Spreading Center

    NASA Astrophysics Data System (ADS)

    Krishnaswami, S.; Turekian, K. K.

    1982-08-01

    The concentrations of 226Ra, 238U and 210Pb have been measured in waters from the Mussel Bed and the Rose Garden thermal fields at the Galapagos spreading center over a temperature range of ˜2.5-16°C. The 226Ra-T plots yield slopes of 0.112 and 0.036 dpm/kg°C for the Mussel Bed and the Rose Garden respectively yielding a global hydrothermal 226Ra flux less than 5% of that required to sustain the oceanic inventory. 238U concentration in waters <9°C is the same as that in ambient sea water whereas water hotter than ˜9°C shows a decreasing trend with temperature to zero 238U at ˜29°C. 210Pb concentration in Mussel Bed increases with temperature, and extrapolated to ˜350°C yields a 210Pb concentration considerably less than that expected from 222Rn decay and basalt alteration.

  20. Benthic foraminiferal distribution in deep-water periplatform carbonate environments

    SciTech Connect

    Martin, R.E.

    1987-05-01

    In contrast to clastic depositional environments, bathymetric distribution of benthic foraminifera in deep-water carbonate environments has been largely neglected. Approximately 260 species and morphotypes of benthic foraminifera were identified from 12 sediment samples (piston core top and grab) collected along two transverses approximately 25 km apart across the northern (windward) margin of Little Bahama Bank at depths of 275 to 1135 m. Most species exhibit great variation in abundance with depth. However, Globocassidulina subglobosa, Cibicides rugosus, and Cibicides wuellerstorfi are all reliable depth indicators (Spearman's r > 0.91; p < 0.005), being most abundant at depths > 1000 m, and correspond to lower slope (> 900 m) periplatform aprons. Individual foraminiferal suborders (Miliolina, Rotaliina, Textulariina) show no consistent depth-related trends. However, certain operational taxonomic groups, such as reef-dwelling peneroplids and soritids (suborder Miliolina) and rotaliines (suborder Rotaliina) are significant more abundant at depths < 300 m (95% C.I.: 2.6 +/- 2.2% and 6.9 +/- 2.7%, respectively) than at greater depths (95% C.I.: 0.3 +/- 0.2% and 2.0 +/- 0.8%; Mann-Whitney U, p < 0.01), reflecting downslope bottom transport in proximity to bank-margin reefs. Small miliolines (i.e., suborder Miliolina minus peneroplids and soritids) and rosalinids and discorbids (suborder Rotaliina) are also more abundant at depths < 300 m (95% C.I.: 27.5 +/- 7.4% and 32.6 +/- 8.5%, respectively) than at greater depths (95% C.I.: 10.0 +/- 3.9% and 1.5 +/- 1.6%; Mann-Whitney U, p < 0.01) and are winnowed from the carbonate platform. Assemblages exhibit greatest variation in diversity (species number, s; Shannon-Weaver, H'; evenness, J') at depths > 900 m; indices for shallower assemblages tend to be grouped more tightly at relatively high values.

  1. The EGI-Engage EPOS Competence Center - Interoperating heterogeneous AAI mechanisms and Orchestrating distributed computational resources

    NASA Astrophysics Data System (ADS)

    Bailo, Daniele; Scardaci, Diego; Spinuso, Alessandro; Sterzel, Mariusz; Schwichtenberg, Horst; Gemuend, Andre

    2016-04-01

    The mission of EGI-Engage project [1] is to accelerate the implementation of the Open Science Commons vision, where researchers from all disciplines have easy and open access to the innovative digital services, data, knowledge and expertise they need for collaborative and excellent research. The Open Science Commons is grounded on three pillars: the e-Infrastructure Commons, an ecosystem of services that constitute the foundation layer of distributed infrastructures; the Open Data Commons, where observations, results and applications are increasingly available for scientific research and for anyone to use and reuse; and the Knowledge Commons, in which communities have shared ownership of knowledge, participate in the co-development of software and are technically supported to exploit state-of-the-art digital services. To develop the Knowledge Commons, EGI-Engage is supporting the work of a set of community-specific Competence Centres, with participants from user communities (scientific institutes), National Grid Initiatives (NGIs), technology and service providers. Competence Centres collect and analyse requirements, integrate community-specific applications into state-of-the-art services, foster interoperability across e-Infrastructures, and evolve services through a user-centric development model. One of these Competence Centres is focussed on the European Plate Observing System (EPOS) [2] as representative of the solid earth science communities. EPOS is a pan-European long-term plan to integrate data, software and services from the distributed (and already existing) Research Infrastructures all over Europe, in the domain of the solid earth science. EPOS will enable innovative multidisciplinary research for a better understanding of the Earth's physical and chemical processes that control earthquakes, volcanic eruptions, ground instability and tsunami as well as the processes driving tectonics and Earth's surface dynamics. EPOS will improve our ability to better

  2. Study On Burst Location Technology under Steady-state in Water Distribution System

    NASA Astrophysics Data System (ADS)

    Liu, Xianpin; Li, Shuping; Wang, Shaowei; He, Fang; He, Zhixun; Cao, Guodong

    2010-11-01

    According to the characteristics of hydraulic information under the state of burst in water distribution system, to get the correlation of monitoring values and burst location and locate the position of burst on time by mathematical fitting. This method can effectively make use of the information of SCADA in water distribution system to active locating burst position. A new idea of burst location in water distribution systems to shorten the burst time, reduce the impact on urban water supply, economic losses and waste of water resources.

  3. Origin and Distribution of Water Contents in Continental and Oceanic Lithospheric Mantle

    NASA Technical Reports Server (NTRS)

    Peslier, Anne H.

    2013-01-01

    The water content distribution of the upper mantle will be reviewed as based on the peridotite record. The amount of water in cratonic xenoliths appears controlled by metasomatism while that of the oceanic mantle retains in part the signature of melting events. In both cases, the water distribution is heterogeneous both with depth and laterally, depending on localized water re-enrichments next to melt/fluid channels. The consequence of the water distribution on the rheology of the upper mantle and the location of the lithosphere-asthenosphere boundary will also be discussed.

  4. Public water supply and distribution at the FEMP

    SciTech Connect

    Neary, C.

    1997-10-01

    On February 17th, 1996, the Fernald Environmental Management Project (FEMP), a former Department of Energy uranium processing facility near the rural town of Fernald, Ohio, became a ``user`` instead of a ``producer``, of potable water by tying into the Cincinnati Water Works new Public Water Supply System. This satisfied the future site needs of potable water and nullified the need to follow the sampling requirements set forth by the Environmental Protection Agency and the Safe Drinking Water Act for potable water producers. This transformation into a customer also reduced the long water transmission time from the Cincinnati Water Works station to the small community that would have occurred without a large user such as the FEMP being on line.

  5. The Relationship between Phytoplankton Distribution and Water Column Characteristics in North West European Shelf Sea Waters

    PubMed Central

    Davidson, Keith; Bolch, Christopher J. S.; Brand, Tim D.; Narayanaswamy, Bhavani E.

    2012-01-01

    Phytoplankton underpin the marine food web in shelf seas, with some species having properties that are harmful to human health and coastal aquaculture. Pressures such as climate change and anthropogenic nutrient input are hypothesized to influence phytoplankton community composition and distribution. Yet the primary environmental drivers in shelf seas are poorly understood. To begin to address this in North Western European waters, the phytoplankton community composition was assessed in light of measured physical and chemical drivers during the “Ellett Line” cruise of autumn 2001 across the Scottish Continental shelf and into adjacent open Atlantic waters. Spatial variability existed in both phytoplankton and environmental conditions, with clear differences not only between on and off shelf stations but also between different on shelf locations. Temperature/salinity plots demonstrated different water masses existed in the region. In turn, principal component analysis (PCA), of the measured environmental conditions (temperature, salinity, water density and inorganic nutrient concentrations) clearly discriminated between shelf and oceanic stations on the basis of DIN∶DSi ratio that was correlated with both salinity and temperature. Discrimination between shelf stations was also related to this ratio, but also the concentration of DIN and DSi. The phytoplankton community was diatom dominated, with multidimensional scaling (MDS) demonstrating spatial variability in its composition. Redundancy analysis (RDA) was used to investigate the link between environment and the phytoplankton community. This demonstrated a significant relationship between community composition and water mass as indexed by salinity (whole community), and both salinity and DIN∶DSi (diatoms alone). Diatoms of the Pseudo-nitzschia seriata group occurred at densities potentially harmful to shellfish aquaculture, with the potential for toxicity being elevated by the likelihood of DSi limitation

  6. The relationship between phytoplankton distribution and water column characteristics in North West European shelf sea waters.

    PubMed

    Fehling, Johanna; Davidson, Keith; Bolch, Christopher J S; Brand, Tim D; Narayanaswamy, Bhavani E

    2012-01-01

    Phytoplankton underpin the marine food web in shelf seas, with some species having properties that are harmful to human health and coastal aquaculture. Pressures such as climate change and anthropogenic nutrient input are hypothesized to influence phytoplankton community composition and distribution. Yet the primary environmental drivers in shelf seas are poorly understood. To begin to address this in North Western European waters, the phytoplankton community composition was assessed in light of measured physical and chemical drivers during the "Ellett Line" cruise of autumn 2001 across the Scottish Continental shelf and into adjacent open Atlantic waters. Spatial variability existed in both phytoplankton and environmental conditions, with clear differences not only between on and off shelf stations but also between different on shelf locations. Temperature/salinity plots demonstrated different water masses existed in the region. In turn, principal component analysis (PCA), of the measured environmental conditions (temperature, salinity, water density and inorganic nutrient concentrations) clearly discriminated between shelf and oceanic stations on the basis of DIN:DSi ratio that was correlated with both salinity and temperature. Discrimination between shelf stations was also related to this ratio, but also the concentration of DIN and DSi. The phytoplankton community was diatom dominated, with multidimensional scaling (MDS) demonstrating spatial variability in its composition. Redundancy analysis (RDA) was used to investigate the link between environment and the phytoplankton community. This demonstrated a significant relationship between community composition and water mass as indexed by salinity (whole community), and both salinity and DIN:DSi (diatoms alone). Diatoms of the Pseudo-nitzschia seriata group occurred at densities potentially harmful to shellfish aquaculture, with the potential for toxicity being elevated by the likelihood of DSi limitation of

  7. The relationship between phytoplankton distribution and water column characteristics in North West European shelf sea waters.

    PubMed

    Fehling, Johanna; Davidson, Keith; Bolch, Christopher J S; Brand, Tim D; Narayanaswamy, Bhavani E

    2012-01-01

    Phytoplankton underpin the marine food web in shelf seas, with some species having properties that are harmful to human health and coastal aquaculture. Pressures such as climate change and anthropogenic nutrient input are hypothesized to influence phytoplankton community composition and distribution. Yet the primary environmental drivers in shelf seas are poorly understood. To begin to address this in North Western European waters, the phytoplankton community composition was assessed in light of measured physical and chemical drivers during the "Ellett Line" cruise of autumn 2001 across the Scottish Continental shelf and into adjacent open Atlantic waters. Spatial variability existed in both phytoplankton and environmental conditions, with clear differences not only between on and off shelf stations but also between different on shelf locations. Temperature/salinity plots demonstrated different water masses existed in the region. In turn, principal component analysis (PCA), of the measured environmental conditions (temperature, salinity, water density and inorganic nutrient concentrations) clearly discriminated between shelf and oceanic stations on the basis of DIN:DSi ratio that was correlated with both salinity and temperature. Discrimination between shelf stations was also related to this ratio, but also the concentration of DIN and DSi. The phytoplankton community was diatom dominated, with multidimensional scaling (MDS) demonstrating spatial variability in its composition. Redundancy analysis (RDA) was used to investigate the link between environment and the phytoplankton community. This demonstrated a significant relationship between community composition and water mass as indexed by salinity (whole community), and both salinity and DIN:DSi (diatoms alone). Diatoms of the Pseudo-nitzschia seriata group occurred at densities potentially harmful to shellfish aquaculture, with the potential for toxicity being elevated by the likelihood of DSi limitation of

  8. Water Pressure Distribution on a Flying Boat Hull

    NASA Technical Reports Server (NTRS)

    Thompson, F L

    1931-01-01

    This is the third in a series of investigations of the water pressures on seaplane floats and hulls, and completes the present program. It consisted of determining the water pressures and accelerations on a Curtiss H-16 flying boat during landing and taxiing maneuvers in smooth and rough water.

  9. 24 CFR 3280.609 - Water distribution systems.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... to the manufactured home or water supply piping. When a master cold water shutoff full flow valve is... flows, at least equal to the cross-sectional area of the nominal size of the pipe in which the valve is... provide an adequate quantity of water to each plumbing fixture at a flow rate sufficient to keep...

  10. 24 CFR 3280.609 - Water distribution systems.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... to the manufactured home or water supply piping. When a master cold water shutoff full flow valve is... flows, at least equal to the cross-sectional area of the nominal size of the pipe in which the valve is... provide an adequate quantity of water to each plumbing fixture at a flow rate sufficient to keep...

  11. Condition Assessment for Drinking Water Transmission and Distribution Mains

    EPA Science Inventory

    This project seeks to improve the capability to characterize the condition of water infrastructure. The integrity of buried drinking water mains is critical, as it influences water quality, losses, pressure and cost. This research complements the U.S. Environmental Protection A...

  12. A distributed model: redefining a robust research subject advocacy program at the Harvard Clinical and Translational Science Center.

    PubMed

    Winkler, Sabune J; Cagliero, Enrico; Witte, Elizabeth; Bierer, Barbara E

    2014-08-01

    The Harvard Clinical and Translational Science Center ("Harvard Catalyst") Research Subject Advocacy (RSA) Program has reengineered subject advocacy, distributing the delivery of advocacy functions through a multi-institutional, central platform rather than vesting these roles and responsibilities in a single individual functioning as a subject advocate. The program is process-oriented and output-driven, drawing on the strengths of participating institutions to engage local stakeholders both in the protection of research subjects and in advocacy for subjects' rights. The program engages stakeholder communities in the collaborative development and distributed delivery of accessible and applicable educational programming and resources. The Harvard Catalyst RSA Program identifies, develops, and supports the sharing and distribution of expertise, education, and resources for the benefit of all institutions, with a particular focus on the frontline: research subjects, researchers, research coordinators, and research nurses.

  13. Identifying and Remediating High Water Production Problems in Basin-Centered Formations

    SciTech Connect

    R.L. Billingsley

    2005-12-01

    Through geochemical analyses of produced waters, petrophysics, and reservoir simulation we developed concepts and approaches for mitigating unwanted water production in tight gas reservoirs and for increasing recovery of gas resources presently considered noncommercial. Only new completion research (outside the scope of this study) will validate our hypothesis. The first task was assembling and interpreting a robust regional database of historical produced-water analyses to address the production of excessive water in basin-centered tight gas fields in the Greater Green (GGRB ) and Wind River basins (WRB), Wyoming. The database is supplemented with a sampling program in currently active areas. Interpretation of the regional water chemistry data indicates most produced waters reflect their original depositional environments and helps identify local anomalies related to basement faulting. After the assembly and evaluation phases of this project, we generated a working model of tight formation reservoir development, based on the regional nature and occurrence of the formation waters. Through an integrative approach to numerous existing reservoir concepts, we synthesized a generalized development scheme organized around reservoir confining stress cycles. This single overarching scheme accommodates a spectrum of outcomes from the GGRB and Wind River basins. Burial and tectonic processes destroy much of the depositional intergranular fabric of the reservoir, generate gas, and create a rock volume marked by extremely low permeabilities to gas and fluids. Stress release associated with uplift regenerates reservoir permeability through the development of a penetrative grain bounding natural fracture fabric. Reservoir mineral composition, magnitude of the stress cycle and local tectonics govern the degree, scale and exact mechanism of permeability development. We applied the reservoir working model to an area of perceived anomalous water production. Detailed water analyses

  14. Fluorine distribution in waters of Nalgonda District, Andhra Pradesh, India

    NASA Astrophysics Data System (ADS)

    Ramamohana Rao, N. V.; Rao, N.; Surya Prakash Rao, K.; Schuiling, R. D.

    1993-04-01

    Geochemical and hydrochemical studies were conducted in Nalgonda District (A.P.), to explore the causes of high fluorine in waters, causing a widespread incidence of fluorosis in the local population. Samples of granitic rocks, soils, stream sediments, and waters were analyzed for F and other salient chemical parameters. Samples from the area of Hyderabad city were analyzed for comparison. The F content of waters in areas with endemic fluorosis ranges from 0.4 to 20 mg/l. The low calcium content of rocks and soils, and the presence of high levels of sodium bicarbonate in soils and waters are important factors favoring high levels of F in waters.

  15. Feasibility study and roadmap to improve residential hot water distribution systems

    SciTech Connect

    Lutz, James D.

    2004-03-31

    Residential building practice currently ignores the losses of energy and water caused by the poor design of hot water systems. These losses include: the waste of water while waiting for hot water to get to the point of use; the wasted heat as water cools down in the distribution system after a draw; and the energy to reheat water that was already heated once before. A feasibility study and an action plan for a proposed research project involving residential hot water distribution systems is being developed. The feasibility study will use past work to estimate of hot water and energy loses caused by current hot water distribution systems in residences. Proposed research project, or roadmap, will develop recommendations for improvements to residential hot water distribution systems. The roadmap addresses the technical obstacles and gaps in our knowledge that prevent water and energy reductions and market adoption of water- and energy-efficient technologies. The initial results of the feasibility study are presented here along with a discussion of a roadmap to improve the efficiency of residential hot water distribution systems.

  16. Detection of contamination of municipal water distribution systems

    DOEpatents

    Cooper, John F.

    2012-01-17

    A system for the detection of contaminates of a fluid in a conduit. The conduit is part of a fluid distribution system. A chemical or biological sensor array is connected to the conduit. The sensor array produces an acoustic signal burst in the fluid upon detection of contaminates in the fluid. A supervisory control system connected to the fluid and operatively connected to the fluid distribution system signals the fluid distribution system upon detection of contaminates in the fluid.

  17. [Distribution of picophytoplanktons in Qingdao offshore and its adjacent waters in winter].

    PubMed

    Wang, Min; Liang, Yan-tao; Bai, Xiao-ge; Jiang, Xue-jiao; Wang, Fang; Qiao, Qian

    2008-11-01

    Picophytoplankton (0.2-2.0 microm in size) is the smallest group of autotrophic plankton, being abundant and widespread in the world ocean and playing an important role in the organic matter cycling in ocean. By the method of epifluorescence microscopy (EFM), the abundance and its spatial and diurnal variations of the picophytoplanktons in Qingdao offshore and its adjacent waters in winter were investigated. The results showed that in the study area in winter, phycoerythrin-rich (PE) Synechococcus cells were dominant, followed by Picoeukaryote (Euk) cells, while the abundance of phycocyanin-rich (PC) Synechococcus cells was low and no Prochlorococcus (Pro) cells were observed. The abundance of Synechococcus (Syn) and Euk varied from 8.97 x 10(3) to 1.95 x 10(5) cells x ml(-1) (averaged 4.67 x 10(4) cells x ml(-1) and from 1.95 x 10(2) to 1.01 x 10(4) cells x m(l-1)(averaged 2.39 x 10(3) cells x ml(1) respectively. There was a high-value of Syn abundance in Jiaonan offshore and a low-value in Jimo and southeast Laoshan off-shores, while a high-value of Euk abundance in Rizhao offshore and a low-value in Laoshan offshore. No significant difference was observed in the vertical distribution of Syn and Euk abundance among four water layers (P>0.05) at a continuous station located in the center of Jiaozhou Bay, the abundance had an obvious diurnal fluctuation. Pearson correlation analysis indicated that Syn was positively correlated with water temperature and electrical conductivity (P<0.01) but negatively correlated with dissolved oxygen concentration (P<0.01) and Euk was negatively correlated with water salinity and dissolved oxygen concentration. In the study area in winter, picophytoplankton contributed about 20% to the total phytoplanktonic biomass. PMID:19238842

  18. Reductions in bacterial microorganisms by filtration and ozonation of the surface water supply at the USFWS Northeast Fishery Center

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A water filtration and ozonation system was recently installed to treat creek water used to culture species of concern at the U.S. Fish and Wildlife Service's Northeast Fishery Center, Lamar National Fish Hatchery (NFH). Past experience with fish culture indicates that the following bacterial pathog...

  19. Assessment of a bidirectional reflectance distribution correction of above-water and satellite water-leaving radiance in coastal waters.

    PubMed

    Hlaing, Soe; Gilerson, Alexander; Harmel, Tristan; Tonizzo, Alberto; Weidemann, Alan; Arnone, Robert; Ahmed, Samir

    2012-01-10

    Water-leaving radiances, retrieved from in situ or satellite measurements, need to be corrected for the bidirectional properties of the measured light in order to standardize the data and make them comparable with each other. The current operational algorithm for the correction of bidirectional effects from the satellite ocean color data is optimized for typical oceanic waters. However, versions of bidirectional reflectance correction algorithms specifically tuned for typical coastal waters and other case 2 conditions are particularly needed to improve the overall quality of those data. In order to analyze the bidirectional reflectance distribution function (BRDF) of case 2 waters, a dataset of typical remote sensing reflectances was generated through radiative transfer simulations for a large range of viewing and illumination geometries. Based on this simulated dataset, a case 2 water focused remote sensing reflectance model is proposed to correct above-water and satellite water-leaving radiance data for bidirectional effects. The proposed model is first validated with a one year time series of in situ above-water measurements acquired by collocated multispectral and hyperspectral radiometers, which have different viewing geometries installed at the Long Island Sound Coastal Observatory (LISCO). Match-ups and intercomparisons performed on these concurrent measurements show that the proposed algorithm outperforms the algorithm currently in use at all wavelengths, with average improvement of 2.4% over the spectral range. LISCO's time series data have also been used to evaluate improvements in match-up comparisons of Moderate Resolution Imaging Spectroradiometer satellite data when the proposed BRDF correction is used in lieu of the current algorithm. It is shown that the discrepancies between coincident in-situ sea-based and satellite data decreased by 3.15% with the use of the proposed algorithm. This confirms the advantages of the proposed model over the current

  20. Massachusetts Water Resource Research Center: Annual program report, 1988 (FY 1987)

    SciTech Connect

    Not Available

    1988-12-01

    The Massachusetts Water Resources Research Center program for 1987-88 (Federal Fiscal Year FY87) focused on several research areas of high priority for the state and New England region: acid deposition impacts, the minimization of nitrate contamination of groundwater from on-site wastewater treatment, the pricing of drinking water to meet future infrastructure needs, and the proposed diversion of water from a ''Wild and Scenic'' river. Three WRIP Projects were begun in FY87. One evaluates cloud and fog acidity in central Massachusetts, another evaluates the use of peat in rural sewage disposal systems to minimize nitrate contamination of groundwater, and the third will determine the true cost of water so that utilities may appropriately plan for new sources or infrastructure renovation. The Cooperative Aquatic Research Program (CARP) funded five projects; four were acid deposition-related projects. Phase III of the Acid Rain Monitoring Project continued monitoring 500 randomly selected and 300 special interest surface waters quarterly and will continue into its fourth year of the ten year program. Investigation of the role of acid deposition in enhancing microorganisms in lake sediment that may play a role in methylating heavy metals such as mercury continued. Similarly, the study of mechanisms of control of aluminum mobility in watersheds subjected to acid deposition and the study of the impact of acid deposition on salamander communities were continued. Research on the role of sulfate reduction in lakes as a natural mechanism for neutralizing acidity funded in its first year by WRIP, has been continued. All but the Acid Rain Monitoring Project are to be completed in 1988.

  1. The CUAHSI Water Data Center: Enabling Data Publication, Discovery and Re-use

    NASA Astrophysics Data System (ADS)

    Seul, M.; Pollak, J.

    2014-12-01

    The CUAHSI Water Data Center (WDC) supports a standards-based, services-oriented architecture for time-series data and provides a separate service to publish spatial data layers as shape files. Two new services that the WDC offers are a cloud-based server (Cloud HydroServer) for publishing data and a web-based client for data discovery. The Cloud HydroServer greatly simplifies data publication by eliminating the need for scientists to set up an SQL-server data base, a requirement that has proven to be a significant barrier, and ensures greater reliability and continuity of service. Uploaders have been developed to simplify the metadata documentation process. The web-based data client eliminates the need for installing a program to be used as a client and works across all computer operating systems. The services provided by the WDC is a foundation for big data use, re-use, and meta-analyses. Using data transmission standards enables far more effective data sharing and discovery; standards used by the WDC are part of a global set of standards that should enable scientists to access unprecedented amount of data to address larger-scale research questions than was previously possible. A central mission of the WDC is to ensure these services meet the needs of the water science community and are effective at advancing water science.

  2. Unifying Water Data Sources: How the CUAHSI Water Data Center is Enabling and Improving Access to a Growing Catalog of over 100 Data Providers

    NASA Astrophysics Data System (ADS)

    Pollak, J.; Berry, K.; Couch, A.; Arrigo, J.; Hooper, R. P.

    2013-12-01

    Scientific data about water are collected and distributed by numerous sources which can differ tremendously in scale. As competition for water resources increases, increasing access to and understanding of information about water will be critical. The mission of the new CUAHSI Water Data Center (WDC) is to provide those researchers who collect data a medium to publish their datasets and give those wanting to discover data the proper tools to efficiently find the data that they seek. These tools include standards-based data publication, data discovery tools based upon faceted and telescoping search, and a data analysis tool HydroDesktop that downloads and unifies data in standardized formats. The CUAHSI Hydrologic Information System (HIS) is a community developed and open source system for sharing water data. As a federated, web service oriented system it enables data publication for a diverse user population including scientific investigators (Research Coordination Networks, Critical Zone Observatories), government agencies (USGS, NASA, EPA), and citizen scientists (watershed associations). HydroDesktop is an end user application for data consumption in this system that the WDC supports. This application can be used for finding, downloading, and analyzing data from the HIS. It provides a GIS interface that allows users to incorporate spatial data that are not accessible via HIS, simple analysis tools to facilitate graphing and visualization, tools to export data to common file types, and provides an extensible architecture that developers can build upon. HydroDesktop, however, is just one example of a data access client for HIS. The web service oriented architecture enables data access by an unlimited number of clients provided they can consume the web services used in HIS. One such example developed at the WDC is the 'Faceted Search Client', which capitalizes upon exploratory search concepts to improve accuracy and precision during search. We highlight such

  3. Geohydrology and water quality of the Durham Center Area, Durham, Connecticut

    USGS Publications Warehouse

    Melvin, R.L.; Stone, J.R.; Craft, P.A.; Lane, J.W.; Davies, B. S.

    1995-01-01

    Contaminated ground water is widespread and persistent beneath the Durham Center area in the town of Durham, Conn. Most of the contaminants are organic halides, usually trichloroethene, 1,1,1-trichloroethane, and tetrachloroethene. Less extensive chemical contamination of surface water, soil, and glacial sediments also has been detected. Two manufacturing companies, located at the northern and southern ends of this largely residential area, are believed to be the principal sources of the organic compounds detected in ground water. The contamination of water in the bedrock, the primary source of drinking water throughout the area, is the major environmental concern. Maximum concentrations of trichloroethene in three bed- rock wells range from 4,500 to about 5,500 mg/L (micrograms per liter). Concentrations of trichloroethene greater than 5 mg/L, the maximum contaminant level established for drinking water by the U.S Environmental Protection Agency, have regularly been detected in water samples from many other bedrock wells for at least 9 years. The geohydrology of the area is highly complex. Compact lodgment till that is up to 30 feet thick and probably fractured, overlies the bedrock. The bedrock is lithologically heterogeneous, and con- sists mostly of red fluvial sandstone, siltstone, and conglomerate; it is locally interbedded with black lacustrine shales and gray sandstones. Lithology and stratigraphy interpreted from borehole-geophysical logs at Durham Center are consistent with the Portland Formation subfacies described in earlier geologic studies. Beds strike nearly north-south and dip gently eastward. At least one high-angle normal fault transects the bedrock; it strikes northeast and dips northwest. Acoustic televiewer logs, measurements at out-crops, and azimuthal, square-array, resistivity data indicate a dominance of northeast-striking fractures that dip steeply northwest and southeast. Less prevalent strike directions are north to east-north-east. The

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

    SciTech Connect

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

    2007-09-01

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

  5. Distributed sensor for water and pH measurements using fiber optics and swellable polymeric systems

    NASA Astrophysics Data System (ADS)

    Michie, W. C.; Culshaw, B.; McKenzie, I.; Konstantakis, M.; Graham, N. B.; Moran, C.; Santos, F.; Bergqvist, E.; Carlstrom, B.

    1995-01-01

    We report on the design, construction and test of a generic form of sensor for making distributed measurements of a range of chemical parameters. The technique combines optical time-domain reflectometry with chemically sensitive water-swellable polymers (hydrogels). Initial experiments have concentrated on demonstrating a distributed water detector; however, gels have been developed that enable this sensor to be

  6. CHANGES IN BACTERIAL COMPOSITION OF BIOFILM IN A METROPOLITAN DRINKING WATER DISTRIBUTION SYSTEM

    EPA Science Inventory

    This study examined the development of bacterial biofilms within a metropolitan distribution system. The distribution system is fed with different source water (i.e., groundwater, GW and surface water, SW) and undergoes different treatment processes in separate facilities. The b...

  7. PHYSIO-CHEMICAL CHARACTERIZATION OF IRON TUBERCULATION FROM A SINGLE DRINKING WATER DISTRIBUTION SYSTEM

    EPA Science Inventory

    Corrosion of iron pipes in Drinking Water Distribution Systems (DWDS) contributes to the formation of tubercles whose physio-chemical properties are influenced by the composition of the waters in the distribution system. Thus the objective of this study was to assess the extent o...

  8. Water Distribution System Operation and Maintenance. A Field Study Training Program. Second Edition.

    ERIC Educational Resources Information Center

    Kerri, Kenneth D.; And Others

    Proper installation, inspection, operation, maintenance, repair and management of water distribution systems have a significant impact on the operation and maintenance cost and effectiveness of the systems. The objective of this manual is to provide water distribution system operators with the knowledge and skills required to operate and maintain…

  9. The Water Discovery Center: A Cooperative Effort of the Youth Science Institute, Santa Clara Valley Water District, and Santa Clara County Parks and Recreation Department.

    ERIC Educational Resources Information Center

    Tzitz, Carolyn J.

    1984-01-01

    Describes a water discovery center which focuses on water ecology and conservation. Also describes nine instructional panels used with visiting school groups (or casual visitors) taking part in the four-hour program and related instructional materials containing pre- and post-visit activities. (BC)

  10. Formation and conversion of defect centers in low water peak single mode optical fiber induced by gamma rays irradiation

    SciTech Connect

    Wen, J. X.; Luo, W. Y.; Xiao, Z. Y.; Wang, T. Y.; Chen, Z. Y.; Zeng, X. L.

    2010-02-15

    The formation and conversion processes of defect centers in low water peak single mode optical (LWPSM) fiber irradiated with gamma rays were investigated at room temperature using electron spin resonance. Germanium electron center (GEC) and self-trapped hole center (STH) occur when the fibers are irradiated with 1 and 5 kGy cumulative doses, respectively. With the increase in irradiation doses, the GEC defect centers disappear, and new defect centers such as E{sup '} centers (Si and Ge) and nonbridge oxygen hole centers (NBOHCs) generate. The generation of GEC and STH is attributed to the electron transfer, which is completely balanced. This is the main reason that radiation-induced attenuation (RIA) of the LWPSM fiber is only 10 dB/km at communication window. The new defect centers come from the conversion of GEC and STH to E{sup '} centers and NBOHC, and the conversion processes cause bond cleavage, which is the root cause that the RIA of the LWPSM fiber significantly increases up to 180 dB/km at working window. Furthermore, the concentration of new defect centers is saturated easily even by increasing cumulative doses.

  11. Biomechanical evaluation of the Eco-Pick lift assist: A device designed to facilitate product selection tasks in distribution centers.

    PubMed

    Lavender, Steven A; Ko, Pei-Ling; Sommerich, Carolyn M

    2013-03-01

    Developing lift assist devices to aid workers performing case tasks in distribution centers has been challenging given the movement of workers through a distribution facility. The objective of this work was to biomechanically evaluate a lift assist that can be integrated with pallet jacks and thereby move through the facility with the workers. Twelve participants transferred 16.4 kg boxes from one pallet to another manually and using the Eco-Pick lift assist. Electromyographic (EMG) activities were measured bilaterally in the Bicep, Deltoid, Latissimus Dorsi, and Erector Spinae muscles. The analysis showed that the 90th percentile normalized EMG values were significantly reduced in 4 of the 8 muscles sampled when using the Eco-Pick. Likewise, the 50th percentile normalized EMG data were significantly reduced for the Erector Spinae, Latissimus Dorsi, and the Bicep muscles when using the assist. For some of the muscles the advantage of the Eco-Pick was dependent upon the initial lift height or the placement height. Overall, it appears that this evaluation of the Eco-Pick's efficacy indicates that the device has the potential to be an effective means of reducing worker exposure to risk factors associated with back and shoulder injuries experienced during manual palletizing tasks found in distribution centers. PMID:22884290

  12. Qualitative Uncertainty Assessment for Distributed Surface Water Quality Models

    NASA Astrophysics Data System (ADS)

    Meixner, T.; Bubb, K.; van Griensven, A.

    2006-12-01

    Water quality models are often used to aid water quality regulators in the United States and around the world make critical decisions about how to improve water quality. Basin scale water quality models generally simplify spatial complexity to some degree. This problem is especially relevant in water quality modeling since the sources of pollution as well as the hydrologic drivers vary spatially across the landscape. The spatial complexity problem also presents specific challenges for estimating model predictive uncertainty. Questions of how to integrate multiple sources of stream water and water quality data at multiple locations are likely to be even more daunting than they are for surface water hydrologic models. At this time, given the complexity of water quality models and the general lack of data available, true statistical techniques of integrating, multiple data sources and calculating uncertainty bounds are probably not reasonable approaches. For this reason, we propose evaluation methods that are not based on statistics in order to evaluate the fit-to- purpose of particular model applications. Within SWAT2005, both a statistical method for uncertainty analysis, ParaSol, and an evaluation method, SUNGLASSES, have been incorporated. Additionally weighted averages of prediction errors are integrated into a global objective function and used to evaluate the reasonableness of model assumptions. This integration occurs across multiple objective functions and multiple locations. These methods have been applied in the context of a hypothetical water quality control problem in the San Jacinto watershed in southern California. The analysis includes an extension of the uncertainty analysis into its economic implications. The economic impact of the uncertainty methods proposed here are compared to more traditional uncertainty methods. The economic implications of uncertainty are shown to be important but only under circumstances where water quality targets are close

  13. Distribution of Water in Nominally Anhydrous Minerals during Metamorphic Reactions

    NASA Astrophysics Data System (ADS)

    Van Lankvelt, A.; Seaman, S. J.; Williams, M. L.

    2014-12-01

    Nominally anhydrous minerals are a reservoir for water in otherwise dry rocks. This water may play a role in facilitating metamorphic reactions and enhancing deformation. In this study, we examined orthopyroxene-bearing granites from the Athabasca Granulite terrane in northern Saskatchewan. These rocks intruded the lower crust (pressures of 1 GPa) at circa 2.6 Ga at temperatures of > 900 ºC and were subsequently metamorphosed at granulite facies conditions (700 ºC and 1 GPa) in the Paleoproterozoic (Williams et al., 2000). One of the primary reactions recorded by these rocks is locally known as the "Mary" reaction and involves the anhydrous reaction: orthopyroxene + Ca-plagioclase = clinopyroxene + garnet + Na-plagioclase. Measurements of water concentrations in both product and reactant assemblages were performed using a Bruker Vertex 70 Fourier transform infrared spectrometer and revealed that there is a slight excess of water in product minerals over reactant minerals. There are two possible explanations for this. The first is that water was derived from an external source, possibly hydrous, likely contemporaneous, mafic dikes. This interpretation is supported by higher concentrations of K, which is essentially absent from the reactant minerals, in the Na-rich rims of plagioclase. However, only modest amounts of external fluids could have been introduced, or amphiboles would have been stabilized at the expense of clinopyroxene (Moore & Carmichael, 1998). An alternative interpretation is that slightly more water-rich minerals reacted more readily, releasing water that was then incorporated into their products, whereas the water-poorer minerals failed to react. Support for this interpretation comes from very low water concentrations in orthopyroxene and plagioclase from an unreacted and undeformed sample. This interpretation suggests that water in anhydrous minerals may catalyze metamorphic reactions, and a lack of water may be critical for preserving metastable

  14. Spatial Description of Drinking Water Bacterial Community Structures in Bulk Water Samples Collected in a Metropolitan Distribution System

    EPA Science Inventory

    The description of microorganisms inhabiting drinking water distribution systems has commonly been performed using techniques that are biased towards easy to culture bacterial populations. As most environmental microorganisms cannot be grown on artificial media, our understanding...

  15. "Ice Cubes" in the Center of the Milky Way: Water-ice and Hydrocarbons in the Central Parsec

    NASA Astrophysics Data System (ADS)

    Moultaka, J.; Eckart, A.; Mužić, K.

    2015-06-01

    The close environment of the central supermassive black hole of our Galaxy has been studied thoroughly for decades in order to shed light on the behavior of the central regions of galaxies in general and of active galaxies in particular. The Galactic center (GC) has shown a wealth of structures on different scales with a complicated mixture of early- and late-type stars, ionized and molecular gas, dust, and winds. Here we aim to study the distribution of water-ices and hydrocarbons in the central parsec, as well as along the line of sight. This study is made possible thanks to L-band spectroscopy. This spectral band, from 2.8 to 4.2 μm, hosts important signatures of the circumstellar medium and interstellar dense and diffuse media among which deep absorption features are attributed to water-ices and hydrocarbons. We observed the GC in the L band of the ISAAC spectrograph located on the UT1/VLT ESO telescope. By mapping the central half parsec using 27 slit positions, we were able to build the first data cube of the region in this wavelength domain. Thanks to a calibrator spectrum of the foreground extinction in the L band derived in a previous paper, we corrected our data cube for the line-of-sight extinction and validated our calibrator spectrum. The data show that a residual absorption due to water-ices and hydrocarbons is present in the corrected data cube. This suggests that the features are produced in the local environment of the GC, implying very low temperatures well below 80 K. This is in agreement with our finding of local CO ices in the central parsec described in Moultaka et al. Resulting from ESO VLT observations of program ID numbers 71.C-0192A and 077.C-0286A.

  16. “ICE CUBES” IN THE CENTER OF THE MILKY WAY: WATER-ICE AND HYDROCARBONS IN THE CENTRAL PARSEC

    SciTech Connect

    Moultaka, J.; Eckart, A.; Muzic, K. E-mail: eckart@ph1.uni-koeln.de

    2015-06-20

    The close environment of the central supermassive black hole of our Galaxy has been studied thoroughly for decades in order to shed light on the behavior of the central regions of galaxies in general and of active galaxies in particular. The Galactic center (GC) has shown a wealth of structures on different scales with a complicated mixture of early- and late-type stars, ionized and molecular gas, dust, and winds. Here we aim to study the distribution of water-ices and hydrocarbons in the central parsec, as well as along the line of sight. This study is made possible thanks to L-band spectroscopy. This spectral band, from 2.8 to 4.2 μm, hosts important signatures of the circumstellar medium and interstellar dense and diffuse media among which deep absorption features are attributed to water-ices and hydrocarbons. We observed the GC in the L band of the ISAAC spectrograph located on the UT1/VLT ESO telescope. By mapping the central half parsec using 27 slit positions, we were able to build the first data cube of the region in this wavelength domain. Thanks to a calibrator spectrum of the foreground extinction in the L band derived in a previous paper, we corrected our data cube for the line-of-sight extinction and validated our calibrator spectrum. The data show that a residual absorption due to water-ices and hydrocarbons is present in the corrected data cube. This suggests that the features are produced in the local environment of the GC, implying very low temperatures well below 80 K. This is in agreement with our finding of local CO ices in the central parsec described in Moultaka et al.

  17. Evaluating Domestic Hot Water Distribution System Options with Validated Analysis Models

    SciTech Connect

    Weitzel, E.; Hoeschele, E.

    2014-09-01

    A developing body of work is forming that collects data on domestic hot water consumption, water use behaviors, and energy efficiency of various distribution systems. Transient System Simulation Tool (TRNSYS) is a full distribution system developed that has been validated using field monitoring data and then exercised in a number of climates to understand climate impact on performance. In this study, the Building America team built upon previous analysis modeling work to evaluate differing distribution systems and the sensitivities of water heating energy and water use efficiency to variations of climate, load, distribution type, insulation and compact plumbing practices. Overall, 124 different TRNSYS models were simulated. The results of this work are useful in informing future development of water heating best practices guides as well as more accurate (and simulation time efficient) distribution models for annual whole house simulation programs.

  18. Evaluating Domestic Hot Water Distribution System Options With Validated Analysis Models

    SciTech Connect

    Weitzel, E.; Hoeschele, M.

    2014-09-01

    A developing body of work is forming that collects data on domestic hot water consumption, water use behaviors, and energy efficiency of various distribution systems. A full distribution system developed in TRNSYS has been validated using field monitoring data and then exercised in a number of climates to understand climate impact on performance. This study builds upon previous analysis modelling work to evaluate differing distribution systems and the sensitivities of water heating energy and water use efficiency to variations of climate, load, distribution type, insulation and compact plumbing practices. Overall 124 different TRNSYS models were simulated. Of the configurations evaluated, distribution losses account for 13-29% of the total water heating energy use and water use efficiency ranges from 11-22%. The base case, an uninsulated trunk and branch system sees the most improvement in energy consumption by insulating and locating the water heater central to all fixtures. Demand recirculation systems are not projected to provide significant energy savings and in some cases increase energy consumption. Water use is most efficient with demand recirculation systems, followed by the insulated trunk and branch system with a central water heater. Compact plumbing practices and insulation have the most impact on energy consumption (2-6% for insulation and 3-4% per 10 gallons of enclosed volume reduced). The results of this work are useful in informing future development of water heating best practices guides as well as more accurate (and simulation time efficient) distribution models for annual whole house simulation programs.

  19. Providing International Research Experiences in Water Resources Through a Distributed REU Program

    NASA Astrophysics Data System (ADS)

    Judge, J.; Sahrawat, K.; Mylavarapu, R.

    2012-12-01

    Research experiences for undergraduates offer training in problem solving and critical thinking via hands-on projects. The goal of the distributed Research Experience for Undergraduates (REU) Program in the Agricultural and Biological Engineering Department (ABE) at the University of Florida (UF) is to provide undergraduate students a unique opportunity to conduct research in water resources using interdisciplinary approaches, integrating research and extension, while the cohort is not co-located. The eight-week REU Program utilizes the extensive infrastructure of UF - Institute of Food and Agricultural Sciences (IFAS) through the Research and Education Centers (RECs). To provide international research and extension experience, two students were located at the International Crop Research Institute for the Semi-Arid Tropics (ICRISAT), in India. Prior to the beginning of the Program, the students worked closely with their research mentors at University of Florida and ICRISAT to develop a project plan for understanding the water quality issues in two watersheds. The students were co-located during the Orientation week at the University of Florida. During the Program, they achieved an enriching cohort experience through social networking, daily blogs, and weekly video conferences to share their research and other REU experiences. The group meetings and guest lectures are conducted via synchronously through video conferencing. The students who were distributed across Florida benefited from the research experiences of the students who were located in India, as their project progressed. They described their challenges and achievements during the group meetings and in the blogs. This model of providing integrated research and extension opportunities in hydrology where not all the REU participants are physically co-located, is unique and can be extended to other disciplines.

  20. [Investigation of the distribution of water clusters in vegetables, fruits, and natural waters by flicker noise spectroscopy].

    PubMed

    Zubov, A V; Zubov, K V; Zubov, V A

    2007-01-01

    The distribution of water clusters in fresh rain water and in rain water that was aged for 30 days (North Germany, 53 degrees 33' N, 12 degrees 47' E, 293 K, rain on 25.06.06) as well as in fresh vegetables and fruits was studied by flicker noise spectroscopy. In addition, the development of water clusters in apples and potatoes during ripening in 2006 was investigated. A different distribution of water clusters in irrigation water (river and rain) and in the biomatrix of vegetables (potatoes, onions, tomatoes, red beets) and fruits (apples, bananas) was observed. It was concluded that the cluster structure of irrigation water differs from that of water of the biomatrix of vegetables and fruits and depends on drought and the biomatrix nature. Water clusters in plants are more stable and reproducible than water clusters in natural water. The main characteristics of cluster formation in materials studied were given. The oscillation frequencies of water clusters in plants (biofield) are given at which they interact with water clusters of the Earth hydrosphere. A model of series of clusters 16(H2O)100 <--> 4(H2O)402 <--> 2(H2O)903 <--> (H2O)1889 in the biomatrix of vegetables and fruits was discussed.

  1. Mapping the ecological dimensions and potential distributions of endangered relic shrubs in western Ordos biodiversity center.

    PubMed

    Zhu, Geng-Ping; Li, Hui-Qi; Zhao, Li; Man, Liang; Liu, Qiang

    2016-01-01

    Potential distributions of endemic relic shrubs in western Ordos were poorly mapped, which hindered our implementation of proper conservation. Here we investigated the applicability of ecological niche modeling for endangered relic shrubs to detect areas of priority for biodiversity conservation and analyze differences in ecological niche spaces used by relic shrubs. We applied ordination and niche modeling techniques to assess main environmental drivers of five endemic relic shrubs in western Ordos, namely, Ammopiptanthus mongolicus, Amygdalus mongolica, Helianthemum songaricum, Potaninia mongolica, and Tetraena mongolica. We calculated niche overlap metrics in gridded environmental spaces and compared geographical projections of ecological niches to determine similarities and differences of niches occupied by relic shrubs. All studied taxa presented different responses to environmental factors, which resulted in a unique combination of niche conditions. Precipitation availability and soil quality characteristics play important roles in the distributions of most shrubs. Each relic shrub is constrained by a unique set of environmental conditions, the distribution of one species cannot be implied by the distribution of another, highlighting the inadequacy of one-fits-all type of conservation measure. Our stacked habitat suitability maps revealed regions around Yellow River, which are highly suitable for most species, thereby providing high conservation value. PMID:27199260

  2. Mapping the ecological dimensions and potential distributions of endangered relic shrubs in western Ordos biodiversity center

    PubMed Central

    Zhu, Geng-Ping; Li, Hui-Qi; Zhao, Li; Man, Liang; Liu, Qiang

    2016-01-01

    Potential distributions of endemic relic shrubs in western Ordos were poorly mapped, which hindered our implementation of proper conservation. Here we investigated the applicability of ecological niche modeling for endangered relic shrubs to detect areas of priority for biodiversity conservation and analyze differences in ecological niche spaces used by relic shrubs. We applied ordination and niche modeling techniques to assess main environmental drivers of five endemic relic shrubs in western Ordos, namely, Ammopiptanthus mongolicus, Amygdalus mongolica, Helianthemum songaricum, Potaninia mongolica, and Tetraena mongolica. We calculated niche overlap metrics in gridded environmental spaces and compared geographical projections of ecological niches to determine similarities and differences of niches occupied by relic shrubs. All studied taxa presented different responses to environmental factors, which resulted in a unique combination of niche conditions. Precipitation availability and soil quality characteristics play important roles in the distributions of most shrubs. Each relic shrub is constrained by a unique set of environmental conditions, the distribution of one species cannot be implied by the distribution of another, highlighting the inadequacy of one-fits-all type of conservation measure. Our stacked habitat suitability maps revealed regions around Yellow River, which are highly suitable for most species, thereby providing high conservation value. PMID:27199260

  3. Distributed H2 Supply for Fuel Cell Utility Vehicles Year 6 - Activity 3.5 - Development fo a National Center for Hydrogen Technology

    SciTech Connect

    Almlie, Jay

    2012-04-15

    The Energy & Environmental Research Center (EERC) has developed a high-pressure hydrogen production system that reforms a liquid organic feedstock and water at operating pressures up to 800 bar (~12,000 psig). The advantages of this system include the elimination of energy-intensive hydrogen compression, a smaller process footprint, and the elimination of gaseous or liquid hydrogen transport. This system could also potentially enable distributed hydrogen production from centralized coal. Processes have been investigated to gasify coal and then convert the syngas into alcohol or alkanes. These alcohols and alkanes could then be easily transported in bulk to distributed high-pressure water-reforming (HPWR)-based systems to deliver hydrogen economically. The intent of this activity was to utilize the EERC’s existing HPWR hydrogen production process, previously designed and constructed in a prior project phase, as a basis to improve operational and production performance of an existing demonstration unit. Parameters to be pursued included higher hydrogen delivery pressure, higher hydrogen production rates, and the ability to refill within a 5-minute time frame.

  4. Anaerobic degradation of solid material: importance of initiation centers for methanogenesis, mixing intensity, and 2D distributed model.

    PubMed

    Vavilin, V A; Angelidaki, I

    2005-01-01

    Batch anaerobic codigestion of municipal household solid waste (MHSW) and digested manure in mesophilic conditions was carried out. The different waste-to-biomass ratios and intensity of mixing were studied theoretically and experimentally. The experiments showed that when organic loading was high, intensive mixing resulted in acidification and failure of the process, while low mixing intensity was crucial for successful digestion. However, when loading was low, mixing intensity had no significant effect on the process. We hypothesized that mixing was preventing establishment of methanogenic zones in the reactor space. The methanogenic zones are important to withstand inhibition due to development of acids formed during acidogenesis. The 2D distributed models of symmetrical cylinder reactor are presented based on the hypothesis of the necessity of a minimum size of methanogenic zones that can propagate and establish a good methanogenic environment. The model showed that at high organic loading rate spatial separation of the initial methanogenic centers from active acidogenic areas is the key factor for efficient conversion of solids to methane. The initial level of methanogenic biomass in the initiation centers is a critical factor for the survival of these centers. At low mixing, most of the initiation methanogenic centers survive and expand over the reactor volume. However, at vigorous mixing the initial methanogenic centers are reduced in size, averaged over the reactor volume, and finally dissipate. Using fluorescence in situ hybridization, large irregular cocci of microorganisms were observed in the case with minimal mixing, while in the case with high stirring mainly dead cells were found. PMID:15540194

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

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

  6. Luminescence and color center distributions in K3YB6O12:Ce3+ phosphor

    NASA Astrophysics Data System (ADS)

    Yang, Li; Wan, Yingpeng; Weng, Honggen; Huang, Yanlin; Chen, Cuili; Seo, Hyo Jin

    2016-08-01

    Polycrystalline Ce3+-doped K3YB6O12 (1–14 mol%) phosphors were prepared by facile chemical sol–gel synthesis. The phase formation of the phosphors was confirmed by x-ray powder diffraction (XRD) analysis. The photoluminescence excitation spectra (PLE), emission spectra (PL) and the luminescence decay curves were tested. Under the near-UV light, the phosphors present the emission from blue color to yellowish green due to the allowed 4f –5d transitions of Ce3+ ions. The absolute quantum efficiency (QE) of K3YB6O12:Ce3+ can reach 53% under the excitation of near-UV light. The luminescence thermal quenching of the phosphor was investigated by the temperature-dependent spectra. The crystallographic site of Ce3+ ions in the lattice was identified and discussed on the basis of luminescence characteristics and structural data. There is only one isolated Ce3+ center occupying the Y(II) sites in the lightly doped samples presenting a typical doublet emission profile. While the Ce3+ multi-centers could be created with the enhancement of the doping levels, which could induce the distinct red-shift of the spectra due to the dipole–dipole interactions. The result in this work could be useful for the further investigation of other rare earth ions in this host.

  7. Luminescence and color center distributions in K3YB6O12:Ce3+ phosphor

    NASA Astrophysics Data System (ADS)

    Yang, Li; Wan, Yingpeng; Weng, Honggen; Huang, Yanlin; Chen, Cuili; Seo, Hyo Jin

    2016-08-01

    Polycrystalline Ce3+-doped K3YB6O12 (1-14 mol%) phosphors were prepared by facile chemical sol-gel synthesis. The phase formation of the phosphors was confirmed by x-ray powder diffraction (XRD) analysis. The photoluminescence excitation spectra (PLE), emission spectra (PL) and the luminescence decay curves were tested. Under the near-UV light, the phosphors present the emission from blue color to yellowish green due to the allowed 4f -5d transitions of Ce3+ ions. The absolute quantum efficiency (QE) of K3YB6O12:Ce3+ can reach 53% under the excitation of near-UV light. The luminescence thermal quenching of the phosphor was investigated by the temperature-dependent spectra. The crystallographic site of Ce3+ ions in the lattice was identified and discussed on the basis of luminescence characteristics and structural data. There is only one isolated Ce3+ center occupying the Y(II) sites in the lightly doped samples presenting a typical doublet emission profile. While the Ce3+ multi-centers could be created with the enhancement of the doping levels, which could induce the distinct red-shift of the spectra due to the dipole-dipole interactions. The result in this work could be useful for the further investigation of other rare earth ions in this host.

  8. Distribution flow: A general process in the top layer of water repellent soils

    SciTech Connect

    Ritsema, C.J.; Dekker, L.W.

    1995-05-01

    Water and solute input rates on the soil surface may vary considerably from place to place. Distribution flow, i.e., the process of water and solute flow in a lateral direction over and through the very first millimeter or centimeter of the soil profile, is an extremely important process in distributing the rainfall toward places where vertical transport occurs. This study was carried out to quantify the process the distribution flow and its underlying process mechanism. A KBr tracer was applied on two water repellent sandy soils to follow the actual flow paths of water and solutes in the upper part of the profile. On both experimental fields, distribution flow actually displaced the applied bromide laterally through a very thin layer on the top of the soil profile, referred to as the {open_quotes}distribution layer.{close_quotes} Distribution flow was directed to locations within the 0- to 2.5- cm layer, where the soil was the least water repellent. On these relatively wet areas, the highest concentrations of bromide could be found. There was an acceleration in the vertical transport of water and bromide on these sites. Effects of distribution flow on the local concentration of water and solutes can be expected to be even more pronounced in uneven terrains, where lateral displacements may increase from the millimeter-centimeter scale to tens of meters. Implications for modeling field-scale water and solute flow are outlined. 71 refs., 9 figs., 2 tabs.

  9. Distribution Flow: A General Process in the Top Layer of Water Repellent Soils

    NASA Astrophysics Data System (ADS)

    Ritsema, Coen J.; Dekker, Louis W.

    1995-05-01

    Water and solute input rates on the soil surface may vary considerably from place to place. Distribution flow, i.e., the process of water and solute flow in a lateral direction over and through the very first millimeter or centimeter of the soil profile, is an extremely important process in distributing the rainfall toward places where vertical transport occurs. This study was carried out to quantify the process of distribution flow and its underlying process mechanism. A KBr tracer was applied on two water repellent sandy soils to follow the actual flow paths of water and solutes in the upper part of the profile. On both experimental fields, distribution flow actually displaced the applied bromide laterally through a very thin layer on the top of the soil profile, referred to here as the "distribution layer." Distribution flow was directed to locations within the 0- to 2.5-cm layer, where the soil was the least water repellent. On these relatively wet areas, the highest concentrations of bromide could be found. There was an acceleration in the vertical transport of water and bromide on these sites. Effects of distribution flow on the local concentration of water and solutes can be expected to be even more pronounced in uneven terrains, where lateral displacements may increase from the millimeter-centimeter scale to tens of meters. Implications for modeling field-scale water and solute flow are outlined.

  10. MODELING THE IMPACTS OF FIRE FLOWS ON DISTRIBUTION SYSTEM WATER QUALITY, DESIGN AND OPERATION

    EPA Science Inventory

    In most water distribution systems, a significant amount of the piping and storage capacity is used to provide adequate quantities of water during fire conditions. This increased capacity results in higher capital costs and potential negative impacts on water quality due to longe...

  11. Diversity of free-living amoebae in a dual distribution (potable and recycled) water system

    EPA Science Inventory

    Free-living amoebae are known to facilitate the growth of water associated pathogens. This study, for the first time, explored the diversity of free-living amoebae in a dual distribution (potable and recycled) water system in Rouse Hill NSW, Australia. Water and biofilm samples w...

  12. Water Purification, Distribution and Sewage Disposal. Appropriate Technologies for Development. Reprint R-29.

    ERIC Educational Resources Information Center

    1979

    This document, designed to serve as a training manual for technical instructors and as a field resource reference for Peace Corps volunteers, consists of nine units. Unit topics focus on: (1) water supply sources; (2) water treatment; (3) planning water distribution systems; (4) characteristics of an adequate system; (5) construction techniques;…

  13. Distribution and Availability of State and Areawide Water Quality Reports in Oklahoma Libraries.

    ERIC Educational Resources Information Center

    McClure, Charles R.; Million, Anne

    This report examines the distribution and availability of water quality reports in the state of Oklahoma. Based on legislation from the Clean Water Act and regulations from the Environmental Protection Agency's "Public Participation Handbook for Water Quality Management," depository libraries must be established to provide citizen access to…

  14. IRON TUBERCULATION: PHYSIO-CHEMICAL CHARACTERIZATION OF A SINGLE PIPE FROM A DRINKING WATER DISTRIBUTION SYSTEM

    EPA Science Inventory

    The nature of iron tubercles inside unlined iron pipes of drinking water distribution systems are influenced by water quality and therefore susceptible to changes in water chemistry. The underlying assumption is that tubercles in a system have similar physio-chemical properties. ...

  15. Virus contamination from operation and maintenance practices in small drinking water distribution systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We tested the association of common events in drinking water distribution systems with contamination of household tap water with human enteric viruses. Viruses were enumerated by qPCR in the tap water of 14 municipal systems that use non-disinfected groundwater. Ultra-violet disinfection was install...

  16. EFFECTS OF MIXING AND AGING ON WATER QUALITY IN DISTRIBUTION SYSTEM STORAGE FACILITIES

    EPA Science Inventory

    Aging of water in distribution system storage facilities can lead to deterioration of the water quality due to loss of disinfectant residual and bacterial regrowth. Facilities should be operated to insure that the age of the water is not excessive taking into account the quality...

  17. Microbial Community Profile of a Lead Service Line Removed from a Drinking Water Distribution System

    EPA Science Inventory

    A corroded lead water pipe was removed from a drinking water distribution system and the microbial community was profiled using 16S rDNA techniques. This is the first report of the characterization of biofilm on a surface of a corroded lead drinking water pipe. The majority of ...

  18. Realizing the potential of the CUAHSI Water Data Center to advance Earth Science

    NASA Astrophysics Data System (ADS)

    Hooper, R. P.; Seul, M.; Pollak, J.; Couch, A.

    2015-12-01

    The CUAHSI Water Data Center has developed a cloud-based system for data publication, discovery and access. Key features of this system are a semantically enabled catalog to discover data across more than 100 different services and delivery of data and metadata in a standard format. While this represents a significant technical achievement, the purpose of this system is to support data reanalysis for advancing science. A new web-based client, HydroClient, improves access to the data from previous clients. This client is envisioned as the first step in a workflow that can involve visualization and analysis using web-processing services, followed by download to local computers for further analysis. The release of the WaterML library in the R package CRAN repository is an initial attempt at linking the WDC services in a larger analysis workflow. We are seeking community input on other resources required to make the WDC services more valuable in scientific research and education.

  19. Distribution of bacteria within operating laboratory water purification systems.

    PubMed Central

    McFeters, G A; Broadaway, S C; Pyle, B H; Egozy, Y

    1993-01-01

    Experiments were conducted to measure communities of bacteria within operating ultrapure water treatment systems intended for laboratory use. Samples from various locations within Milli-Q Plus and Milli-Q UV Plus systems were analyzed for populations of planktonic bacteria at weekly intervals over 3 months of operation. Relatively high initial densities of planktonic bacteria (10(2) to 10(3) bacteria per ml) were seen within both units when they were challenged with source water of poor quality, although the product water continued to be acceptable with regard to bacterial numbers, resistivity, and endotoxin concentration. Under more normal operating conditions, significant differences were seen in planktonic populations throughout the systems with excellent product water quality. A great deal of variability was observed in biofilm populations analyzed from various system surfaces after 3 months of operation. The concentrations of planktonic bacteria and biofilm densities were much lower in the unit containing a UV lamp. These findings suggest that a range of microenvironmental conditions exist within purified water systems, leading to variable populations of bacteria. However, product water of excellent quality was obtained despite the bacterial communities. PMID:8517737

  20. Using and Distributing Spaceflight Data: The Johnson Space Center Life Sciences Data Archive

    NASA Technical Reports Server (NTRS)

    Cardenas, J. A.; Buckey, J. C.; Turner, J. N.; White, T. S.; Havelka,J. A.

    1995-01-01

    Life sciences data collected before, during and after spaceflight are valuable and often irreplaceable. The Johnson Space Center Life is hard to find, and much of the data (e.g. Sciences Data Archive has been designed to provide researchers, engineers, managers and educators interactive access to information about and data from human spaceflight experiments. The archive system consists of a Data Acquisition System, Database Management System, CD-ROM Mastering System and Catalog Information System (CIS). The catalog information system is the heart of the archive. The CIS provides detailed experiment descriptions (both written and as QuickTime movies), hardware descriptions, hardware images, documents, and data. An initial evaluation of the archive at a scientific meeting showed that 88% of those who evaluated the catalog want to use the system when completed. The majority of the evaluators found the archive flexible, satisfying and easy to use. We conclude that the data archive effectively provides key life sciences data to interested users.

  1. Final Report: Phase II Nevada Water Resources Data, Modeling, and Visualization (DMV) Center

    SciTech Connect

    Jackman, Thomas; Minor, Timothy; Pohll, Gregory

    2013-07-22

    Water is unquestionably a critical resource throughout the United States. In the semi-arid west -- an area stressed by increase in human population and sprawl of the built environment -- water is the most important limiting resource. Crucially, science must understand factors that affect availability and distribution of water. To sustain growing consumptive demand, science needs to translate understanding into reliable and robust predictions of availability under weather conditions that could be average but might be extreme. These predictions are needed to support current and long-term planning. Similar to the role of weather forecast and climate prediction, water prediction over short and long temporal scales can contribute to resource strategy, governmental policy and municipal infrastructure decisions, which are arguably tied to the natural variability and unnatural change to climate. Change in seasonal and annual temperature, precipitation, snowmelt, and runoff affect the distribution of water over large temporal and spatial scales, which impact the risk of flooding and the groundwater recharge. Anthropogenic influences and impacts increase the complexity and urgency of the challenge. The goal of this project has been to develop a decision support framework of data acquisition, digital modeling, and 3D visualization. This integrated framework consists of tools for compiling, discovering and projecting our understanding of processes that control the availability and distribution of water. The framework is intended to support the analysis of the complex interactions between processes that affect water supply, from controlled availability to either scarcity or deluge. The developed framework enables DRI to promote excellence in water resource management, particularly within the Lake Tahoe basin. In principle, this framework could be replicated for other watersheds throughout the United States. Phase II of this project builds upon the research conducted during

  2. Pesticides in surface waters: distribution, trends, and governing factors

    USGS Publications Warehouse

    Larson, Steven J.; Capel, Paul D.; Majewski, Michael

    1997-01-01

    Pesticde use in agriculture and non-agriculture settings has increased dramatically over the last several decades. Concern about adverse effects on the environment and human health has spurred an enormous amount of research into their environmental behavior and fate. Pesticides in Surface Waters presents a comprehensive summary of this research. This book evaluates published studies that focus on measuring pesticide concentration. The studies chosen include peer reviewed scientific literature, government reports, laboratory studies, and those using microcosms and artificial streams and ponds. The authors used this information to develop their overview of pesticide contamination of surface waters. The exhaustive compilation of data along with the fundamental science make this book essential for those involved in pesticide use, environmental protection, water quality, and human or ecological risk assessment. Pesticides in Surface Waters covers the results of actual studies, sources of pesticides to surface water, fate and transport, and environmental significance. Hundreds of data-packed tables, maps, charts, and drawings illustrate the key points, making research and application easy and cost effective.

  3. Total Absorption Gamma-ray Spectrometer (TAGS) Intensity Distributions from INL's Gamma-Ray Spectrometry Center

    DOE Data Explorer

    Greenwood, R. E.

    A 252Cf fission-product source and the INL on-line isotope separator were used to supply isotope-separated fission-product nuclides to a total absorption -ray spectrometer. This spectrometer consisted of a large (25.4-cm diameter x 30.5-cm long) NaI(Tl) detector with a 20.3-cm deep axial well in which is placed a 300-mm2 x 1.0-mm Si detector. The spectra from the NaI(Tl) detector are collected both in the singles mode and in coincidence with the B-events detected in the Si detector. Ideally, this detector would sum all the energy of the B- rays in each cascade following the population of daughter level by B- decay, so that the event could be directly associated with a particular daughter level. However, there are losses of energy from attenuation of the rays before they reach the detector, transmission of rays through the detector, escape of secondary photons from Compton scattering, escape of rays through the detector well, internal conversion, etc., and the measured spectra are thus more complicated than the ideal case and the analysis is more complex. Analysis methods have been developed to simulate all of these processes and thus provide a direct measure of the B- intensity distribution as a function of the excitation energy in the daughter nucleus. These data yield more accurate information on the B- distribution than conventional decay-scheme studies for complex decay schemes with large decay energies, because in the latter there are generally many unobserved and observed but unplaced rays. The TAGS data have been analyzed and published [R. E. Greenwood et al., Nucl Instr. and metho. A390(1997)] for 40 fission product-nuclides to determine the B- intensity distributions. [Copied from the TAGS page at http://www.inl.gov/gammaray/spectrometry/tags.shtml]. Those values are listed on this page for quick reference.

  4. On the vertical distribution of water vapor in the Martian tropics

    NASA Technical Reports Server (NTRS)

    Haberle, Robert M.

    1988-01-01

    Although measurements of the column abundance of atmospheric water vapor on Mars have been made, measurements of its vertical distribution have not. How water is distributed in the vertical is fundamental to atmosphere-surface exchange processes, and especially to transport within the atmosphere. Several lines of evidence suggest that in the lowest several scale heights of the atmosphere, water vapor is nearly uniformly distributed. However, most of these arguments are suggestive rather than conclusive since they only demonstrate that the altitude to saturation is very high if the observed amount of water vapor is distributed uniformly. A simple argument is presented, independent of the saturation constraint, which suggests that in tropical regions, water vapor on Mars should be very nearly uniformly mixed on an annual and zonally averaged basis.

  5. Spatial Distribution of CO Isotopologue Abundance Ratios in the Center of NGC 1068

    NASA Astrophysics Data System (ADS)

    Taniguchi, A.; Kohno, K.; Tamura, Y.; Izumi, T.; Takano, S.; Nakajima, T.; Tosaki, T.

    2015-12-01

    We present an initial result of the spatial distribution of [12CO]/[13CO] and [C16O]/[C18O] abundance ratios in the central ˜1 kpc region of the nearby Seyfert 2 galaxy NGC 1068 observed with ALMA Cycle 0. With non-LTE analyses, both ratios are found to be different between the central circumnuclear disk (CND) and surrounding starburst ring (the Ring). The very high (˜300-1000) value may reflects the difference of chemical evolution and environment at the Ring.

  6. Archiving and Distributing Seismic Data at the Southern California Earthquake Data Center (SCEDC)

    NASA Astrophysics Data System (ADS)

    Appel, V. L.

    2002-12-01

    The Southern California Earthquake Data Center (SCEDC) archives and provides public access to earthquake parametric and waveform data gathered by the Southern California Seismic Network and since January 1, 2001, the TriNet seismic network, southern California's earthquake monitoring network. The parametric data in the archive includes earthquake locations, magnitudes, moment-tensor solutions and phase picks. The SCEDC waveform archive prior to TriNet consists primarily of short-period, 100-samples-per-second waveforms from the SCSN. The addition of the TriNet array added continuous recordings of 155 broadband stations (20 samples per second or less), and triggered seismograms from 200 accelerometers and 200 short-period instruments. Since the Data Center and TriNet use the same Oracle database system, new earthquake data are available to the seismological community in near real-time. Primary access to the database and waveforms is through the Seismogram Transfer Program (STP) interface. The interface enables users to search the database for earthquake information, phase picks, and continuous and triggered waveform data. Output is available in SAC, miniSEED, and other formats. Both the raw counts format (V0) and the gain-corrected format (V1) of COSMOS (Consortium of Organizations for Strong-Motion Observation Systems) are now supported by STP. EQQuest is an interface to prepackaged waveform data sets for select earthquakes in Southern California stored at the SCEDC. Waveform data for large-magnitude events have been prepared and new data sets will be available for download in near real-time following major events. The parametric data from 1981 to present has been loaded into the Oracle 9.2.0.1 database system and the waveforms for that time period have been converted to mSEED format and are accessible through the STP interface. The DISC optical-disk system (the "jukebox") that currently serves as the mass-storage for the SCEDC is in the process of being replaced

  7. Distribution of tritium in precipitation and surface water in California

    NASA Astrophysics Data System (ADS)

    Harms, Patrick A.; Visser, Ate; Moran, Jean E.; Esser, Brad K.

    2016-03-01

    The tritium concentration in the surface hydrosphere throughout California was characterized to examine the reasons for spatial variability and to enhance the applicability of tritium in hydrological investigations. Eighteen precipitation samples were analyzed and 148 samples were collected from surface waters across California in the Summer and Fall of 2013, with repeat samples from some locations collected in Winter and Spring of 2014 to examine seasonal variation. The concentration of tritium in present day precipitation varied from 4.0 pCi/L near the California coast to 17.8 pCi/L in the Sierra Nevada Mountains. Concentrations in precipitation increase in spring due to the 'Spring Leak' phenomenon. The average coastal concentration (6.3 ± 1.2 pCi/L) in precipitation matches estimated pre-nuclear levels. Surface water samples show a trend of increasing tritium with inland distance. Superimposed on that trend, elevated tritium concentrations are found in the San Francisco Bay area compared to other coastal areas, resulting from municipal water imported from inland mountain sources and local anthropogenic sources. Tritium concentrations in most surface waters decreased between Summer/Fall 2013 and Winter/Spring 2014 likely due to an increased groundwater signal as a result of drought conditions in 2014. A relationship between tritium and electrical conductivity in surface water was found to be indicative of water provenance and anthropogenic influences such as agricultural runoff. Despite low initial concentrations in precipitation, tritium continues to be a valuable tracer in a post nuclear bomb pulse world.

  8. MONOCHLORAMINE DECAY IN MODEL AND DISTRIBUTION SYSTEM WATER. (R826832)

    EPA Science Inventory

    Abstract

    Chloramines have long been used to provide a disinfecting residual in distribution systems where it is difficult to maintain a free chlorine residual or where disinfection by-product (DBP) formation is of concern. While chloramines are generally considered les...

  9. The inorganic carbon distribution in Irish coastal waters

    NASA Astrophysics Data System (ADS)

    McGrath, Triona; Cave, Rachel; McGovern, Evin; Kivimae, Caroline

    2014-05-01

    Despite their relatively small surface area, coastal and shelf waters play a crucial role in the global climate through their influence on major biogeochemical cycles. Due to growing concern about ocean acidification as a result of increasing atmospheric CO2 concentrations, measurements of inorganic carbon parameters (dissolved inorganic carbon (DIC), total alkalinity (TA), pH and pCO2) have been made with increasing regularity over the past two decades. While it is clear that open ocean surface waters are acidifying at a fairly uniform rate ( -0.02 pH units per decade), less is known about changes in coastal waters due to the high complexity and spatial variability in these regions. Large spatial and temporal variability in coastal CO2 parameters is mainly due to nutrient inputs, biological activity, upwelling and riverine inputs of alkalinity and inorganic and organic carbon. The inorganic carbon system in Irish coastal waters is presented here, gathered from 9 surveys around the Irish coastline between 2009 and 2013. There are striking contrasts in the CO2 system between different areas, largely attributed to the bedrock composition of the nearby rivers. Freshwater end-member concentrations of TA, calculated from TA-salinity relationships in outer estuarine and nearshore coastal water, were supported by riverine TA data from the Irish Environmental Protection Agency. A large portion of Ireland is covered with limestone bedrock and as a result, many of the rivers have extremely high TA (>5000μmol/kg) due to the carbonate mineral content of the underlying bedrock. While such high TA has resulted in elevated pH and calcium carbonate saturation states in some coastal waters, (e.g. Galway Bay and Dublin Bay), the high TA in other areas was accompanied by particularly high DIC (e.g. River Shannon on the west coast), resulting in lower pH and aragonite/calcite saturation states and even CO2 degassing in the Shannon estuary. Due to non-limestone lithology in many parts

  10. Tritium distribution in ground water around large underground fusion explosions

    USGS Publications Warehouse

    Stead, F.W.

    1963-01-01

    Tritium will be released in significant amounts from large underground nuclear fusion explosions in the Plowshare Program. The tritium could become highly concentrated in nearby ground waters, and could be of equal or more importance as a possible contaminant than other long-lived fission-product and induced radionuclides. Behavior of tritiated water in particular hydrologic and geologic environments, as illustrated by hypothetical explosions in dolomite and tuff, must be carefully evaluated to predict under what conditions high groundwater concentrations of tritium might occur.

  11. An inherent-optical-property-centered approach to correct the angular effects in water-leaving radiance.

    PubMed

    Lee, Zhong Ping; Du, Keping; Voss, Kenneth J; Zibordi, Giuseppe; Lubac, Bertrand; Arnone, Robert; Weidemann, Alan

    2011-07-01

    Remote-sensing reflectance (R(rs)), which is defined as the ratio of water-leaving radiance (L(w)) to downwelling irradiance just above the surface (E(d)(0⁺)), varies with both water constituents (including bottom properties of optically-shallow waters) and angular geometry. L(w) is commonly measured in the field or by satellite sensors at convenient angles, while E(d)(0⁺) can be measured in the field or estimated based on atmospheric properties. To isolate the variations of R(rs) (or L(w)) resulting from a change of water constituents, the angular effects of R(rs) (or L(w)) need to be removed. This is also a necessity for the calibration and validation of satellite ocean color measurements. To reach this objective, for optically-deep waters where bottom contribution is negligible, we present a system centered on water's inherent optical properties (IOPs). It can be used to derive IOPs from angular Rrs and offers an alternative to the system centered on the concentration of chlorophyll. This system is applicable to oceanic and coastal waters as well as to multiband and hyperspectral sensors. This IOP-centered system is applied to both numerically simulated data and in situ measurements to test and evaluate its performance. The good results obtained suggest that the system can be applied to angular R(rs) to retrieve IOPs and to remove the angular variation of R(rs).

  12. Transformation of Bisphenol A in Water Distribution Systems, A Pilot-scale Study

    EPA Science Inventory

    Halogenations of bisphenol A (BPA) in a pilot-scale water distribution system (WDS) of cement-lined ductile cast iron pipe were investigated under the condition: pH 7.3±0.3, water flow velocity of 1.0 m/s, and 25 °C ± 1 °C in water temperature. The testing water was chlorinated f...

  13. Strontium-90 and cesium-137 distribution in Baltic Sea waters

    SciTech Connect

    Lazarev, L.N.; Gedeonov, L.I.; Ivanova, L.M.; Stepanov, A.V.

    1988-09-01

    The strontium-90 and cesium-137 concentrations determined in 1983 in the Baltic Sea proper and the Gulf of Finland and in the Soviet Baltic rivers are furnished. The cesium-137 content has been found to be directly proportional to the salinity of the water. Significant influx of technogenic radioactive contaminants from the North to the Baltic Sea was noted in 1983.

  14. State of Technology for Rehabilitation of Water Distribution Systems

    EPA Science Inventory

    The impact that the lack of investment in water infrastructure will have on the performance of aging underground infrastructure over time is well documented and the needed funding estimates range as high as $325 billion over the next 20 years. With the current annual replacement...

  15. Investigations into Drinking Water Distribution System Nitrification: EPA Microelectrode Research

    EPA Science Inventory

    Because of the Stage 1 and Stage 2 Disinfectants and Disinfection Byproduct Rules, chloramination for secondary disinfection in the United States is predicted to increase to 57% of all surface and 7% of all ground water treatment systems. Chloramination comes with the risk of di...

  16. Rehabilitation of Wastewater Collection and Water Distribution Systems

    EPA Science Inventory

    The nation’s 54,000 drinking water systems and 16,000 wastewater systems are nearing the end of their useful life and need to be replaced/repaired to comply with federal regulations. Rehabilitation includes a broad spectrum of approaches, from repair to replacement that attempt ...

  17. Identification, distribution, and toxigenicity of obligate anaerobes in polluted waters.

    PubMed Central

    Daily, O P; Joseph, S W; Gillmore, J D; Colwell, R R; Seidler, R J

    1981-01-01

    A seasonal occurrence of obligately anaerobic bacteria, predominantly of the genera Bacteroides and Clostridium, in a polluted water site has been observed. The number of anaerobes varied from 1.8 X 10(3) cells/ml in the warmer months to 10 cells/ml in winter. Several isolates were toxigenic, indicating a potential human health hazard. PMID:7235706

  18. Hydrogeologic and water-quality data for the main site, Naval Surface Warfare Center, Dahlgren Laboratory, Dahlgren, Virginia

    USGS Publications Warehouse

    Bell, Clifton F.; Bolles, Thomas P.; Harlow,, George E.

    1994-01-01

    Hydrogeologic and water-quality data were collected at the Naval Surface Warfare Center, Dahlgren Laboratory at Dahlgren, Virginia, as part of a hydrogeologic assessment of the shallow aquifer system begun in 1992. The U.S. Geological Survey conducted this study to provide the Navy with hydrogeologic data to meet the requirements of a Spill Contingency Plan. This report describes the ground-water observation-well network, hydro- geologic, and water-quality data collected between August 1992 and September 1993. The report includes a description of the locations and con- struction of 35 observation wells on the Main Site. Hydrologic data include lithologic core samples, geophysical logs, and vertical hydraulic conductivity measurements of selected core intervals. Hydrologic data include synoptic and hourly measurements of ground-water levels, observation-well slug tests to determine horizontal hydraulic conductivity, and tide data. Water-quality data include analyses of major dissolved constituents in ground water and surface water.

  19. Protozoan Bacterivory and Escherichia coli Survival in Drinking Water Distribution Systems

    PubMed Central

    Sibille, I.; Sime-Ngando, T.; Mathieu, L.; Block, J. C.

    1998-01-01

    The development of bacterial communities in drinking water distribution systems leads to a food chain which supports the growth of macroorganisms incompatible with water quality requirements and esthetics. Nevertheless, very few studies have examined the microbial communities in drinking water distribution systems and their trophic relationships. This study was done to quantify the microbial communities (especially bacteria and protozoa) and obtain direct and indirect proof of protozoan feeding on bacteria in two distribution networks, one of GAC water (i.e., water filtered on granular activated carbon) and the other of nanofiltered water. The nanofiltered water-supplied network contained no organisms larger than bacteria, either in the water phase (on average, 5 × 107 bacterial cells liter−1) or in the biofilm (on average, 7 × 106 bacterial cells cm−2). No protozoa were detected in the whole nanofiltered water-supplied network (water plus biofilm). In contrast, the GAC water-supplied network contained bacteria (on average, 3 × 108 cells liter−1 in water and 4 × 107 cells cm−2 in biofilm) and protozoa (on average, 105 cells liter−1 in water and 103 cells cm−2 in biofilm). The water contained mostly flagellates (93%), ciliates (1.8%), thecamoebae (1.6%), and naked amoebae (1.1%). The biofilm had only ciliates (52%) and thecamoebae (48%). Only the ciliates at the solid-liquid interface of the GAC water-supplied network had a measurable grazing activity in laboratory test (estimated at 2 bacteria per ciliate per h). Protozoan ingestion of bacteria was indirectly shown by adding Escherichia coli to the experimental distribution systems. Unexpectedly, E. coli was lost from the GAC water-supplied network more rapidly than from the nanofiltered water-supplied network, perhaps because of the grazing activity of protozoa in GAC water but not in nanofiltered water. Thus, the GAC water-supplied network contained a functional ecosystem with well-established and

  20. Safety of packaged water distribution limited by household recontamination in rural Cambodia.

    PubMed

    Holman, Emily J; Brown, Joe

    2014-06-01

    Packaged water treatment schemes represent a growing model for providing safer water in low-income settings, yet post-distribution recontamination of treated water may limit this approach. This study evaluates drinking water quality and household water handling practices in a floating village in Tonlé Sap Lake, Cambodia, through a pilot cross-sectional study of 108 households, approximately half of which used packaged water as the main household drinking water source. We hypothesized that households purchasing drinking water from local packaged water treatment plants would have microbiologically improved drinking water at the point of consumption. We found no meaningful difference in microbiological drinking water quality between households using packaged, treated water and those collecting water from other sources, including untreated surface water, however. Households' water storage and handling practices and home hygiene may have contributed to recontamination of drinking water. Further measures to protect water quality at the point-of-use may be required even if water is treated and packaged in narrow-mouthed containers.

  1. Risk of viral acute gastrointestinal illness from nondisinfected drinking water distribution systems.

    PubMed

    Lambertini, Elisabetta; Borchardt, Mark A; Kieke, Burney A; Spencer, Susan K; Loge, Frank J

    2012-09-01

    Acute gastrointestinal illness (AGI) resulting from pathogens directly entering the piping of drinking water distribution systems is insufficiently understood. Here, we estimate AGI incidence from virus intrusions into the distribution systems of 14 nondisinfecting, groundwater-source, community water systems. Water samples for virus quantification were collected monthly at wells and households during four 12-week periods in 2006-2007. Ultraviolet (UV) disinfection was installed on the communities' wellheads during one study year; UV was absent the other year. UV was intended to eliminate virus contributions from the wells and without residual disinfectant present in these systems, any increase in virus concentration downstream at household taps represented virus contributions from the distribution system (Approach 1). During no-UV periods, distribution system viruses were estimated by the difference between well water and household tap virus concentrations (Approach 2). For both approaches, a Monte Carlo risk assessment framework was used to estimate AGI risk from distribution systems using study-specific exposure-response relationships. Depending on the exposure-response relationship selected, AGI risk from the distribution systems was 0.0180-0.0661 and 0.001-0.1047 episodes/person-year estimated by Approaches 1 and 2, respectively. These values represented 0.1-4.9% of AGI risk from all exposure routes, and 1.6-67.8% of risk related to drinking water exposure. Virus intrusions into nondisinfected drinking water distribution systems can contribute to sporadic AGI.

  2. Estimation of water withdrawal and distribution, water use, and wastewater collection and return flow in Cumberland, Rhode Island, 1988. Water resources investigation

    SciTech Connect

    Horn, M.A.; Craft, P.A.; Bratton, L.

    1994-12-31

    The purpose of the report is to demonstrate integration of water-use data collected by different State agencies or maintained by different public suppliers and wastewater-treatment facilities. The report presents a brief discussion of data compilation, organization and computer storage, and analysis. A detailed description of the methods used and the resulting water-use data are presented on withdrawal, distribution, use, wastewater collection, return flow, and import of water into and export of water out of Cumberland. At the end of each section, an overview provides a discussion of how water that is withdrawn, distributed, used, collected, and returned in the study area affects the availability and distribution of water resources.

  3. Virus contamination from operation and maintenance events in small drinking water distribution systems.

    PubMed

    Lambertini, Elisabetta; Spencer, Susan K; Kieke, Burney A; Loge, Frank J; Borchardt, Mark A

    2011-12-01

    We tested the association of common events in drinking water distribution systems with contamination of household tap water with human enteric viruses. Viruses were enumerated by qPCR in the tap water of 14 municipal systems that use non-disinfected groundwater. Ultraviolet disinfection was installed at all active wellheads to reduce virus contributions from groundwater to the distribution systems. As no residual disinfectant was added to the water, any increase in virus levels measured downstream at household taps would be indicative of distribution system intrusions. Utility operators reported events through written questionnaires. Virus outcome measures were related to distribution system events using binomial and gamma regression. Virus concentrations were elevated in the wells, reduced or eliminated by ultraviolet disinfection, and elevated again in distribution systems, showing that viruses were, indeed, directly entering the systems. Pipe installation was significantly associated with higher virus levels, whereas hydrant flushing was significantly associated with lower virus levels. Weak positive associations were observed for water tower maintenance, valve exercising, and cutting open a water main. Coliform bacteria detections from routine monitoring were not associated with viruses. Understanding when distribution systems are most vulnerable to virus contamination, and taking precautionary measures, will ensure delivery of safe drinking water.

  4. Characterization of dissolved organic matter biodegradability in waters: Impact of water treatment and bacterial regrowth in distribution systems

    SciTech Connect

    Pierre, S.; Patrick, L.; Dominique, G.

    1996-11-01

    Bacterial growth in distribution systems leading to the degradation of the bacteriological water quality is an actual problem for many water works. The increase in bacterial abundance can be at the origin of various problems for drinking producers and consumers, including heterotrophic plate counts higher than the recommendation values (in Europe, 100 cells/ml at 20 {degrees}C and 10 cells/ml at 37 {degrees}C), development of a trophic web with growth of higher organisms, modification of the water characteristics (turbidity, taste, odor, color), interference in the detection of sanitary indicators. In this context, several studies have been conducted in the last two years to investigate the role of various factors on bacterial dynamics in distribution systems. In order to prevent and control bacterial multiplication in distribution systems, most of the water utilities used chlorination of treated water. An alternative approach to control bacterial growth in distribution system is the limitation of the nutrient source required for the growth of heterotrophic bacteria, i.e. the biodegradable organic matter (BOM). This solution, in addition to reduce bacterial growth by limiting the nutrient sources, offers two additional advantages: removal of organic matter initially reduces the formation of undesirable disinfection by products as THM during chlorination and also increases the stability of the chlorine residual in the distribution system by reducing chlorine demand.

  5. Three-dimensional observation of water distribution in PEFC by neutron CT

    NASA Astrophysics Data System (ADS)

    Sakata, I.; Ueda, T.; Murakawa, H.; Sugimoto, K.; Asano, H.; Takenaka, N.; Yasuda, R.; Tomura, T.; Shiozawa, M.

    2009-06-01

    A polymer electrolyte fuel cell (PEFC) consists of a membrane electrode assembly (MEA), gas diffusion layers (GDL), hydrogen and oxygen supply channels. At the anode, protons and electrons are generated, while at the cathode the protons and electrons combine to form water. The condensed water may affect the fuel cell performance. In order to clarify the effect of water distribution on the PEFC performance, three-dimensional water distribution in the PEFC was visualized by using a neutron radiography facility at JRR-3 in JAEA. For observing the detailed water distribution, a small sized PEFC was designed. Size of the gas channel is 1 mm width and 0.5 mm depth. Thickness of the MEA and the GDL are about 50 and 200 μm. The electrode area is 0.35×3.5 cm 2. The PEFC was set on an automatic rotating stage, and a picture was taken every 2.25° by using a cooled CCD camera with grey scale of 16 bit. The exposure time was set at 15 s. Using the 80 pictures which correspond to 180°, a computed tomography (CT) was carried out. In order to observe water distribution with high spatial resolution, the LiF scintillator with a thickness of 50 μm was used. From the water distributions parallel and perpendicular to the MEA, existence of water around O-ring can be confirmed. However, the detailed distribution in the PEFC is difficult to obtain from the two-dimensional pictures. On the other hand, CT pictures make possible to obtain the three-dimensional water distribution. In this study, the spatial resolution of 76.5 μm was achieved, and existence of water in the PEFC could be confirmed.

  6. Data Access Tools And Services At The Goddard Distributed Active Archive Center (GDAAC)

    NASA Technical Reports Server (NTRS)

    Pham, Long; Eng, Eunice; Sweatman, Paul

    2003-01-01

    As one of the largest providers of Earth Science data from the Earth Observing System, GDAAC provides the latest data from the Moderate Resolution Imaging Spectroradiometer (MODIS), Atmospheric Infrared Sounder (AIRS), Solar Radiation and Climate Experiment (SORCE) data products via GDAAC's data pool (50TB of disk cache). In order to make this huge volume of data more accessible to the public and science communities, the GDAAC offers multiple data access tools and services: Open Source Project for Network Data Access Protocol (OPeNDAP), Grid Analysis and Display System (GrADS/DODS) (GDS), Live Access Server (LAS), OpenGlS Web Map Server (WMS) and Near Archive Data Mining (NADM). The objective is to assist users in retrieving electronically a smaller, usable portion of data for further analysis. The OPeNDAP server, formerly known as the Distributed Oceanographic Data System (DODS), allows the user to retrieve data without worrying about the data format. OPeNDAP is capable of server-side subsetting of HDF, HDF-EOS, netCDF, JGOFS, ASCII, DSP, FITS and binary data formats. The GrADS/DODS server is capable of serving the same data formats as OPeNDAP. GDS has an additional feature of server-side analysis. Users can analyze the data on the server there by decreasing the computational load on their client's system. The LAS is a flexible server that allows user to graphically visualize data on the fly, to request different file formats and to compare variables from distributed locations. Users of LAS have options to use other available graphics viewers such as IDL, Matlab or GrADS. WMS is based on the OPeNDAP for serving geospatial information. WMS supports OpenGlS protocol to provide data in GIs-friendly formats for analysis and visualization. NADM is another access to the GDAAC's data pool. NADM gives users the capability to use a browser to upload their C, FORTRAN or IDL algorithms, test the algorithms, and mine data in the data pool. With NADM, the GDAAC provides an

  7. Evaluating online data of water quality changes in a pilot drinking water distribution system with multivariate data exploration methods.

    PubMed

    Mustonen, Satu M; Tissari, Soile; Huikko, Laura; Kolehmainen, Mikko; Lehtola, Markku J; Hirvonen, Arja

    2008-05-01

    The distribution of drinking water generates soft deposits and biofilms in the pipelines of distribution systems. Disturbances in water distribution can detach these deposits and biofilms and thus deteriorate the water quality. We studied the effects of simulated pressure shocks on the water quality with online analysers. The study was conducted with copper and composite plastic pipelines in a pilot distribution system. The online data gathered during the study was evaluated with Self-Organising Map (SOM) and Sammon's mapping, which are useful methods in exploring large amounts of multivariate data. The objective was to test the usefulness of these methods in pinpointing the abnormal water quality changes in the online data. The pressure shocks increased temporarily the number of particles, turbidity and electrical conductivity. SOM and Sammon's mapping were able to separate these situations from the normal data and thus make those visible. Therefore these methods make it possible to detect abrupt changes in water quality and thus to react rapidly to any disturbances in the system. These methods are useful in developing alert systems and predictive applications connected to online monitoring.

  8. The spatial distribution of pollutants in pipe-scale of large-diameter pipelines in a drinking water distribution system.

    PubMed

    Liu, Jingqing; Chen, Huanyu; Yao, Lingdan; Wei, Zongyuan; Lou, Liping; Shan, Yonggui; Endalkachew, Sahle-Demessie; Mallikarjuna, Nadagouda; Hu, Baolan; Zhou, Xiaoyan

    2016-11-01

    In large-diameter drinking water pipelines, spatial differences in hydraulic and physiochemical conditions may also result in spatial variations in pipe corrosion, biofilm growth and pollutant accumulation. In this article, the spatial distributions of various metals and organic contaminants in two 19-year-old grey cast iron pipes which had an internal diameter of 600mm (DN600), were investigated and analyzed by Atomic Absorption Spectrometry, Gas Chromatography-Mass Spectrometry, Energy Dispersive Spectrometer, X-ray Diffraction, etc. The spatial distribution of heavy metals varied significantly across the pipe section, and iron, manganese, lead, copper, and chromium were highest in concentration in the upper portion pipe-scales. However, the highest aluminum and zinc content was detected in the lower portion pipe-scales. Apart from some common types of hydrocarbons formed by microbial metabolites, there were also some microalgae metabolites and exogenous contaminants accumulated in pipe-scale, which also exhibited high diversity between different spatial locations. The spatial distributions of the physical and chemical properties of pipe-scale and contaminants were quite different in large-diameter pipes. The finding put forward higher requirements on the research method about drinking water distribution system chemical safety. And the scientific community need understand trend and dynamics of drinking water pipe systems better. PMID:27244696

  9. The spatial distribution of pollutants in pipe-scale of large-diameter pipelines in a drinking water distribution system.

    PubMed

    Liu, Jingqing; Chen, Huanyu; Yao, Lingdan; Wei, Zongyuan; Lou, Liping; Shan, Yonggui; Endalkachew, Sahle-Demessie; Mallikarjuna, Nadagouda; Hu, Baolan; Zhou, Xiaoyan

    2016-11-01

    In large-diameter drinking water pipelines, spatial differences in hydraulic and physiochemical conditions may also result in spatial variations in pipe corrosion, biofilm growth and pollutant accumulation. In this article, the spatial distributions of various metals and organic contaminants in two 19-year-old grey cast iron pipes which had an internal diameter of 600mm (DN600), were investigated and analyzed by Atomic Absorption Spectrometry, Gas Chromatography-Mass Spectrometry, Energy Dispersive Spectrometer, X-ray Diffraction, etc. The spatial distribution of heavy metals varied significantly across the pipe section, and iron, manganese, lead, copper, and chromium were highest in concentration in the upper portion pipe-scales. However, the highest aluminum and zinc content was detected in the lower portion pipe-scales. Apart from some common types of hydrocarbons formed by microbial metabolites, there were also some microalgae metabolites and exogenous contaminants accumulated in pipe-scale, which also exhibited high diversity between different spatial locations. The spatial distributions of the physical and chemical properties of pipe-scale and contaminants were quite different in large-diameter pipes. The finding put forward higher requirements on the research method about drinking water distribution system chemical safety. And the scientific community need understand trend and dynamics of drinking water pipe systems better.

  10. GEOPHYSICAL CHARACTERIZATION, REDOX ZONATION, AND CONTAMINANT DISTRIBUTION AT A GROUNDWATER/SURFACE WATER INTERFACE

    EPA Science Inventory

    Three transects along a groundwater/surface water interface were characterized for spatial distributions of chlorinated aliphatic hydrocarbons and geochemical conditions to evaluate the natural bioremediation potential of this environmental system. Partly on the basis of ground p...

  11. Regression modeling of particle size distributions in urban storm water: advancements through improved sample collection methods

    USGS Publications Warehouse

    Fienen, Michael N.; Selbig, William R.

    2012-01-01

    A new sample collection system was developed to improve the representation of sediment entrained in urban storm water by integrating water quality samples from the entire water column. The depth-integrated sampler arm (DISA) was able to mitigate sediment stratification bias in storm water, thereby improving the characterization of suspended-sediment concentration and particle size distribution at three independent study locations. Use of the DISA decreased variability, which improved statistical regression to predict particle size distribution using surrogate environmental parameters, such as precipitation depth and intensity. The performance of this statistical modeling technique was compared to results using traditional fixed-point sampling methods and was found to perform better. When environmental parameters can be used to predict particle size distributions, environmental managers have more options when characterizing concentrations, loads, and particle size distributions in urban runoff.

  12. Assessing soil water storage distribution under sprinkler irrigation by coupling 3D simulations and field observations

    NASA Astrophysics Data System (ADS)

    Taha, Uday; Shabeeb, Ahmed; dragonetti, giovanna; Lamaddalena, Nicola; Coppola, Antonio

    2016-04-01

    This work analyzed the variability of sprinkler irrigation application over a bare soil, both in terms of water application efficiency and uniformity, by integrating and comparing the information on the irrigation depth data (ID), as measured by catch cans, soil water storage in the upper root zone, as measured by TDR probes, and a 3D simulations of water flow in soils. Three irrigation tests were performed at three different pressures (2, 3 and 4 bar). A lateral water redistribution was observed and simulated after each irrigation event by comparing spatial distributions of site-specific water application efficiency (AEs), as well as ratios of site-specific actual water storage increase (SWEs) and irrigation depth (IDs) to the water content before irrigation. Because of soil water redistribution processes, distribution uniformity based on soil storages was systematically higher than the catch can uniformity. The obvious consequence of lateral water redistribution processes was that the soil smoothing action on non-uniformity observed at the surface increased both with depth and over time. At a given depth the uniformity of soil water storages always attained the same value, whatever the pressure considered and the catch can-based uniformity coefficient. It was concluded that, for the case of random distribution of ID, the uniformity of water storages is driven by the soil behavior rather than by the irrigation system.

  13. Bacterial regrowth in water reclamation and distribution systems revealed by viable bacterial detection assays.

    PubMed

    Lin, Yi-wen; Li, Dan; Gu, April Z; Zeng, Si-yu; He, Miao

    2016-02-01

    Microbial regrowth needs to be managed during water reclamation and distribution. The aim of present study was to investigate the removal and regrowth of Escherichia coli (E. coli) and Salmonella in water reclamation and distribution system by using membrane integrity assay (PMA-qPCR), reverse transcriptional activity assay (Q-RT-PCR) and culture-based assay, and also to evaluate the relationships among bacterial regrowth, and environmental factors in the distribution system. The results showed that most of the water reclamation processes potentially induced bacteria into VBNC state. The culturable E. coli and Salmonella regrew 1.8 and 0.7 log10 in distribution system, which included reactivation of bacteria in the viable but non-culturable (VBNC) state and reproduction of culturable bacteria. The regrowth of culturable E. coli and Salmonella in the distribution system mainly depended on the residual chlorine levels, with correlations (R(2)) of -0.598 and -0.660. The abundances of membrane integrity and reverse transcriptional activity bacteria in reclamation effluents had significant correlations with the culturable bacteria at the end point of the distribution system, demonstrating that PMA-qPCR and Q-RT-PCR are sensitive and accurate tools to determine and predict bacterial regrowth in water distribution systems. This study has improved our understanding of microbial removal and regrowth in reclaimed water treatment and distribution systems. And the results also recommended that more processes should be equipped to remove viable bacteria in water reclamation plants for the sake of inhibition microbial regrowth during water distribution and usages.

  14. Water and soil biotic relations in Mercury distribution

    NASA Technical Reports Server (NTRS)

    Siegel, S. M.; Siegel, B. Z.; Puerner, N.; Speitel, T.; Thorarinsson, F.

    1975-01-01

    The distribution of Hg is considered both in terms of its availability in soil fractions and the relationship between Hg in plant samples and Hg in ambient soils or other supportive media. The plants were grouped by habitat into epipedic-epiphytic (mosses, lichens) and endopedic-aquatic-marine (Basidiomycetes and algae) samples; nonvascular and vascular forms were also distinguished. Sources included Alaska, Hawaii, New England and Iceland. Brief consideration was also given to Hg distribution in a plant-animal-soil community. Data were expressed in terms of plant Hg content and plant substratum concentration ratio. Average Hg contents and concentration ratios, and modal ranges for the ratios were determined. The results showed similar average Hg contents in all groups (126 to 199 ppb) but a low value (84 ppb) in the lichens; terrestrial forms had ratios of 3.5 to 7.6 whereas the marine algae yielded a figure of 78.7. A secondary mode in the range 0 to 0.1 appeared only in the Alaska-New England Group, over 500 km distant from active thermal sites. Evidence for both exclusion and concentration behavior was obtained.

  15. Observations of Water Ice Distribution in the HD169142 Disk

    NASA Astrophysics Data System (ADS)

    Honda, Mitsuhiko

    2013-01-01

    Icy grains play an important role on planetesimal/planet formation and related matters. Therefore, to reveal ice dust distribution within a protoplanetary disk is an important work for understanding planet formation. However, observations of icy grain IN THE DISK are scarce due to various observational limitations. Here we propose observations to trace the icy grains by making K, H_2O ice, and L' imaging photometric observations of disk scattered light to derive H_2O ice dust distribution in a disk surface via 3.1 mu m absorption. For the moment, only Gemini/NICI is capable of such observations. We have already demonstrated the effectiveness of such observing method toward Herbig Fe star HD142527. Since some theoretical studies suggest that there are no ice grains at the surface of the disk around A/B stars due to intense UV irradiation, we propose to observe disks around Herbig Ae star HD169142. When we fail to detect the ice feature, it supports the theoretical prediction that photodesorption is important. While the ice feature is detected, it requires reconsideration of the theories and provides an important constraint for the disk chemistry.

  16. Prediction of full-scale dewatering results of sewage sludges by the physical water distribution.

    PubMed

    Kopp, J; Dichtl, N

    2001-01-01

    The dewaterability of sewage sludge can be described by the total solids concentration of the sludge cake and the polymer-demand for conditioning. The total solids concentration of the sludge cake depends on the physical water distribution. The various types of water in sewage sludge are mainly distinguished by the type and the intensity of their physical bonding to the solids. In a sewage sludge suspension four different types of water can be distinguished. These are the free water, which is not bound to the particles, the interstitial water, which is bound by capillary forces between the sludge flocs, the surface water, which is bound by adhesive forces and intracellular water. Only the share of free water can be separated during mechanical dewatering. It can be shown, that by thermo-gravimeteric measurement of the free water content, an exact prediction of full-scale dewatering results is possible. By separation of all free water during centrifugation the maximum dewatering result is reached. Polymer conditioning increases the velocity of the sludge water release, but the free water content is not influenced by this process. Furthermore it is not possible, to replace the measuring of the water distribution by other individual parameters such as ignition loss.

  17. [Retrieve of red tide distributions from MODIS data based on the characteristics of water spectrum].

    PubMed

    Qiu, Zhong-Feng; Cui, Ting-Wei; He, Yi-Jun

    2011-08-01

    After comparing the spectral differences between red tide water and normal water, we developed a method to retrieve red tide distributions from MODIS data based on the characteristics of red tide water spectrum. The authors used the 119 series of in situ observations to validate the method and found that only one observation has not been detected correctly. The authors then applied this method to MODIS data on April 4, 2005. In the research areas three locations of red tide water were apparently detected with the total areas about 2 000 km2. The retrieved red tide distributions are in good agreement with the distributions of high chlorophyll a concentrations. The research suggests that the method is available to eliminating the influence of suspended sediments and can be used to retrieve the locations and areas of red tide water.

  18. Targeted VLA Observations of 22 GHz Water Masers Towards the Galactic Center

    NASA Astrophysics Data System (ADS)

    Rickert, Matthew; Ott, Juergen; Yusef-Zadeh, Farhad; Meier, David S.

    2015-01-01

    The Central Molecular Zone (CMZ) has a unique environment with a large amount (5 x107 M⊙) of dense (104 cm-3) warm (75-200 K) molecular gas. To probe sites of ongoing star formation in this region, we carried out follow-up VLA observations targeting 22 GHz water masers detected by a recent Mopra survey of the inner 3° x 1° of the Galactic Center (Chambers et al. 2014, A&A 563, A68). We present preliminary results of these measurements with higher angular resolution (2" x 0.9"), spectral resolution (0.2 km s-1), and sensitivity (40 mJy beam-1) and a velocity coverage of -200 to 250 km s-1. A total of 32 maser positions are detected. Several sources display complex spectra with a number of new velocity components. From the 32 maser positions, over 200 spectral features have been identified, indicating clusters of masers. The complex spectra are indicative of young (< 105 years) star forming regions, with some of the components likely being produced from outflows. The brightest component is over 500 Jy beam-1 towards the HII region G359.14+0.03 with a vLSR of -9 km s-1. The most prominent location of water masers is the star forming region Sgr B2, where over 80 spectral components are identified from 9 different positions with peak flux densities ranging from 0.8 to 142 Jy beam-1. Three of these positions contain enhanced 4.5 μm green extended sources, indicating these masers are likely associated with outflows. Sgr C contains 3 separate maser positions with a total of 4 spectral components ranging from -70 to -66 km s-1 and peak flux densities of 4 to 15 Jy beam-1. One of these positions is also associated with a green source. We will compare the water maser positions with positions of radiatively pumped 6.7 GHz methanol masers and other green (3-8 μm) sources. This comparison will be used to verify that star formation is the underlying source of these masers and to identify masers associated with outlfows.

  19. Review on water leakage control in distribution networks and the associated environmental benefits.

    PubMed

    Xu, Qiang; Liu, Ruiping; Chen, Qiuwen; Li, Ruonan

    2014-05-01

    Water supply is the primary element of an urban system. Due to rapid urbanization and water scarcity, maintaining a stable and safe water supply has become a challenge to many cities, whereas a large amount of water is lost from the pipes of distribution systems. Water leakage is not only a waste of water resources, but also incurs great socio-economic costs. This article presents a comprehensive review on the potential water leakage control approaches and specifically discusses the benefits of each to environmental conservation. It is concluded that water leakage could be further reduced by improving leakage detection capability through a combination of predictive modeling and monitoring instruments, optimizing pipe maintenance strategy, and developing an instant pressure regulation system. The environment could benefit from these actions because of water savings and the reduction of energy consumption as well as greenhouse gas emissions.

  20. National Space Science Data Center data archive and distribution service (NDADS) automated retrieval mail system user's guide

    NASA Technical Reports Server (NTRS)

    Perry, Charleen M.; Vansteenberg, Michael E.

    1992-01-01

    The National Space Science Data Center (NSSDC) has developed an automated data retrieval request service utilizing our Data Archive and Distribution Service (NDADS) computer system. NDADS currently has selected project data written to optical disk platters with the disks residing in a robotic 'jukebox' near-line environment. This allows for rapid and automated access to the data with no staff intervention required. There are also automated help information and user services available that can be accessed. The request system permits an average-size data request to be completed within minutes of the request being sent to NSSDC. A mail message, in the format described in this document, retrieves the data and can send it to a remote site. Also listed in this document are the data currently available.

  1. Production of Astatine-211 at the Duke University Medical Center for its regional distribution

    SciTech Connect

    Zalutsky, Michael

    2016-01-01

    Systemic targeted radiation therapy and radioimmunotherapy continue to be important tools in the treatment of certain cancers. Because of their high energy and short path length, alpha particle emitters such as 211At are more effective than either external beam x- ray or in vivo beta radiation in delivering potentially curative doses of radiation. The limited clinical trials that have been conducted to date have yielded encouraging responses in some patients, e.g., malignant brain tumors. In order to escalate the additional necessary research and development in radiochemistry, radiobiology and efficacy evaluation of alpha particle radiotherapeutics, it is universally agreed that access to an affordable, reliable supply of 211At is warranted. In conjunction with the Department of Energy's intent to enhance stable and radioactive isotope availability for research applications, it is the primary objective of this project to improve 211At production and purification capabilities at Duke so that this radionuclide can be supplied to researchers at other institutions throughout the US.The most widely used 211At production method involves the α,2n reaction on Bismuth using a cyclotron with beams ≤ 28 MeV. Yields can be enhanced with use of an internal target that allows for a higher alpha fluence plus efficient heat dissipation in the target. Both of these items are in place at Duke; however, in order to support production for multi-institutional use, irradiation campaigns in excess of 50 µAp and four hours duration will be needed. Further, post-irradiation processing equipment is lacking that will enable the distribution process. Financial support is sought for i) a shielded, ventilated processing/containment hood; ii) development of a post-irradiation target retrieval system; iii) fabrication of a 211At distillation and recovery module and iv) a performance review and, where needed, an enhancement of seven major

  2. Dissolved water distribution in vesicular magmatic glass records both decompressive bubble growth and quench resorption

    NASA Astrophysics Data System (ADS)

    McIntosh, I. M.; Llewellin, E.; Humphreys, M.; Nichols, A. R.; Burgisser, A.; Schipper, C.

    2013-12-01

    Water distribution in magma varies over the lifetime of an eruption due to a variety of processes, including decompressive degassing of the melt, cooling during the quench from melt to glass, and post-emplacement hydration under ambient conditions. Correct interpretation of water distributions in erupted pyroclasts can therefore offer crucial insights into the dynamics of eruption mechanisms and emplacement histories. Volcanic eruptions are driven by the nucleation and growth of bubbles in magma. Bubbles grow as volatile species in the melt, of which water is volumetrically the most important, diffuse down a concentration gradient towards and across the bubble wall. On cooling, the melt quenches to glass, preserving the spatial distribution of water concentration around the bubbles (now vesicles). We use Backscatter Scanning Electron Microscopy (BSEM), Secondary Ion Mass Spectrometry (SIMS) and Fourier Transform Infra-Red spectroscopy (FTIR) to measure the spatial distribution of water around vesicles in experimentally-vesiculated samples. We find that, contrary to expectation, the total water concentration increases (by up to 2 wt.%) in the ~30 microns closest to the vesicle wall. Our samples record significant resorption of water back into the melt around bubbles during the quench process, a process which represents ';regassing' of the magma. We propose that the observed total water resorption profiles result from the increase in the equilibrium solubility of water as temperature decreases during the quench to glass, and that this resorption locally overprints the pre-existing concentration total water profile resulting from bubble growth during decompression. This resorption occurs over the very short timescales of rapid experimental quench (3-10 seconds) resulting in strongly disequilibrium water speciation. Water re-enters the melt as molecular water leading to enrichment in molecular water around vesicles, while the distribution of hydroxyl groups remains

  3. A Framework for Developing pH Guidance for Drinking Water Treatment and Distribution - abstract

    EPA Science Inventory

    Worldwide, many agencies have historically limited the range of pH values of distributed water between 6.5 and 8.5. Although this range is not a regulatory limit, many jurisdictions have used it as one. In some cases, the range has been a barrier to optimizing distribution syste...

  4. A Framework for Developing pH Guidance for Drinking Water Treatment and Distribution

    EPA Science Inventory

    Worldwide, many agencies have historically limited the range of pH values of distributed water between 6.5 and 8.5. Although this range is not a regulatory limit, many jurisdictions have used it as one. In some cases, the range has been a barrier to optimizing distribution syste...

  5. Condition Assessment of Ferrous Water Transmission and Distribution Systems State of Technology Review Report

    EPA Science Inventory

    This White Paper was developed to serve as the basis for discussion at a Technology Forum on Condition Assessment of Water Transmission and Distribution Systems that was held on September 9 and 10, 2008, at Edison, NJ. It was distributed to the Forum participants for review in a...

  6. PHYLOGENETIC DIVERSITY IN DRINKING WATER BACTERIA IN A DISTRIBUTION SYSTEM SIMULATOR

    EPA Science Inventory

    This work was carried out to characterize the composition of microbial populations in a distribution system simulator (DSS) by direct sequence analysis of 16S rDNA clone libraries. Bacterial populations were examined in chlorinated distribution water and chloraminated DSS feed an...

  7. MIXING IN DISTRIBUTION SYSTEM STORAGE TANKS: ITS EFFECT ON WATER QUALITY

    EPA Science Inventory

    Nearly all distribution systems in the US include storage tanks and reservoirs. They are the most visible components of a wate distribution system but are generally the least understood in terms of their impact on water quality. Long residence times in storage tanks can have nega...

  8. Assimilation of spatially distributed water levels into a shallow-water flood model. Part I: Mathematical method and test case

    NASA Astrophysics Data System (ADS)

    Lai, X.; Monnier, J.

    2009-10-01

    SummaryRecent applications of remote sensing techniques produce rich spatially distributed observations for flood monitoring. In order to improve numerical flood prediction, we have developed a variational data assimilation method (4D-var) that combines remote sensing data (spatially distributed water levels extracted from spatial images) and a 2D shallow water model. In the present paper (part I), we demonstrate the efficiency of the method with a test case. First, we assimilated a single fully observed water level image to identify time-independent parameters (e.g. Manning coefficients and initial conditions) and time-dependent parameters (e.g. inflow). Second, we combined incomplete observations (a time series of water elevations at certain points and one partial image). This last configuration was very similar to the real case we analyze in a forthcoming paper (part II). In addition, a temporal strategy with time overlapping is suggested to decrease the amount of memory required for long-duration simulation.

  9. Distribution and migration of nitrobenzene in water following a simulated spill.

    PubMed

    Li, Peijun; Yin, Wei; Li, Peng; Li, Xiaojun; Zhang, Chungui; Stagnitti, Frank; Xiong, Xianzhe

    2010-10-15

    Releases of nitrobenzene into the aquatic environment pose a threat to human health and aquatic resources, and have attracted much attention world-wide. In order to find out the distribution and migration patterns of pooled nitrobenzene underwater in different conditions, laboratory column experiments were designed to simulate stagnant water, flowing water and rainfall disturbance events. The results showed that in stagnant water there was a slow diffusion of the nitrobenzene from the pool leading to higher concentrations of the chemical deeper in the water column. In flowing water, the removal of the substance was rapid and water concentrations were much lower and more uniform throughout the column. The disturbance event brought a substantial quantity of nitrobenzene into the water column which then dissipated according to the flow regime. Analysis of the data showed that distribution pattern of nitrobenzene in the stagnant water column followed a logarithmic equation C(NB) = a ln(t) + b, and in disturbed flowing water, the distribution pattern of nitrobenzene followed a negative exponential regression equation C(NB) = Ne(-Mt). These conclusions have practical significance in developing remediation technologies for water polluted by nitrobenzene. PMID:20667658

  10. Removal of soft deposits from the distribution system improves the drinking water quality.

    PubMed

    Lehtola, Markku J; Nissinen, Tarja K; Miettinen, Ilkka T; Martikainen, Pertti J; Vartiainen, Terttu

    2004-02-01

    Deterioration in drinking water quality in distribution networks represents a problem in drinking water distribution. These can be an increase in microbial numbers, an elevated concentration of iron or increased turbidity, all of which affect taste, odor and color in the drinking water. We studied if pipe cleaning would improve the drinking water quality in pipelines. Cleaning was arranged by flushing the pipes with compressed air and water. The numbers of bacteria and the concentrations of iron and turbidity in drinking water were highest at 9 p.m., when the water consumption was highest. Soft deposits inside the pipeline were occasionally released to bulk water, increasing the concentrations of iron, bacteria, microbially available organic carbon and phosphorus in drinking water. The cleaning of the pipeline decreased the diurnal variation in drinking water quality. With respect to iron, only short-term positive effects were obtained. However, removing of the nutrient-rich soft deposits did decrease the microbial growth in the distribution system during summer when there were favorable warm temperatures for microbial growth. No Norwalk-like viruses or coliform bacteria were detected in the soft deposits, in contrast to the high numbers of heterotrophic bacteria.

  11. Morphological and physicochemical characteristics of iron corrosion scales formed under different water source histories in a drinking water distribution system.

    PubMed

    Yang, Fan; Shi, Baoyou; Gu, Junnong; Wang, Dongsheng; Yang, Min

    2012-10-15

    The corrosion scales on iron pipes could have great impact on the water quality in drinking water distribution systems (DWDS). Unstable and less protective corrosion scale is one of the main factors causing "discolored water" issues when quality of water entering into distribution system changed significantly. The morphological and physicochemical characteristics of corrosion scales formed under different source water histories in duration of about two decades were systematically investigated in this work. Thick corrosion scales or densely distributed corrosion tubercles were mostly found in pipes transporting surface water, but thin corrosion scales and hollow tubercles were mostly discovered in pipes transporting groundwater. Magnetite and goethite were main constituents of iron corrosion products, but the mass ratio of magnetite/goethite (M/G) was significantly different depending on the corrosion scale structure and water source conditions. Thick corrosion scales and hard shell of tubercles had much higher M/G ratio (>1.0), while the thin corrosion scales had no magnetite detected or with much lower M/G ratio. The M/G ratio could be used to identify the characteristics and evaluate the performances of corrosion scales formed under different water conditions. Compared with the pipes transporting ground water, the pipes transporting surface water were more seriously corroded and could be in a relatively more active corrosion status all the time, which was implicated by relatively higher siderite, green rust and total iron contents in their corrosion scales. Higher content of unstable ferric components such as γ-FeOOH, β-FeOOH and amorphous iron oxide existed in corrosion scales of pipes receiving groundwater which was less corroded. Corrosion scales on groundwater pipes with low magnetite content had higher surface area and thus possibly higher sorption capacity. The primary trace inorganic elements in corrosion products were Br and heavy metals. Corrosion

  12. Morphological and physicochemical characteristics of iron corrosion scales formed under different water source histories in a drinking water distribution system.

    PubMed

    Yang, Fan; Shi, Baoyou; Gu, Junnong; Wang, Dongsheng; Yang, Min

    2012-10-15

    The corrosion scales on iron pipes could have great impact on the water quality in drinking water distribution systems (DWDS). Unstable and less protective corrosion scale is one of the main factors causing "discolored water" issues when quality of water entering into distribution system changed significantly. The morphological and physicochemical characteristics of corrosion scales formed under different source water histories in duration of about two decades were systematically investigated in this work. Thick corrosion scales or densely distributed corrosion tubercles were mostly found in pipes transporting surface water, but thin corrosion scales and hollow tubercles were mostly discovered in pipes transporting groundwater. Magnetite and goethite were main constituents of iron corrosion products, but the mass ratio of magnetite/goethite (M/G) was significantly different depending on the corrosion scale structure and water source conditions. Thick corrosion scales and hard shell of tubercles had much higher M/G ratio (>1.0), while the thin corrosion scales had no magnetite detected or with much lower M/G ratio. The M/G ratio could be used to identify the characteristics and evaluate the performances of corrosion scales formed under different water conditions. Compared with the pipes transporting ground water, the pipes transporting surface water were more seriously corroded and could be in a relatively more active corrosion status all the time, which was implicated by relatively higher siderite, green rust and total iron contents in their corrosion scales. Higher content of unstable ferric components such as γ-FeOOH, β-FeOOH and amorphous iron oxide existed in corrosion scales of pipes receiving groundwater which was less corroded. Corrosion scales on groundwater pipes with low magnetite content had higher surface area and thus possibly higher sorption capacity. The primary trace inorganic elements in corrosion products were Br and heavy metals. Corrosion

  13. WATER QUALITY EARLY WARNING SYSTEMS FOR SOURCE WATER AND DISTRIBUTION SYSTEM MONITORING

    EPA Science Inventory

    A variety of probes for use in continuous monitoring of water quality exist. They range from single parameter chemical/physical probes to comprehensive screening systems based on whole organism responses. Originally developed for monitoring specific characteristics of water qua...

  14. Microbial community profile of a lead service line removed from a drinking water distribution system.

    PubMed

    White, Colin; Tancos, Matthew; Lytle, Darren A

    2011-08-01

    A corroded lead service line was removed from a drinking water distribution system, and the microbial community was profiled using 16S rRNA gene techniques. This is the first report of the characterization of a biofilm on the surface of a corroded lead drinking water service line. The majority of phylotypes have been linked to heavy-metal-contaminated environments.

  15. ASSESSING AND PREVENTING THE SPREAD OF CONTAMINANTS IN A DRINKING WATER DISTRIBUTION SYSTEM

    EPA Science Inventory

    Remote monitoring data, field studies, and the modeling software ? EPANET, can be used by drinking water utilities and consulting engineers to predict flow dynamics and information on the spatial distribution and concentration of contaminants in a drinking water system. A field ...

  16. Evaluation of Select Sensors for Real-Time Monitoring of Escherichia coli in Water Distribution Systems▿

    PubMed Central

    Miles, Syreeta L.; Sinclair, Ryan G.; Riley, Mark R.; Pepper, Ian L.

    2011-01-01

    This study evaluated real-time sensing of Escherichia coli as a microbial contaminant in water distribution systems. Most sensors responded to increased E. coli concentrations, showing that select sensors can detect microbial water quality changes and be utilized as part of a contaminant warning system. PMID:21357435

  17. Controlling Disinfection Residual Losses in Drinking Water Distribution Systems: Results from Experimental Studies

    EPA Science Inventory

    It is generally accepted that water quality can deteriorate in a distribution system through reactions in the bulk phase and/or at the pipe wall. These reactions may be physical, chemical and/or microbiological in nature. Perhaps one of the most serious aspects of water quality...

  18. THE OCCURRENCE OF CONTAMINANT ACCUMULATION IN LEAD PIPE SCALES FROM DOMESTIC DRINKING WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Previous work has shown that contaminants, such as Al, As and Ra, can accumulate in drinking water distribution system solids. The release of accumulated contaminants back into the water supply could result in elevated levels at consumers’ taps, and current monitoring practices d...

  19. Controlling Disinfection Residual Losses in Drinking Water Distribution Systems: Results from Experimental Studies

    EPA Science Inventory

    It has become generally accepted that water quality can deteriorate in a distribution system through reactions in the bulk phase and/or at the pipe wall. These reactions may be physical, chemical and/or microbiological in nature. Perhaps one of the most serious aspects of water...

  20. Water Quality in Small Community Distribution Systems. A Reference Guide for Operators

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) has developed this reference guide to assist the operators and managers of small- and medium-sized public water systems. This compilation provides a comprehensive picture of the impact of the water distribution system network on dist...

  1. Sediment-water distribution of contaminants of emerging concern in a mixed use watershed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated the occurrence and distribution of 15 contaminants of emerging concern (CEC) in stream water and sediments in the Zumbro River watershed in Minnesota and compared these with sub-watershed land uses. Sixty pairs of sediment and water samples were collected across all seasons from...

  2. A Comprehensive Investigation of Copper Pitting Corrosion in a Drinking Water Distribution System

    EPA Science Inventory

    Copper pipe pitting is a complicated corrosion process for which exact causes and solutions are uncertain. This paper presents the findings of a comprehensive investigation of a cold water copper pitting corrosion problem in a drinking water distribution system, including a refi...

  3. Second-Order Chlorine Decay and Trihalomethanes Formation in a Pilot-Scale Water Distribution Systems

    EPA Science Inventory

    It is well known that model-building of chlorine decay in real water distribution systems is difficult because chlorine decay is influenced by many factors (e.g., bulk water demand, pipe-wall demand, piping material, flow velocity, and residence time). In this paper, experiments ...

  4. The Benefit-Cost Relationship in Entry Job Training in Water Distribution.

    ERIC Educational Resources Information Center

    Reames, J. P. (Jim)

    The benefit-cost relationship analysis concerns the cost effectiveness of employment and training in the Water Distribution Division of the Dallas Water Utilities Department and deals specifically with 104 entry workers hired to become pipe fitters. Half of the entry workers were enrolled in the Public Service Careers (PSC) training program and…

  5. Microbial Community Dynamics of a Simulated Chloraminated Drinking Water Distribution System Subjected to Episodes of Nitrification

    EPA Science Inventory

    Bacterial populations were examined in a simulated chloraminated drinking water distribution system (i.e. loop). The loop (BW-AB-I) received chlorinated municipal water (BW-C) amended with ammonia (2mg/L monochloramine). After six years of continuous operation, the operational ...

  6. Imaging of water distribution in the rat brain by activation autoradiography

    SciTech Connect

    Kogure, K.; Kawashima, K.; Iwata, R.; Ido, T. )

    1990-01-01

    Regional water distribution in the rat brain was obtained autoradiographically by activation analysis. The autoradiogram obtained for the normal rat brain showed high accumulation of water in the areas of sensory-motor cortex, hippocampus, thalamus, and amygdaloid cortex, whereas corpus callosum and internal capsule showed low water contents as expected. The estimated values of water content were 78.6 +/- 4.9 weight % for gray matter, and 73.5 +/- 4.9 weight % for white matter, respectively. The mean values of the water content were consistent with those obtained by a conventional drying-weighing method.

  7. EARTHQUAKE HAZARDS TO DOMESTIC WATER DISTRIBUTION SYSTEMS IN SALT LAKE COUNTY, UTAH.

    USGS Publications Warehouse

    Highland, Lynn M.

    1985-01-01

    A magnitude-7. 5 earthquake occurring along the central portion of the Wasatch Fault, Utah, may cause significant damage to Salt Lake County's domestic water system. This system is composed of water treatment plants, aqueducts, distribution mains, and other facilities that are vulnerable to ground shaking, liquefaction, fault movement, and slope failures. Recent investigations into surface faulting, landslide potential, and earthquake intensity provide basic data for evaluating the potential earthquake hazards to water-distribution systems in the event of a large earthquake. Water supply system components may be vulnerable to one or more earthquake-related effects, depending on site geology and topography. Case studies of water-system damage by recent large earthquakes in Utah and in other regions of the United States offer valuable insights in evaluating water system vulnerability to earthquakes.

  8. Symmetry-related mutants in the quinone binding sites of the reaction center -- The effects of changes in charge distribution

    SciTech Connect

    Hanson, D.K.; Schiffer, M.

    1997-09-01

    To probe the structural elements that contribute to the functional asymmetries of the two ubiquinone{sub 10}binding pockets in the reaction center of Rhodobacter capsulatus, the authors targeted the L212Glu-L213Asp (near Q{sub B}) and the M246Ala-M247Ala (near Q{sub A}) pairs of symmetry-related residues for site-specific mutagenesis. They have constructed site-specific mutants that eliminate the sequence differences at these positions (L212Glu-L213Asp{yields}Ala-Ala or M246Ala-M247Ala{yields}Glu-Asp), and have reversed that asymmetry by constructing a quadruple-mutant strain, RQ (L212Glu-L213Asp-M246Ala-M247Ala{yields}Ala-Ala-Glu-Asp). The mutations were designed to change the charge distribution in the quinone-binding region of the reaction center; none of the strains is capable of photosynthetic growth. In photocomponent phenotypic revertants of the RQ strain, second-site mutations which affect Q{sub B} function are coupled to mutations in the Q{sub A} site which restore an Ala or substitute a Tyr at the M247 site; one strain carries an additional Met{yields}Glu substitution at M260 near Q{sub A}. All of the RQ revertants retain the engineered M246Ala{yields}Glu mutation in the Q{sub A} site as well as the L212Ala-L213Ala mutations in the Q{sub B} site. Kinetic characterization of the RQ revertants will give them an idea of what structural and functional elements are important for restoring efficiency to electron and proton transfer pathways in the RQRC, which is far from native. To date, these preliminary results underscore the importance of an asymmetric distribution of polar amino acids in the quinone binding pockets and its influence on the functional properties of the reaction center.

  9. Modeling spatial variation of brominates trihalomethane in a water distribution system of Ontario, Canada.

    PubMed

    Chaib, Embarka; Moschandreas, Demetrios

    2006-01-01

    Conventional approaches to characterize and model the formation of trihalomethanes (THM) species in the distribution system use either residence time or water temperature. A significant deviation of THM levels were observed at the beginning and the end of a selected distribution system in Ontario, which may be because the consumption rate of residual chlorine is not constant in the distribution system. The approach developed in this study incorporates water temperature and proceeds with a trend and decomposition modeling method to incorporate the traveled distance and to explain the seasonal THM variation in the distribution system. The model has been tested and verified using a database from the Bettravia distribution system in Ontario, Canada. The deviations at the extremes of the distribution system were minimized due to the modeling technique used to develop the model and by including more factors that affect THM formation in the distribution system. The agreement between predicted and measured THM values at the beginning and the end of the distribution system is pronounced. The model presented in this paper is a robust tool that may be used by SDWAA to evaluate regulatory options and justify potential regulations regarding THM levels of the drinking water distribution system.

  10. Final Technical Report: Hawaii Hydrogen Center for Development and Deployment of Distributed Energy Systems

    SciTech Connect

    Rocheleau, Richard E.

    2008-09-30

    -efficiency CIGS and a-Si:H with operating features compatible with high-efficiency photoelectrochemical (PEC) water-splitting. The objective of one activity under the hydrogen production from biomass task was to conduct parametric testing of the Pearson gasifier and to determine the effects of gasifier operating conditions on the gas yields and quality. The hydrogen yield from this gasifier was evaluated in a parametric test series over a range of residence times from 0.8 to 2.2 seconds. H2 concentrations as high as 55% (volume) were measured in the product gas at the longer residence times and this corresponds to a hydrogen yield of 90 kg per tonne of bagasse without gas upgrading. The objective of another activity was to develop hot gas clean-up capabilities for the HNEI gasifier test facility to support hydrogen-from-biomass research. The product gas stream at the outlet of the hot gas filter was characterized for concentrations of permanent gas species and contaminants. Biomass feedstock processing activity included a preliminary investigation into methods for processing sugar cane trash at the Puunene Sugar Factory on the island of Maui, Hawaii. The objective of the investigation was to explore treatment methods that would enable the successful use of cane trash as fuel for the production of hydrogen via gasification. Analyses were completed for the technical and economic feasibility of producing biofuel from photosynthetic marine microbes on a commercial scale. Results included estimates for total costs, energy efficiency, and return on investment. The biohydrogen team undertook a comprehensive review of the field and came to what is considered a realistic conclusion. To summarize, continued research is recommended in the fundamentals of the science related to genetic engineering and specific topics to cover knowledge gaps. In the meantime, the team also advocates continued development of related processes which can be linked to pollution control and other real world

  11. Pollution-control equipment (Brazil). Water treatment and distribution equipment, June 1992. Export trade information

    SciTech Connect

    Not Available

    1992-06-01

    The market of water treatment and distribution equipment in Brazil is expected to reach US $330 million in 1992, up 11% from 1991. Much needed investments in the sanitation sector by municipal water supply companies should stimulate this market to recover from the idle production capacity and reduced output it is currently experiencing. The lower import duties imposed on water supply equipment and instruments should cause imports also to rise from US $24 million in 1991 to around US $27 million in 1992.

  12. Family of Oxygen-Oxygen Radial Distribution Functions for Water.

    PubMed

    Brookes, David H; Head-Gordon, Teresa

    2015-08-01

    In a typical X-ray diffraction experiment, the elastically scattered intensity, I(Q), is the experimental observable. I(Q) contains contributions from both intramolecular as well as intermolecular correlations embodied in the scattering factors, HOO(Q) and HOH(Q), with negligible contributions from HHH(Q). Thus, to accurately define the oxygen-oxygen radial distribution function, gOO(r), a model of the electron density is required to accurately weigh the HOO(Q) component relative to the intramolecular and oxygen-hydrogen correlations from the total intensity observable. In this work, we carefully define the electron density model and its underlying assumptions and more explicitly utilize two restraints on the allowable gOO(r) functions, which must conform to both very low experimental errors at high Q and the need to satisfy the isothermal compressibility at low Q. Although highly restrained by these conditions, the underdetermined nature of the problem is such that we present a family of gOO(r) values that provide equally good agreement with the high-Q intensity and compressibility restraints and with physically correct behavior at small r. PMID:26267185

  13. Evaluation of wetting area and water distribution on different soils in subsurface drip irrigation emitters

    NASA Astrophysics Data System (ADS)

    Karimi, B.; Sohrabi, T.; Mirzaei, F.; Rodríguez-Sinobas, L.

    2012-04-01

    Growing pressure on the world's available water resources has led to an increase in the efficiency and productivity of water-use of irrigation systems in arid and semi-arid regions with water scarcity. In this context, sub-surface drip irrigation, where emitters discharge water underneath the soil surface, might help by saving water since soil evaporation, surface runoff, and deep percolation are greatly reduced or eliminated. In this paper, the wetting area and water distribution on light, medium and heavy texture homogeneous soils in subsurface drip irrigation emitters were evaluated. Experimental tests were carried out in a plexiglass lysimeter container with transparent walls. Emitters were buried at 15, 30 and 45 cm depths and discharge rates of 2 and 4 L/h were applied. Observations of wetting bulbs dimensions showed that water moved more laterally than downwards for higher emitter discharges. However, small emitter discharges enhanced water to move downwards. Likewise, higher emitter discharges also favored water to move upwards toward the soil surface. Water redistribution was affected by emitter depth. For the same emitter discharge, the deepest depth showed less water redistributed in the down vertical and horizontal directions but the contrary was observed for shallow depths. This could be explained considering the dry soil area above the emitter that is larger in the deepest emitters. Observations on wetting bulb dimensions and water distributions could aim at the selection of proper design variables (emitter depth), and/or operation variables (inlet head and irrigation time) in the studied soils under different scenarios of cropping patterns. Key Words: subsurface drip irrigation, wetting bulb, soil water distribution, water redistribution, optimum management

  14. Water-column Observations During a Seafloor Eruption on the Northeast Lau Spreading Center

    NASA Astrophysics Data System (ADS)

    Baker, E. T.; Walker, S. L.; Resing, J.; Baumberger, T.; Lilley, M. D.; Lupton, J. E.; Lavelle, J. W.; Rubin, K. H.; Embley, R. W.; Greene, R.

    2009-12-01

    Midocean ridge eruptions offer rare opportunities to study the creation of new ocean crust and the accelerated release of heat and chemicals into the ocean. Only 7 such events have been documented since the first observation of eruption-induced fluid discharge in 1986. Their hallmark is “event plumes,” symmetrical boluses of hydrothermally rich water typically ~0.5 km thick and 5-20 km in diameter. Past sampling of such plumes has occurred from 10 days to months after an eruption. In Nov. 2008 on the Northeast Lau Spreading Center, we detected not a typical event plume but a uniquely different series of young, apparently eruption-generated plumes. At 0700 UTC on 20 Nov., a CTD tow detected layers of thin (<100 m) plumes between 600 and 1200 m depth, above a local ridge depth of ~1600 m. These plumes had unusually intense light-scattering (NTU>0.6), oxidation-reduction potential (ORP or “Eh”) (>250 mv), temperature (ΔT >0.7°C), and H2 (6873 nM) anomalies, plus abundant glass shards (>50μm). These characteristics imply a very young plume. 21 hours later, another tow mapped abundant plume layers extending from 900 m depth to the seafloor, marking the probable eruption site as 15.39°S, 174.25°W. High H2 (up to 9031 nM) and low 3He (68 δ(3He)%) in the shallowest plumes suggests their source was magma-seawater contact. In contrast, low H2 (33 nM) and high 3He (up to 146 δ(3He)%) in the deeper plumes implies their source was a more evolved hydrothermal fluid. CO2 values were high in all plumes. By 24 Nov. shallow plumes were absent above the eruption site, with only weak remnants found a few km south. By 27 Nov. no plumes shallower than 1450 m were found within our ~5 km sampling radius. Bottom-water temperature anomalies over the eruption site declined during the same time frame. Three near-bottom tows (15-50 mab) consistently identified bottom waters with significant ΔT between 15.405° and 15.380°S (~4 km) along the ridge crest. Maximum ΔT seen on the

  15. Vertical distribution of water in the atmosphere of Venus - A simple thermochemical explanation

    NASA Technical Reports Server (NTRS)

    Lewis, John S.; Grinspoon, David H.

    1990-01-01

    Several lines of evidence concerning the vertical abundance profile of water in the atmosphere of Venus lead to strikingly unusual distributions (the water vapor abundance decreases sharply in the immediate vicinity of the surface) or to serious conflicts in the profiles (different IR bands suggest water abundances that are discrepant by a factor of 2.5 to 10). These data sets can be reconciled if (1) water molecules associate with carbon dioxide and sulfur trioxide to make gaseous carbonic acid and sulfuric acid in the lower atmosphere, and (2) the discrepant 0.94-micrometer water measurements are due to gaseous sulfuric acid, requiring it to be a somewhat stronger absorber than water vapor in this wavelength region. A mean total water abundance of 50 + or - 20 parts/million and a near-surface free water vapor abundance of 10 + or - 4 parts/million are derived.

  16. The temperature and size distribution of large water clusters from a non-equilibrium model

    SciTech Connect

    Gimelshein, N.; Gimelshein, S.; Pradzynski, C. C.; Zeuch, T.; Buck, U.

    2015-06-28

    A hybrid Lagrangian-Eulerian approach is used to examine the properties of water clusters formed in neon-water vapor mixtures expanding through microscale conical nozzles. Experimental size distributions were reliably determined by the sodium doping technique in a molecular beam machine. The comparison of computed size distributions and experimental data shows satisfactory agreement, especially for (H{sub 2}O){sub n} clusters with n larger than 50. Thus validated simulations provide size selected cluster temperature profiles in and outside the nozzle. This information is used for an in-depth analysis of the crystallization and water cluster aggregation dynamics of recently reported supersonic jet expansion experiments.

  17. Humidity distribution affected by freely exposed water surfaces: Simulations and experimental verification

    NASA Astrophysics Data System (ADS)

    Hygum, M. A.; Popok, V. N.

    2014-07-01

    Accurate models for the water vapor flux at a water-air interface are required in various scientific, reliability and civil engineering aspects. Here, a study of humidity distribution in a container with air and freely exposed water is presented. A model predicting a spatial distribution and time evolution of relative humidity based on statistical rate theory and computational fluid dynamics is developed. In our approach we use short-term steady-state steps to simulate the slowly evolving evaporation in the system. Experiments demonstrate considerably good agreement with the computer modeling and allow one to distinguish the most important parameters for the model.

  18. Hydraulic model analysis of water distribution system, Rockwell International, Rocky Flats, Colorado

    SciTech Connect

    Perstein, J.; Castellano, J.A.

    1989-01-20

    Rockwell International requested an analysis of the existing plant site water supply distribution system at Rocky Flats, Colorado, to determine its adequacy. On September 26--29, 1988, Hughes Associates, Inc., Fire Protection Engineers, accompanied by Rocky Flats Fire Department engineers and suppression personnel, conducted water flow tests at the Rocky Flats plant site. Thirty-seven flows from various points throughout the plant site were taken on the existing domestic supply/fire main installation to assure comprehensive and thorough representation of the Rocky Flats water distribution system capability. The analysis was completed in four phases which are described, together with a summary of general conclusions and recommendations.

  19. The temperature and size distribution of large water clusters from a non-equilibrium model.

    PubMed

    Gimelshein, N; Gimelshein, S; Pradzynski, C C; Zeuch, T; Buck, U

    2015-06-28

    A hybrid Lagrangian-Eulerian approach is used to examine the properties of water clusters formed in neon-water vapor mixtures expanding through microscale conical nozzles. Experimental size distributions were reliably determined by the sodium doping technique in a molecular beam machine. The comparison of computed size distributions and experimental data shows satisfactory agreement, especially for (H2O)n clusters with n larger than 50. Thus validated simulations provide size selected cluster temperature profiles in and outside the nozzle. This information is used for an in-depth analysis of the crystallization and water cluster aggregation dynamics of recently reported supersonic jet expansion experiments. PMID:26133426

  20. The temperature and size distribution of large water clusters from a non-equilibrium model

    NASA Astrophysics Data System (ADS)

    Gimelshein, N.; Gimelshein, S.; Pradzynski, C. C.; Zeuch, T.; Buck, U.

    2015-06-01

    A hybrid Lagrangian-Eulerian approach is used to examine the properties of water clusters formed in neon-water vapor mixtures expanding through microscale conical nozzles. Experimental size distributions were reliably determined by the sodium doping technique in a molecular beam machine. The comparison of computed size distributions and experimental data shows satisfactory agreement, especially for (H2O)n clusters with n larger than 50. Thus validated simulations provide size selected cluster temperature profiles in and outside the nozzle. This information is used for an in-depth analysis of the crystallization and water cluster aggregation dynamics of recently reported supersonic jet expansion experiments.

  1. Validation of a Hot Water Distribution Model Using Laboratory and Field Data

    SciTech Connect

    Backman, C.; Hoeschele, M.

    2013-07-01

    Characterizing the performance of hot water distribution systems is a critical step in developing best practice guidelines for the design and installation of high performance hot water systems. Developing and validating simulation models is critical to this effort, as well as collecting accurate input data to drive the models. In this project, the ARBI team validated the newly developed TRNSYS Type 604 pipe model against both detailed laboratory and field distribution system performance data. Validation efforts indicate that the model performs very well in handling different pipe materials, insulation cases, and varying hot water load conditions. Limitations of the model include the complexity of setting up the input file and long simulation run times. In addition to completing validation activities, this project looked at recent field hot water studies to better understand use patterns and potential behavioral changes as homeowners convert from conventional storage water heaters to gas tankless units. Based on these datasets, we conclude that the current Energy Factor test procedure overestimates typical use and underestimates the number of hot water draws. This has implications for both equipment and distribution system performance. Gas tankless water heaters were found to impact how people use hot water, but the data does not necessarily suggest an increase in usage. Further study in hot water usage and patterns is needed to better define these characteristics in different climates and home vintages.

  2. Validation of a Hot Water Distribution Model Using Laboratory and Field Data

    SciTech Connect

    Backman, C.; Hoeschele, M.

    2013-07-01

    Characterizing the performance of hot water distribution systems is a critical step in developing best practice guidelines for the design and installation of high performance hot water systems. Developing and validating simulation models is critical to this effort, as well as collecting accurate input data to drive the models. In this project, the Building America research team ARBI validated the newly developed TRNSYS Type 604 pipe model against both detailed laboratory and field distribution system performance data. Validation efforts indicate that the model performs very well in handling different pipe materials, insulation cases, and varying hot water load conditions. Limitations of the model include the complexity of setting up the input file and long simulation run times. This project also looked at recent field hot water studies to better understand use patterns and potential behavioral changes as homeowners convert from conventional storage water heaters to gas tankless units. The team concluded that the current Energy Factor test procedure overestimates typical use and underestimates the number of hot water draws, which has implications for both equipment and distribution system performance. Gas tankless water heaters were found to impact how people use hot water, but the data does not necessarily suggest an increase in usage. Further study in hot water usage and patterns is needed to better define these characteristics in different climates and home vintages.

  3. The abundance and distribution of water vapor in Jupiter's atmosphere

    NASA Technical Reports Server (NTRS)

    Bjoraker, Gordon L.; Larson, Harold P.; Kunde, Virgil G.

    1986-01-01

    The atmospheric transmission window between 1800 and 2250 cm(-1) in Jupiter's atmosphere was observed from the Kuiper Airborne Observatory (KAO) and by the infrared spectrometer (IRIS) on Voyager. The vertical distribution of H2O was derived for the 1 to 6 bar portion of Jupiter's troposphere. The spatial variation of H2O was measured using IRIS spectra of the Hot Spots in the North and South Equatorial Belts, the Equatorial Zone, and for an average of the North and South Tropical Zones. The H2O column abundance above the 4 bar level is the same in the zones as in the SEB Hot Spots, about 20 cm-amagat. The NEB Hot Spots are desiccated by a factor of 3 with respect to the rest of Jupiter. For an average between -40 to 40 deg latitude, the H2O mole fraction, qH2O, is saturated for P less than 2 bars, qH2O = 4x10 to the -6 in the 2 to 4 bar range and it increases to 3x10 to the -5 at 6 bars. A similar vertical profile applies to the spatially resolved zone and belt spectra, except that H2O falls off more rapidly at P less than 4 bars in the NEB Hot Spots. The massive H2O cloud at 5 bars, T = 273 K, proposed in solar composition models, is inconsistent with the observations. Instead, a thin H2O ice cloud would form at 2 bars, T = 200 K. The O/H ratio in Jupiter, inferred from H2O measurements in both belts and zones at 6 bars, is depleted by a factor of 50 with respect to the Sun. The implications for the origin of Jupiter of globally depleted O/H, but enhanced C/H and N/H, are discussed.

  4. Assessing HYDRUS-2D model to estimate soil water contents and olive tree transpiration fluxes under different water distribution systems

    NASA Astrophysics Data System (ADS)

    Autovino, Dario; Negm, Amro; Rallo, Giovanni; Provenzano, Giuseppe

    2016-04-01

    In Mediterranean countries characterized by limited water resources for agricultural and societal sectors, irrigation management plays a major role to improve water use efficiency at farm scale, mainly where irrigation systems are correctly designed to guarantee a suitable application efficiency and the uniform water distribution throughout the field. In the last two decades, physically-based agro-hydrological models have been developed to simulate mass and energy exchange processes in the soil-plant-atmosphere (SPA) system. Mechanistic models like HYDRUS 2D/3D (Šimunek et al., 2011) have been proposed to simulate all the components of water balance, including actual crop transpiration fluxes estimated according to a soil potential-dependent sink term. Even though the suitability of these models to simulate the temporal dynamics of soil and crop water status has been reported in the literature for different horticultural crops, a few researches have been considering arboreal crops where the higher gradients of root water uptake are the combination between the localized irrigation supply and the three dimensional root system distribution. The main objective of the paper was to assess the performance of HYDRUS-2D model to evaluate soil water contents and transpiration fluxes of an olive orchard irrigated with two different water distribution systems. Experiments were carried out in Castelvetrano (Sicily) during irrigation seasons 2011 and 2012, in a commercial farm specialized in the production of table olives (Olea europaea L., var. Nocellara del Belice), representing the typical variety of the surrounding area. During the first season, irrigation water was provided by a single lateral placed along the plant row with four emitters per plant (ordinary irrigation), whereas during the second season a grid of emitters laid on the soil was installed in order to irrigate the whole soil surface around the selected trees. The model performance was assessed based on the

  5. Comparison of Particle-Associated Bacteria from a Drinking Water Treatment Plant and Distribution Reservoirs with Different Water Sources

    NASA Astrophysics Data System (ADS)

    Liu, G.; Ling, F. Q.; van der Mark, E. J.; Zhang, X. D.; Knezev, A.; Verberk, J. Q. J. C.; van der Meer, W. G. J.; Medema, G. J.; Liu, W. T.; van Dijk, J. C.

    2016-02-01

    This study assessed the characteristics of and changes in the suspended particles and the associated bacteria in an unchlorinated drinking water distribution system and its reservoirs with different water sources. The results show that particle-associated bacteria (PAB) were present at a level of 0.8-4.5 × 103 cells ml-1 with a biological activity of 0.01-0.04 ng l-1 ATP. Different PAB communities in the waters produced from different sources were revealed by a 16S rRNA-based pyrosequencing analysis. The quantified biomass underestimation due to the multiple cells attached per particle was ≥ 85%. The distribution of the biologically stable water increased the number of cells per particle (from 48 to 90) but had minor effects on the PAB community. Significant changes were observed at the mixing reservoir. Our results show the characteristics of and changes in suspended PAB during distribution, and highlight the significance of suspended PAB in the distribution system, because suspended PAB can lead to a considerable underestimation of biomass, and because they exist as biofilm, which has a greater mobility than pipe-wall biofilm and therefore presents a greater risk, given the higher probability that it will reach the customers’ taps and be ingested.

  6. Comparison of Particle-Associated Bacteria from a Drinking Water Treatment Plant and Distribution Reservoirs with Different Water Sources

    PubMed Central

    Liu, G.; Ling, F. Q.; van der Mark, E. J.; Zhang, X. D.; Knezev, A.; Verberk, J. Q. J. C.; van der Meer, W. G. J.; Medema, G. J.; Liu, W. T.; van Dijk, J. C.

    2016-01-01

    This study assessed the characteristics of and changes in the suspended particles and the associated bacteria in an unchlorinated drinking water distribution system and its reservoirs with different water sources. The results show that particle-associated bacteria (PAB) were present at a level of 0.8–4.5 × 103 cells ml−1 with a biological activity of 0.01–0.04 ng l−1 ATP. Different PAB communities in the waters produced from different sources were revealed by a 16S rRNA-based pyrosequencing analysis. The quantified biomass underestimation due to the multiple cells attached per particle was ≥ 85%. The distribution of the biologically stable water increased the number of cells per particle (from 48 to 90) but had minor effects on the PAB community. Significant changes were observed at the mixing reservoir. Our results show the characteristics of and changes in suspended PAB during distribution, and highlight the significance of suspended PAB in the distribution system, because suspended PAB can lead to a considerable underestimation of biomass, and because they exist as biofilm, which has a greater mobility than pipe-wall biofilm and therefore presents a greater risk, given the higher probability that it will reach the customers’ taps and be ingested. PMID:26832989

  7. Comparison of Particle-Associated Bacteria from a Drinking Water Treatment Plant and Distribution Reservoirs with Different Water Sources.

    PubMed

    Liu, G; Ling, F Q; van der Mark, E J; Zhang, X D; Knezev, A; Verberk, J Q J C; van der Meer, W G J; Medema, G J; Liu, W T; van Dijk, J C

    2016-01-01

    This study assessed the characteristics of and changes in the suspended particles and the associated bacteria in an unchlorinated drinking water distribution system and its reservoirs with different water sources. The results show that particle-associated bacteria (PAB) were present at a level of 0.8-4.5 × 10(3) cells ml(-1) with a biological activity of 0.01-0.04 ng l(-1) ATP. Different PAB communities in the waters produced from different sources were revealed by a 16S rRNA-based pyrosequencing analysis. The quantified biomass underestimation due to the multiple cells attached per particle was ≥ 85%. The distribution of the biologically stable water increased the number of cells per particle (from 48 to 90) but had minor effects on the PAB community. Significant changes were observed at the mixing reservoir. Our results show the characteristics of and changes in suspended PAB during distribution, and highlight the significance of suspended PAB in the distribution system, because suspended PAB can lead to a considerable underestimation of biomass, and because they exist as biofilm, which has a greater mobility than pipe-wall biofilm and therefore presents a greater risk, given the higher probability that it will reach the customers' taps and be ingested. PMID:26832989

  8. Comparison of Particle-Associated Bacteria from a Drinking Water Treatment Plant and Distribution Reservoirs with Different Water Sources

    NASA Astrophysics Data System (ADS)

    Liu, G.; Ling, F. Q.; van der Mark, E. J.; Zhang, X. D.; Knezev, A.; Verberk, J. Q. J. C.; van der Meer, W. G. J.; Medema, G. J.; Liu, W. T.; van Dijk, J. C.

    2016-02-01

    This study assessed the characteristics of and changes in the suspended particles and the associated bacteria in an unchlorinated drinking water distribution system and its reservoirs with different water sources. The results show that particle-associated bacteria (PAB) were present at a level of 0.8–4.5 × 103 cells ml‑1 with a biological activity of 0.01–0.04 ng l‑1 ATP. Different PAB communities in the waters produced from different sources were revealed by a 16S rRNA-based pyrosequencing analysis. The quantified biomass underestimation due to the multiple cells attached per particle was ≥ 85%. The distribution of the biologically stable water increased the number of cells per particle (from 48 to 90) but had minor effects on the PAB community. Significant changes were observed at the mixing reservoir. Our results show the characteristics of and changes in suspended PAB during distribution, and highlight the significance of suspended PAB in the distribution system, because suspended PAB can lead to a considerable underestimation of biomass, and because they exist as biofilm, which has a greater mobility than pipe-wall biofilm and therefore presents a greater risk, given the higher probability that it will reach the customers’ taps and be ingested.

  9. Occurrence and distribution of polycyclic aromatic hydrocarbons in reclaimed water and surface water of Tianjin, China.

    PubMed

    Cao, Zhonghong; Wang, Yuqiu; Ma, Yongmin; Xu, Ze; Shi, Guoliang; Zhuang, Yuanyi; Zhu, Tan

    2005-06-30

    Persistent organic pollutants (POPs) such as polycyclic aromatic hydrocarbons (PAHs) are of great concern due to their persistence, bioaccumulation and toxic effects. In this work, 16 PAHs included in the US Environmental Protection Agency's (EPA) priority pollutant list were analyzed using solid-phase extraction-gas chromatography-mass spectrometry (SPE-GC-MS) with a selected ion monitoring (SIM) mode. Reclaimed water and surface water sampling was undertaken in Tianjin, northern China. Total PAH concentrations varied from 1800 to 35,000 ng/L in surface waters (main rivers, tributaries, ditches, etc.) with mean value of 14,000 ng/L and from 227 to 600 ng/L in reclaimed water with mean value of 352 ng/L, respectively. The PAH profiles were dominated by low molecular weight PAHs (two- and three-ring components) in reclaimed water samples and surface water samples. These indicated that PAHs in reclaimed water and surface water might origin from oil or sewage contamination (petrogenic input). To elucidate sources, molecular indices based on indices among phenanthrene versus anthracene and fluoranthene versus pyrene were used to evaluate the possible source (pyrogenic and petrogenic sources, respectively) of PAH contamination in reclaimed water and surface water. The collected data showed that petrogenic input was predominant at almost all the stations investigated. To discriminate pattern differences and similarities among samples, principal component analysis (PCA) was performed using a correlation matrix. PCA revealed the latent relationships among all the surface water stations investigated and confirmed our analytical results. The analysis results of the ratios and PCA in this study showed that the ratios and PCA could be applied to the surface water investigation to some extent. PMID:15943926

  10. Water Distribution System Deficiencies and Gastrointestinal Illness: A Systematic Review and Meta-Analysis

    PubMed Central

    Gruber, Joshua S.; Colford, John M.

    2014-01-01

    Background: Water distribution systems are vulnerable to performance deficiencies that can cause (re)contamination of treated water and plausibly lead to increased risk of gastrointestinal illness (GII) in consumers. Objectives: It is well established that large system disruptions in piped water networks can cause GII outbreaks. We hypothesized that routine network problems can also contribute to background levels of waterborne illness and conducted a systematic review and meta-analysis to assess the impact of distribution system deficiencies on endemic GII. Methods: We reviewed published studies that compared direct tap water consumption to consumption of tap water re-treated at the point of use (POU) and studies of specific system deficiencies such as breach of physical or hydraulic pipe integrity and lack of disinfectant residual. Results: In settings with network malfunction, consumers of tap water versus POU-treated water had increased GII [incidence density ratio (IDR) = 1.34; 95% CI: 1.00, 1.79]. The subset of nonblinded studies showed a significant association between GII and tap water versus POU-treated water consumption (IDR = 1.52; 95% CI: 1.05, 2.20), but there was no association based on studies that blinded participants to their POU water treatment status (IDR = 0.98; 95% CI: 0.90, 1.08). Among studies focusing on specific network deficiencies, GII was associated with temporary water outages (relative risk = 3.26; 95% CI: 1.48, 7.19) as well as chronic outages in intermittently operated distribution systems (odds ratio = 1.61; 95% CI: 1.26, 2.07). Conclusions: Tap water consumption is associated with GII in malfunctioning distribution networks. System deficiencies such as water outages also are associated with increased GII, suggesting a potential health risk for consumers served by piped water networks. Citation: Ercumen A, Gruber JS, Colford JM Jr. 2014. Water distribution system deficiencies and gastrointestinal illness: a systematic review and

  11. Simulation of Deposition the Corrosion Waste in a Water Distribution System

    NASA Astrophysics Data System (ADS)

    Jeleníková, Ivana; Šikula, Ondřej; Peráčková, Jana

    2013-04-01

    In water distribution systems can be found particles of rust and other mechanical contaminants. The particles are deposited in locations where the low velocity of water flow. Where a can cause the pitting corrosion. Is a concern in the systems made of galvanized steel pipes. The contribution deals with CFD (Computational Fluid Dynamics) simulations of water flow and particles deposition in water distribution system. CFD Simulations were compared with the corrosive deposits in real pipeline. Corrosion is a spontaneous process of destruction of metal material due to electrochemical reactions of metal with the aggressive surrounding. Electrochemical corrosion is caused by the thermodynamic instability of metal and therefore can not be completely suppress, it can only influence the speed of corrosion. The requirement is to keep metal properties during the whole its lifetime. Requested service lifetime the water pipe according to EN 806-2 is 50 years.

  12. [CCA of water beetles' distribution and environmental factors in lentic samples of north Changbai Mountain].

    PubMed

    We, Yulian; Ji, Lanzhu; Wang, Miao; Zhao, Min

    2002-01-01

    The relationship between 28 species water beetles in 12 lentic samples and environmental factors of North Chang-bai Mountain was studied by Cononical Correspondence Analysis (CCA). The results showed that degree of underwater humus and altitude are the major factors correlated with beetles distribution, and the correlation coefficients of environmental factors and axes of CCA were 0.8371 and 0.7206 respectively, while water temperature and plant density also had certain effects. Under the influence of environmental factors, the water beetles' populations were different in different habitat. Coelambus impressopunctatus, Colymbetes magnus, Helophorus browni, Haliplus spp. distributed in deep water pool. Water temperature was not important for those beetles. Ilybius sp. and Limnebius glabriventris correlated with altitude and humus.

  13. Columbia River monitoring: Distribution of tritium in Columbia River water at the Richland Pumphouse

    SciTech Connect

    Dirkes, R.L.

    1993-02-01

    The Surface Environmental Surveillance Project (SESP) is conducted by the Pacific Northwest Laboratory (PNL) for the US Department of Energy (DOE). This report presents the results of a special study conducted as part of the SESP to supplement the routine Columbia River monitoring program and provide information relative to the dispersion and distribution of Hanford origin contaminants entering the river through the seepage of ground water along the Hanford Site. Sampling was conducted along cross sections to determine the distribution of tritium within the Columbia River at Richland, Washington. The investigation was also designed to evaluate the relationship between the average tritium concentrations in the river water at this location and in water collected from the routine SESP river monitoring system located at the city of Richland drinking water intake (Richland Pumphouse). This study was conducted during the summers of 1987 and 1988. Water samples were collected along cross sections located at or near the Richland Pumphouse monitoring station.

  14. [Effect of reclaimed water irrigation on soil properties and vertical distribution of heavy metal].

    PubMed

    Zhao, Zong-Ming; Chen, Wei-Ping; Jiao, Wen-Tao; Wang, Mei-E

    2012-12-01

    Utilization of reclaimed water is one of the important methods to alleviate water shortage. The effect of reclaimed water irrigation on soil is always a concern. To understand the effect of long time reclaimed water irrigation on soil, typical farmland irrigated with reused water was selected. Soil properties and heavy metal concentration of soil and water samples were analyzed to identify the effect of the irrigation on heavy metal vertical distribution and organic matter content, total carbon, total nitrogen and pH value in soil. The results show that heavy metal contents of irrigation water used in Liangshuihe farmland are 2.5 to 10.5 times higher than that of Beiyechang farmland, and reclaimed water irrigation could cause changes of soil properties that soil organic matter content, total carbon, total nitrogen were increased and pH values were reduced. Based on the field investigation results, the soil nutrient conditions benefit from irrigate reclaimed water, however, the accumulation of heavy metal in soil could raise the risk. As a source of soil heavy metal, reclaimed water irrigation could make differences on the accumulation and mobility of soil heavy metal. Also the distribution and mobility of soil heavy metal are influenced by soil organic matter content and there are more heavy metal were taken up by plants or transferred to the deeper area in Liangshuihe farmland.

  15. Root distribution of Nitraria sibirica with seasonally varying water sources in a desert habitat.

    PubMed

    Zhou, Hai; Zhao, Wenzhi; Zheng, Xinjun; Li, Shoujuan

    2015-07-01

    In water-limited environments, the water sources used by desert shrubs are critical to understanding hydrological processes. Here we studied the oxygen stable isotope ratios (δ (18)O) of stem water of Nitraria sibirica as well as those of precipitation, groundwater and soil water from different layers to identify the possible water sources for the shrub. The results showed that the shrub used a mixture of soil water, recent precipitation and groundwater, with shallow lateral roots and deeply penetrating tap (sinker) roots, in different seasons. During the wet period (in spring), a large proportion of stem water in N. sibirica was from snow melt and recent precipitation, but use of these sources declined sharply with the decreasing summer rain at the site. At the height of summer, N. sibirica mainly utilized deep soil water from its tap roots, not only supporting the growth of shoots but also keeping the shallow lateral roots well-hydrated. This flexibility allowed the plants to maintain normal metabolic processes during prolonged periods when little precipitation occurs and upper soil layers become extremely dry. With the increase in precipitation that occurs as winter approaches, the percentage of water in the stem base of a plant derived from the tap roots (deep soil water or ground water) decreased again. These results suggested that the shrub's root distribution and morphology were the most important determinants of its ability to utilize different water sources, and that its adjustment to water availability was significant for acclimation to the desert habitat. PMID:26003322

  16. Water track distribution and effects on carbon dioxide flux in an eastern Siberian upland tundra landscape

    NASA Astrophysics Data System (ADS)

    Curasi, Salvatore R.; Loranty, Michael M.; Natali, Susan M.

    2016-04-01

    Shrub expansion in tundra ecosystems may act as a positive feedback to climate warming, the strength of which depends on its spatial extent. Recent studies have shown that shrub expansion is more likely to occur in areas with high soil moisture and nutrient availability, conditions typically found in sub-surface water channels known as water tracks. Water tracks are 5–15 m wide channels of subsurface water drainage in permafrost landscapes and are characterized by deeper seasonal thaw depth, warmer soil temperatures, and higher soil moisture and nutrient content relative to adjacent tundra. Consequently, enhanced vegetation productivity, and dominance by tall deciduous shrubs, are typical in water tracks. Quantifying the distribution of water tracks may inform investigations of the extent of shrub expansion and associated impacts on tundra ecosystem carbon cycling. Here, we quantify the distribution of water tracks and their contribution to growing season CO2 dynamics for a Siberian tundra landscape using satellite observations, meteorological data, and field measurements. We find that water tracks occupy 7.4% of the 448 km2 study area, and account for a slightly larger proportion of growing season carbon uptake relative to surrounding tundra. For areas inside water tracks dominated by shrubs, field observations revealed higher shrub biomass and higher ecosystem respiration and gross primary productivity relative to adjacent upland tundra. Conversely, a comparison of graminoid-dominated areas in water tracks and inter-track tundra revealed that water track locations dominated by graminoids had lower shrub biomass yet increased net uptake of CO2. Our results show water tracks are an important component of this landscape. Their distribution will influence ecosystem structural and functional responses to climate, and is therefore of importance for modeling.

  17. Water track distribution and effects on carbon dioxide flux in an eastern Siberian upland tundra landscape

    NASA Astrophysics Data System (ADS)

    Curasi, Salvatore R.; Loranty, Michael M.; Natali, Susan M.

    2016-04-01

    Shrub expansion in tundra ecosystems may act as a positive feedback to climate warming, the strength of which depends on its spatial extent. Recent studies have shown that shrub expansion is more likely to occur in areas with high soil moisture and nutrient availability, conditions typically found in sub-surface water channels known as water tracks. Water tracks are 5-15 m wide channels of subsurface water drainage in permafrost landscapes and are characterized by deeper seasonal thaw depth, warmer soil temperatures, and higher soil moisture and nutrient content relative to adjacent tundra. Consequently, enhanced vegetation productivity, and dominance by tall deciduous shrubs, are typical in water tracks. Quantifying the distribution of water tracks may inform investigations of the extent of shrub expansion and associated impacts on tundra ecosystem carbon cycling. Here, we quantify the distribution of water tracks and their contribution to growing season CO2 dynamics for a Siberian tundra landscape using satellite observations, meteorological data, and field measurements. We find that water tracks occupy 7.4% of the 448 km2 study area, and account for a slightly larger proportion of growing season carbon uptake relative to surrounding tundra. For areas inside water tracks dominated by shrubs, field observations revealed higher shrub biomass and higher ecosystem respiration and gross primary productivity relative to adjacent upland tundra. Conversely, a comparison of graminoid-dominated areas in water tracks and inter-track tundra revealed that water track locations dominated by graminoids had lower shrub biomass yet increased net uptake of CO2. Our results show water tracks are an important component of this landscape. Their distribution will influence ecosystem structural and functional responses to climate, and is therefore of importance for modeling.

  18. Distribution of hydrophobic ionizable xenobiotics between water and lipid membranes: pentachlorophenol and pentachlorophenate. A comparison with octanol-water partition.

    PubMed

    Smejtek, P; Wang, S

    1993-09-01

    We have studied distribution of pentachlorophenol (PCP)--a major environmental pollutant--between egg-phosphatidylcholine (egg-PC) membranes and water. The objectives were (1) to compare the membrane-water partition of the un-ionized (HA) and ionized (A) PCP, and (2) to establish similarities and differences between the partition of PCP into lipid membranes and into octanol. The studies were made with egg-PC liposomes. It is shown that the distribution isotherms can be understood in terms of the Langmuir-Stern-Grahame adsorption model. The model is applicable to both the HA and A species; it takes into account the electrostatic interactions at the membrane-water interface charged by the adsorbed pentachlorophenate. Relationships between the membrane surface adsorption and bulk partition characteristics were presented and used to relate the partition of PCP into egg-PC membranes to those for octanol-water systems. Results (egg-PC membranes): bulk distribution coeff. gamma HA = 2.9 x 10(5), gamma A = 1.6 x 10(4), association constant KmHA = 2.9 x 10(5) M-1, KmA = 0.7 x 10(5) M-1, adsorption site area PsHA = 0.6 nm2, PsA = 3.5 nm2, and linear partition coeff. Beta mHA = 550 microns, beta mA = 30 microns. Comparable to gamma HA and gamma A for octanol-water are P(ow)(HA) approximately 1.3 x 10(5) and P(ow)(A) approximately 30. The major difference is in the distribution of ionized PCP which is several hundred times greater for egg-PC membranes compared to octanol. The difference is associated with the properties of the membrane-water interface. PMID:8215590

  19. Pesticide distributions in surface water: The distribution of pesticide concentrations at two study sites points to herbicides that may affect management of public water supplies

    USGS Publications Warehouse

    Stamer, J.K.; Wieczorek, M.E.

    1996-01-01

    Distributions of concentrations of 46 pesticides were documented from May 1992 through March 1994 for Maple Creek near Nickerson, Neb., and Platte River at Louisville, Neb. As their source of public water supplies, Lincoln and the western part of Omaha withdraw groundwater from the adjacent alluvium near the Platte River site, which is hydraulically connected to the Platte River. Organonitrogen herbicides dominated the pesticide distributions at each site. Variations in the distributions of pesticides at the two sites partly reflect differences in land use and land management practices. Diazinon, an insecticide used in urban areas, was commonly detected at the Platte River site but not at the Maple Creek site. Of the 46 pesticides analyzed at the Platte River site, the herbicides atrazine and alachlor were more likely to exceed their respective maximum contaminant levels of 3.0 and 2.0 pg/L; cyanazine was more likely to exceed the health advisory level of 1.0 ??g/L.

  20. Dynamics of bacterial communities before and after distribution in a full-scale drinking water network.

    PubMed

    El-Chakhtoura, Joline; Prest, Emmanuelle; Saikaly, Pascal; van Loosdrecht, Mark; Hammes, Frederik; Vrouwenvelder, Hans

    2015-05-01

    Understanding the biological stability of drinking water distribution systems is imperative in the framework of process control and risk management. The objective of this research was to examine the dynamics of the bacterial community during drinking water distribution at high temporal resolution. Water samples (156 in total) were collected over short time-scales (minutes/hours/days) from the outlet of a treatment plant and a location in its corresponding distribution network. The drinking water is treated by biofiltration and disinfectant residuals are absent during distribution. The community was analyzed by 16S rRNA gene pyrosequencing and flow cytometry as well as conventional, culture-based methods. Despite a random dramatic event (detected with pyrosequencing and flow cytometry but not with plate counts), the bacterial community profile at the two locations did not vary significantly over time. A diverse core microbiome was shared between the two locations (58-65% of the taxa and 86-91% of the sequences) and found to be dependent on the treatment strategy. The bacterial community structure changed during distribution, with greater richness detected in the network and phyla such as Acidobacteria and Gemmatimonadetes becoming abundant. The rare taxa displayed the highest dynamicity, causing the major change during water distribution. This change did not have hygienic implications and is contingent on the sensitivity of the applied methods. The concept of biological stability therefore needs to be revised. Biostability is generally desired in drinking water guidelines but may be difficult to achieve in large-scale complex distribution systems that are inherently dynamic.